HDAC抑制剂下调乳腺癌细胞系HER-2的表达及miRNA表达谱的变化

Histone deacetylase inhibitor down-regulated the expression of HER-2 in breast cancer through the changes in miRNA

目的:探讨组蛋白去乙酰化酶(histone deacetylase,HDAC)抑制剂下调乳腺癌HER-2的表达机制,为乳腺癌抗HER-2治疗提供新的实验依据。方法:利用HDAC抑制剂处理HER-2阳性乳腺细胞,q PCR和Western检测HER-2基因和蛋白水平的变化,同时采用mi RNA芯片筛选HDAC抑制剂相关的mi RNA谱,q PCR验证mi RNA表达变化。结果:体外细胞实验证实HDAC抑制剂TSA和SAHA可下调乳腺癌细胞系HER-2的表达,TSA可下调BT474的HER-2基因表达,浓度为100 nmol时下调10.7%,浓度为200 nmol时下调38.9%(P<0.05)。TSA对原代细胞HER-2基因表达无明显下调(P>0.05)。SAHA对BT474中HER-2基因表达的影响,浓度5μmol/L组下调93.9%(P<0.05),而1μmol/L组无明显下调。SAHA对原代细胞HER-2基因表达下调较为明显,浓度1μmol/L时下调92.7%,浓度5μmol/L时下调87.1%。通过mi RNA芯片筛选出7条mi RNA,q PCR监测SAHA、TSA处理后,mi R-762基因表达上调2.11倍。结论:HDAC抑制剂可能通过mi RNA表达谱改变介导下调乳腺癌HER-2的表达。

Objective：To investigate the mechanism of histone deacetylase （HDAC） inhibitor in down-regulating the expression of HER-2 in breast cancer cells and to provide an innovative therapeutic option to overcome the disadvantages of anti-HER-2 therapy. Meth-ods：HER-2-positive breast cell lines were treated with HDAC inhibitors. The changes in the gene and protein levels of HER-2 were de-tected by qPCR and Western blot. MiRNA microarray was used to identify the HDAC inhibitors, whereas qPCR was used to verify the miRNA expression. Results：In vitro cell experiments confirmed that the HDAC inhibitors TSA and SAHA can down-regulate the expres-sion of HER-2 in breast cancer cell lines. TSA can down-regulate the expression of HER-2 gene in BT474 and decrease the concentra-tions of 100 nmol by 10.7%and 200 nmol by 38.9%（P〈0.05）. TSA had no effect on the primary cells. The expression of HER-2 gene of BT474 was down-regulated by 93.9%（P〈0.05） in the 5μmol/L group but not in the 1μmol/L group. SAHA significantly affected the pri-mary cells at a concentration of 1μmol/L and reduced the cells at 87.1%at a concentration of 5μmol/L. Seven miRNAs were identified from the miRNA microarray. MiR-762 was used as a basis to identify the changes in miRNA. The miRNA sputum identified by miRNA microarray and qPCR may be associated with the down-regulation of HER-2 by HDAC inhibitors. Conclusion： HDAC inhibitors may down-regulate the expression of HER-2 in breast cancer cells by changing some miRNAs.