Project description:This study uses whole-genome bisulfite sequencing to characterize the methylomes of the AOM/DSS mouse model at single-base resolution. In this model, mice are treated with dextran sodium sulfate (DSS) to induce colitis. When this treatment is preceded by injections of the weak carcinogen azoxymethane (AOM) the mice develop intestinal tumors. Our results identify hypermethylated DMVs as a prominent feature of the colitis methylome that is conserved in intestinal adenocarcinomas. Further analyses reveal a subset of DMV-associated genes, expressed in normal intestinal epithelial cells, that were silenced and hypermethylated in inflamed and cancerous intestinal cells. Together, these findings provide strong support for the hypothesis that inflammatory signals induce a higher risk for cancer development by manipulating the epigenome. .
Project description:This study uses whole-genome bisulfite sequencing to characterize the methylomes of the AOM/DSS mouse model at single-base resolution. In this model, mice are treated with dextran sodium sulfate (DSS) to induce colitis. When this treatment is preceded by injections of the weak carcinogen azoxymethane (AOM) the mice develop intestinal tumors. Our results identify hypermethylated DMVs as a prominent feature of the colitis methylome that is conserved in intestinal adenocarcinomas. Further analyses reveal a subset of DMV-associated genes, expressed in normal intestinal epithelial cells, that were silenced and hypermethylated in inflamed and cancerous intestinal cells. Together, these findings provide strong support for the hypothesis that inflammatory signals induce a higher risk for cancer development by manipulating the epigenome. . Whole genome methylation analysis of M. musculus. Three conditions were sequenced analyzed, the first is an untreated control, the second corresponds to inflammation, the third to cancer induced by inflammation. All three conditions were analyzed using three replicates.
Project description:This study uses whole-transcriptome sequencing to characterize the transcriptomes of the AOM/DSS mouse model. In this model, mice are treated with dextran sodium sulfate (DSS) to induce colitis. When this treatment is preceded by injections of the weak carcinogen azoxymethane (AOM) the mice develop intestinal tumors. Our results identify sets of differentially expressed genes which are correlated with methylation changes of the corresponding genes. Whole transcriptome analysis of Mus musculus. Three conditions were sequenced and analyzed, the first is an untreated control, the second corresponds to inflammation induced by applying DSS, the third to cancer induced by inflammation and application of AOM. The control condition as well as the AOM-induced cancer condition were analyzed using three replicates, the second condition using 4 replicates.
Project description:This study uses whole-transcriptome sequencing to characterize the transcriptomes of the AOM/DSS mouse model. In this model, mice are treated with dextran sodium sulfate (DSS) to induce colitis. When this treatment is preceded by injections of the weak carcinogen azoxymethane (AOM) the mice develop intestinal tumors. Our results identify sets of differentially expressed genes which are correlated with methylation changes of the corresponding genes.
Project description:Several Butyrophilin (BTN) and Btn-like (BTNL) molecules control T lymphocyte responses, and are genetically associated with inflammatory disorders and cancer. In this study, we present a comprehensive expression analysis of human and murine BTN and BTNL genes in conditions associated with intestinal inflammation and cancer. Using real-time PCR, expression of human BTN and BTNL genes was analyzed in samples from patients with ulcerative colitis, irritable bowel syndrome, and colon tumors. Expression of murine Btn and Btnl genes was examined in mouse models of spontaneous colitis (Muc2-/-) and intestinal tumorigenesis (ApcMin/+). Our analysis indicates a strong association of several of the human genes with ulcerative colitis and colon cancer; while especially BTN1A1, BTN2A2, BTN3A3, and BTNL8 were significantly altered in inflammation, colonic tumors exhibited significantly decreased levels of BTNL2, BTNL3, BTNL8, and BTNL9 as compared to unaffected tissue. Colonic inflammation in Muc2-/- mice significantly down-regulated the expression of particularly Btnl1, Btnl4, and Btnl6 mRNA, and intestinal polyps derived from ApcMin/+ mice displayed altered levels of Btn1a1, Btn2a2, and Btnl1 transcripts. Thus, our data present an association of BTN and BTNL genes with intestinal inflammation and cancer and represent a valuable resource for further studies of this gene family.
Project description:Free fatty acid receptor 2 (FFAR2, also named GPR43), is activated by short-chain fatty acids (SCFAs), such as butyrate, that are produced when gut bacteria ferment dietary fiber. FFAR2 has been suggested to regulate colonic inflammation, which is a major risk factor for the development of colon cancer and is also linked to epigenetic dysregulation in colon carcinogenesis. The current study assessed whether FFAR2, acting as an epigenetic regulator, protects against colon carcinogenesis. To mimic the mild inflammation that promotes human colon cancer, we treated mice with dextran sodium sulfate (DSS) overnight, which avoids excessive inflammation but induces mild inflammation that promotes colon carcinogenesis in the ApcMin/+ and the azoxymethane (AOM)-treated mice. Our results showed that FFAR2 deficiency promotes the development of colon adenoma in the ApcMin/+ /DSS mice and the progression of adenoma to adenocarcinoma in the AOM/DSS mice. FFAR2's downstream cAMP-PKA-CREB pathway was enhanced, leading to overexpression of histone deacetylases (HDACs) in the FFAR2-deficient mice. ChIP-qPCR analysis revealed differential binding of H3K27me3 and H3K4me3 histone marks onto the promoter regions of inflammation suppressors (e.g., sfrp1, dkk3, socs1), resulting in decreased expression of these genes in the FFAR2-deficient mice. Also, more neutrophils infiltrated into tumors and colon lamina propria of the FFAR2-deficient mice. Depletion of neutrophils blocked the progression of colon tumors. In addition, FFAR2 is required for butyrate to suppress HDAC expression and hypermethylation of inflammation suppressors. Therefore, our results suggest that FFAR2 is an epigenetic tumor suppressor that acts at multiple stages of colon carcinogenesis.
Project description:We have compared DNA methylation in normal colon mucosa between patients with colon cancer and patients without cancer. We identified significant differences in methylation between the two groups at 114 to 874 genes. The majority of the differences are in pathways involved in the metabolism of carbohydrates, lipids, and amino acids. We also compared transcript levels of genes in the insulin signaling pathway. We found that the mucosa of patients with cancer had significantly higher transcript levels of several hormones regulating glucose metabolism and significantly lower transcript levels of a glycolytic enzyme and a key regulator of glucose and lipid homeostasis. These differences suggest that the normal colon mucosa of patients with cancer metabolizes dietary components differently than the colon mucosa of controls. Because the differences identified are present in morphologically normal tissue, they may be diagnostic of colon cancer and/or prognostic of colon cancer susceptibility.
Project description:ObjectiveThe colonic microbiota is altered in patients with colorectal cancer (CRC). We investigated the microbiota composition of patients with colon cancer compared with controls devoid of neoplastic or inflammatory disease and the potential to modify the colonic microbiota with probiotics.DesignBiopsy samples were obtained from the normal mucosa and tumour during colonoscopy from 15 patients with colon cancer. Subsequent patient-matched samples were taken at surgery from the tumour and nearby mucosa from the patients with cancer, eight of whom had received two daily tablets totalling 1.4×1010 CFUs Bifidobacterium lactis Bl-04 and 7×109 CFUs Lactobacillus acidophilus NCFM. Faecal samples were obtained after colonoscopy prior to starting the intervention and at surgery. In addition, 21 mucosal biopsies from non-cancer controls were obtained during colonoscopy followed by later faecal samples. The colonic and faecal microbiota was assessed by 16S rRNA gene amplicon sequencing.ResultsThe tumour microbiota was characterised by increased microbial diversity and enrichment of several taxa including Fusobacterium, Selenomonas and Peptostreptococcus compared with the control microbiota. Patients with colon cancer that received probiotics had an increased abundance of butyrate-producing bacteria, especially Faecalibacterium and Clostridiales spp in the tumour, non-tumour mucosa and faecal microbiota. CRC-associated genera such as Fusobacterium and Peptostreptococcus tended to be reduced in the faecal microbiota of patients that received probiotics.ConclusionsPatients with colon cancer harbour a distinct microbiota signature in the tumour tissue and nearby mucosa, which was altered with probiotic intervention. Our results show promise for potential therapeutic benefits in CRC by manipulation of the microbiota.Trial registration numberNCT03072641; Results.
Project description:Variants in the gene locus encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) are associated with inflammatory disorders, including inflammatory bowel diseases, rheumatoid arthritis, and type 1 diabetes. The anti-inflammatory role of PTPN2 is highlighted by the fact that PTPN2-deficient mice die a few weeks after birth because of systemic inflammation and severe colitis. However, the tissues, cells, and molecular mechanisms that contribute to this phenotype remain unclear. Here, we demonstrate that myeloid cell-specific deletion of PTPN2 in mice (PTPN2-LysMCre) promotes intestinal inflammation but protects from colitis-associated tumor formation in an IL-1β-dependent manner. Elevated levels of mature IL-1β production in PTPN2-LysMCre mice are a consequence of increased inflammasome assembly due to elevated phosphorylation of the inflammasome adaptor molecule ASC. Thus, we have identified a dual role for myeloid PTPN2 in directly regulating inflammasome activation and IL-1β production to suppress pro-inflammatory responses during colitis but promote intestinal tumor development.