DEN-induced HCC in c-Met knockout mice
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ABSTRACT: HGF has been reported to have both positive and negative effects on carcinogenesis. Here we show that the loss of c-Met signaling in hepatocytes enhanced rather than suppressed the early stages of chemical hepatocarcinogenesis. c-Met conditional knockout mice (c-metfl/fl, AlbCre+/-; MetLivKO) treated with N-nitrosodiethylamine (DEN) developed significantly more and bigger tumors and with a shorter latency as compared with control (wt/wt, AlbCre+/-; Cre-Ctrl) mice. Accelerated tumor development was associated with increased rate of cell proliferation and prolonged activation of epidermal growth factor receptor (EGFR) signaling. MetLivKO livers treated with DEN also displayed elevated lipid peroxidation, decreased ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG), and upregulation of superoxide dismutase 1 (Sod1) and heat shock protein 70 (Hsp70), all consistent with increased oxidative stress. Likewise, gene expression profiling performed at 3 and 5 months after DEN treatment revealed upregulation of genes associated with cell proliferation and stress responses in c-Met mutant livers. The negative effects of c-Met-deficiency were reversed by chronic oral administration of anti-oxidant N-acetylcysteine (NAC). NAC blocked the EGFR activation and reduced the DEN-initiated hepatocarcinogenesis to the levels of Cre-Ctrl mice. These results argue that intact HGF/c-Met signaling is essential for maintaining normal redox homeostasis in the liver and has tumor suppressor effect(s) during the early stages of DEN-induced hepatocarcinogenesis. Keywords: compound treatment design
ORGANISM(S): Mus musculus
PROVIDER: GSE8747 | GEO | 2008/08/09
SECONDARY ACCESSION(S): PRJNA102017
REPOSITORIES: GEO
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