Abstract: Objective: To explore the effect of Oxaliplatin on the proliferation and apoptosis of human tongue squamous cell carcinoma CAL27 cells, and to clarify its underlying mechanism. Methods: The CAL27 cells were treated with different concentrations of Oxaliplatin (0,10, 20, 40 and 80 mg·L^-1) and used as control group and 10, 20, 40 and 80 mg·L^-1 Oxaliplatin groups. The morphology of CAL27 cells in various groups were observed by crystal violet staining. The proliferation rates of the CAL27 cells in various groups were detected by CCK-8 assay. The percentages of CAL27 cells in different cell cycles and the apoptotic rates in various groups were detected by flow cytometry. The expression levels of cyclin-dependent kinase 2(CDK2)and E-type cyclin(cyclin E) mRNA in the CAL27 cells in various groups were analyzed by Real-time fluorescence quantitative PCR. The expression levels of anti-apoptotic protein survivin and pro-apoptotic protein Bax in the CAL27 cells in various groups were determined by Western blotting method. Results: Compared with control group, the CAL27 cells in 40 mg·L^-1 Oxaliplatin group wrinkled; the cells in 80 mg·L^-1 Oxaliplatin group lost the former morphology, and the intercellular connections of cells disapeared. Compared with control group, the proliferation rates of CAL27 cells in 10, 20, 40 and 80 mg·L^-1 Oxaliplatin groups were significantiy decreased (P<0.05 or P<0.01).Compared with control group, the percentage of CAL27 cells in G₀/G₁ phase in 40 mg·L^-1 Oxaliplatin group was significantly increased (P<0.01), and the expression levels of CDK2 and cyclin E mRNA were significantly decreased (P<0.05).Compared with control group, the apoptptic rates of CAL27 cells in 40 and 80 mg·L^-1 Oxaliplatin groups were markedly increased (P<0.01). Compared with control group, the expression levels of survivin protein in CAL27 cells in 40 and 80 mg·L^-1 Oxaliplatin groups were significantly decreased (P<0.01), and the expression levels of Bax protein were obviously increased (P<0.05 or P<0.01). Conclusion: Oxaliplatin can inhibit the proliferation and induce the apoptosis of CAL27 cells, and its mechanism may be related to arresting G₀/G₁ phase, up-regulating the expression level of survivin and down-regulating the expression level of Bax.

Key words: tongue squamous cell carcinoma, Oxaliplatin, cell proliferation, apoptosis, cell cycle