Apoptosis in human embryonal cell carcinoma: preliminary results

Disorders in the regulation of apoptotic cell death may contribute to cance r. Furthermore, lymphocytes are supposed to play a role in counteracting tu morigenesis by inducing apoptosis in different human tumors. In this study, for the first time, tumor cell and lymphocyte apoptosis were investigated systematically in human embryonal cell carcinoma. DNA fragmentation and DNA condensation were measured simultaneously on double-fluorescence-labeled t estis tumor sections using immunofluorescence microscopy. Different apoptot ic indices (AIs), based either on biochemical (DNA fragmentation) or morpho logical criteria (DNA condensation) alone or on a combination of both, were determined in different histological regions in and around the tumor. Usin g morphological criteria alone, 40-75% of all apoptotic cells were not dete cted. Based on previous observations this finding might be related to subse ts of apoptotic cells which induce the process of DNA condensation without activation of processes responsible for DNA fragmentation. Moreover, the AI s of tumor cells and lymphocytes were highest in the tumor region, compared with regions around the tumor and distant from it; these findings are disc ussed in the context of the Fas/FasL system.