Gu Shi-Yan, Chen Hong-Yu, Dai Huang-Mei, Li Xin-Yang, Zhang Zun-Zhen
Department of Enviromental Health and Occupational Medicine,West China School of Public Health,Sichuan University,Chengdu 610041,China.
Sichuan Da Xue Xue Bao Yi Xue Ban. 2017 Nov;48(6):828-833.
To explore the changes of micro RNA 155 (miR-155),BTB and CNC homologous protein 1 (BACH1),quinone oxidoreductase 1 (NQO1) and heme-oxygenase-1 (HO-1) in the process of arsenic trioxide-induced cell death,and to clarify the relationship between miR-155 and BACH1,providing experimental basis for the sensitivity of arsenic trioxide (ATO) treatment.
Human lung adenocarcinoma cell line A549 cells were treated with different concentrations of ATO. MTT assay and total antioxidant capacity detection kit were used to determine cell viability and total antioxidant capacity,respectively. BACH1,NQO1 and HO-1 protein expression were probed by Western blot and real-time fluorescence quantitative (qRT-PCR) was utilized to test the miR-155 level. A549 cells were transfected with miR-155 mimic and its negative control,then the expression level of miR-155 was detected by qRT-PCR,and these cells were treated with 20 μmol/L for 24 h followed by MTT and Western blot detection.
10 μmol/L ATO significantly reduced the cell viability in A549 cells. 10 μmol/L and 20 μmol/L ATO treatment activated BACH1 expression and inhibited miR-155,NQO1 and HO-1 expression,leading to decreased total antioxidant capacity. Importantly,the cell death induced by 20 μmol/L ATO was significantly decreased in miR-155 mimic transfection cells in comparison with non-transfected cells and miR-155 mimic negative control transfected cells. Moreover,high expression of miR-155 reduced BACH1 activation and increased NQO1 and HO-1 expression in cells treated with 20 μmol/L ATO ( <0.05).
Restraining total antioxidant capacity contributes to ATO induced cell death,the underlying mechanisms may be that ATO can activate BACH1 expression through inhibition of the miR-155 level,leading to subsequent inhibition of NQO1 and HO-1 expression. Taken together,these data suggest that miR-155 and BACH1 could be used as sensitivity targets for ATO treatment in lung cancer.
探讨三氧化二砷诱导细胞死亡过程中微小RNA 155（miR-155）、BTB和CNC同源蛋白1（BACH1）、醌氧化还原酶1（NQO1）和血红素加氧酶-1（HO-1）的变化，阐明miR-155与BACH1之间的关系，为三氧化二砷（ATO）治疗的敏感性提供实验依据。
用不同浓度的ATO处理人肺腺癌细胞系A549细胞。分别采用MTT法和总抗氧化能力检测试剂盒测定细胞活力和总抗氧化能力。通过蛋白质免疫印迹法检测BACH1、NQO1和HO-1蛋白表达，利用实时荧光定量（qRT-PCR）检测miR-155水平。将miR-155模拟物及其阴性对照转染A549细胞，然后通过qRT-PCR检测miR-155的表达水平，并用20 μmol/L处理这些细胞24 h，随后进行MTT和蛋白质免疫印迹检测。
10 μmol/L ATO显著降低A549细胞的活力。10 μmol/L和20 μmol/L ATO处理激活了BACH1表达，抑制了miR-155、NQO和HO-1表达，导致总抗氧化能力下降。重要的是，与未转染细胞和miR-155模拟物阴性对照转染细胞相比，miR-155模拟物转染细胞中20 μmol/L ATO诱导的细胞死亡显著减少。此外，在20 μmol/L ATO处理的细胞中，miR-155的高表达降低了BACH1的激活，并增加了NQO1和HO-1的表达（<0.05）。
抑制总抗氧化能力有助于ATO诱导细胞死亡，其潜在机制可能是ATO通过抑制miR-155水平激活BACH1表达，进而导致随后NQO1和HO-1表达的抑制。综上所述，这些数据表明miR-155和BACH1可作为肺癌ATO治疗敏感性的靶点。
