The Study Of Cytotoxic Effect And Radiation Enhancement Of Docetaxel On Nasopharyngeal Carcinoma Cell Line CNE2 And Its Mechanism

[Objective] To investigate cytotoxic and radiosensitizing effect of docetaxel on nasopharyngeal carcinoma cell line CNE2 and its sensitization mechanism.[Methods] MTT was used to test the cytotoxic effect of Docetaxel on CNE2 cells. Flow cytometry was performed to show the number of apoptosis cells that had been stained with Annexin-V/PI. The changes of cell cycle were observed and recorded through propidium iodide (PI) staining. Western blot was applied to detect the expression of bc1-2,bax,caspase-3 and cox-2 proteins after treatment with docetaxel. Colony formation assay was employed to investigate the radiosensitization effects of docetaxel on the proliferation of CNE2 cells.[Results] Docetaxel significantly inhibited the growth of human nasopharyngeal carcinoma CNE2 cells and its IC50 is 1.64μg/ mL. Docetaxel induced apoptosis of CNE2 cells and the ratio of G2/M phase increased conspicuously. Compared with the control group, the expression level of bax and caspase-3 proteins were significantly enhanced by docetaxel in CNE2 cells; while the expression level of bcl-2 decreased. However, the expression level of cox-2 was not changed. 0.001μg/ mL docetaxel plus radiation has a radiosensitizing effect and the sensition enhanencement ratio (SER) is 1.547.[Conclusion] Docetaxel has significant cytotoxic and radiosensitizing effect on nasopharyngeal carcinoma cell line CNE2, which maybe attributed to the enhanced expression of bax and caspase-3 protein and the inhibition of bcl-2 protein.