Low Expression of Mitochondrial Ribosomal Protein S5 is Associated With Poor Prognosis in Patients With Clear Cell Renal Cell Carcinoma.

Abstract

Mitochondrial ribosomal protein S5 (MRPS5) is abnormally expressed in various tumor tissues and may be a key molecule for the regulation of tumors. Our aim is to investigate the relationship between the expression of MRPS5 in clear cell renal cell carcinoma (ccRCC) and the prognosis of patients. MRPS5 expression in fresh tumoral tissues and peritumoral tissues of patients with ccRCC was examined by quantitative reverse transcription polymerase chain reaction, western blotting, and immunohistochemical staining, respectively. MRPS5 expression level in paraffin-embedded tumoral tissue samples with ccRCC was evaluated by immunohistochemical scoring criteria. The relationship between the expression of MRPS5 and the clinicopathological parameters and prognosis of patients with ccRCC was analyzed statistically. The expression of MRPS5 mRNA and protein in fresh tumoral tissues was lower than that in peritumoral tissues. Among 160 paraffin-embedded tumoral tissue samples, 99 cases (61.9%) showed high expression and 61 cases (38.1%) showed low expression of MRPS5. The expression level of MRPS5 was significantly correlated with T classification, TNM stage, and Fuhrman grade. Kaplan-Meier method and log-rank test indicated that patients with low MRPS5 expression had significantly poorer overall survival and recurrence-free survival than high MRPS5 expression. Multivariate analysis revealed that MRPS5 expression was an independent predictor of overall survival and recurrence-free survival, respectively. MRPS5 low expression was a risk factor for the prognosis of patients. The expression level of MRPS5 is significantly correlated with the postoperative survival status, which has the potential to be used as a novel prognostic biomarker for patients with ccRCC.