Staurosporine induces apoptosis in NG108-15 cells.

AIM: To observe if staurosporine induced apoptosis in NG108-15 cells and its effect on protein expression level of several genes related to apoptosis. METHODS: Phase-contrast microscopy, fluorescence microscopy, and transmission electron microscopy were used to observe staurosporine-induced morphological changes. Agarose gel electrophoresis was used to detect DNA fragmentation. Western blots were used to measure protein expression level of several genes related to apoptosis. RESULTS: Cells treated with staurosporine 0.1 micromol/L showed typical morphological changes of apoptosis. A "ladder" pattern representing fragmentation of DNA into oligonucleosome length fragments was observed after 6 h of staurosporine treatment and sustained until 24 h. The Bax expression increased significantly at 6 h after exposure to staurosporine, peaked at 12 h compared with vehicle cultures, and decreased at 24 h. The Bcl-2 expression increased and reached the highest level at 3 h. It was then decreased gradually but still higher than normal expression level. There was an obvious caspase-3 cleavage at 6 h after exposing the cells to staurosporine. Treatment with staurosporine for 12 h markedly decreased the expression of p53 protein. Cdk5 protein expression did not have obvious changes after the cells were exposed to staurosporine. CONCLUSION: Staurosporine induced apoptotic death in NG108-15 cells. Cells might die via a pathway that is dependent on Bax expression but independent of p53, and caspase-3 cleavage was involved.