Abstract: Objective   To investigate the expression of microRNA-30c （miR-30c） in renal cell carcinoma and its relationship with clinicopathological features and prognosis. Methods Ninety-five cases of surgical removed renal cell carcinoma tissues and 82 cases of paracancerous tissues from January 2012 to December 2015 were collected. Real-time quantitative PCR （QPCR） was used to detect the level of miR-30c in the above tissues. The relationship between miR-30c expression and clinicopathological parameters （gender， age， TNM stage， lymph node metastasis， distant metastasis and T staging） and prognosis of renal cell carcinoma were analyzed. Cox regression model was used for multivariate analysis. Results QPCR detection showed that the expression level of miR-30c in 95 cases of renal cell carcinoma was 0.561±0.378， lower than 1.220±0.820 in 82 cases of adjacent tissues （P＜0.001）. The expression of miR-30 in renal cell carcinoma was not related to sex， age and distant metastasis （P＞0.05）， but related to TNM stage， lymph node metastasis and T stage （P＜0.05）. The relative expressions of miR-30c in Ⅲ-Ⅳ stage， lymph node metastasis and T3-T4 stage were 0.422±0.219， 0.442±0.299 and 0.408±0.194， lower than 0.671±0.439， 0.619±0.400 and 0.654±0.431 in Ⅰ-Ⅱ stage， no lymph node metastasis and T1-T2 stage （P＜0.05）. The high expression rates of miR-30c in Ⅲ-Ⅳ stage， lymph node metastasis and T3-T4 stage were 21.43％（9／42）， 16.13％（5／31） and 19.44％（7／36）， lower than 41.51％（22／53）， 16.13％（26／64） and 40.68％（24／59） of Ⅰ-Ⅱ stage， no lymph node metastasis and T1-T2 stage （P＜0.05）. The median overall survival of miR-30c expression in the low level group was 37.0 months， which was significantly shorter than that in the high level group （＞60.0 months）， and the difference was statistically significant （P＜0.05）. Cox regression analysis showed that TNM stage， lymph node metastasis， distant metastasis， T stage and miR-30c expression were independent prognostic factors of renal cell carcinoma. Conclusion The low expression of miR-30c in renal carcinoma is involved in the development of renal cancer and is related to the prognosis. The prognosis of low expression of miR-30c is poor， and the level of miR-30c is an independent factor affecting the prognosis.

Key words: Renal cell carcinoma, MicroRNA-30c, Clinicopathology, Prognosis