[Expression of glycoprotein non-metastatic melanoma protein B in clear-cell renal cell carcinoma and clinical implication thereof].

Objective: To elucidate the glycoprotein non-metastatic melanoma protein B(Gpnmb) expression in clear-cell renal cell carcinoma (ccRCC) and to determine its potential prognostic relevance.
Methods: A total of 12 pairs of ccRCC tissue specimens were collected from patients undergoing surgery in our hospital from March 2009 to March 2012. Gpnmb expression were determined by immunohistochemistry and correlated with clinical variables. Survival analysis was carried out for another 43 evaluable patients.
Results: The expression level of Gpnmb was significantly higher in metastatic ccRCCs than that in matched primary samples ((6.36±4.01) vs (3.14±2.38) scores, P=0.036). The high expression of Gpnmb was not affected by age, gender, clinical stage and pathological grade (all P>0.05). Kaplan-Meier analysis disclosed significant differences in overall survival for patients with higher and lower average Gpnmb expression levels (P=0.020). Cox regression analysis revealed that a high Gpnmb protein expression level in the tumor cell could be identified as an independent poor prognostic marker of overall survival in ccRCC patients (P=0.049).
Conclusion: Over expression of Gpnmb in tumour cell predicts a poor prognosis of patients with ccRCC.