Project description:Estrogen receptor α (ERα) is the major driving transcription factor in normal mammary gland development as well as breast cancer initiation and progression.However,the fundamental mechanisms,including global cistromic and genomic transcriptional responses that are required to elicit mammary epithelial cell proliferation in response to estradiol, have not been elucidated. We used RNA-seq analysis to identify global gene expression signatures that are acutely regulated by estroegn receptors in the mouse mammary gland after acute estradiol treatment.
Project description:Both ovarian and pituitary hormones are required for the pubertal development of the mouse mammary gland. Estradiol directs ductal elongation and branching within the adipose stroma of the adolescent mouse mammary gland, while progesterone leads to tertiary branching and alveolar development. The purpose of this investigation was to identify the estrogen-responsive genes that are associated with estrogen-stimulated ductal elongation and branching in the mouse mammary gland in the absence of other ovarian hormones. We also wanted to determine if estrogen-responsive gene regulation at early stages of ductal elongation (ie. when ductal growth was minimal) was similar to those regulated after significant ductal elongation had occurred. To identify estrogen-regulated genes, ovariectomized prepubertal mice were exposed to 17beta-estradiol for four weeks, and mammary gland global gene expression analyzed by microarray analysis at various points during this time course. We determined that while many genes are regulated in all weeks of treatment, there remained a subset of genes that was uniquely regulated at each time-point. This observation was reflected in the biological functions of these genes; some categories were represented in all weeks of treatment while others were specific to only certain time-points. We have also identified estradiol-responsive genes in the mouse mammary gland that co-express with Estrogen Receptor alpha in human breast cancer, which may represent novel effectors of estrogen action and/or biomarkers for the progression of estrogen-dependent cancers and other estrogen-driven diseases.
Project description:Estrogen induce organ-specific cell proliferation and development in female reproductive organs, though the reproductive differentiation, sex maturation, implantation and lactation. However, the mechanism of organ-specific estrogen responsive genes is unknown. Thus, we examined early estrogen responsive genes in mouse uterus, vagina and mammary gland. Keywords: organ specificity 70-day-old ovariectomized mice (C57BL/6J)(n=4) were treated with 17beta-estradiol (5micro g/kg) or sesame oil. Whole uterus (Ut), vagina (Vg) and mammary gland (Mg) were sacrificed 6h after the injection.
Project description:Both ovarian and pituitary hormones are required for the pubertal development of the mouse mammary gland. Estradiol directs ductal elongation and branching within the adipose stroma of the adolescent mouse mammary gland, while progesterone leads to tertiary branching and alveolar development. The purpose of this investigation was to identify the estrogen-responsive genes that are associated with estrogen-stimulated ductal elongation and branching in the mouse mammary gland in the absence of other ovarian hormones. We also wanted to determine if estrogen-responsive gene regulation at early stages of ductal elongation (ie. when ductal growth was minimal) was similar to those regulated after significant ductal elongation had occurred. To identify estrogen-regulated genes, ovariectomized prepubertal mice were exposed to 17beta-estradiol for four weeks, and mammary gland global gene expression analyzed by microarray analysis at various points during this time course. We determined that while many genes are regulated in all weeks of treatment, there remained a subset of genes that was uniquely regulated at each time-point. This observation was reflected in the biological functions of these genes; some categories were represented in all weeks of treatment while others were specific to only certain time-points. We have also identified estradiol-responsive genes in the mouse mammary gland that co-express with Estrogen Receptor alpha in human breast cancer, which may represent novel effectors of estrogen action and/or biomarkers for the progression of estrogen-dependent cancers and other estrogen-driven diseases. Experiment Overall Design: For each time-course experiment, one frozen #4 mammary gland was individually pulverized from four to five animals per treatment group, then homogenized in 3mL Trizol (Invitrogen, Carlsbad, CA) and RNA was prepared according to the manufacturerâ??s protocol. The RNA from individual animals was then pooled for each treatment group (four to five animals per group) and further purified using the QIAGEN (Valencia, CA) RNeasy Mini kit (Cat. No. 74104) clean-up protocol. Experiment Overall Design: Gene expression analysis was conducted using Agilent Mouse Oligo arrays (pattern number 011978) (Agilent Technologies, Palo Alto, CA). Total RNA was amplified using the Agilent Low RNA Input Fluorescent Linear Amplification Kit protocol. Starting with 500ng of total RNA, Cy3 or Cy5 labeled cRNA was produced according to manufacturerâ??s protocol. For each two color comparison, 750ng of each Cy3 and Cy5 labeled cRNAs were mixed and fragmented using the Agilent In Situ Hybridization Kit protocol. In each case, samples from estradiol-treated animals were co-hybridized with the day 7 placebo sample. Due to the rapid increase in adiposity in the mammary fat pad in the ovariectomized placebo-treated mice in days 14 and 28, the day 7 placebo sample was used as a control for all estradiol treated samples to avoid any variation due to this biological difference. Hybridizations were performed for 17 hours in a rotating hybridization oven using the Agilent 60-mer oligo microarray processing protocol. Slides were washed as indicated in this protocol and then scanned with an Agilent Scanner. Data was obtained using the Agilent Feature Extraction software (v7.5), using defaults for all parameters. Experiment Overall Design: The Agilent Feature Extraction Software performed error modeling, adjusting for additive and multiplicative noise. The resulting data were processed using the Rosetta Resolver® system (version 7.1) (Rosetta Biosoftware, Kirkland, WA).
Project description:Progesterone (P) acting through its cognate nuclear receptors (PRs) plays an essential role in driving pregnancy-associated branching morphogenesis of the mammary gland. However, the fundamental mechanisms, including global cistromic and acute genomic transcriptional responses that are required to elicit active branching morphogenesis in response to P, have not been elucidated. We used microarray analysis to identify global gene expression signatures that are acutely regulated by PRs in the mouse mammary gland after acute P treatment. Mammary gland gene expression data from 10-week-old ovariectomized wildtype and progesterone receptor null mice treated subcutaneously with 17β-Estradiol for 24 hours and then 17β-Estradiol plus Progesterone for 8 or 24 hours. Three replicate pools were tested with three mice per pool.
Project description:Progesterone (P) acting through its cognate nuclear receptors (PRs) plays an essential role in driving pregnancy-associated branching morphogenesis of the mammary gland. However, the fundamental mechanisms, including global cistromic and acute genomic transcriptional responses that are required to elicit active branching morphogenesis in response to P, have not been elucidated. We used chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) to identify P-regulated genes that directly recruit PRs in the mouse mammary gland after acute P treatment. Two replicate PR ChIP samples and two replicate input DNA control samples from mouse mammary glands after mice are treated subcutaneously with 17?-Estradiol for 24 hours and then 17?-Estradiol plus Progesterone for 6 hours.
Project description:In mammals, argonaute (AGO) proteins have been characterized for their roles in small RNA-mediated post-transcriptional and also in transcriptional gene silencing. We report here a different role for AGO1 in estradiol-triggered transcriptional activation in human cells. We show that in MCF-7 mammary gland cells AGO1 associates to transcriptional enhancers of estrogen receptor alpha (ERα) and that this association is upregulated by treating the cells with estrogen (E2), displaying a positive correlation with the activation of these enhancers.
Project description:Estrogen Receptor is a key transcriptional regulator in mammary gland development and breast cancer. In this study, we have mapped the Estrogen Receptor chromatin binding patterns in healthy mouse mammary gland
Project description:Estrogen Receptor is a key transcriptional regulator in mammary gland development and breast cancer. In this study, we have mapped the Estrogen Receptor chromatin binding patterns in healthy mouse mammary gland A minimum of 6 pairs of mouse mammary gland pads from mice at 5-6 weeks of age were excised and Estrogen Receptor ChIp-seq was performed.