肿瘤易感基因101在胃癌耐药细胞中的表达及作用

目的 探讨肿瘤易感基因(TSG)101在多药耐药胃癌细胞中的表达和作用。方法 应用半定量RT-PCR和Western blot方法观察TSG101在胃癌细胞SGC7901及其长春新碱(VCR)耐药亚系SGC7901／VCR中的表达。将TSG101真核表达载体转染SGC7901细胞，通过Western blot方法鉴定转染细胞TSG101蛋白的表达。用流式细胞仪检测细胞周期的变化和细胞内阿霉素(ADR)的平均荧光强度。用MTT法检测细胞生长曲线和对VCR、ADR的药敏性。结果 胃癌耐药细胞SGC7901／VCR与亲本细胞SGC7901相比，TSG101的表达明显增高。SGC7901细胞转染TSG101真核表达载体后其表达较对照细胞明显增高，G1期细胞比例减少而S期比例增加，细胞增殖加快，且对VCR、ADR的敏感性减低，细胞内阿霉素蓄积和潴留减少。结论 TSG101真核表达载体转染SGC7901后其耐药性明显增强，提示TSG101在胃癌多药耐药中发挥了一定的作用。

Expression and function of tumor susceptibility gene 101 in multidrug- resistant gastric cancer cells

Objective To investigate the expression and possible function of tumor susceptibility gene 101 (TSG101) in multidrug-resistant cell lines of gastric cancer.Methods The expression of TSG101 was examined in gastric cancer cell line SGC7901 and its vincristine(VCR)-resistant subline SGC7901/VCR with semi -quantitative RT-PCR and Western blot. TSG101 eukaryotic expression vector was transfected into SGC7901 cells by lipofectamine TM 2000. The expression levels of TSG101 in SGC7901 and the transfectants were detected with Western blot. Fluorescence-activated cell sorting was applied to examine the cell cycle alteration and the intracellular mean fluorescence intensity of adriamycin (ADR). Growth curve and drug sensitivity of cells to VCR and ADR were analyzed by MTT assay.Results TSG101 was highly expressed in VCR resistant gastric cancer cells. The expression of TSG101 in TSG101 transfectants was up-regulated compared with that in SGC7901 transfected with empty vector or in SGC7901 cells. TSG101 transfectants were accumulated in S phase, with a concomitant decrease of cell population in G 1 phase. MTT assay showed that TSG101 transfectants proliferated rapidly and were more resistant to VCR and ADR than control cells. Conclusions The over-expression of TSG101 could promote the multidrug resistance phenotype of sGC7901 cells. TSG101 may play a certain role in multidrug resistance of gastric cancer.