title: Expression of 5-lipoxygenase by human colorectal carcinoma Caco-2 cells during butyrate-induced cell differentiation.
abstract: Butyrate, a short-chain fatty acid, modulates proliferation and differentiation of normal and neoplastic colonocytes. We examined the expression of 5-lipoxygenase (5-LO) and its metabolites in human colorectal carcinoma (Caco-2) cells, exposed to differentiation-inducing doses of butyrate. Treatment with butyrate significantly increased 5-lipoxygenase mRNA and protein in comparison to nontreated cells. Cyclooxygenases (COX)-1 and COX-2 mRNA were not significantly influenced by the treatment. However, 5-LO activity, low in nontreated cells, increased only minimally after butyrate, and its metabolic product (5-HETE) was detectable neither in control nor in treated cells. In contrast, 15-HETE (a product of 15-LO, which is also upregulated by butyrate) rose significantly. We conclude that, although being overexpressed by butyrate on mRNA and protein level, 5-LO remains inactive in differentiating Caco-2 cells. This is likely to be due either to some associated actions of butyrate, or to 5-LO-inhibition by 15-HETE, concomitantly induced by butyrate treatment.
authors.affiliation: Second Department of Medicine, J. W. Goethe-University of Frankfurt, Frankfurt/Main, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Wächtershäuser
authors.forename: D
authors.initials: D
authors.lastname: Steinhilber
authors.forename: S M
authors.initials: SM
authors.lastname: Loitsch
authors.forename: J
authors.initials: J
authors.lastname: Stein
mesh_terms: D058927:5-Lipoxygenase-Activating Proteins; D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics* / Q000378:metabolism*; D020148:Butyric Acid / Q000494:pharmacology*; D018938:Caco-2 Cells; D002352:Carrier Proteins / Q000037:antagonists & inhibitors; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D008565:Membrane Proteins / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D058927:5-Lipoxygenase-Activating Proteins; C548592:ALOX5AP protein, human; D002352:Carrier Proteins; D016861:Cyclooxygenase Inhibitors; D006893:Hydroxyeicosatetraenoic Acids; D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D016212:Transforming Growth Factor beta; D020148:Butyric Acid; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D001094:Arachidonate 5-Lipoxygenase