5氮杂脱氧胞苷对乳腺癌MCF-7细胞中抑癌基因p16mRNA表达的影响

目的 探讨5氮杂脱氧胞苷(5-aza-cdr)对乳腺癌细胞中p16基因mRNA表达的影响.方法 分别用5-aza-cdr 5、10和20 μmol/L处理乳腺癌细胞MCF-7,未处理的MCF-7细胞作为对照.采用甲基化特异性聚合酶链反应(MSP)对药物处理前后的细胞进行p16基因甲基化检测;绿色荧光染料实时反转录聚合酶链反应(SYBR Green qRT-PCR)检测p16 mRNA表达.结果 在未处理的MCF-7细胞中(对照)p16基因呈完全甲基化状态,随着5-aza-cdr浓度增加,甲基化水平逐渐减弱,至5-aza-cdr 20 μmol/L时p16基因甲基化状态完全被逆转;p16 mRNA表达水平也随着药物剂量的递增逐渐增加,5-aza-cdr 20 μmol/L处理组与5、10 μmol/L处理组以及未处理组比较差异均有统计学意义(均P＜0.01).结论 乳腺癌细胞MCF-7中p16基因的甲基化能被5-aza-cdr逆转,去甲基化后可以促进p16 mRNA表达.

Effect of 5-aza-2 '-deoxycytidine on demethylation of p16 gene in breast cancer cell line MCF-7

Objective To investigate the effect of 5-aza-2 ＇-deoxycytidine（5-aza-cdr） on p16 gene demethylation mRNA expression in breast cancer cell. Methods MCF-7 cells were treated with 5-aza-cdr 5,10,20 umol/L and the untreated MCF-7 cell served as control. Methylation and mRNA levels for p16 gene were analyzed by methylation- specific polymerase chain reaction（MSP） and SYBR Green qRT-PCR. Results p16 gene was completely methylated in the control group. After culturing with the increased 5-aza-cdr, methylation levels in MCF-7 cells were gradually weakened and the completely reversed methylation occurred in the concentration 20 umol/L, p16 mRNA levels were stepped up with 5-aza-cdr increasing. This mRNA level in 20 /~mol/L treated group showed significant improvement in comparison with 5,10 umol/L treated group as well as control group （ P d0.01）. Conclusion The methylation of p16 gene can be reversed in MCF-7 cell treated by 5-aza-cdr. This demethylation can promote expression of p16 gene mRNA.