Localization of apoptotic cells in situ of brain tumors.

The apoptotic cells in situ of normal tissues and human brain tumors were analyzed by the modified method of TUNEL, and the relationship between the localization of apoptotic cells and the expression of bcl-2 protein was examined. The localization of apoptotic cells in normal tissue was situated at fast renewing tissues, and differed from the localization of the expression of bcl-2 protein. In the cases of medulloblastoma, 7 out of 8 cases (87.5%) showed apoptotic cells. In contrast to the results of high frequency of apoptotic cells in medulloblastoma and germinoma, the expression of bcl-2 protein was found very low incidence in those tumors, which were thought to be sensitive against radiation or chemotherapy. These results suggested that the detection of apoptosis in situ by this method could predict the sensitivity of radiation or chemotherapy of the tumor cells.