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Molecular and Cellular Endocrinology Jun 2012This paper reviews work on progesterone and the progesterone receptor (PR) in the mouse mammary gland that has been used extensively as an experimental model. Studies... (Review)
Review
This paper reviews work on progesterone and the progesterone receptor (PR) in the mouse mammary gland that has been used extensively as an experimental model. Studies have led to the concept that progesterone controls proliferation and morphogenesis of the luminal epithelium in a tightly orchestrated manner at distinct stages of development by paracrine signaling pathways, including receptor activator of nuclear factor κB ligand (RANKL) as a major paracrine factor. Progesterone also drives expansion of stem cells by paracrine signals to generate progenitors required for alveologenesis. During mid-to-late pregnancy, progesterone has another role to suppress secretory activation until parturition mediated in part by crosstalk between PR and prolactin/Stat5 signaling to inhibit induction of milk protein gene expression, and by inhibiting tight junction closure. In models of hormone-dependent mouse mammary tumors, the progesterone/PR signaling axis enhances pre-neoplastic progression by a switch from a paracrine to an autocrine mode of proliferation and dysregulation of the RANKL signaling pathway. Limited experiments with normal human breast show that progesterone/PR signaling also stimulates epithelial cell proliferation by a paracrine mechanism; however, the signaling pathways and whether RANKL is a major mediator remains unknown. Work with human breast cancer cell lines, patient tumor samples and clinical studies indicates that progesterone is a risk factor for breast cancer and that alteration in progesterone/PR signaling pathways contributes to early stage human breast cancer progression. However, loss of PR expression in primary tumors is associated with a less differentiated more invasive phenotype and worse prognosis, suggesting that PR may limit later stages of tumor progression.
Topics: Animals; Breast Neoplasms; Female; Humans; Mammary Glands, Animal; Mammary Glands, Human; Mice; Pregnancy; Progesterone; Progestins; RANK Ligand; Receptors, Progesterone; Signal Transduction
PubMed: 22193050
DOI: 10.1016/j.mce.2011.10.030 -
Breast Cancer Research : BCR Jun 2015Mammographic density (MD), after adjustment for a women's age and body mass index, is a strong and independent risk factor for breast cancer (BC). Although the BC risk...
INTRODUCTION
Mammographic density (MD), after adjustment for a women's age and body mass index, is a strong and independent risk factor for breast cancer (BC). Although the BC risk attributable to increased MD is significant in healthy women, the biological basis of high mammographic density (HMD) causation and how it raises BC risk remain elusive. We assessed the histological and immunohistochemical differences between matched HMD and low mammographic density (LMD) breast tissues from healthy women to define which cell features may mediate the increased MD and MD-associated BC risk.
METHODS
Tissues were obtained between 2008 and 2013 from 41 women undergoing prophylactic mastectomy because of their high BC risk profile. Tissue slices resected from the mastectomy specimens were X-rayed, then HMD and LMD regions were dissected based on radiological appearance. The histological composition, aromatase immunoreactivity, hormone receptor status and proliferation status were assessed, as were collagen amount and orientation, epithelial subsets and immune cell status.
RESULTS
HMD tissue had a significantly greater proportion of stroma, collagen and epithelium, as well as less fat, than LMD tissue did. Second harmonic generation imaging demonstrated more organised stromal collagen in HMD tissues than in LMD tissues. There was significantly more aromatase immunoreactivity in both the stromal and glandular regions of HMD tissues than in those regions of LMD tissues, although no significant differences in levels of oestrogen receptor, progesterone receptor or Ki-67 expression were detected. The number of macrophages within the epithelium or stroma did not change; however, HMD stroma exhibited less CD206(+) alternatively activated macrophages. Epithelial cell maturation was not altered in HMD samples, and no evidence of epithelial-mesenchymal transition was seen; however, there was a significant increase in vimentin(+)/CD45(+) immune cells within the epithelial layer in HMD tissues.
CONCLUSIONS
We confirmed increased proportions of stroma and epithelium, increased aromatase activity and no changes in hormone receptor or Ki-67 marker status in HMD tissue. The HMD region showed increased collagen deposition and organisation as well as decreased alternatively activated macrophages in the stroma. The HMD epithelium may be a site for local inflammation, as we observed a significant increase in CD45(+)/vimentin(+) immune cells in this area.
Topics: Adult; Biomarkers, Tumor; Breast; Breast Density; Breast Neoplasms; Collagen; Epithelial-Mesenchymal Transition; Epithelium; Female; Humans; Immunohistochemistry; Immunophenotyping; Macrophages; Mammary Glands, Human; Mammography; Middle Aged; Phenotype; Risk Factors; Stromal Cells
PubMed: 26040322
DOI: 10.1186/s13058-015-0592-1 -
Breast Cancer Research : BCR May 2014Although estrogen and progesterone play a key role in normal mammary development and in breast cancer, the potential for proliferation and lineage differentiation as...
INTRODUCTION
Although estrogen and progesterone play a key role in normal mammary development and in breast cancer, the potential for proliferation and lineage differentiation as well as origin of cells that express the estrogen receptor (ER) in normal breast epithelium are not known. Some evidence suggests that normal human mammary stem/progenitor cells are ER-, but the identity of these cells and the cellular hierarchy of breast epithelium are still subjects of controversy. It is likely that elucidation of these aspects will bring insight into the cellular origin of breast cancer subtypes.
METHODS
We used fluorescence-activated cell sorting of primary human mammary epithelial cells along with in vitro and in vivo functional assays to examine the hierarchic relation between cells with aldehyde dehydrogenase enzymatic activity (ALDH+ cells) and ER+ cells in the normal human breast epithelium. We assessed the proliferation and lineage differentiation potential of these cells in vitro and in vivo. A gene reporter assay was used to separate live ER+ and ER- mammary epithelial cells. With shRNA-mediated knockdown, we investigated the role of ALDH isoforms in the functionality of mammary epithelial progenitor cells.
RESULTS
We describe a cellular hierarchy in the normal human mammary gland in which ER-/ALDH+ cells with functional properties of stem/progenitor cells generate ER+ progenitor cells, which in turn give rise to cells of luminal lineage. We show that the ALDH1A1 isoform, through its function in the retinoic acid metabolism, affects the proliferation and/or early differentiation of stem/progenitor cells and is important for branching morphogenesis.
CONCLUSIONS
This study presents direct evidence that ER+ cells are generated by ER-/ALDH+ stem/progenitor cells. We also show that ER+ cells are able to generate cell progeny of luminal lineage in vitro and in vivo. Loss of ALDH1A1 function impairs this process, as well as branching morphogenesis and clonogenicity in suspension culture. This latter effect is reversed by treatment with retinoic acid.
Topics: Aldehyde Dehydrogenase; Aldehyde Dehydrogenase 1 Family; Aldehyde Oxidoreductases; Cell Differentiation; Cell Lineage; Cell Proliferation; Cells, Cultured; Female; Flow Cytometry; Humans; Mammary Glands, Human; Protein Isoforms; RNA Interference; RNA, Small Interfering; Receptors, Estrogen; Retinal Dehydrogenase; Stem Cells; Tretinoin
PubMed: 24887554
DOI: 10.1186/bcr3663 -
Cancer Research Dec 2012Overexpression of cyclin D1 is believed to endow mammary epithelial cells (MEC) with a proliferative advantage by virtue of its contribution to pRB inactivation....
Overexpression of cyclin D1 is believed to endow mammary epithelial cells (MEC) with a proliferative advantage by virtue of its contribution to pRB inactivation. Accordingly, abrogation of the kinase-dependent function of cyclin D1 is sufficient to render mice resistant to breast cancer initiated by ErbB2. Here, we report that mouse cyclin D1(KE/KE) MECs (deficient in cyclin D1 activity) upregulate an autophagy-like process but fail to implement ErbB2-induced senescence in vivo. In addition, immortalized cyclin D1(KE/KE) MECs retain high rates of autophagy and reduced ErbB2-mediated transformation in vitro. However, highlighting its dual role during tumorigenesis, downregulation of autophagy led to an increase in senescence in cyclin D1(KE/KE) MECs. Autophagy upregulation was also confirmed in human mammary epithelial cells (HMEC) subjected to genetic and pharmacologic inhibition of cyclin D1 activity and, similar to our murine system, simultaneous inhibition of Cdk4/6 and autophagy in HMECs enhanced the senescence response. Collectively, our findings suggest a previously unrecognized function of cyclin D1 in suppressing autophagy in the mammary epithelium.
Topics: Animals; Autophagy; Cell Line, Tumor; Cell Proliferation; Cellular Senescence; Cyclin D1; Epithelium; Female; Genes, erbB-2; Mammary Glands, Animal; Mice; Mice, Inbred C57BL; Mice, Inbred NOD; Mice, SCID; Mice, Transgenic
PubMed: 23041550
DOI: 10.1158/0008-5472.CAN-11-4139 -
Developmental Biology Oct 2001Development of glandular organs such as the kidney, lung, and prostate involves the process of branching morphogenesis. The developing organ begins as an epithelial bud... (Review)
Review
Development of glandular organs such as the kidney, lung, and prostate involves the process of branching morphogenesis. The developing organ begins as an epithelial bud that invades the surrounding mesenchyme, projecting dividing epithelial cords or tubes away from the site of initiation. This is a tightly regulated process that requires complex epithelial-mesenchymal interactions, resulting in a three-dimensional treelike structure. We propose that activins are key growth and differentiation factors during this process. The purpose of this review is to examine the direct, indirect, and correlative lines of evidence to support this hypothesis. The expression of activins is reviewed together with the effect of activins and follistatins in the development of branched organs. We demonstrate that activin has both negative and positive effects on cell growth during branching morphogenesis, highlighting the complex nature of activin in the regulation of proliferation and differentiation. We propose potential mechanisms for the way in which activins modify branching and address the issue of whether activin is a regulator of branching morphogenesis.
Topics: Activins; Animals; Breast; Cell Differentiation; Cell Division; Epithelium; Female; Gene Expression Regulation, Developmental; Humans; Inhibins; Kidney; Lung; Male; Mesoderm; Mice; Models, Biological; Pancreas; Prostate; Salivary Glands; Signal Transduction; Transforming Growth Factor beta
PubMed: 11783989
DOI: 10.1006/dbio.2001.0399 -
Reproductive Toxicology (Elmsford, N.Y.) Jul 2015Iatrogenic gestational exposure to diethylstilbestrol (DES) induced alterations of the genital tract and predisposed individuals to develop clear cell carcinoma of the... (Review)
Review
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.
Topics: Age Factors; Animals; Benzhydryl Compounds; Breast Neoplasms; Cell Communication; Cell Transformation, Neoplastic; Dose-Response Relationship, Drug; Endocrine Disruptors; Epithelial Cells; Estrogens; Female; Gestational Age; Humans; Hypothalamus; Mammary Glands, Animal; Mammary Glands, Human; Maternal Exposure; Phenols; Pregnancy; Prenatal Exposure Delayed Effects; Risk Assessment; Risk Factors; Stromal Cells
PubMed: 25277313
DOI: 10.1016/j.reprotox.2014.09.012 -
Biomaterials Jan 2017Matrix systems used to study complex three-dimensional (3D) cellular processes like mammary epithelial tissue morphogenesis and tumorigenesis ex vivo often require...
Matrix systems used to study complex three-dimensional (3D) cellular processes like mammary epithelial tissue morphogenesis and tumorigenesis ex vivo often require ill-defined biological components, which lead to poor reproducibility and a lack of control over physical parameters. In this study, a well-defined, tunable synthetic biohybrid hydrogel composed of the glycosaminoglycan heparin, star-shaped poly(ethylene glycol) (starPEG), and matrix metalloproteinase- (MMP-) cleavable crosslinkers was applied to dissect the biophysical and biochemical signals promoting human mammary epithelial cell (MEC) morphogenesis. We show that compliant starPEG-heparin matrices promote the development of polarized MEC acini. Both the presence of heparin and MMP-cleavable crosslinks are essential in facilitating MEC morphogenesis without supplementation of exogenous adhesion ligands. In this system, MECs secrete and organize laminin in basement membrane-like assemblies to promote integrin signaling and drive acinar development. Therefore, starPEG-heparin hydrogels provide a versatile platform to study mammary epithelial tissue morphogenesis in a chemically defined and precisely tunable 3D in vitro microenvironment. The system allows investigation of biophysical and biochemical aspects of mammary gland biology and potentially a variety of other organoid culture studies.
Topics: Biomimetic Materials; Cell Line; Cell Proliferation; Epithelial Cells; Extracellular Matrix; Glycosaminoglycans; Humans; Hydrogels; Mammary Glands, Human; Morphogenesis; Organ Culture Techniques; Printing, Three-Dimensional; Tissue Engineering; Tissue Scaffolds
PubMed: 27741500
DOI: 10.1016/j.biomaterials.2016.10.007 -
Philosophical Transactions of the Royal... May 2017Branched networks are ubiquitous throughout nature, particularly found in tissues that require large surface area within a restricted volume. Many tissues with a... (Review)
Review
Branched networks are ubiquitous throughout nature, particularly found in tissues that require large surface area within a restricted volume. Many tissues with a branched architecture, such as the vasculature, kidney, mammary gland, lung and nervous system, function to exchange fluids, gases and information throughout the body of an organism. The generation of branched tissues requires regulation of branch site specification, initiation and elongation. Branching events often require the coordination of many cells to build a tissue network for material exchange. Recent evidence has emerged suggesting that cell cooperativity scales with the number of cells actively contributing to branching events. Here, we compare mechanisms that regulate branching, focusing on how cell cohorts behave in a coordinated manner to build branched tissues.This article is part of the themed issue 'Systems morphodynamics: understanding the development of tissue hardware'.
Topics: Animals; Cardiovascular System; Embryonic Development; Epithelium; Humans; Kidney; Lung; Mammary Glands, Human; Morphogenesis; Nervous System
PubMed: 28348257
DOI: 10.1098/rstb.2015.0527 -
Laboratory Investigation; a Journal of... Mar 2012The E26 transformation-specific (ETS) family of transcription factors comprises of 27 and 26 members in humans and mice, respectively, which are known to regulate many... (Review)
Review
The E26 transformation-specific (ETS) family of transcription factors comprises of 27 and 26 members in humans and mice, respectively, which are known to regulate many different biological processes, including cell proliferation, cell differentiation, embryonic development, neoplasia, hematopoiesis, angiogenesis, and inflammation. The epithelium-specific ETS transcription factor-1 (ESE-1) is a physiologically important ETS transcription factor, which has been shown to play a role in the pathogenesis of various diseases, and was originally characterized as having an epithelial-restricted expression pattern, thus placing it within the epithelium-specific ETS subfamily. Despite a large body of published work on ETS biology, much remains to be learned about the precise functions of ESE-1 and other epithelium-specific ETS factors in regulating diverse disease processes. Clues as to the specific function of ESE-1 in the setting of various diseases can be obtained from studies aimed at examining the expression of putative target genes regulated by ESE-1. Thus, this review will focus primarily on the various roles of ESE-1 in different pathophysiological processes, including regulation of epithelial cell differentiation during both intestinal development and lung regeneration; regulation of dendritic cell-driven T-cell differentiation during allergic airway inflammation; regulation of mammary gland development and breast cancer; and regulation of the effects of inflammatory stimuli within the setting of synovial joint and vascular inflammation. Understanding the exact mechanisms by which ESE-1 regulates these processes can have important implications for the treatment of a wide range of diseases.
Topics: Adenocarcinoma; Animals; Breast Neoplasms; Carcinoma, Large Cell; Cell Differentiation; DNA-Binding Proteins; Embryonic Development; Epithelium; Female; Humans; Intestines; Lung; Lung Neoplasms; Mammary Glands, Human; Mice; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-ets; Regeneration; Transcription Factors
PubMed: 22157719
DOI: 10.1038/labinvest.2011.186 -
Breast Cancer Research : BCR Jan 2016Triple-negative breast cancer (TNBC), an aggressive disease comprising several subtypes including basal-like and claudin-low, involves frequent deletions or point...
BACKGROUND
Triple-negative breast cancer (TNBC), an aggressive disease comprising several subtypes including basal-like and claudin-low, involves frequent deletions or point mutations in TP53, as well as loss of PTEN. We previously showed that combined deletion of both tumor suppressors in the mouse mammary epithelium invariably induced claudin-low-like TNBC. The effect of p53 mutation plus Pten deletion on mammary tumorigenesis and whether this combination can induce basal-like TNBC in the mouse are unknown.
METHODS
WAP-Cre:Pten(f/f):p53(lox.stop.lox_R270H) composite mice were generated in which Pten is deleted and a p53-R270H mutation in the DNA-binding domain is induced upon expression of Cre-recombinase in pregnancy-identified alveolar progenitors. Tumors were characterized by histology, marker analysis, transcriptional profiling [GEO-GSE75989], bioinformatics, high-throughput (HTP) FDA drug screen as well as orthotopic injection to quantify tumor-initiating cells (TICs) and tail vein injection to identify lung metastasis.
RESULTS
Combined Pten deletion plus induction of p53-R270H mutation accelerated formation of four distinct mammary tumors including poorly differentiated adenocarcinoma (PDA) and spindle/mesenchymal-like lesions. Transplantation assays revealed highest frequency of TICs in PDA and spindle tumors compared with other subtypes. Hierarchical clustering demonstrated that the PDA and spindle tumors grouped closely with human as well as mouse models of basal and claudin-low subtypes, respectively. HTP screens of primary Pten(∆):p53(∆) vs. Pten(∆):p53(R270H) spindle tumor cells with 1120 FDA-approved drugs identified 8-azaguanine as most potent for both tumor types, but found no allele-specific inhibitor. A gene set enrichment analysis revealed increased expression of a metastasis pathway in Pten(∆):p53(R270H) vs. Pten(∆):p53(∆) spindle tumors. Accordingly, following tail vein injection, both Pten(∆):p53(R270H) spindle and PDA tumor cells induced lung metastases and morbidity significantly faster than Pten(∆):p53(∆) double-deletion cells, and this was associated with the ability of Pten(∆):p53(R270H) tumor cells to upregulate E-cadherin expression in lung metastases.
CONCLUSIONS
Our results demonstrate that WAP-Cre:Pten(f/f):p53(lox.stop.lox_R270H) mice represent a tractable model to study basal-like breast cancer because unlike p53 deletion, p53(R270H) mutation in the mouse does not skew tumors toward the claudin-low subtype. The WAP-Cre:Pten(f/f):p53(lox.stop.lox_R270H) mice develop basal-like breast cancer that is enriched in TICs, can readily form lung metastasis, and provides a preclinical model to study both basal-like and claudin-low TNBC in immune-competent mice.
Topics: Animals; Cadherins; Claudins; Epithelium; Female; Gene Expression Regulation, Neoplastic; Humans; Mammary Glands, Animal; Mammary Glands, Human; Mammary Neoplasms, Animal; Mice; Neoplasms, Basal Cell; Neoplastic Stem Cells; PTEN Phosphohydrolase; Pregnancy; Sequence Deletion; Triple Negative Breast Neoplasms; Tumor Suppressor Protein p53
PubMed: 26781438
DOI: 10.1186/s13058-015-0668-y