Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients with ulcerative colitis (UC) exhibit an increased risk for the development of cancer of the colon and rectum. This association is widely attributed to colonic inflammation. However, the severity of colonic inflammation necessary for the development of dysplasia and/or cancer remains unknown. In this study, we investigated the pattern of cell proliferation in colorectal carcinogenesis in an experimental murine model of UC. Chronic colitis was induced by administration of four cycles of dextran sulfate sodium (DSS) (each cycle: 5% or 2% DSS for 7 days and then distilled water for 14 days). Mice were sacrificed after every cycle and at 120 days following the completion of the fourth cycle. Colonic cell proliferation was immunohistochemically evaluated using the thymidine analogue bromodeoxyuridine and the labeling index (LI) was determined. The incidence of dysplasia and/or cancer was 28%, 6.7%, and 0% in the 5% DSS, 2% DSS, and normal control groups respectively. All gross lesions were present in the middle to distal colon. Disease activity index and total LI after four cycles of DSS were significantly higher in the 5% DSS group compared to the 2% DSS group. In the 5% DSS group, the LI was significantly higher in the middle colon than in the proximal colon. Simple repeated administration of the non-genotoxic colon carcinogen DSS induced dysplasia and/or cancer. In addition, we have demonstrated the presence of regional differences in proliferation pattern between the middle and the proximal colon during carcinogenesis in experimental murine UC. These findings may provide insight into the development of colorectal cancer in humans with long-standing UC.
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PMID:Increased proliferation of middle to distal colonic cells during colorectal carcinogenesis in experimental murine ulcerative colitis. 1798 30

Cyclooxygenase-2 (COX-2) is known to suppress sporadic colorectal cancer, but effect of selective COX-2 inhibitor in UC-associated neoplasia is still unknown. This study investigated effect of a selective COX-2 inhibitor on colorectal carcinogenesis in experimental murine UC. Chronic colitis was induced in mice by four cycles of administration of dextran sulfate sodium (DSS) (i. e., 5 % DSS for 7 days and distilled water for the following 14 days), and the mice were sacrificed 120 days after the end of the fourth cycle. The mice were divided into the following five groups: Group A, served as a disease control; Group B, received a diet mixed with 400 ppm of nimesulide (NIM), a selective COX-2 inhibitor, during the whole period; Group C, received NIM during the four cycles of DSS administration; Group D, received NIM for 120 days from the end of the fourth cycle; Group E, served as a normal control. In Group D, NIM significantly suppressed the occurrence of dysplasia and/or cancer. The results show that NIM inhibited both dysplasia and cancer in DSS-treated mice, thus showing that NIM has preventive effects on the remission phase of carcinogenesis.
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PMID:Effects of nimesulide, a cyclooxygenase-2 selective inhibitor, on colitis induced tumors. 1825 3