5-Aza-CdR和TSA联合调控乳腺癌maspin基因表达的研究

Combination of 5-Aza-CdR and trichostatin A on cell proliferation and maspin gene expression in breast cancer cell line MDA-MB-435S

目的:研究5-氮-2′-脱氧胞苷(5-A-za-CdR)和曲古菌素A(TSA)对乳腺癌MDA-MB-435S细胞增殖及抑癌基因maspin表达的影响。方法:用特异性甲基转移酶抑制剂5-Aza-CdR和组蛋白去乙酰酶抑制剂TSA分别单独和联合作用MDA-M-B-435S乳腺癌细胞株5～8d,用MTT比色法观察细胞在药物作用前后的生长活性;RT-PCR检测细胞作用前后maspin mRNA的表达。结果:5μmol/L5-Aza-CdR作用乳腺癌细胞株MDA-MB-435S8d后,与对照组比较能明显抑制肿瘤细胞的生长;不同浓度TSA作用该细胞5d后,在>100ng/mL浓度时才能显著的抑制该细胞的增殖。RT-PCR显示,5-Aza-CdR和TSA联合作用时可显著的诱导maspin mRNA的重新表达;而两药单用时其诱导作用相对较弱。结论:在人乳腺癌MDA-MB-435S细胞中,maspin基因可能因表观遗传改变而导致转录失活,maspin基因的重新表达能有效的抑制细胞生长。5-Aza-CdR和TSA可作为乳腺癌治疗的新方向。

OBJECTIVE： To investigate the effects of 5-Aza-2＇-deoxycytidine （5-Aza-CdR） and trichostatin A （TSA） on the proliferation of MDA-MB-435S cells and the expression of tumor suppressor gene maspin. METHODS： Human breast cancer cell line MDA-MB-435S was treated with either 5 μmol/L 5-Aza-CdR （a specific demethylating agent） or different concentrations of TSA （a specific histone deacetylase inhibitor） for 5 to 8 days. The growth of MDA-MB-435S cells was observed by MTT assay. The expression of maspin mRNA was observed by reverse transcription-polymerase chain reaction （RT-PCR） before and after 5-Aza-CdR and/or TSA treatment. RESULTS： MDA-MB-435S cells treated with 5-Aza-CdR displayed a slowed growth in comparison with the control cells. TSA significantly inhibited the proliferation of the same cancer cell at 100 ng/mL, maspin mRNA was re-expressed in MDA-MB-435S cells after 5-Aza-CdR and/or TSA treatment. Moreover, the combination of the two drugs significantly induced the re-expression of maspin mRNA compared with the single drug alone. CONCLUSIONS： maspin gene might be transcriptional silencing by abnormal epigenetic changes and the re-expression of maspin gene by 5-Aza-CdR/TSA can inhibit the proliferation of MDA-M-B-435S breast cancer cells. It suggests that 5-Aza-CdR/TSA may be a potential therapeutic agent in the treatment of breast cancer.