Effect of Fenofibrate on Oxidative DNA Damage and on Gene Expression Related to Cell Proliferation and Apoptosis in Rats

• Published in: Toxicological sciences 2007-05, Vol.97 (1), p.44-54
• Main Authors: Nishimura, Jihei, Dewa, Yasuaki, Muguruma, Masako, Kuroiwa, Yuichi, Yasuno, Hiroaki, Shima, Tomomi, Jin, Mailan, Takahashi, Miwa, Umemura, Takashi, Mitsumori, Kunitoshi
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis - drug effects; Apoptosis - genetics; Apoptosis Regulatory Proteins - metabolism; Biotransformation - genetics; Catalase - metabolism; Cell Cycle Proteins - metabolism; Cell Proliferation - drug effects; Cell Transformation, Neoplastic - drug effects; Cell Transformation, Neoplastic - genetics; Cell Transformation, Neoplastic - metabolism; Deoxyguanosine - analogs & derivatives; Deoxyguanosine - metabolism; DNA Damage; DNA Repair Enzymes - metabolism; Dose-Response Relationship, Drug; fenofibrate; Fenofibrate - toxicity; Gene Expression Profiling - methods; hepatocarcinogenesis; Ki-67 Antigen - metabolism; Lipid Metabolism - drug effects; liver; Liver - drug effects; Liver - enzymology; Liver - pathology; Male; Microsomes, Liver - drug effects; Microsomes, Liver - metabolism; Oligonucleotide Array Sequence Analysis; oxidative stress; Oxidative Stress - drug effects; Peroxisome Proliferators - toxicity; peroxisome proliferators-activated receptor alpha agonist; rat; Rats; Rats, Inbred F344; Reactive Oxygen Species - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; ROS; Superoxide Dismutase - metabolism; Time Factors
• ISSN: 1096-6080; 1096-0929
• DOI: 10.1093/toxsci/kfm011

To investigate the relationship between fenofibrate (FF) and oxidative stress, enzymatic, histopathological, and molecular biological analyses were performed in the liver of male F344 rats fed 2 doses of FF (Experiment 1; 0 and 6000 ppm) for 3 weeks and 3 doses (Experiment 2; 0, 3000, and 6000 ppm) for 9 weeks. FF treatment increased the activity of enzymes such as carnitine acetyltransferase, carnitine palmitoyltransferase, fatty acyl–CoA oxidizing system, and catalase in the liver. However, it decreased those of superoxide dismutase in the liver in both experiments. Increased 8-hydroxy-2′-deoxyguanosine levels in liver DNA and lipofuscin accumulation were observed in the treated rats of Experiment 2. In vitro measurement of reactive oxygen species (ROS) in rat liver microsomes revealed a dose-dependent increase due to FF treatment. Microarray (only Experiment 1) or real-time reverse transcription–polymerase chain reaction analyses revealed that the expression levels of metabolism and DNA repair–related genes such as Aco, Cyp4a1, Cat, Yc2, Gpx2, Apex1, Xrcc5, Mgmt, Mlh1, Gadd45a, and Nbn were increased in FF-treated rats. These results provide evidence of a direct or indirect relationship between oxidative stress and FF treatment. In addition, increases in the expression levels of cell cycle–related genes such as Chek1, Cdc25a, and Ccdn1; increases in the expression levels of cell proliferation–related genes such as Hdgfrp3 and Vegfb; and fluctuations in the expression levels of apoptosis-related genes such as Casp11 and Trp53inp1 were observed in these rats. This suggests that cell proliferation induction, apoptosis suppression, and DNA damage due to oxidative stresses are probably involved in the mechanism of hepatocarcinogenesis due to FF in rats.