title: Conjugated linoleic acid alters global gene expression in human intestinal-like Caco-2 cells in an isomer-specific manner.
abstract: Conjugated linoleic acid (CLA) exhibits isomer-specific effects on transepithelial calcium (Ca) transport as well as on cell growth in human intestinal-like Caco-2 cells. However, the molecular mechanisms of action are still unclear. Therefore, this study used a transcriptomic approach to help elucidate the molecular mechanisms underlying such isomer-specific effects. Caco-2 cells were treated with 80 micromol/L linoleic acid (control), 80 micromol/L trans-10, cis-12 CLA, or 80 micromol/L cis-9, trans-11 CLA for 12 d. Ca transport was measured radio-isotopically. RNA was isolated from the cells, labeled, and hybridized to the Affymetrix U133 2.0 Plus arrays (n = 3). Data and functional analysis was preformed using Bioconductor. Using a minimum fold-change criterion of 1.6 and a false discovery rate criterion of P-value <or= 0.05, trans-10, cis-12 CLA altered the expression of 918 genes, whereas, cis-9, trans-11 CLA had no effect on gene expression. Gene ontology analysis revealed that trans-10, cis-12 CLA strongly modulated a number of processes inherently related to carcinogenesis, such as cell cycle, cell proliferation, and DNA metabolism. Trans-10, cis-12 CLA, but not cis-9, trans-11 CLA, increased transepithelial Ca transport in Caco-2 cells, which corresponded to changes in molecular mediators of paracellular (including claudin 2 and 4) and transcellular (calbindin D(9)k and vitamin D receptor) Ca transport. This microarray-based study highlighted a number of gene expression patterns of relevance to 2 important intestinal processes (carcinogenesis and Ca transport), which were modulated by trans-10, cis-12 CLA. These may help our mechanistic understanding of the role of CLA in promoting gut function and health.
authors.affiliation: Department of Food and Nutritional Sciences, University College, Cork, Ireland.
authors.forename: Eileen F
authors.initials: EF
authors.lastname: Murphy
authors.forename: Guido J
authors.initials: GJ
authors.lastname: Hooiveld
authors.forename: Michael
authors.initials: M
authors.lastname: Muller
authors.forename: Raffaele A
authors.initials: RA
authors.lastname: Calogero
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Cashman
mesh_terms: D000230:Adenocarcinoma; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms; D019295:Computational Biology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000737:chemistry / Q000494:pharmacology*; D020411:Oligonucleotide Array Sequence Analysis; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D013329:Structure-Activity Relationship
chemical_list: D044243:Linoleic Acids, Conjugated; D012334:RNA, Neoplasm; D002118:Calcium