Abstract: Objective To investigate the effect of miR?29a?3p on the proliferation and invasion of kidney renal clear cell carcinoma (KIRC) by regulating the expression of lysine?specific demethylase 5B (KDM5B) and its clinical significance. Methods The expression of KDM5B in patients with different KIRC stages and its impact on the prognosis and survival of KIRC were analyzed by using TCGA database. TCGA data were used to analyze the expression of miR?29a?3p in patients with different KIRC stages and its correlation with KDM5B. The miR?29a?3p mimics, mimics?NC and miR?29a?3p inhibitor, denoted by miR?29a mimic group, mimics NC group and inhibitor group, respectively, were transfected into KIRC 786?O and Caki?1 cells, respectively, by liposome transfection technology. The expre?ssion levels of miR?29a?3p and KDM5B were detected by RT?qPCR. The cell proliferation ability was detected by MTS, and the cell invasion ability was detected by transwell. Dual luciferase reporter assay was used to verify the targeting relationship between miR?29a?3p and KDM5B. Results TCGA database analysis showed that the expression of KDM5B differed most among the patients with different KIRC stages, which were significantly affected the prognosis of KIRC patients (HR=2.882, P<0.001). The expression of miR?29a?3p bound to KDM5B was most different among the patients with different KIRC stages (P<0.001), and had the strongest correlation with KDM5B (r=-0.283, P<0.001). Dual luciferase reporter assay confirmed that miR?29a?3p was specifically bound to KDM5B. After overexpression of miR?29a?3p, the expression level of KDM5B was down?regulated in 786?O and Caki?1 cells, and the cell proliferation ability and the number of transmembrane cells were decreased (all P<0.05). After miR?29a?3p silencing, the expression level of KDM5B was up?regulated, and the cell proliferation ability and the number of transmembrane cells were increased (all P<0.05). Conclusions miR?29a?3p may inhibit the proliferation and invasion of KIRC cell lines 786?O and Caki?1 by inhibiting the expression of H3K4 demethylase KDM5B.

Key words: Kidney renal clear cell carcinoma, miR?29a?3p, KDM5B, Proliferation, Invasion