title: Diets high in corn oil or extra-virgin olive oil differentially modify the gene expression profile of the mammary gland and influence experimental breast cancer susceptibility.
abstract: OBJECTIVE
  Nutritional factors, especially dietary lipids, may have a role in the etiology of breast cancer. We aimed to analyze the effects of high-fat diets on the susceptibility of the mammary gland to experimental malignant transformation.
  
  
  METHODS
  Female Sprague-Dawley rats were fed a low-fat, high-corn-oil, or high-extra-virgin olive oil (EVOO) diet from weaning or from induction. Animals were induced with 7,12-dimethylbenz[a]anthracene at 53 days and euthanized at 36, 51, 100 and 246 days. Gene expression profiles of mammary glands were determined by microarrays. Further molecular analyses were performed by real-time PCR, TUNEL and immunohistochemistry. Carcinogenesis parameters were determined at 105 and 246 days.
  
  
  RESULTS
  High-corn-oil diet increased body weight and mass when administered from weaning. The EVOO diet did not modify these parameters and increased the hepatic expression of UCP2, suggesting a decrease in intake/expenditure balance. Both diets differentially modified the gene expression profile of the mammary gland, especially after short dietary intervention. Corn oil down-regulated the expression of genes related to immune system and apoptosis, whereas EVOO modified the expression of metabolism genes. Further analysis suggested an increase in proliferation and lower apoptosis in the mammary glands by effect of the high-corn-oil diet, which may be one of the mechanisms of its clear stimulating effect on carcinogenesis.
  
  
  CONCLUSIONS
  The high-corn-oil diet strongly stimulates mammary tumorigenesis in association with modifications in the expression profile and an increased proliferation/apoptosis balance of the mammary gland.
authors.affiliation: Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Moral
authors.affiliation: Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Escrich
authors.affiliation: Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Solanas
authors.affiliation: Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Vela
authors.affiliation: Department of Statistics, Universitat de Barcelona, 08028, Barcelona, Spain.
authors.forename: M Carme
authors.initials: MC
authors.lastname: Ruiz de Villa
authors.affiliation: Physiology Unit, Department of Cell Biology, Physiology and Immunology, Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain. Eduard.Escrich@uab.cat.
authors.forename: Eduard
authors.initials: E
authors.lastname: Escrich
mesh_terms: D000818:Animals; D017209:Apoptosis; D001835:Body Weight; D001943:Breast Neoplasms / Q000235:genetics*; D003314:Corn Oil / Q000008:administration & dosage / Q000009:adverse effects*; D004032:Diet; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000008:administration & dosage / Q000032:analysis; D004195:Disease Models, Animal; D004198:Disease Susceptibility / Q000378:metabolism*; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D008099:Liver / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000503:physiopathology*; D000069463:Olive Oil / Q000008:administration & dosage / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D059467:Transcriptome; D000071246:Uncoupling Protein 2 / Q000235:genetics / Q000378:metabolism
chemical_list: D004041:Dietary Fats; D000069463:Olive Oil; C000604391:Ucp2 protein, rat; D000071246:Uncoupling Protein 2; D003314:Corn Oil
keywords: Corn oil; Dietary lipids; Experimental tumors; Extra-virgin olive oil; Gene expression profile; Mammary gland