Abstract
Wy-14,643 (WY) is a hypolipidemic drug that induces hepatic peroxisome proliferation and tumors in rodents. We previously showed that peroxisome proliferators increase NF-κB DNA binding activity in rats, mice, and hepatoma cell lines, and that mice deficient in the p50 subunit of NF-κB had much lower cell proliferation in response to the peroxisome proliferator ciprofibrate. In this study we examined the promotion of hepatocarcinogenesis by WY in the p50 knockout (-/-) mice. The p50 -/- and wild type mice were first administered diethylnitrosamine (DEN) as an initiating agent. Mice were then fed a control diet or a diet containing 0.05% WY for 38 weeks. Wild-type mice receiving DEN only developed a low incidence of tumors, and the majority of wild-type mice receiving both DEN and WY developed tumors. However, no tumors were seen in any of the p50 -/- mice. Cell proliferation and apoptosis were measured in hepatocytes by BrdU labeling and the TUNEL assay, respectively. Treatment with DEN + WY increased both cell proliferation and apoptosis in both the wild-type and p50 -/- mice; DEN treatment alone has no effect. In the DEN/WY-treated mice, cell proliferation and apoptosis were slightly lower in the p50 -/- mice than in the wild-type mice. These data demonstrate that NF-κB is involved in the promotion of hepatic tumors by the peroxisome proliferator WY; however, the difference in tumor incidence could not be attributed to alterations in either cell proliferation or apoptosis.
Original language | English |
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Pages (from-to) | 331-336 |
Number of pages | 6 |
Journal | Toxicological Sciences |
Volume | 90 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2006 |
Bibliographical note
Funding Information:This study was supported by National Cancer Institute grant CA74147, National Institute of Environmental Health Sciences grant ES11526, and the Kentucky Agricultural Experiment Station.
Keywords
- Apoptosis
- B
- Carcinogenesis
- Cell proliferation
- NF-κ
- Peroxisome
ASJC Scopus subject areas
- Toxicology