ABSTRACT
Objective To investigate the apoptosis induction effects and the possible mechanism of YM155 on triple negative breast cancer MDA-MB-231cells.Methods MDA-MB-231 cells were treated with dif-ferent concentrations of YM 155, and the survival rate of the cells was determined by CCK-8 assay and the half maximal inhibitory concentration ( IC50 ) value of YM155 was calculated .The apoptosis rate was examined by An-nexin V-FITC/PI double staining.mRNA expression of survivin and bcl-2 in MDA-MB-231cells was detected by RT-PCR.The protein expression of survivin , bcl-2, caspase-3, and PARP were detected by Western blot .Re-sults YM155 significantly inhibited the growth of MDA-MB-231 cells in a dose-and-time-dependenct way .IC50 was(1.749 ±0.265) ng/ml and(0.823 ±0.125) ng/ml respectively at 24 and 48 hours.The apoptosis rate of cells treated with 0.5 ng/ml, 1.0 ng/ml, and 1.5 ng/ml YM155 was (10.93 ±0.94)%,(31.10 ±1.51)%, and(46.83 ±2.92)%respectively, which had significant difference compared to that of the control group (6.4 ± 1.2)%(P<0.01).YM155 could significantly decrease mRNA and protein expression of surviving , besides, it reduced bcl-2 expression and increased caspase-3 and PARP protein expression .Conclusions YM155 can ef-fectively induce the apoptosis of MDA-MB-231 cells by downregulating survivin and activating caspase pathway . Bcl-2 might play a role in the apoptosis .