1
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Nerger BA, Jaslove JM, Elashal HE, Mao S, Košmrlj A, Link AJ, Nelson CM. Local accumulation of extracellular matrix regulates global morphogenetic patterning in the developing mammary gland. Curr Biol 2021; 31:1903-1917.e6. [PMID: 33705716 DOI: 10.1016/j.cub.2021.02.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/23/2020] [Accepted: 02/08/2021] [Indexed: 01/19/2023]
Abstract
The tree-like pattern of the mammary epithelium is formed during puberty through a process known as branching morphogenesis. Although mammary epithelial branching is stochastic and generates an epithelial tree with a random pattern of branches, the global orientation of the developing epithelium is predictably biased along the long axis of the gland. Here, we combine analysis of pubertal mouse mammary glands, a three-dimensional (3D)-printed engineered tissue model, and computational models of morphogenesis to investigate the origin and the dynamics of the global bias in epithelial orientation during pubertal mammary development. Confocal microscopy analysis revealed that a global bias emerges in the absence of pre-aligned networks of type I collagen in the fat pad and is maintained throughout pubertal development until the widespread formation of lateral branches. Using branching and annihilating random walk simulations, we found that the angle of bifurcation of terminal end buds (TEBs) dictates both the dynamics and the extent of the global bias in epithelial orientation. Our experimental and computational data demonstrate that a local increase in stiffness from the accumulation of extracellular matrix, which constrains the angle of bifurcation of TEBs, is sufficient to pattern the global orientation of the developing mammary epithelium. These data reveal that local mechanical properties regulate the global pattern of mammary epithelial branching and may provide new insight into the global patterning of other branched epithelia.
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Affiliation(s)
- Bryan A Nerger
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Jacob M Jaslove
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Graduate School of Biomedical Sciences, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Hader E Elashal
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Sheng Mao
- Department of Mechanics and Engineering Science, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China; Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Andrej Košmrlj
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA
| | - A James Link
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Celeste M Nelson
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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2
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Feigman MJ, Moss MA, Chen C, Cyrill SL, Ciccone MF, Trousdell MC, Yang ST, Frey WD, Wilkinson JE, Dos Santos CO. Pregnancy reprograms the epigenome of mammary epithelial cells and blocks the development of premalignant lesions. Nat Commun 2020; 11:2649. [PMID: 32461571 PMCID: PMC7253414 DOI: 10.1038/s41467-020-16479-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 05/05/2020] [Indexed: 02/06/2023] Open
Abstract
Pregnancy causes a series of cellular and molecular changes in mammary epithelial cells (MECs) of female adults. In addition, pregnancy can also modify the predisposition of rodent and human MECs to initiate oncogenesis. Here, we investigate how pregnancy reprograms enhancer chromatin in the mammary epithelium of mice and influences the transcriptional output of the oncogenic transcription factor cMYC. We find that pregnancy induces an expansion of the active cis-regulatory landscape of MECs, which influences the activation of pregnancy-related programs during re-exposure to pregnancy hormones in vivo and in vitro. Using inducible cMYC overexpression, we demonstrate that post-pregnancy MECs are resistant to the downstream molecular programs induced by cMYC, a response that blunts carcinoma initiation, but does not perturb the normal pregnancy-induced epigenomic landscape. cMYC overexpression drives post-pregnancy MECs into a senescence-like state, and perturbations of this state increase malignant phenotypic changes. Taken together, our findings provide further insight into the cell-autonomous signals in post-pregnancy MECs that underpin the regulation of gene expression, cellular activation, and resistance to malignant development. Mammary epithelial cells are epigenetically modified during pregnancy, these changes can influence the pre-disposition to cancer. Here, the authors examine the epigenetic landscape of mammary epithelial cells pre and post pregnancy and identify changes to the epigenetic landscape, which can protect mice from Myc induced cancer.
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Affiliation(s)
- Mary J Feigman
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Matthew A Moss
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, 11549, USA
| | - Chen Chen
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Samantha L Cyrill
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Michael F Ciccone
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | | | - Shih-Ting Yang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Wesley D Frey
- School of Medicine, Tulane University, New Orleans, LA, 70118, USA
| | - John E Wilkinson
- Department of Comparative Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Camila O Dos Santos
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA.
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3
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Abstract
The mammary gland undergoes a spectacular series of changes as it develops, and maintains a remarkable capacity to remodel and regenerate for several decades. Mammary morphogenesis has been investigated for over 100 years, motivated by the dairy industry and cancer biologists. Over the past decade, the gland has emerged as a major model system in its own right for understanding the cell biology of tissue morphogenesis. Multiple signalling pathways from several cell types are orchestrated together with mechanical cues and cell rearrangements to establish the pattern of the mammary gland. The integrated mechanical and molecular pathways that control mammary morphogenesis have implications for the developmental regulation of other epithelial organs.
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4
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Macias H, Moran A, Samara Y, Moreno M, Compton JE, Harburg G, Strickland P, Hinck L. SLIT/ROBO1 signaling suppresses mammary branching morphogenesis by limiting basal cell number. Dev Cell 2011; 20:827-40. [PMID: 21664580 PMCID: PMC3129866 DOI: 10.1016/j.devcel.2011.05.012] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 04/12/2011] [Accepted: 05/16/2011] [Indexed: 01/08/2023]
Abstract
In the field of breast biology, there is a growing appreciation for the "gatekeeping function" of basal cells during development and disease processes yet mechanisms regulating the generation of these cells are poorly understood. Here, we report that the proliferation of basal cells is controlled by SLIT/ROBO1 signaling and that production of these cells regulates outgrowth of mammary branches. We identify the negative regulator TGF-β1 upstream of Robo1 and show that it induces Robo1 expression specifically in the basal layer, functioning together with SLIT2 to restrict branch formation. Loss of SLIT/ROBO1 signaling in this layer alone results in precocious branching due to a surplus of basal cells. SLIT2 limits basal cell proliferation by inhibiting canonical WNT signaling, increasing the cytoplasmic and membrane pools of β-catenin at the expense of its nuclear pool. Together, our studies provide mechanistic insight into how specification of basal cell number influences branching morphogenesis.
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Affiliation(s)
- Hector Macias
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Angel Moran
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Yazeed Samara
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Melissa Moreno
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Jennifer E Compton
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Gwyndolen Harburg
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Phyllis Strickland
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Lindsay Hinck
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
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5
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Tetzlaff S, Murani E, Schellander K, Ponsuksili S, Wimmers K. Differential expression of growth factors and their receptors indicates their involvement in the inverted teat defect in pigs1. J Anim Sci 2009; 87:3451-7. [DOI: 10.2527/jas.2008-1660] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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6
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Marlow R, Strickland P, Lee JS, Wu X, PeBenito M, Binnewies M, Le EK, Moran A, Macias H, Cardiff RD, Sukumar S, Hinck L. SLITs suppress tumor growth in vivo by silencing Sdf1/Cxcr4 within breast epithelium. Cancer Res 2008; 68:7819-27. [PMID: 18829537 PMCID: PMC3075571 DOI: 10.1158/0008-5472.can-08-1357] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The genes encoding Slits and their Robo receptors are silenced in many types of cancer, including breast, suggesting a role for this signaling pathway in suppressing tumorigenesis. The molecular mechanism underlying these tumor-suppressive effects has not been delineated. Here, we show that loss of Slits, or their Robo1 receptor, in murine mammary gland or human breast carcinoma cells results in coordinate up-regulation of the Sdf1 and Cxcr4 signaling axis, specifically within mammary epithelium. This is accompanied by hyperplastic changes in cells and desmoplastic alterations in the surrounding stroma. A similar inverse correlation between Slit and Cxcr4 expression is identified in human breast tumor tissues. Furthermore, we show in a xenograft model that Slit overexpression down-regulates CXCR4 and dominantly suppresses tumor growth. These studies classify Slits as negative regulators of Sdf1 and Cxcr4 and identify a molecular signature in hyperplastic breast lesions that signifies inappropriate up-regulation of key prometastatic genes.
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Affiliation(s)
- Rebecca Marlow
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
| | - Phyllis Strickland
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
| | - Ji Shin Lee
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Xinyan Wu
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Milana PeBenito
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
| | - Mikhail Binnewies
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
| | - Elizabeth K. Le
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
| | - Angel Moran
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
| | - Hector Macias
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
| | - Robert D. Cardiff
- University of California Davis Center of Comparative Medicine, Davis, California
| | - Saraswati Sukumar
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Lindsay Hinck
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, California
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7
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Trott JF, Vonderhaar BK, Hovey RC. Historical perspectives of prolactin and growth hormone as mammogens, lactogens and galactagogues--agog for the future! J Mammary Gland Biol Neoplasia 2008; 13:3-11. [PMID: 18204889 DOI: 10.1007/s10911-008-9064-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Accepted: 01/02/2008] [Indexed: 10/22/2022] Open
Abstract
Around 80 years ago researchers first established that the pituitary gland regulates mammary gland function as demonstrated by the ability of its extracts to promote both mammogenesis and lactogenesis in animal models. Little did they realize that in fact two hormones, prolactin (PRL) and growth hormone (GH), were contributing to these effects. By the mid 1930s PRL had been purified as a distinct lactogen, while the galactopoietic effect of GH was confirmed after its purification in the 1940s. Interest in these hormones initially centered about their potential for increasing milk production, while in the latter half of the twentieth century it became obvious that these hormones also had the potential to influence mammary cancer development. During the past 50 years large strides have been made into understanding how these hormones signal to, and within, cells of the mammary gland, paralleling rapid developments in the fields of cellular and molecular biology. In compiling this review we have summarized the progress that has been made to date regarding roles for these hormones in the mammary gland, with a goal of ensuring that some of the seminal literature is not diluted or forgotten. In doing so it is clear that there are lessons to be learned from past experiences, where new methods and technologies will continue to present exciting new opportunities to revisit lingering questions regarding these fascinating hormones and this fascinating organ.
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Affiliation(s)
- Josephine F Trott
- Lactation and Mammary Gland Biology Group, Department of Animal Science, The University of Vermont, Burlington, VT 05401, USA
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8
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Sutherland KD, Lindeman GJ, Choong DYH, Wittlin S, Brentzell L, Phillips W, Campbell IG, Visvader JE. Differential hypermethylation of SOCS genes in ovarian and breast carcinomas. Oncogene 2004; 23:7726-33. [PMID: 15361843 DOI: 10.1038/sj.onc.1207787] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Suppressor of cytokine signaling (SOCS) proteins have emerged as critical attenuators of cytokine-mediated processes, suggesting a role in the suppression of tumorigenesis. In the ovary and mammary gland, cytokines such as prolactin and IL-6 are important regulators of growth and differentiation. We have investigated whether silencing or inactivation of SOCS genes occurs in ovarian and breast carcinomas. The SOCS1 and SOCS2 CpG islands were found to be hypermethylated in 23 and 14% of primary ovarian cancers, respectively, whereas only SOCS1 was methylated in breast cancers (9%). Methylation of these genes did not occur in normal tissues. No correlation was apparent between methylation and loss of heterozygosity, and no somatic mutations were found in a large panel of carcinomas. Aberrant methylation of these SOCS genes correlated with transcriptional silencing in ovarian and breast cancer cell lines, since expression was induced by the demethylating agent 5-azadeoxycytidine. SOCS3 was not hypermethylated in either cancer type. Consistent with this data, SOCS1 and SOCS2 but not SOCS3 suppressed the growth of ovarian and breast cancer cells. Hypermethylation and silencing of specific SOCS genes in the ovary, and to a lesser extent in breast, may augment cytokine responsiveness in these tissues, thereby contributing to oncogenesis.
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Affiliation(s)
- Kate D Sutherland
- The Walter and Eliza Hall Institute of Medical Research and Bone Marrow Research Laboratories, Royal Melbourne Hospital, Parkville, VIC 3050, Australia
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9
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Bussmann UA, Lanuza GM, Bussmann LE. Activin and follistatin in rat mammary gland. Mol Cell Endocrinol 2004; 221:9-19. [PMID: 15223128 DOI: 10.1016/j.mce.2004.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2003] [Revised: 01/22/2004] [Accepted: 04/20/2004] [Indexed: 10/26/2022]
Abstract
Mammary gland morphogenesis and differentiation are mediated through the combined activities of systemic hormones and locally synthesized growth factors. Activin, a member of the transforming growth factor (TGF)-beta superfamily, is known to regulate the growth and differentiation of several cell types. In the present study, we investigated the role of activin in rat mammary gland on different stages of development. We found that activin A in vitro inhibits the proliferation of isolated acini, and this effect increases with the development of the gland. This factor also produces in vitro an inhibition of the final differentiation of acini obtained from 19th day pregnant rats. We also report the expression of activin receptors IIA and IIB mRNA in whole rat mammary gland and acini, with decreased levels of expression of type IIA (in both compartments) and IIB (in acini) during pregnancy and lactogenesis. In addition, we show that activin betaB-subunit mRNA decreases throughout pregnancy, and that the mRNA levels of follistatin (Fst) (its ligand protein) are high in cycling rats and at the beginning of pregnancy and diminish thereafter, having the acini higher levels of expression. Our data show that activin betaB-subunit, follistatin and ActRIIA and IIB transcripts are expressed in rat mammary gland at appropriate times and locations during development, allowing an interplay that might regulate activin action on growth and differentiation of the gland.
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Affiliation(s)
- Ursula A Bussmann
- Instituto de Biología y Medicina Experimental, Vuelta de Obligado 2490, 1428 Buenos Aires, Argentina
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10
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Lewis MT, Veltmaat JM. Next stop, the twilight zone: hedgehog network regulation of mammary gland development. J Mammary Gland Biol Neoplasia 2004; 9:165-81. [PMID: 15300011 DOI: 10.1023/b:jomg.0000037160.24731.35] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The hedgehog signal transduction network is a critical mediator of cell-cell communication during embryonic development. Evidence also suggests that properly regulated hedgehog network function is required in some adult organs for stem cell maintenance or renewal. Mutation, or misexpression, of network genes is implicated in the development of several different types of cancer, particularly that of skin, brain, lung, and pancreas. Recent studies in the mouse mammary gland have demonstrated roles for hedgehog network genes at virtually every phase of mammary gland development where it regulates such diverse processes as embryonic mammary gland induction, establishment of ductal histoarchitecture, and functional differentiation in lactation. Further, studies suggest a role for misregulated network function in the progression of breast cancer.
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11
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Raccurt M, Tam SP, Lau P, Mertani HC, Lambert A, Garcia-Caballero T, Li H, Brown RJ, McGuckin MA, Morel G, Waters MJ. Suppressor of cytokine signalling gene expression is elevated in breast carcinoma. Br J Cancer 2003; 89:524-32. [PMID: 12888825 PMCID: PMC2394374 DOI: 10.1038/sj.bjc.6601115] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Cytokines are important for breast cell function, both as trophic hormones and as mediators of host defense mechanisms against breast cancer. Recently, inducible feedback suppressors of cytokine signalling (SOCS/JAB/SSI) have been identified, which decrease cell sensitivity to cytokines. We examined the expression of SOCS genes in 17 breast carcinomas and 10 breast cancer lines, in comparison with normal tissue and breast lines. We report elevated expression of SOCS-1-3 and CIS immunoreactive proteins within in situ ductal carcinomas and infiltrating ductal carcinomas relative to normal breast tissue. Significantly increased expression of SOCS-1-3 and CIS transcripts was also shown by quantitative in situ hybridisation within both tumour tissue and reactive stroma. CIS transcript expression was elevated in all 10 cancer lines, but not in control lines. However, there was no consistent elevation of other SOCS transcripts. CIS protein was shown by immunoblot to be present in all cancer lines at increased levels, mainly as the 47 kDa ubiquitinylated form. A potential proliferative role for CIS overexpression is supported by reports that CIS activates ERK kinases, and by strong induction in transient reporter assays with an ERK-responsive promoter. The in vivo elevation of SOCS gene expression may be part of the host/tumour response or a response to autocrine/paracrine GH and prolactin. However, increased CIS expression in breast cancer lines appears to be a specific lesion, and could simultaneously shut down STAT 5 signalling by trophic hormones, confer resistance to host cytokines and increase proliferation through ERK kinases.
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MESH Headings
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- Carcinoma/genetics
- Carcinoma/pathology
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Intraductal, Noninfiltrating/genetics
- Carcinoma, Intraductal, Noninfiltrating/pathology
- Carrier Proteins/biosynthesis
- Carrier Proteins/pharmacology
- Cytokines/pharmacology
- DNA-Binding Proteins
- Female
- Gene Expression Regulation, Neoplastic
- Human Growth Hormone/pharmacology
- Humans
- Immediate-Early Proteins/biosynthesis
- In Situ Hybridization
- Intracellular Signaling Peptides and Proteins
- Prolactin/pharmacology
- Protein Biosynthesis
- Proteins/pharmacology
- Repressor Proteins
- Signal Transduction
- Suppressor of Cytokine Signaling 1 Protein
- Suppressor of Cytokine Signaling 3 Protein
- Suppressor of Cytokine Signaling Proteins
- Trans-Activators
- Transcription Factors
- Tumor Cells, Cultured
- src Homology Domains
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Affiliation(s)
- M Raccurt
- CNRS UMR 5123, Bât. Raphael Dubois, Université Claude Bernard-Lyon 1, 43 Blvd 11 Novembre 1918, F69622 Villeurbanne cedex, France
| | - S P Tam
- School of Biomedical Sciences and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - P Lau
- School of Biomedical Sciences and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - H C Mertani
- CNRS UMR 5123, Bât. Raphael Dubois, Université Claude Bernard-Lyon 1, 43 Blvd 11 Novembre 1918, F69622 Villeurbanne cedex, France
| | - A Lambert
- CNRS UMR 5123, Bât. Raphael Dubois, Université Claude Bernard-Lyon 1, 43 Blvd 11 Novembre 1918, F69622 Villeurbanne cedex, France
| | - T Garcia-Caballero
- Departamento de Ciencias Morfológicas, Facultad de Medicina, Universidad Santiago de Compostela, c/San Francisco s/n, Santiago de Compostela 15705, Spain
| | - H Li
- School of Biomedical Sciences and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - R J Brown
- School of Biomedical Sciences and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - M A McGuckin
- Mater Medical Research Institute, Level 3, Aubigny Place, Mater Misericordiae Hospital, S. Brisbane, Queensland 4101, Australia
| | - G Morel
- CNRS UMR 5123, Bât. Raphael Dubois, Université Claude Bernard-Lyon 1, 43 Blvd 11 Novembre 1918, F69622 Villeurbanne cedex, France
| | - M J Waters
- School of Biomedical Sciences and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
- School of Biomedical Sciences and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia. E-mail:
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12
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Plaut K, Dean A, Patnode T, Casey T. Effect of Transforming Growth Factor-beta (TGF-β) on Mammary Development. J Dairy Sci 2003. [DOI: 10.3168/jds.s0022-0302(03)74036-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Snyderwine EG, Venugopal M, Yu M. Mammary gland carcinogenesis by food-derived heterocyclic amines and studies on the mechanisms of carcinogenesis of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Mutat Res 2002; 506-507:145-52. [PMID: 12351154 DOI: 10.1016/s0027-5107(02)00161-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The heterocyclic amines (HCAs) comprise a family of mutagenic/carcinogenic compounds found in cooked meat. Several HCAs including 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) are mammary gland carcinogens in rats. One mammary gland carcinogen, PhIP, is the most prevalent in the human diet. This article reviews the mechanisms of mammary gland carcinogenesis of PhIP including metabolic processing, DNA adduct formation, effects on mammary gland development, cell signaling, and the genomic alterations found in PhIP-induced rat mammary gland carcinomas.
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Affiliation(s)
- Elizabeth G Snyderwine
- Chemical Carcinogenesis Section, NCI Center for Cancer Research, Building 37, Room 3C28, 37 Convent Drive MSC 4258, Bethesda, MD 20892, USA.
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14
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Abstract
Mammary glands develop postnatally by branching morphogenesis creating an arborated ductal system on which secretory lobuloalveoli develop at pregnancy. This review focuses on the interrelated questions of how ductal and alveolar morphogenesis and growth are regulated in the mouse mammary gland and covers progress made over approximately the last decade. After a brief overview of glandular development, advances in understanding basic structural questions concerning mechanisms of duct assembly, elongation, and bifurcation are considered. Turning to growth regulation, remarkable progress has taken place based largely on the study of genetically engineered mice that lack or overexpress a single gene. The use of mammary glands from these and wildtype animals in sophisticated epithelial-stromal or epithelial-epithelial recombination experiments are reviewed and demonstrate paracrine mechanisms of action for the classical endocrine mammogens, estrogen, progesterone, growth hormone, and prolactin. In addition, IGF-1, EGF, or related peptides, and elements of the activin/inhibin family, were shown to be necessary for ductal growth. The inhibition of ductal growth, and in particular, lateral branching, is necessary to preserve stromal space for later lobuloalveolar development. Excellent evidence that TGF-beta1 naturally inhibits this infilling, possibly by blocking hepatocyte growth factor synthesis, is reviewed along with evidence indicating that the action of TGF-beta1 is modulated by its association with the extracellular matrix. Finally, experimental approaches that may help integrate the wealth of new findings are discussed.
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Affiliation(s)
- G B Silberstein
- Department of Biology, Sinsheimer Laboratories, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
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15
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Kawamori T, Uchiya N, Watanabe K, Ohta T, Sugimura T, Wakabayashi K. Effects of heterocyclic amines with mammary gland carcinogenic potential on estrogenic response of uterus in ovariectomized rats. Cancer Lett 2001; 162:31-7. [PMID: 11121860 DOI: 10.1016/s0304-3835(00)00626-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heterocyclic amines (HCAs) present in cooked foods are suggested to be involved in human breast cancer development. Estrogen plays a pivotal role in mammary gland carcinogenesis. Therefore, we designed an in vivo experiment to investigate potential estrogenic effects of two HCAs, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which induce mammary gland cancers in rodents, on the uterus of ovariectomized (OVX) Sprague-Dawley (SD) rats. Female SD rats ovariectomized at 35 days of age were given intraperitoneal injections of 17beta-estradiol (E2) at doses of 0, 30 or 50 microg/kg or one of the HCAs at a dose of 50 mg/kg b.w. once a day at 47, 48, and 49 days of age. E2 dramatically increased uterine weights, stromal thickness, epithelial cell height, and 5-bromo-2'-deoxyuridine (BrdU) positive cell counts in a dose dependent manner. Intraperitoneal administration of PhIP or IQ, in contrast, did not produce any estrogenic responses in this assay system. These results indicate that the carcinogenicities of these two HCAs in mammary glands are not associated with estrogenic potential.
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Affiliation(s)
- T Kawamori
- Cancer Prevention Division, National Cancer Center Research Institute, 1-1 Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045, Japan.
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16
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Abstract
Maspin, a unique member of the serpin family, is a secreted protein encoded by a class II tumor suppressor gene whose downregulation is associated with the development of breast and prostate cancers. Overexpression of maspin in breast tumor cells limits their growth and metastases in vivo. In this report we demonstrate that maspin is an effective inhibitor of angiogenesis. In vitro, it acted directly on cultured endothelial cells to stop their migration towards basic fibroblast growth factor and vascular endothelial growth factor and to limit mitogenesis and tube formation. In vivo, it blocked neovascularization in the rat cornea pocket model. Maspin derivatives mutated in the serpin reactive site lost their ability to inhibit the migration of fibroblasts, keratinocytes, and breast cancer cells but were still able to block angiogenesis in vitro and in vivo. When maspin was delivered locally to human prostate tumor cells in a xenograft mouse model, it blocked tumor growth and dramatically reduced the density of tumor-associated microvessels. These data suggest that the tumor suppressor activity of maspin may depend in large part on its ability to inhibit angiogenesis and raise the possibility that maspin and similar serpins may be excellent leads for the development of drugs that modulate angiogenesis.
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Affiliation(s)
- M Zhang
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
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17
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Snyderwine EG. Mammary gland carcinogenesis by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in rats: possible mechanisms. Cancer Lett 1999; 143:211-5. [PMID: 10503906 DOI: 10.1016/s0304-3835(99)00127-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine derived from cooked meat. Mammary gland cancer can be induced in female Sprague-Dawley rats by administration of several oral doses of PhIP. The mechanism of mammary gland carcinogenesis by PhIP in this rat model is not fully understood but appears to involve several factors. One factor is the formation of PhIP-DNA adducts in the mammary gland after metabolic activation of PhIP. Possible target cell populations include the epithelial cells of the mammary gland terminal end buds (TEBs), putative sites of origin of carcinomas. Another factor involved in the mammary carcinogenicity of PhIP may be an increased proliferation in epithelial cells of the TEBs which occurs after a carcinogenic dose of PhIP is administered. This proliferation would be likely to enhance the fixation of mutations from PhIP-DNA adducts in target cells and facilitate the initiation of carcinogenesis. PhIP exposure also transiently inhibits the development of the mammary gland by retarding the differentiation of TEBs to alveolar buds and lobules. As a consequence, more TEBs are available for neoplastic transformation. Recent studies in rats have also shown that PhIP increases the levels of serum prolactin, a well-recognized promoter of mammary gland cancer, which may further explain the targeting of PhIP to the mammary gland. The results to date indicate that PhIP has multiple effects on the mammary gland and hormone status in rats that could potentially play a role in its ability to induce mammary gland cancer.
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Affiliation(s)
- E G Snyderwine
- Chemical Carcinogenesis Section, Laboratory of Experimental Carcinogenesis, National Cancer Institute, Bethesda, MD 20892-4255, USA.
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18
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Brandt R, Ebert AD. Growth inhibitors for mammary epithelial cells. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 1999; 20:197-248. [PMID: 9928532 DOI: 10.1007/978-3-642-72149-6_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- R Brandt
- Novartis Pharma Inc., Basel, Switzerland
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19
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Haik-Creguer KL, Dunbar GL, Sabel BA, Schroeder U. Small drug sample fabrication of controlled release polymers using the microextrusion method. J Neurosci Methods 1998; 80:37-40. [PMID: 9606048 DOI: 10.1016/s0165-0270(97)00193-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ethylene vinylacetate polymer (EVA) has been used for many years to fabricate controlled-release polymeric implant devices with which drugs of high or low molecular weight compounds could be delivered with zero-order kinetics. However, because the known fabrication methods such as solvent evaporation, casting and possible shrinkage are not sufficiently controllable we have now developed the microextrusion method with which even small amount of clinically important and expensive drugs can be incorporated into EVA with high reproducibility. We show here that devices produced by the microextrusion method allows for a controlled delivery of several neurotoxic and neurotherapeutic compounds such as alpha-methyl-p-tyrosine, diazepam, quinolinic acid, and phencyclidine. Each substance is slowly released from the polymer, as evidenced by spectrophotometric data, for up to 120 days at daily rates varying from 18.4 microg of phencyclidine to 97.6 microg/day of diazepam. Thus, microextrusion is a valuable method for fabricating controlled-release polymers in which small amounts of scarce drugs can be incorporated. Another advantage of the current procedure is that polymers can be fabricated with very little amount of solvent.
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Affiliation(s)
- K L Haik-Creguer
- Central Michigan University, Department of Psychology, Mount Pleasant, USA
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20
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DiAugustine RP, Richards RG, Sebastian J. EGF-related peptides and their receptors in mammary gland development. J Mammary Gland Biol Neoplasia 1997; 2:109-17. [PMID: 10882297 DOI: 10.1023/a:1026395513038] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The discovery of multiple EGF-like ligands and erbB receptors offers the potential for a highly diverse signaling system allowing specific ligand/receptor complexes to be created in response to a certain hormone(s) or stage of mammary development. The known erbB receptors and several of the erbB-related ligands are synthesized by the normal mammary gland and have different temporal and spatial expression patterns. For instance, cumulative findings support the concepts that the EGF receptor has an essential role in morphogenesis of the mammary gland and that activation of this receptor occurs in response to estradiol-stimulated synthesis of an EGF receptor ligand in mammary stromal cells. The importance of both epithelial and stromal mammary cells in the hormonal activation of erbB-related pathways is underscored in this review. Current experimental protocols that utilize erbB mutant mice or enable detection of phosphorylated erbB members and their proximal substrates should permit more precise identification of the pathways operative in the mammary gland.
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Affiliation(s)
- R P DiAugustine
- Hormones and Cancer Section, Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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21
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Neuenschwander S, Schwartz A, Wood TL, Roberts CT, Hennighausen L, LeRoith D. Involution of the lactating mammary gland is inhibited by the IGF system in a transgenic mouse model. J Clin Invest 1996; 97:2225-32. [PMID: 8636401 PMCID: PMC507301 DOI: 10.1172/jci118663] [Citation(s) in RCA: 166] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Development of the mammary gland during puberty, pregnancy, and lactation is controlled by steroid and peptide hormones and growth factors. To determine the role of the insulin-like growth factors (IGFs) in this process we developed a transgenic model using the whey acidic protein (WAP) gene to direct expression of rat IGF-I and human IGF binding protein-3 (IGFBP-3) to mammary tissue during late pregnancy and throughout lactation. High levels of expression of transgenic IGF-I and IGFBP-3 were seen in lobular-alveolar cells by in situ hybridization. There was no obvious effect on mammary development during pregnancy and lactation; indeed, mothers were capable of nursing their pups normally and the only structural difference seen in the mammary glands at peak lactation was an overall smaller size of the alveoli. We also evaluated the role of IGF-I and IGFBP-3 in the remodeling of mammary tissue during involution. Compared with control animals, the process of involution was modified in both transgenic lines. The degree of apoptotic cells was lower in the WAP-IGF-I and WAP-BP-3 expressing mice. In addition, there was a more quiescent pattern of involution with residual lobular secretary ability and a muted host inflammatory reaction with fewer lumenal microcalcifications. These results demonstrate that IGF-I and IGFBP-3 may modulate the involutionary process of the lactating mammary gland.
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Affiliation(s)
- S Neuenschwander
- Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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22
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Lincoln DT, Sinowatz F, el-Hifnawi E, Hughes RL, Waters M. Evidence of a direct role for growth hormone (GH) in mammary gland proliferation and lactation. Anat Histol Embryol 1995; 24:107-15. [PMID: 8588701 DOI: 10.1111/j.1439-0264.1995.tb00020.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A panel of monoclonal antibodies to the growth hormone (GH) receptor/binding protein was used to demonstrate the existence and detail the expression of GH receptors in ductal and alveolar epithelial cells from rat and rabbit mammary glands by immunohistochemistry. Intense immunoreactivity was present in membrane, cytoplasm and some nuclei of epithelial cells during proliferation and lactation. Receptor expression decreased during weaning and was absent or weak in regressive mammary glands. Immunoreactivity was weak in ductal epithelial cells from virgin adult animals. Pronounced expression of GH receptor/binding protein was observed with two monoclonal antibodies and lesser reactivity was seen with others, paralleling their affinities for the receptor. The cytoplasmic presence of this putatively plasma membrane located GH receptor is accounted for by the existence of a soluble form on the GH receptor, namely the growth hormone binding protein derived from the membrane receptor by cleavage. Primary localization of the receptor in proliferating and lactating epithelial cells suggests that the rat and rabbit mammary gland is a GH target tissue. This finding is in contradiction to both classical GH action and the somatomedin hypothesis and challenges the widely held view that GH has no direct influence on mammary growth and function.
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Affiliation(s)
- D T Lincoln
- Independent Research Foundation, Chapel Hill, Australia
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23
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Popnikolov NK, Yang J, Guzman RC, Swanson SM, Thordarson G, Collins G, Talamantes F, Nandi S. In vivo growth stimulation of collagen gel embedded normal human and mouse primary mammary epithelial cells. J Cell Physiol 1995; 163:51-60. [PMID: 7896900 DOI: 10.1002/jcp.1041630107] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A new system for studying growth of normal human mammary epithelial cells in an in vivo environment using athymic nude mice is described. Human mammary epithelial cells dissociated from reduction mammoplasty specimens were embedded within collagen gels and subsequently transplanted subcutaneously into nude mice. Histological sections of recovered collagen gels showed epithelial cells arranged as short tubules with some branching. Proliferation of mammary epithelial cells was quantitated in vivo by 3 days' continuous infusion with 5 bromo-2'-deoxy-uridine followed by immunostaining of sections from recovered gels. Ovarian steroids administered to the host animals, resulting in blood serum levels normally found in the human female, had little or no effect on the proliferation of human mammary epithelial cells. Collagen gel embedded mouse mammary epithelial cells, mouse mammary explants, and host mammary glands all responded similarly to ovarian steroids, suggesting that the unresponsiveness of the human mammary epithelial cells under these conditions was not due to dissociation per se. However, an increased dose of 17 beta-estradiol or a growth factor combination containing epidermal growth factor, cholera toxin, and cortisol significantly stimulated the proliferation of human outgrowths. The growth factor response was dependent on the location of the cells, with the greatest response seen in the part of the gel proximal to the osmotic pump delivering the growth factors and the effect gradually waning in area more distal to the pump. The effect was especially striking since the mitotic figures could be easily identified and the labeling index was as high as 75%. The host mouse mammary gland also responded to growth factors, resulting in ductal hyperplasia. The proliferative and morphogenetic effects of various agents on normal human mammary epithelial cells embedded in collagen gel can be studied in vivo in nude mice.
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Affiliation(s)
- N K Popnikolov
- Cancer Research Laboratory, University of California, Berkeley 94720
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24
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Stelwagen K, Grieve DG, Walton JS, Ball JL, McBride BW. Effect of prepartum bovine somatotropin in primigravid ewes on mammogenesis, milk production, and hormone concentrations. J Dairy Sci 1993; 76:992-1001. [PMID: 8486851 DOI: 10.3168/jds.s0022-0302(93)77427-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Twenty-five primigravid ewes were used to investigate the effect of bST, between 97 and 124 d of gestation, on mammogenesis and subsequent milk production. Five ewes (reference group) were slaughtered at 96 d of gestation, and the remaining ewes were injected daily with saline (control group: n = 10) or .1 mg/kg of BW of bST (bST group: n = 10). Following bST treatment, 5 control and 5 bST group ewes were slaughtered (slaughter group). The remaining ewes were slaughtered after lambing and being milked for 8 wk (production group). Weekly blood samples were obtained from both slaughter and production group ewes. Slaughter group ewes were also subjected to 8-h serial blood sampling at 98 d (period 1) and 123 d (period 2) of gestation. Milk production was 42% higher in ewes treated prepartum with bST than in those treated with saline. Results suggest that the increase in milk was due to an increase in mammary parenchymal cell number rather than to an increase in cellular activity. The high rate of [3H]thymidine incorporation into parenchymal tissue in reference group ewes suggests that the increase in parenchyma during the second trimester of gestation is due to cellular hyperplasia but that cellular hypertrophy may be more important during the last trimester. Plasma IGF-I concentrations were significantly higher during bST treatment and remained elevated between daily injections; the increase was greatest in period 2.
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Affiliation(s)
- K Stelwagen
- Department of Animal and Poultry Science, University of Guelph, ON, Canada
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25
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Vassilacopoulou D, Boylan ES. Mammary gland morphology and responsiveness to regulatory molecules following prenatal exposure to diethylstilbestrol. TERATOGENESIS, CARCINOGENESIS, AND MUTAGENESIS 1993; 13:59-74. [PMID: 8102210 DOI: 10.1002/tcm.1770130203] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Female ACI rats were exposed to diethylstilbestrol (DES) in utero to evaluate the effects on the peri-pubertal mammary gland with respect to 1) mammary gland morphology, 2) sensitivity to natural and synthetic estrogens, and 3) sensitivity to endogenous epidermal growth factor (EGF). Pregnant rats were injected with vehicle (sesame oil) or DES (total dose, 8.0 micrograms) on days 15 and 18 of gestation. DES-exposed and control offspring were ovariectomized at 34 days of age and sacrificed at day 53 to ascertain the morphology of the mammary glands in peri-pubertal rats. Elvax pellets containing 5 or 11 ng 17 beta-estradiol (E2) or DES were implanted subcutaneously adjacent to the third mammary gland pair. Furthermore, additional groups of rats were subjected to bilateral sialoadenectomy at the day of ovariectomy to remove the major source of endogenous EGF. A significant proportion of mammary glands of DES-exposed animals exhibited atypical mammary gland morphology, with approximately 25% displaying hypo-differentiation, and about 5% with aberrant hyper-proliferation. From the pellet implantation experiments, the DES-exposed glands were found to be refractory to stimulation by 5 and 11 ng DES; however, there was no significant difference in the degree of local stimulation elicited by either dose of E2. Sialoadenectomy at d34 had no apparent effect on mammary gland morphology in either the DES-exposed or vehicle-exposed groups. These data support the premise that the mammary gland of the peri-pubertal ACI rat is morphologically and physiologically aberrant as a function of transplacental exposure to DES, with a significant percentage hypo-differentiated and refractory to subsequent hormonal stimulation.
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Affiliation(s)
- D Vassilacopoulou
- Department of Biology, Queens College, City University of New York, Flushing 11367
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26
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Talhouk RS, Bissell MJ, Werb Z. Coordinated expression of extracellular matrix-degrading proteinases and their inhibitors regulates mammary epithelial function during involution. J Cell Biol 1992; 118:1271-82. [PMID: 1512297 PMCID: PMC2289583 DOI: 10.1083/jcb.118.5.1271] [Citation(s) in RCA: 331] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Extracellular matrix (ECM) plays an important role in the maintenance of mammary epithelial differentiation in culture. We asked whether changes in mouse mammary specific function in vivo correlate with changes in the ECM. We showed, using expression of beta-casein as a marker, that the temporal expression of ECM-degrading proteinases and their inhibitors during lactation and involution are inversely related to functional differentiation. After a lactation period of 9 d, mammary epithelial cells maintained beta-casein expression up to 5 d of involution. Two metalloproteinases, 72-kD gelatinase (and its 62-kD active form), and stromelysin, and a serine proteinase tissue plasminogen activator were detected by day four of involution, and maintained expression until at least day 10. The expression of their inhibitors, the tissue inhibitor of metalloproteinases (TIMP) and plasminogen activator inhibitor-1, preceded the onset of ECM-degrading proteinase expression and was detected by day two of involution, and showed a sharp peak of expression centered on days 4-6 of involution. When involution was accelerated by decreasing lactation to 2 d, there was an accelerated loss of beta-casein expression evident by day four and a shift in expression of ECM-remodeling proteinases and inhibitors to a focus at 2-4 d of involution. To further extend the correlation between mammary-specific function and ECM remodeling we initiated involution by sealing just one gland in an otherwise hormonally sufficient lactating animal. Alveoli in the sealed gland contained casein for at least 7 d after sealing, and closely resembled those in a lactating gland. The relative expression of TIMP in the sealed gland increased, whereas the expression of stromelysin was much lower than that of a hormone-depleted involuting gland, indicating that the higher the ratio of TIMP to ECM-degrading proteinases the slower the process of involution. To test directly the functional role of ECM-degrading proteinases in the loss of tissue-specific function we artificially perturbed the ECM-degrading proteinase-inhibitor ratio in a normally involuting gland by maintaining high concentrations of TIMP protein with the use of surgically implanted slow-release pellets. In a concentration-dependent fashion, involuting mammary glands that received TIMP implants maintained high levels of casein and delayed alveolar regression. These data suggest that the balance of ECM-degrading proteinases and their inhibitors regulates the organization of the basement membrane and the tissue-specific function of the mammary gland.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- R S Talhouk
- Division of Cell and Molecular Biology, Lawrence Berkeley Laboratory, CA 94720
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27
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Silberstein GB, Flanders KC, Roberts AB, Daniel CW. Regulation of mammary morphogenesis: evidence for extracellular matrix-mediated inhibition of ductal budding by transforming growth factor-beta 1. Dev Biol 1992; 152:354-62. [PMID: 1644225 DOI: 10.1016/0012-1606(92)90142-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Branching morphogenesis in the mammary gland involves focal regions of cell proliferation, the terminal and lateral ductal buds, that exist simultaneously with extensive regions of differentiated ducts in which budding and growth are actively suppressed. Exogenous transforming growth factor-beta 1 (TGF-beta 1) has previously been shown to locally inhibit the formation and growth of mammary ductal buds. Here we report that endogenous TGF-beta 1, produced by epithelial and stromal mammary cells, forms complexes with extracellular matrix (ECM) molecules surrounding those ductal structures in which budding is inhibited. The largest amounts of immunostainable TGF-beta 1 are found in mature periductal ECM, and the least in newly synthesized ECM. In all areas of active ductal growth, where DNA-synthetic buds were forming new ductal branches, we found a highly focal loss of TGF-beta 1 from the periductal ECM at the bud-forming region of the duct. When growth of the new buds terminated, the structures again became associated with TGF-beta-rich ECM. These findings indicate that ECM must reach a certain state of maturity before it becomes associated with TGF-beta 1 and that TGF-beta 1 can be depleted selectively from the periductal ECM at focal growth points. A different type of growth point, the alveolar (secretory) buds, was also investigated. These buds are known not to be inhibited by exogenous TGF-beta 1, and we found them not to be associated with changes in ECM-bound TGF-beta 1. Our results support the concept that the periductal ECM acts as a reservoir for TGF-beta 1 that functions to maintain an open pattern of mammary branching by inhibiting ductal, but not alveolar, bud formation.
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Affiliation(s)
- G B Silberstein
- Department of Biology, Sinsheimer Laboratories, University of California, Santa Cruz 95064
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28
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Abstract
We have previously shown that TGF-beta 1 rapidly and reversibly inhibits ductal growth in vivo when administered by miniature slow-release plastic implants. A possible role for endogenous TGF-beta 1 was suggested by the observation that the normal gland displayed substantial, developmentally regulated levels of TGF-beta 1 transcripts and protein. These studies have now been extended to include the other two mammalian TGF-beta isoforms. When tested with slow-release plastic implants, TGF-beta 2 and TGF-beta 3 also caused disappearance of the proliferating mammary stem cell layer, with rapid involution of ductal end buds and cessation of glandular growth. None of the isoforms was active in inhibiting alveolar morphogenesis. We conclude that under the conditions of these tests, the three mammalian isoforms are functionally equivalent. However, striking differences in patterns of gene expression and in the distribution of immunoreactive peptides suggest that TGF-beta 2 was expressed only at low levels, and mainly during pregnancy. TGF-beta 3 was expressed in ductal stroma and epithelium, and was the only isoform detected in myoepithelial cells. Developing alveolar tissue and its associated ducts displayed striking TGF-beta 3 gene expression and immunostaining, which were greatly reduced during lactation. We are now investigating the possibility that the observed high levels of TGF-beta expression in pregnancy, particularly of TGF-beta 3, and the absence of substantial expression of any isoform during lactation, may indicate a role for the TGF-beta in regulating functional differentiation or the onset of milk secretion.
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Affiliation(s)
- C W Daniel
- Department of Biology, University of California, Thimann Laboratories, Santa Cruz 95064
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29
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Fernig DG, Smith JA, Rudland PS. Relationship of growth factors and differentiation in normal and neoplastic development of the mammary gland. Cancer Treat Res 1991; 53:47-78. [PMID: 1672090 DOI: 10.1007/978-1-4615-3940-7_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The different mammary cell lines described herein appear to be representative of the cell types found in both normal glands and benign tumors of rats and humans. The epithelial cell lines can differentiate to both alveolar-like and myoepithelial-like cells in culture. The epithelial cell lines and particularly those cell lines representing intermediate stages in the myoepithelial differentiation pathway are candidates for the epithelial stem cells found in rat and possibly in human terminal ductal structures. The systemic mammatrophic hormones that are thought to control the growth of the mammary gland in vivo have little or no stimulatory effect alone on the growth of normal and neoplastic rat mammary cells in culture. The pituitary growth factors (fibroblast growth factor [FGF] and pituitary-derived mammary growth factor [PMGF],) and the growth factors released from the different cell lines, (stromal prostaglandin E2 [PGE2] and myoepithelial transforming growth factor alpha [TGF-alpha]) are much more potent mitogenic agents for the mammary cell lines. The ability of FGF and epidermal growth factor (EGF) -related molecules to simulate growth of the different mammary cell types in culture correlates with the presence of their high-affinity receptors. Thus these growth factors are promising candidates for some of the primary effectors of mammary growth in vivo. Malignant mammary epithelial cells have a greatly reduced rate of growth compared to their normal and benign counterparts. They also fail to differentiate or to respond to PMGF but can still respond to PGE2 and TGF-alpha. In addition, highly malignant variants appear capable of adapting to a new growth environment in vivo. This suggests that simple molecular explanations based solely on the autostimulation of cell growth may not be sufficient to explain some of the properties of the slowly growing, highly malignant cells.
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30
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31
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Waters MJ, Barnard RT, Lobie PE, Lim L, Hamlin G, Spencer SA, Hammonds RG, Leung DW, Wood WI. Growth hormone receptors--their structure, location and role. ACTA PAEDIATRICA SCANDINAVICA. SUPPLEMENT 1990; 366:60-72. [PMID: 2206008 DOI: 10.1111/j.1651-2227.1990.tb11600.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- M J Waters
- Department of Physiology and Pharmacology, University of Queensland, St Lucia, Australia
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32
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Coleman S, Daniel CW. Inhibition of mouse mammary ductal morphogenesis and down-regulation of the EGF receptor by epidermal growth factor. Dev Biol 1990; 137:425-33. [PMID: 2303169 DOI: 10.1016/0012-1606(90)90267-m] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
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.
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Affiliation(s)
- S Coleman
- Department of Biology, University of California, Santa Cruz 95064
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33
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Daniel CW, Silberstein GB, Van Horn K, Strickland P, Robinson S. TGF-beta 1-induced inhibition of mouse mammary ductal growth: developmental specificity and characterization. Dev Biol 1989; 135:20-30. [PMID: 2767334 DOI: 10.1016/0012-1606(89)90154-1] [Citation(s) in RCA: 145] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
TGF-beta 1, implanted into growing mouse mammary glands, was previously shown to inhibit ductal growth in an apparently normal and fully reversible manner. In this report we extend these findings to show that TGF-beta 1 inhibition is highly specific. In pregnant or hormone-treated mice, doses of TGF-beta 1 that were capable of fully inhibiting ductal elongation had little effect on the proliferation of lobuloalveolar structures. Additionally, the inhibitory action of TGF-beta 1 on ducts is epithelium-specific, resulting in cessation of DNA synthesis in the rapidly proliferating epithelium of mammary end buds, but does not inhibit DNA synthesis in the stroma surrounding the end buds. At the cellular level, transplant studies showed that TGF-beta 1 inhibited the regeneration of mammary ductal cells when implanted into mammary gland-free fat pads by suppressing the formation of new end buds, without inhibiting maintenance DNA synthesis in ductal lumenal epithelium; this observation indicates the potential of TGF-beta 1 to maintain patterning by suppressing adventitious lateral branching. The time-course of TGF-beta 1 inhibition of end buds was rapid, with cessation of DNA synthesis by 12 hr, followed by loss of the stem cell (cap cell) layer. The question of glandular exposure to TGF-beta 1 administered in EVAc implants was also investigated. Incorporation of TGF-beta 1 into EVAc was found not to degrade the hormone, while the release kinetics of the ligand from implants, its retention in the gland, and the demonstrable zone of exposure were consistent with observed inhibitory effects. These results support the hypothesis that TGF-beta 1 is a natural regulator of mammary ductal growth.
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Affiliation(s)
- C W Daniel
- Department of Biology, Thimann Laboratory, University of California, Santa Cruz 95064
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34
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Affiliation(s)
- I A Forsyth
- AFRC Institute for Grassland and Animal Production, Hurley, Maidenhead, Berks
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Coleman S, Silberstein GB, Daniel CW. Ductal morphogenesis in the mouse mammary gland: evidence supporting a role for epidermal growth factor. Dev Biol 1988; 127:304-15. [PMID: 3259938 DOI: 10.1016/0012-1606(88)90317-x] [Citation(s) in RCA: 189] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
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.
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Affiliation(s)
- S Coleman
- Department of Biology, University of California, Santa Cruz 95064
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