单羧酸转运蛋白1增强乳腺癌细胞对3-溴丙酮酸的敏感性

目的 探究单羧酸转运蛋白1(MCT1)在增强乳腺癌细胞对3-溴丙酮酸(3-BrPA)敏感性中的作用,为乳腺癌治疗提供新思路.方法 MTT法检测3-BrPA对乳腺癌细胞的增殖抑制作用,溴化丙啶单染法流式细胞术检测细胞凋亡,ELISA试剂盒检测细胞内己糖激酶Ⅱ、乳酸脱氢酶、乳酸、三磷酸腺苷水平,Western blot检测MCT1蛋白的表达,瞬时转染cDNA上调MCTl的表达后,检测3-BrPA对MDA-MB-231细胞的增殖和三磷酸腺苷水平的影响.结果 3-BrPA对MDA-MB-231细胞增殖和凋亡的影响不明显,200 μmol/L作用24 h后增殖抑制率和凋亡率仅为8.72％和7.8％;但200 μmol/L 3-BrPA作用MCF-7细胞24 h后其增殖抑制率和凋亡率为84.6％和82.3％.MDA-MB-231细胞的MCT1过表达后,200 μmol/L 3-BrPA对细胞的增殖抑制率为72.44％,明显高于对照组(P＜0.05);25、50、100、200 μmol/L 3-BrPA作用细胞6h后,细胞内三磷酸腺苷水平和对照组相比分别为96.98％、88.44％、43.3％、27.56％.结论 MCT1能增强乳腺癌细胞对3-BrPA的敏感性,其机制可能是将3-BrPA转运到细胞内,从而抑制细胞糖酵解来发挥抗肿瘤作用.

Monocarboxylate transporter 1 enhances the sensitivity of breast cancer cells to 3-bromopvruvate in vitro

Objective To investigate the role of monocarboxylate transporter 1 (MCT1) in enhancing the sensitivity of breast cancer cells to 3-bromopyruvate (3-BrPA).Methods The inhibitory effect of 3-BrPA on the proliferation of breast cancer cells was assessed with MTT assay,and brominated propidium bromide single staining flow cytometry was used for detecting the cell apoptosis.An ELISA kit was used to detect the intracellular levels of hexokinase II,lactate dehydrogenase,lactate,and adenosine triphosphate,and Western blotting was performed to detect the expression of MCT1.MDA-MB-231 cells were transiently transfected with MCT1 cDNA for over-expressing MCT1,and the effect of 3-BrPA on the cell proliferation and adenosine triphosphate level was deteced.Results 3-BrPA did not produce significant effects on the proliferation and apoptosis of MDA-MB-231 cells,and the cells treated with 200 μmol/L 3-BrPA for 24 h showed an inhibition rate and an apoptosis rate of only 8.72％ and 7.8％,respectively.The same treatment,however,produced an inhibition rate and an apoptosis rate of 84.6％ and 82.3％ in MCF-7 cells,respectively.In MDA-MB-231 cells with MCT1 overexpression,200 μmol/L 3-BrPA resulted in an inhibition rate of 72.44％,significantly higher than that in the control cells (P＜0.05);treatment of the cells with 25,50,100,and 200 μmol/L 3-BrPA for 6 h resulted in intracellular adenosine triphosphate levels of 96.98％,88.44％,43.3％ and 27.56％ relative to the control level respectively.Conclusion MCT1 can enhance the sensitivity of breast cancer cells to 3-BrPA possibly by transporting 3-BrPA into cells to inhibit cell glycolysis.