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Sample records for lobuloalveolar mammary development

  1. Cytokine signalling in mammary gland development.

    PubMed

    Watson, Christine J; Oliver, Carrie H; Khaled, Walid T

    2011-03-01

    Mammary gland development occurs in three distinct stages during the lifetime of the female mammal: in embryonic, pubertal and reproductive life. At each of these developmental stages, different signalling molecules induce changes in both the epithelium and the surrounding stroma. However, it is during pregnancy that the most dramatic changes occur, resulting in a massive increase in the number of epithelial cells and in their function. Pregnancy initiates the development of a new epithelial lineage, the alveolar cells, which form the milk-producing lobuloalveolar structures. These cells become redundant at the end of lactation and are removed in an exquisitely controlled process of tissue remodelling coupled with extensive cell death. All of these events require not only steroid hormones but also sequential signalling by cytokines. A recent surprising discovery was that the signalling pathways and cytokines that regulate lineage determination in T helper cells are also involved in mammary gland development during pregnancy.

  2. 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...

  3. Keratin 6 is not essential for mammary gland development

    PubMed Central

    Grimm, Sandra L; Bu, Wen; Longley, Mary Ann; Roop, Dennis R; Li, Yi; Rosen, Jeffrey M

    2006-01-01

    PR-positive mammary epithelial cells and decreased proliferation after exposure to steroid hormones. There was also increased co-localization of PR and bromodeoxyuridine, suggesting alterations in patterning events important for normal lobuloalveolar development. PMID:16790075

  4. Loss of glutaredoxin 3 impedes mammary lobuloalveolar development during pregnancy and lactation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammalian glutaredoxin 3 (Grx3) has been shown to be important for regulating cellular redox homeostasis in the cell. Our previous studies indicate that Grx3 is significantly overexpressed in various human cancers including breast cancer and demonstrate that Grx3 controls cancer cell growth and inva...

  5. Investigating the Role of FIP200 in Mammary Carcinogenesis Using a Transgenic Mouse Model

    DTIC Science & Technology

    2006-04-01

    in the mammary gland of virgin mice however, lactating mice have severe lobulo-alveolar hypoplasia in the mammary gland. 15. SUBJECT TERMS...mammary gland of virgin mice however, lactating mice have severe lobulo-alveolar hypoplasia in the mammary gland. Body Aim 1. Generation of mammary...leads to dwarfism and pregnant females have severe lobulo-alveolar hypoplasia affecting the mammary gland and, as a consequence, have difficulty

  6. Socs2 and elf5 mediate prolactin-induced mammary gland development.

    PubMed

    Harris, Jessica; Stanford, Prudence M; Sutherland, Kate; Oakes, Samantha R; Naylor, Matthew J; Robertson, Fiona G; Blazek, Katrina D; Kazlauskas, Michael; Hilton, Heidi N; Wittlin, Sergio; Alexander, Warren S; Lindeman, Geoffrey J; Visvader, Jane E; Ormandy, Christopher J

    2006-05-01

    The proliferative phase of mammary alveolar morphogenesis is initiated during early pregnancy by rising levels of serum prolactin and progesterone, establishing a program of gene expression that is ultimately responsible for the development of the lobuloalveoli and the onset of lactation. To explore this largely unknown genetic program, we constructed transcript profiles derived from transplanted mammary glands formed by recombination of prolactin receptor (Prlr) knockout or wild-type mammary epithelium with wild-type mammary stroma. Comparison with profiles derived from prolactin-treated Scp2 mammary epithelial cells produced a small set of commonly prolactin-regulated genes that included the negative regulator of cytokine signaling, Socs2 (suppressor of cytokine signaling 2), and the ets transcription factor, E74-like factor 5 (Elf5). Homozygous null mutation of Socs2 rescued the failure of lactation and reduction of mammary signal transducer and activator of transcription 5 phosphorylation that characterizes Prlr heterozygous mice, demonstrating that mammary Socs2 is a key regulator of the prolactin-signaling pathway. Reexpression of Elf5 in Prlr nullizygous mammary epithelium restored lobuloalveolar development and milk production, demonstrating that Elf5 is a transcription factor capable of substituting for prolactin signaling. Thus, Socs2 and Elf5 are key members of the set of prolactin-regulated genes that mediate prolactin-driven mammary development.

  7. Mammary gland development.

    PubMed

    Macias, Hector; Hinck, Lindsay

    2012-01-01

    The mammary gland develops through several distinct stages. The first transpires in the embryo as the ectoderm forms a mammary line that resolves into placodes. Regulated by epithelial–mesenchymal interactions, the placodes descend into the underlying mesenchyme and produce the rudimentary ductal structure of the gland present at birth. Subsequent stages of development—pubertal growth, pregnancy, lactation, and involution—occur postnatally under the regulation of hormones. Puberty initiates branching morphogenesis, which requires growth hormone (GH) and estrogen, as well as insulin-like growth factor 1 (IGF1), to create a ductal tree that fills the fat pad. Upon pregnancy, the combined actions of progesterone and prolactin generate alveoli, which secrete milk during lactation. Lack of demand for milk at weaning initiates the process of involution whereby the gland is remodeled back to its prepregnancy state. These processes require numerous signaling pathways that have distinct regulatory functions at different stages of gland development. Signaling pathways also regulate a specialized subpopulation of mammary stem cells that fuel the dramatic changes in the gland occurring with each pregnancy. Our knowledge of mammary gland development and mammary stem cell biology has significantly contributed to our understanding of breast cancer and has advanced the discovery of therapies to treat this disease.

  8. Angiotensin II accelerates mammary gland development independently of high blood pressure in pregnancy-associated hypertensive mice.

    PubMed

    Murata, Kazuya; Baasanjav, Altansarnai; Kwon, Chulwon; Hashimoto, Misuzu; Ishida, Junji; Fukamizu, Akiyoshi

    2015-09-01

    Angiotensin II (AngII) is a vasopressor hormone that has critical roles in maintenance of normal blood pressure and pathogenesis of cardiovascular diseases. We previously generated pregnancy-associated hypertensive (PAH) mice by mating female human angiotensinogen transgenic mice with male human renin transgenic mice. PAH mice exhibit hypertension in late pregnancy by overproducing AngII. A recent study demonstrated that angiotensin II type I (AT1) receptor is expressed in mammary epithelial cells and its signaling is critical for mammary gland involution after weaning. However, the role of AngII-AT1 receptor signaling in the development of mammary gland during pregnancy remains unclear. In this study, to investigate the role of AngII-AT1 receptor signaling in mammary gland development during pregnancy, we analyzed the mammary gland of PAH mice. Histological and gene expression analyses revealed that lobuloalveolar development was accelerated with increased milk protein production and lipid accumulation in the mammary gland of PAH mice. Furthermore, AT1 receptor blocker treatment suppressed acceleration of mammary gland development in PAH mice, while the treatment of hydralazine, another antihypertensive drug, did not. These data suggest that AngII-AT1 receptor-induced signaling accelerates mammary gland development during pregnancy through hypertension-independent mechanism.

  9. The Influence of Stromal Transforming Growth Factor-Beta Receptor Signaling on Mouse Mammary Neoplasia

    DTIC Science & Technology

    2004-08-01

    and -P3) are members of a family of peptide growth factors that include inhibins, bone morphogenic proteins (BMPs) and growth and differentiation...DNIIR) in the mammary epithelium and in stromal fibroblasts resulted in precocious lobuloalveolar development and increased lateral branching...necessary for proper ductal development during puberty . It has been suggested that TGF-P regulates pubertal mammary development through the epithelium and

  10. Impaired mouse mammary gland growth and development is mediated by melatonin and its MT1G protein-coupled receptor via repression of ERα, Akt1, and Stat5.

    PubMed

    Xiang, Shulin; Mao, Lulu; Yuan, Lin; Duplessis, Tamika; Jones, Frank; Hoyle, Gary W; Frasch, Tripp; Dauchy, Robert; Blask, David E; Chakravarty, Geetika; Hill, Steven M

    2012-10-01

    To determine whether melatonin, via its MT(1)  G protein-coupled receptor, impacts mouse mammary gland development, we generated a mouse mammary tumor virus (MMTV)-MT1-Flag-mammary gland over-expressing (MT1-mOE) transgenic mouse. Increased expression of the MT(1) -Flag transgene was observed in the mammary glands of pubescent MT1-mOE transgenic female mice, with further significant increases during pregnancy and lactation. Mammary gland whole mounts from MT1-mOE mice showed significant reductions in ductal growth, ductal branching, and terminal end bud formation. Elevated MT(1) receptor expression in pregnant and lactating female MT1-mOE mice was associated with reduced lobulo-alveolar development, inhibition of mammary epithelial cell proliferation, and significant reductions in body weights of suckling pups. Elevated MT(1) expression in pregnant and lactating MT1-mOE mice correlated with reduced mammary gland expression of Akt1, phospho-Stat5, Wnt4, estrogen receptor alpha, progesterone receptors A and B, and milk proteins β-casein and whey acidic protein. Estrogen- and progesterone-stimulated mammary gland development was repressed by elevated MT(1) receptor expression and exogenous melatonin administration. These studies demonstrate that the MT(1) melatonin receptor and its ligand melatonin play an important regulatory role in mammary gland development and lactation in mice through both growth suppression and alteration of developmental paradigms.

  11. Caveolin-1-deficient Mice Show Accelerated Mammary Gland Development During Pregnancy, Premature Lactation, and Hyperactivation of the Jak-2/STAT5a Signaling Cascade

    PubMed Central

    Park, David S.; Lee, Hyangkyu; Frank, Philippe G.; Razani, Babak; Nguyen, Andrew V.; Parlow, Albert F.; Russell, Robert G.; Hulit, James; Pestell, Richard G.; Lisanti, Michael P.

    2002-01-01

    It is well established that mammary gland development and lactation are tightly controlled by prolactin signaling. Binding of prolactin to its cognate receptor (Prl-R) leads to activation of the Jak-2 tyrosine kinase and the recruitment/tyrosine phosphorylation of STAT5a. However, the mechanisms for attenuating the Prl-R/Jak-2/STAT5a signaling cascade are just now being elucidated. Here, we present evidence that caveolin-1 functions as a novel suppressor of cytokine signaling in the mammary gland, akin to the SOCS family of proteins. Specifically, we show that caveolin-1 expression blocks prolactin-induced activation of a STAT5a-responsive luciferase reporter in mammary epithelial cells. Furthermore, caveolin-1 expression inhibited prolactin-induced STAT5a tyrosine phosphorylation and DNA binding activity, suggesting that caveolin-1 may negatively regulate the Jak-2 tyrosine kinase. Because the caveolin-scaffolding domain bears a striking resemblance to the SOCS pseudosubstrate domain, we examined whether Jak-2 associates with caveolin-1. In accordance with this homology, we demonstrate that Jak-2 cofractionates and coimmunoprecipitates with caveolin-1. We next tested the in vivo relevance of these findings using female Cav-1 (−/−) null mice. If caveolin-1 normally functions as a suppressor of cytokine signaling in the mammary gland, then Cav-1 null mice should show premature development of the lobuloalveolar compartment because of hyperactivation of the prolactin signaling cascade via disinhibition of Jak-2. In accordance with this prediction, Cav-1 null mice show accelerated development of the lobuloalveolar compartment, premature milk production, and hyperphosphorylation of STAT5a (pY694) at its Jak-2 phosphorylation site. In addition, the Ras-p42/44 MAPK cascade is hyper-activated. Because a similar premature lactation phenotype is observed in SOCS1 (−/−) null mice, we conclude that caveolin-1 is a novel suppressor of cytokine signaling. PMID:12388746

  12. Investigating the Role of FIP200 in Mammary Carcinogenesis Using a Transgenic Mouse Model

    DTIC Science & Technology

    2007-04-01

    the mammary gland of virgin mice however, lactating mice have severe lobulo-alveolar hypoplasia in the mammary gland. After completing the analysis... hypoplasia which renders the dams unable to lactate). In the 1B mating scheme a female mouse with FAKFlox/Flox genotype was mated to a male MMTV...Epithelial-Specific Deletion of the Focal Adhesion Kinase Gene Leads to Severe Lobulo-Alveolar Hypoplasia and Secretory Immaturity of the Murine Mammary

  13. 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...

  14. Perinatal Exposure to Bisphenol A or Diethylstilbestrol Increases the Susceptibility to Develop Mammary Gland Lesions After Estrogen Replacement Therapy in Middle-Aged Rats.

    PubMed

    Gomez, Ayelen L; Delconte, Melisa B; Altamirano, Gabriela A; Vigezzi, Lucia; Bosquiazzo, Veronica L; Barbisan, Luís F; Ramos, Jorge G; Luque, Enrique H; Muñoz-de-Toro, Mónica; Kass, Laura

    2017-04-01

    The development of the mammary gland is a hormone-regulated event. Several factors can dysregulate its growth and make the gland more susceptible to cellular transformation. Among these factors, perinatal exposure to xenoestrogens and hormone replacement therapy has been associated with increased risk of developing breast cancer. Here, we assessed the effects induced by estrogen replacement therapy (ERT) in ovariectomized (OVX) middle-aged rats and whether perinatal exposure to diethylstilbestrol (DES) or bisphenol A (BPA) modified these effects in the mammary gland. Pregnant rats were orally exposed to vehicle, 5 μg DES/kg/day, or 0.5 or 50 μg BPA/kg/day from gestational day 9 until weaning. Then, 12-month-old offspring were OVX and treated with 17β-estradiol for 3 months. Morphological changes and the percentage of epithelial cells that proliferated or expressed estrogen receptor alpha (ESR1) and progesterone receptor (PR) were analyzed in mammary gland samples of 15-month-old animals. ERT induced lobuloalveolar hyperplasia and ductal cysts in the mammary gland of middle-aged rats, associated with a higher proliferation index of epithelial cells. Perinatal exposure to DES followed by ERT increased the number of cysts and induced the formation of fibroadenoma and ductal carcinoma in situ, without modifying the expression of ESR1 or PR. Also, after 3 months of ERT, BPA-exposed rats had a higher incidence of ductal hyperplasia and atypical lobular hyperplasia than animals under ERT alone. In conclusion, perinatal exposure to xenoestrogens increases the susceptibility of the mammary gland to develop cysts and hyperplastic lesions when confronted with ERT later in life.

  15. Comparative aspects of mammary gland development and homeostasis.

    PubMed

    Capuco, Anthony V; Ellis, Steven E

    2013-01-01

    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, differentiation, lactation, and regression that are coordinated to provide nutrients for offspring or are driven by strategies to manage reproduction and milk production of domesticated species. Growth and maintenance of the mammary epithelium depends on the function of mammary stem cells and progenitor cells. In this review, we provide an overview of postnatal mammary gland development, cyclical phases of mammary gland regression (regression during lactation and between successive lactations), and mammary stem cells and progenitor cells. Where possible, these processes are related to animal production and compared across species, particularly bovine, porcine, murine, and human.

  16. N-sulfation of heparan sulfate regulates early branching events in the developing mammary gland.

    PubMed

    Bush, Kevin T; Crawford, Brett E; Garner, Omai B; Nigam, Kabir B; Esko, Jeffrey D; Nigam, Sanjay K

    2012-12-07

    Branching morphogenesis, a fundamental process in the development of epithelial organs (e.g. breast, kidney, lung, salivary gland, prostate, pancreas), is in part dependent on sulfation of heparan sulfate proteoglycans. Proper sulfation is mediated by biosynthetic enzymes, including exostosin-2 (Ext2), N-deacetylase/N-sulfotransferases and heparan sulfate O-sulfotransferases. Recent conditional knockouts indicate that whereas primary branching is dependent on heparan sulfate, other stages are dependent upon selective addition of N-sulfate and/or 2-O sulfation (Crawford, B .E., Garner, O. B., Bishop, J. R., Zhang, D. Y., Bush, K. T., Nigam, S. K., and Esko, J. D. (2010) PLoS One 5, e10691; Garner, O .B., Bush, K. T., Nigam, S .K., Yamaguchi, Y., Xu, D., Esko, J. D., and Nigam, S. K. (2011) Dev. Biol. 355, 394-403). Here, we analyzed the effect of deleting both Ndst2 and Ndst1. Whereas deletion of Ndst1 has no major effect on primary or secondary branching, deletion of Ndst2 appears to result in a mild increase in branching. When both genes were deleted, ductal growth was variably diminished (likely due to variable Cre-recombinase activity), but an overabundance of branched structures was evident irrespective of the extent of gland growth or postnatal age. "Hyperbranching" is an unusual phenotype. The effects on N-sulfation and growth factor binding were confirmed biochemically. The results indicate that N-sulfation or a factor requiring N-sulfation regulates primary and secondary branching events in the developing mammary gland. Together with previous work, the data indicate that different stages of ductal branching and lobuloalveolar formation are regulated by distinct sets of heparan sulfate biosynthetic enzymes in an appropriate growth factor context.

  17. 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...

  18. Leukocytes in Mammary Development and Cancer

    PubMed Central

    Coussens, Lisa M.; Pollard, Jeffrey W.

    2011-01-01

    Leukocytes, of both the innate and adaptive lineages, are normal cellular components of all tissues. These important cells not only are critical for regulating normal tissue homeostasis, but also are significant paracrine regulators of all physiologic and pathologic tissue repair processes. This article summarizes recent insights regarding the trophic roles of leukocytes at each stage of mammary gland development and during cancer development, with a focus on Murids and humans. PMID:21123394

  19. 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.

  20. Positional variations in mammary gland development and cancer.

    PubMed

    Veltmaat, Jacqueline M; Ramsdell, Ann F; Sterneck, Esta

    2013-06-01

    Most mammals develop their mammary glands in pairs of which the two counterparts are symmetrically displaced away from the ventral midline. Based on this symmetry and the same functional outcome as a milk-producing organ, the mammary glands are easily presumed to be mere copies of one another. Based on our analysis of published data with inclusion of new results related to mammary development and pathology in mice, we argue that this presumption is incorrect: Between and within pairs, mammary glands differ from one another, and tumor incidence and biology depend on the position along the anterior-posterior and the left-right axis as well. This insight has implications for experimental designs with mouse models and for data extrapolation between mammary glands within and between species. We suggest that improved documentation of location-specific mammary gland features will lead to more insights into the molecular mechanisms of mammary gland development and cancer biology in both mice and humans.

  1. Transplantation of a mammary stromal cell line into a mammary fat pad: development of the site-specific in vivo analysis system for mammary stromal cells.

    PubMed

    Nakatani, Hajime; Aoki, Naohito; Nadano, Daita; Matsuda, Tsukasa

    2011-01-01

    The interaction between mammary epithelial and stromal tissue is considered to be important in breast tissue development. In this study, we developed a transplantation procedure for the mammary stromal fibroblastic cell line (MSF) to examine its life in vivo. First we established MSF cells which stably expressed lacZ (lacZ/MSF) and had characteristics of mammary stromal cells. The lacZ/MSF cells were then transplanted into a cleared mammary fat pad of syngenic mice with and without mammary primary epithelial organoids. Whole mount X-gal and carmine staining of the transplants revealed that a number of undifferentiated lacZ/MSF cells survived around the mammary epithelial tissue when transplanted with organoids. These results indicate that transplantation of MSF cells into mammary fat pad was accomplished by co-transplantation with primary mammary organoids. Finally, we discuss the application of transplantation procedure for in vivo studies of the mammary stromal tissue development and stromal-epithelial interactions.

  2. 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

  3. Mammary development and breast cancer: the role of stem cells.

    PubMed

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

    2011-06-01

    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.

  4. 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.

  5. Plk2 regulates mitotic spindle orientation and mammary gland development.

    PubMed

    Villegas, Elizabeth; Kabotyanski, Elena B; Shore, Amy N; Creighton, Chad J; Westbrook, Thomas F; Rosen, Jeffrey M

    2014-04-01

    Disruptions in polarity and mitotic spindle orientation contribute to the progression and evolution of tumorigenesis. However, little is known about the molecular mechanisms regulating these processes in vivo. Here, we demonstrate that Polo-like kinase 2 (Plk2) regulates mitotic spindle orientation in the mammary gland and that this might account for its suggested role as a tumor suppressor. Plk2 is highly expressed in the mammary gland and is required for proper mammary gland development. Loss of Plk2 leads to increased mammary epithelial cell proliferation and ductal hyperbranching. Additionally, a novel role for Plk2 in regulating the orientation of the mitotic spindle and maintaining proper cell polarity in the ductal epithelium was discovered. In support of a tumor suppressor function for Plk2, loss of Plk2 increased the formation of lesions in multiparous glands. Collectively, these results demonstrate a novel role for Plk2 in regulating mammary gland development.

  6. Luminal progenitors restrict their lineage potential during mammary gland development.

    PubMed

    Rodilla, Veronica; Dasti, Alessandro; Huyghe, Mathilde; Lafkas, Daniel; Laurent, Cécile; Reyal, Fabien; Fre, Silvia

    2015-02-01

    The hierarchical relationships between stem cells and progenitors that guide mammary gland morphogenesis are still poorly defined. While multipotent basal stem cells have been found within the myoepithelial compartment, the in vivo lineage potential of luminal progenitors is unclear. Here we used the expression of the Notch1 receptor, previously implicated in mammary gland development and tumorigenesis, to elucidate the hierarchical organization of mammary stem/progenitor cells by lineage tracing. We found that Notch1 expression identifies multipotent stem cells in the embryonic mammary bud, which progressively restrict their lineage potential during mammary ductal morphogenesis to exclusively generate an ERαneg luminal lineage postnatally. Importantly, our results show that Notch1-labelled cells represent the alveolar progenitors that expand during pregnancy and survive multiple successive involutions. This study reveals that postnatal luminal epithelial cells derive from distinct self-sustained lineages that may represent the cells of origin of different breast cancer subtypes.

  7. Luminal Progenitors Restrict Their Lineage Potential during Mammary Gland Development

    PubMed Central

    Rodilla, Veronica; Dasti, Alessandro; Huyghe, Mathilde; Lafkas, Daniel; Laurent, Cécile; Reyal, Fabien; Fre, Silvia

    2015-01-01

    The hierarchical relationships between stem cells and progenitors that guide mammary gland morphogenesis are still poorly defined. While multipotent basal stem cells have been found within the myoepithelial compartment, the in vivo lineage potential of luminal progenitors is unclear. Here we used the expression of the Notch1 receptor, previously implicated in mammary gland development and tumorigenesis, to elucidate the hierarchical organization of mammary stem/progenitor cells by lineage tracing. We found that Notch1 expression identifies multipotent stem cells in the embryonic mammary bud, which progressively restrict their lineage potential during mammary ductal morphogenesis to exclusively generate an ERαneg luminal lineage postnatally. Importantly, our results show that Notch1-labelled cells represent the alveolar progenitors that expand during pregnancy and survive multiple successive involutions. This study reveals that postnatal luminal epithelial cells derive from distinct self-sustained lineages that may represent the cells of origin of different breast cancer subtypes. PMID:25688859

  8. 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.

  9. Stem cells and the developing mammary gland.

    PubMed

    Makarem, Maisam; Spike, Benjamin T; Dravis, Christopher; Kannan, Nagarajan; Wahl, Geoffrey M; Eaves, Connie J

    2013-06-01

    The mammary gland undergoes dynamic changes throughout life. In the mouse, these begin with initial morphogenesis of the gland in the mid-gestation embryo followed by hormonally regulated changes during puberty and later in adulthood. The adult mammary gland contains a hierarchy of cell types with varying potentials for self-maintenance and differentiation. These include cells able to produce complete, functional mammary glands in vivo and that contain daughter cells with the same remarkable regenerative potential, as well as cells with more limited clonogenic activity in vitro. Here we review how applying in vitro and in vivo methods for quantifying these cells in adult mammary tissue to fetal mammary cells has enabled the first cells fulfilling the functional criteria of transplantable, isolated mammary stem cells to be identified a few days before birth. Thereafter, the number of these cells increases rapidly. Populations containing these fetal stem cells display growth and gene expression programs that differ from their adult counterparts but share signatures characteristic of certain types of breast cancer. Such observations reinforce growing evidence of important differences between tissue-specific fetal and adult cells with stem cell properties and emphasize the merits of investigating their molecular basis.

  10. Immune cell location and function during post-natal mammary gland development.

    PubMed

    Reed, Johanna R; Schwertfeger, Kathryn L

    2010-09-01

    Post-natal mammary gland development requires complex interactions between the epithelial cells and various cell types within the stroma. Recent studies have illustrated the importance of immune cells and their mediators during the various stages of mammary gland development. However, the mechanisms by which these immune cells functionally contribute to mammary gland development are only beginning to be understood. This review provides an overview of the localization of immune cells within the mammary gland during the various stages of post-natal mammary gland development. Furthermore, recent studies are summarized that illustrate the mechanisms by which these cells are recruited to the mammary gland and their functional roles in mammary gland development.

  11. Hippo pathway in mammary gland development and breast cancer.

    PubMed

    Shi, Peiguo; Feng, Jing; Chen, Ceshi

    2015-01-01

    Accumulated evidence suggests that the Hippo signaling pathway plays crucial roles in mammary gland development and breast cancer. Key components of the Hippo pathway regulate breast epithelial cell proliferation, migration, invasion, and stemness. Additionally, the Hippo pathway regulates breast tumor growth, metastasis, and drug resistance. It is expected that the Hippo pathway will provide novel therapeutic targets for breast cancer. This review will discuss and summarize the roles of several core components of the Hippo pathway in mammary gland development and breast cancer.

  12. Notch in mammary gland development and breast cancer.

    PubMed

    Politi, Katerina; Feirt, Nikki; Kitajewski, Jan

    2004-10-01

    Notch signaling has been implicated in many processes including cell fate determination and oncogenesis. In mice, the Notch1 and Notch4 genes are both targets for insertion and rearrangement by the mouse mammary tumor virus and these mutations promote epithelial mammary tumorigenesis. Moreover, expression of a constitutively active form of Notch4 in mammary epithelial cells inhibits epithelial differentiation and leads to tumor formation in this organ. These data implicate the Notch pathway in breast tumorigenesis and provide the foundation for future experiments that will aid in our understanding of the role of Notch in human breast cancer development. Here, we review studies of mammary tumorigenesis induced by Notch in mouse and in vitro culture models providing evidence that Notch activation is a causal factor in human breast cancer.

  13. Windows in early mammary development: critical or not?

    PubMed

    Knight, C H; Sorensen, A

    2001-09-01

    Two critical windows in mammary development have been proposed. The first arises from observations in rodents that nutrition during fetal and neonatal periods can affect mammary ductular outgrowth, subsequent proliferative activity and, eventually, tumorigenesis, that is, potentially it could have a long-term effect on pathological outcome (breast cancer) in women. The second similarly involves early diet, but in this case the outcome is phenotypic, in that dairy heifers reared too quickly during the peripubertal period subsequently show impaired udder development and reduced milk yield persisting throughout life. Most mammary development occurs during pregnancy, but this period is usually thought of only in terms of the immediate outcome for the subsequent lactation; it is not believed to be a critical window, at least in terms of lifetime mammary productivity. This review examines the evidence underlying these various claims and attempts to define the mechanisms involved, and also considers whether derangements occurring earlier in life (prenatally) could also have long-term consequences for physiological or pathological mammary development.

  14. Alcohol exposure in utero leads to enhanced prepubertal mammary development and alterations in mammary IGF and estradiol systems.

    PubMed

    Polanco, Tiffany A; Crismale-Gann, Catina; Cohick, Wendie S

    2011-08-01

    Exposure to alcohol during fetal development increases susceptibility to mammary cancer in adult rats. This study determined if early changes in mammary morphology and the insulin-like growth factor (IGF)/estradiol axis are involved in the mechanisms that underlie this increased susceptibility. Pregnant Sprague-Dawley rats were fed a liquid diet containing 6.7% ethanol (alcohol), an isocaloric liquid diet (pair-fed), or rat chow ad libitum from days 11 to 21 of gestation. At birth, female pups were cross-fostered to ad libitum-fed control dams. Offspring were euthanized at postnatal days (PND) 20, 40, or 80. Animals were injected with BrdU before euthanasia, then mammary glands, serum, and livers were collected. Mammary glands from animals exposed to alcohol in utero displayed increased epithelial cell proliferation and aromatase expression at PND 20 and 40. Mammary IGF-I mRNA was higher in alcohol-exposed animals relative to controls at PND 20, while mammary IGFBP-5 mRNA was lower in this group at PND 40. Hepatic IGF-I mRNA expression was increased at all time points in alcohol-exposed animals, however, circulating IGF-I levels were not altered. These data indicate that alcohol exposure in utero may advance mammary development via the IGF and estradiol systems, which could contribute to increased susceptibility to mammary cancer later in life.

  15. 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...

  16. 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...

  17. 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 ...

  18. The role of activin in mammary gland development and oncogenesis.

    PubMed

    Dunphy, Karen A; Schneyer, Alan L; Hagen, Mary J; Jerry, D Joseph

    2011-06-01

    TGFβ contributes to mammary gland development and has paradoxical roles in breast cancer because it has both tumor suppressor and tumor promoter activity. Another member of the TGFβ superfamily, activin, also has roles in the developing mammary gland, but these functions, and the role of activin in breast cancer, are not well characterized. TGFβ and activin share the same intracellular signaling pathways, but divergence in their signaling pathways are suggested. The purpose of this review is to compare the spatial and temporal expression of TGFβ and activin during mammary gland development, with consideration given to their functions during each developmental period. We also review the contributions of TGFβ and activin to breast cancer resistance and susceptibility. Finally, we consider the systemic contributions of activin in regulating obesity and diabetes; and the impact this regulation has on breast cancer. Elevated levels of activin in serum during pregnancy and its influence on pregnancy associated breast cancer are also considered. We conclude that evidence demonstrates that activin has tumor suppressing potential, without definitive indication of tumor promoting activity in the mammary gland, making it a good target for development of therapeutics.

  19. The Analysis of Cell Population Dynamics in Mammary Gland Development and Tumorigenesis

    DTIC Science & Technology

    2006-08-01

    processes of mammary epithelial cell differentiation during developmentand tumorigenesis. Using FACS, mammary epithelial cell ( MEC ) populations from tumors...developed techniques for viral transduction andtransplantation of primary MECs . 15. SUBJECT TERMS mammary, stem cell, lentivirus, FACS, cancer, imaging 16...epithelial cell ( MEC ) populations from tumors and wildtype tissue was investigated for their outgrowth potential or tumorigenic capacity. We also developed

  20. Role of progestin-induced mammary-derived growth hormone in the pathogenesis of cystic endometrial hyperplasia in the bitch.

    PubMed

    Bhatti, Sofie F M; Rao, Nagesha A S; Okkens, Auke C; Mol, Jan A; Duchateau, Luc; Ducatelle, Richard; van den Ingh, Ted S G A M; Tshamala, Mulenda; Van Ham, Luc M L; Coryn, Marc; Rijnberk, Ad; Kooistra, Hans S

    2007-10-01

    Endogenous progesterone and synthetic progestins may induce hypersecretion of growth hormone (GH) of mammary origin, hyperplastic ductular changes in the mammary gland, and the development of cystic endometrial hyperplasia (CEH) in dogs. It was investigated whether progestin-induced mammary GH plays a role in the pathogenesis of CEH in the bitch. During 1 year, bitches with surgically excised mammary glands and healthy control bitches received medroxyprogesterone acetate (MPA). Before and after MPA treatment, uterine and mammary tissues were collected for histological, immunohistochemical, and RT-PCR examination. After MPA administration, the mammary tissue in the control dogs had differentiated into lobulo-alveolar structures and CEH was present in all uteri of both dog groups. In the MPA-exposed mammary tissue of the control dogs, GH could only be demonstrated immunohistochemically in proliferating epithelium. After treatment with MPA the dogs of both groups had immunohistochemically demonstrable GH in the cytoplasm of hyperplastic glandular uterine epithelial cells. RT-PCR analysis of the mammary gland tissue after MPA administration demonstrated a significant higher GH gene, and lower GHR gene expression than before treatment. In the uterus, the expression of the gene encoding for GH was significantly increased in the mastectomized dogs, whereas in the control dogs the expression of the gene encoding for insulin-like growth factor-I had significantly increased with MPA administration. MPA treatment significantly down regulated PR gene expression in the uterus in both dog groups. These results indicate that progestin-induced GH of mammary origin is not an essential component in the development of CEH in the bitch.

  1. RUNX2 in mammary gland development and breast cancer.

    PubMed

    Ferrari, Nicola; McDonald, Laura; Morris, Joanna S; Cameron, Ewan R; Blyth, Karen

    2013-06-01

    Runx2 is best known as an essential factor in osteoblast differentiation and bone development but, like many other transcription factors involved in development, is known to operate over a much wider tissue range. Our understanding of these other aspects of Runx2 function is still at a relatively early stage and the importance of its role in cell fate decisions and lineage maintenance in non-osseous tissues is only beginning to emerge. One such tissue is the mammary gland, where Runx2 is known to be expressed and participate in the regulation of mammary specific genes. Furthermore, differential and temporal expression of this gene is observed during mammary epithelial differentiation in vivo, strongly indicative of an important functional role. Although the precise nature of that role remains elusive, preliminary evidence hints at possible involvement in the regulation of mammary stem and/or progenitor cells. As with many genes important in regulating cell fate, RUNX2 has also been linked to metastatic cancer where in some established breast cell lines, retention of expression is associated with a more invasive phenotype. More recently, expression analysis has been extended to primary breast cancers where high levels of RUNX2 align with a specific subtype of the disease. That RUNX2 expression correlates with the so called "Triple Negative" subtype is particularly interesting given the known cross talk between Runx2 and estrogen receptor signaling pathways. This review summaries our current understanding of Runx2 in mammary gland development and cancer, and postulates a role that may link both these processes.

  2. Mammary development, hyperestrogenemia, and hypocortisolemia in a male cat with an adrenal cortical carcinoma

    PubMed Central

    Nadolski, Amy C.; Markovich, Jessica E.; Jennings, Samuel H.; Mahony, Orla M.

    2016-01-01

    A 14-year-old neutered male domestic shorthaired cat was diagnosed with an adrenal cortical carcinoma causing hyperestrogenemia that resulted in mammary hyperplasia and sexual behavior. A right adrenalectomy and mammary gland biopsy were performed. Adrenal cortical neoplasia should be ruled out in any neutered male cat with mammary development and/or exhibiting sexual behavior. PMID:27708447

  3. Mammary development, hyperestrogenemia, and hypocortisolemia in a male cat with an adrenal cortical carcinoma.

    PubMed

    Nadolski, Amy C; Markovich, Jessica E; Jennings, Samuel H; Mahony, Orla M

    2016-10-01

    A 14-year-old neutered male domestic shorthaired cat was diagnosed with an adrenal cortical carcinoma causing hyperestrogenemia that resulted in mammary hyperplasia and sexual behavior. A right adrenalectomy and mammary gland biopsy were performed. Adrenal cortical neoplasia should be ruled out in any neutered male cat with mammary development and/or exhibiting sexual behavior.

  4. Amphiregulin: role in mammary gland development and breast cancer.

    PubMed

    McBryan, Jean; Howlin, Jillian; Napoletano, Silvia; Martin, Finian

    2008-06-01

    Extensive epithelial cell proliferation underlies the ductal morphogenesis of puberty that generates the mammary tree that will eventually fill the fat pad. This estrogen-dependent process is believed to be essentially dependent on locally produced growth factors that act in a paracrine fashion. EGF-like growth factor ligands, acting through EGF receptors are some of the principal promoters of pubertal ductal morphogenesis. Amphiregulin is the most abundant EGF-like growth factor in the pubertal mammary gland. Its gene is transcriptionally regulated by ERalpha, and recent evidence identifies it as a key mediator of the estrogen-driven epithelial cell proliferation of puberty: The pubertal deficiency in mammary gland ductal morphogenesis in ERalpha, amphiregulin, and EGFR knockout mice phenocopy each other. As a prognostic indicator in human breast cancer, amphiregulin indicates an outcome identical to that predicted by ERalpha presence. Despite this, a range of studies both on preneoplastic human breast tissue and on cell culture based models of breast cancer, suggest a possibly significant role for amphiregulin in driving human breast cancer progression. Here we summarise our current understanding of amphiregulin's contribution to mammary gland development and breast cancer progression.

  5. Mammary gland development: cell fate specification, stem cells and the microenvironment.

    PubMed

    Inman, Jamie L; Robertson, Claire; Mott, Joni D; Bissell, Mina J

    2015-03-15

    The development of the mammary gland is unique: the final stages of development occur postnatally at puberty under the influence of hormonal cues. Furthermore, during the life of the female, the mammary gland can undergo many rounds of expansion and proliferation. The mammary gland thus provides an excellent model for studying the 'stem/progenitor' cells that allow this repeated expansion and renewal. In this Review, we provide an overview of the different cell types that constitute the mammary gland, and discuss how these cell types arise and differentiate. As cellular differentiation cannot occur without proper signals, we also describe how the tissue microenvironment influences mammary gland development.

  6. Anti-Inflammatory Cytokine II-10 and Mammary Gland Development

    DTIC Science & Technology

    2008-08-01

    We then mated IL10+/- male with IL10+/- females to generate 144 experimental female mice with +/+ or -/- genotype (72 each) from 80 litters. After...IL-10 heterozygous female with IL-10 heterozygous male ; second, to develop essential techniques for mammary gland analysis so that we can compare...Since then, we have mated IL10+/- male with IL10+/- females to generate 144 experimental female mice with +/+ or -/- genotype (72 each) from 80

  7. 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

  8. Characterization of WWOX inactivation in murine mammary gland development.

    PubMed

    Abdeen, Suhaib K; Salah, Zaidoun; Khawaled, Saleh; Aqeilan, Rami I

    2013-07-01

    The WW domain-containing oxidoreductase (WWOX) is commonly inactivated in multiple human cancers, including breast cancer. Wwox null mice die prematurely precluding adult tumor analysis. Nevertheless, aging Wwox-heterozygous mice at C3H genetic background develop higher incidence of mammary tumors. We recently generated a Wwox conditional knockout mouse in which loxp sites flank exon 1 in the Wwox allele and showed that total ablation of WWOX in these mice resembles that of conventional targeting of Wwox. Here, we report the characterization of WWOX ablation in mouse mammary gland using MMTV-Cre transgenic line. We demonstrated that WWOX ablation leads to impaired mammary ductal growth. Moreover, targeted deletion of WWOX is associated with increased levels of fibronectin, a component of the extracellular matrix. In addition, we showed that shRNA knockdown of WWOX in MCF10A breast epithelial cells dramatically increased fibronectin and is associated with enhanced cell survival and impaired growth in three-dimensional culture Matrigel assay. Taken together our results are consistent with a critical role for WWOX in normal breast development and tumorigenesis.

  9. Morinda citrifolia (Noni) Juice Augments Mammary Gland Differentiation and Reduces Mammary Tumor Growth in Mice Expressing the Unactivated c-erbB2 Transgene

    PubMed Central

    Clafshenkel, William P.; King, Tracy L.; Kotlarczyk, Mary P.; Cline, J. Mark; Foster, Warren G.; Davis, Vicki L.; Witt-Enderby, Paula A.

    2012-01-01

    Morinda citrifolia (noni) is reported to have many beneficial properties, including on immune, inflammatory, quality of life, and cancer endpoints, but little is known about its ability to prevent or treat breast cancer. To test its anticancer potential, the effects of Tahitian Noni Juice (TNJ) on mammary carcinogenesis were examined in MMTV-neu transgenic mice. Mammary tumor latency, incidence, multiplicity, and metastatic incidence were unaffected by TNJ treatment, which suggests that it would not increase or decrease breast cancer risk in women taking TNJ for its other benefits. However, noni may be useful to enhance treatment responses in women with existing HER2/neu breast cancer since TNJ resulted in significant reductions in tumor weight and volume and in longer tumor doubling times in mice. Remarkably, its ability to inhibit the growth of this aggressive form of cancer occurred with the mouse equivalent of a recommended dose for humans (<3 oz/day). A 30-day treatment with TNJ also induced significant changes in mammary secondary ductule branching and lobuloalveolar development, serum progesterone levels, and estrous cycling. Additional studies investigating TNJ-induced tumor growth suppression and modified reproductive responses are needed to characterize its potential as a CAM therapy for women with and without HER2+ breast cancer. PMID:22619689

  10. Morinda citrifolia (Noni) Juice Augments Mammary Gland Differentiation and Reduces Mammary Tumor Growth in Mice Expressing the Unactivated c-erbB2 Transgene.

    PubMed

    Clafshenkel, William P; King, Tracy L; Kotlarczyk, Mary P; Cline, J Mark; Foster, Warren G; Davis, Vicki L; Witt-Enderby, Paula A

    2012-01-01

    Morinda citrifolia (noni) is reported to have many beneficial properties, including on immune, inflammatory, quality of life, and cancer endpoints, but little is known about its ability to prevent or treat breast cancer. To test its anticancer potential, the effects of Tahitian Noni Juice (TNJ) on mammary carcinogenesis were examined in MMTV-neu transgenic mice. Mammary tumor latency, incidence, multiplicity, and metastatic incidence were unaffected by TNJ treatment, which suggests that it would not increase or decrease breast cancer risk in women taking TNJ for its other benefits. However, noni may be useful to enhance treatment responses in women with existing HER2/neu breast cancer since TNJ resulted in significant reductions in tumor weight and volume and in longer tumor doubling times in mice. Remarkably, its ability to inhibit the growth of this aggressive form of cancer occurred with the mouse equivalent of a recommended dose for humans (<3 oz/day). A 30-day treatment with TNJ also induced significant changes in mammary secondary ductule branching and lobuloalveolar development, serum progesterone levels, and estrous cycling. Additional studies investigating TNJ-induced tumor growth suppression and modified reproductive responses are needed to characterize its potential as a CAM therapy for women with and without HER2(+) breast cancer.

  11. Neuregulin 3 and erbb signalling networks in embryonic mammary gland development.

    PubMed

    Kogata, Naoko; Zvelebil, Marketa; Howard, Beatrice A

    2013-06-01

    We review the role of Neuregulin 3 (Nrg3) and Erbb receptor signalling in embryonic mammary gland development. Neuregulins are growth factors that bind and activate its cognate Erbb receptor tyrosine kinases, which form a signalling network with established roles in breast development and breast cancer. Studies have shown that Nrg3 expression profoundly impacts early stages of embryonic mammary development. Network analysis shows how Nrg/Erbb signals could integrate with other major regulators of embryonic mammary development to elicit the morphogenetic processes and cell fate decisions that occur as the mammary lineage is established.

  12. Nonrandom frequency distribution of mitoses in rat lobuloaveolar mammary gland epithelium.

    PubMed Central

    Purnell, D. M.; Stowers, D. J.

    1977-01-01

    A quantitative microscopic technique was employed to examine the distribution of mitotic activity in the rat mammary gland. The frequency distribution of mitoses per unit volume of lobuloalveolar mammary gland epithelium in virgin Lewis/Mai rats at each phase of the estrous cycle were determined and compared to the expected Poisson frequency distributions, assuming random mitotic activity. Both pooled data and data from individual rats were compared to expected Poisson distributions. At each phase of the estrous cycle, the pooled observed distributions deviated significantly from Poisson distributions. Sixty-seven percent (72/108) of the observed frequency distributions obtained from individual rats also deviated significantly from expected Poisson distributions. These data indicate a nonrandom distribution of mitoses in rat lobuloalveolar mammary gland epithelium. This observation suggests that local cell products and/or a variation in the extent of replicative synchrony of lobuloalveolar cell populations may determine in part the pattern of mitotic activity in this tissue. A nonrandom distribution of mitoses in mammary epithelium may have significance in relation to the genesis of hyperplastic and neoplastic lesions of the mammary gland. PMID:560125

  13. Integrin β4 regulation of PTHrP underlies its contribution to mammary gland development.

    PubMed

    Li, Jiarong; Sun, Huayan; Feltri, M Laura; Mercurio, Arthur M

    2015-11-15

    The integrin α6β4 (referred to as β4) is expressed in epithelial cells where it functions as a laminin receptor. Although in vitro studies have implicated β4 in the biology of mammary epithelial cells, its contribution to mammary gland development has not been settled. To address this problem, we generated and analyzed itgb4(flox/flox)MMTV-Cre(-) and itgb4(flox/flox)MMTV-Cre(+) mice. The salient features of embryonic mammary tissue from itgb4(flox/flox)MMTV-Cre(+) mice were significantly smaller mammary buds and increased apoptosis in the surrounding mesenchyme. Also, compared to control glands, the itgb4-deleted mammary buds lacked expression of the progenitor cell marker CK14 and they were unable to generate mammary glands upon transplantation into cleared fat pads of recipient mice. Analysis of mammary glands at puberty and during pregnancy revealed that itgb4-diminished mammary tissue was unable to elongate and undergo branching morphogenesis. Micro-dissection of epithelial cells in the mammary bud and of the surrounding mesenchyme revealed that loss of β4 resulted in a significant decrease in the expression of parathyroid hormone related protein (PTHrP) in epithelial cells and of target genes of the PTHrP receptor in mesenchymal cells. Given that the phenotype of the itgb4-deleted mammary tissue mimicked that of the PTHrP knockout, we hypothesized that β4 contributes to mammary gland development by sustaining PTHrP expression and enabling PTHrP signaling. Indeed, the inability of itgb4-deleted mammary buds to elongate was rescued by exogenous PTHrP. These data implicate a critical role for the β4 integrin in mammary gland development and provide a mechanism for this role.

  14. 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.

  15. 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.

  16. The biology of zinc transport in mammary epithelial cells: implications for mammary gland development, lactation, and involution.

    PubMed

    McCormick, Nicholas H; Hennigar, Stephen R; Kiselyov, Kirill; Kelleher, Shannon L

    2014-03-01

    Zinc plays a critical role in a vast array of cellular functions including gene transcription, protein translation, cell proliferation, differentiation, bioenergetics, and programmed cell death. The mammary gland depends upon tight coordination of these processes during development and reproduction for optimal expansion, differentiation, and involution. For example, zinc is required for activation of matrix metalloproteinases, intracellular signaling cascades such as MAPK and PKC, and the activation of both mitochondrial-mediated apoptosis and lysosomal-mediated cell death. In addition to functional needs, during lactation the mammary gland must balance providing optimal zinc for cellular requirements with the need to secrete a substantial amount of zinc into milk to meet the requirements of the developing neonate. Finally, the mammary gland exhibits the most profound example of programmed cell death, which is driven by both apoptotic and lysosomal-mediated cell death. Two families of zinc-specific transporters regulate zinc delivery for these diverse functions. Members of the ZIP family of zinc transporters (ZIP1-14) import zinc into the cytoplasm from outside the cell or from subcellular organelles, while members of the ZnT family (ZnT1-10) export zinc from the cytoplasm. Recently, the ion channel transient receptor potential mucolipin 1 (TRPML1) has also been implicated in zinc transport. Herein, we review our current understanding of the molecular mechanisms through which mammary epithelial cells utilize zinc with a focus on the transport of zinc into discrete subcellular organelles for specific cellular functions during mammary gland development, lactation, and involution.

  17. Interplay between progesterone and prolactin in mammary development and implications for breast cancer.

    PubMed

    Lee, Heather J; Ormandy, Christopher J

    2012-06-24

    Progesterone and prolactin remodel mammary morphology during pregnancy by acting on the mammary epithelial cell hierarchy. The roles of each hormone in mammary development have been well studied, but evidence of signalling cross-talk between progesterone and prolactin is still emerging. Factors such as receptor activator of NFkB ligand (RANKL) may integrate signals from both hormones to orchestrate their joint actions on the epithelial cell hierarchy. Common targets of progesterone and prolactin signalling are also likely to integrate their pro-proliferative actions in breast cancer. Therefore, a thorough understanding of the interplay between progesterone and prolactin in mammary development may reveal therapeutic targets for breast cancer. This review summarises our understanding of Pg and PRL action in mammary gland development before focusing on molecular mechanisms of signalling cross-talk and the implications for breast cancer.

  18. s-SHIP promoter expression marks activated stem cells in developing mouse mammary tissue

    PubMed Central

    Bai, Lixia; Rohrschneider, Larry R.

    2010-01-01

    Mammary stem cells (MaSCs) play critical roles in normal development and perhaps tumorigenesis of the mammary gland. Using combined cell markers, adult MaSCs have been enriched in a basal cell population, but the exact identity of MaSCs remains unknown. We used the s-SHIP promoter to tag presumptive stem cells with GFP in the embryos of a transgenic mouse model. Here we show, in postnatal mammary gland development, that GFP+ cap cells in puberty and basal alveolar bud cells in pregnancy each exhibit self-renewal and regenerative capabilities for all mammary epithelial cells of a new functional mammary gland upon transplantation. Single GFP+ cells can regenerate the mammary epithelial network. GFP+ mammary epithelial cells are p63+, CD24mod, CD49fhigh, and CD29high; are actively proliferating; and express s-SHIP mRNA. Overall, our results identify the activated MaSC population in vivo at the forefront of rapidly developing terminal end buds (puberty) and alveolar buds (pregnancy) in the mammary gland. In addition, GFP+ basal cells are expanded in MMTV-Wnt1 breast tumors but not in ErbB2 tumors. These results enable MaSC in situ identification and isolation via a consistent single parameter using a new mouse model with applications for further analyses of normal and potential cancer stem cells. PMID:20810647

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

    PubMed Central

    LÍŠKA, Ján; BRTKO, Július; DUBOVICKÝ, Michal; MACEJOVÁ, Dana; KISSOVÁ, Viktória; POLÁK, Štefan; UJHÁZY, Eduard

    2015-01-01

    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

  20. 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

    2016-01-01

    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.

  1. 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 ...

  2. Impact of diethylhexyl phthalate on gene expression and development of mammary glands of pregnant mouse.

    PubMed

    Li, Lan; Liu, Jing-Cai; Zhao, Yong; Lai, Fang-Nong; Yang, Fan; Ge, Wei; Dou, Cheng-Li; Shen, Wei; Zhang, Xi-Feng; Chen, Hong

    2015-10-01

    The widely used diethylhexyl phthalate (DEHP) is a known endocrine disruptor that causes persistent alterations in the structure and function of female reproductive system, including ovaries, uterus and oviducts. To explore the molecular mechanism of the effect of DEHP on the development of mammary glands, we investigated the cell cycle, growth, proliferation and gene expression of mammary gland cells of pregnant mice exposed to DEHP. It was demonstrated, for the first time, that the mammary gland cells of pregnant mice treated with DEHP for 0.5-3.5 days post-coitum had increased proliferation, growth rate and number of cells in the G2/S phase. The expression of cell proliferation-related genes was significantly altered after short time and low-dose DEHP treatment of mammary gland cells in vivo and in vitro. These findings showed adverse effects of DEHP on mammary gland cells in pregnant mice.

  3. Mixtures of environmentally relevant endocrine disrupting chemicals affect mammary gland development in female and male rats.

    PubMed

    Mandrup, Karen Riiber; Johansson, Hanna Katarina Lilith; Boberg, Julie; Pedersen, Anne Stilling; Mortensen, Mette Sidsel; Jørgensen, Jennifer Solgaard; Vinggaard, Anne Marie; Hass, Ulla

    2015-07-01

    Estrogenic chemicals are able to alter mammary gland development in female rodents, but little is known on the effects of anti-androgens and mixtures of endocrine disrupting chemicals (EDCs) with dissimilar modes of action. Pregnant rat dams were exposed during gestation and lactation to mixtures of environmentally relevant EDCs with estrogenic, anti-androgenic or dissimilar modes of action (TotalMix) of 100-, 200- or 450-fold high end human intake estimates. Mammary glands of prepubertal and adult female and male offspring were examined. Oestrogens increased mammary outgrowth in prepubertal females and the mRNA level of matrix metalloproteinase-3, which may be a potential biomarker for increased outgrowth. Mixtures of EDCs gave rise to ductal hyperplasia in adult males. Adult female mammary glands of the TotalMix group showed morphological changes possibly reflecting increased prolactin levels. In conclusion both estrogenic and anti-androgenic chemicals given during foetal life and lactation affected mammary glands in the offspring.

  4. Differential roles of ERα and ERβ in normal and neoplastic development in the mouse mammary gland.

    PubMed

    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.

  5. Shh expression is required for embryonic hair follicle but not mammary gland development.

    PubMed

    Michno, Kinga; Boras-Granic, Kata; Mill, Pleasantine; Hui, C C; Hamel, Paul A

    2003-12-01

    The embryonic mammary gland and hair follicle are both derived from the ventral ectoderm, and their development depends on a number of common fundamental developmental pathways. While the Hedgehog (Hh) signaling pathway is required for hair follicle morphogenesis, the role of this pathway during embryonic mammary gland development remains undetermined. We demonstrate here that, unlike the hair follicle, both Shh and Ihh are expressed in the developing embryonic mouse mammary rudiment as early as E12.5. In Shh(-/-) embryos, hair follicle development becomes arrested at an early stage, while the mammary rudiment, which continues to express Ihh, develops in a manner indistinguishable from that of wild-type littermates. The five pairs of mammary buds in Shh(-/-) female embryos exhibit normal branching morphogenesis at E16.5, forming a rudimentary ductal structure identical to wild-type embryonic mammary glands. We further demonstrate that loss of Hh signaling causes altered cyclin D1 expression in the embryonic dermal mesenchyme. Specifically, cyclin D1 is expressed at E14.5 principally in the condensed mesenchymal cells of the presumptive hair follicles and in both mesenchymal and epithelial cells of the mammary rudiments in wild-type and Shh-deficient embryos. By E18.5, robust cyclin D1 expression is maintained in mammary rudiments of both wild-type and Shh-deficient embryos. In hair follicles of wild-type embryos by E18.5, cyclin D1 expression switches to follicular epithelial cells. In contrast, strong cyclin D1 expression is observed principally in the mesenchymal cells of arrested hair follicles in Shh(-/-) embryos at E18.5. These data reveal that, despite the common embryonic origin of hair follicles and mammary glands, distinct patterns of Hh-family expression occur in these two tissues. Furthermore, these data suggest that cyclin D1 expression in the embryonic hair follicle is mediated by both Hh-independent and Hh-dependent mechanisms.

  6. Estrogen receptor alpha is required for mammary development and the induction of mammary hyperplasia and epigenetic alterations in the aromatase transgenic mice.

    PubMed

    Tekmal, Rajeshwar Rao; Liu, Ya-Guang; Nair, Hareesh B; Jones, Jeremy; Perla, Rao P; Lubahn, Dennis B; Korach, Kenneth S; Kirma, Nameer

    2005-05-01

    Aromatase transgenic mice exhibit hyperplastic and dysplastic changes, attesting to the importance of local estrogen in breast carcinogenesis. These mice also show increased levels of the estrogen receptor alpha and beta (ERalpha, ERbeta) suggesting that this receptor may play an important role in the initiation of estrogen-mediated mammary hyperplasia observed in these mice. To address the specific role of ERalpha in the mammary development and in the induction of estrogen-mediated hyperplasia in aromatase transgenic mice, we have generated MMTV-aromatase x ERalpha knockout cross (referred as aromatase/ERKO). Even though ERbeta is expressed in aromatase/ERKO mice, lack of ERalpha leads to impaired mammary growth in these mice. The data suggest that ERalpha plays an important role in the mammary gland development as well as in the induction of mammary hyperplasia in aromatase transgenic mice. Lack of ERalpha expression in the aromatase/ERKO mice resulted in a decrease in the expression of Cyclin D1, PCNA and TGFbeta relative to the aromatase parental strain. The studies involving aromatase/ERKO mice show that lack of ERalpha results in impaired mammary development even in the presence of continuous tissue estrogen, suggesting estrogen/ERalpha-mediated actions are critical for mammary development and carcinogenesis.

  7. 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.

  8. Mammary epithelial cell: Influence of extracellular matrix composition and organization during development and tumorigenesis

    PubMed Central

    Kass, Laura; Erler, Janine T.; Dembo, Micah; Weaver, Valerie M.

    2009-01-01

    Stromal–epithelial interactions regulate mammary gland development and are critical for the maintenance of tissue homeostasis. The extracellular matrix, which is a proteinaceous component of the stroma, regulates mammary epithelial growth, survival, migration and differentiation through a repertoire of transmembrane receptors, of which integrins are the best characterized. Integrins modulate cell fate by reciprocally transducing biochemical and biophysical cues between the cell and the extracellular matrix, facilitating processes such as embryonic branching morphogenesis and lactation in the mammary gland. During breast development and cancer progression, the extracellular matrix is dynamically altered such that its composition, turnover, processing and orientation change dramatically. These modifications influence mammary epithelial cell shape, and modulate growth factor and hormonal responses to regulate processes including branching morphogenesis and alveolar differentiation. Malignant transformation of the breast is also associated with significant matrix remodeling and a progressive stiffening of the stroma that can enhance mammary epithelial cell growth, perturb breast tissue organization, and promote cell invasion and survival. In this review, we discuss the role of stromal–epithelial interactions in normal and malignant mammary epithelial cell behavior. We specifically focus on how dynamic modulation of the biochemical and biophysical properties of the extracellular matrix elicit a dialogue with the mammary epithelium through transmembrane integrin receptors to influence tissue morphogenesis, homeostasis and malignant transformation. PMID:17719831

  9. 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...

  10. 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...

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

    PubMed

    Johnson, Abby L; Zinser, Glendon M; Waltz, Susan E

    2014-10-15

    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.

  12. Pleiotropic functions of fibroblast growth factor signaling in embryonic mammary gland development.

    PubMed

    Kim, Eun-Jung; Jung, Han-Sung; Lu, Pengfei

    2013-06-01

    The mammary gland is an ectodermal appendage and a defining feature of mammals. Consistent with it being a recent evolutionary novelty, many of the molecules essential for the ontogeny and morphogenesis of various vertebrate organs, including those in the fibroblast growth factor (FGF) signaling pathway, are co-opted for induction, maintenance and morphogenesis of the mammary glands. Understanding the mechanism whereby FGF signaling regulates the fundamental cell behavior during normal mammary gland develop may facilitate determination of the consequences of its deregulation during breast cancer progression.

  13. Differential requirement of GRP94 and GRP78 in mammary gland development

    PubMed Central

    Zhu, Genyuan; Wang, Miao; Spike, Benjamin; Gray, Peter C.; Shen, Jieli; Lee, Sung-Hyung; Chen, Si-Yi; Lee, Amy S.

    2014-01-01

    Glucose Regulated Protein (GRP) 94 and GRP78 are critical molecular chaperones and regulators of signaling. Conditional knockout mouse models have revealed tissue specific requirements for GRP94 and GRP78, including selection for allele retention in specific cell types. Here we report the consequences of mammary-targeted knockout of these GRPs. Our studies revealed that MMTV-Cre, Grp94f/f mammary glands, despite GRP94 deficiency, exhibited normal proliferation and ductal morphogenesis. Interestingly, MMTV-Cre, Grp78f/f mammary glands displayed only slightly reduced GRP78 protein levels, associating with the retention of the non-recombined Grp78 floxed alleles in isolated mammary epithelial cells and displayed phenotypes comparable to wild-type glands. In contrast, transduction of isolated Grp78f/f mammary epithelial stem/progenitor cells with adenovirus expressing GFP and Cre-recombinase was successful in GRP78 ablation, and the GFP sorted cells failed to give rise to repopulated mammary glands in de-epithelialized recipient mice. These studies imply GRP78, but not GRP94, is required for mammary gland development. PMID:24953136

  14. Evidence that the growth hormone receptor mediates differentiation and development of the mammary gland.

    PubMed

    Feldman, M; Ruan, W; Cunningham, B C; Wells, J A; Kleinberg, D L

    1993-10-01

    We have shown that nonlactogenic rat (r) GH is far more potent than rPRL in inducing rat mammary development. To determine the relative roles of GH and PRL in mammary development and their mechanisms of action, we have compared the abilities of a group of native and mutant GHs, PRLs, and placental lactogens (PLs) to induce mammary development, bind to GH receptors, and activate lactogenic receptors. Mammary development was assessed histologically by counting terminal end buds and alveolar structures in glands from sexually immature, hypophysectomized, castrated, estradiol-treated rats. Hormones were implanted, in Elvax pellets, into the lumbar mammary gland. Significant increases in terminal end buds (P < 0.03) over internal control values were obtained with rGH, recombinant human GH (rhGH), rbGH, and one of two mutant rhGHs. These four hormones were also found to bind to GH receptors with high affinity. In contrast, little development occurred with hPRL, rPRL, rhPL, ovine PRL, mutant forms of rhPRL and rhPL, and a mutant of rhGH altered to reduce binding to GH and PRL receptors. All of these substances are more than 50-fold reduced in binding to the GH receptor, yet can bind and activate lactogenic receptors. Thus, only those natural or mutant pituitary or placental hormones with high binding affinity to GH receptors induce mammary development, suggesting that GH receptors play a central role in this process.

  15. Development of novel murine mammary imaging windows to examine wound healing effects on leukocyte trafficking in mammary tumors with intravital imaging

    PubMed Central

    Sobolik, Tammy; Su, Ying-Jun; Ashby, Will; Schaffer, David K.; Wells, Sam; Wikswo, John P.; Zijlstra, Andries; Richmond, Ann

    2016-01-01

    ABSTRACT We developed mammary imaging windows (MIWs) to evaluate leukocyte infiltration and cancer cell dissemination in mouse mammary tumors imaged by confocal microscopy. Previous techniques relied on surgical resection of a skin flap to image the tumor microenvironment restricting imaging time to a few hours. Utilization of mammary imaging windows offers extension of intravital imaging of the tumor microenvironment. We have characterized strengths and identified some previously undescribed potential weaknesses of MIW techniques. Through iterative enhancements of a transdermal portal we defined conditions for improved quality and extended confocal imaging time for imaging key cell-cell interactions in the tumor microenvironment. PMID:28243517

  16. Development of novel murine mammary imaging windows to examine wound healing effects on leukocyte trafficking in mammary tumors with intravital imaging.

    PubMed

    Sobolik, Tammy; Su, Ying-Jun; Ashby, Will; Schaffer, David K; Wells, Sam; Wikswo, John P; Zijlstra, Andries; Richmond, Ann

    2016-01-01

    We developed mammary imaging windows (MIWs) to evaluate leukocyte infiltration and cancer cell dissemination in mouse mammary tumors imaged by confocal microscopy. Previous techniques relied on surgical resection of a skin flap to image the tumor microenvironment restricting imaging time to a few hours. Utilization of mammary imaging windows offers extension of intravital imaging of the tumor microenvironment. We have characterized strengths and identified some previously undescribed potential weaknesses of MIW techniques. Through iterative enhancements of a transdermal portal we defined conditions for improved quality and extended confocal imaging time for imaging key cell-cell interactions in the tumor microenvironment.

  17. Gli activity is critical at multiple stages of embryonic mammary and nipple development.

    PubMed

    Chandramouli, Anupama; Hatsell, Sarah J; Pinderhughes, Alicia; Koetz, Lisa; Cowin, Pamela

    2013-01-01

    Gli3 is a transcriptional regulator of Hedgehog (Hh) signaling that functions as a repressor (Gli3(R)) or activator (Gli3(A)) depending upon cellular context. Previously, we have shown that Gli3(R) 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 Gli3(xt/xt) mice. Importantly, mice genetically manipulated to misactivate Hh signaling displayed the same phenotypic spectrum demonstrating that the repressor function of Gli3(R) 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 Gli3(R) is critical for early placodal patterning and later mammary mesenchyme specification whereas positive Hh signaling occurs during nipple development.

  18. Lifelong exposure to n-3 PUFA affects pubertal mammary gland development.

    PubMed

    Anderson, Breanne M; MacLennan, Mira B; Hillyer, Lyn M; Ma, David W L

    2014-06-01

    There is growing evidence that early developmental periods may importantly influence future breast cancer risk. Also, there is great interest in the role of dietary fat in breast cancer risk, but the role of dietary fat during pubertal mammary gland development remains poorly understood. This study investigated the effect of n-3 polyunsaturated fatty acids (PUFA) using complementary dietary and genetic approaches to examine the effect of lifelong exposure of n-3 PUFA or n-6 PUFA (control) on mammary gland development and fatty acid composition. n-3 PUFA from both diet and genetics were enriched in mammary glands as early as 3 weeks of age. Parameters related to mammary gland development, including number of terminal end buds (TEB), percent coverage of ductal tree, and infiltration of TEB, were influenced by n-3 PUFA at 3 and 4 weeks of age. Overall, findings suggest that n-3 PUFA incorporation into the mammary gland early in life plays a role in the morphological development of the mammary gland during puberty.

  19. Endocrine hormones and local signals during the development of the mouse mammary gland.

    PubMed

    Brisken, Cathrin; Ataca, Dalya

    2015-01-01

    Most of mammary gland development occurs postnatally under the control of female reproductive hormones, which in turn interact with other endocrine factors. While hormones impinge on many tissues and trigger very complex biological responses, tissue recombination experiments with hormone receptor-deficient mammary epithelia revealed eminent roles for estrogens, progesterone, and prolactin receptor (PrlR) signaling that are intrinsic to the mammary epithelium. A subset of the luminal mammary epithelial cells expresses the estrogen receptor α (ERα), the progesterone receptor (PR), and the PrlR and act as sensor cells. These cells convert the detected systemic signals into local signals that are developmental stage-dependent and may be direct, juxtacrine, or paracrine. This setup ensures that the original input is amplified and that the biological responses of multiple cell types can be coordinated. Some key mediators of hormone action have been identified such as Wnt, EGFR, IGFR, and RANK signaling. Multiple signaling pathways such as FGF, Hedgehog, and Notch signaling participate in driving different aspects of mammary gland development locally but how they link to the hormonal control remains to be elucidated. An increasing number of endocrine factors are appearing to have a role in mammary gland development, the adipose tissue is increasingly recognized to play a role in endocrine regulation, and a complex role of the immune system with multiple different cell types is being revealed. For further resources related to this article, please visit the WIREs website.

  20. Development and characterization of a novel rat model of estrogen-induced mammary cancer.

    PubMed

    Dennison, Kirsten L; Samanas, Nyssa Becker; Harenda, Quincy Eckert; Hickman, Maureen Peters; Seiler, Nicole L; Ding, Lina; Shull, James D

    2015-04-01

    The ACI rat model of 17β-estradiol (E2)-induced mammary cancer is highly relevant for use in establishing the endocrine, genetic, and environmental bases of breast cancer etiology and identifying novel agents and strategies for preventing breast cancer. E2 treatment rapidly induces mammary cancer in female ACI rats and simultaneously induces pituitary lactotroph hyperplasia and adenoma. The pituitary tumors can result in undesired morbidity, which compromises long-term studies focused on mammary cancer etiology and prevention. We have defined the genetic bases of susceptibility to E2-induced mammary cancers and pituitary tumors and have utilized the knowledge gained in these studies to develop a novel inbred rat strain, designated ACWi, that retains the high degree of susceptibility to E2-induced mammary cancer exhibited by ACI rats, but lacks the treatment-related morbidity associated with pituitary lactotroph hyperplasia/adenoma. When treated with E2, female ACWi rats developed palpable mammary cancer at a median latency of 116 days, an incidence of 100% by 161 days and exhibited an average of 15.6 mammary tumors per rat following 196 days of treatment. These parameters did not differ from those observed for contemporaneously treated ACI rats. None of the E2-treated ACWi rats were killed before the intended experimental end point due to any treatment-related morbidity other than mammary cancer burden, whereas 20% of contemporaneously treated ACI rats exhibited treatment-related morbidity that necessitated premature killing. The ACWi rat strain is well suited for use by those in the research community, focusing on breast cancer etiology and prevention.

  1. Atypical chemokine receptor ACKR2 controls branching morphogenesis in the developing mammary gland.

    PubMed

    Wilson, Gillian J; Hewit, Kay D; Pallas, Kenneth J; Cairney, Claire J; Lee, Kit M; Hansell, Christopher A; Stein, Torsten; Graham, Gerard J

    2017-01-01

    Macrophages are important regulators of branching morphogenesis during development and postnatally in the mammary gland. Regulation of macrophage dynamics during these processes can therefore have a profound impact on development. We demonstrate here that the developing mammary gland expresses high levels of inflammatory CC-chemokines, which are essential in vivo regulators of macrophage migration. We further demonstrate that the atypical chemokine receptor ACKR2, which scavenges inflammatory CC-chemokines, is differentially expressed during mammary gland development. We have previously shown that ACKR2 regulates macrophage dynamics during lymphatic vessel development. Here, we extend these observations to reveal a novel role for ACKR2 in regulating the postnatal development of the mammary gland. Specifically, we show that Ackr2(-/-) mice display precocious mammary gland development. This is associated with increased macrophage recruitment to the developing gland and increased density of the ductal epithelial network. These data demonstrate that ACKR2 is an important regulator of branching morphogenesis in diverse biological contexts and provide the first evidence of a role for chemokines and their receptors in postnatal development processes.

  2. Atypical chemokine receptor ACKR2 controls branching morphogenesis in the developing mammary gland

    PubMed Central

    Hewit, Kay D.; Pallas, Kenneth J.; Cairney, Claire J.; Lee, Kit M.; Hansell, Christopher A.; Stein, Torsten

    2017-01-01

    Macrophages are important regulators of branching morphogenesis during development and postnatally in the mammary gland. Regulation of macrophage dynamics during these processes can therefore have a profound impact on development. We demonstrate here that the developing mammary gland expresses high levels of inflammatory CC-chemokines, which are essential in vivo regulators of macrophage migration. We further demonstrate that the atypical chemokine receptor ACKR2, which scavenges inflammatory CC-chemokines, is differentially expressed during mammary gland development. We have previously shown that ACKR2 regulates macrophage dynamics during lymphatic vessel development. Here, we extend these observations to reveal a novel role for ACKR2 in regulating the postnatal development of the mammary gland. Specifically, we show that Ackr2−/− mice display precocious mammary gland development. This is associated with increased macrophage recruitment to the developing gland and increased density of the ductal epithelial network. These data demonstrate that ACKR2 is an important regulator of branching morphogenesis in diverse biological contexts and provide the first evidence of a role for chemokines and their receptors in postnatal development processes. PMID:27888192

  3. The Cellular Targets of Estrogen in Mammary Ductal Development

    DTIC Science & Technology

    2000-06-01

    DAMD17-99-1-9109 Organization: University of California, San Francisco Those portions of the technical data contained in this report marked as limited...Src tyrosine kinase is required for the induction of mammary tumors in transgenic mice. Genes Dev, 8,23-32 Li, B., Rosen, J. M., McMenamin , B. J

  4. Key signalling nodes in mammary gland development and cancer. Mitogen-activated protein kinase signalling in experimental models of breast cancer progression and in mammary gland development.

    PubMed

    Whyte, Jacqueline; Bergin, Orla; Bianchi, Alessandro; McNally, Sara; Martin, Finian

    2009-01-01

    Seven classes of mitogen-activated protein kinase (MAPK) intracellular signalling cascades exist, four of which are implicated in breast disease and function in mammary epithelial cells. These are the extracellular regulated kinase (ERK)1/2 pathway, the ERK5 pathway, the p38 pathway and the c-Jun N-terminal kinase (JNK) pathway. In some forms of human breast cancer and in many experimental models of breast cancer progression, signalling through the ERK1/2 pathway, in particular, has been implicated as being important. We review the influence of ERK1/2 activity on the organised three-dimensional association of mammary epithelial cells, and in models of breast cancer cell invasion. We assess the importance of epidermal growth factor receptor family signalling through ERK1/2 in models of breast cancer progression and the influence of ERK1/2 on its substrate, the oestrogen receptor, in this context. In parallel, we consider the importance of these MAPK-centred signalling cascades during the cycle of mammary gland development. Although less extensively studied, we highlight the instances of signalling through the p38, JNK and ERK5 pathways involved in breast cancer progression and mammary gland development.

  5. Inhibition of peripubertal sheep mammary gland development by cysteamine through reducing progesterone and growth factor production.

    PubMed

    Zhao, Yong; Feng, Yanni; Zhang, Hongfu; Kou, Xin; Li, Lan; Liu, Xinqi; Zhang, Pengfei; Cui, Liantao; Chu, Meiqiang; Shen, Wei; Min, Lingjiang

    2017-02-01

    Cysteamine has been used for treating cystinosis for many years, and furthermore it has also been used as a therapeutic agent for different diseases including Huntington's disease, Parkinson's disease (PD), nonalcoholic fatty liver disease, malaria, cancer, and others. Although cysteamine has many potential applications, its use may also be problematic. The effects of low doses of cysteamine on the reproductive system, especially the mammary glands are currently unknown. In the current investigation, low dose (10 mg/kg BW/day) of cysteamine did not affect sheep body weight gain or organ index of the liver, spleen, or heart; it did, however, increase the levels of blood lymphocytes, monocytes, and platelets. Most interestingly, it inhibited mammary gland development after 2 or 5 months of treatment by reducing the organ index and the number of mammary gland ducts. Plasma growth hormone and estradiol remained unchanged; however, plasma progesterone levels and the protein level of HSD3β1 in sheep ovaries were decreased by cysteamine. In addition to steroid hormones, growth factors produced in the mammary glands also play crucial roles in mammary gland development. Results showed that protein levels of HGF, GHR, and IGF1R were decreased after 5 months of cysteamine treatment. These findings together suggest that progesterone and local growth factors in mammary glands might be involved in cysteamine initiated inhibition of pubertal ovine mammary gland development. Furthermore, it may lead to a reduction in fertility. Therefore, cysteamine should be used with great caution until its actions have been further investigated and its limitations overcome.

  6. Effects of the Insulin-like Growth Factor Pathway on the Regulation of Mammary Gland Development

    PubMed Central

    Ha, Woo Tae; Jeong, Ha Yeon; Lee, Seung Yoon; Song, Hyuk

    2016-01-01

    The insulin-like growth factor (IGF) pathway is a key signal transduction pathway involved in cell proliferation, migration, and apoptosis. In dairy cows, IGF family proteins and binding receptors, including their intracellular binding partners, regulate mammary gland development. IGFs and IGF receptor interactions in mammary glands influence the early stages of mammogenesis, i.e., mammary ductal genesis until puberty. The IGF pathway includes three major components, IGFs (such as IGF-I, IGF-II, and insulin), their specific receptors, and their high-affinity binding partners (IGF binding proteins [IGFBPs]; i.e., IGFBP1–6), including specific proteases for each IGFBP. Additionally, IGFs and IGFBP interactions are critical for the bioactivities of various intracellular mechanisms, including cell proliferation, migration, and apoptosis. Notably, the interactions between IGFs and IGFBPs in the IGF pathway have been difficult to characterize during specific stages of bovine mammary gland development. In this review, we aim to describe the role of the interaction between IGFs and IGFBPs in overall mammary gland development in dairy cows. PMID:27795999

  7. Integrated extracellular matrix signaling in mammary gland development and breast cancer progression.

    PubMed

    Zhu, Jieqing; Xiong, Gaofeng; Trinkle, Christine; Xu, Ren

    2014-09-01

    Extracellular matrix (ECM), a major component of the cellular microenvironment, plays critical roles in normal tissue morphogenesis and disease progression. Binding of ECM to membrane receptor proteins, such as integrin, discoidin domain receptors, and dystroglycan, elicits biochemical and biomechanical signals that control cellular architecture and gene expression. These ECM signals cooperate with growth factors and hormones to regulate cell migration, differentiation, and transformation. ECM signaling is tightly regulated during normal mammary gland development. Deposition and alignment of fibrillar collagens direct migration and invasion of mammary epithelial cells during branching morphogenesis. Basement membrane proteins are required for polarized acinar morphogenesis and milk protein expression. Deregulation of ECM proteins in the long run is sufficient to promote breast cancer development and progression. Recent studies demonstrate that the integrated biophysical and biochemical signals from ECM and soluble factors are crucial for normal mammary gland development as well as breast cancer progression.

  8. Epigenetic Modifications Unlock the Milk Protein Gene Loci during Mouse Mammary Gland Development and Differentiation

    PubMed Central

    Rijnkels, Monique; Freeman-Zadrowski, Courtneay; Hernandez, Joseph; Potluri, Vani; Wang, Liguo; Li, Wei; Lemay, Danielle G.

    2013-01-01

    Background Unlike 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 organization plays a key role in transcriptional regulation and underlies epigenetic regulation during development and differentiation. However, the role of chromatin organization in mammary gland development and differentiation is less well-defined. Here, we have studied the changes in chromatin organization at the milk protein gene loci (casein, whey acidic protein, and others) in the mouse mammary gland before and after functional differentiation. Methodology/Principal Findings Distal regulatory elements within the casein gene cluster and whey acidic protein gene region have an open chromatin organization after pubertal development, while proximal promoters only gain open-chromatin marks during pregnancy in conjunction with the major induction of their expression. In contrast, other milk protein genes, such as alpha-lactalbumin, already have an open chromatin organization in the mature virgin gland. Changes in chromatin organization in the casein gene cluster region that are present after puberty persisted after lactation has ceased, while the changes which occurred during pregnancy at the gene promoters were not maintained. In general, mammary gland expressed genes and their regulatory elements exhibit developmental stage- and tissue-specific chromatin organization. Conclusions/Significance A progressive gain of epigenetic marks indicative of open/active chromatin on genes marking functional differentiation accompanies the development of the mammary gland. These results support a model in which a chromatin organization is established during pubertal development that is then poised to respond to the systemic hormonal signals of pregnancy and lactation to achieve the

  9. Epithelial Xbp1 Is Required for Cellular Proliferation and Differentiation during Mammary Gland Development

    PubMed Central

    Hasegawa, Daisuke; Calvo, Veronica; Avivar-Valderas, Alvaro; Lade, Abigale; Chou, Hsin-I; Lee, Youngmin A.; Farias, Eduardo F.; Aguirre-Ghiso, Julio A.

    2015-01-01

    Xbp1, a key mediator of the unfolded protein response (UPR), is activated by IRE1α-mediated splicing, which results in a frameshift to encode a protein with transcriptional activity. However, the direct function of Xbp1 in epithelial cells during mammary gland development is unknown. Here we report that the loss of Xbp1 in the mammary epithelium through targeted deletion leads to poor branching morphogenesis, impaired terminal end bud formation, and spontaneous stromal fibrosis during the adult virgin period. Additionally, epithelial Xbp1 deletion induces endoplasmic reticulum (ER) stress in the epithelium and dramatically inhibits epithelial proliferation and differentiation during lactation. The synthesis of milk and its major components, α/β-casein and whey acidic protein (WAP), is significantly reduced due to decreased prolactin receptor (Prlr) and ErbB4 expression in Xbp1-deficient mammary epithelium. Reduction of Prlr and ErbB4 expression and their diminished availability at the cell surface lead to reduced phosphorylated Stat5, an essential regulator of cell proliferation and differentiation during lactation. As a result, lactating mammary glands in these mice produce less milk protein, leading to poor pup growth and postnatal death. These findings suggest that the loss of Xbp1 induces a terminal UPR which blocks proliferation and differentiation during mammary gland development. PMID:25713103

  10. Prenatal Mammary Gland Development in the Mouse: Research Models and Techniques for Its Study from Past to Present.

    PubMed

    Veltmaat, Jacqueline M

    2017-01-01

    Mammary gland development starts during prenatal life, when at designated positions along the ventrolateral boundary of the embryonic or fetal trunk, surface ectodermal cells coalesce to form primordia for mammary glands, instead of differentiating into epidermis. With the wealth of genetically engineered mice available as research models, our understanding of the prenatal phase of mammary development has recently greatly advanced. This understanding includes the recognition of molecular and mechanistic parallels between prenatal and postnatal mammary morphogenesis and even tumorigenesis, much of which can moreover be extrapolated to human. This makes the murine embryonic mammary gland a useful model for a myriad of questions pertaining to normal and pathological breast development. Hence, unless indicated otherwise, this review describes embryonic mammary gland development in mouse only, and lists mouse models that have been examined for defects in embryonic mammary development. Techniques that originated in the field of developmental biology, such as explant culture and tissue recombination, were adapted specifically to research on the embryonic mammary gland. Detailed protocols for these techniques have recently been published elsewhere. This review describes how the development and adaptation of these techniques moved the field forward from insights on (comparative) morphogenesis of the embryonic mammary gland to the understanding of tissue and molecular interactions and their regulation of morphogenesis and functional development of the embryonic mammary gland. It is here furthermore illustrated how generic molecular biology and biochemistry techniques can be combined with these older, developmental biology techniques, to address relevant research questions. As such, this review should provide a solid starting point for those wishing to familiarize themselves with this fascinating and important subdomain of mammary gland biology, and guide them in designing a

  11. The pivotal role of insulin-like growth factor I in normal mammary development.

    PubMed

    Kleinberg, David L; Barcellos-Hoff, Mary Helen

    2011-09-01

    Mammary development begins in puberty in response to an estrogen (E(2)) surge. E(2) does not act alone. It relies on pituitary growth hormone (GH) to induce insulin-like growth factor I (IGF-I) production in the mammary stromal compartment. In turn, IGF-I permits E(2) (and progesterone) action. During puberty, E(2) and IGF-I synergize for ductal morphogenesis. During pregnancy, progesterone joins IGF-I and E(2) to stimulate secretory differentiation necessary to produce milk. Prolactin stimulates milk production, while transforming growth factor-β inhibits proliferation. The orchestrated action of hormones, growth factors, and receptors necessary for mammary development and function are also critical in breast cancer.

  12. Ectodysplasin/NF-κB signaling in embryonic mammary gland development.

    PubMed

    Lindfors, Päivi H; Voutilainen, Maria; Mikkola, Marja L

    2013-06-01

    The ectodysplasin (Eda) signaling pathway consists of a TNF-like ligand Eda, its receptor Edar, and an adaptor protein Edaradd and its activation leads to NF-κB mediated transcription. In humans, mutations in the EDA pathway genes cause hypohidrotic ectodermal dysplasia, a disorder characterized by defective formation of hair follicles, teeth, and several exocrine glands including the breast. Embryonic mammary gland development proceeds via placode, bud, bulb and sprout stages before the onset of branching morphogenesis. Studies on mouse models have linked Eda with two aspects of embryonic mammary gland morphogenesis: placode induction and ductal growth and branching. Here we summarize the current knowledge on the role of Eda/NF-κB in mammary gland development.

  13. R-spondin1 is required for normal epithelial morphogenesis during mammary gland development.

    PubMed

    Chadi, Sead; Buscara, Laurine; Pechoux, Christine; Costa, José; Laubier, Johann; Chaboissier, Marie-Christine; Pailhoux, Eric; Vilotte, Jean-Luc; Chanat, Eric; Le Provost, Fabienne

    2009-12-18

    The R-spondin (Rspo) proteins constitute a novel class of ligands that induce Wnt signalling. Rspo1 knockout XX mice were previously shown to be sex-reversed, but some remain sub-fertile. These last were unable to feed their pups for some unknown reason. Using these mice and transplanted mammary tissues from Rspo1(-/-) virgin mice in nude mice, we report that the lack of Rspo1 expression results in the absence of duct side-branching development and subsequent alveolar formation, explaining the above mentioned phenotype. Our data demonstrate that local epithelial Rspo1 signalling is required for normal development of the mammary gland.

  14. Pubertal Mammary Gland Development: Elucidation of In Vivo Morphogenesis Using Murine Models.

    PubMed

    McBryan, Jean; Howlin, Jillian

    2017-01-01

    During the past 25 years, the combination of increasingly sophisticated gene targeting technology with transplantation techniques has allowed researchers to address a wide array of questions about postnatal mammary gland development. These in turn have significantly contributed to our knowledge of other branched epithelial structures. This review chapter highlights a selection of the mouse models exhibiting a pubertal mammary gland phenotype with a focus on how they have contributed to our overall understanding of in vivo mammary morphogenesis. We discuss mouse models that have enabled us to assign functions to particular genes and proteins and, more importantly, have determined when and where these factors are required for completion of ductal outgrowth and branch patterning. The reason for the success of the mouse mammary gland model is undoubtedly the suitability of the postnatal mammary gland to experimental manipulation. The gland itself is very amenable to investigation and the combination of genetic modification with accessibility to the tissue has allowed an impressive number of studies to inform biology. Excision of the rudimentary epithelial structure postnatally allows genetically modified tissue to be readily transplanted into wild type stroma or vice versa, and has thus defined the contribution of each compartment to particular phenotypes. Similarly, whole gland transplantation has been used to definitively discern local effects from indirect systemic effects of various growth factors and hormones. While appreciative of the power of these tools and techniques, we are also cognizant of some of their limitations, and we discuss some shortcomings and future strategies that can overcome them.

  15. 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

  16. 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...

  17. Fibroblast growth factor receptor signaling is essential for normal mammary gland development and stem cell function.

    PubMed

    Pond, Adam C; Bin, Xue; Batts, Torey; Roarty, Kevin; Hilsenbeck, Susan; Rosen, Jeffrey M

    2013-01-01

    Fibroblast growth factor (FGF) signaling plays an important role in embryonic stem cells and adult tissue homeostasis, but the function of FGFs in mammary gland stem cells is less well defined. Both FGFR1 and FGFR2 are expressed in basal and luminal mammary epithelial cells (MECs), suggesting that together they might play a role in mammary gland development and stem cell dynamics. Previous studies have demonstrated that the deletion of FGFR2 resulted only in transient developmental defects in branching morphogenesis. Using a conditional deletion strategy, we investigated the consequences of FGFR1 deletion alone and then the simultaneous deletion of both FGFR1 and FGFR2 in the mammary epithelium. FGFR1 deletion using a keratin 14 promoter-driven Cre-recombinase resulted in an early, yet transient delay in development. However, no reduction in functional outgrowth potential was observed following limiting dilution transplantation analysis. In contrast, a significant reduction in outgrowth potential was observed upon the deletion of both FGFR1 and FGFR2 in MECs using adenovirus-Cre. Additionally, using a fluorescent reporter mouse model to monitor Cre-mediated recombination, we observed a competitive disadvantage following transplantation of both FGFR1/R2-null MECs, most prominently in the basal epithelial cells. This correlated with the complete loss of the mammary stem cell repopulating population in the FGFR1/R2-attenuated epithelium. FGFR1/R2-null MECs were partially rescued in chimeric outgrowths containing wild-type MECs, suggesting the potential importance of paracrine mechanisms involved in the maintenance of the basal epithelial stem cells. These studies document the requirement for functional FGFR signaling in mammary stem cells during development.

  18. Growth hormone and insulin-like growth factor-I in the transition from normal mammary development to preneoplastic mammary lesions.

    PubMed

    Kleinberg, David L; Wood, Teresa L; Furth, Priscilla A; Lee, Adrian V

    2009-02-01

    Adult female mammary development starts at puberty and is controlled by tightly regulated cross-talk between a group of hormones and growth factors. Although estrogen is the initial driving force and is joined by luteal phase progesterone, both of these hormones require GH-induced IGF-I in the mammary gland in order to act. The same group of hormones, when experimentally perturbed, can lead to development of hyperplastic lesions and increase the chances, or be precursors, of mammary carcinoma. For example, systemic administration of GH or IGF-I causes mammary hyperplasia, and overproduction of IGF-I in transgenic animals can cause the development of usual or atypical hyperplasias and sometimes carcinoma. Although studies have clearly demonstrated the transforming potential of both GH and IGF-I receptor in cell culture and in animals, debate remains as to whether their main role is actually instructive or permissive in progression to cancer in vivo. Genetic imprinting has been shown to occur in precursor lesions as early as atypical hyperplasia in women. Thus, the concept of progression from normal development to cancer through precursor lesions sensitive to hormones and growth factors discussed above is gaining support in humans as well as in animal models. Indeed, elevation of estrogen receptor, GH, IGF-I, and IGF-I receptor during progression suggests a role for these pathways in this process. New agents targeting the GH/IGF-I axis may provide a novel means to block formation and progression of precursor lesions to overt carcinoma. A novel somatostatin analog has recently been shown to prevent mammary development in rats via targeted IGF-I action inhibition at the mammary gland. Similarly, pegvisomant, a GH antagonist, and other IGF-I antagonists such as IGF binding proteins 1 and 5 also block mammary gland development. It is, therefore, possible that inhibition of IGF-I action, or perhaps GH, in the mammary gland may eventually play a role in breast cancer

  19. 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.

  20. IGF-I, GH, and sex steroid effects in normal mammary gland development.

    PubMed

    Kleinberg, David L; Ruan, Weifeng

    2008-12-01

    Although the pubertal surge of estrogen is the immediate stimulus to mammary development, the action of estrogen depends upon the presence of pituitary growth hormone and the ability of GH to stimulate production of IGF-I in the mammary gland. Growth hormone binds to its receptor in the mammary fat pad, after which production of IGF-I mRNA and IGF-I protein occurs. It is likely that IGF-I then works through paracrine means to stimulate formation of TEBs, which then form ducts by bifurcating or trifurcating and extending through the mammary fat pad. By the time pubertal development is complete a tree-like structure of branching ducts fills the rodent mammary fat pad. In addition to requiring IGF-I in order to act, estradiol also directly synergizes with IGF-I to enhance formation of TEBs and ductal morphogenesis. Together they increase IRS-1 phosphorylation and cell proliferation, and inhibit apoptosis. In fact, the entire process of ductal morphogenesis, in oophorectomized IGF-I(-/-) knockout female mice, can occur as a result of the combined actions of estradiol and IGF-I. IGF-I also permits progesterone action in the mammary gland. Together they have been shown to stimulate a form of ductal morphogenesis, which is anatomically different from the kind induced by IGF-I and estradiol. Although both progesterone and estradiol synergize with IGF-I by increasing IGF-I action parameters, there must be other, as yet unknown mechanisms that account for the anatomical differences in the different forms of ductal morphogenesis observed (hyperplasia in response to IGF-I plus estradiol and single layered ducts in response to IGF-I plus progesterone).

  1. The effect of caffeine on mammary gland development and milk yield in primiparous sows.

    PubMed

    Li, S; Hacker, R R

    1995-02-01

    Pregnant Yorkshire gilts (n = 42) were fed caffeine (6 g/d) or served as controls from d 60 of pregnancy until d 4 postpartum to test the effect of caffeine on mammary gland development, milk yield, and feed consumption. Caffeine reduced voluntary feed intake (P = .001) and body weight gain (P = .001) of gilts from d 60 to 109 of gestation. Pig birth weight in the treated group was less than (P = .01) that in the control group. However, pig viability score at birth was not affected by maternal caffeine ingestion. For assessing mammary gland DNA, RNA, dry fat-free tissue (DFFT), fat, and protein content, four sows from the caffeine group and three controls were slaughtered on the 1st d of lactation. Immediately after slaughter, mammary systems were removed, separated by gland, and dissected free of skin, muscle, and fatty pad, which had not been invaded by glandular tissue. The DNA and RNA content were evaluated in DFFT. Caffeine increased mammary RNA content (P = .023) and milk yield (P = .001) on d 1 of lactation. However, DNA, DFFT, fat, and protein were not significantly increased, although values were somewhat greater in the treatment group (approximately 82%). On d 21 of lactation, milk yield of treated sows did not differ from that of controls. The increased milk yield on d 1 of lactation was due to increased mammary epithelial cell activity and cell numbers. These results indicate that caffeine feeding can have a positive effect on porcine mammary gland development as well as milk yield.

  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. 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...

  4. 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...

  5. 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...

  6. Hypoxia-inducible factor-1α induces ErbB4 signaling in the differentiating mammary gland.

    PubMed

    Paatero, Ilkka; Seagroves, Tiffany N; Vaparanta, Katri; Han, Wen; Jones, Frank E; Johnson, Randall S; Elenius, Klaus

    2014-08-08

    Conditional knock-out of Hif1a in the mouse mammary gland impairs lobuloalveolar differentiation during lactation. Here, we demonstrate that expression of ErbB4 was reduced in the lobulalveoli of mice with mammary gland-specific deletion of Hif1a. Erbb4 was not, however, a direct target gene for transcriptional regulation by HIF-1α in vitro. HIF-1α overexpression or HIF accumulating prolyl hydroxylase inhibitors reduced ErbB4 endocytosis, promoted transcriptional co-regulatory activity of ErbB4, and stimulated ErbB4-induced differentiation of mammary carcinoma cells. Consistently, RNA interference-mediated down-regulation of HIF-1α resulted in reduced ErbB4 protein amount and reduced mammary carcinoma cell differentiation. These findings indicate that HIF-1α is a physiologically relevant regulator of ErbB4 and that ErbB4 is involved in HIF-regulated differentiation of the mammary gland.

  7. Segregated responses of mammary gland development and vaginal opening to prepubertal genistein exposure in Bscl2(-/-) female mice with lipodystrophy.

    PubMed

    Li, Rong; El Zowalaty, Ahmed E; Chen, Weiqin; Dudley, Elizabeth A; Ye, Xiaoqin

    2015-07-01

    Berardinelli-Seip congenital lipodystrophy 2-deficient (Bscl2(-/-)) mice recapitulate human BSCL2 disease with lipodystrophy. Bscl2-encoded seipin is detected in adipocytes and epithelium of mammary gland. Postnatal mammary gland growth spurt and vaginal opening signify pubertal onset in female mice. Bscl2(-/-) females have longer and dilated mammary gland ducts at 5-week old and delayed vaginal opening. Prepubertal exposure to 500ppm genistein diet increases mammary gland area and accelerates vaginal opening in both control and Bscl2(-/-) females. However, genistein treatment increases ductal length in control but not Bscl2(-/-) females. Neither prepubertal genistein treatment nor Bscl2-deficiency affects phospho-estrogen receptor α or progesterone receptor expression patterns in 5-week old mammary gland. Interestingly, Bscl2-deficiency specifically reduces estrogen receptor β expression in mammary gland ductal epithelium. In summary, Bscl2(-/-) females have accelerated postnatal mammary ductal development but delayed vaginal opening; they display segregated responses in mammary gland development and vaginal opening to prepubertal genistein treatment.

  8. New insights into cathepsin D in mammary tissue development and remodeling.

    PubMed

    Margaryan, Naira V; Kirschmann, Dawn A; Lipavsky, Alina; Bailey, Caleb M; Hendrix, Mary J C; Khalkhali-Ellis, Zhila

    2010-09-01

    Cathepsin D (CatD) is a lysosomal aspartyl endopeptidase originally considered a "house keeping enzyme" involved in the clearance of unwanted proteins. However, recent studies have revealed CatD's involvement in apoptosis and autophagy, thus signifying an important function in the proper development and maintenance of multi-cellular organs. In the mammary gland, matrix degradation and the remodeling process are orchestrated by proteolytic enzymes, but the role of CatD at distinct developmental stages has remained mostly unexplored. Based on our previous studies we sought to address the role of this endopeptidase in mammary gland development and remodeling. By employing a mouse model, we report a previously unidentified participation of CatD in different stages of mammary gland development. Our findings reveal that CatD undergoes distinct protein processing at different stages of mammary gland development, and this customized processing results in differential enzymatic activity (constitutive and low pH activatable) best fitting particular stage(s) of development. In addition, at the onset of involution the N-glycan structure of this endopeptidase switches from a mixed high mannose and hybrid structure to an almost exclusively high mannose type, but reverts back to the original N-glycan composition by day 4 of involution. Our findings illuminate (at least in part) the "raison d'être" for CatD's numerous and highly regulated proteolytic processing steps from the pro-form to the mature enzyme. In the mammary gland, specific cleavage product(s) perform specialized function(s) befitting each stage of remodeling. It is noteworthy that deregulated synthesis, secretion and glycosylation of CatD are hallmarks of cancer progression. Thus, identifying the role of CatD in a dynamic normal tissue undergoing highly regulated cycles of remodeling could provide valuable information illuminating the deregulation of CatD associated with cancer development and metastasis.

  9. Induced p53 loss in mouse luminal cells causes clonal expansion and development of mammary tumours

    PubMed Central

    Tao, Luwei; Xiang, Dongxi; Xie, Ying; Bronson, Roderick T.; Li, Zhe

    2017-01-01

    Most breast cancers may have a luminal origin. TP53 is one of the most frequently mutated genes in breast cancers. However, how p53 deficiency contributes to breast tumorigenesis from luminal cells remains elusive. Here we report that induced p53 loss in Krt8+ mammary luminal cells leads to their clonal expansion without directly affecting their luminal identity. All induced mice develop mammary tumours with 9qA1 (Yap1) and/or 6qA2 (Met) amplification(s). These tumours exhibit a mammary stem cell (MaSC)-like expression signature and most closely resemble claudin-low breast cancer. Thus, although p53 does not directly control the luminal fate, its loss facilitates acquisition of MaSC-like properties by luminal cells and predisposes them to development of mammary tumours with loss of luminal identity. Our data also suggest that claudin-low breast cancer can develop from luminal cells, possibly via a basal-like intermediate state, although further study using a different luminal promoter is needed to fully support this conclusion. PMID:28194015

  10. STAT5A Regulates the Survival of Mammary Epithelial Cells and the Development of Mammary Cancer

    DTIC Science & Technology

    2002-07-01

    cleared. Gel was dried according to the man- stored in 7 0% ethanol until processed by standard embedding and ufacturer’s protocol (Research Products...fixative, and stored in 70% ethanol until processed and technical support and Dr. J. Shillingford for developing the Stat5a by standard embedding and...that the process of involution could remove significant numbers of cells that could potentially contribute to the development of tumors. But it also

  11. STAT5A Regulates the Survival of Mammary Epithelial Cells and the Development of Mammary Cancer

    DTIC Science & Technology

    2000-07-01

    Bill Kemp, and Sandra Price for animal husbandry for 5 h in Tellyzinckys fixative, and stored in 70% ethanol until processed and technical support and...of tumor formation was the same as the control group. This suggested that the process of involution can remove significant numbers of cells that could...potentially contribute to the development of tumors. But it also suggested that there remained sufficient cells after the process of involution, that

  12. Inhibition of prolactin in the last trimester of gestation decreases mammary gland development in gilts.

    PubMed

    Farmer, C; Sorensen, M T; Petitclerc, D

    2000-05-01

    Prolactin is required for mammary development in various species but its possible role for mammogenesis in pigs is not known. The goal of the present study was therefore to determine the effect of prolactin inhibition by bromocriptine during the last third of gestation on mammary gland development in gilts. Twenty-eight primigravid gilts were assigned as controls (n = 15) or received 10 mg of bromocriptine orally thrice daily (n = 13) from d 70 to 110 of gestation. Jugular blood samples were collected on d 70 of gestation and every 8 d thereafter and were assayed for prolactin, IGF-I, estradiol, and progesterone. Gilts were slaughtered on d 110 of gestation and fetuses were counted and weighed. One row of mammary glands was used for dissection of parenchymal and extraparenchymal tissues and for determination of DNA, RNA, dry matter, protein, and fat contents. Tissue from the other row was used for measures of prolactin receptor number and affinity. Concentrations of prolactin were drastically reduced throughout the bromocriptine treatment period (P < .001), whereas there was no overall treatment effect on progesterone and IGF-I levels (P > .10). Total weight and extraparenchymal tissue weight of the mammary glands were unaffected by treatment (P > or = .1), but weight of parenchymal tissue, total DNA, and total RNA decreased (P < .01) with bromocriptine treatment. Percentages of fat and dry matter in parenchymal tissue increased with bromocriptine treatment (P < .01) and the percentage of protein decreased (P < .01). Number of prolactin receptors in parenchymal tissue decreased with bromocriptine treatment (P < .001) and receptor affinity increased (P < .001). Average fetal weight was lower in gilts receiving bromocriptine than in control gilts (P = .05), but fetal number did not differ (P > .1). These results clearly demonstrate that prolactin is essential for normal mammary gland development and can affect fetal growth during the last third of gestation in gilts.

  13. Effect of heat stress during the dry period on mammary gland development.

    PubMed

    Tao, S; Bubolz, J W; do Amaral, B C; Thompson, I M; Hayen, M J; Johnson, S E; Dahl, G E

    2011-12-01

    Heat stress during the dry period negatively affects hepatic metabolism and cellular immune function during the transition period, and milk production in the subsequent lactation. However, the cellular mechanisms involved in the depressed mammary gland function remain unknown. The objective of the present study was to determine the effect of heat stress during the dry period on various indices of mammary gland development of multiparous cows. Cows were dried off approximately 46 d before expected calving and randomly assigned to 2 treatments, heat stress (HT, n=15) or cooling (CL, n=14), based on mature equivalent milk production. Cows in the CL treatment were provided with sprinklers and fans that came on when ambient temperatures reached 21.1°C, whereas HT cows were housed in the same barn without fans and sprinklers. After parturition, all cows were housed in a freestall barn with cooling. Rectal temperatures were measured twice daily (0730 and 1430 h) and respiration rates recorded at 1500 h on a Monday-Wednesday-Friday schedule from dry off to calving. Milk yield and composition were recorded daily up to 280 d in milk. Daily dry matter intake was measured from dry off to 42 d relative to calving. Mammary biopsies were collected at dry off, -20, 2, and 20 d relative to calving from a subset of cows (HT, n=7; CL, n=7). Labeling with Ki67 antigen and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling were used to evaluate mammary cell proliferation and apoptosis, respectively. The average temperature-humidity index during the dry period was 76.6 and not different between treatments. Heat-stressed cows had higher rectal temperatures in the morning (38.8 vs. 38.6°C) and afternoon (39.4 vs. 39.0°C), greater respiration rates (78.4 vs. 45.6 breath/min), and decreased dry matter intake (8.9 vs. 10.6 kg/d) when dry compared with CL cows. Relative to HT cows, CL cows had greater milk production (28.9 vs. 33.9 kg/d), lower milk protein

  14. 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.

  15. 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.

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

    PubMed

    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.

  17. Twisted Gastrulation as a BMP Modulator during Mammary Gland Development and Tumorigenesis

    DTIC Science & Technology

    2014-05-01

    preplacodal ectoderm specification (Kwon et al., 2010), and hair follicle morphogenesis (Kobielak et al., 2003). In the MG, GATA-3 deficiency...BMP4 and PTHrP interact to stimulate ductal outgrowth during embryonic mammary development and to inhibit hair follicle induction. Development. 2007...others tested expressed the same levels as MCF10A (data not shown.) We chose to move forward with the MD-MBA-231 and select other triple negative breast

  18. 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.

  19. 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 ...

  20. 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.

  1. 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

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

    PubMed

    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.

  3. Investigation of the Role of the Mitogenic Neuropeptide Galanin in Mammary Gland Development and Carcinogenesis

    DTIC Science & Technology

    2001-08-01

    phosphorylation and secretion MATTHEW J . NAYLOR*, RUSSELL C. HOVEY§, TIMOTHY W. C. HOt , DAVID WYNICKI, BARBARA K. VONDERHAAR§, AMEAE M. WALKER t AND...CHRISTOPHER J . ORMANDY,* Provisional authorship.To be submitted shortly. Conclusions Galanin modulates mammary gland development indirectly via the...MATTHEW J . NAYLOR*, RUSSELL C. HOVEY§, TIMOTHY W. C. HOt , DAVID WYNICKI, BARBARA K. VONDERHAAR§, AMEAE M. WALKER t A N D CHRISTOPHER J . ORMANDY’ 12

  4. Humanization of the mouse mammary gland.

    PubMed

    Wronski, A; Arendt, L M; Kuperwasser, Charlotte

    2015-01-01

    Although mouse models have provided invaluable information on the mechanisms of mammary gland development, anatomical and developmental differences between human and mice limit full understanding of this fundamental process. Humanization of the mouse mammary gland by injecting immortalized human breast stromal cells into the cleared murine mammary fat pad enables the growth and development of human mammary epithelial cells or tissue. This facilitates the characterization of human mammary gland development or tumorigenesis by utilizing the mouse mammary fat pad. Here we describe the process of isolating human mammary stromal and epithelial cells as well as their introduction into the mammary fat pads of immunocompromised mice.

  5. Abnormal Mammary Development in 129:STAT1-Null Mice is Stroma-Dependent.

    PubMed

    Chen, Jane Q; Mori, Hidetoshi; Cardiff, Robert D; Trott, Josephine F; Hovey, Russell C; Hubbard, Neil E; Engelberg, Jesse A; Tepper, Clifford G; Willis, Brandon J; Khan, Imran H; Ravindran, Resmi K; Chan, Szeman R; Schreiber, Robert D; Borowsky, Alexander D

    2015-01-01

    Female 129:Stat1-null mice (129S6/SvEvTac-Stat1(tm1Rds) homozygous) uniquely develop estrogen-receptor (ER)-positive mammary tumors. Herein we report that the mammary glands (MG) of these mice have altered growth and development with abnormal terminal end buds alongside defective branching morphogenesis and ductal elongation. We also find that the 129:Stat1-null mammary fat pad (MFP) fails to sustain the growth of 129S6/SvEv wild-type and Stat1-null epithelium. These abnormalities are partially reversed by elevated serum progesterone and prolactin whereas transplantation of wild-type bone marrow into 129:Stat1-null mice does not reverse the MG developmental defects. Medium conditioned by 129:Stat1-null epithelium-cleared MFP does not stimulate epithelial proliferation, whereas it is stimulated by medium conditioned by epithelium-cleared MFP from either wild-type or 129:Stat1-null females having elevated progesterone and prolactin. Microarrays and multiplexed cytokine assays reveal that the MG of 129:Stat1-null mice has lower levels of growth factors that have been implicated in normal MG growth and development. Transplanted 129:Stat1-null tumors and their isolated cells also grow slower in 129:Stat1-null MG compared to wild-type recipient MG. These studies demonstrate that growth of normal and neoplastic 129:Stat1-null epithelium is dependent on the hormonal milieu and on factors from the mammary stroma such as cytokines. While the individual or combined effects of these factors remains to be resolved, our data supports the role of STAT1 in maintaining a tumor-suppressive MG microenvironment.

  6. Abnormal Mammary Development in 129:STAT1-Null Mice is Stroma-Dependent

    PubMed Central

    Cardiff, Robert D.; Trott, Josephine F.; Hovey, Russell C.; Hubbard, Neil E.; Engelberg, Jesse A.; Tepper, Clifford G.; Willis, Brandon J.; Khan, Imran H.; Ravindran, Resmi K.; Chan, Szeman R.; Schreiber, Robert D.; Borowsky, Alexander D.

    2015-01-01

    Female 129:Stat1-null mice (129S6/SvEvTac-Stat1tm1Rds homozygous) uniquely develop estrogen-receptor (ER)-positive mammary tumors. Herein we report that the mammary glands (MG) of these mice have altered growth and development with abnormal terminal end buds alongside defective branching morphogenesis and ductal elongation. We also find that the 129:Stat1-null mammary fat pad (MFP) fails to sustain the growth of 129S6/SvEv wild-type and Stat1-null epithelium. These abnormalities are partially reversed by elevated serum progesterone and prolactin whereas transplantation of wild-type bone marrow into 129:Stat1-null mice does not reverse the MG developmental defects. Medium conditioned by 129:Stat1-null epithelium-cleared MFP does not stimulate epithelial proliferation, whereas it is stimulated by medium conditioned by epithelium-cleared MFP from either wild-type or 129:Stat1-null females having elevated progesterone and prolactin. Microarrays and multiplexed cytokine assays reveal that the MG of 129:Stat1-null mice has lower levels of growth factors that have been implicated in normal MG growth and development. Transplanted 129:Stat1-null tumors and their isolated cells also grow slower in 129:Stat1-null MG compared to wild-type recipient MG. These studies demonstrate that growth of normal and neoplastic 129:Stat1-null epithelium is dependent on the hormonal milieu and on factors from the mammary stroma such as cytokines. While the individual or combined effects of these factors remains to be resolved, our data supports the role of STAT1 in maintaining a tumor-suppressive MG microenvironment. PMID:26075897

  7. The T-box transcription factors TBX2 and TBX3 in mammary gland development and breast cancer.

    PubMed

    Douglas, Nataki C; Papaioannou, Virginia E

    2013-06-01

    TBX2 and TBX3, closely related members of the T-box family of transcription factor genes, are expressed in mammary tissue in both humans and mice. Ulnar mammary syndrome (UMS), an autosomal dominant disorder caused by mutations in TBX3, underscores the importance of TBX3 in human breast development, while abnormal mammary gland development in Tbx2 or Tbx3 mutant mice provides models for experimental investigation. In addition to their roles in mammary development, aberrant expression of TBX2 and TBX3 is associated with breast cancer. TBX2 is preferentially amplified in BRCA1/2-associated breast cancers and TBX3 overexpression has been associated with advanced stage disease and estrogen-receptor-positive breast tumors. The regulation of Tbx2 and Tbx3 and the downstream targets of these genes in development and disease are not as yet fully elucidated. However, it is clear that the two genes play unique, context-dependent roles both in mammary gland development and in mammary tumorigenesis.

  8. ErbB/EGF Signaling and EMT in Mammary Development and Breast Cancer

    PubMed Central

    Hardy, Katharine M.; Booth, Brian W.; Hendrix, Mary J. C.; Salomon, David S.

    2010-01-01

    Activation of the ErbB family of receptor tyrosine kinases via cognate Epidermal Growth Factor (EGF)-like peptide ligands constitutes a major group of related signaling pathways that control proliferation, survival, angiogenesis and metastasis of breast cancer. In this respect, clinical trials with various ErbB receptor blocking antibodies and specific tyrosine kinase inhibitors have proven to be partially efficacious in the treatment of this heterogeneous disease. Induction of an embryonic program of epithelial-to-mesenchymal transition (EMT) in breast cancer, whereupon epithelial tumor cells convert to a more mesenchymal-like phenotype, facilitates the migration, intravasation, and extravasation of tumor cells during metastasis. Breast cancers which exhibit properties of EMT are highly aggressive and resistant to therapy. Activation of ErbB signaling can regulate EMT-associated invasion and migration in normal and malignant mammary epithelial cells, as well as modulating discrete stages of mammary gland development. The purpose of this review is to summarize current information regarding the role of ErbB signaling in aspects of EMT that influence epithelial cell plasticity during mammary gland development and tumorigenesis. How this information may contribute to the improvement of therapeutic approaches in breast cancer will also be addressed. PMID:20369376

  9. ErbB/EGF signaling and EMT in mammary development and breast cancer.

    PubMed

    Hardy, Katharine M; Booth, Brian W; Hendrix, Mary J C; Salomon, David S; Strizzi, Luigi

    2010-06-01

    Activation of the ErbB family of receptor tyrosine kinases via cognate Epidermal Growth Factor (EGF)-like peptide ligands constitutes a major group of related signaling pathways that control proliferation, survival, angiogenesis and metastasis of breast cancer. In this respect, clinical trials with various ErbB receptor blocking antibodies and specific tyrosine kinase inhibitors have proven to be partially efficacious in the treatment of this heterogeneous disease. Induction of an embryonic program of epithelial-to-mesenchymal transition (EMT) in breast cancer, whereupon epithelial tumor cells convert to a more mesenchymal-like phenotype, facilitates the migration, intravasation, and extravasation of tumor cells during metastasis. Breast cancers which exhibit properties of EMT are highly aggressive and resistant to therapy. Activation of ErbB signaling can regulate EMT-associated invasion and migration in normal and malignant mammary epithelial cells, as well as modulating discrete stages of mammary gland development. The purpose of this review is to summarize current information regarding the role of ErbB signaling in aspects of EMT that influence epithelial cell plasticity during mammary gland development and tumorigenesis. How this information may contribute to the improvement of therapeutic approaches in breast cancer will also be addressed.

  10. Cytokine networks that mediate epithelial cell-macrophage crosstalk in the mammary gland: implications for development and cancer.

    PubMed

    Sun, Xuan; Ingman, Wendy V

    2014-07-01

    Dynamic interactions between the hormone responsive mammary gland epithelium and surrounding stromal macrophage populations are critical for normal development and function of the mammary gland. Macrophages are versatile cells capable of diverse roles in mammary gland development and maintenance of homeostasis, and their function is highly dependent on signals within the local cytokine microenvironment. The mammary epithelium secretes a number of cytokines, including colony stimulating factor 1 (CSF1), transforming growth factor beta 1 (TGFB1), and chemokine ligand 2 (CCL2) that affect the abundance, phenotype and function of macrophages. However, aberrations in these interactions have been found to increase the risk of tumour formation, and utilisation of stromal macrophage support by tumours can increase the invasive and metastatic potential of the cancer. Studies utilising genetically modified mouse models have shed light on the significance of epithelial cell-macrophage crosstalk, and the cytokines that mediate this communication, in mammary gland development and tumourigenesis. This article reviews the current status of our understanding of the roles of epithelial cell-derived cytokines in mammary gland development and cancer, with a focus on the crosstalk between epithelial cells and the local macrophage population.

  11. Quantification of progesterone binding in mammary tissue of pregnant ewes

    SciTech Connect

    Smith, J.J.; Capuco, A.V.; Akers, R.M.

    1987-06-01

    Progestin-binding sites in mammary tissue from 14 prepartum, multiparous ewes at 50, 80, 115, and 140 d of gestation were demonstrated by the binding of (/sup 3/H) R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione) to ovine mammary cytosol in the presence of sodium molybdate and excess cortisol. Homogenization extracted 89% of total mammary receptors (nuclear) into cytosol. Binding was specific for progestins and was of high affinity. The average dissociation constant for (/sup 3/H) R5020 specifically bound to receptors extracted into mammary cytosol was 1.9 (+/- .4) x 10/sup -9/ M (n = 14) and did not change significantly over the test period. However, binding capacities (fmol/mg cytosolic protein) differed according to stage of gestation with averages of 125 +/- 53, 149 +/- 26, 656 +/- 216, 57 +/- 22 at 50, 80, 115, and 140 d of pregnancy, respectively. Increased number of progestin-binding sites at 115 d of gestation (whether data are expressed per unit of tissue weight, DNA, or cytosolic protein) suggests that an increase per mammary epithelial cell may be necessary to produce the full lobuloalveolar proliferation observed at this stage of gestation.

  12. Involvement of Notch1 in the development of mouse mammary tumors.

    PubMed

    Diévart, A; Beaulieu, N; Jolicoeur, P

    1999-10-28

    The MMTV/neu transgenic (Tg) mice spontaneously develop mammary tumors stochastically after a long latent period, suggesting that the c-neu/erbB2 oncogene is not sufficient for tumor formation. To identify putative collaborator(s) of the c-neu/erbB2, we used the provirus insertional mutagenesis approach with mammary tumors arising in MMTV/neu Tg mice infected with the mouse mammary tumor virus (MMTV). The Notch1 gene was identified as a novel target for MMTV provirus insertional activation. In Notch1-rearranged tumors, the Notch1 gene was interrupted by the MMTV provirus insertion upstream of the exons coding for the TM domain. These insertions led to overexpression of novel 5' truncated approximately 7 kb RNA coding for 280 kDa mutant protein harboring only the Notch1 ectodomain, N(EC)mut. These may be involved in tumor formation. Another consequence of these insertions was the expression of truncated 3' Notch1 transcripts (3.5 - 4.5 kb) and proteins (86 - 110 kDa) deleted of most of the extracellular sequences (Notch1intra). We found that 3' truncated Notch1intra can transform HC11 mouse mammary epithelial cells in vitro. Deletion analysis revealed that the ankyrin-repeats and the domain 1 (aa 1751 - 1821) are required, while a signal peptide, the two conserved cysteines (C1652 and C1685) and the OPA and PEST sequences are dispensable for transformation. These results indicate that the N-terminally truncated Notch1intra protein behaves as an oncogene in this system.

  13. Gpr177 deficiency impairs mammary development and prohibits Wnt-induced tumorigenesis.

    PubMed

    Maruyama, Eri Ohfuchi; Yu, H-M Ivy; Jiang, Ming; Fu, Jiang; Hsu, Wei

    2013-01-01

    Aberrant regulation of the Wnt pathway, essential for various developmental processes, is tightly linked to human breast cancers. By hijacking this evolutionary conserved signaling pathway, cancer cells acquire sustaining proliferation ability, leading to modification of physiologic properties necessary for tumor initiation and progression. An enormous wealth of knowledge on the importance of Wnt signaling in breast development and cancer has been obtained, but the cell types responsible for production of this proliferative signal operating within normal and malignant tissues remains poorly understood. Here we report that Wnt production mediated by Gpr177 is essential for mammary morphogenesis. The loss of Gpr177 interferes with mammary stem cells, leading to deficiencies in cell proliferation and differentiation. Genetic analysis further demonstrates an indispensable role of Gpr177 in Wnt-induced tumorigenesis. The Gpr177-deficiency mice are resistant to malignant transformation. This study not only demonstrates the necessity of Wnt in mammary organogenesis but also provides a proof-of-principle for targeting of Gpr177 as a potential new treatment for human diseases with aberrant Wnt stimulation.

  14. The V-ATPase a2 isoform controls mammary gland development through Notch and TGF-β signaling

    PubMed Central

    Pamarthy, Sahithi; Mao, Liquin; Katara, Gajendra K; Fleetwood, Sara; Kulshreshta, Arpita; Gilman-Sachs, Alice; Beaman, Kenneth D

    2016-01-01

    Among all tissues and organs, the mammary gland is unique because most of its development occurs in adulthood. Notch signaling has a major role in mammary gland development and has been implicated in breast cancer. The vacuolar-ATPase (V-ATPase) is a proton pump responsible for the regulation and control of pH in intracellular vesicles and the extracellular milieu. We have previously reported that a2V-ATPase (a2V), an isoform of ‘a' subunit of V-ATPase, regulates processing of Notch receptor and alters Notch signaling in breast cancer. To study the role of a2V in mammary gland development, we generated an a2V-KO model (conditional mammary knockout a2V mouse strain). During normal mammary gland development, the basal level expression of a2V increased from puberty, virginity, and pregnancy through the lactation stage and then decreased during involution. Litters of a2V-KO mice weighed significantly less when compared with litters from wild-type mice and showed reduced expression of the lactation marker β-casein. Whole-mount analysis of mammary glands demonstrated impaired ductal elongation and bifurcation in a2V-KO mice. Consequently, we found disintegrated mammary epithelium as seen by basal and luminal epithelial staining, although the rate of proliferation remained unchanged. Delayed mammary morphogenesis in a2V-KO mice was associated with aberrant activation of Notch and TGF-β (transforming growth factor-β) pathways. Notably, Hey1 (hairy/enhancer-of-split related with YRPW motif) and Smad2, the key downstream mediators of Notch and TGF-β pathways, respectively, were upregulated in a2V-KO mice and also in human mammary epithelial cells treated with a2V siRNA. Taken together, our results show that a2V deficiency disrupts the endolysosomal route in Notch and TGF signaling, thereby impairing mammary gland development. Our findings have broader implications in developmental and oncogenic cellular environments where V-ATPase, Notch and TGF-β are crucial for cell

  15. Mediator subunits MED1 and MED24 cooperatively contribute to pubertal mammary gland development and growth of breast carcinoma cells.

    PubMed

    Hasegawa, Natsumi; Sumitomo, Akiko; Fujita, Azusa; Aritome, Nami; Mizuta, Shumpei; Matsui, Keiji; Ishino, Ruri; Inoue, Kana; Urahama, Norinaga; Nose, Junko; Mukohara, Toru; Kamoshida, Shingo; Roeder, Robert G; Ito, Mitsuhiro

    2012-04-01

    The Mediator subunit MED1 is essential for mammary gland development and lactation, whose contribution through direct interaction with estrogen receptors (ERs) is restricted to involvement in pubertal mammary gland development and luminal cell differentiation. Here, we provide evidence that the MED24-containing submodule of Mediator functionally communicates specifically with MED1 in pubertal mammary gland development. Mammary glands from MED1/MED24 double heterozygous knockout mice showed profound retardation in ductal branching during puberty, while single haploinsufficient glands developed normally. DNA synthesis of both luminal and basal cells were impaired in double mutant mice, and the expression of ER-targeted genes encoding E2F1 and cyclin D1, which promote progression through the G(1)/S phase of the cell cycle, was attenuated. Luciferase reporter assays employing double mutant mouse embryonic fibroblasts showed selective impairment in ER functions. Various breast carcinoma cell lines expressed abundant amounts of MED1, MED24, and MED30, and attenuated expression of MED1 and MED24 in breast carcinoma cells led to attenuated DNA synthesis and growth. These results indicate functional communications between the MED1 subunit and the MED24-containing submodule that mediate estrogen receptor functions and growth of both normal mammary epithelial cells and breast carcinoma cells.

  16. 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.

  17. Mammary Tumor Development: Stromal-Epithelial Interactions in Oncogenesis.

    DTIC Science & Technology

    1996-09-01

    address experimentally the strong association of p53 mutations with human breast cancers, and to test whether this association holds for experimental...may develop secretory tumors (32,45,46). MG tumors are reported in transgenic mice expressing c-myc, c- erbB2 /neu, int-1, int-3 and Ha-ras, and in F1...Yasui, W, Takekura, N, Kameda, T, Oda, N, Ito, M, Ito, H, Tahara, E: Effect of epider- mal growth factor on rat stomach carcinogenesis induced by N

  18. Isoform-specific degradation of PR-B by E6-AP is critical for normal mammary gland development.

    PubMed

    Ramamoorthy, Sivapriya; Dhananjayan, Sarath C; Demayo, Francesco J; Nawaz, Zafar

    2010-11-01

    E6-associated protein (E6-AP), which was originally identified as an ubiquitin-protein ligase, also functions as a coactivator of estrogen (ER-α) and progesterone (PR) receptors. To investigate the in vivo role of E6-AP in mammary gland development, we generated transgenic mouse lines that either overexpress wild-type (WT) human E6-AP (E6-AP(WT)) or ubiquitin-protein ligase-defective E6-AP (E6-AP(C833S)) in the mammary gland. Here we show that overexpression of E6-AP(WT) results in impaired mammary gland development. In contrast, overexpression of E6-AP(C833S) or loss of E6-AP (E6-AP(KO)) increases lateral branching and alveolus-like protuberances in the mammary gland. We also show that the mammary phenotypes observed in the E6-AP transgenic and knockout mice are due, in large part, to the alteration of PR-B protein levels. We also observed alteration in ER-α protein level, which might contribute to the observed mammary phenotype by regulating PR expression. Furthermore, E6-AP regulates PR-B protein levels via the ubiquitin-proteasome pathway. Additionally, we also show that E6-AP impairs progesterone-induced Wnt-4 expression by decreasing the steady state level of PR-B in both mice and in human breast cancer cells. In conclusion, we present the novel observation that E6-AP controls mammary gland development by regulating PR-B protein turnover via the ubiquitin proteasome pathway. For the first time, we show that the E3-ligase activity rather than the coactivation function of E6-AP plays an important role in the mammary gland development, and the ubiquitin-dependent PR-B degradation is not required for its transactivation functions. This mechanism appears to regulate normal mammogenesis, and dysregulation of this process may be an important contributor to mammary cancer development and progression.

  19. Effects of restricted feeding of prepubertal ewe lambs on growth performance and mammary gland development.

    PubMed

    Villeneuve, L; Cinq-Mars, D; Lacasse, P

    2010-06-01

    The aim of this study was to determine the effects of restricted feeding before puberty on growth performance and mammary gland development in replacement ewe lambs. At weaning, 72 Dorset ewe lambs were assigned to one of the three diets: an ad libitum control diet with medium-quality forage (MQF; diet A-MQF); a restricted diet with the same forage as A, but less feed concentrate (diet R-MQF); or a high-quality forage (HQF) diet (diet F-HQF). The quantity of concentrate offered to the group R-MQF and F-HQF ewe lambs was adjusted to obtain 70% of the control ewe lambs' growth rate. The diets were offered for 75 days after weaning to cover the allometric phase of mammary gland development. During this period, average daily gain (ADG) was 223 and 229 g/day for groups R-MQF and F-HQF, respectively, compared to 305 g/day for group A-MQF (P < 0.0001). At the end of this period, 28 ewe lambs were slaughtered and their mammary gland was collected. Parenchymal fresh tissue weight tended to be higher for groups R-MQF and F-HQF compared to group A-MQF (P = 0.09). Stroma weight was greater (P < 0.05) for the group A-MQF ewe lambs than for those in the other treatments. Total DNA and total protein in parenchymal tissue tended to be greater for groups R-MQF and F-HQF (P = 0.09 and P = 0.07, respectively). Dry fat-free tissue was greater for groups R-MQF and F-HQF (P < 0.05). The remaining ewe lambs were fed the same haylage and barley diet until their first lambing. During this period, compensatory growth was observed. ADG was greater (P < 0.01) for groups R-MQF and F-HQF than for group A-MQF, and feed conversion was improved (P < 0.01) for groups R-MQF and F-HQF compared with the control, whereas the dry matter intake was similar for all groups. Live body weight, loin eye depth and backfat depth at breeding and around lambing were similar for all groups. The results of this study suggest that restricted feeding before puberty improves mammary gland development without

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

    PubMed

    Freetly, H C; Vonnahme, K A; McNeel, A K; Camacho, L E; Amundson, O L; Forbes, E D; Lents, C A; Cushman, R A

    2014-12-01

    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 feed to ensure heifers reach puberty before the time that they are mated to calve at 2 yr of age. Nutrition level during development has been associated with altered milk production and stayability. We hypothesized that heifers exposed to a lower nutrition level during the peripubertal period would have less methylation of the DNA in the mammary gland and ovarian cortex. We also hypothesized that the ovarian reserve would decrease in heifers fed for rapid growth compared to heifers fed for slow growth during puberty. At 257±1 d of age, heifers in the Stair-Step treatment (n=6) received 157 kcal ME/BW kg0.75 for 84 d and heifers in the Conventional treatment (n=6) were offered 228 kcal ME/BW kg0.75. At d 84, heifers were fed for an additional 83 d. Stair-Step heifers were offered 277 kcal ME/BW kg0.75, and heifers on the Conventional treatment received 228 kcal ME/BW kg0.75. Mammary weights (P=0.43), capillary area density (P=0.74), and capillary surface density (P=0.18) did not differ between treatments and neither did alveolar number (P=0.55) and alveolar density (P=0.49). Reproductive tract weights (P=0.69) and ovarian weight (P=0.68) and ovarian size (P>0.75) did not differ between treatments. In histological sections, Stair-Step heifers had more primordial follicles than Conventional heifers (P=0.02), but primary (P=0.59) and secondary (P=0.15) follicles did not differ. Global methylation of parenchymal tissue (P=0.82), mammary fat pad (P=0.45), and ovarian cortex (P=0.14) did not differ between treatments. Anterior pituitary weight did not differ between treatments (P=0.16). Our hypothesis that modifying peripubertal nutrition modifies global methylation of the

  1. Perinatal Exposure to Bisphenol-A Alters Peripubertal Mammary Gland Development in Mice

    PubMed Central

    Muñoz-de-Toro, Monica; Markey, Caroline M.; Wadia, Perinaaz R.; Luque, Enrique H.; Rubin, Beverly S.; Sonnenschein, Carlos; Soto, Ana M.

    2010-01-01

    Developmental exposure to estrogenic chemicals induces morphological, functional, and behavioral anomalies associated with reproduction. Humans are exposed to bisphenol-A (BPA), an estrogenic compound that leaches from dental materials and plastic food and beverage containers. The aim of the present study was to determine the effects of perinatal exposure to low, environmentally relevant doses of BPA [25 and 250 ng BPA/kg body weight (bw)·d] on the peripubertal development of the mammary gland. BPA exposure enhanced the mammary glands' sensitivity to estradiol in ovariectomized CD-1 mice. In their intact 30-d-old littermates, the area and numbers of terminal end buds relative to the gland ductal area increased whereas their apoptotic activity decreased. There was a positive correlation between ductal length and the age at first proestrus; that was reduced as the BPA dose increased, suggesting that BPA exposure slows down ductal invasion of the stroma. There was also a significant increase of progesterone receptor-positive ductal epithelial cells that were localized in clusters, suggesting future branching points. Indeed, lateral branching was significantly enhanced at 4 months of age in mice exposed to 25 ng BPA /kg bw·d. In conclusion, perinatal exposure to environmentally relevant BPA doses results in persistent alterations in mammary gland morphogenesis. Of special concern is the increased terminal end bud density at puberty as well as the increased number of terminal ends reported previously in adult animals, as these two structures are the sites at which cancer arises in humans and rodents. PMID:15919749

  2. Development of Hyperplasias, Preneoplasias, and Mammary Tumors in MMTV-c-erbB-2 and MMTV-TGFα Transgenic Rats

    PubMed Central

    Davies, Barry R.; Platt-Higgins, Angela M.; Schmidt, Gunter; Rudland, Philip S.

    1999-01-01

    Human cDNAs corresponding to two epidermal growth factor-related products that are overexpressed in human breast cancers, that for c-erbB-2 (HER-2) and for transforming growth factor α (TGFα), have been cloned downstream of the mouse mammary tumor virus (MMTV) long terminal repeat promoter and injected into the pronucleus of fertilized oocytes of Sprague-Dawley rats to produce transgenic offspring. Expression of the transgenic mRNAs is not detectable in mammary tissue from virgin transgenic rats but is detected in mammary tissue from certain lines of mid-pregnant transgenic rats. When two such lines of either type of transgenic rat are subjected to repeated cycles of pregnancy and lactation, they produce, primarily in the mammary glands, extensive pathologies, whereas virgin transgenic rats produce no such abnormalities. Multiparous transgenic female offspring from c-erbB-2-expressing lines develop a variety of focal hyperplastic and benign lesions that resemble lesions commonly found in human breasts. These lesions include lobular and ductal hyperplasia, fibroadenoma, cystic expansions, and papillary adenomas. More malignant lesions, including ductal carcinoma in situ and carcinoma, also develop stochastically at low frequency. The mammary glands of transgenic females invariably fail to involute fully after lactation. Similar phenotypes are observed in female MMTV-TGFα transgenic rats. In addition, multiparous TGFα-expressing female transgenics frequently develop severe pregnancy-dependent lactating hyperplasias as well as residual lobules of hyperplastic secretory epithelium and genuine lactating adenomas after weaning. These transgenic rat models confirm the conclusions reached in transgenic mice that overexpression of the c-erbB-2 and TGFα genes predisposes the mammary gland to stochastic tumor development. PMID:10393862

  3. Functional Disruption of the Netrin-1 Guidance Gue Leads to Disruption in Mammary Gland Development and Increased Tumor Incidence

    DTIC Science & Technology

    2005-07-01

    during gland development and disease . 15. SUBJECT TERMS Netrin-1, tumor suppressor, neogenin, Slit2 16. SECURITY CLASSIFICATION OF: 17. LIMITATION 18...and whether this loss serves as a prognostic indicator of disease outcome. Appendixes: 4 Netrin-1/Neogenin Interaction Stabilizes Multipotent...luminal epithelial bi-layers during ductal morphogenesis is uncertain. Desmosomal constituents are present during postnatal mammary gland development, but

  4. Evaluating chemical effects on mammary gland development: A critical need in disease prevention.

    PubMed

    Osborne, Gwendolyn; Rudel, Ruthann; Schwarzman, Megan

    2015-07-01

    Although understanding the environmental factors that contribute to breast cancer could improve disease prevention, standard chemical testing protocols do not adequately evaluate chemicals' effects on breast development. Evidence suggests: (1) mammary gland (MG) development is a complex process that extends from gestation through fetal and neonatal growth, puberty, and pregnancy; (2) altered MG development can increase the risk of breast cancer and other adverse outcomes; and (3) chemical exposures during susceptible windows of development may alter the MG in ways that increase risk for later disease. Together, these highlight the need to better understand the complex relationship between exposure to endocrine disrupting compounds (EDCs) and the alterations in MG morphology and gene expression that ultimately increase disease risk. Changing guideline toxicity testing studies to incorporate perinatal exposures and MG whole mounts would generate critical knowledge about the effects of EDCs on the MG and could ultimately inform disease prevention.

  5. Role of insulin-like growth factor binding proteins in mammary gland development.

    PubMed

    Flint, D J; Tonner, E; Beattie, J; Allan, G J

    2008-12-01

    Insulin-like growth factors (IGFs) play an important role in mammary gland development and their effects are, in turn, influenced by a family of 6 IGF-binding proteins (IGFBPs). The IGFBPs are expressed in time- and tissue-specific fashion during the periods of rapid growth and involution of the mammary gland. The precise roles of these proteins in vivo have, however, been difficult to determine. This review examines the indirect evidence (evolution, chromosomal location and roles in lower life-forms) the evidence from in vitro studies and the attempts to examine their roles in vivo, using IGFBP-deficient and over-expression models. Evidence exists for a role of the IGFBPs in inhibition of the survival effects of IGFs as well as in IGF-enhancing effects from in vitro studies. The location of the IGFBPs, often associated with the extracellular matrix, suggests roles as a reservoir of IGFs or as a potential barrier, restricting access of IGFs to distinct cellular compartments. We also discuss the relative importance of IGF-dependent versus IGF-independent effects. IGF-independent effects include nuclear localization, activation of proteases and interaction with a variety of extracellular matrix and cell surface proteins. Finally, we examine the increasing evidence for the IGFBPs to be considered as part of a larger family of extracellular matrix proteins involved in morphogenesis and tissue re-modeling.

  6. Investigation of the Role of the Mitogenic Neuropeptide Galanin in Mammary Gland Development and Carcinogenesis

    DTIC Science & Technology

    2002-08-01

    mammary epithelial cells. 5 commenced in Gal’ mice, where small alveoli showed colostrum retention (Fig. 2C). Differentiation of the mammary epithelium...compared to wild type animals there were many more ducts that had not commenced lactation and which retained colostrum (Fig. 2C). Analysis of milk protein...are clear Naylor et al. Galanin regulation of mammary epithelial cells. 25 and open, while non-lactating less differentiated ducts retain colostrum

  7. Role of Fibroblast Growth Factor Binding Protein-1 in Mammary Development and Tumorigenesis

    DTIC Science & Technology

    2009-10-01

    Hens and Wysolmerski 2005). At the future site of each nipple , five disk-like placodes line up and invade into the underlying mesenchyme. Referred...mouse mammary gland forms a single ductal tree leading to each nipple . The nascent mammary gland remains quiescent until puberty where the...harvested as described in this original proposal. 12 Apoptosis at regular intervals is a normal part of mammary physiology . In murine models

  8. Transcriptome analysis of embryonic mammary cells reveals insights into mammary lineage establishment

    PubMed Central

    2011-01-01

    Introduction The mammary primordium forms during embryogenesis as a result of inductive interactions between its constitutive tissues, the mesenchyme and epithelium, and represents the earliest evidence of commitment to the mammary lineage. Previous studies of embryonic mouse mammary epithelium indicated that, by mid-gestation, these cells are determined to a mammary cell fate and that a stem cell population has been delimited. Mammary mesenchyme can induce mammary development from simple epithelium even across species and classes, and can partially restore features of differentiated tissue to mouse mammary tumours in co-culture experiments. Despite these exciting properties, the molecular identity of embryonic mammary cells remains to be fully characterised. Methods Here, we define the transcriptome of the mammary primordium and the two distinct cellular compartments that comprise it, the mammary primordial bud epithelium and mammary mesenchyme. Pathway and network analysis was performed and comparisons of embryonic mammary gene expression profiles to those of both postnatal mouse and human mammary epithelial cell sub-populations and stroma were made. Results Several of the genes we have detected in our embryonic mammary cell signatures were previously shown to regulate mammary cell fate and development, but we also identified a large number of novel candidates. Additionally, we determined genes that were expressed by both embryonic and postnatal mammary cells, which represent candidate regulators of mammary cell fate, differentiation and progenitor cell function that could signal from mammary lineage inception during embryogenesis through postnatal development. Comparison of embryonic mammary cell signatures with those of human breast cells identified potential regulators of mammary progenitor cell functions conserved across species. Conclusions These results provide new insights into genetic regulatory mechanisms of mammary development, particularly

  9. 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

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

    PubMed

    Tiede, Benjamin; Kang, Yibin

    2011-02-01

    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.

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. Elf5 inhibits the epithelial-mesenchymal transition in mammary gland development and breast cancer metastasis by transcriptionally repressing Snail2.

    PubMed

    Chakrabarti, Rumela; Hwang, Julie; Andres Blanco, Mario; Wei, Yong; Lukačišin, Martin; Romano, Rose-Anne; Smalley, Kirsten; Liu, Song; Yang, Qifeng; Ibrahim, Toni; Mercatali, Laura; Amadori, Dino; Haffty, Bruce G; Sinha, Satrajit; Kang, Yibin

    2012-11-01

    The epithelial-mesenchymal transition (EMT) is a complex process that occurs during organogenesis and in cancer metastasis. Despite recent progress, the molecular pathways connecting the physiological and pathological functions of EMT need to be better defined. Here we show that the transcription factor Elf5, a key regulator of mammary gland alveologenesis, controls EMT in both mammary gland development and metastasis. We uncovered this role for Elf5 through analyses of Elf5 conditional knockout animals, various in vitro and in vivo models of EMT and metastasis, an MMTV-neu transgenic model of mammary tumour progression and clinical breast cancer samples. Furthermore, we demonstrate that Elf5 suppresses EMT by directly repressing the transcription of Snail2, a master regulator of mammary stem cells and a known inducer of EMT. These findings establish Elf5 not only as a key cell lineage regulator during normal mammary gland development, but also as a suppressor of EMT and metastasis in breast cancer.

  17. Mammary Duct Ectasia

    MedlinePlus

    ... tenderness or inflammation of the clogged duct (periductal mastitis). Mammary duct ectasia most often occurs in women ... that's turned inward (inverted) A bacterial infection called mastitis also may develop in the affected milk duct, ...

  18. Mammary tumors

    SciTech Connect

    Weller, R.E.

    1988-10-01

    Mammary neoplasia is one of the more common malignancies affecting domestic species. Despite their importance, they are often over- diagnosed, undertreated and subject to several misconceptions propagated by veterinarians and pet owners alike. Mammary neoplasia is the most frequent tumor type encountered in the female accounting for almost half of all malignancies reported. The canine has the highest incidence of mammary tumors of all domestic species. In the dog, about 65 percent of mammary tumors are benign mixed tumors, and 25 percent are carcinomas. The rest are adenomas, myoepitheliomas, and malignant mixed tumors. The age distribution of mammary tumors closely follows the age distribution of most tumors in the dog. Mammary tumors are rare in dogs 2 years old, but incidence begins to increase sharply at approximately 6 years of age. Median age at diagnosis is about 10 years. No breed predilection has been consistently reported.

  19. Milk from dams fed an obesogenic diet combined with a high-fat/high-sugar diet induces long-term abnormal mammary gland development in the rabbit.

    PubMed

    Hue-Beauvais, C; Koch, E; Chavatte-Palmer, P; Galio, L; Chat, S; Letheule, M; Rousseau-Ralliard, D; Jaffrezic, F; Laloë, D; Aujean, E; Révillion, F; Lhotellier, V; Gertler, A; Devinoy, E; Charlier, M

    2015-04-01

    Alterations to the metabolic endocrine environment during early life are crucial to mammary gland development. Among these environmental parameters, the initial nutritional event after birth is the consumption of milk, which represents the first maternal support provided to mammalian newborns. Milk is a complex fluid that exerts effects far beyond its immediate nutritional value. The present study, therefore, aimed to determine the effect of the nutritional changes during the neonatal and prepubertal periods on the adult mammary phenotype. Newborn rabbits were suckled by dams fed a high-fat/high-sugar obesogenic (OD) or a control (CON) diet and then subsequently fed either the OD or CON diets from the onset of puberty and throughout early pregnancy. Mammary glands were collected during early pregnancy (Day 8 of pregnancy). Rabbits fed with OD milk and then subjected to an OD diet displayed an abnormal development of the mammary gland: the mammary ducts were markedly enlarged (P < 0.05) and filled with abundant secretory products. Moreover, the alveolar secretory structures were disorganized, with an abnormal aspect characterized by large lumina. Mammary epithelial cells contained numerous large lipid droplets and exhibited fingering of the apical membrane and abnormally enlarged intercellular spaces filled with casein micelles. Leptin has been shown to be involved in modulating several developmental processes. We therefore analyzed its expression in the mammary gland. Mammary leptin mRNA was strongly expressed in rabbits fed with OD milk and subjected to an OD diet by comparison with the CON rabbits. Leptin transcripts and protein were localized in the epithelial cells, indicating that the increase in leptin synthesis occurs in this compartment. Taken together, these findings suggest that early-life nutritional history, in particular through the milking period, can determine subsequent mammary gland development. Moreover, they highlight the potentially important

  20. SNORD-host RNA Zfas1 is a regulator of mammary development and a potential marker for breast cancer.

    PubMed

    Askarian-Amiri, Marjan E; Crawford, Joanna; French, Juliet D; Smart, Chanel E; Smith, Martin A; Clark, Michael B; Ru, Kelin; Mercer, Tim R; Thompson, Ella R; Lakhani, Sunil R; Vargas, Ana C; Campbell, Ian G; Brown, Melissa A; Dinger, Marcel E; Mattick, John S

    2011-05-01

    Long noncoding RNAs (lncRNAs) are increasingly recognized to play major regulatory roles in development and disease. To identify novel regulators in breast biology, we identified differentially regulated lncRNAs during mouse mammary development. Among the highest and most differentially expressed was a transcript (Zfas1) antisense to the 5' end of the protein-coding gene Znfx1. In vivo, Zfas1 RNA is localized within the ducts and alveoli of the mammary gland. Zfas1 intronically hosts three previously undescribed C/D box snoRNAs (SNORDs): Snord12, Snord12b, and Snord12c. In contrast to the general assumption that noncoding SNORD-host transcripts function only as vehicles to generate snoRNAs, knockdown of Zfas1 in a mammary epithelial cell line resulted in increased cellular proliferation and differentiation, while not substantially altering the levels of the SNORDs. In support of an independent function, we also found that Zfas1 is extremely stable, with a half-life >16 h. Expression analysis of the SNORDs revealed these were expressed at different levels, likely a result of distinct structures conferring differential stability. While there is relatively low primary sequence conservation between Zfas1 and its syntenic human ortholog ZFAS1, their predicted secondary structures have similar features. Like Zfas1, ZFAS1 is highly expressed in the mammary gland and is down-regulated in breast tumors compared to normal tissue. We propose a functional role for Zfas1/ ZFAS1 in the regulation of alveolar development and epithelial cell differentiation in the mammary gland, which, together with its dysregulation in human breast cancer, suggests ZFAS1 as a putative tumor suppressor gene.

  1. Insulin-like growth factor binding proteins and mammary gland development.

    PubMed

    Sureshbabu, Angara; Tonner, Elizabeth; Flint, David J

    2011-01-01

    Mammary gland development is dependent upon insulin-like growth factors (IGFs) as survival factors. The actions of the IGFs are modulated by a family of IGF-binding proteins (IGFBP1-6). Expression of the IGFBPs is both time-dependent and cell-specific during both the developmental phases and the involution of the mammary gland. Although studied extensively in vitro, understanding the roles of IGFBPs in vivo has been difficult, largely due to the fact that IGFBP knock-out mice have no dramatic phenotypes. This review examines the evidence from in vitro studies and the attempts to examine in vivo actions utilising models with IGFBP deficiency or over-expression. In vitro studies demonstrate that IGFBPs can act by inhibition of the survival effects of IGFs, as well as by enhancing the effects of IGFs. Because the IGFBPs are found associated with the extracellular matrix, a role for IGFBPs as a reservoir of IGFs or, alternatively as a potential barrier to IGFs, thereby restricting their entry into particular tissues or cellular compartments was postulated. We also provide evidence with respect to the IGF-independent actions of the IGFBPs which include receptors, nuclear localization, and interaction with the extracellular matrix and cell surface proteins including integrins. We believe that recent findings place some of the IGFBPs in a larger family of extracellular proteins, the secreted cysteine-rich protein (CCN) family, which have similar structural domains (involved in binding to IGFs, extracellular matrix and integrins) and are heavily implicated in tissue re-modeling and morphogenesis.

  2. 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...

  3. Adhesion in Mammary Development: Novel Roles for E-Cadherin in Individual and Collective Cell Migration

    PubMed Central

    Shamir, Eliah R.; Ewald, Andrew J.

    2015-01-01

    Epithelial tissues are essential for barrier function, secretion, and regulation of fluid transport. Their function requires cell polarity and cell–cell adhesion, mediated through intercellular junctions. Conversely, disruption of adhesion and polarity is thought to drive cancer progression. The mammary gland is an important model for cell adhesion due to its postnatal hormonally regulated development; ducts undergo branching morphogenesis in response to steroid hormones during puberty. These hormonal signals induce a transition from simple to stratified architecture, initiated by asymmetric luminal cell divisions. Ductal elongation is accomplished by this multilayered, low-polarity epithelium, and polarity is reestablished as elongation ceases. The requirement for cell adhesion has been tested in 3D culture and in vivo, using gene deletion, knockdown, and misexpression in both developmental and homeostatic contexts. Attention has focused on E-cadherin, the major classical cadherin in luminal epithelial cells. Classic studies revealed a requirement for E-cadherin during lactation, and E-cadherin loss is widely posited to promote metastasis. However, recent findings demonstrated a broader requirement for E-cadherin during branching morphogenesis and homeostasis and also, surprisingly, in epithelial dissemination. These studies suggest that longstanding models of the role of adhesion in epithelial biology need to be revisited. Advances in inducible gene expression and knockdown, CRISPR/Cas9 technology, and fluorescent labeling of genetically modified cells offer the opportunity to test the roles of diverse adhesion systems and to develop a mechanistic understanding of how cell adhesion regulates development and cancer. PMID:25733146

  4. CUZD1 is a critical mediator of the JAK/STAT5 signaling pathway that controls mammary gland development during pregnancy

    PubMed Central

    Li, Quanxi; Kannan, Athilakshmi; Anandan, Lavanya; Lydon, John P.; Bagchi, Indrani C.; Bagchi, Milan K.

    2017-01-01

    In the mammary gland, genetic circuits controlled by estrogen, progesterone, and prolactin, act in concert with pathways regulated by members of the epidermal growth factor family to orchestrate growth and morphogenesis during puberty, pregnancy and lactation. However, the precise mechanisms underlying the crosstalk between the hormonal and growth factor pathways remain poorly understood. We have identified the CUB and zona pellucida-like domain-containing protein 1 (CUZD1), expressed in mammary ductal and alveolar epithelium, as a novel mediator of mammary gland proliferation and differentiation during pregnancy and lactation. Cuzd1-null mice exhibited a striking impairment in mammary ductal branching and alveolar development during pregnancy, resulting in a subsequent defect in lactation. Gene expression profiling of mammary epithelium revealed that CUZD1 regulates the expression of a subset of the EGF family growth factors, epiregulin, neuregulin-1, and epigen, which act in an autocrine fashion to activate ErbB1 and ErbB4 receptors. Proteomic studies further revealed that CUZD1 interacts with a complex containing JAK1/JAK2 and STAT5, downstream transducers of prolactin signaling in the mammary gland. In the absence of CUZD1, STAT5 phosphorylation in the mammary epithelium during alveologenesis was abolished. Conversely, elevated expression of Cuzd1 in mammary epithelial cells stimulated prolactin-induced phosphorylation and nuclear translocation of STAT5. Chromatin immunoprecipitation confirmed co-occupancy of phosphorylated STAT5 and CUZD1 in the regulatory regions of epiregulin, a potential regulator of epithelial proliferation, and whey acidic protein, a marker of epithelial differentiation. Collectively, these findings suggest that CUZD1 plays a critical role in prolactin-induced JAK/STAT5 signaling that controls the expression of key STAT5 target genes involved in mammary epithelial proliferation and differentiation during alveolar development. PMID

  5. The Effects of Folate on the Development of Breast Cancer in a Chemical Rodent Model of Mammary Carcinogenesis

    DTIC Science & Technology

    2002-08-01

    AD Award Number: DAMD17-01- 1 -0428 TITLE: The Effects of Folate on the Development of Breast Cancer in a Chemical Rodent Model of Mammary...DOCUMENTATION PAGE OMB No. 074-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including...Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503 1 . AGENCY USE

  6. Alveolar progenitor cells develop in mouse mammary glands independent of pregnancy and lactation.

    PubMed

    Booth, Brian W; Boulanger, Corinne A; Smith, Gilbert H

    2007-09-01

    We have previously described pluripotent, parity-induced mammary epithelial cells (PI-MEC) marked by Rosa26-lacZ expression in the mammary glands of parous females. PI-MEC act as lobule-limited epithelial stem/progenitor cells. To determine whether parity is necessary to generate PI-MEC, we incubated mammary explant cultures from virgin mice in vitro with insulin alone (I), hydrocortisone alone (H), prolactin alone (Prl), or a combination of these lactogenic hormones (IHPrl). Insulin alone activated the WAP-Cre gene. Hydrocortisone and prolactin alone did not. Any combination of hormones that included insulin was effective. Only I, H and Prl together were able to induce secretory differentiation and milk protein synthesis. In addition, EGF, IGF-2 and IGF-1 added individually produced activated (lacZ(+)) PI-MEC in explant cultures. Neither estrogen nor progesterone induced WAP-Cre expression in the explants. None of these positive initiators of WAP-Cre expression in PI-MEC were effective in mammospheres or two-dimensional cultures of mammary epithelium, indicating the indispensability of epithelial-stromal interaction in PI-MEC activation. Like PI-MEC, lacZ(+) cells from virgin explants proliferated and contributed progeny to mammospheres in vitro and to epithelial outgrowths in vivo after transplantation. LacZ(+) cells induced in virgin mouse mammary explants were multipotent (like PI-MEC) in impregnated hosts producing lacZ(+) mammary alveolar structures comprised of both myoepithelial and luminal progeny. These data demonstrate PI-MEC, a mammary epithelial sub-population of lobule-limited progenitor cells, are present in nulliparous female mice before parity and, like the PI-MEC observed following parity, are capable of proliferation, self-renewal and the capacity to produce progeny of diverse epithelial cell fates.

  7. 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

    2016-03-04

    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.

  8. An immunoreceptor tyrosine activation motif in the mouse mammary tumor virus envelope protein plays a role in virus-induced mammary tumors.

    PubMed

    Ross, Susan R; Schmidt, John W; Katz, Elad; Cappelli, Laura; Hultine, Stacy; Gimotty, Phyllis; Monroe, John G

    2006-09-01

    Mouse mammary tumor virus (MMTV) induces breast cancer with almost 100% efficiency in susceptible strains through insertional activation of protooncogenes, such as members of the wnt and fibroblast growth factor (fgf) families. We previously showed that expression of the MMTV envelope protein (Env) in normal immortalized mammary epithelial cells grown in three-dimensional cultures caused their morphological transformation, and that this phenotype depended on an immunoreceptor tyrosine-based activation motif (ITAM) present in Env and signaling through the Syk tyrosine kinase (E. Katz, M. H. Lareef, J. C. Rassa, S. M. Grande, L. B. King, J. Russo, S. R. Ross, and J. G. Monroe, J. Exp. Med. 201:431-439, 2005). Here, we examined the role of the Env protein in virus-induced mammary tumorigenesis in vivo. Similar to the effect seen in vitro, Env expression in the mammary glands of transgenic mice bearing either full-length wild-type provirus or only Env transgenes showed increased lobuloalveolar budding. Introduction of the ITAM mutation into the env of an infectious, replication-competent MMTV or into MMTV/murine leukemia virus pseudotypes had no effect on incorporation of Env into virus particles or on in vitro infectivity. Moreover, replication-competent MMTV bearing the ITAM mutation in Env infected lymphoid and mammary tissue at the same level as wild-type MMTV and was transmitted through milk. However, mammary tumor induction was greatly attenuated, and the pattern of oncogene activation was altered. Taken together, these studies indicate that the MMTV Env protein participates in mammary epithelial cell transformation in vivo and that this requires a functional ITAM in the envelope protein.

  9. Identification of reliable reference genes for qRT-PCR studies of the developing mouse mammary gland

    PubMed Central

    van de Moosdijk, Anoeska Agatha Alida; van Amerongen, Renée

    2016-01-01

    Cell growth and differentiation are often driven by subtle changes in gene expression. Many challenges still exist in detecting these changes, particularly in the context of a complex, developing tissue. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) allows relatively high-throughput evaluation of multiple genes and developmental time points. Proper quantification of gene expression levels by qRT-PCR requires normalization to one or more reference genes. Traditionally, these genes have been selected based on their presumed “housekeeping” function, with the implicit assumption that they are stably expressed over the entire experimental set. However, this is rarely tested empirically. Here we describe the identification of novel reference genes for the mouse mammary gland based on their stable expression in published microarray datasets. We compared eight novel candidate reference genes (Arpc3, Clock, Ctbp1, Phf7, Prdx1, Sugp2, Taf11 and Usp7) to eight traditional ones (18S, Actb, Gapdh, Hmbs, Hprt, Rpl13a, Sdha and Tbp) and analysed all genes for stable expression in the mouse mammary gland from pre-puberty to adulthood using four different algorithms (GeNorm, DeltaCt, BestKeeper and NormFinder). Prdx1, Phf7 and Ctbp1 were validated as novel and reliable, tissue-specific reference genes that outperform traditional reference genes in qRT-PCR studies of postnatal mammary gland development. PMID:27752147

  10. Changes in mammary histology and transcriptome profiles by low-dose exposure to environmental phenols at critical windows of development.

    PubMed

    Gopalakrishnan, Kalpana; Teitelbaum, Susan L; Lambertini, Luca; Wetmur, James; Manservisi, Fabiana; Falcioni, Laura; Panzacchi, Simona; Belpoggi, Fiorella; Chen, Jia

    2017-01-01

    Exposure to environmental chemicals has been linked to altered mammary development and cancer risk at high doses using animal models. Effects at low doses comparable to human exposure remain poorly understood, especially during critical developmental windows. We investigated the effects of two environmental phenols commonly used in personal care products - methyl paraben (MPB) and triclosan (TCS) - on the histology and transcriptome of normal mammary glands at low doses mimicking human exposure during critical windows of development. Sprague-Dawley rats were exposed during perinatal, prepubertal and pubertal windows, as well as from birth to lactation. Low-dose exposure to MPB and TCS induced measurable changes in both mammary histology (by Masson's Trichrome Stain) and transcriptome (by microarrays) in a window-specific fashion. Puberty represented a window of heightened sensitivity to MPB, with increased glandular tissue and changes of expression in 295 genes with significant enrichment in functions such as DNA replication and cell cycle regulation. Long-term exposure to TCS from birth to lactation was associated with increased adipose and reduced glandular and secretory tissue, with expression alterations in 993 genes enriched in pathways such as cholesterol synthesis and adipogenesis. Finally, enrichment analyses revealed that genes modified by MPB and TCS were over-represented in human breast cancer gene signatures, suggesting possible links with breast carcinogenesis. These findings highlight the issues of critical windows of susceptibility that may confer heightened sensitivity to environmental insults and implicate the potential health effects of these ubiquitous environmental chemicals in breast cancer.

  11. t10,c12-CLA decreases adiposity in peripubertal mice without dose-related detrimental effects on mammary development, inflammation status, and metabolism.

    PubMed

    Foote, M R; Giesy, S L; Bernal-Santos, G; Bauman, D E; Boisclair, Y R

    2010-12-01

    The trans 10, cis 12-conjugated linoleic acid (10,12-CLA) isomer reduces adiposity in several animal models. In the mouse, however, this effect is associated with adipose tissue inflammation, hyperinsulinemia and hepatic lipid accumulation. Moreover, 10,12-CLA was recently shown to promote mammary ductal hyperplasia and ErbB2/Her2-driven mammary cancer in the mouse. Reasons for detrimental effects of 10,12-CLA on the mouse mammary gland could relate to its effect on the mammary fat pad (MFP), which is essential for normal development. Accordingly, we hypothesized that mammary effects of 10,12-CLA were mediated through the MFP in a dose-dependent manner. Female FVB mice were fed 10,12-CLA at doses of 0%, 0.1%, 0.2%, or 0.5% of the diet from day 24 of age, and effects on mammary development and metabolism were measured on day 49. The 0.5% dose reduced ductal elongation and caused premature alveolar budding. These effects were associated with increased expression of inflammatory markers and genes shown to alter epithelial growth (IGF binding protein-5) and alveolar budding (TNF-α and receptor of activated NF-κB ligand). The 0.5% dose also caused hyperinsulinemia and hepatic lipid accumulation. In contrast, the 0.1% 10,12-CLA dose had no adverse effects on mammary development, metabolic events, and inflammatory responses, but remained effective in decreasing adipose weights and lipogenic gene expression. These results show that a low dose of 10,12-CLA reduces adiposity in the mouse without negative effects on mammary development, inflammation, and metabolism, and suggest that previously reported detrimental effects relate to the use of excessive doses.

  12. 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...

  13. P190-B, a Novel RhoGAP, in Mammary Gland Development and Breast Cancer Progression

    DTIC Science & Technology

    2005-09-01

    B overexpression during mammary gland involution, pl90-B/MMTV-rtTA bigenic female mice at eight weeks of age were bred to wildtype male mice. Age...for eight weeks at which time the mice were bred to wildtype FVB males . Three days after parturition mammary glands were collected and analyzed by H&E...overexpression during pregnancy and lactation, 12 week-old bigenic (n=6), and MTB (n=3) and wildtype littermate (n=3) control mice were bred to wildtype male

  14. Developing a Novel Mouse Model for Breast Cancer by Targeting Oncogenes to Mammary Progenitor Cells

    DTIC Science & Technology

    2005-04-01

    obtained and rederived into our facility this line of mice from another investigator Tom O’Brien (1). We are in the process of testing this line for...Breed K6-rtTA transgenic mice with established tetO-c-Myc mice. Transplant the mammary cells from the resulting bi -transgenic mice into 10 inguinal...concentrated RCAS-K-RasG12D-IRES-Cre virus to inguinal mammary glands of 10 pubertal and 10 estrogen-stimulated K6-TVA /p53flox/flox bi -genic females. Monitor

  15. Administration of Additional Phosphorylated Prolactin During Pregnancy Inhibits Mammary Ductal Branching and Promotes Premature Lobuloalveolus Development

    DTIC Science & Technology

    2002-07-01

    promotes differentiation. Further, we have demonstrated that these effects of U-PRL and S179D PRL are produced directly on the mammary gland. In...addition, we have been able to show that U-PRL and S179D PRL exert these very different effects by changing the balance of signaling between the two major

  16. 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...

  17. 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.

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

    PubMed

    Swanson, T J; Hammer, C J; Luther, J S; Carlson, D B; Taylor, J B; Redmer, D A; Neville, T L; Reed, J J; Reynolds, L P; Caton, J S; Vonnahme, K A

    2008-09-01

    To examine effects of nutritional plane and 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 breeding (d = 0) [adequate Se (9.5 mug/kg of BW) vs. high Se (81.8 mug/kg of BW)], and plane of nutrition, which began at d 50 of gestation [60% (RES), 100% (CON), and 140% (HIGH) of requirements]. Upon parturition, lambs were immediately separated from dams and weighed. Three hours after lambing, colostrum yield was determined, and samples were obtained for components and immunoglobulin G (IgG) analysis. Ewes were slaughtered within 24 h of parturition, and mammary tissues were collected for determination of alveolar secretory epithelial cell proliferation index and luminal area. Gestation length was reduced (P < 0.01) in HIGH ewes compared with RES and CON ewes. Although birth weights were reduced (P < 0.01) in RES and HIGH compared with CON ewes, there was little effect of diet on placental size. Mammary gland weight was reduced (P mammary gland weight in HIGH ewes was less (P = 0.03) compared with RES and CON. Colostrum weight and volume were reduced (P < 0.01) in RES and HIGH ewes compared with CON. Although colostrum IgG concentration was greater in RES ewes compared with CON and HIGH, total IgG was lower (P /= 0.15) on mammary gland weight, colostrum quantity, or IgG concentration in pregnant ewe lambs

  19. 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

  20. Ductal barriers in mammary epithelium

    PubMed Central

    Owens, Mark B; Hill, Arnold DK; Hopkins, Ann M

    2013-01-01

    Tissue barriers play an integral role in the biology and pathobiology of mammary ductal epithelium. In normal breast physiology, tight and adherens junctions undergo dynamic changes in permeability in response to hormonal and other stimuli, while several of their proteins are directly involved in mammary tumorigenesis. This review describes first the structure of mammary ductal epithelial barriers and their role in normal mammary development, examining the cyclical changes in response to puberty, pregnancy, lactation and involution. It then examines the role of adherens and tight junctions and the participation of their constituent proteins in mammary tumorigenic functions such as migration, invasion and metastasis. Finally, it discusses the potential of these adhesion proteins as both prognostic biomarkers and potential therapeutic targets in breast cancer. PMID:24665412

  1. 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

  2. Effect of conjoint administration of tamoxifen and high-dose radiation on the development of mammary carcinoma

    SciTech Connect

    Kantorowitz, D.A. ); Thompson, H.J. ); Furmanski, P. )

    1993-04-30

    Tamoxifen is currently advocated for post-menopausal breast cancer patients receiving definitive irradiation after limited surgery. The purpose of this study was to assess in an experimental model for breast cancer whether the efficacy of irradiation is altered by conjoint administration of tamoxifen. To this end, rats with small tumors induced by 1-methyl-1-nitrosourea (MNU) were treated with tamoxifen, radiation, or a combination of the two modalities. Female Sprague Dawley rats were injected i.p. with 50 mg MNU/kg body weight at 50 days of age. At 64 days post carcinogen, the majority of the rats had at least one palpable mammary tumor. At that time radiation with or without tamoxifen treatment was initiated and given 5 days per week for 5 weeks. Radiation dose was 4500 cGy delivered as 25, 180 cGy fractions. Tamoxifen, 500 mg/kg body weight, was administered subcutaneously each day during the irradiation interval. The study was terminated 28 weeks after carcinogen treatment. High dose radiation alone induced a reduction in the size of existing tumors, but resulted in a significant increase in the number of tumors that were detected. Treatment with tamoxifen alone also caused a reduction in tumor volume, but had no effect on final incidence or number of mammary tumors. Combined modality treatment resulted in a significant reduction in the volume of existing tumors and suppressed the enhanced occurrence of additional tumors observed when only radiation alone was administered. The findings of this study indicate that in the context of fractionated, high dose radiation treatment of established mammary cancers, tamoxifen may reduce the likelihood of subsequent tumor development and by so doing prove a helpful simultaneous conjoint adjuvant treatment to post-operative irradiation. 35 refs., 1 fig., 2 tabs.

  3. 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.

  4. Wwox inactivation enhances mammary tumorigenesis.

    PubMed

    Abdeen, S K; Salah, Z; Maly, B; Smith, Y; Tufail, R; Abu-Odeh, M; Zanesi, N; Croce, C M; Nawaz, Z; Aqeilan, R I

    2011-09-08

    Breast cancer is the leading cause of cancer-related death in women worldwide. Expression of the WWOX tumor suppressor is absent or reduced in a large proportion of breast tumors suggesting that loss of WWOX may contribute to breast tumorigenesis. Wwox-deficient mice die by 3-4 weeks of age precluding adult tumor analysis. To evaluate the effect of WWOX-altered expression on mammary tumor formation, the Wwox-heterozygous allele was back crossed onto the C3H mammary tumor-susceptible genetic background (Wwox(C3H)+/-) and incidence of mammary tumor formation was evaluated. Although 50% of the female Wwox(C3H)+/- mice developed mammary carcinomas, only 7% of Wwox(C3H)+/+ mice did. Intriguingly, mammary tumors in Wwox(C3H)+/- mice frequently lost WWOX protein expression suggesting a genetic predisposition toward mammary tumorigenesis. Immunohistochemical staining of hormone receptors revealed loss of estrogen receptor-α (ER) and progesterone receptor in the majority of these tumors. In vitro, depletion of WWOX in MCF7 ER-positive cells led to reduced ER expression and reduced sensitivity to tamoxifen and estrogen treatment and was associated with enhanced survival and anchorage-independent growth. Finally, cDNA array analyses of murine normal mammary epithelial cells and mammary tumors identified 163 significantly downreguated and 129 upregulated genes in the tumors. The majority of differentially expressed genes were part of pathways involved in cellular movement, cell-to-cell signaling and interaction, cellular development, cellular growth and proliferation and cell death. These changes in gene expression of mouse mammary tumors in Wwox(C3H)+/- mice resemble, at least in part, human breast cancer development. Our findings demonstrate the critical role that the WWOX tumor suppressor gene has in preventing tumorigenesis in breast cancer.

  5. Prenatal exposure to BPA alters the epigenome of the rat mammary gland and increases the propensity to neoplastic development.

    PubMed

    Dhimolea, Eugen; Wadia, Perinaaz R; Murray, Tessa J; Settles, Matthew L; Treitman, Jo D; Sonnenschein, Carlos; Shioda, Toshi; Soto, Ana M

    2014-01-01

    Exposure to environmental estrogens (xenoestrogens) may play a causal role in the increased breast cancer incidence which has been observed in Europe and the US over the last 50 years. The xenoestrogen bisphenol A (BPA) leaches from plastic food/beverage containers and dental materials. Fetal exposure to BPA induces preneoplastic and neoplastic lesions in the adult rat mammary gland. Previous results suggest that BPA acts through the estrogen receptors which are detected exclusively in the mesenchyme during the exposure period by directly altering gene expression, leading to alterations of the reciprocal interactions between mesenchyme and epithelium. This initiates a long sequence of altered morphogenetic events leading to neoplastic transformation. Additionally, BPA induces epigenetic changes in some tissues. To explore this mechanism in the mammary gland, Wistar-Furth rats were exposed subcutaneously via osmotic pumps to vehicle or 250 µg BPA/kg BW/day, a dose that induced ductal carcinomas in situ. Females exposed from gestational day 9 to postnatal day (PND) 1 were sacrificed at PND4, PND21 and at first estrus after PND50. Genomic DNA (gDNA) was isolated from the mammary tissue and immuno-precipitated using anti-5-methylcytosine antibodies. Detection and quantification of gDNA methylation status using the Nimblegen ChIP array revealed 7412 differentially methylated gDNA segments (out of 58207 segments), with the majority of changes occurring at PND21. Transcriptomal analysis revealed that the majority of gene expression differences between BPA- and vehicle-treated animals were observed later (PND50). BPA exposure resulted in higher levels of pro-activation histone H3K4 trimethylation at the transcriptional initiation site of the alpha-lactalbumin gene at PND4, concomitantly enhancing mRNA expression of this gene. These results show that fetal BPA exposure triggers changes in the postnatal and adult mammary gland epigenome and alters gene expression patterns

  6. Experimental mammary carcinogenesis - Rat models.

    PubMed

    Alvarado, Antonieta; Faustino-Rocha, Ana I; Colaço, Bruno; Oliveira, Paula A

    2017-03-15

    Mammary cancer is one of the most common cancers, victimizing more than half a million of women worldwide every year. Despite all the studies in this field, the current therapeutic approaches are not effective and have several devastating effects for patients. In this way, the need to better understand the mammary cancer biopathology and find effective therapies led to the development of several rodent models over years. With this review, the authors intended to provide the readers with an overview of the rat models used to study mammary carcinogenesis, with a special emphasis on chemically-induced models.

  7. LPA receptor activity is basal specific and coincident with early pregnancy and involution during mammary gland postnatal development

    PubMed Central

    Acosta, Deanna; Bagchi, Susmita; Broin, Pilib Ó; Hollern, Daniel; Racedo, Silvia E.; Morrow, Bernice; Sellers, Rani S.; Greally, John M.; Golden, Aaron; Andrechek, Eran; Wood, Teresa; Montagna, Cristina

    2016-01-01

    During pregnancy, luminal and basal epithelial cells of the adult mammary gland proliferate and differentiate resulting in remodeling of the adult gland. While pathways that control this process have been characterized in the gland as a whole, the contribution of specific cell subtypes, in particular the basal compartment, remains largely unknown. Basal cells provide structural and contractile support, however they also orchestrate the communication between the stroma and the luminal compartment at all developmental stages. Using RNA-seq, we show that basal cells are extraordinarily transcriptionally dynamic throughout pregnancy when compared to luminal cells. We identified gene expression changes that define specific basal functions acquired during development that led to the identification of novel markers. Enrichment analysis of gene sets from 24 mouse models for breast cancer pinpoint to a potential new function for insulin-like growth factor 1 (Igf1r) in the basal epithelium during lactogenesis. We establish that β-catenin signaling is activated in basal cells during early pregnancy, and demonstrate that this activity is mediated by lysophosphatidic acid receptor 3 (Lpar3). These findings identify novel pathways active during functional maturation of the adult mammary gland. PMID:27808166

  8. 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

  9. Sustained trophism of the mammary gland is sufficient to accelerate and synchronize development of ErbB2/Neu-induced tumors

    PubMed Central

    Landis, MD; Seachrist, DD; Abdul-Karim, FW; Keri, RA

    2006-01-01

    Epidemiological studies indicate that parity enhances HER2/ErbB2/Neu-induced breast tumorigenesis. Furthermore, recent studies using multiparous, ErbB2/Neu-overexpressing mouse mammary tumor virus (MMTV-Neu) mice have shown that parity induces a population of cells that are targeted for ErbB2/Neu-induced transformation. Although parity accelerates mammary tumorigenesis, the pattern of tumor development in multiparous MMTV-Neu mice remains stochastic, suggesting that additional events are required for ErbB2/Neu to cause mammary tumors. Whether such events are genetic in nature or reflective of the dynamic hormonal control of the gland that occurs with pregnancy remains unclear. We postulated that young age at pregnancy initiation or chronic trophic maintenance of mammary epithelial cells might provide a cellular environment that significantly increases susceptibility to ErbB2/Neu-induced tumorigenesis. MMTV-Neu mice that were maintained pregnant or lactating beginning at 3 weeks of age demonstrated accelerated tumorigenesis, but this process was still stochastic, indicating that early pregnancy does not provide the requisite events of tumorigenesis. However, bitransgenic mice that were generated by breeding MMTV-Neu mice with a luteinizing hormone-overexpressing mouse model of ovarian hyperstimulation developed multifocal mammary tumors in an accelerated, synchronous manner compared to virgin MMTV-Neu animals. This synchrony of tumor development in the bitransgenic mice suggests that trophic maintenance of the mammary gland provides the additional events required for tumor formation and maintains the population of cells that are targeted by ErbB2/Neu for transformation. Both the synchrony of tumor appearance and the ability to characterize a window of commitment by ovariectomy/palpation studies permitted microarray analysis to evaluate changes in gene expression over a defined timeline that spans the progression from normal to preneoplastic mammary tissue. These

  10. Application of Sholl analysis to quantify changes in growth and development in rat mammary gland whole mounts.

    PubMed

    Stanko, Jason P; Easterling, Michael R; Fenton, Suzanne E

    2015-07-01

    Studies that utilize the rodent mammary gland (MG) as an endpoint for assessing the developmental toxicity of chemical exposures typically employ either basic dimensional measurements or developmental scoring of morphological characteristics as a means to quantify MG development. There are numerous means by which to report these developmental changes, leading to inconsistent translation across laboratories. The Sholl analysis is a method historically used for quantifying neuronal dendritic patterns. The present study describes the use of the Sholl analysis to quantify MG branching characteristics. Using this method, we were able to detect significant differences in branching density in MG of peripubertal female Sprague Dawley rats that had been exposed to vehicle or a potent estrogen. These data suggest the Sholl analysis can be an effective tool for quantitatively measuring an important characteristic of MG development and for examining associations between MG growth and density and adverse effects in the breast.

  11. The Role of BRCA1 in Suppressing Epithelial-Mesenchymal Transition in Mammary Gland and Tumor Development

    DTIC Science & Technology

    2015-09-01

    balance of cell lineages in mammary epithelium during pregnancy. Dev Biol. 2006;293(2):565-80. 15. Wagner KU, Wall RJ, St- Onge L, Gruss P, Wynshaw...Brca1 in mammary epithelial cells results in blunted ductal morphogenesis and tumour formation. Nat Genet 1999;22:37–43. 22. Wagner KU,Wall RJ, St- Onge

  12. Trajectory Clustering: a Non-Parametric Method for Grouping Gene Expression Time Courses, with Applications to Mammary Development

    PubMed Central

    Phang, T.L.; Neville, M.C.; Rudolph, M.; Hunter, L.

    2008-01-01

    Trajectory clustering is a novel and statistically well-founded method for clustering time series data from gene expression arrays. Trajectory clustering uses non-parametric statistics and is hence not sensitive to the particular distributions underlying gene expression data. Each cluster is clearly defined in terms of direction of change of expression for successive time points (its ‘trajectory’), and therefore has easily appreciated biological meaning. Applying the method to a dataset from mouse mammary gland development, we demonstrate that it produces different clusters than Hierarchical, K-means, and Jackknife clustering methods, even when those methods are applied to differences between successive time points. Compared to all of the other methods, trajectory clustering was better able to match a manual clustering by a domain expert, and was better able to cluster groups of genes with known related functions. PMID:12603041

  13. Vitamin D and the mammary gland: a review on its role in normal development and breast cancer.

    PubMed

    Lopes, Nair; Paredes, Joana; Costa, José Luis; Ylstra, Bauke; Schmitt, Fernando

    2012-05-31

    Breast cancer is a heterogeneous disease associated with diverse biological behaviours and clinical outcome. Although some molecular subgroups of breast cancer have a targeted therapy, the most aggressive tumours still lack a molecular target. Despite vitamin D being classically associated with the physiological role of calcium regulation and phosphate transport in bone metabolism, several studies have demonstrated a wide range of functions for this hormone, which are particularly important in the field of cancer. The mechanisms underlying the protective actions of vitamin D in cancer development are only sparsely understood, but evidence shows that vitamin D participates in cell growth regulation, apoptosis and cell differentiation. In addition, it has been implicated in the suppression of cancer cell invasion, angiogenesis and metastasis. Most of vitamin D biological actions are mediated by the vitamin D receptor and the synthesis and catabolism of this hormone are regulated by the enzymes CYP27B1 and CYP24A1. In the present review we highlight research data concerning the function of this hormone in the mammary gland, with a special focus on breast carcinogenesis. Hence, and although the available data are controversial, we consider not only updated information on the epidemiology of vitamin D in breast cancer and its potential value as a therapeutic agent or prophylactic (with an emphasis on molecular mechanisms and effectors of vitamin D action), but include data on its role in other stages of breast cancer progression as well. Accordingly, we review data on the influence of vitamin D in the development of normal breast and the expression of vitamin D-related proteins (VDR, CYP27B1 and CYP24A21) in benign mammary lesions and ductal carcinomas in situ.

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

    DOE PAGES

    Castillo-Lluva, Sonia; Hontecillas-Prieto, Lourdes; Blanco-Gómez, Adrian; ...

    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

  15. 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.

  16. Development of a subset of forelimb muscles and their attachment sites requires the ulnar-mammary syndrome gene Tbx3

    PubMed Central

    Colasanto, Mary P.; Eyal, Shai; Mohassel, Payam; Bamshad, Michael; Bonnemann, Carsten G.; Zelzer, Elazar; Moon, Anne M.

    2016-01-01

    ABSTRACT In the vertebrate limb over 40 muscles are arranged in a precise pattern of attachment via muscle connective tissue and tendon to bone and provide an extensive range of motion. How the development of somite-derived muscle is coordinated with the development of lateral plate-derived muscle connective tissue, tendon and bone to assemble a functional limb musculoskeletal system is a long-standing question. Mutations in the T-box transcription factor, TBX3, have previously been identified as the genetic cause of ulnar-mammary syndrome (UMS), characterized by distinctive defects in posterior forelimb bones. Using conditional mutagenesis in mice, we now show that TBX3 has a broader role in limb musculoskeletal development. TBX3 is not only required for development of posterior forelimb bones (ulna and digits 4 and 5), but also for a subset of posterior muscles (lateral triceps and brachialis) and their bone eminence attachment sites. TBX3 specification of origin and insertion sites appears to be tightly linked with whether these particular muscles develop and may represent a newly discovered mechanism for specification of anatomical muscles. Re-examination of an individual with UMS reveals similar previously unrecognized muscle and bone eminence defects and indicates a conserved role for TBX3 in regulating musculoskeletal development. PMID:27491074

  17. 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.

  18. ‘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

  19. 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.

  20. Inhibition of mouse mammary ductal morphogenesis and down-regulation of the EGF receptor by epidermal growth factor.

    PubMed

    Coleman, S; Daniel, C W

    1990-02-01

    EGF, initially demonstrated to be a potent mitogen for a variety of cell types, has more recently been shown to inhibit proliferation of several cell lines. Few studies, however, have addressed the effects of EGF on growth and morphogenesis of tissues in vivo, particularly with regard to EGF as a possible inhibitor. We now demonstrate that EGF treatment of vigorously growing mammary ducts, administered directly to the glands by slow release plastic implants, inhibited normal ductal growth. Inhibition was restricted to the region around the implant and untreated glands in the same animal were normal, indicating direct effects of EGF. EGF-treated end buds were smaller and demonstrated reduced levels of DNA synthesis, although remnants of a stem (cap) cell layer persisted. Full inhibition of growth occurred within 3 days of implantation and required extended exposure to EGF, since treatment of 5 hr or less had no effect on ductal growth. At the lower inhibitory doses tested, growth resumed within 8 days, indicating reversibility of inhibition. No lobuloalveolar or hyperplastic response was seen. 125I-EGF autoradiography revealed that ductal growth inhibition was preceded by the disappearance of EGF receptors located in the cap cell layer of the end bud epithelium and in stromal cells adjacent to the buds. These results, in conjunction with our previous evidence demonstrating the growth-stimulatory effect by EGF on nonproliferating mammary ducts, suggest a growth regulatory role for EGF in mouse mammary ductal morphogenesis.

  1. In Utero Exposure to Low-Dose Alcohol Induces Reprogramming of Mammary Development and Tumor Risk in MMTV-erbB-2 Transgenic Mice

    PubMed Central

    Ma, Zhikun; Blackwelder, Amanda J.; Lee, Harry; Zhao, Ming; Yang, Xiaohe

    2015-01-01

    There is increasing evidence that prenatal exposure to environmental factors may modify breast cancer risk later in life. This study aimed to investigate the effects of in utero exposure to low-dose alcohol on mammary development and tumor risk. Pregnant MMTV-erbB-2 mice were exposed to alcohol (6 g/kg/day) between day 13 and day 19 of gestation, and the female offspring were examined for tumor risk. Whole mount analysis indicated that in utero exposure to low-dose alcohol induced significant increases in ductal extension at 10 weeks of age. Molecular analysis showed that in utero alcohol exposure induced upregulation of ERα signaling and activation of Akt and Erk1/2 in pubertal mammary glands. However, enhanced signaling in the EGFR/erbB-2 pathway appeared to be more prominent in 10-week-old glands than did signaling in the other pathways. Interestingly, tumor development in mice with in utero exposure to low-dose alcohol was slightly delayed compared to control mice, but tumor multiplicity was increased. The results indicate that in utero exposure to low-dose alcohol induces the reprogramming of mammary development by mechanisms that include altered signaling in the estrogen receptor (ER) and erbB-2 pathways. The intriguing tumor development pattern might be related to alcohol dose and exposure conditions, and warrants further investigation. PMID:25853264

  2. 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.

  3. Effects of ewe size and nutrition on fetal mammary gland development and lactational performance of offspring at their first lactation.

    PubMed

    van der Linden, D S; Kenyon, P R; Blair, H T; Lopez-Villalobos, N; Jenkinson, C M C; Peterson, S W; Mackenzie, D D S

    2009-12-01

    Many environmental factors applied postnatally are known to affect milk production of the dam, but to date, the effects of different fetal environments on subsequent first lactational performance of the offspring have not been reported. Four hundred fifty heavy (H; 60.8 kg +/- 0.18) and 450 light (L; 42.5 kg +/- 0.17) dams were randomly allocated to ad libitum (A) or maintenance (M) nutritional regimens from d 21 until d 140 of pregnancy, under pastoral grazing conditions (HA, n = 151; HM, n = 153; LA, n = 155; LM, n = 153). At d 100 of pregnancy, a sub-group of twin-bearing dams was killed and fetal mammary glands collected. From 1 wk before lambing, all remaining dams were fed ad libitum until weaning. After weaning, female progeny were managed and fed under pastoral conditions as 1 group. At 2 yr of age, 72 twin-rearing ewe offspring were milked once a week for 7 wk. Fetuses from M-dams had heavier mammary glands (P = 0.03) compared with A-fetuses. Fetuses from H-dams had greater (P = 0.0008) mammary duct area compared with L-fetuses. At 2 yr of age, M-offspring had greater milk yields at d 7 (P = 0.02) and d 28 (P = 0.09) of lactation and tended to have greater accumulated milk yields (P = 0.11) compared with A-offspring. Ewes born to M-dams showed greater lactose percentage at d 14 (P = 0.002), d 21 (P = 0.06), and d 28 (P = 0.07) of lactation and greater (P = 0.049) accumulated lactose yields and CP (P = 0.06) yields compared with A-offspring. Ewes born to H-dams displayed greater milk yields at d 14 (P = 0.08) and d 21 (P = 0.02) and had greater accumulated milk yield (P = 0.08) and lactose yield (P = 0.04) compared with L-offspring. Lambs born to M-offspring were heavier at birth (P = 0.02) and grew faster until weaning (P = 0.02), matching the milk yield and composition data, compared with their ad libitum counterparts. Birth weight was not affected (P > 0.10) by grand dam size; however, lambs born to H-offspring grew faster from birth until d 49 of age (P

  4. Quantitative Analysis of the Human Milk Whey Proteome Reveals Developing Milk and Mammary-Gland Functions across the First Year of Lactation

    PubMed Central

    Zhang, Qiang; Cundiff, Judy K.; Maria, Sarah D.; McMahon, Robert J.; Woo, Jessica G.; Davidson, Barbara S.; Morrow, Ardythe L.

    2013-01-01

    In-depth understanding of the changing functions of human milk (HM) proteins and the corresponding physiological adaptions of the lactating mammary gland has been inhibited by incomplete knowledge of the HM proteome. We analyzed the HM whey proteome (n = 10 women with samples at 1 week and 1, 3, 6, 9 and 12 months) using a quantitative proteomic approach. One thousand three hundred and thirty three proteins were identified with 615 being quantified. Principal component analysis revealed a transition in the HM whey proteome-throughout the first year of lactation. Abundance changes in IgG, sIgA and sIgM display distinct features during the first year. Complement components and other acute-phase proteins are generally at higher levels in early lactation. Proteomic analysis further suggests that the sources of milk fatty acids (FA) shift from more direct blood influx to more de novo mammary synthesis over lactation. The abundances of the majority of glycoproteins decline over lactation, which is consistent with increased enzyme expression in glycoprotein degradation and decreased enzyme expression in glycoprotein synthesis. Cellular detoxification machinery may be transformed as well, thereby accommodating increased metabolic activities in late lactation. The multiple developing functions of HM proteins and the corresponding mammary adaption become more apparent from this study. PMID:28250401

  5. Quantitative Analysis of the Human Milk Whey Proteome Reveals Developing Milk and Mammary-Gland Functions across the First Year of Lactation.

    PubMed

    Zhang, Qiang; Cundiff, Judy K; Maria, Sarah D; McMahon, Robert J; Woo, Jessica G; Davidson, Barbara S; Morrow, Ardythe L

    2013-09-03

    In-depth understanding of the changing functions of human milk (HM) proteins and the corresponding physiological adaptions of the lactating mammary gland has been inhibited by incomplete knowledge of the HM proteome. We analyzed the HM whey proteome (n = 10 women with samples at 1 week and 1, 3, 6, 9 and 12 months) using a quantitative proteomic approach. One thousand three hundred and thirty three proteins were identified with 615 being quantified. Principal component analysis revealed a transition in the HM whey proteome-throughout the first year of lactation. Abundance changes in IgG, sIgA and sIgM display distinct features during the first year. Complement components and other acute-phase proteins are generally at higher levels in early lactation. Proteomic analysis further suggests that the sources of milk fatty acids (FA) shift from more direct blood influx to more de novo mammary synthesis over lactation. The abundances of the majority of glycoproteins decline over lactation, which is consistent with increased enzyme expression in glycoprotein degradation and decreased enzyme expression in glycoprotein synthesis. Cellular detoxification machinery may be transformed as well, thereby accommodating increased metabolic activities in late lactation. The multiple developing functions of HM proteins and the corresponding mammary adaption become more apparent from this study.

  6. A Tale of Two Signals: AR and WNT in Development and Tumorigenesis of Prostate and Mammary Gland

    PubMed Central

    Pakula, Hubert; Xiang, Dongxi; Li, Zhe

    2017-01-01

    Prostate cancer (PCa) is one of the most common cancers and among the leading causes of cancer deaths for men in industrialized countries. It has long been recognized that the prostate is an androgen-dependent organ and PCa is an androgen-dependent disease. Androgen action is mediated by the androgen receptor (AR). Androgen deprivation therapy (ADT) is the standard treatment for metastatic PCa. However, almost all advanced PCa cases progress to castration-resistant prostate cancer (CRPC) after a period of ADT. A variety of mechanisms of progression from androgen-dependent PCa to CRPC under ADT have been postulated, but it remains largely unclear as to when and how castration resistance arises within prostate tumors. In addition, AR signaling may be modulated by extracellular factors among which are the cysteine-rich glycoproteins WNTs. The WNTs are capable of signaling through several pathways, the best-characterized being the canonical WNT/β-catenin/TCF-mediated canonical pathway. Recent studies from sequencing PCa genomes revealed that CRPC cells frequently harbor mutations in major components of the WNT/β-catenin pathway. Moreover, the finding of an interaction between β-catenin and AR suggests a possible mechanism of cross talk between WNT and androgen/AR signaling pathways. In this review, we discuss the current knowledge of both AR and WNT pathways in prostate development and tumorigenesis, and their interaction during development of CRPC. We also review the possible therapeutic application of drugs that target both AR and WNT/β-catenin pathways. Finally, we extend our review of AR and WNT signaling to the mammary gland system and breast cancer. We highlight that the role of AR signaling and its interaction with WNT signaling in these two hormone-related cancer types are highly context-dependent. PMID:28134791

  7. A Tale of Two Signals: AR and WNT in Development and Tumorigenesis of Prostate and Mammary Gland.

    PubMed

    Pakula, Hubert; Xiang, Dongxi; Li, Zhe

    2017-01-27

    Prostate cancer (PCa) is one of the most common cancers and among the leading causes of cancer deaths for men in industrialized countries. It has long been recognized that the prostate is an androgen-dependent organ and PCa is an androgen-dependent disease. Androgen action is mediated by the androgen receptor (AR). Androgen deprivation therapy (ADT) is the standard treatment for metastatic PCa. However, almost all advanced PCa cases progress to castration-resistant prostate cancer (CRPC) after a period of ADT. A variety of mechanisms of progression from androgen-dependent PCa to CRPC under ADT have been postulated, but it remains largely unclear as to when and how castration resistance arises within prostate tumors. In addition, AR signaling may be modulated by extracellular factors among which are the cysteine-rich glycoproteins WNTs. The WNTs are capable of signaling through several pathways, the best-characterized being the canonical WNT/β-catenin/TCF-mediated canonical pathway. Recent studies from sequencing PCa genomes revealed that CRPC cells frequently harbor mutations in major components of the WNT/β-catenin pathway. Moreover, the finding of an interaction between β-catenin and AR suggests a possible mechanism of cross talk between WNT and androgen/AR signaling pathways. In this review, we discuss the current knowledge of both AR and WNT pathways in prostate development and tumorigenesis, and their interaction during development of CRPC. We also review the possible therapeutic application of drugs that target both AR and WNT/β-catenin pathways. Finally, we extend our review of AR and WNT signaling to the mammary gland system and breast cancer. We highlight that the role of AR signaling and its interaction with WNT signaling in these two hormone-related cancer types are highly context-dependent.

  8. 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...

  9. 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.

  10. Ductal morphogenesis in the mouse mammary gland: evidence supporting a role for epidermal growth factor.

    PubMed

    Coleman, S; Silberstein, G B; Daniel, C W

    1988-06-01

    Epidermal growth factor (EGF) is a potent mitogen for a variety of cells in vitro, but studies on its effects in vivo and its possible role as a natural growth regulator are few. Using slow-release plastic implants, capable of delivering EGF to small regions of the gland over a period of several days, we have shown that EGF reinitiated ductal growth and morphogenesis in growth-static glands of ovariectomized mice. The effects of implanted EGF were confined to the zone around the implant and were time and dose dependent. Unimplanted glands in the same animal were unaffected. Local effects included (1) the formation of new ductal growth points (end buds), (2) the restoration of normal end bud histomorphology and the reappearance of a stem (cap) cell layer, (3) the reinitiation of epithelial DNA synthesis, and (4) an increase in ductal diameter. No lobulo-alveolar or hyperplastic growth was seen. Competitive binding assays and autoradiography were used to characterize EGF receptor activity in growing and static glands. High and low affinity receptors were demonstrated in each tissue, while 125I-EGF autoradiography revealed differential, specific binding of the ligand to certain epithelial and stromal elements. In the epithelium, label was concentrated in the cap cells of the end buds and in myoepithelial cells of the mammary ducts. Stromal cell label was heaviest adjacent to the epithelium in the end bud flank and subtending ducts, suggesting the induction of stromal EGF receptors by mammary epithelium. Because exogenous EGF is both a mitogenic and morphogenetic factor in this tissue and can serve as a locally acting substitute for known systemic mammogens such as estrogen and prolactin, it must be considered a strong candidate for a naturally occurring mammary tissue mitogen.

  11. Mammary gland: From embryogenesis to adult life.

    PubMed

    Musumeci, Giuseppe; Castrogiovanni, Paola; Szychlinska, Marta Anna; Aiello, Flavia Concetta; Vecchio, Giada Maria; Salvatorelli, Lucia; Magro, Gaetano; Imbesi, Rosa

    2015-01-01

    The aim of this review is to focus on the molecular factors that ensure the optimal development and maintenance of the mammary gland thanks to their integration and coordination. The development of the mammary gland is supported, not only by endocrine signals, but also by regulatory molecules, which are able to integrate signals from the surrounding microenvironment. A major role is certainly played by homeotic genes, but their incorrect expression during the spatiotemporal regulation of proliferative, functional and differentiation cycles of the mammary gland, may result in the onset of neoplastic processes. Attention is directed also to the endocrine aspects and sexual dimorphism of mammary gland development, as well as the role played by ovarian steroids and their receptors in adult life.

  12. Role and regulation of autophagy in the development of acinar structures formed by bovine BME-UV1 mammary epithelial cells.

    PubMed

    Sobolewska, Agnieszka; Motyl, Tomasz; Gajewska, Malgorzata

    2011-10-01

    Autophagy is a catabolic process providing an alternative energy source for cells under stressful conditions such as starvation, growth factor deprivation or hypoxia. During involution of the bovine mammary gland autophagy is induced in mammary epithelial cells (MECs) as a survival mechanism, and is tightly regulated by hormones and growth factors necessary for gland development. In the present study we adapted the three-dimensional culture model to investigate the role of autophagy during formation of alveoli-like structures by bovine BME-UV1 MECs grown on extracellular matrix (ECM) components. Using confocal microscopy and Western-blot analyses of autophagic and apoptotic markers: LC3, and cleaved caspase-3, we showed that autophagy was induced in centrally localized cells within the developing acini. These cells lacked a direct contact with ECM, and formed a distinct population from the outer layer of cells. Induction of autophagy preceded apoptosis, but did not inhibit the formation of a hollow lumen. In the presence of steroid hormones: 17β-estradiol and progesterone, although autophagy was augmented, acini formation proceeded normally. In contrast, the major lactogenic hormone: prolactin, which supports functional differentiation of alveoli, did not alter induction of autophagy within the spheroids. BME-UV1 cells cultured on Matrigel in the presence of growth factors IGF-I and EGF formed larger, underdeveloped acini without lumens due to caspase-3 inhibition, and sustained autophagy in the centre of the spheroids, while TGF-β1 accelerated apoptosis, and increased autophagy significantly. Our observations suggest that sex steroids 17β-estradiol and progesterone, as well as growth factor TGF-β1 may regulate the development of the bovine mammary gland by inducing autophagy in addition to regulating proliferation and apoptosis of MECs. These data indicate that autophagy may play an important role during alveolargenesis.

  13. In Utero Exposure to Cadmium, Mammary Gland Development, and Breast Cancer Risk

    DTIC Science & Technology

    2007-05-01

    of cadmium, 0.075 or 0.15 mg/kg feed cadmium throughout pregnancy. The effects on (i) birth weight , (ii) postnatal weight development, (iii) vaginal...switched to AIN93 laboratory chow. Birth - weight was not affected by fetal cadmium exposure, but the higher cadmium dose induced a long-lasting increase

  14. 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...

  15. Energy balance modulation impacts epigenetic reprogramming, ERα and ERβ expression and mammary tumor development in MMTV-neu transgenic mice.

    PubMed

    Rossi, Emily L; Dunlap, Sarah M; Bowers, Laura W; Khatib, Subreen A; Doerstling, Steven S; Smith, Laura A; Sharma, Manu A; Holley, Darcy; Brown, Powel H; Estecio, Marcos R; Kusewitt, Donna F; deGraffenried, Linda A; Bultman, Scott J; Hursting, Stephen D

    2017-04-03

    The association between obesity and breast cancer risk and prognosis is well established in ER-positive disease but less clear in HER2-positive disease. Here, we report preclinical evidence suggesting weight maintenance through calorie restriction may limit risk of HER2-positive breast cancer. In female MMTV-HER2/neu transgenic mice, we found that ERα and ERβ expression, mammary tumorigenesis and survival are energy balance-dependent in association with epigenetic reprogramming. Mice were randomized to receive a calorie restriction (CR), overweight (OW)-inducing, or diet-induced obesity (DIO) regimen (n = 27/group). Subsets of mice (n = 4/group/time point) were euthanized after 1, 3 and 5 months to characterize diet-dependent metabolic, transcriptional, and epigenetic perturbations. Remaining mice were followed up to 22 months. Relative to the OW and DIO regimens, CR decreased body weight, adiposity, and serum metabolic hormones as expected, and also elicited an increase in mammary ERα and ERβ expression. Increased DNA methylation accompanied this pattern, particularly at CpG dinucleotides located within binding or flanking regions for the transcriptional regulator CCCTC-binding factor (CTCF) of ESR1 and ESR2, consistent with sustained transcriptional activation of ERα and ERβ. Mammary expression of the DNA methylation enzyme DNMT1 was stable in CR mice but increased over time in OW and DIO mice, suggesting CR obviates epigenetic alterations concurrent with chronic excess energy intake. In the survival study, CR elicited a significant suppression in spontaneous mammary tumorigenesis. Overall, our findings suggest a mechanistic rationale to prevent or reverse excess body weight as a strategy to reduce HER2-positive breast cancer risk.

  16. Pmg-1 and pmg-2 constitute a novel family of KAP genes differentially expressed during skin and mammary gland development.

    PubMed

    Kuhn, F; Lassing, C; Range, A; Mueller, M; Hunziker, T; Ziemiecki, A; Andres, A C

    1999-08-01

    The epidermis, by invagination of the undifferentiated ectodermal cells, gives rise to several distinct structures including hair, sebaceous, eccrine sweat and mammary glands. We have recently isolated a novel gene, pmg-1, expressed in the pubertal mouse mammary gland. While investigating its genomic structure, we identified a related gene in close proximity, which we have termed pmg-2. pmg-1 and pmg-2 are intron-less, are transcribed in opposite directions and are separated by a potential promoter region of 2.8 kb containing putative binding motifs for the developmental transcription factors Lef-1, Sox5 and D-STAT. pmg-1 and pmg-2 encode small proteins rich in G, S, F, Y and Q and contain characteristic repeats reminiscent of the keratin-associated proteins (KAPs). Both genes are expressed in growing hair follicles in skin as well as in sebaceous and eccrine sweat glands. Interestingly, expression is also detected in the mammary epithelium where it is limited to the onset of the pubertal growth phase and is independent of ovarian hormones. Their broad, developmentally controlled expression pattern, together with their unique amino acid composition, demonstrate that pmg-1 and pmg-2 constitute a novel KAP gene family participating in the differentiation of all epithelial cells forming the epidermal appendages.

  17. Dasatinib inhibits mammary tumour development in a genetically engineered mouse model.

    PubMed

    Karim, Saadia A; Creedon, Helen; Patel, Hitesh; Carragher, Neil O; Morton, Jennifer P; Muller, William J; Evans, Thomas Rj; Gusterson, Barry; Sansom, Owen J; Brunton, Valerie G

    2013-08-01

    Src family kinase activity is elevated in a number of human cancers including breast cancer. This increased activity has been associated with aggressive disease and poor prognosis. Src inhibitors are currently in clinical development with a number of trials currently assessing their activity in breast cancer. However, the results to date have been disappointing and a further evaluation of the preclinical effects of Src inhibitors is required to help establish whether these agents will be useful in the treatment of breast cancer. In this study we investigate the effects of dasatinib, which is a potent inhibitor of Src family kinases, on the initiation and development of breast cancer in a genetically engineered model of the disease. The mouse model utilized is driven by expression of activated ErbB-2 under the transcriptional control of its endogenous promoter coupled with conditional loss of Pten under the control of Cre recombinase expressed by the BLG promoter. We show that daily oral administration of dasatinib delays tumour onset and increases overall survival but does not inhibit the proliferation of established tumours. The striking difference between the dasatinib-treated group of tumours and the vehicle controls was the prominent squamous metaplasia that was seen in six out of 11 dasatinib-treated tumours. This was accompanied by a dramatic up-regulation of both E-cadherin and β-catenin and down-regulation of ErbB-2 in the dasatinib-treated tumours. Dasatinib also inhibited both the migration and the invasion of tumour-derived cell lines in vitro. Together these data support the argument that benefits of Src inhibitors may predominate in early or even pre-invasive disease.

  18. The mammary cellular hierarchy and breast cancer.

    PubMed

    Oakes, Samantha R; Gallego-Ortega, David; Ormandy, Christopher J

    2014-11-01

    Advances in the study of hematopoietic cell maturation have paved the way to a deeper understanding the stem and progenitor cellular hierarchy in the mammary gland. The mammary epithelium, unlike the hematopoietic cellular hierarchy, sits in a complex niche where communication between epithelial cells and signals from the systemic hormonal milieu, as well as from extra-cellular matrix, influence cell fate decisions and contribute to tissue homeostasis. We review the discovery, definition and regulation of the mammary cellular hierarchy and we describe the development of the concepts that have guided our investigations. We outline recent advances in in vivo lineage tracing that is now challenging many of our assumptions regarding the behavior of mammary stem cells, and we show how understanding these cellular lineages has altered our view of breast cancer.

  19. 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

  20. 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

  1. 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

  2. Development of a Novel Therapeutic Paradigm Utilizing a Mammary Gland-Targeted, Bin-1 Knockout Mouse Model

    DTIC Science & Technology

    2007-03-01

    allogeneic MHC class I and class II molecules. Used to assess T-cell functional capacity. Plasmacytoid morphology There are two main subsets of...STAT3β- transfected tumour cells led to increased expression of IL12, MHC class II and CD40, and concomitantly increased the ability of the DCs to...operation of the ‘floxed’ allele in the mammary gland. In the ‘tri-lox’ scheme used, deletion of exon 3 leads to exon 2 to 4 splicing, producing an

  3. The Role of BRCA1 in Suppressing Epithelial-Mesenchymal Transition in Mammary Gland and Tumor Development

    DTIC Science & Technology

    2014-09-01

    expression of EMT-TFs and observed that 77% (n=13, >one year of age) of p18-/- ;Brca1+/- tumors were stained positive for Twist, Foxc1, Foxc2, Slug, and Snail ...At least two EMT-inducing transcription factors (EMT-TFs), which include Twist, Slug, Snail , Foxc1 and Foxc2, stained positive in >2% tumor cells...Slug Snail Foxc1 Twist Twist2 0 20 40 60 80 8 results indicate that haploid or near complete loss of Brca1 in mammary epithelium not only

  4. Feline Mammary Carcinoma: A Retrospective Evaluation of 17 Cases

    PubMed Central

    Tomlinson, M. J.; Barteaux, L.; Ferns, L. E.; Angelopoulos, E.

    1984-01-01

    Seventeen biopsies of feline mammary carcinoma submitted to the Veterinary Pathology Laboratory, Nova Scotia Department of Agriculture and Marketing were reviewed. All 17 cases were female cats. Data on age, reproductive status (sexually intact vs. neutered), therapy, outcome of the cases and histological features were consistent with data on feline mammary carcinoma previously reported. Four of these 17 cats had a history of receiving exogenous progestin prior to tumor development. The possible role of progestins as initiators or promoters of feline mammary carcinoma was discussed. The use of feline mammary carcinoma as a model for carcinoma of the breast in women was reviewed. ImagesFigure 1. PMID:17422482

  5. 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...

  6. Mammary transcriptome analysis of lactating dairy cows following administration of bovine growth hormone.

    PubMed

    McCoard, S A; Hayashi, A A; Sciascia, Q; Rounce, J; Sinclair, B; McNabb, W C; Roy, N C

    2016-12-01

    The galactopoietic effect of growth hormone (GH) in lactating ruminants is well established; however the mechanisms that mediate these effects are not well understood. The first objective of this study was to determine the effect of GH on the synthesis of the major casein and whey proteins. The second objective was to identify the genes and pathways that may be involved in mediating the effect of GH on milk synthesis. A single subcutaneous injection of a commercially available slow release formulation of GH (Lactatropin®), or physiological saline solution (control) was administered to non-pregnant dairy cows (n=4/group) in mid-late lactation. Milk samples were collected for composition analysis and mammary lobulo-alveolar tissue was collected postmortem 6 days post injection. Gene expression profiles were evaluated using either a 22 000 bovine complementary DNA microarray or quantitative PCR (qPCR), and microarrays were validated by qPCR. The yield of all the major casein and whey proteins was increased 32% to 41% in GH-treated cows, with the exception of α-lactalbumin yield which was elevated by 70% relative to controls. Treatment with GH treatment tended to increase the concentration of α-lactalbumin but had no effect on the concentration of any of the major milk proteins. Messenger RNA (mRNA) abundance of the major whey and casein genes, with the exception of α-s2-casein, was increased in response to GH compared with controls, which is consistent with the positive effect of GH on milk production. Treatment with GH treatment influenced the mRNA abundance of genes involved in cell growth and proliferation, transcriptional and translational regulation, actin cytoskeleton signalling, lipid metabolism and cell death. This study has provided new insights into the cell signalling that may be involved in mediating the effect of GH on milk production in the mammary gland of lactating dairy cows.

  7. 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...

  8. Stem cells in normal mammary gland and breast cancer.

    PubMed

    Luo, Jie; Yin, Xin; Ma, Tao; Lu, Jun

    2010-04-01

    The mammary gland is a structurally dynamic organ that undergoes dramatic alterations with age, menstrual cycle, and reproductive status. Mammary gland stem cells, the minor cell population within the mature organ, are thought to have multiple functions in regulating mammary gland development, tissue maintenance, major growth, and structural remodeling. In addition, accumulative evidence suggests that breast cancers are initiated and maintained by a subpopulation of tumor cells with stem cell features (called cancer stem cells). A variety of methods have been developed to identify and characterize mammary stem cells, and several signal transduction pathways have been identified to be essential for the self-renewal and differentiation of mammary gland stem cells. Understanding the origin of breast cancer stem cells, their relationship to breast cancer development, and the differences between normal and cancer stem cells may lead to novel approaches to breast cancer diagnosis, prevention, and treatment.

  9. Notch1-induced mammary tumor development is cyclin D1-dependent and correlates with expansion of pre-malignant multipotent duct-limited progenitors.

    PubMed

    Ling, H; Sylvestre, J-R; Jolicoeur, P

    2010-08-12

    Members of the Notch family are involved in the development of breast cancer in animal models and in humans. In young transgenic mice, expressing intracellular activated Notch1 (N1(IC)) in mammary cells, we found that CD24(+) CD29(high) progenitor cells had enhanced survival, and were expanded through a cyclin D1-dependent pathway. This expansion positively correlated with the later cyclin D1-dependent formation of basal-like ductal tumors. This expanded population exhibited abnormal differentiation skewed toward the basal cells, showed signs of pre-malignancy (low PTEN/p53 and high c-myc) and contained stem cells with impaired self-renewal in vivo, and more numerous multipotent, ductal-restricted progenitors. Our data suggest that N1(IC) can favor transformation of progenitor cells early in life through a cyclin D1-dependent pathway.

  10. 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.

  11. 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...

  12. 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

  13. 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.

  14. 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

  15. Identification of rat mammary tumor-1 gene (RMT-1), which is highly expressed in rat mammary tumors.

    PubMed

    Chiou, S; Yoo, J; Loh, K C; Guzman, R C; Gopinath, G R; Rajkumar, L; Chou, Y C; Yang, J; Popescu, N C; Nandi, S

    2001-12-10

    Full-term pregnancy early in life results in a permanent reduction in lifetime breast cancer risk in women. Parous rats and mice are also refractory to chemical carcinogenesis. Therefore, investigation of the differences between mammary glands from virgin and parous rats would provide valuable information regarding the protective effects of early full-term pregnancy. In this report, we examined the gene expression patterns in mammary glands from virgin and parous Lewis rats. Using differential display technology, a novel 4.2 kb cDNA, designated rat mammary tumor-1 (RMT-1) was isolated. Northern blot analysis of RMT-1 showed that RMT-1 expression was higher in the pre-pubertal and pubertal stages during rat mammary gland development while it was down-regulated in mammary glands from mature virgin and parous rats. RMT-1 expression was highest in rat mammary cancers compared with either the mammary glands of virgin or parous rats. At the Northern blot sensitivity level, RMT-1 expression was found only in the mammary gland. Northern blot analysis also showed that the expression of this gene was found in 74% of N-methyl-nitrosourea (MNU)-induced mammary cancers while it was not found in MNU-induced cancers from other organs. The examination of the RMT-1 gene structure revealed that it consists of five exons spanning 5.9 kb. Using fluorescence in situ hybridization, the gene was localized on rat chromosome 1 band q 43-51. The present data show that there is a correlation between high RMT-1 expression and rat mammary carcinogenesis or decreased RMT-1 expression and parity associated refractoriness to chemically induced mammary carcinogenesis. However, whether or not RMT-1 gene has a functional role in these processes remains to be investigated.

  16. Genetic Mechanisms in Apc-Mediated Mammary Tumorigenesis

    PubMed Central

    Kuraguchi, Mari; Ohene-Baah, Nana Yaw; Sonkin, Dmitriy; Bronson, Roderick Terry; Kucherlapati, Raju

    2009-01-01

    Many components of Wnt/β-catenin signaling pathway also play critical roles in mammary tumor development, yet the role of the tumor suppressor gene APC (adenomatous polyposis coli) in breast oncongenesis is unclear. To better understand the role of Apc in mammary tumorigenesis, we introduced conditional Apc mutations specifically into two different mammary epithelial populations using K14-cre and WAP-cre transgenic mice that express Cre-recombinase in mammary progenitor cells and lactating luminal cells, respectively. Only the K14-cre–mediated Apc heterozygosity developed mammary adenocarcinomas demonstrating histological heterogeneity, suggesting the multilineage progenitor cell origin of these tumors. These tumors harbored truncation mutation in a defined region in the remaining wild-type allele of Apc that would retain some down-regulating activity of β-catenin signaling. Activating mutations at codons 12 and 61 of either H-Ras or K-Ras were also found in a subset of these tumors. Expression profiles of acinar-type mammary tumors from K14-cre; ApcCKO/+ mice showed luminal epithelial gene expression pattern, and clustering analysis demonstrated more correlation to MMTV-neu model than to MMTV-Wnt1. In contrast, neither WAP-cre–induced Apc heterozygous nor homozygous mutations resulted in predisposition to mammary tumorigenesis, although WAP-cre–mediated Apc deficiency resulted in severe squamous metaplasia of mammary glands. Collectively, our results suggest that not only the epithelial origin but also a certain Apc mutations are selected to achieve a specific level of β-catenin signaling optimal for mammary tumor development and explain partially the colon- but not mammary-specific tumor development in patients that carry germline mutations in APC. PMID:19197353

  17. P-Cadherin Expression in Feline Mammary Tissues

    PubMed Central

    Figueira, Ana Catarina; Teodósio, Ana Sofia; Carvalheira, Júlio; Lacerda, Manuela; de Matos, Augusto; Gärtner, Fátima

    2012-01-01

    The search for molecular markers in the feline mammary gland, namely, the adhesion molecules belonging to the cadherin family, is useful in the understanding of the development of mammary carcinomas in felines and humans. To study P-cadherin expression in the feline mammary gland, 61 samples of normal (n = 4), hyperplastic (n = 12), and neoplastic (n = 45) feline mammary tissues were examined. In both normal and hyperplastic mammary tissues as well as in benign tumours, P-cadherin immunolabelling was restricted to myoepithelial cells. In malignant tumours, however, there was an aberrant epithelial P-cadherin immunoexpression in 64.1% (n = 25) of cases, with a membranous and/or cytoplasmic pattern of distribution. A statistically significant relationship was seen between epithelial P-cadherin expression and malignant mammary lesions (P = 0.0001). In malignant mammary tumours, there was likewise a statistically significant relationship between aberrant P-cadherin immunoexpression and histological grade (P = 0.0132). Aberrant epithelial P-cadherin expression seems to be related to malignancy in the feline mammary gland. To confirm the results of this investigation, further studies with larger samples and follow-up studies are warranted. PMID:23091776

  18. Mammary gland stem cells and their application in breast cancer.

    PubMed

    Yang, Xing; Wang, Hui; Jiao, Baowei

    2017-02-07

    The mammary gland is an organ comprising two primary lineages, specifically the inner luminal and the outer myoepithelial cell layers. Mammary gland stem cells (MaSCs) are highly dynamic and self-renewing, and can give rise to these mammary gland lineages. The lineages are responsible for gland generation during puberty as well as expansion during pregnancy. In recent years, researchers have focused on understanding how MaSCs are regulated during mammary gland development and transformation of breast cancer. Here, we summarize the identification of MaSCs, and how they are regulated by the signaling transduction pathways, mammary gland microenvironment, and non-coding RNAs (ncRNAs). Moreover, we debate the evidence for their serving as the origin of breast cancer, and discuss the therapeutic perspectives of targeting breast cancer stem cells (BCSCs). In conclusion, a better understanding of the key regulators of MaSCs is crucial for the clinical treatment of breast cancer.

  19. Proteomic analysis of microsomes from lactating bovine mammary gland.

    PubMed

    Peng, Lifeng; Rawson, Pisana; McLauchlan, Danyl; Lehnert, Klaus; Snell, Russell; Jordan, T William

    2008-04-01

    Mammary gland has multiple metabolic potential including for large-scale synthesis of milk proteins, carbohydrate, and lipids including nutrient triacylglycerols. We have carried out a proteomic analysis of mammary tissue to discover proteins that affect lipid metabolism. Unfractionated microsomes from lactating bovine mammary tissue were analyzed using one-dimensional SDS-PAGE with RPLC-ESI-MS/MS. This approach gave 703 proteins including 160 predicted transmembrane proteins. Proteins were classified according to their subcellular localizations and biological functions. Over 50 proteins were associated with cellular uptake, metabolism, and secretion of lipids, including some enzymes that have been previously associated with breast cancer and potential therapeutic targets. This database develops a proteomic view of the metabolic potential of mammary gland that can be expected to contribute to a greater understanding of gene expression and tissue remodeling associated with lactation, and to further dissection of normal and pathological processes in mammary tissue.

  20. 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.

  1. CDP Is a Repressor of Mouse Mammary Tumor Virus Expression in the Mammary Gland

    PubMed Central

    Zhu, Quan; Gregg, Keqin; Lozano, Mary; Liu, Jinqi; Dudley, Jaquelin P.

    2000-01-01

    Mouse mammary tumor virus (MMTV) transcription is highest in the lactating mammary gland but is detectable in a variety of other tissues. Previous results have shown that MMTV expression is suppressed in lymphoid and other tissues through the binding of the homeodomain-containing repressor special AT-rich binding protein 1 to a negative regulatory element (NRE) in the MMTV long terminal repeat (LTR). Another homeoprotein repressor, CCAAT displacement protein (CDP), also binds to the MMTV NRE, but a role for CDP in MMTV transcriptional suppression has not yet been demonstrated. In this paper, we show that the level of CDP decreases during development of the mammary gland and that this decline in CDP level correlates with the known increase in MMTV expression observed during mammary gland differentiation. Moreover, CDP overexpression was able to suppress MMTV LTR-reporter gene activity up to 20-fold in transient-transfection assays of mouse mammary cells. To determine if this effect was due to direct binding of CDP to the promoter-proximal NRE, we performed DNase I protection assays to map two CDP-binding sites from +835 to +845 and +920 to +931 relative to the first base of the LTR. Mutations engineered into each of these sites decreased CDP binding to the proximal NRE, whereas a combination of these mutations further reduced binding. Subsequently, each of these mutations was introduced into the full-length MMTV LTR upstream of the luciferase reporter gene. Analysis of stable transfectants of LTR constructs showed that CDP binding site mutations in the proximal NRE elevated reporter gene expression two- to sixfold compared to wild-type LTR constructs. Thus, MMTV expression increases during mammary gland development, in part due to decreased CDP levels and CDP binding to the LTR. Together, these experiments provide the first evidence that CDP acts as a repressor of MMTV transcription in the mammary gland. PMID:10864645

  2. Canine mammary gland tumors.

    PubMed

    Sorenmo, Karin

    2003-05-01

    The National Consensus Group recommends that all women with tumors larger than 1 cm be offered chemotherapy regardless of tumor histology of lymph node status. This recommendation is to ensure that everyone at risk for failing, even though the risk may be low in women with relatively small tumors and favorable histology, has a choice and receives the benefit of adjuvant chemotherapy. This type of treatment recommendation may also be made in dogs based on recognized, well-accepted prognostic factors such as tumor size, stage, type, and histologic differentiation. Based on the limited clinical information available in veterinary medicine, the drugs that are effective in human breast cancer, such as cyclophosphamide, 5-fluorouracil, and doxorubicin, may also have a role in the treatment of malignant mammary gland tumors in dogs. Randomized prospective studies are needed, however, to evaluate the efficacy of chemotherapy in dogs with high-risk mammary gland tumors and to determine which drugs and protocols are the most efficacious. Until such studies are performed, the treatment of canine mammary gland tumors will be based on the individual oncologist's understanding of tumor biology, experience, interpretation of the available studies, and a little bit of gut-feeling. Table 2 is a proposal for treatment guidelines for malignant canine mammary gland tumors according to established prognostic factors, results from published veterinary studies, and current recommendations for breast cancer treatment in women.

  3. The male mammary gland: a target for the xenoestrogen bisphenol A.

    PubMed

    Vandenberg, Laura N; Schaeberle, Cheryl M; Rubin, Beverly S; Sonnenschein, Carlos; Soto, Ana M

    2013-06-01

    Males of some strains of mice retain their mammary epithelium even in the absence of nipples. Here, we have characterized the mammary gland in male CD-1 mice both in whole mounts and histological sections. We also examined the effects of bisphenol A (BPA), an estrogen mimic that alters development of the female mouse mammary gland. BPA was administered at a range of environmentally relevant doses (0.25-250μg/kg/day) to pregnant and lactating mice and then the mammary glands of male offspring were examined at several periods in adulthood. We observed age- and dose-specific effects on mammary gland morphology, indicating that perinatal BPA exposures alter the male mammary gland in adulthood. These results may provide insight into gynecomastia, the most common male breast disease in humans, where proliferation of the mammary epithelium leads to breast enlargement.

  4. Disruption of reelin signaling alters mammary gland morphogenesis

    PubMed Central

    Khialeeva, Elvira; Lane, Timothy F.; Carpenter, Ellen M.

    2011-01-01

    Reelin signaling is required for appropriate cell migration and ductal patterning during mammary gland morphogenesis. Dab1, an intracellular adaptor protein activated in response to reelin signaling, is expressed in the developing mammary bud and in luminal epithelial cells in the adult gland. Reelin protein is expressed in a complementary pattern, first in the epithelium overlying the mammary bud during embryogenesis and then in the myoepithelium and periductal stroma in the adult. Deletion in mouse of either reelin or Dab1 induced alterations in the development of the ductal network, including significant retardation in ductal elongation, decreased terminal branching, and thickening and disorganization of the luminal wall. At later stages, some mutant glands overcame these early delays, but went on to exhibit enlarged and chaotic ductal morphologies and decreased terminal branching: these phenotypes are suggestive of a role for reelin in spatial patterning or structural organization of the mammary epithelium. Isolated mammary epithelial cells exhibited decreased migration in response to exogenous reelin in vitro, a response that required Dab1. These observations highlight a role for reelin signaling in the directed migration of mammary epithelial cells driving ductal elongation into the mammary fat pad and provide the first evidence that reelin signaling may be crucial for regulating the migration and organization of non-neural tissues. PMID:21266412

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

    PubMed

    Haricharan, S; Li, Y

    2014-01-25

    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, programmed 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.

  6. 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. ...

  7. The Role of Nuclear Receptor Coactivator A1B1 in Growth Factor-Mediated Mammary Tumorigenesis

    DTIC Science & Technology

    2007-03-01

    gland development, dwarfism and abnormal reproductive function [8]. I want to determine whether the loss of AIB1 in MMTV-Neu mice alters the mammary...study display dwarfism and the retardation of mammary gland growth [9]. At the 4-month time point, I similarly observed an overall decrease in mammary

  8. 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.

  9. Mouse mammary tumor virus suppresses apoptosis of mammary epithelial cells through ITAM-mediated signaling.

    PubMed

    Kim, Hyoung H; Grande, Shannon M; Monroe, John G; Ross, Susan R

    2012-12-01

    Many receptors in hematopoietic cells use a common signaling pathway that relies on a highly conserved immunoreceptor tyrosine-based activation motif (ITAM), which signals through Src family tyrosine kinases. ITAM-bearing proteins are also found in many oncogenic viruses, including the mouse mammary tumor virus (MMTV) envelope (Env). We previously showed that MMTV Env expression transformed normal mammary epithelial cells and that Src kinases were important mediators in this transformation. To study how ITAM signaling affects mammary cell transformation, we utilized mammary cell lines expressing two different ITAM-containing proteins, one encoding a MMTV provirus and the other a B cell receptor fusion protein. ITAM-expressing cells were resistant to both serum starvation- and chemotherapeutic drug-induced apoptosis, whereas cells transduced with these molecules bearing ITAM mutations were indistinguishable from untransduced cells in their sensitivity to these treatments. We also found that Src kinase was activated in the MMTV-expressing cells and that MMTV-induced apoptosis resistance was completely restored by the Src inhibitor PP2. In vivo, MMTV infection delayed involution-induced apoptosis in the mouse mammary gland. Our results show that MMTV suppresses apoptosis through ITAM-mediated Src tyrosine kinase signaling. These studies could lead to the development of effective treatment of nonhematopoietic cell cancers in which ITAM-mediated signaling plays a role.

  10. Modulatory effects of neonatal exposure to TCDD, or a mixture of PCBs, p,p'-DDT, and p-p'-DDE, on methylnitrosourea-induced mammary tumor development in the rat.

    PubMed Central

    Desaulniers, D; Leingartner, K; Russo, J; Perkins, G; Chittim, B G; Archer, M C; Wade, M; Yang, J

    2001-01-01

    The role of organochlorine (OC) exposure in the etiology of breast cancer remains controversial. Thus, our objective was to determine whether the most abundant and toxic OCs found in human milk could, when ingested during the neonatal period, modulate the development of mammary tumors in the rat. We prepared a mixture composed of p,p'-dichlorodiphenyltrichloroethane (DDT), its major metabolite, p,p'-dichlorodiphenyldichloroethene (DDE), and 19 polychlorinated biphenyls (PCB) based on their concentrations found in the milk of Canadian women. Neonate rats at 1, 5, 10, 15, and 20 days of age were gavaged with this mixture, at 10, 100, and 1,000 times the amount that a human baby would consume. An additional group received 2.5 microg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)/kg body weight (bw) by gavage at 18 days of age, instead of the mixture. On day 21, all treatment groups, except for a control group and a 1,000-mix group, received a single intraperitoneal injection of methylnitrosourea (MNU, 30 mg/kg bw), the initiator of the carcinogenic process. The average number of rats per treatment group was 33. Rats were sacrificed when their tumors reached 1 cm in size, or at 308 days of age. We prepared mammary tumors and mammary gland whole mounts for histologic analysis. There were no significant effects when only the malignant or only the benign tumors were considered. After all benign and malignant lesions were pooled, the number of mammary tumors differed among all MNU-treated groups (p = 0.02) with more lesions developing in the MNU-1,000[times] (median = 4.5; p = 0.05) and MNU-TCDD (median = 5.5; p = 0.07) compared to the MNU-0 rats (median = 2). Compared to the MNU-0 group, the percentage of rats that developed palpable tumors (benign plus malignant) was slightly higher (p = 0.06) in the MNU-TCDD group, but not in the MNU-1,000[times] group. The percentage of palpable tumors that were malignant was higher (p = 0.02) in the MNU-100[times] group (15/16, 94%) than

  11. Mammary tumor modifiers in BALB/cJ mice heterozygous for p53.

    PubMed

    Koch, Joanna G; Gu, Xiangjun; Han, Younghun; El-Naggar, Adel K; Olson, Melissa V; Medina, Daniel; Jerry, D Joseph; Blackburn, Anneke C; Peltz, Gary; Amos, Christopher I; Lozano, Guillermina

    2007-05-01

    BALB/c mice are predisposed to developing spontaneous mammary tumors, which are further increased in a p53 heterozygous state. C57BL/6J mice are resistant to induced mammary tumors and develop less than 1% mammary tumors in both wild-type and p53+/- states. To map modifiers of mammary tumorigenesis, we have established F1 and F2 crosses and backcrosses to BALB/cJ (N2-BALB/cJ) and C57BL/6J (N2-C57BL/6J) strains. All cohorts developed mammary carcinomas in p53+/- females, suggesting that multiple loci dominantly and recessively contributed to mammary tumorigenesis. We mapped two modifiers of mammary tumorigenesis in the BALB/cJ strain. Mtsm1 (mammary tumor susceptibility modifier), a dominant-acting modifier, is located on chromosome 7. Mtsm1 is suggestive for linkage to mammary tumorigenesis (p = 0.001). We have analyzed the Mtsm1 region to locate candidate genes by comparing it to a rat modifier region, Mcs3, which shares syntenic conservation with Mtsm1. Expression data and SNPs were also taken into account. Five potential candidate genes within Mtsm1 are Aldh1a3, Chd2, Nipa2, Pcsk6, and Tubgcp5. The second modifier mapped is Mtsm2, a recessive-acting modifier. Mtsm2 is located on chromosome X and is significantly linked to mammary tumorigenesis (p = 1.03 x 10(-7)).

  12. Tissue-specific ceruloplasmin gene expression in the mammary gland.

    PubMed Central

    Jaeger, J L; Shimizu, N; Gitlin, J D

    1991-01-01

    Using a ceruloplasmin cDNA clone in RNA blot analysis, a single 3.7 kb ceruloplasmin-specific transcript was detected in rat mammary gland tissue from pregnant and lactating animals. Ceruloplasmin gene expression in the mammary gland was tissue-specific, with no evidence of expression in brain, heart or other extrahepatic tissues. Ceruloplasmin mRNA was also detected in mammary gland tissue from male, virgin female and non-pregnant/multiparous animals, and the abundance of ceruloplasmin-specific transcripts in virgin female rats was independent of their stage of oestrus. In virgin female mammary gland the content of ceruloplasmin mRNA was 20% of that in hepatic tissue from these animals and approx. 2-3-fold greater than that found in mammary gland tissue of pregnant or lactating animals. Development studies revealed ceruloplasmin gene expression in male and female mammary gland by only 2 weeks of age, prior to the onset of puberty. Biosynthetic studies indicated that the ceruloplasmin mRNA in mammary gland tissue was translated into a 132 kDa protein qualitatively similar to that synthesized in liver. By in situ hybridization, ceruloplasmin gene expression was localized to the epithelium lining the mammary gland alveolar ducts, without evidence of expression in the surrounding mesenchyme. Ceruloplasmin gene expression was also detected in a human breast adenocarcinoma cell line and in biopsy tissue from women with invasive ductal carcinoma. Taken together, these data indicate that the mammary gland is a prominent site of extrahepatic ceruloplasmin gene expression and add to the evidence that ceruloplasmin biosynthesis is associated with growth and differentiation in non-hepatic tissues. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:1764031

  13. 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

  14. The prostaglandin E2 receptor EP2 is required for cyclooxygenase 2-mediated mammary hyperplasia.

    PubMed

    Chang, Sung-Hee; Ai, Youxi; Breyer, Richard M; Lane, Timothy F; Hla, Timothy

    2005-06-01

    Expression of cyclooxygenase 2 (COX-2) in breast cancer correlates with poor prognosis, and COX-2 enzyme inhibitors reduce breast cancer incidence in humans. We recently showed that COX-2 overexpression in the mammary gland of transgenic mice induced mammary cancer. Because prostaglandin E2 (PGE2) is the major eicosanoid and because the EP2 subtype of the PGE2 receptor is highly expressed in the mammary tumors, we tested if this G protein-coupled receptor is required for tumorigenesis. We crossed the MMTV-COX-2 transgenic mice with Ep2-/- mice and studied tumor development in bigenic mice. Lack of EP2 receptor strongly suppressed COX-2-induced effects such as precocious development of the mammary gland in virgins and the development of mammary hyperplasia in multiparous female mice. Interestingly, the expression of amphiregulin, a potent mammary epithelial cell growth factor was down regulated in mammary glands of Ep2-/- mice. Total cyclic AMP (cAMP) levels were reduced in Ep2-/- mammary glands suggesting that PGE2 signaling via the EP2 receptor activates the Gs/cAMP/protein kinase A pathway. In mammary tumor cell lines, expression of the EP2 receptor followed by treatment with CAY10399, an EP2-specific agonist, strongly induced amphiregulin mRNA levels in a protein kinase A-dependent manner. These data suggest that PGE2 signaling via the EP2 receptor in mammary epithelial cells regulate mammary gland hyperplasia by the cAMP-dependent induction of amphiregulin. Inhibition of the EP2 pathway in the mammary gland may be a novel approach in the prevention and/or treatment of mammary cancer.

  15. The methyltransferase EZH2 is not required for mammary cancer development, although high EZH2 and low H3K27me3 correlate with poor prognosis of ER-positive breast cancers.

    PubMed

    Bae, Woo Kyun; Yoo, Kyung Hyun; Lee, Ji Shin; Kim, Young; Chung, Ik-Joo; Park, Min Ho; Yoon, Jung Han; Furth, Priscilla A; Hennighausen, Lothar

    2015-10-01

    Enhancer of zeste homolog 2 (EZH2) catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) and its demethylation is catalyzed by UTX. EZH2 levels are frequently elevated in breast cancer and have been proposed to control gene expression through regulating repressive H3K27me3 marks. However, it is not fully established whether breast cancers with different levels of H3K27me3, EZH2 and UTX exhibit different biological behaviors. Levels of H3K27me3, EZH2 and UTX and their prognostic significance were evaluated in 146 cases of breast cancer. H3K27me3 levels were higher in HER2-negative samples. EZH2 expression was higher in cancers that were LN+, size > 20mm, and with higher tumor grade and stage. Using a Cox regression model, H3K27me3 levels and EZH2 expression were identified as independent prognostic factors for overall survival for all the breast cancers studied as well as the ER-positive subgroup. The combination of low H3K27me3 and high EZH2 expression levels were significantly associated with shorter survival. UTX expression was not significantly associated with prognosis and there were no correlations between H3K27me3 levels and EZH2/UTX expression. To determine if EZH2 is required to establish H3K27me3 marks in mammary cancer, Brca1 and Ezh2 were deleted in mammary stem cells in mice. Brca1-deficient mammary cancers with unaltered H3K27me3 levels developed in the absence of EZH2, demonstrating that EZH2 is not a mandatory H3K27 methyltransferase in mammary neoplasia and providing genetic evidence for biological independence between H3K27me3 and EZH2 in this tissue.

  16. Physiologically activated mammary fibroblasts promote postpartum mammary cancer

    PubMed Central

    Guo, Qiuchen; Burchard, Julja; Spellman, Paul

    2017-01-01

    Women diagnosed with breast cancer within 5 years of childbirth have poorer prognosis than nulliparous or pregnant women. Weaning-induced breast involution is implicated, as the collagen-rich, immunosuppressive microenvironment of the involuting mammary gland is tumor promotional in mice. To investigate the role of mammary fibroblasts, isolated mammary PDGFRα+ cells from nulliparous and postweaning mice were assessed for activation phenotype and protumorigenic function. Fibroblast activation during involution was evident by increased expression of fibrillar collagens, lysyl oxidase, Tgfb1, and Cxcl12 genes. The ability of mammary tumors to grow in an isogenic, orthotopic transplant model was increased when tumor cells were coinjected with involution-derived compared with nulliparous-derived mammary fibroblasts. Mammary tumors in the involution-fibroblast group had increased Ly6C+ monocytes at the tumor border, and decreased CD8+ T cell infiltration and tumor cell death. Ibuprofen treatment suppressed involution-fibroblast activation and tumor promotional capacity, concurrent with decreases in tumor Ly6C+ monocytes, and increases in intratumoral CD8+ T cell infiltration, granzyme levels, and tumor cell death. In total, our data identify a COX/prostaglandin E2 (PGE2)–dependent activated mammary fibroblast within the involuting mammary gland that displays protumorigenic, immunosuppressive activity, identifying fibroblasts as potential targets for the prevention and treatment of postpartum breast cancer. PMID:28352652

  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. The rat mammary gland: morphologic changes as an indicator of systemic hormonal perturbations induced by xenobiotics.

    PubMed

    Lucas, Julia N; Rudmann, Daniel G; Credille, Kelly M; Irizarry, Armando R; Peter, Augustine; Snyder, Paul W

    2007-02-01

    The development and morphology of the rat mammary gland are dependent upon several hormones including estrogens, androgens, progesterone, growth hormone and prolactin. In toxicology studies, treatment with xenobiotics may alter these hormones resulting in changes in the morphology of reproductive tissues such as the mammary gland. In the rat, male and female mammary glands exhibit striking morphologic differences that can be altered secondary to hormonal perturbations. Recognizing these morphologic changes can help the pathologist predict potential xenobiotic-induced perturbations in the systemic hormonal milieu. This review examines the development of the rat mammary gland and the influence of sex hormones on the morphology of the adult male and female rat mammary gland. Specific case examples from the literature and data from our laboratory highlight the dynamic nature of the rat mammary gland in response to hormonal changes.

  20. Deregulated ephrin-B2 expression in the mammary gland interferes with the development of both the glandular epithelium and vasculature and promotes metastasis formation.

    PubMed

    Haldimann, Mirjam; Custer, Domenica; Munarini, Nadia; Stirnimann, Christoph; Zürcher, Gisela; Rohrbach, Valeria; Djonov, Valentin; Ziemiecki, Andrew; Andres, Anne-Catherine

    2009-09-01

    Eph receptor tyrosine kinases and their membrane-bound ephrin ligands play key roles during morphogenesis and adult tissue homeostasis. Receptor-ligand interactions result in forward and reverse signalling from the receptor and ligand respectively. To delineate the role(s) of forward and reverse signalling in mammary gland biology we have established transgenic mice exhibiting mammary epithelial-specific overexpression of either the native ephrin-B2 or a dominant negative ephrin-B2 mutant incapable of reverse signalling. During pregnancy and lactation overexpression of the native ephrin-B2 resulted in precocious differentiation, whereas overexpression of mutated ephrin-B2 caused delayed epithelial differentiation and in disturbed tissue architecture. Both transgenes affected also mammary vascularisation. Whereas ephrin-B2 induced superfluous but organised capillaries, mutant ephrin-B2 overexpression resulted in an irregular vasculature with blind-ending capillaries. Mammary tumours were not observed in either transgenic line, however, the crossing with NeuT transgenic animals revealed that mutated ephrin-B2 expression significantly accelerated tumour growth and imposed a metastatic phenotype.

  1. 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...

  2. Technical note: Mammary gland ultrasonography to evaluate mammary parenchymal composition in prepubertal heifers.

    PubMed

    Albino, R L; Guimarães, S E F; Daniels, K M; Fontes, M M S; Machado, A F; Dos Santos, G B; Marcondes, M I

    2017-02-01

    Bovine mammary gland development studies are often terminal or involve invasive biopsy procedures. Therefore, noninvasive means of assessing mammary development should be considered as alternative methods in live animals. The objective was to test if mammary ultrasonography can be used as a noninvasive way to estimate mammary parenchyma (PAR) composition in prepubertal dairy heifers with different average daily body weight gains. In the 84 d preceding, the ultrasound exam heifers were maintained in 1 of 3 treatment groups. Individual heifers were fed a high gain (1 kg/d; n = 6), low gain (0.5 kg/d, n = 6), or maintenance (n = 6) treatment diet. To achieve desired body weight gains, heifers were fed differing amounts of the same silage-based diet. Mammary glands of 18 crossbred heifers Holstein:Gyr underwent a single mammary ultrasound exam immediately before heifer slaughter, which took place when heifers weighed 142.0 ± 8.0 kg and were 200 d old. The 4 mammary glands of each heifer were evaluated using a real-time B-mode ultrasound machine equipped with a 6.5-MHz micro-convex transducer. Digital images (8-bit) of glands were obtained and PAR was identified within gland. Average pixel values per unit of PAR area were determined for each gland and analyzed at the level of heifer. Pixel results were interpreted on the basis that lower average pixel values reflect PAR with relatively high amounts of protein as opposed to fat. To help validate that the pixel value within PAR is associated with composition of PAR, pixel findings were compared with histological [number of adipocytes in PAR (Nad) and epithelial area in PAR (Ep)] and biochemical [percent crude protein in PAR (%CP), percent ether extract in PAR (%EE), PAR weight (WPAR), and mammary fat pad weight (WFAT)] composition of PAR in these same heifers. Within PAR, %EE and WFAT were positively correlated with pixel values, whereas %CP, Ep, and Nad were negatively correlated. Parenchyma weight did not correlate

  3. Canonical Wnt Signaling as a Specific Marker of Normal and Tumorigenic Mammary Stem Cells

    DTIC Science & Technology

    2013-02-01

    mammary epithelium impacts glandular development . We found ductal abnormali ties; however, the phenotype was not as severe as expected. Approximately...In previous reports we have clearly showed that cells w ith activated canonical Wnt signaling are present within the mammary epithelium starting at...Wnt1 transgenic cells. We generated a mouse line in which ~-catenin is conditionally deleted in the mammary epithelium of MMTV-Wnt1 transgenic

  4. Comparative Roles of Overexpressed and Mutated H- and K-ras in Mammary Carcinogenesis.

    DTIC Science & Technology

    1996-08-01

    initiated tumors ) using the mismatch amplification mutation assay ( MAMA ) developed by Cha et al (5). Our initial studies indicated that there was...fold more potent at inducing mammary tumors than the activated K-ras gene. Yet, the K-ras oncogene was still effective at mammary carcinoma induction...transgenic rats harboring a H-ras gene (HrHr transgenics) or K-ras gene (HrKr transgenics) controlled by H-ras gene regulatory elements. Mammary tumor

  5. Characterization of Human Mammary Epithelial Stem Cells

    DTIC Science & Technology

    2007-10-01

    robust and reproducible methodology to detect, quantify and isolate stem cells in normal human mammary tissue, using a xenotransplantation system...covers the first year of the grant, during which substantial progress has been made in the development and validation of the xenotransplantation assay...Subrenal xenotransplantation surgery. The hair on the back of anesthetized mice was shaved, and the skin swabbed with 70% alcohol. An anterior to

  6. Soy isoflavones increase latency of spontaneous mammary tumors in mice.

    PubMed

    Jin, Zeming; MacDonald, Ruth S

    2002-10-01

    Soy protein, with and without isoflavones, is being added to foods by manufacturers in response to the Food and Drug Administration (FDA)-approved health claim for cardiovascular protection. Furthermore, soy isoflavones are increasingly consumed by women in the United States as an alternative to hormone replacement therapy. The role of these phytoestrogens in breast cancer is controversial. Although exposure of rodents to soy isoflavones during the perinatal period appears to reduce mammary cancer formation, exposure in utero or during adulthood may increase tumor growth. The mouse mammary tumor virus (MMTV)-neu mouse spontaneously develops mammary tumors due to overexpression of the ErbB-2/neu/HER2 oncogene. This model is comparable with human breast cancer because overexpression of the neu oncogene occurs in 20-40% of human breast cancers. We fed MMTV-neu mice AIN-93G diets containing no isoflavones, 250 mg/kg genistein, 250 mg/kg daidzein or an isoflavone mixture (NovaSoy, equivalent to 250 mg genistein/kg) from 7 wk of age. Mammary tumor latency was significantly delayed in mice fed isoflavones compared with the control. Once tumors formed, however, the isoflavones did not reduce the number or size of tumors such that at 34 wk of age there were no differences in tumor burden among the treatment groups. Hence, in the MMTV-neu mouse, soy isoflavones delayed mammary tumorigenesis. Further studies are warranted to define the cellular mechanisms through which these compounds affect mammary tumorigenesis in this model.

  7. Immunohistochemical characterization of mammary squamous cell carcinoma of the dog.

    PubMed

    Sassi, Francesco; Sarli, Giuseppe; Brunetti, Barbara; Morandi, Federico; Benazzi, Cinzia

    2008-11-01

    Squamous cell carcinoma of the mammary gland is rare in both veterinary and human medicine. Whereas human metaplastic and squamous variants are known, the objectives of the current study were to ascertain the presence of such entities in canine mammary tumors and to distinguish them from other (epidermal, sweat gland) squamous tumors that may develop in the same area. A panel of antibodies (anti-cytokeratin [CK] 19, CK 14, CK 5/6, pancytokeratin, and vimentin) was used on 18 mammary gland malignancies with squamous features and 16 malignant skin tumors (11 squamous cell carcinomas of the skin and 5 sweat glands). Fifteen of the 18 mammary carcinomas were classified as metaplastic carcinomas, and the remaining 3 were classified as squamous cell carcinomas. The 2 most useful markers to establish the histogenesis of mammary tumors were pancytokeratin and CK 19. All other antibodies were equally expressed (CK 14 and 5/6) in all histotypes. The antibody panel discriminated primary epidermal squamous tumors (pancytokeratin positive and CK 19 negative) from gland-derived squamous neoplasms (pancytokeratin positive and CK 19 positive) but failed to distinguish primary mammary tumors from other squamous tumors of glandular origin.

  8. 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.

  9. Slugging their way to immortality: driving mammary epithelial cells into a stem cell-like state.

    PubMed

    Soady, Kelly; Smalley, Matthew J

    2012-09-10

    Delineating the molecular factors that define and maintain the mammary stem cell state is vital for understanding normal development and tumourigenesis. A recent study by Guo and colleagues identifies two master transcriptional regulators of mammary stem cells, Slug and Sox9, ectopic expression of which confers stem cell attributes on differentiated mammary epithelial cells. Slug and Sox9 expression was also shown to determine in vivo metastatic potential of human breast cancer cell lines. Understanding these factors in the context of normal lineage differentiation is an important step toward elucidating the mammary epithelial cell hierarchy and the origins of cancer stem cells.

  10. Mammary ductoscopy: past, present, and future.

    PubMed

    Pereira, Bernadette; Mokbel, Kefah

    2005-04-01

    Mammary ductoscopy (MD) allows direct visual access to the mammary ducts, using fiberoptic microendoscopes inserted through the ductal opening onto the nipple surface. Therefore it has a potential role in the diagnosis and treatment of intraductal breast disease. This article describes the anatomy of the mammary ductal system, the early beginnings of MD, its ongoing evolution, and the need for further development for its future usage in increasing clinical indications. MD is a useful diagnostic adjunct in patients with pathological nipple discharge (PND) and can guide duct excision surgery. However, its potential use in the early detection of breast cancer, in guiding breast-conserving surgery (BCS) for cancer, and in the therapeutic ablation of intraductal disease, as well as in guiding risk-reducing strategies among high-risk women, requires further research and evaluation. The development of a biopsy kit that obtains adequate microbiopsy samples for histological diagnosis under direct visualization will enhance the use of this technique by breast surgeons and radiologists. Future developments also include combining MD with molecular diagnostic markers and optical biopsy systems for the diagnosis of premalignant and early malignant disease, and combining MD with radiofrequency for curative ablation of intraductal lesions.

  11. Mammary ductoscopy: current issues and perspectives.

    PubMed

    Uchida, Ken; Fukushima, Hisaki; Toriumi, Yasuo; Kawase, Kazumi; Tabei, Isao; Yamashita, Akinori; Nogi, Hiroko

    2009-01-01

    Until recently, the mammary duct had not been directly observed in vivo. Starting with the success of Teboul et al., studies of mammary ductoscopy (MD) for nipple discharge have been performed in Japan and other East Asian countries. Ductal lavage screening trials for breast cancer started in the 2000s. Concurrently, the number of English-language articles about MD increased. Sixty-nine English-language and 74 Japanese-language papers published in the last 19 years were reviewed. Important reports and studies were analyzed. MD has undergone significant technological development, and studies of MD have taken place in many countries. As a result, endoscopic images of the mammary duct have developed, and the endoscopic diagnosis for nipple discharge has become possible. MD-guided biopsy and surgery have been studied. Findings of MD are useful for diagnosing intraductal lesions with nipple discharge. As a result, MD has reduced the number and extent of microdochectomies. MD is also helpful in guiding breast-conserving surgery. Many pioneers have tried direct biopsy or interventions under MD, but further developments are necessary for its practical use.

  12. 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.

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

    PubMed

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

    2014-10-01

    Emerging evidence suggests that cancer is populated and maintained by tumour-initiating cells (TICs) with stem-like properties similar to those 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 signalling. Importantly, Fzd7-dependent enhancement of Wnt signalling by ΔNp63 also governs tumour-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.

  14. Apples prevent mammary tumors in rats.

    PubMed

    Liu, Rui Hai; Liu, Jiaren; Chen, Bingqing

    2005-03-23

    Regular consumption of fruits and vegetables has been consistently shown to be associated with reduced risk of developing chronic diseases such as cancer and cardiovascular disease. Apples are commonly consumed and are the major contributors of phytochemicals in human diets. It was previously reported that apple extracts exhibit strong antioxidant and antiproliferative activities and that the major part of total antioxidant activity is from the combination of phytochemicals. Phytochemicals, including phenolics and flavonoids, are suggested to be the bioactive compounds contributing to the health benefits of apples. Here it is shown that whole apple extracts prevent mammary cancer in a rat model in a dose-dependent manner at doses comparable to human consumption of one, three, and six apples a day. This study demonstrated that whole apple extracts effectively inhibited mammary cancer growth in the rat model; thus, consumption of apples may be an effective strategy for cancer protection.

  15. 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; Rillema, James A; 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

  16. Role of the Mouse Pygopus 2 Gene and Wnt Signaling in Normal and Malignant Development of Mammary Glands and Hair Follicles

    DTIC Science & Technology

    2006-05-01

    catenin, which is believed to abolish canonical Wnt signaling, or transgenic expression of Dkk1 , an inhibitor of Wnt signaling, in skin prior to...reduced proliferation of embryonic mammary epithelial cells Disruption of Wnt signaling by overexpressing Dkk1 abolishes the ability of the ectoderm to...signaling is disrupted by Dkk1 overexpression. Is mpygo2 required for Wnt signaling after all? We directly addressed this question using double transgenic

  17. Genes affected by mouse mammary tumor virus (MMTV) proviral insertions in mouse mammary tumors are deregulated or mutated in primary human mammary tumors

    PubMed Central

    Callahan, Robert; Mudunuri, Uma; Bargo, Sharon; Raafat, Ahmed; McCurdy, David; Boulanger, Corinne; Lowther, William; Stephens, Robert; Luke, Brian T.; Stewart, Claudia; Wu, Xiaolin; Munroe, David; Smith, Gilbert H.

    2012-01-01

    The accumulation of mutations is a contributing factor in the initiation of premalignant mammary lesions and their progression to malignancy and metastasis. We have used a mouse model in which the carcinogen is the mouse mammary tumor virus (MMTV) which induces clonal premalignant mammary lesions and malignant mammary tumors by insertional mutagenesis. Identification of the genes and signaling pathways affected in MMTV-induced mouse mammary lesions provides a rationale for determining whether genetic alteration of the human orthologues of these genes/pathways may contribute to human breast carcinogenesis. A high-throughput platform for inverse PCR to identify MMTV-host junction fragments and their nucleotide sequences in a large panel of MMTV-induced lesions was developed. Validation of the genes affected by MMTV-insertion was carried out by microarray analysis. Common integration site (CIS) means that the gene was altered by an MMTV proviral insertion in at least two independent lesions arising in different hosts. Three of the new genes identified as CIS for MMTV were assayed for their capability to confer on HC11 mouse mammary epithelial cells the ability for invasion, anchorage independent growth and tumor development in nude mice. Analysis of MMTV induced mammary premalignant hyperplastic outgrowth (HOG) lines and mammary tumors led to the identification of CIS restricted to 35 loci. Within these loci members of the Wnt, Fgf and Rspo gene families plus two linked genes (Npm3 and Ddn) were frequently activated in tumors induced by MMTV. A second group of 15 CIS occur at a low frequency (2-5 observations) in mammary HOGs or tumors. In this latter group the expression of either Phf19 or Sdc2 was shown to increase HC11 cells invasion capability. Foxl1 expression conferred on HC11 cells the capability for anchorage-independent colony formation in soft agar and tumor development in nude mice. The published transcriptome and nucleotide sequence analysis of gene

  18. Characterization of neutral TRH-like peptides in mammary gland, mammary tumors and milk.

    PubMed

    Ghilchik, M W; Tobaruela, M; del Rio-Garcia, J; Smyth, D G

    2000-06-01

    Three pyroglutamylpeptide amides, pGlu-Glu-Pro amide, pGlu-Phe-Pro amide and pGlu-Gln-Pro amide, with similar structures to thyrotropin-releasing hormone (TRH), have been identified previously in the male reproductive system. We report here that rat and human mammary gland contain neutral TRH-immunoreactive peptides which are not retained on cation or anion exchange chromatography and that similar peptides occur in the milk of rat, cow, ewe and sow. The TRH-like peptides in lyophilized milk from the cow were purified by gel exclusion chromatography, mini-column cation exchange chromatography and reversed phase high performance liquid chromatography (HPLC) and the chromatographed peptides were located by TRH radioimmunoassay (RIA). In each chromatographic system the major TRH-immunoreactive peptide from cow milk exhibited identical behavior to pGlu-Phe-Pro amide; in addition there were two minor TRH-immunoreactive components. The possible physiological role of the TRH-like peptides in the mammary gland is discussed. In a series of patients with breast carcinoma, mammary tumor tissue was shown to contain approximately four times more TRH-like peptide than normal mammary tissue from the same patient, raising the possibility that the TRH-like peptides may be implicated in tumor development.

  19. HCG hastens both the development of mammary carcinoma and the metastatization of HCG/LH and ERBB-2 receptor-positive cells in mice.

    PubMed

    Iezzi, Manuela; Quaglino, E; Cappello, P; Toto, V; Sabatini, F; Curcio, C; Garotta, G; Musiani, P; Cavallo, F

    2011-01-01

    Breast cancer is more frequent in human nulliparae, whereas its incidence is reduced by early fullterm pregnancy. Rodent studies suggest that chorionic gonadotropin secretion during pregnancy affords protection by inducing breast structure differentiation. Opposite effects, however, have been observed in cancer prone transgenic mice overexpressing the β subunit of chorionic gonadotropin or pituitary luteinic hormone (LH). Here we assessed the effect of administration of human chorionic gonadotropin (hCG) for 21 days (corresponding to the duration of a mouse pregnancy) in virgin female mice transgenic for the activated rat (r-) ERBB-2 oncogene (BALB-neuT). In these mice, the onset of atypical mammary duct hyperplasia and its progression towards multiple mammary carcinomas is accelerated by hCG. hCG enhances the in vitro proliferation and in vivo metastatization of tumor cells from a BALB-neuT mammary tumor expressing the hCG/LH as well as the ERBB-2 receptors. These findings suggest that hCG favours the growth and progression of hCG/LH and ERBB-2 receptor-positive breast tumors.

  20. Transgenic Mammary Epithelial Osteopontin (Spp1) Expression Induces Proliferation and Alveologenesis

    PubMed Central

    Hubbard, Neil E.; Chen, Qian J.; Sickafoose, Laura K.; Wood, Meghan B.; Gregg, Jeffrey P.; Abrahamsson, Ninnie M.; Engelberg, Jesse A.; Walls, Judith E.

    2013-01-01

    Osteopontin (OPN) Spp1 is involved in differentiation of the mammary gland. We engineered mice to overexpress OPN in mammary epithelium and describe an altered mammary phenotype. Three transgenic (Tg) founder lines FVB/N Tg(MMTV-Opn)(1-3BOR) were propagated after FVB/NJ pronuclear injections. Mammary glands from Tg-OPN mice compared to littermate controls showed, at 4 weeks of age, exaggerated terminal end buds; at 8 and 12 weeks, more numerous and complex ducts with increased luminal protein; and at 16 weeks, increased lobulogenesis. Lactational Tg-OPN mammary glands showed more rapid lobulogenesis and lactational changes with slower gland involution and regression following weaning. Ex vivo lobulogenesis was noticeably increased from organoids of Tg-OPN mice. Immunohistochemistry revealed cytoplasmic OPN accumulation and increased Ki-67 positive mammary epithelial cells in Tg-OPN mammary glands. OPN appears to convey a proliferative stimulus for mammary epithelial cells and alters development and differentiation. These OPN mammary overexpressing mice provide a means to study the role of OPN in cancer progression. PMID:24069507

  1. Growth hormone mRNA in mammary gland tumors of dogs and cats.

    PubMed Central

    Mol, J A; van Garderen, E; Selman, P J; Wolfswinkel, J; Rijinberk, A; Rutteman, G R

    1995-01-01

    We have shown recently that in the dog progestin administration results in mammary production of immunoreactive growth hormone (GH). At present we demonstrate the expression of the gene encoding GH in the mammary gland of dogs and cats using reverse-transcriptase PCR. GH mRNA was found in the great majority of normal mammary tissues as well as benign and malignant mammary tumors of the dog and was associated with the presence of immunoreactive GH in cryostat sections. The mammary PCR product proved to be identical to that of the pituitary. The highest expression levels were found after prolonged treatment with progestins. In carcinomas GH mRNA was also found in progesterone receptor-negative tissue samples, indicating that after malignant transformation GH gene expression may become progestin independent. GH mRNA was also present in mammary tissues of cats with progestin-induced fibroadenomatous changes. It is concluded that GH gene expression occurs in normal, hyperplastic, and neoplastic mammary tissue of the dog. The expression in normal tissue is stimulated by progestins and might mediate the progestin-stimulated development of canine mammary tumors. The demonstration of progestin-stimulated GH expression in mammary tissue of cats indicates that the phenomenon is more generalized among mammals. Images PMID:7738169

  2. 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.

  3. Mammary Analogue Secretory Carcinoma.

    PubMed

    Stevens, Todd M; Parekh, Vishwas

    2016-09-01

    Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumor that shares the same histologic appearance and ETV6 gene (12p13) rearrangement as secretory carcinoma of the breast. Prior to its recognition, MASC cases were commonly labeled acinic cell carcinoma and adenocarcinoma, not otherwise specified. Despite distinctive histologic features, MASC may be difficult to distinguish from other salivary gland tumors, in particular zymogen-poor acinic cell carcinoma and low-grade salivary duct carcinoma. Although characteristic morphologic and immunohistochemical features form the basis of a diagnosis of MASC, the presence of an ETV6-NTRK3 gene fusion is confirmatory. Given its recent recognition the true prognostic import of MASC is not yet clearly defined.

  4. Cloning of Mammary Stem Cells

    DTIC Science & Technology

    2001-11-01

    these parity-induced cells do represent a totipotent mammary stem cell population per se, but these cells might support stem cell maintenance as... Stem Cells PRINCIPAL INVESTIGATOR: Dr. Kay-Uwe Wagner CONTRACTING ORGANIZATION: University of Nebraska Medical Center Omaha, Nebraska 68198-6810 REPORT...Mammary Stem Cells DAMD17-00-1-0641 6. AUTHOR(S) Dr. Kay-Uwe Wagner 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT

  5. Hormonal regulation of the immune microenvironment in the mammary gland.

    PubMed

    Need, Eleanor F; Atashgaran, Vahid; Ingman, Wendy V; Dasari, Pallave

    2014-07-01

    It is well established that the development and homeostasis of the mammary gland are highly dependent upon the actions of ovarian hormones progesterone and estrogen, as well as the availability of prolactin for the pregnant and lactating gland. More recently it has become apparent that immune system cells and cytokines play essential roles in both mammary gland development as well as breast cancer. Here, we review hormonal effects on mammary gland biology during puberty, menstrual cycling, pregnancy, lactation and involution, and dissect how hormonal control of the immune system may contribute to mammary development at each stage via cytokine secretion and recruitment of macrophages, eosinophils, mast cells and lymphocytes. Collectively, these alterations may create an immunotolerant or inflammatory immune environment at specific developmental stages or phases of the menstrual cycle. Of particular interest for further research is investigation of the combinatorial actions of progesterone and estrogen during the luteal phase of the menstrual cycle and key developmental points where the immune system may play an active role both in mammary development as well as in the creation of an immunotolerant environment, thereby affecting breast cancer risk.

  6. Presence of hyperplastic pectoral mammary glands in a white-footed mouse (Peromyscus leucopus) from a Superfund Site in Oklahoma, USA.

    PubMed

    Hays, Kimberly A; Breshears, Melanie A

    2011-01-01

    Laboratory experiments have documented the effects of hormones and endocrine-disrupting compounds on mammary development in mammals. However, few observations of mammary hyperplasia have been presented for wild rodents. We describe hyperplastic mammary glands in a wild-caught white-footed mouse (Peromyscus leucopus) from an area contaminated with heavy metals.

  7. Differential transformation of mammary epithelial cells by Wnt genes.

    PubMed Central

    Wong, G T; Gavin, B J; McMahon, A P

    1994-01-01

    The mouse Wnt family includes at least 10 genes that encode structurally related secreted glycoproteins. Wnt-1 and Wnt-3 were originally identified as oncogenes activated by the insertion of mouse mammary tumor virus in virus-induced mammary adenocarcinomas, although they are not expressed in the normal mammary gland. However, five other Wnt genes are differentially expressed during development of adult mammary tissue, suggesting that they may play distinct roles in various phases of mammary gland growth and development. Induction of transformation by Wnt-1 and Wnt-3 may be due to interference with these normal regulatory events; however, there is no direct evidence for this hypothesis. We have tested Wnt family members for the ability to induce transformation of cultured mammary cells. The results demonstrate that the Wnt gene family can be divided into three groups depending on their ability to induce morphological transformation and altered growth characteristics of the C57MG mammary epithelial cell line. Wnt-1, Wnt-3A, and Wnt-7A were highly transforming and induced colonies which formed and shed balls of cells. Wnt-2, Wnt-5B, and Wnt-7B also induced transformation but with a lower frequency and an apparent decrease in saturation density. In contrast, Wnt-6 and two other family members which are normally expressed in C57MG cells, Wnt-4 and Wnt-5A, failed to induce transformation. These data demonstrate that the Wnt genes have distinct effects on cell growth and should not be regarded as functionally equivalent. Images PMID:8065359

  8. 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...

  9. 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...

  10. Down-regulation of sfrp1 in a mammary epithelial cell line promotes the development of a cd44high/cd24low population which is invasive and resistant to anoikis

    PubMed Central

    Gauger, Kelly J; Hugh, Jeremy M; Troester, Melissa A; Schneider, Sallie Smith

    2009-01-01

    Background The Wnt family of secreted proteins is implicated in the regulation of cell fate during development, as well as in cell proliferation, morphology, and migration. Aberrant activation of the Wnt/β-catenin signaling pathway leads to the development of several human cancers, including breast cancer. Secreted frizzled-related protein 1 (SFRP1) antagonizes this pathway by competing with the Frizzled receptor for Wnt ligands resulting in an attenuation of the signal transduction cascade. Loss of SFRP1 expression is observed in breast cancer, along with several other cancers, and is associated with poor patient prognosis. However, it is not clear whether the loss of SFRP1 expression predisposes the mammary gland to tumorigenesis. Results When SFRP1 is knocked down in a non-malignant immortalized mammary epithelial cell line (76 N TERT), nuclear levels of β-catenin rise and the Wnt pathway is stimulated. The SFRP1 knockdown cells exhibit increased expression of the pro-proliferative Cyclin D1 gene and increased cellular proliferation, undergo a partial epithelial-mesenchymal transition (EMT), are resistant to anchorage-independent cell death, exhibit increased migration, are significantly more invasive, and exhibit a CD24low/CD44high cell surface marker expression pattern. Conclusion Our study suggests that loss of SFRP1 allows non-malignant cells to acquire characteristics associated with breast cancer cells. PMID:19422694

  11. 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.

  12. Id-1 is not expressed in the luminal epithelial cells of mammary glands

    PubMed Central

    Uehara, Norihisa; Chou, Yu-Chien; Galvez, Jose J; de-Candia, Paola; Cardiff, Robert D; Benezra, Robert; Shyamala, Gopalan

    2003-01-01

    Background The family of inhibitor of differentiation/DNA binding (Id) proteins is known to regulate development in several tissues. One member of this gene family, Id-1, has been implicated in mammary development and carcinogenesis. Mammary glands contain various cell types, among which the luminal epithelial cells are primarily targeted for proliferation, differentiation and carcinogenesis. Therefore, to assess the precise significance of Id-1 in mammary biology and carcinogenesis, we examined its cellular localization in vivo using immunohistochemistry. Methods Extracts of whole mammary glands from wild type and Id-1 null mutant mice, and tissue sections from paraffin-embedded mouse mammary glands from various developmental stages and normal human breast were subjected to immunoblot and immunohistochemical analyses, respectively. In both these procedures, an anti-Id-1 rabbit polyclonal antibody was used for detection of Id-1. Results In immunoblot analyses, using whole mammary gland extracts, Id-1 was detected. In immunohistochemical analyses, however, Id-1 was not detected in the luminal epithelial cells of mammary glands during any stage of development, but it was detected in vascular endothelial cells. Conclusion Id-1 is not expressed in the luminal epithelial cells of mammary glands. PMID:12631395

  13. Evidence for a multipotent mammary progenitor with pregnancy-specific activity

    PubMed Central

    2013-01-01

    Introduction The mouse mammary gland provides a powerful model system for studying processes involved in epithelial tissue development. Although markers that enrich for mammary stem cells and progenitors have been identified, our understanding of the mammary developmental hierarchy remains incomplete. Methods We used the MMTV promoter linked to the reverse tetracycline transactivator to induce H2BGFP expression in the mouse mammary gland. Mammary epithelial cells (MECs) from virgin mice were sorted by flow cytometry for expression of the mammary stem cell/progenitor markers CD24 and CD29, and H2BGFP. Sorted populations were analyzed for in vivo repopulation ability, expression of mammary lineage markers, and differential gene expression. Results The reconstituting activity of CD24+/CD29+ cells in cleared fat pad transplantation assays was not distinguished in GFP+ compared to GFP- subpopulations. However, within the CD24+/CD29lo luminal progenitor-enriched population, H2BGFP+, but not H2BGFP-, MECs formed mammary structures in transplantation assays; moreover, this activity was dramatically enhanced in pregnant recipients. These outgrowths contained luminal and myoepithelial mammary lineages and produced milk, but lacked the capacity for serial transplantation. Transcriptional microarray analysis revealed that H2BGFP+/CD24+/CD29lo MECs are distinct from H2BGFP-/CD24+/CD29lo MECs and enriched for gene expression signatures with both the stem cell (CD24+/CD29+) and luminal progenitor (CD24+/CD29lo/CD61+) compartments. Conclusions We have identified a population of MECs containing pregnancy-activated multipotent progenitors that are present in the virgin mammary gland and contribute to the expansion of the mammary gland during pregnancy. PMID:23947835

  14. Insights into the role of connexins in mammary gland morphogenesis and function.

    PubMed

    Stewart, Michael K G; Simek, Jamie; Laird, Dale W

    2015-06-01

    Gap junctions formed of connexin subunits link adjacent cells by direct intercellular communication that is essential for normal tissue homeostasis in the mammary gland. The mammary gland undergoes immense remodeling and requires exquisite regulation to control the proliferative, differentiating, and cell death mechanisms regulating gland development and function. The generation of novel genetically modified mice with reduced or ablated connexin function within the mammary gland has advanced our understanding of the role of gap junctions during the complex and dynamic process of mammary gland development. These studies have revealed an important stage-specific role for Cx26 (GJA1) and Cx43 (GJB2), while Cx30 (GJB6) and Cx32 (Gjb1) can be eliminated without compromising the gland. Yet, there remain gaps in our understanding of the role of mammary gland gap junctions.

  15. 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.

  16. Mammary Cancer and Activation of Transposable Elements

    DTIC Science & Technology

    2014-09-01

    AD_________________ Award Number: W81XWH-11-1-0402 TITLE: Mammary Cancer and Activation...TYPE Annual 3. DATES COVERED 1 Sep 2013 – 31 Aug 2014 4. TITLE AND SUBTITLE Mammary Cancer and Activation of Transposable Elements 5a. CONTRACT...investigate molecular events occurring in the preclinical stages of mammary cancer. Specifically, the project investigates the intersection between the

  17. Keratinocyte Growth Factor Causes Cystic Dilation of the Mammary Glands of Mice

    PubMed Central

    Yi, Eunhee S.; Bedoya, Adriana A.; Lee, Hyesun; Kim, Seokhyun; Housley, Regina M.; Aukerman, Sharon L.; Tarpley, John E.; Starnes, Charles; Yin, Songmei; Pierce, Glenn F.; Ulich, Thomas R.

    1994-01-01

    Keratinocyte growth factor (KGF) is a paracrine mediator of epithelial cell proliferation that has been reported to induce marked proliferation of mammary epithelium in rats. In this study, systemic administration of KGF into naive and oophorectomized mice causes mammary gland proliferation, as evidenced histologically by the appearance of cysts lined by a single layer of epithelium and by hyperplastic epithelium. Whole mount preparations of the mammary glands reveal that the histologically noted cysts are actually ducts that are dilated along much of their length. The histology of the mammary glands of KGF-treated mice is similar to the histology of fibrocystic disease in the buman female breast. The response in mice differs significantly from the appearance of the mammary glands in KGF-treated rats in which ductal epithelial proliferation is most prominent. Estrogen and progesterone when administered in combination but not alone cause the development of numerous endbuds in the mouse mammary gland. KGF in estrogen- and progesterone-pretreated mice causes the growth of dilated ducts, hyperplastic epithelium within ducts and endbuds, and a fibrous metamorphosis of periductal adipose tissue. The mammary epithelial hyperplasia caused by KGF is rapidly reversible in both mice and rats after cessation of KGF treatment. The spectrum of KGF-, estrogen-, and progesterone-induced mammary histopathology in mice provides a model for the study of fibrocystic and hyperplastic breast disease. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:7977634

  18. CRIPTO/GRP78 Signaling Maintains Fetal and Adult Mammary Stem Cells Ex Vivo

    PubMed Central

    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.

    2014-01-01

    Summary 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

  19. Int-6, a highly conserved, widely expressed gene, is mutated by mouse mammary tumor virus in mammary preneoplasia.

    PubMed Central

    Marchetti, A; Buttitta, F; Miyazaki, S; Gallahan, D; Smith, G H; Callahan, R

    1995-01-01

    With a unique mouse mammary tumor model system in which mouse mammary tumor virus (MMTV) insertional mutations can be detected during progression from preneoplasia to frank malignancy, including metastasis, we have discovered a new common integration site (designated Int-6) for MMTV in mouse mammary tumors. MMTV was integrated into Int-6 in a mammary hyperplastic outgrowth line, its tumors and metastases, and two independent mammary tumors arising in unrelated mice. The Int-6 gene is ubiquitously expressed as a 1.4-kb RNA species in adult tissues and is detected beginning at day 8 of embryonic development. The nucleotide sequence of Int-6 is unrelated to any of the known genes in the GenBank database. MMTV integrates within introns of the gene in the opposite transcriptional orientation. In each tumor tested, this results in the expression of a truncated Int-6/long terminal repeat (LTR) chimeric RNA species which is terminated at a cryptic termination signal in the MMTV LTR. Since the nonrearranged Int-6 alleles in these tumors contain no mutations, we favor the conclusion that truncation of the Int-6 gene product either biologically activates its function or represents a dominant-negative mutation. PMID:7853537

  20. The contribution of growth hormone to mammary neoplasia

    PubMed Central

    Perry, Jo K; Mohankumar, Kumarasamypet M; Emerald, B Starling; Mertani, Hichem C; Lobie, Peter E

    2008-01-01

    While the effects of growth hormone (GH) on longitudinal growth are well established, the observation that GH contributes to neoplastic progression is more recent. Accumulating literature implicates GH-mediated signal transduction in the development and progression of a wide range malignancies including breast cancer. Recently autocrine human GH been demonstrated to be an orthotopically expressed oncogene for the human mammary gland. This review will highlight recent evidence linking GH and mammary carcinoma and discuss GH-antagonism as a potential therapeutic approach for treatment of breast cancer. PMID:18253708

  1. FACS Sorting Mammary Stem Cells.

    PubMed

    Iriondo, Oihana; Rábano, Miriam; Vivanco, María D M

    2015-01-01

    Fluorescent-activated cell sorting (FACS) represents one of the key techniques that have been used to isolate and characterize stem cells, including cells from the mammary gland. A combination of approaches, including recognition of cell surface antigens and different cellular activities, has facilitated the identification of stem cells from the healthy mammary gland and from breast tumors. In this chapter we describe the protocol to use FACS to separate breast cancer stem cells, but most of the general principles discussed could be applied to sort other types of cells.

  2. Mammary Cancer and Activation of Transposable Elements

    DTIC Science & Technology

    2013-09-01

    cytes and ADS-derived induced pluripotent stem cells (ADS-iPSCs) (19) and primary mouse ES cells to isolated sperm and oocytes (20). We selected an...051 59 5 92% H9-IMR90 5875 7 669 782 605 58 91% oocyte - ES cell (mouse) 4727 1 204 883 334 25 93% sperm - ES cell (mouse) 4580 4 364 748 1027 104 91...collaborator, Dr. Anne Peaston, developed a genetically engineered mouse model in which a specific mammary cell population is fluorescently marked upon

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

    PubMed Central

    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

  4. New insights into fetal mammary gland morphogenesis: differential effects of natural and environmental estrogens

    PubMed Central

    Speroni, Lucia; Voutilainen, Maria; Mikkola, Marja L.; Klager, Skylar A.; Schaeberle, Cheryl M.; Sonnenschein, Carlos; Soto, Ana M.

    2017-01-01

    An increased breast cancer risk during adulthood has been linked to estrogen exposure during fetal life. However, the impossibility of removing estrogens from the feto-maternal unit has hindered the testing of estrogen’s direct effect on mammary gland organogenesis. To overcome this limitation, we developed an ex vivo culture method of the mammary gland where the direct action of estrogens can be tested during embryonic days (E)14 to 19. Mouse mammary buds dissected at E14 and cultured for 5 days showed that estrogens directly altered fetal mammary gland development. Exposure to 0.1 pM, 10 pM, and 1 nM 17 β-estradiol (E2) resulted in monotonic inhibition of mammary buds ductal growth. In contrast, Bisphenol-A (BPA) elicited a non-monotonic response. At environmentally relevant doses (1 nM), BPA significantly increased ductal growth, as previously observed in vivo, while 1 μM BPA significantly inhibited ductal growth. Ductal branching followed the same pattern. This effect of BPA was blocked by Fulvestrant, a full estrogen antagonist, while the effect of estradiol was not. This method may be used to study the hormonal regulation of mammary gland development, and to test newly synthesized chemicals that are released into the environment without proper assessment of their hormonal action on critical targets like the mammary gland. PMID:28102330

  5. Targeted Overexpression of EZH2 in the Mammary Gland Disrupts Ductal Morphogenesis and Causes Epithelial Hyperplasia

    PubMed Central

    Li, Xin; Gonzalez, Maria E.; Toy, Katherine; Filzen, Tracey; Merajver, Sofia D.; Kleer, Celina G.

    2009-01-01

    The Polycomb group protein enhancer of zeste homolog 2 (EZH2), which has roles during development of numerous tissues, is a critical regulator of cell type identity. Overexpression of EZH2 has been detected in invasive breast carcinoma tissue samples and is observed in human breast tissue samples of morphologically normal lobules up to 12 years before the development of breast cancer. The function of EZH2 during preneoplastic progression in the mammary gland is unknown. To investigate the role of EZH2 in the mammary gland, we targeted the expression of EZH2 to mammary epithelial cells using the mouse mammary tumor virus long terminal repeat. EZH2 overexpression resulted in aberrant terminal end bud architecture. By the age of 4 months, 100% of female mouse mammary tumor virus-EZH2 virgin mice developed intraductal epithelial hyperplasia resembling the human counterpart accompanied by premature differentiation of ductal epithelial cells and up-regulation of the luminal marker GATA-3. In addition, remodeling of the mammary gland after parturition was impaired and EZH2 overexpression caused delayed involution. Mechanistically, we found that EZH2 physically interacts with β-catenin, inducing β-catenin nuclear accumulation in mammary epithelial cells and activating Wnt/β-catenin signaling. The biological significance of these data to human hyperplasias is demonstrated by EZH2 up-regulation and colocalization with β-catenin in human intraductal epithelial hyperplasia, the earliest histologically identifiable precursor of breast carcinoma. PMID:19661437

  6. Effects of milk replacer formulation on measures of mammary growth and composition in Holstein heifers.

    PubMed

    Daniels, K M; Capuco, A V; McGilliard, M L; James, R E; Akers, R M

    2009-12-01

    Overfeeding prepubertal heifers may impair mammary parenchymal growth and reduce milk production, but evidence suggests that increased intake of a high-protein milk replacer before weaning may be beneficial. This study was designed to evaluate effects of milk replacer (MR) composition on mass and composition of mammary parenchyma and fat pad, growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis gene expression, and putative mammary epithelial stem cells. Specifically, we hypothesized that positive effects of faster rates of gain during the preweaning period alter the development, persistence, or activity of populations of putative mammary epithelial stem cells, possibly through involvement of GH/IGF-I axis molecules. Twenty-four newborn heifers were fed 1 of 4 MR diets (n = 6/diet): control [20% crude protein (CP), 21% fat MR fed at 441 g of dry matter (DM)/d], high protein, low fat (28% CP, 20% fat MR fed at 951 g of DM/d), high protein, high fat (27% CP, 28% fat MR fed at 951 g of DM/d), and high protein, high fat+ (27% CP, 28% fat MR fed at 1,431 g of DM/d). Water and starter (20% CP, 1.43% fat) were offered ad libitum. Animals were killed on d 65 and mammary tissue was subjected to biochemical, molecular, and histological examination. No differences in mammary parenchymal mass or composition, with or without adjusting for empty body weight, were detected. Mass was increased and composition of the mammary fat pad was altered by nutrient intake. No diet differences in putative mammary epithelial stem cell abundance or abundance of transcripts for genes of the GH/IGF-I axis were detected. In this study, growth of the mammary epithelium, size of the mammary epithelial stem cell population, and components of the GH/IGF-I axis did not depend on diet. However, an underlying positive correlation between telomerase, a marker of mammary stem cells, and growth of the mammary parenchyma was detected. Implications of diet-induced effects on mammary fat pad and

  7. 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.

  8. Efficient BLG-Cre mediated gene deletion in the mammary gland.

    PubMed

    Selbert, S; Bentley, D J; Melton, D W; Rannie, D; Lourenço, P; Watson, C J; Clarke, A R

    1998-09-01

    Using the phage P1-derived Cre/loxP recombination system, we have developed a strategy for efficient mammary tissue specific inactivation of floxed genes. Transgenic mice were generated which express Cre DNA-recombinase under the control of the mammary gland specific promoter of the ovine beta-lactoglobulin (BLG) gene. To test the specificity of Cre mediated recombination, we crossed these mice to animals harbouring a floxed DNA ligase I allele. We show that the BLG-Cre construct specifies mammary specific gene deletion, and furthermore that it is temporally regulated, predominantly occurring during lactation. We fully characterised the extent of gene deletion in one line (line 74). In this strain the virgin gland is characterised by low levels (7%) of Cre mediated deletion, whereas 70-80% of cells within the lactating mammary gland have undergone recombination. Immunohistochemistry and indirect in situ PCR were used respectively to demonstrate that both Cre protein and Cre activity were evenly distributed throughout the population of secretory epithelial cells. The level of background recombination in non-mammary tissues was found to be < or = 1.1%, irrespective of mammary gland developmental status. Crossing the transgenic BLG-Cre strain described here to mice harbouring other floxed alleles will facilitate the functional analysis of those genes during differentiation and development of the mammary gland.

  9. Paracrine Overexpression of Insulin-Like Growth Factor-1 Enhances Mammary Tumorigenesis in Vivo

    PubMed Central

    de Ostrovich, Krisztina Kovács; Lambertz, Isabel; Colby, Jennifer K. L.; Tian, Jie; Rundhaug, Joyce E.; Johnston, Dennis; Conti, Claudio J.; DiGiovanni, John; Fuchs-Young, Robin

    2008-01-01

    Insulin-like growth factor-1 (IGF-1) stimulates proliferation, regulates tissue development, protects against apoptosis, and promotes the malignant phenotype in the breast and other organs. Some epidemiological studies have linked high circulating levels of IGF-1 with an increased risk of breast cancer. To study the role of IGF-1 in mammary tumorigenesis in vivo, we used transgenic mice in which overexpression of IGF-1 is under the control of the bovine keratin 5 (BK5) promoter and is directed to either the myoepithelial or basal cells in a variety of organs, including the mammary gland. This model closely recapitulates the paracrine exposure of breast epithelium to stromal IGF-1 seen in women. Histologically, mammary glands from transgenic mice were hyperplastic and highly vascularized. Mammary glands from prepubertal transgenic mice had significantly increased ductal proliferation compared with wild-type tissues, although this difference was not maintained after puberty. Transgenic mice also had increased susceptibility to mammary carcinogenesis, and 74% of the BK5.IGF-1 mice treated with 7,12-dimethylbenz[a]anthracene (20 μg/day) developed mammary tumors compared with 29% of the wild-type mice. Interestingly, 31% of the vehicle-treated BK5.IGF-1 animals, but none of the wild-type animals, spontaneously developed mammary cancer. The mammary tumors were moderately differentiated adenocarcinomas that expressed functional, nuclear estrogen receptor at both the protein and mRNA levels. These data support the hypothesis that tissue overexpression of IGF-1 stimulates mammary tumorigenesis. PMID:18688034

  10. Notch3 marks clonogenic mammary luminal progenitor cells in vivo

    PubMed Central

    Lafkas, Daniel; Rodilla, Veronica; Huyghe, Mathilde; Mourao, Larissa; Kiaris, Hippokratis

    2013-01-01

    The identity of mammary stem and progenitor cells remains poorly understood, mainly as a result of the lack of robust markers. The Notch signaling pathway has been implicated in mammary gland development as well as in tumorigenesis in this tissue. Elevated expression of the Notch3 receptor has been correlated to the highly aggressive “triple negative” human breast cancer. However, the specific cells expressing this Notch paralogue in the mammary gland remain unknown. Using a conditionally inducible Notch3-CreERT2SAT transgenic mouse, we genetically marked Notch3-expressing cells throughout mammary gland development and followed their lineage in vivo. We demonstrate that Notch3 is expressed in a highly clonogenic and transiently quiescent luminal progenitor population that gives rise to a ductal lineage. These cells are capable of surviving multiple successive pregnancies, suggesting a capacity to self-renew. Our results also uncover a role for the Notch3 receptor in restricting the proliferation and consequent clonal expansion of these cells. PMID:24100291

  11. Notch3 marks clonogenic mammary luminal progenitor cells in vivo.

    PubMed

    Lafkas, Daniel; Rodilla, Veronica; Huyghe, Mathilde; Mourao, Larissa; Kiaris, Hippokratis; Fre, Silvia

    2013-10-14

    The identity of mammary stem and progenitor cells remains poorly understood, mainly as a result of the lack of robust markers. The Notch signaling pathway has been implicated in mammary gland development as well as in tumorigenesis in this tissue. Elevated expression of the Notch3 receptor has been correlated to the highly aggressive "triple negative" human breast cancer. However, the specific cells expressing this Notch paralogue in the mammary gland remain unknown. Using a conditionally inducible Notch3-CreERT2(SAT) transgenic mouse, we genetically marked Notch3-expressing cells throughout mammary gland development and followed their lineage in vivo. We demonstrate that Notch3 is expressed in a highly clonogenic and transiently quiescent luminal progenitor population that gives rise to a ductal lineage. These cells are capable of surviving multiple successive pregnancies, suggesting a capacity to self-renew. Our results also uncover a role for the Notch3 receptor in restricting the proliferation and consequent clonal expansion of these cells.

  12. 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

  13. 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.

  14. Genetic variations of BRCA1 and BRCA2 genes in dogs with mammary tumours.

    PubMed

    Enginler, S O; Akış, I; Toydemir, T S F; Oztabak, K; Haktanir, D; Gündüz, M C; Kırşan, I; Fırat, I

    2014-03-01

    Mammary tumours are the most common tumour type in female dogs. The formation of the mammary tumours is multifactorial but the high incidence of tumour disease in certain canine breeds suggests a strong genetic component. BRCA1 and BRCA2 are the most important genes significantly associated with mammary tumours. The aim of this study was to determine the association between the variations of these two genes and canine mammary tumours. 5'-untranslated region, intron 8 and exon 9 of BRCA1 and exons 12, 24, 27 of BRCA2 were sequenced in order to detect the genetic variations. In addition to six previously identified polymorphisms, six novel single nucleotide polymorphisms (SNPs) were detected. Five of the coding SNPs were synonymous and three of them were non-synonymous. The comparison of the sequences from 25 mammary tumour bearing and 10 tumour free dogs suggested that the two SNPs in intron 8 and exon 9 of BRCA1 and two SNPs in exon 24 and exon 27 of BRCA2, which are firstly identified in this study, might be associated with mammary tumour development in dogs. Especially one SNP in exon 9 of BRCA1 and one SNP in exon 24 of BRCA2 were found to be significantly associated with canine mammary tumours.

  15. Genetic variations of BRCA1 and BRCA2 genes in dogs with mammary tumours.

    PubMed

    Enginler, S O; Akış, I; Toydemir, T S F; Oztabak, K; Haktanir, D; Gündüz, M C; Kırşan, I; Fırat, I

    2014-03-01

    Mammary tumours are the most common tumour type in female dogs. The formation of the mammary tumours is multifactorial but the high incidence of tumour disease in certain canine breeds suggests a strong genetic component. BRCA1 and BRCA2 are the most important genes significantly associated with mammary tumours. The aim of this study was to determine the association between the variations of these two genes and canine mammary tumours. 5′-untranslated region, intron 8 and exon 9 of BRCA1 and exons 12, 24, 27 of BRCA2 were sequenced in order to detect the genetic variations. In addition to six previously identified polymorphisms, six novel single nucleotide polymorphisms (SNPs) were detected. Five of the coding SNPs were synonymous and three of them were non-synonymous. The comparison of the sequences from 25 mammary tumour bearing and 10 tumour free dogs suggested that the two SNPs in intron 8 and exon 9 of BRCA1 and two SNPs in exon 24 and exon 27 of BRCA2, which are firstly identified in this study, might be associated with mammary tumour development in dogs. Especially one SNP in exon 9 of BRCA1 and one SNP in exon 24 of BRCA2 were found to be significantly associated with canine mammary tumours.

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

    PubMed Central

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

    2016-01-01

    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

  17. Premature mammary gland involution with repeated corticosterone injection in interleukin 10-deficient mice.

    PubMed

    Hwang, Woo-Sung; Bae, Ji-Hyun; Yeom, Su-Cheong

    2016-12-01

    Recently, we found that maternal stress could induce premature mammary gland involution in interleukin 10 knock out (IL-10(-/-)) mice. To elucidate correlation between stress, IL-10, and mammary gland involution, corticosterone was injected into the lactating wild type and IL-10-deficient mice and assessed mammary gland phenotype. Repetitive corticosterone injection developed premature mammary gland involution only in B6.IL-10(-/-) mice; moreover, it induced alopecia in nursing pups. Corticosterone injection induced several typical changes such as mammary gland epithelial cell apoptosis, macrophage infiltration, fat deposition in adipocyte, STAT3 phosphorylation, and upregulation of tyrosine hydroxylase gene in adrenal gland. Overall incidence of pup alopecia and mammary gland involution was relatively high in corticosterone than control B6.IL-10(-/-) group (57% vs. 20%). Our finding demonstrates that IL-10 is important for stress modulation, and B6.Il-10(-/-) with corticosterone has several advantage such as simple to establish, well-defined onset of mammary gland involution, high incidence, and inducing pup alopecia.

  18. Both ovarian hormones estrogen and progesterone are necessary for hormonal mammary carcinogenesis in ovariectomized ACI rats.

    PubMed

    Blank, Edward W; Wong, Po-Yin; Lakshmanaswamy, Rajkumar; Guzman, Raphael; Nandi, Satyabrata

    2008-03-04

    August-Copenhagen-Irish (ACI) rats are unique in that the ovary-intact females develop high incidence of mammary cancers induced solely by hormones upon prolonged exposure to high levels of estrogen alone. Studies have also shown that such prolonged exposure to high-dose estrogen results in human-like aneuploid mammary cancers in ovary-intact ACI rats. To determine the role of progesterone in mammary carcinogenesis, six-week-old intact and ovariectomized ACI rats were continuously exposed to low- and high-dose estrogen alone, progesterone alone, low-dose estrogen plus progesterone, and ovariectomized ACI rats with high-dose estrogen plus progesterone. Also, ovariectomized ACI rats were treated with high-dose estrogen plus progesterone plus testosterone to determine the role of the androgen, testosterone, if any, in hormonal mammary carcinogenesis. The results indicate that continuous exposure to high, but not low, concentrations of estrogen alone can induce mammary carcinogenesis in intact but not in ovariectomized rats. Mammary carcinogenesis in ovariectomized ACI rats requires continuous exposure to high concentrations of estrogen and progesterone. The addition of testosterone propionate does not affect tumor incidence in such rats. These results suggest that both ovarian hormones estrogen and progesterone are necessary for mammary carcinogenesis induced solely by hormones in ovariectomized ACI rats. Our results are in agreement with the Women's Health Initiative studies, where treatment of postmenopausal women with estrogen (ERT) alone did not increase the risk of breast cancer, but estrogen and progesterone (HRT) did.

  19. p130Cas over-expression impairs mammary branching morphogenesis in response to estrogen and EGF.

    PubMed

    Camacho Leal, Maria del Pilar; Pincini, Alessandra; Tornillo, Giusy; Fiorito, Elisa; Bisaro, Brigitte; Di Luca, Elisa; Turco, Emilia; Defilippi, Paola; Cabodi, Sara

    2012-01-01

    p130Cas adaptor protein regulates basic processes such as cell cycle control, survival and migration. p130Cas over-expression has been related to mammary gland transformation, however the in vivo consequences of p130Cas over-expression during mammary gland morphogenesis are not known. In ex vivo mammary explants from MMTV-p130Cas transgenic mice, we show that p130Cas impairs the functional interplay between Epidermal Growth Factor Receptor (EGFR) and Estrogen Receptor (ER) during mammary gland development. Indeed, we demonstrate that p130Cas over-expression upon the concomitant stimulation with EGF and estrogen (E2) severely impairs mammary morphogenesis giving rise to enlarged multicellular spherical structures with altered architecture and absence of the central lumen. These filled acinar structures are characterized by increased cell survival and proliferation and by a strong activation of Erk1/2 MAPKs and Akt. Interestingly, antagonizing the ER activity is sufficient to re-establish branching morphogenesis and normal Erk1/2 MAPK activity. Overall, these results indicate that high levels of p130Cas expression profoundly affect mammary morphogenesis by altering epithelial architecture, survival and unbalancing Erk1/2 MAPKs activation in response to growth factors and hormones. These results suggest that alteration of morphogenetic pathways due to p130Cas over-expression might prime mammary epithelium to tumorigenesis.

  20. Aquaporin water channels in the mammary gland: from physiology to pathophysiology and neoplasia.

    PubMed

    Mobasheri, Ali; Barrett-Jolley, Richard

    2014-03-01

    Aquaporins are membrane proteins that play fundamental roles in water and small solute transport across epithelial and endothelial barriers. Recent studies suggest that several aquaporin proteins are present in the mammary gland. Immunohistochemical techniques have confirmed the presence of aquaporin 1 (AQP1) and AQP3 water channels in rat, mouse, bovine and human mammary glands. Studies suggest that in addition to AQP1 and AQP3 AQP4, AQP5 and AQP7 proteins are expressed in different locations in the mammary gland. Aquaporins play key roles in tumor biology and are involved in cell growth, migration and formation of ascites via increased water permeability of micro-vessels. Emerging evidence suggests that expression of these proteins is altered in mammary tumors and in breast cancer cell lines although it is not yet clear whether this is a cause or a consequence of neoplastic development. This review analyzes the expression and potential functional roles of aquaporin water channels in the mammary gland. The physiological mechanisms involved in the transport of water and small solutes across mammary endothelial and epithelial barriers are discussed in the context of milk production and lactation. This paper also reviews papers from the recent cancer literature that implicate aquaporins in mammary neoplasia.

  1. 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.

  2. CELL CONTACTS IN THE MOUSE MAMMARY GLAND

    PubMed Central

    Pitelka, Dorothy R.; Hamamoto, Susan T.; Duafala, Joan G.; Nemanic, Michael K.

    1973-01-01

    The nature and distribution of cell contacts have been examined in thin sections and freeze-fracture replicas of mammary gland samples from female C3H/Crgl mice at stages from birth through pregnancy, lactation, and postweaning involution. Epithelial cells of major mammary ducts at all stages examined are linked at their luminal borders by junctional complexes consisting of tight junctions, variable intermediate junctions, occasional small gap junctions, and one or more series of desmosomes. Scattered desmosomes and gap junctions link ductal epithelial and myoepithelial cells in all combinations; hemidesmosomes attach myoepithelial cells to the basal lamina. Freeze-fracture replicas confirm the erratic distribution of gap junctions and reveal a loose, irregular network of ridges comprising the continuous tight-junctional belts. Alveoli develop early in gestation and initially resemble ducts. Later, as alveoli and small ducts become actively secretory, they lose all desmosomes and most intermediate junctions, whereas tight and gap junctions persist, The tight-junctional network becomes compact and orderly, its undulating ridges oriented predominantly parallel to the luminal surface. It is suggested that these changes in junctional morphology, occurring in secretory cells around parturition, may be related to the greatly enhanced rate of movement of milk precursors and products through the lactating epithelium, or to the profound and recurrent changes in shape of secretory cells that occur in relation to myoepithelial cell contraction, or to both. PMID:4569313

  3. Cooling of heat-stressed cows during the dry period alters lymphocyte but not mammary gland gene expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress (HT) during the dry period compromises mammary gland development, decreases future milk production, and impairs immune status of dairy cows. Our objective was to evaluate the effects of cooling heat-stressed cows during the dry period on gene expression of the mammary gland and lymphocyt...

  4. Distinct FAK activities determine progenitor and mammary stem cell characteristics

    PubMed Central

    Luo, Ming; Zhao, Xiaofeng; Chen, Song; Liu, Suling; Wicha, Max S.; Guan, Jun-Lin

    2013-01-01

    Mammary stem (MaSCs) and progenitor cells are important for mammary gland development and maintenance and may give rise to mammary cancer stem cells (MaCSCs). Yet there remains limited understanding of how these cells contribute to tumorigenesis. Here we show that conditional deletion of focal adhesion kinase (FAK) in embryonic mammary epithelial cells (MaECs) decreases luminal progenitors (LPs) and basal MaSCs, reducing their colony-forming and regenerative potentials in a cell autonomous manner. Loss of FAK kinase activity in MaECs specifically impaired LP proliferation and alveologenesis, whereas a kinase-independent activity of FAK supported ductal invasion and basal MaSC activity. Deficiency in LPs suppressed tumorigenesis and MaCSC formation in a mouse model of breast cancer. In contrast to the general inhibitory effect of FAK attenuation, inhibitors of FAK kinase preferentially inhibited proliferation and tumorsphere formation of LP-like, but not MaSC-like, human breast cancer cells. Our findings establish distinct kinase dependent and independent activities of FAK that differentially regulate LPs and basal MaSCs. We suggest that targeting these distinct functions may tailor therapeutic strategies to address breast cancer heterogeneity more effectively. PMID:23832665

  5. From genes to milk: genomic organization and epigenetic regulation of the mammary transcriptome.

    PubMed

    Lemay, Danielle G; Pollard, Katherine S; Martin, William F; Freeman Zadrowski, Courtneay; Hernandez, Joseph; Korf, Ian; German, J Bruce; Rijnkels, Monique

    2013-01-01

    Even in genomes lacking operons, a gene's position in the genome influences its potential for expression. The mechanisms by which adjacent genes are co-expressed are still not completely understood. Using lactation and the mammary gland as a model system, we explore the hypothesis that chromatin state contributes to the co-regulation of gene neighborhoods. The mammary gland represents a unique evolutionary model, due to its recent appearance, in the context of vertebrate genomes. An understanding of how the mammary gland is regulated to produce milk is also of biomedical and agricultural importance for human lactation and dairying. Here, we integrate epigenomic and transcriptomic data to develop a comprehensive regulatory model. Neighborhoods of mammary-expressed genes were determined using expression data derived from pregnant and lactating mice and a neighborhood scoring tool, G-NEST. Regions of open and closed chromatin were identified by ChIP-Seq of histone modifications H3K36me3, H3K4me2, and H3K27me3 in the mouse mammary gland and liver tissue during lactation. We found that neighborhoods of genes in regions of uniquely active chromatin in the lactating mammary gland, compared with liver tissue, were extremely rare. Rather, genes in most neighborhoods were suppressed during lactation as reflected in their expression levels and their location in regions of silenced chromatin. Chromatin silencing was largely shared between the liver and mammary gland during lactation, and what distinguished the mammary gland was mainly a small tissue-specific repertoire of isolated, expressed genes. These findings suggest that an advantage of the neighborhood organization is in the collective repression of groups of genes via a shared mechanism of chromatin repression. Genes essential to the mammary gland's uniqueness are isolated from neighbors, and likely have less tolerance for variation in expression, properties they share with genes responsible for an organism's survival.

  6. Prevention of Human Mammary Carcinogenesis.

    DTIC Science & Technology

    1996-07-01

    of HER-2/neu oncogene-transformed human mammary epithelial cells by a green tea polyphenol. Breast Cancer Res Treat 38:100; 1996 8. Telang NT, Katdare...apoptosis and anchorage-dependent colony forming efficiency. Appendix Figure 5 (AF-5): Effect of (-) epigallo catechin gallate (EGCG) on 184- B5/HER cells is... tea polyphenol. Ann. NY Acad. Sci. 768: 215- 222, 1995. Appendix Pubilcation 5 (AP-5): Fishman J, Osborne MP, Telang NT. The role of estrogen in

  7. Consequences of epithelial or stromal TGFβ1 depletion in the mammary gland.

    PubMed

    Nguyen, David H; Martinez-Ruiz, Haydeliz; Barcellos-Hoff, Mary Helen

    2011-06-01

    Transforming growth factor β1 (TGFβ) affects stroma and epithelial composition and interactions that mediate mammary development and determine the course of cancer. The reduction of TGFβ in Tgfβ1 heterozygote mice, which are healthy and long-lived, provides an important model to dissect the contribution of TGFβ in mammary gland biology and cancer. We used both intact mice and mammary chimeras in conjunction with Tgfβ1 genetic depletion and TGFβ neutralizing antibodies to evaluate how stromal or epithelial TGFβ depletion affect mammary development and response to physiological stimuli. Our studies of radiation carcinogenesis have revealed new aspects of TGFβ biology and suggest that the paradoxical TGFβ switch from tumor suppressor to tumor promoter can be resolved by assessing distinct stromal versus epithelial actions.

  8. Paradoxical zinc toxicity and oxidative stress in the mammary gland during marginal dietary zinc deficiency

    PubMed Central

    Bostanci, Zeynep; Mack, Ronald P.; Lee, Sooyeon; Soybel, David I.; Kelleher, Shannon L.

    2014-01-01

    Zinc (Zn) regulates numerous cellular functions. Zn deficiency is common in females; ~80% of women and 40% of adolescent girls consume inadequate Zn. Zn deficiency enhances oxidative stress, inflammation and DNA damage. Oxidative stress and inflammation is associated with breast disease. We hypothesized that Zn deficiency increases oxidative stress in the mammary gland, altering the microenvironment and architecture. Zn accumulated in the mammary glands of Zn deficient mice and this was associated with macrophage infiltration, enhanced oxidative stress and over-expression of estrogen receptor α. Ductal and stromal hypercellularity was associated with aberrant collagen deposition and disorganized e-cadherin. Importantly, these microenvironmental alterations were associated with substantial impairments in ductal expansion and mammary gland development. This is the first study to show that marginal Zn deficiency creates a toxic microenvironment in the mammary gland impairing breast development. These changes are consistent with hallmarks of potential increased risk for breast disease and cancer. PMID:25088245

  9. Estrogens in the wrong place at the wrong time: Fetal BPA exposure and mammary cancer.

    PubMed

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

    2015-07-01

    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.

  10. Phyllodes tumor of the breast: role of Axl and ST6GalNAcII in the development of mammary phyllodes tumors.

    PubMed

    Ren, Dongliang; Li, Yanyan; Gong, Yanxin; Xu, Jingchao; Miao, Xiaolong; Li, Xiangnan; Liu, Chen; Jia, Li; Zhao, Yongfu

    2014-10-01

    Phyllodes tumor exhibits an aggressive growth. The expression of many biological markers has been explored to discriminate between different grades of phyllodes tumor and to predict their behavior. The purpose of this study was to evaluate the implications of Axl and ST6GalNAcII in phyllodes tumors. Real-time PCR, Western blot, and immunohistochemical were used to analyze differential expression of ST6GalNAcII and Axl in phyllodes tumor (PT) cell lines and tissue specimens. RNAi assay, ECM invasion assay, and tumorigenicity assay were used to analyze the altered expression of ST6GalNAcII gene effects on the expression of Axl and invasive ability of phyllodes tumor cells in vitro and in vivo. Compared to benign tumors, borderline and malignant ones showed a remarkable increase in mRNA levels of Axl and ST6GalNAcII gene, and it was higher in malignant tumor cells than in borderline tumor cells. When ST6GalNAcII was silenced, compared to the control, the expression level of Axl was significantly reduced in malignant tumor cell transfectants and knockdown of ST6GalNAcII gene significantly inhibited invasive activity in malignant tumor cells. The high expression of ST6GalNAcII and Axl was significantly correlated with tumor grade and distance metastasis by immunohistochemical analysis. Axl and ST6GalNAcII expression increases with increasing tumor grade in mammary phyllodes tumors. ST6GalNAc II might be participated in the glycosylation of Axl, and this Axl glycosylation may mediate the tumorigenicity, invasion, and distant metastasis of PT cells.

  11. Reversible fibroadenomatous mammary hyperplasia in male and female New Zealand white rabbits associated with cyclosporine A administration.

    PubMed

    Krimer, P M; Harvey, S B; Blas-Machado, U; Lauderdale, J D; Moore, P A

    2009-11-01

    All male and female New Zealand white rabbits in a limbal cell graft study developed marked generalized mammary gland hypertrophy. Postprocedural medications included ophthalmic 0.1% dexamethasone, ophthalmic 0.5% cyclosporine, and subcutaneous cyclosporine A. Cytologic examination revealed epithelial clusters with minimal malignant criteria. On histologic evaluation, there was diffuse glandular hyperplasia with mild cellular atypia and ductal ectasia separated by abundant hypercellular fibrous stroma, consistent with fibroadenomatous mammary gland hyperplasia. The hyperplasia resolved within 2 weeks of cessation of cyclosporine, and at necropsy identifiable mammary masses were not found. Very little has been reported about the use of cyclosporine in laboratory rabbits and its association with development of mammary gland hyperplasia. This is the first report in which administration of cyclosporine to male and female rabbits at a dose as low as 5 mg/kg/day induced benign fibroadenomatous mammary gland hyperplasia. This change regressed after cessation of the drug.

  12. Wnt and Neuregulin1/ErbB signalling extends 3D culture of hormone responsive mammary organoids

    PubMed Central

    Jardé, Thierry; Lloyd-Lewis, Bethan; Thomas, Mairian; Kendrick, Howard; Melchor, Lorenzo; Bougaret, Lauriane; Watson, Peter D.; Ewan, Kenneth; Smalley, Matthew J.; Dale, Trevor C.

    2016-01-01

    The development of in vitro culture systems quantitatively and qualitatively recapitulating normal breast biology is key to the understanding of mammary gland biology. Current three-dimensional mammary culture systems have not demonstrated concurrent proliferation and functional differentiation ex vivo in any system for longer than 2 weeks. Here, we identify conditions including Neuregulin1 and R-spondin 1, allowing maintenance and expansion of mammary organoids for 2.5 months in culture. The organoids comprise distinct basal and luminal compartments complete with functional steroid receptors and stem/progenitor cells able to reconstitute a complete mammary gland in vivo. Alternative conditions are also described that promote enrichment of basal cells organized into multiple layers surrounding a keratinous core, reminiscent of structures observed in MMTV-Wnt1 tumours. These conditions comprise a unique tool that should further understanding of normal mammary gland development, the molecular mechanism of hormone action and signalling events whose deregulation leads to breast tumourigenesis. PMID:27782124

  13. 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

  14. 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

  15. Targeting the Prometastatic Microenvironment of the Involuting Mammary Gland

    DTIC Science & Technology

    2014-09-01

    breast-cancer-research.com/content/15/6/R111induces ductal morphogenesis, differentiation of nipple epithelium and suppression of hair follicles ...LacZ expression (blue stain) in the mammary rudiments (white arrows) and developing hair follicles (red arrowheads). (B) Nuclear fast red (NFR...to inhibit hair follicle induction. Development 2007, 134:1221–1230. 56. Noguera I, Obata H, Gualandris A, Cowin P, Rifkin DB: Molecular cloning of

  16. Effect of Estrogen on Mutagenesis in Human Mammary Epithelial Cells

    DTIC Science & Technology

    2005-06-01

    estrogen signaling through the estrogen receptor alpha (ERa) may induce a mutator phenotype by suppressing DNA repair activity in ERa positive mammary...measure DNA MMR activity in live cells. We have also developed a method to measure mutation rate as a function of estrogen/ER signaling . Our goals were to...whether 1713-estradiol signaling through ER inhibits DNA MMR activity, we developed a method that can quantitatively assess MMR efficiency in live

  17. Aurora kinase-A overexpression in mouse mammary epithelium induces mammary adenocarcinomas harboring genetic alterations shared with human breast cancer.

    PubMed

    Treekitkarnmongkol, Warapen; Katayama, Hiroshi; Kai, Kazuharu; Sasai, Kaori; Jones, Jennifer Carter; Wang, Jing; Shen, Li; Sahin, Aysegul A; Gagea, Mihai; Ueno, Naoto T; Creighton, Chad J; Sen, Subrata

    2016-12-01

    Recent data from The Cancer Genome Atlas analysis have revealed that Aurora kinase A (AURKA) amplification and overexpression characterize a distinct subset of human tumors across multiple cancer types. Although elevated expression of AURKA has been shown to induce oncogenic phenotypes in cells in vitro, findings from transgenic mouse models of Aurora-A overexpression in mammary glands have been distinct depending on the models generated. In the present study, we report that prolonged overexpression of AURKA transgene in mammary epithelium driven by ovine β-lactoglobulin promoter, activated through multiple pregnancy and lactation cycles, results in the development of mammary adenocarcinomas with alterations in cancer-relevant genes and epithelial-to-mesenchymal transition. The tumor incidence was 38.9% (7/18) in Aurora-A transgenic mice at 16 months of age following 4-5 pregnancy cycles. Aurora-A overexpression in the tumor tissues accompanied activation of Akt, elevation of Cyclin D1, Tpx2 and Plk1 along with downregulation of ERα and p53 proteins, albeit at varying levels. Microarray comparative genomic hybridization (CGH) analyses of transgenic mouse mammary adenocarcinomas revealed copy gain of Glp1r and losses of Ercc5, Pten and Tcf7l2 loci. Review of human breast tumor transcriptomic data sets showed association of these genes at varying levels with Aurora-A gain of function alterations. Whole exome sequencing of the mouse tumors also identified gene mutations detected in Aurora-A overexpressing human breast cancers. Our findings demonstrate that prolonged overexpression of Aurora-A can be a driver somatic genetic event in mammary adenocarcinomas associated with deregulated tumor-relevant pathways in the Aurora-A subset of human breast cancer.

  18. 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.

  19. Met Receptor Acts Uniquely for Survival and Morphogenesis of EGFR-Dependent Normal Mammary Epithelial and Cancer Cells

    PubMed Central

    Bersani, Francesca; Quaglino, Elena; Martignani, Eugenio; Baratta, Mario

    2012-01-01

    Mammary gland development and breast cancer growth require multiple factors both of endocrine and paracrine origin. We analyzed the roles of Epidermal Growth Factor Receptor (EGFR) and Hepatocyte Growth Factor Receptor (Met) in mammary epithelial cells and mammary tumor cells derived from a mutated-ErbB2 transgenic mice. By using highly specific tyrosine kinase inhibitors we found that MCF-10A and NMuMG mammary epithelial cell lines are totally dependent on EGFR activation for their growth and survival. Proliferation and 3D-morphogenesis assays showed that HGF had no role in maintaining mammary cell viability, but was the only cytokine able to rescue EGFR-inhibited mammary cells. Insulin-Like Growth Factor-I (IGF-I), basic-Fibroblast Growth Factor (b-FGF) and Neuregulin, which are well known mammary morphogenic factors, did not rescue proliferation or morphogenesis in these cell lines, following EGFR inhibition. Similarly, ErbB2-driven tumor cells are EGFR-dependent and also display HGF-mediated rescue. Western-blot analysis of the signaling pathways involved in rescue after EGFR inhibition indicated that concomitant ERK1/2 and AKT activation was exclusively driven by Met, but not by IGF-I or b-FGF. These results describe a unique role for EGFR and Met in mammary epithelial cells by showing that similar pathways can be used by tumorigenic cells to sustain growth and resist to EGFR-directed anti-tumorigenic drugs. PMID:23028720

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

    SciTech Connect

    Simian, Marina; Hirai, Yohei; Navre, Marc; Werb, Zena; Lochter, Andre; Bissell, Mina 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.

  1. 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.

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

    PubMed

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

    2009-10-01

    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. ERalpha 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.

  3. 9 CFR 310.17 - Inspection of mammary glands.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Inspection of mammary glands. 310.17... INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.17 Inspection of mammary glands. (a) Lactating mammary glands and diseased mammary glands of cattle, sheep, swine, and goats shall be removed...

  4. 9 CFR 310.17 - Inspection of mammary glands.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Inspection of mammary glands. 310.17... INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.17 Inspection of mammary glands. (a) Lactating mammary glands and diseased mammary glands of cattle, sheep, swine, and goats shall be removed...

  5. 9 CFR 310.17 - Inspection of mammary glands.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Inspection of mammary glands. 310.17... INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.17 Inspection of mammary glands. (a) Lactating mammary glands and diseased mammary glands of cattle, sheep, swine, and goats shall be removed...

  6. 9 CFR 310.17 - Inspection of mammary glands.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Inspection of mammary glands. 310.17... INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.17 Inspection of mammary glands. (a) Lactating mammary glands and diseased mammary glands of cattle, sheep, swine, and goats shall be removed...

  7. 9 CFR 310.17 - Inspection of mammary glands.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Inspection of mammary glands. 310.17... INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.17 Inspection of mammary glands. (a) Lactating mammary glands and diseased mammary glands of cattle, sheep, swine, and goats shall be removed...

  8. Mammary carcinogen-protein binding potentials: novel and biologically relevant structure-activity relationship model descriptors.

    PubMed

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

    2010-07-01

    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 oestrogenic 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.

  9. Estrogen decreases chemokine levels in murine mammary tissue: implications for the regulatory role of MIP-1 alpha and MCP-1/JE in mammary tumor formation.

    PubMed

    Fanti, Peter; Nazareth, Michael; Bucelli, Robert; Mineo, Michael; Gibbs, Kathleen; Kumin, Michael; Grzybek, Kevin; Hoeltke, Janice; Raiber, Lisa; Poppenberg, Kristin; Janis, Kelly; Schwach, Catherine; Aronica, Susan M

    2003-11-01

    Estrogen contributes to the development of breast cancer through mechanisms that are not completely understood. Estrogen influences the function of immune effector cells, primarily through alterations in cytokine expression. Chemokines are proinflammatory cytokines that attract various immune cells to the site of tissue injury or inflammation, and activate many cell types, including T lymphocytes and monocytes. As an initial step toward ultimately determining whether regulation of chemokine expression and/or biological activity by estrogen could potentially be a contributing factor to the development and progression of mammary tumors, we evaluated the effect of estrogen on the expression of specific chemokines in murine mammary tissue. We also evaluated whether exposure of female mice to various chemokines could alter the growth of mammary tumors in the presence of estrogen. We report here that estrogen significantly decreases levels of the chemokines MIP-1alpha and MCP-1/JE in murine mammary tissue. Co-treatment with 4-hydroxytamoxifen partially reverses the suppressive effect of estrogen on MIP-1alpha levels. Estrogen increases the growth of CCL- 51 cell-based tumors in the mammary glands of female mice. Co-treatment with the chemokine MIP-1alpha or MCP- 1/JE substantially decreases the ability of estrogen to stimulate the formation of CCL-51 cell-based tumors. Our results show that estrogen might influence the bioactivity of specific chemokines through alteration of chemokine expression in mammary tissue, and further suggest that decreases in murine chemokines evoked by estrogen exposure could contribute to the promotion of mammary tumor growth.

  10. Metabotropic glutamate receptor 1 disrupts mammary acinar architecture and initiates malignant transformation of mammary epithelial cells

    PubMed Central

    Teh, Jessica L. F.; Shah, Raj; La Cava, Stephanie; Dolfi, Sonia C.; Mehta, Madhura S.; Kongara, Sameera; Price, Sandy; Ganesan, Shridar; Reuhl, Kenneth R.; Hirshfield, Kim M.

    2016-01-01

    Metabotropic glutamate receptor 1 (mGluR1/Grm1) is a member of the G-protein-coupled receptor superfamily, which was once thought to only participate in synaptic transmission and neuronal excitability, but has more recently been implicated in non-neuronal tissue functions. We previously described the oncogenic properties of Grm1 in cultured melanocytes in vitro and in spontaneous melanoma development with 100 % penetrance in vivo. Aberrant mGluR1 expression was detected in 60–80 % of human melanoma cell lines and biopsy samples. As most human cancers are of epithelial origin, we utilized immortalized mouse mammary epithelial cells (iMMECs) as a model system to study the transformative properties of Grm1. We introduced Grm1 into iMMECs and isolated several stable mGluR1-expressing clones. Phenotypic alterations in mammary acinar architecture were assessed using three-dimensional morphogenesis assays. We found that mGluR1-expressing iMMECs exhibited delayed lumen formation in association with decreased central acinar cell death, disrupted cell polarity, and a dramatic increase in the activation of the mitogen-activated protein kinase pathway. Orthotopic implantation of mGluR1-expressing iMMEC clones into mammary fat pads of immunodeficient nude mice resulted in mammary tumor formation in vivo. Persistent mGluR1 expression was required for the maintenance of the tumorigenic phenotypes in vitro and in vivo, as demonstrated by an inducible Grm1-silencing RNA system. Furthermore, mGluR1 was found be expressed in human breast cancer cell lines and breast tumor biopsies. Elevated levels of extracellular glutamate were observed in mGluR1-expressing breast cancer cell lines and concurrent treatment of MCF7 xenografts with glutamate release inhibitor, riluzole, and an AKT inhibitor led to suppression of tumor progression. Our results are likely relevant to human breast cancer, highlighting a putative role of mGluR1 in the pathophysiology of breast cancer and the potential

  11. Mammary Malignancy in The Male

    PubMed Central

    Alexander, Leslie L.; Benninghoff, David L.; Camiel, Mortimer R.; Medina, Antonio

    1978-01-01

    Mammary carcinoma in the male, a relatively uncommon disease, represents about 0.9 to 1.5 percent of all breast cancers. 1,2 The authors reviewed 16 cases of male breast cancer seen in a 30-year period at the State University of New York, Kings County Hospital Medical Center in Brooklyn, and the North Shore University Hospital in Manhasset. Epidemiology, etiology, demography, signs and symptoms, management, and prognosis are discussed. A review of pertinent literature is presented. ImagesFigure 1Figure 2 PMID:722829

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

    PubMed

    Montales, Maria Theresa E; Rahal, Omar M; Nakatani, Hajime; Matsuda, Tsukasa; Simmen, Rosalia C M

    2013-07-01

    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 in rodent breast cancer models. Despite the suggested linkage between obesity and breast cancer, the local influence of bioactive dietary components on mammary adiposity for antitumor effects remains unknown. Herein, we report that post-weaning dietary exposure to soy protein isolate and its bioactive isoflavone genistein (GEN) lowered mammary adiposity and increased mammary tumor suppressor PTEN and E-cadherin expression in female mice, relative to control casein diet. To ascertain GEN's role in mammary adipose deposition that may affect underlying epithelial cell phenotype, we evaluated GEN's effects on SV40-immortalized mouse mammary stromal fibroblast-like (MSF) cells during differentiation into adipocytes. MSF cells cultured in a differentiation medium with 40 nM GEN showed reductions in mature adipocyte numbers, triglyceride accumulation, and Pparγ (Pparg) and fatty acid synthase transcript levels. GEN inhibition of adipose differentiation was accompanied by increased estrogen receptor β (Erβ (Esr2)) gene expression and was modestly recapitulated by ERβ-selective agonist 2,3-bis-(4-hydroxyphenyl)-propionitrile (DPN). Reduction of Erβ expression by siRNA targeting increased Pparγ transcript levels and stromal fibroblast differentiation into mature adipocytes; the latter was reversed by GEN but not by DPN. Conditioned medium from GEN-treated adipocytes diminished anchorage-independent mammosphere formation of human MCF-7 breast cancer cells. Our results suggest a mechanistic pathway to support direct regulation of mammary adiposity by GEN for breast cancer prevention.

  13. 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.

  14. Genetic Susceptibility to Estrogen-Induced Mammary Cancers

    DTIC Science & Technology

    2001-11-01

    Susceptibility to Estrogen -Induced Mammary Cancers PRINCIPAL INVESTIGATOR: Dr. James D. Shull CONTRACTING ORGANIZATION: University of Nebraska Medical Center Omaha...DATES COVERED blank) November 2001 Final (01 Oct 98 - 01 Oct 01) 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Genetic Susceptibility to Estrogen -Induced...Street, Fort Detrick, Maryland 21702-5012. 13. ABSTRACT (Maximum 200 Words) Estrogens are important in the etiology of breast cancer. We have developed

  15. Clonogenic assay allows for selection of a primitive mammary epithelial cell population in bovine.

    PubMed

    Martignani, Eugenio; Cravero, Diego; Miretti, Silvia; Accornero, Paolo; Baratta, Mario

    2015-11-01

    Adult mammary stem cells have been identified in several species including the bovine. They are responsible for the development of the gland and for cyclic remodeling during estrous cycles and pregnancy. Epithelial cell subpopulations exist within the mammary gland. We and others showed previously that the Colony Forming Cell (CFC) assay can be used to detect lineage-restricted mammary progenitors. We carried out CFCs with bovine mammary cells and manually separated colonies with specific morphologies associated with either a luminal or a myoepithelial phenotype. Expression of specific markers was assessed by immunocytochemistry or by flow cytometry to confirm that the manual separation resulted in isolation of phenotipically different cells. When transplanted in recipient immunodeficient mice, we found that only myoepithelial-like colonies gave rise to outgrowths that resembled bovine mammary alveoli, thus proving that adult stem cells were maintained during culture and segregated with myoepithelial cells. After recovery of the cells from the transplanted mice and subsequent progenitor content analysis, we found a tendency to detect a higher progenitor frequency when myoepithelial-like colonies were transplanted. We here demonstrate that bovine adult mammary stem cells can be sustained in short-term culture and that they can be enriched by manually selecting for basal-like morphology.

  16. Progesterone receptors in normal mammary gland: receptor modulations in relation to differentiation

    PubMed Central

    1980-01-01

    The biological basis for the observed modulation in cytoplasmic progesterone receptors (PgR) of normal mammary gland occurring during mammary development was investigated. Specifically, the relative roles of hormones vs. differentiation on (a) the decrease in PgR concentration during pregnancy and lactation and (b) the loss of mammary responsiveness to estrogen during lactation were examined. PgR were measured using the synthetic progestin, R5020, as the ligand. The hormones estrogen and progesterone were tested in vivo for their effect of PgR concentration. Mammary gland differentiation was assessed morphologically and by measuring enzymatically active alpha- lactalbumin. These studies show that there is a stepwise decrease in PgR that occurs in two stages. The first decrease is completed by day 12 of pregnancy and the second decrease occurs only after parturition. There appears to be a hormonal basis for the first decrease and it appears to be caused by the negative effect of progesterone on estrogen- mediated increase in PgR. In direct contrast, the absence of PgR during lactation and the mammary tissue insensitivity to estrogenic stimulation of PgR were not related to the hormonal milieu of lactation but were directly related to the secretory state of the mammary gland and lactation per se. PMID:7410476

  17. 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.

  18. Form and function: how estrogen and progesterone regulate the mammary epithelial hierarchy.

    PubMed

    Arendt, Lisa M; Kuperwasser, Charlotte

    2015-06-01

    The mammary gland undergoes dramatic post-natal growth beginning at puberty, followed by full development occurring during pregnancy and lactation. Following lactation, the alveoli undergo apoptosis, and the mammary gland reverses back to resemble the nonparous gland. This process of growth and regression occurs for multiple pregnancies, suggesting the presence of a hierarchy of stem and progenitor cells that are able to regenerate specialized populations of mammary epithelial cells. Expansion of epithelial cell populations in the mammary gland is regulated by ovarian steroids, in particular estrogen acting through its receptor estrogen receptor alpha (ERα) and progesterone signaling through progesterone receptor (PR). A diverse number of stem and progenitor cells have been identified based on expression of cell surface markers and functional assays. Here we review the current understanding of how estrogen and progesterone act together and separately to regulate stem and progenitor cells within the human and mouse mammary tissues. Better understanding of the hierarchal organization of epithelial cell populations in the mammary gland and how the hormonal milieu affects its regulation may provide important insights into the origins of different subtypes of breast cancer.

  19. /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)

  20. Cellular quiescence in mammary stem cells and breast tumor stem cells: got testable hypotheses?

    PubMed

    Harmes, David C; DiRenzo, James

    2009-03-01

    Cellular quiescence is a state of reversible cell cycle arrest and has more recently been shown to be a blockade to differentiation and to correlate with resistance to cancer chemotherapeutics and other xenobiotics; features that are common to adult stem cells and possibly tumor stem cells. The biphasic kinetics of mammary regeneration, coupled to its cyclic endocrine control suggest that mammary stem cells most likely divide during a narrow window of the regenerative cycle and return to a state of quiescence. This would enable them to retain their proliferative capacity, resist differentiation signals and preserve their prolonged life span. There is accumulating evidence that mammary stem cells and other adult stem cells utilize quiescence for this purpose, however the degree to which tumor stem cells do so is largely unknown. The retained proliferative capacity of mammary stem cells likely enables them to accumulate and harbor mutations that lead to breast cancer initiation. However it is currently unclear if these causative lesions lead to defective or deranged quiescence in mammary stem cells. Evidence of such effects could potentially lead to the development of diagnostic systems that monitor mammary stem cell quiescence or activation. Such systems may be useful for the evaluation of patients who are at significant risk of breast cancer. Additionally quiescence has been postulated to contribute to therapeutic resistance and tumor recurrence. This review aims to evaluate what is known about the mechanisms governing cellular quiescence and the role of tumor stem cell quiescence in breast cancer recurrence.

  1. A novel effect of dioxin: exposure during pregnancy severely impairs mammary gland differentiation.

    PubMed

    Vorderstrasse, Beth A; Fenton, Suzanne E; Bohn, Andrea A; Cundiff, Jennifer A; Lawrence, B Paige

    2004-04-01

    Many ligands for the aryl hydrocarbon receptor (AhR) are considered endocrine disruptors and carcinogens, and assessment of adverse health effects in humans exposed to such chemicals has often focused on malignancies, including breast cancer. Mammary tissue contains the AhR, and inappropriate activation of the AhR during fetal development causes defects in mammary development that persist into adulthood. However, it is not known whether the extensive differentiation of mammary tissue that occurs during pregnancy is also sensitive to disruption by AhR activation. To examine this, we exposed pregnant C57Bl/6 mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on days 0, 7, and 14 of pregnancy. Examination of mammary glands on days 9, 12, and 17 of pregnancy and on the day of parturition showed severe defects in development, including stunted growth, decreased branching, and poor formation of lobular alveolar structures. This impaired differentiation was biologically significant, as expression of whey acidic protein in the gland was suppressed, and all pups born to TCDD-treated dams died within 24 h of birth. Analysis of circulating progesterone, prolactin, and estradiol suggest that hormone production was slightly impaired by inappropriate activation of the AhR. However, hormone levels were affected only very late in pregnancy. Given that the observed defects in gland development preceded these hormonal effects, altered hormone levels are an unlikely mechanistic explanation for impaired mammary development. This novel finding that AhR activation during pregnancy disrupts mammary gland differentiation raises questions about the susceptibility of mammary tissue to direct injury by endocrine disrupting agents and the potential for AhR-mediated signaling to adversely affect lactation and breast tissue development in human populations.

  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. Hedgehog signaling in the normal and neoplastic mammary gland.

    PubMed

    Visbal, Adriana P; Lewis, Michael T

    2010-09-01

    The hedgehog signal transduction network is a critical regulator of metazoan development. Inappropriate activation of this network is implicated in several different cancers, including breast. Genetic evidence in mice as well as molecular biological studies in human cells clearly indicate that activated signaling can lead to mammary hyperplasia and, in some cases, tumor formation. However, the exact role(s) activated hedgehog signaling plays in the development or progression of breast cancer also remain unclear. In this review, we have discussed recent data regarding the mechanism(s) by which the hedgehog network may signal in the mammary gland, as well as the data implicating activated signaling as a contributing factor to breast cancer development. Finally, we provide a brief update on the available hedgehog signaling inhibitors with respect to ongoing clinical trials, some of which will include locally advanced or metastatic breast cancers. Given the growing intensity with which the hedgehog signaling network is being studied in the normal and neoplastic mammary gland, a more complete understanding of this network should allow more effective targeting of its activities in breast cancer treatment or prevention.

  4. 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.

  5. Proteomic Analysis of Genistein Mammary Cancer

    DTIC Science & Technology

    2005-07-01

    pathways we found up-regulated P-ERK-1, but no significant short-term changes in the tyrosine hydroxylase and iNOS protein expressions in mammary glands...of 21 day old rats. At day 50, there was significant up-regulation of tyrosine hydroxylase and VEGF-R2. This and previous work suggests that early...mammary glands of 21 day old rats only. In 50 day old rats, mammary tyrosine hydroxylase protein expression was up- regulated and now we report that

  6. 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.

  7. 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.

  8. Reduced circulating insulin-like growth factor I levels delay the onset of chemically and genetically induced mammary tumors.

    PubMed

    Wu, Yiping; Cui, Karen; Miyoshi, Keiko; Hennighausen, Lothar; Green, Jeffrey E; Setser, Jennifer; LeRoith, Derek; Yakar, Shoshana

    2003-08-01

    Insulin-like growth factors (IGFs) play a crucial role in regulating cell proliferation and differentiation. The aim of this study was to examine the potential relationship between serum IGF-I levels and breast cancer risk. To do this, we studied liver-specific IGF-I gene-deleted (LID) mice, in which circulating IGF-I levels are 25% of that in control mice. Mammary tumors were induced in two ways: (a) by exposing mice to the carcinogen 7,12-dimethybenz (a)anthracene; and (b) by crossing LID mice with C3(1)/SV40 large T-antigen transgenic mice. In both models, LID mice exhibited a delayed latency period of mammary tumor development. In the 7,12-dimethybenz (a)anthracene-induced mammary tumor model, the incidence of palpable mammary tumors was significantly lower in LID mice (26% versus 56% in controls), and the onset of the tumors was delayed (74 +/- 1.2 days in LID mice versus 59.5 +/- 1.1 days in controls). Histological analysis showed extensive squamous metaplasia in late-stage mammary tumors of control mice, whereas late-stage tumors from LID mice exhibited extensive hyperplasia, but little metaplasia. In control mice, the onset of C3(1)/SV40-large T-antigen-induced mammary tumors occurred at 21.6 +/- 1.8 weeks of age, whereas in LID mice the average age of onset was 30.2 +/- 1.7 weeks. In addition, 60% of the mice in the control group developed two or more mammary tumors per mouse, whereas in the LID mice only 30% developed more than one mammary tumor per mouse. Our data demonstrate that circulating IGF-I levels play a significant role as a risk factor in the onset and development of mammary tumors in two well-established animal models of breast cancer.

  9. Mammary Gland Evaluation in Juvenile Toxicity Studies: Temporal Developmental Patterns in the Male and Female Harlan Sprague-Dawley Rat.

    PubMed

    Filgo, Adam J; Foley, Julie F; Puvanesarajah, Samantha; Borde, Aditi R; Midkiff, Bentley R; Reed, Casey E; Chappell, Vesna A; Alexander, Lydia B; Borde, Pretish R; Troester, Melissa A; Bouknight, Schantel A Hayes; Fenton, Suzanne E

    2016-10-01

    There are currently no reports describing mammary gland development in the Harlan Sprague-Dawley (HSD) rat, the current strain of choice for National Toxicology Program (NTP) testing. Our goals were to empower the NTP, contract labs, and other researchers in understanding and interpreting chemical effects in this rat strain. To delineate similarities/differences between the female and male mammary gland, data were compiled starting on embryonic day 15.5 through postnatal day 70. Mammary gland whole mounts, histology sections, and immunohistochemically stained tissues for estrogen, progesterone, and androgen receptors were evaluated in both sexes; qualitative and quantitative differences are highlighted using a comprehensive visual timeline. Research on endocrine disrupting chemicals in animal models has highlighted chemically induced mammary gland anomalies that may potentially impact human health. In order to investigate these effects within the HSD strain, 2,3,7,8-tetrachlorodibenzo-p-dioxin, diethylstilbestrol, or vehicle control was gavage dosed on gestation day 15 and 18 to demonstrate delayed, accelerated, and control mammary gland growth in offspring, respectively. We provide illustrations of normal and chemically altered mammary gland development in HSD male and female rats to help inform researchers unfamiliar with the tissue and may facilitate enhanced evaluation of both male and female mammary glands in juvenile toxicity studies.

  10. Hoxc8 initiates an ectopic mammary program by regulating Fgf10 and Tbx3 expression and Wnt/β-catenin signaling

    PubMed Central

    Carroll, Lara S.; Capecchi, Mario R.

    2015-01-01

    The role of Hox genes in the formation of cutaneous accessory organs such as hair follicles and mammary glands has proved elusive, a likely consequence of overlapping function and expression among various homeobox factors. Lineage and immunohistochemical analysis of Hoxc8 in mice revealed that this midthoracic Hox gene has transient but strong regional expression in ventrolateral surface ectoderm at E10.5, much earlier than previously reported. Targeted mice were generated to conditionally misexpress Hoxc8 from the Rosa locus using select Cre drivers, which significantly expanded the domain of thoracic identity in mutant embryos. Accompanying this expansion was the induction of paired zones of ectopic mammary development in the cervical region, which generated between three and five pairs of mammary placodes anterior to the first wild-type mammary rudiment. These rudiments expressed the mammary placode markers Wnt10b and Tbx3 and were labeled by antibodies to the mammary mesenchyme markers ERα and androgen receptor. Somitic Fgf10 expression, which is required for normal mammary line formation, was upregulated in mutant cervical somites, and conditional ablation of ectodermal Tbx3 expression eliminated all normally positioned and ectopic mammary placodes. We present evidence that Hoxc8 participates in regulating the initiation stages of mammary placode morphogenesis, and suggest that this and other Hox genes are likely to have important roles during regional specification and initiation of these and other cutaneous accessory organs. PMID:26459221

  11. Trace element transport in the mammary gland.

    PubMed

    Lönnerdal, Bo

    2007-01-01

    The mammary gland has a remarkable capacity to adapt to maternal deficiency or excess of iron, copper, and zinc and to homeostatically control milk concentrations of these essential nutrients. Similarly, it can regulate changes in concentrations of iron, copper, and zinc change during lactation. For iron, this regulation is achieved by transferrin receptor, DMT1, and ferroportin, whereas mammary gland copper metabolism is regulated by Ctr1, ATP7A, and ATP7B. Zinc homeostasis is complex, involving both zinc importers (Zip3) and zinc exporters (ZnT-1, ZnT-2, and ZnT-4). Both transcriptional and post-translational regulation can affect protein abundance and cellular localization of these transporters, finely orchestrating uptake, intracellular trafficking, and secretion of iron, copper, and zinc. The control of mammary gland uptake and milk secretion of iron, copper, and zinc protects both the mammary gland and the breast-fed infant against deficiency and excess of these nutrients.

  12. Gordon Research Conference on Mammary Gland Biology

    SciTech Connect

    Not Available

    1989-01-01

    The 1989 conference was the tenth in the series of biennial Gordon Research Conferences on Mammary Gland Biology. Traditionally this conference brings together scientists from diverse backgrounds and experience but with a common interest in the biology of the mammary gland. Investigators from agricultural and medical schools, biochemists, cell and molecular biologists, endocrinologists, immunologists, and representatives from the emerging biotechnology industries met to discuss current concepts and results on the function and regulation of the normal and neoplastic mammary gland in a variety of species. Of the participants, approximately three-fourths were engaged in studying the normal mammary gland function, whereas the other quarter were engaged in studying the neoplastic gland. The interactions between scientists, clinicians, veterinarians examining both normal and neoplastic cell function serves to foster the multi-disciplinary goals of the conference and has stimulated many cooperative projects among participants in previous years.

  13. Mammary fibroadenoma in a lamb

    PubMed Central

    Guvenc, Tolga; Yarim, Murat; Kabak, Yonca B.; Sozgen, Yuksel

    2007-01-01

    A fibroadenoma was diagnosed in the left udder of a 3-month-old female Chios lamb. No recurrence was observed after surgery. Grossly, the tumor had a whitish-gray lobular appearance, and the lobules were interlaced with thin septa. Microscopically, the tumor was composed of proliferating fibroepithelial tissue, including differentiated ducts lined by whorls and interlacing bundles of abundant loose fibrovascular stroma. Immunohistochemistry revealed the ductal epithelium to be positive for pancytokeratin (AE1/AE3) and loose fibrovascular stroma was positive for vimentin and basal cells covering the ductal epithelium of alpha-smooth-muscle actin. Immunostaining for the estrogen and progesterone receptors was negative. A diagnosis of mammary fibroadenoma was made based on the histological and immunohistochemical findings. PMID:17993758

  14. Identification of Mammary Specific Transcription Factors.

    DTIC Science & Technology

    1998-01-01

    per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...release; distribution unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (Maximum 200 words) The Mouse Mammary Tumor Virus (MMTV) achieves its highest...levels of expression in the mammary glands of lactating mice . Previous work showed that the MMTV Long Terminal Repeat (LTR) has a modest level of

  15. Genetic ablation of the fatty acid binding protein FABP5 suppresses HER2-induced mammary tumorigenesis

    PubMed Central

    Levi, Liraz; Lobo, Glenn; Doud, Mary Kathryn; von Lintig, Johannes; Seachrist, Darcie; Tochtrop, Gregory P.; Noy, Noa

    2014-01-01

    The fatty acid binding protein FABP5 shuttles ligands from the cytosol to the nuclear receptor PPARβ/δ (encoded for by Pparδ), thereby enhancing the transcriptional activity of the receptor. This FABP5/PPARδ pathway is critical for induction of proliferation of breast carcinoma cells by activated EGFR. In this study, we show that FABP5 is highly upregulated in human breast cancers and we provide genetic evidence of the pathophysiological significance of FABP5 in mammary tumorigenesis. Ectopic expression of FABP5 was found to be oncogenic in 3T3 fibroblasts where it augmented the ability of PPARδ to enhance cell proliferation, migration and invasion. To determine whether FABP5 was essential for EGFR-induced mammary tumor growth, we interbred FABP5-null mice with MMTV-ErbB2/HER2 oncomice which spontaneously develop mammary tumors. FABP5 ablation relieved activation of EGFR downstream effector signals, decreased expression of PPARδ target genes that drive cell proliferation, and suppressed mammary tumor development. Our findings establish that FABP5 is critical for mammary tumor development, rationalizing the development of FABP5 inhibitors as novel anticarcinogenic drugs. PMID:23722546

  16. The effects of spaceflight on mammary metabolism in pregnant rats

    NASA Technical Reports Server (NTRS)

    Plaut, K.; Maple, R.; Vyas, C.; Munaim, S.; Darling, A.; Casey, T.; Alberts, J. R.

    1999-01-01

    The effects of spaceflight on mammary metabolism of 10 pregnant rats was measured on Day 20 of pregnancy and after parturition. Rats were flown on the space shuttle from Day 11 through Day 20 of pregnancy. After their return to earth, glucose oxidation to carbon dioxide increased 43% (P < 0.05), and incorporation into fatty acids increased 300% (P < 0.005) compared to controls. It is unclear whether the enhanced glucose use is due to spaceflight or a response to landing. Casein mRNA and gross histology were not altered at Day 20 of pregnancy. Six rats gave birth (on Day 22 to 23 of pregnancy) and mammary metabolic activity was measured immediately postpartum. The earlier effects of spaceflight were no longer apparent. There was also no difference in expression of beta-casein mRNA. It is clear from these studies that spaceflight does not impair the normal development of the mammary gland, its ability to use glucose, nor the ability to express mRNA for a major milk protein.

  17. Genistein chemoprevention: timing and mechanisms of action in murine mammary and prostate.

    PubMed

    Lamartiniere, Coral A; Cotroneo, Michelle S; Fritz, Wayne A; Wang, Jun; Mentor-Marcel, Roycelynn; Elgavish, Ada

    2002-03-01

    We investigated the potential of genistein, the primary isoflavone of soy, to protect against breast and prostate cancers in animal models. For mammary cancer studies, Sprague-Dawley rats were fed AIN-76A diet plus minus 250 mg genistein/kg diet. Dimethylbenz[a]anthracene was administered by gavage at d 50 postpartum to induce mammary tumors. Mammary cancer chemoprevention was demonstrated after prepubertal and combined prepubertal and adult genistein treatments but not after prenatal- or adult-only treatments, demonstrating that the timing of exposure to genistein is important for mammary cancer chemoprevention. The cellular mechanism of action was found to be mammary gland and cell differentiation, as shown by whole-mount analysis and beta-casein expression. An imprinting effect was shown for epidermal growth factor receptor expression in mammary terminal end buds. For prostate cancer studies, we used two models. The first was a chemically (N-methylnitrosourea) induced prostate cancer rat model. Genistein in the diet inhibited the development of invasive adenocarcinomas in a dose-dependent manner. The second model was a transgenic mouse model that resulted in spontaneously developing adenocarcinoma tumor of the prostate. Genistein in the diet reduced the incidence of poorly differentiated prostatic adenocarcinomas in a dose-dependent manner and down-regulated androgen receptor, estrogen receptor-alpha, progesterone receptor, epidermal growth factor receptor, insulin-like growth factor-I, and extracellular signal-regulated kinase-1 but not estrogen receptor-beta and transforming growth factor-alpha mRNA expressions. We conclude that dietary genistein protects against mammary and prostate cancers by regulating specific sex steroid receptors and growth factor signaling pathways.

  18. Mammary glands exhibit molecular laterality and undergo left-right asymmetric ductal epithelial growth in MMTV-cNeu mice.

    PubMed

    Robichaux, J P; Hallett, R M; Fuseler, J W; Hassell, J A; Ramsdell, A F

    2015-04-09

    Significant left-right (L-R) differences in tumor incidence and disease outcome occur for cancers of paired organs, including the breasts; however, the basis for this laterality is unknown. Here, we show that despite their morphologic symmetry, left versus right mammary glands in wild-type mice have baseline differences in gene expression that are L-R independently regulated during pubertal development, including genes that regulate luminal progenitor cell renewal, luminal cell differentiation, mammary tumorigenesis, tamoxifen sensitivity and chemotherapeutic resistance. In MMTV-cNeu(Tg/Tg) mice, which model HER2/Neu-amplified breast cancer, baseline L-R differences in mammary gene expression are amplified, sustained or inverted in a gene-specific manner and the mammary ductal epithelium undergoes L-R asymmetric growth and patterning. Comparative genomic analysis of mouse L-R mammary gene expression profiles with gene expression profiles of human breast tumors revealed significant linkage between right-sided gene expression and decreased breast cancer patient survival. Collectively, these findings are the first to demonstrate that mammary glands are lateralized organs, and, moreover, that mammary glands have L-R differential susceptibility to HER2/Neu oncogene-mediated effects on ductal epithelial growth and differentiation. We propose that intrinsic molecular laterality may have a role in L-R asymmetric breast tumor incidence and, furthermore, that interplay between the L-R molecular landscape and oncogene activity may contribute to the differential disease progression and patient outcome that are associated with tumor situs.

  19. Involvement of Connective Tissue Growth Factor (CTGF) in Insulin-like Growth Factor-I (IGF1) Stimulation of Proliferation of a Bovine Mammary Epithelial Cell Line

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insulin-like growth factor I (IGF1) plays an important role in mammary gland development and lactation in part by stimulating proliferation of the milk-producing epithelial cells. In this study, we used the bovine mammary epithelial cell line MAC-T cells as a model to understand the mechanism by whi...

  20. Short Communication: Effect of heat stress during the dry period on gene expression in mammary tissue and peripheral blood mononuclear cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress (HT) during the dry period compromises mammary gland development, decreases future milk production, and impairs immune status of dairy cows. Our objective was to evaluate the effect of cooling HT cows during the dry period on gene expression of the mammary gland and lymphocytes. Cows wer...

  1. MicroRNA Expression Profiling of Lactating Mammary Gland in Divergent Phenotype Swine Breeds

    PubMed Central

    Peng, Jing; Zhao, Jun-Sheng; Shen, Yi-Fei; Mao, Hai-Guang; Xu, Ning-Ying

    2015-01-01

    MicroRNA (miRNA) plays a key role in development and specific biological processes, such as cell proliferation, differentiation, and apoptosis. Extensive studies of mammary miRNAs have been performed in different species and tissues. However, little is known about porcine mammary gland miRNAs. In this study, we report the identification and characterization of miRNAs in the lactating mammary gland in two distinct pig breeds, Jinhua and Yorkshire. Many miRNAs were detected as significantly differentially expressed between the two libraries. Among the differentially expressed miRNAs, many are known to be related to mammary gland development and lactation by interacting with putative target genes in previous studies. These findings suggest that miRNA expression patterns may contribute significantly to target mRNA regulation and influence mammary gland development and peak lactation performance. The data we obtained provide useful information about the roles of miRNAs in the biological processes of lactation and the mechanisms of target gene expression and regulation. PMID:25580536

  2. Mammary Branching Morphogenesis Requires Reciprocal Signaling by Heparanase and MMP-14.

    PubMed

    Gomes, Angélica Maciel; Bhat, Ramray; Correia, Ana Luísa; Mott, Joni D; Ilan, Neta; Vlodavsky, Israel; Pavão, Mauro S G; Bissell, Mina

    2015-08-01

    The development of the mammary gland involves formation of a branched arboreal structure resulting from the penetration and proliferation of epithelial cells into the fat pad. The mammary cells invade by remodeling their surrounding extracellular matrix (ECM), which are rich in proteins, and glycans such as heparan sulfate proteoglycans (HSPGs). There is increasing literature on how the interaction between signaling by ECM and matrix metalloproteinases (MMPs) is relevant to morphogenetic and physiological contexts. Here we sought to understand how heparanase, the sole mammalian heparan sulfate-degrading endoglycosidase may regulate mammary gland development. We found a robust localization of heparanase within growing end buds during branching in vivo. Using three-dimensional (3D) organotypic cultures, we showed that heparanase expression and activity are required for mammary epithelial invasion/branching within dense collagen I gels. Morphometric analysis of glands from both heparanase-overexpressing and knockout mice showed a direct correlation between degree of branching and the heparanase levels, confirming our 3D organotypic culture observations. Finally, we uncovered a reciprocal association between levels of heparanase and MMP14, a membrane-bound MMP, shedding further light on how branching occurs within developing mammary glands.

  3. Morphological and histological characteristics of mammary dysplasias occurring in cell dissociation-derived murine mammary outgrowths

    SciTech Connect

    Ethier, S.P.; Adams, L.M.; Ullrich, R.L.

    1984-10-01

    The morphological and histological characteristics of ductal dysplasias that were observed in mammary outgrowths derived from monodispersed mammary cells of carcinogen-treated mice are described. Mammary outgrowths were derived by injecting either 10(4) or 10(5) enzymatically dissociated mammary cells, obtained from control or carcinogen-treated BALB/c mice, into gland-free mammary fat pads of syngeneic hosts. The mammary dysplasias observed varied considerably in morphological and histological characteristics. The majority of the lesions were ductal in origin and were associated with epithelial hyperplasia which ranged from mild hyperplasia, in which only a few extra layers of epithelium were present, to severe hyperplasia, in which the ducts and end buds were occluded and distended with epithelial cells. In addition, papillary and lobular lesions were observed which were also associated with varying degrees of hyperplasia. The range of mammary dysplasias observed in these outgrowths closely resembles that of lesions associated with the pathogenesis of mammary carcinoma in mice, rats, and humans.

  4. Terminal end bud maintenance in mammary gland is dependent upon FGFR2b signaling.

    PubMed

    Parsa, Sara; Ramasamy, Suresh K; De Langhe, Stijn; Gupte, Varsha V; Haigh, Jody J; Medina, Daniel; Bellusci, Savério

    2008-05-01

    We previously demonstrated that Fibroblast Growth Factor 10 (FGF10) and its receptor FGFR2b play a key role in controlling the very early stages of mammary gland development during embryogenesis [Mailleux, A.A., Spencer-Dene, B., Dillon, C., Ndiaye, D., Savona-Baron, C., Itoh, N., Kato, S., Dickson, C., Thiery, J.P., and Bellusci, S. (2002). Role of FGF10/FGFR2b signaling during mammary gland development in the mouse embryo. Development 129, 53-60. Veltmaat, J. M., Relaix, F., Le, L.T., Kratochwil, K., Sala, F.G., van Veelen, W., Rice, R., Spencer-Dene, B., Mailleux, A.A., Rice, D.P., Thiery, J.P., and Bellusci, S. (2006). Gli3-mediated somitic Fgf10 expression gradients are required for the induction and patterning of mammary epithelium along the embryonic axes. Development 133, 2325-35.]. However, the role of FGFR2b signaling in postnatal mammary gland development is still elusive. We show that FGF10 is expressed at high level throughout the adipose tissue in the mammary gland of young virgin female mice whereas its main receptor FGFR2 is found mostly in the epithelium. Using a rtTA transactivator/tetracycline promoter approach allowing inducible and reversible attenuation of the FGFR2b signaling throughout the adult mouse, we are now reporting that FGFR2b signaling is also critical during postnatal mammary gland development. Ubiquitous attenuation of FGFR2b signaling in the postnatal mouse for 6 weeks starting immediately after birth is not lethal and leads to minor defects in the animal. Upon dissection of the mammary glands, a 40% reduction in size compared to the WT control is observed. Further examination shows a rudimentary mammary epithelial tree with completely absent terminal end buds (TEBs), compared to a well-branched structure observed in wild type. Transplantation of mammary gland explants into cleared fat pad of wild type mouse recipients indicates that the observed abnormal branching results from defective FGFR2b signaling in the epithelium. We

  5. Conditional Wwox Deletion in Mouse Mammary Gland by Means of Two Cre Recombinase Approaches

    PubMed Central

    Ferguson, Brent W.; Gao, Xinsheng; Kil, Hyunsuk; Lee, Jaeho; Benavides, Fernando; Abba, Martin C.; Aldaz, C. Marcelo

    2012-01-01

    Loss of WWOX expression has been reported in many different cancers including breast cancer. Elucidating the function of this gene in adult tissues has not been possible with full Wwox knockout models. Here we characterize the first conditional models of Wwox ablation in mouse mammary epithelium utilizing two transgenic lines expressing Cre recombinase, keratin 5-Cre (BK5-Cre) and MMTV-Cre. In the BK5-Cre model we observed very efficient Wwox ablation in KO mammary glands. However, BK5-Cre Wwox KO animals die prematurely for unknown reasons. In the MMTV-Cre model we observed significant ablation of Wwox in mammary epithelium with no effect on survival. In both of these models we found that Wwox deletion resulted in impaired mammary branching morphogenesis. We demonstrate that loss of Wwox is not carcinogenic in our KO models. Furthermore, no evidence of increase proliferation or development of premalignant lesions was observed. In none of the models did loss of a single Wwox allele (i.e. haploinsufficiency) have any observable phenotypic effect in mammary gland. To better understand the function of Wwox in the mammary gland, transcriptome profiling was performed. We observed that Wwox ablation results in the deregulation of genes involved in various cellular processes. We found that expression of the non-canonical Wnt ligand, Wnt5a, was significantly upregulated in Wwox KO mammary epithelium. Interestingly, we also determined that components of the Jak/Stat3 signaling pathway were upregulated in KO mice and this correlated with a very robust increase in phospho-Stat3 signaling, which warrants further testing. Even though the loss of Wwox expression in breast and other cancers is very well documented, our findings suggest that Wwox does not act as a classical tumor suppressor as previously thought. PMID:22574198

  6. Estradiol, progesterone and prolactin modulate mammary gland morphogenesis in adult female plains vizcacha (Lagostomus maximus).

    PubMed

    Halperin, Julia; Dorfman, Veronica B; Fraunhoffer, Nicolas; Vitullo, Alfredo D

    2013-06-01

    We studied for the first time the mammary gland morphogenesis and its hormonal modulation by immunolocalizing estradiol, progesterone and prolactin receptors (ER, PR and PRLR) in adult females of Lagostomus maximus, a caviomorph rodent which shows a pseudo-ovulatory process at mid-gestation. Mammary ductal system of non-pregnant females lacks expression of both ERα and ERβ. Yet throughout pregnancy, ERα and ERβ levels increase as well as the expression of PR. These increments are concomitant with ductal branching and alveolar differentiation. Even though mammary gland morphology is quite similar to that described for other rodents, alveolar proliferation and differentiation are accelerated towards the second half of pregnancy, once pseudo-ovulation had occurred. Moreover, this exponential growth correlates with an increment of both progesterone and estradiol serum-induced pseudo-ovulation. As expected, PR and PRLR are strongly expressed in the alveolar epithelium during pregnancy and lactation. Strikingly, PRLR is also present in ductal epithelia of cycling glands suggesting that prolactin function may not be restricted to its trophic effect on mammary glands of pregnant and lactating females, but it also regulates other physiological processes in mammary glands of non-pregnant animals. In conclusion, this report suggests that pseudo-ovulation at mid-gestation may be associated to L. maximus mammary gland growth and differentiation. The rise in P and E2-induced pseudo-ovulation as well as the increased expression of their receptors, all events that correlate with the development of a more elaborated and differentiated ductal network, pinpoint a possible relation between this peculiar physiological event and mammary gland morphogenesis.

  7. Bovine mammary epithelial cells retain stem-like phenotype in long-term cultures.

    PubMed

    Cravero, Diego; Diego, Cravero; Martignani, Eugenio; Eugenio, Martignani; Miretti, Silvia; Silvia, Miretti; Macchi, Elisabetta; Elisabetta, Macchi; Accornero, Paolo; Paolo, Accornero; Baratta, Mario; Mario, Baratta

    2014-10-01

    The detection and characterization of bovine mammary stem cells may give a better understanding of the cyclic characteristic of mammary gland development. In turn, this could potentially offer techniques to manipulate lactation yield and for regenerative medicine. We previously demonstrated that adult stem cells reside in the bovine mammary gland and possess an intrinsic regenerative potential. In vitro maintenance and expansion of this primitive population is a challenging task that could make easier the study of adult mammary stem cells. The aim of this study is to investigate this possibility. Different subpopulations of mammary epithelial cells emerge when they are cultured in two defined culture conditions. Specific cell differentiation markers as cytokeratin 18 (CK18) and cytokeratin 14 (CK14) were expressed with significant differences according to culture conditions. Vimentin, a well-known fibroblast marker was observed to increase significantly (P < 0.5) only after day 20. In both conditions, after prolonged culture (25 days) a subset of cells still retained regenerative capabilities. These cells were able to form organized pseudo-alveoli when transplanted in immunodeficient mice as shown by the expression of cytokeratin 14 (CK14), cytokeratin 18 (CK18), p63 (a mammary basal cell layer marker) and Epithelial Cell Adhesion Molecule (EpCAM). We also were able to observe the presence of milk proteins signal in these regenerated structures, which is a specific marker of functional mammary alveoli. Progenitor content was also analyzed in vitro through Colony-Forming Cell (CFC) assays with no substantial differences among culture conditions and time points. These results demonstrate that long-term culture of a multipotent cell subpopulation with intrinsic regenerative potential is possible.

  8. Oestrogen receptor-alpha regulates non-canonical Hedgehog-signalling in the mammary gland

    PubMed Central

    Okolowsky, Nadia; Furth, Priscilla A.; Hamel, Paul A.

    2014-01-01

    Mesenchymal dysplasia (mes) mice harbour a truncation in the C-terminal region of the Hh-ligand receptor, Patched-1 (mPtch1). While the mes variant of mPtch1 binds to Hh-ligands with an affinity similar to that of wild type mPtch1 and appears to normally regulate canonical Hh-signalling via smoothened, the mes mutation causes, among other non-lethal defects, a block to mammary ductal elongation at puberty. We demonstrated previously Hh-signalling induces the activation of Erk1/2 and c-src independently of its control of smo activity. Furthermore, mammary epithelial cell-directed expression of an activated allele of c-src rescued the block to ductal elongation in mes mice, albeit with delayed kinetics. Given that this rescue was accompanied by an induction in estrogen receptor-alpha (ERα) expression and that complex regulatory interactions between ERα and c-src are required for normal mammary gland development, it was hypothesized that expression of ERα would also overcome the block to mammary ductal elongation at puberty in the mes mouse. We demonstrate here that conditional expression of ERα in luminal mammary epithelial cells on the mes background facilitates ductal morphogenesis with kinetics similar to that of the MMTV-c-srcAct mice. We demonstrate further that Erk1/2 is activated in primary mammary epithelial cells by Shh-ligand and that this activation is blocked by the inhibitor of c-src, PP2, is partially blocked by the ERα inhibitor, ICI 182780 but is not blocked by the smo-inhibitor, SANT-1. These data reveal an apparent Hh-signalling cascade operating through c-src and ERα that is required for mammary gland morphogenesis at puberty. PMID:24769368

  9. Autophagy regulator BECN1 suppresses mammary tumorigenesis driven by WNT1 activation and following parity.

    PubMed

    Cicchini, Michelle; Chakrabarti, Rumela; Kongara, Sameera; Price, Sandy; Nahar, Ritu; Lozy, Fred; Zhong, Hua; Vazquez, Alexei; Kang, Yibin; Karantza, Vassiliki

    2014-01-01

    Earlier studies reported allelic deletion of the essential autophagy regulator BECN1 in breast cancers implicating BECN1 loss, and likely defective autophagy, in tumorigenesis. Recent studies have questioned the tumor suppressive role of autophagy, as autophagy-related gene (Atg) defects generally suppress tumorigenesis in well-characterized mouse tumor models. We now report that, while it delays or does not alter mammary tumorigenesis driven by Palb2 loss or ERBB2 and PyMT overexpression, monoallelic Becn1 loss promotes mammary tumor development in 2 specific contexts, namely following parity and in association with wingless-type MMTV integration site family, member 1 (WNT1) activation. Our studies demonstrate that Becn1 heterozygosity, which results in immature mammary epithelial cell expansion and aberrant TNFRSF11A/TNR11/RANK (tumor necrosis factor receptor superfamily, member 11a, NFKB activator) signaling, promotes mammary tumorigenesis in multiparous FVB/N mice and in cooperation with the progenitor cell-transforming WNT1 oncogene. Similar to our Becn1(+/-);MMTV-Wnt1 mouse model, low BECN1 expression and an activated WNT pathway gene signature correlate with the triple-negative subtype, TNFRSF11A axis activation and poor prognosis in human breast cancers. Our results suggest that BECN1 may have nonautophagy-related roles in mammary development, provide insight in the seemingly paradoxical roles of BECN1 in tumorigenesis, and constitute the basis for further studies on the pathophysiology and treatment of clinically aggressive triple negative breast cancers (TNBCs).

  10. Differentiation of Human Induced Pluripotent Stem Cells to Mammary-like Organoids.

    PubMed

    Qu, Ying; Han, Bingchen; Gao, Bowen; Bose, Shikha; Gong, Yiping; Wawrowsky, Kolja; Giuliano, Armando E; Sareen, Dhruv; Cui, Xiaojiang

    2017-02-14

    Human induced pluripotent stem cells (iPSCs) can give rise to multiple cell types and hold great promise in regenerative medicine and disease-modeling applications. We have developed a reliable two-step protocol to generate human mammary-like organoids from iPSCs. Non-neural ectoderm-cell-containing spheres, referred to as mEBs, were first differentiated and enriched from iPSCs using MammoCult medium. Gene expression profile analysis suggested that mammary gland function-associated signaling pathways were hallmarks of 10-day differentiated mEBs. We then generated mammary-like organoids from 10-day mEBs using 3D floating mixed gel culture and a three-stage differentiation procedure. These organoids expressed common breast tissue, luminal, and basal markers, including estrogen receptor, and could be induced to produce milk protein. These results demonstrate that human iPSCs can be directed in vitro toward mammary lineage differentiation. Our findings provide an iPSC-based model for studying regulation of normal mammary cell fate and function as well as breast disease development.

  11. Human mammary microenvironment better regulates the biology of human breast cancer in humanized mouse model.

    PubMed

    Zheng, Ming-Jie; Wang, Jue; Xu, Lu; Zha, Xiao-Ming; Zhao, Yi; Ling, Li-Jun; Wang, Shui

    2015-02-01

    During the past decades, many efforts have been made in mimicking the clinical progress of human cancer in mouse models. Previously, we developed a human breast tissue-derived (HB) mouse model. Theoretically, it may mimic the interactions between "species-specific" mammary microenvironment of human origin and human breast cancer cells. However, detailed evidences are absent. The present study (in vivo, cellular, and molecular experiments) was designed to explore the regulatory role of human mammary microenvironment in the progress of human breast cancer cells. Subcutaneous (SUB), mammary fat pad (MFP), and HB mouse models were developed for in vivo comparisons. Then, the orthotopic tumor masses from three different mouse models were collected for primary culture. Finally, the biology of primary cultured human breast cancer cells was compared by cellular and molecular experiments. Results of in vivo mouse models indicated that human breast cancer cells grew better in human mammary microenvironment. Cellular and molecular experiments confirmed that primary cultured human breast cancer cells from HB mouse model showed a better proliferative and anti-apoptotic biology than those from SUB to MFP mouse models. Meanwhile, primary cultured human breast cancer cells from HB mouse model also obtained the migratory and invasive biology for "species-specific" tissue metastasis to human tissues. Comprehensive analyses suggest that "species-specific" mammary microenvironment of human origin better regulates the biology of human breast cancer cells in our humanized mouse model of breast cancer, which is more consistent with the clinical progress of human breast cancer.

  12. Prevalence of Glomerulopathies in Canine Mammary Carcinoma

    PubMed Central

    2016-01-01

    The incidence and prevalence of paraneoplastic glomerulopathy, especially associated with carcinoma, are a matter of debate and the causal link between cancer and glomerular diseases remains unclear. The aim of this study was to evaluate renal biopsies of selected bitches with spontaneous mammary gland carcinoma. We hypothesized that dogs with mammary carcinomas would show histologic evidence of glomerular pathology. A prospective study was performed in dogs with naturally occurring mammary carcinoma that were undergoing tumor resection and ovariohysterectomy. We evaluated renal biopsies of 32 bitches with spontaneous mammary gland carcinoma and 11 control dogs without mammary gland neoplasia. Samples were obtained from the left kidney and the biopsy material was divided for light microscopy (LM), immunofluorescence (IF) and transmission electron microscopy (TEM). Light microscopy abnormalities were identified in 78.1% of dogs with mammary carcinoma (n = 25) and in none of the dogs in the control group. Focal glomerular mesangial matrix expansion was the most common alteration (n = 15, 60.0%), but mesangial cell proliferation (n = 9, 36.0%) and focal segmental glomerulosclerosis (n = 9, 36.0%), synechiae (n = 7, 28.0%), and globally sclerotic glomeruli (n = 6, 24.0%) were also frequent in dogs with malignancy. Immunofluorescence microscopy revealed strong IgM staining was demonstrated in 64.3% (n = 18) of carcinoma dogs. Transmission electron microscopy from dogs with carcinoma revealed slight changes, the most frequent of which was faint sub-endothelial and mesangial deposits of electron-dense material (78%). Mesangial cell interpositioning and segmental effacement of podocyte foot processes were identified in some specimens (45%). Changes in the glomerulus and proteinuria are common in dogs with naturally occurring mammary carcinoma and this condition appears to provide an excellent large animal model for cancer-associated glomerulopathy in humans. PMID:27764139

  13. Hormone signaling requirements for the conversion of non-mammary mouse cells to mammary cell fate(s) in vivo.

    PubMed

    Boulanger, Corinne A; Rosenfield, Sonia M; George, Andrea L; Smith, Gilbert H

    2015-06-01

    Mammotropic hormones and growth factors play a very important role in mammary growth and differentiation. Here, hormones including Estrogen, Progesterone, Prolactin, their cognate receptors, and the growth factor Amphiregulin, are tested with respect to their roles in signaling non-mammary cells from the mouse to redirect to mammary epithelial cell fate(s). This was done in the context of glandular regeneration in pubertal athymic female mice. Our previous studies demonstrated that mammary stem cell niches are recapitulated during gland regeneration in vivo. During this process, cells of exogenous origin cooperate with mammary epithelial cells to form mammary stem cell niches and thus respond to normal developmental signals. In all cases tested with the possible exception of estrogen receptor alpha (ER-α), hormone signaling is dispensable for non-mammary cells to undertake mammary epithelial cell fate(s), proliferate, and contribute progeny to chimeric mammary outgrowths. Importantly, redirected non-mammary cell progeny, regardless of their source, have the ability to self-renew and contribute offspring to secondary mammary outgrowths derived from transplanted chimeric mammary fragments; thus suggesting that some of these cells are capable of mammary stem cell/progenitor functions.

  14. Fetal alcohol exposure and mammary tumorigenesis in offspring: role of the estrogen and insulin-like growth factor systems.

    PubMed

    Cohick, Wendie S; Crismale-Gann, Catina; Stires, Hillary; Katz, Tiffany A

    2015-01-01

    Fetal alcohol spectrum disorders affect a significant number of live births each year, indicating that alcohol consumption during pregnancy is an important public health issue. Environmental exposures and lifestyle choices during pregnancy may affect the offspring's risk of disease in adulthood, leading to the idea that a woman's risk of breast cancer may be pre-programmed prior to birth. Exposure of pregnant rats to alcohol increases tumorigenesis in the adult offspring in response to mammary carcinogens. The estrogen and insulin-like growth factor (IGF-I) axes occupy central roles in normal mammary gland development and breast cancer. 17-β estradiol (E2) and IGF-I synergize to regulate formation of terminal end buds and ductal elongation during pubertal development. The intracellular signaling pathways mediated by the estrogen and IGF-I receptors cross-talk at multiple levels through both genomic and non-genomic mechanisms. Several components of the E2 and IGF-I systems are altered in early development in rat offspring exposed to alcohol in utero, therefore, these changes may play a role in the enhanced susceptibility to mammary carcinogens observed in adulthood. Alcohol exposure in utero induces a number of epigenetic alterations in non-mammary tissues in the offspring and other adverse in utero exposures induce epigenetic modifications in the mammary gland. Future studies will determine if fetal alcohol exposure can induce epigenetic modifications in genes that regulate E2/IGF action at key phases of mammary development, ultimately leading to changes in susceptibility to carcinogens.

  15. USF-1 as an Inhibitor of Mammary Gland Carcinogenesis

    DTIC Science & Technology

    2002-09-01

    was targeted to the mammary gland under the control of the mouse mammary tumor virus (mmtv) long terminal repeat. Of eight lines of transgenic mice ...be explored by testing the hypothesis that targeted overexpression of USF-2 in the mammary glands of MMTV-myc transgenic mice will cause withdrawal...USF-2 under the control of the mouse mammary tumor virus long terminal repeat. Once in hand this new line of transgenic mice would be crossed with a

  16. Quantification of mammary organoid toxicant response and mammary tissue motility using OCT fluctuation spectroscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Yu, Xiao; Blackmon, Richard L.; Carabas-Hernendez, Patricia; Fuller, Ashley; Troester, Melissa A.; Oldenburg, Amy L.

    2016-03-01

    Mammary epithelial cell (MEC) organoids in 3D culture recapitulate features of breast ducts in vivo. OCT has the ability to monitor the evolution of MEC organoids non-invasively and longitudinally. The anti-cancer drug Doxorubicin (Dox) is able to inhibit proliferation of cancer cells and has been widely used for chemotherapy of breast cancers; while environmental toxins implicated in breast cancer such as estrogen regulates mammary tumor growth and stimulates the proliferation and metastatic potential of breast cancers. Here we propose a quantitative method for measuring motility of breast cells in 3D cultures based upon OCT speckle fluctuation spectroscopy. The metrics of the inverse power-law exponent (α) and fractional modulation amplitude (M) were extracted from speckle fluctuation spectra. These were used to quantify the responses of MEC organoids to Dox, and estrogen. We investigated MEC organoids comprised of two different MEC lines: MCF10DCIS.com exposed to Dox, and MCF7 exposed to estrogen. We found an increase (p<0.001) in α of MEC along time (t=0, 1 hour, 24 hours, 48 hours and 6 days) at each dose of Dox (0, 1 μM and 10 μM), indicating lower fluctuation intensity at higher frequencies. We also observed a decrease (p<0.001) in M for increasing time. However, both α and M of MCF7 treated with estrogen (0, 1 nM and 10 nM) exhibited the opposite trend along time. This novel technology provides rapid and non-invasive measurements of the effects of toxicants on MEC motility for understanding breast cancer development and assessing anti-cancer drugs.

  17. Protein quality and quantity and insulin control of mammary gland glucose utilization during lactation

    SciTech Connect

    Masor, M.L.

    1987-01-01

    Virgin Sprague-Dawley rats were bred, and fed laboratory stock (STOCK), 13% casein plus methionine, 13% wheat gluten, or 5% casein plus methionine through gestation and 4 days of lactation. Diets were switched at parturition to determine the effects of dietary protein quality and quantity fed during gestation and/or lactation on insulin stimulation of mammary glucose utilization. On day 20 of gestation (20G) and day 4 of lactation (4L) the right inguinal-abdominal mammary glands were removed, and acini and tissue slices were incubated in Krebs buffer with or without insulin containing (U-/sup 14/C)-glucose and 5mM glucose for 1 hour at 37/degrees/C. Glucose incorporation into CO/sub 2/, lipid and lactose was determined. Glucose incorporation into CO/sub 2/ and lipid, but not lactose was stimulated by insulin in mammary slices. Diet effects on glucose utilization in acini were confirmed in slices for basal and insulin stimulated levels. Treatment affected the absolute increase of insulin stimulation. Regression analysis significantly correlated pup weight gain with total glucose utilization. Poor dietary protein quality and quantity fed during gestation impaired both overall response of mammary glucose utilization to insulin stimulation, and mammary development during pregnancy. Improving protein value at parturition did not overcome those deficits by 4L.

  18. Function of phosphoenolpyruvate carboxykinase in mammary gland epithelial cells[S

    PubMed Central

    Hsieh, Chang-Wen; Huang, Charles; Bederman, Ilya; Yang, Jianqi; Beidelschies, Michelle; Hatzoglou, Maria; Puchowicz, Michelle; Croniger, Colleen M.

    2011-01-01

    Previously, we have shown that Pck1 expression in mammary gland adipocytes and white adipose tissue maintains triglyceride stores through glyceroneogenesis, and these lipids were used for synthesis of milk triglycerides during lactation. Reduced milk triglycerides during lactation resulted in patterning of the newborn for insulin resistance. In this study, the role of Pck1 in mammary gland epithelial cells was analyzed. The developmental expression of Pck1 decreased in isolated mouse mammary gland epithelial cells through development and during lactation. Using HC11, a clonal mammary epithelial cell line, we found that both Janus kinase 2 signal transducers and activators of transcription 5 and the AKT pathways contributed to the repression of Pck1 mRNA by prolactin. These pathways necessitate three accessory factor regions of the Pck1 promoter for repression by prolactin. Using [U-13C6]glucose, [U-13C3]pyruvate, and [U-13C3]glycerol in HC11 cells, we determined that Pck1 functions in the pathway for the conversion of gluconeogenic precursors to glucose and contributes to glycerol-3-phosphate synthesis through glyceroneogenesis. Therefore, Pck1 plays an important role in both the mammary gland adipocytes and epithelial cells during lactation. PMID:21504969

  19. Identification of mouse mammary epithelial cells by immunofluorescence with rabbit and guinea pig antikeratin antisera.

    PubMed Central

    Asch, B B; Burstein, N A; Vidrich, A; Sun, T T

    1981-01-01

    Few markers are available to identify the three types of mammary epithelial cells--ductal, alveolar, and myoepithelial--especially in pathological conditions and in cell cultures. We have used antisera to human keratins in immunofluorescence to facilitate the identification of the three mouse mammary epithelial cell types. In frozen tissue sections and primary cell cultures, a rabbit antikeratin antiserum specifically stained cytoplasmic filaments in all three types of epithelial cells. A guinea pig antiserum against the same keratin preparation, however, reacted preferentially with filaments in myoepithelial cells and readily detected this cell type in normal, dysplastic, and malignant mammary tissues and cell cultures. Neither antisera reacted with fibroblasts or any other mesenchymal cells. The combined use of the two antikeratin antisera thereby permits rapid surveys of tissue sections and cultures for the localization of not only all epithelial cells but also the subpopulation of myoepithelial cells. Moreover, when mammary cultures established from late-pregnant or lactating mice were stained simultaneously with guinea pig antikeratin and rabbit anticasein antisera, three populations of epithelial cells were mutually exclusive: those stained by anticasein antiserum, those stained by guinea pig antikeratin antiserum, and those stained by neither, consistent with properties of alveolar, myoepithelial, and ductal cells, respectively. These antisera thus offer a tool for studying different epithelial cell types during mammary development, tumorigenesis, and malignant progression. Images PMID:6170984

  20. A Comparative Approach of Tumor-Associated Inflammation in Mammary Cancer between Humans and Dogs.

    PubMed

    Carvalho, Maria Isabel; Silva-Carvalho, Ricardo; Pires, Isabel; Prada, Justina; Bianchini, Rodolfo; Jensen-Jarolim, Erika; Queiroga, Felisbina L

    2016-01-01

    Infiltrating cells of the immune system are widely accepted to be generic constituents of tumor microenvironment. It has been well established that the development of mammary cancer, both in humans and in dogs, is associated with alterations in numbers and functions of immune cells at the sites of tumor progression. These tumor infiltrating immune cells seem to exhibit exclusive phenotypic and functional characteristics and mammary cancer cells can take advantage of signaling molecules released by them. Cancer related inflammation has an important role in mammary carcinogenesis, contributing to the acquisition of core hallmark capabilities that allow cancer cells to survive, proliferate, and disseminate. Indeed, recent studies in human breast cancer and in canine mammary tumors have identified a growing list of signaling molecules released by inflammatory cells that serve as effectors of their tumor-promoting actions. These include the COX-2, the tumor EGF, the angiogenic VEGF, other proangiogenic factors, and a large variety of chemokines and cytokines that amplify the inflammatory state. This review describes the intertwined signaling pathways shared by T-lymphocytic/macrophage infiltrates and important tissue biomarkers in both human and dog mammary carcinogenesis.

  1. PREPARATION OF EPITHELIAL AND MESENCHYMAL STEM CELLS FROM MURINE MAMMARY GLAND

    PubMed Central

    Guest, I.; Ilic, Z.; Ma, J.

    2011-01-01

    The mammary gland is a complex organ consisting of multiple cell types that undergo extensive remodeling during pregnancy and involution, cyclical changes that suggest the existence of a resident stem cell population that is responsible for this remarkable tissue regeneration. The basic functional unit of the mammary gland is the terminal duct lobular unit, which invades the stromal tissue (fat, connective tissue, blood vessels, etc.). Luminal epithelial cells line the ducts while outer myoepithelial cells secrete the basal lamina that separates the mammary gland parenchyma from the mesenchymal cells of the stroma. Within the epithelial cell population of the ducts resides the mammary gland stem cells and it is believed that this population is the origin of the mammary gland cancer stem cells as well. In the mouse, epithelial stem cells can be separated from mesenchymal cells on the basis of CD24, CD44 and CD49f expression. This allows for the determination of both normal and cancer stem cell potential of these two populations and permits investigation into their interaction in tumour development. PMID:22058055

  2. Effect of spaying and timing of spaying on survival of dogs with mammary carcinoma.

    PubMed

    Sorenmo, K U; Shofer, F S; Goldschmidt, M H

    2000-01-01

    The risk of developing mammary gland tumors in dogs is significantly decreased by ovariohysterectomy at an early age. However, previous studies have not found a benefit to ovariohysterectomy concurrent with tumor removal in dogs with established mammary gland tumors, suggesting that the progression of these tumors is independent of continued estrogen stimulation. The purpose of this study was to evaluate the effect of spaying and of the timing of spaying on survival in dogs with mammary gland carcinoma. Signalment, spay status and spay age, tumor characteristics, treatment. survival, and cause of death of 137 dogs with mammary gland carcinoma were analyzed. The dogs were classified into 3 groups according to spay status and spay time: intact dogs, dogs spayed less than 2 years before tumor surgery (SPAY 1), and dogs spayed more than 2 years before their tumor surgery (SPAY 2). Dogs in the SPAY 1 group lived significantly longer than dogs in SPAY 2 and intact dogs (median survival of 755 days, versus 301 and 286 days, respectively, P = .02 and .03). After adjusting for differences between the spay groups with regard to age, histologic differentiation, and vascular invasion, SPAY 1 dogs survived 45% longer compared to dogs that were either intact or in the SPAY 2 group (RR = .55; 95% CI .32-.93; P = .03). This study reveals ovariohysterectomy to be an effective adjunct to tumor removal in dogs with mammary gland carcinoma and that the timing of ovariohysterectomy is important in influencing survival.

  3. A Comparative Approach of Tumor-Associated Inflammation in Mammary Cancer between Humans and Dogs

    PubMed Central

    Silva-Carvalho, Ricardo; Pires, Isabel; Bianchini, Rodolfo; Jensen-Jarolim, Erika

    2016-01-01

    Infiltrating cells of the immune system are widely accepted to be generic constituents of tumor microenvironment. It has been well established that the development of mammary cancer, both in humans and in dogs, is associated with alterations in numbers and functions of immune cells at the sites of tumor progression. These tumor infiltrating immune cells seem to exhibit exclusive phenotypic and functional characteristics and mammary cancer cells can take advantage of signaling molecules released by them. Cancer related inflammation has an important role in mammary carcinogenesis, contributing to the acquisition of core hallmark capabilities that allow cancer cells to survive, proliferate, and disseminate. Indeed, recent studies in human breast cancer and in canine mammary tumors have identified a growing list of signaling molecules released by inflammatory cells that serve as effectors of their tumor-promoting actions. These include the COX-2, the tumor EGF, the angiogenic VEGF, other proangiogenic factors, and a large variety of chemokines and cytokines that amplify the inflammatory state. This review describes the intertwined signaling pathways shared by T-lymphocytic/macrophage infiltrates and important tissue biomarkers in both human and dog mammary carcinogenesis. PMID:28053982

  4. On the possible role of mammary-derived growth hormone in human breast cancer.

    PubMed

    Thijssen, Jos H H

    2009-12-01

    The incidence of breast cancer has risen worldwide, especially in countries where it used to be low, very probably as a result of economic prosperity and changes in life-style. In women, the available data have resulted in the concept of progression from normal breast development to cancer through precursor lesions sensitive to hormones and growth factors that can be produced locally in the mammary gland, acting as paracrine or autocrine stimulating agents. The local endocrine environment in the breast can be different from the situation in the circulation. In the dog, growth hormone (GH) can be produced locally in the mammary glands and its production can be stimulated by progestins. This GH probably plays a paracrine role in the progesterone-induced proliferation and differentiation of mammary epithelium. There is increasing evidence that the local mammary progestin/GH-axis is operational not only in dogs but also in human breast cancer. No data are yet available on the production of mammary-derived GH in women.

  5. Cutaneous metastases of a mammary carcinoma in a llama.

    PubMed Central

    Leichner, T L; Turner, O; Mason, G L; Barrington, G M

    2001-01-01

    An 8-year-old, female llama was evaluated for nonhealing, ulcerative, cutaneous lesions, which also involved the mammary gland. Biopsies of the lesions distant from and within the mammary gland area revealed an aggressive carcinoma. The tumor was confirmed at necropsy to be a mammary gland adenocarcinoma with cutaneous metastasis. Images Figure 1. PMID:11265189

  6. Pigmented mammary paget disease misdiagnosed as malignant melanoma.

    PubMed

    Lee, Ji Hye; Kim, Tae Hyung; Kim, Soo-Chan; Kim, You Chan; Roh, Mi Ryung

    2014-12-01

    Pigmented mammary Paget disease is a very rare clinicopathologic variant of mammary Paget disease. Diagnosis is often difficult because its clinical and histological features are very similar to those of malignant melanoma. Herein, we report a case of pigmented mammary Paget disease misdiagnosed as malignant melanoma.

  7. Epidermal growth factor and hepatocyte growth factor receptors collaborate to induce multiple biological responses in bovine mammary epithelial cells.

    PubMed

    Accornero, P; Martignani, E; Miretti, S; Starvaggi Cucuzza, L; Baratta, M

    2009-08-01

    The aim of this work was to explore whether epidermal growth factor (EGF) and hepatocyte growth factor (HGF) could increase the biological responses of a mammary epithelial cell line of bovine origin when added simultaneously. We also investigated a possible molecular mechanism underlying this cooperation. The development of mammary gland requires several circulating and locally produced hormones. Hepatocyte growth factor and its tyrosine kinase receptor, mesenchymal-epithelial transition factor (MET), are expressed and temporally regulated during mammary development and differentiation. Epidermal growth factor receptor and its ligands have also been implicated in the growth and morphogenesis of the mammary epithelium. Both EGF and HGF seem to exert a morphogenic program in this tissue; therefore, we hypothesized that these cytokines could act cooperatively in bovine mammary epithelial cells. We have already shown that the bovine BME-UV cell line, a nontumorigenic mammary epithelial line, expresses both MET and EGF receptor. Simultaneous treatment with HGF and EGF elicited an increase in proliferation, dispersion, degradation of extracellular matrix, and motility. Following EGF treatment, BME-UV mammary cells exhibited an increase in MET expression at both the mRNA and protein levels. Long-term treatment of BME-UV cells with HGF and EGF together increased the level of activation of the extracellular signal-regulated kinase 1/2 and protein kinase B signaling pathways when compared with HGF or EGF alone. These data outline a possible cooperative role of the EGF and HGF pathways and indicate that cross-talk between their respective receptors may modulate mammary gland development in the cow.

  8. Natural and abrupt involution of the mammary gland affects differently the metabolic and health consequences of weaning.

    PubMed

    Silanikove, Nissim

    2014-04-25

    In most mammals under natural conditions weaning is gradual. Weaning occurs after the mammary gland naturally produces much less milk than it did at peak and established lactation. Involution occurs following the cessation of milk evacuation from the mammary glands. The abrupt termination of the evacuation of milk from the mammary gland at peak and established lactation induces abrupt involution. Evidence on mice has shown that during abrupt involution, mammary gland utilizes some of the same tissue remodeling programs that are activated during wound healing. These results led to the proposition of the "involution hypothesis". According to the involution hypothesis, involution is associated with increased risk for developing breast cancer. However, the involution hypothesis is challenged by the metabolic and immunological events that characterize the involution process that follows gradual weaning. It has been shown that gradual weaning is associated with pre-adaption to the forthcoming break between dam and offspring and is followed by an orderly reprogramming of the mammary gland tissue. As discussed herein, such response may actually protect the mammary glands against the development of breast cancer and thus, may explain the protective effect of extended breastfeeding. On the other hand, the termination of breastfeeding during the first 6 months of lactation is likely associated with an abrupt involution and thus with an increased risk for developing breast cancer. Review of the literature on the epidemiology of breast cancer principally supports those conclusions.

  9. Measurement by radioimmunoassay of casein content in rabbit mammary gland during pregnancy and after prolactin stimulation in organ culture

    SciTech Connect

    Jahn, G.; Dusanter-Fourt, I.; Kelly, P.A.; Houdebine, L.M.; Djiane, J.

    1987-01-01

    A specific homologous radioimmunoassay was developed to measure rabbit ..beta..-casein in rabbit mammary gland with a sensitivity of 0.5 ng/ml protein. It was used to measure casein concentration during pregnancy and in organ culture of mammary gland explants. Casein was detectable in virgin mammary glands, showed a small increase during the first half of pregnancy, increased more than 20-fold between Days 21 and 27, and diminished somewhat on the first days of lactation. After 24 hr of culture, mammary gland explants had no detectable casein, but the addition of increasing concentrations of prolactin to a culture medium which contained insulin (5 ..mu..g/ml) and cortisol (0.5 ..mu..g/ml) induced a regular increase in the casein content of the tissue. Casein started to increase when 10 ng/ml of prolactin was present and maximal values were achieved for 100 ng/ml of the hormone.

  10. Modulation of Notch Signaling Elicits Signature Tumors and Inhibits Hras1-Induced Oncogenesis in the Mouse Mammary Epithelium

    PubMed Central

    Kiaris, Hippokratis; Politi, Katerina; Grimm, Lisa M.; Szabolcs, Matthias; Fisher, Peter; Efstratiadis, Argiris; Artavanis-Tsakonas, Spyros

    2004-01-01

    Deregulation of Notch signaling, which normally affects a broad spectrum of cell fates, has been implicated in various neoplastic conditions. Here we describe a transgenic mouse model, which demonstrates that expression of a constitutively active form of the Notch1 receptor in the mammary epithelium induces the rapid development of pregnancy/lactation-dependent neoplasms that consistently exhibit a characteristic histopathological pattern. These signature tumors retain the ability to respond to apoptotic stimuli and regress on initiation of mammary gland involution, but eventually appear to progress in subsequent pregnancies to nonregressing malignant adenocarcinomas. Additionally, we present evidence indicating that cyclin D1 is an in vivo target of Notch signals in the mammary glands and demonstrate that we can effectively inhibit Hras1-driven, cyclin D1-dependent mammary oncogenesis by transgenic expression of the Notch antagonist Deltex. PMID:15277242

  11. Mammary phenotypic expression induced in epidermal cells by embryonic mammary mesenchyme.

    PubMed

    Cunha, G R; Young, P; Christov, K; Guzman, R; Nandi, S; Talamantes, F; Thordarson, G

    1995-01-01

    The goal of this research was to establish methods for inducing mammary epithelial differentiation from nonmammary epithelium. For this purpose, mid-ventral or dorsal epidermis (skin epithelium; SKE) from 13-day rat or mouse embryos was associated with 13-day embryonic mouse mammary mesenchyme (mammary gland mesenchyme; MGM) (mouse MGM+rat or mouse SKE). The resultant MGM+SKE recombinants as well as controls (homotypic mouse mammary recombinants, homotypic mouse skin recombinants and mouse mammary mesenchyme by itself) were grafted under the renal capsule of syngeneic or athymic female nude mouse hosts. Most female hosts were induced to undergo lactogenesis by grafting an adult pituitary which elicited a state of hyperprolactinemia. Tissue recombinants of mouse MGM+rat or mouse SKE grown for 1 month in vivo formed a hair-bearing keratinized skin from which mammary ductal structures extended into the mesenchyme. The ducts were composed of columnar luminal epithelial cells as well as basal, actin-positive myoepithelial cells. When grown in pituitary-grafted hosts, the ductal epithelial cells expressed casein and alpha-lactalbumin as judged by immunocytochemistry. The expression of caseins in MGM+SKE recombinants was confirmed by Western blot. The epithelial cells in mouse MGM+rat SKE recombinants expressing milk proteins were shown to be rat cells while the surrounding connective tissue was composed of mouse cells based upon staining with Hoechst dye 33258. Using mammary-specific markers, these studies confirmed the earlier morphological studies of Propper and unequivocally demonstrated for the first time that embryonic mammary mesenchyme can induce morphological and functional mammary differentiation from nonmammary epithelium.

  12. Keratinocyte growth factor causes cystic dilation of the mammary glands of mice. Interactions of keratinocyte growth factor, estrogen, and progesterone in vivo.

    PubMed

    Yi, E S; Bedoya, A A; Lee, H; Kim, S; Housley, R M; Aukerman, S L; Tarpley, J E; Starnes, C; Yin, S; Pierce, G F

    1994-11-01

    Keratinocyte growth factor (KGF) is a paracrine mediator of epithelial cell proliferation that has been reported to induce marked proliferation of mammary epithelium in rats. In this study, systemic administration of KGF into naive and oophorectomized mice causes mammary gland proliferation, as evidenced histologically by the appearance of cysts lined by a single layer of epithelium and by hyperplastic epithelium. Whole mount preparations of the mammary glands reveal that the histologically noted cysts are actually ducts that are dilated along much of their length. The histology of the mammary glands of KGF-treated mice is similar to the histology of fibrocystic disease in the human female breast. The response in mice differs significantly from the appearance of the mammary glands in KGF-treated rats in which ductal epithelial proliferation is most prominent. Estrogen and progesterone when administered in combination but not alone cause the development of numerous endbuds in the mouse mammary gland. KGF in estrogen- and progesterone-pretreated mice causes the growth of dilated ducts, hyperplastic epithelium within ducts and endbuds, and a fibrous metamorphosis of periductal adipose tissue. The mammary epithelial hyperplasia caused by KGF is rapidly reversible in both mice and rats after cessation of KGF treatment. The spectrum of KGF-, estrogen-, and progesterone-induced mammary histopathology in mice provides a model for the study of fibrocystic and hyperplastic breast disease.

  13. ADVERSE EFFECTS OF PRENATAL EXPOSURE TO ATRAZINE DURING A CRITICAL PERIOD OF MAMMARY GLAND GROWTH

    EPA Science Inventory

    Prenatal exposure to 100 mg/kg atrazine (ATR) was previously shown to delay mammary gland (MG) development in the female offspring of Long Evans (LE) rats. To determine if the fetal MG was most sensitive to ATR effects during specific periods of development, timed-pregnant dams ...

  14. Inhibition of STAT3 signaling blocks obesity-induced mammary hyperplasia in a mouse model

    PubMed Central

    Park, Jeong Won; Zhao, Li; Willingham, Mark C; Cheng, Sheue-Yann

    2017-01-01

    Compelling epidemiologic evidence indicates that obesity is a risk factor for human cancers, including breast. However, molecular mechanisms by which obesity could contribute to the development of breast cancer remain unclear. To understand the impact of obesity on breast cancer development, we used a mutant mouse that expresses a mutated thyroid hormone receptor β (denoted as PV) with haplodeficiency of the Pten gene (ThrbPV/PVPten+/- mice). We previously showed that adult nulliparous female ThrbPV/PVPten+/- mice developed extensive mammary hyperplasia and breast tumors. In this study, we induced obesity in ThrbPV/PVPten+/- mice by feeding them a high fat diet (HFD). We found HFD exacerbated the extent of mammary hyperplasia in ThrbPV/PVPten+/- mice. HFD elevated serum leptin levels but had no effect on the levels of serum thyroid stimulating hormone, thyroid hormones, and estrogens. Molecular analysis showed that the obesity-induced hyperplasia was mediated by the leptin/leptin receptor-JAK1-STAT3 pathway to increase key cell cycle regulators to stimulate mammary epithelial cell proliferation. Activated STAT3 signaling led to altered expression in the key regulators of epithelial-mesenchymal-transition (EMT) to augment invasiveness and migration of mammary proliferating epithelial cells. Moreover, treatment of HFD-ThrbPV/PVPten+/- mice with a STAT3 inhibitor, S3I-201, markedly reversed the obesity-induced mammary hyperplasia and reduced EMT signals to lessen cell invasiveness and migration. Our studies not only elucidated how obesity could contribute to mammary hyperplasia at the molecular level, but also, importantly, demonstrated that inhibition of the STAT3 activity could be a novel treatment strategy for obesity-induced breast cancer progression.

  15. Mammary stem cells have myoepithelial cell properties

    PubMed Central

    Prater, Michael D.; Petit, Valérie; Russell, I. Alasdair; Giraddi, Rajshekhar; Shehata, Mona; Menon, Suraj; Schulte, Reiner; Kalajzic, Ivo; Rath, Nicola; Olson, Michael F.; Metzger, Daniel; Faraldo, Marisa M.; Deugnier, Marie-Ange; Glukhova, Marina A.; Stingl, John

    2014-01-01

    Contractile myoepithelial cells dominate the basal layer of the mammary epithelium and are considered to be differentiated cells. However, we observe that up to 54% of single basal cells can form colonies when seeded into adherent culture in the presence of agents that disrupt acin-myosin interactions, and on average, 65% of the single-cell-derived basal colonies can repopulate a mammary gland when transplanted in vivo. This indicates that a high proportion of basal myoepithelial cells can give rise to a mammary repopulating unit (MRU). We demonstrate that myoepithelial cells, flow-sorted using 2 independent myoepithelial-specific reporter strategies, have MRU capacity. Using an inducible lineage tracing approach we follow the progeny of α-smooth muscle actin-expressing myoepithelial cells and show that they function as long-lived lineage-restricted stem cells in the virgin state and during pregnancy. PMID:25173976

  16. Quantitative Assessment of Mouse Mammary Gland Morphology Using Automated Digital Image Processing and TEB Detection.

    PubMed

    Blacher, Silvia; Gérard, Céline; Gallez, Anne; Foidart, Jean-Michel; Noël, Agnès; Péqueux, Christel

    2016-04-01

    The assessment of rodent mammary gland morphology is largely used to study the molecular mechanisms driving breast development and to analyze the impact of various endocrine disruptors with putative pathological implications. In this work, we propose a methodology relying on fully automated digital image analysis methods including image processing and quantification of the whole ductal tree and of the terminal end buds as well. It allows to accurately and objectively measure both growth parameters and fine morphological glandular structures. Mammary gland elongation was characterized by 2 parameters: the length and the epithelial area of the ductal tree. Ductal tree fine structures were characterized by: 1) branch end-point density, 2) branching density, and 3) branch length distribution. The proposed methodology was compared with quantification methods classically used in the literature. This procedure can be transposed to several software and thus largely used by scientists studying rodent mammary gland morphology.

  17. Bioengineered silk scaffolds in 3D tissue modeling with focus on mammary tissues.

    PubMed

    Maghdouri-White, Yas; Bowlin, Gary L; Lemmon, Christopher A; Dréau, Didier

    2016-02-01

    In vitro generation of three-dimensional (3D) biological tissues and organ-like structures is a promising strategy to study and closely model complex aspects of the molecular, cellular, and physiological interactions of tissue. In particular, in vitro 3D tissue modeling holds promises to further our understanding of breast development. Indeed, biologically relevant 3D structures that combine mammary cells and engineered matrices have improved our knowledge of mammary tissue growth, organization, and differentiation. Several polymeric biomaterials have been used as scaffolds to engineer 3D mammary tissues. Among those, silk fibroin-based biomaterials have many biologically relevant properties and have been successfully used in multiple medical applications. Here, we review the recent advances in engineered scaffolds with an emphasis on breast-like tissue generation and the benefits of modified silk-based scaffolds.

  18. A simple ductal mammary papilloma in a male maned wolf (Chrysocyon brachyurus).

    PubMed

    Cassali, Geovanni D; Bertagnolli, Angélica C; Ferreira, Enio; Malta, Marcelo C C

    2009-01-01

    A 1-cm-diameter nodule was identified in the left inguinal mammary gland of a 9-year-old male maned wolf (Chrysocyon brachyurus). The mass was surgically excised and examined histologically. Microscopically, the neoplasm consisted of papillary proliferations of epithelial cells on well-defined fibrovascular stalks. A myoepithelial layer was located between the single layer of epithelial cells and the fibrovascular stalk. This histologic appearance was compatible with a diagnosis of simple ductal mammary papilloma. Immunohistochemical staining was positive for p63, cytokeratins AE1/AE3, and estrogen receptors. The clinical and histologic observations in the present case indicate that male maned wolves may develop mammary tumors that are similar to those observed in domestic dogs and humans.

  19. Identification and characterization of cancer stem cells in canine mammary tumors.

    PubMed

    Rybicka, Agata; Król, Magdalena

    2016-12-19

    Cancer stem cells (CSC) represent a small subpopulation of cells in malignant tumors that possess the unique ability to self-renew, differentiate and resist chemo- and radiotherapy. These cells have been postulated to be the basis for some of the difficulties in treating cancer, and therefore, numerous approaches have been developed to specifically target and eliminate CSC in diverse types of cancer, including breast cancer. Spontaneously occurring mammary tumors in canines share clinical and molecular similarities with the human counterpart, making the dog a potentially powerful model for the study of human breast cancer and clinical trials. Studies focused on canine mammary CSC might therefore enhance our understanding of the biology and possible treatment of the disease in both dogs and humans. In this review, we discuss various approaches currently in use to isolate and characterize canine mammary CSC.

  20. MTA family of transcriptional metaregulators in mammary gland morphogenesis and breast cancer.

    PubMed

    Singh, Rajesh R; Kumar, Rakesh

    2007-09-01

    Since breast cancer and its associated metastasis are a global health problem and a major cause of mortality among women, research efforts to understand the development, morphogenesis, and functioning of the mammary gland are a high priority. Myriad signaling pathways, transcription factors, and associated transcriptional coregulators have been identified in both normal functioning and neoplastic transformation of the mammary gland. The discovery of the metastasis tumor antigen 1 (MTA1) gene, its overexpression in cancer and metastasis and its subsequent identification as an integral part of the chromatin remodeling complex heralded extensive research on its physiological role. Subsequent identification of additional gene family members, namely MTA1s, MTA2, and MTA3, and their functions in the cell has resulted in the establishment of the significance of the MTA family. The role of these proteins in modulating hormonal responses in normal mammary glands and in breast cancer has resulted in their identification as important molecular markers and potential therapeutic targets.

  1. Remodeling of endogenous mammary epithelium by breast cancer stem cells.

    PubMed

    Parashurama, Natesh; Lobo, Neethan A; Ito, Ken; Mosley, Adriane R; Habte, Frezghi G; Zabala, Maider; Smith, Bryan R; Lam, Jessica; Weissman, Irving L; Clarke, Michael F; Gambhir, Sanjiv S

    2012-10-01

    Poorly regulated tissue remodeling results in increased breast cancer risk, yet how breast cancer stem cells (CSC) participate in remodeling is unknown. We performed in vivo imaging of changes in fluorescent, endogenous duct architecture as a metric for remodeling. First, we quantitatively imaged physiologic remodeling of primary branches of the developing and regenerating mammary tree. To assess CSC-specific remodeling events, we isolated CSC from MMTV-Wnt1 (mouse mammary tumor virus long-term repeat enhancer driving Wnt1 oncogene) breast tumors, a well studied model in which tissue remodeling affects tumorigenesis. We confirm that CSC drive tumorigenesis, suggesting a link between CSC and remodeling. We find that normal, regenerating, and developing gland maintain a specific branching pattern. In contrast, transplantation of CSC results in changes in the branching patterns of endogenous ducts while non-CSC do not. Specifically, in the presence of CSC, we identified an increased number of branches, branch points, ducts which have greater than 40 branches (5/33 for CSC and 0/39 for non-CSC), and histological evidence of increased branching. Moreover, we demonstrate that only CSC implants invade into surrounding stroma with structures similar to developing mammary ducts (nine for CSC and one for non-CSC). Overall, we demonstrate a novel approach for imaging physiologic and pathological remodeling. Furthermore, we identify unique, CSC-specific, remodeling events. Our data suggest that CSC interact with the microenvironment differently than non-CSC, and that this could eventually be a therapeutic approach for targeting CSC.

  2. Genetic bases of estrogen-induced tumorigenesis in the rat: mapping of loci controlling susceptibility to mammary cancer in a Brown Norway x ACI intercross.

    PubMed

    Schaffer, Beverly S; Lachel, Cynthia M; Pennington, Karen L; Murrin, Clare R; Strecker, Tracy E; Tochacek, Martin; Gould, Karen A; Meza, Jane L; McComb, Rodney D; Shull, James D

    2006-08-01

    Exposure to estrogens is associated with an increased risk of breast cancer. Our laboratory has shown that the ACI rat is uniquely susceptible to 17beta-estradiol (E2)-induced mammary cancer. We previously mapped two loci, Emca1 and Emca2 (estrogen-induced mammary cancer), that act independently to determine susceptibility to E2-induced mammary cancer in crosses between the susceptible ACI rat strain and the genetically related, but resistant, Copenhagen (COP) rat strain. In this study, we evaluate susceptibility to E2-induced mammary cancer in a cross between the ACI strain and the unrelated Brown Norway (BN) rat strain. Whereas nearly 100% of the ACI rats developed mammary cancer when treated continuously with E2, BN rats did not develop palpable mammary cancer during the 196-day course of E2 treatment. Susceptibility to E2-induced mammary cancer segregated as a dominant or incompletely dominant trait in a cross between BN females and ACI males. In a population of 251 female (BN x ACI)F(2) rats, we observed evidence for a total of five genetic determinants of susceptibility. Two loci, Emca4 and Emca5, were identified when mammary cancer status at sacrifice was evaluated as the phenotype, and three additional loci, Emca6, Emca7, and Emca8, were identified when mammary cancer number was evaluated as the phenotype. A total of three genetic interactions were identified. These data indicate that susceptibility to E2-induced mammary cancer in the BN x ACI cross behaves as a complex trait controlled by at least five loci and multiple gene-gene interactions.

  3. Methods for preparing fluorescent and neutral red-stained whole mounts of mouse mammary glands.

    PubMed

    Landua, John D; Visbal, Adriana P; Lewis, Michael T

    2009-12-01

    Whole mount preparations of mouse mammary glands are useful for evaluating overall changes in growth and morphology, and are essential for detecting and evaluating focal or regionally-localized phenotypes that would be difficult to detect or analyze using other techniques. We present three newly developed methods for preparing whole mounts of mammary glands from genetically-engineered mice expressing fluorescent proteins, as well as using either neutral red or a variety of fluorescent dyes. Unlike traditional hematoxylin- or carmine-stained preparations, neutral red-stained and some fluorescent preparations can be used for several common downstream analyses.

  4. Suppression of ICE and Apoptosis in Mammary Epithelial Cells by Extracellular Matrix

    SciTech Connect

    Boudreau, Nancy; Sympson, C. J.; Werb, Zena; Bissell, Mina J.

    1994-12-01

    Apoptosis (programmed cell death) plays a major role in development and tissue regeneration. Basement membrane extracellular matrix (ECM), but not fibronectin or collagen, was shown to suppress apoptosis of mammary epithelial cells in tissue culture and in vivo. Apoptosis was induced by antibodies to beta 1 integrins or by overexpression of stromelysin-1, which degrades ECM. Expression of interleukin-1 beta converting enzyme (ICE) correlated with the loss of ECM, and inhibitors of ICE activity prevented apoptosis. These results suggest that ECM regulates apoptosis in mammary epithelial cells through an integrin-dependent negative regulation of ICE expression.

  5. Canine mammary tumour cell lines established in vitro.

    PubMed

    Hellmén, E

    1993-01-01

    Mammary tumours are the most common tumours in the female dog. The tumours have a complex histology and exist in epithelial, mixed and mesenchymal forms. To study the biology of canine mammary tumours, five cell lines have been established and characterized. The results indicate that canine mammary tumours might be derived from mammary stem cells and that the tumour growth is independent of oestrogens. The established canine mammary tumour cell lines will be valuable tools in further studies of the histogenesis and pathogenesis of these tumours.

  6. Characterization of Human Mammary Epithelial Stem Cells

    DTIC Science & Technology

    2009-10-01

    Appendix……………………………………………………………………………… 11 Eirew,P., Stingl,J., Raouf,A., Turashvili,G., Aparicio ,S., Emerman,J.T., and Eaves,C.J. A method for... Aparicio , Joanne Emerman and Connie Eaves. A method for quantifying normal human mammary epithelial stem cells with in vivo regenerative ability...Abstracts Peter Eirew, John Stingl, Afshin Raouf, Gulisa Turshvili, Sam Aparicio , Joanne Emerman and Connie Eaves, “Identification of Human Mammary

  7. Protein tyrosine kinase 6 promotes ERBB2-induced mammary gland tumorigenesis in the mouse

    PubMed Central

    Peng, M; Ball-Kell, S M; Tyner, A L

    2015-01-01

    Protein tyrosine kinase 6 (PTK6) expression, activation, and amplification of the PTK6 gene have been reported in ERBB2/HER2-positive mammary gland cancers. To explore contributions of PTK6 to mammary gland tumorigenesis promoted by activated ERBB2, we crossed Ptk6−/− mice with the mouse mammary tumor virus-ERBB2 transgenic mouse line expressing activated ERBB2 and characterized tumor development and progression. ERBB2-induced tumorigenesis was significantly delayed and diminished in mice lacking PTK6. PTK6 expression was induced in the mammary glands of ERBB2 transgenic mice before tumor development and correlated with activation of signal transducer and activator of transcription 3 (STAT3) and increased proliferation. Disruption of PTK6 impaired STAT3 activation and proliferation. Phosphorylation of the PTK6 substrates focal adhesion kinase (FAK) and breast cancer anti-estrogen resistance 1 (BCAR1; p130CAS) was decreased in Ptk6−/− mammary gland tumors. Reduced numbers of metastases were detected in the lungs of Ptk6−/− mice expressing activated ERBB2, compared with wild-type ERBB2 transgenic mice. PTK6 activation was detected at the edges of ERBB2-positive tumors. These data support roles for PTK6 in both ERBB2-induced mammary gland tumor initiation and metastasis, and identify STAT3, FAK, and BCAR1 as physiologically relevant PTK6 substrates in breast cancer. Including PTK6 inhibitors as part of a treatment regimen could have distinct benefits in ERBB2/HER2-positive breast cancers. PMID:26247733

  8. The role of unfolded protein response in differentiation of mammary epithelial cells.

    PubMed

    Tsuchiya, Megumi; Koizumi, Yumiko; Hayashi, Satoko; Hanaoka, Miyuki; Tokutake, Yukako; Yonekura, Shinichi

    2017-03-18

    The accumulation of misfolded proteins in the ER provokes ER stress by increasing the demand for energy, chaperones, and other proteins that are needed to fold client proteins or to degrade unfoldable secretory cargo. This stress activates a signaling network called the unfolded protein response (UPR). However, recent accumulated data suggested that the UPR also provides important signals for regulating cell differentiation and maturation. However, the relationship between UPR and mammary gland development has not been fully elucidated. To define the involvement of the UPR in mammary gland development, mammary glands were collected from non-pregnant mice, at days 5, 10 and 15 of pregnancy, at days 1 and 7 of lactation, and the expression patterns of UPR-related genes were determined by real-time PCR. We found that the mRNA expression of ATF4 and XBP1 significant increased during pregnancy. Moreover, we found that both ATF4 and XBP1 proteins are expressed in mammary epithelial cells by immunohistological analysis. In order to know the role of ATF4 and XBP1 in the differentiation of mammary epithelial cell, we performed gene knockdown experiment using HC11 cells. We found that ATF4 or XBP1 knockdown suppressed the mRNA expression of beta-casein and lactogenic hormone receptor in differentiating HC11 cells. Our results demonstrate that XBP1 and ATF4, which are UPR-related transcription factors, directly or indirectly participate in cell differentiation mechanisms through the regulation of the expression of lactogenic hormone receptors in mouse mammary epithelial cells.

  9. CLINICOPATHOLOGIC FEATURES OF MAMMARY MASSES IN CAPTIVE LIONS (PANTHERA LEO).

    PubMed

    Sadler, Ryan A; Craig, Linden E; Ramsay, Edward C; Helmick, Kelly; Collins, Darin; Garner, Michael M

    2016-03-01

    A multi-institutional retrospective analysis of 330 pathology accessions from 285 different lions found 15 captive, female African lions (Panthera leo) with confirmed mammary masses. Aside from the presence of a mammary mass, the most common initial clinical sign was inappetence. Histologic diagnoses were predominantly adenocarcinoma (n = 12), though two benign masses (mammary hyperplasia and a mammary cyst) and one squamous cell carcinoma were identified. Nine of 13 malignant tumors had metastasized to lymph nodes or viscera at the time of necropsy. Six lions with adenocarcinoma and two lions with benign mammary masses had received hormonal contraception, though little evidence of mammary lobular hyperplasia was seen in association with the adenocarcinomas. The most common concurrent disease processes found at necropsy were chronic urinary tract disease and other malignancies. These cases demonstrate that mammary malignancies occur in captive lions and frequently metastasize.

  10. Ligand-Independent Canonical Wnt Activity in Canine Mammary Tumor Cell Lines Associated with Aberrant LEF1 Expression

    PubMed Central

    van Wolferen, Monique E.; Rao, Nagesha A. S.; Grizelj, Juraj; Vince, Silvijo; Hellmen, Eva; Mol, Jan A.

    2014-01-01

    Pet dogs very frequently develop spontaneous mammary tumors and have been suggested as a good model organism for breast cancer research. In order to obtain an insight into underlying signaling mechanisms during canine mammary tumorigenesis, in this study we assessed the incidence and the mechanism of canonical Wnt activation in a panel of 12 canine mammary tumor cell lines. We show that a subset of canine mammary cell lines exhibit a moderate canonical Wnt activity that is dependent on Wnt ligands, similar to what has been described in human breast cancer cell lines. In addition, three of the tested canine mammary cell lines have a high canonical Wnt activity that is not responsive to inhibitors of Wnt ligand secretion. Tumor cell lines with highly active canonical Wnt signaling often carry mutations in key members of the Wnt signaling cascade. These cell lines, however, carry no mutations in the coding regions of intracellular Wnt pathway components (APC, β-catenin, GSK3β, CK1α and Axin1) and have a functional β-catenin destruction complex. Interestingly, however, the cell lines with high canonical Wnt activity specifically overexpress LEF1 mRNA and the knock-down of LEF1 significantly inhibits TCF-reporter activity. In addition, LEF1 is overexpressed in a subset of canine mammary carcinomas, implicating LEF1 in ligand-independent activation of canonical Wnt signaling in canine mammary tumors. We conclude that canonical Wnt activation may be a frequent event in canine mammary tumors both through Wnt ligand-dependent and novel ligand–independent mechanisms. PMID:24887235

  11. The hedgehog signaling network, mammary stem cells, and breast cancer: connections and controversies.

    PubMed

    Lewis, M T; Visbal, A P

    2006-01-01

    Several signal transduction networks have been implicated in the regulation of mammary epithelial stem cell self-renewal and maintenance (Kalirai and Clarke 2006; Liu et al. 2005). These signaling networks include those of the Wnt, Notch, TGFO, EGF, FGF, IGF, and most recently, the Hedgehog (Hh) families of secreted ligands. However, we currently know very little about the cellular and molecular mechanisms by which these signaling pathways function to regulate normal epithelial stem/progenitor cells. What is clear is that the regulatory signaling networks thought to control normal stem/progenitor cell self-renewal and maintenance are, with the current sole exception of the hedgehog network, well-documented to have contributory roles in mammary cancer development and disease progression when misregulated. In this review, genetic regulation of mammary gland development by hedgehog network genes is outlined, highlighting a developing controversy as to whether activated hedgehog signaling regulates normal regenerative mammary epithelial stem cells or, indeed, whether activated hedgehog signaling functions at all in ductal development. In addition, the question of whether inappropriate hedgehog network activation influences breast cancer development is addressed, with emphasis on the prospects for using hedgehog signaling antagonists clinically for breast cancer treatment or prevention.

  12. The Par3/aPKC interaction is essential for end bud remodeling and progenitor differentiation during mammary gland morphogenesis

    PubMed Central

    McCaffrey, Luke Martin; Macara, Ian G.

    2009-01-01

    Mammalian polarity proteins have been studied predominantly in cell culture systems, and little is known about their functions in vivo. To address this issue, we used a shRNA lentiviral system to manipulate gene expression in mouse mammary stem/progenitor cells. Transplantation of Par3-depleted stem/progenitor cells into the mammary fat pad severely disrupted mammary development, and glands were characterized by ductal hyperplasia, luminal filling, and highly disorganized end bud structures that were unable to remodel into normal ductal structures. Unexpectedly, Par3-depleted mammary glands also had an expanded progenitor population. We identified a novel function for the atypical protein kinase C (aPKC)-binding domain of Par3 in restricting Par3 and aPKC to the apical region in mammary epithelia in vivo, and found that mammary morphogenesis is dependent on the ability of Par3 to directly bind aPKC. These results reveal a new function for Par3 in the regulation of progenitor differentiation and epithelial morphogenesis in vivo and demonstrate for the first time an essential requirement for the Par3–aPKC interaction. PMID:19528321

  13. Early neoplastic and metastatic mammary tumours of transgenic mice detected by 5-aminolevulinic acid-stimulated protoporphyrin IX accumulation

    PubMed Central

    Dorward, A M; Fancher, K S; Duffy, T M; Beamer, W G; Walt, H

    2005-01-01

    A photodynamic technique for human breast cancer detection founded upon the ability of tumour cells to rapidly accumulate the fluorescent product protoporphyrin IX (PpIX) has been applied to transgenic mouse models of mammary tumorigenesis. A major goal of this investigation was to determine whether mouse mammary tumours are reliable models of human disease in terms of PpIX accumulation, for future mechanistic and therapeutic studies. The haeme substrate 5-aminolevulinic acid (5-ALA) (200 mg kg−1) was administered to mouse strains that develop mammary tumours of various histological subtypes upon expression of the transgenic oncogenes HRAS, Polyoma Virus middle T antigen, or Simian Virus 40 large T antigen in the mammary gland. Early neoplastic lesions, primary tumours and metastases showed consistent and rapid PpIX accumulation compared to the normal surrounding tissues, as evidenced by red fluorescence (635 nm) when the tumours were directly illuminated with blue light (380–440 nm). Detection of mouse mammary tumours at the stage of ductal carcinoma in situ by red fluorescence emissions suggests that enhanced PpIX synthesis is a good marker for early tumorigenic processes in the mammary gland. We propose the mouse models provide an ideal experimental system for further investigation of the early diagnostic and therapeutic potential of 5-ALA-stimulated PpIX accumulation in human breast cancer patients. PMID:16251872

  14. Xanthosine administration does not affect the proportion of epithelial stem cells in bovine mammary tissue, but has a latent negative effect on cell proliferation

    SciTech Connect

    Rauner, Gat; Barash, Itamar

    2014-10-15

    The challenge in manipulating the proportion of somatic stem cells lies in having to override tissue homeostasis. Xanthosine infusion via the teat canal has been reported to augment the number of label-retaining cells in the mammary gland of 3-month-old bovine calves. To further delineate xanthosine's effect on defined stem cells in the mammary gland of heifers—which are candidates for increased prospective milk production following such manipulation—bovine mammary parenchymal tissue was transplanted and integrated into the cleared mammary fat pad of immunodeficient mice. Xanthosine administration for 14 days did not affect the number of label-retaining cells after 10- and 11-week chases. No change in stem cell proportion, analyzed according to CD49f and CD24 expression, was noted. Clone formation and propagation rate of cultured cells, as well as expression of stem cell markers, were also unaffected. In contrast, a latent 50% decrease in bovine mammary cell proliferation rate was observed 11 weeks after xanthosine administration. Tumor development in mice was also limited by xanthosine administration. These effects may have resulted from an initial decrease in expression of the rate-limiting enzyme in guanine synthesis, IMPDH. The data indicate that caution should be exerted when considering xanthosine for stem cell manipulation. - Highlights: • Novel “bovinized“ mouse model for exogenous effects on bovine mammary gland. • Xanthosine did not affect stem cell number/function in bovine mammary gland. • Xanthosine caused an immediate decrease in IMPDH expression in bovine mammary gland. • Xanthosine had latent negative effect on cell proliferation in bovine mammary gland. • Xanthosine administration limited mammary tumor growth.

  15. Hyaluronan modulates growth factor induced mammary gland branching in a size dependent manner.

    PubMed

    Tolg, Cornelia; Yuan, Han; Flynn, Sarah M; Basu, Kaustuv; Ma, Jenny; Tse, Kenneth Chor Kin; Kowalska, Beatrice; Vulkanesku, Diana; Cowman, Mary K; McCarthy, James B; Turley, Eva A

    2017-02-21

    Mammary gland morphogenesis begins during fetal development but expansion of the mammary tree occurs postnatally in response to hormones, growth factors and extracellular matrix. Hyaluronan (HA) is an extracellular matrix polysaccharide that has been shown to modulate growth factor-induced branching in culture. Neither the physiological relevance of HA to mammary gland morphogenesis nor the role that HA receptors play in these responses are currently well understood. We show that HA synthase (HAS2) is expressed in both ductal epithelia and stromal cells but HA primarily accumulates in the stroma. HA accumulation and expression of the HA receptors CD44 and RHAMM are highest during gestation when gland remodeling, lateral branch infilling and lobulo-alveoli formation is active. Molecular weight analyses show that approximately 98% of HA at all stages of morphogenesis is >300kDa. Low levels of 7-114kDa HA fragments are also detected and in particular the accumulation of 7-21kDa HA fragments are significantly higher during gestation than other morphogenetic stages (p<0.05). Using these in vivo results as a guide, in culture analyses of mammary epithelial cell lines (EpH4 and NMuMG) were performed to determine the roles of high molecular weight, 7-21kDa (10kDa MWavg) and HA receptors in EGF-induced branching morphogenesis. Results of these assays show that while HA synthesis is required for branching and 10kDa HA fragments strongly stimulate branching, the activity of HA decreases with increasing molecular weight and 500kDa HA strongly inhibits this morphogenetic process. The response to 10kDa HA requires RHAMM function and genetic deletion of RHAMM transiently blunts lateral branching in vivo. Collectively, these results reveal distinct roles for HA polymer size in modulating growth factor induced mammary gland branching and implicates these polymers in both the expansion and sculpting of the mammary tree during gestation.

  16. Wound healing-like immune program facilitates postpartum mammary gland involution and tumor progression.

    PubMed

    Martinson, Holly A; Jindal, Sonali; Durand-Rougely, Clarissa; Borges, Virginia F; Schedin, Pepper

    2015-04-15

    Women diagnosed with breast cancer within 5 years postpartum have poor survival rates. The process of postpartum mammary gland involution, whereby the lactating gland remodels to its prepregnant state, promotes breast cancer progression in xenograft models. Macrophage influx occurs during mammary gland involution, implicating immune modulation in the promotion of postpartum breast cancer. Herein, we characterize the postpartum murine mammary gland and find an orchestrated influx of immune cells similar to that which occurs during wound healing. Further, the normal involuting gland may be in an immunosuppressed state as discerned by the transient presence of Foxp3(+) regulatory T cells and IL-10(+) macrophages with T cell suppressive function. To determine the influence of the postpartum immune microenvironment on mammary tumor promotion, we developed an immune-competent model. In this model, mammary tumors in the involution group are sixfold larger than nulliparous group tumors, have decreased CD4(+) and CD8(+) T cell infiltrates and contain a greater number of macrophages with the ability to inhibit T cell activation. Targeting involution with a neutralizing antibody against the immunosuppressive cytokine IL-10 reduces tumor growth in involution group mice but not in nulliparous mice, implicating the involution microenvironment as the primary target of αIL-10 treatment. Relevance to women is implicated, as we find postlactational human breast tissue has transient high IL-10(+) and Foxp3(+) immune cell infiltrate. These data show an immune modulated microenvironment within the normal involuting mammary gland suggestive of immunosuppression, that when targeted reduces tumor promotion, revealing possible immune-based strategies for postpartum breast cancer.

  17. Epidermal growth factor precursor in mouse lactating mammary gland alveolar cells

    SciTech Connect

    Brown, C.F.; Teng, C.T.; Pentecost, B.T.; DiAugustine, R.P. )

    1989-07-01

    Previous studies have demonstrated that high levels of epidermal growth factor (EGF) occur in human and rodent milk and that oral administration of this polypeptide stimulates rodent gastrointestinal development. It is not known whether EGF in milk originates from cells of the lactating mammary gland or is sequestered from an extramammary source. In the present study, prepro-EGF mRNA (approximately 4.7 kilobases) was detected in the CD-1 mouse mammary gland throughout the period of lactation; by comparison, negligible levels of this EGF transcript were found in the gland during pregnancy. Low levels of EGF immunoreactivity (4-5 ng/g wet wt tissue) were extracted from lactating (day 18) mammary glands with dilute acetic acid. Immunolocalization was evident with antisera to either EGF or two other regions of the EGF precursor in essentially all alveolar cells of the lactating gland. The most prominent staining with antiserum to EGF was observed along the luminal borders of cells; this pattern of cellular staining required proteolytic pretreatment of tissue sections. Western blot analyses of cell membranes isolated from the day 16 lactating mammary gland revealed an EGF-immunoreactive band at about 145K, which was equivalent in size to the EGF precursor found in mouse kidney cell membranes. Despite these findings, labeling of lactating mammary gland mince with L-(35S)methionine and cysteine for up to 4 h did not reveal any specific bands in immunoprecipitates. These cumulative findings suggest that the precursor form of EGF occurs in alveolar cells of lactating mammary gland and that this protein is translocated to the cell membrane.

  18. Histopathological and in vivo evidence of regucalcin as a protective molecule in mammary gland carcinogenesis

    SciTech Connect

    Marques, Ricardo; Vaz, Cátia V.; Maia, Cláudio J.; Gomes, Madalena; Gama, Adelina; Alves, Gilberto; Santos, Cecília R.; Schmitt, Fernando; Socorro, Sílvia

    2015-01-15

    Regucalcin (RGN) is a calcium-binding protein, which has been shown to be underexpressed in cancer cases. This study aimed to determine the association of RGN expression with clinicopathological parameters of human breast cancer. In addition, the role of RGN in malignancy of mammary gland using transgenic rats overexpressing the protein (Tg-RGN) was investigated. Wild-type (Wt) and Tg-RGN rats were treated with 7,12-dimethylbenz[α]anthracene (DMBA). Carcinogen-induced tumors were histologically classified and the Ki67 proliferation index was estimated. Immunohistochemistry analysis showed that RGN immunoreactivity was negatively correlated with the histological grade of breast infiltrating ductal carcinoma suggesting that progression of breast cancer is associated with loss of RGN. Tg-RGN rats displayed lower incidence of carcinogen-induced mammary gland tumors, as well as lower incidence of invasive forms. Moreover, higher proliferation was observed in non-invasive tumors of Wt animals comparatively with Tg-RGN. Overexpression of RGN was associated with diminished expression of cell-cycle inhibitors and increased expression of apoptosis inducers. Augmented activity of apoptosis effector caspase-3 was found in the mammary gland of Tg-RGN. RGN overexpression protected from carcinogen-induced mammary gland tumor development and was linked with reduced proliferation and increased apoptosis. These findings indicated the protective role of RGN in the carcinogenesis of mammary gland. - Highlights: • RGN immunoreactivity was negatively correlated with breast cancer differentiation. • Transgenic overexpression of RGN diminished incidence of carcinogen-induced tumors. • Transgenic overexpression of RGN restricted proliferation and fostered apoptosis. • RGN has a protective role in the carcinogenesis of mammary gland.

  19. Mouse mammary tumor virus-like nucleotide sequences in canine and feline mammary tumors.

    PubMed

    Hsu, Wei-Li; Lin, Hsing-Yi; Chiou, Shyan-Song; Chang, Chao-Chin; Wang, Szu-Pong; Lin, Kuan-Hsun; Chulakasian, Songkhla; Wong, Min-Liang; Chang, Shih-Chieh

    2010-12-01

    Mouse mammary tumor virus (MMTV) has been speculated to be involved in human breast cancer. Companion animals, dogs, and cats with intimate human contacts may contribute to the transmission of MMTV between mouse and human. The aim of this study was to detect MMTV-like nucleotide sequences in canine and feline mammary tumors by nested PCR. Results showed that the presence of MMTV-like env and LTR sequences in canine malignant mammary tumors was 3.49% (3/86) and 18.60% (16/86), respectively. For feline malignant mammary tumors, the presence of both env and LTR sequences was found to be 22.22% (2/9). Nevertheless, the MMTV-like LTR and env sequences also were detected in normal mammary glands of dogs and cats. In comparisons of the MMTV-like DNA sequences of our findings to those of NIH 3T3 (MMTV-positive murine cell line) and human breast cancer cells, the sequence similarities ranged from 94 to 98%. Phylogenetic analysis revealed that intermixing among sequences identified from tissues of different hosts, i.e., mouse, dog, cat, and human, indicated the MMTV-like DNA existing in these hosts. Moreover, the env transcript was detected in 1 of the 19 MMTV-positive samples by reverse transcription-PCR. Taken together, our study provides evidence for the existence and expression of MMTV-like sequences in neoplastic and normal mammary glands of dogs and cats.

  20. Mouse Mammary Tumor Virus-Like Nucleotide Sequences in Canine and Feline Mammary Tumors▿

    PubMed Central

    Hsu, Wei-Li; Lin, Hsing-Yi; Chiou, Shyan-Song; Chang, Chao-Chin; Wang, Szu-Pong; Lin, Kuan-Hsun; Chulakasian, Songkhla; Wong, Min-Liang; Chang, Shih-Chieh

    2010-01-01

    Mouse mammary tumor virus (MMTV) has been speculated to be involved in human breast cancer. Companion animals, dogs, and cats with intimate human contacts may contribute to the transmission of MMTV between mouse and human. The aim of this study was to detect MMTV-like nucleotide sequences in canine and feline mammary tumors by nested PCR. Results showed that the presence of MMTV-like env and LTR sequences in canine malignant mammary tumors was 3.49% (3/86) and 18.60% (16/86), respectively. For feline malignant mammary tumors, the presence of both env and LTR sequences was found to be 22.22% (2/9). Nevertheless, the MMTV-like LTR and env sequences also were detected in normal mammary glands of dogs and cats. In comparisons of the MMTV-like DNA sequences of our findings to those of NIH 3T3 (MMTV-positive murine cell line) and human breast cancer cells, the sequence similarities ranged from 94 to 98%. Phylogenetic analysis revealed that intermixing among sequences identified from tissues of different hosts, i.e., mouse, dog, cat, and human, indicated the MMTV-like DNA existing in these hosts. Moreover, the env transcript was detected in 1 of the 19 MMTV-positive samples by reverse transcription-PCR. Taken together, our study provides evidence for the existence and expression of MMTV-like sequences in neoplastic and normal mammary glands of dogs and cats. PMID:20881168

  1. Mammary Cancer and Activation of Transposable Elements

    DTIC Science & Technology

    2014-09-01

    AD_________________ AWARD NUMBER: W81XWH-11-1-0401 TITLE: Mammary Cancer and Activation of Transposable Elements PRINCIPAL INVESTIGATOR...way as transcripts from the regular gene promoter. Transcriptional activation of retrotransposons is strongly linked with their CpG DNA methylation

  2. Early effects of dietary soy and genistein in rodent models of mammary tumorigenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The risk of breast cancer is highly modifiable by diet. Breast cancer may have its origins during early mammary development, thus the increasing popularity of soy food consumption among pregnant and breast-feeding women and early exposure to soy protein and bioactive components through soy infant fo...

  3. Myoepithelial cell differentiation markers in prepubertal bovine mammary gland: Effect of ovariectomy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously reported that ovariectomy alters prepubertal development of mammary myoepithelial cells (MC), but the mechanisms involved are not well understood. We therefore analyzed the expression of the myoepithelial differentiation markers a-smooth muscle actin (SMA) and the common acute ly...

  4. A Rapid Method for BrdU Immunostaining in Bovine Mammary Cryosections that Retains RNA Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid method of 5-bromo-2’-deoxyuridine (BrdU) immunostaining was developed in cryosections of bovine mammary tissue, while preserving RNA quality of the stained section. BrdU is a thymidine analog that is incorporated into DNA of proliferating cells and thus serves as a proliferation marker. Im...

  5. Generation and characterization of a breast carcinoma model by PyMT overexpression in mammary epithelial cells of tree shrew, an animal close to primates in evolution.

    PubMed

    Ge, Guang-Zhe; Xia, Hou-Jun; He, Bao-Li; Zhang, Hai-Lin; Liu, Wen-Jing; Shao, Ming; Wang, Chun-Yan; Xiao, Ji; Ge, Fei; Li, Fu-Bing; Li, Yi; Chen, Ceshi

    2016-02-01

    The tree shrew is becoming an attractive experimental animal model for human breast cancer owing to a closer relationship to primates/humans than rodents. Tree shrews are superior to classical primates because tree shrew are easier to manipulate, maintain and propagate. It is required to establish a high-efficiency tree shrew breast cancer model for etiological research and drug assessment. Our previous studies suggest that 7,12-dimethylbenz(a)anthracene (DMBA) and medroxyprogesterone acetate (MPA) induce breast tumors in tree shrews with a low frequency (<50%) and long latency (∼ 7-month), making these methods less than ideal. We induced mammary tumors in tree shrew (Tupaia belangeri chinensis) by injection of lentivirus expressing the PyMT oncogene into mammary ducts of 22 animals. Most tree shrews developed mammary tumors with a latency of about three weeks, and by 7 weeks all injected tree shrews had developed mammary tumors. Among these, papillary carcinoma is the predominant tumor type. One case showed lymph node and lung metastasis. Interestingly, the expression levels of phosphorylated AKT, ERK and STAT3 were elevated in 41-68% of PyMT-induced mammary tumors, but not all tumors. Finally, we observed that the growth of PyMT-induced tree shrew mammary tumors was significantly inhibited by Cisplatin and Epidoxorubicin. PyMT-induced tree shrew mammary tumor model may be suitable for further breast cancer research and drug development, due to its high efficiency and short latency.

  6. Molecular cytogenetic characterization of mammary neuroendocrine carcinoma.

    PubMed

    Xiang, De-Bing; Wei, Bing; Abraham, Susan C; Huo, Lei; Albarracin, Constance T; Zhang, Hong; Babiera, Gildy; Caudle, Abigail S; Akay, Catherine L; Rao, Pulivarthi; Zhao, Yi-Jue; Lu, Xinyan; Wu, Yun

    2014-09-01

    Primary mammary neuroendocrine carcinoma (NEC) is an uncommon entity that accounts for 2% to 5% of breast carcinomas. Recent reports have shown that NEC of the breast is an aggressive subtype of mammary carcinoma that is distinct from invasive ductal carcinoma, not otherwise specified, and have suggested that these tumors have a poorer prognosis than invasive ductal carcinoma, not otherwise specified. In this study, we provide the first cytogenetic characterization of mammary NEC using both conventional G-banding and spectral karyotype on a group of 7 tumors. We identified clonal chromosomal aberrations in 5 (71.4%) cases, with 4 of them showing complex karyotypes. Of these, recurrent numerical aberrations included gain of chromosome 7 (n = 2) and loss of chromosome 15 (n = 2). Recurrent clonal structural chromosomal aberrations involved chromosomes 1 (n = 3), 3 (n = 2), 6q (n = 3), and 17q (n = 3). Of the 4 (57.1%) cases with complex karyotypes, 2 showed evidence of chromothripsis, a phenomenon in which tens to hundreds of genomic rearrangements occur in a one-off cellular crisis. One of these had evidence of chromothripsis involving chromosomes 1, 6, 8, and 15. The other also had evidence of chromosome 8 chromothripsis, making this a recurrent finding shared by both cases. We also found that mammary NEC shared some cytogenetic abnormalities--such as trisomy 7 and 12--with other neuroendocrine tumors in the lung and gastrointestinal tract, suggesting trisomy 7 and 12 as potential common molecular aberrations in neuroendocrine tumors. To our knowledge, this is the first report on molecular cytogenetic characterization of mammary NEC.

  7. Mouse mammary tumor virus infection accelerates mammary carcinogenesis in Wnt-1 transgenic mice by insertional activation of int-2/Fgf-3 and hst/Fgf-4.

    PubMed Central

    Shackleford, G M; MacArthur, C A; Kwan, H C; Varmus, H E

    1993-01-01

    Transgenic mice carrying the Wnt-1 protooncogene modified for expression in mammary epithelial cells exhibit hyperplastic mammary glands and stochastically develop mammary carcinomas, suggesting that additional events are necessary for tumorigenesis. To induce such events and to identify the genes involved, we have infected Wnt-1 transgenic mice with mouse mammary tumor virus (MMTV), intending to insertionally activate, and thereby molecularly tag, cooperating protooncogenes. Infection of breeding female Wnt-1 transgenics decreased the average age at which tumors appeared from approximately 4 months to approximately 2.5 months and increased the average number of primary tumors per mouse from 1-2 to > 5. A smaller effect was observed in virgin females, and infection of transgenic males showed no significant effect on tumor latency. More than half of the tumors from the infected breeding group contained one or more newly acquired MMTV proviruses in a pattern suggesting that most cells in tumors arose from a single infected cell. Analyses of provirus-containing tumors for induced or altered expression of int-2/Fgf-3, hst/Fgf-4, int-3, and Wnt-3 showed activation of int-2 in 39% of tumors, hst in 3%, and both int-2 and hst in 3%. DNA analyses with probes for protooncogenes and MMTV confirmed that the activations resulted from proviral insertions. There was no evidence for proviral insertions at the int-3, Wnt-3, or Wnt-1 loci. These findings provide further evidence that fibroblast growth factors Int-2 and Hst can cooperate with Wnt-1, another secreted factor, in mammary tumorigenesis, and they illustrate the capacity of this system to identify cooperating oncogenes. Images PMID:8380647

  8. Radiogenic neoplasia in thyroid and mammary clonogens

    SciTech Connect

    Clifton, K.H.

    1992-05-20

    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. Previous results indicated that these clonogens are the precursor cells of radiogenic cancer, and that initiation, is common event at the clonegenic cell level. Detailed information on the physiologic control of clonogen proliferation, differentiation, and total numbers is thus essential to an understanding of the carcinogenic process. We report here studies on investigations on the relationships between grafted thyroid cell number and the rapidity and degree of reestablishment of the thyroid-hypothalamus-pituitary feedback 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 a 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. 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 cell interactions during the neoplastic process.

  9. Regeneration of Bovine Mammary Gland in Immunodeficient Mice by Transplantation of Bovine Mammary Epithelial Cells Mixed with Matrigel

    PubMed Central

    Park, Hyun Jung; Lee, Won Young; Jeong, Ha Yeon; Song, Hyuk

    2016-01-01

    Background and Objectives With the global demand for dairy protein for consumption growing annually, there has been increasing activity in the research field of dairy protein synthesis and production. From a manipulation perspective, it is more difficult to use live cattle for laboratory studies on the production of milk as well as of dairy protein such as casein, as compared with using laboratory animals like rodents. Therefore, we aimed to develop a mouse model of bovine mammary alveolar ducts for laboratory-scale studies. We studied the formation of the bovine mammary gland ductal structure by transplanting the MAC-T bovine alveolar cell line into mice. Methods and Results MAC-T cells (1×107) were suspended in Matrigel and injected into the dorsal tissue of 8-week-old male BALB/C nude mice. Histological analysis of tissue dissected from the MAC-T cell-transplanted mice after 6 weeks showed the typical morphology of the tubuloalveolar female gland, as well as glands made up of branching ducts that were surrounded by smooth muscle with small alveoli budding off the ducts. In addition, the epithelial markers CK14 and CK18 were expressed within the duct-like structure. Prolactin was detected in the duct interior in these CK14+ and CK18+ cells but not in the non-transplanted MAC-T cells. Conclusions These results showed that duct-like tissue had been successfully formed after 6 weeks of transplantation of the CK14+ and CK18+ MAC-T cells into mice dorsal tissue. This mouse model will be a useful tool for further research on the bovine mammary gland. PMID:27788570

  10. Mammary ductal growth is impaired in mice lacking leptin-dependent signal transducer and activator of transcription 3 signaling.

    PubMed

    Thorn, Stephanie R; Giesy, Sarah L; Myers, Martin G; Boisclair, Yves R

    2010-08-01

    Mice lacking leptin (ob/ob) or its full-length receptor (db/db) are obese and reproductively incompetent. Fertility, pregnancy, and lactation are restored, respectively, in ob/ob mice treated with leptin through mating, d 6.5 post coitum, and pregnancy. Therefore, leptin signaling is needed for lactation, but the timing of its action and the affected mammary process remain unknown. To address this issue, we used s/s mice lacking only leptin-dependent signal transducer and activator of transcription (STAT)3 signaling. These mice share many features with db/db mice, including obesity, but differ by retaining sufficient activity of the hypothalamic-pituitary-ovarian axis to support reproduction. The s/s mammary epithelium was normal at 3 wk of age but failed to expand through the mammary fat pad (MFP) during the subsequent pubertal period. Ductal growth failure was not corrected by estrogen therapy and did not relate to inadequate IGF-I production by the MFP or to the need for epithelial or stromal leptin-STAT3 signaling. Ductal growth failure coincided with adipocyte hypertrophy and increased MFP production of leptin, TNFalpha, and IL6. These cytokines, however, were unable to inhibit the proliferation of a collection of mouse mammary epithelial cell lines. In conclusion, the very first step of postnatal mammary development fails in s/s mice despite sufficient estrogen IGF-I and an hypothalamic-pituitary-ovarian axis capable of supporting reproduction. This failure is not caused by mammary loss of leptin-dependent STAT3 signaling or by the development of inflammation. These data imply the existence of an unknown mechanism whereby leptin-dependent STAT3 signaling and obesity alter mammary ductal development.

  11. Photodynamic therapy for the treatment of induced mammary tumor in rats.

    PubMed

    Ferreira, Isabelle; Ferreira, Juliana; Vollet-Filho, José Dirceu; Moriyama, Lilian T; Bagnato, Vanderlei S; Salvadori, Daisy Maria Favero; Rocha, Noeme S

    2013-02-01

    The objective of this work was to evaluate photodynamic therapy (PDT) by using a hematoporphyrin derivative as a photosensitizer and light-emitting diodes (LEDs) as light source in induced mammary tumors of Sprague-Dawley (SD) rats. Twenty SD rats with mammary tumors induced by DMBA were used. Animals were divided into four groups: control (G1), PDT only (G2), surgical removal of tumor (G3), and submitted to PDT immediately after surgical removal of tumor (G4). Tumors were measured over 6 weeks. Lesions and surgical were LEDs lighted up (200 J/cm(2) dose). The light distribution in vivo study used two additional animals without mammary tumors. In the control group, the average growth of tumor diameter was approximately 0.40 cm/week. While for PDT group, a growth of less than 0.15 cm/week was observed, suggesting significant delay in tumor growth. Therefore, only partial irradiation of the tumors occurred with a reduction in development, but without elimination. Animals in G4 had no tumor recurrence during the 12 weeks, after chemical induction, when compared with G3 animals that showed 60 % recurrence rate after 12 weeks of chemical induction. PDT used in the experimental model of mammary tumor as a single therapy was effective in reducing tumor development, so the surgery associated with PDT is a safe and efficient destruction of residual tumor, preventing recurrence of the tumor.

  12. Oncogenic AKT1(E17K) mutation induces mammary hyperplasia but prevents HER2-driven tumorigenesis.

    PubMed

    Mancini, Maria L; Lien, Evan C; Toker, Alex

    2016-04-05

    One of the most frequently deregulated signaling pathways in breast cancer is the PI 3-K/Akt cascade. Genetic lesions are commonly found in PIK3CA, PTEN, and AKT, which lead to excessive and constitutive activation of Akt and downstream signaling that results in uncontrolled proliferation and increased cellular survival. One such genetic lesion is the somatic AKT1(E17K) mutation, which has been identified in 4-8% of breast cancer patients. To determine how this mutation contributes to mammary tumorigenesis, we constructed a genetically engineered mouse model that conditionally expresses human AKT1(E17K) in the mammary epithelium. Although AKT1(E17K) is only weakly constitutively active and does not promote proliferation in vitro, it is capable of escaping negative feedback inhibition to exhibit sustained signaling dynamics in vitro. Consistently, both virgin and multiparous AKT1(E17K) mice develop mammary gland hyperplasia that do not progress to carcinoma. This hyperplasia is accompanied by increased estrogen receptor expression, although exposure of the mice to estrogen does not promote tumor development. Moreover, AKT1(E17K) prevents HER2-driven mammary tumor formation, in part through negative feedback inhibition of RTK signaling. Analysis of TCGA breast cancer data revealed that the mRNA expression, total protein levels, and phosphorylation of various RTKs are decreased in human tumors harboring AKT1(E17K).

  13. Influence of selenium on the growth of N-nitrosomethylurea-induced mammary tumor cells in culture

    SciTech Connect

    Lewko, W.M.; McConnell, K.P.

    1985-10-01

    Selenium is an essential dietary trace element which has anticancer properties. Among its effects in rats, selenium has been shown to inhibit the development of carcinogen-induced mammary tumors by interfering with the post-initiation, promotion phase of carcinogenesis. We studied the effects of selenium on the growth of rat mammary tumor cells in primary culture. The objective was to determine whether selenium had any direct influence on cell growth which might explain its influence on tumor development. Rat mammary tumors were induced by N-nitrosomethylurea. The addition of low concentrations of sodium selenite, less than 1.0 ..mu..g/ml, stimulated tumor cell proliferation. Protein synthesis and the production of type IV collagen increased within the first hour of exposure, prior to any measurable increase in DNA synthesis. Concentrations of selenite greater than 1.0 ..mu..g/ml inhibited cell proliferation, the synthesis of protein, and the replication of DNA in a dose-related manner. These studies demonstrated that selenium has the potential to influence the post-initiation phase of rat mammary tumorigenesis by directly altering the growth of tumor cells, possibly through the regulation of protein synthesis.

  14. RANKL/RANK control Brca1 mutation-driven mammary tumors

    PubMed Central

    Sigl, Verena; Owusu-Boaitey, Kwadwo; Joshi, Purna A; Kavirayani, Anoop; Wirnsberger, Gerald; Novatchkova, Maria; Kozieradzki, Ivona; Schramek, Daniel; Edokobi, Nnamdi; Hersl, Jerome; Sampson, Aishia; Odai-Afotey, Ashley; Lazaro, Conxi; Gonzalez-Suarez, Eva; Pujana, Miguel A; CIMBA, for; Heyn, Holger; Vidal, Enrique; Cruickshank, Jennifer; Berman, Hal; Sarao, Renu; Ticevic, Melita; Uribesalgo, Iris; Tortola, Luigi; Rao, Shuan; Tan, Yen; Pfeiler, Georg; Lee, Eva YHP; Bago-Horvath, Zsuzsanna; Kenner, Lukas; Popper, Helmuth; Singer, Christian; Khokha, Rama; Jones, Laundette P; Penninger, Josef M

    2016-01-01

    Breast cancer is the most common female cancer, affecting approximately one in eight women during their life-time. Besides environmental triggers and hormones, inherited mutations in the breast cancer 1 (BRCA1) or BRCA2 genes markedly increase the risk for the development of breast cancer. Here, using two different mouse models, we show that genetic inactivation of the key osteoclast differentiation factor RANK in the mammary epithelium markedly delayed onset, reduced incidence, and attenuated progression of Brca1;p53 mutation-driven mammary cancer. Long-term pharmacological inhibition of the RANK ligand RANKL in mice abolished the occurrence of Brca1 mutation-driven pre-neoplastic lesions. Mechanistically, genetic inactivation of Rank or RANKL/RANK blockade impaired proliferation and expansion of both murine Brca1;p53 mutant mammary stem cells and mammary progenitors from human BRCA1 mutation carriers. In addition, genome variations within the RANK locus were significantly associated with risk of developing breast cancer in women with BRCA1 mutations. Thus, RANKL/RANK control progenitor cell expansion and tumorigenesis in inherited breast cancer. These results present a viable strategy for the possible prevention of breast cancer in BRCA1 mutant patients. PMID:27241552

  15. Mammary gland neoplasia in long-term rodent studies.

    PubMed Central

    Russo, I H; Russo, J

    1996-01-01

    Breast cancer, the most frequent spontaneous malignancy diagnosed in women in the western world, is continuously increasing in incidence in industrialized nations. Although breast cancer develops in women as the result of a combination of external and endogenous factors such as exposure to ionizing radiation, diet, socioeconomic status, and endocrinologic, familial, or genetic factors, no specific etiologic agent(s) or the mechanisms responsible of the disease has been identified as yet. Thus, experimental models that exhibit the same complex interactions are needed for testing various mechanisms and for assessing the carcinogenic potential of given chemicals. Rodent mammary carcinomas represent such a model to a great extent because, in these species, mammary cancer is a multistep complex process that can be induced by either chemicals, radiation, viruses, or genetic factors. Long-term studies in rodent models have been particularly useful for dissecting the initiation, promotion, and progression steps of carcinogenesis. The susceptibility of the rodent mammary gland to develop neoplasms has made this organ a unique target for testing the carcinogenic potential of specific genotoxic chemicals and environmental agents. Mammary tumors induced by indirect- or direct-acting carcinogens such as 7, 12-dimethlbenz(a)anthracene or N-methyl-N-nitrosourea are, in general, hormone dependent adenocarcinomas whose incidence, number of tumors per animal, tumor latency, and tumor type are influenced by the age, reproductive history, and endocarinologic milieu of the host at the time of carcinogen exposure. Rodent models are informative in the absence of human data. They have provided valuable information on the dose and route of administration to be used and optimal host conditions for eliciting maximal tumorigenic response. Studies of the influence of normal gland development on the pathogenesis of chemically induced mammary carcinomas have clarified the role of differentiation

  16. Dietary effects of mead acid on N-methyl-N-nitrosourea-induced mammary cancers in female Sprague-Dawley rats.

    PubMed

    Kinoshita, Yuichi; Yoshizawa, Katsuhiko; Hamazaki, Kei; Emoto, Yuko; Yuri, Takashi; Yuki, Michiko; Kawashima, Hiroshi; Shikata, Nobuaki; Tsubura, Airo

    2016-01-01

    The effect of mead acid (MA; 5,8,11-eicosatrienoic acid) on the suppression of the development and growth of N-methyl-N-nitrosourea (MNU)-induced mammary cancer in female Sprague-Dawley rats was examined. The MA diet (2.4% MA) or control (CTR) diet (0% MA) was started at 6 weeks of age, MNU was injected intraperitoneally at 7 weeks of age, and the rats were maintained on the respective diets for the whole experimental period (until 19 weeks of age). All induced mammary tumors were luminal A subtype carcinomas (estrogen and progesterone receptor positive and HER2/neu negative). The MA diet significantly suppressed the initiation and promotion phases of mammary carcinogenesis; MA suppressed the development (incidence, 61.5 vs. 100%; multiplicity, 2.1 vs. 4.5) and the growth (final tumor weight, 427.1 vs. 1,796.3 mg) of mammary cancers by suppressing cell proliferation, but not by accelerating cell death. There were evident changes in the major fatty acid composition of n-3, n-6, and n-9 fatty acids in the serum of the MA diet group; there was a significant increase in MA and significant decreases in oleic acid (OA), linoleic acid, arachidonic acid and docosahexaenoic acid. In non-tumorous mammary tissue, there was a significant increase in MA and a significant decrease in OA in the MA diet group. The n-6/n-3 ratios in serum and mammary tissue of the MA diet group were significantly decreased. The MA diet suppressed MNU-induced luminal A mammary cancer by lowering cancer cell proliferation. Therefore, MA may be a chemopreventive and chemotherapeutic agent. In addition to hormone therapy, MA supplementation may be a beneficial chemotherapeutic agent for the luminal A subtype of breast cancer.

  17. Genetic Susceptibility to Estrogen-Induced Mammary Cancers

    DTIC Science & Technology

    2000-11-01

    mammary glands were reflected in mammary histology. (A and E) Thin sections from Fig. 3. E2 induced pituitary growth and hyperprolactinemia similarly in...with E2 5 (33%) exhibited a normal DNA profile where the great for 12 wk induced pituitary growth and hyperprolactinemia in majority of cells displayed...etal. , " terone, or PRL. Hyperprolactinemia has been shown to be sufficient to induce mammary cancer in certain strains of mouse 1 , (29-31) and rat

  18. Radiologic and histologic presentation of male mammary myofibroblastoma.

    PubMed

    Omar, Lena A; Rojanapremsuk, Theera; Saluja, Karan; Merchant, Kanwal A; Sharma, Pooja B

    2016-07-01

    Mammary myofibroblastoma is a rare mesenchymal neoplasm that typically presents in older men and women. Less commonly, these benign tumors may also occur in soft tissues located outside of the breast, in which case they are referred to as mammary-type myofibroblastomas. The histologic composition of this benign spindle cell tumor can be markedly varied. We present a case of a large mammary myofibroblastoma in a male patient and discuss the typical imaging and histologic makeup of these tumors.

  19. USF-1 as an Inhibitor of Mammary Gland Carcinogenesis

    DTIC Science & Technology

    2001-09-01

    The hypothesis tested in this proposal is that overexpression of USF in the mammary glands of transgenic mice will inhibit myc-dependent...tumorigenesis. To test this hypothesis, a transgene was constructed to target the overexpression of FLAG-tagged USF-2 to the mammary glands of transgenic mice ...under the control of the mouse mammary tumor virus (mmtv) long terminal repeat. A total of eight lines of transgenic mice were generated. Of these, one

  20. Establishment of mammary gland model in vitro: culture and evaluation of a yak mammary epithelial cell line.

    PubMed

    Fu, Mei; Chen, Yabing; Xiong, Xianrong; Lan, Daoliang; Li, Jian

    2014-01-01

    This study aimed to establish yak mammary epithelial cells (YMECs) for an in vitro model of yak mammary gland biology. The primary culture of YMECs was obtained from mammary gland tissues of lactating yak and then characterized using immunocytochemistry, RT-PCR, and western blot analysis. Whether foreign genes could be transfected into the YMECs were examined by transfecting the EGFP gene into the cells. Finally, the effect of Staphylococcus aureus infection on YMECs was determined. The established YMECs retained the mammary epithelial cell characteristics. A spontaneously immortalized yak mammary epithelial cell line was established and could be continuously subcultured for more than 60 passages without senescence. The EGFP gene was successfully transferred into the YMECs, and the transfected cells could be maintained for a long duration in the culture by continuous subculturing. The cells expressed more antimicrobial peptides upon S.aureus invasion. Therefore, the established cell line could be considered a model system to understand yak mammary gland biology.

  1. Inbreeding and canine mammary cancer: a retrospective study.

    PubMed

    Dorn, C R; Schneider, R

    1976-09-01

    Using files of the Animal Neoplasm Registry (ANR) in Alameda and Contra Costa Counties, California, we conducted a retrospective study to compare the degree of inbreeding in the ancestry of purebred dogs with mammary and other cancers, and of those without tumors. Wright's coefficients of inbreeding, calculated for all animals in the three groups, ranged from 0.000 to 0.535. The median inbreeding coefficients of the mammary cancer and comparison groups (consisting of other cancers) were approximately twice that of the nonneoplastic group, but neither difference was statistically significant. Dogs with mammary adenocarcinoma and mixed mammary cancer had similar degrees of inbreeding.

  2. Bovine mammary stem cells: new perspective for dairy science.

    PubMed

    Martignani, E; Cravero, D; Miretti, S; Accornero, P; Baratta, M

    2014-01-01

    Mammary stem cells provide opportunities for the cyclic remodelling of the bovine mammary gland. Therefore, understanding the character and regulation of mammary stem cells is important for increasing animal health and productivity. The exciting possibility that stem cell expansion can influence milk production is currently being investigated by several researchers. In fact, appropriate regulation of mammary stem cells could hopefully benefit milk yield, persistency of lactation, dry period management and tissue repair. Accordingly, we and others have attempted to characterize and regulate the function of bovine mammary stem cells. However, research on mammary stem cells requires tissue biopsies, which represents a limitation for the management of animal welfare. Interestingly, different studies recently reported the identification of putative mammary stem cells in human breast milk. The possible identification of primitive cell types within cow's milk may provide a non-invasive source of relevant mammary cells for a wide range of applications. In this review, we have summarized the main achievements in this field for dairy cow science and described the interesting perspectives open to manipulate milk persistency during lactation and to cope with oxidative stress during the transition period by regulating mammary stem cells.

  3. Growth requirements of human mammary epithelial cells in culture.

    PubMed

    Taylor-Papadimitriou, J; Shearer, M; Stoker, M G

    1977-12-15

    Colony-forming epithelial cells can be separated from the non-dividing "foam cells" in human milk by differential adhesion to glass and freezing. The growth of such partially purified mammary epithelial cells is stimulated by co-culture with non-dividing feeder cells. Foam cells, mitomycin-treated mouse fibroblast lines and human mammary fibroblasts and calf lens epithelial cells are all effective in promoting mammary epithelial cell growth. Contact between epithelial cells and feeders is not required for the growth-promoting effect. The mitogenic effect of epidermal growth factor on mammary epithelial cells also requires feeder cell activity.

  4. Keeping abreast of the mammary epithelial hierarchy and breast tumorigenesis.

    PubMed

    Visvader, Jane E

    2009-11-15

    The epithelium of the mammary gland exists in a highly dynamic state, undergoing dramatic morphogenetic changes during puberty, pregnancy, lactation, and regression. The recent identification of stem and progenitor populations in mouse and human mammary tissue has provided evidence that the mammary epithelium is organized in a hierarchical manner. Characterization of these normal epithelial subtypes is an important step toward understanding which cells are predisposed to oncogenesis. This review summarizes progress in the field toward defining constituent cells and key molecular regulators of the mammary epithelial hierarchy. Potential relationships between normal epithelial populations and breast tumor subtypes are discussed, with implications for understanding the cellular etiology underpinning breast tumor heterogeneity.

  5. Estrogenic Plant Extracts Reverse Weight Gain and Fat Accumulation without Causing Mammary Gland or Uterine Proliferation

    PubMed Central

    Saunier, Elise F.; Vivar, Omar I.; Rubenstein, Andrea; Zhao, Xiaoyue; Olshansky, Moshe; Baggett, Scott; Staub, Richard E.; Tagliaferri, Mary; Cohen, Isaac; Speed, Terence P.; Baxter, John D.; Leitman, Dale C.

    2011-01-01

    Long-term estrogen deficiency increases the risk of obesity, diabetes and metabolic syndrome in postmenopausal women. Menopausal hormone therapy containing estrogens might prevent these conditions, but its prolonged use increases the risk of breast cancer, as wells as endometrial cancer if used without progestins. Animal studies indicate that beneficial effects of estrogens in adipose tissue and adverse effects on mammary gland and uterus are mediated by estrogen receptor alpha (ERα). One strategy to improve the safety of estrogens to prevent/treat obesity, diabetes and metabolic syndrome is to develop estrogens that act as agonists in adipose tissue, but not in mammary gland and uterus. We considered plant extracts, which have been the source of many pharmaceuticals, as a source of tissue selective estrogens. Extracts from two plants, Glycyrrhiza uralensis (RG) and Pueraria montana var. lobata (RP) bound to ERα, activated ERα responsive reporters, and reversed weight gain and fat accumulation comparable to estradiol in ovariectomized obese mice maintained on a high fat diet. Unlike estradiol, RG and RP did not induce proliferative effects on mammary gland and uterus. Gene expression profiling demonstrated that RG and RP induced estradiol-like regulation of genes in abdominal fat, but not in mammary gland and uterus. The compounds in extracts from RG and RP might constitute a new class of tissue selective estrogens to reverse weight gain, fat accumulation and metabolic syndrome in postmenopausal women. PMID:22163294

  6. Innate and Adaptive Immunity Synergize to Trigger Inflammation in the Mammary Gland

    PubMed Central

    Rainard, Pascal; Cunha, Patricia; Gilbert, Florence B.

    2016-01-01

    The mammary gland is able to detect and react to bacterial intrusion through innate immunity mechanisms, but mammary inflammation can also result from antigen-specific adaptive immunity. We postulated that innate and adaptive immune responses could synergize to trigger inflammation in the mammary gland. To test this hypothesis, we immunized cows with the model antigen ovalbumin and challenged the sensitized animals with either Escherichia coli lipopolysaccharide (LPS) as innate immunity agonist, ovalbumin as adaptive immunity agonist, or both agonists in three different udder quarters of lactating cows. There was a significant amplification of the initial milk leukocytosis in the quarters challenged with the two agonists compared to leukocytosis in quarters challenged with LPS or ovalbumin alone. This synergistic response occurred only with the cows that developed the ovalbumin-specific inflammatory response, and there were significant correlations between milk leukocytosis and production of IL-17A and IFN-γ in a whole-blood ovalbumin stimulation assay. The antigen-specific response induced substantial concentrations of IL-17A and IFN-γ in milk contrary to the response to LPS. Such a synergy at the onset of the reaction of the mammary gland suggests that induction of antigen-specific immune response with bacterial antigens could improve the initial immune response to infection, hence reducing the bacterial load and contributing to protection. PMID:27100324

  7. Activation of int-1 and int-2 loci in GRf mammary tumors.

    PubMed

    Gray, D A; Jackson, D P; Percy, D H; Morris, V L

    1986-10-30

    The Mtv-2 locus is known to be associated with a high mammary tumor incidence (97%) and early development of mammary tumors (3-13 months) in GR mice. However, it was not previously known whether the provirus which resides at the Mtv-2 locus is tumorigenic in and of itself or whether reintegration of proviruses generated from Mtv-2 is required for tumorigenesis. Foster-nursing GR mice on C57/BL mice eliminates the milk-borne source of GR virus, and allows the study of Mtv-2 derived proviruses alone. Using this approach, we have tested predictions which follow from the "positional" versus "reintegrational" models of tumorigenesis. Specifically, we have examined tumors from primary foster-nursed (GRf) mice to determine if MMTV proviruses derived from Mtv-2 were scattered randomly throughout the genome or were clustered in the vicinity of the int-1 and int-2 loci, which are thought to be associated with mammary tumorigenesis. It was found that the majority of spontaneous GRf mammary tumors that were tested have MMTV proviral integrations in either or both of the int-1 and int-2 loci and have transcription of either or both of the int loci. Tumors induced by Mtv-2, therefore, appear to have arisen via a mechanism similar to the activation of the int loci by exogenous (milk-borne) MMTV proviruses.

  8. Isolation of canine mammary cells with stem cell properties and tumour-initiating potential.

    PubMed

    Cocola, C; Anastasi, P; Astigiano, S; Piscitelli, E; Pelucchi, P; Vilardo, L; Bertoli, G; Beccaglia, M; Veronesi, M C; Sanzone, S; Barbieri, O; Reinbold, R A; Luvoni, G C; Zucchi, I

    2009-07-01

    Recent data suggest that mammary carcinogenesis may be driven by cancer stem cells (CSCs) derived from mutated adult stem cells, which have acquired aberrant cell self-renewal or by progenitor cells that have acquired the capacity for cell self-renewal. Spontaneous mammary cancers in cats and dogs are important models for the understanding of human breast cancer and may represent alternative species model systems that can significantly contribute to the study of human oncogenesis. With the goal of identifying markers for isolating human breast CSCs, we have generated a canine model system to isolate and characterize normal and CSCs from dog mammary gland. Insight into the hierarchical organization of canine tumours may contribute to the development of universal concepts in oncogenesis by CSCs. Cells with stem cell properties were isolated from normal and tumoural canine breast tissue and propagated as mammospheres and tumourspheres in long-term non-adherent culture conditions. We showed that cells obtained from spheres that display self-renewing properties, have multi-lineage differentiation potential, could generate complex branched tubular structures in vitro and form tumours in NOD/SCID mice. We analysed these cells for the expression of human stem and CSC markers and are currently investigating the tumour-initiating properties of these cells and the hierarchical organization of normal and neoplastic canine mammary tissue.

  9. Radiation induces genomic instability and mammary ductal dysplasia in Atm heterozygous mice

    NASA Technical Reports Server (NTRS)

    Weil, M. M.; Kittrell, F. S.; Yu, Y.; McCarthy, M.; Zabriskie, R. C.; Ullrich, R. L.

    2001-01-01

    Ataxia-telangiectasia (AT) is a genetic syndrome resulting from the inheritance of two defective copies of the ATM gene that includes among its stigmata radiosensitivity and cancer susceptibility. Epidemiological studies have demonstrated that although women with a single defective copy of ATM (AT heterozygotes) appear clinically normal, they may never the less have an increased relative risk of developing breast cancer. Whether they are at increased risk for radiation-induced breast cancer from medical exposures to ionizing radiation is unknown. We have used a murine model of AT to investigate the effect of a single defective Atm allele, the murine homologue of ATM, on the susceptibility of mammary epithelial cells to radiation-induced transformation. Here we report that mammary epithelial cells from irradiated mice with one copy of Atm truncated in the PI-3 kinase domain were susceptible to radiation-induced genomic instability and generated a 10% incidence of dysplastic mammary ducts when transplanted into syngenic recipients, whereas cells from Atm(+/+) mice were stable and formed only normal ducts. Since radiation-induced ductal dysplasia is a precursor to mammary cancer, the results indicate that AT heterozygosity increases susceptibility to radiogenic breast cancer in this murine model system.

  10. Suppression of mammary epithelial cell differentiation by the helix-loop-helix protein Id-1

    SciTech Connect

    Desprez, P.; Hara, E.; Bissell, M.J.

    1995-06-01

    Cell proliferation and differentiation are precisely coordinated during the development and maturation of the mammary gland, and this balance invariably is disrupted during carcinogenesis. Little is known about the cell-specific transcription factors that regulate these processes in the mammary gland. The mouse mammary epithelial cell line SCp2 grows well under standard culture conditions but arrests growth, forms alveolus-like structures, and expresses {beta}-casein, a differentiation marker, 4 to 5 days after exposure to basement membrane and lactogenic hormones (differentiation signals). The authors show that this differentiation entails a marked decline in the expression of Id-1, a helix-loop-helix (HLH) protein that inactivates basic HLH transcription factors in other cell types. SCp2 cells stably transfected with an Id-1 expression vector grew more rapidly than control cells under standard conditions, but in response to differentiation signals, they lost three-dimensional organization, invaded the basement membrane, and then resumed growth. SCp2 cells expressing an Id-1 antisense vector grew more slowly than controls; in response to differentiation signals, they remained stably growth arrested and fully differentiated, as did control cells. The authors suggest that Id-1 renders cells refractory to differentiation signals and receptive to growth signals by inactivating one or more basic HLH proteins that coordinate growth and differentiation in the mammary epithelium. 53 refs., 6 figs.

  11. Detection of differentially expressed genes in methylnitrosourea-induced rat mammary adenocarcinomas.

    PubMed

    Hu, L; Lin, L; Crist, K A; Kelloff, G J; Steele, V E; Lubet, R A; You, M; Wang, Y

    1997-01-01

    In this study, altered gene expression in five methylnitrosourea (MNU)-induced rat mammary adenocarcinomas was investigated using a newly developed competitive cDNA library screening assay. In order to detect the differentially expressed cDNA transcripts, three cDNA libraries (rat mammary, rat liver, and rat kidney) with over 18,000 clones were differentially screened with competing normal and neoplastic mammary cDNA probes. Ninety-eight clones indicated by competitive hybridization to be differentially expressed in tumors were verified by dot-blot hybridization analysis. Of these clones, 45 were found to be overexpressed while 53 were underexpressed in tumors. Forty-five of the confirmed clones were further analyzed by single-pass cDNA sequence determination. Four clones showed homology with cytochrome oxidase subunit I, polyoma virus PTA noncoding region, cytoplasmic beta-actin, and mouse secretory protein containing thrombospondin motifs. Further investigation into the potential roles of these identified genes should contribute significantly to our understanding of the molecular mechanism(s) of rat mammary tumorigenesis.

  12. The Transcriptional Repressor ZNF503/Zeppo2 Promotes Mammary Epithelial Cell Proliferation and Enhances Cell Invasion*

    PubMed Central

    Shahi, Payam; Slorach, Euan M.; Wang, Chih-Yang; Chou, Jonathan; Lu, Angela; Ruderisch, Aline; Werb, Zena

    2015-01-01

    The NET (nocA, Nlz, elB, TLP-1) subfamily of zinc finger proteins is an important mediator during developmental processes. The evolutionary conserved zinc finger protein ZNF503/Zeppo2 (zinc finger elbow-related proline domain protein 2, Zpo2) plays critical roles during embryogenesis. We found that Zpo2 is expressed in adult tissue and examined its function. We found that ZPO2 is a nuclearly targeted transcriptional repressor that is expressed in mammary epithelial cells. Elevated Zpo2 levels increase mammary epithelial cell proliferation. Zpo2 promotes cellular invasion through down-regulation of E-cadherin and regulates the invasive phenotype in a RAC1-dependent manner. We detect elevated Zpo2 expression during breast cancer progression in a MMTV-PyMT transgenic mouse model. Tumor transplant experiments indicated that overexpression of Zpo2 in MMTV-PyMT mammary tumor cell lines enhances lung metastasis. Our findings suggest that Zpo2 plays a significant role in mammary gland homeostasis and that deregulation of Zpo2 may promote breast cancer development. PMID:25538248

  13. The evolving role of mammary ductoscopy.

    PubMed

    Mokbel, Kefah; Elkak, Abd Elrafea

    2002-01-01

    Mammary ductoscopy (MD) is an emerging technique that allows direct visualisation of the mammary duct system, and that produces sharp and clear video images and ductal washings for cytological analysis. There is a growing body of evidence that MD may have a role in the management of women with pathological nipple discharge, the guiding of breast conserving surgery for cancer, and the screening of high risk women. Further research is required to confirm these potential applications and the feasibility of its use in the rapid intervention and outpatient setting under local anaesthesia. Furthermore, the addition of molecular and genetic analysis of cells obtained by MD and the emergence of newer generations of microendoscopes are likely to enhance the use of this technique.

  14. Low-dose BPA exposure alters the mesenchymal and epithelial transcriptomes of the mouse fetal mammary gland.

    PubMed

    Wadia, Perinaaz R; Cabaton, Nicolas J; Borrero, Michael D; Rubin, Beverly S; Sonnenschein, Carlos; Shioda, Toshi; Soto, Ana M

    2013-01-01

    Exposure of rodent fetuses to low doses of the endocrine disruptor bisphenol A (BPA) causes subtle morphological changes in the prenatal mammary gland and results in pre-cancerous and cancerous lesions during adulthood. To examine whether the BPA-induced morphological alterations of the fetal mouse mammary glands are a) associated with changes in mRNA expression reflecting estrogenic actions and/or b) dependent on the estrogen receptor α (ERα), we compared the transcriptomal effects of BPA and the steroidal estrogen ethinylestradiol (EE2) on fetal mammary tissues of wild type and ERα knock-out mice. Mammary glands from fetuses of dams exposed to vehicle, 250 ng BPA/kg BW/d or 10 ng EE2/kg BW/d from embryonic day (E) 8 were harvested at E19. Transcriptomal analyses on the ductal epithelium and periductal stroma revealed altered expression of genes involved in the focal adhesion and adipogenesis pathways in the BPA-exposed stroma while genes regulating the apoptosis pathway changed their expression in the BPA-exposed epithelium. These changes in gene expression correlated with previously reported histological changes in matrix organization, adipogenesis, and lumen formation resulting in enhanced maturation of the fat-pad and delayed lumen formation in the epithelium of BPA-exposed fetal mammary glands. Overall similarities in the transcriptomal effects of BPA and EE2 were more pronounced in the epithelium, than in the stroma. In addition, the effects of BPA and EE2 on the expression of various genes involved in mammary stromal-epithelial interactions were suppressed in the absence of ERα. These observations support a model whereby BPA and EE2 act directly on the stroma, which expresses ERα, ERβ and GPR30 in fetal mammary glands, and that the stroma, in turn, affects gene expression in the epithelium, where ERα and ERβ are below the level of detection at this stage of development.

  15. Progesterone receptor gene maps to human chromosome band 11q13, the site of the mammary oncogene int-2

    SciTech Connect

    Law, M.L.; Kao, F.T.; Wei, Q.; Hartz, J.A.; Greene, G.L.; Zarucki-Schulz, T.; Conneely, O.M.; Jones, C.; Puck, T.T.; O'Malley, B.W.; Horwitz, K.B.

    1987-05-01

    Progesterone is involved in the development and progression of breast cancers, and progesterone receptors (PR) are important markers of hormone dependence and disease prognosis. The authors have used a human PR cDNA probe, genomic DNA blotting of a series of Chinese hamster-human cell hybrids, and in situ hybridization to map the human PR gene to chromosome 11, band q13. This band also contains the human homolog of the mouse mammary tumor virus integration site, int-2, which surrounds a protooncogene thought to be involved in the development of murine mammary cancers. That these two genes share the same chromosomal location raises important questions about their possible linkage and about the relationship between the mammary-specific oncogene and the steroid hormone in the development, growth, and hormone dependence of human breast cancers.

  16. [Secret excretion from the mouse mammary gland].

    PubMed

    Tolkunov, Iu A; Balakina, G B; Markov, A G

    2000-02-01

    Histological studies revealed that the mammary gland nipple have smooth muscle fibres along the nipple channel. These fibres infiltrate the connective tissue parallel to the skin. The ring muscles are not obvious. Delays in the milk excretion in mice may be due to specifics of allocation and functioning of the nipple smooth muscles. To obtain milk, a mechanical action upon the nipple and a synchronised release of oxitocin into the blood are necessary.

  17. Human breast cancer cells are redirected to mammary epithelial cells upon interaction with the regenerating mammary gland microenvironment in-vivo.

    PubMed

    Bussard, Karen M; Smith, Gilbert H

    2012-01-01

    Breast cancer is the second leading cause of cancer deaths in the United States. At present, the etiology of breast cancer is unknown; however the possibility of a distinct cell of origin, i.e. a cancer stem cell, is a heavily investigated area of research. Influencing signals from the tissue niche are known to affect stem cells. Literature has shown that cancer cells lose their tumorigenic potential and display 'normal' behavior when placed into 'normal' ontogenic environments. Therefore, it may be the case that the tissue microenvironment is able to generate signals to redirect cancer cell fate. Previously, we showed that pluripotent human embryonal carcinoma cells could be redirected by the regenerating mammary gland microenvironment to contribute epithelial progeny for 'normal' gland development in-vivo. Here, we show that that human metastatic, non-metastatic, and metastasis-suppressed breast cancer cells proliferate and contribute to normal mammary gland development in-vivo without tumor formation. Immunochemistry for human-specific mitochondria, keratin 8 and 14, as well as human-specific milk proteins (alpha-lactalbumin, impregnated transplant hosts) confirmed the presence of human cell progeny. Features consistent with normal mammary gland development as seen in intact hosts (duct, lumen formation, development of secretory acini) were recapitulated in both primary and secondary outgrowths from chimeric implants. These results suggest the dominance of the tissue microenvironment over cancer cell fate. This work demonstrates that cultured human breast cancer cells (metastatic and non-metastatic) respond developmentally to signals generated by the mouse mammary gland microenvironment during gland regeneration in-vivo.

  18. Oxytocin binding sites in bovine mammary tissue

    SciTech Connect

    Zhao, Xin.

    1989-01-01

    Oxytocin binding sites were identified and characterized in bovine mammary tissue. ({sup 3}H)-oxytocin binding reached equilibrium by 50 min at 20{degree}C and by 8 hr at 4{degree}C. The half-time of displacement at 20{degree}C was approximately 1 hr. Thyrotropin releasing hormone, adrenocorticotropin, angiotensin I, angiotensin II, pentagastrin, bradykinin, xenopsin and L-valyl-histidyl-L-leucyl-L-threonyl-L-prolyl-L-valyl-L-glutamyl-L-lysine were not competitive. In the presence of 10 nM LiCl, addition of oxytocin to dispersed bovine mammary cells, in which phosphatidylinositol was pre-labelled, caused a time and dose-dependent increase in radioactive inositiol monophosphate incorporation. The possibility that there are distinct vasopressin receptors in bovine mammary tissue was investigated. ({sup 3}H)-vasopressin binding reached equilibrium by 40 min at 20{degree}. The half-time of displacement at 20{degree}C was approximately 1 hr. The ability of the peptides to inhibit ({sup 3}H)-vasopressin binding was: (Thr{sup 4},Gly{sup 7})-oxytocin > Arg{sup 8}-vasopressin > (lys{sup 8})-vasopressin > (Deamino{sup 1},D-arg{sup 8})-vasopressin > oxytocin > d (CH{sub 2}){sub 5}Tyr(Me)AVP.

  19. 4-Vinylcyclohexene diepoxide (VCD) inhibits mammary epithelial differentiation and induces fibroadenoma formation in female Sprague Dawley rats.

    PubMed

    Wright, Laura E; Frye, Jennifer B; Lukefahr, Ashley L; Marion, Samuel L; Hoyer, Patricia B; Besselsen, David G; Funk, Janet L

    2011-07-01

    4-Vinylcyclohexene diepoxide (VCD), an occupational chemical that targets ovarian follicles and accelerates ovarian failure in rodents, was used to test the effect of early-onset reproductive senescence on mammary fibroadenoma formation. One-month female Sprague Dawley rats were dosed with VCD (80 mg/kg or 160 mg/kg) and monitored for 22 months for persistent estrus and tumor development. Only high-dose VCD treatment accelerated the onset of persistent estrus relative to controls. However, both doses of VCD accelerated mammary tumor onset by 5 months, increasing incidence to 84% (vs. 38% in controls). Tumor development was independent of time in persistent estrus, 17 β-estradiol, androstenedione and prolactin. Delay in VCD administration until after completion of mammary epithelial differentiation (3 months) did not alter tumor formation despite acceleration of ovarian senescence. VCD administration to 1-month rats acutely decreased mammary alveolar bud number and expression of β-casein, suggesting that VCD's tumorigenic effect requires exposure during mammary epithelial differentiation.

  20. Mammary extracellular matrix directs differentiation of testicular and embryonic stem cells to form functional mammary glands in vivo

    PubMed Central

    Bruno, Robert D.; Fleming, Jodie M.; George, Andrea L.; Boulanger, Corinne A.; Schedin, Pepper; Smith, Gilbert H.

    2017-01-01

    Previously, we demonstrated the ability of the normal mammary microenvironment (niche) to direct non-mammary cells including testicular and embryonic stem cells (ESCs) to adopt a mammary epithelial cell (MEC) fate. These studies relied upon the interaction of transplanted normal MECs with non-mammary cells within the mammary fat-pads of recipient mice that had their endogenous epithelium removed. Here, we tested whether acellular mammary extracellular matrix (mECM) preparations are sufficient to direct differentiation of testicular-derived cells and ESCs to form functional mammary epithelial trees in vivo. We found that mECMs isolated from adult mice and rats were sufficient to redirect testicular derived cells to produce normal mammary epithelial trees within epithelial divested mouse mammary fat-pads. Conversely, ECMs isolated from omental fat and lung did not redirect testicular cells to a MEC fate, indicating the necessity of tissue specific components of the mECM. mECM preparations also completely inhibited teratoma formation from ESC inoculations. Further, a phenotypically normal ductal outgrowth resulted from a single inoculation of ESCs and mECM. To the best of our knowledge, this is the first demonstration of a tissue specific ECM driving differentiation of cells to form a functional tissue in vivo. PMID:28071703

  1. Multiphoton intravital microscopy setup to visualize the mouse mammary gland

    NASA Astrophysics Data System (ADS)

    Adur, Javier; Herrera Torres, Ana M.; Masedunskas, Andrius; Baratti, Mariana O.; de Thomaz, Andre A.; Pelegati, Vitor B.; Carvalho, Hernandes F.; Cesar, Carlos L.

    2013-06-01

    Recently, light microscopy-based techniques have been extended to live mammalian models leading to the development of a new imaging approach called intravital microscopy (IVM). Although IVM has been introduced at the beginning of the last century, its major advancements have occurred in the last twenty years with the development of non-linear microscopy that has enabled performing deep tissue imaging. IVM has been utilized to address many biological questions in basic research and is now a fundamental tool that provide information on tissues such as morphology, cellular architecture, and metabolic status. IVM has become an indispensable tool in numerous areas. This study presents and describes the practical aspects of IVM necessary to visualize epithelial cells of live mouse mammary gland with multiphoton techniques.

  2. Effect of milk on the 7,12-dimethylbenz[a]-anthracene-induced mammary tumor model in rat.

    PubMed

    Zhou, Hong; Qin, Li-Qiang; Tang, Fu-Lei; Ma, De-Fu; Wang, Pei-Yu; Wang, Yan

    2007-10-01

    Milk may be one of the risk factors in the development of breast cancer from epidemiological investigations. Our study investigated the hormones and main ingredients in milk and assessed the effects of milk on the development of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in rats by comparing differences among three groups: commercial milk (C), traditional milk (T) or water (W). During the 20-weeks experiment the C and T groups showed higher incidences of mammary tumors than the W group. After excluding potential confounding factors including fat and calcium, the C group was found to score higher than the T group in the indices of tumorigenesis. These findings suggested that DMBA-induced mammary tumors are more prevalent in milk-fed groups due in part to the contribution of estrogen and progesterone in milk.