DNA methylation of adenomas from Apc-Min mice with additional Tet1 and Tdg mutations
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PROVIDER: PRJNA743221 | ENA |
REPOSITORIES: ENA
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Project description:Aberrant DNA methylation is frequent in colorectal cancer (CRC), but the underlying mechanisms and pathological consequences are poorly understood. Ten-Eleven Translocation (TET) dioxygenases and Thymine DNA Glycosylase (TDG) mediate active DNA demethylation by generating and removing oxidized cytosine species. TET1 and TDG mutations, and altered levels of oxidized cytosines have been identified in human CRC. To investigate the TET-TDG demethylation axis in intestinal tumorigenesis, we generated ApcMin mice that are devoid of Tet1 and/or Tdg, and characterized the methylome and transcriptome of intestinal adenomas. There were increased numbers (>30) of adenomas in ApcMin mice expressing the dominant-negative TdgN151A allele, whereas Tet1-deficient and Tet1/Tdg-double heterozygous ApcMin adenomas were larger and displayed features of erosion and invasion. Methylome analysis revealed reduction in global DNA hypomethylation in colonic adenomas from Tet1- and Tdg-mutant ApcMin mice, and hypermethylation of CpG islands in Tet1-mutant ApcMin mice. In addition, RNA sequencing showed upregulation of inflammatory, immune and interferon response genes in Tet1- and Tdg-mutant colonic adenomas compared to control ApcMin adenomas. The corresponding 127-gene inflammatory signature separated human colonic adenocarcinomas in four groups, closely aligned with their microsatellite or chromosomal instability, and characterized by different levels of DNA methylation and DNMT1 expression that anti-correlated with TET1 expression. These findings demonstrate a novel mechanism of epigenetic regulation during intestinal tumorigenesis by which TET1-TDG-mediated DNA demethylation may decrease methylation levels and inflammatory/interferon/immune responses, and is linked to the type of genomic instability.
2024-07-01 | GSE179313 | GEO
Project description:Aberrant DNA methylation is frequently observed in colorectal cancer (CRC), but the underlying mechanisms and pathological consequences are poorly understood. Ten-Eleven Translocation (TET) dioxygenases and Thymine DNA Glycosylase (TDG) are involved in active DNA demethylation by generating and removing novel oxidized cytosine species. TET1 and TDG mutations, and alterations of the levels of oxidized cytosines have been identified in human CRC. To clarify the biological significance of the TET-TDG demethylation axis in intestinal tumorigenesis, we generated ApcMin mice that are devoid of Tet1 and/or Tdg, and characterized the methylome and transcriptome of intestinal adenomas by DREAM and RNA sequencing, respectively. Tet1-deficient and Tet1/Tdg-double heterozygous ApcMin adenomas manifested increased adenoma size and features of erosion or invasion, whereas an increased number (>30) of adenomas was found in Tdg-mutant ApcMin mice. Methylome analysis revealed progressive loss of global DNA hypomethylation in colonic adenomas from Tet1- and Tdg-deficient ApcMin mice, and hypermethylation of CpG islands in Tet1-deficient ApcMin mice. In addition, RNA sequencing showed upregulation of genes in inflammatory, immune and interferon response in Tet1- and Tdg-mutant colonic adenomas compared to control ApcMin adenomas. The corresponding 135-gene inflammatory signature separated human colonic adenocarcinomas into four groups, closely aligned with their microsatellite or chromosomal instability profile, and characterized by different levels of DNA methylation and DNMT1 expression levels that anti-correlated with TET1 expression levels. These findings demonstrate a novel mechanism of epigenetic regulation during intestinal tumorigenesis by which TET1-TDG-mediated active DNA demethylation decreases not only methylation levels, but also inflammatory/interferon/immune response, which impinges on the intrinsic features of genomic instability of the tumors. This study establishes a novel link, via inflammatory response, between epigenomic and genomic instability.
2023-10-01 | GSE179526 | GEO
Project description:RNA-Seq of adenomas from Apc-Min mice with additional Tet1 and Tdg mutations
| PRJNA744146 | ENA
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
2014-10-31 | E-GEOD-59283 | biostudies-arrayexpress
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.
2014-10-31 | GSE59283 | GEO
Project description:Emerging data suggest that some high-risk subjects benefit more than others from preventive intervention. The goal of this study was to determine the efficacy of sulindac (Sul) and/or atorvastatin (Atorva) against spontaneous colorectal adenomas in Apc+/Min-FCCC mice in which the tumor-bearing status was known at the time of treatment initiation. Administration of Sul/Atorva to tumor-bearing mice led to a 43% reduction in the multiplicity of colorectal adenomas as compared to that of untreated tumor-bearing mice. Atorvastatin completely inhibited the formation of microadenomas in mice that were tumor-free at baseline, with associated decreases in the expression of inflammatory mediators observed. Expression of Hoxb13 and Rprm was enhanced significantly following Sul/Atorva treatment, suggesting the importance of cell cycle regulation in colon tumor inhibition. The tumor status of animals at treatment initiation dictates response to atorvastatin, sulindac and Sul/Atorva. The tumor inhibition observed with Sul/Atorva in tumor-bearing mice was greater than that achieved with either agent alone.
2018-08-31 | GSE81375 | GEO
Project description:We sought to identify gene transcripts altered in level between the normal epithelium and adenomas in colon of the Apc-Min/+ mouse. These differences in level can be compared to those observed for the colons of the Apc-Pirc/+ rat and the human.
2017-11-21 | GSE107139 | GEO
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).
2007-11-06 | E-GEOD-422 | biostudies-arrayexpress
Project description:Small intestinal adenomas in mice with Apc deficiency following tamoxifen-induced genetic recombination.
2021-02-19 | GSE167008 | GEO
Project description:Because it excises thymine from GM-bM-^@M-"T mismatches, TDG was proposed to counter mutagenesis by 5-methylcytosine deamination. Yet, TDG was also observed to attack 5-methycytosine itself, making it a candidate DNA demethylase, and interactions with transcription factors implicated additional functions in gene regulation. Unlike other DNA glycosylases, TDG is essential for embryonic development. Fibroblasts from Tdg null embryos show massively impaired gene regulation, and this correlates with imbalanced histone modification and CpG methylation. TDG associates with the promoters of affected genes in MEFs and in embryonic stem cells, but epigenetic aberrations appear only in differentiated cells. TDG also contributes to the maintenance of active and bivalent chromatin during cell differentiation, using its DNA glycosylase activity to counter aberrant de novo methylation. Thus, TDG dependent DNA repair stabilizes epigenetic states during cell differentiation. Comparison of 3 Tdg+/- MEF replicates with 3 Tdg-/- MEF replicates. Comparison of Tdg+/- and Tdg-/- ES cells and respective in vitro differentiated neuronal progenitors. Each condition is represented by 3 replicas.
2011-01-31 | E-GEOD-20693 | biostudies-arrayexpress