目的 探讨二甲双胍下调谷胱甘肽S转移酶（GSTpi）和拓扑异构酶Ⅱα（TopⅡα）对顺铂（cDDP）耐药的宫颈癌细胞系SiHa/cDDP增殖的抑制作用。方法 构建SiHa/cDDP耐药细胞株并进行鉴定。CCK8法测定cDDP对SiHa和SiHa/cDDP细胞的抑制率；绘制SiHa、SiHa/cDDP细胞的生长曲线，按Patterson公式计算SiHa和SiHa/cDDP细胞的群体倍增时间；观察cDDP对SiHa、SiHa/cDDP细胞形态的影响；CCK8法测定不同浓度二甲双胍对SiHa和SiHa/cDDP细胞的抑制率；细胞迁移实验、Transwell细胞侵袭实验分别检测二甲双胍对SiHa、SiHa/cDDP细胞侧向迁移能力及纵向迁移能力的影响；RT-qPCR法检测SiHa/cDDP细胞较SiHa细胞GSTpi、TopⅡα mRNA的表达变化，以及二甲双胍对SiHa/cDDP细胞作用后GSTpi、TopⅡα mRNA的表达变化。结果 cDDP对SiHa、SiHa/cDDP细胞的抑制作用与cDDP的浓度正相关，相同浓度下对SiHa/cDDP细胞的抑制率明显低于对SiHa细胞的抑制率（P<0.01）；SiHa、SiHa/cDDP细胞的群体倍增时间分别为（30.69±0.58）、（38.39±1.05）h，比较差异具有统计学意义（P<0.001）；顺铂对SiHa细胞形态的影响较大，而对SiHa/cDDP细胞基本没有影响；二甲双胍对SiHa、SiHa/cDDP细胞生长均有抑制作用，抑制率与二甲双胍浓度正相关，相同浓度下对SiHa/cDDP细胞的抑制率明显高于对SiHa细胞的抑制率（P<0.01）；与SiHa细胞相比，二甲双胍能更明显抑制SiHa/cDDP细胞迁移和侵袭（P<0.01）；RT-qPCR结果显示，与SiHa细胞相比，SiHa/cDDP中GSTpi、TopⅡα mRNA的表达明显升高（P<0.01、0.05），且二甲双胍能抑制SiHa/cDDP细胞中GSTpi、TopⅡαmRNA的表达（P<0.01）。结论 二甲双胍能通过下调GSTpi、TopⅡα的表达抑制SiHa/cDDP的增殖、侵袭和迁移。

Objective To investigate the effects of metformin on SiHa/cDDP cells proliferation by down-regulating GSTpi and TopⅡα. Methods SiHa/cDDP cells were constructed and authenticated. The inhibition rates of cDDP on SiHa and SiHa/cDDP cells were estimated by Cell Counting Kit-8 (CCK8) assay. Cell growth curve of SiHa and SiHa/cDDP cells was drawed, and population doubling time of SiHa and SiHa/cDDP cells was calculated by the manner of Patterson formula. The effects of cDDP on the morphology of SiHa and SiHa/cDDP cells were observed. The inhibition rates of metformin in different concentration on SiHa and SiHa/cDDP cells were estimated by CCK8 assay. The effects of metformin on SiHa and SiHa/cDDP cells were detected by wound healing assay to evaluate lateral migration, and by transwell assay to evaluate longitudinal migration, respectively. Changes of expression of GSTpi and TopⅡα mRNA in SiHa/cDDP cells compared with those in SiHa cells were detected by RT-qPCR, and changes of expression of GSTpi and TopⅡα mRNA in SiHa/cDDP cells treated with metformin were detected. Results The inhibition of cDDP on SiHa and SiHa/cDDP cells was positively correlated with the concentration of cDDP. The inhibition rate in SiHa/cDDP cells was significantly lower than that in SiHa cells (P < 0.01) under the same concentration of cDDP. The population doubling time of SiHa and SiHa/cDDP cells was (30.69 ±0.58) h and (38.39 ±1.05) h respectively, (P < 0.001). Cisplatin had a significant effect on the morphology of SiHa cells, but had few effects on SiHa/cDDP cells. Metformin inhibited the growth of both SiHa and SiHa/cDDP cells, with positively correlated with the concentration of merformin. The inhibition rate in SiHa/cDDP cells was significantly higher than that in SiHa cells (P < 0.01) under the same concentration of merformin. Compared with SiHa cells, metformin inhibited the migration and invasion of SiHa/cDDP cells more significantly (P < 0.01). RT-qPCR results showed that the expression of GSTpi, and TopⅡα mRNA in SiHa/cDDP cells was significantly higher than that in SiHa cells (P < 0.01, 0.05), and metformin could inhibit mRNA expression of GSTpi, TopⅡα in SiHa/cDDP cells (P < 0.01). Concousion Metformin inhibits SiHa/cDDP cells proliferation, motility, and invasiveness by down-regulating expression levels of genes GSTpi and TopⅡα.

佛山市科技创新项目（2018AB000031）；广州医科大学博士、留学回国人员科研项目（2016C23）；佛山市科技创新项目（医学科技创新平台建设项目，FS0AA-KJ218-1301-0008）