Expression Of Histidine Triad Nucleotide-binding Protein 1 In Clear Cell Renal Cell Carcinoma And Its Clinical Significance

Objective To determine the expression of histidine triad nucleotide-binding protein 1 (HINT1) mRNA and protein in clear cell renal carcinoma(ccRCC) and their relationships with clinicopathological features.Methods The SYBR Green I real time quantitative reverse transcription PCR (RFQ-RT-PCR) was used to detect the expression of HINT1 mRNA in 36 cases of fresh ccRCC and 37 cases of normal kidney tissues (29 paired cases), as well as their relationships with clinicopatholgical features were analysized; Immunohistochemistry was used to detect the distribution and expression of HINT1 proteins in 30 cases of paraffin-embedded fresh ccRCC tissues and 12 cases of paraffin-embedded adjacent normal kidney tissues, as well as their relationships with clinicopatholgical features were analysized.Results The expression levels of HINT1 mRNA in 29 cases of paired ccRCC and normal kidney tissues were 0.209±0.033 and 0.733±0.136, respectively (P<0.001). The expression levels of HINT1 mRNA in 36 cases of ccRCC and 37 cases of normal kidney tissues was 0.245±0.035 and 0.694±0.108, respectively (P<0.001). The positive expression rate of HINT1 protein in the adjacent normal kidney tissues was 100% (12/12), diffusibly distributing in nucleus and cytoplasm. HINT1 protein immuostaining in proximal convoluted tubule was stronger than in distal convoluted tubule, while it was partially weaker in glomerular basement membrane and Bowman's capsule. HINT1 protein expression was negative in renal interstitium. HINT1 protein expression distributing in nucleus and cytoplasm was 60%(18/30) positive in ccRCC, while it was negative in intercellular substance (P<0.01). The tendency of HINT1 mRNA expression in ccRCC and normal kidney tissues and its relationship with clinicopatholgical features were the same with the expression of HINT1 protein. The expressions of HINT1 mRNA and protein in stages T1+2 of ccRCC were higher than those in stages T3+4 (P<0.05), and the same was found in normal kidney tissues and ccRCC tissues. The expression of HINT1 mRNA and protein were not correlated with Fuhrman grade, gender, age and tumor size (P>0.05).Conclusion HINT1 may play a role as tumor suppressor gene in ccRCC. The abnormal expression of HINT1 may be associated with the abnormal regulation before the level of translation. Abnormal expressions of HINT1 mRNA and protein may serve as a marker for the prognosis of ccRCC patients.