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Fish oil and pectin may suppress colon carcinogenesis via inhibition of the MAPK and TGFβpathways
Author(s) -
Cho Youngmi,
Martinez Josue G.,
Turner Nancy D.,
Taddeo Stella S.,
Davidson Laurie A.,
Wang Naisyin,
Vannucci Marina,
Carroll Raymond J.,
Chapkin Robert S.,
Lupton Joanne R.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.885.8
Subject(s) - azoxymethane , fish oil , mapk/erk pathway , carcinogenesis , gene expression , biology , colorectal cancer , signal transduction , corn oil , pectin , gene , endocrinology , medicine , fish <actinopterygii> , microbiology and biotechnology , cancer , biochemistry , genetics , fishery
We have shown that fish oil/pectin(FP) diets are protective against colon cancer compared to corn oil/cellulose(CC). In this study we determined if the protection is conferred by influencing the temporal changes in expression of genes relevant to the MAPK and TGF βpathway that are involved in colon carcinogenesis. Diets contained either FP or CC. Half of the rats were exposed to radiation (1 Gy, 1 GeV/nucleon iron) and all rats were injected with azoxymethane (2x, 15 mg/kg BW, sc) 10 and 17 d after irradiation. Exfoliated colonocyte polyA+ RNA was collected at 7, 14, and 28 wk in the same rats and gene expression determined using GE Codelink arrays. There were 301 differentially expressed genes for the diet X time interaction including five genes relevant to the MAPK pathway, e.g. expression of IL‐1βwas maintained over time in FP‐fed rats whereas expression in the 28 wk sample was 4.7 times (P=0.01) that in the 7 wk sample in CC‐fed rats. Also, three genes related to the TGF βpathway were affected by the interaction, e.g. expression of Smad4, a tumor suppressor, was maintained over time in the FP‐fed rats but decreased at the tumor stage in CC‐fed rats (P=0.03). Our data indicate that a diet containing fish oil/pectin could suppress colon carcinogenesis by regulating expression of genes within the MAPK/TGF βsignaling axis. Funded by NSBRI NASA NCC 9‐58, NIEHS (P30‐ES09106), and NIH (CA59034, CA57030).