EXTENT OF APOPTOSIS IN RELATION TO P53 AND BCL-2 EXPRESSION IN GERM-CELL TUMORS

This study investigates the extent of apoptosis in 53 testicular and o varian germ cell tumors by using the in situ 3'-end DNA labeling techn ique on tumor sections. The tumors were also immunostained with antibo dies to the p53 and bcl-2 proteins. The extent of apoptosis was highes t in embryonal carcinoma (mean, 2.9%) followed by seminoma (mean, 1.1% ), choriocarcinoma (mean, 0.7%) and immature teratoma (mean, 0.7%). In individual components of the mixed germ cell tumors the apoptotic ind ex was in the same range as in the corresponding pure germ cell tumors . Mature teratomas rarely contained any apoptotic cells. Sixty-two per cent of all the tumors expressed p53 protein. p53 expression was quant itatively strongest in embryonal carcinomas which also showed the high est level of apoptosis. Bcl-2 positivity could only be detected in som e mesenchymal and epithelial components of the immature and mature ter atomas; embryonal carcinomas, seminomas, or choriocarcinomas did not e xpress bcl-2 at all. Our results show that the level of apoptosis in g erm cell tumors associates with the histological type of the neoplasti c component independent of whether it is singly present or a component of a mixed germ cell tumor. The results suggest that the quantity of p53 expression may contribute to the level of apoptosis in different t umor groups. Copyright (C) 1996 by W.B. Saunders Company