Fondos de el Congreso de Investigación Médica Dirigida subvención del Fondo (DAMD17-01-0264) a ML Cutler y militar de Estados Unidos Instituto de Cáncer de ML Cutler apoyó el trabajo.

<ol><li> El HC11 células fueron cultivadas hasta confluencia durante 6 días en medio RPMI 1640 suplementado con suero bovino fetal al 10%, insulina 5μg/ml, HEPES 10 mM, el factor de 10ng/ml crecimiento epidérmico (EGF) la debida competencia. </li><li> Las células fueron lavadas con PBS y se mantiene en los medios de crecimiento sin EGF durante 24 horas. </li><li> Para inducir la diferenciación lactogénica las células fueron incubadas en medio de diferenciación, es decir, RPMI con dexametasona (10 -6 M), insulina (5 mg / ml) y la prolactina (5 mg / ml) se refiere a disminuir a medida. </li><li> En el momento indicado post-DIP Además, mammospheres fueron fotografiados y se enumeran por microscopía de contraste de fase con una Olympus IX71 microscopio con cámara digital. </li></ol> Los resultados representativos: Ampliación de potencia bajo de lo normal monocapas de células epiteliales mamarias y mammospheres múltiples, así como la ampliación de potencia de alta de un mammosphere solo se muestran en la Figura 1, respectivamente. <img src="/files/ftp_upload/1265/1265fig1.jpg" alt="" /> Figura 1. Mammospheres. (A) Normal monocapas de células epiteliales mamarias debe mostrarse como una capa plana de células confluentes. (B) Después de 3-5 días de estimulación DIP mammospheres aparecen múltiples. Fotografía tomada 5 días post DIP adición. (C) Mayor aumento de un solo campo que contiene mammospheres menos 5 días después de la DIP adición.

<ol>
	<li>Blatchford, D. R., Hendry, K. A., Turner, M. D., Burgoyne, R. D., Wilde, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vectorial+secretion+by+constitutive+and+regulated+secretory+pathways+in+mammary+epithelial+cells.">Vectorial secretion by constitutive and regulated secretory pathways in mammary epithelial cells.</a> Epithelial Cell Biol. 4, 8-16 (1995).</li><li>Wang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glucocorticoid+induced+expression+of+connective+tissue+growth+factor+contributes+to+lactogenic+differentiation+of+mouse+mammary+epithelial+cells.">Glucocorticoid induced expression of connective tissue growth factor contributes to lactogenic differentiation of mouse mammary epithelial cells.</a> J Cell Physiol. 214, 38-46 (2008).</li></ol>

Para que esta técnica tenga éxito y sea de la mejor calidad, las células epiteliales se debe mantener en la confluencia antes de ser inducido con hormonas lactogénica. Puede haber situaciones en las que se mammospheres numerosas, lo que hace difícil la cuantificación. Por lo tanto, a efectos cuantitativos, es mejor para fotografiar el mammospheres en un punto de tiempo cuando el número de mammospheres es capaz de ser contados. Si bien existen diversos marcadores moleculares para deter...

<table><tbody><tr><td>RPMI</td><td>Invitrogen</td><td>21870076</td><td></td></tr><tr><td>Fetal Bovine Serum</td><td>Atlanta Biologicals</td><td>S11550</td><td></td></tr><tr><td>L-Glutamine</td><td>GIBCO, by Life Technologies</td><td>25030</td><td></td></tr><tr><td>PenStrep</td><td>GIBCO, by Life Technologies</td><td>15140</td><td></td></tr><tr><td>Hepes</td><td>Quality Biological, Inc.</td><td>118089060</td><td></td></tr><tr><td>EGF</td><td>Sigma-Aldrich</td><td>E9644</td><td></td></tr><tr><td>Insulin</td><td>GIBCO, by Life Technologies</td><td>12585-014</td><td></td></tr><tr><td>Dexamethasone</td><td>Sigma-Aldrich</td><td>D1756</td><td></td></tr><tr><td>Microscope</td><td>Olympus Corporation</td><td>IX71</td><td></td></tr><tr><td>Digital Camera</td><td>QImaging</td><td>Retiga 2000RV Fast 1394</td><td></td></tr></tbody></table>

mouse mammary epithelial cells form mammospheres during lactogenic differentiation

A medida fenotípica comúnmente utilizado para determinar el grado de diferenciación en lactogénica mamario de ratón cultivos de células epiteliales es la formación de estructuras en forma de cúpula de la célula conocida como mammospheres<sup&gt; 1</sup&gt;. La línea celular HC11 ha sido empleado como un sistema modelo para el estudio de la regulación de la diferenciación mamaria lactogénica tanto<em&gt; In vitro</em&gt; Y<em&gt; In vivo</em<sup&gt; 2</sup&gt;. El HC11 células se diferencian y sintetizar las proteínas de la leche en respuesta al tratamiento con hormonas lactogénica. Tras el crecimiento de la HC11 ratón las células epiteliales mamarias a la confluencia, la diferenciación lactogénica fue inducida por la adición de una combinación de hormonas lactogénica incluyendo la dexametasona, insulina y prolactina, que se refiere a disminuir a medida. El HC11 células inducidas a diferenciarse fueron fotografiados, a veces hasta 120 horas después de la inducción de la diferenciación y el número de mammospheres que aparecieron en cada cultura se enumeran. El tamaño de la mammospheres individuo se correlaciona con el grado de diferenciación y esto se muestra en las imágenes de la diferenciación de las células.

Watch this Scientific Journal Video about Mouse Mammary Epithelial Cells form Mammospheres During Lactogenic Differentiation at JoVE.com

Mouse Mammary Epithelial Cells form Mammospheres During Lactogenic Differentiation

HC11 diferenciación lactogénica se caracteriza por la formación de estructuras abovedadas conocida como mammospheres. Las estructuras se pueden enumerar por microscopía de contraste de fases para ayudar en la cuantificación de la diferenciación lactogénica.

Células epiteliales mamarias de ratón forma Mammospheres durante la diferenciación lactogénica

A phenotypic measure commonly used to determine the degree of lactogenic differentiation in mouse mammary epithelial cell cultures is the formation of ...

mouse-mammary-epithelial-cells-form-mammospheres-during-lactogenic

Research

JoVE Journal

Biology

13.3K vistas.  F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD. HC11 diferenciación lactogénica se caracteriza por la formación de estructuras abovedadas conocida como mammospheres. Las estructuras se pueden enumerar por microscopía de contraste de fases para ayudar en la cuantificación de la diferenciación lactogénica.

Video: Mouse Mammary Epithelial Cells form Mammospheres During Lactogenic Differentiation

Differentiation of Mouse Breast Epithelial HC11 and EpH4 Cells

Cadherins play an important role in the regulation of cell differentiation as well as neoplasia. Here we describe the origins and methods of the induction of differentiation of two mouse breast epithelial cell lines, HC11 and EpH4, and their use to study complementary stages of mammary gland development and neoplastic transformation.
The HC11 mouse breast epithelial cell line originated from the mammary gland of a pregnant Balb/c mouse. It differentiates when grown to confluence attached to a plastic Petri dish surface in medium containing fetal calf serum and Hydrocortisone, Insulin and Prolactin (HIP medium). Under these conditions, HC11 cells produce the milk proteins &#946;-casein and whey acidic protein (WAP), similar to lactating mammary epithelial cells, and form rudimentary mammary gland-like structures termed &#34;domes&#34;.
The EpH4 cell line was derived from spontaneously immortalized mouse mammary gland epithelial cells isolated from a pregnant Balb/c mouse. Unlike HC11, EpH4 cells can fully differentiate into spheroids (also called mammospheres) when cultured under three-dimensional (3D) growth conditions in HIP medium. Cells are trypsinized, suspended in a 20% matrix consisting of a mixture of extracellular matrix proteins produced by Engelbreth-Holm-Swarm (EHS) mouse sarcoma cells, plated on top of a layer of concentrated matrix coating a plastic Petri dish or multiwell plate, and covered with a layer of 10% matrix-containing HIP medium. Under these conditions, EpH4 cells form hollow spheroids that exhibit apical-basal polarity, a hollow lumen, and produce &#946;-casein and WAP.
Using these techniques, our results demonstrated that the intensity of the cadherin/Rac signal is critical for the differentiation of HC11 cells. While Rac1 is necessary for differentiation and low levels of activated RacV12 increase differentiation, high RacV12 levels block differentiation while inducing neoplasia. In contrast, EpH4 cells represent an earlier stage in mammary epithelial differentiation, which is inhibited by even low levels of RacV12.

We describe techniques for differentiation induction of two breast epithelial lines, HC11 and EpH4. While both require fetal calf serum, insulin, and prolactin to produce milk proteins, EpH4 cells can fully differentiate into mammospheres in three-dimensional culture. These complementary models are useful for signal transduction studies of differentiation and neoplasia.

Diferenciación de células epiteliales de mama de ratón HC11 y EpH4

Cadherins play an important role in the regulation of cell differentiation as well as neoplasia. Here we describe the origins and methods of the induction ...

Investigación

Investigación sobre el cáncer

Transfer of Mammary Gland-forming Ability Between Mammary Basal Epithelial Cells and Mammary Luminal Cells via Extracellular Vesicles/Exosomes

Cells can communicate via exosomes, ~100-nm extracellular vesicles (EVs) that contain proteins, lipids, and nucleic acids. Non-adherent/mesenchymal mammary epithelial cell (NAMEC)-derived extracellular vesicles can be isolated from NAMEC medium via differential ultracentrifugation. Based on their density, EVs can be purified via ultracentrifugation at 110,000 x g. The EV preparation from ultracentrifugation can be further separated using a continuous density gradient to prevent contamination with soluble proteins. The purified EVs can then be further evaluated using nanoparticle-tracking analysis, which measures the size and number of vesicles in the preparation. The extracellular vesicles with a size ranging from 50 to 150 nm are exosomes. The NAMEC-derived EVs/exosomes can be ingested by mammary epithelial cells, which can be measured by flow cytometry and confocal microscopy. Some mammary stem cell properties (e.g., mammary gland-forming ability) can be transferred from the stem-like NAMECs to mammary epithelial cells via the NAMEC-derived EVs/exosomes. Isolated primary EpCAMhi/CD49flo luminal mammary epithelial cells cannot form mammary glands after being transplanted into mouse fat pads, while EpCAMlo/CD49fhi basal mammary epithelial cells form mammary glands after transplantation. Uptake of NAMEC-derived EVs/exosomes by EpCAMhi/CD49flo luminal mammary epithelial cells allows them to generate mammary glands after being transplanted into fat pads. The EVs/exosomes derived from stem-like mammary epithelial cells transfer mammary gland-forming ability to EpCAMhi/CD49flo luminal mammary epithelial cells.

This protocol describes methods for purifying, quantitating, and characterizing extracellular vesicles (EVs)/exosomes from non-adherent/mesenchymal mammary epithelial cells and for using them to transfer mammary gland-forming ability to luminal mammary epithelial cells. EVs/exosomes derived from stem-like mammary epithelial cells can transfer this cell property to cells that ingest the EVs/exosomes.

Transferencia de la capacidad de formación de glándulas mamarias entre las células epiteliales basales mamarias y las células lumminales mamarias mediante vesículas extracelulares / exosomas

Cells can communicate via exosomes, ~100-nm extracellular vesicles (EVs) that contain proteins, lipids, and nucleic acids. Non-adherent/mesenchymal ...

Biología del Desarrollo

Engineering Three-dimensional Epithelial Tissues Embedded within Extracellular Matrix

The architecture of branched organs such as the lungs, kidneys, and mammary glands arises through the developmental process of branching morphogenesis, which is regulated by a variety of soluble and physical signals in the microenvironment. Described here is a method created to study the process of branching morphogenesis by forming engineered three-dimensional (3D) epithelial tissues of defined shape and size that are completely embedded within an extracellular matrix (ECM). This method enables the formation of arrays of identical tissues and enables the control of a variety of environmental factors, including tissue geometry, spacing, and ECM composition. This method can also be combined with widely used techniques such as traction force microscopy (TFM) to gain more information about the interactions between cells and their surrounding ECM. The protocol can be used to investigate a variety of cell and tissue processes beyond branching morphogenesis, including cancer invasion.

This manuscript describes a soft lithography-based technique to engineer uniform arrays of three-dimensional (3D) epithelial tissues of defined geometry surrounded by extracellular matrix. This method is amenable to a wide variety of cell types and experimental contexts and allows for high-throughput screening of identical replicates.

Ingeniería tridimensionales epiteliales tejidos embebidos dentro de la matriz extracelular

The architecture of branched organs such as the lungs, kidneys, and mammary glands arises through the developmental process of branching morphogenesis, ...

Bioingeniería

Quantification of Self-renewal in Murine Mammosphere Cultures

The mammary gland is characterized by extensive regeneration capacity, as it goes through massive hormonal changes throughout the life cycle of a female. The role of mammary stem cells (MaSCs) is widely studied both in the physiological/developmental context and with regards to breast carcinogenesis. In this aspect, ex vivo studies focused on MaSC properties are highly sought after. Mammosphere cultures represent a surrogate of organ formation and have become a valuable tool for both basic and translational research. Here, we present a detailed protocol for the generation of murine primary mammosphere cultures and the quantitation of MaSC growth properties. The protocol includes mammary gland collection and digestion, isolation of primary mammary epithelial cells (MECs), establishment of primary mammosphere cultures, serial passaging, quantitation of mammosphere growth parameters and interpretation of the results. As an example, we present the effect of low-level constitutive Myc expression on normal MECs leading to increased self-renewal and proliferation.

Here, we describe the implementation and interpretation of the results of an in vitro mammosphere self-renewal quantitative assay.

Cuantificación de la auto-renovación en las culturas de la maméfera de la muriña

The mammary gland is characterized by extensive regeneration capacity, as it goes through massive hormonal changes throughout the life cycle of a female. ...

Generation of Mosaic Mammary Organoids by Differential Trypsinization

Organoids offer self-organizing, three-dimensional tissue structures that recapitulate physiological processes in the convenience of a dish. The murine mammary gland is composed of two distinct epithelial cell compartments, serving different functions: the outer, contractile myoepithelial compartment and the inner, secretory luminal compartment. Here, we describe a method by which the cells comprising these compartments are isolated and then combined to investigate their individual lineage contributions to mammary gland morphogenesis and differentiation. The method is simple and efficient and does not require sophisticated separation technologies such as fluorescence activated cell sorting. Instead, we harvest and enzymatically digest the tissue, seed the epithelium on adherent tissue culture dishes, and then use differential trypsinization to separate myoepithelial from luminal cells with ~90% purity. The cells are then plated in an extracellular matrix where they organize into bilayered, three-dimensional (3D) organoids that can be differentiated to produce milk after 10 days in culture. To test the effects of genetic mutations, cells can be harvested from wild type or genetically engineered mouse models, or they can be genetically manipulated prior to 3D culture. This technique can be used to generate mosaic organoids that allow investigation of gene function specifically in the luminal or myoepithelial compartment.

The mammary gland is a bilayered structure, comprising outer myoepithelial and inner luminal epithelial cells. Presented is a protocol to prepare organoids using differential trypsinization. This efficient method allows researchers to separately manipulate these two cell types to explore questions concerning their roles in mammary gland form and function.

Generación de organoides mamarios de mosaico por trippsinización diferencial

Organoids offer self-organizing, three-dimensional tissue structures that recapitulate physiological processes in the convenience of a dish. The murine ...

Mammosphere Formation Assay from Human Breast Cancer Tissues and Cell Lines

Similar to healthy tissues, many blood and solid malignancies are now thought to be organised hierarchically, with a subset of stem-like cancer cells that self-renew while giving rise to more differentiated progeny. Understanding and targeting these cancer stem cells in breast cancer, which may possess enhanced chemo- and radio-resistance compared to the non-stem tumor bulk, has become an important research area. Markers including CD44, CD24, and ALDH activity can be assessed using fluorescence activated cell sorting (FACS) to prospectively isolate cells that display enhanced tumorigenicity when implanted into immunocompromised mice: the mammosphere assay has also become widely used for its ability to retrospectively identify sphere-forming cells that develop from single stem cell-like clones. Here we outline approaches for the appropriate culturing of mammospheres from cell lines or primary patient samples, their passaging, and calculations to estimate sphere forming efficiency (SFE). First we discuss key considerations and pitfalls in the appropriate planning and interpretation of mammosphere experiments.

Floating mammosphere assays can investigate the subset of stem-like breast cancer cells that survive in suspension conditions and show enhanced tumorigenesis when implanted into mice. This protocol provides a convenient in vitro measure of sphere-forming ability, a proxy for in vivo tumorigenesis, while facilitating analysis of the stem-associated transcriptional landscape.

Mammosphere Ensayo Formación de cáncer de mama humano tejidos y líneas celulares

Similar to healthy tissues, many blood and solid malignancies are now thought to be organised hierarchically, with a subset of stem-like cancer cells that ...

Medicina

Evaluation of Mammary Gland Development and Function in Mouse Models

The human mammary gland is composed of 15-20 lobes that secrete milk into a branching duct system opening at the nipple. Those lobes are themselves composed of a number of terminal duct lobular units made of secretory alveoli and converging ducts1. In mice, a similar architecture is observed at pregnancy in which ducts and alveoli are interspersed within the connective tissue stroma. The mouse mammary gland epithelium is a tree like system of ducts composed of two layers of cells, an inner layer of luminal cells surrounded by an outer layer of myoepithelial cells denoted by the confines of a basement membrane2. At birth, only a rudimental ductal tree is present, composed of a primary duct and 15-20 branches. Branch elongation and amplification start at the beginning of puberty, around 4 weeks old, under the influence of hormones3,4,5. At 10 weeks, most of the stroma is invaded by a complex system of ducts that will undergo cycles of branching and regression in each estrous cycle until pregnancy2. At the onset of pregnancy, a second phase of development begins, with the proliferation and differentiation of the epithelium to form grape-shaped milk secretory structures called alveoli6,7. Following parturition and throughout lactation, milk is produced by luminal secretory cells and stored within the lumen of alveoli. Oxytocin release, stimulated by a neural reflex induced by suckling of pups, induces synchronized contractions of the myoepithelial cells around the alveoli and along the ducts, allowing milk to be transported through the ducts to the nipple where it becomes available to the pups 8. Mammary gland development, differentiation and function are tightly orchestrated and require, not only interactions between the stroma and the epithelium, but also between myoepithelial and luminal cells within the epithelium9,10,11. Thereby, mutations in many genes implicated in these interactions may impair either ductal elongation during puberty or alveoli formation during early pregnancy, differentiation during late pregnancy and secretory activation leading to lactation12,13. In this article, we describe how to dissect mouse mammary glands and assess their development using whole mounts. We also demonstrate how to evaluate myoepithelial contractions and milk ejection using an ex-vivo oxytocin-based functional assay. The effect of a gene mutation on mammary gland development and function can thus be determined in situ by performing these two techniques in mutant and wild-type control mice.

This method describes how to dissect and assess mammary gland development and function from mice. Excised mammary glands are assessed for the degree of development using whole mount while milk ejection is evaluated using an oxytocin-based myoepithelial cell contraction assay.

Evaluación de la glándula mamaria de desarrollo y función en modelos de ratón

The human mammary gland is composed of 15-20 lobes that secrete milk into a branching duct system opening at the nipple. Those lobes are themselves ...

Biología

Non-enzymatic, Serum-free Tissue Culture of Pre-invasive Breast Lesions for Spontaneous Generation of Mammospheres

Breast ductal carcinoma in situ (DCIS), by definition, is proliferation of neoplastic epithelial cells within the confines of the breast duct, without breaching the collagenous basement membrane. While DCIS is a non-obligate precursor to invasive breast cancers, the molecular mechanisms and cell populations that permit progression to invasive cancer are not fully known. To determine if progenitor cells capable of invasion existed within the DCIS cell population, we developed a methodology for collecting and culturing sterile human breast tissue at the time of surgery, without enzymatic disruption of tissue.
Sterile breast tissue containing ductal segments is harvested from surgically excised breast tissue following routine pathological examination. Tissue containing DCIS is placed in nutrient rich, antibiotic-containing, serum free medium, and transported to the tissue culture laboratory. The breast tissue is further dissected to isolate the calcified areas. Multiple breast tissue pieces (organoids) are placed in a minimal volume of serum free medium in a flask with a removable lid and cultured in a humidified CO2 incubator. Epithelial and fibroblast cell populations emerge from the organoid after 10 - 14 days. Mammospheres spontaneously form on and around the epithelial cell monolayer. Specific cell populations can be harvested directly from the flask without disrupting neighboring cells. Our non-enzymatic tissue culture system reliably reveals cytogenetically abnormal, invasive progenitor cells from fresh human DCIS lesions.

Primary cell culture using intact tissue organoids provides a model system that mimics the multi-cellular in vivo microenvironment. We developed a serum-free primary breast epithelium tissue culture model that perpetuates mixed cell culture lineages and exhibits differentiated morphology, without enzymatic tissue disruption. Breast organoids remain viable for &#62;6 months.

No enzimática, libre de suero Cultivo de Tejidos de lesiones de mama pre-invasivas para la generación espontánea de mammospheres

Breast ductal carcinoma in situ (DCIS), by definition, is proliferation of neoplastic epithelial cells within the confines of the breast duct, without ...

Indirect Immunofluorescence on Frozen Sections of Mouse Mammary Gland

Indirect immunofluorescence is used to detect and locate proteins of interest in a tissue. The protocol presented here describes a complete and simple method for the immune detection of proteins, the mouse lactating mammary gland being taken as an example. A protocol for the preparation of the tissue samples, especially concerning the dissection of mouse mammary gland, tissue fixation and frozen tissue sectioning, are detailed. A standard protocol to perform indirect immunofluorescence, including an optional antigen retrieval step, is also presented. The observation of the labeled tissue sections as well as image acquisition and post-treatments are also stated. This procedure gives a full overview, from the collection of animal tissue to the cellular localization of a protein. Although this general method can be applied to other tissue samples, it should be adapted to each tissue/primary antibody couple studied.

The indirect immunofluorescence protocol described in this article allows the detection and the localization of proteins in the mouse mammary gland. A complete method is given to prepare mammary gland samples, to perform immunohistochemistry, to image the tissue sections by fluorescence microscopy, and to reconstruct images.

Inmunofluorescencia indirecta en secciones congeladas de ratón Glándula Mamaria

Indirect immunofluorescence is used to detect and locate proteins of interest in a tissue. The protocol presented here describes a complete and simple ...

Isolation of Intact, Whole Mouse Mammary Glands for Analysis of Extracellular Matrix Expression and Gland Morphology

The goal of this procedure was to harvest the #4 abdominal mammary glands from female nulliparous mice in order to assess ECM expression and ductal architecture. Here, a small pocket below the skin was created using Mayo scissors, allowing separation of the glands within the subcutaneous tissue from the underlying peritoneum. Visualization of the glands was aided by the use of 3.5x-R surgical micro loupes. The pelt was inverted and pinned back allowing identification of the intact mammary fat pads. Each of the #4 abdominal glands was bluntly dissected by sliding the scalpel blade laterally between the subcutaneous layer and the glands. Immediately post-harvest, glands were placed in 10% neutral buffered formalin for subsequent tissue processing. Excision of the entire gland is advantageous because it primarily eliminates the risk of excluding important tissue-wide interactions between ductal epithelial cells and other microenvironmental cellular populations that could be missed in a partial biopsy. One drawback of the methodology is the use of serial sections from fixed tissues which limits analyses of ductal morphogenesis and protein expression to discrete locations within the gland. As such, changes in ductal architecture and protein expression in 3 dimensions (3D) is not readily obtainable. Overall, the technique is applicable to studies requiring whole intact murine mammary glands for downstream investigations such as developmental ductal morphogenesis or breast cancer.

Here, we present a protocol for the isolation of whole, intact mouse mammary glands to investigate extracellular matrix (ECM) expression and ductal morphology. Mouse #4 abdominal glands were extracted from 8-10 week old female nulliparous mice, fixed in neutral buffered formalin, sectioned and stained using immunohistochemistry for ECM proteins.

Aislamiento de las glándulas mamarias del ratón intacto, todo para el análisis de expresión de la matriz extracelular y la morfología de la glándula

The goal of this procedure was to harvest the #4 abdominal mammary glands from female nulliparous mice in order to assess ECM expression and ductal ...