AIM:Peroxisome proliferator-activated receptor γ(PPARγ)is known to regulate growth arrest and terminal differentiationof adipocytes and is used clinically as a new class ofantidiabetic drugs.Recently,several studies have reportedthat treatment of cancer cells with PPARy ligands couldinduce cell differentiation and apoptosis,suggesting apotential application as chemopreventive agents againstcarcinogenesis.In the present study,3 different kinds ofPPARy ligands were subjected to the experiments to confirmtheir suppressive effects on liver carcinogenesis.METHODS:Three PPARy ligands,pioglitazone(Pio)(200 ppm),rosiglitazone(Rosi)(200 ppm),and troglitazone(Tro)(1000 ppm)were investigated on the induction of theplacental form of rat glutathione S-transferase(rGST P)positive foci,a precancerous lesion of the liver,and livercancer formation using a diethylnitrosamine-induced livercancer model in Wistar rats,and dose dependency of aPPARy ligand was also examined.RESULTS:PPARy ligands reduced the formation of rGSTP-positive loci By diethylnitrosamine and induction of livercancers was also markedly suppressed by a continuousfeeding of Pio at 200 ppm.CONCLUSION:PPARy ligands are potential chemopreventiveagents for liver carcinogenesis. AIM: Peroxisome proliferator-activated receptor γ (PPARγ) is known to regulate growth arrest and terminal differentiation of adipocytes and is used clinically as a new class of antidiabetic drugs. Recently, several studies have reported treatment of cancer cells with PPARγ ligands couldinduce cell differentiation and apoptosis , suggesting apotential application as chemopreventive agents againstcarcinogenesis. In the present study, 3 different kinds of PPARy ligands were subjected to the experiments to confirm their suppressive effects on liver carcinogenesis. METHODS: Three PPARy ligands, pioglitazone (Pio) (200 ppm), rosiglitazone (Rosi (200 ppm), and troglitazone (Tro) (1000 ppm) were investigated on the induction of the placental form of rat glutathione S-transferase (rGST P) positive foci, a precancerous lesion of the liver, and liver cancer formation using a diethylnitrosamine- induced livercancer model in Wistar rats, and dose dependency of a PPARy ligand was also examined .RESULTS: PPARy ligands reduced th e formation of rGSTP-positive loci By diethylnitrosamine and induction of liver cancer was also markedly suppressed by a continuous feed of Pio at 200 ppm. CONCLUSION: PPARy ligands are potential chemopreventive agents for liver carcinogenesis.