Clofibric Acid, a Peroxisome Proliferator-activated Receptor Alpha Ligand, Enhances a Suppressive Effect of Cis-diaminedichloroplatinum on Proliferation of Ovarian Carcinoma Cells

The purpose of this study was to elucidate the possible mechanism that clofibric acid (CA), a peroxisome proliferator-activated receptor α ligand, enhances a suppressive effect of cis-diaminedichloroplatinum (CDDP) on proliferation of the ovarian carcinoma line OVCAR-3. These cells was incubated with 0.5 μM/ml CDDP in the presence or absence of 50 μM CA or incubated with 50 μM CA alone for 72 hr. While treatment with CA alone did not affect proliferation of OVCAR-3 cells, simultaneous treatment with CDDP and CA significantly suppressed proliferation of the cells and significantly induced apoptosis compared to that with CDDP alone. Treatment with CDDP and CA significantly decreased the prostaglandin (PG) E2 level in the medium of the cells compared with treatment with CDDP alone. These results suggest the ability of CA to enhance a suppressive effect of CDDP on proliferation of the ovarian carcinoma cells through reduction of PGE2 level.