ABSTRACT
@#【Objective】 To investigate the relationship between the expression of PRDX3 （thioredoxin-dependent peroxide reductase）and the occurrence and development of ccRCC （clear cell renal cell carcinoma）. 【Methods】 The expression of PRDX3 was first verified in 16 cases of ccRCC tissues and adjacent normal tissues. In the present study ， according to the PRDX3 over-expression level，we established the stable PRDX3 overexpression cell lines and knockdown cell lines in 786-O cell lines. We detected the growth rate of tumor cells after overexpression and knockdown of PRDX3. Interaction proteins with PRDX3 were searched by anti-flag pull-down test combined with LC- MS/MS technique. The interaction between PRDX3 and PRDX1（peroxiredoxin 1）was preliminarily explored.【Results】The western blot results showed that PRDX3 were down- regulated in 14 out of 16 ccRCC tissue samples about 1.78 times. Stable PRDX3 overexpression and knockdown cell lines and those control group were successfully established［786O- PRDX3（+）and 786O- PRDX3（-），786O- PRDX3 KN and 786O- PRDX3 NCi］. PRDX3 expression in 786O- PRDX3（+）was 2.1 times higher than 786O- PRDX3（-）at mRNA level and 1.8 times at protein level. PRDX3 expression in 786O- PRDX3 KN was 0.48 times lower than 786O-PRDX3 NCi at mRNA level and 0.51 times at protein level. The cell growth rate of 786O-PRDX3 （+）cell lines was significantly lower than that of 786O-PRDX3（-）. Meanwhile ，there was no significant difference in 786O-PRDX3 KN and NCi cell lines. Pull-down results shows that PRDX3 may interact with PRDX1 through disulfide bond and the binding sites of those two proteins were identified respectively.【Conclusion】PRDX3 was down- regulated expression in renal clear cell carcinoma and the interaction with PRDX1 may be involved in the occurrence and development of tumor. Increasing the expression level of PRDX3 can significantly reduce the growth rate of tumor cells. Based on PRDX3 ，it is possible to develop targeted drugs for treating renal clear cell carcinoma.