Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Gene expression profiling of colitis-associated and sporadic colorectal tumors in mice

ABSTRACT: To uncover molecular mechanisms specifically involved in the pathogenesis of colitis-associated colon cancer (CAC), we studied tumorigenesis in experimental models of CAC and sporadic CRC that mimic characteristics of human CRC. Using comparative whole genome expression profiling, we observed differential expression of epiregulin (Ereg) in mouse models of colitis-associated, but not sporadic colorectal cancer. Similarly, highly significant upregulation of Ereg expression was found in cohorts of patients with colitis-associated cancer in inflammatory bowel disease but not in sporadic colorectal cancer. Furthermore, tumor-associated fibroblasts were identified as major source of Ereg in colitis-associated neoplasias. Functional studies showed that Ereg-deficient mice, although more prone to colitis, are strongly protected from colitis-associated tumors, and data from serial endoscopic studies revealed that Ereg promotes growth rather than initiation of tumors. 4 samples of individual distal colitis-associated tumors (CAC) from 4 mice, 2 samples of tumor-free distal colon epithelium with a pool of 5 mice per sample (CAC contr), 5 samples of individual Apcmin/+ tumors from the distal colorectum of 5 mice (sporCRC) and 3 samples of tumor-free distal colon epithelium (pool of 4 mice per sample) (sporCRC contr). Colitis-associated tumorigenesis was performed by intraperitoneal injection of Azoxymethane (10mg/kg) (Sigma) into C57BL/6J wildtype mice followed by 3 cycles of Dextran Sodium Sulfate (DSS) in drinking water. Each DSS-cycle was composed of DSS (2.5% (w/v) (MP Biomedicals) in drinking water for 7 days, followed by a recovery phase with regular drinking water for 14 days. Sporadic tumors were from C57BL/6J-ApcMin/+/J mice. All tumors were obtained from the from the lower 6th of the large intestine and they had the same size covering between Â¼ and up to Â½ of the colonic circumferenc as evaluated by mini-endoscopy.

ORGANISM(S): Mus musculus

SUBMITTER: Clemens Neufert

PROVIDER: E-GEOD-43338 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:MUC1 is a tumor-associated antigen that is aberrantly expressed in cancer and inflammatory bowel disease (IBD). Even though immune cells express low MUC1 levels, their modulations of MUC1 are important in tumor progression. Consistent with previous clinical data that show increased myeloid-derived suppressor cells (MDSCs) in IBD, we now show that down-regulation of MUC1 on hematopoietic cells increases MDSCs in IBD, similar to our data in tumor-bearing mice. We hypothesize that MDSC expansion in IBD is critical for tumor progression. In order to mechanistically confirm the linkage between Muc1 down-regulation and MDSC expansion, we generated chimeric mice that did not express Muc1 in the hematopoietic compartment (KOM-bM-^FM-^RWT). These mice were used in 2 models of colitis and colitis-associated cancer (CAC) and their responses were compared to wildtype chimeras (WTM-bM-^FM-^RWT). KOM-bM-^FM-^RWT mice show increased levels of MDSCs during colitis that was responsible for the larger colon tumors that eventually developed in these mice. Using microarray and qRT-PCR analysis, we observed increased pro-tumorigenic signaling in the colons of KOM-bM-^FM-^RWT mice during colitis as compared to WTM-bM-^FM-^RWT mice. Our RNA (microarray and qRT-PCR analysis) and protein analysis demonstrate increased up-regulation of metalloproteinases, collagenases, defensins, complements, growth factors, cytokines and chemokines in KOM-bM-^FM-^RWT mice as compared to WTM-bM-^FM-^RWT mice. Antibody-mediated depletion of MDSCs in mice during colitis reduced colon tumor formation during CAC. Development of CAC is a serious complication of colitis and our data highlight MDSCs as a targetable link between inflammation and cancer. A total of 12 samples were analysed. RNA was made from the mucosa of the colon of WTM-bM-^FM-^RWT and KOM-bM-^FM-^RWT mice that were either untreated or treated with azoxymethane (AOM) and dextran sodium sulfate (DSS). There are 4 groups, n=3 for each group: untreated WTM-bM-^FM-^RWT mice, untreated KOM-bM-^FM-^RWT mice, AOM+DSS treated WTM-bM-^FM-^RWT mice, AOM+DSS treated KOM-bM-^FM-^RWT mice = 12 samples in total.

Project description:Background: MicroRNAs (miRNAs) acting as negative regulators of gene expression are differentially expressed in intestinal tissues of patients with inflammatory bowel disease (IBD). Assessing the functional role of miRNAs in murine models of colitis facilitates elucidating the role of specific miRNAs in human IBD. The aim of this study was to determine the miRNA signature of murine models of colitis and to assess the influence of miR-21 on intestinal inflammation. Methods: miRNAs expression was accessed by microarray for acute and chronic murine model of colitis induced by DSS or TNBS. miR-21-deficient mouse and littermates controls were assessed in the standard DSS, TNBS and CD4+ T cell transfer models of colitis. RNAs of mouse colon and CD4+CD45RBHigh cells were analyzed by miRNA and mRNA microarray, and quantitative RT-PCR. Th1 polarization was accessed by flow-cytometry and ELISA. Results: Alterations of in miRNAs expression were identified for acute and chronic DSS colitis and TNBS colitis, receptively. The Expression of miRs-21, -142-3p and -223 was were distinct between DSS and TNBS models while overlap of numerous miRNAs was seen. Importantly, miRs-19b, -192 and -215, that are decreased in IBD, were significantly decreased in all 4 models of colitis. miR-21, which is increased in IBD, was increased in TNBS colitis but not the DSS colitis models. Further assessment of the miR-21-deficient 1-/- mice revealed that the deletion of miR-21 results in the exacerbation of both the TNBS and T cell-transfer models of colitis. Conclusions: miRNAs are differentially expressed in both human IBD and murine colitis, with overlap of several IBD-associated miRNAs. The demonstration that miR-21 deletion exacerbated CD4+ T cell-mediated models of colitis provides further evidence that miRNAs play significant roles in the pathogenesis of IBD. miRNAs expression was accesed for acute and chronic murine model of colitis induced by DSS or TNBS.Total of 20 samples with duplicates were analyed in this study.

Dataset Information

Gene expression profiling of colitis-associated and sporadic colorectal tumors in mice

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets