Studies on apoptosis in bone tumor cells induced by ~(153)Sm

The apoptosis in human bone tumor cells induced by internal irradiation with 153Sm was studied. The morphological changes in bone tumor cells were observed by electronic and fluorescent microscopy, as well as DNA agarose gel eletrophoresis. DNA chain fragmentation, microautoradiographic tracing and the inhibition rate of prolif- eration in bone tumor cells exposed to 153Sm with different duration time were examined. It was demonstrated that the bone tumor cells exposed to 153Sm displayed nuclear fragmentation, pyknosis, margination of condensed chroma- tin, and formation of membrane bounded apoptotic bodies, whereas the percentage of DNA chain fragmentation of bone tumor cells increases in direct proportion to the duration of irradiation with153 Sm, as well as DNA ladder for- mation in apoptotic cells. Also a marked inhibition effect of proliferation in bone tumor cells after exposure with 153Sm was observed.