Project description:Perinatal exposure to bisphenol A (BPA) has been shown to cause aberrant mammary gland morphogenesis and mammary neoplastic transformation. Yet, the underlying mechanism is poorly understood. We tested the hypothesis that mammary glands exposed to BPA during a susceptible window may lead to its susceptibility to tumorigenesis through a stem-cell mediated mechanism. We exposed 21-day-old Balb/c mice to BPA by gavage (25 µg/kg/day) during puberty for 3 weeks, and a subset of animals were further challenged with one oral dose (30 mg/kg) of 7,12-dimethylbenz[a]anthracene (DMBA) at 2 months of age. Primary mammary cells were isolated at 6 weeks, and 2 and 4 months of age for mammary stem cell (MaSC) quantification and function analysis. Pubertal exposure to the low-dose BPA increased lateral branches and hyperplasia in adult mammary glands and caused an acute increase of MaSC in 6-week-old glands and a delayed increase of luminal progenitors in 4-month-old adult gland. Most importantly, pubertal BPA exposure altered the function of MaSC from different age groups, causing pre-neoplastic lesions in their regenerated glands similar to those induced by DMBA exposure, which indicates that MaSCs are susceptible to BPA-induced transformation. Deep sequencing analysis on MaSC-enriched mammospheres identified a set of aberrantly expressed genes associated with pre-neoplastic lesions in human breast cancer patients. Thus, our study for the first time shows that pubertal BPA exposure altered MaSC gene expression and function such that they induced early neoplastic transformation.
Project description:Bisphenol A (BPA) is a xenobiotic endocrine disrupting chemical. In vitro and in vivo studies indicated that BPA alters endocrine-metabolic pathways in adipose tissue increasing the risk of developing metabolic disorders. BPA effects on human adipocytes, specifically in children, are poorly investigated. To investigate in childhood the effect of exposure to BPA on metabolic disorders we analyzed in vitro the effects of environmentally relevant doses of BPA on gene expression of mature human adipocytes from pre-pubertal lean patients and on related physiological outcomes. Adipocytes from children were treated in vitro with BPA and gene expression was evaluated by qRT-PCR. Genome wide analyses were performed using GeneChip Human Gene 1.0 ST array. Lipid content in adipocytes was estimated by ORO staining and Triglyceride Quantification Kit. Secreted IL-1beta, in adipocytes culture medium, and insulin, in PANC-1 culture medium, were performed using ELISA assays. BPA was found to promote up-regulation of ER? and ERR?, and down-regulation of GPR30 expression modulating estrogen signaling and following a non-linear dose-response. Microarray data analysis demonstrated that BPA increases the gene expression of pro-inflammatory cytokines and lipid metabolism-related FABP4 and CD36 in adipocytes. PCSK1 resulted the most interesting gene being down-regulated by BPA thus impairing insulin production in pancreas. BPA promotes inflammation and lipid metabolism dysregulation in adipocytes from lean children. Moreover, PCSK1 can be a key gene in BPA action modulating insulin production. Exposure to BPA in childhood may be an important risk factor in developing obesity and metabolic disorders. Three prototypic situations were analyzed (5 replication each): untreated cells (C), 10 nM BPA treated cells (BPA), 1 nM 17-beta Estradiol treated cells (ES).
Project description:Environmental chemicals such as bisphenol A (BPA) are thought to contribute to carcinogenesis through their endocrine-disrupting effects. However BPA replacement chemicals are structurally similar, and little data exist describing their effects on the human body and environment. We established non-malignant human mammary organoid cultures to investigate the effects of BPA replacement chemicals on organoid morphology and protein abundance. At low-nanomolar doses, replacement chemicals, in particular BPS, induced branching and disrupted the organized mammary organoid architecture. BPS exposure likely alters mammary cell-type proportions and induces branching of predominately myoepithelial cells. Treatment with different replacement chemicals resulted in distinct proteomic changes. BPS exposure induced Cdc42-interacting protein 4 (CIP4), a protein known to support invadopodia formation and mesenchymal phenotypes. Our study provides evidence that replacement bisphenols have pro-tumorigenic effects on mammary morphology and the proteome, highlighting the necessity of comprehensive studies to evaluate the potential harm of replacement chemicals.
Project description:A transcriptome study in mouse hematopoietic stem cells was performed using a sensitive SAGE method, in an attempt to detect medium and low abundant transcripts expressed in these cells. Among a total of 31,380 unique transcript, 17,326 (55%) known genes were detected, 14,054 (45%) low-copy transcripts that have no matches to currently known genes. 3,899 (23%) were alternatively spliced transcripts of the known genes and 3,754 (22%) represent anti-sense transcripts from known genes.
Project description:Bisphenol A (BPA) is a xenobiotic endocrine disrupting chemical. In vitro and in vivo studies indicated that BPA alters endocrine-metabolic pathways in adipose tissue increasing the risk of developing metabolic disorders. BPA effects on human adipocytes, specifically in children, are poorly investigated. To investigate in childhood the effect of exposure to BPA on metabolic disorders we analyzed in vitro the effects of environmentally relevant doses of BPA on gene expression of mature human adipocytes from pre-pubertal lean patients and on related physiological outcomes. Adipocytes from children were treated in vitro with BPA and gene expression was evaluated by qRT-PCR. Genome wide analyses were performed using GeneChip® Human Gene 1.0 ST array. Lipid content in adipocytes was estimated by ORO staining and Triglyceride Quantification Kit. Secreted IL-1β, in adipocytes culture medium, and insulin, in PANC-1 culture medium, were performed using ELISA assays. BPA was found to promote up-regulation of ERα and ERRγ, and down-regulation of GPR30 expression modulating estrogen signaling and following a non-linear dose-response. Microarray data analysis demonstrated that BPA increases the gene expression of pro-inflammatory cytokines and lipid metabolism-related FABP4 and CD36 in adipocytes. PCSK1 resulted the most interesting gene being down-regulated by BPA thus impairing insulin production in pancreas. BPA promotes inflammation and lipid metabolism dysregulation in adipocytes from lean children. Moreover, PCSK1 can be a key gene in BPA action modulating insulin production. Exposure to BPA in childhood may be an important risk factor in developing obesity and metabolic disorders.