Expression of nNOS and correlation with clinical prognosis in renal clear cell carcinoma

Abstract

Objective To investigate the expression of neural-nitric oxide synthase (nNOS) in renal clear cell carcinoma and its clinical significance. Methods The expression of nNOS mRNA in 533 samples of TCGA database was analyzed with Student t test, and statistical analysis was performed to assess the relationship between nNOS expression and clinical prognosis with Kapla-Meier test. Western blot analysis of nNOS protein expression in 10 cases of clear cell renal cell carcinoma(ccRCC) from department of urology of Wuhan union hospital with student t test. Results The mRNA levels of nNOS in 72 cases of ccRCC in tumor tissues and adjacent tissues and were 2.99±0.28 and -1.57±0.17, it is significantly lower than those in adjacent tissues (P<0.01). The mRNA levels of nNOS in 533 cases of ccRCC, in tumor tissues and adjacent tissues and were 2.99±0.28 and -1.76±0.05, it is significantly lower than those in adjacent tissues (P<0.01 ). A total of 533 sample studies showed a low correlation between nNOS expression and clinical T stage, T1 -1.59±0.08, T2 -1.96±0.13, T3 -1.90±0.09, T4 -2.38±0.28 (P=0.0029) and -1.63±0.06 and -2.16±0.13 between non-metastasis and no-metastasis (P=0.0009), and -1.57±0.08 and -2.03±0.11 between non-recurrence and recurrence (P=0.008). Survival analysis showed that the overall survival time were (40.3±5.6) months and (48.3±5.7) months in lower and higher nNOS expression, and disease free survival time were(37.1±2.1) months and (40.3±5.6) months in lower and higher nNOS expression, both with shorter time in low expression of nNOS (P<0.01). nNOS proteins were 1.02±0.16 and 0.61±0.11 in tumor tissues and adjacent tissues with significantly lower expression(P<0.05). Conclusions The mRNA and protein of nNOS are lower in ccRCC with a poor prognosis of ccRCC. Key words: Clear cell renal cell carcinoma; Neural-nitric oxide synthase; Prognosis