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Nicolas J Cabaton,
Cécile Canlet,
Perinaaz R Wadia,
Marie Tremblay-Franco,
Roselyne Gautier,
Jérôme Molina, Carlos Sonnenschein,
Jean-Pierre Cravedi,
Beverly S Rubin,
Ana M Soto,
Daniel Zalko
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ABSTRACT: BACKGROUND: Bisphenol A (BPA) is a well-known endocrine disruptor used to manufacture polycarbonate plastics and epoxy resins. Exposure of pregnant rodents to low doses of BPA results in pleiotropic effects in their offspring. Metabolomics, a method used to reveal metabolic changes in response to nutritional, pharmacological, or toxic stimuli is used here to examine effects of BPA exposure. OBJECTIVES: We report the use of metabolomics to identify metabolic shifts induced in vivo by perinatal exposure to low doses of BPA in CD-1 mice. METHODS: Male offspring born to pregnant CD-1 mice that were exposed to vehicle, 0.025µg, 0.25µg or 25μg BPA/kg BW/day, from gestational day 8 through day 16 of lactation, were examined on PND2 or PND 21. Aqueous extracts of newborns (PND2, whole animal), and of livers, brains, and serum samples from PND21 pups were submitted to 1H NMR spectroscopy. Data were analyzed using Partial Least Squares Discriminant Analysis (PLS-DA). RESULTS: Examination of endogenous metabolic fingerprints revealed remarkable discrimination in the four PND2 newborn groups (whole extracts) strongly suggesting changes in the global metabolism. Furthermore, at PND 21, statistical analyses also successfully discriminated among treatment groups for liver, serum, and brain samples. Variations in glucose, pyruvate, some amino-acids, and neurotransmitters (GABA and Glutamate) were identified. CONCLUSIONS: Low doses of BPA disrupt global metabolism, including energy metabolism and brain function in perinatally exposed CD-1 mouse pups. Metabolomics can be used to highlight the effects of low doses of endocrine disruptors by linking perinatal exposure to changes in global metabolism.
Environmental Health Perspectives 02/2013; · 7.04 Impact Factor
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ABSTRACT: Males of some strains of mice retain their mammary epithelium even in the absence of nipples. Here, we have characterized the mammary gland in male CD-1 mice both in whole mounts and histological sections. We also examined the effects of bisphenol A (BPA), an estrogen mimic that alters development of the female mouse mammary gland. BPA was administered at a range of environmentally relevant doses (0.25-250μg/kg/day) to pregnant and lactating mice and then the mammary glands of male offspring were examined at several periods in adulthood. We observed age- and dose-specific effects on mammary gland morphology, indicating that perinatal BPA exposures alter the male mammary gland in adulthood. These results may provide insight into gynecomastia, the most common male breast disease in humans, where proliferation of the mammary epithelium leads to breast enlargement.
Reproductive Toxicology 01/2013; · 3.23 Impact Factor
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ABSTRACT: Collagen-based gels have been widely used to determine the factors that regulate branching morphogenesis in the mammary gland. The patterns of biomechanical gradients and collagen reorganization influence the shape and orientation of epithelial structures in three-dimensional (3D) conditions. We explored in greater detail whether collagen type I fibers with distinct biomechanical and fiber-assembling properties, isolated from either bovine or rat tail tendon, differentially affected the epithelial phenotype in a tissue culture model of the human breast. Rat tail collagen fibers were densely packed into significantly longer and thicker bundles compared to those of the bovine type (average fascicle length 7.35 and 2.29 μm, respectively; p = 0.0001), indicating increased fiber alignment and biomechanical enablement in the former. MCF10A epithelial cells formed elaborated branched tubular structures in bovine but only nonbranched ducts and acini in rat tail collagen matrices. Ductal branching in bovine collagen was associated with interactions between neighboring structures mediated through packed collagen fibers; these fiber-mediated interactions were absent in rat tail collagen gels. Normal breast fibroblasts increased the final size and number of ducts only in rat tail collagen gels while not affecting branching. Our results suggest that the species of origin of collagen used in organotypic cultures may influence epithelial differentiation into alveolar or ductal structures and the patterns of epithelial branching. These observations underscore the importance of considering the species of origin and fiber alignment properties of collagen when engineering branching organs in 3D matrices and interpreting their role in the tissue phenotype. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:2905-2912, 2012.
Journal of Biomedical Materials Research Part A 06/2012; 100(11):2905-12. · 2.63 Impact Factor
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ABSTRACT: The xenoestrogen bisphenol A (BPA) used in the manufacturing of various plastics and resins for food packaging and consumer products has been shown to produce numerous endocrine and developmental effects in rodents. Exposure to low doses of BPA during fetal mammary gland development resulted in significant alterations in the gland's morphology that varied from subtle ones observed during the exposure period to precancerous and cancerous lesions manifested in adulthood. This study assessed the effects of BPA on fetal mammary gland development in nonhuman primates. Pregnant rhesus monkeys were fed 400 μg of BPA per kg of body weight daily from gestational day 100 to term, which resulted in 0.68 ± 0.312 ng of unconjugated BPA per mL of maternal serum, a level comparable to that found in humans. At birth, the mammary glands of female offspring were removed for morphological analysis. Morphological parameters similar to those shown to be affected in rodents exposed prenatally to BPA were measured in whole-mounted glands; estrogen receptor (ER) α and β expression were assessed in paraffin sections. Student's t tests for equality of means were used to assess differences between exposed and unexposed groups. The density of mammary buds was significantly increased in BPA-exposed monkeys, and the overall development of their mammary gland was more advanced compared with unexposed monkeys. No significant differences were observed in ER expression. Altogether, gestational exposure to the estrogen-mimic BPA altered the developing mammary glands of female nonhuman primates in a comparable manner to that observed in rodents.
Proceedings of the National Academy of Sciences 05/2012; 109(21):8190-5. · 9.68 Impact Factor
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ABSTRACT: At the beginning of the 21st century cancer research has reached an impasse similar to that experienced in developmental biology in the first decades of the 20th century when conflicting results and interpretations co-existed for a long time until these differences were resolved and contradictions were eliminated. In cancer research, instead of this healthy "weeding-out" process, there have been attempts to reach a premature synthesis, while no hypothesis is being rejected. Systems Biology could help cancer research to overcome this stalemate by resolving contradictions and identifying spurious data. First, in silico experiments should allow cancer researchers to be bold and a priori reject sets of data and hypotheses in order to gain a deeper understanding of how each dataset and each hypothesis contributes to the overall picture. In turn, this process should generate novel hypotheses and rules, which could be explored using these in silico approaches. These activities are significantly less costly and much faster than "wet-experiments". Consequently, Systems Biology could be advantageously used both as a heuristic tool to guide "wet-experiments" and to refine hypotheses and test predictions.
Cancer Cell International 03/2012; 12(1):12. · 1.97 Impact Factor
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ABSTRACT: Epithelial-mesenchymal interactions during embryogenesis are critical in defining the phenotype of tissues and organs. The initial elongation of the mammary bud represents a central morphological event requiring extensive epithelial-mesenchymal crosstalk. The precise mechanism orchestrating this outgrowth is still unknown and mostly animal models have been relied upon to explore this process. Highly tunable three-dimensional (3D) culture models are a complementary approach to address the question of phenotypic determination. Here, we used a 3D in vitro culture to study the roles of stromal cells and extracellular matrix components during mammary tubulogenesis. Fibroblasts, adipocytes, and type I collagen actively participated in this process, whereas reconstituted basement membrane inhibited tubulogenesis by affecting collagen organization. We conclude that biochemical and biomechanical signals mediate the interaction between cells and matrix components and are necessary to induce tubulogenesis in vitro.
Tissue Engineering Part A 09/2011; 18(5-6):520-32. · 4.64 Impact Factor
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BioEssays 09/2011; 33(9):657-9. · 4.95 Impact Factor
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ABSTRACT: Excess estrogen exposure in developing individuals increases the risk of developing breast cancer later in life. This excess
estrogen can originate from high levels of maternal endogenous estrogens or from exposure to exogenous endocrine disrupting
compounds that mimic estrogen actions. One of those compounds is the ubiquitous bisphenol A or BPA, a chemical that has been
found in over 90% of the American population tested and that mimics the actions of estradiol both in vitro and in vivo. The
breast is a target organ for both estradiol and BPA. In this chapter we will discuss the effects of BPA on the developing
mammary gland and its long-lasting consequences on the organ’s health, and we will argue that prenatal and early life exposure
to endocrine disrupting chemicals contributes to the increased incidence of breast cancer observed during the last decades.
KeywordsEndocrine disruptors-Bisphenol A-Estrogen mimic-Mammary gland-Prenatal exposures-Carcinoma in situ-Precancerous lesions-Breast cancer incidence
08/2011: pages 55-68;
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Progress in Biophysics and Molecular Biology 08/2011; 106(2):337-9. · 3.20 Impact Factor
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ABSTRACT: Response/Comment on the SMT theory as defined by David L Vaux (DOI: 10.1002/bies.201100022) by Soto & Sonnenschein
BioEssays : news and reviews in molecular, cellular and developmental biology. 07/2011;
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ABSTRACT: The stroma plays an important role in the development and progression of human diseases. Pulmonary diseases such as asthma, fibrosis and cancer are thought to be the result of altered communications between the epithelial and stromal tissue compartments. In order to study these epithelial-mesenchymal interactions, we developed a three dimensional (3D) in vitro model of the human airway that mimics bronchial morphology and function. This model consists of a type-I collagen matrix, normal human fetal lung fibroblasts (IMR-90) or primary human adult lung cancer-associated fibroblasts (LuCAFs), and a surface epithelium of normal human bronchial epithelial cells (HBECs). When cultured at an air-liquid interface (ALI), the epithelial component generated a well-differentiated pseudo-stratified bronchial epithelium that contained basal, ciliated, and non-ciliated (secretory) epithelial cells. IMR-90 and LuCAFs differentially altered the phenotype of HBECs in distinct ways. While IMR-90 permitted HBECs to form a typical respiratory surface epithelium, LuCAFs promoted HBECs to invade the collagen gel forming both epithelial nodules and cysts, suggesting that LuCAFs may alter the HBEC phenotype by modifying biomechanical signals conveyed through the extracellular matrix (ECM). Furthermore, LuCAFs secreted soluble factors that induced HBECs to express genes associated with immune responses, apoptosis, mitosis, cell survival, differentiation and cancer.
Biomaterials 07/2011; 32(29):7169-80. · 7.40 Impact Factor
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Seminars in Cancer Biology 05/2011; 21(3):147-9. · 6.47 Impact Factor
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ABSTRACT: The somatic mutation theory (SMT) of cancer has been and remains the prevalent theory attempting to explain how neoplasms arise and progress. This theory proposes that cancer is a clonal, cell-based disease, and implicitly assumes that quiescence is the default state of cells in multicellular organisms. The SMT has not been rigorously tested, and several lines of evidence raise questions that are not addressed by this theory. Herein, we propose experimental strategies that may validate the SMT. We also call attention to an alternative theory of carcinogenesis, the tissue organization field theory (TOFT), which posits that cancer is a tissue-based disease and that proliferation is the default state of all cells. Based on epistemological and experimental evidence, we argue that the TOFT compellingly explains carcinogenesis, while placing it within an evolutionarily relevant context.
BioEssays 05/2011; 33(5):332-40. · 4.95 Impact Factor
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ABSTRACT: For a century, the perception that there are qualitative differences between a normal cell and a cell belonging to a tumor has dominated discussions aimed at explaining cancer. However, an analysis of the experimental evidence suggests that individual normal cells and individual cancer cells share the same two fundamental behavioral properties, namely, proliferation and motility. Each individual cancer cell carries no recognizable molecules or structures that make them consistently distinguishable from normal cells. Herein, we argue that the differences between normal and cancerous states are instead identifiable at the tissue level of biological organization, and therefore, the search for identification of a cancer cell should be abandoned.
Cancer Research 04/2011; 71(13):4334-7. · 7.86 Impact Factor
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Nicolas J Cabaton,
Perinaaz R Wadia,
Beverly S Rubin,
Daniel Zalko,
Cheryl M Schaeberle,
Michael H Askenase,
Jennifer L Gadbois,
Andrew P Tharp,
Gregory S Whitt, Carlos Sonnenschein,
Ana M Soto
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ABSTRACT: Perinatal exposure to low-doses of bisphenol A (BPA) results in alterations in the ovary, uterus, and mammary glands and in a sexually dimorphic region of the brain known to be important for estrous cyclicity.
We aimed to determine whether perinatal exposure to environmentally relevant doses of BPA alters reproductive capacity.
Female CD-1 mice that were exposed to BPA at 0, 25 ng, 250 ng, or 25 µg/kg body weight (BW)/day or diethylstilbestrol (DES) at 10 ng/kg BW/day (positive control) from gestational day 8 through day 16 of lactation were continuously housed with proven breeder males for 32 weeks starting at 2 months of age. At each delivery, pups born to these mating pairs were removed. The cumulative number of pups, number of deliveries, and litter size were recorded. The purity of the BPA used in this and our previous studies was assessed using HPLC, mass spectrometry, and nuclear magnetic resonance.
The forced breeding experiment revealed a decrease in the cumulative number of pups, observed as a nonmonotonic dose-response effect, and a decline in fertility and fecundity over time in female mice exposed perinatally to BPA. The BPA was 97% pure, with no evidence of contamination by other phenolic compounds.
Perinatal exposure to BPA leads to a dose-dependent decline in the reproductive capacity of female mice. The effects on the cumulative number of pups are comparable to those previously reported in mice developmentally exposed to DES, a compound well known to impair reproduction in women. This association suggests the possibility that early BPA exposure may also affect reproductive capacity in women.
Environmental Health Perspectives 11/2010; 119(4):547-52. · 7.04 Impact Factor
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ABSTRACT: Environmental endocrine disrupting chemicals (EDCs), including pesticides and industrial chemicals, have been and are released into the environment producing deleterious effects on wildlife and humans. The effects observed in animal models after exposure during organogenesis correlate positively with an increased incidence of malformations of the male genital tract and of neoplasms and with the decreased sperm quality observed in European and US populations. Exposure to EDCs generates additional effects, such as alterations in male and female reproduction and changes in neuroendocrinology, behavior, metabolism and obesity, prostate cancer and thyroid and cardiovascular endocrinology. This Review highlights the carcinogenic properties of EDCs, with a special focus on bisphenol A. However, humans and wildlife are exposed to a mixture of EDCs that act contextually. To explain this mindboggling complexity will require the design of novel experimental approaches that integrate the effects of different doses of structurally different chemicals that act at different ages on different target tissues. The key to this complex problem lies in the adoption of mathematical modeling and computer simulations afforded by system biology approaches. Regardless, the data already amassed highlight the need for a public policy to reduce exposure to EDCs.
Nature Reviews Endocrinology 07/2010; 6(7):363-70. · 9.97 Impact Factor
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ABSTRACT: Collagen-based three-dimensional (3D) in vitro models that recapitulate the structural and functional context of normal and malignant tissues provide a relevant surrogate to animal models in the study of developmental and carcinogenic processes. Human breast epithelial MCF10A cells embedded in a collagen gel formed both acinar and tubular structures only when the gel was detached (floating) from the cell culture plate's well, and allowed to be contracted by the cells. Epithelial phenotype depended upon the time and the location within the gel, as ducts formed exclusively on the upper layer of the gel while ductal branching occurred earlier in the central area of the gel, and gradually progressed toward the periphery. The addition of fibroblasts accelerated tubulogenesis. MCF10A cells facilitated the organization of thick collagen fibers packed into large bundles at the tip of the ducts and parallel to the direction of ductal elongation. In gels that were not detached from the well's wall, MCF10A cells organized in monolayer and collagen fibers were aligned along the axis of outstretched sprouts stemming from those cellular aggregates. Partial gel release induced uniaxial tubulogenesis associated with orderly aligned collagen fibers. These results suggest that proper collagen organization is necessary for epithelial morphogenesis to occur, and that biomechanical interactions between fibers and cells mediated duct formation, elongation and branching.
Biomaterials 02/2010; 31(13):3622-30. · 7.40 Impact Factor
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ABSTRACT: Epithelial-stromal interactions play a crucial role in normal embryonic development and carcinogenesis of the human breast while the underlying mechanisms of these events remain poorly understood. To address this issue, we constructed a physiologically relevant, three-dimensional (3D) culture surrogate of complex human breast tissue that included a tri-culture system made up of human mammary epithelial cells (MCF10A), human fibroblasts and adipocytes, i.e., the two dominant breast stromal cell types, in a Matrigel/collagen mixture on porous silk protein scaffolds. The presence of stromal cells inhibited MCF10A cell proliferation and induced both alveolar and ductal morphogenesis and enhanced casein expression. In contrast to the immature polarity exhibited by co-cultures with either fibroblasts or adipocytes, the alveolar structures formed by the tri-cultures exhibited proper polarity similar to that observed in breast tissue in vivo. Only alveolar structures with reverted polarity were observed in MCF10A monocultures. Consistent with their phenotypic appearance, more functional differentiation of epithelial cells was also observed in the tri-cultures, where casein alpha- and -beta mRNA expression was significantly increased. This in vitro tri-culture breast tissue system sustained on silk scaffold effectively represents a more physiologically relevant 3D microenvironment for mammary epithelial cells and stromal cells than either co-cultures or monocultures. This experimental model provides an important first step for bioengineering an informative human breast tissue system, with which to study normal breast morphogenesis and neoplastic transformation.
Biomaterials 02/2010; 31(14):3920-9. · 7.40 Impact Factor
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Frederick S vom Saal,
Benson T Akingbemi,
Scott M Belcher,
David A Crain,
David Crews,
Linda C Guidice,
Patricia A Hunt,
Csaba Leranth,
John Peterson Myers,
Angel Nadal, [......],
Gilbert Schoenfelder, Carlos Sonnenschein,
Ana M Soto,
Richard W Stahlhut,
Shanna H Swan,
Laura N Vandenberg,
Hong-Sheng Wang,
Cheryl S Watson,
Wade V Welshons,
Robert T Zoeller
Toxicological Sciences 02/2010; 115(2):612-3; author reply 614-20. · 4.65 Impact Factor
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ABSTRACT: Abstract
Background
Stromal-epithelial interactions mediate breast development, and the initiation and progression of breast cancer. In the present study, we developed 3-dimensional (3D) in vitro models to study breast cancer tissue organization and the role of the microenvironment in phenotypic determination.
Methods
The human breast cancer MCF7 cells were grown alone or co-cultured with primary human breast fibroblasts. Cells were embedded in matrices containing either type I collagen or a combination of reconstituted basement membrane proteins and type I collagen. The cultures were carried out for up to 6 weeks. For every time point (1-6 weeks), the gels were fixed and processed for histology, and whole-mounted for confocal microscopy evaluation. The epithelial structures were characterized utilizing immunohistochemical techniques; their area and proliferation index were measured using computerized morphometric analysis. Statistical differences between groups were analyzed by ANOVA, Dunnett's T3 post-hoc test and chi-square.
Results
Most of the MCF7 cells grown alone within a collagen matrix died during the first two weeks; those that survived organized into large, round and solid clusters. The presence of fibroblasts in collagen gels reduced MCF7 cell death, induced cell polarity, and the formation of round and elongated epithelial structures containing a lumen. The addition of reconstituted basement membrane to collagen gels by itself had also survival and organizational effects on the MCF7 cells. Regardless of the presence of fibroblasts, the MCF7 cells both polarized and formed a lumen. The addition of fibroblasts to the gel containing reconstituted basement membrane and collagen induced the formation of elongated structures.
Conclusions
Our results indicate that a matrix containing both type I collagen and reconstituted basement membrane, and the presence of normal breast fibroblasts constitute the minimal permissive microenvironment to induce near-complete tumor phenotype reversion. These human breast 3D tissue morphogenesis models promise to become reliable tools for studying tissue interactions, therapeutic screening and drug target validation.
BMC Cancer. 01/2010;
