LncRNA SNHG12 contributes to multidrug resistance through activating the MAPK/Slug pathway by sponging miR-181a in non-small cell lung cancer

Small nucleolar RNA host gene 12 (SNHG12), as one of the long non-coding RNAs (lncRNAs), plays an oncogenic role in various cancers, however, its role in the chemoresistance of non-small cell lung cancer (NSCLC) is unclear. In this study, we investigated the effect of SNHG12 on multidrug resistance (MDR) in NSCLC. The results showed that SNHG12 was high-expressed and miR-181a was low-expressed in NSCLC tumor tissues and cell lines. Knockdown of SNHG12 reversed the resistance to cisplatin, paclitaxel and gefitinib in A549/DDP, A549/PTX and PC9/AB2 cells through inducing cell apoptosis. Moreover, SNHG12 silencing suppressed MAPK1 and MAP2K1 expression by upregulating miR-181a, leading to inhibition of the MAPK/Slug pathway through decreasing phosphorylated MAPK1 (p-MAPK1), phosphorylated MAP2K1 (p-MAP2K1) and Slug levels. Furthermore, downregulation of SNHG12 enhanced the sensitivity of NSCLC cells to cisplatin in nude mice. Overall, our study is the first to identify a SNHG12-miR-181a-MAPK/Slug axis to elucidate in part how SNHG12 exert functions in NSCLC MDR, providing a novel therapeutic target to overcome MDR in NSCLC.