左卡尼汀对多西他赛在NCI-H520细胞中抗肿瘤作用影响的研究

目的:探究左卡尼汀对多西他赛抑制肺癌细胞NCI-H520增殖的影响，并初步探索其机制。方法:实验将NCI-H520细胞分为阴性对照组，左卡尼汀组，多西他赛组以及联合用药组。四甲基偶氮唑蓝（MTT）法检测细胞增殖情况，流式细胞仪检测细胞凋亡和细胞周期，蛋白质免疫印迹法检测目标蛋白P21，P53，BAX和BCL-2的表达情况。结果:与不同单药组（左卡尼汀组和多西他赛组）相比，联合用药组对细胞增殖的抑制作用均增强，细胞增殖率分别由（95.5±3.97）%和（65.73±2.22）%下降到（54.4±1.67）%，P＜0.01，镜下细胞密度下降。联合用药使G1/G0期细胞分别由（67.21±6.0）%和（11.52±0.89）%下降到（3.98±0.42）%，P＜0.05。G2/M期细胞分别由（11.84±5.05）%和（54.91±2.38）%上升到（64.56±0.9）%，P＜0.05。周期相关蛋白P21，P53的表达量增加，且差异均具有统计学意义。所有实验组之间的细胞凋亡率和凋亡相关蛋白BAX，BCL-2的表达量没有明显差异。结论:24 h时，联合用药组中，左卡尼汀可能通过上调P21，P53的蛋白表达来增强细胞的G2/M期阻滞，进而增强多西他赛对NCI-H520细胞增殖的抑制作用。

Influence of l-carnitine on the antitumor effects of docetaxel in NCI-H520 cells

Objective: To investigate the influences of l-carnitine on the inhibitory effects of docetaxel in NCI-H52O cells, and to explore its mechanism. Methods: NCI-H520 cells were divided into control group, L-carnitine group, docetaxel group and combination drugs group. MTT assay was used to detect the cell proliferation, flow cytometry was applied to determine cell apoptosis and cell cycle，and Western blot was performed to determine the expression of target protein- P21, P53, BAX and BCL-2. Results: Compared with the different single drug group（l-carnitine group and docetaxel group）, the combined drugs group enhanced the inhibition of cell proliferation, the cell proliferation rate decreased from (95.5±3.97)% and (65.73±2.22)% to (54.4±1.67)%, P＜0.01, and the cells density decreased under the microscope. The combination drugs decreased the cells in G0/G1 phase from (67.21±6.0)% and (11.52±0.89)% to (3.98±0.42)%, P＜0.05. And the cells in G2/M phase increased from (11.84±5.05)% and (54.91±2.38)% to (64.56±0.9)%, P＜0.05. The expression levels of cycle-related proteins P21 and P53 were up-regulated, and these changes were statistically different. There were no significant differences in the apoptosis rate and the expression of apoptosis-related proteins BAX and BCL-2 among all groups. Conclusion: In the combination drugs group, l-carnitine may enhance the G2/M phase arrest by up-regulating the expression of P21 and P53 proteins at 24 h, and thus enhance the inhibitory effects of docetaxel on NCI-H520 cell proliferation.