title: 15-LOX-1 inhibits p21 (Cip/WAF 1) expression by enhancing MEK-ERK 1/2 signaling in colon carcinoma cells.
abstract: Currently, some controversy exists regarding the precise role of 15-lipoxygenase-1 (15-LOX-1) in colorectal carcinogenesis and other aspects of cancer biology. The aim of this study was to evaluate the effect of 15-LOX-1 on p21 (Cip/WAF 1) expression and growth regulation in human colon carcinoma cells. The effect of 13-S-hydroxyoctadecadienoic acid (HODE), a product of 15-LOX-1, on p21 (Cip/WAF 1) expression was evaluated in Caco-2 cells treated with sodium butyrate (NaBT) and/or nordihydroguaiarectic acid (NDGA), a LOX inhibitor. The effect of transfecting HCT-116 cells with 15-LOX-1 was also examined. NaBT-induced p21 (Cip/WAF 1) expression was enhanced by treatment with NDGA and 13-S-HODE reversed NaBT-induced p21 (Cip/WAF 1) expression in Caco-2 cells. Overexpression of 15-LOX-1 induced extracellular signal-related kinase (ERK) 1/2 phosphorylation, decreased p21 (Cip/WAF 1) expression, and increased HCT-116 cell growth. Treatment with NDGA decreased ERK 1/2 phosphorylation, and increased p21 (Cip/WAF 1) expression in 15-LOX-1 overexpressing HCT-116 cells. Our experimental results support the hypothesis that 15-LOX-1 may have "pro-neoplastic" effects during the development of colorectal cancer.
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, Nashville, TN 37232-2279, USA.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yoshinaga
authors.forename: F Gregory
authors.initials: FG
authors.lastname: Buchanan
authors.forename: Raymond N
authors.initials: RN
authors.lastname: DuBois
mesh_terms: D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism*; D002087:Butyrates / Q000493:pharmacokinetics; D018938:Caco-2 Cells; D002277:Carcinoma / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D045325:HCT116 Cells; D006801:Humans; D015289:Leukotrienes / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D009637:Masoprocol / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013229:Stearic Acids / Q000494:pharmacology
chemical_list: D002087:Butyrates; C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D015289:Leukotrienes; D008054:Lipid Peroxides; D016859:Lipoxygenase Inhibitors; D013229:Stearic Acids; C025086:15-hydroperoxy-5,8,11,13-eicosatetraenoic acid; D009637:Masoprocol; D001093:Arachidonate 15-Lipoxygenase; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3