title: The Role of Dietary Extra Virgin Olive Oil and Corn Oil on the Alteration of Epigenetic Patterns in the Rat DMBA-Induced Breast Cancer Model.
abstract: Disruption of epigenetic patterns is a major change occurring in all types of cancers. Such alterations are characterized by global DNA hypomethylation, gene-promoter hypermethylation and aberrant histone modifications, and may be modified by environment. Nutritional factors, and especially dietary lipids, have a role in the etiology of breast cancer. Thus, we aimed to analyze the influence of different high fat diets on DNA methylation and histone modifications in the rat dimethylbenz(a)anthracene (DMBA)-induced breast cancer model. Female Sprague-Dawley rats were fed a low-fat, a high corn-oil or a high extra-virgin olive oil (EVOO) diet from weaning or from induction with DMBA. In mammary glands and tumors we analyzed global and gene specific (RASSF1A, TIMP3) DNA methylation by LUMA and bisulfite pyrosequencing assays, respectively. We also determined gene expression and enzymatic activity of DNA methyltransferases (DNMT1, DNMT3a and DNMT3b) and evaluated changes in histone modifications (H3K4me2, H3K27me3, H4K20me3 and H4K16ac) by western-blot. Our results showed variations along time in the global DNA methylation of the mammary gland displaying decreases at puberty and with aging. The olive oil-enriched diet, on the one hand, increased the levels of global DNA methylation in mammary gland and tumor, and on the other, changed histone modifications patterns. The corn oil-enriched diet increased DNA methyltransferase activity in both tissues, resulting in an increase in the promoter methylation of the tumor suppressor genes RASSF1A and TIMP3. These results suggest a differential effect of the high fat diets on epigenetic patterns with a relevant role in the neoplastic transformation, which could be one of the mechanisms of their differential promoter effect, clearly stimulating for the high corn-oil diet and with a weaker influence for the high EVOO diet, on breast cancer progression.
authors.affiliation: Grup Multidisciplinari per a l'Estudi del Càncer de Mama, Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodríguez-Miguel
authors.affiliation: Grup Multidisciplinari per a l'Estudi del Càncer de Mama, Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Moral
authors.affiliation: Grup Multidisciplinari per a l'Estudi del Càncer de Mama, Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Escrich
authors.affiliation: Grup Multidisciplinari per a l'Estudi del Càncer de Mama, Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Vela
authors.affiliation: Grup Multidisciplinari per a l'Estudi del Càncer de Mama, Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Solanas
authors.affiliation: Grup Multidisciplinari per a l'Estudi del Càncer de Mama, Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Escrich
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D003314:Corn Oil / Q000494:pharmacology*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects; D059305:Diet, High-Fat; D004195:Disease Models, Animal; D044127:Epigenesis, Genetic / Q000187:drug effects*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006657:Histones / Q000378:metabolism; D015674:Mammary Neoplasms, Animal / Q000139:chemically induced* / Q000235:genetics*; D008325:Mammary Neoplasms, Experimental / Q000235:genetics* / Q000473:pathology; D000069463:Olive Oil / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D006657:Histones; D000069463:Olive Oil; C560857:RASSF1 protein, rat; D012333:RNA, Messenger; D019717:Tissue Inhibitor of Metalloproteinase-3; D025521:Tumor Suppressor Proteins; D015127:9,10-Dimethyl-1,2-benzanthracene; D003314:Corn Oil; D004248:DNA (Cytosine-5-)-Methyltransferases