Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer fatalities in Western societies, characterized by high metastatic potential and resistance to chemotherapy. Critical molecular mechanisms of these phenotypical features still remain unknown, thus hampering the development of effective prognostic and therapeutic measures in PDAC. Here we show that transcriptional co-factor Transducin beta-like (TBL) 1 was over-expressed in both human and murine PDAC. Inactivation of TBL1 in human and mouse pancreatic cancer cells reduced cellular proliferation and enhanced chemosensitivity, correlating with diminished glucose uptake, glycolytic flux, and PI3kinase signaling. TBL1 deficiency both prevented and reversed pancreatic tumor growth in mice, triggering transcriptional PI3kinase inhibition also in vivo. As TBL1 mRNA levels were also found to correlate with overall and disease-free survival in a cohort of human PDAC patients and to predict therapy responsiveness in these subjects, TBL1 expression may serve both as a novel prognostic marker and molecular target in the treatment of human PDAC.
Transcriptional co-factor Transducin beta-like (TBL) 1 acts as a checkpoint in pancreatic cancer malignancy.
Cell line, Treatment
View SamplesBackground and Aims: It is well demonstrated that in the beta cell population of the pancreas there is a dynamic turnover, which results from the net balance of several processes; beta cell replication, apoptosis and neogenesis. These processes have been studied in partial pancreatectomy and glucagon-like peptide 1 treated animals, where an increase in pancreas regeneration has been observed. Similarly, sodium tungstate, which decreases hyperglycemia in several animal models of diabetes, promotes a rise in the beta cell mass of nSTZ and STZ animals. However, the molecular mechanisms underlying this pancreas regeneration remain unknown. Therefore the objective of this study is to identify which genes are up or down regulated in the increase of the beta cell population of STZ rats treated with sodium tungstate.
Molecular mechanisms of tungstate-induced pancreatic plasticity: a transcriptomics approach.
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Methyl-CpG-binding protein MBD2 plays a key role in maintenance and spread of DNA methylation at CpG islands and shores in cancer.
Cell line
View SamplesCancer is characterised by DNA hypermethylation and gene silencing of CpG island-associated promoters, including tumour suppressor genes The methyl-CpG-binding domain (MBD) family of proteins bind to methylated DNA and can aid in the meditation of gene silencing by interaction with histone deacetylases and histone methyltransferases. However the mechanisms responsible for eliciting CpG island hypermethylation in cancer, and the potential role that MBD may proteins play in modulation of the methylome remain unclear. Our previous work demonstrated that MBD2 preferentially binds to the hypermethylated GSTP1 promoter CpG island in prostate cancer cells. Here, we use functional genetic approaches to investigate if MBD2 plays an active role in promoting DNA methylation. First, we show that loss of MBD2 results in inhibition of both maintenance and spread of de novo methylation of a transfected construct containing the GSTP1 promoter CpG island in prostate cancer cells and Mbd2-/- mouse fibroblasts. De novo methylation was rescued by transient expression of Mbd2 in Mbd2-/- cells. Second, we show that MBD2 depletion triggers significant hypomethylation genome-wide in prostate cancer cells with concomitant loss of MBD2 binding at promoter and enhancer regulatory regions. Finally, CpG islands and shores that become hypomethylated after MBD2 depletion in LNCaP cancer cells show significant hypermethylation in clinical prostate cancer, highlighting a potential active role of MBD2 in promoting cancer specific hypermethylation. Importantly, co-immunoprecipiation of MBD2 reveals that MBD2 associates with DNA methyltransferase (DNMT) enzymes 1 and 3A. Together our results demonstrate that MBD2 plays a critical role in rewriting the cancer methylome at specific regulatory regions.
Methyl-CpG-binding protein MBD2 plays a key role in maintenance and spread of DNA methylation at CpG islands and shores in cancer.
Cell line
View SamplesA three-dimensional chromatin state underpins the structural and functional basis of the genome by bringing regulatory elements and genes into close spatial proximity to ensure proper, cell-type specific gene expression profiles. Here, we perform HiC chromosome conformation, ChIP-seq and RNA-seq to investigate how the three-dimensional organization of the cancer genome is disrupted in the context of epigenetic remodelling and atypical gene expression programs. Overall design: Hi-C, ChIP-seq and RNA-seq were conducted in three human prostate cell lines: normal prostate epithelial cells (PrEC) and prostate cancer cells (PC3 and LNCaP).
Three-dimensional disorganization of the cancer genome occurs coincident with long-range genetic and epigenetic alterations.
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MicroRNA profiling of the pubertal mouse mammary gland identifies miR-184 as a candidate breast tumour suppressor gene.
Sex, Age, Specimen part, Cell line
View SamplesThe study of mammalian development has offered many insights into the molecular aetiology of cancer. We previously used analysis of mammary morphogenesis to discover a critical role for GATA-3 in mammary developmental and carcinogenesis. In recent years an important role for MicroRNAs (miRNAs) in a myriad of cellular processes in development and in oncogenesis has emerged. In this study, microRNA profiling of stromal and epithelial cellular subsets microdissected from the developing mouse mammary gland revealed many microRNAs with expression restricted to various cellular subsets. MicroRNA-184 (miR-184) was exclusively expressed in epithelial cells and markedly upregulated during differentiation of the proliferative, invasive cells of the pubertal terminal end bud (TEB) into ductal epithelial cells in vivo and in FACS-sorted mammary stem cells (MaSCs) versus luminal epithelial cells. miR-184 expression was silenced in mouse tumour models compared to non-transformed epithelium and in a majority of breast cancer cell line models. Ectopic reactivation of miR-184 inhibited the proliferation and self-renewal of metastatic triple negative breast cancer (TNBC) cell lines in vitro and delayed tumour formation and reduced metastasis in vivo. Gene expression studies uncovered multi-factorial direct regulation of genes in the AKT/mTORC1 pathway by miR-184. In clinical breast cancer tissues, expression of miR-184 is lost in primary TNBCs while the miR-184 promoter is methylated in a subset of lymph node metastases from TNBC patients. These studies elucidated a new layer of regulation in the PI3K/AKT/mTOR pathway with relevance to mammary development and tumour proliferation and metastasis.
MicroRNA profiling of the pubertal mouse mammary gland identifies miR-184 as a candidate breast tumour suppressor gene.
Sex, Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Enduring epigenetic landmarks define the cancer microenvironment.
Sex, Specimen part, Subject
View SamplesTo understand the molecular differences between adipocytes and their contribution to cell-type specific function, we comprehensively characterised the transcriptomes and DNA methylomes using WGBS of isolated adipocytes from the SAT and VAT from normal weight individuals Overall design: WGBS, RNA-seq, and microarrays were used to study epigenetics and transcriptomics human cancer isolated subcutaneous (abdominal - SA) and vieceral (omental - VA) adipocyte, peripheral blood leukocytes (PBL) and visceral adipose tissue (VAT).
Methylome and transcriptome maps of human visceral and subcutaneous adipocytes reveal key epigenetic differences at developmental genes.
Sex, Specimen part, Subject
View SamplesCancer Associated Fibroblasts (CAFs) play an active role in tumourigenesis. It is unknown how the permanent phenotypic changes in CAFs are encoded at the molecular level. Here we use whole genome sequencing and microarray analysis to interrogate the epigenome, transcriptome and genome of patient-matched CAF and non-malignant prostate fibroblast (NPF) cells.
Enduring epigenetic landmarks define the cancer microenvironment.
Sex, Specimen part, Subject
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