stathmin Silencing Increases Sensitivity of Esophageal Squamous Cell Carcinoma Cells to Paclitaxel

Objective To investigate the effects of stathmin silencing on the sensitivity of esophageal squamous cell carcinoma(ESCC) cells to paclitaxel. Methods RT-PCR and Western blot were used to identify the effect of stathmin silencing on KYSE150 cells by small interfering RNA technology. The sensitivity of cells to paclitaxel was measured by CCK-8 assay. Flow cytometry assays were performed to detect the changes of cell cycle. Mitosis was detected by mitotic index assays. Results Both RT-PCR and Western blot indicted stathmin gene was completely silenced in pSilencer4.1-CMVneo-siRNA (pSC-siR) stathmin transfected KYSE150 cells. The sensitivity of pSC-siR stathmin transfected KYSE150 cells was increased 191.4-fold to paclitaxel. IC50 (50% inhibitory concentration) of paclitaxel in pSC-siR stathmin transfected and non transfected KYSE150 cells were 0.018 and 3.445 nM. After paclitaxel intervention at 0.0.1nM for 72h, flow cytometry showed knockdown of stathmin in KYSE150 cells led to cell cycle arrest in G2/M phase [(55.4±6.2)% vs. (19.1±2.7)%, P=0.000]. Moreover, mitotic index assay indicated the population of cells in mitosis was decreased significantly in pSC-siR stathmin transfected KYSE150 cells compared with untransfected KYSE150 cells [(5.6±0.8)% vs. (13.5±3.7)%, P=0.000)]. Conclusion stathmin silencing increases the sensitivity of esophageal squamous carcinoma cells to paclitaxel through G₂/M phase block.