APOPTOSIS IN GASTRIC CARCINOMAS AND ITS ASSOCIATION WITH CELL-PROLIFERATION AND DIFFERENTIATION

The significance of apoptosis in human gastric carcinomas was investig ated in comparison with proliferative activity and p53 accumulation, u sing an in situ DNA nick end labeling method and immunohistochemistry for both Ki-67 antigen and p53 protein. Apoptotic labeling indices (LI ) of 51 differentiated carcinomas (21 of early and 22 of advanced stag e) were significantly lower than for 33 undifferentiated tumors (9 of early and 24 of advanced stage) (P < 0.05). In both types, apoptotic L I of advanced stage lesions were significantly higher than for the ear ly stage cases (P < 0.005, P < 0.03). The distribution of apoptotic ce lls was different from that of Ki-67-positive cells, generally exhibit ing an inverse correlation for areas of predominance. In contrast, the re was no significant correlation between p53 immunoreactivity and eit her apoptotic LI or Ki-67 LI. It is concluded that in human gastric ca rcinomas the susceptibility to apoptosis is related to tumor cell diff erentiation and depth of invasion, and may play a role in selection of clonal subpopulations with high growth potential.