ORCID Profile
0000-0002-7673-4655
Current Organisation
Alfred Health
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Publisher: Springer Science and Business Media LLC
Date: 23-06-2016
DOI: 10.1007/S10456-016-9520-Y
Abstract: Desmogleins (DSG) are a family of cadherin adhesion proteins that were first identified in desmosomes and provide cardiomyocytes and epithelial cells with the junctional stability to tolerate mechanical stress. However, one member of this family, DSG2, is emerging as a protein with additional biological functions on a broader range of cells. Here we reveal that DSG2 is expressed by non-desmosome-forming human endothelial progenitor cells as well as their mature counterparts [endothelial cells (ECs)] in human tissue from healthy in iduals and cancer patients. Analysis of normal blood and bone marrow showed that DSG2 is also expressed by CD34(+)CD45(dim) hematopoietic progenitor cells. An inability to detect other desmosomal components, i.e., DSG1, DSG3 and desmocollin (DSC)2/3, on these cells supports a solitary role for DSG2 outside of desmosomes. Functionally, we show that CD34(+)CD45(dim)DSG2(+) progenitor cells are multi-potent and pro-angiogenic in vitro. Using a 'knockout-first' approach, we generated a Dsg2 loss-of-function strain of mice (Dsg2 (lo/lo)) and observed that, in response to reduced levels of Dsg2: (i) CD31(+) ECs in the pancreas are hypertrophic and exhibit altered morphology, (ii) bone marrow-derived endothelial colony formation is impaired, (iii) ex vivo vascular sprouting from aortic rings is reduced, and (iv) vessel formation in vitro and in vivo is attenuated. Finally, knockdown of DSG2 in a human bone marrow EC line reveals a reduction in an in vitro angiogenesis assay as well as relocalisation of actin and VE-cadherin away from the cell junctions, reduced cell-cell adhesion and increased invasive properties by these cells. In summary, we have identified DSG2 expression in distinct progenitor cell subpopulations and show that, independent from its classical function as a component of desmosomes, this cadherin also plays a critical role in the vasculature.
Publisher: WORLD SCIENTIFIC
Date: 12-2007
Publisher: Cold Spring Harbor Laboratory
Date: 12-06-2020
DOI: 10.1101/2020.06.12.145276
Abstract: Targeting the right cancer-specific peptides presented by Human Leukocyte antigen (HLA) class I and II molecules on the tumor cell surface is a crucial step in cancer immunotherapy. Numerous approaches have been proposed to predict the presentation of potential neoepitopes that may be targeted through immune-based therapies. Often founded on patient specific somatic mutations, the routine validation of their actual appearance on the tumor cell surface is a significant barrier to realising personalized cancer immunotherapy. This can be attributed to the lack of robust and adaptable assays for antigen presentation that offer the required sensitivity to deal with the limited amounts of patient tumor tissue available. Rather than personalize in idual assays we propose the use mass spectrometry to identify tumor neoepitopes from HLA-bound peptides directly isolated form the surface of tumor biopsies. We have developed a microscale HLA-peptide complex immunoprecipitation protocol combined with tandem mass tagging (TMT) to directly sequence HLA-bound peptides using mass spectrometry. Using this strategy, we identified HLA-bound peptides from as few as ~1000 cultured cells and from a small piece (~1 mg) of whole melanoma tumour tissue, encompassing epitopes derived from Melanoma-associated antigens and potential neoantigens.
Publisher: Springer Science and Business Media LLC
Date: 12-09-2016
DOI: 10.1038/NBT.3674
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 12-2015
Publisher: BMJ
Date: 02-2021
DOI: 10.1136/BMJOPEN-2020-040751
Abstract: To identify patient-reported outcome measures (PROMs) and patient-reported experience measures (PREMs) in clinical quality registries, for people with cutaneous melanoma, to inform a new Australian Melanoma Clinical Outcomes Registry and describe opportunities and challenges of routine PROM/PREM collection, especially in primary care. Systematic review. Which PROMs and PREMs are used in clinical quality registries for people with cutaneous melanoma, how they are collected, frequency of collection, participant recruitment methods and funding models for each registry. 1134 studies were identified from MEDLINE, PreMEDLINE, Embase, PsychInfo, Cochrane Database of Abstracts of Reviews of Effects databases and TUFTS Cost-Effectiveness Analysis Registry, alongside grey literature, from database inception to 5th February 2020. Following screening, 14 studies were included, identifying four relevant registries: Dutch Melanoma Registry, Adelphi Real-World Disease-Specific Programme (Melanoma), Patient-Reported Outcomes Following Initial treatment and Long-term Evaluation of Survivorship Registry, and Cancer Experience Registry. These used seven PROMs: EuroQol-5 Dimensions, Functional Assessment of Cancer-General (FACT-G) and FACT-Melanoma (FACT-M), European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Cancer 30 (EORTC QLQ-C30), Fatigue Assessment Scale Hospital Anxiety and Depression Scale, Patient-Reported Outcome Measures Information System-29 and one PREM EORTC QLQ-Information Module 26. PROMs/PREMs in registries were reported to improve transparency of care facilitate clinical auditing for quality assessment enable cost-effectiveness analyses and create large-scale research platforms. Challenges included resource burden for data entry and potential collection bias toward younger, more affluent respondents. Feedback from patients with melanoma highlighted the relevance of PROMs/PREMs in assessing patient outcomes and patient experiences. Clinical registries indicate PROMs/PREMs for melanoma care can be incorporated and address important gaps, however cost and collection bias may limit generalisability. CRD42018086737.
Publisher: Oxford University Press (OUP)
Date: 19-07-2006
DOI: 10.1093/JNCI/DJJ267
Abstract: The estrogen receptor alpha (ERalpha), progesterone receptor (PR), and erbB2 (Her2 in humans) are important prognostic markers of human breast cancer, and they are variably expressed in different subtypes of breast cancer. The basal subtype, for ex le, is negative for ERalpha, PR, and Her2 by immunohistochemistry. We investigated the expression of these signaling molecules in enriched populations of mouse mammary stem cells and luminal cells that were isolated according to their differential expression of CD24 and the alpha6beta1-integrin complex. We found that the basal population, which is enriched in mouse mammary stem cells, did not express ERalpha, PR, or ErbB2/Her2 but did express epidermal growth factor receptor (EGFR)/ErbB1, whereas the subset of cells enriched for luminal cells expressed ERalpha (37% of cells) and PR (40% of cells) but not ErbB2/Her2 or EGFR/ErbB1. Ovariectomy confirmed the importance of estrogen signaling to luminal cell proliferation but had no effect on the size of the mouse mammary stem cell-enriched population. Thus, mouse mammary stem cells were negative for ERalpha, PR, and ErbB2 and appeared to share common properties with poor-prognosis basal breast cancer.
Publisher: American Association for Cancer Research (AACR)
Date: 30-09-2008
DOI: 10.1158/0008-5472.CAN-08-1949
Abstract: The cells of origin and mechanisms that underpin tumor heterogeneity in breast cancer are poorly understood. Here, we have examined three mouse models of mammary tumorigenesis (MMTV-wnt-1, MMTV-neu, and p53+/−) for changes in their epithelial cell hierarchy during the preneoplastic and neoplastic stages of tumor progression. In preneoplastic tissue, only MMTV-wnt-1 mice showed a perturbation in their epithelial subpopulations. In addition to an expanded mammary stem cell pool, repopulating cells capable of yielding extensive mammary outgrowths in vivo were revealed in the committed luminal progenitor population. These findings indicate that wnt-1 activation induces the appearance of aberrant progenitor cells, and suggest that both mammary stem and progenitor cells can serve as the cellular targets of wnt-1–induced tumorigenesis. In tumors arising in MMTV-wnt-1 tumors, the luminal epithelial progenitor marker CD61/β3 integrin identified a cancer stem cell (CSC) population that was highly enriched for tumorigenic capability relative to the CD61− subset. CD61 expression also defined a CSC subset in 50% of p53+/−–derived tumors. No CSCs, however, could be identified in the more homogeneous MMTV-neu/erbB2 model, suggesting an alternative model of tumorigenesis. Overall, our findings show the utility of the progenitor marker CD61 in the identification of CSCs that sustain specific mammary tumors. [Cancer Res 2008 (19):7711–7]
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1038/JID.2011.18
Abstract: Cellular heterogeneity is a frequently noted feature of melanoma. As reported in this issue, Kupas et al. identified heterogeneous expression of receptor activator of nuclear factor-κB (RANK) in melanoma cells in tumors and peripheral blood from patients. Increased expression of RANK was associated with the presence of metastatic disease and increased tumorigenicity in melanoma cells, raising the possibility that RANK signaling contributes to melanoma progression.
Publisher: American Association for Cancer Research (AACR)
Date: 07-2019
DOI: 10.1158/1541-7786.MCR-18-0407
Abstract: Our studies highlight the YAP oncoprotein as a potential therapeutic target in select subgroups of melanoma patients, although successful treatment with anti-YAP therapies will depend on identification of biomarkers additional to YAP protein expression.
Publisher: Elsevier BV
Date: 07-2018
Abstract: As early detection of recurrent melanoma maximizes treatment options, patients usually undergo post-operative imaging surveillance, increasingly with FDG-PET/CT (PET). To assess this, we evaluated stage 3 melanoma patients who underwent prospectively applied and sub-stage-specific schedules of PET surveillance. From 2009, patients with stage 3 melanoma routinely underwent PET +/- MRI brain scans via defined schedules based on sub-stage-specific relapse probabilities. Data were collected regarding patient characteristics and outcomes. Contingency analyses were carried out of imaging outcomes. One hundred and seventy patients (stage 3A: 34 3B: 93 3C: 43) underwent radiological surveillance. Relapses were identified in 65 (38%) patients, of which 45 (69%) were asymptomatic. False-positive imaging findings occurred in 7%, and 6% had treatable second (non-melanoma) malignancies. Positive predictive values (PPV) of in idual scans were 56%-83%. Negative scans had predictive values of 89%-96% for true non-recurrence [negative predictive values (NPV)] until the next scan. A negative PET at 18 months had NPVs of 80%-84% for true non-recurrence at any time in the 47-month (median) follow-up period. Sensitivity and specificity of the overall approach of sub-stage-specific PET surveillance were 70% and 87%, respectively. Of relapsed patients, 33 (52%) underwent potentially curative resection and 10 (16%) remained disease-free after 24 months (median). Application of sub-stage-specific PET in stage 3 melanoma enables asymptomatic detection of most recurrences, has high NPVs that may provide patient reassurance, and is associated with a high rate of detection of resectable and potentially curable disease at relapse.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-11-2012
DOI: 10.1126/SCITRANSLMED.3004599
Abstract: The ability of melanomas to produce circulating tumor cells and to metastasize in immunocompromised mice correlates with their ability to form distant metastases in patients.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 21-09-2020
Publisher: Impact Journals, LLC
Date: 22-01-2019
Publisher: Wiley
Date: 19-03-2009
DOI: 10.1002/DVDY.21917
Abstract: The Fas-associated death domain (FADD/Mort1) adaptor protein was originally identified as a key mediator of apoptosis, although pleiotropic functions for FADD have also been reported. FADD-mediated tumoricidal effects have been described in breast cancer cells however, its physiological role in normal mammary gland epithelium is not well understood. To determine the role of FADD signaling during mammary gland development, we generated transgenic mice overexpressing dominant-negative FADD (DN-FADD) in mammary epithelium, using the steroid responsive mouse mammary tumor virus promoter. Transgenic mice exhibited a perturbation in lactation resulting in impaired milk production and pup growth retardation. Reduced expansion of alveoli was evident during early lactation with extensive shedding of luminal alveolar cells. Significantly more TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling)-positive cells were present at this time point and a subsequent increase in bromodeoxyuridine-positive cells was observed. These findings suggest a role for FADD in maintaining the survival of mammary secretory alveolar cells after the establishment of lactation.
Publisher: Elsevier BV
Date: 04-2023
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.CELL.2009.08.017
Abstract: The identification and characterization of cancer stem cells might lead to more effective treatments for some cancers by focusing therapy on the most malignant cells. To achieve this goal it will be necessary to determine which cancers follow a cancer stem cell model and which do not, to address technical issues related to tumorigenesis assays, and to test the extent to which cancer cell heterogeneity arises from genetic versus epigenetic differences.
Publisher: Springer Science and Business Media LLC
Date: 04-04-2022
Publisher: Elsevier BV
Date: 10-2023
Publisher: Proceedings of the National Academy of Sciences
Date: 22-06-2005
Publisher: Springer Science and Business Media LLC
Date: 02-12-2022
DOI: 10.1186/S40959-022-00149-8
Abstract: Immune checkpoint inhibitors (ICI) are associated with immune-mediated adverse effects, potentially involving any organ. ICI has also been associated with an increased risk of cardiovascular disease in cancer populations. To characterize the incidence and risk of major atherosclerotic cardiovascular events associated with ICI use in a high-risk and advanced melanoma population. We conducted a retrospective cohort study of patients with high-risk or advanced melanoma (AJCC stage II, III or IV) presenting to an academic tertiary hospital between 2015–2020. The main outcome was major atherosclerotic cardiovascular events (MACE) including acute myocardial infarction, ischemic stroke, acute limb ischemia and coronary revascularization. The study cohort consisted of 646 patients, including 289 who had been treated with ICI. The incidence of MACE was higher in the ICI treated group (3.6 vs. 0.9 events per 100-person years). After adjusting for age, sex, smoking history and prior BRAF and/or MEK inhibitor use, ICI treatment was associated with an increased risk of MACE (HR adj 2.8, 95% CI 1.1–6.9, p = 0.03). Elevated risk was especially pronounced in patients with a past history of MACE (HR 14.4, 95% CI 1.9–112.3, p = 0.01). Patients with high-risk or advanced melanoma are at an increased risk of atherosclerotic cardiovascular events following ICI treatment, particularly those with a history of cardiovascular disease.
Publisher: Wiley
Date: 02-2019
DOI: 10.1002/HSR2.115
Publisher: BMJ
Date: 09-2022
DOI: 10.1136/BMJOPEN-2022-062139
Abstract: Australia has the highest incidence of melanoma in the world with variable care provided by a erse range of clinicians. Clinical quality registries aim to identify these variations in care and provide anonymised, benchmarked feedback to clinicians and institutions to improve patient outcomes. The Australian Melanoma Clinical Outcomes Registry (MelCOR) aims to collect population-wide, clinical-level data for the early management of cutaneous melanoma and provide anonymised feedback to healthcare providers. A modified Delphi process will be undertaken to identify key clinical quality indicators for inclusion in the MelCOR pilot. MelCOR will prospectively collect data relevant to these quality indicators, initially for all people over the age of 18 years living in Victoria and Queensland with a melanoma diagnosis confirmed by histopathology, via a two-stage recruitment and consent process. In stage 1, existing State-based cancer registries contact the treating clinician and provide an opportunity for them to opt themselves or their patients out of direct contact with MelCOR. After stage 1, re-identifiable clinical data are provided to the MelCOR under a waiver of consent. In stage 2, the State-based cancer registry will approach the patient directly and invite them to opt in to MelCOR and share identifiable data. If a patient elects to opt in, MelCOR will be able to contact patients directly to collect patient-reported outcome measures. Aggregated data will be used to provide benchmarked, comparative feedback to participating institutions/clinicians. Following the successful collection of pilot data, the feasibility of an Australia-wide roll out will be evaluated. Key quality indicator data will be the core of the MelCOR dataset, with additional data points added later. Annual reports will be issued, first to the relevant stakeholders followed by the public. MelCOR is approved by the Alfred Ethics Committee (58280/127/20).
Publisher: Massachusetts Medical Society
Date: 26-08-2010
Publisher: Impact Journals, LLC
Date: 22-06-2016
Publisher: Springer Science and Business Media LLC
Date: 04-03-2021
DOI: 10.1038/S41467-021-21576-8
Abstract: Although melanoma is initiated by acquisition of point mutations and limited focal copy number alterations in melanocytes-of-origin, the nature of genetic changes that characterise lethal metastatic disease is poorly understood. Here, we analyze the evolution of human melanoma progressing from early to late disease in 13 patients by s ling their tumours at multiple sites and times. Whole exome and genome sequencing data from 88 tumour s les reveals only limited gain of point mutations generally, with net mutational loss in some metastases. In contrast, melanoma evolution is dominated by whole genome doubling and large-scale aneuploidy, in which widespread loss of heterozygosity sculpts the burden of point mutations, neoantigens and structural variants even in treatment-naïve and primary cutaneous melanomas in some patients. These results imply that dysregulation of genomic integrity is a key driver of selective clonal advantage during melanoma progression.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 18-08-2015
DOI: 10.1126/SCISIGNAL.AAB1111
Abstract: The transcriptional regulator c-JUN is a key mediator of the metastatic potential and drug resistance in melanoma.
Publisher: Springer Science and Business Media LLC
Date: 18-04-2005
Abstract: LMO4, a member of the LIM-only family of zinc-finger proteins, is overexpressed in a significant proportion of breast carcinomas and acts as a negative regulator of mammary epithelial differentiation. To delineate cell types within the developing mouse mammary gland that express Lmo4, we analysed different stages of mammopoiesis by immunohistochemistry. Lmo4 was found to be highly expressed in the proliferating cap cells of the terminal end bud and in the ductal and alveolar luminal cells of the mature mammary gland but was negligible or low in myoepithelial cells. To assess the physiological role of Lmo4 in the mammary gland, we generated conditionally targeted mice lacking Lmo4 in the mammary epithelium during pregnancy. Acute loss of Lmo4 in late pregnancy impaired lobuloalveolar development, accompanied by a two-fold reduction in the percentage of BrdU-positive cells. In contrast, germline loss of Lmo4 did not alter lobuloalveolar development arising from transplanted mammary anlagen, implying the existence of a compensatory mechanism in these knockout mice. Thus, the use of a conditional targeting strategy has revealed that Lmo4 is required for proper development of the mammary gland during pregnancy and indicated that Lmo4 acts as a positive regulator of alveolar epithelial proliferation.
Publisher: Research Square Platform LLC
Date: 12-2021
DOI: 10.21203/RS.3.RS-1083624/V1
Abstract: The enhancer of zeste homolog 2 (EZH2) oncogene is a histone methyltransferase that functions canonically as a catalytic subunit of the polycomb repressive complex 2 (PRC2) to tri-methylate histone H3 at Lys 27 (H3K27me3). Although targeting of EZH2 methyltransferase is a promising therapeutic strategy against cancer, methyltransferase-independent oncogenic functions of EZH2 are also described. Moreover, pharmacological EZH2 methyltransferase inhibition was only variably effective in pre-clinical and clinical studies, suggesting that targeting EZH2 methyltransferase alone may be insufficient. Here, we demonstrate a non-canonical mechanism of EZH2’s oncogenic activity through interactions with inosine monophosphate dehydrogenase 2 (IMPDH2) and downstream promotion of guanosine-5'-triphosphate (GTP) production. Liquid Chromatography-Mass Spectrometry (LC-MS) of EZH2 immunoprecipitates from melanoma cell lines and human patient-derived xenografts (PDXs) revealed EZH2-IMPDH2 interactions that were verified to occur between the N-terminal EED-binding domain of cytosolic EZH2 and the CBS domain of IMPDH2 in a PRC2- and methylation-independent manner. EZH2 silencing reduced cellular GTP, ribosome biogenesis, RhoA-mediated actomyosin contractility and melanoma cell proliferation and invasion by impeding the activity and cytosolic localization of IMPDH2. Guanosine, which replenishes GTP, reversed these effects and thereby promoted invasive and clonogenic cell states even in EZH2 silenced cells. IMPDH2 silencing antagonized the proliferative and invasive effects of EZH2, also in a guanosine-reversible manner. In human melanomas, high cytosolic EZH2 and IMPDH2 expression were associated with nucleolar enlargement, a marker for ribosome biogenesis. We also identified EZH2-IMPDH2 complexes in a range of cancers in which Sappanone A (SA), which inhibits EZH2-IMPDH2 interactions and thereby IMPDH2 tetramerization, was anti-tumorigenic, although notably non-toxic in normal human melanocytes and bone marrow derived blood progenitor cells that lacked observable EZH2-IMPDH2 interactions. These findings illuminate a previously unrecognized, non-canonical, methyltransferase-independent, but GTP-dependent mechanism by which EZH2 regulates tumorigenicity in melanoma and other cancers, opening new avenues for development of anti-EZH2 therapeutics.
Publisher: Wiley
Date: 20-05-2014
DOI: 10.1111/ANS.12673
Abstract: The prognosis for patients with stage IV melanoma has historically been extremely poor and there have until recently been no effective treatment options. The last 3 years have seen a seismic shift in the management of these patients with the entry to the clinic of a number of novel agents with proven efficacy. These agents fall into two main classes: molecular-targeted therapy and immunotherapy. Molecular therapies have primarily targeted the mitogen-activated protein kinase pathway, most notably with oral inhibitors targetting oncogenic BRAF. Immunotherapy agents such as ipilimumab, and more recently antibodies against PD-1 boost the host immune response against the melanoma. It is important for surgeons to be aware of these advances for a number of reasons. Firstly, to be able to inform their patients of the general options available in the event of disease progression. Secondly, these agents are currently being assessed in the adjuvant setting and are likely to demonstrate efficacy for earlier stages of disease. Finally, it is important for surgeons to be able to advocate on their patients' behalf to minimize the lag time between publication of these promising results and the availability of these agents in the clinic. Furthermore, patients with advanced melanoma should be offered participation in clinical trials in order to refine the indications for these agents to maximize their chance of benefit.
Publisher: Cold Spring Harbor Laboratory
Date: 08-11-2019
DOI: 10.1101/835454
Abstract: Melanoma is a deadly form of skin cancer that accounts for a disproportionally large proportion of cancer-related deaths in younger people. Compared to most other skin cancers, a feature of melanoma is its high metastatic capacity, although molecular mechanisms that confer this are not well understood. The Hippo pathway is a key regulator of organ growth and cell fate that is deregulated in many cancers. To analyse the Hippo pathway in cutaneous melanoma, we generated a transcriptional signature of pathway activity in melanoma cells. Hippo-mediated transcriptional activity varied in melanoma cell lines but failed to cluster with known genetic drivers of melanomagenesis such as BRAF and NRAS mutation status. Instead, it correlated strongly with published gene expression profiles linked to melanoma cell invasiveness. Consistent with this, the central Hippo oncogene, YAP, was both necessary and sufficient for melanoma cell invasion in vitro. In in vivo murine studies, YAP promoted spontaneous melanoma metastasis, whilst the growth of YAP-expressing primary tumours was impeded. Finally, we identified the YAP target genes AXL , THBS1 and CYR61 as key mediators of YAP-induced melanoma cell invasion. These data suggest that the Hippo pathway is a critical regulator of melanoma metastasis.
Publisher: Elsevier BV
Date: 07-2015
Publisher: American Association for Cancer Research (AACR)
Date: 05-2017
DOI: 10.1158/1535-7163.MCT-15-0235
Abstract: Extracellular acidity is a hallmark of cancers and is independent of hypoxia. Because acidity potentiates malignant phenotypes, therapeutic strategies that enhance the targeting of oncogenic mechanisms in an acidic microenvironment should be effective. We report here that drugs which abrogate mitochondrial respiration show enhanced cytotoxicity against melanoma cells in a normoxic but acidic extracellular pH, independent from P53 mutations, BRAF (V600E) mutations, and/or resistance against BRAF inhibitors. Conversely, the cytotoxicity against melanoma cells of mitochondrial inhibitors is impaired by a neutral or alkaline extracellular pH, and in vivo systemic alkalinization with NaHCO3 enhanced subcutaneous tumor growth and lung metastasis of B16F10 cells in mice treated with the mitochondrial inhibitor phenformin. Intracellular calcium (Ca2+) was significantly increased in melanoma cells treated with mitochondrial inhibitors at an acidic extracellular pH and an intracellular Ca2+ chelator, BAPTA/AM, inhibited cytoplasmic Ca2+ as well as melanoma cell death. Surprisingly, ROS scavengers synergized with increased apoptosis in cells treated with mitochondrial inhibitors, suggesting that ROS contributes to cell survival in this context. Notably, the cytotoxic enhancement of mitochondrial inhibitors by acidity was distinct from PGC1alpha-driven mitochondrial addiction, from therapy-induced senescence, and from slow, JARID1B-high–associated cell cycling, all of which have been shown to promote vulnerability to mitochondrial inhibition. These data indicate that extracellular pH profoundly modulates the cytotoxicity of mitochondrial inhibitors against cancer cells. Mol Cancer Ther 16(5) 936–47. ©2017 AACR.
Publisher: American Medical Association (AMA)
Date: 03-2009
Publisher: Wiley
Date: 23-06-2010
Publisher: Wiley
Date: 03-03-2019
DOI: 10.1111/PCMR.12775
Publisher: Springer Science and Business Media LLC
Date: 05-2017
DOI: 10.1038/NATURE22071
Abstract: Melanoma of the skin is a common cancer only in Europeans, whereas it arises in internal body surfaces (mucosal sites) and on the hands and feet (acral sites) in people throughout the world. Here we report analysis of whole-genome sequences from cutaneous, acral and mucosal subtypes of melanoma. The heavily mutated landscape of coding and non-coding mutations in cutaneous melanoma resolved novel signatures of mutagenesis attributable to ultraviolet radiation. However, acral and mucosal melanomas were dominated by structural changes and mutation signatures of unknown aetiology, not previously identified in melanoma. The number of genes affected by recurrent mutations disrupting non-coding sequences was similar to that affected by recurrent mutations to coding sequences. Significantly mutated genes included BRAF, CDKN2A, NRAS and TP53 in cutaneous melanoma, BRAF, NRAS and NF1 in acral melanoma and SF3B1 in mucosal melanoma. Mutations affecting the TERT promoter were the most frequent of all however, neither they nor ATRX mutations, which correlate with alternative telomere lengthening, were associated with greater telomere length. Most melanomas had potentially actionable mutations, most in components of the mitogen-activated protein kinase and phosphoinositol kinase pathways. The whole-genome mutation landscape of melanoma reveals erse carcinogenic processes across its subtypes, some unrelated to sun exposure, and extends potential involvement of the non-coding genome in its pathogenesis.
Publisher: Elsevier
Date: 2017
Publisher: Wiley
Date: 06-2015
DOI: 10.1002/JSO.23938
Abstract: Metastasectomy can provide durable disease control for selected patients with metastatic melanoma. Vemurafenib is a BRAF kinase inhibitor which has demonstrated significant improvement in disease-specific survival in patients with metastatic melanoma with a BRAF gene mutation. This study examined the efficacy and safety of metastasectomy during treatment with vemurafenib. A retrospective review was performed of all patients receiving vemurafenib at Peter MacCallum Cancer Centre. Patient records were reviewed to identify patients undergoing surgery within 30 days of vemurafenib therapy. Descriptive statistics and survival analysis were performed. Nineteen patients underwent 21 metastasectomies including craniotomy (57%), spinal decompression (14%), small bowel resection (14%), lung resection (9.5%) and neck dissection (4.5%). Indications for surgery were: an isolated residual focus of disease (n = 2) isolated progressive disease in the setting of stability elsewhere (n = 9) and symptomatic disease (n = 8). Grade 2 or higher surgical complications occurred in 19% of cases and there was one peri-operative death. Median post-operative survival was seven months. There was a trend toward improved post-operative survival for patients with longer duration of vemurafenib therapy (P = 0.04) and for those undergoing elective surgery (P = 0.07). Resection of oligometastatic disease during BRAF-targeted therapy is safe. Selected patients have durable post-operative disease control.
Publisher: The Royal Australian College of General Practitioners
Date: 22-01-2021
Publisher: Cold Spring Harbor Laboratory
Date: 2008
Abstract: Reconstitution assays have shown that mouse mammary stem cells reside within the mature mammary gland in vivo. Single cells could be prospectively isolated and shown to regenerate an entire mammary gland that exhibited full developmental capacity. The more recent identification of luminal progenitor populations has indicated that the mammary epithelium is organized in a hierarchical manner. Further definition of epithelial cell types in both mouse and human mammary glands will provide insight into the "cells of origin" in the different subtypes of breast cancer, as well as the nature of cancer-propagating cells. Here, we review the known characteristics of mammary stem and progenitor cells, their steroid receptor status, and the pathways that have thus far been implicated in regulating their self-renewal and differentiation.
Publisher: American Association for Cancer Research (AACR)
Date: 14-12-2015
DOI: 10.1158/0008-5472.CAN-15-1877
Abstract: Merkel cell carcinoma (MCC) is an uncommon, but highly malignant, cutaneous tumor. Merkel cell polyoma virus (MCV) has been implicated in a majority of MCC tumors however, viral-negative tumors have been reported to be more prevalent in some geographic regions subject to high sun exposure. While the impact of MCV and viral T-antigens on MCC development has been extensively investigated, little is known about the etiology of viral-negative tumors. We performed targeted capture and massively parallel DNA sequencing of 619 cancer genes to compare the gene mutations and copy number alterations in MCV-positive (n = 13) and -negative (n = 21) MCC tumors and cell lines. We found that MCV-positive tumors displayed very low mutation rates, but MCV-negative tumors exhibited a high mutation burden associated with a UV-induced DNA damage signature. All viral-negative tumors harbored mutations in RB1, TP53, and a high frequency of mutations in NOTCH1 and FAT1. Additional mutated or lified cancer genes of potential clinical importance included PI3K (PIK3CA, AKT1, PIK3CG) and MAPK (HRAS, NF1) pathway members and the receptor tyrosine kinase FGFR2. Furthermore, looking ahead to potential therapeutic strategies encompassing immune checkpoint inhibitors such as anti-PD-L1, we also assessed the status of T-cell–infiltrating lymphocytes (TIL) and PD-L1 in MCC tumors. A subset of viral-negative tumors exhibited high TILs and PD-L1 expression, corresponding with the higher mutation load within these cancers. Taken together, this study provides new insights into the underlying biology of viral-negative MCC and paves the road for further investigation into new treatment opportunities. Cancer Res 75(24) 5228–34. ©2015 AACR.
Publisher: Springer Science and Business Media LLC
Date: 22-08-2016
DOI: 10.1038/NCOMMS12336
Abstract: New therapies are required for melanoma. Here, we report that multiple cardiac glycosides, including digitoxin and digoxin, are significantly more toxic to human melanoma cells than normal human cells. This reflects on-target inhibition of the ATP1A1 Na + /K + pump, which is highly expressed by melanoma. MEK inhibitor and/or BRAF inhibitor additively or synergistically combined with digitoxin to induce cell death, inhibiting growth of patient-derived melanomas in NSG mice and synergistically extending survival. MEK inhibitor and digitoxin do not induce cell death in human melanocytes or haematopoietic cells in NSG mice. In melanoma, MEK inhibitor reduces ERK phosphorylation, while digitoxin disrupts ion gradients, altering plasma membrane and mitochondrial membrane potentials. MEK inhibitor and digitoxin together cause intracellular acidification, mitochondrial calcium dysregulation and ATP depletion in melanoma cells but not in normal cells. The disruption of ion homoeostasis in cancer cells can thus synergize with targeted agents to promote tumour regression in vivo .
Publisher: Wiley
Date: 09-2010
Publisher: Oxford University Press (OUP)
Date: 02-01-2014
DOI: 10.1093/BIOINFORMATICS/BTT767
Abstract: Motivation: Methods for detecting somatic genome rearrangements in tumours using next-generation sequencing are vital in cancer genomics. Available algorithms use one or more sources of evidence, such as read depth, paired-end reads or split reads to predict structural variants. However, the problem remains challenging due to the significant computational burden and high false-positive or false-negative rates. Results: In this article, we present Socrates (SOft Clip re-alignment To idEntify Structural variants), a highly efficient and effective method for detecting genomic rearrangements in tumours that uses only split-read data. Socrates has single-nucleotide resolution, identifies micro-homologies and untemplated sequence at break points, has high sensitivity and high specificity and takes advantage of parallelism for efficient use of resources. We demonstrate using simulated and real data that Socrates performs well compared with a number of existing structural variant detection tools. Availability and implementation: Socrates is released as open source and available from bioinf.wehi.edu.au/socrates. Contact: papenfuss@wehi.edu.au Supplementary information: Supplementary data are available at Bioinformatics online.
Publisher: American Society for Clinical Investigation
Date: 23-11-2015
DOI: 10.1172/JCI82534
Publisher: American Society of Clinical Oncology (ASCO)
Date: 11-0011
DOI: 10.1200/PO.16.00009
Abstract: Circulating tumor DNA (ctDNA) allows noninvasive disease monitoring across a range of malignancies. In metastatic melanoma, the extent to which ctDNA reflects changes in metabolic disease burden assessed by 18 F-labeled fluorodeoxyglucose positron emission tomography (FDG-PET) is unknown. We assessed the role of ctDNA analysis in combination with FDG-PET to monitor tumor burden and genomic heterogeneity throughout treatment. We performed a comprehensive analysis of serial ctDNA and FDG-PET in 52 patients who received systemic therapy for metastatic melanoma. Next-generation sequencing and digital polymerase chain reaction were used to analyze plasma s les from the cohort. ctDNA levels were monitored across patients with mutant BRAF, NRAS, and BRAF/NRAS wild type disease. Mutant BRAF and NRAS ctDNA levels correlated closely with changes in metabolic disease burden throughout treatment. TERT promoter mutant ctDNA levels also paralleled changes in tumor burden, which provide an alternative marker for disease monitoring. Of note, subcutaneous and cerebral disease sites were not well represented in plasma. Early changes in ctDNA and metabolic disease burden were important indicators of treatment response. Patients with an early decrease in ctDNA post-treatment had improved progression-free survival compared with patients in whom ctDNA levels remained unchanged or increased over time (hazard ratio, 2.6 P = .05). ctDNA analysis contributed key molecular information through the identification of putative resistance mechanisms to targeted therapy. A detailed comparison of the genomic architecture of plasma and multiregional tumor biopsy specimens at autopsy revealed the ability of ctDNA to comprehensively capture genomic heterogeneity across multiple disease sites. The findings highlight the powerful role of ctDNA in metastatic melanoma as a complementary modality to functional imaging that allows real-time monitoring of both tumor burden and genomic changes throughout therapy.
Publisher: Proceedings of the National Academy of Sciences
Date: 13-07-2004
Abstract: NY-ESO-1 is a “cancer-testis” antigen expressed in many cancers. ISCOMATRIX is a saponin-based adjuvant that induces antibody and T cell responses. We performed a placebo-controlled clinical trial evaluating the safety and immunogenicity of recombinant NY-ESO-1 protein with ISCOMATRIX adjuvant. Forty-six evaluable patients with resected NY-ESO-1-positive tumors received three doses of vaccine intramuscularly at monthly intervals. The vaccine was well tolerated. We observed high-titer antibody responses, strong delayed-type hypersensitivity reactions, and circulating CD8+ and CD4+ T cells specific for a broad range of NY-ESO-1 epitopes, including known and previously unknown epitopes. In an unplanned analysis, vaccinated patients appeared to have superior clinical outcomes to those treated with placebo or protein alone. The vaccine is safe and highly potent immunologically.
Publisher: Public Library of Science (PLoS)
Date: 30-05-2012
Publisher: Wiley
Date: 2002
Publisher: Springer Science and Business Media LLC
Date: 21-07-2020
Publisher: Cold Spring Harbor Laboratory
Date: 06-03-2021
DOI: 10.1101/2021.03.04.433988
Abstract: Cellular heterogeneity in cancer is linked to disease progression and therapy response, although the mechanisms regulating distinct cellular states within tumours are not well understood. To address this, we identified melanin pigment content as a major source of phenotypic and functional heterogeneity in melanoma and compared RNAseq data from high (HPC) and low pigmented melanoma cells (LPC), revealing the polycomb repressor complex protein, EZH2, as a master regulator of these states. EZH2 protein, but not RNA expression, was found to be upregulated in LPCs and inversely correlated with melanin in pigmented patient melanomas. Surprisingly, conventional EZH2 methyltransferase inhibitors, GSK126 and EPZ6438, had no effect on LPC survival, clonogenicity and pigmentation, despite fully inhibiting methyltransferase activity. In contrast, EZH2 silencing by siRNA strategy or DZNep, MS1943 that reduces EZH2 protein levels, significantly inhibited cell growth in LPCs by h ering ribosome biogenesis. In addition, decline in EZH2 protein level induces pigmented cell phenotype by inducing melanin biosynthesis. Proteasomal inhibitor, MG132 treatment induced EZH2 protein levels in HPCs prompted us to look for differentially regulated ubiquitin system proteins in HPC vs LPCs. UBE2L6, E2 conjugating enzyme has been shown to be downregulated significantly in LPCs by UHRF1-mediated CpG methylation. Both biochemical assays and animal studies demonstrated that UBE2L6 expression decline, in turn, promotes EZH2 protein stability due to lack of ubiquitination on K381 residue in LPCs. UBR4 cooperates with UBE2L6 to facilitate this ubiquitination process. Targeting UHRF1/UBE2L6/UBR4 axis can be a better treatment option to trigger HPC state in melanoma in which conventional EZH2 inhibitors are ineffective.
Publisher: Elsevier BV
Date: 03-2011
Publisher: Springer Science and Business Media LLC
Date: 04-01-2006
DOI: 10.1038/NATURE04496
Abstract: Elucidation of the cellular and molecular mechanisms that maintain mammary epithelial tissue integrity is of broad interest and paramount to the design of more effective treatments for breast cancer. Evidence from both in vitro and in vivo experiments suggests that mammary cell differentiation is a hierarchical process originating in an uncommitted stem cell with self-renewal potential. However, analysis of the properties and regulation of mammary stem cells has been limited by a lack of methods for their prospective isolation. Here we report the use of multi-parameter cell sorting and limiting dilution transplant analysis to demonstrate the purification of a rare subset of adult mouse mammary cells that are able in idually to regenerate an entire mammary gland within 6 weeks in vivo while simultaneously executing up to ten symmetrical self-renewal isions. These mammary stem cells are phenotypically distinct from and give rise to mammary epithelial progenitor cells that produce adherent colonies in vitro. The mammary stem cells are also a rapidly cycling population in the normal adult and have molecular features indicative of a basal position in the mammary epithelium.
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.EJCA.2018.09.027
Abstract: Rheumatic immune-related adverse events (irAEs) occur in approximately 10-20% of anti-programmed death 1 (anti-PD1)-treated cancer patients. There are limited data on the natural history, optimal treatment and long-term oncological outcomes of patients with rheumatic irAEs. The objective of the study was to describe the spectrum and natural history of rheumatic irAEs and the potential impact of rheumatic irAEs and immunomodulators on anti-PD1 tumour efficacy. Cancer patients with pre-existing rheumatic disease before anti-PD1 therapy or de novo rheumatic irAEs on anti-PD1 therapy were retrospectively reviewed across three sites. Patient demographics, treatment history, anti-PD1 irAEs, and anti-PD1 responses were evaluated. Relationships between the development or pre-existence of rheumatic irAE, use of immunomodulatory agents and outcomes were evaluated. This multicenter case series describes 36 cancer patients who had rheumatic disease before anti-PD1 therapy (n = 12) or developed de novo rheumatic irAEs (n = 24). Thirty-four of the 36 patients sustained rheumatic irAEs (median time to rheumatic irAE: 14.5 weeks), including 24 de novo (18 inflammatory arthritis, three myositis, two polymyalgia rheumatica, one fasciitis) and 10 flares in 12 patients with pre-existing rheumatic disease. Corticosteroids were used in 30 of 36 patients (median duration: 10 months), and disease-modifying antirheumatic drugs were used in 14 of 36 patients (median duration: 5.5 months). The objective response rate to anti-PD1 therapy was 69% (n = 25/36) overall and 81% (n = 21/26) in the melanoma subgroup. Rheumatic irAEs are often chronic and require prolonged immunomodulatory therapy. Prospective studies are required to define optimal management of rheumatic irAEs that maintain long-term anticancer outcomes.
Publisher: Springer Science and Business Media LLC
Date: 12-2008
DOI: 10.1038/NATURE07567
Publisher: Elsevier BV
Date: 11-2010
Publisher: Springer Science and Business Media LLC
Date: 22-07-2012
DOI: 10.1038/NM.2863
Publisher: Wiley
Date: 30-03-2020
Publisher: American Society of Hematology
Date: 09-2003
DOI: 10.1182/BLOOD-2002-12-3854
Abstract: Dendritic cells (DCs) are a family of leukocytes that initiate T- and B-cell immunity against pathogens. Migration of antigen-loaded DCs from sites of infection into draining lymphoid tissues is fundamental to the priming of T-cell immune responses. In humans, the major peripheral blood DC (PBDC) types, CD1c+ DCs and interleukin 3 receptor–positive (IL-3R+) plasmacytoid DCs, are significantly expanded in vivo with the use of Flt3 ligand (FL). DC-like cells can also be generated from monocyte precursors (MoDCs). A detailed comparison of the functional potential of these types of DCs (in an autologous setting) has yet to be reported. Here, we compared the functional capacity of FL-expanded CD1c+ PBDCs with autologous MoDCs in response to 3 different classes of stimuli: (1) proinflammatory mediators, (2) soluble CD40 ligand trimer (CD40L), and (3) intact bacteria (Escherichia coli). Significant differences in functional capacities were found with respect to changes in phenotype, migratory capacity, cytokine secretion, and T-cell stimulation. MoDCs required specific stimuli for the expression of functions. They responded vigorously to CD40L or E coli, expressing cytokines known to regulate interferon-γ (IFN-γ) in T cells (IL-12p70, IL-18, and IL-23), but required prostaglandin E2 (PGE2) during stimulation to migrate to chemokines. In contrast, PBDCs matured in response to minimal stimulation, rapidly acquired migratory function in the absence of PGE2-containing stimuli, and were low cytokine producers. Interestingly, both types of DCs were equivalent with respect to stimulation of allogeneic T-cell proliferation and presentation of peptides to cytotoxic T lymphocyte (CTL) lines. These distinct differences are of particular importance when considering the choice of DC types for clinical applications.
Publisher: Cold Spring Harbor Laboratory
Date: 04-11-2021
DOI: 10.1101/2021.11.02.467024
Abstract: The enhancer of zeste homolog 2 (EZH2) oncoprotein is a histone methyltransferase that functions canonically as a catalytic subunit of the polycomb repressive complex 2 (PRC2) to tri-methylate histone H3 at Lys 27 (H3K27me3). Although targeting EZH2 methyltransferase is a promising therapeutic strategy against cancer, methyltransferase-independent oncogenic functions of EZH2 are described. Moreover, pharmacological EZH2 methyltransferase inhibition was only variably effective in pre-clinical and clinical studies, suggesting that targeting EZH2 methyltransferase alone may be insufficient. Here, we demonstrate a non-canonical mechanism of EZH2’s oncogenic activity characterized by interactions with inosine monophosphate dehydrogenase 2 (IMPDH2) and downstream promotion of guanosine-5’-triphosphate ( GTP ) production. EZH2-IMPDH2 interactions identified by Liquid Chromatography-Mass Spectrometry (LC-MS) of EZH2 immunoprecipitates from melanoma cells were verified to occur between the N-terminal EED-binding domain of cytosolic EZH2 and the CBS domain of IMPDH2 in a methyltransfersase-independent manner. EZH2 silencing reduced cellular GTP, ribosome biogenesis, RhoA-mediated actomyosin contractility and melanoma cell proliferation and invasion by impeding the activity of IMPDH2. Guanosine, which replenishes GTP, reversed these effects and thereby promoted invasive and clonogenic cell states even in EZH2 silenced cells. IMPDH2 silencing antagonized the proliferative and invasive effects of EZH2, also in a guanosine-reversible manner. In human melanomas, high cytosolic EZH2 and IMPDH2 expression were associated with nucleolar enlargement, a marker of ribosome biogenesis. EZH2-IMPDH2 complexes were also observed in a range of cancers in which Sappanone A (SA), which inhibits EZH2-IMPDH2 interactions, was anti-tumorigenic, although notably non-toxic in normal cells. These findings illuminate a previously unrecognized, non-canonical, methyltransferase-independent, and GTP-dependent mechanism by which EZH2 regulates tumorigenicity in melanoma and other cancers, opening new avenues for development of anti-EZH2 therapeutics. EZH2 has non-canonical methyltransferase-independent and GTP-dependent tumorigenic and metastatic functions in melanoma. The N-terminal EED-binding domain of EZH2 interacts with the CBS domain of IMPDH2 in a polycomb repressive complex 2- (PRC2-) and methylation-independent manner. EZH2 accumulates with IMPDH2 in the cytoplasm and increases IMPDH2’s tetramerization-mediated activity independently of EZH2 methyltransferase. EZH2 upregulates GTP synthesis by IMPDH2 activation and thereby activates ribosome biogenesis via rRNA synthesis and actomyosin contractility via RhoA GTPase. Sappanone A (SA) inhibits IMPDH2-EZH2 interactions and is anti-proliferative across a range of cancers including melanoma, but not in normal cells.
Publisher: American Association for Cancer Research (AACR)
Date: 30-06-2016
DOI: 10.1158/0008-5472.CAN-15-2377
Abstract: The stability of markers that identify cancer cells that propagate disease is important to the outcomes of targeted therapy strategies. In human melanoma, conflicting data exist as to whether hierarchical expression of CD271 75/NGFR (nerve growth factor receptor) marks cells with enriched tumorigenicity, which would compel their specific targeting in therapy. To test whether these discrepancies relate to differences among groups in assay approaches, we undertook side-by-side testing of published methods of patient-derived melanoma xenografting (PDX), including comparisons of tissue digestion procedures or coinjected Matrigel formulations. We found that CD271− and CD271+ melanoma cells from each of seven patients were similarly tumorigenic, regardless of assay variations. Surprisingly variable CD271 expression patterns were observed in the analyses of sibling PDX tumors (n = 68) grown in the same experiments from either CD271− or CD271+ cells obtained from patients. This indicates unstable intratumoral lineage relationships between CD271− and CD271+ melanoma cells that are inconsistent with classical, epigenetically based theories of disease progression, such as the cancer stem cell and plasticity models. SNP genotyping of pairs of sibling PDX tumors grown from phenotypically identical CD271− or CD271+ cells showed large pairwise differences in copy number (28%–48%). Differences were also apparent in the copy number profiles of CD271− and CD271+ cells purified directly from each of the four melanomas (1.4%–23%). Thus, CD271 expression in patient melanomas is unstable, not consistently linked to increased tumorigenicity and associated with genetic heterogeneity, undermining its use as a marker in clinical studies. Cancer Res 76(13) 3965–77. ©2016 AACR.
Publisher: Springer Science and Business Media LLC
Date: 22-10-2020
DOI: 10.1038/S41416-020-01121-Y
Abstract: Adjuvant targeted therapy (TT) improves relapse free survival in patients with resected BRAF mutant stage III melanoma. The outcomes and optimal management of patients who relapse after adjuvant TT is unknown. Patients from twenty-one centres with recurrent melanoma after adjuvant TT were included. Disease characteristics, adjuvant therapy, recurrence, treatment at relapse and outcomes were examined. Eighty-five patients developed recurrent melanoma nineteen (22%) during adjuvant TT. Median time to first recurrence was 18 months and median follow-up from first recurrence was 31 months. Fifty-eight (68%) patients received immunotherapy (IT) or TT as 1st line systemic therapy at either first or subsequent recurrence and had disease that was assessable for response. Response to anti-PD-1 (±trial agent), combination ipilimumab-nivolumab, TT rechallenge and ipilimumab monotherapy was 63%, 62% 25% and 10% respectively. Twenty-eight (33%) patients had died at census, all from melanoma. Two-year OS was 84% for anti-PD-1 therapy (±trial agent), 92% for combination ipilimumab and nivolumab, 49% for TT and 45% for ipilimumab monotherapy ( p = 0.028). Patients who relapse after adjuvant TT respond well to subsequent anti-PD-1 based therapy and have outcomes similar to those seen when first line anti-PD-1 therapy is used in stage IV melanoma.
Publisher: Springer Science and Business Media LLC
Date: 19-06-2020
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.1038/NATURE04372
Abstract: The existence of mammary stem cells (MaSCs) has been postulated from evidence that the mammary gland can be regenerated by transplantation of epithelial fragments in mice. Interest in MaSCs has been further stimulated by their potential role in breast tumorigenesis. However, the identity and purification of MaSCs has proved elusive owing to the lack of defined markers. We isolated discrete populations of mouse mammary cells on the basis of cell-surface markers and identified a subpopulation (Lin-CD29hiCD24+) that is highly enriched for MaSCs by transplantation. Here we show that a single cell, marked with a LacZ transgene, can reconstitute a complete mammary gland in vivo. The transplanted cell contributed to both the luminal and myoepithelial lineages and generated functional lobuloalveolar units during pregnancy. The self-renewing capacity of these cells was demonstrated by serial transplantation of clonal outgrowths. In support of a potential role for MaSCs in breast cancer, the stem-cell-enriched subpopulation was expanded in premalignant mammary tissue from MMTV-wnt-1 mice and contained a higher number of MaSCs. Our data establish that single cells within the Lin-CD29hiCD24+ population are multipotent and self-renewing, properties that define them as MaSCs.
Publisher: Springer Science and Business Media LLC
Date: 11-03-2023
DOI: 10.1038/S41388-023-02631-8
Abstract: Cellular heterogeneity in cancer is linked to disease progression and therapy response, although mechanisms regulating distinct cellular states within tumors are not well understood. We identified melanin pigment content as a major source of cellular heterogeneity in melanoma and compared RNAseq data from high-pigmented (HPCs) and low-pigmented melanoma cells (LPCs), suggesting EZH2 as a master regulator of these states. EZH2 protein was found to be upregulated in LPCs and inversely correlated with melanin deposition in pigmented patient melanomas. Surprisingly, conventional EZH2 methyltransferase inhibitors, GSK126 and EPZ6438, had no effect on LPC survival, clonogenicity and pigmentation, despite fully inhibiting methyltransferase activity. In contrast, EZH2 silencing by siRNA or degradation by DZNep or MS1943 inhibited growth of LPCs and induced HPCs. As the proteasomal inhibitor MG132 induced EZH2 protein in HPCs, we evaluated ubiquitin pathway proteins in HPC vs LPCs. Biochemical assays and animal studies demonstrated that in LPCs, the E2-conjugating enzyme UBE2L6 depletes EZH2 protein in cooperation with UBR4, an E3 ligase, via ubiquitination at EZH2’s K381 residue, and is downregulated in LPCs by UHRF1-mediated CpG methylation. Targeting UHRF1/UBE2L6/UBR4-mediated regulation of EZH2 offers potential for modulating the activity of this oncoprotein in contexts in which conventional EZH2 methyltransferase inhibitors are ineffective.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Wiley
Date: 2023
DOI: 10.1002/CTI2.1466
Publisher: Wiley
Date: 20-12-2022
DOI: 10.1111/AJCO.13913
Abstract: Recommendations for surveillance imaging for resected melanoma vary considerably. This study examined the utility of imaging in patients with a high‐risk primary melanoma undergoing a protocolized imaging schedule. This retrospective study involved data collection regarding imaging, recurrence, and outcome characteristics for patients referred to the Victorian Melanoma Service from January 2016–April 2020 and managed for resected stage IIC or III melanoma. Patients with a T4b tumor who did not undergo a sentinel lymph node biopsy were included (T4bNX). Recurrences were “clinically detected” if they were primarily detected by patient symptoms or physical examination, or ‘imaging‐detected’ if the patient was asymptomatic. Cox regression models including time‐varying co‐variates were used to assess the impact of imaging‐detected versus clinically‐detected recurrence on overall survival. Over a median follow‐up time of 2.7 years, 199 patients underwent surveillance imaging (T4bNX:22, IIC:33, IIIA:22, IIIB:60, IIIC:61, IIID:1), and 44% ( n = 88) experienced disease recurrence. Imaging detected over half (53%) of all recurrences. In adjusted analyses, mortality risk was reduced after an imaging‐detected compared to clinically‐detected recurrence at any given time from the start of surveillance (hazard ratio 0.25, 95% confidence interval 0.10–0.66, p = .005). Our study indicates that routine imaging in the early follow‐up period of resected T4bNX, stage IIC and III melanoma plays an important role in the detection of asymptomatic recurrences. Imaging‐detected recurrence may be associated with a survival benefit and studies with more prolonged follow‐up are required to confirm these findings.
Publisher: Cold Spring Harbor Laboratory
Date: 11-2022
DOI: 10.1101/2022.10.31.514484
Abstract: Functional variation between cancer cells (intra-tumoral heterogeneity) poses a major challenge to treating and managing cancer patients. Melanomas are typically composed of cancer cells with heterogeneous content of melanin pigment. Pigment production is a hallmark of normal melanocytic differentiation, however the functional consequences of melanin production in melanoma cells remains poorly understood owing to a lack of experimental approaches for detection of pigment in unfixed cells. Here, we describe a novel flow cytometric method for high purity separation of viable melanoma cells based on their content of melanin pigment, exploiting the infrared light scattering properties of melanin. By fluorescence-activated cell sorting, we show that melanoma cells with low-pigment content (LPCs) in culture and in patient tumors are far more abundant than high-pigment cells (HPCs), and have substantially increased potentials for colony formation in vitro and for tumor formation in vivo. RNAseq analysis revealed activation of P53 in HPCs associated with perturbed cell cycling, whereas LPCs displayed upregulation of MYC-associated transcription and activated ribosome biogenesis. The latter was reduced by topoisomerase 2 beta targeting with CX-5461, which also induced senescent HPC phenotypes and irreversible loss of clonogenic activity. These data illuminate an ‘inverted pyramid’ hierarchical model of melanoma cell propagation wherein abundant LPCs frequently renew their own malignant potential to propagate disease, but also rarely generate HPCs that lose this ability in a manner that may be promoted as an anti-melanoma strategy.
Publisher: Elsevier BV
Date: 05-2021
DOI: 10.1016/J.CLLC.2020.06.001
Abstract: The impact of radiotherapy (RT) on the efficacy and toxicity of immune checkpoint inhibitors (ICIs) in patients with metastatic non-small-cell lung cancer (NSCLC) is unclear. We identified patients with metastatic NSCLC treated with the anti-programmed death 1 antibodies nivolumab or pembrolizumab between January 2016 and May 2019 at 3 tertiary centers, who were also treated with palliative RT either during or within 3 months of starting anti-programmed death 1 treatment. Patient demographics, tumor characteristics, and treatment history were collected. Response rates, progression-free survival (PFS), and overall survival (OS) were analyzed and correlated with RT use. A total of 269 patients were identified, with a median follow-up of 19.4 months. The median age was 70 years (range, 35-90 years), and they were 63% male, 60% smokers, and 65% had adenocarcinoma histology. At the commencement of ICI treatment, the majority (86%) had ≥ 1 line of prior therapy and 34% had brain metastases. A total of 102 (38%) patients received RT within 3 months of starting ICI or subsequently during ICI treatment. Of patients that received RT, 86 (84%) received conventional hypofractionated RT, and, in the majority, 81 (79%) the intent of RT was symptom control. The use of RT did not increase grade 3/4 immune-related adverse events. The overall median PFS was 2.0 months (95% confidence interval, 1.3-2.6 months) and the median OS was 9.0 months (95% confidence interval, 6.4-9.5 months). There were no significant differences in median PFS (3.0 vs. 2.0 months P = .515) and median OS (9.0 vs. 9.0 months P = .917) in the patients who received RT versus those that did not. In patients with metastatic NSCLC, the addition of RT to ICI was not associated with increased toxicity or improved survival.
Publisher: Springer Science and Business Media LLC
Date: 24-12-2006
DOI: 10.1038/NCB1530
Abstract: The transcription factor Gata-3 is a defining marker of the 'luminal' subtypes of breast cancer. To gain insight into the role of Gata-3 in breast epithelial development and oncogenesis, we have explored its normal function within the mammary gland by conditionally deleting Gata-3 at different stages of development. We report that Gata-3 has essential roles in the morphogenesis of the mammary gland in both the embryo and adult. Through the discovery of a novel marker (beta3-integrin) of luminal progenitor cells and their purification, we demonstrate that Gata-3 deficiency leads to an expansion of luminal progenitors and a concomitant block in differentiation. Remarkably, introduction of Gata-3 into a stem cell-enriched population induced maturation along the alveolar luminal lineage. These studies provide evidence for the existence of an epithelial hierarchy within the mammary gland and establish Gata-3 as a critical regulator of luminal differentiation.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 06-2016
Publisher: Wiley
Date: 11-2004
DOI: 10.1111/J.1445-5994.2004.00637.X
Abstract: To examine the level of agreement among observers regarding changes between serial images of bone metastases. Thirty-five pairs of bone X-rays and 30 pairs of bone scans were selected from the files of patients with breast cancer involving the skeleton. All images in a pair were of the same site and had been taken at least 12 weeks apart. Thirteen radiologists and 14 nuclear medicine physicians examined the X-ray and bone scan pairs, respectively. Each assessed whether the changes between sequential films represented improvement, stability or worsening. Inter-observer agreement was analysed using the kappa statistic (kappa). There was only fair overall agreement among radiologists regarding changes between X-rays (kappa = 0.23), but there was substantial agreement among nuclear medicine physicians for bone scan assessments (kappa = 0.62). Neither the experience of the observers nor the time between images had a significant effect on agreement. For X-rays, agreement was poorer if the response category was 'improvement' and if the type of bone lesion was mixed lytic/sclerotic. Evaluation of serial X-rays is unreliable for determining the response of bone metastases. Scintigraphic evaluation has a higher internal validity for the determination of response, but it should not be used in isolation from other clinical data.
Publisher: Springer Science and Business Media LLC
Date: 27-05-2015
DOI: 10.1038/NATURE14410
Abstract: Patients with high-grade serous ovarian cancer (HGSC) have experienced little improvement in overall survival, and standard treatment has not advanced beyond platinum-based combination chemotherapy, during the past 30 years. To understand the drivers of clinical phenotypes better, here we use whole-genome sequencing of tumour and germline DNA s les from 92 patients with primary refractory, resistant, sensitive and matched acquired resistant disease. We show that gene breakage commonly inactivates the tumour suppressors RB1, NF1, RAD51B and PTEN in HGSC, and contributes to acquired chemotherapy resistance. CCNE1 lification was common in primary resistant and refractory disease. We observed several molecular events associated with acquired resistance, including multiple independent reversions of germline BRCA1 or BRCA2 mutations in in idual patients, loss of BRCA1 promoter methylation, an alteration in molecular subtype, and recurrent promoter fusion associated with overexpression of the drug efflux pump MDR1.
Publisher: Wiley
Date: 29-04-2022
DOI: 10.1111/AJD.13848
Abstract: Clinical quality registries aim to identify significant variations in care and provide anonymised feedback to institutions to improve patient outcomes. Thirty‐six Australian organisations with an interest in melanoma, raised funds through three consecutive Melanoma Marches, organised by Melanoma Institute Australia, to create a national Melanoma Clinical Outcomes Registry (MelCOR). This study aimed to formally develop valid clinical quality indicators for the diagnosis and early management of cutaneous melanoma as an important step in creating the registry. Potential clinical quality indicators were identified by examining the literature, including Australian and international melanoma guidelines, and by consulting with key melanoma and registry opinion leaders. A modified two‐round Delphi survey method was used, with participants invited from relevant health professions routinely managing melanoma as well as relevant consumer organisations. Nineteen participants completed at least one round of the Delphi process. 12 of 13 proposed clinical quality indictors met the validity criteria. The clinical quality indicators included acceptable biopsy method, appropriate excision margins, standardised pathology reporting, indications for sentinel lymph node biopsy, and involvement of multidisciplinary care and referrals. This study provides a multi‐stakeholder consensus for important clinical quality indicators that define optimal practice that will now be used in the Australian Melanoma Clinical Outcomes Registry (MelCOR).
Publisher: American Medical Association (AMA)
Date: 02-06-2021
Publisher: Elsevier BV
Date: 04-2010
DOI: 10.1016/J.SEMCANCER.2010.04.002
Abstract: The functional capabilities of normal stem cells and tumorigenic cancer cells are conceptually similar in that both cell types are able to proliferate extensively. Indeed, mechanisms that regulate the defining property of normal stem cells - self-renewal - also frequently mediate oncogenesis. These conceptual links are strengthened by observations in some cancers that tumorigenic cells can not only renew their malignant potential but also generate bulk populations of non-tumorigenic cells in a manner that parallels the development of differentiated progeny from normal stem cells. But cancer cells are not normal. Although tumorigenic cells and normal stem cells are similar in some ways, they are also fundamentally different in other ways. Understanding both shared and distinguishing mechanisms that regulate normal stem cell proliferation and tumor propagation is likely to reveal opportunities for improving the treatment of patients with cancer.
Publisher: Springer Science and Business Media LLC
Date: 10-07-2007
DOI: 10.1007/S12015-007-0018-2
Abstract: The isolation and characterisation of mammary stem cells is an important step towards elucidating the hierarchy of epithelial cell development in the mammary gland and identifying cells that are targets of breast carcinogenesis. Mammary stem cells have recently been prospectively isolated through the identification of specific cell surface markers and in vivo transplantation into cleared fat pads. These cells were demonstrated to reconstitute an entire mammary gland comprising all mature epithelial cell types and to be capable of self-renewal on serial transplantation, thus possessing the defining features of stem cells. Notably, mouse mammary stem cells were found to share the hallmark properties of the basal subtype of breast cancer. This review will summarize the strategy used in the identification of mouse mammary stem cells and their characterisation.
Publisher: MDPI AG
Date: 14-09-2020
DOI: 10.3390/JCM9092969
Abstract: Immunotherapies and targeted therapies have revolutionised treatment of metastatic melanoma and improved survival rates. However, survivors treated with novel therapies are vulnerable to high levels of fear of cancer recurrence or progression (FCR). Existing FCR interventions have rarely been trialled in people with advanced cancer. The current study aimed to evaluate the acceptability and feasibility of Fear-Less: a stepped-care model to treat FCR in people with metastatic melanoma treated with immunotherapy or targeted therapy. Sixty-one outpatients with metastatic melanoma were screened using the Fear of Cancer Recurrence Inventory Short Form (FCRI-SF) and Fear of Progression Questionnaire Short Form (FoP-Q-SF). Survivors with subthreshold FCR were stratified to a self-management intervention while those with clinical levels of FCR were provided with an in idual therapy, Conquer Fear. Survivor experience surveys and rescreening were administered post-intervention completion. Results indicated that Fear-Less was an acceptable and feasible FCR intervention. Results provided preliminary support for the potential impact of Fear-Less in reducing FCR. Fear-Less is a promising first step in providing an acceptable and feasible stepped-care model to treat FCR in survivors with metastatic disease.
Location: Australia
No related grants have been discovered for Mark Shackleton.