ORCID Profile
0000-0002-8613-3570
Current Organisation
Edith Cowan University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Fish Physiology and Genetics | Infectious Agents | Marine and Estuarine Ecology (incl. Marine Ichthyology) | Plant Cell and Molecular Biology | Microbial Ecology | Plant Developmental and Reproductive Biology | Genomics | Animal Neurobiology | Biochemistry and Cell Biology | Crop and Pasture Improvement (Selection and Breeding) | Genetics | Zoology | Plant Biology | Signal Transduction | Cell Development, Proliferation and Death
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Biological Sciences | Plant Production and Plant Primary Products not elsewhere classified | Biofuel (Biomass) Energy | Winter Grains and Oilseeds not elsewhere classified | Fisheries - Wild Caught not elsewhere classified | Animal Production and Animal Primary Products not elsewhere classified | Marine Flora, Fauna and Biodiversity |
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Publications
Circulating Melanoma Cell Subpopulations: Their Heterogeneity and Differential Responses to Treatment
Publisher: Elsevier BV
Date: 08-2015
DOI: 10.1038/JID.2015.127
Publisher Correction: Exercise-induced myokines and their effect on prostate cancer (Nature Reviews Urology, (2021), 10.1038/s41585-021-00476-y)
Publisher: Springer Science and Business Media LLC
Date: 06-07-2021
Genetic analysis of heterogeneous subsets of circulating tumour cells from high grade serous ovarian carcinoma patients
Publisher: Springer Science and Business Media LLC
Date: 13-02-2023
DOI: 10.1038/S41598-023-29416-Z
Abstract: Circulating tumour cells (CTCs) are heterogenous and contain genetic information from the tumour of origin. They bear specific intra- and extra-cellular protein markers aiding in their detection. However, since these markers may be shared with other rare cells in the blood, only genetic testing can confirm their malignancy. Herein, we analyse different CTC subsets using single cell whole genome DNA sequencing to validate their malignant origin. We randomly selected putative CTCs identified by immunostaining that were isolated from 4 patients with high grade serous ovarian cancer (HGSOC) and one with benign cystadenoma. We specifically targeted CTCs positive for epithelial (CK/EpCAM pos ), mesenchymal (vimentin pos ), and pseudoendothelial (CK/EpCAM pos plus CD31 pos ) markers. We isolated these cells and performed whole genome lification (WGA) and low-pass whole-genome sequencing (LP-WGS) for analysis of copy number alterations (CNA). Of the CK/EpCAM pos cells analysed from the HGSOC patients, 2 of 3 cells showed erse chromosomal CNAs. However, the 4 pseudoendothelial cells (CK/EpCAM pos plus CD31 pos ) observed in the HGSOC cases did not carry any CNA. Lastly, two of the clusters of vimentin positive cells sequenced from those found in the benign cystadenoma case had CNA. Despite the low number of cells analysed, our results underscore the importance of genetic analysis of putative CTCs to confirm their neoplastic origin. In particular, it highlights the presence of a population of CK/EpCAM pos cells that are not tumour cells in patients with HGSOC, which otherwise would be counted as CTCs.
Repurposing nano-enabled polymeric scaffolds for tumor-wound management and 3D tumor engineering
Publisher: Future Medicine Ltd
Date: 10-2020
Abstract: The main challenges of cancer drugs are toxicity, effect on wound healing atient outcome and in vivo instability. Polymeric scaffolds have been used separately for tissue regeneration in wound healing and as anticancer drug releasing devices. Bringing these two together in bifunctional scaffolds can provide a tool for postoperative local tumor management by promoting healthy tissue regrowth and to deliver anticancer drugs. Another addition to the versatility of polymeric scaffold is its recently discovered ability to act as 3D cell culture models for in vitro isolation and lification of cancer cells for personalized drug screening and to recapitulate the tumor microenvironment. This review focuses on the repurposing of 3D polymeric scaffolds for local tumor-wound management and development of in vitro cell culture models.
Detection of BRAF-V600E and V600K in melanoma circulating tumour cells by droplet digital PCR
Publisher: Elsevier BV
Date: 10-2015
DOI: 10.1016/J.CLINBIOCHEM.2014.12.007
Abstract: Defining the BRAF mutation status in metastatic melanoma patients is critical to selecting patients for therapeutic treatment with targeted therapies. Circulating tumour cells (CTCs) can provide an alternative source of contemporaneous tumour genetic material. However methodologies to analyse the presence of rare mutations in a background of wild-type DNA requires a detailed assessment. Here we evaluate the sensitivity of two technologies for cancer mutation detection and the suitability of whole genome lified DNA as a template for the detection of BRAF-V600 mutations. Serial dilutions of mutant BRAF-V600E DNA in wild-type DNA were tested using both competitive allele-specific PCR (castPCR) and droplet digital PCR (ddPCR), with and without previous whole genome lification (WGA). Using immunomagnetic beads, we partially enriched CTCs from blood obtained from metastatic melanoma patients with confirmed BRAF mutation positive tumours and extracted RNA and DNA from the CTCs. We used RT-PCR of RNA to confirm the presence of melanoma cells in the CTC fraction then the DNAs of CTC positive fractions were WGA and tested for BRAF V600E or V600K mutations by ddPCRs. WGA DNA produced lower than expected fractional abundances by castPCR analysis but not by ddPCR. Moreover, ddPCR was found to be 200 times more sensitive than castPCR and in combination with WGA produced the most concordant results, with a limit of detection of 0.0005%. BRAF-V600E or V600K mutated DNA was detected in 77% and 44%, respectively, of enriched CTC fractions from metastatic melanoma patients carrying the corresponding mutations. Our results demonstrate that using ddPCR in combination with WGA DNA allows the detection with high sensitivity of cancer mutations in partially enriched CTC fractions.
Polyclonal B Cell Responses to Conserved Neutralization Epitopes in a Subset of HIV-1-Infected Individuals
Publisher: American Society for Microbiology
Date: 11-2011
DOI: 10.1128/JVI.05363-11
Abstract: A small proportion of HIV-infected in iduals generate a neutralizing antibody (NAb) response of exceptional magnitude and breadth. A detailed analysis of the critical epitopes targeted by broadly neutralizing antibodies should help to define optimal targets for vaccine design. HIV-1-infected subjects with potent cross-reactive serum neutralizing antibodies were identified by assaying sera from 308 subjects against a multiclade panel of 12 “tier 2” viruses (4 each of subtypes A, B, and C). Various neutralizing epitope specificities were determined for the top 9 neutralizers, including clade A-, clade B-, clade C-, and clade A/C-infected donors, by using a comprehensive set of assays. In some subjects, neutralization breadth was mediated by two or more antibody specificities. Although antibodies to the gp41 membrane-proximal external region (MPER) were identified in some subjects, the subjects with the greatest neutralization breadth targeted gp120 epitopes, including the CD4 binding site, a glycan-containing quaternary epitope formed by the V2 and V3 loops, or an outer domain epitope containing a glycan at residue N332. The broadly reactive HIV-1 neutralization observed in some subjects is mediated by antibodies targeting several conserved regions on the HIV-1 envelope glycoprotein.
Supplementary Data from Circulating Tumor DNA Predicts Outcome from First-, but not Second-line Treatment and Identifies Melanoma Patients Who May Benefit from Combination Immunotherapy
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.22477679.V1
Abstract: Tables S1-S8 and Figures S1-S4
Differences in HIV Type 1 Neutralization Breadth in 2 Geographically Distinct Cohorts in Africa
Publisher: Oxford University Press (OUP)
Date: 14-11-2014
The Development of CD4 Binding Site Antibodies during HIV-1 Infection
Publisher: American Society for Microbiology
Date: 15-07-2012
DOI: 10.1128/JVI.00734-12
Abstract: Broadly neutralizing antibodies to the CD4 binding site (CD4bs) of gp120 are generated by some HIV-1-infected in iduals, but little is known about the prevalence and evolution of this antibody response during the course of HIV-1 infection. We analyzed the sera of 113 HIV-1 seroconverters from three cohorts for binding to a panel of gp120 core proteins and their corresponding CD4bs knockout mutants. Among sera collected between 99 and 258 weeks post-HIV-1 infection, 88% contained antibodies to the CD4bs and 47% contained antibodies to resurfaced stabilized core (RSC) probes that react preferentially with broadly neutralizing CD4bs antibodies (BNCD4), such as monoclonal antibodies (MAbs) VRC01 and VRC-CH31. Analysis of longitudinal serum s les from a subset of 18 subjects revealed that CD4bs antibodies to gp120 arose within the first 4 to 16 weeks of infection, while the development of RSC-reactive antibodies was more varied, occurring between 10 and 152 weeks post-HIV-1 infection. Despite the presence of these antibodies, serum neutralization mediated by RSC-reactive antibodies was detected in sera from only a few donors infected for more than 3 years. Thus, CD4bs antibodies that bind a VRC01-like epitope are often induced during HIV-1 infection, but the level and potency required to mediate serum neutralization may take years to develop. An improved understanding of the immunological factors associated with the development and maturation of neutralizing CD4bs antibodies during HIV-1 infection may provide insights into the requirements for eliciting this response by vaccination.
Stopping targeted therapy for complete responders in advanced BRAF mutant melanoma
Publisher: Springer Science and Business Media LLC
Date: 02-11-2020
DOI: 10.1038/S41598-020-75837-5
Abstract: BRAF inhibitors revolutionised the management of melanoma patients and although resistance occurs, there is a subgroup of patients who maintain durable disease control. For those cases with durable complete response (CR) it is not clear whether it is safe to cease therapy. Here we identified 13 patients treated with BRAF +/− MEK inhibitors, who cease therapy after prolonged CR (median = 34 months, range 20–74). Recurrence was observed in 3/13 (23%) patients. In the remaining 10 patients with sustained CR off therapy, the median follow up after discontinuation was 19 months (range 8–36). We retrospectively measured ctDNA levels using droplet digital PCR (ddPCR) in longitudinal plasma s les. CtDNA levels were undetectable in 11/13 cases after cessation and remained undetectable in patients in CR (10/13). CtDNA eventually became detectable in 2/3 cases with disease recurrence, but remained undetectable in 1 patient with brain only progression. Our study suggests that consideration could be given to ceasing targeted therapy in the context of prolonged treatment, durable response and no evidence of residual disease as measured by ctDNA.
Prognostic Relevance of CCDC88C (Daple) Transcripts in the Peripheral Blood of Patients with Cutaneous Melanoma
Publisher: Springer Science and Business Media LLC
Date: 21-12-2018
DOI: 10.1038/S41598-018-36173-X
Abstract: A loss of balance between G protein activation and deactivation has been implicated in the initiation of melanomas, and non-canonical Wnt signaling via the Wnt5A/Frizzled (FZD) pathway has been shown to be critical for the switch to an invasive phenotype. Daple [CCDC88C], a cytosolic guanine nucleotide exchange modulator (GEM) which enhances non-canonical Wnt5A/FZD signaling via activation of trimeric G protein, Gαi, has been shown to serve opposing roles–as an inducer of EMT and invasiveness and a potent tumor suppressor–via two isoforms, V1 (full-length) and V2 (short spliced isoform), respectively. Here we report that the relative abundance of these isoforms in the peripheral circulation, presumably largely from circulating tumor cells (CTCs), is a prognostic marker of cutaneous melanomas. Expression of V1 is increased in both the early and late clinical stages ( p 0.001, p = 0.002, respectively) V2 is decreased exclusively in the late clinical stage ( p = 0.003). The two isoforms have opposing prognostic effects: high expression of V2 increases relapse-free survival (RFS p = 0.014), whereas high expression of V1 tends to decrease RFS ( p = 0.051). Furthermore, these effects are additive, in that melanoma patients with a low V2-high V1 signature carry the highest risk of metastatic disease. We conclude that detection of Daple transcripts in the peripheral blood (i.e., liquid biopsies) of patients with melanoma may serve as a prognostic marker and an effective strategy for non-invasive long-term follow-up of patients with melanoma.
Mannose-rich glycosylation patterns on HIV-1 subtype C gp120 and sensitivity to the lectins, Griffithsin, Cyanovirin-N and Scytovirin
Publisher: Elsevier BV
Date: 06-2010
Detection and prognostic role of heterogeneous populations of melanoma circulating tumour cells.
Publisher: Springer Science and Business Media LLC
Date: 10-02-2020
DOI: 10.1038/S41416-020-0750-9
Abstract: Circulating tumour cells (CTCs) can be assessed through a minimally invasive blood s le with potential utility as a predictive, prognostic and pharmacodynamic biomarker. The large heterogeneity of melanoma CTCs has hindered their detection and clinical application. Here we compared two microfluidic devices for the recovery of circulating melanoma cells. The presence of CTCs in 43 blood s les from patients with metastatic melanoma was evaluated using a combination of immunocytochemistry and transcript analyses of five genes by RT-PCR and 19 genes by droplet digital PCR (ddPCR), whereby a CTC score was calculated. Circulating tumour DNA (ctDNA) from the same patient blood s le, was assessed by ddPCR targeting tumour-specific mutations. Our analysis revealed an extraordinary heterogeneity amongst melanoma CTCs, with multiple non-overlapping subpopulations. CTC detection using our multimarker approach was associated with shorter overall and progression-free survival. Finally, we found that CTC scores correlated with plasma ctDNA concentrations and had similar pharmacodynamic changes upon treatment initiation. Despite the high phenotypic and molecular heterogeneity of melanoma CTCs, multimarker derived CTC scores could serve as viable tools for prognostication and treatment response monitoring in patients with metastatic melanoma.
Strain-Specific V3 and CD4 Binding Site Autologous HIV-1 Neutralizing Antibodies Select Neutralization-Resistant Viruses
Publisher: Elsevier BV
Date: 09-2015
Binding of the Mannose-Specific Lectin, Griffithsin, to HIV-1 gp120 Exposes the CD4-Binding Site
Publisher: American Society for Microbiology
Date: 09-2011
DOI: 10.1128/JVI.02675-10
Abstract: The glycans on HIV-1 gp120 play an important role in shielding neutralization-sensitive epitopes from antibody recognition. They also serve as targets for lectins that bind mannose-rich glycans. In this study, we investigated the interaction of the lectin griffithsin (GRFT) with HIV-1 gp120 and its effects on exposure of the CD4-binding site (CD4bs). We found that GRFT enhanced the binding of HIV-1 to plates coated with anti-CD4bs antibodies b12 and b6 or the CD4 receptor mimetic CD4-IgG2. The average enhancement of b12 or b6 binding was higher for subtype B viruses than for subtype C, while for CD4-IgG2, it was similar for both subtypes, although lower than observed with antibodies. This GRFT-mediated enhancement of HIV-1 binding to b12 was reflected in synergistic neutralization for 2 of the 4 viruses tested. The glycan at position 386, which shields the CD4bs, was involved in both GRFT-mediated enhancement of binding and neutralization synergism between GRFT and b12. Although GRFT enhanced CD4bs exposure, it simultaneously inhibited ligand binding to the coreceptor binding site, suggesting that GRFT-dependent enhancement and neutralization utilize independent mechanisms. This study shows for the first time that GRFT interaction with gp120 exposes the CD4bs through binding the glycan at position 386, which may have implications for how to access this conserved site.
Identification and characterisation of putative drug binding sites in human ATP-binding cassette B5 (ABCB5) transporter
Publisher: Elsevier BV
Date: 2021
UCLA1 aptamer inhibition of human immunodeficiency virus type 1 subtype C primary isolates in macrophages and selection of resistance
Publisher: Elsevier BV
Date: 09-2016
Circulating Tumour DNA in Advanced Melanoma Patients Ceasing PD1 Inhibition in the Absence of Disease Progression
Publisher: MDPI AG
Date: 23-11-2020
Abstract: Immunotherapy is an important and established treatment option for patients with advanced melanoma. Initial anti-PD1 trials arbitrarily defined a two-year treatment duration, but a shorter treatment duration may be appropriate. In this study, we retrospectively assessed 70 patients who stopped anti-PD1 therapy in the absence of progressive disease (PD) to determine clinical outcomes. In our cohort, the median time on treatment was 11.8 months. Complete response was attained at time of anti-PD1 discontinuation in 61 (87%). After a median follow up of 34.2 months (range: 2–70.8) post discontinuation, 81% remained disease free. Using ddPCR, we determine the utility of circulating tumour DNA (ctDNA) to predict progressive disease after cessation (n = 38). There was a significant association between presence of ctDNA at cessation and disease progression (p = 0.012, Fisher’s exact test) and this conferred a negative and positive predictive value of 0.82 (95% CI: 0.645–0.930) and 0.80 (95% CI 0.284–0.995), respectively. Additionally, dichotomised treatment-free survival in patients with or without ctDNA at cessation was significantly longer in the latter group (p 0.001, HR: 0.008, 95% CI: 0.001–0.079). Overall, our study confirms that durable disease control can be achieved with cessation of therapy in the absence of disease progression and undetectable ctDNA at cessation was associated with longer treatment-free survival.
Circulating tumour DNA (ctDNA) as a biomarker in metachronous melanoma and colorectal cancer- a case report
Publisher: Springer Science and Business Media LLC
Date: 14-11-2019
DOI: 10.1186/S12885-019-6336-3
Abstract: Circulating tumour DNA (ctDNA) has emerged as a promising blood-based biomarker for monitoring disease status of patients with advanced cancers. The presence of ctDNA in the blood is a result of biological processes, namely tumour cell apoptosis and/or necrosis, and can be used to monitor different cancers by targeting cancer-specific mutation. We present the case of a 67 year old Caucasian male that was initially treated with BRAF inhibitors followed by anti-CTLA4 and then anti-PD1 immunotherapy for metastatic melanoma but later developed colorectal cancer. The kinetics of ctDNA derived from each cancer type were monitored targeting BRAF V600R (melanoma) and KRAS G13D (colon cancer), specifically reflected the status of the patient’s tumours. In fact, the discordant pattern of BRAF and KRAS ctDNA was significantly correlated with the clinical response of melanoma to pembrolizumab treatment and progression of colorectal cancer noted by PET and/or CT scan. Based on these results, ctDNA can be used to specifically clarify disease status of patients with metachronous cancers. Using cancer-specific mutational targets, we report here for the first time the efficacy of ctDNA to accurately provide a comprehensive outlook of the tumour status of two different cancers within one patient. Thus, ctDNA analysis has a potential clinical utility to delineate clinical information in patients with multiple cancer types.
Potent and Broad Neutralization of HIV-1 Subtype C by Plasma Antibodies Targeting a Quaternary Epitope Including Residues in the V2 Loop
Publisher: American Society for Microbiology
Date: 04-2011
DOI: 10.1128/JVI.02658-10
Abstract: The targets of broadly cross-neutralizing (BCN) antibodies are of great interest in the HIV vaccine field. We have identified a subtype C HIV-1-superinfected in idual, CAP256, with high-level BCN activity, and characterized the antibody specificity mediating breadth. CAP256 developed potent BCN activity peaking at 3 years postinfection, neutralizing 32 (76%) of 42 heterologous viruses, with titers of antibodies against some viruses exceeding 1:10,000. CAP256 showed a subtype bias, preferentially neutralizing subtype C and A viruses over subtype B viruses. CAP256 BCN serum targeted a quaternary epitope which included the V1V2 region. Further mapping identified residues F159, N160, L165, R166, D167, K169, and K171 (forming the FN/LRD-K-K motif) in the V2 region as crucial to the CAP256 epitope. However, the fine specificity of the BCN response varied over time and, while consistently dependent on R166 and K169, became gradually less dependent on D167 and K171, possibly contributing to the incremental increase in breadth over 4 years. The presence of an intact FN/LRD-K-K motif in heterologous viruses was associated with sensitivity, although the length of the adjacent V1 loop modulated the degree of sensitivity, with a shorter V1 region significantly associated with higher titers. Repair of the FN/LRD-K-K motif in resistant heterologous viruses conferred sensitivity, with titers sometimes exceeding 1:10,000. Comparison of the CAP256 epitope with that of the PG9/PG16 monoclonal antibodies suggested that these epitopes overlapped, adding to the mounting evidence that this may represent a common neutralization target that should be further investigated as a potential vaccine candidate.
N-Linked Glycan Modifications in gp120 of Human Immunodeficiency Virus Type 1 Subtype C Render Partial Sensitivity to 2G12 Antibody Neutralization
Publisher: American Society for Microbiology
Date: 10-2007
DOI: 10.1128/JVI.01106-07
Abstract: The monoclonal antibody (MAb) 2G12 recognizes a cluster of high-mannose oligosaccharides on the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 and is one of a select group of MAbs with broad neutralizing activity. However, subtype C viruses are generally resistant to 2G12 neutralization. This has been attributed to the absence of a glycosylation site at position 295 in most subtype C gp120s, which instead is typically occupied by a Val residue. Here we show that N-linked glycans in addition to the one at position 295 are important in the formation of the 2G12 epitope in subtype C gp120. Introduction of the glycosylation site at position 295 into three subtype C molecular clones, Du151.2, COT9.6, and COT6.15, did increase 2G12 binding to all three mutagenized gp120s, but at various levels. The COT9-V295N mutant showed the strongest 2G12 binding and was the only mutant to become sensitive to 2G12 neutralization, although very high antibody concentrations were required. Introduction of a glycosylation site at position 448 into mutant COT6-V295N, which occurs naturally in COT9, resulted in a virus that was partially sensitive to 2G12. Interestingly, a glycosylation site at position 442, which is common among subtype C viruses, also contributed to the 2G12 epitope. The addition of this glycan increased virus neutralization sensitivity to 2G12, whereas its deletion conferred resistance. Collectively, our results indicate that the 2G12 binding site cannot readily be reconstituted on the envelopes of subtype C viruses, suggesting structural differences from other HIV subtypes in which the 2G12 epitope is naturally expressed.
Isolation of a Monoclonal Antibody That Targets the Alpha-2 Helix of gp120 and Represents the Initial Autologous Neutralizing-Antibody Response in an HIV-1 Subtype C-Infected Individual
Publisher: American Society for Microbiology
Date: 08-2011
DOI: 10.1128/JVI.00563-11
Abstract: The C3-V4 region is a major target of autologous neutralizing antibodies in HIV-1 subtype C infection. We previously identified a Center for AIDS Program of Research in South Africa (CAPRISA) participant, CAP88, who developed a potent neutralizing-antibody response within 3 months of infection that targeted an epitope in the C3 region of the HIV-1 envelope (P. L. Moore et al., PLoS Pathog. 5:e1000598, 2009). Here we showed that these type-specific antibodies could be adsorbed using recombinant gp120 from the transmitted/founder virus from CAP88 but not by gp120 made from other isolates. Furthermore, this activity could be depleted using a chimeric gp120 protein that contained only the C3 region from the CAP88 viral envelope engrafted onto the unrelated CAP63 viral envelope (called 63-88C3). On the basis of this, a differential sorting of memory B cells was performed using gp120s made from 63-88C3 and CAP63 labeled with different fluorochromes as positive and negative probes, respectively. This strategy resulted in the isolation of a highly specific monoclonal antibody (MAb), called CAP88-CH06, that neutralized the CAP88 transmitted/founder virus and viruses from acute infection but was unable to neutralize CAP88 viruses isolated at 6 and 12 months postinfection. The latter viruses contained 2 amino acid changes in the alpha-2 helix of C3 that mediated escape from this MAb. One of these changes involved the introduction of an N-linked glycan at position 339 that occluded the epitope, while the other mutation (either E343K or E350K) was a charge change. Our data validate the use of differential sorting to isolate a MAb targeting a specific epitope in the envelope glycoprotein and provided insights into the mechanisms of autologous neutralization escape.
Future perspectives of uveal melanoma blood based biomarkers
Publisher: Springer Science and Business Media LLC
Date: 21-02-2022
DOI: 10.1038/S41416-022-01723-8
Abstract: Uveal melanoma (UM) is the most common primary intraocular malignancy affecting adults. Despite successful local treatment of the primary tumour, metastatic disease develops in up to 50% of patients. Metastatic UM carries a particularly poor prognosis, with no effective therapeutic option available to date. Genetic studies of UM have demonstrated that cytogenetic features, including gene expression, somatic copy number alterations and specific gene mutations can allow more accurate assessment of metastatic risk. Pre-emptive therapies to avert metastasis are being tested in clinical trials in patients with high-risk UM. However, current prognostic methods require an intraocular tumour biopsy, which is a highly invasive procedure carrying a risk of vision-threatening complications and is limited by s ling variability. Recently, a new diagnostic concept known as “liquid biopsy” has emerged, heralding a substantial potential for minimally invasive genetic characterisation of tumours. Here, we examine the current evidence supporting the potential of blood circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), microRNA (miRNA) and exosomes as biomarkers for UM. In particular, we discuss the potential of these biomarkers to aid clinical decision making throughout the management of UM patients.
Investigating primary preservice teachers’ ultraviolet radiation awareness and perceived ability to teach sun safety
Publisher: Wiley
Date: 27-08-2020
DOI: 10.1002/HPJA.401
Abstract: Sun protection practices in Australian primary schools remain inconsistent. Therefore, this study investigates primary PSTs sun protective sun behaviours, ultraviolet (UV) radiation awareness and perceived ability to teach sun safety. A convenience s le of undergraduate PSTs (N = 275 mean age = 23.13 years) enrolled at one Western Australian university completed an online survey. Descriptive analyses provided features of the data. Factors associated with sun protection behaviours and perceived knowledge and skill to teach sun safety were explored using multivariable logistic regression models. Lesser than 10% of participants reported using sun protective measures daily (midday shade use: 6.5% sunscreen: 7.6% hat: 4.4%). Only 56.3% reported they understand the UV index, with 68.0% rarely/never using it to aid sun protection. Under half the participants reported they felt they had the knowledge (38.5%) or skills (40%) to effectively teach sun safety in primary schools. Regression analysis revealed gender, undergraduate, year and skin sensitivity were not predictors of UV index use ( P .05) or perceived knowledge of sun safety ( P .05). Skin sensitivity was the strongest predictor for shade usage ( P = .02), hat usage ( P = .05) and perceived skill to teach sun safety ( P = .02). Survey data indicate UV radiation is inconsistently understood by PSTs. Many felt that they did not have the required knowledge or skill to teach sun safety effectively. Improving PSTs UV radiation knowledge while at university is a potential opportunity to improve sun safety delivery in primary schools. A targeted intervention for PSTs is warranted.
Isolation and detection of circulating tumour cells from metastatic melanoma patients using a slanted spiral microfluidic device.
Publisher: Impact Journals, LLC
Date: 27-06-2017
Melanoma circulating tumor cells: Benefits and challenges required for clinical application
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.CANLET.2018.03.013
Abstract: The implementation of novel therapeutic interventions has improved the survival rates of melanoma patients with metastatic disease. Nonetheless, only 33% of treated cases exhibit long term responses. Circulating tumor cell (CTC) measurements are currently of clinical value in breast, prostate and colorectal cancers. However, the clinical utility of melanoma CTCs (MelCTCs) is still unclear due to challenges that appear intrinsic to MelCTCs (i.e. rarity, heterogeneity) and a lack of standardization in their isolation, across research laboratories. Here, we review the latest developments, pinpoint the challenges in MelCTC isolation and address their potential role in melanoma management.
Exercise-induced myokines and their effect on prostate cancer
Publisher: Springer Science and Business Media LLC
Date: 22-06-2021
DOI: 10.1038/S41585-021-00476-Y
Abstract: Exercise is recognized by clinicians in the field of clinical oncology for its potential role in reducing the risk of certain cancers and in reducing the risk of disease recurrence and progression yet, the underlying mechanisms behind this reduction in risk are not fully understood. Studies applying post-exercise blood serum directly to various types of cancer cell lines provide insight that exercise might have a role in inhibiting cancer growth via altered soluble and cell-free blood contents. Myokines, which are cytokines produced by muscle and secreted into the bloodstream, might offer multiple benefits to cellular metabolism (such as a reduction in insulin resistance, improved glucose uptake and reduced adiposity), and blood myokine levels can be altered with exercise. Alterations in the levels of myokines such as IL-6, IL-15, IL-10, irisin, secreted protein acidic risk in cysteine (SPARC), myostatin, oncostatin M and decorin might exert a direct inhibitory effect on cancer growth via inhibiting proliferation, promoting apoptosis, inducing cell-cycle arrest and inhibiting the epithermal transition to mesenchymal cells. The association of insulin resistance, hyperinsulinaemia and hyperlipidaemia with obesity can create a tumour-favourable environment exercise-induced myokines can manipulate this environment by regulating adipose tissue and adipocytes. Exercise-induced myokines also have a critical role in increasing cytotoxicity and the infiltration of immune cells into the tumour.
Circulating Tumor DNA Reflects Uveal Melanoma Responses to Protein Kinase C Inhibition
Publisher: MDPI AG
Date: 06-04-2021
Abstract: The prognosis for patients with UM is poor, and recent clinical trials have failed to prolong overall survival (OS) of these patients. Over 95% of UM harbor activating driver mutations, and this allows for the investigation of ctDNA. In this study, we investigated the value of ctDNA for adaptive clinical trial design in metastatic UM. Longitudinal plasma s les were analyzed for ctDNA in 17 metastatic UM patients treated with PKCi-based therapy in a phase 1 clinical trial setting. Plasma ctDNA was assessed using digital droplet PCR (ddPCR) and a custom melanoma gene panel for targeted next generation sequencing (NGS). Baseline ctDNA strongly correlated with baseline lactate dehydrogenase (LDH) (p 0.001) and baseline disease burden (p = 0.002). Early during treatment (EDT) ctDNA accurately predicted patients with clinical benefit to PKCi using receiver operator characteristic (ROC) curves (AUC 0.84, [95% confidence interval 0.65–1.0, p = 0.026]). Longitudinal ctDNA assessment was informative for establishing clinical benefit and detecting disease progression with 7/8 (88%) of patients showing a rise in ctDNA and targeted NGS of ctDNA revealed putative resistance mechanisms prior to radiological progression. The inclusion of longitudinal ctDNA monitoring in metastatic UM can advance adaptive clinical trial design.
Longitudinal Monitoring of ctDNA in Patients with Melanoma and Brain Metastases Treated with Immune Checkpoint Inhibitors
Publisher: American Association for Cancer Research (AACR)
Date: 08-2020
DOI: 10.1158/1078-0432.CCR-19-3926
Abstract: Brain involvement occurs in the majority of patients with metastatic melanoma. The potential of circulating tumor DNA (ctDNA) for surveillance and monitoring systemic therapy response in patients with melanoma brain metastases merits investigation. This study examined circulating BRAF, NRAS, and c-KIT mutations in patients with melanoma with active brain metastases receiving PD-1 inhibitor–based therapy. Intracranial and extracranial disease volumes were measured using the sum of product of diameters, and response assessment performed using RECIST. Longitudinal plasma s les were analyzed for ctDNA over the first 12 weeks of treatment (threshold 2.5 copies/mL plasma). Of a total of 72 patients, 13 patients had intracranial metastases only and 59 patients had concurrent intracranial and extracranial metastases. ctDNA detectability was 0% and 64%, respectively, and detectability was associated with extracranial disease volume (P & 0.01). Undetectable ctDNA on-therapy was associated with extracranial response (P & 0.01) but not intracranial response. The median overall survival in patients with undetectable (n = 34) versus detectable (n = 38) ctDNA at baseline was 39.2 versus 10.6 months [HR, 0.51 95% confidence interval (CI), 0.28–0.94 P = 0.03] and on-therapy was 39.2 versus 9.2 months (HR, 0.32 95% CI, 0.16–0.63 P & 0.01). ctDNA remains a strong prognostic biomarker in patients with melanoma with brain metastases, especially in patients with concurrent extracranial disease. However, ctDNA was not able to detect or monitor intracranial disease activity, and we recommend against using ctDNA as a sole test during surveillance and therapeutic monitoring in patients with melanoma.
Genomic Analysis of Circulating Tumor DNA Using a Melanoma-Specific UltraSEEK Oncogene Panel
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.JMOLDX.2018.12.001
Abstract: The analysis of circulating tumor DNA provides a minimally invasive molecular interrogation that has the potential to guide treatment selection and disease monitoring. Here, the authors evaluated a custom UltraSEEK melanoma panel for the MassARRAY system, probing for 61 mutations over 13 genes. The analytical sensitivity and clinical accuracy of the UltraSEEK melanoma panel was compared with droplet digital PCR. The blinded analysis of 68 mutations detected in 48 plasma s les from stage IV melanoma patients revealed a concordance of 88% between the two platforms. Further comparison of both methods for the detection of BRAF V600E mutations in 77 plasma s les demonstrated a Cohen's κ of 0.826 (bias-corrected and accelerated 95% CI, 0.669-0.946). These results indicate that the UltraSEEK melanoma panel is as sensitive as droplet digital PCR for the detection of circulating tumor DNA in this cohort of patients but highlight the need for detected variants to be confirmed orthogonally to mitigate any false-positive results. The MassARRAY system enables rapid and sensitive genotyping for the detection of multiple melanoma-associated mutations in plasma.
Data from Circulating Tumor DNA Predicts Outcome from First-, but not Second-line Treatment and Identifies Melanoma Patients Who May Benefit from Combination Immunotherapy
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.C.6529724
Abstract: AbstractPurpose: We evaluated the predictive value of pretreatment ctDNA to inform therapeutic outcomes in patients with metastatic melanoma relative to type and line of treatment. Experimental Design: Plasma circulating tumor DNA (ctDNA) was quantified in 125 s les collected from 110 patients prior to commencing treatment with immune checkpoint inhibitors (ICIs), as first- ( i n /i = 32) or second-line ( i n /i = 27) regimens, or prior to commencing first-line BRAF/MEK inhibitor therapy ( i n /i = 66). An external validation cohort included 128 patients commencing ICI therapies in the first- ( i N /i = 77) or second-line ( i N /i = 51) settings. Results: In the discovery cohort, low ctDNA (≤20 copies/mL) prior to commencing therapy predicted longer progression-free survival (PFS) in patients treated with first-line ICIs [HR, 0.20 95% confidence interval (CI) 0.07–0.53 i P /i 0.0001], but not in the second-line setting. An independent cohort validated that ctDNA is predictive of PFS in the first-line setting (HR, 0.42 95% CI, 0.22–0.83 i P /i = 0.006), but not in the second-line ICI setting. Moreover, ctDNA prior to commencing ICI treatment was not predictive of PFS for patients pretreated with BRAF/MEK inhibitors in either the discovery or validation cohorts. Reduced PFS and overall survival were observed in patients with high ctDNA receiving anti–PD-1 monotherapy, relative to those treated with combination anti–CTLA-4/anti–PD-1 inhibitors. Conclusions: Pretreatment ctDNA is a reliable indicator of patient outcome in the first-line ICI treatment setting, but not in the second-line ICI setting, especially in patients pretreated with BRAF/MEK inhibitors. Preliminary evidence indicated that treatment-naïve patients with high ctDNA may preferentially benefit from combined ICIs. /
Associations of Physical Activity and Exercise with Health-related Outcomes in Patients with Melanoma During and After Treatment: A Systematic Review
Publisher: SAGE Publications
Date: 2021
DOI: 10.1177/15347354211040757
Abstract: Although exercise medicine is recommended to counter treatment-related side-effects and improve health-related outcomes of patients affected by different cancers, no specific recommendations exist for patients with melanoma. As a result, we systematically examined the current evidence regarding the effects of physical activity and exercise on objectively-measured and patient-reported outcomes among patients with melanoma. Searches were conducted in PubMed, CINAHL, EMBASE, SPORTDiscus, and Web of Science databases. This review included published data involving physical activity or exercise and objectively-measured or patient-reported outcomes of patients with cutaneous melanoma. The quality of included studies was assessed using the McMaster University Critical Appraisal Tool for Quantitative Studies. Six studies including 882 patients with melanoma were included. Studies presented heterogeneity of design with 2 cross-sectional surveys, 2 retrospective analyses, and 2 non-randomized intervention trials. No statistically significant change in quality of life, fatigue, physical function, cardiorespiratory fitness, body composition, psychological distress, cognitive function, or treatment-related side-effects were attributable to physical activity or exercise. Importantly, physical activity or exercise during melanoma treatment or into survivorship did not adversely impact patients/survivors. In summary, physical activity or exercise did not adversely impact quality of life, objectively-measured or patient-reported outcomes in patients with melanoma. In addition, there is a paucity of quality studies examining the effects of physical activity or exercise on patients with melanoma throughout the cancer care continuum.
Changes in plasma hydroxyproline and plasma cell-free DNA concentrations after higher- versus lower-intensity eccentric cycling
Publisher: Springer Science and Business Media LLC
Date: 13-01-2021
Data from Circulating Tumor DNA Predicts Outcome from First-, but not Second-line Treatment and Identifies Melanoma Patients Who May Benefit from Combination Immunotherapy
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.C.6529724.V1
Abstract: AbstractPurpose: We evaluated the predictive value of pretreatment ctDNA to inform therapeutic outcomes in patients with metastatic melanoma relative to type and line of treatment. Experimental Design: Plasma circulating tumor DNA (ctDNA) was quantified in 125 s les collected from 110 patients prior to commencing treatment with immune checkpoint inhibitors (ICIs), as first- ( i n /i = 32) or second-line ( i n /i = 27) regimens, or prior to commencing first-line BRAF/MEK inhibitor therapy ( i n /i = 66). An external validation cohort included 128 patients commencing ICI therapies in the first- ( i N /i = 77) or second-line ( i N /i = 51) settings. Results: In the discovery cohort, low ctDNA (≤20 copies/mL) prior to commencing therapy predicted longer progression-free survival (PFS) in patients treated with first-line ICIs [HR, 0.20 95% confidence interval (CI) 0.07–0.53 i P /i 0.0001], but not in the second-line setting. An independent cohort validated that ctDNA is predictive of PFS in the first-line setting (HR, 0.42 95% CI, 0.22–0.83 i P /i = 0.006), but not in the second-line ICI setting. Moreover, ctDNA prior to commencing ICI treatment was not predictive of PFS for patients pretreated with BRAF/MEK inhibitors in either the discovery or validation cohorts. Reduced PFS and overall survival were observed in patients with high ctDNA receiving anti–PD-1 monotherapy, relative to those treated with combination anti–CTLA-4/anti–PD-1 inhibitors. Conclusions: Pretreatment ctDNA is a reliable indicator of patient outcome in the first-line ICI treatment setting, but not in the second-line ICI setting, especially in patients pretreated with BRAF/MEK inhibitors. Preliminary evidence indicated that treatment-naïve patients with high ctDNA may preferentially benefit from combined ICIs. /
The Prognostic Impact of Circulating Tumour DNA in Melanoma Patients Treated with Systemic Therapies—Beyond BRAF Mutant Detection
Publisher: MDPI AG
Date: 16-12-2020
Abstract: In this study, we evaluated the predictive value of circulating tumour DNA (ctDNA) to inform therapeutic outcomes in metastatic melanoma patients receiving systemic therapies. We analysed 142 plasma s les from metastatic melanoma patients prior to commencement of systemic therapy: 70 were treated with BRAF/MEK inhibitors and 72 with immunotherapies. Patient-specific droplet digital polymerase chain reaction assays were designed for ctDNA detection. Plasma ctDNA was detected in 56% of patients prior to first-line anti-PD1 and/or anti-CTLA-4 treatment. The detection rate in the immunotherapy cohort was comparably lower than those with BRAF inhibitors (76%, p = 0.0149). Decreasing ctDNA levels within 12 weeks of treatment was strongly concordant with treatment response (Cohen’s k = 0.798, p 0.001) and predictive of longer progression free survival. Notably, a slower kinetic of ctDNA decline was observed in patients treated with immunotherapy compared to those on BRAF/MEK inhibitors. Whole exome sequencing of ctDNA was also conducted in 9 patients commencing anti-PD-1 therapy to derive tumour mutational burden (TMB) and neoepitope load measurements. The results showed a trend of high TMB and neoepitope load in responders compared to non-responders. Overall, our data suggest that changes in ctDNA can serve as an early indicator of outcomes in metastatic melanoma patients treated with systemic therapies and therefore may serve as a tool to guide treatment decisions.
Erdheim-Chester disease associated with a novel, complex BRAF p.Thr599_Val600delinsArgGlu mutation.
Publisher: BMJ
Date: 28-04-2017
Antibody Specificities Associated with Neutralization Breadth in Plasma from Human Immunodeficiency Virus Type 1 Subtype C-Infected Blood Donors
Publisher: American Society for Microbiology
Date: 09-2009
DOI: 10.1128/JVI.00758-09
Abstract: Defining the specificities of the anti-human immunodeficiency virus type 1 (HIV-1) envelope antibodies able to mediate broad heterologous neutralization will assist in identifying targets for an HIV-1 vaccine. We screened 70 plasmas from chronically HIV-1-infected in iduals for neutralization breadth. Of these, 16 (23%) were found to neutralize 80% or more of the viruses tested. Anti-CD4 binding site (CD4bs) antibodies were found in almost all plasmas independent of their neutralization breadth, but they mainly mediated neutralization of the laboratory strain HxB2 with little effect on the primary virus, Du151. Adsorption with Du151 monomeric gp120 reduced neutralizing activity to some extent in most plasma s les when tested against the matched virus, although these antibodies did not always confer cross-neutralization. For one plasma, this activity was mapped to a site overlapping the CD4-induced (CD4i) epitope and CD4bs. Anti-membrane-proximal external region (MPER) ( r = 0.69 P 0.001) and anti-CD4i ( r = 0.49 P 0.001) antibody titers were found to be correlated with the neutralization breadth. These anti-MPER antibodies were not 4E10- or 2F5-like but spanned the 4E10 epitope. Furthermore, we found that anti-cardiolipin antibodies were correlated with the neutralization breadth ( r = 0.67 P 0.001) and anti-MPER antibodies ( r = 0.6 P 0.001). Our study suggests that more than one epitope on the envelope glycoprotein is involved in the cross-reactive neutralization elicited during natural HIV-1 infection, many of which are yet to be determined, and that polyreactive antibodies are possibly involved in this phenomenon.
Detection of clinical progression through plasma ctDNA in metastatic melanoma patients: a comparison to radiological progression
Publisher: Springer Science and Business Media LLC
Date: 09-08-2021
DOI: 10.1038/S41416-021-01507-6
Abstract: The validity of circulating tumour DNA (ctDNA) as an indicator of disease progression compared to medical imaging in patients with metastatic melanoma requires detailed evaluation. Here, we carried out a retrospective ctDNA analysis of 108 plasma s les collected at the time of disease progression. We also analysed a validation cohort of 66 metastatic melanoma patients monitored prospectively after response to systemic therapy. ctDNA was detected in 62% of patients at the time of disease progression. For 67 patients that responded to treatment, the mean ctDNA level at progressive disease was significantly higher than at the time of response ( P 0.0001). However, only 30 of these 67 (45%) patients had a statistically significant increase in ctDNA by Poisson test. A validation cohort of 66 metastatic melanoma patients monitored prospectively indicated a 56% detection rate of ctDNA at progression, with only two cases showing increased ctDNA prior to radiological progression. Finally, a correlation between ctDNA levels and metabolic tumour burden was only observed in treatment naïve patients but not at the time of progression in a subgroup of patients failing BRAF inhibition ( N = 15). These results highlight the low efficacy of ctDNA to detect disease progression in melanoma when compared mainly to standard positron emission tomography imaging.
Role of Serum Vascular Endothelial Growth Factor (VEGF) as a Potential Biomarker of Response to Immune Checkpoint Inhibitor Therapy in Advanced Melanoma: Results of a Pilot Study
Publisher: Frontiers Media SA
Date: 30-06-2020
Incidence and mortality of uveal melanoma in Australia (1982–2014)
Publisher: BMJ
Date: 08-12-2021
DOI: 10.1136/BJOPHTHALMOL-2021-319700
Abstract: We aimed to estimate the incidence and mortality of uveal melanoma (UM) in Australia from 1982 to 2014. Deidentified unit data for all cases of ocular melanoma were extracted from the Australian Cancer Database from 1 January 1982 to 31 December 2014. UM cases were extracted and trends in incidence and disease-specific mortality were calculated. Incidence rates were age-standardised against the 2001 Australian Standard Population. Mortality was assessed using Cox regression. From 1982 to 2014, there were 5087 cases of ocular melanoma in Australia, of which 4617 were classified as UM. The average age-standardised incidence rate of UM was 7.6 (95% CI 7.3 to 7.9) per million. There was an increase (p=0.0502) in the incidence of UM from 1982 to 1993 with an annual percent change (APC) of +2.5%, followed by a significant decrease in the incidence of UM from 1993 to 2014 (APC −1.2%). The average 5-year survival from 1982 to 2011 did not significantly change from an average of 81%, with an average APC (AAPC) of +0.1%. A multivariate Cox regression revealed that residence in Western Australia (p=0.001) or Tasmania (p=0.05), age ≥60 years (p .001) and histological classification as mixed (p .001) or epithelioid cells (p .001) were significantly associated with reduced survival. In conclusion, we found that the incidence of UM peaked in the 1990s. Although treatment for primary UM has improved in the last 30 years, overall survival did not change significantly in the last 30 years.
Is the Blood an Alternative for Programmed Cell Death Ligand 1 Assessment in Non-Small Cell Lung Cancer?
Publisher: MDPI AG
Date: 30-06-2019
Abstract: Anti-programmed cell death (PD)-1/PD-ligand 1 (L1) therapies have significantly improved the outcomes for non-small cell lung cancer (NSCLC) patients in recent years. These therapies work by reactivating the immune system and enabling it to target cancer cells once more. There is a general agreement that expression of PD-L1 on tumour cells predicts the therapeutic response to PD-1/PD-L1 inhibitors in NSCLC. Hence, immunohistochemical staining of tumour tissue biopsies from NSCLC patients with PD-L1 antibodies is the current standard used to aid selection of patients for treatment with anti-PD-1 as first line therapy. However, issues of small tissue s les, tissue heterogeneity, the emergence of new metastatic sites, and dynamic changes in the expression of PD-L1 may influence PD-L1 status during disease evolution. Re-biopsy would expose patients to the risk of complications and tardy results. Analysis of PD-L1 expression on circulating tumour cells (CTCs) may provide an accessible and non-invasive means to select patients for anti-PD-1 therapies. Additionally, CTCs could potentially provide a useful biomarker in their own right. Several published studies have assessed PD-L1 expression on CTCs from NSCLC patients. Overall, analysis of PD-L1 on CTCs is feasible and could be detected prior to and after frontline therapy. However, there is no evidence on whether PD-L1 expression on CTCs could predict the response to anti-PD-1/PD-L1 treatment. This review examines the challenges that need to be addressed to demonstrate the clinical validity of PD-L1 analysis in CTCs as a biomarker capable of predicting the response to immune checkpoint blockade.
PD-L1 Expression on Circulating Tumor Cells May Be Predictive of Response to Pembrolizumab in Advanced Melanoma: Results from a Pilot Study.
Publisher: Oxford University Press (OUP)
Date: 05-12-2019
DOI: 10.1634/THEONCOLOGIST.2019-0557
Abstract: PD-1 inhibitors are routinely used for the treatment of advanced melanoma. This study sought to determine whether PD-L1 expression on circulating tumor cells (CTCs) can serve as a predictive biomarker of clinical benefit and response to treatment with the PD-1 inhibitor pembrolizumab. Blood s les were collected from patients with metastatic melanoma receiving pembrolizumab, prior to treatment and 6–12 weeks after initiation of therapy. Multiparametric flow cytometry was used to identify CTCs and evaluate the expression of PD-L1. CTCs were detected in 25 of 40 patients (63%). Patients with detectable PD-L1+ CTCs (14/25, 64%) had significantly longer progression-free survival (PFS) compared with patients with PD-L1− CTCs (26.6 months vs. 5.5 months p = .018). The 12-month PFS rates were 76% versus 22% in the PD-L1+ versus PD-L1− CTCs groups (p = .012), respectively. A multivariate linear regression analysis confirmed that PD-L1+ CTC is an independent predictive biomarker of PFS (hazard ratio, 0.229 95% confidence interval, 0.052–1.012 p = .026). Our results reveal the potential of CTCs as a noninvasive real-time biopsy to evaluate PD-L1 expression in patients with melanoma. PD-L1 expression on CTCs may be predictive of response to pembrolizumab and longer PFS.
Liquid biopsy in ovarian cancer using circulating tumor DNA and cells: Ready for prime time?
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.CANLET.2019.10.014
Abstract: Liquid biopsies hold the potential to inform cancer patient prognosis and to guide treatment decisions at the time when direct tumor biopsy may be impractical due to its invasive nature, inaccessibility and associated complications. Specifically, circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) have shown promising results as companion diagnostic biomarkers for screening, prognostication and/or patient surveillance in many cancer types. In ovarian cancer (OC), CTC and ctDNA analysis allow comprehensive molecular profiling of the primary, metastatic and recurrent tumors. These biomarkers also correlate with overall tumor burden and thus, they provide minimally-invasive means for patient monitoring during clinical course to ascertain therapy response and timely treatment modification in the context of disease relapse. Here, we review recent reports of the potential clinical value of CTC and ctDNA in OC, expatiating on their use in diagnosis and prognosis. We critically appraise the current evidence, and discuss the issues that still need to be addressed before liquid biopsies can be implemented in routine clinical practice for OC management.
Circulating tumor DNA to monitor treatment response and detect acquired resistance in patients with metastatic melanoma
Publisher: Impact Journals, LLC
Date: 22-09-2015
Circulating tumour DNA (ctDNA) as a liquid biopsy for melanoma
Publisher: No publisher found
Date: 2017
DOI: 10.1016/J.CANLET.2017.06.030
Abstract: Circulating tumour DNA (ctDNA) has emerged as a promising blood-based biomarker for monitoring disease status of patients with advanced cancers. In melanoma, ctDNA has been shown to have clinical value as an alternative tumour source for the detection clinically targetable mutations for the assessment of response to therapy. This review provides a critical summary of the evidence that gives credence to the utility of ctDNA as a biomarker for monitoring of disease status in advanced melanoma and the steps required for its implementation into clinical settings.
Intra- and intertumoral heterogeneity of liver metastases in a patient with uveal melanoma revealed by single-cell RNA sequencing
Publisher: Cold Spring Harbor Laboratory
Date: 09-2021
DOI: 10.1101/MCS.A006111
Abstract: Tumor heterogeneity is a major obstacle to the success of cancer treatment. An accurate understanding and recognition of tumor heterogeneity is critical in the clinical management of cancer patients. Here, we utilized single-cell RNA sequencing (scRNA-seq) to uncover the intra- and intertumoral heterogeneity of liver metastases from a patient with metastatic uveal melanoma. The two metastases analyzed were largely infiltrated by noncancerous cells with significant variability in the proportion of different cell types. Analysis of copy-number variations (CNVs) showed gain of 8q and loss of 6q in both tumors, but loss of Chromosome 3 was only detected in one of the tumors. Single-nucleotide polymorphism (SNP) array revealed a uniparental isodisomy 3 in the tumor with two copies of Chromosome 3, indicating a regain of Chromosome 3 during the development of the metastatic disease. In addition, both tumors harbored subclones with additional CNVs. Pathway enrichment analysis of differentially expressed genes revealed that cancer cells in the metastasis with isodisomy 3 showed up-regulation in epithelial–mesenchymal transition and myogenesis related genes. In contrast, up-regulation in interferon signaling was observed in the metastasis with monosomy 3 and increased T-cell infiltrate. This study highlights the complexity and heterogeneity of different metastases within an in idual case of uveal melanoma.
The lectins griffithsin, cyanovirin-N and scytovirin inhibit HIV-1 binding to the DC-SIGN receptor and transfer to CD4+ cells
Publisher: Elsevier BV
Date: 02-2012
Locally performed postoperative circulating tumour DNA testing performed during routine clinical care to predict recurrence of colorectal cancer
Publisher: Wiley
Date: 15-03-2023
DOI: 10.1111/ANS.18385
Abstract: Identifying patients at high risk for colorectal cancer recurrence is essential for improving prognosis. In the postoperative period, circulating tumour DNA (ctDNA) has been demonstrated as a significant prognostic indicator of recurrence. These results have been obtained under the strict rigours of clinical trials, but not validated in a real‐world setting using in‐house testing. We report the outcomes of locally performed postoperative ctDNA testing conducted during routine clinical care and the association with the recurrence of colorectal cancer. We recruited 36 consecutive patients with newly diagnosed colorectal cancer between 2018 and 2020. Postoperative plasma s les were collected at the first outpatient review following resection. Tumour‐informed ctDNA analysis was performed using droplet digital polymerase chain reaction or targeted next‐generation sequencing. At the time of surgery, there were 24 patients (66.7%) with localized cancer, nine (25%) with nodal spread, and three (8.3%) with metastatic disease. The median time from surgery to plasma s le donation was 22 days (IQR 20–28 days). At least one somatic mutation was identified in primary tumour tissue for 28 (77.8%) patients. Postoperative ctDNA was detected in five patients (13.9%). The median duration of follow‐up was 32.0 months (IQR 27.2–38.1 months). Two patients (5.56%) developed metastatic recurrence. However, neither had detectable postoperative ctDNA. There were no instances of loco‐regional recurrence. Analysis of postoperative ctDNA testing can be performed locally, however this study did not reproduce the adverse association between detectable postoperative ctDNA and the development of colorectal cancer recurrence seen in clinical trials.
Monitoring changes in circulating tumour cells as a prognostic indicator of overall survival and treatment response in patients with metastatic melanoma
Publisher: Springer Science and Business Media LLC
Date: 11-06-2014
Analysis of a Clonal Lineage of HIV-1 Envelope V2/V3 Conformational Epitope-Specific Broadly Neutralizing Antibodies and Their Inferred Unmutated Common Ancestors
Publisher: American Society for Microbiology
Date: 10-2011
DOI: 10.1128/JVI.05045-11
Abstract: V2/V3 conformational epitope antibodies that broadly neutralize HIV-1 (PG9 and PG16) have been recently described. Since an elicitation of previously known broadly neutralizing antibodies has proven elusive, the induction of antibodies with such specificity is an important goal for HIV-1 vaccine development. A critical question is which immunogens and vaccine formulations might be used to trigger and drive the development of memory B cell precursors with V2/V3 conformational epitope specificity. In this paper we identified a clonal lineage of four V2/V3 conformational epitope broadly neutralizing antibodies (CH01 to CH04) from an African HIV-1-infected broad neutralizer and inferred their common reverted unmutated ancestor (RUA) antibodies. While conformational epitope antibodies rarely bind recombinant Env monomers, a screen of 32 recombinant envelopes for binding to the CH01 to CH04 antibodies showed monoclonal antibody (MAb) binding to the E.A244 gp120 Env and to chronic Env AE.CM243 MAbs CH01 and CH02 also bound to transmitted/founder Env B.9021. CH01 to CH04 neutralized 38% to 49% of a panel of 91 HIV-1 tier 2 pseudoviruses, while the RUAs neutralized only 16% of HIV-1 isolates. Although the reverted unmutated ancestors showed restricted neutralizing activity, they retained the ability to bind to the E.A244 gp120 HIV-1 envelope with an affinity predicted to trigger B cell development. Thus, E.A244, B.9021, and AE.CM243 Envs are three potential immunogen candidates for studies aimed at defining strategies to induce V2/V3 conformational epitope-specific antibodies.
Evolution of an HIV glycan–dependent broadly neutralizing antibody epitope through immune escape
Publisher: Springer Science and Business Media LLC
Date: 21-10-2012
DOI: 10.1038/NM.2985
Data from Longitudinal Monitoring of ctDNA in Patients with Melanoma and Brain Metastases Treated with Immune Checkpoint Inhibitors
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.C.6529769.V1
Abstract: AbstractPurpose: Brain involvement occurs in the majority of patients with metastatic melanoma. The potential of circulating tumor DNA (ctDNA) for surveillance and monitoring systemic therapy response in patients with melanoma brain metastases merits investigation. Experimental Design: This study examined circulating i BRAF, NRAS /i , and i c-KIT /i mutations in patients with melanoma with active brain metastases receiving PD-1 inhibitor–based therapy. Intracranial and extracranial disease volumes were measured using the sum of product of diameters, and response assessment performed using RECIST. Longitudinal plasma s les were analyzed for ctDNA over the first 12 weeks of treatment (threshold 2.5 copies/mL plasma). Results: Of a total of 72 patients, 13 patients had intracranial metastases only and 59 patients had concurrent intracranial and extracranial metastases. ctDNA detectability was 0% and 64%, respectively, and detectability was associated with extracranial disease volume ( i P /i 0.01). Undetectable ctDNA on-therapy was associated with extracranial response ( i P /i 0.01) but not intracranial response. The median overall survival in patients with undetectable ( i n /i = 34) versus detectable ( i n /i = 38) ctDNA at baseline was 39.2 versus 10.6 months [HR, 0.51 95% confidence interval (CI), 0.28–0.94 i P /i = 0.03] and on-therapy was 39.2 versus 9.2 months (HR, 0.32 95% CI, 0.16–0.63 i P /i 0.01). Conclusions: ctDNA remains a strong prognostic biomarker in patients with melanoma with brain metastases, especially in patients with concurrent extracranial disease. However, ctDNA was not able to detect or monitor intracranial disease activity, and we recommend against using ctDNA as a sole test during surveillance and therapeutic monitoring in patients with melanoma. /
A comparative study of extracellular vesicle-associated and cell-free DNA and RNA for HPV detection in oropharyngeal squamous cell carcinoma
Publisher: Springer Science and Business Media LLC
Date: 08-04-2020
DOI: 10.1038/S41598-020-63180-8
Abstract: Purpose: This study compares the detection sensitivity of two separate liquid biopsy sources, cell-free (cf) DNA/RNA and extracellular vesicle (EV)-associated DNA/RNA (EV-DNA/RNA), to identify circulating Human Papilloma Virus (HPV) DNA/RNA in plasma obtained from patients with oropharyngeal squamous cell carcinoma (OPCSCC). We also report on the longitudinal changes observed in HPV-DNA levels in response to treatment. Experimental design: A prospective study was conducted that included 22 patients with locally advanced disease and six patients with metastatic OPCSCC. Twenty-three patients had HPV-related OPCSCC defined by p16 immunohistochemistry. Levels of circulating HPV-DNA and HPV-RNA from plasma-derived cf-DNA/RNA and EV-DNA/RNA were quantified using digital droplet PCR. Results: Circulating HPV-DNA was detected with higher sensitivity in cf-DNA compared to EV-DNA at 91% vs. 42% ( p = .001). Similarly, circulating tumoral HPV-RNA was detected at a higher sensitivity in cf-RNA compared to EV-RNA, at 83% vs. 50% ( p = 0.0019). In the locally advanced cohort, 100% (n = 16) of HPV-OPCSCC patients demonstrated a reduction in circulating HPV-DNA levels in cf-DNA following curative treatment, with 81% of patients demonstrating complete clearance to undetectable levels. However, in metastatic HPV-OPCSCC patients (n = 4), HPV-DNA levels did not correlate with treatment response. Conclusion: Our study demonstrates that although HPV-DNA/RNA can be detected in EV associated DNA/RNA, cf-DNA/RNA is the more sensitive liquid biopsy medium. As circulating HPV-DNA levels were found to only correlate with treatment response in the locally advanced but not metastatic setting in our small cohort of patients, the use of HPV-DNA as a dynamic biomarker to monitor treatment response requires further evaluation.
Low-Pass Whole-Genome Sequencing as a Method of Determining Copy Number Variations in Uveal Melanoma Tissue Samples.
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.JMOLDX.2019.12.005
Abstract: Analysis of specific somatic copy number alterations (SCNAs) using multiplex ligation-dependent probe lification (MLPA) is used routinely as a prognostic test for uveal melanoma (UM). This technique requires relatively large amounts of input DNA, unattainable from many small fine-needle aspirate biopsy specimens. Herein, we compared the use of MLPA with whole-genome lification (WGA) combined with low-pass whole-genome sequencing (LP-WGS) for detection of SCNA profiles in UM biopsy specimens. DNA was extracted from 21 formalin-fixed, paraffin-embedded UM s les and SCNAs were assessed using MLPA and WGA followed by LP-WGS. Cohen's κ was used to assess the concordance of copy number calls of each in idual chromosome arm for each patient. MLPA and WGA/LP-WGS detection of SCNAs in chromosomes 1p, 3, 6, and 8 were compared and found to be highly concordant with a Cohen's κ of 0.856 (bias-corrected and accelerated 95% CI, 0.770-0.934). Only 13 of 147 (8.8%) chromosomal arms investigated resulted in discordant calls, predominantly SCNAs detected by WGA/LP-WGS but not MLPA. These results indicate that LP-WGS might be a suitable alternative or adjunct to MLPA for the detection of SCNAs associated with prognosis of UM, for cases with limiting tissue or DNA yields.
Resistance mechanisms to targeted therapy in BRAF-mutant melanoma - A mini review.
Publisher: Elsevier BV
Date: 2020
Amino Acid Changes in the HIV-1 gp41 Membrane Proximal Region Control Virus Neutralization Sensitivity
Publisher: Elsevier BV
Date: 10-2016
SIRT1 activation mediates heat-induced survival of UVB damaged Keratinocytes
Publisher: Springer Science and Business Media LLC
Date: 10-06-2017
Monitoring melanoma recurrence with circulating tumor DNA: a proof of concept from three case studies
Publisher: Impact Journals, LLC
Date: 04-01-2019
Identification of broadly neutralizing antibody epitopes in the HIV-1 envelope glycoprotein using evolutionary models
Publisher: Springer Science and Business Media LLC
Date: 12-2013
Abstract: Identification of the epitopes targeted by antibodies that can neutralize erse HIV-1 strains can provide important clues for the design of a preventative vaccine. We have developed a computational approach that can identify key amino acids within the HIV-1 envelope glycoprotein that influence sensitivity to broadly cross-neutralizing antibodies. Given a sequence alignment and neutralization titers for a panel of viruses, the method works by fitting a phylogenetic model that allows the amino acid frequencies at each site to depend on neutralization sensitivities. Sites at which viral evolution influences neutralization sensitivity were identified using Bayes factors (BFs) to compare the fit of this model to that of a null model in which sequences evolved independently of antibody sensitivity. Conformational epitopes were identified with a Metropolis algorithm that searched for a cluster of sites with large Bayes factors on the tertiary structure of the viral envelope. We applied our method to ID 50 neutralization data generated from seven HIV-1 subtype C serum s les with neutralization breadth that had been tested against a multi-clade panel of 225 pseudoviruses for which envelope sequences were also available. For each s le, between two and four sites were identified that were strongly associated with neutralization sensitivity (2ln(BF) 6), a subset of which were experimentally confirmed using site-directed mutagenesis. Our results provide strong support for the use of evolutionary models applied to cross-sectional viral neutralization data to identify the epitopes of serum antibodies that confer neutralization breadth.
Droplet Digital PCR for Mutation Detection in Formalin-Fixed, Paraffin-Embedded Melanoma Tissues
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.JMOLDX.2017.11.009
Abstract: The identification of somatic mutations is crucial for guiding therapeutic decisions about personalized melanoma treatment. However, genetic analysis of tumors is usually performed on limited and often low-quality DNA from tumors with low tumor cellularity and high tumor heterogeneity. Different mutation-detection platforms exist, with varying analytical sensitivities. Here we evaluated the detection of common mutations in BRAF, NRAS, and TERT promoter in 40 melanoma FFPE tissues using Droplet Digital (dd)PCR, and compared the results to the detection rates obtained by Sanger sequencing and pyrosequencing. The cellularity of tumors analyzed ranged from 5% to 50% (n = 28) and 50% to 90% (n = 12). Overall, droplet digital (dd)PCR was more sensitive, detecting mutations in 12.5% and 23% of tumors deemed as wild-type by pyrosequencing and Sanger sequencing, respectively. The increased sensitivity of ddPCR was more apparent among tumors with <50% tumor cellularity. Implementation of ddPCR-based assays may facilitate analysis of early-stage tumors and support research into improving outcomes in melanoma patients.
Limited Neutralizing Antibody Specificities Drive Neutralization Escape in Early HIV-1 Subtype C Infection
Publisher: Public Library of Science (PLoS)
Date: 18-09-2009
Evaluation of a multi-marker immunomagnetic enrichment assay for the quantification of circulating melanoma cells
Publisher: Springer Science and Business Media LLC
Date: 15-09-2012
Abstract: Circulating melanoma cells (CMCs) are thought to be valuable in improving measures of prognosis in melanoma patients and may be a useful marker of residual disease to identify non-metastatic patients requiring adjuvant therapy. We investigated whether immunomagnetic enrichment targeting multiple markers allows more efficient enrichment of CMCs from patient peripheral blood than targeting a single marker. Furthermore, we aimed to determine whether the number of CMCs in patient blood was associated with disease stage. We captured CMCs by targeting the melanoma associated markers MCSP and MCAM as well as the melanoma stem cell markers ABCB5 and CD271, both in idually and in combination, by immunomagnetic enrichment. CMCs were enriched and quantified from the peripheral blood of 10 non-metastatic and 13 metastatic melanoma patients. Targeting all markers in combination resulted in the enrichment of more CMCs than when any in idual marker was targeted (p 0.001-0.028). Furthermore, when a combination of markers was targeted, a greater number of CMCs were enriched in metastatic patients compared with non-metastatic patients (p = 0.007). Our results demonstrated that a combination of markers should be targeted for optimal isolation of CMCs. In addition, there are significantly more CMCs in metastatic patients compared with non-metastatic patients and therefore quantification of CMCs may prove to be a useful marker of disease progression.
Multi-marker immunofluorescent staining and pd-l1 detection on circulating tumour cells from ovarian cancer patients
Publisher: MDPI AG
Date: 10-12-2021
Abstract: Detection of ovarian cancer (OC) circulating tumour cells (CTCs) is primarily based on targeting epithelial markers, thus failing to detect mesenchymal tumour cells. More importantly, the immune checkpoint inhibitor marker PD-L1 has not been demonstrated on CTCs from OC patients. An antibody staining protocol was developed and tested using SKOV-3 and OVCA432 OC cell lines. We targeted epithelial (cytokeratin (CK) and EpCAM), mesenchymal (vimentin), and OC-specific (PAX8) markers for detection of CTCs, and CD45/16 and CD31 were used for the exclusion of white blood and vascular endothelial cells, respectively. PD-L1 was used for CTC characterisation. CTCs were enriched using the Parsortix™ system from 16 OC patients. Results revealed the presence of CTCs in 10 (63%) cases. CTCs were heterogeneous, with 113/157 (72%) cells positive for CK/EpCAM (epithelial marker), 58/157 (37%) positive for vimentin (mesenchymal marker), and 17/157 (11%) for both (hybrid). PAX8 was only found in 11/157 (7%) CTCs. In addition, 62/157 (39%) CTCs were positive for PD-L1. Positivity for PD-L1 was significantly associated with the hybrid phenotype when compared with the epithelial (p = 0.007) and mesenchymal (p = 0.0009) expressing CTCs. Characterisation of CTC phenotypes in relation to clinical outcomes is needed to provide insight into the role that epithelial to mesenchymal plasticity plays in OC and its relationship with PD-L1.
Assessment of a Size-Based Method for Enriching Circulating Tumour Cells in Colorectal Cancer
Publisher: MDPI AG
Date: 15-07-2022
Abstract: Circulating tumour cells (CTC) from solid tumours are a prerequisite for metastasis. Isolating CTCs and understanding their biology is essential for developing new clinical tests and precision oncology. Currently, CellSearch is the only FDA (U.S. Food and Drug Administration)-approved method for CTC enrichment but possesses several drawbacks owing to a reliance on the epithelial cell adhesion molecule (EpCAM) and a resource-intensive nature. Addressing these shortcomings, we optimised an existing size-based method, MetaCell, to enrich CTCs from blood of colorectal cancer (CRC) patients. We evaluated the ability of MetaCell to enrich CTCs by spiking blood with CRC cell lines and assessing the cell recovery rates and WBC depletion via immunostaining and gene expression. We then applied MetaCell to s les from 17 CRC patients and seven controls. Recovery rates were % in cell lines, with % depletion in WBCs. MetaCell yielded CTCs and CTC clusters in 52.9% and 23.5% of the patients, respectively, without false positives in control patients. CTCs and cluster detection did not correlate with histopathological parameters. Overall, we demonstrated that the MetaCell platform enriched CRC cells with high recovery rates and high purity. Our pilot study also demonstrated the ability of MetaCell to detect CTCs in CRC patients.
Tumour PD-L1 Expression in Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis.
Publisher: MDPI AG
Date: 31-10-2020
DOI: 10.3390/CELLS9112393
Abstract: Antibodies against programmed death-1 (PD-1), and its ligand, (PD-L1) have been approved recently for the treatment of small-cell lung cancer (SCLC). Although there are previous reports that addressed PD-L1 detection on tumour cells in SCLC, there is no comprehensive meta-analysis on the prevalence of PD-L1 expression in SCLC. We performed a systematic search of the PubMed, Cochrane Library and EMBASE databases to assess reports on the prevalence of PD-L1 expression and the association between PD-L1 expression and overall survival (OS). This meta-analysis included 27 studies enrolling a total of 2792 patients. The pooled estimate of PD-L1 expression was 26.0% (95% CI 17.0–37.0), (22.0% after removing outlying studies). The effect size was significantly heterogeneous (I2 = 97.4, 95% CI: 95.5–98.5, p 0.0001).Positive PD-L1 expression was a favourable prognostic factor for SCLC but not statistically significant (HR = 0.86 (95% CI (0.49–1.50), p = 0.5880 I2 = 88.7%, p 0.0001). Begg’s funnel plots and Egger’s tests indicated no publication bias across included studies (p 0.05). Overall, there is heterogeneity in the prevalence of PD-L1 expression in SCLC tumour cells across studies. This is significantly moderated by factors such as immunohistochemistry (IHC) evaluation cut-off values, and assessment of PD-L1 staining patterns as membranous and/or cytoplasmic. There is the need for large size, prospective and multicentre studies with well-defined protocols and endpoints to advance the clinical value of PD-L1 expression in SCLC.
Supplementary Figure from Longitudinal Monitoring of ctDNA in Patients with Melanoma and Brain Metastases Treated with Immune Checkpoint Inhibitors
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.22477832.V1
Abstract: Supplementary Figure 1. Flow chart of patient selection. Supplementary Figure 2. Flowchart of patients with disease response assessment available (n = 57).
Sensitive droplet digital PCR method for detection of TERT promoter mutations in cell free DNA from patients with metastatic melanoma
Publisher: Impact Journals, LLC
Date: 18-08-2017
Clinical Application of Circulating Tumor Cells and Circulating Tumor DNA in Uveal Melanoma.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 11-2018
DOI: 10.1200/PO.17.00279
Abstract: To evaluate the feasibility of using circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) for the management of uveal melanoma (UM). Low-coverage whole-genome sequencing was used to determine somatic chromosomal copy number alterations (SCNAs) in primary UM tumors, ctDNA, and whole-genome lified CTCs. CTCs were immunocaptured using an antimelanoma-associated chondroitin sulfate antibody conjugated to magnetic beads and immunostained for melanoma antigen recognised by T cells 1 (MART1)/glycoprotein 100 (gp100)/S100 calcium-binding protein β (S100β). ctDNA was quantified using droplet digital polymerase chain reaction assay for mutations in the GNAQ, GNA11, PLCβ4, and CYSLTR2 genes. SCNA analysis of CTCs and ctDNA isolated from a patient with metastatic UM showed good concordance with the enucleated primary tumor. In a cohort of 30 patients with primary UM, CTCs were detected in 58% of patients (one to 37 CTCs per 8 mL of blood), whereas only 26% of patients had detectable ctDNA (1.6 to 29 copies/mL). The presence of CTCs or ctDNA was not associated with tumor size or other prognostic markers. However, the frequent detection of CTCs in patients with early-stage UM supports a model in which CTCs can be used to derive tumor-specific SCNA relevant for prognosis. Monitoring of ctDNA after treatment of the primary tumor allowed detection of metastatic disease earlier than 18 F-labeled fluorodeoxyglucose positron emission tomography in two patients. The presence of CTCs in localized UM can be used to ascertain prognostic SCNA, whereas ctDNA can be used to monitor patients for early signs of metastatic disease. This study paves the way for the analysis of CTCs and ctDNA as a liquid biopsy that will assist with treatment decisions in patients with UM.
Advances in personalized targeted treatment of metastatic melanoma and non-invasive tumor monitoring
Publisher: Frontiers Media SA
Date: 2013
Heat stress: A risk factor for skin carcinogenesis
Publisher: Elsevier BV
Date: 08-2201
DOI: 10.1016/J.CANLET.2013.05.039
Abstract: Recent evidence suggests that heat stress may also be a risk factor of skin carcinogenesis. Heat stress causes activation of heat shock proteins (HSPs), chaperone proteins which prevent cells from undergoing apoptosis and ensuring their cellular function. However, HSPs recruitment may also have deleterious effects particularly if the cells rescued from apoptosis carry oncogenic mutations. We hypothesise that exposures to both heat and UV induce skin cancer(s) by concomitant expression of HSPs and oncogenic mutant proteins. Here we review studies demonstrating that heat stress-activated heat shock proteins such as HSP72 and HSP90 can influence signalling pathways such as MAPK, JNK and p53, which are all involved in regulating cell proliferation, survival and apoptosis.
Application of multiplex ligation-dependent probe amplification (MLPA) and low pass whole genome sequencing (LP-WGS) to the classification / characterisation of low grade glioneuronal tumours
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.PRP.2021.153724
Abstract: Glioneuronal tumours, although rare, are an important cause of treatment-resistant epilepsy. Differential diagnosis of glioneuronal tumour subtypes is complicated by their variable histological appearance and the lack of pathognomonic histological or molecular biomarkers. In this study we have applied techniques available in a diagnostic laboratory setting to characterise molecular and cytogenetic abnormalities in a single institution cohort of glioneuronal tumours. A cohort of 29 glioneuronal tumours that included 21 gangliogliomas and 5 dysembryoplastic neuroepithelial tumours (DNETs) was analysed using low pass whole genome sequencing (WGS) and 2 multiplex ligation-dependent probe lification (MLPA) central nervous system (CNS) tumour probesets. Low pass WGS identified chromosomal or subchromosomal alterations in 15 specimens. The most common chromosomal alterations were gains of chromosome 7 (n = 8) and chromosome 16 (n = 3). The BRAF The combination of low pass WGS and MLPA identifies multiple, erse genetic and chromosomal alterations in glioneuronal tumours, irrespective of histological tumour grade.
Isolation of a Human Anti-HIV gp41 Membrane Proximal Region Neutralizing Antibody by Antigen-Specific Single B Cell Sorting
Publisher: Public Library of Science (PLoS)
Date: 30-09-2011
Detection of BRAF splicing variants in plasma-derived cell-free nucleic acids and extracellular vesicles of melanoma patients failing targeted therapy therapies.
Publisher: Impact Journals, LLC
Date: 03-11-2020
Myokine Expression and Tumor-suppressive Effect of Serum following 12 Weeks of Exercise in Prostate Cancer Patients on ADT
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 22-09-2021
DOI: 10.1249/MSS.0000000000002783
Abstract: Although several mechanisms have been proposed for the tumor-suppressive effect of exercise, little attention has been given to myokines, even though skeletal muscle is heavily recruited during exercise resulting in myokine surges. We measured resting serum myokine levels before and after an exercise-based intervention and the effect of this serum on prostate cancer cell growth. Ten prostate cancer patients undertaking androgen deprivation therapy (age, 73.3 ± 5.6 yr) undertook a 12-wk exercise-based intervention including supervised resistance training, self-directed aerobic exercise, and protein supplementation. Body composition was assessed by dual-energy x-ray absorptiometry and muscle strength by the one-repetition maximum method. Fasting blood was collected at baseline and postintervention, and serum levels of myokines—secreted protein acidic and rich in cysteine, oncostatin M (OSM), decorin, insulin-like growth factor-1, and insulin-like growth factor binding protein-3 (IGFBP-3)—were measured. The growth of the prostate cancer cell line DU145 with baseline and postintervention serum was measured. Body weight ( P = 0.011), fat mass ( P = 0.012), and percent body fat ( P = 0.033) were reduced, whereas percent lean mass ( P = 0.001) increased, as did strength (leg press, P = 0.006 chest press, P = 0.020) across the intervention. Serum OSM levels ( P = 0.020) and relative serum OSM levels ( P = 0.020) increased compared with baseline. A significant reduction in DU145 Cell Index ( P = 0.012) and growth rate ( P = 0.012) was observed after applying postintervention serum compared with baseline serum. This study provides evidence for enhanced myokine expression and tumor-suppressive effects of serum from chronically exercise-trained prostate cancer patients on androgen deprivation therapy.
Specificity of the autologous neutralizing antibody response
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2009
UCLA1, a Synthetic Derivative of a gp120 RNA Aptamer, Inhibits Entry of Human Immunodeficiency Virus Type 1 Subtype C
Publisher: American Society for Microbiology
Date: 05-2012
DOI: 10.1128/JVI.06893-11
Abstract: Entry of human immunodeficiency virus type 1 (HIV-1) into cells is mediated by the virion surface envelope (Env) glycoproteins, making it a desirable target for antiretroviral entry inhibitors. We previously isolated a family of gp120 binding RNA aptamers and showed that they neutralized the infectivity of HIV-1. In this study, we assessed the activity of a shortened synthetic derivative of the B40 aptamer, called UCLA1, against a large panel of HIV-1 subtype C viruses. UCLA1 tightly bound to a consensus HIV-1 subtype C gp120 and neutralized isolates of the same subtype with 50% inhibitory concentrations (IC 50 s) in the nanomolar range. The aptamer had little toxicity in tests with cell lines and primary cells. Furthermore, it exhibited high therapeutic indices, suggesting that it may be effective at very low doses. Mapping of UCLA1 binding sites on gp120 revealed eight amino acid residues that modulated neutralization resistance. This included residues within the coreceptor binding site, at the base of the V3 loop, and in the bridging sheet within the conserved V1/V2 stem-loop of gp120. The aptamer was also shown to have synergistic effects with T20, a gp41 fusion inhibitor, and IgG1b12 (b12), an anti-CD4 binding site monoclonal antibody. These results suggest that UCLA1 may be suitable for development as a potent HIV-1 entry inhibitor.
Viral Escape from HIV-1 Neutralizing Antibodies Drives Increased Plasma Neutralization Breadth through Sequential Recognition of Multiple Epitopes and Immunotypes
Publisher: Public Library of Science (PLoS)
Date: 31-10-2013
High titer HIV-1 V3-specific antibodies with broad reactivity but low neutralizing potency in acute infection and following vaccination
Publisher: Elsevier BV
Date: 05-2009
Circulating Tumor DNA Predicts Outcome from First-, but not Second-line Treatment and Identifies Melanoma Patients Who May Benefit from Combination Immunotherapy
Publisher: American Association for Cancer Research (AACR)
Date: 13-11-2020
DOI: 10.1158/1078-0432.CCR-20-2251
Abstract: We evaluated the predictive value of pretreatment ctDNA to inform therapeutic outcomes in patients with metastatic melanoma relative to type and line of treatment. Plasma circulating tumor DNA (ctDNA) was quantified in 125 s les collected from 110 patients prior to commencing treatment with immune checkpoint inhibitors (ICIs), as first- (n = 32) or second-line (n = 27) regimens, or prior to commencing first-line BRAF/MEK inhibitor therapy (n = 66). An external validation cohort included 128 patients commencing ICI therapies in the first- (N = 77) or second-line (N = 51) settings. In the discovery cohort, low ctDNA (≤20 copies/mL) prior to commencing therapy predicted longer progression-free survival (PFS) in patients treated with first-line ICIs [HR, 0.20 95% confidence interval (CI) 0.07–0.53 P & 0.0001], but not in the second-line setting. An independent cohort validated that ctDNA is predictive of PFS in the first-line setting (HR, 0.42 95% CI, 0.22–0.83 P = 0.006), but not in the second-line ICI setting. Moreover, ctDNA prior to commencing ICI treatment was not predictive of PFS for patients pretreated with BRAF/MEK inhibitors in either the discovery or validation cohorts. Reduced PFS and overall survival were observed in patients with high ctDNA receiving anti–PD-1 monotherapy, relative to those treated with combination anti–CTLA-4/anti–PD-1 inhibitors. Pretreatment ctDNA is a reliable indicator of patient outcome in the first-line ICI treatment setting, but not in the second-line ICI setting, especially in patients pretreated with BRAF/MEK inhibitors. Preliminary evidence indicated that treatment-naïve patients with high ctDNA may preferentially benefit from combined ICIs.
Data from Longitudinal Monitoring of ctDNA in Patients with Melanoma and Brain Metastases Treated with Immune Checkpoint Inhibitors
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.C.6529769
Abstract: AbstractPurpose: Brain involvement occurs in the majority of patients with metastatic melanoma. The potential of circulating tumor DNA (ctDNA) for surveillance and monitoring systemic therapy response in patients with melanoma brain metastases merits investigation. Experimental Design: This study examined circulating i BRAF, NRAS /i , and i c-KIT /i mutations in patients with melanoma with active brain metastases receiving PD-1 inhibitor–based therapy. Intracranial and extracranial disease volumes were measured using the sum of product of diameters, and response assessment performed using RECIST. Longitudinal plasma s les were analyzed for ctDNA over the first 12 weeks of treatment (threshold 2.5 copies/mL plasma). Results: Of a total of 72 patients, 13 patients had intracranial metastases only and 59 patients had concurrent intracranial and extracranial metastases. ctDNA detectability was 0% and 64%, respectively, and detectability was associated with extracranial disease volume ( i P /i 0.01). Undetectable ctDNA on-therapy was associated with extracranial response ( i P /i 0.01) but not intracranial response. The median overall survival in patients with undetectable ( i n /i = 34) versus detectable ( i n /i = 38) ctDNA at baseline was 39.2 versus 10.6 months [HR, 0.51 95% confidence interval (CI), 0.28–0.94 i P /i = 0.03] and on-therapy was 39.2 versus 9.2 months (HR, 0.32 95% CI, 0.16–0.63 i P /i 0.01). Conclusions: ctDNA remains a strong prognostic biomarker in patients with melanoma with brain metastases, especially in patients with concurrent extracranial disease. However, ctDNA was not able to detect or monitor intracranial disease activity, and we recommend against using ctDNA as a sole test during surveillance and therapeutic monitoring in patients with melanoma. /
The C3-V4 Region Is a Major Target of Autologous Neutralizing Antibodies in Human Immunodeficiency Virus Type 1 Subtype C Infection
Publisher: American Society for Microbiology
Date: 15-02-2008
DOI: 10.1128/JVI.02187-07
Abstract: The early autologous neutralizing antibody response in human immunodeficiency virus type 1 (HIV-1) subtype C infections is often characterized by high titers, but the response is type specific with little to no cross-neutralizing activity. The specificities of these early neutralizing antibodies are not known however, the type specificity suggests that they may target the variable regions of the envelope. Here, we show that cross-reactive anti-V3 antibodies developed within 3 to 12 weeks in six in iduals but did not mediate autologous neutralization. Using a series of chimeric viruses, we found that antibodies directed at the V1V2, V4, and V5 regions contributed to autologous neutralization in some in iduals, with V1V2 playing a more substantial role. However, these antibodies did not account for the total neutralizing capacity of these sera against the early autologous virus. Antibodies directed against the C3-V4 region were involved in autologous neutralization in all four sera studied. In two sera, transfer of the C3-V4 region rendered the chimera as sensitive to antibody neutralization as the parental virus. Although the C3 region, which contains the highly variable α2-helix was not a direct target in most cases, it contributed to the formation of neutralization epitopes as substitution of this region resulted in neutralization resistance. These data suggest that the C3 and V4 regions combine to form important structural motifs and that epitopes in this region are major targets of the early autologous neutralizing response in HIV-1 subtype C infection.
Characterization of anti-HIV-1 neutralizing and binding antibodies in chronic HIV-1 subtype C infection
Publisher: Elsevier BV
Date: 11-2012
Mechanisms of HIV-1 subtype C resistance to GRFT, CV-N and SVN
Publisher: Elsevier BV
Date: 11-2013
Supplementary Data from Circulating Tumor DNA Predicts Outcome from First-, but not Second-line Treatment and Identifies Melanoma Patients Who May Benefit from Combination Immunotherapy
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.22477679
Abstract: Tables S1-S8 and Figures S1-S4
Supplementary Figure from Longitudinal Monitoring of ctDNA in Patients with Melanoma and Brain Metastases Treated with Immune Checkpoint Inhibitors
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/1078-0432.22477832
Abstract: Supplementary Figure 1. Flow chart of patient selection. Supplementary Figure 2. Flowchart of patients with disease response assessment available (n = 57).
Locus-specific concordance of genomic alterations between tissue and plasma circulating tumor DNA in metastatic melanoma
Publisher: Wiley
Date: 07-12-2019
Prognostic value of HLA-I homozygosity in patients with non-small cell lung cancer treated with single agent immunotherapy
Publisher: BMJ
Date: 11-2020
Abstract: We aimed to assess the impact of genomic human leukocyte antigen (HLA)-I/II homozygosity on the survival benefit of patients with unresectable locally advanced, metastatic non-small lung cancer treated by single-agent programmed cell death protein-1 rogrammed death ligand 1 (PD1/PDL1) inhibitors. We collected blood from 170 patients with advanced lung cancer treated with immunotherapy at two major oncology centers in Western Australia. Genomic DNA was extracted from white blood cells and used for HLA-I/II high-resolution typing. HLA-I/II homozygosity was tested for association with survival outcomes. Univariable and multivariable Cox regression models were constructed to determine whether HLA homozygosity was an independent prognostic factor affecting Overall Survival (OS) and Progression Free Survival (PFS). We also investigated the association between in idual HLA-A and -B supertypes with OS. Homozygosity at HLA-I loci, but not HLA-II, was significantly associated with shorter OS (HR=2.17, 95% CI 1.13 to 4.17, p=0.02) in both univariable and multivariable analysis. The effect of HLA-I homozygosity in OS was particularly relevant for patients with tumors expressing PDL1 ≥50% (HR=3.93, 95% CI 1.30 to 11.85, p .001). The adverse effect of HLA-I homozygosity on PFS was only apparent after controlling for interactions between PDL1 status and HLA-I genotype (HR=2.21, 95% CI 1.04 to 4.70, p=0.038). The presence of HLA-A02 supertype was the only HLA-I supertype to be associated with improved OS (HR=0.56, 95% CI 0.34 to 0.93, p=0.023). Our results suggest that homozygosity at ≥1 HLA-I loci is associated with short OS and PFS in patients with advanced non-small cell lung cancer with PDL1 ≥50% treated with single-agent immunotherapy. Carriers of HLA-A02 supertype reported better survival outcomes in this cohort of patients.
Editorial: Insights Into Biomarkers, Cytokines, and Chemokines in Skin Cancer
Publisher: Frontiers Media SA
Date: 25-09-2019
Analysis of Circulating Tumour Cells in Early-Stage Uveal Melanoma: Evaluation of Tumour Marker Expression to Increase Capture
Publisher: MDPI AG
Date: 28-11-2021
Abstract: (1) Background: The stratification of uveal melanoma (UM) patients into prognostic groups is critical for patient management and for directing patients towards clinical trials. Current classification is based on clinicopathological and molecular features of the tumour. Analysis of circulating tumour cells (CTCs) has been proposed as a tool to avoid invasive biopsy of the primary tumour. However, the clinical utility of such liquid biopsy depends on the detection rate of CTCs. (2) Methods: The expression of melanoma, melanocyte, and stem cell markers was tested in a primary tissue microarray (TMA) and UM cell lines. Markers found to be highly expressed in primary UM were used to either immunomagnetically isolate or immunostain UM CTCs prior to treatment of the primary lesion. (3) Results: TMA and cell lines had heterogeneous expression of common melanoma, melanocyte, and stem cell markers. A multi-marker panel of immunomagnetic beads enabled isolation of CTCs in 37/43 (86%) patients with UM. Detection of three or more CTCs using the multi-marker panel, but not MCSP alone, was a significant predictor of shorter progression free (p = 0.040) and overall (p = 0.022) survival. (4) Conclusions: The multi-marker immunomagnetic isolation protocol enabled the detection of CTCs in most primary UM patients. Overall, our results suggest that a multi-marker approach could be a powerful tool for CTC separation for non-invasive prognostication of UM.
Insensitivity of paediatric HIV-1 subtype C viruses to broadly neutralising monoclonal antibodies raised against subtype B.
Publisher: Public Library of Science (PLoS)
Date: 18-07-2006
Isolation and Quantification of Plasma Circulating Tumor DNA from Melanoma Patients
Publisher: Springer US
Date: 2021
Transcript-Based Detection of Circulating Melanoma Cells.
Publisher: Springer US
Date: 2021
Multi-Marker Immunomagnetic Enrichment of Circulating Melanoma Cells
Publisher: Springer US
Date: 2021
Broad Neutralization of Human Immunodeficiency Virus Type 1 Mediated by Plasma Antibodies against the gp41 Membrane Proximal External Region
Publisher: American Society for Microbiology
Date: 11-2009
DOI: 10.1128/JVI.01359-09
Abstract: We identified three cross-neutralizing plasma s les with high-titer anti-membrane proximal external region (MPER) peptide binding antibodies from among 156 chronically human immunodeficiency virus type 1-infected in iduals. In order to establish if these antibodies were directly responsible for the observed neutralization breadth, we used MPER-coated magnetic beads to deplete plasmas of these specific antibodies. Depletion of anti-MPER antibodies from BB34, CAP206, and SAC21 resulted in 77%, 68%, and 46% decreases, respectively, in the number of viruses neutralized. Antibodies eluted from the beads showed neutralization profiles similar to those of the original plasmas, with potencies comparable to those of the known anti-MPER monoclonal antibodies (MAbs), 4E10, 2F5, and Z13e1. The anti-MPER neutralizing antibodies in BB34 were present in the immunoglobulin G3 subclass-enriched fraction. Alanine scanning of the MPER showed that the antibodies from these three plasmas had specificities distinct from those of the known MAbs, requiring one to three crucial residues at positions 670, 673, and 674. These data demonstrate the existence of MPER-specific cross-neutralizing antibodies in plasma, although the ability to elicit such potent antiviral antibodies during natural infection appears to be rare. Nevertheless, the identification of three novel antibody specificities within the MPER supports its further study as a promising target for vaccine design.
4E10-Resistant Variants in a Human Immunodeficiency Virus Type 1 Subtype C-Infected Individual with an Anti-Membrane-Proximal External Region-Neutralizing Antibody Response
Publisher: American Society for Microbiology
Date: 03-2008
DOI: 10.1128/JVI.02161-07
Abstract: The broadly neutralizing monoclonal antibody (MAb) 4E10 recognizes a linear epitope in the C terminus of the membrane-proximal external region (MPER) of gp41. This epitope is particularly attractive for vaccine design because it is highly conserved among human immunodeficiency virus type 1 (HIV-1) strains and neutralization escape in vivo has not been observed. Multiple env genes were cloned from an HIV-1 subtype C virus isolated from a 7-year-old perinatally infected child who had anti-MPER neutralizing antibodies. One clone (TM20.13) was resistant to 4E10 neutralization as a result of an F673L substitution in the MPER. Frequency analysis showed that F673L was present in 33% of the viral variants and in all cases was linked to the presence of an intact 2F5 epitope. Two other envelope clones were sensitive to 4E10 neutralization, but TM20.5 was 10-fold less sensitive than TM20.6. Substitutions at positions 674 and 677 within the MPER rendered TM20.5 more sensitive to 4E10 but had no effect on TM20.6. Using chimeric and mutant constructs of these two variants, we further demonstrated that the lentivirus lytic peptide-2 domain in the cytoplasmic tail affected the accessibility of the 4E10 epitope, as well as virus infectivity. Collectively, these genetic changes in the face of a neutralizing antibody response to the MPER strongly suggested immune escape from antibody responses targeting this region.
Correlation between circulating tumour DNA and metabolic tumour burden in metastatic melanoma patients
Publisher: Springer Science and Business Media LLC
Date: 09-07-2018
A diagnostic autoantibody signature for primary cutaneous melanoma.
Publisher: Impact Journals, LLC
Date: 17-07-2018
Powering single-cell genomics to unravel circulating tumour cell subpopulations in non-small cell lung cancer patients
Publisher: Springer Science and Business Media LLC
Date: 28-07-2023
DOI: 10.1007/S00432-022-04202-Y
Abstract: Circulating tumour cells (CTCs) are attractive “liquid biopsy” candidates that could provide insights into the different phenotypes of tumours present within a patient. The epithelial-to-mesenchymal transition (EMT) of CTCs is considered a critical step in tumour metastasis however, it may confound traditional epithelial feature-based CTC isolation and detection. We applied single-cell copy number alteration (CNA) analysis for the identification of genomic alterations to confirm the neoplastic nature of circulating cells with only mesenchymal phenotypes. We isolated CTCs from blood s les collected from 46 NSCLC patients using the Parsortix system. Enriched cells were subjected to immunofluorescent staining for CTC identification using a multi-marker panel comprising both epithelial and mesenchymal markers. A subset of isolated CTCs was subjected to whole genome lification (WGA) and low-pass whole-genome sequencing (LP-WGS) for the analysis of copy number alterations (CNAs). CTCs were detected in 16/46 (34.8%) patients, inclusive of CK + /EpCAM + CTCs (3/46, 6.5%) and Vim + CTCs (13/46, 28.3%). Clusters of Vim + cells were detected in 8 s les, which constitutes 50% of the total number of NSCLC patients with CTCs. No patients had detectable hybrid CK + /EpCAM + /Vim + cells. All of the tested CK + /EpCAM + CTCs and 7/8 Vim + CTCs or CTC clusters carried CNAs confirming their neoplastic nature. Notably, the Vim + cluster with no CNAs was characterised by spindle morphology and, therefore, defined as normal mesenchymal circulating cells. Our results revealed that CK-negative, vimentin-expressing cells represent a large proportion of CTCs detected in NSCLC patients, which are likely missed by standard epithelial-marker-dependent CTC categorisation.
Heat-mediated reduction of apoptosis in UVB-damaged keratinocytes in vitro and in human skin ex vivo
Publisher: Springer Science and Business Media LLC
Date: 26-05-2016
Whole genome landscapes of uveal melanoma show an ultraviolet radiation signature in iris tumours
Publisher: Springer Science and Business Media LLC
Date: 15-05-2020
DOI: 10.1038/S41467-020-16276-8
Abstract: Uveal melanoma (UM) is the most common intraocular tumour in adults and despite surgical or radiation treatment of primary tumours, ~50% of patients progress to metastatic disease. Therapeutic options for metastatic UM are limited, with clinical trials having little impact. Here we perform whole-genome sequencing (WGS) of 103 UM from all sites of the uveal tract (choroid, ciliary body, iris). While most UM have low tumour mutation burden (TMB), two subsets with high TMB are seen one driven by germline MBD4 mutation, and another by ultraviolet radiation (UVR) exposure, which is restricted to iris UM. All but one tumour have a known UM driver gene mutation ( GNAQ, GNA11, BAP1, PLCB4, CYSLTR2, SF3B1, EIF1AX ). We identify three other significantly mutated genes ( TP53 , RPL5 and CENPE ).
Evolution of antibody landscape and viral envelope escape in an HIV-1 CRF02_AG infected patient with 4E10-like antibodies.
Publisher: Springer Science and Business Media LLC
Date: 12-2009
The Neutralization Breadth of HIV-1 Develops Incrementally over Four Years and Is Associated with CD4 + T Cell Decline and High Viral Load during Acute Infection
Publisher: American Society for Microbiology
Date: 15-05-2011
DOI: 10.1128/JVI.00198-11
Abstract: An understanding of how broadly neutralizing activity develops in HIV-1-infected in iduals is needed to guide vaccine design and immunization strategies. Here we used a large panel of 44 HIV-1 envelope variants (subtypes A, B, and C) to evaluate the presence of broadly neutralizing antibodies in serum s les obtained 3 years after seroconversion from 40 women enrolled in the CAPRISA 002 acute infection cohort. Seven of 40 participants had serum antibodies that neutralized more than 40% of viruses tested and were considered to have neutralization breadth. Among the s les with breadth, CAP257 serum neutralized 82% (36/44 variants) of the panel, while CAP256 serum neutralized 77% (33/43 variants) of the panel. Analysis of longitudinal s les showed that breadth developed gradually starting from year 2, with the number of viruses neutralized as well as the antibody titer increasing over time. Interestingly, neutralization breadth peaked at 4 years postinfection, with no increase thereafter. The extent of cross-neutralizing activity correlated with CD4 + T cell decline, viral load, and CD4 + T cell count at 6 months postinfection but not at later time points, suggesting that early events set the stage for the development of breadth. However, in a multivariate analysis, CD4 decline was the major driver of this association, as viral load was not an independent predictor of breadth. Mapping of the epitopes targeted by cross-neutralizing antibodies revealed that in one in idual these antibodies recognized the membrane-proximal external region (MPER), while in two other in iduals, cross-neutralizing activity was adsorbed by monomeric gp120 and targeted epitopes that involved the N-linked glycan at position 332 in the C3 region. Serum antibodies from the other four participants targeted quaternary epitopes, at least 2 of which were PG9/16-like and depended on the N160 and/or L165 residue in the V2 region. These data indicate that fewer than 20% of HIV-1 subtype C-infected in iduals develop antibodies with cross-neutralizing activity after 3 years of infection and that these antibodies target different regions of the HIV-1 envelope, including as yet uncharacterized epitopes.
Genetic characteristics of HIV-1 subtype C envelopes inducing cross-neutralizing antibodies
Publisher: Elsevier BV
Date: 11-2007
DOI: 10.1016/J.VIROL.2007.06.013
Abstract: This study aimed to characterize genetic features of HIV-1 subtype C envelope glycoproteins capable of eliciting cross-reactive neutralizing antibodies during natural infections. The gp160 sequences were determined for 36 HIV-1 subtype C isolates (donor viruses) from infected in iduals residing in Malawi, Zimbabwe, Zambia and South Africa, whose sera displayed a range of cross-neutralizing activities against a panel of 5 subtype C and 5 subtype B viruses (panel viruses). Hierarchical clustering analysis of neutralization data of the panel viruses predicted phylogenetic relationships between subtype B and C panel viruses, suggesting some subtype-specific neutralization determinants. A similar comparison of subtype C donor viruses showed no significant correlation however of three donor sequence pairs resolvable by phylogenetic analysis, two were also associated within the neutralization clustering dendrogram, suggesting that closely related viruses may elicit antibodies targeting common neutralization determinants. Significantly, viruses that had shorter V1-V4 loops induced antibodies that showed more neutralization breadth against the subtype C panel viruses (p=0.0135). This study indicates that that some structural features of envelope, such as shorter variable loops, may facilitate the elicitation of cross-reactive neutralizing antibodies in natural infections. Collectively these data provide some insights into design features of an envelope immunogen aimed at inducing neutralizing antibodies.
Human leucocyte antigen genotype association with the development of immune-related adverse events in patients with non-small cell lung cancer treated with single agent immunotherapy
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.EJCA.2022.05.021
Abstract: Biomarkers that predict the risk of immune-mediated adverse events (irAEs) among patients with non-small cell lung cancer (NSCLC) may reduce morbidity and mortality associated with these treatments. We carried out high resolution human leucocyte antigen (HLA)-I typing on 179 patients with NSCLC treated with anti-program death (PD)-1 rogram death ligand (PDL)-1. Toxicity data were collected and graded as per common terminology criteria for adverse event (CTCAE) v5.0. We used 14.8-week for landmark analysis to address lead-time bias to investigate the correlation between HLA-I/II zygosity, supertypes and alleles with irAE. Furthermore, we assessed the association for irAE with clinical benefit rate (CBR), progression-free survival (PFS) and overall survival (OS). Homozygosity at one or more HLA-I loci, but not HLA-II, was associated with a reduced risk of irAE (relative risk (RR) = 0.61, 95% CI 0.33-0.95, P = 0.035) especially pneumonitis or any grade 3 toxicity. Patients with HLA-A03 supertype had a higher risk of developing irAE (RR = 1.42, 95% CI 1.02-2.01, P = 0.039). The occurrence of any irAE was significantly associated with improved CBR (RR = 1.48, P 0.0001), PFS (HR = 0.45, P = 0.0003) and OS (HR = 0.34, P 0.0001). Homozygosity at one or more HLA-I loci may serve as biomarker to predict patients who are unlikely to experience severe irAEs among patients with NSCLC and treated with anti-PD1/PDL1, but less likely to derive clinical benefit. Patients with HLA-I homozygous might benefit from additional therapy.
Immunomagnetic-Enriched Subpopulations of Melanoma Circulating Tumour Cells (CTCs) Exhibit Distinct Transcriptome Profiles
Publisher: MDPI AG
Date: 30-01-2019
Abstract: Cutaneous melanoma circulating tumour cells (CTCs) are phenotypically and molecularly heterogeneous. We profiled the gene expression of CTC subpopulations immunomagnetic-captured by targeting either the melanoma-associated marker, MCSP, or the melanoma-initiating marker, ABCB5. Firstly, the expression of a subset of melanoma genes was investigated by RT-PCR in MCSP-enriched and ABCB5-enriched CTCs isolated from a total of 59 blood draws from 39 melanoma cases. Of these, 6 MCSP- and 6 ABCB5-enriched CTC fractions were further analysed using a genome-wide gene expression microarray. The transcriptional programs of both CTC subtypes included cell survival maintenance, cell proliferation, and migration pathways. ABCB5-enriched CTCs were specifically characterised by up-regulation of genes involved in epithelial to mesenchymal transition (EMT), suggesting an invasive phenotype. These findings underscore the presence of at least two distinct melanoma CTC subpopulations with distinct transcriptional programs, which may have distinct roles in disease progression and response to therapy.
Arterial or Venous: Where Are the Circulating Tumor Cells?
Publisher: Elsevier BV
Date: 11-2015
Is Tissue Still the Issue? The Promise of Liquid Biopsy in Uveal Melanoma
Publisher: MDPI AG
Date: 21-02-2022
DOI: 10.3390/BIOMEDICINES10020506
Abstract: Uveal melanoma (UM) is the second most frequent type of melanoma. Therapeutic options for UM favor minimally invasive techniques such as irradiation for vision preservation. As a consequence, no tumor material is obtained. Without available tissue, molecular analyses for gene expression, mutation or copy number analysis cannot be performed. Thus, proper patient stratification is impossible and patients’ uncertainty about their prognosis rises. Minimally invasive techniques have been studied for prognostication in UM. Blood-based biomarker analysis has become more common in recent years however, no clinically standardized protocol exists. This review summarizes insights in biomarker analysis, addressing new insights in circulating tumor cells, circulating tumor DNA, extracellular vesicles, proteomics, and metabolomics. Additionally, medical imaging can play a significant role in staging, surveillance, and prognostication of UM and is addressed in this review. We propose that combining multiple minimally invasive modalities using tumor biomarkers should be the way forward and warrant more attention in the coming years.
Recommendations for radiographers and radiation therapists drawn from an analysis of errors on Australian Radiation Incident Registers
Publisher: Wiley
Date: 05-01-2017
DOI: 10.1002/JMRS.206
Profiling the specificity of neutralizing antibodies in a large panel of plasmas from patients chronically infected with human immunodeficiency virus type 1 subtypes B and C.
Publisher: American Society for Microbiology
Date: 12-2008
DOI: 10.1128/JVI.01762-08
Abstract: Identifying the viral epitopes targeted by broad neutralizing antibodies (NAbs) that sometimes develop in human immunodeficiency virus type 1 (HIV-1)-infected subjects should assist in the design of vaccines to elicit similar responses. Here, we investigated the activities of a panel of 24 broadly neutralizing plasmas from subtype B- and C-infected donors using a series of complementary mapping methods, focusing mostly on JR-FL as a prototype subtype B primary isolate. Adsorption with gp120 immobilized on beads revealed that an often large but variable fraction of plasma neutralization was directed to gp120 and that in some cases, neutralization was largely mediated by CD4 binding site (CD4bs) Abs. The results of a native polyacrylamide gel electrophoresis assay using JR-FL trimers further suggested that half of the subtype B and a smaller fraction of subtype C plasmas contained a significant proportion of NAbs directed to the CD4bs. Anti-gp41 neutralizing activity was detected in several plasmas of both subtypes, but in all but one case, constituted only a minor fraction of the overall neutralization activity. Assessment of the activities of the subtype B plasmas against chimeric HIV-2 viruses bearing various fragments of the membrane proximal external region (MPER) of HIV-1 gp41 revealed mixed patterns, implying that MPER neutralization was not dominated by any single specificity akin to known MPER-specific monoclonal Abs. V3 and 2G12-like NAbs appeared to make little or no contribution to JR-FL neutralization titers. Overall, we observed significant titers of anti-CD4bs NAbs in several plasmas, but approximately two-thirds of the neutralizing activity remained undefined, suggesting the existence of NAbs with specificities unlike any characterized to date.
Multiple Pathways of Escape from HIV Broadly Cross-Neutralizing V2-Dependent Antibodies
Publisher: American Society for Microbiology
Date: 05-2013
DOI: 10.1128/JVI.03424-12
Abstract: Broadly cross-neutralizing (BCN) antibodies are likely to be critical for an effective HIV vaccine. However, the ontogeny of such antibodies and their relationship with autologous viral evolution is unclear. Here, we characterized viral evolution in CAP256, a subtype C-infected in idual who developed potent BCN antibodies targeting positions R166 and K169 in the V2 region. CAP256 was superinfected at 3 months postinfection with a virus that was highly sensitive to BCN V2-dependent monoclonal antibodies. The autologous neutralizing response in CAP256 was directed at V1V2, reaching extremely high titers ( :40,000) against the superinfecting virus at 42 weeks, just 11 weeks prior to the development of the BCN response targeting the same region. Recombination between the primary and superinfecting viruses, especially in V2 and gp41, resulted in two distinct lineages by 4 years postinfection. Although neutralization of some CAP256 clones by plasma from as much as 2 years earlier suggested incomplete viral escape, nonetheless titers against later clones were reduced at least 40-fold to less than 1:1,000. Escape mutations were identified in each lineage, either at R166 or at K169, suggesting that strain-specific and BCN antibodies targeted overlapping epitopes. Furthermore, the early dependence of CAP256 neutralizing antibodies on the N160 glycan decreased with the onset of neutralization breadth, indicating a change in specificity. These data suggest rapid maturation, within 11 weeks, of CAP256 strain-specific antibodies to acquire breadth, with implications for the vaccine elicitation of BCN V2-dependent antibodies. Overall these studies demonstrate that ongoing viral escape is possible, even from BCN antibodies.
The Epigenetic landscape of Circulating tumour cells
Publisher: Elsevier BV
Date: 04-2021
South African HIV-1 subtype C transmitted variants with a specific V2 motif show higher dependence on α4β7 for replication
Publisher: Springer Science and Business Media LLC
Date: 24-06-2015
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