MicroRNA‐501‐3p inhibits the proliferation of kidney cancer cells by targeting WTAP

BACKGROUND: Emerging evidence suggests that miR‐501‐3p plays an important role in the pathogenesis and progression of various carcinomas. However, its role and underlying mechanisms in renal cell carcinoma (RCC) remain to be elucidated. METHODS: Quantitative RT‐PCR, western blot, and bioinformatics methods were used to evaluate the expression of miR‐501‐3p and Wilms’ tumor 1‐associating protein (WTAP) in RCC cell lines and clinical tissues. The effects of miR‐501‐3p on the proliferation of RCC cells were investigated using flow cytometric, colony formation, and CCK8 assays. The target gene of miR‐501‐3p was confirmed by western blotting, qRT‐PCR, and dual‐luciferase reporter assays. The levels of RNA methylation with N6‐methyladenosine (m(6)A) following miR‐501‐3p overexpression or knockdown of its target gene were quantified using a dot‐blot assay. RESULTS: miR‐501‐3p expression was significantly downregulated in human RCC cell lines and tissues. In contrast, its overexpression markedly inhibited cancer cell proliferation in vitro by inducing G1 phase arrest. Moreover, WTAP was verified as a direct target gene of miR‐501‐3p. WTAP gene knockdown alone efficiently produced the same cancer‐inhibiting effects as miR‐501‐3p overexpression, with the level of m(6)A in RCC cells being decreased under both scenarios. The intermolecular interaction between miR‐501‐3p and WTAP was further substantiated by rescue experiments. CONCLUSION: RCC progression is regulated via the miR‐501‐3p/WTAP/CDK2 axis and is inhibited by the overexpression of miR‐501‐3p.