塞来昔布增强口腔癌化疗敏感性与阻滞周期进程的相关性

Celecoxib enhances chemosensitivity of oral cancer cells by blocking cell cycle progression in vitro

目的探讨塞来昔布增强口腔癌细胞化疗敏感性与其阻滞细胞周期进程及调节P-gp之间的相关性。方法塞来昔布10、20、40、80μmol/L和/或长春新碱0.375、0.75、1.5、3μmol/L处理KB/VCR细胞后,分别采用MTT法检测KB/VCR细胞生长抑制率;流式细胞术检测细胞周期分布情况;Western blot检测周期相关蛋白Cyclin D1、p21WAF1/CIP1及P-gp的蛋白表达。结果塞来昔布浓度较低时(<20μmol/L)对KB/VCR生长增殖无明显影响,但小剂量的塞来昔布10μmol/L可显著增强VCR对KB/VCR细胞的毒性作用,并呈时间依赖性。塞来昔布与长春新碱联合作用于KB/VCR细胞24、48、72 h后,其生长抑制率分别为(37.53±2.05)%、(46.67±3.17)%及(54.02±1.53)%,显著高于塞来昔布和长春新碱单独用药组(P均<0.01)。塞来昔布与VCR联合应用能改变细胞周期分布,与VCR组相比,联合用药组G0/G1期细胞数量增加(56.08±0.46)%,S期和G2/M期细胞数目降低[S期:(22.83±0.20)%;G2/M期:(21.09±0.66)%]。此外,与VCR组细胞相比,联合用药能显著降低Cyclin D1的表达,增强p21WAF1/CIP1的表达,并且Cyclin D1蛋白水平的降低及p21WAF1/CIP1蛋白水平的上升伴随着P-gp蛋白的下调。结论塞来昔布下调节P-gp而增强KB/VCR细胞对化疗药物的敏感性可能与Cyclin D1和p21WAF1/CIP1蛋白变化引起的细胞周期阻滞有关。

Objective To investigate the effect of celecoxib in enhancing the chemosensitivity of oral cancer cells and the correlation of this effect with cell cycle arrest. Methods KB/VCR cell line was treated with celecoxib （10, 20, 40, and 80 umol/L） and/or VCR （0.375, 0.75, 1.5, and 3 umol/L）, and the growth inhibition rates of KB/VCR cells were assessed with MTT assay. Flow cytometry was employed to analyze the distribution of cell cycle. Western blotting was performed to detect the expression of P-glycoprotein （P-gp） and the cell cycle related proteins Cyclin D1 and p21^wAFI/CIP1 Results Low concentrations of celecoxib （〈20 umol/L） produced no obvious effect on the proliferation of the cells. But at 10 gmol/L, celecoxib significantly enhanced the toxicity of VCR in a time-dependent manner, and the combined treatments for 24, 48, and 72 h caused growth inhibition rates of （37.53± 2.05）%, （46.67± 3.17）% and （54.02± 1.53）%, respectively, significantly higher than those following treatments with celecoxib or VCR alone （P〈0.01）. Compared with the cells treated with VCR alone, the cells with combined treatments showed a significantly increased cell percentage in G0/G1 phase [（56.08±0.46）% ] with decrease percentages in S phase [（22.83±0.20）% ] and GriM phase [（21.09%±0.66）% ]. The combined treatment also significantly down-regulated cyclin D1, up-regulated p21^wAFI/CIP1, and reduced P-gp expressions in the cells. Conclusions Celecoxib enhances the chemosensitivity of KB/VCR cells by down-regulating P-gp expression, which is partially mediated by modification of cyclin D1 and p21^wAFI/CIP1 to result in cell cycle arrest.