OncoTargets and Therapy (Apr 2020)
Long Non-Coding RNA SPRY4-IT1 Reverses Cisplatin Resistance by Downregulating MPZL-1 via Suppressing EMT in NSCLC
Abstract
Yunyao Ye,1,2,* Jingyao Gu,1,* Pei Liu,1,3,* He Wang,1,4 Lihua Jiang,1 Tianyao Lei,1 Shanxun Yu,2 Gaohua Han,2 Zhaoxia Wang1 1Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People’s Republic of China; 2Department of Oncology, Taizhou People’s Hospital, Taizhou, Jiangsu, People’s Republic of China; 3Department of Digestive Oncology, The Fourth Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People’s Republic of China; 4Department of Oncology, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zhaoxia WangDepartment of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, People’s Republic of ChinaTel +86-25-58509810Fax +86-25-58509994Email [email protected]: Long non-coding RNA (lncRNA) SPRY4 intronic transcript 1 (SPRY4-IT1) is reported to play important roles in the occurrence and development of many tumors. However, the possible role of SPRY4-IT1 in cisplatin (DDP) resistance of non-small-cell lung cancer (NSCLC) remains unclear. The aim of this study is to investigate the functions and molecular mechanisms underlying SPRY4-IT1 of cisplatin resistance in NSCLC.Methods: Expression of SPRY4-IT1 was analyzed in A549 and cisplatin-resistant A549/DDP cell lines by quantitative real-time polymerase chain reaction (RT-qPCR). Overexpression techniques were applied to investigate the biological functions of SPRY4-IT1 in cisplatin-resistant A549/DDP cells. The effects of SPRY4-IT1 on proliferation and apoptosis were evaluated using cell counting kit-8 (CCK8) assays, colony formation assay and flow-cytometric analysis. The expressions of epithelial–mesenchymal transition (EMT)-associated proteins, including E-cadherin and Vimentin, were detected by Western blot. Microarray analysis was performed to identify the putative targets of SPRY4-IT1, which were further verified by Western blotting and RT-qPCR. A549/DDP cells transfected with pCDNA-SPRY4-IT1 were injected into nude mice in order to verify the effect of SPRY4-IT1 on cisplatin resistance in vivo.Results: The present study demonstrated that SPRY4-IT1 expression was decreased in A549/DDP cells compared with parental A549 cells. Upregulation of SPRY4-IT1 suppressed cell proliferation and caused apoptosis of A549/DDP cells both in vitro and in vivo. MPZL-1 was negatively regulated by SPRY4-IT1. Furthermore, upregulation of SPRY4-IT1 and downregulation of MPZL-1 could suppress epithelial–mesenchymal transition (EMT), which was characterized by increased E-cadherin expression and decreased Vimentin expression.Conclusion: Upregulation of SPRY4-IT1 reversed the cisplatin-resistant phenotype of NSCLC partially by downregulating MPZL-1 via inhibiting EMT process.Keywords: long non-coding RNA, SPRY4-IT1, cisplatin resistance, MPZL-1, EMT
