Li Angui, Song Jianfei, Lai Qi, Liu Bangqing, Wang Haiyong, Xu Yinhui, Feng Xiaoyan, Sun Xiaolin, Du Zhenzong
Department of Cardiothoracic Surgery, The Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China.
Department of Cardiothoracic Surgery, The 2nd Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China.
Int J Exp Pathol. 2016 Dec;97(6):412-421. doi: 10.1111/iep.12212. Epub 2016 Dec 20.
Development of multiple drug resistance has been attributed to the overexpression of the ATP-binding cassette B1 (ABCB1) gene. In this study, the major purpose was to assess the expression and methylation levels of ABCB1 in human lung adenocarcinoma and to reveal the relationship between these processes and acquisition of cisplatin (DDP) resistance in the human cancer cell line A549. Methylation and expression levels of the ABCB1 gene ABCB1 in clinical human lung tissue were assessed using bisulphite sequencing, reverse transcription real-time PCR (RT -PCR) and Western blot methods. Cell viability, DDP resistance and apoptosis of A549 cells were evaluated using the Cell Counting Kit-8 and fluorescence-activated cell sorter analysis. Our results showed that the onset of resistance to the cisplatin analogue, DDP, was associated with hypermethylation of the ABCB1 gene. Expression of the ABCB1 gene was enhanced at both mRNA and protein levels. Treatment with 5-Aza-C contributed to the hypomethylation of the ABCB1 gene and decreased ABCB1 protein expression in A549 cells. In conclusion, this in vitro and human tissue study of lung adenocarcinoma cells demonstrated that hypermethylation of the ABCB1 gene correlated with increased gene expression and was associated with the acquisition of resistance to the cisplatin analogue, DDP in human lung adenocarcinoma cells. Taken together, our study highlighted the connection between increased ABCB1 methylation level and upregulated expression of the gene in lung cancer. Moreover, the abnormally high expression of ABCB1 in A549 cells contributed to the development of the DDP resistance.
多重耐药性的产生归因于ATP结合盒B1（ABCB1）基因的过表达。在本研究中，主要目的是评估ABCB1在人肺腺癌中的表达和甲基化水平，并揭示这些过程与人类癌细胞系A549中顺铂（DDP）耐药性获得之间的关系。使用亚硫酸氢盐测序、逆转录实时PCR（RT-PCR）和蛋白质印迹法评估临床人肺组织中ABCB1基因的甲基化和表达水平。使用细胞计数试剂盒-8和荧光激活细胞分选仪分析评估A549细胞的细胞活力、DDP耐药性和凋亡。我们的结果表明，对顺铂类似物DDP的耐药性产生与ABCB1基因的高甲基化有关。ABCB1基因在mRNA和蛋白质水平上的表达均增强。用5-氮杂胞苷处理导致A549细胞中ABCB1基因的低甲基化并降低ABCB1蛋白表达。总之，这项对肺腺癌细胞的体外和人体组织研究表明，ABCB1基因的高甲基化与基因表达增加相关，并与人类肺腺癌细胞中对顺铂类似物DDP的耐药性获得有关。综上所述，我们的研究突出了肺癌中ABCB1甲基化水平升高与基因表达上调之间的联系。此外，A549细胞中ABCB1的异常高表达促成了DDP耐药性的发展。
