Construct Derived from the Rat Acyl-CoA Oxidase Promoter in Detection of Peroxisome Proliferators Using a Reporter

Peroxisome proliferators are nougenotoxic carcinogens capable of causing rapid transcriptional activation of genes comprising the rodent fl-oxidation pathway. Numerous compounds, such as hypoilpidemic drugs, herbicides, plasticizers, and analgesics have been identified as peroxisome proliferators in rodents. We have developed a whole-cellin viEwassay to detect peroxisome proliferators in approximately 48 h. A promoter.:chloramphenicol acetyl transferase (CAT) fusion coastnict for rat acyl-CoA oxidase (ACOX), the rate-lhniting enzyme in the peroxisomal fl-OxidatiOnpathway, was stably traasfected into the rat liver cell line H.4-H-E. Treatment ofthe recombinant cell line (ACOX::CAT) with peroxisome proliferators, WY 14,643,dofibrate@ dl(2-ethythexyl) phtathate, and acetylsalicylic acid resulted in differential increases of CAT protein 48 h after exposure@NOusterOidalanti-inflamma tory drugs Induding ibuprofen, fenbupen, naproxen,and acetaminophen also up-regulated ACOX::CAT. Phorbol 12-myristate 13-acetate, a anngenotoxic carcinogen that is not classified as a peroxisome proilferator, also resulted in a slightinductionofACOX::CAT,consistent with the role ofcell proliferation in tumor progression. The carcinogenic compounds 4-nitroquinoline N-oxide, ethyl methanesulfonate, diethylstilbestrol, and 2.aminoanthracene did not induce ACOX::CAT. Although the significance of peroxisome proliferators and their impact on humans Is still unknown, the ability to identify them is of interest to the pharmaceutical and chemical industries. This assay was able to detect known peroxisome proliferators tested In approxhnately 48 h of expo sure and to distinguish them from genotoxic cardnogens