Induction of Catalase Gene Expression in Hepatoma and Fibroblast Cell Lines with Peroxisome Proliferator (Clofibric Acid)

Emi Nakamura, Yuu Maeda, Keizo Ito, Masaharu Sakai* and Kenzo Sato

Department of Molecular Biology, Faculty of Medicine, Tottori University, Yonago 683 and *Department of Biochemistry, Hokkaido University School of Medicine, Sapporo 012, Japan

Peroxisome proliferators, which have been clinically used as hypolipidemic drugs, activate fatty acid β-oxidation enzymes in peroxisomes. Catalase, which decomposes hydrogen peroxide to water and oxygen, is one of peroxisomal enzymes. In this study, transcription of the catalase gene was shown to be slightly stimulated in hepatomas and fibroblast cell lines treated with clofibrate, as well as in the liver of the drug-administered animal. Furthermore, stimulation of the gene was also observed in the skin and brain tissues of the animal. Chloramphenicol acetyltransferase assays revealed that the catalase gene was regulated positively and negatively by clofibrate in the fibroblast, and that the peroxisome proliferator-responsive element (PPRE) located at -3957 base pair (bp) in the catalase gene served as positive regulator element of the transcription, meanwhile PPREs at -3151 bp and -301 bp negatively modulated the gene.

Key words: catalase gene; gene expression; hepatoma; peroxisome proliferator clofibrate

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