TRAIL联合顺铂对胃癌多药耐药基因GST-π的影响

Effects of TRAIL in combination with DDP on the expression of GST-π gene in gastric cancer cells

目的探讨肿癌坏死因子相关凋亡配体(TRAIL)与顺铂联合应用对胃癌耐药细胞株SGC-7901/VCR多药耐药(MDR)基因谷胱甘肽S-转移酶-π(GST-π)的影响。方法采用MTT法检测不同浓度顺铂的抗癌活性并计算其亚毒性剂量IC10。流式细胞术检测TRAIL(200μg/L)及顺铂(亚毒性剂量)单用及联合应用后的细胞凋亡率。分别采用RT-PCR和ELISA法检测加药前后耐药基因GST-πmRNA及蛋白的表达情况。结果对照组、顺铂组、TRAIL组以及TRAIL顺铂联合用药组作用48 h后胃癌细胞凋亡率分别为2.69%、8.26%、9.71%和31.13%,与对照及单药组比较,联合用药组细胞凋亡明显升高(P<0.05)。RT-PCR和ELISA法结果显示,与单药组比较,联合用药组协同作用明显,多药耐药(MDR)基因GST-πmRNA和蛋白表达下降(P<0.05)。结论 TRAIL和顺铂联合应用能协同诱杀胃癌细胞,其机制可能是通过下调GST-π基因和蛋白表达,逆转或部分逆转MDR。

Objective To study the effect of tumor necrosis factor related apoptosis inducing ligand（TRAIL） combined with chemotherapeutic drug cisplatin on expression of muhidrug resistance genc GST-π in the gastric cancer cell line SGC-7901/VCR. Methods SGC-7901/VCR cells were cultured with cisplatin in different concentrations.. MTF assay was used to measure the antieancer activity of cisplatin. The apoptosis rate was separately measured by a flow cytometer in cisplatin （sub-toxic dose） alone in TRAIL （200 p,g/L） alone and in the combination of the two. Both RT-PCR and ELISA were used to detect the expression level of GST-π mRNA and protein with or without cisplatin. Results The apoptosis rate of control group, cisplatin group, TRAIL group and combination group in 48 h were 2.69%, 8.26%, 9.71% and 31.13% respectively. The apoptosis rate in combination group was significantly higher than that in the other groups （p 〈 0. 05 ）. According to the results of RT-PCR and ELISA, the expression of GST-π mRNA and protein of combination group had statistically significant differences compared with other groups （P 〈0. 05 ）. Conclusion Cisplatin can enhance the effect of TRAIL in anticancer therapy. Its mechanism might involve in the down-regulate of multidrug resistance gene GST-π, which may play a potential role in overcoming the chemotherapeutic resistance of gastric cancer cells.