胃癌SGC7901表柔比星耐药细胞亚系的建立与耐药机制研究

The Mechanisms of Drug Resistance in Newly Established Epirubicin-Resistant Gastric Cancer Cell Line

目的:建立人胃癌SGC7901表柔比星耐药细胞系,探讨其对表柔比星的耐药机制。方法:采用逐步增加表柔比星浓度,间歇作用体外诱导法,建立人胃癌SGC7901表柔比星耐药细胞亚系SGC7901/EPI。用MTT法测定药物敏感性;流式细胞仪检测其药物排除能力和凋亡抵抗能力等生物学指标的改变,western blot检测相关蛋白的表达。结果:经过12个月建成人胃癌SGC7901表柔比星耐药细胞系SGC7901/EPI,其对表柔比星明显耐药,且对其他多种抗癌药具有不同程度的交叉耐药性,阿霉素蓄积潴留实验显示SGC7901/EPI的阿霉素含量明显低于亲本细胞,Western blot显示MRP1的表达上调;SGC7901/EPI凋亡抵抗能力明显上升,Bcl-2表达比亲本细胞增高,而Bax的表达下调。结论:SGC7901/EPI细胞具有多药耐药表型,其可能通过MRP1的上调增加药物排出和上调Bcl-2/Bax的比值促进凋亡抵抗等机制产生耐药。该胃癌多药耐药细胞亚系为进一步研究胃癌耐药机制及逆转方法奠定基础。

Objective： To establish the drug resistant cell model of gastric cancer and investigate the potential mechanisms of epirubicin drug resistance.Methods： Epirubicin-resistant cell line（SGC7901/EPI） was established by increasing dose of epirubicin.Drug sensitivity of the cell line was measured by in vitro MTT assay.Cell based assays for drug transportation and apoptosis were carried out.The expression levels of MRP1,Bcl-2,Bax were detected using western blot.Results： Significant difference was found in drug resistance between parent gastric cancer cell line SGC7901 and drug resistant subline 7901/EPI.Compared with SGC7901 cells,7901/EPI showed not only increased drug resistance,but also decreased drug sensitivity to other drugs.Increased drug transport was confirmed by the elevated expressions of MRP in 7901/EPI.Apoptosis rate of the SGC7901/EPI cell line was remarkably reduced due to increased expression of Bcl-2 and decreased Bax.Conclusion： Epirubicin resistant gastric cancer cell subline SGC7901/EPI was successfully established.The mechanisms of epirubicin may include elevated expression of MRP1 and increased Bcl-2/Bax ratio.