单羧酸转运蛋白基因过表达对MDA-MB-231乳腺癌细胞生物学行为的影响

Effect of over-expressed monocarboxylate transporter on the biological behavior of MDA-MB-231 breast cancer cells

目的研究单羧酸转运蛋白(MCT)基因过表达对乳腺癌MDA-MB-231细胞凋亡、细胞周期、侵袭和转移能力的影响。方法将真核表达质粒pcDNA3.1/MCT及空质粒pcDNA3.1分别转染乳腺癌MDA-MB-231细胞。采用实时定量PCR(qRTPCR)和Western blot法分别检测转染后细胞内MCT基因的表达。Annexin V-FITC/PI染色和PI单染色结合流式细胞术检测MCT基因过表达对乳腺癌MDA-MB-231细胞凋亡、细胞周期的影响,Transwell实验检测MCT基因过表达对乳腺癌MDA-MB-231细胞侵袭能力的影响,划痕实验检测MCT基因过表达对乳腺癌MDA-MB-231细胞迁移能力的影响。结果实验组MCT的mRNA和蛋白水平明显高于转染空质粒的阴性对照组和未处理组;MCT过表达能促进乳腺癌MDA-MB-231细胞的凋亡,G2期细胞减少、S期细胞增多,同时能抑制癌细胞的侵袭和迁移能力。结论 MCT基因过表达能促进MDA-MB-231细胞的凋亡、调节细胞G2/M期检控点,抑制细胞的侵袭和迁移能力。

Objective To investigate the effect of over-expressed monocarboxylate transporter （MCT） on apoptosis, cell cycle, migration and invasion of MDA-MB-231 breast cancer cells. Methods Eukaryotic expression plasmid pcDNA3. 1/MCT and empty plasmid pcDNA3, 1 were respectively transfected into MDA-MB-231cells. The expression of MCT gene was tested by real-time quantitative PCR （qRT-PCR） and Western blotting. After stained respectively by annexin V-FITC/PI and PI, the apoptosis and cell cycle in the MDA-MB-231 cells over-expressing MCT were detected by flow cytometry. The abilities of invasion and migration in the MDA-MB-231 cells with over-expressed MCT were respectively determined by TranswellTM and scratch wound healing assays. Results In mRNA and protein levels, the expression of MCT was higher in pcDNA3.1/MCT transfected group than in negative control group and untreated group. Over-expression of MCT in the MDA-MB-231 cells enhanced cell apoptosis, reduced the cell number of G2 phase and increased the cell number of S phase. The abilities of invasion and migration in the MDA-MB-231 cells were inhibited significantly. Conclusion Over-expression of MCT in the MDA-MB-231 cells promotes apoptosis, regulates G2/M checkpoint and inhibits the abilities of invasion and migration.