Oct-4基因在胃癌顺铂耐药中的作用

目的:建立胃癌BGC-823顺铂耐药细胞株,研究Oct-4基因在胃癌顺铂耐药中的作用。方法:使用顺铂逐步增加剂量法诱导胃癌BGC-823细胞,以建立其多药耐药细胞株BGC-823/DDP;MTT细胞毒实验检测顺铂对肿瘤细胞的细胞毒作用;半定量RT-PCR检测Oct-4基因的表达;基因转染干扰Oct-4表达;Western blot实验检测Oct-4蛋白的表达改变。结果:经过30～34周的诱导我们建立了胃癌BGC-823顺铂耐药细胞株;MTT细胞毒实验结果显示顺铂对BGC-823和BGC-823/DDP细胞的IC50值分别为(2.33±0.12)和(21.46±0.97)μmol/L(P<0.01),与BGC-823细胞比较,BGC-823/DDP细胞对顺铂耐药是其9.21倍;半定量RT-PCR检测显示胃癌耐药株BGC-823/DDP高表达Oct-4基因;Western blot结果显示化学合成的siRNA可以靶向下调Oct-4蛋白的表达;siRNA干扰BGC-823/DDP细胞Oct-4基因的表达后,BGC-823/DDP细胞对顺铂的的IC50值从(22.04±1.84)μmol/L减小到(6.15±0.53)μmol/L,二者差异具有统计学意义(P<0.01)。结论:研究结果表明,Oct-4基因的高表达在胃癌顺铂的耐药中起着重要的作用。

Effect of Oct-4 on chemosensitivity of cisplatin against gastric cancer cells

AIM: To explore the mechanisms of multidrug resistance in human gastric cancer by establishing a cisplatin(DDP) resistance BGC-823 cell line.METHODS: The human cancer BGC-823 cells were exposed in a gradually increasing dose of DDP.MTT assay was used to detect the cytotoxic activity of DDP against BGC-823 and BGC-823/DDP cells.The mRNA expression of Oct-4 was detected by RT-PCR analysis.The small interfering RNA was used to specifically knockdown Oct-4 in BGC-823/DDP cells.The protein expression of Oct-4 was determined by Western blot analysis.RESULTS:DDP resistance cell line BGC-823/DDP was established by DDP 30-34 weeks contionuous inducing.The IC50 values of DDP against BGC-823 and BGC-823/DDP cells were(2.33±0.12)and(21.46±0.97) μmol/L by MTT assay,respectively.Compared with the BGC-823 cells,the resistance to cisplatin of BGC-823/DDP cells was 9.21 times.Semi-quantitative RT-PCR analysis showed that the mRNA expression of Oct-4 was upregulated in BGC-823/DDP cells.Western blot showed that the expression of Oct-4 protein was down-regulated by the chemical synthesis siRNA;After interfered the Oct-4 gene expression of BGC-823/DDP cells by siRNA,the IC50 values of cisplatin against BGC-823/DDP cells was decreased from(22.04±1.84) to(6.15±0.53) μmol/L;there was no significant difference(P<0.01).CONCLUSION: The results show that Oct-4 gene expression plays an important role in gastric cancer with cisplatin resistance.