Objective  To investigate the mechanism of uc.339 in promoting proliferation, apoptosis and migration of renal cell carcinoma cells by miR-95/K-RAS.

  Method  Renal clear cell carcinoma and adjacent normal tissues of 76 cases were collected. The expression of uc.339 was detected by RNA in situ hybridization, and its correlation with pathological parameters of patients with ccRCC was analyzed. The proliferative activity of renal clear cell carcinoma cells was detected by CCK-8; Annexin V/PI was used to detect apoptosis; Transwell chamber was used to detect the migration ability of renal cancer cells; the regulation of miR-95 on the target gene K-RAS was verified by the double luciferase report experiment. Western blot was used to analyze the expression of the downstream gene protein of uc.339.

  Results  The uc.339 was positive in renal clear cell carcinoma, accounting for 77.63%(59/76); the positive expression was closely related to tumor size and TNM stage (P < 0.05). Uc.339 had no effect on the migration ability of renal cell carcinoma cells. Overexpression of uc.339 promoted the proliferative activity and inhibited apoptosis of renal cell carcinoma, while reduced the expression of uc.339 inhibited the proliferative activity and promoted apoptosis of renal cell carcinoma (P < 0.05). Quantitative real-time polymerase chain reaction (qRT-PCR) confirmed that the downstream target gene of uc.339 was miR-95; the double luciferase reporter gene experiment showed that the binding-site between miR-95 and K-RAS was specific, and K-RAS was the direct target gene of miR-95. The results of Western blot and rescue showed that K-RAS could be regulated by uc.339 regardless of the changes of uc.339 and miR-95.

  Conclusion  In renal cell carcinoma, uc.339 inhibits the expression of miR-95 and increases the level of K-RAS protein, and promotes the growth of renal cell carcinoma. This study provides a strong theoretical basis for the diagnosis and treatment of renal cell carcinoma in the future.