Effect of staurosporine induced apoptosis of MCF7/GFP-Bax stable cell line on Bax translocation from cytosol into mitochondria

To investigate Bax translocation from cytosol into mitochondria induced by staurosporine (STS) in GFP-Bax-tagged MCF7 stable cell line, the viability was measured by MTT method. Bax translocation from cytosol into mitochondria was investigated under the fluorescence microscope. The dose-effect and time-course relationships were also observed and the percentage of GFP-Bax punctuate cells were calculated. Immunofluoresence method was used to observe Bax translocation to mitochondria, Cyt-c release from mitochondria and Annexin V label. The TMRE assay was used to investigate membrane pertential (ΔΨm) and function of mitochondria. Western blotting was used to observe the mechanism of apoptosis induced by STS. The results showed that STS can induce Bax translocation from cytoplasm to mitochondria, Cyt-c release from mitochondria and Annexin V label. The Western blotting analysis presented the inhibitory effect on apoptosis induced by STS of SP600125 which is a specific JNK inhibitor. The study revealed the mechanism of STS induced apoptosis associated with JNK activated pathway.