ORCID Profile
0000-0002-5135-6504
Current Organisations
SA Health
,
University of South Australia
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Publisher: Research Square Platform LLC
Date: 11-01-2022
DOI: 10.21203/RS.3.RS-1215526/V1
Abstract: Perinatal death, of a fetus or newborn, is a devastating event for families. Following nationwide multicentre recruitment, we assessed ‘genomic autopsy’ as an adjunct to standard autopsy for 200 families who experienced perinatal death, and provided a definite or candidate genetic diagnosis in 105 families. From this understudied cohort, half of the (candidate) diagnoses were phenotype expansions or novel disease genes, revealing previously unknown in-utero presentations of existing developmental disorders, and genomic disorders that are likely incompatible with life. Among the definite diagnoses, 43% were recessively or dominantly inherited, posing a 25% or 50% recurrence risk for future pregnancies. Ten families used their diagnosis for preimplantation or prenatal diagnosis of 12 pregnancies, facilitating the delivery of ten healthy newborns and management of two affected pregnancies. We emphasize the clinical importance of genomic investigations of perinatal death, with short turn-around times, enabling accurate counselling and options for families to prevent recurrence.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854334
Abstract: Increasing IL3Rα/βc ratios lead to hexameric receptor assembly and augmented quiescence.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709849.V1
Abstract: Summary of the key interactions in the IL-3R ternary complex in the IL-3R ternary complex crystal structure.
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.CELL.2015.02.014
Abstract: Circular RNAs (circRNAs), formed by non-sequential back-splicing of pre-mRNA transcripts, are a widespread form of non-coding RNA in animal cells. However, it is unclear whether the majority of circRNAs represent splicing by-products without function or are produced in a regulated manner to carry out specific cellular functions. We show that hundreds of circRNAs are regulated during human epithelial-mesenchymal transition (EMT) and find that the production of over one-third of abundant circRNAs is dynamically regulated by the alternative splicing factor, Quaking (QKI), which itself is regulated during EMT. Furthermore, by modulating QKI levels, we show the effect on circRNA abundance is dependent on intronic QKI binding motifs. Critically, the addition of QKI motifs is sufficient to induce de novo circRNA formation from transcripts that are normally linearly spliced. These findings demonstrate circRNAs are both purposefully synthesized and regulated by cell-type specific mechanisms, suggesting they play specific biological roles in EMT.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854331
Abstract: Increasing IL3Rα/βc ratios and enforced hexamer signaling lead to reduced differentiation in in vivo engraftments.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709855.V1
Abstract: Increasing IL3Rα/βc ratios and enforced hexamer signaling lead to reduced differentiation in in vivo engraftments.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854325.V1
Abstract: Summary of the key interactions in the IL-3R ternary complex in the IL-3R ternary complex crystal structure.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709870.V1
Abstract: Key interactions between distinct residues in the IL-3R ternary complex crystal structure.
Publisher: The Endocrine Society
Date: 16-06-2020
Abstract: Germline mutations in the succinate dehydrogenase genes (SDHA/B/C/D, SDHAF2—collectively, “SDHx”) have been implicated in paraganglioma (PGL), renal cell carcinoma (RCC), gastrointestinal stromal tumor (GIST), and pituitary adenoma (PA). Negative SDHB tumor staining is indicative of SDH-deficient tumors, usually reflecting an underlying germline SDHx mutation. However, approximately 20% of in iduals with SDH-deficient tumors lack an identifiable germline SDHx mutation. We performed whole-exome sequencing (WES) of germline and tumor DNA followed by Sanger sequencing validation, transcriptome analysis, metabolomic studies, and haplotype analysis in 2 Italian-Australian families with SDH-deficient PGLs and various neoplasms, including RCC, GIST, and PA. Germline WES revealed a novel SDHC intronic variant, which had been missed during previous routine testing, in 4 affected siblings of the index family. Transcriptome analysis demonstrated aberrant SDHC splicing, with the retained intronic segment introducing a premature stop codon. WES of available tumors in this family showed chromosome 1 deletion with loss of wild-type SDHC in a PGL and a somatic gain-of-function KIT mutation in a GIST. The SDHC intronic variant identified was subsequently detected in the second family, with haplotype analysis indicating a founder effect. This is the deepest intronic variant to be reported among the SDHx genes. Intronic variants beyond the limits of standard gene sequencing analysis should be considered in patients with SDH-deficient tumors but negative genetic test results.
Publisher: American Association for Cancer Research (AACR)
Date: 25-07-2022
DOI: 10.1158/2767-9764.CRC-21-0139
Abstract: Inhibiting the androgen receptor (AR), a ligand-activated transcription factor, with androgen deprivation therapy is a standard-of-care treatment for metastatic prostate cancer. Paradoxically, activation of AR can also inhibit the growth of prostate cancer in some patients and experimental systems, but the mechanisms underlying this phenomenon are poorly understood. This study exploited a potent synthetic androgen, methyltestosterone (MeT), to investigate AR agonist-induced growth inhibition. MeT strongly inhibited growth of prostate cancer cells expressing AR, but not AR-negative models. Genes and pathways regulated by MeT were highly analogous to those regulated by DHT, although MeT induced a quantitatively greater androgenic response in prostate cancer cells. MeT potently downregulated DNA methyltransferases, leading to global DNA hypomethylation. These epigenomic changes were associated with dysregulation of transposable element expression, including upregulation of endogenous retrovirus (ERV) transcripts after sustained MeT treatment. Increased ERV expression led to accumulation of double-stranded RNA and a “viral mimicry” response characterized by activation of IFN signaling, upregulation of MHC class I molecules, and enhanced recognition of murine prostate cancer cells by CD8+ T cells. Positive associations between AR activity and ERVs/antiviral pathways were evident in patient transcriptomic data, supporting the clinical relevance of our findings. Collectively, our study reveals that the potent androgen MeT can increase the immunogenicity of prostate cancer cells via a viral mimicry response, a finding that has potential implications for the development of strategies to sensitize this cancer type to immunotherapies. Our study demonstrates that potent androgen stimulation of prostate cancer cells can elicit a viral mimicry response, resulting in enhanced IFN signaling. This finding may have implications for the development of strategies to sensitize prostate cancer to immunotherapies.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709873
Abstract: IL3Rα/βc transcript and protein expression ratio in AML patient s les.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709870
Abstract: Key interactions between distinct residues in the IL-3R ternary complex crystal structure.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709858.V1
Abstract: Increasing IL3Rα/βc ratios lead to hexameric receptor assembly and augmented quiescence.
Publisher: Public Library of Science (PLoS)
Date: 06-12-2010
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709861.V1
Abstract: Enrichment of the IL-3R hexamer versus dodecamer gene signature in primitive normal and leukemic stem cells.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854334.V1
Abstract: Increasing IL3Rα/βc ratios lead to hexameric receptor assembly and augmented quiescence.
Publisher: American Association for Cancer Research (AACR)
Date: 20-08-0006
DOI: 10.1158/2159-8290.23854328.V1
Abstract: Data collection and refinement statistics for the IL-3R ternary complex crystal structure.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 2021
DOI: 10.1016/J.CELREP.2020.108585
Abstract: Potent therapeutic inhibition of the androgen receptor (AR) in prostate adenocarcinoma can lead to the emergence of neuroendocrine prostate cancer (NEPC), a phenomenon associated with enhanced cell plasticity. Here, we show that microRNA-194 (miR-194) is a regulator of epithelial-neuroendocrine transdifferentiation. In clinical prostate cancer s les, miR-194 expression and activity were elevated in NEPC and inversely correlated with AR signaling. miR-194 facilitated the emergence of neuroendocrine features in prostate cancer cells, a process mediated by its ability to directly target a suite of genes involved in cell plasticity. One such target was FOXA1, which encodes a transcription factor with a vital role in maintaining the prostate epithelial lineage. Importantly, a miR-194 inhibitor blocked epithelial-neuroendocrine transdifferentiation and inhibited the growth of cell lines and patient-derived organoids possessing neuroendocrine features. Overall, our study reveals a post-transcriptional mechanism regulating the plasticity of prostate cancer cells and provides a rationale for targeting miR-194 in NEPC.
Publisher: Elsevier BV
Date: 2022
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2019
DOI: 10.1158/2159-8290.23854361
Abstract: IL3Rα/βc transcript and protein expression ratio in AML patient s les.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709867.V1
Abstract: IL3Rα P248 at the IL-3R assembly interface is critical for cell differentiation.
Publisher: Oxford University Press (OUP)
Date: 11-09-2017
DOI: 10.1093/NAR/GKX788
Publisher: Springer Science and Business Media LLC
Date: 22-01-2019
DOI: 10.1038/S41419-018-1296-0
Abstract: Caspase-2 is a highly conserved cysteine protease with roles in apoptosis and tumor suppression. Our recent findings have also demonstrated that the tumor suppression function of caspase-2 is context specific. In particular, while caspase-2 deficiency augments lymphoma development in the EμMyc mouse model, it leads to delayed neuroblastoma development in Th-MYCN mice. However, it is unclear how caspase-2 mediates these differential outcomes. Here we utilized RNA sequencing to define the transcriptomic changes caused by caspase-2 ( Casp2 −/− ) deficiency in tumors from EμMyc and Th-MYCN mice. We describe key changes in both lymphoma and neuroblastoma-associated genes and identified differential expression of the EGF-like domain-containing gene, Megf6 , in the two tumor types that may contribute to tumor outcome following loss of Casp2 . We identified a panel of genes with altered expression in Th-MYCN/Casp2 −/− tumors that are strongly associated with neuroblastoma outcome, with roles in melanogenesis, Wnt and Hippo pathway signaling, that also contribute to neuronal differentiation. In contrast, we found that key changes in gene expression in the EμMyc/Casp2 −/− tumors, are associated with increased immune signaling and T-cell infiltration previously associated with more aggressive lymphoma progression. In addition, Rap1 signaling pathway was uniquely enriched in Casp2 deficient EμMyc tumors. Our findings suggest that Casp2 deficiency augments immune signaling pathways that may be in turn, enhance lymphomagenesis. Overall, our study has identified new genes and pathways that contribute to the caspase-2 tumor suppressor function and highlight distinct roles for caspase-2 in different tissues.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709864
Abstract: The IL-3R dodecamer activates STAT1 to induce cell differentiation.
Publisher: Springer Science and Business Media LLC
Date: 2023
DOI: 10.1038/S41591-022-02142-1
Abstract: Pregnancy loss and perinatal death are devastating events for families. We assessed ‘genomic autopsy’ as an adjunct to standard autopsy for 200 families who had experienced fetal or newborn death, providing a definitive or candidate genetic diagnosis in 105 families. Our cohort provides evidence of severe atypical in utero presentations of known genetic disorders and identifies novel phenotypes and disease genes. Inheritance of 42% of definitive diagnoses were either autosomal recessive (30.8%), X-linked recessive (3.8%) or autosomal dominant (excluding de novos, 7.7%), with risk of recurrence in future pregnancies. We report that at least ten families (5%) used their diagnosis for preimplantation (5) or prenatal diagnosis (5) of 12 pregnancies. We emphasize the clinical importance of genomic investigations of pregnancy loss and perinatal death, with short turnaround times for diagnostic reporting and followed by systematic research follow-up investigations. This approach has the potential to enable accurate counseling for future pregnancies.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709861
Abstract: Enrichment of the IL-3R hexamer versus dodecamer gene signature in primitive normal and leukemic stem cells.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709864.V1
Abstract: The IL-3R dodecamer activates STAT1 to induce cell differentiation.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854361.V1
Abstract: IL3Rα/βc transcript and protein expression ratio in AML patient s les.
Publisher: EMBO
Date: 06-06-2018
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854340.V1
Abstract: Enrichment of the IL-3R hexamer versus dodecamer gene signature in primitive normal and leukemic stem cells.
Publisher: American Society of Hematology
Date: 23-01-2020
DOI: 10.1182/BLOODADVANCES.2019000586
Abstract: Cyclin-dependent kinase 9 and bromodomain and extraterminal inhibitors are synergistic in MLL-rearranged leukemia. Multiple AML driver genes are downregulated by the combined therapy suggesting broad applicability for this subtype.
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.DEVCEL.2019.03.017
Abstract: The correct assignment of cell fate within fields of multipotent progenitors is essential for accurate tissue ersification. The first lymphatic vessels arise from pre-existing veins after venous endothelial cells become specified as lymphatic progenitors. Prox1 specifies lymphatic fate and labels these progenitors however, the mechanisms restricting Prox1 expression and limiting the progenitor pool remain unknown. We identified a zebrafish mutant that displayed premature, expanded, and prolonged lymphatic specification. The gene responsible encodes the regulator of alternative splicing, Nova2. In zebrafish and human endothelial cells, Nova2 selectively regulates pre-mRNA splicing for components of signaling pathways and phosphoproteins. Nova2-deficient endothelial cells display increased Mapk/Erk signaling, and Prox1 expression is dynamically controlled by Erk signaling. We identify a mechanism whereby Nova2-regulated splicing constrains Erk signaling, thus limiting lymphatic progenitor cell specification. This identifies the capacity of a factor that tunes mRNA splicing to control assignment of cell fate during vascular differentiation.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854328
Abstract: Data collection and refinement statistics for the IL-3R ternary complex crystal structure.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709867
Abstract: IL3Rα P248 at the IL-3R assembly interface is critical for cell differentiation.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854325
Abstract: Summary of the key interactions in the IL-3R ternary complex in the IL-3R ternary complex crystal structure.
Publisher: Springer Science and Business Media LLC
Date: 03-09-2020
DOI: 10.1038/S41598-020-71323-0
Abstract: The attachment of unique molecular identifiers (UMIs) to RNA molecules prior to PCR lification and sequencing, makes it possible to lify libraries to a level that is sufficient to identify rare molecules, whilst simultaneously eliminating PCR bias through the identification of duplicated reads. Accurate de-duplication is dependent upon a sufficiently complex pool of UMIs to allow unique labelling. In applications dealing with complex libraries, such as total RNA-seq, only a limited variety of UMIs are required as the variation in molecules to be sequenced is enormous. However, when sequencing a less complex library, such as small RNAs for which there is a more limited range of possible sequences, we find increased variation in UMIs are required, even beyond that provided in a commercial kit specifically designed for the preparation of small RNA libraries for sequencing. We show that a pool of UMIs randomly varying across eight nucleotides is not of sufficient depth to uniquely tag the microRNAs to be sequenced. This results in over de-duplication of reads and the marked under-estimation of expression of the more abundant microRNAs. Whilst still arguing for the utility of UMIs, this work demonstrates the importance of their considered design to avoid errors in the estimation of gene expression in libraries derived from select regions of the transcriptome or small genomes.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.C.6749895.V2
Abstract: Abstract Leukemia stem cells (LSC) possess distinct self-renewal and arrested differentiation properties that are responsible for disease emergence, therapy failure, and recurrence in acute myeloid leukemia (AML). Despite AML displaying extensive biological and clinical heterogeneity, LSC with high interleukin-3 receptor (IL3R) levels are a constant yet puzzling feature, as this receptor lacks tyrosine kinase activity. Here, we show that the heterodimeric IL3Rα/βc receptor assembles into hexamers and dodecamers through a unique interface in the 3D structure, where high IL3Rα/βc ratios bias hexamer formation. Importantly, receptor stoichiometry is clinically relevant as it varies across the in idual cells in the AML hierarchy, in which high IL3Rα/βc ratios in LSCs drive hexamer-mediated stemness programs and poor patient survival, while low ratios mediate differentiation. Our study establishes a new paradigm in which alternative cytokine receptor stoichiometries differentially regulate cell fate, a signaling mechanism that may be generalizable to other transformed cellular hierarchies and of potential therapeutic significance. Significance: Stemness is a hallmark of many cancers and is largely responsible for disease emergence, progression, and relapse. Our finding that clinically significant stemness programs in AML are directly regulated by different stoichiometries of cytokine receptors represents a hitherto unexplained mechanism underlying cell-fate decisions in cancer stem cell hierarchies. i a href="ancerdiscovery/article/doi/10.1158/2159-8290.CD-13-8-ITI" target="_blank" This article is highlighted in the In This Issue feature, p. 1749 /a /i /
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.C.6749895.V1
Abstract: Abstract Leukemia stem cells (LSC) possess distinct self-renewal and arrested differentiation properties that are responsible for disease emergence, therapy failure, and recurrence in acute myeloid leukemia (AML). Despite AML displaying extensive biological and clinical heterogeneity, LSC with high interleukin-3 receptor (IL3R) levels are a constant yet puzzling feature, as this receptor lacks tyrosine kinase activity. Here, we show that the heterodimeric IL3Rα/βc receptor assembles into hexamers and dodecamers through a unique interface in the 3D structure, where high IL3Rα/βc ratios bias hexamer formation. Importantly, receptor stoichiometry is clinically relevant as it varies across the in idual cells in the AML hierarchy, in which high IL3Rα/βc ratios in LSCs drive hexamer-mediated stemness programs and poor patient survival, while low ratios mediate differentiation. Our study establishes a new paradigm in which alternative cytokine receptor stoichiometries differentially regulate cell fate, a signaling mechanism that may be generalizable to other transformed cellular hierarchies and of potential therapeutic significance. Significance: Stemness is a hallmark of many cancers and is largely responsible for disease emergence, progression, and relapse. Our finding that clinically significant stemness programs in AML are directly regulated by different stoichiometries of cytokine receptors represents a hitherto unexplained mechanism underlying cell-fate decisions in cancer stem cell hierarchies. /
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854355
Abstract: Key interactions between distinct residues in the IL-3R ternary complex crystal structure.
Publisher: Elsevier BV
Date: 2021
Publisher: Royal Society of Chemistry (RSC)
Date: 1999
DOI: 10.1039/A809571J
Publisher: Wiley
Date: 2020
DOI: 10.1002/CTI2.1191
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854352
Abstract: IL3Rα P248 at the IL-3R assembly interface is critical for cell differentiation.
Publisher: Springer Science and Business Media LLC
Date: 15-07-2022
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854346.V1
Abstract: The IL-3R dodecamer activates STAT1 to induce cell differentiation.
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.GIM.2021.09.001
Abstract: Genetic variants causing aberrant premessenger RNA splicing are increasingly being recognized as causal variants in genetic disorders. In this study, we devise standardized practices for polymerase chain reaction (PCR)-based RNA diagnostics using clinically accessible specimens (blood, fibroblasts, urothelia, biopsy). A total of 74 families with erse monogenic conditions (31% prenatal-congenital onset, 47% early childhood, and 22% teenage-adult onset) were triaged into PCR-based RNA testing, with comparative RNA sequencing for 19 cases. Informative RNA assay data were obtained for 96% of cases, enabling variant reclassification for 75% variants that can be used for genetic counseling (71%), to inform clinical care (32%) and prenatal counseling (41%). Variant-associated mis-splicing was highly reproducible for 28 cases with s les from ≥2 affected in iduals or heterozygotes and 10 cases with ≥2 biospecimens. PCR licons encompassing another segregated heterozygous variant was vital for clinical interpretation of 22 of 79 variants to phase RNA splicing events and discern complete from partial mis-splicing. RNA diagnostics enabled provision of a genetic diagnosis for 64% of recruited cases. PCR-based RNA diagnostics has capacity to analyze 81.3% of clinically significant genes, with long licons providing an advantage over RNA sequencing to phase RNA splicing events. The Australasian Consortium for RNA Diagnostics (SpliceACORD) provide clinically-endorsed, standardized protocols and recommendations for interpreting RNA assay data.
Publisher: Frontiers Media SA
Date: 06-04-2022
DOI: 10.3389/FIMMU.2022.850226
Abstract: Glioblastoma is the most common and aggressive form of primary brain cancer, with no improvements in the 5-year survival rate of 4.6% over the past three decades. T-cell-based immunotherapies such as immune-checkpoint inhibitors and chimeric antigen receptor T-cell therapy have prolonged the survival of patients with other cancers and have undergone early-phase clinical evaluation in glioblastoma patients. However, a major challenge for T-cell-based immunotherapy of glioblastoma and other solid cancers is T-cell infiltration into tumours. This process is mediated by chemokine-chemokine receptor and integrin-adhesion molecule interactions, yet the specific nature of the molecules that may facilitate T-cell homing into glioblastoma are unknown. Here, we have characterised chemokine receptor and integrin expression profiles of endogenous glioblastoma-infiltrating T cells, and the chemokine expression profile of glioblastoma-associated cells, by single-cell RNA-sequencing. Subsequently, chemokine receptors and integrins were validated at the protein level to reveal enrichment of receptors CCR2, CCR5, CXCR3, CXCR4, CXCR6, CD49a, and CD49d in glioblastoma-infiltrating T-cell populations relative to T cells in matched patient peripheral blood. Complementary chemokine ligand expression was then validated in glioblastoma biopsies and glioblastoma-derived primary cell cultures. Together, enriched expression of homing receptor-ligand pairs identified in this study implicate a potential role in mediating T-cell infiltration into glioblastoma. Importantly, our data characterising the migratory receptors on endogenous tumour-infiltrating T cells could be exploited to enhance the tumour-homing properties of future T-cell immunotherapies for glioblastoma.
Publisher: EMBO
Date: 07-05-2018
Publisher: Oxford University Press (OUP)
Date: 12-2014
DOI: 10.1093/NAR/GKU1242
Publisher: Wiley
Date: 02-06-2016
DOI: 10.1111/PBI.12388
Abstract: Elucidation of the gene networks underlying the response to N supply and demand will facilitate the improvement of the N uptake efficiency of plants. We undertook a transcriptomic analysis of maize to identify genes responding to both a non-growth-limiting decrease in NO3- provision and to development-based N demand changes at seven representative points across the life cycle. Gene co-expression networks were derived by cluster analysis of the transcript profiles. The majority of NO3--responsive transcription occurred at 11 (D11), 18 (D18) and 29 (D29) days after emergence, with differential expression predominating in the root at D11 and D29 and in the leaf at D18. A cluster of 98 probe sets was identified, the expression pattern of which is similar to that of the high-affinity NO3- transporter (NRT2) genes across the life cycle. The cluster is enriched with genes encoding enzymes and proteins of lipid metabolism and transport, respectively. These are candidate genes for the response of maize to N supply and demand. Only a few patterns of differential gene expression were observed over the entire life cycle however, the composition of the classes of the genes differentially regulated at in idual time points was unique, suggesting tightly controlled regulation of NO3--responsive gene expression.
Publisher: Massachusetts Medical Society
Date: 27-07-2000
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709852
Abstract: Data collection and refinement statistics for the IL-3R ternary complex crystal structure.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.C.6749895
Abstract: Abstract Leukemia stem cells (LSC) possess distinct self-renewal and arrested differentiation properties that are responsible for disease emergence, therapy failure, and recurrence in acute myeloid leukemia (AML). Despite AML displaying extensive biological and clinical heterogeneity, LSC with high interleukin-3 receptor (IL3R) levels are a constant yet puzzling feature, as this receptor lacks tyrosine kinase activity. Here, we show that the heterodimeric IL3Rα/βc receptor assembles into hexamers and dodecamers through a unique interface in the 3D structure, where high IL3Rα/βc ratios bias hexamer formation. Importantly, receptor stoichiometry is clinically relevant as it varies across the in idual cells in the AML hierarchy, in which high IL3Rα/βc ratios in LSCs drive hexamer-mediated stemness programs and poor patient survival, while low ratios mediate differentiation. Our study establishes a new paradigm in which alternative cytokine receptor stoichiometries differentially regulate cell fate, a signaling mechanism that may be generalizable to other transformed cellular hierarchies and of potential therapeutic significance. Significance: Stemness is a hallmark of many cancers and is largely responsible for disease emergence, progression, and relapse. Our finding that clinically significant stemness programs in AML are directly regulated by different stoichiometries of cytokine receptors represents a hitherto unexplained mechanism underlying cell-fate decisions in cancer stem cell hierarchies. i a href="ancerdiscovery/article/doi/10.1158/2159-8290.CD-13-8-ITI" target="_blank" This article is highlighted in the In This Issue feature, p. 1749 /a /i /
Publisher: American Association for Cancer Research (AACR)
Date: 16-05-2023
DOI: 10.1158/2159-8290.CD-22-1396
Abstract: Stemness is a hallmark of many cancers and is largely responsible for disease emergence, progression, and relapse. Our finding that clinically significant stemness programs in AML are directly regulated by different stoichiometries of cytokine receptors represents a hitherto unexplained mechanism underlying cell-fate decisions in cancer stem cell hierarchies. This article is highlighted in the In This Issue feature, p. 1749
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.CELS.2018.05.019
Abstract: MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression, functioning in part by facilitating the degradation of target mRNAs. They have an established role in controlling epithelial-mesenchymal transition (EMT), a reversible phenotypic program underlying normal and pathological processes. Many studies demonstrate the role of in idual miRNAs using overexpression at levels greatly exceeding physiological abundance. This can influence transcripts with relatively poor targeting and may in part explain why over 130 different miRNAs are directly implicated as EMT regulators. Analyzing a human mammary cell model of EMT we found evidence that a set of miRNAs, including the miR-200 and miR-182/183 family members, co-operate in post-transcriptional regulation, both reinforcing and buffering transcriptional output. Investigating this, we demonstrate that combinatorial treatment altered cellular phenotype with miRNA concentrations much closer to endogenous levels and with less off-target effects. This suggests that co-operative targeting by miRNAs is important for their physiological function and future work classifying miRNAs should consider such combinatorial effects.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854355.V1
Abstract: Key interactions between distinct residues in the IL-3R ternary complex crystal structure.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709858
Abstract: Increasing IL3Rα/βc ratios lead to hexameric receptor assembly and augmented quiescence.
Publisher: Springer Science and Business Media LLC
Date: 12-05-2022
DOI: 10.1038/S41467-022-30223-9
Abstract: The interaction of germline variation and somatic cancer driver mutations is under-investigated. Here we describe the genomic mitochondrial landscape in adult acute myeloid leukaemia (AML) and show that rare variants affecting the nuclear- and mitochondrially-encoded complex I genes show near-mutual exclusivity with somatic driver mutations affecting isocitrate dehydrogenase 1 ( IDH1 ), but not IDH2 suggesting a unique epistatic relationship. Whereas AML cells with rare complex I variants or mutations in IDH1 or IDH2 all display attenuated mitochondrial respiration, heightened sensitivity to complex I inhibitors including the clinical-grade inhibitor, IACS-010759, is observed only for IDH1 -mutant AML. Furthermore, IDH1 mutant blasts that are resistant to the IDH1-mutant inhibitor, ivosidenib, retain sensitivity to complex I inhibition. We propose that the IDH1 mutation limits the flexibility for citrate utilization in the presence of impaired complex I activity to a degree that is not apparent in IDH2 mutant cells, exposing a mutation-specific metabolic vulnerability. This reduced metabolic plasticity explains the epistatic relationship between the germline complex I variants and oncogenic IDH1 mutation underscoring the utility of genomic data in revealing metabolic vulnerabilities with implications for therapy.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709855
Abstract: Increasing IL3Rα/βc ratios and enforced hexamer signaling lead to reduced differentiation in in vivo engraftments.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854346
Abstract: The IL-3R dodecamer activates STAT1 to induce cell differentiation.
Publisher: Oxford University Press (OUP)
Date: 02-08-2019
DOI: 10.1093/NAR/GKZ664
Abstract: Epithelial–mesenchymal transition (EMT) has been a subject of intense scrutiny as it facilitates metastasis and alters drug sensitivity. Although EMT-regulatory roles for numerous miRNAs and transcription factors are known, their functions can be difficult to disentangle, in part due to the difficulty in identifying direct miRNA targets from complex datasets and in deciding how to incorporate ‘indirect’ miRNA effects that may, or may not, represent biologically relevant information. To better understand how miRNAs exert effects throughout the transcriptome during EMT, we employed Exon–Intron Split Analysis (EISA), a bioinformatic technique that separates transcriptional and post-transcriptional effects through the separate analysis of RNA-Seq reads mapping to exons and introns. We find that in response to the manipulation of miRNAs, a major effect on gene expression is transcriptional. We also find extensive co-ordination of transcriptional and post-transcriptional regulatory mechanisms during both EMT and mesenchymal to epithelial transition (MET) in response to TGF-β or miR-200c respectively. The prominent transcriptional influence of miRNAs was also observed in other datasets where miRNA levels were perturbed. This work cautions against a narrow approach that is limited to the analysis of direct targets, and demonstrates the utility of EISA to examine complex regulatory networks involving both transcriptional and post-transcriptional mechanisms.
Publisher: Springer Science and Business Media LLC
Date: 25-01-2023
Publisher: Springer Science and Business Media LLC
Date: 04-2021
DOI: 10.1186/S42490-021-00049-5
Abstract: Organoids are a reliable model used in the study of human brain development and under pathological conditions. However, current methods for brain organoid culture generate tissues that range from 0.5 to 2 mm of size, which need to be constantly agitated to allow proper oxygenation. The culture conditions are, therefore, not suitable for whole-brain organoid live imaging, required to study developmental processes and disease progression within physiologically relevant time frames (i.e. days, weeks, months). Here we designed 3D-printed microplate inserts adaptable to standard 24 multi-well plates, which allow the growth of multiple organoids in pre-defined and fixed XYZ coordinates. This innovation facilitates high-resolution imaging of whole-cerebral organoids, allowing precise assessment of organoid growth and morphology, as well as cell tracking within the organoids, over long periods. We applied this technology to track neocortex development through neuronal progenitors in brain organoids, as well as the movement of patient-derived glioblastoma stem cells within healthy brain organoids. This new bioengineering platform constitutes a significant advance that permits long term detailed analysis of whole-brain organoids using multimodal inverted fluorescence microscopy.
Publisher: Springer Science and Business Media LLC
Date: 10-07-2023
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854340
Abstract: Enrichment of the IL-3R hexamer versus dodecamer gene signature in primitive normal and leukemic stem cells.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709873.V1
Abstract: IL3Rα/βc transcript and protein expression ratio in AML patient s les.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709852.V1
Abstract: Data collection and refinement statistics for the IL-3R ternary complex crystal structure.
Publisher: American Society of Hematology
Date: 09-02-2017
DOI: 10.1182/BLOOD-2016-06-720433
Abstract: Inhibition of SPHK1 in human AML cells induces MCL1 degradation and caspase-dependent cell death. SPHK1 inhibitors reduce leukemic burden and prolong survival in orthotopic patient-derived xenografts of AML.
Publisher: Springer Science and Business Media LLC
Date: 10-08-2016
DOI: 10.1007/S11103-016-0512-5
Abstract: We found metabolites, enzyme activities and enzyme transcript abundances vary significantly across the maize lifecycle, but weak correlation exists between the three groups. We identified putative genes regulating nitrate assimilation. Progress in improving nitrogen (N) use efficiency (NUE) of crop plants has been h ered by the complexity of the N uptake and utilisation systems. To understand this complexity we measured the activities of seven enzymes and ten metabolites related to N metabolism in the leaf and root tissues of Gaspe Flint maize plants grown in 0.5 or 2.5 mM NO3 (-) throughout the lifecycle. The amino acids had remarkably similar profiles across the lifecycle except for transient responses, which only appeared in the leaves for aspartate or in the roots for asparagine, serine and glycine. The activities of the enzymes for N assimilation were also coordinated to a certain degree, most noticeably with a peak in root activity late in the lifecycle, but with wide variation in the activity levels over the course of development. We analysed the transcriptional data for gene sets encoding the measured enzymes and found that, unlike the enzyme activities, transcript levels of the corresponding genes did not exhibit the same coordination across the lifecycle and were only weakly correlated with the levels of various amino acids or in idual enzyme activities. We identified gene sets which were correlated with the enzyme activity profiles, including seven genes located within previously known quantitative trait loci for enzyme activities and hypothesise that these genes are important for the regulation of enzyme activities. This work provides insights into the complexity of the N assimilation system throughout development and identifies candidate regulatory genes, which warrant further investigation in efforts to improve NUE in crop plants.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854331.V1
Abstract: Increasing IL3Rα/βc ratios and enforced hexamer signaling lead to reduced differentiation in in vivo engraftments.
Publisher: American Association for Cancer Research (AACR)
Date: 04-08-2023
DOI: 10.1158/2159-8290.23854352.V1
Abstract: IL3Rα P248 at the IL-3R assembly interface is critical for cell differentiation.
Publisher: American Association for Cancer Research (AACR)
Date: 19-07-2023
DOI: 10.1158/2159-8290.23709849
Abstract: Summary of the key interactions in the IL-3R ternary complex in the IL-3R ternary complex crystal structure.
Publisher: Elsevier BV
Date: 07-2023
Publisher: Wiley
Date: 03-09-2013
DOI: 10.1111/NPH.12468
Abstract: High expression of zinc ( Z n)‐regulated, iron‐regulated transporter‐like protein ( ZIP ) genes increases root Z n uptake in dicots, leading to high accumulation of Z n in shoots. However, none of the ZIP genes tested previously in monocots could enhance shoot Z n accumulation. In this report, barley ( H ordeum vulgare ) H v ZIP 7 was investigated for its functions in Z n transport. The functions of H v ZIP 7 in planta were studied using in situ hybridization and transient analysis of subcellular localization with a green fluorescent protein ( GFP ) reporter. Transgenic barley lines overexpressing H v ZIP 7 were also generated to further understand the functions of H v ZIP 7 in metal transport. H v ZIP 7 is strongly induced by Z n deficiency, primarily in vascular tissues of roots and leaves, and its protein was localized in the plasma membrane. These properties are similar to its closely related homologs in dicots. Overexpression of H v ZIP 7 in barley plants increased Z n uptake when moderately high concentrations of Z n were supplied. Significantly, there was a specific enhancement of shoot Z n accumulation, with no measurable increase in iron ( F e), manganese ( M n), copper ( C u) or cadmium ( C d). H v ZIP 7 displays characteristics of low‐affinity Z n transport. The unique function of H v ZIP 7 provides new insights into the role of ZIP genes in Z n homeostasis in monocots, and offers opportunities to develop Z n biofortification strategies in cereals.
No related grants have been discovered for John Toubia.