ABSTRACT: Transcriptome of normal mammary glands of Sprague-Dawley rats at six stages of development: pre-pubertal, peri-pubertal, pubertal, lactation, adult parous and age-matched nulliparous
Project description:There is a lack of systematic investigations of large-scale transcriptome patterns associated with normal breast development. Herein, we profiled whole-transcriptome (by microarrays) of normal mammary glands in female Sprague-Dawley rats, an animal model widely used in breast cancer research, across six distinctive developmental stages – pre-pubertal, peri-pubertal, pubertal, lactation, and adult parous and age-matched nulliparous.
Project description:Cross-species hybridization analysis of mammary glands during pregnancy and lactation. Results provide insight into putative conserved molecular mechanisms regulating mammary gland development. This study was performed to identify orthologous transcripts that are differentially co-expressed in the mammary gland at 2 stages of development (pregnancy and lactation) in wild type Sprague-Dawley rats. Key points are examined in a time series of Sprague Dawley rat mammary gland development, secretory activation and lactation. Triplicate rat (three biological replicates) at each time point were used for statistical power totalling 12 individual arrays in this study. Rats were as staged pregnant day 1 the day that post coital plug was observed, and similarly, lactation day 1 was the first day after birth. Whole mammary glands No. 4 (inguinal) were obtained from female rats at stages of development: virgin (adulthood, 14 wks of age), Pregnant (5 and 14 days of pregnancy) and Lactating (day 1 and 12 postpartum). The two-color (Cy5/Cy3) microarray experiment was designed to hybridize samples from each group against a common reference, a pool of RNA from mammary gland of three parous or virgin female rats.
Project description:Exposure to common environmental chemicals, including those found in personal care products has been linked to mammary cancer at high doses in animal models. Their effects at low doses at levels comparable to human exposure remain poorly understood. Using a Sprague-Dawley rat model, we investigated the effects of three prevalently used environmental chemicals – diethyl phthalate (DEP), methyl paraben (MPB), triclosan (TCS) – and their mixture (MIX) on the transcriptome of normal developing mammary at levels mimicking human exposure. Rats were exposed from birth to adulthood in parous and nulliparous settings. We used affymetrix arrays to assess the influence of diethyl phthalate (DEP), methyl paraben (MPB), triclosan (TCS) and their mixture (MIX) on global gene expression profiles in rat mammary tissues, using doses comparable to human exposure. Exposure was from birth to adulthood (postnatal day 1 – 180) in parous and nulliparous rats.
Project description:Cross-species hybridization analysis of mammary glands during pregnancy and lactation. Results provide insight into putative conserved molecular mechanisms regulating mammary gland development. This study was performed to identify orthologous transcripts that are differentially co-expressed in the mammary gland at 2 stages of development (pregnancy and lactation) in wild type Sprague-Dawley rats.
Project description:Case-control study for the analysis of the gene expression profile of epithelial cells microdissected from normal breast tissues obtained from 17 parous and 7 nulliparous women free of breast pathology (controls), and 39 parous and 8 nulliparous women with history of breast cancer (cases). Keywords: genetic modifications
Project description:Exposure to common environmental chemicals, including those found in personal care products has been linked to mammary cancer at high doses in animal models. Their effects at low doses at levels comparable to human exposure, especially during critical windows of development remain poorly understood. Using a Sprague-Dawley rat model, we investigated the effects of of three environmental chemicals – diethyl phthalate (DEP), methyl paraben (MPB) and triclosan (TCS) – on the transcriptome of normal developing mammary glands at low doses mimicking human exposure. Rats were exposed during three windows of early development – perinatal (gestation day (GD) 1 - 20 or postnatal day (PND) 1 - 20), prepubertal (PND 21 - 41) and pubertal (PND 42 - 62), as well as chronic exposure from birth to end of lactation (PND 1 - 146). Mammary gland whole-transcriptomes were profiled by Affymetrix rat gene 2.0 st arrays.
Project description:Case-control study for the analysis of the gene expression profile of epithelial cells microdissected from normal breast tissues obtained from 17 parous and 7 nulliparous women free of breast pathology (controls), and 39 parous and 8 nulliparous women with history of breast cancer (cases). Keywords: genetic modifications Four-condition experiment: nulliparous case, nulliparous control, parous case and parous control labeled with Cy5 and Universal human reference used as a common reference labeled with Cy3. Moderated t statistic was used as the basic statistic for significance analysis; it was computed for each probe and for each contrast. False discovery rate was controlled using the Benjamini and Hochberg. All genes with P value below a threshold of 0.05 were selected as differentially expressed, maintaining the proportion of false discoveries in the selected group below the threshold value, in this case 5%. Breast 11 parous control HuII, Breast 28 parous case HuII, and Breast 62 nulliparous control HuIII excluded: raw data is missing
Project description:The objective of the study was to comprehensively compare the genomic profiles in the breast of parous and nulliparous postmenopausal women to identify genes that permanently change their expression following pregnancy. The study was designed as a two-phase approach. In the discovery phase, we compared breast genomic profiles of 37 parous with 18 nulliparous postmenopausal women. In the validation phase, confirmation of the genomic patterns observed in the discovery phase was sought in an independent set of 30 parous and 22 nulliparous postmenopausal women.
Project description:To investigate the gene expression changes observed with exposure to organophosphate esters in the adrenal glands of Sprague Dawley rats.
Project description:Gene level analysis of lactating day 10-11 16h Sprague-Dawley dams compared against age matched virgins. Lactation is a time of significantly increased energy demands imposed by the suckling young that requires a proportional adjustment in the ability of the lactating dam to absorb nutrients and to synthesize critical biomolecules to meet the dietary needs of both the offspring and the dam. We have shown an increase in the size and hydrophobicity of the bile acid pool during lactation [1], implying an increased absorption and disposition of lipids, sterols, nutrients, and xenobiotics. In order to investigate changes at the level of mRNA, we utilized an exon array and calculated gene level summaries to investigate changes in gene expression in the liver, duodenum, jejunum, and ileum of lactating dams when compared against age-matched virgin controls. Affymetrix Rat Exon 1.0ST arrays were used to determine expression of genes in the livers and small intestines of day 10-11 lactating Sprague Dawley rats and compared against virgins of comparable age.
