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Overexpression of dominant oncogenes and the loss of tumor suppressor genes are basic genetic events in the acquisition of the malignant phenotype. The erb-b2 receptor tyrosine kinase 2 (ERBB-2) proto-oncogene is overexpressed in 20-30% of human breast cancers. The StAR related lipid transfer domain containing 13 gene (STARD13), also known as Deleted in Liver Cancer-2 (DLC-2), maps to chromosome band 13q12.3 and is frequently downregulated in human cancers, including 72% of breast cancers. It encodes a RhoGAP protein with sterile α motif (SAM) and StAR-related lipid transfer (START) domains. The objective of this study was to determine if loss of Stard13 plays a role in mammary tumor progression using transgenic mice expressing the activated ErbB-2 (Neu) oncogene and Cre recombinase (NIC) in mammary epithelium under transcriptional control of the murine mammary tumor virus (MMTV) promoter (MMTV-NIC). These mice were crossed with a conditional Stard13 knockout mouse (floxed exon 3), resulting in simultaneous Neu expression and Stard13 deletion, specifically in the mammary epithelium. We found that loss of Stard13 did not alter tumor growth nor significantly modify overall survival and tumor free survival. However, there was an increase in the total number of lung metastases in the Stard13 heterozygous or homozygous mice compared with the parental MMTV-NIC strain. Altogether our results indicate that Stard13 acts as a metastasis suppressor rather than a tumor suppressor gene, in Neu oncogene induced mammary tumorigenesis.
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Neoplasias Mamarias Experimentales/genética , Receptor ErbB-2/genética , Proteínas Supresoras de Tumor/genética , Animales , Femenino , Genes Supresores de Tumor , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Noqueados , Ratones Transgénicos , Metástasis de la Neoplasia , Proto-Oncogenes Mas , Receptor ErbB-2/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
BACKGROUND/AIMS: Blocking estrogen signaling with endocrine therapies (Tamoxifen or Fulverstrant) is an effective treatment for Estrogen Receptor-α positive (ER+) breast cancer tumours. Unfortunately, development of endocrine therapy resistance (ETR) is a frequent event resulting in disease relapse and decreased overall patient survival. The long noncoding RNA, H19, was previously shown to play a significant role in estrogen-induced proliferation of both normal and malignant ER+ breast epithelial cells. We hypothesized that H19 expression is also important for the proliferation and survival of ETR cells. METHODS: Here we utilized established ETR cell models; the Tamoxifen (Tam)-resistant LCC2 and the Fulvestrant and Tam cross-resistant LCC9 cells. Gain and loss of H19 function were achieved through lentiviral transduction as well as pharmacological inhibitors of the Notch and c-Met receptor signaling pathways. The effects of altered H19 expression on cell viability and ETR were assessed using three-dimensional (3D) organoid cultures and 2D co-cultures with low passage tumour-associated fbroblasts (TAFs). RESULTS: Here we report that treating ETR cells with Tam or Fulvestrant increases H19 expression and that it's decreased expression overcomes resistance to Tam and Fulvestrant in these cells. Interestingly, H19 expression is regulated by Notch and HGF signaling in the ETR cells and pharmacological inhibitors of Notch and c-MET signaling together significantly reverse resistance to Tam and Fulvestrant in an H19-dependent manner in these cells. Lastly, we demonstrate that H19 regulates ERα expression at the transcript and protein levels in the ETR cells and that H19 protects ERα against Fulvestrant-mediated downregulation of ERα protein. We also observed that blocking Notch and the c-MET receptor signaling also overcomes Fulvestrant and Tam resistance in 3D organoid cultures by decreasing ERα and H19 expression in the ETR cells. CONCLUSION: In endocrine therapy resistant breast cancer cells Fulvestrant is ineffective in decreasing ERα levels. Our data suggest that in the ETR cells, H19 expression acts as an ER modulator and that its levels and subsequently ERα levels can be substantially decreased by blocking Notch and c-MET receptor signaling. Consequently, treating ETR cells with these pharmacological inhibitors helps overcome resistance to Fulvestrant and Tamoxifen.
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Antineoplásicos Hormonales/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Resistencia a Antineoplásicos , Receptor alfa de Estrógeno/genética , Fulvestrant/farmacología , ARN Largo no Codificante/genética , Tamoxifeno/farmacología , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , HumanosRESUMEN
Mechanisms that control the levels and activities of reactive oxygen species (ROS) in normal human mammary cells are poorly understood. We show that purified normal human basal mammary epithelial cells maintain low levels of ROS primarily by a glutathione-dependent but inefficient antioxidant mechanism that uses mitochondrial glutathione peroxidase 2. In contrast, the matching purified luminal progenitor cells contain higher levels of ROS, multiple glutathione-independent antioxidants and oxidative nucleotide damage-controlling proteins and consume O2 at a higher rate. The luminal progenitor cells are more resistant to glutathione depletion than the basal cells, including those with in vivo and in vitro proliferation and differentiation activity. The luminal progenitors also are more resistant to H2O2 or ionizing radiation. Importantly, even freshly isolated "steady-state" normal luminal progenitors show elevated levels of unrepaired oxidative DNA damage. Distinct ROS control mechanisms operating in different subsets of normal human mammary cells could have differentiation state-specific functions and long-term consequences.
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Células Epiteliales/clasificación , Células Epiteliales/metabolismo , Glutatión/metabolismo , Glándulas Mamarias Humanas/citología , Estrés Oxidativo/fisiología , Western Blotting , Daño del ADN/fisiología , Citometría de Flujo , Humanos , Consumo de Oxígeno/fisiología , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Células Madre/metabolismoRESUMEN
Many normal adult tissues contain rare stem cells with extensive self-maintaining regenerative potential. During development, the stem cells of the hematopoietic and neural systems undergo intrinsically specified changes in their self-renewal potential. In the mouse, mammary stem cells with transplantable regenerative activity are first detectable a few days before birth. They share some phenotypic properties with their adult counterparts but are enriched in a subpopulation that displays a distinct gene expression profile. Here we show that fetal mammary epithelial cells have a greater direct and inducible growth potential than their adult counterparts. The latter feature is revealed in a novel culture system that enables large numbers of in vitro clonogenic progenitors as well as mammary stem cells with serially transplantable activity to be produced within 7 days from single fetal or adult input cells. We further show that these responses are highly dependent on novel factors produced by fibroblasts. These findings provide new avenues for elucidating mechanisms that regulate normal mammary epithelial stem cell properties at the single-cell level, how these change during development, and how their perturbation may contribute to transformation.
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Células Epiteliales/citología , Glándulas Mamarias Animales/citología , Células 3T3 , Animales , Células Epiteliales/fisiología , Femenino , Inmunohistoquímica , Glándulas Mamarias Animales/fisiología , RatonesRESUMEN
BACKGROUND: Deleted in Liver Cancer 1 (Dlc1) is a tumor suppressor gene, which maps to human chromosome 8p21-22 and is found frequently deleted in many cancers including breast cancer. The promoter of the remaining allele is often found methylated. The Dlc1 gene encodes a RhoGAP protein that regulates cell proliferation, migration and inhibits cell growth and invasion when restored in Dlc1 deficient tumor cell lines. This study focuses on determining the role of Dlc1 in normal mammary gland development and epithelial cell polarity in a Dlc1 gene trapped (gt) mouse. METHODS: Mammary gland whole mount preparations from 10-week virgin heterozygous Dlc1(gt/+) gene-trapped mice were compared with age-matched wild type (WT) controls. Hematoxylin-Eosin (H&E) and Masson's Trichrome staining of histological sections were carried out. Mammary glands from Dlc1(gt/+) mice and WT controls were enzymatically digested with collagenase and dispase and then cultured overnight to deplete hematopoietic and endothelial cells. The single cell suspensions were then cultured in Matrigel for 12 days. To knockdown Dlc1 expression, primary WT mammary epithelial cells were infected with short hairpin (sh) RNA expressing lentivirus or with a scrambled shRNA control. RESULTS: Dlc1(gt/+) mice showed anomalies in the mammary gland that included increased ductal branching and deformities in terminal end buds and branch points. Compared to the WT controls, Masson's Trichrome staining showed a thickened stromal layer with increased collagen deposition in mammary glands from Dlc1(gt/+) mice. Dlc1(gt/+) primary mammary epithelial cells formed increased solid acinar spheres in contrast with WT and scrambled shRNA control cells, which mostly formed hollow acinar structures when plated in 3D Matrigel cultures. These solid acinar structures were similar to the acinar structures formed when Dlc1 gene expression was knocked down in WT mammary cells by shRNA lentiviral transduction. The solid acinar structures were not due to a defect in apoptosis as determined by a lack of detectible cleaved caspase 3 antibody staining. Primary mammary cells from Dlc1(gt/+) mice showed increased RhoA activity compared with WT cells. CONCLUSIONS: The results illustrate that decreased Dlc1 expression can disrupt the normal cell polarization and mammary ductal branching. Altogether this study suggests that Dlc1 plays a role in maintaining normal mammary epithelial cell polarity and that Dlc1 is haploinsufficient.
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Polaridad Celular/fisiología , Células Epiteliales/fisiología , Proteínas Activadoras de GTPasa/fisiología , Haploinsuficiencia/fisiología , Glándulas Mamarias Animales/crecimiento & desarrollo , Proteínas Supresoras de Tumor/fisiología , Animales , Western Blotting , Neoplasias de la Mama/genética , Femenino , Técnica del Anticuerpo Fluorescente , Ratones , Microscopía Confocal , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Current evidence suggests that similar to other tissues in the human body mammary epithelia cells are being maintained by the unique properties of stem cells, undifferentiated as well as lineage-restricted progenitors. Because of their longevity, proliferation and differentiation potentials these primitive breast epithelial cells are likely targets of transforming mutations that can cause them to act as cancer initiating cells. In this context, understanding the molecular mechanisms that regulate the normal functions of the human breast epithelial stem cells and progenitors and how alterations to these same mechanisms can confer a cancer stem cell phenotype on these rare cell populations is crucial to the development of new and more effective therapies again breast cancer. This review article will examine the current state of knowledge about the isolation and characterization of human breast epithelial progenitors and their relevance to breast cancer research.
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Glándulas Mamarias Humanas/metabolismo , Células Madre/metabolismo , Animales , Separación Celular , Glándulas Endocrinas/metabolismo , Humanos , Glándulas Mamarias Humanas/citología , ARN Pequeño no Traducido/metabolismo , Células Madre/citología , Factores de Transcripción/metabolismoRESUMEN
The ability to differentiate tumor initiating stem cells (TISCs) from healthy, normal stem cells (NSCs) could have important diagnostic and therapeutic implications for patients with hepatocellular carcinoma (HCC). The aim of this study was to document and compare cell membrane potentials (PDs) and GABAA receptor subunit expression in hepatic TISCs and NSCs. PD values were determined in CD133(+) Huh-7 TISCs and CD133(+) WBF344 NSCs by single channel microelectrode impalement. GABAA receptor subunit expression was documented using immunohistochemistry (IH) in both cell lines as well as surgically resected HCC and healthy liver tissues. TISCs were significantly depolarized compared with NSCs (-4.0 ± 1.8 versus -11.0 ± 2.4 mV, respectively; p < 0.05). GABAA α6 subunit expression was either absent or markedly attenuated, while γ3 subunit expression was abundant in TISCs and HCC compared with NSCs and healthy liver tissues. Exposure to the GABAA receptor agonist muscimol caused hyperpolarization of TISCs (Δ -4.4 ± 1.1) but depolarization of NSCs (Δ + 5.2 ± 2.3) and attenuation of TISC proliferative activity. We conclude that TISCs and NSCs have significantly different cell membrane potentials and these differences are associated with differences in GABAA receptor subunit expression.
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Hepatocitos/fisiología , Neoplasias Hepáticas/metabolismo , Potenciales de la Membrana , Células Madre Neoplásicas/fisiología , Receptores de GABA-A/metabolismo , Antígeno AC133 , Antígenos CD/sangre , Antígenos CD/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Agonistas del GABA/farmacología , Glicoproteínas/sangre , Glicoproteínas/metabolismo , Hepatocitos/efectos de los fármacos , Humanos , Neoplasias Hepáticas/patología , Muscimol/farmacología , Células Madre Neoplásicas/efectos de los fármacos , Péptidos/sangre , Péptidos/metabolismo , Subunidades de Proteína/metabolismoRESUMEN
Metastasis remains a major challenge in treating breast cancer. Breast tumors metastasize to organ-specific locations such as the brain, lungs, and bone, but why some organs are favored over others remains unclear. Breast tumors also show heterogeneity, plasticity, and distinct microenvironments. This contributes to treatment failure and relapse. The interaction of breast cancer cells with their metastatic microenvironment has led to the concept that primary breast cancer cells act as seeds, whereas the metastatic tissue microenvironment (TME) is the soil. Improving our understanding of this interaction could lead to better treatment strategies for metastatic breast cancer. Targeted treatments for different subtypes of breast cancers have improved overall patient survival, even with metastasis. However, these targeted treatments are based upon the biology of the primary tumor and often these patients' relapse, after therapy, with metastatic tumors. The advent of immunotherapy allowed the immune system to target metastatic tumors. Unfortunately, immunotherapy has not been as effective in metastatic breast cancer relative to other cancers with metastases, such as melanoma. This review will describe the heterogeneic nature of breast cancer cells and their microenvironments. The distinct properties of metastatic breast cancer cells and their microenvironments that allow interactions, especially in bone and brain metastasis, will also be described. Finally, we will review immunotherapy approaches to treat metastatic breast tumors and discuss future therapeutic approaches to improve treatments for metastatic breast cancer.
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The scratch assay is an in vitro assay that allows for high-throughput quantification of wound closure by keratinocytes and fibroblasts with relative ease. However, this assay is amenable to experimental variables, which can result in false-positive and false-negative data, making the interpretation of such data difficult. Also, data variability decreases the sensitivity of the scratch assay. Here, we identify important sources of data variation in the scratch assay and provide rational mitigation strategies that enable robust and highly reproducible quantification of scratch width and area, and ultimately the scratch closure rates. By eliminating these sources of variability, the sensitivity of the scratch assay is enhanced, thereby allowing for identification of dependent variables with wide-ranging impacts on wound closure in a robust and standardized manner.
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Stromal vascular fraction (SVF) cells, and the adipose-derived mesenchymal stem cells they contain, have shown enhanced wound healing in vitro and in vivo, yet their clinical application has been limited. In this regard, understanding the mechanisms that govern SVF-enhanced wound healing would improve their application in the clinic. Here, we show that the SVF cells and keratinocytes engage in a paracrine crosstalk during wound closure, which results in a new cytokine profile that is distinct from the cytokines regularly secreted by either cell type on their own. We identify 11 cytokines, 5 of which are not regularly secreted by the SVF cells, whose expressions are significantly increased during wound closure by the keratinocytes. This new cytokine profile could be used to accelerate wound closure and initiate re-epithelialization without the need to obtain the SVF cells from the patient.
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Células Madre Mesenquimatosas , Fracción Vascular Estromal , Humanos , Queratinocitos , Comunicación Paracrina , CitocinasRESUMEN
Recent evidence suggests that a rare-cell population with a stem cell phenotype maintains breast tumors. Therefore, to devise breast cancer therapies that are more effective, we need to understand the unique biology of these cancer stem cells. Currently, very little is known about the origin of cancer stem cells and their relationship to the tumor phenotype. A recent study from Smalley's group demonstrates that targeting an inactivating Brca1 mutation to the luminal progenitors could yield basal-like breast cancers. This observation suggests that the inherent plasticity of the primitive cells can be hijacked by the tumorigenic processes to produce tumors with an unpredictable phenotype.
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Neoplasias de la Mama/patología , Genes BRCA1 , Neoplasias Basocelulares/patología , Células Madre Neoplásicas/patología , Animales , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Femenino , Perfilación de la Expresión Génica , Humanos , Ratones , Mutación , Fenotipo , Receptores de Estrógenos/análisisRESUMEN
The epithelial cells in an adult woman's breast tissue are continuously replaced throughout their reproductive life during pregnancy and estrus cycles. Such extensive epithelial cell turnover is governed by the primitive mammary stem cells (MaSCs) that proliferate and differentiate into bipotential and lineage-restricted progenitors that ultimately generate the mature breast epithelial cells. These cellular processes are orchestrated by tightly-regulated paracrine signals and crosstalk between breast epithelial cells and their tissue microenvironment. However, current evidence suggests that alterations to the communication between MaSCs, epithelial progenitors and their microenvironment plays an important role in breast carcinogenesis. In this article, we review the current knowledge regarding the role of the breast tissue microenvironment in regulating the special functions of normal and cancer stem cells. Understanding the crosstalk between MaSCs and their microenvironment will provide new insights into how an altered breast tissue microenvironment could contribute to breast cancer development, progression and therapy response and the implications of this for the development of novel therapeutic strategies to target cancer stem cells.
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BACKGROUND: Adult stem cells and progenitors are responsible for breast tissue regeneration. Human breast epithelial progenitors are organized in a lineage hierarchy consisting of bipotent progenitors (BPs), myoepithelial- and luminal-restricted progenitors (LRPs) where the LRP differentiation into mature luminal cells requires estrogen receptor (ER) signaling. However, the experimental evidence exploring the relationship between the BPs and LRPs has remained elusive. In this study, we report the presence of a basal-like luminal progenitor (BLP) in human breast epithelial cells. METHODS: Breast reduction samples were used to obtain different subsets of human breast epithelial cell based on cell surface marker expression using flow cytometry. Loss of function and gain of function studies were employed to demonstrate the role of NOTCH3 (NR3)-FRIZZLED7 (FZD7) signaling in luminal cell fate commitment. RESULTS: Our results suggest that, NR3-FZD7 signaling axis was necessary for luminal cell fate commitment. Similar to LRPs, BLPs (NR3highFZD7highCD90+MUC1-ER-) differentiate to generate NR3medFZD7medCD90-MUC1+ER+ luminal cells. Unlike LRPs however, BLP's proliferation and differentiation potentials depend on NR3 and regulated in part by FZD7 signaling. Lastly, we show that BLPs have a higher colony-forming potential than LRPs and that they are continuously generated from the NOTCH3-FZD7low subset of the bipotent progenitors. CONCLUSION: Our data indicate that BPs differentiate to generate basal-like luminal progenitors that in turn differentiate into LRPs. These results provide new insights into the hierarchical organization of human breast epithelial cell and how cooperation between the Notch and Wnt signaling pathways define a new progenitor cell type.
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Biomarcadores/metabolismo , Mama/citología , Diferenciación Celular , Células Epiteliales/citología , Células Madre/citología , Mama/metabolismo , Células Cultivadas , Células Epiteliales/metabolismo , Femenino , Receptores Frizzled/metabolismo , Perfilación de la Expresión Génica , Humanos , Receptor Notch3/metabolismo , Células Madre/metabolismo , Vía de Señalización WntRESUMEN
Breast cancer-induced activated fibroblasts support tumor progression. However, the role of normal fibroblasts in tumor progression remains controversial. In this study, we used modified patient-derived organoid cultures and demonstrate that constitutively secreted cytokines from normal breast fibroblasts initiate a paracrine signaling mechanism with estrogen receptor-positive (ER+) breast cancer cells, which results in the creation of an interleukin (IL)-1ß-enriched microenvironment. We found that this paracrine signaling mechanism is shared between normal and activated fibroblasts. Interestingly, we observed that in reconstructed tumor microenvironment containing autologous ER+ breast cancer cells, activated fibroblasts, and immune cells, tamoxifen is more effective in reducing tumor cell proliferation when this paracrine signaling is blocked. Our findings then suggest that ER+ tumor cells could create a growth-promoting environment without activating stromal fibroblasts and that in breast-conserving surgeries, normal fibroblasts could be a significant modulator of tumor recurrence by enhancing the proliferation of residual breast cancer cells in the tumor-adjacent breast tissue.
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BACKGROUND: Normal human breast epithelial cells are maintained by the proliferation and differentiation of different human breast epithelial progenitors (HBEPs). However, these progenitor subsets can only be obtained at low frequencies, limiting their further characterization. Recently, it was reported that HBEPs can be minimally expanded in Matrigel cocultures with stromal feeder cells. However, variability of generating healthy feeder cells significantly impacts the effective expansion of HBEPs. METHODS: Here, we report a robust feeder cell-free culture system for large-scale expansion of HBEPs in two-dimensional cultures. RESULTS: Using this cell culture system HBEPs can be exponentially expanded as bulk cultures. Moreover, purified HBEP subtypes can also be separately expanded using our cell culture system. The expanded HBEPs retain their undifferentiated phenotype and form distinct epithelial colonies in colony forming cell assays. CONCLUSIONS: The availability of a culture system enabling the large-scale expansion of HBEPs facilitates their application to screening platforms and other cell-based assays.
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Células Epiteliales/citología , Células Madre Mesenquimatosas/citología , Organoides/citología , Grasa Subcutánea/citología , Antígenos CD/genética , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Cadherinas/genética , Cadherinas/metabolismo , Proliferación Celular , Técnicas de Cocultivo , Colágeno/química , Ensayo de Unidades Formadoras de Colonias , Combinación de Medicamentos , Células Epiteliales/metabolismo , Transición Epitelial-Mesenquimal/genética , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Células Nutrientes , Femenino , Expresión Génica , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Queratina-19/genética , Queratina-19/metabolismo , Laminina/química , Glándulas Mamarias Humanas/citología , Glándulas Mamarias Humanas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Organoides/metabolismo , Cultivo Primario de Células , Proteoglicanos/química , Grasa Subcutánea/metabolismoRESUMEN
Human breast cancer cells are known to activate adjacent "normal-like" cells to enhance their own growth, but the cellular and molecular mechanisms involved are poorly understood. We now show by both phenotypic and functional measurements that normal human mammary progenitor cells are significantly under-represented in the mammary epithelium of patients' tumor-adjacent tissue (TAT). Interestingly, fibroblasts isolated from TAT samples showed a reduced ability to support normal EGF-stimulated mammary progenitor cell proliferation in vitro via their increased secretion of transforming growth factor ß. In contrast, TAT fibroblasts promoted the proliferation of human breast cancer cells when these were co-transplanted in immunodeficient mice. The discovery of a common stromal cell-mediated mechanism that has opposing growth-suppressive and promoting effects on normal and malignant human breast cells and also extends well beyond currently examined surgical margins has important implications for disease recurrence and its prevention.
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Neoplasias de la Mama/metabolismo , Fibroblastos/metabolismo , Células Madre Neoplásicas/metabolismo , Animales , Neoplasias de la Mama/patología , Femenino , Fibroblastos/patología , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/patología , Células del Estroma/metabolismo , Células del Estroma/patología , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
The evolutionarily conserved Notch and Wnt signaling pathways have demonstrated roles in normal mammary gland development and in breast carcinogenesis. We previously reported that in human mammary gland, signaling through NOTCH3 alone regulates the commitment of the undifferentiated bipotential progenitors to the luminal cell fate, indicating that NOTCH3 may regulate the expression of unique genes apart from the other Notch receptors. In this study, we used gain of function and loss of function experiments and found that a Wnt signaling receptor, Frizzled7 (FZD7), is a unique and nonredundant target of NOTCH3 in human breast epithelial cells. Interestingly, neither the constitutively active forms of NOTCH1-2, 4 nor loss of expression of these receptors were able to alter expression of FZD7 in human breast epithelial cells. We further show that FZD7-expressing cells are found more frequently in the luminal progenitor-enriched subpopulation of cells obtained from breast reduction samples compared with the undifferentiated bipotent progenitors. Also, we show that NOTCH3-induced expression of FZD7 occurs in the absence of CSL (CBF1-Suppressor of Hairless-Lag-1). Our data suggest that noncanonical Notch signaling through NOTCH3 could modulate Wnt signaling via FZD7 and in this way, might be involved in luminal cell differentiation.
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Células Epiteliales/metabolismo , Receptores Frizzled/metabolismo , Glándulas Mamarias Humanas/citología , Receptor Notch3/metabolismo , Vía de Señalización Wnt , Línea Celular , Células Cultivadas , Células Epiteliales/citología , Femenino , Receptores Frizzled/genética , Humanos , Glándulas Mamarias Humanas/metabolismo , Células Madre/citología , Células Madre/metabolismoRESUMEN
BACKGROUND: Few descriptive epidemiological studies on the incidence, treatment and survival can accurately reflect a whole population. Manitoba, Canada has an accurate cancer registry, a drug information program network and a breast screening program since 1995. This combined with a stable population provides true population data that can accurately describe the region. METHODS: Using a retrospective cohort design all Breast Cancer cases were obtained from 2004-2010 (N=5399) and grouped by Intrinsic sub-type. Identifiable co-morbidities, prescribed endocrine therapy, staging, surgery, treatment and overall and disease-free survival by intrinsic sub-type were evaluated. RESULTS: Prevalence of Luminal A (41.7%), Luminal B HER2- (15.6%), Luminal B HER2+ (8.9%), Basal-like(10.8%), and HER2+ non-luminal (5.1%) were consistent with other descriptive studies in Canada and Spain. Over this time period the number of lumpectomies increased 1.7% per year (P=0.007). There was a steady increase of 3.4% per year in the use of aromatase inhibitors (P=0.005). Pre-menopausal patients had an increased proportion of HER2+ and Basal-like sub-types. The 7year overall/disease-free survival percentages for Luminal A, Luminal B HER2-, Luminal B HER2+, Basal-like, and HER2+ non-luminal were 88.7%/83.6, 78.2%/73.0, 81.5%/73.3%, 67.7%/63.2%, 70.4%/65.6% respectively. CONCLUSIONS: Reasons for variability in the prevalence of intrinsic sub-type by region is not fully understood. Manitoba is unique due the stability of the population, completeness of the registry and length of breast cancer screening program. Few true population-based studies grouped by intrinsic sub-type are available. IMPACT: Descriptive epidemiological studies guide future research by identifying factors that can affect treatment, recurrence, and survival.
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Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/terapia , Anciano , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/metabolismo , Terapia Combinada , Femenino , Humanos , Manitoba/epidemiología , Persona de Mediana Edad , Recurrencia Local de Neoplasia/epidemiología , Recurrencia Local de Neoplasia/metabolismo , Estadificación de Neoplasias , Pronóstico , Receptor ErbB-2/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
Although the role of estrogen signaling in breast cancer development has been extensively studied, the mechanisms that regulate the indispensable role of estrogen in normal mammary gland development have not been well studied. Because of the unavailability of culture system to maintain estrogen-receptor-positive (ERα(+)) cells in vitro, the molecular mechanisms that regulate estrogen/ERα signaling in the normal human breast are unknown. In the present study, we examined the effects of estrogen signaling on ERα(+) human luminal progenitors using a modified matrigel assay and found that estrogen signaling increased the expansion potential of these progenitors. Furthermore, we found that blocking ERα attenuated luminal progenitor expansion and decreased the luminal colony-forming potential of these progenitors. Additionally, blocking ERα decreased H19 expression in the luminal progenitors and led to the development of smaller luminal colonies. We further showed that knocking down the H19 gene in the luminal progenitors significantly decreased the colony-forming potential of the luminal progenitors, and this phenotype could not be rescued by the addition of estrogen. Lastly, we explored the clinical relevance of the estrogen-H19 signaling axis in breast tumors and found that ERα(+) tumors exhibited a higher expression of H19 as compared with ERα(-) tumors and that H19 expression showed a positive correlation with ERα expression in those tumors. Taken together, the present results indicate that the estrogen-ERα-H19 signaling axis plays a role in regulating the proliferation and differentiation potentials of the normal luminal progenitors and that this signaling network may also be important in the development of ER(+) breast cancer tumors.