Biomarker-based prediction of inflammatory bowel disease-related colorectal cancer: a case–control study

Regular colonoscopic surveillance for detection of dysplasia is recommended in longstanding inflammatory bowel disease (IBD), however, its sensitivity is disputed. Screening accuracy may increase by using a biomarker-based surveillance strategy.A case-control study was performed to determine the prognostic value of DNA ploidy and p53 in IBD-related neoplasia. Cases with IBD-related colorectal cancer (CRC), detected in our surveillance program between 1985-2008, were selected and matched with two controls, for age, gender, disease characteristics, interval of follow-up, PSC, and previous surgery. Biopsies were assessed for DNA ploidy, p53, grade of inflammation and neoplasia. Progression to neoplasia was analyzed with Cox regression analysis, adjusting for potentially confounding variables.Adjusting for age, we found statistically significant Hazard ratios (HR) between development of CRC, and low grade dysplasia (HR5.5; 95%CI 2.6-11.5), abnormal DNA ploidy (DNA index (DI) 1.06-1.34, HR4.7; 95%CI 2.9-7.8 and DI>1.34, HR6.6; 95%CI 3.7-11.7) and p53 immunopositivity (HR3.0; 95%CI 1.9-4.7) over time. When adjusting for all confounders, abnormal DNA ploidy (DI 1.06-1.34, HR4.7; 95%CI 2.7-7.9 and DI>1.34, HR5.0; 95%CI 2.5-10.0) and p53 immunopositivity (HR1.7; 95%CI 1.0-3.1) remained statistically significant predictive of neoplasia. In longstanding IBD, abnormal DNA ploidy and p53 immunopositivity are important risk factors of developing CRC. The yield of surveillance may potentially increase by adding these biomarkers to the routine assessment of biopsies

Characterization of Chromosomal Instability in Murine Colitis-Associated Colorectal Cancer

Patients suffering from ulcerative colitis (UC) bear an increased risk for colorectal cancer. Due to the sparsity of colitis-associated cancer (CAC) and the long duration between UC initiation and overt carcinoma, elucidating mechanisms of inflammation-associated carcinogenesis in the gut is particularly challenging. Adequate murine models are thus highly desirable. For human CACs a high frequency of chromosomal instability (CIN) reflected by aneuploidy could be shown, exceeding that of sporadic carcinomas. The aim of this study was to analyze mouse models of CAC with regard to CIN. Additionally, protein expression of p53, beta-catenin and Ki67 was measured to further characterize murine tumor development in comparison to UC-associated carcinogenesis in men.The AOM/DSS model (n = 23) and IL-10(-/-) mice (n = 8) were applied to monitor malignancy development via endoscopy and to analyze premalignant and malignant stages of CACs. CIN was assessed using DNA-image cytometry. Protein expression of p53, beta-catenin and Ki67 was evaluated by immunohistochemistry. The degree of inflammation was analyzed by histology and paralleled to local interferon-γ release.CIN was detected in 81.25% of all murine CACs induced by AOM/DSS, while all carcinomas that arose in IL-10(-/-) mice were chromosomally stable. Beta-catenin expression was strongly membranous in IL-10(-/-) mice, while 87.50% of AOM/DSS-induced tumors showed cytoplasmatic and/or nuclear translocation of beta-catenin. p53 expression was high in both models and Ki67 staining revealed higher proliferation of IL-10(-/-)-induced CACs.AOM/DSS-colitis, but not IL-10(-/-) mice, could provide a powerful murine model to mechanistically investigate CIN in colitis-associated carcinogenesis

Multiple Polymorphisms Affect Expression and Function of the Neuropeptide S Receptor (NPSR1)

Peer reviewe