Maternal Western-style diet alters the transcriptome of chemically induced mammary tumors in female offspring rats

Some previous experimental studies have shown that early in life intake of high-fat or Western-style diets did alter the development of mammary cancer in adulthood female rats. Thus, the present study investigated the distinct gene expression patterns of chemically induced mammary tumors derived from female offspring whose dams intake control diet (CD) or Western-style diet (WD). During gestational days (GD) 12-21 and post-natal days (PND) 1-21, pregnant Sprague-Dawley (SD) rats were fed a CD diet or WD (high-fat and low-fiber and oligoelements) diet. On postnatal day (PND) 21, the female offspring received a single dose of carcinogen N-Methyl-N-Nitrosourea (MNU, 50 mg/kg) and CD diet for 12 weeks. Latency, incidence and tumor burden were registered. Mammary tumors samples were collected and histopathology and gene expression analysis were performed. Pregnant Sprague-Dawley (SD) rats received control diet (CD) or Western-style diet (WD) from gestational days (GD) 12-20 and post-natal days (PND) 1-21. At weaning, the female offspring received CD until the end of the tumor bioassay. Female offspring 3 weeks old from both CD and WD groups received a single intraperitoneal dose of 50 mg/kg of N-Methyl-N-Nitrosourea (MNU) dissolved in phosphate-buffered saline acidified with acetic acid. At the end of study, the animals were euthanized and mammary tumors were removed and kept at -80°C for molecular analysis.