[Apoptosis: bcl-2 as a key protein for programmed cell death]

The realization that malignant tumors may grow not only due to proliferation but also because cells don't die when they should provides absolute new directions in basic and clinical tumor research. Thus, apoptosis, the programmed cell death is very hot now in the scientific community. In the center of interest are the regulation mechanisms of apoptosis and its significance in different tumor entities. Recently, numerous studies on apoptosis during embryogenesis, different stages of tissue development and in epithelial and hormone dependent tumors have been published. The data suggested an important role of bcl-2 in regulation of apoptosis. In this view the demonstration of bcl-2 oncogene expression in osteosarcoma, a mesenchymal tumor, is of potential great interest.