A Study on Expression Pattern of p53, Rb Gene and Apoptosis in Ovarian Epithelial Borderline Tumors and Invasive Carcinoma

Ha, Myeong Wan; Ko, Hyeong Kweon; Kang, Gi Joo; Yoon, Man Soo; Sol, Mee Young

Abstract

OBJECTIVE
The aim of this study is to evaluate the role of tumor suppressor genes, p53 and Rb gene, as well as apoptosis in the carcinogenesis of ovarian epithelial tumors. And the value of these factors as prognostic markers to tell the transformation of borderline tumors to overt carcinomas is also studied. METHOD: Thirty cases of ovarian epithelial benign and borderline tumors and invasive carcinoma were used and the expression of the p53 protein and Rb gene protein were evaluated by immunohistochemical method. The apoptosis was evaluated by TUNNEL method.
RESULTS
Positive rate of p53 expression in benign, borderline and invasive tumors were 0, 28, and 94 %, respectively. And also, p53 was highly expressed in chemoresistant cases (2/3), in residual tumor (4/5) and in recurred cancer (2/2). Rb protein was partly lost in the borderline tumors, but the rate of Rb protein loss in both borderline tumors and invasive carcinomas were similar. Apoptosis were more active in overt carcinomas than in borderline and benign tumors. In borderline tumors, p53 protein was expressed as 28.6% positivity, and apoptosis was expressed as 28.6% negativity, which showed indirectly that there was apoptosis induction effect of p53. In ten cases of invasive carcinomas showing highly expressed p53, apoptosis revealed all positive reaction except 2 cases, and Rb protein revealed variously. This result supported the apoptosis imduction effect of p53, but it was difficult to find the association of expression degree between the two tumor supressor genes
CONCLUSION
In conclusion, the values of p53 is a discriminating factor of malignancy from benign and the expression of p53 is related with clinical aggressivity such as recurrence and residual cancers. Apoptosis are more active in overt carcinoma than in benign & borderline tumor, and in borderline tumor the expression of p53 is related to apoptosis induction which results to carcinomatous change.