CircRNA/mRNA expression data for the different phases of colitis-associated colorectal cancer in a mouse model

The causal relationships between inflammation and cancer are now widely recognized and discussed. Epidemiological and experimental studies have shown that patients with inflammatory bowel disease (IBD) are major risk factors for developing CRC than the general population. Approximately 18.4% of patients with IBD are reported to develop into colitis associated cancer (CAC) within 30 years after the onset of disease . CAC has become the major cause of death in IBD patients. While these mechanisms by which chronic inflammation promotes colonic carcinogenesis are being investigated, many unanswered questions remain. Circular RNA (CircRNA) is a newly discovered type of non-coding RNAs, which is involved in the colorectal cancer (CRC) development by diverse mechanisms. In our current study, we employed the widely used Dextran Sodium Sulfate (DSS)-induced acute colitis and Azoxymethane (AOM)/DSS-induced CAC models to screen the circRNA and mRNA expression profiles in inflammation and inflammation-associated cancer by the high throughput sequencing. 30 six-week-old male BALB/c mice (18-20g in weight) were divided into 3 groups: the blank control (NC, n=5), colitis (DSS, n=5) and CAC group (AOM/DSS, n=5). Mice of the NC group drank water for 75 days. Colitis was induced by replacing drinking water with 3.0% DSS (MW: 35,000-50,000, MP Biomedicals, Solon, USA) for 7 days. For the mouse CAC model, mice were intraperitoneally injected with 12.5 mg/kg azoxymethane (AOM, Sigma, USA). After 5 days, 3.0% DSS was included in the drinking water for 7 days, followed by 14 days of regular water. This cycle was repeated by three times. Upon sacrifice, the colon was excised from the ileocecal junction to the anus, cut open longitudinally, and prepared for subsequent experiments. Total RNA was extracted from the mice colons using the TRIzol® reagent (Life Technologies, USA). Then the quantity and integrity of total RNAs were measured by the NanoDrop™ ND-2000 (Thermo Fisher Scientifc, Scotts Valley, CA, USA) and Agilent Bioanalyzer 2100 (Agilent Technologies, Santa Clara, CA, USA) respectively. CircRNAs/mRNAs were quantitatively analyzed by Shanghai OE Biotech (Shanghai, China).