OBJECTIVE To investigate the expression of peroxisome proliferator-actived receptor-gamma (PPAR-gamma)and the inducement of apoptosis by PPAR-gamma ligand in renal cell carcinoma(RCC)-derived cell lines.
Methods: RT-PCR and Western blot analysis were performed to determined the expression of PPAR-gamma mRNA and protein in two RCC derived cell lines(786-O and A498) and two normal kidney(NK)-derived cell lines(HK-2 and HMCC). Two RCC cell lines were treated with 50 micromol/L troglitazoned for and evaluated for the effects of antidiabetic thiazolidinediones (TZDs) on the cells apoptosis by fluorescence microscopy and DNA ladder assay. The mutative expressions of Bcl-2 and Bax before and after TZDs treatment were also performed by western blot analysis.
Results: The expression of PPAR-gamma was observed to be stronger in 786-O and A498 cells than in HK-2 and HMCC cells by RT- PCR and Western blot analysis. Treated with 50 micromol/L troglitazone (for 48 h) it induced typical apoatosis in 786-O and A498 cells. After treatment, a decrease in Bcl-2 expression in RCC cells was observed by Western blot analysis,and the expression of Bax,however,was up-regulated.
Conclusion: The results reveal that troglitazone has the tumor-suppressive effect on RCC cells. High-affinity PPAR-gamma ligands (TZDs) may be the candidates for a novel approach to the treatment of this refractory neoplasm.