抑制单羧酸转运蛋白1可增强鼻咽癌细胞HNE1/DDP对顺铂诱导凋亡的敏感性

摘要

目的 探讨siRNA沉默单羧酸转运蛋白1(MCT1)增强鼻咽癌细胞HNE1/DDP对顺铂诱导凋亡的敏感性及其可能机制.方法 Western blot检测HNE1和HNE1/DDP细胞中MCT1的表达及siRNA转染沉默MCT1在HNE1/DDP细胞中MCT1的表达;MTT法检测不同浓度顺铂和MCT1 siRNA联合顺铂对HNE1/DDP细胞的增殖抑制作用;PI单染流式细胞术检测细胞凋亡;线粒体膜电位检测试剂盒(JC-1)检测细胞线粒体膜电位;Western blot检测Mcl-1、Bak、Bcl-2、Bax蛋白的表达.结果 MCT1在HNE1/DDP细胞中高表达,抑制MCT1的表达可增加HNE1/DDP细胞对顺铂的敏感性(P<0.05),部分逆转鼻咽癌细胞对顺铂的耐药.此外,抑制MCT1的表达可增强HNE1/DDP细胞对顺铂诱导凋亡的作用,MCT1 siRNA与8μmol/L顺铂联合作用于HNE1/DDP细胞24 h的凋亡率为(51.23±2.86)%,较单用MCT1 siRNA、顺铂的凋亡率明显升高(P<0.05).同时使细胞线粒体膜电位降低,下调Mcl-1、Bcl-2的表达和上调Bax的表达.结论 抑制MCT1的表达可增强鼻咽癌HNE1/DDP细胞对顺铂诱导凋亡的敏感性,其机制可能与下调Mcl-1、Bcl-2和上调Bax有关.%Objective To investigate the effect of small interfering RNA (siRNA)-mediated silencing of monocarboxylate transporter 1 (MCT1) on the sensitivity of drug-resistant nasopharyngeal carcinoma HNE1/DDP cells to cisplatin (DDP)-induced apoptosis and explore the possible mechanism. Methods The expression of MCT1 was analyzed in HNE1 and HNE1/DDP cells and in HNE1/DDP cells transfected with siRNA using Western blot. MTT assay was used to assess the inhibitory effect of different concentrations of DDP alone or in combination with MCT1 siRNA on the proliferation of HNE1/DDP cells. The apoptosis of cells treated with MCT1 siRNA or/and DDP (8μmol/L) was assessed using flow cytometry with PI staining, and the mitochondrial membrane potential was detected using JC-1 staining assay; the expressions of Mcl-1, Bak, Bcl-2, and Bax were analyzed using Western blotting. Results HNE1/DDP cells showed a high expression of MCT1, and MCT1 silencing using siRNA significantly increased the sensitivity of HNE1/DDP cells to DDP (P<0.05) and partly reversed DDP resistance of the cells. MCT1 silencing enhanced the sensitivity of HNE1/DDP cells to DDP-induced apoptosis. Treatment of HNE1/DDP cells with MCT1 siRNA combined with 8 μmol/L DDP for 24 h resulted in an apoptotic rate of (51.23 ± 2.86)%, significantly higher than that in cells treated with MCT1 siRNA or DDP alone (P<0.05). The combined treatment also reduced the mitochondrial membrane potential, down-regulated the expression of Mcl-1 and Bcl-2, and up-regulated the expression of Bax in the DDP-resistant cells. Conclusion MCT1 siRNA can enhance the sensitivity of HNE1/DDP cells to DDP-induced apoptosis, the mechanism of which may involve the down-regulation of Mcl-1 and Bcl-2 and up-regulation of Bax expression.