ABSTRACT: Genome-wide mapping of Rad21 binding sites and gene expression profiling in wild type mouse small intestinal epithelial crypts and Apc Min adenomas
Project description:To investigate the role of RAD21 in the transcriptional regulation of global gene expression at early stage of colorectal cancer developments, we peformed the genome-wide analysis to map genomic regions bound by Rad21 in normal small testinal crypts and tumors (adenomas) harvested from Apc Min/+ mice using ChIP-seq. ChIP-seq naalysis identified high confidence RAD21 binding sites unique to normal crypts or adenomas, as well as those common to both tissues. We further performed RNA-seq to profile the changes in gene expression from normal WT crypts to adenomas at the very early stage of adenomagenesis in the context of Rad21 heterozygous loss. mRNA profiles of normal small intestinal crypts (WT) and adenomas from Apc Min/+ and Apc Min/+:Rad21+/- double mutant mouse; Mapping of Rad21 genomic binding sites in normal intestinal crypts (WT) and Apc Min/+ adenomas
Project description:To investigate the role of RAD21 in the transcriptional regulation of global gene expression at early stage of colorectal cancer developments, we peformed the genome-wide analysis to map genomic regions bound by Rad21 in normal small testinal crypts and tumors (adenomas) harvested from Apc Min/+ mice using ChIP-seq. ChIP-seq naalysis identified high confidence RAD21 binding sites unique to normal crypts or adenomas, as well as those common to both tissues. We further performed RNA-seq to profile the changes in gene expression from normal WT crypts to adenomas at the very early stage of adenomagenesis in the context of Rad21 heterozygous loss.
Project description:Transcriptional Profiling of the Transition from Normal Intestinal Epithelia to Adenomas and Carcinomas in the APC(Min/+) Mouse. Samples used in analysis:; * GSM6191-GSM6196 (WT): Ilea epithelial cells from C57/BL6 wild-type samples; * GSM6197-GSM6201 (Adenoma): Epithelial cells from crypts of adenomas of APC(Min/+) mice; * GSM6202-GSM6206 (Carcinoma): Epithelial cells from crypts of carcinomas of APC(Min/+) mice; Using a PixCell IIe instrument (Arcturus), ~30,000 laser firings per sample were used to collect cells of interest. RNA was extracted from captured cells by PicoPure (Arcturus) technique, followed by 2 rounds of RiboAmp amplification (Arcturus), with incorporation of biotinylated nucleotides (Enzo) in the IVT of round 2. All protocols were as per manufacturers instructions. 15ug of labeled cRNA from individual samples were hybridized to respective MG_U74Av2 chips (Affymetrix) and washed/stained using the standard EukGEWS2v4 protocol (Affymetrix). Chips were scanned and analyzed using MAS 5 (Affymetrix) and data scaled to TI=500. Pairwise comparisons using the Mann-Whitney test were performed in DMT 3 (Affymetrix), comparing WT vs Adenoma (n=6 x n=5; 83.3% concordance); WT vs Carcinoma (n=5 x n=5; 84% concordance); Adenoma vs Carcinoma (n=5 x n=5; 84% concordance). This resulted in the identification of differentially expressed transcripts. Fold changes were calculated from signal-log-ratios. Identified transcripts were clustered based on functional information which was publicly available at time of analysis, obtained through the NetAffx web portal (Affymetrix).
Project description:Transcriptional Profiling of the Transition from Normal Intestinal Epithelia to Adenomas and Carcinomas in the APC(Min/+) Mouse. Samples used in analysis: * GSM6191-GSM6196 (WT): Ilea epithelial cells from C57/BL6 wild-type samples * GSM6197-GSM6201 (Adenoma): Epithelial cells from crypts of adenomas of APC(Min/+) mice * GSM6202-GSM6206 (Carcinoma): Epithelial cells from crypts of carcinomas of APC(Min/+) mice Using a PixCell IIe instrument (Arcturus), ~30,000 laser firings per sample were used to collect cells of interest. RNA was extracted from captured cells by PicoPure (Arcturus) technique, followed by 2 rounds of RiboAmp amplification (Arcturus), with incorporation of biotinylated nucleotides (Enzo) in the IVT of round 2. All protocols were as per manufacturers instructions. 15ug of labeled cRNA from individual samples were hybridized to respective MG_U74Av2 chips (Affymetrix) and washed/stained using the standard EukGEWS2v4 protocol (Affymetrix). Chips were scanned and analyzed using MAS 5 (Affymetrix) and data scaled to TI=500. Pairwise comparisons using the Mann-Whitney test were performed in DMT 3 (Affymetrix), comparing: * WT vs Adenoma (n=6 x n=5; 83.3% concordance) * WT vs Carcinoma (n=5 x n=5; 84% concordance) * Adenoma vs Carcinoma (n=5 x n=5; 84% concordance) This resulted in the identification of differentially expressed transcripts. Fold changes were calculated from signal-log-ratios. Identified transcripts were clustered based on functional information which was publicly available at time of analysis, obtained through the NetAffx web portal (Affymetrix). Keywords = colon cancer Keywords = gene expression Keywords = DNA microarrays Keywords = beta-catenin Keywords = familial adenomatous polyposis Keywords: ordered
Project description:APC is mutated in the majority of colorectal cancers. Inducible deletion of Apc in intestinal epithelial cells in Apcfl//fl; Villin-CreERT2 mice recapitulates this tumor-initiating mutation resulting in expanded intestinal crypts, including stem cells. We used microarrays to analyze BEC gene expression changes during the early stages of intestinal tumorigenesis.
Project description:We have generated a mouse model for tumor initiation carrying a mutation in APC and lacking IKKα in intestinal epithelial cells. IKKα-deficient intestinal cells primarily failed to generate adenomas, and the few adenomas arising in this background displayed a significant reduction in cell proliferation. Using an in vitro model for intestinal tumoroids (derived from adenoma initiating cells), we have performed RNA sequencing of wild type and IKKα-deficient intestinal tumoroids. This has demonstrated that epithelial IKKα controls transcription of stem cell-related genes and genes associated with proliferation and apoptosis.
Project description:Purpose: to investigate the effects of the cytokine Interluekin-22 (IL-22) on small intestinal epithelial cells, using organoids. Methods: WT or Apc(Min/Min) organoids (day 3) were stimulated with IL-22 (2ng/ml) for 3 hours, and submitted for transcriptomic profiling. Results: The main function of IL-22 in small intestinal epithelial cells is to activate an antimicrobial immune response and defence against infection and stress. Further, we found that loss of Apc lead to a complete loss of response to IL-22
Project description:Somatic mutations in APC or CTNNB1 genes lead to aberrant Wnt signaling and colorectal cancer (CRC) initiation and progression. Activation of Wnt pathway leads to the formation of beta-catenin-T-cell factor/Lymphoid enhancer binding factor 1 (Tcf/Lef1) complexes that activate transcription of oncogenic target genes. Lef1 is the only member of the Tcf gene family that is not expressed in the normal intestine, but is induced during intestinal tumorigenesis. Thus, we wanted to assess the role of Lef1 using genetic mouse models of intestinal adenomas and scRNA-seq technology. Tumorigenesis was initiated by inducing Apc mutation in Lgr5+ stem cells. Intestinal EpCAM+ epithelial cells of Lgr5-CreERT;Apc fl/fl (LApc) mouse and Lgr5-CreERT;Apc fl/fl; Lef1 fl/fl (LApcL) mouse were used to analyze the effects of Lef1 deletion in intestinal adenoma cells. We used WT mice as a control to distinguish adenoma cells.
Project description:Aberrant CpG methylation is a universal trait of cancer cell genomes and can result in epigenetic modulation of gene activity; however, at which stages tumour-specific epigenetic patterns arise is unknown. Here, we analyse the methylome of APCM in mouse intestinal adenoma as a model of intestinal cancer initiation, and inventory a map of over 13,000 adenoma-specific recurrent differentially methylated regions (DMRs). We find that multiple genes coding for Polycomb proteins are upregulated in adenoma, and concomitantly, hypermethylated DMRs form preferentially at Polycomb target sites. We establish that DMRs are absent from proliferating intestinal epithelial cells or intestinal stem cells, and thus arise de novo after loss of APC. Importantly, a core set of DMRs is conserved in human colon cancer, defining a class of early epigenetic alterations that are distinct from known sets of epigenetically silenced tumour suppressors. The data presented suggests a sequence of events that leads to an altered methylome of colon cancer cells, and may allow more specific selection of clinical epigenetic biomarkers. Analysis of the methylome and RNA expression in adenoma of Apc-Min/+ mutant mice and of normal intestine in Apc-Min/+ and Apc-+/+ wild type mice.