Expression of p16 and Rb in 9,10-Dimethyl-1,2-Benzanthracene Induced Rat Ovarian Carcinogenesis

ABSTRACT

BACKGROUND: In order to investigate the roles of p16 and Rb, their expression was evaluated in 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced ovarian cancers of rats. METHODS: DMBA-coated silk was inserted into both ovaries of 20 9-week-old Sprague-Dawley rats. The experimental period lasted 20 weeks. The tumor histology was classified and the expression of p16 and Rb in the ovarian tumors was analyzed by immunohistochemistry and Western blot. RESULTS: The p16 and Rb labeling index was significantly lower in the ovarian cancers than the normal ovarian surface epithelium of a rat. There were no differences among the cancer types. In Western blot analysis, the expressions of p16 and Rb in ovarian cancers were lower than those in normal ovarian tissue. No correlation was present between p16 and Rb. CONCLUSION: The abnormal expression of p16 and Rb occurs in DMBA-induced rat ovarian cancer and might be involved in carcinogenesis.