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Sample records for lobuloalveolar mammary development

  1. ErbB4 signaling in the mammary gland is required for lobuloalveolar development and Stat5 activation during lactation.

    PubMed

    Jones, F E; Welte, T; Fu, X Y; Stern, D F

    1999-10-01

    Signaling by members of the epidermal growth factor receptor family plays an important role in breast development and breast cancer. Earlier work suggested that one of these receptors, ErbB4, is coupled to unique responses in this tissue. To determine the function of ErbB4 signaling in the normal mouse mammary gland, we inactivated ErbB4 signaling by expressing a COOH terminally deleted dominant-negative allele of ErbB4 (ErbB4DeltaIC) as a transgene in the mammary gland. Despite the expression of ErbB4DeltaIC from puberty through later stages of mammary development, an ErbB4DeltaIC-specific phenotype was not observed until mid-lactation. At 12-d postpartum, lobuloalveoli expressing ErbB4DeltaIC protein were condensed and lacked normal lumenal lactation products. In these lobuloalveoli, beta-casein mRNA, detected by in situ hybridization, was normal. However, whey acidic protein mRNA was reduced, and alpha-lactalbumin mRNA was undetectable. Stat5 expression was detected by immunohistochemistry in ErbB4DeltaIC-expressing tissue. However, Stat5 was not phosphorylated at Y694 and was, therefore, probably inactive. When expressed transiently in 293T cells, ErbB4 induced phosphorylation of Stat5. This phosphorylation required an intact Stat5 SH2 domain. In summary, our results demonstrate that ErbB4 signaling is necessary for mammary terminal differentiation and Stat5 activation at mid-lactation. PMID:10508857

  2. C/EBPbeta, but not C/EBPalpha, is essential for ductal morphogenesis, lobuloalveolar proliferation, and functional differentiation in the mouse mammary gland.

    PubMed

    Seagroves, T N; Krnacik, S; Raught, B; Gay, J; Burgess-Beusse, B; Darlington, G J; Rosen, J M

    1998-06-15

    The CCAAT/enhancer binding proteins (C/EBPs) are differentially expressed throughout mammary gland development and interact with binding sites within the promoter of a milk protein gene, beta-casein. The specific roles of C/EBPbeta and C/EBPalpha in mouse mammary gland development and differentiation have been investigated in mice that carry targeted deletions of these genes. C/EBPbeta-/- virgin mice exhibited cystic, enlarged mammary ducts with decreased secondary branching. Transplantation of C/EBPbeta-/- mammary epithelium into the cleared mammary fat pads of nude mice confirmed that this defect in ductal morphogenesis was intrinsic to the epithelium. When treated with estrogen/progesterone (E+P) to simulate pregnancy, C/EBPbeta-/- mammary glands displayed only limited lobuloalveolar development and ductal side branching. Primary mammary epithelial cells obtained from E+P-treated C/EBPbeta-/- mice that were cultured on extracellular matrix gels did not functionally differentiate in response to lactogenic hormones despite their organization into three-dimensional structures. Expression of beta-casein protein was inhibited 85%-100% and whey acidic protein (WAP) was undetectable. In contrast, no detectable alterations in mammary development or beta-casein expression were observed in mammary outgrowths derived from newborn C/EBPalpha-/- mammary epithelium transplanted into the cleared mammary fat pads of syngeneic hosts. These results demonstrate that C/EBPbeta, but not C/EBPalpha, is required for ductal morphogenesis, lobuloalveolar development, and functional differentiation of mammary epithelial cells. PMID:9637692

  3. Peroxisome proliferator-activated receptor-binding protein null mutation results in defective mammary gland development.

    PubMed

    Jia, Yuzhi; Qi, Chao; Zhang, Zhongyi; Zhu, Yiwei Tony; Rao, Sambasiva M; Zhu, Yi-Jun

    2005-03-18

    A conditional null mutation of peroxisome proliferator-activated receptor-binding protein (PBP) gene was generated to understand its role in mammary gland development. PBP-deficient mammary glands exhibited retarded ductal elongation during puberty, and decreased alveolar density during pregnancy and lactation. PBP-deficient mammary glands could not produce milk to nurse pups during lactation. Both the mammary ductal elongation in response to estrogen treatment and the mammary lobuloalveolar proliferation stimulated by estrogen plus progesterone were attenuated in PBP-deficient mammary glands. The proliferation index was decreased in PBP-deficient mammary glands. PBP-deficient mammary epithelial cells expressed abundant beta-casein, whey acidic protein, and WDNM1 mRNA, indicating a relatively intact differentiated function. PBP-deficient epithelial cells were unable to form mammospheres, which were considered to be derived from mammary progenitor/stem cells. We conclude that PBP plays a pivotal role in the normal mammary gland development. PMID:15647257

  4. Expression of novel, putative stem cell markers in prepubertal and lactating mammary glands of bovine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary stem cells (MaSC) are essential for growth and maintenance of the mammary epithelium. Two main phases of mammary growth include ductal elongation prior to puberty and lobulo-alveolar growth and development during pregnancy. Some studies have utilized morphological characteristics and retenti...

  5. REGULATION OF GENE EXPRESSION IN THE BOVINE MAMMARY GLAND BY OVARIAN STEROIDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is well established that estrogen is required for mammary epithelial cell proliferation and ductal development in the growing animal, and that lobuloalveolar development during gestation is dependent upon progesterone. Effects of these steroid hormones on gene expression in the mammary gland are ...

  6. C/EBPβ, but not C/EBPα, is essential for ductal morphogenesis, lobuloalveolar proliferation, and functional differentiation in the mouse mammary gland

    PubMed Central

    Seagroves, Tiffany N.; Krnacik, Susanne; Raught, Brian; Gay, Jason; Burgess-Beusse, Bonnie; Darlington, Gretchen J.; Rosen, Jeffrey M.

    1998-01-01

    The CCAAT/enhancer binding proteins (C/EBPs) are differentially expressed throughout mammary gland development and interact with binding sites within the promoter of a milk protein gene, β-casein. The specific roles of C/EBPβ and C/EBPα in mouse mammary gland development and differentiation have been investigated in mice that carry targeted deletions of these genes. C/EBPβ−/− virgin mice exhibited cystic, enlarged mammary ducts with decreased secondary branching. Transplantation of C/EBPβ−/− mammary epithelium into the cleared mammary fat pads of nude mice confirmed that this defect in ductal morphogenesis was intrinsic to the epithelium. When treated with estrogen/progesterone (E+P) to simulate pregnancy, C/EBPβ−/− mammary glands displayed only limited lobuloalveolar development and ductal side branching. Primary mammary epithelial cells obtained from E+P-treated C/EBPβ−/− mice that were cultured on extracellular matrix gels did not functionally differentiate in response to lactogenic hormones despite their organization into three-dimensional structures. Expression of β-casein protein was inhibited 85%–100% and whey acidic protein (WAP) was undetectable. In contrast, no detectable alterations in mammary development or β-casein expression were observed in mammary outgrowths derived from newborn C/EBPα−/− mammary epithelium transplanted into the cleared mammary fat pads of syngeneic hosts. These results demonstrate that C/EBPβ, but not C/EBPα, is required for ductal morphogenesis, lobuloalveolar development, and functional differentiation of mammary epithelial cells. PMID:9637692

  7. Targeting expression of a transforming growth factor beta 1 transgene to the pregnant mammary gland inhibits alveolar development and lactation.

    PubMed Central

    Jhappan, C; Geiser, A G; Kordon, E C; Bagheri, D; Hennighausen, L; Roberts, A B; Smith, G H; Merlino, G

    1993-01-01

    Transforming growth factor-beta 1 (TGF-beta 1) possesses highly potent, diverse and often opposing cell-specific activities, and has been implicated in the regulation of a variety of physiologic and developmental processes. To determine the effects of in vivo overexpression of TGF-beta 1 on mammary gland function, transgenic mice were generated harboring a fusion gene consisting of the porcine TGF-beta 1 cDNA placed under the control of regulatory elements of the pregnancy-responsive mouse whey-acidic protein (WAP) gene. Females from two of four transgenic lines were unable to lactate due to inhibition of the formation of lobuloalveolar structures and suppression of production of endogenous milk protein. In contrast, ductal development of the mammary glands was not overtly impaired. There was a complete concordance in transgenic mice between manifestation of the lactation-deficient phenotype and expression of RNA from the WAP/TGF-beta 1 transgene, which was present at low levels in the virgin gland, but was greatly induced at mid-pregnancy. TGF-beta 1 was localized to numerous alveoli and to the periductal extracellular matrix in the mammary gland of transgenic females late in pregnancy by immunohistochemical analysis. Glands reconstituted from cultured transgenic mammary epithelial cells duplicated the inhibition of lobuloalveolar development observed in situ in the mammary glands of pregnant transgenic mice. Results from this transgenic model strongly support the hypothesis that TGF-beta 1 plays an important in vivo role in regulating the development and function of the mammary gland. Images PMID:8491177

  8. Mammary Gland Specific Knockdown of the Physiological Surge in Cx26 during Lactation Retains Normal Mammary Gland Development and Function

    PubMed Central

    Stewart, Michael K. G.; Plante, Isabelle; Bechberger, John F.; Naus, Christian C.; Laird, Dale W.

    2014-01-01

    Connexin26 (Cx26) is the major Cx protein expressed in the human mammary gland and is up-regulated during pregnancy while remaining elevated throughout lactation. It is currently unknown if patients with loss-of-function Cx26 mutations that result in hearing loss and skin diseases have a greater susceptibility to impaired breast development. To investigate if Cx26 plays a critical role in mammary gland development and differentiation, a novel Cx26 conditional knockout mouse model was generated by crossing Cx26fl/fl mice with mice expressing Cre under the β-Lactoglobulin promoter. Conditional knockdown of Cx26 from the mammary gland resulted in a dramatic reduction in detectable gap junction plaques confirmed by a significant ∼65-70% reduction in Cx26 mRNA and protein throughout parturition and lactation. Interestingly, this reduction was accompanied by a decrease in mammary gland Cx30 gap junction plaques at parturition, while no change was observed for Cx32 or Cx43. Whole mount, histological and immunofluorescent assessment of breast tissue revealed comparatively normal lobuloalveolar development following pregnancy in the conditionally knockdown mice compared to control mice. In addition, glands from genetically-modified mice were capable of producing milk proteins that were evident in the lumen of alveoli and ducts at similar levels as controls, suggesting normal gland function. Together, our results suggest that low levels of Cx26 expression throughout pregnancy and lactation, and not the physiological surge in Cx26, is sufficient for normal gland development and function. PMID:24988191

  9. Dietary genistein stimulates mammary development in gilts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The possible role of the phytoestrogen, genistein, on prepubertal development of mammary glands, hormonal status and bone resorption was investigated in gilts. Forty-five gilts were fed a control diet containing soya (CTLS, n = 15), a control diet without soya (CTL0, n = 15) or the CTLS diet supplem...

  10. Comparative aspects of mammary gland development and homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary glands are crucial to the reproductive strategy of mammals and the milk of domesticated ruminants serves as an important source of nutrients for the human population. The majority of mammary gland development occurs postnatally and the mammary gland undergoes cyclical periods of growth, dif...

  11. Stromal Effects on Mammary Gland Development and Breast Cancer

    NASA Astrophysics Data System (ADS)

    Wiseman, Bryony S.; Werb, Zena

    2002-05-01

    Breast cancer manifests itself in the mammary epithelium, yet there is a growing recognition that mammary stromal cells also play an important role in tumorigenesis. During its developmental cycle, the mammary gland displays many of the properties associated with breast cancer, and many of the stromal factors necessary for mammary development also promote or protect against breast cancer. Here we review our present knowledge of the specific factors and cell types that contribute to epithelial-stromal crosstalk during mammary development. To find cures for diseases like breast cancer that rely on epithelial-stromal crosstalk, we must understand how these different cell types communicate with each other.

  12. Aryl hydrocarbon receptor (AhR) activation during pregnancy, and in adult nulliparous mice, delays the subsequent development of DMBA-induced mammary tumors

    PubMed Central

    Wang, Tao; Gavin, Heather M.; Arlt, Volker M.; Lawrence, B. Paige; Fenton, Suzanne E.; Medina, Daniel; Vorderstrasse, Beth A.

    2010-01-01

    TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), the prototypic ligand for the aryl hydrocarbon receptor (AhR), promotes tumor formation in some model systems. However with regard to breast cancer, epidemiological and animal studies are inconclusive as to whether exposure increases tumor incidence or may instead be protective. We have previously reported that mice exposed to TCDD during pregnancy have impaired differentiation of mammary tissue, including decreased branching and poor development of lobuloalveolar structures. Because normal pregnancy-induced mammary differentiation may protect against subsequent neoplastic transformation, we hypothesized that TCDD-treated mice would be more susceptible to chemical carcinogenesis after parturition. To test this, mice were treated with TCDD or vehicle during pregnancy. Four weeks later, DMBA (7,12-dimethylbenz[a]anthracene) was administered to induce mammary tumor formation. Contrary to our hypothesis, TCDD-exposed parous mice showed a four-week delay in tumor formation relative to controls, and had a lower tumor incidence throughout the 27-week time course. The same results were obtained in nulliparous mice given TCDD and DMBA on the same schedule. We next addressed whether the delayed tumor incidence was a reflection of decreased tumor initiation, by testing the formation of DMBA-DNA adducts and preneoplastic lesions, induction of cytochrome P450s, and cell proliferation. None of these markers of tumor initiation differed between vehicle- and TCDD-treated animals. The expression of CXCL12 and CXCR4 was also measured to address their possible role in tumorigenesis. Taken together, our results suggest that AhR activation by TCDD slows the promotion of preneoplastic lesions to overt mammary tumors. PMID:20521247

  13. Mammary Development and Breast Cancer: A Wnt Perspective

    PubMed Central

    Yu, Qing Cissy; Verheyen, Esther M.; Zeng, Yi Arial

    2016-01-01

    The Wnt pathway has emerged as a key signaling cascade participating in mammary organogenesis and breast oncogenesis. In this review, we will summarize the current knowledge of how the pathway regulates stem cells and normal development of the mammary gland, and discuss how its various components contribute to breast carcinoma pathology. PMID:27420097

  14. Bovine Mammary Epithelial Cell Lineages and Parenchymal Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary development proceeds from an aggregation of cells in the ventral ectoderm to the establishment of an elaborate tree of alveoli, ducts, and cisternae. However, despite abundant data on endocrine regulation of ruminant mammary growth, we know comparatively little about cell lineages, express...

  15. Mammary Development and Breast Cancer: A Wnt Perspective.

    PubMed

    Yu, Qing Cissy; Verheyen, Esther M; Zeng, Yi Arial

    2016-01-01

    The Wnt pathway has emerged as a key signaling cascade participating in mammary organogenesis and breast oncogenesis. In this review, we will summarize the current knowledge of how the pathway regulates stem cells and normal development of the mammary gland, and discuss how its various components contribute to breast carcinoma pathology. PMID:27420097

  16. Mammary Development and Breast Cancer: The Role of Stem Cells

    PubMed Central

    Ercan, C.; van Diest, P.J.; Vooijs, M.

    2014-01-01

    The mammary gland is a highly regenerative organ that can undergo multiple cycles of proliferation, lactation and involution, a process controlled by stem cells. The last decade much progress has been made in the identification of signaling pathways that function in these stem cells to control self-renewal, lineage commitment and epithelial differentiation in the normal mammary gland. The same signaling pathways that control physiological mammary development and homeostasis are also often found deregulated in breast cancer. Here we provide an overview on the functional and molecular identification of mammary stem cells in the context of both normal breast development and breast cancer. We discuss the contribution of some key signaling pathways with an emphasis on Notch receptor signaling, a cell fate determination pathway often deregulated in breast cancer. A further understanding of the biological roles of the Notch pathway in mammary stem cell behavior and carcinogenesis might be relevant for the development of future therapies. PMID:21506923

  17. Pim-1 kinase expression during murine mammary development

    SciTech Connect

    Gapter, Leslie A.; Magnuson, Nancy S.; Ng, Ka-yun; Hosick, Howard L. . E-mail: hosick@wsu.edu

    2006-07-07

    Pim-1 kinase phosphorylates substrates whose activities are linked to proliferation, survival, differentiation, and apoptosis. Although pim-1 is induced by hormones and cytokines, the hormonal control and contribution of Pim-1 to mammary gland development have not been evaluated. We examined Pim-1 expression in mammary cell lines, investigated whether Pim-1 levels could be altered in breast epithelia by mammogenic hormones, and evaluated Pim-1 expression during mammary development. We found that Pim-1 was elevated in most mammary carcinoma cell lines and progesterone increased Pim-1 protein to some extent in non-tumorigenic mammary epithelia. Pim-1 expression in situ was consistent with the documented profile of progesterone activity in mouse mammary glands. Pim-1 nuclear localization correlated with cytoplasmic distribution for its substrate, p21{sup CIP/Waf1}, and we found that Pim-1 and p21 associate in vitro. Our results suggest that Pim-1 expression may be regulated by progesterone during mammary development and Pim-1 associates with p21 in mammary epithelial cells.

  18. The role of neutralizing antibodies for mouse mammary tumor virus transmission and mammary cancer development

    NASA Astrophysics Data System (ADS)

    Finke, Daniela; Luther, Sanjiv A.; Acha-Orbea, Hans

    2003-01-01

    Mouse mammary tumor virus (MMTV) infection establishes chronic germinal centers and a lifelong neutralizing Ab response. We show that removal of the draining lymph node after establishment of the germinal center reaction led to complete loss of neutralizing Abs despite comparable infection levels in peripheral lymphocytes. Importantly, in the absence of neutralization, only the exocrine organs mammary gland, salivary gland, pancreas, and skin showed strikingly increased infection, resulting in accelerated mammary tumor development. Induction of stronger neutralization did not influence chronic infection levels of peripheral lymphoid organs but strongly inhibited mammary gland infection and virus transmission to the next generation. Taken together, we provide evidence that a tight equilibrium in virus neutralization allows limited infection of exocrine organs and controls cancer development in susceptible mouse strains. These experiments show that a strong neutralizing Ab response induced after infection is not able to control lymphoid MMTV infection. Strong neutralization, however, is capable of blocking amplification of mammary gland infection, tumor development, and virus transmission to the next generation. The results also indicate a role of neutralization in natural resistance to MMTV infection.

  19. The Epigenetic Landscape of Mammary Gland Development and Functional Differentiation

    PubMed Central

    Rijnkels, Monique; Kabotyanski, Elena; Montazer-Torbati, Mohamad B.; Beauvais, C. Hue; Vassetzky, Yegor; Rosen, Jeffrey M.; Devinoy, Eve

    2010-01-01

    Most of the development and functional differentiation in the mammary gland occur after birth. Epigenetics is defined as the stable alterations in gene expression potential that arise during development and proliferation. Epigenetic changes are mediated at the biochemical level by the chromatin conformation initiated by DNA methylation, histone variants, post-translational modifications of histones, non-histone chromatin proteins, and non-coding RNAs. Epigenetics plays a key role in development. However, very little is known about its role in the developing mammary gland or how it might integrate the many signalling pathways involved in mammary gland development and function that have been discovered during the past few decades. An inverse relationship between marks of closed (DNA methylation) or open chromatin (DnaseI hypersensitivity, certain histone modifications) and milk protein gene expression has been documented. Recent studies have shown that during development and functional differentiation, both global and local chromatin changes occur. Locally, chromatin at distal regulatory elements and promoters of milk protein genes gains a more open conformation. Furthermore, changes occur both in looping between regulatory elements and attachment to nuclear matrix. These changes are induced by developmental signals and environmental conditions. Additionally, distinct epigenetic patterns have been identified in mammary gland stem and progenitor cell sub-populations. Together, these findings suggest that epigenetics plays a role in mammary development and function. With the new tools for epigenomics developed in recent years, we now can begin to establish a framework for the role of epigenetics in mammary gland development and disease. PMID:20157770

  20. The epigenetic landscape of mammary gland development and functional differentiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most of the development and functional differentiation in the mammary gland occur after birth. Epigenetics is defined as the stable alterations in gene expression potential that arise during development and proliferation. Epigenetic changes are mediated at the biochemical level by the chromatin conf...

  1. INDUCTION OF MAMMARY GLAND DEVELOPMENT IN ESTROGEN RECEPTOR-ALPHA KNOCKOUT MICE

    EPA Science Inventory

    Mammary glands from the estrogen receptor knockout ( ERKO) mouse do not undergo ductal morphogenesis or alveolar development. Disrupted Er signaling may result in reduced estrogen-responsive gene products in the mammary gland or reduced mammotropic hormones that contribute t...

  2. MAMMARY GLAND DEVELOPMENT: EARLY LIFE EFFECTS FROM THE ENVIRONMENT

    EPA Science Inventory

    Mammary Gland Development: Early Life Effects from the Environment

    S.E. Fenton. Reproductive Toxicology Division, National Health and Environmental Effects Laboratory, ORD, U.S. EPA, Research Triangle Park, NC 27711.

    As signs of precocious puberty in girls reach ...

  3. FEEDING GENISTEIN TO PREPUBERTAL GILTS STIMULATES THEIR MAMMARY DEVELOPMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The possible role of dietary genistein on mammary development of prepubertal gilts was investigated. Forty-five gilts were fed one of three diets from 90 d of age until slaughter (day 183 ± 1). Diets were: without soya (CTL0, n=15); soya-based commercial (CTLS, n=15); and soya-based commercial with ...

  4. Diet-induced obesity disrupts ductal development in the mammary glands of nonpregnant mice.

    PubMed

    Kamikawa, Akihiro; Ichii, Osamu; Yamaji, Daisuke; Imao, Takeshi; Suzuki, Chiharu; Okamatsu-Ogura, Yuko; Terao, Akira; Kon, Yasuhiro; Kimura, Kazuhiro

    2009-05-01

    Mammary glands develop postnatally in response to the hypothalamic-pituitary-gonadal axis. Obesity-induced changes in the local environment, however, retard mammary gland development during late pregnancy and lactation. To clarify the effects of obesity on fundamental duct development, we compared the mammary glands of nulliparous nonpregnant obese mice fed a high-fat diet with those of lean mice fed a normal diet. Obese mice had enlarged mammary glands, reflecting fat pad size, whereas the ducts in obese mice showed a less dense distribution with less frequent branching. Additionally, the ducts were surrounded by thick collagen layers, and were incompletely lined with myoepithelium. Because leptin receptors were localized in the epithelium region and leptin that was highly expressed in the obese glands suppressed mammary epithelial cell proliferation in vitro, the present results suggest that obesity disrupts mammary ductal development, possibly by remodeling the mammary microenvironment and promoting the expression of such paracrine factors as leptin. PMID:19384959

  5. Primary Cilia Regulate Branching Morphogenesis During Mammary Gland Development

    PubMed Central

    McDermott, Kimberly M.; Liu, Bob Y.; Tlsty, Thea D.; Pazour, Gregory J.

    2010-01-01

    Summary During mammary gland development an epithelial bud undergoes branching morphogenesis to expand into a continuous tree-like network of branched ducts [1]. The process involves multiple cell types that are coordinated by hormones and growth factors coupled with signaling events including Wnt and Hedgehog [2-5]. Primary cilia play key roles in the development of many organs by coordinating extracellular signaling (Wnt, Hedgehog) with cellular physiology [6-8]. During mammary development, we find cilia on luminal epithelial, myoepithelial and stromal cells during early branching morphogenesis when epithelial ducts extend into the fat pad and undergo branching morphogenesis. When branching is complete, cilia disappear from luminal epithelial cells but remain on myoepithelial and stromal cells. Ciliary dysfunction caused by intraflagellar transport (IFT) defects results in branching defects. These include decreased ductal extension and decreased secondary and tertiary branching along with reduced lobular-alveolar development during pregnancy and lactation. We find increased canonical Wnt and decreased Hedgehog signaling in the mutant glands, which is consistent with the role of cilia in regulating these pathways [6-11]. In mammary gland and other organs, increased canonical Wnt [12-14] and decreased Hedgehog [15, 16] signaling decreases branching morphogenesis suggesting that Wnt and Hedgehog signaling connect ciliary dysfunction to branching defects. PMID:20381354

  6. Serotoninergic and Circadian Systems: Driving Mammary Gland Development and Function

    PubMed Central

    Suárez-Trujillo, Aridany; Casey, Theresa M.

    2016-01-01

    Since lactation is one of the most metabolically demanding states in adult female mammals, beautifully complex regulatory mechanisms are in place to time lactation to begin after birth and cease when the neonate is weaned. Lactation is regulated by numerous different homeorhetic factors, all of them tightly coordinated with the demands of milk production. Emerging evidence support that among these factors are the serotonergic and circadian clock systems. Here we review the serotoninergic and circadian clock systems and their roles in the regulation of mammary gland development and lactation physiology. We conclude by presenting our hypothesis that these two systems interact to accommodate the metabolic demands of lactation and thus adaptive changes in these systems occur to maintain mammary and systemic homeostasis through the reproductive cycles of female mammals. PMID:27471474

  7. Non-coding RNAs in Mammary Gland Development and Disease.

    PubMed

    Sandhu, Gurveen K; Milevskiy, Michael J G; Wilson, Wesley; Shewan, Annette M; Brown, Melissa A

    2016-01-01

    Non-coding RNAs (ncRNAs) are untranslated RNA molecules that function to regulate the expression of numerous genes and associated biochemical pathways and cellular functions. NcRNAs include small interfering RNAs (siRNAs), microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs) and long non-coding RNAs (lncRNAs). They participate in the regulation of all developmental processes and are frequently aberrantly expressed or functionally defective in disease. This Chapter will focus on the role of ncRNAs, in particular miRNAs and lncRNAs, in mammary gland development and disease. PMID:26659490

  8. Key stages in mammary gland development: the mammary end bud as a motile organ.

    PubMed

    Hinck, Lindsay; Silberstein, Gary B

    2005-01-01

    In the rodent, epithelial end buds define the tips of elongating mammary ducts. These highly motile structures undergo repeated dichotomous branching as they aggressively advance through fatty stroma and, turning to avoid other ducts, they finally cease growth leaving behind the open, tree-like framework on which secretory alveoli develop during pregnancy. This review identifies the motility of end buds as a unique developmental marker that represents the successful integration of systemic and local mammotrophic influences, and covers relevant advances in ductal growth regulation, extracellular matrix (ECM) remodeling, and cell adhesion in the inner end bud. An unexpected growth-promoting synergy between insulin-like growth factor-1 and progesterone, in which ducts elongate without forming new end buds, is described as well as evidence strongly supporting self-inhibition of ductal elongation by end-bud-secreted transforming growth factor-beta acting on stromal targets. The influence of the matrix metalloproteinase ECM-remodeling enzymes, notably matrix metalloproteinase-2, on end bud growth is discussed in the broader context of enzymes that regulate the polysaccharide-rich glycosaminoglycan elements of the ECM. Finally, a critical, motility-enabling role for the cellular architecture of the end bud is identified and the contribution of cadherins, the netrin/neogenin system, and ErbB2 to the structure and motility of end buds is discussed. PMID:16280048

  9. Primate mammary development. Effects of hypophysectomy, prolactin inhibition, and growth hormone administration.

    PubMed Central

    Kleinberg, D L; Niemann, W; Flamm, E; Cooper, P; Babitsky, G; Valensi, Q

    1985-01-01

    The pituitary gland has been found to be an important factor in mammary development in primates. Hypophysectomy in 12 sexually immature monkeys caused significant inhibition of estradiol (E2)-induced mammary growth and development. A histological index of mammary development in sexually immature hypophysectomized animals was lower (0.82) than in intact E2-treated controls (3.4; P less than 0.008). Hypophysectomy also inhibited growth of the mammary gland as judged by a size index. Despite the hypophysectomy, E2 stimulated some, albeit blunted, mammary growth and development, which may have been due to incomplete hypophysectomy. Selective inhibition of prolactin by ergot drugs in intact animals did not prevent full mammary development, suggesting that there may be pituitary mammogens other than prolactin, or that very low or unmeasurable concentrations of prolactin were sufficient to synergize with E2 to cause full acinar development. The mean histological index was 3.08 in E2-treated animals and 3.16 in animals treated with E2 plus pergolide. There was also no difference in the size of the glands. We evaluated the effect of growth hormone on mammary development by treating three hypophysectomized animals with pure 22,000 mol wt human growth hormone (hGH) (Genentech, Inc., South San Francisco, CA). We found that physiological or slightly supraphysiological concentrations of hGH in animals with unmeasurable prolactin were incapable of restoring the capacity of E2 to induce full mammary growth. These findings suggest that, if growth hormone is a mammary mitogen, that physiological concentrations are insufficient to synergize with E2 to induce full mammary growth or that other forms of hGH are mammogenic. Our studies suggest that the role of the pituitary gland in mammary mitogenesis in primates is more complicated than previously thought. They also raise the possibility that heretofore unidentified pituitary substances may be mammogenic. Images PMID:4008646

  10. ER and PR signaling nodes during mammary gland development

    PubMed Central

    2012-01-01

    The ovarian hormones estrogen and progesterone orchestrate postnatal mammary gland development and are implicated in breast cancer. Most of our understanding of the molecular mechanisms of estrogen receptor (ER) and progesterone receptor (PR) signaling stems from in vitro studies with hormone receptor-positive cell lines. They have shown that ER and PR regulate gene transcription either by binding to DNA response elements directly or via other transcription factors and recruiting co-regulators. In addition they cross-talk with other signaling pathways through nongenomic mechanisms. Mouse genetics combined with tissue recombination techniques have provided insights about the action of these two hormones in vivo. It has emerged that hormones act on a subset of mammary epithelial cells and relegate biological functions to paracrine factors. With regards to hormonal signaling in breast carcinomas, global gene expression analyses have led to the identification of gene expression signatures that are characteristic of ERα-positive tumors that have stipulated functional studies of hitherto poorly understood transcription factors. Here, we highlight what has been learned about ER and PR signaling nodes in these different systems and attempt to lay out in which way the insights may converge. PMID:22809143

  11. Effects of Body Weight and Nutrition on Histological Mammary Development in Holstein Heifers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to determine effects of rate of gain and body weight (BW) on mammary parenchymal tissue development. Mammary tissue samples were available from heifers (n = 54) reared on one of two dietary treatments, restricted (R) 650 g/d or elevated (E) 950 g/d of daily gain), and slaughtered ...

  12. Fatty acid synthase is required for mammary gland development and milk production during lactation

    PubMed Central

    Suburu, Janel; Shi, Lihong; Wu, Jiansheng; Wang, Shihua; Samuel, Michael; Thomas, Michael J.; Kock, Nancy D.; Yang, Guangyu; Kridel, Steven

    2014-01-01

    The mammary gland is one of the few adult tissues that strongly induce de novo fatty acid synthesis upon physiological stimulation, suggesting that fatty acid is important for milk production during lactation. The committed enzyme to perform this function is fatty acid synthase (FASN). To determine whether de novo fatty acid synthesis is obligatory or dietary fat is sufficient for mammary gland development and function during lactation, Fasn was specifically knocked out in mouse mammary epithelial cells. We found that deletion of Fasn hindered the development and induced the premature involution of the lactating mammary gland and significantly decreased medium- and long-chain fatty acids and total fatty acid contents in the milk. Consequently, pups nursing from Fasn knockout mothers experienced growth retardation and preweanling death, which was rescued by cross-fostering pups to a lactating wild-type mother. These results demonstrate that FASN is essential for the development, functional competence, and maintenance of the lactating mammary gland. PMID:24668799

  13. Relationship between histology, development and tumorigenesis of mammary gland in female rat.

    PubMed

    Líška, Ján; Brtko, Július; Dubovický, Michal; Macejová, Dana; Kissová, Viktória; Polák, Štefan; Ujházy, Eduard

    2016-02-14

    The mammary gland is a dynamic organ that undergoes structural and functional changes associated with growth, reproduction, and post-menopausal regression. The postnatal transformations of the epithelium and stromal cells of the mammary gland may contribute to its susceptibility to carcinogenesis. The increased cancer incidence in mammary glands of humans and similarly of rodents in association with their development is believed to be partly explained by proliferative activity together with lesser degree of differentiation, but it is not completely understood how the virgin gland retains its higher susceptibility to carcinogenesis. During its developmental cycle, the mammary gland displays many of the properties associated with breast cancer. An early first full-term pregnancy may have a protective effect. Rodent models are useful for investigating potential breast carcinogens. The purpose of this review is to help recognizing histological appearance of the epithelium and the stroma of the normal mammary gland in rats, and throughout its development in relation to tumorigenic potential. PMID:26424555

  14. Unlocking the milk protein gene loci during mammary gland development and differentiation; a role for chromatin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary gland development and differentiation occur mostly postnatally. Chromatin organization plays a key role in transcriptional and epigenetic regulation during development and differentiation. Considerable knowledge of the systemic hormones and local growth factors important for development and ...

  15. Cdc42 overexpression induces hyperbranching in the developing mammary gland by enhancing cell migration

    PubMed Central

    2013-01-01

    Introduction The Rho GTPase Cdc42 is overexpressed and hyperactivated in breast tumors compared to normal breast tissue. Cdc42 regulates key processes that are critical for mammary gland morphogenesis and become disrupted during the development, progression, and metastasis of breast cancer. However, the contribution of Cdc42 to normal and neoplastic mammary gland development in vivo remains poorly understood. We were therefore interested in investigating the effects of Cdc42 overexpression on mammary gland morphogenesis as a first step toward understanding how its overexpression may contribute to mammary tumorigenesis. Methods We developed a tetracycline-regulatable Cdc42 overexpression mouse model in which Cdc42 can be inducibly overexpressed in the developing mammary gland. The effects of Cdc42 overexpression during postnatal mammary gland development were investigated using in vivo and in vitro approaches, including morphometric analysis of wholemounted mammary glands, quantification of histological markers, and primary mammary epithelial cell (MEC) functional and biochemical assays. Results Analysis of Cdc42-overexpressing mammary glands revealed abnormal terminal end bud (TEB) morphologies, characterized by hyperbudding and trifurcation, and increased side branching within the ductal tree. Quantification of markers of proliferation and apoptosis suggested that these phenotypes were not due to increased cell proliferation or survival. Rather, Cdc42 overexpressing MECs were more migratory and contractile and formed dysmorphic, invasive acini in three-dimensional cultures. Cdc42 and RhoA activities, phosphorylated myosin light chain, and MAPK signaling, which contribute to migration and invasion, were markedly elevated in Cdc42 overexpressing MECs. Interestingly, Cdc42 overexpressing mammary glands displayed several features associated with altered epithelial-stromal interactions, which are known to regulate branching morphogenesis. These included increased

  16. Differential Roles of ERα and ERβ in Normal and Neoplastic Development in the Mouse Mammary Gland

    PubMed Central

    Mehta, Rajendra G.; Hawthorne, Michael; Mehta, Rajeshwari R.; Torres, Karen E. O.; Peng, Xinjian; McCormick, David L.; Kopelovich, Levy

    2014-01-01

    The present experiments were performed to determine the roles of estrogen receptors α and β (ERα and ERβ) in normal and neoplastic development in the mouse mammary gland. In wild-type mice, in vivo administration of estradiol (E) + progesterone (P) stimulated mammary ductal growth and alveolar differentiation. Mammary glands from mice in which the ERβ gene has been deleted (βERKO mice) demonstrated normal ductal growth and differentiation in response to E + P. By contrast, mammary glands from mice in which the ERα gene has been deleted (αERKO mice) demonstrated only rudimentary ductal structures that did not differentiate in response to E + P. EGF demonstrates estrogen-like activity in the mammary glands of αERKO mice: treatment of αERKO mice with EGF + P (without E) supported normal mammary gland development, induced expression of progesterone receptor (PR), and increased levels of G-protein-coupled receptor (GPR30) protein. Mammary gland development in βERKO mice treated with EGF + P was comparable to that of wild-type mice receiving EGF + P; EGF had no statistically significant effects on the induction of PR or expression of GPR30 in mammary glands harvested from either wild-type mice or βERKO mice. In vitro exposure of mammary glands to 7,12-dimethylbenz[a]anthracene (DMBA) induced preneoplastic mammary alveolar lesions (MAL) in glands from wild-type mice and βERKO mice, but failed to induce MAL in mammary glands from αERKO mice. Microarray analysis of DMBA-treated mammary glands identified 28 functional pathways whose expression was significantly different in αERKO mice versus both βERKO and wild-type mice; key functions that were differentially expressed in αERKO mice included cell division, cell proliferation, and apoptosis. The data demonstrate distinct roles for ERα and ERβ in normal and neoplastic development in the mouse mammary gland, and suggest that EGF can mimic the ERα-mediated effects of E in this organ. PMID:25405629

  17. The RhoGEF Net1 is required for normal mammary gland development.

    PubMed

    Zuo, Yan; Berdeaux, Rebecca; Frost, Jeffrey A

    2014-12-01

    Neuroepithelial transforming gene 1 (Net1) is a RhoA subfamily-specific guanine nucleotide exchange factor that is overexpressed in human breast cancer and is required for breast cancer cell migration and invasion. However, the role of Net1 in normal mammary gland development or function has never been assessed. To understand the role of Net1 in the mammary gland, we have created a conditional Net1 knockout mouse model. Whole-body deletion of Net1 results in delayed mammary gland development during puberty characterized by slowed of ductal extension and reduced ductal branching. Epithelial cells within the developing ducts show reduced proliferation that is accompanied by diminished estrogen receptor-α expression and activity. Net1-deficient mammary glands also exhibit reduced phosphorylation of regulatory subunits of myosin light chain and myosin light-chain phosphatase, indicating that RhoA-dependent actomyosin contraction is compromised. Net1 deficiency also leads to disorganization of myoepithelial and ductal epithelial cells and increased periductal collagen deposition. Mammary epithelial cell transplantation experiments indicate that reduced ductal branching and disorganization are cell autonomous. These data identify for the first time a role for NET1 in vivo and indicate that NET1 expression is essential for the proliferation and differentiation of mammary epithelial cells in the developing mammary gland. PMID:25321414

  18. Stromal matrix metalloproteinase-11 is involved in the mammary gland postnatal development.

    PubMed

    Tan, J; Buache, E; Alpy, F; Daguenet, E; Tomasetto, C-L; Ren, G-S; Rio, M-C

    2014-07-31

    MMP-11 is a bad prognosis paracrine factor in invasive breast cancers. However, its mammary physiological function remains largely unknown. In the present study we have investigated MMP-11 function during postnatal mammary gland development and function using MMP-11-deficient (MMP-11-/-) mice. Histological and immunohistochemical analyses as well as whole-mount mammary gland staining show alteration of the mammary gland in the absence of MMP-11, where ductal tree, alveolar structures and milk production are reduced. Moreover, a series of transplantation experiments allowed us to demonstrate that MMP-11 exerts an essential local paracrine function that favors mammary gland branching and epithelial cell outgrowth and invasion through adjacent connective tissues. Indeed, MMP-11-/- cleared fat pads are not permissive for wild-type epithelium development, whereas MMP-11-/- epithelium transplants grow normally when implanted in wild-type cleared fat pads. In addition, using primary mammary epithelial organoids, we show in vitro that this MMP-11 pro-branching effect is not direct, suggesting that MMP-11 acts via production/release of stroma-associated soluble factor(s). Finally, the lack of MMP-11 leads to decreased periductal collagen content, suggesting that MMP-11 has a role in collagen homeostasis. Thus, local stromal MMP-11 might also regulate mammary epithelial cell behavior mechanically by promoting extracellular matrix stiffness. Collectively, the present data indicate that MMP-11 is a paracrine factor involved during postnatal mammary gland morphogenesis, and support the concept that the stroma strongly impact epithelial cell behavior. Interestingly, stromal MMP-11 has previously been reported to favor malignant epithelial cell survival and promote cancer aggressiveness. Thus, MMP-11 has a paracrine function during mammary gland development that might be harnessed to promote tumor progression, exposing a new link between development and malignancy. PMID:24141782

  19. IGF-IR Mediated Mammary Tumorigenesis Is Enhanced during Pubertal Development

    PubMed Central

    Campbell, Craig I.; Moorehead, Roger A.

    2014-01-01

    Although breast cancer typically develops in women over the age of 40, it remains unclear when breast cancer initiating events occur or whether the mammary gland is particularly susceptible to oncogenic transformation at a particular developmental stage. Using MTB-IGFIR transgenic mice that overexpress type I insulin-like growth factor receptor (IGF-IR) in a doxycycline-inducible manner, mammary tumorigenesis was initiated at different developmental stages. Tumor multiplicity was significantly increased while tumor latency was significantly decreased when the IGF-IR transgene was expressed during pubertal development compared to post-pubertal transgene expression. Moreover, metastatic spread of mammary tumors to the lungs was approximately twice as likely when IGF-IR was overexpressed in pubertal mice compared to post-pubertal mice. In addition, engraftment of pubertal MTB-IGFIR mammary tissue into cleared mammary fat pads of pubertal hosts produced tumors more frequently and faster than engraftment into adult hosts. These experiments show that the mammary microenvironment created during puberty renders mammary epithelial cells particularly susceptible to transformation. PMID:25259518

  20. ENVIRONMENTAL TOXICANTS AND DISRUPTED MAMMARY GLAND DEVELOPMENT: THE WINDOW OF SUSCEPTIBILITY

    EPA Science Inventory

    Environmental Toxicants and Altered Mammary Gland Development: The window of susceptibility. Suzanne E. Fenton, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

    There are several enviro...

  1. ENVIRONMENTAL TOXICANTS AND ALTERED MAMMARY GLAND DEVELOPMENT: THE WINDOW OF SUSCEPTIBILITY

    EPA Science Inventory

    Environmental Toxicants and Altered Mammary Gland Development: The window of susceptibility. Suzanne E. Fenton, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

    There are several environm...

  2. Loss of vitamin D receptor signaling from the mammary epithelium or adipose tissue alters pubertal glandular development

    PubMed Central

    Johnson, Abby L.; Zinser, Glendon M.

    2014-01-01

    Vitamin D3 receptor (VDR) signaling within the mammary gland regulates various postnatal stages of glandular development, including puberty, pregnancy, involution, and tumorigenesis. Previous studies have shown that vitamin D3 treatment induces cell-autonomous growth inhibition and differentiation of mammary epithelial cells in culture. Furthermore, mammary adipose tissue serves as a depot for vitamin D3 storage, and both epithelial cells and adipocytes are capable of bioactivating vitamin D3. Despite the pervasiveness of VDR in mammary tissue, individual contributions of epithelial cells and adipocytes, as well as the VDR-regulated cross-talk between these two cell types during pubertal mammary development, have yet to be investigated. To assess the cell-type specific effect of VDR signaling during pubertal mammary development, novel mouse models with mammary epithelial- or adipocyte-specific loss of VDR were generated. Interestingly, loss of VDR in either cellular compartment accelerated ductal morphogenesis with increased epithelial cell proliferation and decreased apoptosis within terminal end buds. Conversely, VDR signaling specifically in the mammary epithelium modulated hormone-induced alveolar growth, as ablation of VDR in this cell type resulted in precocious alveolar development. In examining cellular cross-talk ex vivo, we show that ligand-dependent VDR signaling in adipocytes significantly inhibits mammary epithelial cell growth in part through the vitamin D3-dependent production of the cytokine IL-6. Collectively, these studies delineate independent roles for vitamin D3-dependent VDR signaling in mammary adipocytes and epithelial cells in controlling pubertal mammary gland development. PMID:25139050

  3. Mammary gland development--It's not just about estrogen.

    PubMed

    Berryhill, Grace E; Trott, Josephine F; Hovey, Russell C

    2016-01-01

    The mammary gland (MG) is one of a few organs that undergoes most of its growth after birth. Much of this development occurs concurrently with specific reproductive states, such that the ultimate goal of milk synthesis and secretion is coordinated with the nutritional requirements of the neonate. Central to the reproductive-MG axis is its endocrine regulation, and pivotal to this regulation is the ovarian secretion of estrogen (E). Indeed, it is widely accepted that estrogens are essential for growth of the MG to occur, both for ductal elongation during puberty and for alveolar development during gestation. As the factors regulating MG development continually come to light from the fields of developmental biology, lactation physiology, and breast cancer research, a growing body of evidence serves as a reminder that the MG are not as exclusively dependent on estrogens as might have been thought. The objective of this review is to summarize the state of information regarding our understanding of how estrogen (E) has been implicated as the key regulator of MG development, and to highlight some of the alternative E-independent mechanisms that have been discovered. In particular, we review our findings that dietary trans-10,cis-12 conjugated linoleic acid promotes ductal elongation and that the combination of progesterone (P) and prolactin (PRL) can stimulate branching morphogenesis in the absence of E. Ultimately, these examples stand as a healthy challenge to the question of just how important estrogens are for MG development. Answers to this question, in turn, increase our understanding of MG development across all mammals and the ways in which it can affect milk production. PMID:26506542

  4. Gli Activity Is Critical at Multiple Stages of Embryonic Mammary and Nipple Development

    PubMed Central

    Pinderhughes, Alicia; Koetz, Lisa; Cowin, Pamela

    2013-01-01

    Gli3 is a transcriptional regulator of Hedgehog (Hh) signaling that functions as a repressor (Gli3R) or activator (Gli3A) depending upon cellular context. Previously, we have shown that Gli3R is required for the formation of mammary placodes #3 and #5. Here, we report that this early loss of Gli3 results in abnormal patterning of two critical regulators: Bmp4 and Tbx3, within the presumptive mammary rudiment (MR) #3 zone. We also show that Gli3 loss leads to failure to maintain mammary mesenchyme specification and loss of epithelial Wnt signaling, which impairs the later development of remaining MRs: MR#2 showed profound evagination and ectopic hairs formed within the presumptive areola; MR#4 showed mild invagination defects and males showed inappropriate retention of mammary buds in Gli3xt/xt mice. Importantly, mice genetically manipulated to misactivate Hh signaling displayed the same phenotypic spectrum demonstrating that the repressor function of Gli3R is essential during multiple stages of mammary development. In contrast, positive Hh signaling occurs during nipple development in a mesenchymal cuff around the lactiferous duct and in muscle cells of the nipple sphincter. Collectively, these data show that repression of Hh signaling by Gli3R is critical for early placodal patterning and later mammary mesenchyme specification whereas positive Hh signaling occurs during nipple development. PMID:24260306

  5. Precocious mammary development in an 8-month-old Holstein heifer.

    PubMed

    Ambrose, Divakar J; Emmanuel, Daya G V

    2008-08-01

    An 8-month-old, virgin Holstein heifer with precocious mammary development was presented for examination. Protein, fat, and lactose in the mammary secretion were 14.90%, 0.12%, and 0.20%, respectively; somatic cell count was 3.9 x 10(6)/mL, with no bacterial infection. The heifer was inseminated at 15 months of age, confirmed pregnant, and subsequently slaughtered. PMID:18978977

  6. Tsc1 deficiency impairs mammary development in mice by suppression of AKT, nuclear ERα, and cell-cycle-driving proteins.

    PubMed

    Qin, Zhenqi; Zheng, Hang; Zhou, Ling; Ou, Yanhua; Huang, Bin; Yan, Bo; Qin, Zhenshu; Yang, Cuilan; Su, Yongchun; Bai, Xiaochun; Guo, Jiasong; Lin, Jun

    2016-01-01

    Loss of Tsc1/Tsc2 results in excess cell growth that eventually forms hamartoma in multiple organs. Our study using a mouse model with Tsc1 conditionally knockout in mammary epithelium showed that Tsc1 deficiency impaired mammary development. Phosphorylated S6 was up-regulated in Tsc1(-/-) mammary epithelium, which could be reversed by rapamycin, suggesting that mTORC1 was hyperactivated in Tsc1(-/-) mammary epithelium. The mTORC1 inhibitor rapamycin restored the development of Tsc1(-/-) mammary glands whereas suppressed the development of Tsc1(wt/wt) mammary glands, indicating that a modest activation of mTORC1 is critical for mammary development. Phosphorylated PDK1 and AKT, nuclear ERα, nuclear IRS-1, SGK3, and cell cycle regulators such as Cyclin D1, Cyclin E, CDK2, CDK4 and their target pRB were all apparently down-regulated in Tsc1(-/-) mammary glands, which could be reversed by rapamycin, suggesting that suppression of AKT by hyperactivation of mTORC1, inhibition on nuclear ERα signaling, and down-regulation of cell-cycle-driving proteins play important roles in the retarded mammary development induced by Tsc1 deletion. This study demonstrated for the first time the in vivo role of Tsc1 in pubertal mammary development of mice, and revealed that loss of Tsc1 does not necessarily lead to tissue hyperplasia. PMID:26795955

  7. Triennial Lactation Symposium: Bovine mammary epithelial cell lineages and parenchymal development.

    PubMed

    Ellis, S; Akers, R M; Capuco, A V; Safayi, S

    2012-05-01

    Mammary development proceeds from an aggregation of cells in the ventral ectoderm to the establishment of an elaborate tree of alveoli, ducts, and cisternae. However, despite abundant data on endocrine regulation of ruminant mammary growth, we know comparatively little about cell lineages, expression of differentiation markers, and plasticity in mammary cell phenotype. Histologic analyses have revealed cell populations with distinct histochemical profiles, but functional assessment of cell populations during development has been limited to analysis of proliferation and frequency estimations of morphotypes. The lack of transplantation models, limited availability of validated antibodies with reactivity to bovine antigens, and similar technical challenges have generally hindered the pace of discovery, but the application of new technologies such as laser microdissection, transcriptional profiling, and multispectral image analysis are yielding important clues into bovine mammary cell ontogeny and developmental regulation. Our analyses have shown that prepubertal ovariectomy affects epithelial architecture, increases the proportion of cells expressing the estrogen receptor, and increases myoepithelial cell development, all concomitant with a dramatic reduction in the mass of parenchymal tissue. Our observations point to a dual role for ovarian secretions in the control of not only the rate of epithelial development, but also the nature of the parenchymal development. The balance of stimulus and inhibition pathways cooperatively regulates mammary growth. The increased reliance on objective staining analyses and quantitative approaches will ensure broader repeatability, application, and extension of the findings regarding the impact of the ovary and other regulatory entities and factors. Advances in understanding the ontogeny of mammary epithelial cells, coupled with established and increasing knowledge of endocrine factors affecting mammary development, may yield

  8. Loss of Panx1 Impairs Mammary Gland Development at Lactation: Implications for Breast Tumorigenesis

    PubMed Central

    Stewart, Michael K. G.; Plante, Isabelle; Penuela, Silvia; Laird, Dale W.

    2016-01-01

    Pannexin1 (Panx1) subunits oligomerize to form large-pore channels between the intracellular and extracellular milieu that have been shown to regulate proliferation, differentiation and cell death mechanisms. These key cellular responses are ultimately necessary for normal tissue development and function but the role of Panx1 in development, differentiation and function in many tissues remains unexplored, including that of the breast. Panx1 was identified to be expressed in the mammary gland through western blot and immunofluorescent analysis and is dynamically upregulated during pregnancy and lactation. In order to evaluate the role of Panx1 in the context of mammary gland development and function, Panx1-/- mice were evaluated in comparison to wild-type mice in the mammary glands of virgin, lactating and involuting mice. Our results revealed that Panx1 ablation did not affect virgin or involuting mammary glands following histological and whole mount analysis. Panx1 was necessary for timely alveolar development during early lactation based on a decreased number of alveolar lumen following histological analysis and reduced proliferation following Ki67 immunofluorescent labelling. Importantly, the loss of Panx1 in lactating mammary glands did not overtly affect epithelial or secretory differentiation of the mammary gland suggesting that Panx1 is not critical in normal mammary gland function. In addition, PANX1 mRNA expression was correlated with negative clinical outcomes in patients with breast cancer using in silico arrays. Together, our results suggest that Panx1 is necessary for timely alveolar development following the transition from pregnancy to lactation, which may have implications extending to patients with breast cancer. PMID:27099931

  9. Low-dose effects of bisphenol A on mammary gland development in rats.

    PubMed

    Mandrup, K; Boberg, J; Isling, L K; Christiansen, S; Hass, U

    2016-07-01

    Bisphenol A (BPA) is widely used in food contact materials, toys, and other products. Several studies have indicated that effects observed at doses near human exposure levels may not be observed at higher doses. Many studies have shown effects on mammary glands at low doses of BPA, however, because of small number of animals or few doses investigated these data have not been used by EFSA as point of departure for the newly assessed tolerable daily intake (TDI). We performed a study with perinatal exposure to BPA (0, 0.025, 0.25, 5, and 50 mg/kg bw/day) in rats (n = 22 mated/group). One of the aims was to perform a study robust enough to contribute to the risk assessment of BPA and to elucidate possible biphasic dose-response relationships. We investigated mammary gland effects in the offspring at 22, 100, and 400 days of age. Male offspring showed increased mammary outgrowth on pup day (PD) 22 at 0.025 mg/kg BPA, indicating an increased mammary development at this low dose only. Increased prevalence of intraductal hyperplasia was observed in BPA females exposed to 0.25 mg/kg at PD 400, but not at PD 100, and not at higher or lower doses. The present findings support data from the published literature showing that perinatal exposure to BPA can induce increased mammary growth and proliferative lesions in rodents. Our results indicate that low-dose exposure to BPA can affect mammary gland development in male and female rats, although higher doses show a different pattern of effects. The observed intraductal hyperplasia in female rats could be associated with an increased risk for developing hyperplastic lesions, which are parallels to early signs of breast neoplasia in women. Collectively, current knowledge on effects of BPA on mammary gland at low doses indicates that highly exposed humans may not be sufficiently protected. PMID:27088260

  10. Effect of lapatinib on the development of estrogen receptor-negative mammary tumors in mice.

    PubMed

    Strecker, Tracy E; Shen, Qiang; Zhang, Yun; Hill, Jamal L; Li, Yuxin; Wang, Chunyu; Kim, Hee-Tae; Gilmer, Tona M; Sexton, Krystal R; Hilsenbeck, Susan G; Osborne, C Kent; Brown, Powel H

    2009-01-21

    Lapatinib, a selective orally available inhibitor of epidermal growth factor receptor (EGFR) and ErbB2 receptor tyrosine kinases, is a promising agent for the treatment of breast cancer. We examined the effect of lapatinib on the development of mammary tumors in MMTV-erbB2 transgenic mice, which express wild-type ErbB2 under the control of the mouse mammary tumor virus promoter and spontaneously develop estrogen receptor (ER)-negative and ErbB2-positive mammary tumors by 14 months of age. Mice were treated from age 3 months to age 15 months with vehicle (n = 17) or lapatinib (30 or 75 mg/kg body weight; n = 16 mice per group) by oral gavage twice daily (6 d/wk). All statistical tests were two-sided. By 328 days after the start of treatment, all 17 (100%) of the vehicle-treated mice vs five (31%) of the 16 mice treated with high-dose lapatinib developed mammary tumors (P < .001). Among MMTV-erbB2 mice treated for 5 months (n = 20 mice per group), those treated with lapatinib had fewer premalignant lesions and noninvasive cancers in their mammary glands than those treated with vehicle (P = .02). Lapatinib also effectively blocked epidermal growth factor-induced signaling through the EGFR and ErbB2 receptors, suppressed cyclin D1 and epiregulin mRNA expression, and stimulated p27 mRNA expression in human mammary epithelial cells and in mammary epithelial cells from mice treated for 5 months with high-dose lapatinib. Thus, cyclin D1, epiregulin, and p27 may represent useful biomarkers of lapatinib response in patients. These data suggest that lapatinib is a promising agent for the prevention of ER-negative breast cancer. PMID:19141783

  11. Estrogen receptor coregulators and pioneer factors: the orchestrators of mammary gland cell fate and development

    PubMed Central

    Manavathi, Bramanandam; Samanthapudi, Venkata S. K.; Gajulapalli, Vijay Narasimha Reddy

    2014-01-01

    The steroid hormone, 17β-estradiol (E2), plays critical role in various cellular processes such as cell proliferation, differentiation, migration and apoptosis, and is essential for reproduction and mammary gland development. E2 actions are mediated by two classical nuclear hormone receptors, estrogen receptor α and β (ERs). The activity of ERs depends on the coordinated activity of ligand binding, post-translational modifications (PTMs), and importantly the interaction with their partner proteins called “coregulators.” Because coregulators are proved to be crucial for ER transcriptional activity, and majority of breast cancers are ERα positive, an increased interest in the field has led to the identification of a large number of coregulators. In the last decade, gene knockout studies using mouse models provided impetus to our further understanding of the role of these coregulators in mammary gland development. Several coregulators appear to be critical for terminal end bud (TEB) formation, ductal branching and alveologenesis during mammary gland development. The emerging studies support that, coregulators along with the other ER partner proteins called “pioneer factors” together contribute significantly to E2 signaling and mammary cell fate. This review discusses emerging themes in coregulator and pioneer factor mediated action on ER functions, in particular their role in mammary gland cell fate and development. PMID:25364741

  12. Early Effects of Blueberry and Concord Grape Intake on Rat Mammary Gland Development Suggest Potential Protective Mechanisms for Mammary Tumorigenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberries (BB) and Concord grapes (CG) are rich in anthocyanins and other polyphenols, which may be linked to reduced incidence of chemically induced mammary carcinogenesis in animal models. We evaluated the early effects of dietary exposure to BB and CG on mammary glands of female rat offspring. ...

  13. Bisphenol A alters the development of the rhesus monkey mammary gland.

    PubMed

    Tharp, Andrew P; Maffini, Maricel V; Hunt, Patricia A; VandeVoort, Catherine A; Sonnenschein, Carlos; Soto, Ana M

    2012-05-22

    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. PMID:22566636

  14. New methods in mammary gland development and cancer: proteomics, epigenetics, symmetric division and metastasis

    PubMed Central

    2012-01-01

    The European Network for Breast Development and Cancer (ENBDC) meeting on 'Methods in Mammary Gland Development and Cancer' has become an annual international rendezvous for scientists with interests in the normal and neoplastic breast. The fourth meeting in this series, held in April in Weggis, Switzerland, focused on proteomics, epigenetics, symmetric division, and metastasis. PMID:22809213

  15. Epigenetic modifications unlock the milk protein gene loci during mouse mammary gland development and differentiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unlike with other tissues, development and differentiation of the mammary gland occur mostly after birth. The roles of systemic hormones and local growth factors important for this development and functional differentiation are well-studied. In other tissues, it has been shown that chromatin organiz...

  16. Mammary Gland ECM Remodeling, Stiffness, and Mechanosignaling in Normal Development and Tumor Progression

    PubMed Central

    Schedin, Pepper; Keely, Patricia J.

    2011-01-01

    Cells of the mammary gland are in intimate contact with other cells and with the extracellular matrix (ECM), both of which provide not only a biochemical context, but a mechanical context as well. Cell-mediated contraction allows cells to sense the stiffness of their microenvironment, and respond with appropriate mechanosignaling events that regulate gene expression and differentiation. ECM composition and organization are tightly regulated throughout development of the mammary gland, resulting in corresponding regulation of the mechanical environment and proper tissue architecture. Mechanical regulation is also at play during breast carcinoma progression, as changes in ECM deposition, composition, and organization accompany breast carcinoma. These changes result in stiffer matrices that activate mechanosignaling pathways and thereby induce cell proliferation, facilitate local tumor cell invasion, and promote progression. Thus, understanding the role of forces in the mammary gland is crucial to understanding both normal developmental and pathological processes. PMID:20980442

  17. Amino acids and mammary gland development: nutritional implications for milk production and neonatal growth.

    PubMed

    Rezaei, Reza; Wu, Zhenlong; Hou, Yongqing; Bazer, Fuller W; Wu, Guoyao

    2016-01-01

    Milk is synthesized by mammary epithelial cells of lactating mammals. The synthetic capacity of the mammary gland depends largely on the number and efficiency of functional mammary epithelial cells. Structural development of the mammary gland occurs during fetal growth, prepubertal and post-pubertal periods, pregnancy, and lactation under the control of various hormones (particularly estrogen, growth hormone, insulin-like growth factor-I, progesterone, placental lactogen, and prolactin) in a species- and stage-dependent manner. Milk is essential for the growth, development, and health of neonates. Amino acids (AA), present in both free and peptide-bound forms, are the most abundant organic nutrients in the milk of farm animals. Uptake of AA from the arterial blood of the lactating dam is the ultimate source of proteins (primarily β-casein and α-lactalbumin) and bioactive nitrogenous metabolites in milk. Results of recent studies indicate extensive catabolism of branched-chain AA (leucine, isoleucine and valine) and arginine to synthesize glutamate, glutamine, alanine, aspartate, asparagine, proline, and polyamines. The formation of polypeptides from AA is regulated not only by hormones (e.g., prolactin, insulin and glucocorticoids) and the rate of blood flow across the lactating mammary gland, but also by concentrations of AA, lipids, glucose, vitamins and minerals in the maternal plasma, as well as the activation of the mechanistic (mammalian) target rapamycin signaling by certain AA (e.g., arginine, branched-chain AA, and glutamine). Knowledge of AA utilization (including metabolism) by mammary epithelial cells will enhance our fundamental understanding of lactation biology and has important implications for improving the efficiency of livestock production worldwide. PMID:27042295

  18. The growth hormone receptor antagonist pegvisomant blocks both mammary gland development and MCF-7 breast cancer xenograft growth.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary gland development is dependent upon the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis, this same axis has also been implicated in breast cancer progression. In this study we investigated the effect of a GH antagonist, pegvisomant (Somavert((R)), Pfizer), on normal mammary gla...

  19. GESTATIONAL EXPOSURE TO NONYLPHENOL CAUSES PRECOCIOUS MAMMARY GLAND DEVELOPMENT IN FEMALE RAT OFFSPRING

    EPA Science Inventory

    This study examined whether or not exposure to 4-nonylphenol (NP) during late gestation affects reproductive and mammary development in the offspring of female rats. Time pregnant Long Evans rats were gavaged with NP (10 or 100 mg/kg), atrazine (ATR, 100 mg/kg), or corn oil on ge...

  20. ADVERSE EFFECTS OF TCDD ON MAMMARY GLAND DEVELOPMENT IN LONG EVANS RATS: A TWO GENERATIONAL STUDY

    EPA Science Inventory

    Recent studies have demonstrated variable effects on mammary gland development in rat offspring exposed to TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin, 1 ug/kg, gavage) on day 15 of gestation. We have characterized these effects in Long Evans rats, in both one and two-generational...

  1. INFLUENCE OF ENDOCRINE DISRUPTING COMPOUNDS (EDCS) ON MAMMARY GLAND DEVELOPMENT AND TUMOR SUSCEPTIBILITY

    EPA Science Inventory

    Influence of Endocrine Disrupting Compounds (EDCs) on Mammary Gland Development and Tumor Susceptibility.

    Suzanne E. Fenton1, and Jennifer Rayner1,2

    1 Reproductive Toxicology Division, NHEERL/ORD, U.S. EPA, Research Triangle Park, NC, and 2 Department of Environmen...

  2. NONYLPHENOL AND ATRAZINE INDUCE INVERSE EFFECTS ON MAMMARY GLAND DEVELOPMENT IN FEMALE RATS EXPOSED IN UTERO

    EPA Science Inventory

    Nonylphenol and Atrazine Induce Inverse Effects on Mammary Gland Development in Female Rats Exposed In Utero.
    HJ Moon1, SY Han1, CC Davis2, and SE Fenton2
    1 Department of Toxicology, NITR, Korea FDA, 5Nokbun-Dong, Eunpyung-Gu, Seoul, Korea and 2 Reproductive Toxicology Divi...

  3. Body condition of gilts at the end of gestation affects their mammary development.

    PubMed

    Farmer, C; Duarte, C R A; Vignola, M; Palin, M-F

    2016-05-01

    The impact of body condition at 110 d of gestation on mammary gland development, mammary gene expression, and hormonal and metabolite status of gilts was studied. Thirty-nine gilts were equally divided into 3 groups based on their backfat thickness at the end of gestation: 1) low backfat (LBF; 12-15 mm), 2) medium backfat (MBF; 17-19 mm), or 3) high backfat (HBF; 21-26 mm). Gilts had similar BW (138.1 ± 8.2 kg) and backfat thicknesses (16.4 ± 1.0 mm) at mating and the 3 groups were achieved via ingestion of varying amounts of feed throughout gestation. Jugular blood samples were obtained from all gilts at mating and at 109 d of gestation to assess hormonal and metabolic statuses, and animals were slaughtered on d 110 to collect mammary glands for compositional analyses and for measure of gene expression. The LBF gilts had less extraparenchymal tissue ( < 0.01) and parenchymal tissue ( < 0.05) than HBF gilts. Mammary parenchyma from LBF gilts also tended to contain less DM ( < 0.10), contained more protein ( < 0.05), and had greater RNA concentrations ( < 0.01) than that from HBF gilts. None of the 15 genes studied in mammary parenchymal tissue differed in terms of expression level, and the rate of mammary cell proliferation was similar among treatments ( > 0.10). There was a tendency for circulating leptin concentrations on d 109 of gestation to be lower in LBF gilts than in MBF gilts ( < 0.10), whereas values for HBF gilts did not differ from those of the other treatments ( > 0.10). Current results demonstrate that being too thin at the end of gestation (12-15 mm backfat) has a negative impact on mammary development in gilts, whereas having backfats varying from 17 to 26 mm seems to have no detrimental effects on mammogenesis. Backfat thickness in late pregnancy must therefore be considered to achieve optimal sow lactation performance. PMID:27285687

  4. In-silico QTL mapping of postpubertal mammary ductal development in the mouse uncovers potential human breast cancer risk loci

    PubMed Central

    Hadsell, Darryl L.; Hadsell, Louise A.; Olea, Walter; Rijnkels, Monique; Creighton, Chad J.; Smyth, Ian; Short, Kieran M.; Cox, Liza L.; Cox, Timothy C.

    2015-01-01

    Genetic background plays a dominant role in mammary gland development and breast cancer (BrCa). Despite this, the role of genetic diversity in mammary gland development is only partially understood. This study used strain-dependent variation in an inbred mouse mapping panel, to identify quantitative trait loci (QTL) underlying structural variation in mammary ductal development, and determined if these QTL correlated with genomic intervals conferring breast cancer susceptibility in humans. For about half of the traits, the observed variation among the complete set of strains in this study was greater (P<0.05) than that observed with previously studied strains or with strains that are in current common use for mammary gland biology. Correlations were also detected with previously reported variation in mammary tumor latency and metastasis. In silico genome-wide association (GWAS) identified 20 mammary development QTL (Mdq). Of these, 5 were syntenic with previously reported human BrCa loci. The most highly significant (P=1×10−11) association of the study was on MMU6 and contained the genes Plxna4, Plxna4os1, and Chchd3. On MMU5, a QTL was detected (p=8×10−7) that was syntenic to a human BrCa locus on h12q24.5 containing the genes Tbx3 and Tbx5. Intersection of high-association SNP (r2 >0.8) with genomic and epigenomic features, and intersection of candidate genes with gene expression and survival data from human BrCa highlighted several for further study. These results support the conclusion that genetic variation in mammary ductal development is greater than previously appreciated. They also suggest that mammary tumor latency and metastatic index may be influenced by variations in the same factors that control normal mammary ductal development and that further studies of genetically diverse mice can improve our understanding of the connection between breast development and breast cancer in humans by identifying novel susceptibility genes. PMID:25552398

  5. Paternal selenium deficiency but not supplementation during preconception alters mammary gland development and 7,12-dimethylbenz[a]anthracene-induced mammary carcinogenesis in female rat offspring.

    PubMed

    Guido, Luiza N; Fontelles, Camile C; Rosim, Mariana P; Pires, Vanessa C; Cozzolino, Silvia M F; Castro, Inar A; Bolaños-Jiménez, Francisco; Barbisan, Luis F; Ong, Thomas P

    2016-10-15

    Breast cancer is a global public health problem and accumulating evidence indicates early-life exposures as relevant factors in the disease risk determination. Recent studies have shown that paternal nutrition can influence offspring health including breast cancer risk. Selenium is a micronutrient with essential role in central aspects of embryogenesis, male fertility and cancer and that has been extensively studied as a chemopreventive agent in several breast cancer experimental models. Thus, we designed an animal study to evaluate whether paternal selenium deficiency or supplementation during preconception could affect the female offspring mammary gland development and breast cancer susceptibility. Male Sprague-Dawley rats were fed AIN93-G diet containing 0.15 ppm (control diet), 0.05 ppm (deficient diet) or 1 ppm (supplemented diet) of selenium for 9 weeks and mated with control female rats. Mammary carcinogenesis was induced with 7,12-dimethylbenz[a]anthracene (DMBA) in their female offspring. Paternal selenium deficiency increased the number of terminal end buds, epithelial elongation and cell proliferation in the mammary gland of the female rat offspring and these effects were associated with higher susceptibility to DMBA-induced mammary tumors (increased incidence and higher grade tumors). On the other hand, paternal selenium supplementation did not influence any of these parameters. These results highlight the importance of father's nutrition including selenium status as a relevant factor affecting daughter's breast cancer risk and paternal preconception as a potential developmental stage to start disease preventive strategies. PMID:27270969

  6. Flor-Essence? Herbal Tonic Promotes Mammary Tumor Development in Sprague Dawley Rats

    SciTech Connect

    Bennett, L; Montgomery, J; Steinberg, S; Kulp, K

    2004-01-28

    Background: Women who are diagnosed with breast cancer often self-administer complementary and alternative medicines to augment their conventional treatments, improve health, or prevent recurrence. Flor-Essence{reg_sign} Tonic is a complex mixture of herbal extracts used by cancer patients because of anecdotal evidence that it can treat or prevent disease. Methods: Female Sprague Dawley rats were given water or exposed to 3% or 6% Flor-Essence{reg_sign} beginning at one day of age. Mammary tumors were induced with a single oral 40 mg/kg/bw dose of dimethylbenz(a)anthracene at 50 days of age and sacrificed at 23 weeks. Rats were maintained on AIN-76A diet. Results: Control rats had palpable mammary tumor incidence of 51.0% at 19 weeks of age compared to 65.0% and 59.4% for the 3% and 6% Flor-Essence{reg_sign} groups respectively. Overall, no significant difference in time until first palpable tumor was detected among any of the groups. At necropsy, mammary tumor incidence was 82.5% for controls compared to 90.0% and 97.3% for rats consuming 3% and 6% Flor-Essence{reg_sign}, respectively. Mean mammary tumor multiplicity ({+-}SES) for the controls was 2.8 ({+-} 0.5) and statistically different from the 3% or 6% Flor- Essence{reg_sign} groups with 5.2 ({+-} 0.7), and 4.8 ({+-} 0.6), respectively (p{<=}0.01). As expected, the majority of isolated tumors were diagnosed as adenocarcinomas. Conclusions: Flor-Essence{reg_sign} can promote mammary tumor development in the Sprague Dawley rat model. This observation is contrary to widely available anecdotal evidence as well as the desire of the consumer that this commercially available herbal tonic will suppress and/or inhibit tumor growth.

  7. Alteration of mammary gland development and gene expression by in utero exposure to arsenic

    PubMed Central

    Parodi, Daniela A.; Greenfield, Morgan; Evans, Claire; Chichura, Anna; Alpaugh, Alexandra; Williams, James; Martin, Mary Beth

    2015-01-01

    Early life exposure to estrogens and estrogen like contaminants in the environment are thought to contribute to the early onset of puberty and consequently increase the risk of developing breast cancer in the exposed female. The results of this study show that in utero exposure to the metalloestrogen arsenite altered mammary gland development prior to its effect on puberty onset. In the prepubertal gland, in utero exposure resulted in an increase in the number of mammosphere-forming cells and an increase in branching, epithelial cells, and density. In the postpubertal gland, in utero exposure resulted in the overexpression of estrogen receptor-alpha (ERα) that was due to the increased and altered response of the ERα transcripts derived from exons O and OT to estradiol. These results suggest that, in addition to advancing puberty onset, in utero exposure to arsenite alters the pre- and postpubertal development of the mammary gland and possibly, the risk of developing breast cancer. PMID:25543096

  8. Modulation of Mammary Gland Development and Milk Production by Growth Hormone Expression in GH Transgenic Goats

    PubMed Central

    Bao, Zekun; Lin, Jian; Ye, Lulu; Zhang, Qiang; Chen, Jianquan; Yang, Qian; Yu, Qinghua

    2016-01-01

    Mammary gland development during puberty and reconstruction during pregnancy and lactation is under the control of circulating endocrine hormones, such as growth hormone, which are released from the pituitary. In this study, we explored the influence of overexpression of growth hormone in the mammary gland on breast development and milk production in goats. Using transcriptome sequencing, we found that the number of highly expressed genes was greater in GH transgenic goats than non-transgenic goats. Furthermore, KEGG pathway analysis showed that the majority of the genes belonged to the MAPK signaling pathway and the ECM-receptor interaction pathway. The expression of genes related to breast development was further confirmed using qRT-PCR. Interestingly, both milk production and milk quality were increased. The results of these experiments imply that overexpression of growth hormone in the breast may stimulate breast development and enhances milk production by modulating alveolar cell proliferation or branching through the MAPK signaling pathway. PMID:27445863

  9. Promoting effects of Chinese pangolin and wild pink medicines on the mammary gland development in immature mice.

    PubMed

    Bayin, Jiragara; Matsumoto, Mitsuharu; Islam, Mohammad Saiful; Yabuki, Akira; Kanouchi, Hiroaki; Oka, Tatsuzo; Nishinakagawa, Hayao

    2009-10-01

    The effects of the mixture of crude aqueous extracts from Chinese pangolin and wild pink (C+P), traditional Chinese medicine, on the proliferation and differentiation of mammary gland epithelium in intact and ovariectomized immature mice were investigated by light and electron microscopy and BrdU immunohistochemistry. Although there were no significant differences in mammary gland fat pad and parenchyma areas between the intact experimental groups, the numbers of duct branchings and buds were significantly larger in the C+W treated mice than in the control mice. The ratio of BrdU immunopositive cells to total epithelial cells was higher in C+W treated intact mice. Ultrastructurally, epithelial cells of the mammary buds and ducts possessed an oval and lucent nucleus, and ribosomes increased in number or developed to a greater degree in C+W treated intact mice than in the control mice. Conversely, there were no significant differences in any measurements of mammary gland between the experimental groups of ovariectomized mice. BrdU immunoreactive cells were never seen and the ultrastructure of mammary epihelial cells indicated the inactive cell phase in both ovariectomied mice. In comparison between the intact and overiectomized mice, the mammary fat pad area was larger in the ovariectomized mice than in the intact mice, although another four measurements were larger in the intact groups. These observations suggest that administration with C+W could promote the development of mammary glands via ovary in immature mice. PMID:19887738

  10. Mammary Gland Growth Factors: Roles in Normal Development and in Cancer

    PubMed Central

    Hynes, Nancy E.; Watson, Christine J.

    2010-01-01

    Normal development of the mammary gland proceeds via interactions between the epithelium and the mesenchyme that start during embryogenesis and continue during pubertal outgrowth and differentiation. The function of specific peptide growth factors that bind members of the receptor tyrosine kinase family and the cytokine receptor family are required at each stage. In many cases the peptides are produced in one compartment and act on receptors in the other compartment. One of the striking differences between normal development and cancer is the loss of this cross-talk. Mammary tumor cells often produce a peptide and express the receptor on the same cell leading to autocrine activation of signaling pathways, a mechanism that is characteristic for cancer cells. We will discuss different peptides in the context of normal development and cancer in this review. PMID:20554705

  11. Effects of Perfluorooctanoic Acid on Mouse Mammary Gland Development and Differentiation Resulting from Cross-Foster and Restricted Gestational Exposures

    EPA Science Inventory

    The adverse consequences of developmental exposures to perfluorooctanoic acid (PFOA) have been established, and include impaired development of the offspring mammary gland (MG). However, the relationship between the timing or route of exposure, and the phenotypic consequences in ...

  12. Development of dog mammary tumor xenograft in immunosuppressed Swiss albino mice.

    PubMed

    Rajmani, R S; Singh, Prafull Kumar; Kumar, Sanjay; Kumar, G Ravi; Sahoo, Aditya P; Santra, Lakshman; Saxena, Shikha; Singh, Lakshya Veer; Chaturvedi, Uttara; Saxena, Lovleen; Desai, G S; Gupta, Shishir Kumar; Kumar, Amit; Jadon, N S; Tiwari, Ashok K

    2014-10-01

    Development and study of dog mammary tumour xenograft in immunosuppressed Swiss Albino Mice adds a new dimension in cancer research as dog tumors have many similarities with human tumors regarding progression, histopathology, molecular mechanism, immune response and therapy. Failure of the immune system to recognize and eliminate cancer cells leads to cancer progression and the fight between immune cells and cancer cells has a great role in understanding the mechanism of cancer progression and elimination. Rejection and acceptance of tumour xenograft depends on efficiency of CD4+, CD8+ and NK cell populations. In the present investigation, dog mammary tumor xenograft in cyclosporine-A and gamma-irradiated, immunosuppressed Swiss Albino mice was developed and the immune cell status of graft accepted and rejected mice was assessed. It was observed that all the major immune cells (CD4+, CD8+ and NK cells) play an equal role in tumour rejection. PMID:25345242

  13. Macrophages: Regulators of the Inflammatory Microenvironment during Mammary Gland Development and Breast Cancer

    PubMed Central

    Brady, Nicholas J.; Chuntova, Pavlina; Schwertfeger, Kathryn L.

    2016-01-01

    Macrophages are critical mediators of inflammation and important regulators of developmental processes. As a key phagocytic cell type, macrophages evolved as part of the innate immune system to engulf and process cell debris and pathogens. Macrophages produce factors that act directly on their microenvironment and also bridge innate immune responses to the adaptive immune system. Resident macrophages are important for acting as sensors for tissue damage and maintaining tissue homeostasis. It is now well-established that macrophages are an integral component of the breast tumor microenvironment, where they contribute to tumor growth and progression, likely through many of the mechanisms that are utilized during normal wound healing responses. Because macrophages contribute to normal mammary gland development and breast cancer growth and progression, this review will discuss both resident mammary gland macrophages and tumor-associated macrophages with an emphasis on describing how macrophages interact with their surrounding environment during normal development and in the context of cancer. PMID:26884646

  14. Perinatal Environmental Exposures Affect Mammary Development, Function, and Cancer Risk in Adulthood*

    PubMed Central

    Fenton, Suzanne E.; Reed, Casey; Newbold, Retha R.

    2012-01-01

    Puberty is an important transition that enables reproduction of mammalian species. Precocious puberty, specifically early thelarche (the appearance of breast “buds”), in girls of multiple ethnic backgrounds is a major health problem in the United States and other countries. The cause for a continued decrease in the age of breast development in girls is unknown, but environmental factors likely play a major role. Laboratory and epidemiological studies have identified several individual environmental factors that affect breast development, but further progress is needed. Current research needs include increased attention to and recording of prenatal and neonatal environmental exposures, testing of marketed chemicals for effects on the mammary gland, and understanding of the mammary gland–specific mechanisms that are altered by chemicals. Such research is required to halt the increasing trend toward puberty at earlier ages. PMID:22017681

  15. Models of breast morphogenesis based on localization of stem cells in the developing mammary lobule.

    PubMed

    Honeth, Gabriella; Schiavinotto, Tommaso; Vaggi, Federico; Marlow, Rebecca; Kanno, Tokuwa; Shinomiya, Ireneusz; Lombardi, Sara; Buchupalli, Bharath; Graham, Rosalind; Gazinska, Patrycja; Ramalingam, Vernie; Burchell, Joy; Purushotham, Anand D; Pinder, Sarah E; Csikasz-Nagy, Attila; Dontu, Gabriela

    2015-04-14

    Characterization of normal breast stem cells is important for understanding their role in breast development and in breast cancer. However, the identity of these cells is a subject of controversy and their localization in the breast epithelium is not known. In this study, we utilized a novel approach to analyze the morphogenesis of mammary lobules, by combining one-dimensional theoretical models and computer-generated 3D fractals. Comparing predictions of these models with immunohistochemical analysis of tissue sections for candidate stem cell markers, we defined distinct areas where stem cells reside in the mammary lobule. An increased representation of stem cells was found in smaller, less developed lobules compared to larger, more mature lobules, with marked differences in the gland of nulliparous versus parous women and that of BRCA1/2 mutation carriers versus non-carriers. PMID:25818813

  16. A hybrid agent-based model of the developing mammary terminal end bud.

    PubMed

    Butner, Joseph D; Chuang, Yao-Li; Simbawa, Eman; Al-Fhaid, A S; Mahmoud, S R; Cristini, Vittorio; Wang, Zhihui

    2016-10-21

    Mammary gland ductal elongation is spearheaded by terminal end buds (TEBs), where populations of highly proliferative cells are maintained throughout post-pubertal organogenesis in virgin mice until the mammary fat pad is filled by a mature ductal tree. We have developed a hybrid multiscale agent-based model to study how cellular differentiation pathways, cellular proliferation capacity, and endocrine and paracrine signaling play a role during development of the mammary gland. A simplified cellular phenotypic hierarchy that includes stem, progenitor, and fully differentiated cells within the TEB was implemented. Model analysis finds that mammary gland development was highly sensitive to proliferation events within the TEB, with progenitors likely undergoing 2-3 proliferation cycles before transitioning to a non-proliferative phenotype, and this result is in agreement with our previous experimental work. Endocrine and paracrine signaling were found to provide reliable ductal elongation rate regulation, while variations in the probability a new daughter cell will be of a proliferative phenotype were seen to have minimal effects on ductal elongation rates. Moreover, the distribution of cellular phenotypes within the TEB was highly heterogeneous, demonstrating significant allowable plasticity in possible phenotypic distributions while maintaining biologically relevant growth behavior. Finally, simulation results indicate ductal elongation rates due to cellular proliferation within the TEB may have a greater sensitivity to upstream endocrine signaling than endothelial to stromal paracrine signaling within the TEB. This model provides a useful tool to gain quantitative insights into cellular population dynamics and the effects of endocrine and paracrine signaling within the pubertal terminal end bud. PMID:27475843

  17. Stem and progenitor cell division kinetics during postnatal mouse mammary gland development.

    PubMed

    Giraddi, Rajshekhar R; Shehata, Mona; Gallardo, Mercedes; Blasco, Maria A; Simons, Benjamin D; Stingl, John

    2015-01-01

    The cycling properties of mammary stem and progenitor cells is not well understood. To determine the division properties of these cells, we administered synthetic nucleosides for varying periods of time to mice at different stages of postnatal development and monitored the rate of uptake of these nucleosides in the different mammary cell compartments. Here we show that most cell division in the adult virgin gland is restricted to the oestrogen receptor-expressing luminal cell lineage. Our data also demonstrate that the oestrogen receptor-expressing, milk and basal cell subpopulations have telomere lengths and cell division kinetics that are not compatible with these cells being hierarchically organized; instead, our data indicate that in the adult homeostatic gland, each cell type is largely maintained by its own restricted progenitors. We also observe that transplantable stem cells are largely quiescent during oestrus, but are cycling during dioestrus when progesterone levels are high. PMID:26511661

  18. Early transcriptional events in the udder and teat after intra-mammary Escherichia coli and Staphylococcus aureus challenge.

    PubMed

    Petzl, Wolfram; Günther, Juliane; Mühlbauer, Katharina; Seyfert, Hans-Martin; Schuberth, Hans-Joachim; Hussen, Jamal; Sauter-Louis, Carola; Hafner-Marx, Angela; Zerbe, Holm

    2016-05-01

    Intra-mammary bacterial infections can result in harmful clinical mastitis or subclinical mastitis with persistent infections. Research during the last decades closely examined the pathophysiology of inflamed udders. Initial events after pathogen perception but before the onset of mastitis have not been examined in vivo The objective of this study was to develop a mastitis model in cows by monitoring initial transcriptional pathogen-specific host response before clinical signs occur. We applied a short-term infection model to analyse transcripts encoding chemokines, cytokines and antimicrobial molecules in the teat cistern (TC) and lobulo-alveolar parenchyma (LP) up to 3 h after challenge with E and Staphylococcus aureus Both pathogens elicited an immune reaction by 1 h after challenge. Escherichia coli induced all analysed factors (CCL20, CXCL8, TNF, IL6, IL12B, IL10, LAP, S100A9); however, S. aureus failed to induce IL12B, IL10, LAP and S100A9 expression. The E. coli-induced up-regulation was 25-105 times greater than that after S. aureus challenge. Almost all the responses were restricted to the TC. The short-term mastitis model demonstrates that a divergent pathogen-specific response is generated during the first h. It confirms that the first transcripts are generated in the TC prior to a response in the LP. PMID:27012912

  19. Detection of Expressional Changes Induced by Intrauterine Growth Restriction in the Developing Rat Mammary Gland via Exploratory Pathways Analysis

    PubMed Central

    Beinder, Lea; Faehrmann, Nina; Wachtveitl, Rainer; Winterfeld, Ilona; Hartner, Andrea; Menendez-Castro, Carlos; Rauh, Manfred; Ruebner, Matthias; Huebner, Hanna; Noegel, Stephanie C.; Doerr, Helmuth G.; Rascher, Wolfgang; Fahlbusch, Fabian B.

    2014-01-01

    Background Intrauterine growth restriction (IUGR) is thought to lead to fetal programming that in turn contributes to developmental changes of many organs postnatally. There is evidence that IUGR is a risk factor for the development of metabolic and cardiovascular disease later in life. A higher incidence of breast cancer was also observed after IUGR. This could be due to changes in mammary gland developmental pathways. We sought to characterise IUGR-induced alterations of the complex pathways of mammary development at the level of the transcriptome in a rat model of IUGR, using pathways analysis bioinformatics. Methodology/Principal Findings We analysed the mammary glands of Wistar rats with IUGR induced by maternal low protein (LP) diet at the beginning (d21) and the end (d28) of pubertal ductal morphogenesis. Mammary glands of the LP group were smaller in size at d28, however did not show morphologic changes. We identified multiple differentially expressed genes in the mammary gland using Agilent SurePrint arrays at d21 and d28. In silico analysis was carried out using Ingenuity Pathways Analysis. In mammary gland tissue of LP rats at d21 of life a prominent upregulation of WT1 and CDKN1A (p21) expression was observed. Differentially regulated genes were associated with the extracellular regulated kinase (ERK)-1/-2 pathway. Western Blot analysis showed reduced levels of phosphorylated ERK-1/-2 in the mammary glands of the LP group at d21. To identify possible changes in circulating steroid levels, serum LC-Tandem mass-spectrometry was performed. LP rats showed higher serum progesterone levels and an increased corticosterone/dehydrocorticosterone-ratio at d28. Conclusions/Significance Our data obtained from gene array analysis support the hypothesis that IUGR influences pubertal development of the rat mammary gland. We identified prominent differential regulation of genes and pathways for factors regulating cell cycle and growth. Moreover, we detected new

  20. Overexpression of miR-30b in the Developing Mouse Mammary Gland Causes a Lactation Defect and Delays Involution

    PubMed Central

    Laubier, Johann; Passet, Bruno; Vilotte, Marthe; Castille, Johan; Laloë, Denis; Polyte, Jacqueline; Bouet, Stéphan; Jaffrézic, Florence; Cribiu, Edmond-Paul; Vilotte, Jean-Luc; Le Provost, Fabienne

    2012-01-01

    Background MicroRNA (miRNA) are negative regulators of gene expression, capable of exerting pronounced influences upon the translation and stability of mRNA. They are potential regulators of normal mammary gland development and of the maintenance of mammary epithelial progenitor cells. This study was undertaken to determine the role of miR-30b on the establishment of a functional mouse mammary gland. miR-30b is a member of the miR-30 family, composed of 6 miRNA that are highly conserved in vertebrates. It has been suggested to play a role in the differentiation of several cell types. Methodology/Principal Findings The expression of miR-30b was found to be regulated during mammary gland development. Transgenic mice overexpressing miR-30b in mammary epithelial cells were used to investigate its role. During lactation, mammary histological analysis of the transgenic mice showed a reduction in the size of alveolar lumen, a defect of the lipid droplets and a growth defect of pups fed by transgenic females. Moreover some mammary epithelial differentiated structures persisted during involution, suggesting a delay in the process. The genes whose expression was affected by the overexpression of miR-30b were characterized by microarray analysis. Conclusion/Significance Our data suggests that miR-30b is important for the biology of the mammary gland and demonstrates that the deregulation of only one miRNA could affect lactation and involution. PMID:23029204

  1. Normal mammary development and function in mice with Ift88 deleted in MMTV- and K14-Cre expressing cells

    PubMed Central

    2014-01-01

    Background Primary cilia (PC) are non-motile microtubule based organelles present on almost every cell type and are known to serve as critical organizing centers for several signaling pathways crucial to embryonic and postnatal development. Alterations in the Hh pathway, the most studied signaling pathway regulated by PC, affect mammary gland development as well as maintenance of the stem and progenitor cell populations. Results We developed mouse models with deletion of PC in mammary luminal epithelial, basal epithelial, and stromal cells for evaluation of the function of PC in mammary development via MMTV-Cre, K14-Cre, and Prx1-Cre mediated deletion, respectively. The activity of Cre was confirmed using ROSA26 reporters. Mammary stem and progenitor cells were enriched through growth as mammospheres. Adenovirus-Cre mediated deletion of Ift88 was used to determine a role for PC in this population of cells. Disruption of Ift88 and PC were confirmed in using PCR and immunofluorescent methods. Prx1-Cre; Ift88Del mice demonstrated defects in terminal end buds during puberty. However, these Ift88Del glands exhibited typical terminal end bud formation as well as normal ductal histology when transplanted into wild type hosts, indicating that the phenotype observed was not intrinsic to the mammary gland. Furthermore, no discernable alterations to mammary development were observed in MMTV-Cre- or K14-Cre; Ift88Del lines. These mice were able to feed and support several litters of pups even though wide spread depletion of PC was confirmed. Cells grown in mammosphere culture were enriched for PC containing cells suggesting PC are preferentially expressed on mammary stem and progenitor cells. Deletion of Ift88 in mammary epithelial cells resulted in a significant reduction in the number of primary mammospheres established; however, there was no effect on outgrowth of secondary mammospheres in PC-depleted cells. Conclusions PC regulate systemic factors that can affect mammary

  2. The dynamics of murine mammary stem/progenitor cells

    PubMed Central

    DONG, Qiaoxiang; SUN, Lu-Zhe

    2014-01-01

    The stem/progenitor cells in the murine mammary gland are a highly dynamic population of cells that are responsible for ductal elongation in puberty, homeostasis maintenance in adult, and lobulo-alveolar genesis during pregnancy. In recent years understanding the epithelial cell hierarchy within the mammary gland is becoming particularly important as these different stem/progenitor cells were perceived to be the cells of origin for various subtypes of breast cancer. Although significant advances have been made in enrichment and isolation of stem/progenitor cells by combinations of antibodies against cell surface proteins together with flow cytometry, and in identification of stem/progenitor cells with multi-lineage differentiation and self-renewal using mammary fat pad reconstitution assay and in vivo genetic labeling technique, a clear understanding of how these different stem/progenitors are orchestrated in the mammary gland is still lacking. Here we discuss the different in vivo and in vitro methods currently available for stem/progenitor identification, their associated caveats, and a possible new hierarchy model to reconcile various putative stem/progenitor cell populations identified by different research groups. PMID:25580105

  3. A Novel Nectin-mediated Cell Adhesion Apparatus That Is Implicated in Prolactin Receptor Signaling for Mammary Gland Development.

    PubMed

    Kitayama, Midori; Mizutani, Kiyohito; Maruoka, Masahiro; Mandai, Kenji; Sakakibara, Shotaro; Ueda, Yuki; Komori, Takahide; Shimono, Yohei; Takai, Yoshimi

    2016-03-11

    Mammary gland development is induced by the actions of various hormones to form a structure consisting of collecting ducts and milk-secreting alveoli, which comprise two types of epithelial cells known as luminal and basal cells. These cells adhere to each other by cell adhesion apparatuses whose roles in hormone-dependent mammary gland development remain largely unknown. Here we identified a novel cell adhesion apparatus at the boundary between the luminal and basal cells in addition to desmosomes. This apparatus was formed by the trans-interaction between the cell adhesion molecules nectin-4 and nectin-1, which were expressed in the luminal and basal cells, respectively. Nectin-4 of this apparatus further cis-interacted with the prolactin receptor in the luminal cells to enhance the prolactin-induced prolactin receptor signaling for alveolar development with lactogenic differentiation. Thus, a novel nectin-mediated cell adhesion apparatus regulates the prolactin receptor signaling for mammary gland development. PMID:26757815

  4. The transcriptional repressor Blimp1 is expressed in rare luminal progenitors and is essential for mammary gland development

    PubMed Central

    Ahmed, Mohammed I.; Mould, Arne W.; Bikoff, Elizabeth K.

    2016-01-01

    ABSTRACT Mammary gland morphogenesis depends on a tight balance between cell proliferation, differentiation and apoptosis, to create a defined functional hierarchy within the epithelia. The limited availability of stem cell/progenitor markers has made it challenging to decipher lineage relationships. Here, we identify a rare subset of luminal progenitors that express the zinc finger transcriptional repressor Blimp1, and demonstrate that this subset of highly clonogenic luminal progenitors is required for mammary gland development. Conditional inactivation experiments using K14-Cre and WAPi-Cre deleter strains revealed essential functions at multiple developmental stages. Thus, Blimp1 regulates proliferation, apoptosis and alveolar cell maturation during puberty and pregnancy. Loss of Blimp1 disrupts epithelial architecture and lumen formation both in vivo and in three-dimensional (3D) primary cell cultures. Collectively, these results demonstrate that Blimp1 is required to maintain a highly proliferative luminal subset necessary for mammary gland development and homeostasis. PMID:27190036

  5. The transcriptional repressor Blimp1 is expressed in rare luminal progenitors and is essential for mammary gland development.

    PubMed

    Ahmed, Mohammed I; Elias, Salah; Mould, Arne W; Bikoff, Elizabeth K; Robertson, Elizabeth J

    2016-05-15

    Mammary gland morphogenesis depends on a tight balance between cell proliferation, differentiation and apoptosis, to create a defined functional hierarchy within the epithelia. The limited availability of stem cell/progenitor markers has made it challenging to decipher lineage relationships. Here, we identify a rare subset of luminal progenitors that express the zinc finger transcriptional repressor Blimp1, and demonstrate that this subset of highly clonogenic luminal progenitors is required for mammary gland development. Conditional inactivation experiments using K14-Cre and WAPi-Cre deleter strains revealed essential functions at multiple developmental stages. Thus, Blimp1 regulates proliferation, apoptosis and alveolar cell maturation during puberty and pregnancy. Loss of Blimp1 disrupts epithelial architecture and lumen formation both in vivo and in three-dimensional (3D) primary cell cultures. Collectively, these results demonstrate that Blimp1 is required to maintain a highly proliferative luminal subset necessary for mammary gland development and homeostasis. PMID:27190036

  6. Influence of chronic prolactin suppression during puberty on the development of dimethylbenz(a)anthracene-induced mammary tumors (41163). [Rats

    SciTech Connect

    Cohen, L.A.

    1981-06-01

    In order to assess the effect of early prolactin suppression on the subsequent development of dimethylbenz(a)anthracene (DMBA)-induced mammary cancers, the dopamine agonist, CB-154, was chronically administered to female Sprague-Dawley rats from Day 35 to Day 50 of age. DMBA was then administered and tumor development assessed over a 25-week period. It was found that animals treated with CB-154 exhibited decreased tumor incidence, a longer latent period, and fewer tumors/animal, when compared to vehicle controls. These results are consistent with the hypothesis that the sensitivity of the mammary gland to polycyclic aromatic hydrocarbon (PAH) carcinogenesis is determined by the level of differentiation of the gland at the time of carcinogen administration. Accordingly, perturbations in prolactin secretion patterns, early in life, may accelerate or retard the differentiation of the mammary gland thereby rendering it less susceptible to the carcinogenic effects of PAH.

  7. Feeding a higher plane of nutrition and providing exogenous estrogen increases mammary gland development in Holstein heifer calves.

    PubMed

    Geiger, A J; Parsons, C L M; Akers, R M

    2016-09-01

    Feeding heifers a higher plane of nutrition postweaning but before puberty can negatively affect mammary gland development and future milk yield. However, enhanced nutrition preweaning may promote development and future production. Our objectives were to determine the effects of enhanced feeding preweaning and exogenous estrogen immediately postweaning on mammary gland development and the composition of the mammary parenchyma (PAR) and mammary fat pad (MFP). Thirty-six Holstein heifer calves (<1 wk old) were reared on 1 of 2 dietary treatments for 8 wk: (1) a restricted milk replacer fed at 0.45 kg/d (R; 20% crude protein, 20% fat), or (2) an enhanced milk replacer fed at 1.13 kg/d (EH; 28% crude protein, 25% fat). Upon weaning, calves from each diet (n=6) were given either a placebo or estrogen implant for 2 wk, creating 4 treatments: R, R + estrogen (R-E2), EH, and EH + estrogen (EH-E2). Calves were housed individually with ad libitum access to water. Starter feeding began at wk 5 and was balanced between treatments. Udders were evaluated by palpation and physical measurements weekly. Subsets of calves were killed at weaning (n=6 per diet) and at the conclusion of the trial (n=6 per treatment). Udders were removed, dissected, and weighed. At wk 8, EH calves had longer front and rear teats. Providing estrogen to EH calves increased the length of rear teats during wk 9 and 10. Enhanced-fed calves had 5.2-fold more trimmed mammary gland mass than R calves. Providing estrogen to EH calves further increased mammary gland weight. Masses of PAR and MFP were markedly greater for EH calves than for R calves (e.g., 7.3-fold greater PAR tissue). Estrogen increased the mass of both PAR and MFP in EH calves. Feeding a higher plane of nutrition increased total protein, DNA, and fat in the MFP and total protein and DNA in the PAR. Dual-energy x-ray absorptiometry estimates of mammary fat mass were highly correlated with biochemical analyses of fat content. From histological

  8. Expression of Autoactivated Stromelysin-1 in Mammary Glands of Transgenic Mice Leads to a Reactive Stroma During Early Development

    SciTech Connect

    Thomasset, N.; Lochter, A.; Sympson, C.J.; Lund, L.R.; Williams, D.R.; Behrendtsen, O.; Werb, Z.; Bissell, M.J.

    1998-04-24

    Extracellular matrix and extracellular matrix-degrading matrix metalloproteinases play a key role in interactions between the epithelium and the mesenchyme during mammary gland development and disease. In patients with breast cancer, the mammary mesenchyme undergoes a stromal reaction, the etiology of which is unknown. We previously showed that targeting of an autoactivating mutant of the matrix metalloproteinase stromelysin-1 to mammary epithelia of transgenic mice resulted in reduced mammary function during pregnancy and development of preneoplastic and neoplastic lesions. Here we examine the cascade of alterations before breast tumor formation in the mammary gland stroma once the expression of the stromelysin-1 transgene commences. Beginning in postpubertal virgin animals, low levels of transgene expression in mammary epithelia led to increased expression of endogenous stromelysin-1 in stromal fibroblasts and up-regulation of other matrix metalloproteinases, without basement membrane disruption. These changes were accompanied by the progressive development of a compensatory reactive stroma, characterized by increased collagen content and vascularization in glands from virgin mice. This remodeling of the gland affected epithelial-mesenchymal communication as indicated by inappropriate expression of tenascin-C starting by day 6 of pregnancy. This, together with increased transgene expression, led to basement membrane disruption starting by day 15 of pregnancy. We propose that the highly reactive stroma provides a prelude to breast epithelial tumors observed in these animals. Epithelial development depends on an exquisite series of inductive and instructive interactions between the differentiating epithelium and the mesenchymal (stromal) compartment. The epithelium, which consists of luminal and myoepithelial cells, is separated from the stroma by a basement membrane (BM), which plays a central role in mammary gland homeostasis and gene expression. In vivo, stromal

  9. From milk to malignancy: the role of mammary stem cells in development, pregnancy and breast cancer

    PubMed Central

    Tiede, Benjamin; Kang, Yibin

    2011-01-01

    Adult stem cells of the mammary gland (MaSCs) are a highly dynamic population of cells that are responsible for the generation of the gland during puberty and its expansion during pregnancy. In recent years significant advances have been made in understanding how these cells are regulated during these developmentally important processes both in humans and in mice. Understanding how MaSCs are regulated is becoming a particularly important area of research, given that they may be particularly susceptible targets for transformation in breast cancer. Here, we summarize the identification of MaSCs, how they are regulated and the evidence for their serving as the origins of breast cancer. In particular, we focus on how changes in MaSC populations may explain both the increased risk of developing aggressive ER/PR(−) breast cancer shortly after pregnancy and the long-term decreased risk of developing ER/PR(+) tumors. PMID:21243011

  10. Effects of gestational plane of nutrition and selenium supplementation on mammary development and colostrum quality in pregnant ewe lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine effects of nutritional plane and selenium (Se) supplementation on colostrum quality and mammary development, individually fed, pregnant Rambouillet ewe lambs were allotted randomly to 1 of 6 treatments in a 2 x 3 factorial arrangement. Main effects included dietary Se level which began at...

  11. In-silico QTL mapping of postpubertal mammary ductal development in the mouse uncovers potential human breast cancer risk loci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic background plays a dominant role in mammary gland development and breast cancer (BrCa). Despite this, the role of genetics is only partially understood. This study used strain-dependent variation in an inbred mouse mapping panel, to identify quantitative trait loci (QTL) underlying structura...

  12. Effects of dietary supplementation with flax during prepuberty on mammary development and circulating prolactin and estradiol concentrations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The possible role of dietary flax on mammary development of prepubertal gilts was investigated. Fifty-seven gilts were fed one of four diets from 88 d of age until slaughter (day 212 ± 1). Diets were: standard, CTL (n=14); 10% flaxseed supplementation, FS (n=13); 6.5% flaxseed meal supplementation, ...

  13. Mammary gland development and response to prenatal atrazine exposure in the Sprague Dawley and Long-Evans rats.

    EPA Science Inventory

    Mammary gland (MG) tumor development in Sprague Dawley (SD) rats is increased by longterm dietary exposure to the chlorotriazine herbicide atrazine (ATR). ATR is proposed to cause these changes in the adult SD rat by altering hormonally-regulated estrous cyclicity. In Long-Evans...

  14. HORMONAL CONTROL OF OVARIAN FUNCTION FOLLOWING CHLOROTRIAZINE EXPOSURE: EFFECT ON REPRODUCTIVE FUNCTION AND MAMMARY GLAND TUMOR DEVELOPMENT

    EPA Science Inventory

    Hormonal Control of Ovarian Function Following Chlorotriazine Exposure: Effect on Reproductive Function and Mammary Gland Tumor Development.

    Ralph L. Cooper, Susan C. Laws, Michael G. Narotsky, Jerome M. Goldman, and Tammy E. Stoker

    Abstract
    The studies review...

  15. EXPOSURE PARAMETERS FOR DELAYED PUBERTY AND MAMMARY GLAND DEVELOPMENT IN LONG-EVANS RATS EXPOSED IN UTERO TO ATRAZINE

    EPA Science Inventory

    Exposure Parameters For Delayed Puberty And Mammary Gland Development In Long-Evans Rats Exposed In Utero To Atrazine

    Jennifer L. Rayner1 and Suzanne E. Fenton2

    1 UNC-Chapel Hill, DESE, Chapel Hill, NC, and 2 RTD, USEPA, NHEERL/ORD, RTP,NC

    Prenatal exposure ...

  16. EXPOSURE PARAMETERS NECESSARY FOR DELAYED PUBERTY AND MAMMARY GLAND DEVELOPMENT IN LONG-EVANS RATS EXPOSED IN UTERO TO ATRAZINE

    EPA Science Inventory

    Exposure Parameters Necessary For Delayed Puberty And Mammary Gland Development In Long-Evans Rats Exposed In Utero To Atrazine

    Jennifer L. Rayner1, 2, Carmen Wood2, and Suzanne E. Fenton2

    1 Department of Environmental Sciences and Engineering, School of Public Heal...

  17. GANP protein encoded on human chromosome 21/mouse chromosome 10 is associated with resistance to mammary tumor development.

    PubMed

    Kuwahara, Kazuhiko; Yamamoto-Ibusuki, Mutsuko; Zhang, Zhenhuan; Phimsen, Suchada; Gondo, Naomi; Yamashita, Hiroko; Takeo, Toru; Nakagata, Naomi; Yamashita, Daisuke; Fukushima, Yoshimi; Yamamoto, Yutaka; Iwata, Hiroji; Saya, Hideyuki; Kondo, Eisaku; Matsuo, Keitaro; Takeya, Motohiro; Iwase, Hirotaka; Sakaguchi, Nobuo

    2016-04-01

    Human chromosome 21 is known to be associated with the high risk of hematological malignancy but with resistance to breast cancer in the study of Down syndrome. In human cancers, we previously observed the significant alterations of the protein expression encoded by the ganp/MCM3AP gene on human chromosome 21q22.3. Here, we investigated GANP protein alterations in human breast cancer samples (416 cases) at various stages by immunohistochemical analysis. This cohort study clearly showed that expression of GANP is significantly decreased in human breast cancer cases with poor prognosis as an independent risk factor (relapse-free survival, hazard ratio = 2.37, 95% confidence interval, 1.27-4.42, P = 0.007 [univariate analysis]; hazard ratio = 2.70, 95% confidence interval, 1.42-5.13, P = 0.002 [multivariate analysis]). To investigate whether the altered GANP expression is associated with mammary tumorigenesis, we created mutant mice that were conditionally deficient in the ganp/MCM3AP gene using wap-cre recombinase transgenic mice. Mammary gland tumors occurred at a very high incidence in female mammary gland-specific GANP-deficient mice after severe impairment of mammary gland development during pregnancy. Moreover, tumor development also occurred in female post parous GANP-heterodeficient mice. GANP has a significant role in the suppression of DNA damage caused by estrogen in human breast cancer cell lines. These results indicated that the GANP protein is associated with breast cancer resistance. PMID:26749495

  18. Mammary gland development of dairy heifers fed diets containing increasing levels of metabolisable protein: metabolisable energy.

    PubMed

    Albino, Ronan L; Marcondes, Marcos I; Akers, Robert M; Detmann, Edenio; Carvalho, Bruno C; Silva, Tadeu E

    2015-02-01

    This study was conducted to evaluate the development of the mammary gland in Holstein heifers subjected to different dietary metabolisable protein (MP): metabolisable energy (ME) ratios. Twenty-five Holstein heifers (initial body weight (BW) 213±13·5 kg and initial average age 7·8±0·5 months) were divided into five treatments. The treatments were designed to provide MP:ME ratios equal to 33, 38, 43, 48, and 53 g of MP per Mcal of ME. All diets were formulated to have the same energy content (2·6 Mcal ME/kg dry matter). Actual MP:ME ratios were 36·2, 40·2, 46·2, 47·1, and 50·8 g MP/Mcal ME. The experiment was conducted in a randomised block design, while considering initial BW as a blocking factor to evaluate pre- and post-pubertal periods. Block effect was not observed for all variables evaluated; hence it was considered that the diets had the same influence both on pre- and post-pubertal phases. Dry matter and nutrient intake did not change between treatments, excepting protein intake and digestibility. Serum concentrations of insulin-like growth factor 1 increased linearly across treatments. Changes in the pixel brightness of mammary gland ultrasound images, which are associated with lipid content, were significantly influenced by MP:ME ratios in the diet of heifers that were subjected to accelerated growth rates. It is not recommended to use diets of less than 38 g MP/Mcal ME in diets to heifers allowed to gain more than 1 kg/d. PMID:25592631

  19. Consumption of silibinin, a flavonolignan from milk thistle, and mammary cancer development in the C3(1) SV40 T,t antigen transgenic multiple mammary adenocarcinoma (TAg) mouse.

    PubMed

    Verschoyle, Richard D; Brown, Karen; Steward, William P; Gescher, Andreas J

    2008-07-01

    Silibinin is a flavonolignan extracted from milk thistle with cancer chemopreventive activity in preclinical models of prostate and colorectal cancer. A milk thistle extract, of which silibin is a major component, has recently been shown to exacerbate mammary carcinogenesis in two rodent models. We tested the hypothesis that consumption of silibinin or silipide, a silibinin formulation with pharmaceutical properties superior to the unformulated agent, affect breast cancer development in the C3(1) SV40 T,t antigen transgenic multiple mammary adenocarcinoma mouse model. Mice received silibinin or silipide (0.2% silibinin equivalents) with their diet from weaning, and tumour development was monitored by weekly palpation and the number and weight of neoplasms at the end of the experiment. Intervention neither promoted, nor interfered with, tumour development. The result suggests that promotion of carcinogenesis is not a feature of silibinin consistent across rodent models of mammary carcinogenesis. PMID:17909802

  20. Perfluorooctanoic acid effects on ovaries mediate its inhibition of peripubertal mammary gland development in Balb/c and C57Bl/6 mice

    EPA Science Inventory

    Exposure to perfluorooctanoic acid (PFOA), a synthetic perfluorinated compound and an agonist of peroxisomes proliferator-activated receptor α (PPARα), causes stunted mouse mammary gland development in various developmental stages. However, the underlying mechanisms remain poorly...

  1. Essential Role for Zinc Transporter 2 (ZnT2)-mediated Zinc Transport in Mammary Gland Development and Function during Lactation.

    PubMed

    Lee, Sooyeon; Hennigar, Stephen R; Alam, Samina; Nishida, Keigo; Kelleher, Shannon L

    2015-05-22

    The zinc transporter ZnT2 (SLC30A2) imports zinc into vesicles in secreting mammary epithelial cells (MECs) and is critical for zinc efflux into milk during lactation. Recent studies show that ZnT2 also imports zinc into mitochondria and is expressed in the non-lactating mammary gland and non-secreting MECs, highlighting the importance of ZnT2 in general mammary gland biology. In this study we used nulliparous and lactating ZnT2-null mice and characterized the consequences on mammary gland development, function during lactation, and milk composition. We found that ZnT2 was primarily expressed in MECs and to a limited extent in macrophages in the nulliparous mammary gland and loss of ZnT2 impaired mammary expansion during development. Secondly, we found that lactating ZnT2-null mice had substantial defects in mammary gland architecture and MEC function during secretion, including fewer, condensed and disorganized alveoli, impaired Stat5 activation, and unpolarized MECs. Loss of ZnT2 led to reduced milk volume and milk containing less protein, fat, and lactose compared with wild-type littermates, implicating ZnT2 in the regulation of mammary differentiation and optimal milk production during lactation. Together, these results demonstrate that ZnT2-mediated zinc transport is critical for mammary gland function, suggesting that defects in ZnT2 not only reduce milk zinc concentration but may compromise breast health and increase the risk for lactation insufficiency in lactating women. PMID:25851903

  2. Genetic suppression reveals DNA repair-independent antagonism between BRCA1 and COBRA1 in mammary gland development.

    PubMed

    Nair, Sreejith J; Zhang, Xiaowen; Chiang, Huai-Chin; Jahid, Md Jamiul; Wang, Yao; Garza, Paula; April, Craig; Salathia, Neeraj; Banerjee, Tapahsama; Alenazi, Fahad S; Ruan, Jianhua; Fan, Jian-Bing; Parvin, Jeffrey D; Jin, Victor X; Hu, Yanfen; Li, Rong

    2016-01-01

    The breast cancer susceptibility gene BRCA1 is well known for its function in double-strand break (DSB) DNA repair. While BRCA1 is also implicated in transcriptional regulation, the physiological significance remains unclear. COBRA1 (also known as NELF-B) is a BRCA1-binding protein that regulates RNA polymerase II (RNAPII) pausing and transcription elongation. Here we interrogate functional interaction between BRCA1 and COBRA1 during mouse mammary gland development. Tissue-specific deletion of Cobra1 reduces mammary epithelial compartments and blocks ductal morphogenesis, alveologenesis and lactogenesis, demonstrating a pivotal role of COBRA1 in adult tissue development. Remarkably, these developmental deficiencies due to Cobra1 knockout are largely rescued by additional loss of full-length Brca1. Furthermore, Brca1/Cobra1 double knockout restores developmental transcription at puberty, alters luminal epithelial homoeostasis, yet remains deficient in homologous recombination-based DSB repair. Thus our genetic suppression analysis uncovers a previously unappreciated, DNA repair-independent function of BRCA1 in antagonizing COBRA1-dependent transcription programme during mammary gland development. PMID:26941120

  3. Genetic suppression reveals DNA repair-independent antagonism between BRCA1 and COBRA1 in mammary gland development

    PubMed Central

    Nair, Sreejith J.; Zhang, Xiaowen; Chiang, Huai-Chin; Jahid, Md Jamiul; Wang, Yao; Garza, Paula; April, Craig; Salathia, Neeraj; Banerjee, Tapahsama; Alenazi, Fahad S.; Ruan, Jianhua; Fan, Jian-Bing; Parvin, Jeffrey D.; Jin, Victor X.; Hu, Yanfen; Li, Rong

    2016-01-01

    The breast cancer susceptibility gene BRCA1 is well known for its function in double-strand break (DSB) DNA repair. While BRCA1 is also implicated in transcriptional regulation, the physiological significance remains unclear. COBRA1 (also known as NELF-B) is a BRCA1-binding protein that regulates RNA polymerase II (RNAPII) pausing and transcription elongation. Here we interrogate functional interaction between BRCA1 and COBRA1 during mouse mammary gland development. Tissue-specific deletion of Cobra1 reduces mammary epithelial compartments and blocks ductal morphogenesis, alveologenesis and lactogenesis, demonstrating a pivotal role of COBRA1 in adult tissue development. Remarkably, these developmental deficiencies due to Cobra1 knockout are largely rescued by additional loss of full-length Brca1. Furthermore, Brca1/Cobra1 double knockout restores developmental transcription at puberty, alters luminal epithelial homoeostasis, yet remains deficient in homologous recombination-based DSB repair. Thus our genetic suppression analysis uncovers a previously unappreciated, DNA repair-independent function of BRCA1 in antagonizing COBRA1-dependent transcription programme during mammary gland development. PMID:26941120

  4. Influence of fatty acid-free diet on mammary tumor development and growth rate in HER-2/Neu transgenic mice.

    PubMed

    Rossini, Anna; Zanobbio, Laura; Sfondrini, Lucia; Cavalleri, Adalberto; Secreto, Giorgio; Morelli, Daniele; Palazzo, Marco; Sommariva, Michele; Tagliabue, Elda; Rumio, Cristiano; Balsari, Andrea

    2013-01-01

    Numerous investigations have found a relationship between higher risk of cancer and increased intake of fats, while results of clinical studies of fat reduction and breast cancer recurrence have been mixed. A diet completely free of fats cannot be easily administered to humans, but experimental studies in mice can be done to determine whether this extreme condition influences tumor development. Here, we examined the effects of a FA-free diet on mammary tumor development and growth rate in female FVB-neu proto-oncogene transgenic mice that develop spontaneous multifocal mammary tumors after a long latency period. Mice were fed a fatty acid-free diet beginning at 112, 35, and 30 days of age. In all these experiments, tumor appearance was delayed, tumor incidence was reduced and the mean number of palpable mammary tumors per mouse was lower, as compared to standard diet-fed mice. By contrast, tumor growth rate was unaffected in mice fed the fatty acid-free diet. Plasma of mice fed the fatty acid-free diet revealed significantly higher contents of oleic, palmitoleic and 20:3ω9 acids and lower contents of linoleic and palmitic acids. In conclusion, these findings indicate that a FA-free diet reduces tumor incidence and latency but not tumor growth rate, suggesting that a reduction in dietary FAs in humans may have a protective effect on tumorigenesis but not on tumors once they appear. PMID:22689438

  5. Influence of Prevastein, an isoflavone-rich soy product, on mammary gland development and tumorigenesis in Tg.NK (MMTV/c-neu) mice.

    PubMed

    Thomsen, Anni R; Mortensen, Alicja; Breinholt, Vibeke M; Lindecrona, Rikke H; Peñalvo, José L; Sørensen, Ilona K

    2005-01-01

    We investigated spontaneous mammary tumor development and mammary gland morphogenesis in female Tg.NK mice postnatally exposed to dietary soy isoflavones (0, 11, 39, and 130 mg aglycones/kg diet) added to a Western-style diet. Instead of preventing mammary tumorigenesis, the highest dose of isoflavones was associated with a small but significant increase in the number and size of tumors as compared to mice administered a Western-style control diet (P < 0.05). At postnatal Week 6, dynamic activity (measured as apoptotic density) at the highest dose and the degree of branching of the mammary tree in all isoflavone-exposed groups was increased as compared to controls (P < 0.05). At adulthood, the epithelium appeared more quiescent in the medium- and high-dose groups evident by reduced apoptotic density and a reduction in the percentage of terminal end buds (TEBs), respectively, as compared to controls (P < 0.05). The number of actively dividing cells within the TEBs was unaffected by isoflavone exposure as was the activity of drug-metabolizing and antioxidant enzymes. In conclusion, isoflavones may augment mammary gland and mammary tumor development. PMID:16201849

  6. Mammary cancers and pregnancy.

    PubMed Central

    Anderson, J M

    1979-01-01

    Uncertainties persist about management and prognosis of mammary cancers that occur during and after pregnancy and during lactation. Pathological features of mammary cancers occurring during pregnancy are the same as those in non-pregnant women and survival rates are comparable. Management should be the same as in non-pregnant patients. Termination of pregnancy does not improve survival but it should be advised if the prognosis is poor. Mastectomy apparently presents little danger to the fetus, though treatment such as chemotherapy and irradiation should be avoided. Women who have received treatment for mammary cancer need not be advised against subsequent pregnancy. Routine ovarian radiation in non-pregnant premenopausal women is not generally to be recommended, since it does not prolong survival and would deprive some of the chance of further pregnancy. In lactating women who develop mammary cancers survival is apparently not adversely affected. Lactation should be suppressed initially and followed by mastectomy. Regimens of immunotherapy, chemotherapy, or radiotherapy may then be begun. Until results of current trials of combined treatments of mammary cancers associated with pregnancy are available, management should be neither aggressive nor tentative. It should be based on a well-balanced concept of applying all available treatments, as in non-pregnant patients. PMID:376044

  7. In-Silico Genomic Approaches To Understanding Lactation, Mammary Development, And Breast Cancer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lactation-related traits are influenced by genetics. From a quantitative standpoint, these traits have been well studied in dairy species, but there has also been work on the genetics of lactation in humans and mice. In addition, there is evidence to support the notion that other mammary gland trait...

  8. A noncoding RNA is a potential marker of cell fate during mammary gland development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PINC is a large, alternatively spliced, developmentally regulated, noncoding RNA expressed in the regressed terminal ductal lobular unit-like structures of the parous mammary gland. Previous studies have shown that this population of cells possesses not only progenitor-like qualities (the ability to...

  9. A Compendium of the Mouse Mammary Tumor Biologist: From the Initial Observations in the House Mouse to the Development of Genetically Engineered Mice

    PubMed Central

    Cardiff, Robert D.; Kenney, Nicholas

    2011-01-01

    For over a century, mouse mammary tumor biology and the associated mouse mammary tumor virus (MMTV) have served as the foundation for experimental cancer research, in general, and, in particular, experimental breast cancer research. Spontaneous mouse mammary tumors were the basis for studies of the natural history of neoplasia, oncogenic viruses, host responses, endocrinology and neoplastic progression. However, lacking formal proof of a human mammary tumor virus, the preeminence of the mouse model faded in the 1980s. Since the late 1980s, genetically engineered mice (GEM) have proven extremely useful for studying breast cancer and have become the animal model for human breast cancer. Hundreds of mouse models of human breast cancer have been developed since the first demonstration in 1984. The GEM have attracted a new generation of molecular and cellular biologists eager to apply their skill sets to these surrogates of the human disease. Newcomers often enter the field without an appreciation of the origins of mouse mammary tumor biology and the basis for many of the prevailing concepts. Our purpose in writing this compendium is to extend an “olive branch” while simultaneously deepen the knowledge of the novice mouse mammary tumor biologist as they journey into a field rich in pathology and genetics spanning several centuries. PMID:20961975

  10. A compendium of the mouse mammary tumor biologist: from the initial observations in the house mouse to the development of genetically engineered mice.

    PubMed

    Cardiff, Robert D; Kenney, Nicholas

    2011-06-01

    For over a century, mouse mammary tumor biology and the associated mouse mammary tumor virus (MMTV) have served as the foundation for experimental cancer research, in general, and, in particular, experimental breast cancer research. Spontaneous mouse mammary tumors were the basis for studies of the natural history of neoplasia, oncogenic viruses, host responses, endocrinology and neoplastic progression. However, lacking formal proof of a human mammary tumor virus, the preeminence of the mouse model faded in the 1980s. Since the late 1980s, genetically engineered mice (GEM) have proven extremely useful for studying breast cancer and have become the animal model for human breast cancer. Hundreds of mouse models of human breast cancer have been developed since the first demonstration in 1984. The GEM have attracted a new generation of molecular and cellular biologists eager to apply their skill sets to these surrogates of the human disease. Newcomers often enter the field without an appreciation of the origins of mouse mammary tumor biology and the basis for many of the prevailing concepts. Our purpose in writing this compendium is to extend an "olive branch" while simultaneously deepen the knowledge of the novice mouse mammary tumor biologist as they journey into a field rich in pathology and genetics spanning several centuries. PMID:20961975

  11. The PARP inhibitors, veliparib and olaparib, are effective chemopreventive agents for delaying mammary tumor development in BRCA1-deficient mice

    PubMed Central

    To, Ciric; Kim, Eun-Hee; Royce, Darlene B.; Williams, Charlotte R.; Collins, Ryan M.; Risingsong, Renee; Sporn, Michael B.; Liby, Karen T.

    2014-01-01

    Poly-ADP ribose polymerase (PARP) inhibitors are effective for the treatment of BRCA-deficient tumors. Women with these mutations have an increased risk of developing breast cancer and would benefit from effective chemoprevention. This study examines whether the PARP inhibitors, veliparib and olaparib, are effective for delaying mammary gland tumor development in a BRCA1-deficient (BRCA1Co/Co; MMTV-Cre; p53+/−) mouse model. In dose de-escalation studies, mice were fed control, veliparib (100 mg/kg diet) or olaparib (200, 100, 50 or 25 mg/kg diet) continuously for up to 43 weeks. For intermittent dosing studies, mice cycled through olaparib (200 mg/kg diet) for 2 weeks followed by a 4-week rest period on control diet. To examine biomarkers, mice were fed olaparib using the intermittent dosing regimen and mammary glands were evaluated by immunohistochemistry. In mice treated with veliparib or olaparib (200 mg/kg diet), the average age of the first detectable tumor was delayed by 2.4 weeks and 6.5 weeks, respectively, compared to controls. Olaparib also increased the average lifespan of mice by 7 weeks. In dose de-escalation studies, lower concentrations of olaparib delayed tumor development but were less effective than the highest dose. When fed intermittently, olaparib delayed the onset of the first palpable tumor by 5.7 weeks and significantly reduced proliferation and induced apoptosis in hyperplastic mammary glands. In summary, veliparib and olaparib are effective for delaying tumor development and extending the lifespan of Brca1-deficient mice, and intermittent dosing with olaparib was as effective as continuous dosing. These results suggest that the use of PARP inhibitors is a promising chemopreventive option. PMID:24817481

  12. Histone Demethylase Jumonji AT-rich Interactive Domain 1B (JARID1B) Controls Mammary Gland Development by Regulating Key Developmental and Lineage Specification Genes*

    PubMed Central

    Zou, Mike Ran; Cao, Jian; Liu, Zongzhi; Huh, Sung Jin; Polyak, Kornelia; Yan, Qin

    2014-01-01

    The JmjC domain-containing H3K4 histone demethylase jumonji AT-rich interactive domain 1B (JARID1B) (also known as KDM5B and PLU1) is overexpressed in breast cancer and is a potential target for breast cancer treatment. To investigate the in vivo function of JARID1B, we developed Jarid1b−/− mice and characterized their phenotypes in detail. Unlike previously reported Jarid1b−/− strains, the majority of these Jarid1b−/− mice were viable beyond embryonic and neonatal stages. This allowed us to further examine phenotypes associated with the loss of JARID1B in pubertal development and pregnancy. These Jarid1b−/− mice exhibited decreased body weight, premature mortality, decreased female fertility, and delayed mammary gland development. Related to these phenotypes, JARID1B loss decreased serum estrogen level and reduced mammary epithelial cell proliferation in early puberty. In mammary epithelial cells, JARID1B loss diminished the expression of key regulators for mammary morphogenesis and luminal lineage specification, including FOXA1 and estrogen receptor α. Mechanistically, JARID1B was required for GATA3 recruitment to the Foxa1 promoter to activate Foxa1 expression. These results indicate that JARID1B positively regulates mammary ductal development through both extrinsic and cell-autonomous mechanisms. PMID:24802759

  13. T cell- but not tumor cell-produced TGF-β1 promotes the development of spontaneous mammary cancer

    PubMed Central

    Sarkar, Abira; Donkor, Moses K.; Li, Ming O.

    2011-01-01

    During their development, tumors acquire multiple capabilities that enable them to proliferate, disseminate and evade immunosurveillance. A putative mechanism is through the production of the cytokine TGF-β1. We showed in our recent studies that T cell-produced TGF-β1 inhibits antitumor T cell responses to foster tumor growth raising the question of the precise function of TGF-β1 produced by tumor cells in tumor development. Here, using a transgenic model of mammary cancer, we report that deletion of TGF-β1 from tumor cells did not protect mice from tumor development. However, ablation of TGF-β1 from T cells significantly inhibited mammary tumor growth. Additionally, absence of TGF-β1 in T cells prevented tumors from advancing to higher pathological grades and further suppressed secondary tumor development in the lungs. These findings reveal T cells but not tumor cells as a critical source of TGF-β1 that promotes tumor development. PMID:22248703

  14. Folate exacerbates the effects of ethanol on peripubertal mouse mammary gland development.

    PubMed

    Masso-Welch, Patricia A; Tobias, Menachem E; Vasantha Kumar, Shyam C; Bodziak, MaryLou; Mashtare, Terry; Tamburlin, Judith; Koury, Stephen T

    2012-05-01

    Alcohol consumption is linked with increased breast cancer risk in women, even at low levels of ingestion. The proposed mechanisms whereby ethanol exerts its effects include decreased folate levels resulting in diminished DNA synthesis and repair, and/or acetaldehyde-generated DNA damage. Based on these proposed mechanisms, we hypothesized that ethanol would have increased deleterious effects during periods of rapid mammary gland epithelial proliferation, such as peripuberty, and that folate deficiency alone might mimic and/or exacerbate the effects of ethanol. To test this hypothesis, weight-matched 28-35 day old CD2F1 female mice were pair-fed liquid diets ±3.2% ethanol, ±0.1% folate for 4 weeks. Folate status was confirmed by assay of liver and kidney tissues. In folate deficient mice, no significant ethanol-induced changes to the mammary gland were observed. Folate replete mice fed ethanol had an increased number of ducts per section, due to an increased number of terminal short branches. Serum estrogen levels were increased by ethanol, but only in folate replete mice. These results demonstrate that folate deficiency alone does not mimic the effects of ethanol, and that folate deficiency in the presence of ethanol blocks proliferative effects of ethanol on the mammary ductal tree. PMID:22440688

  15. PTEN and p53 cross-regulation induced by soy isoflavone genistein promotes mammary epithelial cell cycle arrest and lobuloalveolar differentiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The tumor suppressors PTEN and p53 are closely related to the pathogenesis of breast cancer, yet pathway-specific mechanisms underlying their participation in mediating the protective actions of dietary bioactive components on breast cancer risk are poorly understood. We recently showed that dietary...

  16. Design and development of a dedicated mammary and axillary region positron emission tomography system

    NASA Astrophysics Data System (ADS)

    Doshi, Niraj Kumar

    Breast cancer is the second leading cause of cancer death in women. Currently, mammography and physical breast examination, both non-invasive techniques, provide the two most effective methods available for screening potential breast cancer patients. During the management of patients, however, several invasive techniques such as axillary lymph node dissection, core biopsies and lumpectomies, are utilized to determine the stage or malignancy of the disease with significant cost and morbidity associated with them. Positron Emission Tomography (PET), using [F-18] fluorodeoxyglucose (FDG) tracer is a sensitive and non-invasive imaging modality that may be a cost-effective alternative to certain invasive procedures. In this project we have developed a low cost, high performance, dedicated PET camera (maxPET) for mammary and axillary region imaging. The system consists of two 15x15 cm2 planar scintillation detector arrays composed of modular detectors operating in coincidence. The modular detectors are comprised of a 9x9 array of 3x3x20 mm3 lutetiurn oxyorthosilicate (LSO) detector elements, read out by a 5x5 array of position- sensitive photomultiplier tubes. The average measured intrinsic spatial resolution of a detector module is 2.26 mm with a sensitivity of up to 40% for a central point source. The measured coincidence timing resolution for two modules is 2.4 ns. The average energy resolution measured across the entire two detector plates is 21.6%. The coincidence timing resolution for the entire system is 8.1 ns. A line bar phantom was imaged and images were reconstructed using the focal plane tomography algorithm. A 4 mm projection image resolution was measured based on profiles taken through the line bar phantom images. The goal of the maxPET system will be to aid in breast cancer patient management by assisting in imaging women with dense, fibro-glandular breasts, detecting axillary lymph node metastases without surgery, monitoring chemotherapy effectiveness and

  17. Improved development of somatic cell cloned bovine embryos by a mammary gland epithelia cells in vitro model.

    PubMed

    He, Xiao-Ying; Ma, Li-Bing; He, Xiao-Ning; Si, Wan-Tong; Zheng, Yue-Mao

    2016-06-30

    Previous studies have established a bovine mammary gland epithelia cells in vitro model by the adenovirus-mediated telomerase (hTERT-bMGEs). The present study was conducted to confirm whether hTERT-bMGEs were effective target cells to improve the efficiency of transgenic expression and somatic cell nuclear transfer (SCNT). To accomplish this, a mammary-specific vector encoding human lysozyme and green fluorescent protein was used to verify the transgenic efficiency of hTERT-bMGEs, and untreated bovine mammary gland epithelial cells (bMGEs) were used as a control group. The results showed that the hTERT-bMGEs group had much higher transgenic efficiency and protein expression than the bMGEs group. Furthermore, the nontransgenic and transgenic hTERT-bMGEs were used as donor cells to evaluate the efficiency of SCNT. There were no significant differences in rates of cleavage or blastocysts or hatched blastocysts of cloned embryos from nontransgenic hTERT-bMGEs at passage 18 and 28 groups (82.8% vs. 81.9%, 28.6% vs. 24.8%, 58.6% vs. 55.3%, respectively) and the transgenic group (80.8%, 26.5% and 53.4%); however, they were significantly higher than the bMGEs group (71.2%, 12.8% and 14.8%), (p < 0.05). We confirmed that hTERT-bMGEs could serve as effective target cells for improving development of somatic cell cloned cattle embryos. PMID:26243608

  18. Improved development of somatic cell cloned bovine embryos by a mammary gland epithelia cells in vitro model

    PubMed Central

    Ma, Li-bing; He, Xiao-ning; Si, Wan-tong; Zheng, Yue-Mao

    2016-01-01

    Previous studies have established a bovine mammary gland epithelia cells in vitro model by the adenovirus-mediated telomerase (hTERT-bMGEs). The present study was conducted to confirm whether hTERT-bMGEs were effective target cells to improve the efficiency of transgenic expression and somatic cell nuclear transfer (SCNT). To accomplish this, a mammary-specific vector encoding human lysozyme and green fluorescent protein was used to verify the transgenic efficiency of hTERT-bMGEs, and untreated bovine mammary gland epithelial cells (bMGEs) were used as a control group. The results showed that the hTERT-bMGEs group had much higher transgenic efficiency and protein expression than the bMGEs group. Furthermore, the nontransgenic and transgenic hTERT-bMGEs were used as donor cells to evaluate the efficiency of SCNT. There were no significant differences in rates of cleavage or blastocysts or hatched blastocysts of cloned embryos from nontransgenic hTERT-bMGEs at passage 18 and 28 groups (82.8% vs. 81.9%, 28.6% vs. 24.8%, 58.6% vs. 55.3%, respectively) and the transgenic group (80.8%, 26.5% and 53.4%); however, they were significantly higher than the bMGEs group (71.2%, 12.8% and 14.8%), (p < 0.05). We confirmed that hTERT-bMGEs could serve as effective target cells for improving development of somatic cell cloned cattle embryos. PMID:26243608

  19. Heterogeneity in ERK activity as visualized by in vivo FRET imaging of mammary tumor cells developed in MMTV-Neu mice.

    PubMed

    Kumagai, Y; Naoki, H; Nakasyo, E; Kamioka, Y; Kiyokawa, E; Matsuda, M

    2015-02-19

    Human epidermal growth factor receptor2/Neu, which is overexpressed in about 30% of human breast cancers, transduces growth signals in large part via the Ras-Raf-MEK-ERK pathway. Nevertheless, it is a matter of controversy whether high ERK activity in breast cancer tissues correlates with better or worse prognosis, leaving the role of ERK activity in the progression of breast cancers unresolved. To address this issue, we live-imaged ERK activity in mammary tumors developed in mouse mammary tumor virus-Neu transgenic mice, which had been crossed with transgenic mice expressing a Förster resonance energy transfer biosensor for ERK. Observation of the tumor by two-photon microscopy revealed significant heterogeneity in ERK activity among the mammary tumor cells. The level of ERK activity in each cell was stable up to several hours, implying a robust mechanism that maintained the ERK activity within a limited range. By sorting the mammary tumor cells on the basis of their ERK activity, we found that ERK(high) cells less efficiently generated tumorspheres in vitro and tumors in vivo than did ERK(low) cells. In agreement with this finding, the expressions of the cancer stem cell markers CD49f, CD24 and CD61 were decreased in ERK(high) cells. These observations suggest that high ERK activity may suppress the self-renewal of mammary cancer stem cells. PMID:24632612

  20. Effect of the silybin-phosphatidylcholine complex (IdB 1016) on the development of mammary tumors in HER-2/neu transgenic mice.

    PubMed

    Provinciali, Mauro; Papalini, Francesca; Orlando, Fiorenza; Pierpaoli, Sara; Donnini, Alessia; Morazzoni, Paolo; Riva, Antonella; Smorlesi, Arianna

    2007-03-01

    Silybin, a main component of the milk thistle of Silybum marianum, has been reported to possess anticancer activity. We investigated the effects of IdB 1016, a complex of silybin with phosphatidylcholine, on the development of mammary tumors appearing spontaneously in HER-2/neu transgenic mice. The mechanisms involved in the antitumor effect of IdB 1016 were evaluated by studying the apoptosis, senescent-like growth arrest, intratumoral leukocyte infiltrate, and the expression of HER-2/neu and p53 in tumoral mammary glands from transgenic mice and in human breast SKBR3 tumor cells. The administration of IdB 1016 delayed the development of spontaneous mammary tumors, reduced the number and size of mammary tumor masses, and diminished lung metastasization in HER-2/neu transgenic mice. In tumoral mammary glands from IdB 1016-treated mice, a down-regulation of HER-2/neu gene expression was associated with an increased senescent-like growth arrest of tumor cells, and an increased infiltrate of neutrophils, CD4, and CD8 T cells. Both senescent-like growth arrest and apoptosis were significantly increased and were associated with a reduced p185(HER-2/neu) protein and an increased p53 mRNA in SKBR3 in vitro treated with IdB 1016 in comparison with control cells. The results show the antitumor effect of IdB 1016 in the development of spontaneous mammary tumors in HER-2/neu transgenic mice. The effect of IdB 1016 might be related to the down-regulation of HER-2/neu expression and the induction of senescent-like growth arrest and apoptosis through a p53-mediated pathway in tumor cells. PMID:17332330

  1. Loss of EZH2 results in precocious mammary gland development and activation of STAT5-dependent genes.

    PubMed

    Yoo, Kyung Hyun; Oh, Sumin; Kang, Keunsoo; Hensel, Tim; Robinson, Gertraud W; Hennighausen, Lothar

    2015-10-15

    Establishment and differentiation of mammary alveoli during pregnancy are controlled by prolactin through the transcription factors STAT5A and STAT5B (STAT5), which also regulate temporal activation of mammary signature genes. This study addressed the question whether the methyltransferase and transcriptional co-activator EZH2 controls the differentiation clock of mammary epithelium. Ablation of Ezh2 from mammary stem cells resulted in precocious differentiation of alveolar epithelium during pregnancy and the activation of mammary-specific STAT5 target genes. This coincided with enhanced occupancy of these loci by STAT5, EZH1 and RNA Pol II. Limited activation of differentiation-specific genes was observed in mammary epithelium lacking both EZH2 and STAT5, suggesting a modulating but not mandatory role for STAT5. Loss of EZH2 did not result in overt changes in genome-wide and gene-specific H3K27me3 profiles, suggesting compensation through enhanced EZH1 recruitment. Differentiated mammary epithelia did not form in the combined absence of EZH1 and EZH2. Transplantation experiments failed to demonstrate a role for EZH2 in the activity of mammary stem and progenitor cells. In summary, while EZH1 and EZH2 serve redundant functions in the establishment of H3K27me3 marks and the formation of mammary alveoli, the presence of EZH2 is required to control progressive differentiation of milk secreting epithelium during pregnancy. PMID:26250110

  2. Development of new therapy for canine mammary cancer with recombinant measles virus

    PubMed Central

    Shoji, Koichiro; Yoneda, Misako; Fujiyuki, Tomoko; Amagai, Yosuke; Tanaka, Akane; Matsuda, Akira; Ogihara, Kikumi; Naya, Yuko; Ikeda, Fusako; Matsuda, Hiroshi; Sato, Hiroki; Kai, Chieko

    2016-01-01

    Oncolytic virotherapy is a promising treatment strategy for cancer. We previously generated a recombinant measles virus (rMV-SLAMblind) that selectively uses a poliovirus receptor-related 4 (PVRL4/Nectin4) receptor, but not signaling lymphocyte activation molecule (SLAM). We demonstrated that the virus exerts therapeutic effects against human breast cancer cells. Here, we examined the applicability of rMV-SLAMblind to treating canine mammary cancers (CMCs). We found that the susceptibilities of host cells to rMV-SLAMblind were dependent on canine Nectin-4 expression. Nectin-4 was detected in four of nine CMC cell lines. The rMV-SLAMblind efficiently infected those four Nectin-4-positive cell lines and was cytotoxic for three of them (CF33, CHMm, and CTBm). In vivo experiment showed that the administration of rMV-SLAMblind greatly suppressed the progression of tumors in mice xenografted with a CMC cell line (CF33). Immunohistochemistry revealed that canine Nectin-4 was expressed in 45% of canine mammary tumors, and the tumor cells derived from one clinical specimen were efficiently infected with rMV-SLAMblind. These results suggest that rMV-SLAMblind infects CMC cells and displays antitumor activity in vitro, in xenografts, and ex vivo. Therefore, oncolytic virotherapy with rMV-SLAMblind can be a novel method for treating CMCs. PMID:27119113

  3. Development of new therapy for canine mammary cancer with recombinant measles virus.

    PubMed

    Shoji, Koichiro; Yoneda, Misako; Fujiyuki, Tomoko; Amagai, Yosuke; Tanaka, Akane; Matsuda, Akira; Ogihara, Kikumi; Naya, Yuko; Ikeda, Fusako; Matsuda, Hiroshi; Sato, Hiroki; Kai, Chieko

    2016-01-01

    Oncolytic virotherapy is a promising treatment strategy for cancer. We previously generated a recombinant measles virus (rMV-SLAMblind) that selectively uses a poliovirus receptor-related 4 (PVRL4/Nectin4) receptor, but not signaling lymphocyte activation molecule (SLAM). We demonstrated that the virus exerts therapeutic effects against human breast cancer cells. Here, we examined the applicability of rMV-SLAMblind to treating canine mammary cancers (CMCs). We found that the susceptibilities of host cells to rMV-SLAMblind were dependent on canine Nectin-4 expression. Nectin-4 was detected in four of nine CMC cell lines. The rMV-SLAMblind efficiently infected those four Nectin-4-positive cell lines and was cytotoxic for three of them (CF33, CHMm, and CTBm). In vivo experiment showed that the administration of rMV-SLAMblind greatly suppressed the progression of tumors in mice xenografted with a CMC cell line (CF33). Immunohistochemistry revealed that canine Nectin-4 was expressed in 45% of canine mammary tumors, and the tumor cells derived from one clinical specimen were efficiently infected with rMV-SLAMblind. These results suggest that rMV-SLAMblind infects CMC cells and displays antitumor activity in vitro, in xenografts, and ex vivo. Therefore, oncolytic virotherapy with rMV-SLAMblind can be a novel method for treating CMCs. PMID:27119113

  4. Dietary Fat Alters Body Composition, Mammary Development, and Cytochrome P450 Induction after Maternal TCDD Exposure in DBA/2J Mice with Low-Responsive Aryl Hydrocarbon Receptors

    PubMed Central

    La Merrill, Michele; Kuruvilla, Bittu S.; Pomp, Daniel; Birnbaum, Linda S.; Threadgill, David W.

    2009-01-01

    Background Increased fat intake is associated with obesity and may make obese individuals uniquely susceptible to the effects of lipophilic aryl hydrocarbon receptor (AHR) ligands. Objectives We investigated the consequences of high-fat diet (HFD) and AHR ligands on body composition, mammary development, and hepatic P450 expression. Methods Pregnant C57BL/6J (B6) and DBA/2J (D2) dams, respectively expressing high- or low-responsive AHR, were dosed at mid-gestation with TCDD. At parturition, mice were placed on an HFD or a low-fat diet (LFD). Body fat of progeny was measured before dosing with 7,12-dimethylbenz[a]anthracene (DMBA). Fasting blood glucose was measured, and liver and mammary glands were analyzed. Results Maternal TCDD exposure resulted in reduced litter size in D2 mice and, on HFD, reduced postpartum survival in B6 mice. In D2 mice, HFD increased body mass and fat in off-spring, induced precocious mammary gland development, and increased AHR expression compared with mice given an LFD. Maternal TCDD exposure increased hepatic Cyp1a1 and Cyp1b1 expression in offspring on both diets, but DMBA depressed Cyp1b1 expression only in mice fed an HFD. In D2 progeny, TCDD exposure decreased mammary terminal end bud size, and DMBA exposure decreased the number of terminal end buds. Only in D2 progeny fed HFD did perinatal TCDD increase blood glucose and the size of mammary fat pads, while decreasing both branch elongation and the number of terminal end buds. Conclusions We conclude that despite having a low-responsive AHR, D2 progeny fed a diet similar to that consumed by most people are susceptible to TCDD and DMBA exposure effects blood glucose levels, mammary differentiation, and hepatic Cyp1 expression. PMID:19750107

  5. Expression of prolactin receptors in normal canine mammary tissue, canine mammary adenomas and mammary adenocarcinomas

    PubMed Central

    2012-01-01

    Background Mammary tumors represent the most common neoplastic disease in female dogs. Recently, the promoting role of prolactin (PRL) in the development of human breast carcinoma has been shown. Possible proliferative, anti-apoptotic, migratory and angiogenic effects of PRL on human mammary cancer cells in vitro and in vivo were suggested. The effects of PRL are mediated by its receptor, and alterations in receptor expression are likely to play a role in tumor development. Currently, not much data is available about prolactin receptor (PRLR) expression in canine mammary tumors. To set the basis for investigations on the role of PRL in mammary tumorigenesis in this species, prolactin receptor expression was evaluated by semi-quantitative real time PCR and immunohistochemistry on 10 formalin-fixed, paraffin-embedded samples each of canine non-neoplastic mammary tissue, mammary adenomas and adenocarcinomas. Results The highest PRLR expression levels were found in normal mammary tissue, while adenomas, and to an even higher degree adenocarcinomas, showed a significant decrease in prolactin receptor expression. Compared to normal tissue, PRLR mRNA was reduced 2.4 fold (p = 0.0261) in adenomas and 4.8 fold (p = 0.008) in adenocarcinomas. PRLR mRNA expression was significantly lower in malignant than in benign lesions (p = 0.0165). Immunohistochemistry demonstrated PRLR expression in all three tissue types with signals mostly limited to epithelial cells. Conclusions Malignant transformation of mammary tissue was associated with a decline in prolactin receptor expression. Further studies are warranted to address the functional significance of this finding. PMID:22647582

  6. Connexins, E-cadherin, Claudin-7 and β-catenin transiently form junctional nexuses during the post-natal mammary gland development.

    PubMed

    Dianati, Elham; Poiraud, Jérémy; Weber-Ouellette, Anne; Plante, Isabelle

    2016-08-01

    Gap junctions are intercellular channels made of connexins (Cxs) that allow direct communication between adjacent cells. Modulation of Cxs has been associated with abnormal development and function of the mammary gland and breast cancer. However, the mechanisms underlying their expression during normal mammary gland are not yet known. Cxs interact with components of tight and adherens junctions. Thus, we hypothesized that the expression levels of Cxs vary during mammary gland development and are regulated through stage-dependent interactions with members of the tight and adherens junctions. Our specific objectives were to: 1) determine the expression of Cxs and tight and adherens junction proteins throughout development and 2) characterize Cxs interactions with components of tight and adherens junctions. Murine mammary glands were sampled at various developmental stages (pre-pubescent to post-weaning). RT-qPCR and western-blot analyses demonstrated differential expression patterns for all gap (Cx43, Cx32, Cx26, Cx30), tight (Claudin-1, -3, -4, -7) and adherens (β-catenin, E- and P-cadherins) junctions throughout development. Interestingly, co-immunoprecipitation demonstrated interactions between these different types of junctions. Cx30 interacted with Cx26 just at the late pregnancy stage. While Cx43 showed a persistent interaction with β-catenin from virginity to post-weaning, its interactions with E-cadherin and Claudin-7 were transient. Cx32 interacted with Cx26, E-cadherin and β-catenin during lactation. Immunofluorescence results confirmed the existence of a junctional nexus that remodeled during mammary gland development. Together, our results confirm that the expression levels of Cxs vary concomitantly and that Cxs form junctional nexuses with tight and adherens junctions, suggesting the existence of common regulatory pathways. PMID:27291930

  7. Glucose transporter expression in rat mammary gland.

    PubMed Central

    Burnol, A F; Leturque, A; Loizeau, M; Postic, C; Girard, J

    1990-01-01

    The expression of different glucose transporter isoforms was measured during the development and differentiation of the rat mammary gland. Before conception, when the mammary gland is mainly composed of adipocytes, Glut 4 and Glut 1 mRNAs and proteins were present. During pregnancy, the expression of Glut 4 decreased progressively, whereas that of Glut 1 increased. In the lactating mammary gland only Glut 1 was present, and was expressed at a high level. The absence of Glut 4 suggests that glucose transport is not regulated by insulin in the lactating rat mammary gland. Images Fig. 1. Fig. 2. PMID:2396989

  8. Evo-devo of the mammary gland.

    PubMed

    Oftedal, Olav T; Dhouailly, Danielle

    2013-06-01

    We propose a new scenario for mammary evolution based on comparative review of early mammary development among mammals. Mammary development proceeds through homologous phases across taxa, but evolutionary modifications in early development produce different final morphologies. In monotremes, the mammary placode spreads out to form a plate-like mammary bulb from which more than 100 primary sprouts descend into mesenchyme. At their distal ends, secondary sprouts develop, including pilosebaceous anlagen, resulting in a mature structure in which mammary lobules and sebaceous glands empty into the infundibula of hair follicles; these structural triads (mammolobular-pilo-sebaceous units or MPSUs) represent an ancestral condition. In marsupials a flask-like mammary bulb elongates as a sprout, but then hollows out; its secondary sprouts include hair and sebaceous anlagen (MPSUs), but the hairs are shed during nipple formation. In some eutherians (cat, horse, human) MPSUs form at the distal ends of primary sprouts; pilosebaceous components either regress or develop into mature structures. We propose that a preexisting structural triad (the apocrine-pilo-sebaceous unit) was incorporated into the evolving mammary structure, and coupled to additional developmental processes that form the mammary line, placode, bulb and primary sprout. In this scenario only mammary ductal trees and secretory tissue derive from ancestral apocrine-like glands. The mammary gland appears to have coopted signaling pathways and genes for secretory products from even earlier integumentary structures, such as odontode (tooth-like) or odontode-derived structures. We speculate that modifications in signal use (such as PTHrP and BMP4) may contribute to taxonomic differences in MPSU development. PMID:23681303

  9. Differentiation dynamics of mammary epithelial stem cells from Korean holstein dairy cattle under ECM-free conditions.

    PubMed

    Sharma, Neelesh; Kim, Jeong Hyun; Sodhi, Simrinder Singh; Luong, Do Huynh; Kim, Sung-Woo; Oh, Sung Jong; Jeong, Dong Kee

    2015-01-01

    The "stem cells" are commonly defined as "cells capable of self-renewal through replication and differentiating into specific lineages". The mammary gland contains functional stem/progenitor cells. The current study was planned with the objectives to study the differentiation dynamics of Korean Holstein mammary epithelial stem cells (KHMESCs) under the optimum culture conditions. Lineage negative KHMESCs isolated from mammary tissue of lactating cows have shown the typical differentiation dynamics with formation of lobulo-alveolar structures in in vitro culture. This suggests the existence of bipotential mammary epithelial stem cells in the mammary gland. The strong mRNA expression of pluripotency factors indicates stemness, whereas expression of milk protein genes and epithelial cell-specific gene indicate their differentiation capabilities. Further, immunostaining results have shown the differentiation capabilities of KHMESCs into both luminal and basal lineages under the extracellular matrix (ECM, matrigel) free environment. However, under matrigel, the differentiation process was comparatively higher than without matrigel. Immunostaining results also suggested that differentiated cells could secrete milk proteins such as β-casein. To our knowledge, these data represent the first report on the differentiation dynamics and establishment of mammary epithelial stem cells from Korean Holstein with typical stemness properties. It was observed that isolated KHMESCs had normal morphology, growth pattern, differentiation ability, cytogenetic and secretory activity even without ECM. Therefore, it is concluded that established KHMESCs could be used for further studies on Korean Holstein dairy cows related to lactation studies, as non-GMO animal bioreactors and stem cell-based management of bovine mastitis including post-mastitis damage. PMID:25759113

  10. A new role of SNAI2 in postlactational involution of the mammary gland links it to luminal breast cancer development.

    PubMed

    Castillo-Lluva, S; Hontecillas-Prieto, L; Blanco-Gómez, A; Del Mar Sáez-Freire, M; García-Cenador, B; García-Criado, J; Pérez-Andrés, M; Orfao, A; Cañamero, M; Mao, J H; Gridley, T; Castellanos-Martín, A; Pérez-Losada, J

    2015-09-01

    Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pretumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2 oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load-were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper postlactational involution of the breast. At 3 days post lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels of pAKT1, resulting in decreased apoptosis. Abundant noninvoluted ducts were still present at 30 days post lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres and to an increase in the number of tumors. Our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of postlactational involution and breast tumorigenesis in Snai2-null mutant mice. PMID:26096931

  11. A new role of SNAI2 in postlactational involution of the mammary gland links it to luminal breast cancer development

    DOE PAGESBeta

    Castillo-Lluva, Sonia; Hontecillas-Prieto, Lourdes; Blanco-Gómez, Adrian; del Mar Sáez-Freire, María; García-Cenador, Begona; García-Criado, Javier; Pérez-Andrés, Martín; Orfao, Alberto; Cañamero, Marta; Mao, Jian-Hua; et al

    2015-06-22

    Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pretumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2more » oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load-were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper postlactational involution of the breast. At 3 days post lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels of pAKT1, resulting in decreased apoptosis. Abundant noninvoluted ducts were still present at 30 days post lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres and to an increase in the number of tumors. In conclusion, our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of postlactational involution and breast tumorigenesis in Snai2-null mutant mice.« less

  12. A new role of SNAI2 in postlactational involution of the mammary gland links it to luminal breast cancer development

    SciTech Connect

    Castillo-Lluva, Sonia; Hontecillas-Prieto, Lourdes; Blanco-Gómez, Adrian; del Mar Sáez-Freire, María; García-Cenador, Begona; García-Criado, Javier; Pérez-Andrés, Martín; Orfao, Alberto; Cañamero, Marta; Mao, Jian-Hua; Gridley, Thomas; Castellanos-Martín, Andres; Pérez-Losada, Jesus

    2015-06-22

    Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pretumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2 oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load-were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper postlactational involution of the breast. At 3 days post lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels of pAKT1, resulting in decreased apoptosis. Abundant noninvoluted ducts were still present at 30 days post lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres and to an increase in the number of tumors. In conclusion, our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of postlactational involution and breast tumorigenesis in Snai2-null mutant mice.

  13. Lack of a significant effect of arctiin on development of 7,12-dimethylbenz(a)anthracene-induced mammary tumors in ovariectomized Sprague-Dawley rats.

    PubMed

    Hasumura, Mai; Ueda, Makoto; Onose, Jun-ichi; Imai, Toshio; Hirose, Masao

    2007-01-01

    Arctiin, a plant lignan, is metabolized to hormone-like compounds with weak estrogenic and antioxidative activity in experimental animals and man. To clarify its influence on mammary carcinogenesis, female rats were administrated 7,12-dimethylbenz(a)anthracene (DMBA) once, and when the incidence of palpable mammary tumors reached 50%, subjected to ovariectomy (OVX) and divided into tumor-bearing [DMBA-Tumor (+)] and no-tumor-bearing [DMBA-Tumor (-)] groups, subgroups of each then being fed soybean-free diet containing 0, 40, 200, and 1000 ppm of arctiin for 31 wk. The incidence and multiplicity of palpable tumors in the 200 ppm DMBA-Tumor (+) subgroup from week 12 of arctiin treatment tended to be decreased as compared to the 0 ppm subgroup and at terminal sacrifice, the volume of histopathologically defined mammary tumors was decreased in the 40 ppm DMBA-Tumor (-) subgroup, but again without statistical significance. In conclusion, weak inhibitory effects of arctiin on DMBA-induced mammary tumor development were suggested in OVX rats, but any further assessment is needed to obtain conclusive results. PMID:17571954

  14. WFDC2 is differentially expressed in the mammary gland of the tammar wallaby and provides immune protection to the mammary gland and the developing pouch young.

    PubMed

    Watt, Ashalyn P; Sharp, Julie A; Lefevre, Christophe; Nicholas, Kevin R

    2012-03-01

    WAP four disulfide core domain 2 (WFDC2) is a four disulfide core (4-DSC) protein secreted in the milk of the tammar wallaby. It is comprised of two 4-DSC domains assigned domain III at the NH2-terminal end and domain II at the COOH-terminal end. The WFDC2 gene was expressed only during pregnancy, early lactation, towards the end of lactation and involution. The WFDC2 protein showed antibacterial activity against Staphylococcus aureus, Salmonella enterica and Pseudomonas aeruginosa and this activity resided with domain II. There was no antibacterial activity detected against Enterococcus faecalis. The observed expression pattern of tammar WFDC2 and its antibacterial activity suggests a role to either reduce mastitis in the mammary gland caused by S. aureus or to protect the gut of the young at a time when it is not immune-competent. The latter effect could be achieved without disturbing the balance of commensal gut flora such as E. faecalis. PMID:22024352

  15. ‘The charmingest place’: non-coding RNA, lineage tracing, tumor heterogeneity, metastasis and metabolism - new methods in mammary gland development and cancer: the fifth ENBDC Workshop

    PubMed Central

    2013-01-01

    The European Network for Breast Development and Cancer (ENBDC) Workshop on ‘Methods in Mammary Gland Development and Cancer’ has grown into the essential, international technical discussion forum for scientists with interests in the normal and neoplastic breast. The fifth ENBDC meeting was held in Weggis, Switzerland in April, 2013, and focussed on emerging, state-of-the-art techniques for the study of non-coding RNA, lineage tracing, tumor heterogeneity, metastasis and metabolism. PMID:24103450

  16. The Mammary Glands of Macaques

    PubMed Central

    Cline, J. Mark; Wood, Charles E.

    2009-01-01

    This review describes the normal biology and physiology of the mammary gland in macaques, including the typical histologic appearance across the life span (development, reproductive maturity, lactation, and senescence). The molecular events regulating breast morphogenesis are described, as well as systemic and local hormonal regulators of mammary gland proliferation, differentiation, and function. Similarities and differences to the human breast are described. Regulatory events are illuminated by discussion of genetically modified mouse models. Tissue response markers, including immunohistochemical markers of proliferation and other hormonally induced changes and studies to date, regarding the effects of exogenous hormones, are briefly summarized. In general, estrogens stimulate progesterone receptor expression and proliferation in the mammary gland, and combinations of estrogens and progestogens cause greater proliferation than estrogens alone. Evaluation of novel chemical agents in macaques requires careful evaluation of age and hormonal context to avoid the confounding effects of mammary gland development, past reproductive history, and other influences on mammary gland morphology. The expression of proliferation markers and progesterone receptors may be used as biomarkers to measure chemically induced hormonal effects. PMID:21475638

  17. A prognosis classifier for breast cancer based on conserved gene regulation between mammary gland development and tumorigenesis: a multiscale statistical model.

    PubMed

    Tian, Yingpu; Chen, Baozhen; Guan, Pengfei; Kang, Yujia; Lu, Zhongxian

    2013-01-01

    Identification of novel cancer genes for molecular therapy and diagnosis is a current focus of breast cancer research. Although a few small gene sets were identified as prognosis classifiers, more powerful models are still needed for the definition of effective gene sets for the diagnosis and treatment guidance in breast cancer. In the present study, we have developed a novel statistical approach for systematic analysis of intrinsic correlations of gene expression between development and tumorigenesis in mammary gland. Based on this analysis, we constructed a predictive model for prognosis in breast cancer that may be useful for therapy decisions. We first defined developmentally associated genes from a mouse mammary gland epithelial gene expression database. Then, we found that the cancer modulated genes were enriched in this developmentally associated genes list. Furthermore, the developmentally associated genes had a specific expression profile, which associated with the molecular characteristics and histological grade of the tumor. These result suggested that the processes of mammary gland development and tumorigenesis share gene regulatory mechanisms. Then, the list of regulatory genes both on the developmental and tumorigenesis process was defined an 835-member prognosis classifier, which showed an exciting ability to predict clinical outcome of three groups of breast cancer patients (the predictive accuracy 64∼72%) with a robust prognosis prediction (hazard ratio 3.3∼3.8, higher than that of other clinical risk factors (around 2.0-2.8)). In conclusion, our results identified the conserved molecular mechanisms between mammary gland development and neoplasia, and provided a unique potential model for mining unknown cancer genes and predicting the clinical status of breast tumors. These findings also suggested that developmental roles of genes may be important criteria for selecting genes for prognosis prediction in breast cancer. PMID:23565194

  18. Apigenin prevents development of medroxyprogesterone acetate-accelerated 7,12-dimethylbenz(a)anthracene-induced mammary tumors in Sprague-Dawley rats

    PubMed Central

    Mafuvadze, Benford; Benakanakere, Indira; Lopez, Franklin; Besch-Williford, Cynthia; Ellersieck, Mark R.; Hyder, Salman M.

    2011-01-01

    The use of progestins as a component of hormone replacement therapy has been linked to an increase in breast cancer risk in postmenopausal women. We have previously shown that medroxyprogesterone acetate (MPA), a commonly administered synthetic progestin, increases production of the potent angiogenic factor vascular endothelial growth factor (VEGF) by tumor cells, leading to the development of new blood vessels and tumor growth. We sought to identify nontoxic chemicals that would inhibit progestin-induced tumorigenesis. We used a recently developed progestin-dependent mammary cancer model in which tumors are induced in Sprague-Dawley rats by 7,12-dimethylbenz(a)anthracene (DMBA) treatment. The flavonoid apigenin, which we previously found to inhibit progestin-dependent VEGF synthesis in human breast cancer cells in vitro, significantly delayed the development of, and decreased the incidence and multiplicity of, MPA-accelerated DMBA-induced mammary tumors in this animal model. Whereas apigenin decreased the occurrence of such tumors, it did not block MPA-induced intraductal and lobular epithelial cell hyperplasia in the mammary tissue. Apigenin blocked MPA-dependent increases in VEGF, and suppressed VEGF receptor-2 (VEGFR-2) but not VEGFR-1 in regions of hyperplasia. No differences were observed in estrogen or progesterone receptor levels, or the number of estrogen receptor-positive cells, within the mammary gland of MPA-treated animals administered apigenin, MPA-treated animals, and placebo treated animals. However, the number of progesterone receptor-positive cells was reduced in animals treated with MPA or MPA and apigenin compared with those treated with placebo. These findings suggest that apigenin has important chemopreventive properties for those breast cancers that develop in response to progestins. PMID:21505181

  19. Lack of effects of postnatal exposure to a mixture of aryl hydrocarbon-receptor agonists on the development of methylnitrosourea-induced mammary tumors in sprague-dawley rats.

    PubMed

    Desaulniers, Daniel; Leingartner, Karen; Musicki, Biljana; Cole, Jonathan; Li, Ming; Charbonneau, Michel; Tsang, Benjamin K

    2004-09-24

    There are concerns that early life exposure to organochlorines, including aryl hydrocarbon receptor (AhR) agonists, may lead to long-term effects and increase the risk of developing breast cancer. Our objective was to test if postnatal exposure to a mixture of 2,3,7,8-tetrachlorodibenzodioxin (TCDD)-like chemicals would modulate the development of methylnitrosourea (MNU)-induced mammary tumors. Females received by gavage a mixture containing 3 non-ortho-polychlorinated biphenyls (PCBs), 6 polychlorinated dibenzodioxins (PCDDs), and 7 polychlorinated dibenzofurans (PCDFs), at 1, 5, 10, 15, and 20d of age. The doses were equivalent to 0, 1, 10, 100, or 1000 times the amount ingested through breast milk by a human infant during its first 24 d of life. Subgroups of 1000 x reated rats and controls were sacrificed at 21 d of age for assessment of mammary-gland development, cell death, and proliferation. Mammary-tumor development was assessed in MNU (30 mg/kg body weight ip at 50 days of age)-induced rats pre-exposed to the mixture (MNU-0, MNU-1, MNU-10, MNU-100, MNU-1000). Rats were sacrificed when their mammary tumors reached 1 cm in diameter, or when the rats reached > or = 32 wk of age. Mammary-gland whole mounts were analyzed with all palpable and microscopic lesions (n = 1563) histologically classified and grouped as benign, intraductal proliferations, or malignant. There were no marked effects on age at onset of puberty (vaginal opening) and estrous cyclicity. Despite a significant decrease in proliferating cell nuclear antigen (PCNA)-positive mammary cells in 1000 x treated 21-d-old rats, there were no long-term dose-response effects on mammary-gland morphology and tumor development. In conclusion, postnatal exposure to the mixture of AhR agonists had no significant effects on the development of MNU-initiated mammary tumors. PMID:15371232

  20. Cellular Foundations of Mammary Tubulogenesis

    PubMed Central

    Huebner, Robert J.; Ewald, Andrew J.

    2014-01-01

    The mammary gland is composed of a highly branched network of epithelial tubes, embedded within a complex stroma. The mammary epithelium originates during embryonic development from an epidermal placode. However, the majority of ductal elongation and bifurcation occurs postnatally, in response to steroid hormone and growth factor receptor signaling. The process of pubertal branching morphogenesis involves both elongation of the primary ducts across the length of the fat pad and a wave of secondary branching that elaborates the ductal network. Recent studies have revealed that mammary epithelial morphogenesis is accomplished by transitions between simple and stratified organization. During active morphogenesis, the epithelium is stratified, highly proliferative, has few intercellular junctions, and exhibits incomplete apico-basal polarity. In this review, we discuss recent advances in our understanding of the relationship between epithelial architecture, epithelial polarity, and ductal elongation. PMID:24747369

  1. Crosstalk between the p190-B RhoGAP and IGF signaling pathways is required for embryonic mammary bud development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    P190-B RhoGAP (p190-B, also known as ARHGAP5) has been shown to play an essential role in invasion of the terminal end buds (TEBs) into the surrounding fat pad during mammary gland ductal morphogenesis. Here we report that embryos with a homozygous p190-B gene deletion exhibit major defects in embry...

  2. Estimation of mammary gland composition using CdTe series detector developed for photon-counting mammography

    NASA Astrophysics Data System (ADS)

    Ihori, Akiko; Okamoto, Chizuru; Yamakawa, Tsutomu; Yamamoto, Shuichiro; Okada, Masahiro; Nakajima, Ai; Kato, Misa; Kodera, Yoshie

    2016-03-01

    Energy resolved photon-counting mammography is a new technology, which counts the number of photons that passes through an object, and presents it as a pixel value in an image of the object. Silicon semiconductor detectors are currently used in commercial mammography. However, the disadvantage of silicon is the low absorption efficiency for high X-ray energies. A cadmium telluride (CdTe) series detector has a high absorption efficiency over a wide energy range. In this study, we proposed a method to estimate the composition of the mammary gland using a CdTe series detector as a photon-counting detector. The fact that the detection rate of breast cancer in mammography is affected by mammary gland composition is now widely accepted. Assessment of composition of the mammary gland has important implications. An important advantage of our proposed technique is its ability to discriminate photons using three energy bins. We designed the CdTe series detector system using the MATLAB simulation software. The phantom contains nine regions with the ratio of glandular tissue and adipose varying in increments of 10%. The attenuation coefficient for each bin's energy was calculated from the number of input and output photons possessed by each. The evaluation results obtained by plotting the attenuation coefficient μ in a three-dimensional (3D) scatter plot show that the plots had a regular composition order congruent with that of the mammary gland. Consequently, we believe that our proposed method can be used to estimate the composition of the mammary gland.

  3. Mouse mammary tumor biology: a short history.

    PubMed

    Cardiff, Robert D; Kenney, Nicholas

    2007-01-01

    For over a century, mouse mammary tumor biology and the associated Mouse mammary tumor virus (MMTV) have served as the foundation for experimental cancer research, in general, and, in particular, experimental breast cancer research. Spontaneous mouse mammary tumors were the basis for studies of the natural history of neoplasia, oncogenic viruses, host responses, endocrinology, and neoplastic progression. However, lacking formal proof of a human mammary tumor virus, the preeminence of the mouse model faded in the 1980s. Since the late 1980s, genetically engineered mice (GEM) have proven extremely useful for studying breast cancer and have become the animal model for human breast cancer. Hundreds of mouse models of human breast cancer have been developed since the first demonstration, in 1984, that the mouse mammary gland could be molecularly targeted and used to test the oncogenicity of candidate human genes. Now, very few scientists can avoid using a mouse model to test the biology of their favorite gene. The GEM have attracted a new generation of molecular and cellular biologists eager to apply their skills to these surrogates of the human disease. Newcomers often enter the field without an appreciation of the origins of mouse mammary tumor biology and the basis for many of the prevailing concepts. Our purpose in writing this short history of mouse mammary tumor biology is to provide a historical perspective for the benefit of the newcomers. If Einstein was correct in that "we stand on the shoulders of giants," the neophytes should meet their giants. PMID:17433908

  4. Luteolin suppresses development of medroxyprogesterone acetate-accelerated 7,12-dimethylbenz(a)anthracene-induced mammary tumors in Sprague-Dawley rats.

    PubMed

    Cook, Matthew T; Mafuvadze, Benford; Besch-Williford, Cynthia; Ellersieck, Mark R; Goyette, Sandy; Hyder, Salman M

    2016-02-01

    Postmenopausal women undergoing hormone-replacement therapy containing both progestins and estrogens are at an increased risk of developing breast cancer compared with women taking estrogen alone. We recently demonstrated that medroxyprogesterone acetate, a progestin commonly used for hormone-replacement therapy, accelerates development of mammary carcinogenesis in 7,12-dimethylbenz(a)anthracene‑treated Sprague-Dawley rats. Synthetic antiprogestins used to block the deleterious effects of progestins, are themselves associated with toxic side-effects. In order to circumvent this, we used the aforementioned model to identify less toxic natural compounds that may prevent the development of progestin-accelerated tumors. Luteolin, a naturally-occurring flavonoid commonly found in fruits and vegetables, has previously been shown to possess anticancer properties. In our studies, both low (1 mg/kg) and high (25 mg/kg) doses of luteolin significantly suppressed progestin-dependent increases in tumor incidence, while increasing tumor latency and reducing the occurrence of large (>300 mm3) mammary tumors. However, an intermediate dose of luteolin (10 mg/kg), while suppressing the development of large tumors, did not affect either tumor incidence or latency. Immunohistochemical analysis of tumor tissues revealed that all concentrations of luteolin (1, 10, and 25 mg/kg) significantly reduced levels of VEGF within tumors. The suppressive effects of luteolin on tumor incidence and volume, together with its ability to reduce VEGF and blood vessels, persisted even after treatment was terminated. This suggests that luteolin possesses anti‑angiogenic properties which could mechanistically explain its capacity to control tumor progression. Thus luteolin may be a valuable, non-toxic, naturally-occurring anticancer compound which may potentially be used to combat progestin-accelerated mammary tumors. PMID:26719029

  5. The consequence of level of nutrition on heifer ovarian and mammary development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Replacing cows in the herd is second only to nutrition as the single greatest input cost in cow/calf beef production. The increased availability of cereal grains for feeding livestock has allowed replacement heifers to enter the production system at younger ages. Many heifer development programs fe...

  6. Two distinct phases of apoptosis in mammary gland involution: proteinase-independent and -dependent pathways

    SciTech Connect

    Lund, Leif R; Romer, John; Thomasset, Nicole; Solberg, Helene; Pyke, Charles; Bissell, Mina J; Dano, Keld; Werb, Zena

    1996-01-01

    Postlactational involution of the mammary gland is characterized by two distinct physiological events: apoptosis of the secretory, epithelial cells undergoing programmed cell death, and proteolytic degradation of the mammary gland basement membrane. We examined the spatial and temporal patterns of apoptotic cells in relation to those of proteinases during involution of the BALB/c mouse mammary gland. Apoptosis was almost absent during lactation but became evident at day 2 of involution, when {beta}-casein gene expression was still high. Apoptotic cells were then seen at least up to day 8 of involution, when {beta}-casein gene expression was being extinguished. Expression of sulfated glycoprotein-2 (SGP-2), interleukin-1{beta} converting enzyme (ICE) and tissue inhibitor of metalloproteinases-1 was upregulated at day 2, when apoptotic cells were seen initially. Expression of the matrix metalloproteinases gelatinase A and stromelysin-1 and the serine proteinase urokinase-type plasminogen activator, which was low during lactation, was strongly upregulated in parallel starting at day 4 after weaning, coinciding with start of the collapse of the lobulo-alveolar structures and the intensive tissue remodeling in involution. The major sites of mRNA synthesis for these proteinases were fibroblast-like cells in the periductal stroma and stromal cells surrounding the collapsed alveoli, suggesting that the degradative phase of involution is due to a specialized mesenchymal-epithelial interaction. To elucidate the functional role of these proteinases during involution, at the onset of weaning we treated mice systemically with the glucocorticoid hydrocortisone, which is known to inhibit mammary gland involution. Although the initial wave of apoptotic cells appeared in the lumina of the gland, the dramatic regression and tissue remodeling usually evident by day 5 was substantially inhibited by systemic treatment with hydrocortisone. mRNA and protein for gelatinase A, stromelysin

  7. Does cancer start in the womb? altered mammary gland development and predisposition to breast cancer due to in utero exposure to endocrine disruptors.

    PubMed

    Soto, Ana M; Brisken, Cathrin; Schaeberle, Cheryl; Sonnenschein, Carlos

    2013-06-01

    We are now witnessing a resurgence of theories of development and carcinogenesis in which the environment is again being accepted as a major player in phenotype determination. Perturbations in the fetal environment predispose an individual to disease that only becomes apparent in adulthood. For example, gestational exposure to diethylstilbestrol resulted in clear cell carcinoma of the vagina and breast cancer. In this review the effects of the endocrine disruptor bisphenol-A (BPA) on mammary development and tumorigenesis in rodents is used as a paradigmatic example of how altered prenatal mammary development may lead to breast cancer in humans who are also widely exposed to it through plastic goods, food and drink packaging, and thermal paper receipts. Changes in the stroma and its extracellular matrix led to altered ductal morphogenesis. Additionally, gestational and lactational exposure to BPA increased the sensitivity of rats and mice to mammotropic hormones during puberty and beyond, thus suggesting a plausible explanation for the increased incidence of breast cancer. PMID:23702822

  8. Histone Demethylase JMJD2B Functions as a Co-Factor of Estrogen Receptor in Breast Cancer Proliferation and Mammary Gland Development

    PubMed Central

    Kawazu, Masahito; McQuire, Tracy; Goto, Kouichiro; Son, Dong-Ok; Wakeham, Andrew; Miyagishi, Makoto; Mak, Tak W.; Okada, Hitoshi

    2011-01-01

    Estrogen is a key regulator of normal function of female reproductive system and plays a pivotal role in the development and progression of breast cancer. Here, we demonstrate that JMJD2B (also known as KDM4B) constitutes a key component of the estrogen signaling pathway. JMJD2B is expressed in a high proportion of human breast tumors, and that expression levels significantly correlate with estrogen receptor (ER) positivity. In addition, 17-beta-estradiol (E2) induces JMJD2B expression in an ERα dependent manner. JMJD2B interacts with ERα and components of the SWI/SNF-B chromatin remodeling complex. JMJD2B is recruited to ERα target sites, demethylates H3K9me3 and facilitates transcription of ER responsive genes including MYB, MYC and CCND1. As a consequence, knockdown of JMJD2B severely impairs estrogen-induced cell proliferation and the tumor formation capacity of breast cancer cells. Furthermore, Jmjd2b-deletion in mammary epithelial cells exhibits delayed mammary gland development in female mice. Taken together, these findings suggest an essential role for JMJD2B in the estrogen signaling, and identify JMJD2B as a potential therapeutic target in breast cancer. PMID:21445275

  9. PTEN Loss in E-Cadherin-Deficient Mouse Mammary Epithelial Cells Rescues Apoptosis and Results in Development of Classical Invasive Lobular Carcinoma.

    PubMed

    Boelens, Mirjam C; Nethe, Micha; Klarenbeek, Sjoerd; de Ruiter, Julian R; Schut, Eva; Bonzanni, Nicola; Zeeman, Amber L; Wientjens, Ellen; van der Burg, Eline; Wessels, Lodewyk; van Amerongen, Renée; Jonkers, Jos

    2016-08-23

    Invasive lobular carcinoma (ILC) is an aggressive breast cancer subtype with poor response to chemotherapy. Besides loss of E-cadherin, a hallmark of ILC, genetic inactivation of PTEN is frequently observed in patients. Through concomitant Cre-mediated inactivation of E-cadherin and PTEN in mammary epithelium, we generated a mouse model of classical ILC (CLC), the main histological ILC subtype. While loss of E-cadherin induced cell dissemination and apoptosis, additional PTEN inactivation promoted cell survival and rapid formation of invasive mammary tumors that recapitulate the histological and molecular features, estrogen receptor (ER) status, growth kinetics, metastatic behavior, and tumor microenvironment of human CLC. Combined inactivation of E-cadherin and PTEN is sufficient to cause CLC development. These CLCs showed significant tumor regression upon BEZ235-mediated inhibition of PI3K signaling. In summary, this mouse model provides important insights into CLC development and suggests inhibition of phosphatidylinositol 3-kinase (PI3K) signaling as a potential therapeutic strategy for targeting CLC. PMID:27524621

  10. Identification of Putative Ortholog Gene Blocks Involved in Gestant and Lactating Mammary Gland Development: A Rodent Cross-Species Microarray Transcriptomics Approach

    PubMed Central

    Rodríguez-Cruz, Maricela; Coral-Vázquez, Ramón M.; Hernández-Stengele, Gabriel; Sánchez, Raúl; Salazar, Emmanuel; Sanchez-Muñoz, Fausto; Encarnación-Guevara, Sergio; Ramírez-Salcedo, Jorge

    2013-01-01

    The mammary gland (MG) undergoes functional and metabolic changes during the transition from pregnancy to lactation, possibly by regulation of conserved genes. The objective was to elucidate orthologous genes, chromosome clusters and putative conserved transcriptional modules during MG development. We analyzed expression of 22,000 transcripts using murine microarrays and RNA samples of MG from virgin, pregnant, and lactating rats by cross-species hybridization. We identified 521 transcripts differentially expressed; upregulated in early (78%) and midpregnancy (89%) and early lactation (64%), but downregulated in mid-lactation (61%). Putative orthologous genes were identified. We mapped the altered genes to orthologous chromosomal locations in human and mouse. Eighteen sets of conserved genes associated with key cellular functions were revealed and conserved transcription factor binding site search entailed possible coregulation among all eight block sets of genes. This study demonstrates that the use of heterologous array hybridization for screening of orthologous gene expression from rat revealed sets of conserved genes arranged in chromosomal order implicated in signaling pathways and functional ontology. Results demonstrate the utilization power of comparative genomics and prove the feasibility of using rodent microarrays to identification of putative coexpressed orthologous genes involved in the control of human mammary gland development. PMID:24288657

  11. Save or sacrifice the internal mammary pedicle during anterior mediastinotomy?

    PubMed

    Apostolakis, Efstratios; Papakonstantinou, Nikolaos A; Chlapoutakis, Serafeim; Prokakis, Christos

    2014-07-01

    Ligation and dissection of internal mammary vessels is the most under-estimated complication of anterior mediastinotomy. However, patients requiring anterior mediastinotomy may experience long survival that makes the development of ischemic heart disease throughout their life possible. Therefore, the un-judicial sacrifice of the internal mammary pedicle may deprive them from the benefit to have their internal mammary artery used as a graft in order to successfully bypass severe left anterior descending artery stenoses. We recommend the preservation of the internal mammary pedicle during anterior mediastinotomy, which should be a common message among our colleagues from the beginning of their training. PMID:24987471

  12. Epigenetic regulation of LSD1 during mammary carcinogenesis

    PubMed Central

    Wu, Yadi; Zhou, Binhua P

    2014-01-01

    Inheritable epigenetic regulation is integral to the dynamic control of gene expression under different stimuli for cellular homeostasis and disease progression. Histone methylation is a common and important type of chromatin modification. LSD1, the first known histone lysine-specific demethylase, operates as a key component of several corepressor complexes during development and in disease states. In this review, we focus on the regulation of LSD1 in mammary carcinogenesis. LSD1 plays a role in promoting mammary tumor metastasis and proliferation and in maintaining mammary cancer stem cells. Therefore, LSD1 represents a viable therapeutic target for effective treatment of mammary carcinogenesis. PMID:27308339

  13. Interactive effects of selenium and chromium on mammary tumor development and growth in MMTV-infected female mice and their relevance to human cancer.

    PubMed

    Schrauzer, G N

    2006-03-01

    Evidence for interactive effects of chromium and selenium on the appearance of mammary tumors was obtained by exposing female virgin C3H mice infected with the murine mammary tumorvirus (MMTV) to subtoxic levels of Cr [as Cr(III) nitrate] and Se (as sodium selenite) in the supply water. Cr counteracted the inhibitory effect of Se on tumor development in a dose-dependent manner, shortened the tumor latency period, and accelerated tumor growth rates. Exposure to Cr also altered the levels of Se in the liver and kidneys of the mice, indicating that Cr interacts with Se and affects its organ distribution. Chromium must be added to the list of Se-antagonistic elements that weaken or abolish the antitumorigenic effects of Se. These findings are relevant to human cancer as previous studies revealed the age-corrected mortalities from breast and other major forms of cancer in different countries to be inversely correlated with the dietary Se intakes, and directly correlated with the estimated intakes of Cr and of other Se-antagonistic elements. The presence of these elements in foods must be taken into account when estimating the optimal dose of supplemental Se for cancer risk reduction. PMID:16632896

  14. Comparison of the transcriptpmes of long-tern label retaining-cells and C cells microdissected from mammary epithelium: an initial study to character potential stem/progenitor cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary stem cells (MaSC) account for the cell lineage of mammary epithelia and provide for mammary growth, development and tissue homeostasis. The presence of MaSC was clearly demonstrated by the generation of an entire mammary gland from a single cell implanted into epithelium-ablated mammary fat...

  15. Foxa1 is essential for mammary duct formation.

    PubMed

    Liu, Yi; Zhao, Yongbing; Skerry, Benjamin; Wang, Xiao; Colin-Cassin, Christelle; Radisky, Derek C; Kaestner, Klaus H; Li, Zhaoyu

    2016-05-01

    The transcription factor forkhead box protein A1 (FOXA1) plays a critical role in the proliferation of human breast cancer cells, particularly estrogen receptor alpha (ERα)-positive luminal breast cancer cells. However, genetic studies of the requirement for Foxa1 in mammary tumor formation in mice have been hampered by the lack of a conditional gene ablation. We examined three mouse models of mammary-specific ablation of Foxa1 in ductal epithelial cells to identify the best system for complete and mammary-specific ablation of Foxa1. We found that MMTV-Cre and MMTV-rtTA;Tet-On-Cre led to partial deletion of Foxa1 and attenuated mammary duct formation, whereas Krt14-Cre led to complete ablation of Foxa1 and abolished mammary duct formation, in Foxa1(loxP/loxP) mice. These results demonstrate that Foxa1 is essential for mammary duct formation, and reveal a series of mouse models in which mammary expression of Foxa1 can be attenuated or completely blocked. Our study also suggests a potentially powerful model for complete ablation of Foxa1 in mammary epithelial cells using Krt14-driven Cre expression in an inducible manner, such as Krt14-rtTA;Tet-On-Cre. This model system will facilitate further in vivo functional studies of Foxa1 or other factors in mammary gland development and tumor formation and progression. genesis 54:277-285, 2016. © 2016 Wiley Periodicals, Inc. PMID:26919034

  16. ROLES OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF-A) IN MEDIATION OF DIOXIN (TCDD)-INDUCED DELAYS IN DEVELOPMENT OF THE MOUSE MAMMARY GLAND

    EPA Science Inventory

    Roles of Epidermal Growth Factor (EGF) and Transforming Growth Factor-alpha (TGF-a) in Mediation of Dioxin (TCDD)-Induced Delays in Development of the Mouse Mammary Gland.
    Suzanne E. Fenton, Barbara Abbott, Lamont Bryant, and Angela Buckalew. U.S. EPA, NHEERL, Reproductive Tox...

  17. Genistein-mediated inhibition of mammary stromal adipocyte differentiation limits expansion of mammary stem/progenitor cells by paracrine signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary adiposity may contribute to breast cancer development and progression by releasing cytokines and other inflammatory mediators that promote mammary epithelial proliferation. We evaluated the effects of soy isoflavone genistein (GEN) on the adipogenic differentiation of a SV40-immortalized mou...

  18. Molecular evolution of a novel marsupial S100 protein (S100A19) which is expressed at specific stages of mammary gland and gut development.

    PubMed

    Kwek, Joly H L; Wynne, Alicia; Lefèvre, Christophe; Familari, Mary; Nicholas, Kevin R; Sharp, Julie A

    2013-10-01

    a role in gut development, which differs between metatherians and eutherians, and/or include a potential antibacterial role in order to establish the correct flora and protect against spiral bacteria in the immature forestomach. In the mammary gland it may protect the tissue from infection at times of vulnerability during the lactation cycle. PMID:23707702

  19. Controlled release low dose medroxyprogesterone acetate (MPA) inhibits the development of mammary tumors induced by dimethyl-benz(a) anthracene in the rat.

    PubMed

    Labrie, F; Li, S; Bélanger, A; Côté, J; Mérand, Y; Lepage, M

    1993-01-01

    Medroxyprogesterone acetate (MPA) is well recognized to have beneficial effects for the treatment of advanced breast cancer which are comparable to those achieved with other forms of endocrine therapy. Using mammary tumors induced in the rat by dimethylbenz(a)anthracene (DMBA) as a model, we have studied the possibility that low dose MPA could prevent the development of these tumors. Single subcutaneous injection of Depo-Provera (crystalline suspension of MPA) or MPA encapsulated in biodegradable microspheres of 50:50 poly[DL-lactide-co-glycolide] was given 7 days before oral DMBA. While 63% of intact animals developed palpable mammary tumors within 85 days after DMBA administration, tumor incidence decreased to 28% and 23% in animals who had received 30 mg and 100 mg of Depo-Provera, respectively. The same amounts of MPA delivered in microspheres caused a further decrease in tumor incidence to respective values of 7% and 6%. Average tumor area, on the other hand, decreased from 4.89 cm2 in intact rats to about 0.75 (0.57-0.88) cm2 and approximately 0.20 (0.14-0.22) cm2 in the Depo-Provera and microsphere-treated groups, respectively. Using the 50:50 formulation of poly[DL-lactide-co-glycolide] designed to release MPA at a constant rate for a 4-month period, the serum MPA concentration at 3 months was measured at 4.99 +/- 0.43 ng/ml. Such data suggest that administration of a low dose controlled-release formulation of MPA in 50:50 poly[DL-lactide-co-glycolide] microspheres could well be an efficient and well tolerated approach for the prevention of breast cancer in women. PMID:8251650

  20. Dynamic monitoring of GPER-mediated estrogenic effects in breast cancer associated fibroblasts: An alternative role of estrogen in mammary carcinoma development.

    PubMed

    Luo, Haojun; Liu, Manran; Luo, Shujuan; Yu, Tenghua; Wu, Chengyi; Yang, Guanglun; Tu, Gang

    2016-08-01

    Cancer associated fibroblasts (CAFs) are crucial contributors to breast cancer development. Estrogen affects mammary stroma in both physiological and pathophysiological conditions. We show here that estrogen (G-protein coupled) receptor (GPER) could be detected by immunohistochemistry in stromal fibroblasts of primary breast cancers. The presence of GPER expression was further confirmed by immunofluorescence and quantitative PCR in CAFs isolated from primary breast cancers. Based on dynamic monitoring by real time cell analyzer (RTCA) system, 17-β-estradiol (E2) as well as GPER specific agonist G1 were observed to trigger transient cell index increasing within an hour in a dosage-dependent manner in breast CAFs. In addition, E2 and G1 stimulated intracellular calcium modulation and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 within seconds and minutes in CAFs, respectively. Moreover, E2 and G1 promoted cell proliferation of breast CAFs measured by RTCA monitoring, cell viability assay and cell cycle analysis, and this promotion could be blocked by a GPER-selective antagonist G15. Interestingly, dynamic RTCA monitoring indicated that E2 increased adhesion of resuspended cells, and microscopy confirmed that E2 stimulated cell spreading. Both the adhesion and spreading were proposed to be mediated by GPER, since G1 also stimulated these effects similar to E2, and G15 reduced them. Moreover, GPER was found to mediate migration that was increased by E2 and G1 but reduced by G15 in RTCA cell migration assay and transwell assay. Accordingly, GPER mediates not only rapid actions but also slow effects including adhesion/spreading, proliferation and migration in breast CAFs. Estrogen is likely to affect tumor associated stroma and contributes to mammary carcinoma development through CAFs. PMID:27016131

  1. Haploid loss of bax leads to accelerated mammary tumor development in C3(1)/SV40-TAg transgenic mice: reduction in protective apoptotic response at the preneoplastic stage.

    PubMed Central

    Shibata, M A; Liu, M L; Knudson, M C; Shibata, E; Yoshidome, K; Bandey, T; Korsmeyer, S J; Green, J E

    1999-01-01

    The dramatic increase in apoptosis observed during the development of preneoplastic mammary lesions is associated with a significant elevation in Bax expression in C3(1)/SV40 large T antigen (TAg) transgenic mice. The significance of Bax expression during tumor progression in vivo was studied by generating double-transgenic mice carrying the C3(1)/TAg transgene and mutant alleles for bax. C3(1)/TAg transgenic mice carrying mutant bax alleles exhibited accelerated rates of tumor growth, increased tumor numbers, larger tumor mass and decreased survival rates compared with mice carrying wild-type bax. Accelerated tumorigenesis associated with the bax+/- genotype did not require the loss of function of the second bax allele. Thus, haploid insufficiency of bax is enough to accelerate tumor progression, suggesting that the protective effect of Bax is dose-dependent. While levels of apoptosis in the preneoplastic lesions, but not carcinomas, were reduced in bax+/- or bax-/- mice compared with bax+/+ mice, rates of cellular proliferation in mammary lesions were similar among all bax genotypes. These data demonstrate that bax is a critical suppressor of mammary tumor progression at the stage of preneoplastic mammary lesion development through the upregulation of apoptosis, but that this protective effect is lost during the transition from preneoplasia to invasive carcinoma. PMID:10329616

  2. Roles of Fas and Fas ligand during mammary gland remodeling

    PubMed Central

    Song, Joon; Sapi, Eva; Brown, Wendi; Nilsen, Jon; Tartaro, Karrie; Kacinski, Barry M.; Craft, Joseph; Naftolin, Frederick; Mor, Gil

    2000-01-01

    Mammary involution is associated with degeneration of the alveolar structure and programmed cell death of mammary epithelial cells. In this study, we evaluated the expression of Fas and Fas ligand (FasL) in the mammary gland tissue and their possible role in the induction of apoptosis of mammary cells. FasL-positive cells were observed in normal mammary epithelium from pregnant and lactating mice, but not in nonpregnant/virgin mouse mammary tissue. Fas expression was observed in epithelial and stromal cells in nonpregnant mice but was absent during pregnancy. At day 1 after weaning, high levels of both Fas and FasL proteins and caspase 3 were observed and coincided with the appearance of apoptotic cells in ducts and glands. During the same period, no apoptotic cells were found in the Fas-deficient (MRL/lpr) and FasL-deficient (C3H/gld) mice. Increase in Fas and FasL protein was demonstrated in human (MCF10A) and mouse (HC-11) mammary epithelial cells after incubation in hormone-deprived media, before apoptosis was detected. These results suggest that the Fas-FasL interaction plays an important role in the normal remodeling of mammary tissue. Furthermore, this autocrine induction of apoptosis may prevent accumulation of cells with mutations and subsequent neoplastic development. Failure of the Fas/FasL signal could contribute to tumor development. PMID:11086022

  3. A new role of SNAI2 in post-lactational involution of the mammary gland links it to luminal breast cancer development

    PubMed Central

    Castillo-Lluva, Sonia; Hontecillas-Prieto, Lourdes; Blanco-Gómez, Adrián; Sáez-Freire, María del Mar; García-Cenador, Begoña; García-Criado, Javier; Pérez-Andrés, Martín; de Matos, Alberto Orfao; Cañamero, Marta; Mao, Jian-Hua; Gridley, Thomas; Castellanos-Martín, Andrés; Pérez-Losada, Jesús

    2015-01-01

    Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pre-tumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2 oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load- were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper post-lactational involution of the breast. At three days post-lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels pAKT1, resulting in decreased apoptosis. The presence of abundant non-involuted ducts was still present at 30 days post-lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres, and to an increase in the number of tumors. Our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of post-lactational involution and breast tumorigenesis in Snai2-null mutant mice. PMID:26096931

  4. Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development.

    PubMed

    Perri, A F; Dallard, B E; Baravalle, C; Licoff, N; Formía, N; Ortega, H H; Becú-Villalobos, D; Mejia, M E; Lacau-Mengido, I M

    2014-01-01

    Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland. PMID:24931533

  5. An autoregulatory enhancer controls mammary-specific STAT5 functions

    PubMed Central

    Metser, Gil; Shin, Ha Youn; Wang, Chaochen; Yoo, Kyung Hyun; Oh, Sumin; Villarino, Alejandro V.; O'Shea, John J.; Kang, Keunsoo; Hennighausen, Lothar

    2016-01-01

    Signal Transducers and Activators of Transcription (STATs) are principal transcription factors downstream of cytokine receptors. Although STAT5A is expressed in most tissues it remains to be understood why its premier, non-redundant functions are restricted to prolactin-induced mammary gland development and function. We report that the ubiquitously expressed Stat5a/b locus is subject to additional lineage-specific transcriptional control in mammary epithelium. Genome-wide surveys of epigenetic status and transcription factor occupancy uncovered a putative mammary-specific enhancer within the intergenic sequences separating the two Stat5 genes. This region exhibited several hallmarks of genomic enhancers, including DNaseI hypersensitivity, H3K27 acetylation and binding by GR, NFIB, ELF5 and MED1. Mammary-specific STAT5 binding was obtained at two canonical STAT5 binding motifs. CRISPR/Cas9-mediated genome editing was used to delete these sites in mice and determine their biological function. Mutant animals exhibited an 80% reduction of Stat5 levels in mammary epithelium and a concomitant reduction of STAT5-dependent gene expression. Transcriptome analysis identified a class of mammary-restricted genes that was particularly dependent on high STAT5 levels as a result of the intergenic enhancer. Taken together, the mammary-specific enhancer enables a positive feedback circuit that contributes to the remarkable abundance of STAT5 and, in turn, to the efficacy of STAT5-dependent mammary physiology. PMID:26446995

  6. Of Microenvironments and Mammary Stem Cells

    SciTech Connect

    LaBarge, Mark A; Petersen, Ole W; Bissell, Mina J

    2007-06-01

    In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion and directs their critical functions. Thus guided, stem cells are able to maintain tissue homeostasis throughout the ebb and flow of metabolic and physical demands encountered over a lifetime. Indeed, a pool of stem cells maintains mammary gland structure throughout development, and responds to the physiological demands associated with pregnancy. This review discusses how stem cells were identified in both human and mouse mammary glands; each requiring different techniques that were determined by differing biological needs and ethical constraints. These studies together create a robust portrait of mammary gland biology and identify the location of the stem cell niche, elucidate a developmental hierarchy, and suggest how the niche might be manipulated for therapeutic benefit.

  7. Expression of growth hormone in canine mammary tissue and mammary tumors. Evidence for a potential autocrine/paracrine stimulatory loop.

    PubMed Central

    van Garderen, E.; de Wit, M.; Voorhout, W. F.; Rutteman, G. R.; Mol, J. A.; Nederbragt, H.; Misdorp, W.

    1997-01-01

    The role of progestins in the pathogenesis of breast cancer in women remains controversial. To advance this discussion, we report the demonstration and localization of progestin-induced biosynthesis of growth hormone (GH) in canine mammary gland tissue. Nontumorous mammary tissues and tumors, both benign and malignant, were obtained from private household dogs. Immunoreactive GH was localized in mammary epithelial cells and correlated with the presence of GH mRNA. Local synthesis of GH was also proven immunoelectron microscopically by demonstrating GH-containing secretory granules. Cellular GH production in nontumorous tissues was more extensive during the progesterone-dominated luteal phase of the ovarian cycle or during exposure to synthetic progestins than during anestrus. GH was also associated with areas of hyperplastic mammary epithelium, which may indicate that locally produced GH enhances proliferation, acting in an autocrine and/or paracrine manner. In 41 of 44 tumors, GH was present. Of 3 GH-negative tumor samples, 2 were from progestin-depleted, castrated bitches. In nonmalignant mammary tissues, GH production is stimulated by progesterone and synthetic progestins interacting with progesterone receptors. In some progesterone-receptor-negative malignant tumors, GH expression was found, indicating loss of this control. Progestin-induced GH probably participates in the cyclic development of the mammary gland but may promote mammary tumorigenesis by stimulating proliferation of susceptible, and sometimes transformed, mammary epithelial cells. Images Figure 1 Figure 2 PMID:9060840

  8. Expression of growth hormone in canine mammary tissue and mammary tumors. Evidence for a potential autocrine/paracrine stimulatory loop.

    PubMed

    van Garderen, E; de Wit, M; Voorhout, W F; Rutteman, G R; Mol, J A; Nederbragt, H; Misdorp, W

    1997-03-01

    The role of progestins in the pathogenesis of breast cancer in women remains controversial. To advance this discussion, we report the demonstration and localization of progestin-induced biosynthesis of growth hormone (GH) in canine mammary gland tissue. Nontumorous mammary tissues and tumors, both benign and malignant, were obtained from private household dogs. Immunoreactive GH was localized in mammary epithelial cells and correlated with the presence of GH mRNA. Local synthesis of GH was also proven immunoelectron microscopically by demonstrating GH-containing secretory granules. Cellular GH production in nontumorous tissues was more extensive during the progesterone-dominated luteal phase of the ovarian cycle or during exposure to synthetic progestins than during anestrus. GH was also associated with areas of hyperplastic mammary epithelium, which may indicate that locally produced GH enhances proliferation, acting in an autocrine and/or paracrine manner. In 41 of 44 tumors, GH was present. Of 3 GH-negative tumor samples, 2 were from progestin-depleted, castrated bitches. In nonmalignant mammary tissues, GH production is stimulated by progesterone and synthetic progestins interacting with progesterone receptors. In some progesterone-receptor-negative malignant tumors, GH expression was found, indicating loss of this control. Progestin-induced GH probably participates in the cyclic development of the mammary gland but may promote mammary tumorigenesis by stimulating proliferation of susceptible, and sometimes transformed, mammary epithelial cells. PMID:9060840

  9. Mammary Glands: Developmental Changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mammary gland progresses from the accumulation of a few cells in the embryonic ectoderm to a highly arborescent tubulo-alveolar gland capable of secreting a highly nutritious product for consumption. Throughout this progression, various changes occur during each developmental stage: prenatal, pr...

  10. Mammary gland-specific ablation of focal adhesion kinase reduces the incidence of p53-mediated mammary tumour formation

    PubMed Central

    van Miltenburg, M H A M; van Nimwegen, M J; Tijdens, I; Lalai, R; Kuiper, R; Klarenbeek, S; Schouten, P C; de Vries, A; Jonkers, J; van de Water, B

    2014-01-01

    Background: Elevated expression of focal adhesion kinase (FAK) occurs in numerous human cancers including colon-, cervix- and breast cancer. Although several studies have implicated FAK in mammary tumour formation induced by ectopic oncogene expression, evidence supporting a role for FAK in spontaneous mammary tumour development caused by loss of tumour suppressor genes such as p53 is lacking. Alterations in the tumour suppressor gene p53 have been implicated in over 50% of human breast cancers. Given that elevated FAK expression highly correlates with p53 mutation status in human breast cancer, we set out to investigate the importance of FAK in p53-mediated spontaneous mammary tumour development. Methods: To directly assess the role of FAK, we generated mice with conditional inactivation of FAK and p53. We generated female p53lox/lox/FAK+/+/WapCre, p53lox/lox/FAKflox/+/WapCre and p53lox/lox/FAKflox/−/WapCre mice, and mice with WapCre-mediated conditional expression of p53R270H, the mouse equivalent of human p53R273H hot spot mutation, together with conditional deletion of FAK, P53R270H/+/FAKlox/+/WapCre and p53R270H/+/FAKflox/−/WapCre mice. All mice were subjected to one pregnancy to induce WapCre-mediated deletion of p53 or expression of p53 R270H, and Fak genes flanked by two loxP sites, and subsequently followed the development of mammary tumours. Results: Using this approach, we show that FAK is important for p53-induced mammary tumour development. In addition, mice with the mammary gland-specific conditional expression of p53 point mutation R270H, the mouse equivalent to human R273H, in combination with conditional deletion of Fak showed reduced incidence of p53R270H-induced mammary tumours. In both models these effects of FAK were related to reduced proliferation in preneoplastic lesions in the mammary gland ductal structures. Conclusions: Mammary gland-specific ablation of FAK hampers p53-regulated spontaneous mammary tumour formation. Focal adhesion

  11. STAT signaling in mammary gland differentiation, cell survival and tumorigenesis

    PubMed Central

    Haricharan, S; Li, Y

    2013-01-01

    The mammary gland is a unique organ that undergoes extensive and profound changes during puberty, menstruation, pregnancy, lactation and involution. The changes that take place during puberty involve large-scale proliferation and invasion of the fat-pad. During pregnancy and lactation, the mammary cells are exposed to signaling pathways that inhibit apoptosis, induce proliferation and invoke terminal differentiation. Finally, during involution the mammary gland is exposed to milk stasis, programed cell death and stromal reorganization to clear the differentiated milk-producing cells. Not surprisingly, the signaling pathways responsible for bringing about these changes in breast cells are often subverted during the process of tumorigenesis. The STAT family of proteins is involved in every stage of mammary gland development, and is also frequently implicated in breast tumorigenesis. While the roles of STAT3 and STAT5 during mammary gland development and tumorigenesis are well studied, others members, e.g. STAT1 and STAT6, have only recently been observed to play a role in mammary gland biology. Continued investigation into the STAT protein network in the mammary gland will likely yield new biomarkers and risk factors for breast cancer, and may also lead to novel prophylactic or therapeutic strategies against breast cancer. PMID:23541951

  12. Developmental biology: cell fate in the mammary gland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most breast cancers have their origin in the luminal epithelial cells of the mammary gland. Defining how a master regulator controls the development of this cell lineage could provide important hints about why this should be. ...

  13. Persistent mammary hyperplasia in FVB/N mice.

    PubMed

    Nieto, Ana I; Shyamala, G; Galvez, Jose J; Thordarson, Gudmundur; Wakefield, Lalage M; Cardiff, Robert D

    2003-08-01

    The inbred FVB/N mouse strain is widely used for creating transgenic mice. Over the past decade, persistent mammary hyperplasia has been detected in many multiparous FVB/N female mice sent to the University of California, Davis (UCD) Mutant Mouse Pathology Laboratory (MMPL) by a number of different laboratories. However, the experimental details concerning most specimens were not always available. To confirm these empiric findings, experiments were carried out to evaluate the mammary glands of FVB/N mice under controlled conditions. Persistent mammary hyperplasia that related to parity was found. Weeks after their first to fourth pregnancy, 10 FVB/N female mice from the Lawrence Berkeley National Laboratory (LBNL) colony were studied and the mammary glands were evaluated. The percentage of fat pad filled was estimated, using image analysis. Serum samples and the pituitary gland from other FVB/N mice from the LBNL were assayed for prolactin concentration. Multiparous FVB/N females consistently had persistent mammary hyperplasia. Four of seven females in the LBNL colony had hyperplasia after three pregnancies. A few foci of squamous nodules and sporadic carcinomas also were observed. Thus, some FVB/N females may have persistent mammary hyperplasia after three pregnancies without detectable pituitary abnormalities. Mammary carcinomas also may develop sporadically. These background phenotypes must be considered when interpreting the effect of genetic manipulation in FVB/N mice. PMID:14524420

  14. Inhibitory effects of a polypeptide thymic factor on the development of 7,12-dimethylbenz(a)anthragene-induced mammary adenocarcinoma in female rats

    SciTech Connect

    Anisimov, V.N.; Danetskaya, E.V.; Morozov, V.G.; Khavinson, V.Kh.

    1980-01-01

    It has come to be recognized that tumor growth is accompanied by inhibition of cellular immunity and the function of the T lymphocytes. Restitution of T lymphocyte function by means of several pharmacologic agents such as levamisole, phenformin, or epithalamin (an epiphyseal factor) has, in a number of cases, been accompanied by growth inhibition of both spontaneous and induced tumors. In addition, the importance of the thymus in the regulation of T lymphocytes and in antitumor immunity has been recognized. Several indicators point to the fact that the thymus contains physiologically active substances which stimulate T cell-dependent immunity and prevent the occurrence of neoplasms. These considerations have led to attempts at isolation of active thymic factors and studies on their effects on the appearance and growth of tumors. Previously, a thymic factor - thymarin - had been isolated which imparted immunocompetence to the T lymphocytes. This factor differs from other thymic preparations, including thymosine, in terms of a number of physicochemical characteristics and is a polypeptide with a molecular weight of 5000. This study is concerned with its effects on tumor development - mammary gland adenocarcinoma induced in animals with a chemical carcinogen.

  15. Isoflavone intake inhibits the development of 7,12-dimethylbenz(a)anthracene(DMBA)-induced mammary tumors in normal and ovariectomized rats

    PubMed Central

    Ma, Defu; Zhang, Yumei; Yang, Titi; Xue, Yong; Wang, Peiyu

    2014-01-01

    To determine the associations between isoflavone (49.72% genistin, 5.32% daidzin, 34.54% glycitin) and breast cancer risk, 150 rats were given 5 mg 7,12-dimethylbenz(a)anthracene and half of them were ovariectomized. Then normal rats and ovariectomized rats were divided into 5 groups: control group, isoflavone high (HI), middle (MI), or low (LI) dose group consuming 100, 500, or 1000 mg isoflavones/kg diet, estrogen group (2.5 mg stilboestrol/kg diet). After 24 weeks, tumor incidences were 73% in control group, 7% in HI, 7% in MI, 27% in LI, and 80% in estrogen group for normal rats; 60% in control group, 13% in HI, 7% in MI, 13% in LI, and 73% in estrogen group for ovariectomized rats. Isoflavone treatment decreased tumor incidence and mean tumor number per rat and increased mean latent period compared with those in control group and estrogen group group significantly (p<0.05). The mRNA and protein expression of estrogen receptor β were significantly higher in isoflavone treatment groups than those in control group group. Moreover, isoflavone treatment significantly decreased 8-hydroxydeoxyguanosine content and increased superoxide dismutase level in normal rats and decreased malondialdehyde concentrations in ovariectomized rats compared with control group. In conclusions, isoflavone intake significantly inhibited the development of premenopausal and postmenopausal mammary tumors. PMID:24426188

  16. Sequencing the transcriptome of milk production: milk trumps mammary tissue

    PubMed Central

    2013-01-01

    Background Studies of normal human mammary gland development and function have mostly relied on cell culture, limited surgical specimens, and rodent models. Although RNA extracted from human milk has been used to assay the mammary transcriptome non-invasively, this assay has not been adequately validated in primates. Thus, the objectives of the current study were to assess the suitability of lactating rhesus macaques as a model for lactating humans and to determine whether RNA extracted from milk fractions is representative of RNA extracted from mammary tissue for the purpose of studying the transcriptome of milk-producing cells. Results We confirmed that macaque milk contains cytoplasmic crescents and that ample high-quality RNA can be obtained for sequencing. Using RNA sequencing, RNA extracted from macaque milk fat and milk cell fractions more accurately represented RNA from mammary epithelial cells (cells that produce milk) than did RNA from whole mammary tissue. Mammary epithelium-specific transcripts were more abundant in macaque milk fat, whereas adipose or stroma-specific transcripts were more abundant in mammary tissue. Functional analyses confirmed the validity of milk as a source of RNA from milk-producing mammary epithelial cells. Conclusions RNA extracted from the milk fat during lactation accurately portrayed the RNA profile of milk-producing mammary epithelial cells in a non-human primate. However, this sample type clearly requires protocols that minimize RNA degradation. Overall, we validated the use of RNA extracted from human and macaque milk and provided evidence to support the use of lactating macaques as a model for human lactation. PMID:24330573

  17. ApcMin, A Mutation in the Murine Apc Gene, Predisposes to Mammary Carcinomas and Focal Alveolar Hyperplasias

    NASA Astrophysics Data System (ADS)

    Moser, Amy Rapaich; Mattes, Ellen M.; Dove, William F.; Lindstrom, Mary J.; Haag, Jill D.; Gould, Michael N.

    1993-10-01

    ApcMin (Min, multiple intestinal neoplasia) is a point mutation in the murine homolog of the APC gene. Min/+ mice develop multiple intestinal adenomas, as do humans carrying germ-line mutations in APC. Female mice carrying Min are also prone to develop mammary tumors. Min/+ mammary glands are more sensitive to chemical carcinogenesis than are +/+ mammary glands. Transplantation of mammary cells from Min/+ or +/+ donors into +/+ hosts demonstrates that the propensity to develop mammary tumors is intrinsic to the Min/+ mammary cells. Long-term grafts of Min/+ mammary glands also gave rise to focal alveolar hyperplasias, indicating that the presence of the Min mutation also has a role in the development of these lesions.

  18. Ectodysplasin/NF-κB Promotes Mammary Cell Fate via Wnt/β-catenin Pathway

    PubMed Central

    Voutilainen, Maria; Lönnblad, Darielle; Shirokova, Vera; Elo, Teresa; Rysti, Elisa; Schmidt-Ullrich, Ruth; Schneider, Pascal; Mikkola, Marja L.

    2015-01-01

    Mammary gland development commences during embryogenesis with the establishment of a species typical number of mammary primordia on each flank of the embryo. It is thought that mammary cell fate can only be induced along the mammary line, a narrow region of the ventro-lateral skin running from the axilla to the groin. Ectodysplasin (Eda) is a tumor necrosis factor family ligand that regulates morphogenesis of several ectodermal appendages. We have previously shown that transgenic overexpression of Eda (K14-Eda mice) induces formation of supernumerary mammary placodes along the mammary line. Here, we investigate in more detail the role of Eda and its downstream mediator transcription factor NF-κB in mammary cell fate specification. We report that K14-Eda mice harbor accessory mammary glands also in the neck region indicating wider epidermal cell plasticity that previously appreciated. We show that even though NF-κB is not required for formation of endogenous mammary placodes, it is indispensable for the ability of Eda to induce supernumerary placodes. A genome-wide profiling of Eda-induced genes in mammary buds identified several Wnt pathway components as potential transcriptional targets of Eda. Using an ex vivo culture system, we show that suppression of canonical Wnt signalling leads to a dose-dependent inhibition of supernumerary placodes in K14-Eda tissue explants. PMID:26581094

  19. Ectodysplasin/NF-κB Promotes Mammary Cell Fate via Wnt/β-catenin Pathway.

    PubMed

    Voutilainen, Maria; Lindfors, Päivi H; Trela, Ewelina; Lönnblad, Darielle; Shirokova, Vera; Elo, Teresa; Rysti, Elisa; Schmidt-Ullrich, Ruth; Schneider, Pascal; Mikkola, Marja L

    2015-11-01

    Mammary gland development commences during embryogenesis with the establishment of a species typical number of mammary primordia on each flank of the embryo. It is thought that mammary cell fate can only be induced along the mammary line, a narrow region of the ventro-lateral skin running from the axilla to the groin. Ectodysplasin (Eda) is a tumor necrosis factor family ligand that regulates morphogenesis of several ectodermal appendages. We have previously shown that transgenic overexpression of Eda (K14-Eda mice) induces formation of supernumerary mammary placodes along the mammary line. Here, we investigate in more detail the role of Eda and its downstream mediator transcription factor NF-κB in mammary cell fate specification. We report that K14-Eda mice harbor accessory mammary glands also in the neck region indicating wider epidermal cell plasticity that previously appreciated. We show that even though NF-κB is not required for formation of endogenous mammary placodes, it is indispensable for the ability of Eda to induce supernumerary placodes. A genome-wide profiling of Eda-induced genes in mammary buds identified several Wnt pathway components as potential transcriptional targets of Eda. Using an ex vivo culture system, we show that suppression of canonical Wnt signalling leads to a dose-dependent inhibition of supernumerary placodes in K14-Eda tissue explants. PMID:26581094

  20. Effect of ovariohysterectomy in bitches with mammary neoplasms.

    PubMed

    Morris, J S; Dobson, J M; Bostock, D E; O'Farrell, E

    1998-06-13

    Ninety bitches with mammary tumours were studied for two years after the surgical removal of the primary tumour(s). Twenty-nine of the bitches had been spayed before the development of the mammary tumour, 22 were spayed when the tumours were removed and 39 were left entire. Fifty-eight of the bitches (64 per cent) had benign tumours and, of these, 15 (26 per cent) developed a new mammary tumour within two years, irrespective of whether the bitch was spayed. The other 32 bitches had malignant tumours which were grouped into 'invasive' and 'well defined' carcinomas. Sixty-three per cent of the spayed bitches and 57 per cent of the entire bitches, with invasive carcinoma were dead within two years of surgery as a result of their mammary tumours. For those with well defined carcinomas the tumour-related death rates were 18 per cent and 33 per cent respectively for the spayed and entire bitches. These findings suggest that ovariohysterectomy when mammary tumours are removed does not have a significant effect on the progression of malignant disease, and that about one in four bitches with a benign mammary tumour is likely to develop a further tumour in another gland. PMID:9670443

  1. Use of tamoxifen in the control of canine mammary neoplasia.

    PubMed

    Morris, J S; Dobson, J M; Bostock, D E

    1993-11-27

    Ninety-three bitches which had undergone mammary tumour surgery were entered into a clinical trial to examine the effects of ovariohysterectomy (spaying) at the time of mammary surgery and the use of the drug tamoxifen in preventing the recurrence of the tumour and/or the development of new mammary tumours. Twenty-three of the bitches which had been spayed were allocated tamoxifen but only 18 of them complied with the treatment and in nine of these the treatment was stopped owing to side effects (mostly oestrogenic). Too few animals were studied to draw conclusions about the possible preventative effects of tamoxifen on mammary neoplasia, but the high percentage of bitches affected by oestrogen-like side effects may reduce the compliance of owners and prevent tamoxifen being widely used in dogs. PMID:8116156

  2. The Ca2+/H+ antiporter TMEM165 expression, localization in the developing, lactating and involuting mammary gland parallels the secretory pathway Ca2+ATPase (SPCA1)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasma membrane Ca2+-ATPase 2 (PMCA2) knockout mice showed that ~ 60 % of calcium in milk is transported across the mammary cells apical membrane by PMCA2. The remaining milk calcium is thought to arrive via the secretory pathway through the actions of secretory pathway Ca2+-ATPase’s 1 and/or 2 (SP...

  3. Adaptive Immune Regulation of Mammary Postnatal Organogenesis.

    PubMed

    Plaks, Vicki; Boldajipour, Bijan; Linnemann, Jelena R; Nguyen, Nguyen H; Kersten, Kelly; Wolf, Yochai; Casbon, Amy-Jo; Kong, Niwen; van den Bijgaart, Renske J E; Sheppard, Dean; Melton, Andrew C; Krummel, Matthew F; Werb, Zena

    2015-09-14

    Postnatal organogenesis occurs in an immune competent environment and is tightly controlled by interplay between positive and negative regulators. Innate immune cells have beneficial roles in postnatal tissue remodeling, but roles for the adaptive immune system are currently unexplored. Here we show that adaptive immune responses participate in the normal postnatal development of a non-lymphoid epithelial tissue. Since the mammary gland (MG) is the only organ developing predominantly after birth, we utilized it as a powerful system to study adaptive immune regulation of organogenesis. We found that antigen-mediated interactions between mammary antigen-presenting cells and interferon-γ (IFNγ)-producing CD4+ T helper 1 cells participate in MG postnatal organogenesis as negative regulators, locally orchestrating epithelial rearrangement. IFNγ then affects luminal lineage differentiation. This function of adaptive immune responses, regulating normal development, changes the paradigm for studying players of postnatal organogenesis and provides insights into immune surveillance and cancer transformation. PMID:26321127

  4. Anti-tumor effect of SLPI on mammary but not colon tumor growth.

    PubMed

    Amiano, Nicolás O; Costa, María J; Reiteri, R Macarena; Payés, Cristian; Guerrieri, Diego; Tateosian, Nancy L; Sánchez, Mercedes L; Maffia, Paulo C; Diament, Miriam; Karas, Romina; Orqueda, Andrés; Rizzo, Miguel; Alaniz, Laura; Mazzolini, Guillermo; Klein, Slobodanka; Sallenave, Jean-Michel; Chuluyan, H Eduardo

    2013-02-01

    Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor that was related to cancer development and metastasis dissemination on several types of tumors. However, it is not known the effect of SLPI on mammary and colon tumors. The aim of this study was to examine the effect of SLPI on mammary and colon tumor growth. The effect of SLPI was tested on in vitro cell apoptosis and in vivo tumor growth experiments. SLPI over-expressing human and murine mammary and colon tumor cells were generated by gene transfection. The administration of murine mammary tumor cells over-expressing high levels of SLPI did not develop tumors in mice. On the contrary, the administration of murine colon tumor cells over-expressing SLPI, developed faster tumors than control cells. Intratumoral, but not intraperitoneal administration of SLPI, delayed the growth of tumors and increased the survival of mammary but not colon tumor bearing mice. In vitro culture of mammary tumor cell lines treated with SLPI, and SLPI producer clones were more prone to apoptosis than control cells, mainly under serum deprivation culture conditions. Herein we demonstrated that SLPI induces the apoptosis of mammary tumor cells in vitro and decreases the mammary but not colon tumor growth in vivo. Therefore, SLPI may be a new potential therapeutic tool for certain tumors, such as mammary tumors. PMID:22767220

  5. Technical note: Isolation and characterization of porcine mammary epithelial cells.

    PubMed

    Dahanayaka, S; Rezaei, R; Porter, W W; Johnson, G A; Burghardt, R C; Bazer, F W; Hou, Y Q; Wu, Z L; Wu, G

    2015-11-01

    Within the mammary gland, functional synthesis of milk is performed by its epithelial (alveolar) cells. The availability of a stable mammary epithelial cell line is essential for biochemical studies to elucidate cellular and molecular mechanisms responsible for nutritional regulation of lactation. Therefore, porcine mammary epithelial cells (PMEC) were isolated from mammary glands of a 9-mo-old nonpregnant and nonlactating gilt and cultured to establish a nonimmortalized cell line. These cells were characterized by expression of cytokeratin-18 (an intermediate filament specific for epithelial cells), β-casein (a specific marker for mammary epithelial cells), and α-lactalbumin. In culture, the PMEC doubled in number every 24 h and maintained a cobblestone morphology, typical for cultured epithelial cells, for at least 15 passages. Addition of 0.2 to 2 μg/mL prolactin to culture medium for 3 d induced the production of β-casein and α-lactalbumin by PMEC in a dose-dependent manner. Thus, we have successfully developed a useful PMEC line for future studies of cellular and molecular regulation of milk synthesis by mammary epithelial cells of the sow. PMID:26641038

  6. Canine mammary tumours: protective effect of late ovariectomy and stimulating effect of progestins.

    PubMed

    Misdorp, W

    1988-01-01

    Ovariectomy, even when performed at an advanced age, was found to be to some extent protective against mammary tumour development in dogs. Bitches treated with progestins had a slightly higher risk for mammary tumours (all types, benign and malignant) than controls. Progestin treatment did not increase the risk of mammary cancer. Benign tumours in (treated and untreated) dogs appeared earlier than malignant ones. Progestin treatment resulted in earlier appearance of both benign and malignant tumours than in controls. The ratio solitary/multiple mammary tumours was not significantly different between treated and untreated dogs. PMID:3376408

  7. The STAT5-regulated miR-193b locus restrains mammary stem and progenitor cell activity and alveolar differentiation.

    PubMed

    Yoo, Kyung Hyun; Kang, Keunsoo; Feuermann, Yonatan; Jang, Seung Jin; Robinson, Gertraud W; Hennighausen, Lothar

    2014-11-15

    The transcription factor STAT5 mediates prolactin signaling and controls functional development of mammary tissue during pregnancy. This study has identified the miR-193b locus, also encoding miRNAs 365-1 and 6365, as a STAT5 target in mammary epithelium. While the locus was characterized by active histone marks in mammary tissue, STAT5 binding and expression during pregnancy, it was silent in most non-mammary cells. Inactivation of the miR-193b locus in mice resulted in elevated mammary stem/progenitor cell activity as judged by limiting dilution transplantation experiments of primary mammary epithelial cells. Colonies formed by mutant cells were larger and contained more Ki-67 positive cells. Differentiation of mammary epithelium lacking the miR-193b locus was accelerated during puberty and pregnancy, which coincided with the loss of Cav3 and elevated levels of Elf5. Normal colony development was partially obtained upon ectopically expressing Cav3 or upon siRNA-mediated reduction of Elf5 in miR-193b-null primary mammary epithelial cells. This study reveals a previously unknown link between the mammary-defining transcription factor STAT5 and a microRNA cluster in controlling mammary epithelial differentiation and the activity of mammary stem and progenitor cells. PMID:25236432

  8. A novel mechanism of resistance to mouse mammary tumor virus infection.

    PubMed

    Golovkina, T V

    2000-03-01

    Exogenous mouse mammary tumor virus (MMTV) is carried from the gut of suckling pups to the mammary glands by lymphocytes and induces mammary gland tumors. MMTV-induced tumor incidence in inbred mice of different strains ranges from 0 to as high as 100%. For example, mice of the C3H/HeN strain are highly susceptible, whereas mice of the I/LnJ strain are highly resistant. Of the different factors that together determine the susceptibility of mice to development of MMTV-induced mammary tumors, genetic elements play a major role, although very few genes that determine a susceptibility-resistance phenotype have been identified so far. Our data indicate that MMTV fails to infect mammary glands in I/LnJ mice foster nursed on viremic C3H/HeN females, even though the I/LnJ mammary tissue is not refractory to MMTV infection. Lymphocytes from fostered I/LnJ mice contained integrated MMTV proviruses and shed virus but failed to establish infection in the mammary glands of susceptible syngeneic (I x C3H.JK)F(1) females. Based on the susceptible-resistant phenotype distribution in N(2) females, both MMTV mammary gland infection and mammary gland tumor development in I/LnJ mice are controlled by a single locus. PMID:10684291

  9. Comparison of mouse mammary gland imaging techniques and applications: Reflectance confocal microscopy, GFP Imaging, and ultrasound

    PubMed Central

    Tilli, Maddalena T; Parrish, Angela R; Cotarla, Ion; Jones, Laundette P; Johnson, Michael D; Furth, Priscilla A

    2008-01-01

    Background Genetically engineered mouse models of mammary gland cancer enable the in vivo study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue. Methods We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging. Results In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice. Conclusion In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary. PMID:18215290

  10. Neuropilin-2 promotes branching morphogenesis in the mouse mammary gland.

    PubMed

    Goel, Hira Lal; Bae, Donggoo; Pursell, Bryan; Gouvin, Lindsey M; Lu, Shaolei; Mercurio, Arthur M

    2011-07-01

    Although the neuropilins were characterized as semaphorin receptors that regulate axon guidance, they also function as vascular endothelial growth factor (VEGF) receptors and contribute to the development of other tissues. Here, we assessed the role of NRP2 in mouse mammary gland development based on our observation that NRP2 is expressed preferentially in the terminal end buds of developing glands. A floxed NRP2 mouse was bred with an MMTV-Cre strain to generate a mammary gland-specific knockout of NRP2. MMTV-Cre;NRP2(loxP/loxP) mice exhibited significant defects in branching morphogenesis and ductal outgrowth compared with either littermate MMTV-Cre;NRP2(+/loxP) or MMTV-Cre mice. Mechanistic insight into this morphological defect was obtained from a mouse mammary cell line in which we observed that VEGF(165), an NRP2 ligand, induces branching morphogenesis in 3D cultures and that branching is dependent upon NRP2 as shown using shRNAs and a function-blocking antibody. Epithelial cells in the mouse mammary gland express VEGF, supporting the hypothesis that this NRP2 ligand contributes to mammary gland morphogenesis. Importantly, we demonstrate that VEGF and NRP2 activate focal adhesion kinase (FAK) and promote FAK-dependent branching morphogenesis in vitro. The significance of this mechanism is substantiated by our finding that FAK activation is diminished significantly in developing MMTV-Cre;NRP2(loxP/loxP) mammary glands compared with control glands. Together, our data reveal a VEGF/NRP2/FAK signaling axis that is important for branching morphogenesis and mammary gland development. In a broader context, our data support an emerging hypothesis that directional outgrowth and branching morphogenesis in a variety of tissues are influenced by signals that were identified initially for their role in axon guidance. PMID:21693513

  11. ΔNp63 promotes stem cell activity in mammary gland development and basal-like breast cancer by enhancing Fzd7 expression and Wnt signaling

    PubMed Central

    Chakrabarti, Rumela; Wei, Yong; Hwang, Julie; Hang, Xiang; Blanco, Mario Andres; Choudhury, Abrar; Tiede, Benjamin; Romano, Rose-Anne; DeCoste, Christina; Mercatali, Laura; Ibrahim, Toni; Amadori, Dino; Kannan, Nagarajan; Eaves, Connie J; Sinha, Satrajit; Kang, Yibin

    2014-01-01

    Emerging evidence suggests that cancer is populated and maintained by tumor initiating cells (TICs) with stem-like properties similar to that of adult tissue stem cells. Despite recent advances, the molecular regulatory mechanisms that may be shared between normal and malignant stem cells remain poorly understood. Here we show that the ΔNp63 isoform of the Trp63 transcription factor promotes normal mammary stem cell (MaSC) activity by increasing the expression of the Wnt receptor Fzd7, thereby enhancing Wnt signaling. Importantly, Fzd7-dependent enhancement of Wnt signaling by ΔNp63 also governs tumor initiating activity of the basal subtype of breast cancer. These findings establish ΔNp63 as a key regulator of stem cells in both normal and malignant mammary tissues and provide direct evidence that breast cancer TICs and normal MaSCs share common regulatory mechanisms. PMID:25241036

  12. Unexpected severe consequences of Pikfyve deletion by aP2- or Aq-promoter-driven Cre expression for glucose homeostasis and mammary gland development.

    PubMed

    Ikonomov, Ognian C; Sbrissa, Diego; Delvecchio, Khortnal; A Rillema, James; Shisheva, Assia

    2016-06-01

    Systemic deficiency of PIKfyve, the evolutionarily conserved phosphoinositide kinase synthesizing cellular PtdIns5P and PtdIns(3,5)P2 and implicated in insulin signaling, causes early embryonic death in mice. In contrast, mice with muscle-specific Pikfyve disruption have normal lifespan but exhibit early-age whole-body glucose intolerance and muscle insulin resistance, thus establishing the key role of muscle PIKfyve in glucose homeostasis. Fat and muscle tissues control postprandial glucose clearance through different mechanisms, raising questions as to whether adipose Pikfyve disruption will also trigger whole-body metabolic abnormalities, and if so, what the mechanism might be. To clarify these issues, here we have characterized two new mouse models with adipose tissue disruption of Pikfyve through Cre recombinase expression driven by adipose-specific aP2- or adiponectin (Aq) promoters. Whereas both mouse lines were ostensibly normal until adulthood, their glucose homeostasis and systemic insulin sensitivity were severely dysregulated. These abnormalities stemmed in part from accelerated fat-cell lipolysis and elevated serum FFA Intriguingly, aP2-Cre-PIKfyve(fl/fl) but not Aq-Cre-PIKfyve(fl/fl) females had severely impaired pregnancy-induced mammary gland differentiation and lactogenesis, consistent with aP2-Cre-mediated Pikfyve excision in nonadipogenic tissues underlying this defect. Intriguingly, whereas mammary glands from postpartum control and Aq-Cre-PIKfyve(fl/fl) mice or ex vivo mammary gland explants showed profound upregulation of PIKfyve protein levels subsequent to prolactin receptor activation, such increases were not apparent in aP2-Cre-PIKfyve(fl/fl) females. Collectively, our data identify for the first time that adipose tissue Pikfyve plays a key role in the mechanisms regulating glucose homeostasis and that the PIKfyve pathway is critical in mammary epithelial differentiation during pregnancy and lactogenesis downstream of prolactin receptor

  13. Mammary and extramammary Paget's disease

    PubMed Central

    Lloyd, J; Flanagan, A

    2000-01-01

    Mammary and extramammary Paget's disease are uncommon intraepithelial adenocarcinomas. Both conditions have similar clinical features, which mimic inflammatory and infective diseases. Histological diagnostic confusion can arise between Paget's disease and other neoplastic conditions affecting the skin, with the most common differential diagnoses being malignant melanoma and atypical squamous disease. The glandular differentiation of both mammary Paget's disease and extramammary Paget's disease is indicated by morphological appearances, the presence of intracellular mucin in many cases, and positive immunohistochemical staining for glandular cytokeratins, epithelial membrane antigen, and carcinoembryonic antigen. This article provides an overview of mammary and extramammary Paget's disease and discusses recent evidence regarding the cell of origin. The concepts of primary and secondary Paget's disease are presented and the differential diagnosis is discussed with reference to immunohistochemical markers that might be of diagnostic value. Key Words: mammary Paget's disease • extramammary Paget's disease PMID:11064666

  14. Optimization and characterization of an in vitro bovine mammary cell culture system to study regulation of milk protein synthesis and mammary differentiation

    SciTech Connect

    Talhouk, R.S.

    1988-01-01

    A long term bovine mammary cell culture system that maintains normal mammary cell function was established and optimized to study milk protein synthesis and secretion and mammary differentiation. This culture system used bovine mammary acini isolated from developing or lactating mammary gland by enzymatic dissociation, and cryopreserved until thawed and plated for growth in vitro for these studies. Cells in M199 with lactogenic hormones {plus minus} fetal calf serum (FCS) were cultured on plastic, 100ul and 500ul type I collagen, and Matrigel, or embedded within type I collagen. Cell morphology, cell number, and total TCA-precipitable {sup 35}S-labelled proteins were monitored. Milk protein ({alpha}{sub s,1}-casein, lactoferrin (LF), {alpha}-lactalbumin, and {beta}-lactoglobulin) secretion and intracellular levels were determined by an ELISA assay.

  15. Adolescent vitamin A intake alters susceptibility to mammary carcinogenesis in the Sprague-Dawley rat.

    PubMed

    Metz, Richard P; Kaeck, Mark; Stacewicz-Sapuntzakis, Maria; Mitrenga, Terry; McCarty, Heidi; Schedin, Pepper

    2002-01-01

    We tested the hypothesis that adolescent dietary vitamin A intake impacts mammary gland development and subsequent sensitivity to carcinogenesis. Sprague-Dawley rats were fed a purified diet that was vitamin A deficient, adequate (2.2 mg retinyl palmitate/kg diet), or supranutritional (16 mg retinyl palmitate/kg diet) from 21 to 63 days of age, the period of adolescent mammary gland development. At 73 days of age, rats were given 1-methyl-1-nitrosourea (25 mg/kg body wt i.p.) and monitored for mammary tumors. Tumors appeared earlier and more frequently in rats fed vitamin A-deficient or -supplemented diets. Vitamin A deficiency during adolescence was associated with alveolar mammary gland development and precocious milk protein expression, while supplementation was associated with ductal gland development and suppression of milk protein expression. Differences in circulating estradiol and mammary gland estrogen receptor-alpha, and estrogen-responsive progesterone receptor mRNA were not observed, suggesting that the effects of vitamin A on mammary gland development and carcinogenesis are estrogen independent. Mammary expression of another hormone receptor that regulates milk protein expression, the glucocorticoid receptor, was also unaffected. These results demonstrate that vitamin A intake during adolescence alters mammary gland differentiation and indicate that a narrow range of vitamin A intake during adolescence protects against carcinogenesis. PMID:12235654

  16. The insulin-like growth factor system in normal mammary gland function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insulin-like growth factors (IGF) are now known to play an important role in normal mammary gland development and have been implicated as risk factors in the etiology of breast cancer. Studies in genetically engineered mouse models have demonstrated that the IGF system acts within the mammary epithe...

  17. Diet Does Not Affect Putative Mammary Epithelial Stem Cells in Pre-weaned Holstein Heifers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Overfeeding prepubertal heifers can impair mammary epithelial growth and development, processes that depend on stem cells. In this study we evaluated effects of diet composition on putative bovine mammary epithelial stem cell populations using a 5-bromo-2-deoxyrudine (BrdU; a thymidine analog) label...

  18. Repression of mammary adipogenesis by genistein limits mammosphere formation of human MCF-7 cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary adipose tissue may contribute to breast cancer development and progression by altering neighboring epithelial cell behavior and phenotype through paracrine signaling. Dietary exposure to soy foods is associated with lower mammary tumor risk and reduced body weight and adiposity in humans and...

  19. Insulin receptors in the mammary gland

    SciTech Connect

    Smith, D.H.

    1986-01-01

    Insulin binding studies were conducted using mammary membrane preparations to further the authors understanding of insulin's role in regulating mammary metabolism, particularly ruminant mammary metabolism. Specific objectives were to: (1) characterize insulin binding to bovine mammary microsomes and determine if the specificity and kinetics of binding indicate the presence of insulin receptors in bovine mammary gland; (2) examine and compare insulin binding by liver and mammary microsomes of the pig and dairy cow; (3) examine insulin binding to bovine milk fat globule membranes (MFGM) and evaluate this model's usefulness in assessing insulin receptor regulation in the mammary gland of the cow; (4) examine the effect of dietary fat in insulin binding by rat mammary and liver microsomes. The specificity and kinetics of /sup 125/I-insulin binding of bovine mammary microsomes indicated the presence of insulin receptors in bovine mammary gland. Bovine liver and mammary microsomes specifically bound less /sup 125/I-insulin than did the corresponding porcine microsomes, and mammary microsomes, regardless of species, specifically bound less /sup 125/I-insulin than did liver microsomes. These differences in binding suggest differences in insulin responsiveness between pigs and cattle, as well as between the liver and mammary glands.

  20. Netrin-1 Can Affect Morphogenesis and Differentiation of the Mouse Mammary Gland

    PubMed Central

    Strizzi, Luigi; Mancino, Mario; Bianco, Caterina; Raafat, Ahmed; Gonzales, Monica; Booth, Brian W.; Watanabe, Kazuhide; Nagaoka, Tadahiro; Mack, David L.; Howard, Beatrice; Callahan, Robert; Smith, Gilbert H.; Salomon, David S.

    2012-01-01

    Netrin-1 has been shown to regulate the function of the EGF-like protein Cripto-1 (Cr-1) and affect mammary gland development. Since Cr-1 is a target gene of Nanog and Oct4, we investigated the relationship between Netrin-1 and Cr-1, Nanog and Oct4 during different stages of development in the mouse mammary gland. Results from histological analysis show that exogenous Netrin-1 was able to induce formation of alveolar-like structures within the mammary gland terminal end buds of virgin transgenic Cripto-1 mice and enhance mammary gland alveologenesis in early pregnant FVB/N mice. Results from immunostaining and Western blot analysis show that Netrin-1, Nanog and Oct4 are expressed in the mouse embryonic mammary anlage epithelium while Cripto-1 is predominantly expressed outside this structure in the surrounding mesenchyme. We find that in lactating mammary glands of postnatal FVB/N mice, Netrin-1 expression is highest while Cripto-1 and Nanog levels are lowest indicating that Netrin-1 may perform a role in the mammary gland during lactation. HC-11 mouse mammary epithelial cells stimulated with lactogenic hormones and exogenous soluble Netrin-1 showed increased beta-casein expression as compared to control thus supporting the potential role for Netrin-1 during functional differentiation of mouse mammary epithelial cells. Finally, mouse ES cells treated with exogenous soluble Netrin-1 showed reduced levels of Nanog and Cripto-1 and higher levels of beta-III tubulin during differentiation. These results suggest that Netrin-1 may facilitate functional differentiation of mammary epithelial cells and possibly affect the expression of Nanog and/or Cripto-1 in multipotent cells that may reside in the mammary gland. PMID:18425773

  1. Mammary tumor suppression by transforming growth factor beta 1 transgene expression.

    PubMed Central

    Pierce, D F; Gorska, A E; Chytil, A; Meise, K S; Page, D L; Coffey, R J; Moses, H L

    1995-01-01

    In cell culture, type alpha transforming growth factor (TGF-alpha) stimulates epithelial cell growth, whereas TGF-beta 1 overrides this stimulatory effect and is growth inhibitory. Transgenic mice that overexpress TGF-alpha under control of the mouse mammary tumor virus (MMTV) promoter/enhancer exhibit mammary ductal hyperplasia and stochastic development of mammary carcinomas, a process that can be accelerated by administration of the chemical carcinogen 7,12-dimethylbenz[a]anthracene. MMTV-TGF-beta 1 transgenic mice display mammary ductal hypoplasia and do not develop mammary tumors. We report that in crossbreeding experiments involving the production of mice carrying both the MMTV-TGF-beta 1 and MMTV-TGF-alpha transgenes, there is marked suppression of mammary tumor formation and that MMTV-TGF-beta 1 transgenic mice are resistant to 7,12-dimethylbenz[a]anthracene-induced mammary tumor formation. These data demonstrate that overexpression of TGF-beta 1 in vivo can markedly suppress mammary tumor development. Images Fig. 1 Fig. 3 PMID:7753792

  2. Symposium: Role of the extracellular matrix in mammary development. Regulation of milk protein and basement membrane gene expression: The influence of the extracellular matrix

    SciTech Connect

    Aggeler, J.; Park, C.S.; Bissell, M.J.

    1988-10-01

    Synthesis and secretion of milk proteins ({alpha}-casein, {beta}-casein, {gamma}-casein, and transferrin) by cultured primary mouse mammary epithelial cells is modulated by the extracellular matrix. In cells grown on released or floating type I collagen gels, mRNA for {beta}-casein and transferrin is increased as much as 30-fold over cells grown on plastic. Induction of {beta}-casein expression depends strongly on the presence of lactogenic hormones, especially prolactin, in the culture. When cells are plated onto partially purified reconstituted basement membrane, dramatic changes in morphology and milk protein gene expression are observed. Cells cultured on the matrix for 6 to 8 d in the presence of prolactin, insulin, and hydrocortisone form hollow spheres and duct-like structures that are completely surrounded by matrix. The cells lining these spheres appear actively secretory and are oriented with their apices facing the lumen. Hybridization experiments indicate that mRNA for {beta}-casein can be increased as much as 70-fold in these cultures. Because > 90% of the cultured cells synthesize immunoreactive {beta}-casein, as compared with only 40% of cells in the late pregnant gland, the matrix appears to be able to induce protein expression in previously silent cells. Synthesis of laminin and assembly of a mammary-specific basal lamina by cells cultured on different extracellular matrices also appears to depend on the presence of lactogenic hormones. These studies provide support for the concept of dynamic reciprocity in which complex interactions between extracellular matrix and the cellular cytoskeleton contribute to the induction and maintenance of tissue-specific gene expression in the mammary gland.

  3. Tamoxifen induces pleiotrophic changes in mammary stroma resulting in extracellular matrix that suppresses transformed phenotypes

    PubMed Central

    Hattar, Rhonda; Maller, Ori; McDaniel, Shauntae; Hansen, Kirk C; Hedman, Karla J; Lyons, Traci R; Lucia, Scott; Wilson, R Storey; Schedin, Pepper

    2009-01-01

    Introduction The functional unit of the mammary gland has been defined as the epithelial cell plus its microenvironment, a hypothesis that predicts changes in epithelial cell function will be accompanied by concurrent changes in mammary stroma. To test this hypothesis, the question was addressed of whether mammary stroma is functionally altered by the anti-oestrogen drug tamoxifen. Methods Forty female rats at 70 days of age were randomised to two groups of 20 and treated with 1.0 mg/kg tamoxifen or vehicle subcutaneously daily for 30 days, followed by a three-day wash out period. Mammary tissue was harvested and effects of tamoxifen on mammary epithelium and stroma determined. Results As expected, tamoxifen suppressed mammary alveolar development and mammary epithelial cell proliferation. Primary mammary fibroblasts isolated from tamoxifen-treated rats displayed a three-fold decrease in motility and incorporated less fibronectin in their substratum in comparison to control fibroblasts; attributes indicative of fibroblast quiescence. Immunohistochemistry analysis of CD68, a macrophage lysosomal marker, demonstrated a reduction in macrophage infiltration in mammary glands of tamoxifen-treated rats. Proteomic analyses by mass spectrometry identified several extracellular matrix (ECM) proteins with expression levels with tamoxifen treatment that were validated by Western blot. Mammary tissue from tamoxifen-treated rats had decreased fibronectin and increased collagen 1 levels. Further, ECM proteolysis was reduced in tamoxifen-treated rats as detected by reductions in fibronectin, laminin 1, laminin 5 and collagen 1 cleavage fragments. Consistent with suppression in ECM proteolysis with tamoxifen treatment, matrix metalloproteinase-2 levels and activity were decreased. Biochemically extracted mammary ECM from tamoxifen-treated rats suppressed in vitro macrophage motility, which was rescued by the addition of proteolysed collagen or fibronectin. Mammary ECM from

  4. Increased expression of C5a receptor (CD88) mRNA in canine mammary tumors.

    PubMed

    Hezmee, Mohd Noor Mohd; Kyaw-Tanner, Myat; Lee, Jia Yu Peppermint; Shiels, Ian A; Rolfe, Barbara; Woodruff, Trent; Mills, Paul C

    2011-01-01

    Mammary tumors are among the most common neoplastic conditions in dogs, and there is evidence that inflammation plays a role in the development of some tumor types in dogs. The complement system is a major participant in the inflammatory process and the complement activation component, C5a, is a potent inflammatory peptide. This study investigated the mRNA expression of the major receptor for C5a (C5aR; CD88) in histopathological samples of canine mammary tumors by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) using canine-specific primers for CD88. A total of seven canine mammary tumors (four malignant carcinomas, two benign mixed mammary tumors, and one myoepithelioma) and eight normal mammary glands were analysed. All the tumor samples expressed low levels of CD88 mRNA, while none of the normal mammary tissues showed any detectable expression. These preliminary results suggest that C5a-CD88 interaction may play a contributory role in the inflammatory response associated with mammary tumor development in dogs. Further studies investigating the mechanisms behind complement activation and C5a receptor expression in canine mammary tumors are warranted. PMID:20846729

  5. Runx2 contributes to the regenerative potential of the mammary epithelium

    PubMed Central

    Ferrari, Nicola; Riggio, Alessandra I.; Mason, Susan; McDonald, Laura; King, Ayala; Higgins, Theresa; Rosewell, Ian; Neil, James C.; Smalley, Matthew J.; Sansom, Owen J.; Morris, Joanna; Cameron, Ewan R.; Blyth, Karen

    2015-01-01

    Although best known for its role in bone development and associated structures the transcription factor RUNX2 is expressed in a wide range of lineages, including those of the mammary gland. Previous studies have indicated that Runx2 can regulate aspects of mammary cell function and influence the properties of cancer cells. In this study we investigate the role of Runx2 in the mammary stem/progenitor population and its relationship with WNT signalling. Results show that RUNX2 protein is differentially expressed throughout embryonic and adult development of the murine mammary gland with high levels of expression in mammary stem-cell enriched cultures. Importantly, functional analysis reveals a role for Runx2 in mammary stem/progenitor cell function in in vitro and in vivo regenerative assays. Furthermore, RUNX2 appears to be associated with WNT signalling in the mammary epithelium and is specifically upregulated in mouse models of WNT-driven breast cancer. Overall our studies reveal a novel function for Runx2 in regulating mammary epithelial cell regenerative potential, possibly acting as a downstream target of WNT signalling. PMID:26489514

  6. T2* relaxation times of intraductal murine mammary cancer, invasive mammary cancer, and normal mammary gland

    PubMed Central

    Hipp, Elizabeth; Fan, Xiaobing; Jansen, Sanaz A.; Markiewicz, Erica J.; Vosicky, James; Newstead, Gillian M.; Conzen, Suzanne D.; Krausz, Thomas; Karczmar, Gregory S.

    2012-01-01

    Purpose: This study investigates the feasibility of T2* to be a diagnostic indicator of early breast cancer in a mouse model. T2* is sensitive to susceptibility effects due to local inhomogeneity of the magnetic field, e.g., caused by hemosiderin or deoxyhemoglobin. In these mouse models, unlike in patients, the characteristics of single mammary ducts containing pure intraductal cancer can be evaluated. Methods: The C3(1)SV40Tag mouse model of breast cancer (n = 11) and normal FVB/N mice (n = 6) were used to measure T2* of normal mammary gland tissue, intraepithelial neoplasia, invasive cancers, mammary lymph nodes, and muscle. MRI experiments were performed on a 9.4T animal scanner. High resolution (117 microns) axial 2D multislice gradient echo images with fat suppression were acquired first to identify inguinal mammary gland. Then a multislice multigradient echo pulse sequence with and without fat suppression were performed over the inguinal mammary gland. The modulus of a complex double exponential decay detected by the multigradient echo sequence was used to fit the absolute proton free induction decay averaged over a region of interest to determine the T2* of water and fat signals. Results: The measured T2* values of tumor and muscle are similar (∼15 ms), and almost twice that of lymph nodes (∼8 ms). There was a statistically significant difference (p < 0.03) between T2* in normal mammary tissue (13.7 ± 2.9 ms) and intraductal cancers (11 ± 2.0 ms) when a fat suppression pulse was applied. Conclusions: These are the first reported T2* measurements from single mammary ducts. The results demonstrated that T2* measurements may have utility for identifying early pre-invasive cancers in mouse models. This may inspire similar research for patients using T2* for diagnostic imaging of early breast cancer. PMID:22380363

  7. Isolation of Endoplasmic Reticulum Fractions from Mammary Epithelial Tissue.

    PubMed

    Chanat, Eric; Le Parc, Annabelle; Lahouassa, Hichem; Badaoui, Bouabid

    2016-06-01

    In the mammary glands of lactating animals, the mammary epithelial cells that surround the lumen of the acini produce and secrete copious amounts of milk. Functional differentiation of these mammary epithelial cells depends on the development of high-efficiency secretory pathways, notably for protein and lipid secretion. Protein secretion is a fundamental process common to all animal cells that involves a subset of cellular organelles, including the endoplasmic reticulum and the Golgi apparatus. In contrast, en masse secretion of triglycerides and cholesterol esters in the form of milk fat globules is a unique feature of the mammary epithelial cell. Cytoplasmic lipid droplets, the intracellular precursors of milk fat globules, originate from the endoplasmic reticulum, as do most milk-specific proteins. This organelle is therefore pivotal in the biogenesis of milk components. Fractionation of the cell into its subcellular parts is an approach that has proven very powerful for understanding organelle function and for studying the specific role of an organelle in a given cell activity. Here we describe a method for the purification of both smooth and rough microsomes, the membrane-bound endoplasmic reticulum fragments that form from endoplasmic reticulum domains when cells are broken up, from mammary gland tissue at lactation. PMID:27048289

  8. CRIPTO/GRP78 signaling maintains fetal and adult mammary stem cells ex vivo.

    PubMed

    Spike, Benjamin T; Kelber, Jonathan A; Booker, Evan; Kalathur, Madhuri; Rodewald, Rose; Lipianskaya, Julia; La, Justin; He, Marielle; Wright, Tracy; Klemke, Richard; Wahl, Geoffrey M; Gray, Peter C

    2014-04-01

    Little is known about the extracellular signaling factors that govern mammary stem cell behavior. Here, we identify CRIPTO and its cell-surface receptor GRP78 as regulators of stem cell behavior in isolated fetal and adult mammary epithelial cells. We develop a CRIPTO antagonist that promotes differentiation and reduces self-renewal of mammary stem cell-enriched populations cultured ex vivo. By contrast, CRIPTO treatment maintains the stem cell phenotype in these cultures and yields colonies with enhanced mammary gland reconstitution capacity. Surface expression of GRP78 marks CRIPTO-responsive, stem cell-enriched fetal and adult mammary epithelial cells, and deletion of GRP78 from adult mammary epithelial cells blocks their mammary gland reconstitution potential. Together, these findings identify the CRIPTO/GRP78 pathway as a developmentally conserved regulator of fetal and adult mammary stem cell behavior ex vivo, with implications for the stem-like cells found in many cancers. PMID:24749068

  9. Activation of Mammalian target of rapamycin in canine mammary carcinomas: an immunohistochemical study.

    PubMed

    Delgado, L; Gärtner, F; Dias Pereira, P

    2015-01-01

    Mammalian target of rapamycin (mTOR) is a serine-threonine kinase involved in cell growth, proliferation and survival. Activation of mTOR has been reported in various tumour types, including human breast cancer; however, the expression of mTOR in canine mammary tumours has not been examined. In the present study, expression of the activated form of mTOR (phospho-mTOR [p-mTOR]) was examined immunohistochemically in five normal canine mammary glands, 45 canine mammary carcinomas and their corresponding metastatic lesions (n = 15). Phospho-mTOR was not expressed in normal canine mammary tissue, but cytoplasmic labelling was observed in 78% of canine mammary carcinomas. Two carcinomas had both cytoplasmic and nuclear labelling. No significant relationship was found between p-mTOR cytoplasmic expression and histological type or grading of carcinomas, degree of tubular formation, anisokaryosis, mitotic activity or lymph node metastasis. In all except one case, the expression pattern of p-mTOR in lymph node metastases was similar or decreased when compared with the primary lesion. The findings suggest that p-mTOR is involved in mammary carcinogenesis in dogs. However, p-mTOR cytoplasmic expression does not appear to be a prognostic indicator in canine mammary carcinomas, which may be related to its subcellular location in the neoplastic cells. Canine mammary tumours may provide a model for the development of innovative medical strategies involving mTOR inhibitors in human breast cancer. PMID:25670666

  10. Xenobiotic-metabolizing enzymes in canine mammary tumours.

    PubMed

    Kumaraguruparan, R; Subapriya, R; Balachandran, C; Manohar, B Murali; Thangadurai, A; Nagini, S

    2006-09-01

    Mammary tumours are the most common neoplasms in female dogs. The present study was designed to evaluate the relationship between different clinical stages with activities of phase I and phase II carcinogen-metabolizing enzymes in canine mammary tumours. The levels of cytochrome P450 and cytochrome b5 and the activities of glutathione S-transferase (GST), gamma-glutamyl transpeptidase (GGT), DT-diaphorase (DTD) and NADPH diaphorase in tumour tissues of 25 bitches was estimated. Enhanced levels of cytochrome P450 and b5 and phase II enzyme activities were observed in tumour tissues compared to the corresponding uninvolved adjacent tissues. The magnitude of the changes in phase I and phase II enzyme status was, however, more pronounced in stages I and II compared to stages III and IV. The results suggest that the balance between phase I carcinogen activation and phase II detoxification systems may play an important role in canine mammary tumour development. PMID:16014333

  11. [Hormones and mammary tumors in the bitch: a review].

    PubMed

    Rutteman, G R

    1992-02-01

    Toxicity studies as well as epidemiological studies in veterinary medicine have shown that both ovarian steroids and a large number of synthetic derivatives may promote the formation of mammary tumours in dogs. Abnormalities in pituitary function, particularly in the secretion of growth hormones, have been assumed to be involved in this process. In the present paper the possible role of endogenous and exogenous hormones in the pathogenesis of mammary tumours in bitches is reviewed. The available evidence suggests that steroid hormones may act at an early stage in the development of tumours by stimulating the proliferation of normal epithelium. This results in an increase in the number of susceptible cells. In addition a growth-stimulating action may be exerted upon cells which have undergone partial malignant transformation, but possibly to a lesser extent upon fully malignant cells at a late stage of tumour development. In advanced mammary cancers steroid receptors are frequently absent, which may indicate a more autonomous pattern of growth. It seems justified to conclude that in clinical practice ovariectomy at an early age as a measure to prevent oestrus is to be preferred to progestin treatment with regard to the risk of mammary carcinoma. Still, there is no indication that in dogs, ovariectomy will reduce the risk of metastasis once the animal is presented with a mammary carcinoma. The earlier assumption that overproduction of growth hormone is an important factor in the pathogenesis of spontaneous mammary tumours in the dogs could not be proven. The role of prolactin and of thyroid hormones in this process continues to be uncertain. PMID:1736405

  12. Phenotypic and Molecular Alterations in the Mammary Tissue of R-Spondin1 Knock-Out Mice during Pregnancy.

    PubMed

    Chadi, Sead; Polyte, Jacqueline; Lefevre, Lucas; Castille, Johan; Ehanno, Aude; Laubier, Johann; Jaffrézic, Florence; Le Provost, Fabienne

    2016-01-01

    R-spondin1 (Rspo1) is a member of a secreted protein family which has pleiotropic functions in development and stem cell growth. Rspo1 knock-out mice are sex-reversed, but some remain sub-fertile, so they fail to nurse their pups. A lack of Rspo1 expression in the mammary gland results in an absence of duct side-branching development and defective alveolar formation. The aim of this study was to characterize the phenotypic and molecular alterations of mammary gland due to Rspo1 knock-out. Using the transcriptional profiling of mammary tissues, we identified misregulated genes in the mammary gland of Rspo1 knock-out mice during pregnancy. A stronger expression of mesenchymal markers was observed, without modifications to the structure of mammary epithelial tissue. Mammary epithelial cell immunohistochemical analysis revealed a persistence of virgin markers, which signify a delay in cell differentiation. Moreover, serial transplantation experiments showed that Rspo1 is associated with a regenerative potential of mammary epithelial cell control. Our finding also highlights the negatively regulated expression of Rspo1's partners, Lgr4 and RNF43, in the mammary gland during pregnancy. Moreover, we offer evidence that Tgf-β signalling is modified in the absence of Rspo1. Taken together, our results show an abrupt halt or delay to mammary development during pregnancy due to the loss of a further differentiated function. PMID:27611670

  13. Evidence for a nonprolactin, non-growth-hormone mammary mitogen in the human pituitary gland.

    PubMed Central

    Newman, C B; Cosby, H; Friesen, H G; Feldman, M; Cooper, P; De Crescito, V; Pilon, M; Kleinberg, D L

    1987-01-01

    To determine whether the human pituitary contains a previously unidentified, nonprolactin (non-hPRL), non-growth-hormone (non-hGH) factor capable of stimulating mammary development, we tested the effects of whole human pituitary extract (hPE) and pituitary extracts depleted of hPRL and hGH ("stripped hPE") in hypophysectomized, castrated estradiol (E2)-treated male rats and rhesus monkeys. Both whole and stripped hPE significantly stimulated rat mammary development (mean scores = 3.3 and 2.0, respectively, on a scale ranging from 0 to 4) in comparison with controls (mean score = 1.0). Mammary development was not due to minute concentrations of hGH or hPRL remaining in stripped hPE because 30- to 100-fold higher concentrations of hGH (Genentech) and 1000-fold higher concentrations of hPRL were required to stimulate significant mammary development. Non-pituitary extracts of human ovary, muscle, and serum, and bovine serum albumin did not stimulate rat mammary gland growth. Trypsin destroyed the mammary mitogenic activity of whole hPE, indicating that the unidentified factor is likely a protein. Mammary growth and development were also stimulated in hypophysectomized, E2-treated monkeys by stripped hPE (mean histological score = 3.25 vs. 1.35 in control animals). Monkeys receiving stripped hPE had undetectable levels of hGH and hPRL in serum sampled over a 24-hr period. These findings suggest that the human pituitary contains a non-hPRL, non-hGH factor that stimulates mammary growth and may be important in normal mammary growth and development and perhaps in breast cancer. Images PMID:3479780

  14. Charles River Sprague Dawley Rats Lack Early Age-Dependent Susceptibility to DMBA-Induced Mammary Carcinogenesis

    PubMed Central

    Gear, R.B.; Yan, M.; Schneider, J.; Succop, P.; Heffelfinger, S.C.; Clegg, D.J.

    2007-01-01

    Developmental stages of mammary glands influence their susceptibility to initiating events related to carcinogenesis. The “window of susceptibility” to mammary carcinogenesis is classically defined as the time in early puberty when the mammary gland morphology is most sensitive to initiation events. Administration of the polyaromatic hydrocarbon, 7,12-dimethylbenz(a)anthracene (DMBA), in a single oral dose yields maximal mammary tumor formation when administered in this “window”. We examined the DMBA treated mammary glands, precursor lesions, and morphology of the uninvolved mammary epithelium for the first 100 days of life for Charles River Sprague Dawley CDR IGS. Our goal was to determine the DMBA dose at which 50% of the rats (IC50) developed carcinoma in situ (CIS) within three months of dosing. Here we demonstrate, rather than the classical U-shaped dose curve in which there is maximum sensitivity for DMBA at 50 days, there is an increasing degree of sensitivity with age in the CDR IGS rat. Additionally, we report that vehicle-treated animals developed mammary CIS without any known initiator, and 100 day virgin animals demonstrated lactational changes, independent of DMBA exposure or dose. Lastly, we demonstrate this strain of virgin female rats has elevated pituitary prolactin immunoreactivity independent of the level of mammary differentiation. We conclude this strain of Charles River Sprague Dawley rats has prolactin-induced pituitary stimulation, and therefore, the window of susceptibility for mammary tumorigenesis is absent. PMID:17940635

  15. Progesterone facilitates chromosome instability (aneuploidy) in p53 null normal mammary epithelial cells

    NASA Technical Reports Server (NTRS)

    Goepfert, T. M.; McCarthy, M.; Kittrell, F. S.; Stephens, C.; Ullrich, R. L.; Brinkley, B. R.; Medina, D.

    2000-01-01

    Mammary epithelial cells from p53 null mice have been shown recently to exhibit an increased risk for tumor development. Hormonal stimulation markedly increased tumor development in p53 null mammary cells. Here we demonstrate that mammary tumors arising in p53 null mammary cells are highly aneuploid, with greater than 70% of the tumor cells containing altered chromosome number and a mean chromosome number of 56. Normal mammary cells of p53 null genotype and aged less than 14 wk do not exhibit aneuploidy in primary cell culture. Significantly, the hormone progesterone, but not estrogen, increases the incidence of aneuploidy in morphologically normal p53 null mammary epithelial cells. Such cells exhibited 40% aneuploidy and a mean chromosome number of 54. The increase in aneuploidy measured in p53 null tumor cells or hormonally stimulated normal p53 null cells was not accompanied by centrosome amplification. These results suggest that normal levels of progesterone can facilitate chromosomal instability in the absence of the tumor suppressor gene, p53. The results support the emerging hypothesis based both on human epidemiological and animal model studies that progesterone markedly enhances mammary tumorigenesis.

  16. Three-Dimensional Cultures of Mouse Mammary Epithelial Cells

    PubMed Central

    Mroue, Rana; Bissell, Mina J.

    2013-01-01

    The mammary gland is an ideal “model organism” for studying tissue specificity and gene expression in mammals: it is one of the few organs that develop after birth and it undergoes multiple cycles of growth, differentiation and regression during the animal’s lifetime in preparation for the important function of lactation. The basic “functional differentiation” unit in the gland is the mammary acinus made up of a layer of polarized epithelial cells specialized for milk production surrounded by myoepithelial contractile cells, and the two-layered structure is surrounded by basement membrane. Much knowledge about the regulation of mammary gland development has been acquired from studying the physiology of the gland and of lactation in rodents. Culture studies, however, were hampered by the inability to maintain functional differentiation on conventional tissue culture plastic. We now know that the microenvironment, including the extracellular matrix and tissue architecture, plays a crucial role in directing functional differentiation of organs. Thus, in order for culture systems to be effective experimental models, they need to recapitulate the basic unit of differentiated function in the tissue or organ and to maintain its three-dimensional (3D) structure. Mouse mammary culture models evolved from basic monolayers of cells to an array of complex 3D systems that observe the importance of the microenvironment in dictating proper tissue function and structure. In this chapter, we focus on how 3D mouse mammary epithelial cultures have enabled investigators to gain a better understanding of the organization, development and function of the acinus, and to identify key molecular, structural, and mechanical cues important for maintaining mammary function and architecture. The accompanying chapter of Vidi et al. describes 3D models developed for human cells. Here, we describe how mouse primary epithelial cells and cell lines—essentially those we use in our

  17. Surface scanning: an application to mammary surgery

    NASA Astrophysics Data System (ADS)

    Rigotti, Camilla; Ferrigno, Giancarlo; Aliverti, Andrea; Pedotti, Antonio

    1998-04-01

    The possibility of mathematically describing the body surface represents a useful tool for several medical sectors, such as prosthetics or plastic surgery, and could improve diagnosis and objective evaluation of deformities and the follow-up of progressive diseases. The approach presented is based on the acquisition of a surface scanned by a laser beam. The 3D coordinates of the spot generated on the surface by the laser beam are computed by an automatic image analyzer. Using at least two different views of the subject, the 3D coordinates are obtained by stereophotogrammetry. A software package for graphic representation and extraction of linear superficial and volumetric features from the acquired surface has been developed and some preliminary results with mammary reconstruction are presented. A good mammary reconstruction after mastectomy must achieve two results. First, the reconstruction should follow the patients' wishes and second, the reconstructed breast should be as similar as possible to the contralateral one. To achieve these goals, a knowledge of breast volume, area, and shape features are essential for the surgeon. In such a context, this system could be a valuable tool in improving breast reconstructive surgery.

  18. Scintillation Studies of the Mouse Mammary Tumor Virus with ^125I

    NASA Astrophysics Data System (ADS)

    Yazdi, Amir; Blue, Eric; Bradley, Eric; Majewski, Stan; Mohammed, Shira; Qian, Jianguo; Saha, Margaret; Schworer, Stephen; Sutton, Jonathan; Weisenberger, Andrew; Welsh, Robert

    2007-10-01

    We have applied the techniques of scintillation imaging to studies of the mouse mammary tumor virus (MMTV). In these studies, Sodium Iodide Symporter (NIS) transfers the radioactive ^125I to the mammary glands of lactating mice and in particular to those mammaries with visible tumors. These studies have principally been carried out using pixellated scintillators coupled to position sensitive photomultiplier tubes (PSPMTs). More recently, we have initiated such studies with a monolithic slab of LaBr3 scintillator coupled to an array of PSPMTs. Several techniques of mapping and measuring the development of such tumors have been employed. These will be discussed in detail and preliminary results will be reported.

  19. Enrichment for Repopulating Cells and Identification of Differentiation Markers in the Bovine Mammary Gland.

    PubMed

    Rauner, Gat; Barash, Itamar

    2016-06-01

    Elucidating cell hierarchy in the mammary gland is fundamental for understanding the mechanisms governing its normal development and malignant transformation. There is relatively little information on cell hierarchy in the bovine mammary gland, despite its agricultural potential and relevance to breast cancer research. Challenges in bovine-to-mouse xenotransplantation and difficulties obtaining bovine-compatible antibodies hinder the study of mammary stem-cell dynamics in this species. In-vitro indications of distinct bovine mammary epithelial cell populations, sorted according to CD24 and CD49f expression, have been provided. Here, we successfully transplanted these bovine populations into the cleared fat pads of immunocompromised mice, providing in-vivo evidence for the multipotency and self-renewal capabilities of cells that are at the top of the cell hierarchy (termed mammary repopulating units). Additional outgrowths from transplantation, composed exclusively of myoepithelial cells, were indicative of unipotent basal stem cells or committed progenitors. Sorting luminal cells according to E-cadherin revealed three distinct populations: luminal progenitors, and early- and late-differentiating cells. Finally, miR-200c expression was negatively correlated with differentiation levels in both the luminal and basal branches of the bovine mammary cell hierarchy. Together, these experiments provide further evidence for the presence of a regenerative entity in the bovine mammary gland and for the multistage differentiation process within the luminal lineage. PMID:26615610

  20. Lgr5-expressing cells are sufficient and necessary for postnatal mammary gland organogenesis.

    PubMed

    Plaks, Vicki; Brenot, Audrey; Lawson, Devon A; Linnemann, Jelena R; Van Kappel, Eline C; Wong, Karren C; de Sauvage, Frederic; Klein, Ophir D; Werb, Zena

    2013-01-31

    Mammary epithelial stem cells are vital to tissue expansion and remodeling during various phases of postnatal mammary development. Basal mammary epithelial cells are enriched in Wnt-responsive cells and can reconstitute cleared mammary fat pads upon transplantation into mice. Lgr5 is a Wnt-regulated target gene and was identified as a major stem cell marker in the small intestine, colon, stomach, and hair follicle, as well as in kidney nephrons. Here, we demonstrate the outstanding regenerative potential of a rare population of Lgr5-expressing (Lgr5(+)) mammary epithelial cells (MECs). We found that Lgr5(+) cells reside within the basal population, are superior to other basal cells in regenerating functional mammary glands (MGs), are exceptionally efficient in reconstituting MGs from single cells, and exhibit regenerative capacity in serial transplantations. Loss-of-function and depletion experiments of Lgr5(+) cells from transplanted MECs or from pubertal MGs revealed that these cells are not only sufficient but also necessary for postnatal mammary organogenesis. PMID:23352663

  1. Histone Demethylase KDM6A Controls the Mammary Luminal Lineage through Enzyme-Independent Mechanisms.

    PubMed

    Yoo, Kyung Hyun; Oh, Sumin; Kang, Keunsoo; Wang, Chaochen; Robinson, Gertraud W; Ge, Kai; Hennighausen, Lothar

    2016-08-15

    Establishment of the mammary luminal cell lineage is controlled primarily by hormones and through specific transcription factors (TFs). Previous studies have linked histone methyltransferases to the differentiation of mammary epithelium, thus opening the possibility of biological significance of counteracting demethylases. We have now demonstrated an essential role for the H3K27me3 demethylase KDM6A in generating a balanced alveolar compartment. Deletion of Kdm6a in the mammary luminal cell lineage led to a paucity of luminal cells and an excessive expansion of basal cells, both in vivo and in vitro The inability to form structurally normal ducts and alveoli during pregnancy resulted in lactation failure. Mutant luminal cells did not exhibit their distinctive transcription factor pattern and displayed basal characteristics. The genomic H3K27me3 landscape was unaltered in mutant tissue, and support for a demethylase-independent mechanism came from mice expressing a catalytically inactive KDM6A. Mammary tissue developed normally in these mice. Chromatin immunoprecipitation sequencing (ChIP-seq) experiments demonstrated KDM6A binding to putative enhancers enriched for key mammary TFs and H3K27ac. This study demonstrated for the first time that the mammary luminal lineage relies on KDM6A to ensure a transcription program leading to differentiated alveoli. Failure to fully implement this program results in structurally and functionally impaired mammary tissue. PMID:27215382

  2. Value of Mammary Thermography in Differential Diagnosis

    PubMed Central

    Nathan, B. E.; Burn, J. Ian; MacErlean, D. P.

    1972-01-01

    Thermographic examinations of the breasts were carried out in 359 women, most of whom had mammary symptoms. Of the 195 patients with abnormal thermograms, 27 had cancer of the breast, 53 had benign lesions, and 115 had no confirmed organic disease. The incidence of false-positive thermograms was 59%. Of the 164 patients with normal thermograms, 116 had no confirmed organic disease, 41 had benign lesions, and 7 had cancer. The incidence of false-negative mammary thermograms was 29%. We conclude that mammary thermography is of no practical value in the differential diagnosis of symptomatic mammary disease. PMID:5022040

  3. Canine mammary tumours, an overview.

    PubMed

    Sleeckx, N; de Rooster, H; Veldhuis Kroeze, E J B; Van Ginneken, C; Van Brantegem, L

    2011-12-01

    Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Although the prevalence of these tumours decreases in regions where preventive ovari(ohyster)ectomy is performed, it remains an important disease entity in veterinary medicine. Moreover, treatment options are limited in comparison with human breast cancer. Nevertheless, recent human treatment protocols might have potential in bitches suffering from CMTs. PMID:21645126

  4. Mammary neoplasms of the bitch.

    PubMed

    Cotchin, E

    1958-01-01

    In this paper, the interrelationships of the neoplasms of the canine mammary gland are investigated. These neoplasms are a group of tumors of a great variety of histological structure and sometimes of uncertain histogenesis. Particular attention is given to the histogenesis of the mucoid, cartilaginous, and bony elements. From 1950-56, a macroscopic and histological examination of mammary neoplasms from 424 bitches (2-17 years of age) was made. The tumors from 381 bitches were removed surgically while the others came from 43 bitches who were examined postmortem. Of the 160 tumors whose location was recorded, 105 occurred in the 2 hinder glands, 19 in the middle glands, and 46 in one or another of the 2 anterior glands. 186 of the 424 bitches bore malignant mammary tumors (87 carcinomas, 73 sarcomas, 27 complex malignant tumors) and 249 had benign tumors (19 simple and 230 complex). 40 of the benign complex tumors contained bone, an additional 63 contained cartilage but no bone, and 67 showed mucoid tissue but no cartilage or bone. It is suggested that there is a predominant proliferation of myoepithelial cells which tend to become embedded in a mucoid or chondroid matrix. The bone in the tumors appears to be formed by endochondral ossification of preformed cartilage, or by intramembranous ossification in the connective tissue of the tumor. Metastases were present in 41 of the 424 bitches. PMID:12311486

  5. The Type 7 Serotonin Receptor, 5-HT7, Is Essential in the Mammary Gland for Regulation of Mammary Epithelial Structure and Function

    PubMed Central

    Pai, Vaibhav P.; Hernandez, Laura L.; Stull, Malinda A.; Horseman, Nelson D.

    2015-01-01

    Autocrine-paracrine activity of serotonin (5-hydroxytryptamine, 5-HT) is a crucial homeostatic parameter in mammary gland development during lactation and involution. Published studies suggested that the 5-HT7 receptor type was important for mediating several effects of 5-HT in the mammary epithelium. Here, using 5-HT7 receptor-null (HT7KO) mice we attempt to understand the role of this receptor in mediating 5-HT actions within the mammary gland. We demonstrate for the first time that HT7KO dams are inefficient at sustaining their pups. Histologically, the HT7KO mammary epithelium shows a significant deviation from the normal secretory epithelium in morphological architecture, reduced secretory vesicles, and numerous multinucleated epithelial cells with atypically displaced nuclei, during lactation. Mammary epithelial cells in HT7KO dams also display an inability to transition from lactation to involution as normally seen by transition from a columnar to a squamous cell configuration, along with alveolar cell apoptosis and cell shedding. Our results show that 5-HT7 is required for multiple actions of 5-HT in the mammary glands including core functions that contribute to changes in cell shape and cell turnover, as well as specialized secretory functions. Understanding these actions may provide new interventions to improve lactation performance and treat diseases such as mastitis and breast cancer. PMID:25664318

  6. Estrogens in the wrong place at the wrong time: fetal BPA exposure and mammary cancer

    PubMed Central

    Paulose, Tessie; Speroni, Lucia; Sonnenschein, Carlos; Soto, Ana M

    2014-01-01

    Iatrogenic gestational exposure to diethylstilbestrol (DES) induced alterations of the genital tract and predisposed individuals to develop clear cell carcinoma of the vagina as well as breast cancer later in life. Gestational exposure of rodents to a related compound, the xenoestrogen bisphenol-A (BPA) increases the propensity to develop mammary cancer during adulthood, long after cessation of exposure. Exposure to BPA during gestation induces morphological alterations in both the stroma and the epithelium of the fetal mammary gland at 18 days of age. We postulate that the primary target of BPA is the fetal stroma, the only mammary tissue expressing estrogen receptors during fetal life. BPA would then alter the reciprocal stroma-epithelial interactions that mediate mammogenesis. In addition to this direct effect on the mammary gland, BPA is postulated to affect the hypothalamus and thus in turn affect the regulation of mammotropic hormones at puberty and beyond. PMID:25277313

  7. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    NASA Technical Reports Server (NTRS)

    Huso, David L.

    1999-01-01

    Radiations encountered in space include protons and heavy ions such as iron as well as their secondaries. The relative biological effect (RBE) of these ions is not known, particularly at the doses and dose-rates expected for planetary missions. Neutrons, are not particularly relevant to space travel, but have been found experimentally to have an increase in their RBE with decreasing dose. If a similar trend of increasing RBE with decreasing dose is present for heavy ions and protons during irradiation in space, the small doses received during space travel could potentially have substantial carcinogenic risk. Clearly more investigation of the effects of heavy ions and protons is needed before accurate risk assessment for prolonged travel in space can be done. One means to mitigate the increased risk of cancer due to radiation exposure in space is by developing effective countermeasures that can reduce the incidence of tumor development. Tamoxifen has recently been shown to be an effective chemopreventive agent in both animal models and humans for the prevention of mammary tumors. Tamoxifen is a unique drug, with a highly specific mechanism of action affecting a specific radiation-sensitive population of epithelial cells in the mammary gland. In human studies, the annual incidence of a primary tumor in the contralateral breast of women with previous breast cancer is about 8 per 1000, making them an exceedingly high-risk group for the development of breast cancer. In this high risk group, treated with tamoxifen, daily, for 2 years, the incidence of a new primary tumor in the contralateral breast was approximately one third of that noted in the non-tamoxifen treatment group. Tamoxifen antagonizes the action of estrogen by competing for the nuclear receptor complex thereby altering the association of the receptor complex and nuclear binding sites. Its effects in reducing the development of breast cancer could be accomplished by controlling clinically undetectable

  8. Comparative expression pathway analysis of human and canine mammary tumors

    PubMed Central

    Uva, Paolo; Aurisicchio, Luigi; Watters, James; Loboda, Andrey; Kulkarni, Amit; Castle, John; Palombo, Fabio; Viti, Valentina; Mesiti, Giuseppe; Zappulli, Valentina; Marconato, Laura; Abramo, Francesca; Ciliberto, Gennaro; Lahm, Armin; La Monica, Nicola; de Rinaldis, Emanuele

    2009-01-01

    Background Spontaneous tumors in dog have been demonstrated to share many features with their human counterparts, including relevant molecular targets, histological appearance, genetics, biological behavior and response to conventional treatments. Mammary tumors in dog therefore provide an attractive alternative to more classical mouse models, such as transgenics or xenografts, where the tumour is artificially induced. To assess the extent to which dog tumors represent clinically significant human phenotypes, we performed the first genome-wide comparative analysis of transcriptional changes occurring in mammary tumors of the two species, with particular focus on the molecular pathways involved. Results We analyzed human and dog gene expression data derived from both tumor and normal mammary samples. By analyzing the expression levels of about ten thousand dog/human orthologous genes we observed a significant overlap of genes deregulated in the mammary tumor samples, as compared to their normal counterparts. Pathway analysis of gene expression data revealed a great degree of similarity in the perturbation of many cancer-related pathways, including the 'PI3K/AKT', 'KRAS', 'PTEN', 'WNT-beta catenin' and 'MAPK cascade'. Moreover, we show that the transcriptional relationships between different gene signatures observed in human breast cancer are largely maintained in the canine model, suggesting a close interspecies similarity in the network of cancer signalling circuitries. Conclusion Our data confirm and further strengthen the value of the canine mammary cancer model and open up new perspectives for the evaluation of novel cancer therapeutics and the development of prognostic and diagnostic biomarkers to be used in clinical studies. PMID:19327144

  9. ATG proteins mediate efferocytosis and suppress inflammation in mammary involution

    PubMed Central

    Teplova, Irina; Lozy, Fred; Price, Sandy; Singh, Sukhwinder; Barnard, Nicola; Cardiff, Robert D.; Birge, Raymond B.; Karantza, Vassiliki

    2013-01-01

    Involution is the process of post-lactational mammary gland regression to quiescence and it involves secretory epithelial cell death, stroma remodeling and gland repopulation by adipocytes. Though reportedly accompanying apoptosis, the role of autophagy in involution has not yet been determined. We now report that autophagy-related (ATG) proteins mediate dead cell clearance and suppress inflammation during mammary involution. In vivo, Becn1+/− and Atg7-deficient mammary epithelial cells (MECs) produced ‘competent’ apoptotic bodies, but were defective phagocytes in association with reduced expression of the MERTK and ITGB5 receptors, thus pointing to defective apoptotic body engulfment. Atg-deficient tissues exhibited higher levels of involution-associated inflammation, which could be indicative of a tumor-modulating microenvironment, and developed ductal ectasia, a manifestation of deregulated post-involution gland remodeling. In vitro, ATG (BECN1 or ATG7) knockdown compromised MEC-mediated apoptotic body clearance in association with decreased RAC1 activation, thus confirming that, in addition to the defective phagocytic processing reported by other studies, ATG protein defects also impair dead cell engulfment.   Using two different mouse models with mammary gland-associated Atg deficiencies, our studies shed light on the essential role of ATG proteins in MEC-mediated efferocytosis during mammary involution and provide novel insights into this important developmental process. This work also raises the possibility that a regulatory feedback loop exists, by which the efficacy of phagocytic cargo processing in turn regulates the rate of engulfment and ultimately determines the kinetics of phagocytosis and dead cell clearance. PMID:23380905

  10. Null mutation of peroxisome proliferator-activated receptor-interacting protein in mammary glands causes defective mammopoiesis.

    PubMed

    Qi, Chao; Kashireddy, Papreddy; Zhu, Yiwei Tony; Rao, Sambasiva M; Zhu, Yi-Jun

    2004-08-01

    To investigate the role of nuclear receptor coactivator peroxisome proliferator-activated receptor-interacting protein (PRIP) in mammary gland development, we generated a conditional null mutation of PRIP in mammary glands. In PRIP-deficient mammary glands, the elongation of ducts during puberty was not affected, but the numbers of ductal branches were decreased, a condition that persisted long after puberty, indicating that the potential of ductal branching was impaired. During pregnancy, PRIP-deficient mammary glands exhibited decreased alveolar density. The lactating PRIP-deficient glands contained scant lobuloalveoli with many adipocytes, whereas the wild type glands were composed of virtually no adipocytes but mostly lobuloalveoli. As a result, PRIP mammary-deficient glands could not produce enough milk to nurse all the pups during lactation. The ductal branching of mammary glands in response to estrogen treatment was attenuated in PRIP mutant glands. Whereas the proliferation index was similar between wild type and PRIP-deficient glands, increased apoptosis was observed in PRIP-deficient glands. PRIP-deficient glands expressed increased amphiregulin, transforming growth factor-alpha, and betacellulin mRNA as compared with wild type glands. The differentiated function of PRIP-deficient mammary epithelial cells was largely intact, as evidenced by the expression of abundant beta-casein, whey acidic protein (WAP), and WDNM1 mRNA. We conclude that PRIP is important for normal mammary gland development. PMID:15161927

  11. Scribble is required for pregnancy-induced alveologenesis in the adult mammary gland.

    PubMed

    Baker, Leena; BeGora, Michael; Au Yeung, Faith; Feigin, Michael E; Rosenberg, Avi Z; Lowe, Scott W; Kislinger, Thomas; Muthuswamy, Senthil K

    2016-06-15

    The cell polarity protein scribble (SCRIB) is a crucial regulator of polarization, cell migration and tumorigenesis. Whereas SCRIB is known to regulate early stages of mouse mammary gland development, its function in the adult gland is not known. Using an inducible RNA interference (RNAi) mouse model for downregulating SCRIB expression, we report an unexpected role for SCRIB as a positive regulator of cell proliferation during pregnancy-associated mammary alveologenesis. SCRIB was required in the epithelial cell compartment of the mammary gland. Lack of SCRIB attenuated prolactin-induced activation of the JAK2-STAT5 signaling pathway. In addition, loss of SCRIB resulted in the downregulation of prolactin receptor (PRLR) at cell surface and its accumulation in intracellular structures that express markers of the Golgi complex and the recycling endosome. Unlike its role in virgin gland as a negative regulator cell proliferation, SCRIB is a positive regulator of mammary epithelial cell proliferation during pregnancy. PMID:27179074

  12. Mammary tumors induce select cognitive impairments.

    PubMed

    Pyter, Leah M; Cochrane, Sally F; Ouwenga, Rebecca L; Patel, Priyesh N; Pineros, Vanessa; Prendergast, Brian J

    2010-08-01

    Cancer, in addition to many other chronic diseases, is associated with serious and problematic behavioral symptoms, including cognitive impairments. In humans, various factors likely contribute to cancer-associated cognitive deficits including disease awareness and chemotherapy; however, the endogenous biological factors arising from tumor development may also play a causal role. In the present study, rats with mammary tumors exhibited impaired spatial reference memory on a radial arm maze and amnesia for familiar objects in an object recognition memory test. In contrast, their performance in the Morris water maze and in fear conditioning tests was comparable to that of controls. These select cognitive impairments were accompanied by elevations in hippocampal interleukin-1beta mRNA expression, but were not associated with decreases in hippocampal brain-derived neurotrophic factor gene expression. Together the results indicate that peripheral tumors alone are sufficient to induce increases in hippocampal cytokine expression and select deficits in hippocampal-dependent memory tasks. PMID:20188817

  13. Short communication: Expression of T-box 2 and 3 in the bovine mammary gland.

    PubMed

    Hoffman, M L; McFadden, K K; Hoagland, T A; Kazmer, G W; Govoni, K E

    2014-07-01

    To increase our understanding of the mechanisms by which growth hormone (GH) and insulin-like growth factor (IGF)-I influence bovine mammary gland development, the potential roles of T-box2 (TBX2) and T-box3 (TBX3) were investigated. Although no information regarding expression of either transcription factor in the bovine mammary gland exists, it is known that TBX3 and its closely related family member, TBX2, are required for mammary gland development in humans and mice. Additionally, TBX3 mutations in humans and mice lead to ulnar mammary syndrome. Evidence is present in bone that TBX3 is required for proliferation and its expression is regulated by GH, an important regulator of mammary gland development and milk production. We hypothesized that TBX2 and TBX3 are expressed in the bovine mammary gland and that GH, IGF-I, or both increase TBX2 and TBX3 expression in bovine mammary epithelial cells (MEC). Bovine mammary gland tissue, MAC-T cells, primary MEC, and fibroblasts were obtained and TBX2 and TBX3 expression was determined by real-time reverse transcription PCR. In addition, TBX2 and TBX3 expression was examined in cells treated with 100 or 500 ng/mL of GH or 100 or 200 ng/mL of IGF-I for 24 or 48 h. Both TBX2 and TBX3 were expressed in bovine mammary tissue. Surprisingly, expression of TBX2 was only detected in mammary fibroblast cells, whereas TBX3 was expressed in all 3 cell types. Growth hormone did not alter TBX3 expression in MAC-T cells or MEC. However, IGF-I increased TBX3 expression in MAC-T, but not in primary MEC. We did not observe a change in TBX2 or TBX3 expression in fibroblasts treated with GH and IGF. Therefore, we concluded that (1) TBX2 and TBX3 are expressed in bovine mammary gland, (2) their expression is cell-type specific, and (3) IGF-I stimulates TBX3 expression in MAC-T cells. PMID:24767885

  14. Mammary gland tumor formation in transgenic mice overexpressing stromelysin-1

    SciTech Connect

    Sympson, Carolyn J; Bissell, Mina J; Werb, Zena

    1995-06-01

    An intact basement membrane (BM) is essential for the proper function, differentiation and morphology of many epithelial cells. The disruption or loss of this BM occurs during normal development as well as in the disease state. To examine the importance of BM during mammary gland development in vivo, we generated transgenic mice that inappropriately express autoactivating isoforms of the matrix metalloproteinase stromelysin-1. The mammary glands from these mice are both functionally and morphologically altered throughout development. We have now documented a dramatic incidence of breast tumors in several independent lines of these mice. These data suggest that overexpression of stromelysin-1 and disruption of the BM may be a key step in the multi-step process of breast cancer.

  15. Of humans and canines: Immunohistochemical analysis of PCNA, Bcl-2, p53, cytokeratin and ER in mammary tumours.

    PubMed

    Kumaraguruparan, R; Prathiba, D; Nagini, S

    2006-10-01

    Mammary tumours are the most common neoplasms in humans and canines. Human and canine mammary tumours share several important epidemiological, clinicopathological and biochemical features. Development of mammary tumours involves accumulation of mutant cells caused by excessive proliferation and insufficient apoptosis or dysregulation of cellular differentiation. The present study was therefore designed to investigate the expression of proliferation, differentiation, and apoptosis associated proteins together with expression of estrogen receptors (ER) in both human and canine mammary tumours. Thirty breast cancer patients categorized as pre- and postmenopausal, and 30 mammary gland tumours obtained from bitches were included in this study. The expression of proliferating cell nuclear antigen (PCNA), Bcl-2, p53, cytokeratin and ER in tumour tissues and adjacent tissues were investigated using immunohistochemical staining. While the expression of PCNA, Bcl-2, p53 and ER was significantly increased, expression of cytokeratin was significantly lower in both human as well as canine mammary tumours compared to corresponding adjacent tissues. The magnitude of the changes was however more pronounced in premenopausal patients compared to postmenopausal patients. The changes in proliferation, apoptosis and differentiation associated proteins in human and canine mammary tumours validate use of the canine model to understand the molecular mechanisms of mammary carcinogenesis. PMID:16740286

  16. The interplay of matrix metalloproteinases, morphogens and growth factors is necessary for branching of mammary epithelial cells

    SciTech Connect

    Simian, M.; Harail, Y.; Navre, M.; Werb, Z.; Lochter, A.; Bissell, M.J.

    2002-03-06

    The mammary gland develops its adult form by a process referred to as branching morphogenesis. Many factors have been reported to affect this process. We have used cultured primary mammary epithelial organoids and mammary epithelial cell lines in three-dimensional collagen gels to elucidate which growth factors, matrix metalloproteinases (MMPs) and mammary morphogens interact in branching morphogenesis. Branching stimulated by stromal fibroblasts, epidermal growth factor, fibroblast growth factor 7, fibroblast growth factor 2 and hepatocyte growth factor was strongly reduced by inhibitors of MMPs, indicating the requirement of MMPs for three-dimensional growth involved in morphogenesis. Recombinant stromelysin 1/MMP-3 alone was sufficient to drive branching in the absence of growth factors in the organoids. Plasmin also stimulated branching; however, plasmin-dependent branching was abolished by both inhibitors of plasmin and MMPs, suggesting that plasmin activates MMPs. To differentiate between signals for proliferation and morphogenesis, we used a cloned mammary epithelial cell line that lacks epimorphin, an essential mammary morphogen. Both epimorphin and MMPs were required for morphogenesis, but neither was required for epithelial cell proliferation. These results provide direct evidence for a critical role of MMPs in branching in mammary epithelium and suggest that, in addition to epimorphin, MMP activity is a minimum requirement for branching morphogenesis in the mammary gland.

  17. Tamoxifen induces regression of estradiol-induced mammary cancer in ACI.COP-Ept2 rat model

    PubMed Central

    Ruhlen, Rachel L.; Willbrand, Dana M.; Besch-Williford, Cynthia L.; Ma, Lixin; Shull, James D.; Sauter, Edward R.

    2012-01-01

    The ACI rat is a unique model of human breast cancer in that mammary cancers are induced by estrogen without carcinogens, irradiation, xenografts or transgenic manipulations. We sought to characterize mammary cancers in a congenic variant of the ACI rat, the ACI.COP-Ept2. All rats with estradiol implants developed mammary cancers in 5–7 months. Rats bearing estradiol-induced mammary cancers were treated with tamoxifen for three weeks. Tamoxifen reduced tumor mass, measured by magnetic resonance imaging, by 89%. Tumors expressed estrogen receptors (ER), progesterone receptor (PR), and Erbb2. ERα and PR were overexpressed in tumor compared to adjacent non-tumor mammary gland. Thus, this model is highly relevant to hormone responsive human breast cancers. PMID:18830694

  18. B and T cells are required for mouse mammary tumor virus spread within the mammary gland.

    PubMed

    Golovkina, T V; Dudley, J P; Ross, S R

    1998-09-01

    Mouse mammary tumor virus (MMTV) is an infectious retrovirus transmitted through milk from mother to newborns. MMTV encodes a superantigen (SAg) whose activity is indispensable for the virus life cycle, since a genetically engineered virus with a mutation in the sag gene neither amplified in cells of the immune system of suckling pups nor infected their mammary glands. When wild-type MMTV was injected directly into the mammary glands of uninfected pubescent mice, their lymphoid as well as mammary gland cells became virus infected. To test whether this infection of lymphoid cells was dependent on SAg activity and required for virus spread within the mammary gland, we performed mammary gland injections of wild-type MMTV(C3H) into two strains of transgenic mice that lacked SAg-cognate, V beta 14+ T cells. Neither the MTV-ORF or LEL strains showed infection of their mammary glands. Moreover, no MMTV infection of their peripheral lymphocytes was detected. Similar experiments with mice lacking B cells (mu-chain knockouts) showed no detectable virus spread in the mammary glands or lymphoid tissues. These data suggest that SAg activity and MMTV-infected lymphocytes are required, not only for initial steps of viral infection, but also for virus spread within the mammary gland. Virus spread at late times in infection determines whether MMTV induces mammary tumors. PMID:9725233

  19. Mammary Carcinogen-Protein Binding Potentials: Novel and Biologically Relevant Structure-Activity Relationship Model Descriptors

    PubMed Central

    Cunningham, A.R.; Qamar, S.; Carrasquer, C.A.; Holt, P.A.; Maguire, J.M.; Cunningham, S.L.; Trent, J.O.

    2010-01-01

    Previously, SAR models for carcinogenesis used descriptors that are essentially chemical descriptors. Herein we report the development of models with the cat-SAR expert system using biological descriptors (i.e., ligand-receptor interactions) rat mammary carcinogens. These new descriptors are derived from the virtual screening for ligand-receptor interactions of carcinogens, non-carcinogens, and mammary carcinogens to a set of 5494 target proteins. Leave-one-out validations of the ligand mammary carcinogen non-carcinogen model had a concordance between experimental and predicted results of 71% and the mammary carcinogen non-mammary carcinogen model was 72% concordant. The development of a hybrid fragment-ligand model improved the concordances to 85 and 83%, respectively. In a separate external validation exercise, hybrid fragment-ligand models had concordances of 81 and 76%. Analyses of example rat mammary carcinogens including the food mutagen and estrogenic compound PhIP, the herbicide atrazine, and the drug indomethacin, the ligand model identified a number of proteins associated with each compound that had previously been referenced in Medline in conjunction with the test chemical and separately with association to breast cancer. This new modelling approach can enhance model predictivity and help bridge the gap between chemical structure and carcinogenic activity by descriptors that are related to biological targets. PMID:20818582

  20. The mammary gland in small ruminants: major morphological and functional events underlying milk production--a review.

    PubMed

    Lérias, Joana R; Hernández-Castellano, Lorenzo E; Suárez-Trujillo, Aridany; Castro, Noemí; Pourlis, Aris; Almeida, André M

    2014-08-01

    The importance of small ruminants to the dairy industry has increased in recent years, especially in developing countries, where it has a high economic and social impact. Interestingly and despite the fact that the mammary gland is the specialised milk production organ, very few authors studied the modifications occurring in the mammary gland through the lactation period in production animals, particularly in the small ruminants, sheep (Ovis aries) and goat (Capra hircus). Nevertheless, understanding the different mammary gland patterns throughout lactation is essential to improve dairy production. In addition, associating these patterns with different milking frequencies, lactation number or different diets is also of high importance, directly affecting the dairy industry. The mammary gland is commonly composed of parenchyma and stroma, which includes the ductal system, with individual proportions of each changing during the different periods and yields in a lactation cycle. Indeed, during late gestation, as well as during early to mid-lactation, mammary gland expansion occurs, with an increase in the number of epithelial cells and lumen area, which leads to increment of the parenchyma tissue, as well as a reduction of stroma, corresponding macroscopically to the increase in mammary gland volume. Throughout late lactation, the mammary gland volume decreases owing to the regression of the secretory structure. In general, common mammary gland patterns have been shown for both goats and sheep throughout the several lactation stages, although the number of studies is limited. The main objective of this manuscript is to review the colostrogenesis and lactogenesis processes as well as to highlight the mammary gland morphological patterns underlying milk production during the lactation cycle for small ruminants, and to describe potential differences between goats and sheep, hence contributing to a better description of mammary gland development during lactation for these

  1. Radiogenic neoplasia in thyroid and mammary clonogens

    SciTech Connect

    Clifton, K.H.

    1991-05-31

    We have developed rat thyroid and mammary clonogen transplantation systems for the study of radiogenic cancer induction at the target cell level in vivo. The epithelial cell populations of both glands contain small subpopulations of cells which are capable of giving rise to monoclonal glandular structures when transplanted and stimulated with appropriate hormones. During the end of the last grant year and the first half of the current grant year, we have completed analyses and summarized for publication: investigations on the relationship between grafted thyroid cell number and the rapidity and degree of reestablishment of the thyroid-hypothalamicpituitary axis in thyroidectomized rats maintained on a normal diet or an iodine deficient diet; studies of the persistence of, and the differentiation potential and functional characteristics of, the TSH- (thyrotropin-) responsive sub-population of clonogens during goitrogenesis, the plateau-phase of goiter growth, and goiter involution; studies of changes in the size of the clonogen sub-population during goitrogenesis, goiter involution and the response to goitrogen rechallenge; and the results of the large carcinogenesis experiment on the nature of the grafted thyroid cell number-dependent suppression of promotion/progression to neoplasia in grafts of radiation-initiated thyroid cells. We are testing new techniques for the culture, cytofluorescent analysis and characterization mammary epithelial cells and of clonogens in a parallel project, and plan to apply similar technology to the thyroid epithelial cells and clonogen population. Data from these studies will be used in the design of future carcinogenesis experiments on neoplastic initiation by high and low LET radiations and on cells interactions during the neoplastic process.

  2. Mammary and extramammary Paget's disease*

    PubMed Central

    Lopes, Lauro Lourival; Lopes, Ione Maria Ribeiro Soares; Lopes, Lauro Rodolpho Soares; Enokihara, Milvia M. S. S.; Michalany, Alexandre Osores; Matsunaga, Nobuo

    2015-01-01

    Paget's disease, described by Sir James Paget in 1874, is classified as mammary and extramammary. The mammary type is rare and often associated with intraductal cancer (93-100% of cases). It is more prevalent in postmenopausal women and it appears as an eczematoid, erythematous, moist or crusted lesion, with or without fine scaling, infiltration and inversion of the nipple. It must be distinguished from erosive adenomatosis of the nipple, cutaneous extension of breast carcinoma, psoriasis, atopic dermatitis, contact dermatitis, chronic eczema, lactiferous ducts ectasia, Bowen's disease, basal cell carcinoma, melanoma and intraductal papilloma. Diagnosis is histological and prognosis and treatment depend on the type of underlying breast cancer. Extramammary Paget's disease is considered an adenocarcinoma originating from the skin or skin appendages in areas with apocrine glands. The primary location is the vulvar area, followed by the perianal region, scrotum, penis and axillae. It starts as an erythematous plaque of indolent growth, with well-defined edges, fine scaling, excoriations, exulcerations and lichenification. In most cases it is not associated with cancer, although there are publications linking it to tumors of the vulva, vagina, cervix and corpus uteri, bladder, ovary, gallbladder, liver, breast, colon and rectum. Differential diagnoses are candidiasis, psoriasis and chronic lichen simplex. Histopathology confirms the diagnosis. Before treatment begins, associated malignancies should be investigated. Surgical excision and micrographic surgery are the best treatment options, although recurrences are frequent. PMID:25830993

  3. Mammary and extramammary Paget's disease.

    PubMed

    Lopes Filho, Lauro Lourival; Lopes, Ione Maria Ribeiro Soares; Lopes, Lauro Rodolpho Soares; Enokihara, Milvia M S S; Michalany, Alexandre Osores; Matsunaga, Nobuo

    2015-01-01

    Paget's disease, described by Sir James Paget in 1874, is classified as mammary and extramammary. The mammary type is rare and often associated with intraductal cancer (93-100% of cases). It is more prevalent in postmenopausal women and it appears as an eczematoid, erythematous, moist or crusted lesion, with or without fine scaling, infiltration and inversion of the nipple. It must be distinguished from erosive adenomatosis of the nipple, cutaneous extension of breast carcinoma, psoriasis, atopic dermatitis, contact dermatitis, chronic eczema, lactiferous ducts ectasia, Bowen's disease, basal cell carcinoma, melanoma and intraductal papilloma. Diagnosis is histological and prognosis and treatment depend on the type of underlying breast cancer. Extramammary Paget's disease is considered an adenocarcinoma originating from the skin or skin appendages in areas with apocrine glands. The primary location is the vulvar area, followed by the perianal region, scrotum, penis and axillae. It starts as an erythematous plaque of indolent growth, with well-defined edges, fine scaling, excoriations, exulcerations and lichenification. In most cases it is not associated with cancer, although there are publications linking it to tumors of the vulva, vagina, cervix and corpus uteri, bladder, ovary, gallbladder, liver, breast, colon and rectum. Differential diagnoses are candidiasis, psoriasis and chronic lichen simplex. Histopathology confirms the diagnosis. Before treatment begins, associated malignancies should be investigated. Surgical excision and micrographic surgery are the best treatment options, although recurrences are frequent. PMID:25830993

  4. Chronic social isolation is associated with metabolic gene expression changes specific to mammary adipose tissue

    PubMed Central

    Volden, Paul A.; Wonder, Erin L.; Skor, Maxwell N.; Carmean, Christopher M.; Patel, Feenalie N.; Ye, Honggang; Kocherginsky, Masha; McClintock, Martha K.; Brady, Matthew J.; Conzen, Suzanne D.

    2013-01-01

    Chronic social isolation is linked to increased mammary tumor growth in rodent models of breast cancer. In the C3(1)/SV40 T-antigen FVB/N (TAg) mouse model of “triple-negative” breast cancer, the heightened stress response elicited by social isolation has been associated with increased expression of metabolic genes in the mammary gland before invasive tumors develop (i.e. during the in situ carcinoma stage). To further understand the mechanisms underlying how accelerated mammary tumor growth is associated with social isolation, we separated the mammary gland adipose tissue from adjacent ductal epithelial cells and analyzed individual cell types for changes in metabolic gene expression. Specifically, increased expression of the key metabolic genes Acaca, Hk2 and Acly was found in the adipocyte, rather than the epithelial fraction. Surprisingly, metabolic gene expression was not significantly increased in visceral adipose depots of socially isolated female mice. As expected, increased metabolic gene expression in the mammary adipocytes of socially isolated mice coincided with increased glucose metabolism, lipid synthesis, and leptin secretion from this adipose depot. Furthermore, application of media that had been cultured with isolated mouse mammary adipose tissue (conditioned media) resulted in increased proliferation of mammary cancer cells relative to group-housed conditioned media. These results suggest that exposure to a chronic stressor (social isolation) results in specific metabolic reprogramming in mammary gland adipocytes that in turn contributes to increased proliferation of adjacent pre-invasive malignant epithelial cells. Metabolites and/or tumor growth-promoting proteins secreted from adipose tissue could identify biomarkers and/or targets for preventive intervention in breast cancer. PMID:23780289

  5. Influence of catechol-O-methyltransferase (COMT) genotypes on the prognosis of canine mammary tumors.

    PubMed

    Dias Pereira, P; Lopes, C C; Matos, A J F; Pinto, D; Gärtner, F; Lopes, C; Medeiros, R

    2009-11-01

    Catechol-O-methyltransferase (COMT) is an important enzyme involved in inactivation of catechol estrogens, which are metabolites with carcinogenic properties. Some investigations in human breast cancer associate a genetic polymorphism in the COMT gene (COMT val158met) with an increased risk and poor clinical progression of the disease. In dogs, there are 2 recognized single nucleotide polymorphisms in the COMT gene (COMTG216A and COMTG482A); however, their influence on the outcome of mammary neoplasms has never been investigated. The purpose of this study is to investigate the influence of COMT in the clinical progression of canine mammary tumors, namely in recurrence, metastasis and survival by testing 2 SNPs (G216A and G482A), and 2 genotypes of the COMT gene. A case series was conducted analyzing genomic DNA samples by polymerase chain reaction-restriction fragment length polymorphism from 80 bitches with mammary tumors. Animals were submitted to an active follow-up study for a period of 24 months after surgery. We observed that bitches carrying both genetic variations simultaneously are more likely to develop recurrence of mammary lesions. Our results demonstrate a possible role for COMT genotypes in the outcome of mammary neoplasms in the dog. Identifying a genetic factor predictive of recurrence may be useful in selecting the most effective surgical approach for canine mammary neoplasms. PMID:19605895

  6. Biological and genetic properties of the p53 null preneoplastic mammary epithelium

    NASA Technical Reports Server (NTRS)

    Medina, Daniel; Kittrell, Frances S.; Shepard, Anne; Stephens, L. Clifton; Jiang, Cheng; Lu, Junxuan; Allred, D. Craig; McCarthy, Maureen; Ullrich, Robert L.

    2002-01-01

    The absence of the tumor suppressor gene p53 confers an increased tumorigenic risk for mammary epithelial cells. In this report, we describe the biological and genetic properties of the p53 null preneoplastic mouse mammary epithelium in a p53 wild-type environment. Mammary epithelium from p53 null mice was transplanted serially into the cleared mammary fat pads of p53 wild-type BALB/c female to develop stable outgrowth lines. The outgrowth lines were transplanted for 10 generations. The outgrowths were ductal in morphology and progressed through ductal hyperplasia and ductal carcinoma in situ before invasive cancer. The preneoplastic outgrowth lines were immortal and exhibited activated telomerase activity. They are estrogen and progesterone receptor-positive, and aneuploid, and had various levels of tumorigenic potential. The biological and genetic properties of these lines are distinct from those found in most hyperplastic alveolar outgrowth lines, the form of mammary preneoplasia occurring in most traditional models of murine mammary tumorigenesis. These results indicate that the preneoplastic cell populations found in this genetically engineered model are similar in biological properties to a subset of precurser lesions found in human breast cancer and provide a unique model to identify secondary events critical for tumorigenicity and invasiveness.

  7. /sup 20/neon ion- and x-ray-induced mammary carcinogenesis in female rats

    SciTech Connect

    Shellabarger, C.J.; Baum, J.W.; Holtzman, S.; Stone, J.P.

    1983-01-01

    One of the proposed uses of heavy ion irradiation is to image lesions of the human female breast. The rat model system was chosen to assess the carcinogenic potential of heavy ion irradiation in the belief that data obtained from rat studies would have a qualitatively predictive value for the human female. Accordingly, female rats were exposed to /sup 20/Ne ions at the BEVALAC and studied for the development of mammary neoplasia for 312 +- 2 days at Brookhaven along with rats exposed concurrently to x-irradiation or to no irradiation. As the dose of either type of radiation was increased the percent of rats with mammary adenocarcinomas, and the percent of rats with mammary fibroadenomas, tended to increase. At a prevalence of 20%, the RBE for /sup 20/Neon ions for mammary adenocarcinomas was estimated to be larger than 5 and for mammary fibroadenomas the RBE was estimated to be less than 2. No conclusion was reached concerning whether or not the RBE might vary with dose. We suggest that /sup 20/Ne ions do have a carcinogenic potential for rat mammary tissue and that this carcinogenic potential is likely to be greater than for x-irradiation. (DT)

  8. Mammary gland tumors in captive African hedgehogs.

    PubMed

    Raymond, J T; Gerner, M

    2000-04-01

    From December 1995 to July 1999, eight mammary gland tumors were diagnosed in eight adult captive female African hedgehogs (Atelerix albiventris). The tumors presented as single or multiple subcutaneous masses along the cranial or caudal abdomen that varied in size for each hedgehog. Histologically, seven of eight (88%) mammary gland tumors were malignant. Tumors were classified as solid (4 cases), tubular (2 cases), and papillary (2 cases). Seven tumors had infiltrated into the surrounding stroma and three tumors had histologic evidence of neoplastic vascular invasion. Three hedgehogs had concurrent neoplasms. These are believed to be the first reported cases of mammary gland tumors in African hedgehogs. PMID:10813628

  9. Developmental signaling pathways regulating mammary stem cells and contributing to the etiology of triple-negative breast cancer.

    PubMed

    Rangel, Maria Cristina; Bertolette, Daniel; Castro, Nadia P; Klauzinska, Malgorzata; Cuttitta, Frank; Salomon, David S

    2016-04-01

    Cancer has been considered as temporal and spatial aberrations of normal development in tissues. Similarities between mammary embryonic development and cell transformation suggest that the underlying processes required for mammary gland development are also those perturbed during various stages of mammary tumorigenesis and breast cancer (BC) development. The master regulators of embryonic development Cripto-1, Notch/CSL, and Wnt/β-catenin play key roles in modulating mammary gland morphogenesis and cell fate specification in the embryo through fetal mammary stem cells (fMaSC) and in the adult organism particularly within the adult mammary stem cells (aMaSC), which determine mammary progenitor cell lineages that generate the basal/myoepithelial and luminal compartments of the adult mammary gland. Together with recognized transcription factors and embryonic stem cell markers, these embryonic regulatory molecules can be inappropriately augmented during tumorigenesis to support the tumor-initiating cell (TIC)/cancer stem cell (CSC) compartment, and the effects of their deregulation may contribute for the etiology of BC, in particular the most aggressive subtype of BC, triple-negative breast cancer (TNBC). This in depth review will present evidence of the involvement of Cripto-1, Notch/CSL, and Wnt/β-catenin in the normal mammary gland morphogenesis and tumorigenesis, from fMaSC/aMaSC regulation to TIC generation and maintenance in TNBC. Specific therapies for treating TNBC by targeting these embryonic pathways in TICs will be further discussed, providing new opportunities to destroy not only the bulk tumor, but also TICs that initiate and promote the metastatic spread and recurrence of this aggressive subtype of BC. PMID:26968398

  10. Significance of rat mammary tumors for human risk assessment.

    PubMed

    Russo, Jose

    2015-02-01

    We have previously indicated that the ideal animal tumor model should mimic the human disease. This means that the investigator should be able to ascertain the influence of host factors on the initiation of tumorigenesis, mimic the susceptibility of tumor response based on age and reproductive history, and determine the response of the tumors induced to chemotherapy. The utilization of experimental models of mammary carcinogenesis in risk assessment requires that the influence of ovarian, pituitary, and placental hormones, among others, as well as overall reproductive events are taken into consideration, since they are important modifiers of the susceptibility of the organ to neoplastic development. Several species, such as rodents, dogs, cats, and monkeys, have been evaluated for these purposes; however, none of them fulfills all the criteria specified previously. Rodents, however, are the most widely used models; therefore, this work will concentrate on discussing the rat rodent model of mammary carcinogenesis. PMID:25714400