Evaluation of apoptosis in human endometrial adenocarcinoma: comparison of nick end labeling and Le(y) antigen immunostaining method

In situ estimation of DNA fragmentation by the nick end labeling method and immunohistochemical detection of cell surface carbohydrate Le(y) were performed to establish correlation between the results of these two apoptosis-detecting techniques in human solid tumor tissues. Formalin-fixed and paraffin-embedded tissue samples from 10 cases of human endometrial adenocarcinoma were examined and compared by using the two techniques. A substantial fraction of carcinoma cells was found to be definitely stained by both methods, although Le(y) expression did not seem to be positively correlated with DNA fragmentation in the carcinoma tissue. These results suggest that Le(y) expression does not necessarily reflect apoptotic DNA fragmentation, at least in human endometrial adenocarcinomas, and simultaneous application of DNA nick end labeling and Le(y) immunostaining is necessary to show the relevant signs of apoptosis in histologic slides, especially gynecological cancers.