Changes of survivin mRNA and protein expression during paclitaxel treatment in breast cancer cells

In order to investigate the role of antiapoptosis gene, survivin in the resistance to palcitaxel, the expression of survivin mRNA and protein in the process of paclitaxel treatment in breast cancer cell line MCF-7 was detected MCF-7 cells were incubated with paclitaxel at different concentrations. The growth inhibition rate of MCF-7 was investigated by tetrazolium bromide (MTT) colorimetry. The change of apoptosis was detected by Annexin-V/PI methods. The changes in the expression of survivin mRNA and protein were studied by reverse transcription polymerase chain reaction (RT-PCR) and Western-blot assay respectively. The growth inhibition rate of MCF-7 was increased in a concentration-and time-dependent manner. Paclitaxel of higher concentration could effectively induce apoptosis in MCF-7 cells after 48 h, while the expression of survivin was increased at early time (within 6 h) and decreased after 24 h regardless of treatment concentrations of paclitaxel. It suggested that tumor cells might evade the paclitaxel-induced cell cycle arrest and apoptosis by increasing the level of survivin at early treatment time.