The combination of VX-680 and ABT-737 efficiently promotes breast cancer cell line apoptosis

Objective To study the effect of VX-680 combined with ABT737 on apoptosis of breast cancer cell line T47D.Methods T47D cells were cultured in vitro,and cells in logarithmic growth phase were used for this experiment.Cell proliferation was measured by methyl thiazol tetrazolium (MTT)assay.The expression of apoptosis related protein was detected by using Western blotting.The variety of nucleus was tested by using immunofluorescence.Morphological change of apoptotic cells were observed under the fluorescent microscopy.The apoptosis rate was examined by flow cytometry.Results The MTT assay showed that as a single agent,50％ inhibitory concentration ( IC50 ) of VX-680 was ( 25.457±1.406) μmol/L.ABT-737 significantly decrease the IC50 of VX-680 to (0.277 ±0.057) μmol/L.ABT-737 didn't inhibit the proliferation of T47D cells with IC50 being (0.959 ±0.018) μmol/L,but enhanced the inhibitory effect of VX-680 in a does-dependent with IC50 being (0.268 ±0.072) μmol/L VX-680 induced multinuclear phenomenon tested by immunofluorescence.VX-680 combined with ABT737 induced apoptosis in a dose- and time-dependent manner tested by Western blotting.Compared with the single agent,combined use of VX-680 and ABT-737 accelerated the cleavage of poly (ADP-ribose) polymerase (PARP) and caspase3,decreased the expression levels of bcl-2 and bcl-xL,and promoted the expression level of bax.Flow cytometry revealed that the combination of VX-680 and ABT-737 significantly induced apoptosis and increased apoptosis rate to (46.40±0.41)％.Conclusion The ABT-737 can significantly enhance VX-680-induced apoptosis of T47D cells. Key words: Breast carcinoma; VX-680 ; ABT-737 ; Apoptosis