LncRNA SNHG16 Facilitates Nasopharyngeal Carcinoma Progression by Acting as ceRNA to Sponge miR-520a-3p and Upregulate MAPK1 Expression

BACKGROUND: Accumulating evidence shows that lncRNAs are widely involved cellular processes of various tumors. The aim of this study was to explore the potential role and molecular mechanism of lncRNA SNHG16 in nasopharyngeal carcinoma (NPC). METHODS: SNHG16, miR-520a-3p, and MAPK1 levels were measured by RT-qPCR assay. CCK-8, colony formation, transwell, and flow cytometry assays were adopted to analyze the proliferation, migration, invasion, and apoptosis of NPC cell lines (SUNE1 and 5–8F). Murine xenograft model was used to investigate tumor growth and metastasis in vivo. Immunohistochemical staining was employed to evaluate the levels of Bcl-2, cleaved caspase-3, Bax, and Ki-67. Dual-luciferase reporter assays were conducted to analyze the binding ability between miR-520a-3p and SNHG16 or MAPK1. RESULTS: SNHG16 was overexpressed in NPC tissues and cells. High SNHG16 expression indicated a poor prognosis. SNHG16 knockdown could cause significant inhibition on cell proliferation and metastasis, induce cell apoptosis in NPC cells, and repressed tumor growth and metastasis in vivo. Additionally, SNHG16 could directly bind to miR-520a-3p, thus positively regulating MAPK1 expression. Moreover, functional analysis indicated that miR-520a-3p exerted a tumor-suppressing role in NPC progression. Rescue assays demonstrated that MAPK1 upregulation could abrogate the inhibitory effects on NPC cell proliferation and metastasis, as well as the promoting effects on NPC cell apoptosis caused by SNHG16 knockdown. In conclusion, SNHG16 contributed to the proliferation and metastasis of NPC cells by modulating the miR-520a-3p/MAPK1 axis. CONCLUSION: These results suggest that SNHG16 acts as an oncogene in the progression of NPC via modulating the miR-520a-3p/MAPK1 axis.