lncRNA RNCR2 facilitates cell proliferation and epithelial-mesenchymal transition in melanoma through HK2-mediated Warburg effect via targeting miR-495-3p.

Melanoma is a potentially lethal skin cancer with a high death rate. LncRNAs were reported to be implicated in melanoma progression. However, the function and mechanisms of lncRNA RNCR2 in melanoma are little known. In this study, RNCR2, miR-495-3p, and HK2 expression levels were measured in melanoma tissue specimens and cell lines by qPCR. EdU and CCK-8 assays were performed to assess cell proliferation. Enolase activity, ATP level, lactate production, and glucose consumption measurement kits were used to evaluate the glycolysis of tumor cells. Immunofluorescence and western blot were used to detect the expression of epithelial-mesenchymal transition (EMT) and glycolysis-related proteins. Luciferase reporter assay was applied to confirm the target relationships. The role of RNCR2 in tumorigenesis was examined using murine xenograft models. LncRNA RNCR2 was upregulated in melanoma tissues and cell lines. Cell function detection showed that RNCR2 knockdown remarkably inhibited cell proliferation and EMT via glycolysis, as well as reduced the growth of a tumor. Mechanically, RNCR2 was confirmed to bind to miR-495-3p and positively regulated HK2 expression level, and the miR-495-3p level was negatively correlated with RNCR2 or HK2 in melanoma tissues. Further, miR-495-3p downregulation or HK2 upregulation partially reversed RNCR2 knockdown-induced inhibition of melanoma cell growth, EMT, and glycolysis. Collectively, RNCR2 might be an oncogenic lncRNA to promote tumor cell glycolysis and accelerate tumor growth via the miR-495-3p/HK2 axis, providing a promising treatment target for melanoma.