The miR 495-UBE2C-ABCG2/ERCC1 Axis Reverses DDP Resistance via Downregulation of Anti-Drug Genes in Cisplatin Resistant NSCLC Cells

Abstract

Resistance to DDP has become the leading cause of mortality in NSCLC. The microRNA dysregulation plays a vital role in tumor progression. In our study, we found that miR-495 was significantly downregulated in lung cancer tissue specimens. Our objective was to elucidate the functions, direct target genes, and molecular mechanisms of miR-495 in lung cancer. We found that miR-495 downregulated the expression of its substrate UBE2C by directly binds to the 3′-UTR of UBE2C. UBE2C is a proto-oncogene that is activated in lung cancer; however, its role in drug resistance is unclear. We found here that UBE2C expression was higher in cisplatin resistant NSCLC cells; this was associated with induced cisplatin resistant NSCLC cells proliferation, invasion and cisplatin resistant. EMT was contributed to cisplatin resistance. We also found that UBE2C knockdown downregulated the expression of the vimentin. In contrast, E-cadherin was upregulated. Importantly we found that miR-495 and UBE2C were associated with cisplatin resistance. We performed to evaluate their effects on cell proliferation and cisplatin resistant. We also performed EMT, cell migration and invasion assays in cisplatin resistant NSCLC cells overexpressing miR-495 and under expressing UBE2C. Furthermore, Bioinformatics assays coupled with WB and luciferase assays revealed that UBE2C directly binds to the 5′-UTR of the drug resistance genes, ABCG2 and ERCC1. We also found that miR-495 reduced the expression of ABCG2 and ERCC1 via regulation of UBE2C. Collectively, our results indicated that miR495-UBE2C-ABCG2/ERCC1 axis reverses DDP resistance via downregulation of anti-drug genes and reducing EMT in cisplatin resistant NSCLC cells. Funding Statement: This work was supported by the Science and Technology Development Foundation of Yantai (2015ZH082), Natural Science Foundation of Shandong Province (ZR2018QH004, ZR2016HB55, ZR2017PH067 and ZR2017PH028), and Research Foundation of Binzhou Medical University (BY2015KYQD29 and BY2015KJ14). Competing Interests: The authors declare no competing financial interests. Ethics Approval Statement: The experimental protocol was approved by the Research Ethics Committee of Binzhou Medical University, China (No. 2017-016-01 for human lung cancer specimen and No. 2017-009-09 for mouse experiments in vivo) and the written informed consent was obtained from all subjects. Informed consent was obtained from all individual participants included in the study. All patients were staged based on the criteria of the 7th Edition of the AJCC Cancer Staging Manual: Stomach (2010).