5-氮杂脱氧胞苷对MCF7细胞中MEG3基因表达及细胞增殖活性的影响

Effect of 5-aza-2’-deoxycytidine on MEG3 gene expression and proliferation of human mammary cancer line MCF7

背景与目的:MEG3(maternal expressed gene3)基因是一类印记基因,其转录缺失可能诱导多种肿瘤的发生发展。本研究通过检测乳腺癌MCF7细胞中MEG3基因mRNA的转录情况及细胞增殖活性,以探讨DNA甲基化抑制剂5-氮杂脱氧胞苷对MEG3基因转录的诱导作用及其对细胞增殖活性的影响。方法:以浓度为5μmol/L的5-氮杂脱氧胞苷分别作用MCF7细胞0、2、4和6d后,用RT-PCR及Northern blot技术检测MEG3基因mRNA的转录水平;用四甲基偶氮唑蓝(MTT)比色法检测细胞增殖活性的变化。结果:与未处理组相比,5-氮杂脱氧胞苷分别作用2、4和6d后,MCF7细胞中MEG3基因mRNA表达显著增强,并呈现时间依赖性(P<0.01);MTT检测结果显示MCF7细胞的增殖活性受到抑制。与未处理组相比,药物作用2、4和6d的细胞增殖抑制率分别为(23.16±3.93)%、(49.39±2.38)%和(64.73±2.24)%,差异有显著性(P<0.01)。结论:MEG3基因可能具有抑制MCF7细胞生长的作用,其基因转录下调与DNA甲基化有关,可能参与了乳腺癌的发病机制。

Background and purpose： The MEG3 gene is a imprinted gene, whose loss may be associated with the pathogenesis and progression of several tumor types. This study was done to investigate the transcription of MEG3 mRNA in human mammary cancer cell line MCF7 and cell proliferation, in order to explore the effect of the methylation inhibitor, 5-aza-2＇-deoxycytidine （5-aza-CdR） on MEG3 gene expression and proliferation in MCF7. Methods： MCF7 was treated with 5 μmol/L 5-aza-CdR for 2, 4, 6 days, then the alteration of MEG3 gene expression was detected by RT-PCR and Northern blot technology and the proliferation difference in cell growth of MCF7 was observed by MTT. Results： After treated with 5-aza-CdR, the transcription of MEG3 mRNA in MCF7 was increased and the growth of MCF7 was reduced. MCF7 was treated with 5 μmol/L 5-aza-CdR for 2, 4, 6 days, the inhibitory rates were （23.16±3.93）, （49.39±2.38）, （64.73±2.24）, there were significant differences between them. Conclusion： The growth of MCF7 was possibly inhibited by MEG3 gene, and the downregulation of MEG3 gene might result from the methylation, which was involved in the mammary cancer pathogenesis.