Affiliation: Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China.
It has been demonstrated that PPARγ agonists effectively inhibit proliferation, metastasis as well as induce apoptosis in human cancer cell lines. In this study, twenty-two rosiglitazone analogues, 5-benzylidene-3,4- dihalo-furan-2-one derivatives, which have been identified as PPARγ agonists in our previous work, were evaluated for their antitumor effects. Among these compounds, (Z)-3,4-dibromo-5-(3-methoxy-4-((3,5,6-trimethylpyrazin-2- yl)methoxy)benzylidene)furan-2(5H)-one (6w) shows the best antitumor activity, especially against the leukemia cell line U937, resulting in significant cytotoxicity, increased apoptosis and changes in mitochondrial membrane potential. Up-regulation of pro-apoptosis-associated proteins (Bax, caspase-3 and caspase-9) and cleaved PARP as well as down-regulation of anti-apoptosis protein Bcl-2 are observed in 6w-treated U937 cells. It was shown that the antitumor effect of 6w stems from its ability to inhibit the PPARγ-dependent expression of NF-κB and GSK-3β.