miR-20a induces cisplatin resistance of a human gastric cancer cell line via targeting CYLD
miR-20a induces cisplatin resistance of a human gastric cancer cell line via targeting CYLD
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DOI：
10.3892/mmr.2016.5413
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发表时间：
2016-08-01
影响因子：
3.4
通讯作者：
Wang, Tongshan
中科院分区：
文献类型：
--
作者：
Zhu, Mingxia;Zhou, Xin;Wang, Tongshan
已经证明微小RNA（miRNAs）的失调有助于癌细胞的耐药性，并且持续的核因子（NF）κ B活化在肿瘤对化疗的耐药性中也是关键的。在本研究中，确定了miRNA（miR）-20 a在调节胃癌（GC）化疗耐药性中的重要作用。逆转录-定量聚合酶链反应检测miR-20 a的表达水平。此外，使用3-（4，5-二甲基噻唑-2-基）-2，5-二苯基四唑溴化物检测与miR-20 a上调或下调相关的癌细胞耐药表型变化。免疫印迹法和免疫组化法检测蛋白表达水平。流式细胞术检测顺铂诱导的细胞凋亡。发现miR-20 a在GC血浆和组织样品中显著上调。此外，miR-20 a在顺铂（DDP）耐药患者的GC血浆和组织中以及DDP耐药胃癌细胞系（SGC 7901/DDP）中上调。miR-20 a的表达与圆柱瘤病（CYLD）的表达呈负相关。随后，荧光素酶活性的评估证实CYLD是miR-20 a的直接靶基因。miR-20 a抑制剂可上调SGC 7901/DDP细胞CYLD蛋白的表达，下调p65、livin和survivin蛋白的表达，导致细胞凋亡比例升高。而miR-20 a的异位表达可显著抑制CYLD的表达，上调p65、livin和survivin的表达水平，降低DDP诱导的胃癌细胞凋亡。综上所述，本研究的结果表明，miR-20 a直接抑制CYLD的表达，导致NF κ B B通路和下游靶点livin和survivin的激活，这可能诱导GC化疗耐药性。改变miR-20 a的表达可能是治疗胃癌耐药的一个潜在的治疗策略。
The dysregulation of microRNAs (miRNAs) has been demonstrated to contribute to drug resistance of cancer cells, and sustained nuclear factor (NF)kappa B activation is also pivotal in tumor resistance to chemotherapy. In the present study, an essential role for miRNA (miR)-20a was identified in the regulation of gastric cancer (GC) chemoresistance. The expression level of miR-20a was assayed by reverse transcription-quantitative polymerase chain reaction. Additionally, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to detect the drug-resistance phenotype changes of cancer cells associated with upregulation or downregulation of miR-20a. Protein expression levelss were measured by western blotting and immunohistochemistry. Flow cytometry was used to detect cisplatin-induced apoptosis. It was found that miR-20a was markedly upregulated in GC plasma and tissue samples. Additionally, miR-20a was upregulated in GC plasma and tissues from patients with cisplatin (DDP) resistance, and in the DPP-resistant gastric cancer cell line (SGC7901/DDP). The expression of miR-20a was inversely correlated with the expression of cylindromatosis (CYLD). Subsequently, the assessment of luciferase activity verified that CYLD was a direct target gene of miR-20a. Treatment with miR-20a inhibitor increased the protein expression of CYLD, downregulated the expression levels of p65, livin and survivin, and led to a higher proportion of apoptotic cells in the SGC7901/DDP cells. By contrast, ectopic expression of miR-20a significantly repressed the expression of CYLD, upregulated the expression levels of p65, livin and survivin, and resulted in a decrease in the apoptosis induced by DDP in the SGC7901 cells. Taken together, the results of the present study suggested that miR-20a directly repressed the expression of CYLD, leading to activation of the NF kappa B pathway and the downstream targets, livin and survivin, which potentially induced GC chemoresistance. Altering miR-20a expression may be a potential therapeutic strategy for the treatment of chemoresistance in GC in the future.