RESUMO
AIM: To investigate the expression of the oxidative stress proteins in human clear-cell renal cell carcinoma (CRCC) cell line (RLC-310) and normal renal proximal tubule epithelial cell line (HK-2), the CRCC and the corresponding normal renal tissues. METHODS: RLC-310 and HK-2 cells were cultured in vitro. Total proteins of the two cell lines were separated by PF-2D protein fractionation system. The differentially expressed proteins of the two cell lines were analyzed using capillary LC-ESI-MS/MS and identified using the protein database. The representative differential oxidative stress proteins were verified by immunohistochemistry in the CRCC and corresponding normal renal tissues. RESULTS: Twelve differentially expressed oxidative stress proteins were identified, including peroxiredoxin-1, peroxiredoxin-6 (PRX-6), superoxide dismutase[Cu-Zn] SOD1, catalase, glutathione peroxidase 1, glutathione synthetase, glutathione S-transferase Pi (GSTPi), thioredoxin, heat shock protein 10 (HSP10), HSP60, HSP70 and HSP90. Three representative differential proteins PRX-6, HSP60 and GSTPi were both expressed in RLC-310 and HK-2, and the levels of these proteins were significantly higher in RLC-310 than those in HK-2 (P<0.05). The levels of these proteins were significantly higher in CRCC than those in corresponding normal renal tissues (P<0.05). CONCLUSION: A series of oxidative stress proteins are overexpressed in the CRCC. They play an important role in preventing oxidative damage of CRCC cells.