| First Author | Nakanishi M | Year | 2007 |
| Journal | Cancer Sci | Volume | 98 |
| Issue | 8 | Pages | 1157-63 |
| PubMed ID | 17573895 | Mgi Jnum | J:138489 |
| Mgi Id | MGI:3805238 | Doi | 10.1111/j.1349-7006.2007.00528.x |
| Citation | Nakanishi M, et al. (2007) Mouse strain differences in inflammatory responses of colonic mucosa induced by dextran sulfate sodium cause differential susceptibility to PhIP-induced large bowel carcinogenesis. Cancer Sci 98(8):1157-63 |
| abstractText | In mice, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces a high incidence of malignant lymphoma and leukemia, but exhibits little, if any, carcinogenic activity in the large intestine after long-term exposure. However, recent studies have revealed that colonic adenocarcinomas can be efficiently and rapidly induced by combined treatment with PhIP and dextran sulfate sodium (DSS), a potent inducer of colitis. In the present study, the authors investigated the effects of inflammation on PhIP-induced carcinogenesis using two mouse strains, C57BL/6J and MSM/Ms, showing distinct temporal profiles of inflammatory responses to DSS. A long-term carcinogenesis experiment conducted with a single i.g. administration of PhIP (200 mg/kg body weight), followed by DSS treatment in drinking water for 4-6 days, revealed an increase in tumor incidence in C57BL/6J mice in accordance with the DSS intake. In contrast, neoplastic lesions were rarely observed in the MSM/Ms strain. From the short-term exposure to DSS for 4 days, C57BL/6J mice demonstrated severe chronic colitis, accompanied by hyperplastic cryptal epithelium and extensive cellular infiltration. Splenomegaly and swelling of mesenteric lymph nodes were also evident for over 1 month as chronic symptoms of systemic immunological disturbance. However, no inflammatory lesions were detected in MSM/Ms mice. The present results provide strong evidence that prolonged chronic inflammatory responses induced by DSS are directly responsible for the observed enhancement of PhIP-induced large bowel carcinogenicity. |
