紫杉醇联合大蒜素对胃癌细胞的增殖抑制及促凋亡作用

目的：探讨紫杉醇联合大蒜素对胃癌细胞MGC-803的增殖抑制和促凋亡作用及其分子机制。方法：分别及联合应用两药后以MTT法测定MGC-803细胞的增殖，用流式细胞仪检测细胞凋亡，用RT-PCR法观察基因bax和bcl-2 mRNA的表达，用Western blot观察其蛋白表达。 结果：15～60μg/mL大蒜素和4～32μg /mL紫杉醇单用24h对MGC-803细胞均有明显抑制作用，呈剂量依赖性。低剂量大蒜素（9μg /mL）联合紫杉醇（1～16μg/mL）比单用紫杉醇作用更强（P<0.05）。15μg/mL大蒜素,12μg /mL紫杉醇和两药联用24h凋亡率分别为10.7%，30.4%和84.7%（P<0.01 ）。单用大蒜素和紫杉醇对胃癌细胞bax和bcl-2表达无明显影响，两药联用bax基因mRNA和蛋白表达增加，而bcl-2mRNA和蛋白的表达减少。结论：大蒜素可增强紫杉醇对胃癌细胞的增殖抑制作用，两药联用可减少紫杉醇的剂量;其机制可能是通过增强MGC-803细胞的凋亡，后者与bax和bcl-2基因表达有关。

The inhibiting effect of combination of allicin with paclitaxel on proliferation of gastric cancer cells and promotion of apoptosis

Abstract:Objective：To investigate the inhibitory effect of combined treatment of allicin with paclitaxel on gastric cancer cell lines and promotion of apoptosis and its possible mechanism.Methods ：After treatment with allicin or paclitaxel alone or in combination ,the MGC-803 gastric cancer cells growth was determined by MTT assay. Flow cyctometry was used to determine apoptosis of gastric cells.The expression of mRNA of bcl-2 and bax genes was detected by RT-PCR, and the expressions of protein bcl-2 and bax were detected by Western blotting.Results：Both allcin and paclitaxel alone could inhibit the growth of MGC-803 gastric cancer cells in a dose dependent manner . Combined treatment of allcin 9ug/mL with paclitaxel (1-16μg/mL) resulted in a synergistic effect of inhibiting cell growth. After incubation with allcin 15μg/mL,paclitaxel 12μg/mL alone and in combination ,the apoptosis rate was 10.7%,30.4%,84.7%, respectively (P< 0.01).Treatment with combination of the two drugs enhanced expression of pro-apoptotic gene bax and reduced expression of the anti-apoptotic gene bcl-2, but there was no effect when the drugs were used singly.Conclusions：The combined treatment of allicin with paclitaxel has a synergistic inhibiting effect on growth of gastric cancer cell lines, and induction of apoptosis by enhancing bax expression and decreasing bcl-2 expression may be the related mechanism.