Using array comparative genomic hybridization (aCGH), a large number of deleted genomic regions have been identified in human cancers. However, subsequent efforts to identify target genes selected for inactivation in these regions have often been challenging. We integrated here genome-wide copy number data with gene expression data and non-sense mediated mRNA decay rates in breast cancer cell lines to prioritize gene candidates that are likely to be tumour suppressor genes inactivated by bi-allelic genetic events. The candidates were sequenced to identify potential mutations. This integrated genomic approach led to the identification of RIC8A at 11p15 as a putative candidate target gene for the genomic deletion in the ZR-75-1 breast cancer cell line. We identified a truncating mutation in this cell line, leading to loss of expression and rapid decay of the transcript. We screened 127 breast cancers for RIC8A mutations, but did not find any pathogenic mutations. No promoter hypermethylation in these tumours was detected either. However, analysis of gene expression data from breast tumours identified a small group of aggressive tumours that displayed low levels of RIC8A transcripts. Real-time PCR analysis of 38 breast tumours showed a strong association between low RIC8A expression and the presence of TP53 mutations (P=0.006). We demonstrate a data integration strategy leading to the identification of RIC8A as a gene undergoing a classical double-hit genetic inactivation in a breast cancer cell line, as well as in vivo evidence of loss of RIC8A expression in a subgroup of aggressive TP53 mutant breast cancers.
Data integration from two microarray platforms identifies bi-allelic genetic inactivation of RIC8A in a breast cancer cell line.
Sex, Disease, Cell line, Treatment, Time
View SamplesTotal RNA was extracted from apratoxin A or vehicle treated HT29 cells using the RNeasy Mini Kit (Qiagen). Probe values from CEL files were condensed to probe sets using Rosetta Resolver software. Resolver ANOVA analysis was then performed between groups.
A functional genomics approach to the mode of action of apratoxin A.
No sample metadata fields
View SamplesActivation of the canonical Wnt signaling pathway is commonly observed in pancreatic cancer. We therefore sought to identify a gene expression profile associated with the activation of this pathway in pancreatic cancer cells.
Activation of WNT/β-Catenin Signaling Enhances Pancreatic Cancer Development and the Malignant Potential Via Up-regulation of Cyr61.
Specimen part, Cell line
View SamplesSenescence in WI-38 cell context was induce by RASv12 over expression Cellular senescence is a permanent cell cycle arrest that is triggered by cancer- initiating or promoting events in mammalian cells and is now considered a major tumour suppressor mechanism. Here, we did a transcriptomic analysis and compared WI-38 contol wich is a human fibroblaste cell line and WI-38 that overexpressed RASv12 a G protein that induce senescence. The goal of our project is to compare transciptomic profile of human growing fibroblast (WI-38 control) and senescent human fibroblast (WI-38 OERAS)
Senescence is an endogenous trigger for microRNA-directed transcriptional gene silencing in human cells.
Specimen part
View SamplesIn humans, there are four Ago proteins (Ago1–4) and AGO1- and 2 were previously implicated in TGS induced by exogenous siRNAs and microRNAs (miRs) directed against gene promoter transcripts via promotion of changes in histone covalent modifications and DNA methylation. Not-with-standing, many mechanistic details of this process remain poorly defined in human cells, and very little is known about the identity of possible endogenous signals, which may drive this process in human cells. Given the evolutionary conserved role of siRNAs and AGO proteins in TGS and heterochromatin formation, we set out to analyse their possible involvement in senesence-associated repression of E2F target genes. To obtain a detailed picture of AGO-immunoprecipitating miRs (RIP) in senescent cells, we used next-generation sequencing (NGS)(RIP-Seq). We also included histone H3 dimethylated on lysine 9 (H3K9me2) in this analysis to assign potential AGO2-interacting miRs to a repressive chromatin state and unfractionated, cellular RNA from senescent cells for normalisation. Overall design: Determination of AGO AGO-immunoprecipitating miRs in WI-38 senescent human fibroblast
Senescence is an endogenous trigger for microRNA-directed transcriptional gene silencing in human cells.
No sample metadata fields
View SamplesGenome-wide association studies in human type 2 diabetes (T2D) have renewed interest in the pancreatic islet as a major site of T2D risk. In this study, microarray data collected from mouse islets were used to identify genes that are regulated by cytokines at levels consistent with the chronic low-grade inflammation observed in T2D. The most cytokine-sensitive genes were then examined for association of single nucleotide polymorphisms (SNPs) with acute insulin response to glucose (AIRg) measured in the Genetics UndeRlying DIAbetes in HispaNics (GUARDIAN) study. In GUARDIAN, there was evidence of association of AIRg with SNPs in ARAP3 (5q31.3), F13A1 (6p25.3), KLHL6 (3q27.1), NID1 (1q42.3), PAMR1 (11p13), RIPK2 (8q21.3), and STEAP4 (7q21.12). These data support the mouse islet microarray data in detection of seven novel genes with potential importance to islet dysfunction in T2D. To further assess each gene, murine islets were exposed for 48-hrs to the following stressors representing models of beta-cell failure: 20nM rotenone (oxidative stress), 100nM thapsigargin (ER stress), 10pg/ml IL-1B + 20pg/ml IL-6 (cytokines/low-grade inflammation), 28mM glucose (hyperglycemia), or 50uM palmitate + 100uM oleate + 50uM linoleate (lipotoxicity). RT-PCR revealed that F13a1 was downregulated 3.3-fold by cytokines (P<0.05) and 2.6-fold by rotenone (P<0.05), Klhl6 was upregulated 4.3-fold by thapsigargin (P<0.01), Ripk2 was mildly (1.5-3-fold) but significantly upregulated by all stressors (P<0.05), and STEAP4 was profoundly cytokine-sensitive (167-fold upregulation, P<0.01). These findings reveal promising leads in elucidating islet dysfunction during the development of T2D.
An Islet-Targeted Genome-Wide Association Scan Identifies Novel Genes Implicated in Cytokine-Mediated Islet Stress in Type 2 Diabetes.
Specimen part, Treatment
View SamplesMost human cancers present hyperactivated sumoylation, and cancer cell lines are usually highly sensitive to the lack of it, supporting potential application of sumoylation chemical inhibitors in cancer therapy. Here, we explored the impact of hyposumoylation (Ubc9 haploinsufficiency) on cancer development in mice using Apc loss-driven intestinal tumorigenesis model.
An unanticipated tumor-suppressive role of the SUMO pathway in the intestine unveiled by Ubc9 haploinsufficiency.
Specimen part
View SamplesThe Lgr5+ intestinal stem cell, Paneth and transit-amplifying cell compartment constitute the intestinal crypt which is the constant source of differentiated epithelial cells that replenish the intestinal villi ensuring organ maintenance and regeneration. The Lgr5+ crypt-based columnar (CBC) cells have been identified as the intestinal stem cells (ISCs) and, importantly, as cells-of-origin of intestinal cancer.
An unanticipated tumor-suppressive role of the SUMO pathway in the intestine unveiled by Ubc9 haploinsufficiency.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Sumoylation coordinates the repression of inflammatory and anti-viral gene-expression programs during innate sensing.
Specimen part
View SamplesBone marrow derived dendritic cells were generated from Ubc9[fl;-] and Ubc9[+/+] mice. After in vitro derivation in the presence of GM-CSF, dendritic cells were treated with tamoxifen for four days to cause CreERT2 activation, and induce Ubc9 floxed allele deletion. This allowed comparative transcriptomic analysis of Ubc9[+/+] and Ubc9[-/-] dendritic cells unstimulated or stimulated with 10ng/ml LPS for one hour and six hours.
Sumoylation coordinates the repression of inflammatory and anti-viral gene-expression programs during innate sensing.
Specimen part
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