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1.
Establishment and initial characterization of the ovine mammary epithelial cell line nish 总被引:4,自引:0,他引:4
Neta Ilan Itamar Barash Elisha Gootwine Moshe Shani 《In vitro cellular & developmental biology. Animal》1998,34(4):326-332
Summary Analysis of the molecular mechanisms involved in the differentiation and formation of the characteristic three-dimensional
structures of the developing mammary gland of the major milk-producing livestock (ducts, end buds, and alveoli) requires in vitro model cell cultures. The few cell lines that have been established from dairy animals do not fully reproduce the entire program
of mammary differentiation. Here we present the initial characterization of a unique mammary epithelial cell line derived
spontaneously from midpregnant sheep (NISH). These cells form in vitro functional structures resembling ducts, lateral buds, and alveoli that secrete β-lactoglobulin (BLG) in an ECM (extracellular
matrix)-dependent manner. Interestingly, the presence of growth hormone dramatically increased BLG secretion from NISH cells
cultured on ECM. It appears that GH is required not only to establish the structural organization but also is continuously
needed to maintain BLG expression. Stable transfection of NISH cells with BLG/Human Serum Albumin (HSA) hybrid gene constructs
revealed that the relative level of expression was comparable to the in vivo secretion of HSA in transgenic mice carrying these gene sequences. No expression could be detected in cells transfected with
hybrid genes carrying either HSA cDNA or the entire HSA gene, and HSA expression was dependent on the presence of intronic
sequences. These results demonstrate that NISH cells may prove a useful tool for studying the differentiation and organogenesis
of mammary epithelial cells under defined culture conditions. Furthermore, transfected NISH cells may be an alternative for
the transgenic mouse model in evaluating the potential of gene constructs to be efficiently expressed in the mammary gland
of transgenic farm animals. 相似文献
2.
Summary We have used enzymatic and immunomagnetic techniques for the physical separation of the basal and luminal epithelium of the
human mammary gland. Immediately after tissue dissociation and cell sorting, we have examined the steady-state CK composition
of these cells individually by direct two-dimensional gel electrophoresis of intermediate filament extracts. Our results demonstrate
that cytokeratins typical of simple and stratified epithelial cells are simultaneously expressed by both mammary epithelial
subclasses in vivo. Moreover, the entire spectrum of cytokeratins seen in vivo is also maintained in short-term cultures of
human mammary epithelium. A comparison of the data obtained by direct cytokeratin analysis with published indirect immunolocalization
studies is presented. The ability to isolate purified epithelial subsets from normal human breast tissue by a simple immunomagnetic
procedure demonstrated here can facilitate the development of relevant model systems for studying the regulatory components
in growth, differentiation and malignant transformation of the human breast. 相似文献
3.
Targeting expression to the mammary gland: intronic sequences can enhance the efficiency of gene expression in transgenic mice 总被引:8,自引:0,他引:8
C. Bruce A. Whitelaw Alan L. Archibald Stephen Harris Margaret McClenaghan J. Paul Simons A. John Clark 《Transgenic research》1991,1(1):3-13
We are studying the tissue-specific expression of the sheep milk-whey protein gene, β-lactoglobulin. We have used sequences
derived from this gene to target the expression of biomedical proteins into milk with the intention to exploit this technology
in transgenic sheep as a means of protein production. In the present study, a series of β-lactoglobulin hybrid genes and β-lactoglobulin
minigenes were evaluated for expression in the mammary gland of transgenic mice. In particular, we have assessed whether there
is a requirement for introns for efficient transgene expression in the mammary gland, since the coding sequences of many candidate
proteins are available only as cDNAs. The results suggest that the inclusion of natural introns in constructs can enhance
the efficiency of transgene expression. Thus, a hybrid construct comprising 4.3 kb of the immediate 5′ flanking sequences
of β-lactoglobulin fused to a genomic minigene encoding human α-antitrypsin (α1AT) was expressed much more efficiently than an α1AT-cDNA construct containing the same β-lactoglobulin segment. Similarly, the intact β-lactoglobulin gene was expressed more
efficiently than the corresponding intronless β-lactoglobulin minigene. This effect was not seen in transient expression expriments
in baby hamster kidney cells when β-lactoglobulin-α1AT constructs were driven by SV40 enhancer sequences. The effect cannot be explained by a simple requirement for splicing,
since the inclusion of the first β-lactoglobulin intron into cDNA constructs encoding human α1AT or β-lactoglobulin itself failed to enhance the efficiency of transgene expression. It is concluded that sequence elements
within introns may interact with the upstream 5′ flanking sequences of β-lactoglobulin and enable the latter to function efficiently
in the mammary gland of transgenic mice. 相似文献
4.
Tissue type-specific expression of intermediate filament proteins in a cultured epithelial cell line from bovine mammary gland 总被引:15,自引:11,他引:15
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Different clonal cell lines have been isolated from cultures of mammary gland epithelium of lactating cow’s udder and have been grown in culture media containing high concentrations of hydrocortisone, insulin, and prolactin. These cell (BMGE+H), which grow in monolayers of typical epithelial appearance, are not tightly packed, but leave intercellular spaces spanned by desmosomal bridges. The cells contain extended arrays of cytokeratin fibrils, arranged in bundles attached to desmosomes. Gel electophoresis show that they synthesize cytokeratins similar, if not identical, to those found in bovine epidermis and udder, including two large (mol wt 58,500 and 59,000) and basic (pH range: 7-8) and two small (mol wt 45,500 and 50,000) and acidic (pH 5.32 and 5.36) components that also occur in phosphorylated forms. Two further cytokeratins of mol wts 44,000 (approximately pH 5.7) and 53,000 (pH 6.3) are detected as minor cytokeratins in some cell clones. BMGE+H cells do not produce vimentin filaments as determined by immunofluorescence microscopy and gel electrophoresis. By contrast, BMGE-H cells, which have emerged from the same original culture but have been grown without hormones added, are not only morphologically different, but also contain vimentin filaments and a different set of cytokeratins, the most striking difference being the absence of the two acidic cytokeratins of mol wt 50,000 and 45,500. Cells of the BMGE+H line are characterized by an unusual epithelial morphology and represent the first example of a nonmalignant permanent cell line in vitro that produces cytokeratin but not vimentin filaments. The results show that (a) tissue-specific patterns of intermediate filament expression can be maintained in permanent epithelial cell lines in culture, at least under certain growth conditions; (b) loss of expression of relatively large, basic cytokeratins is not an inevitable consequence of growth of epithelial cells in vitro. Our results further show that, during culturing, different cell clones with different cytoskeletal composition can emerge from the same cell population and suggest that the presence of certain hormones may have an influence on the expression of intermediate filament proteins. 相似文献
5.
Ji-Xia Li Abdelrahman Said Xiu-Guo Ge Wenxiu Wang Yong Zhang Tianming Jin 《Cytotechnology》2018,70(1):67-82
This study aimed to develop a bovine mammary epithelial (BME) cell line model, which provides a possibility to determine functional properties of the bovine mammary gland. The primary cell culture was derived from bovine mammary gland tissues and processed enzymatically to obtain cell colonies with epithelial-like morphology. The cultures of BME cells were purified and optimally cultured at 37 °C in DMEM/F12 medium supplemented with 10% fetal bovine serum. The BME cells were identified as epithelial cell line by the evaluating the expression of keratin-18 using immunofluorescence staining. A novel gene expression system strongly enhances the expression of telomerase, has been used to immortalize BME cell line termed hTBME cell line. Interestingly, telomerase remained active even after over 60 passages of hTBME cell line, required for immortalization of BME cells. In addition, the hTBME cell line was continuously subcultured with a spontaneous epithelial-like morphology, with a great proliferation activity, and without evidence of apoptotic and necrotic effects. Further characterization showed that hTBME cell line can be continuously propagated in culture with constant chromosomal features and without tumorigenic properties. Finally, established hTBME cell line was evaluated for mammary gland specific functions. Our results demonstrated that the hTBME cell line was able to retain functional-morphological structure, and functional differentiation by expression of beta (β)-casein as in the bovine mammary gland in vivo. Taken together, our findings suggest that the established hTBME cell line can serve as a valuable tool for the study of bovine mammary gland functions. 相似文献
6.
J. E. Keys A. J. Guidry E. Cifrian 《In vitro cellular & developmental biology. Animal》1997,33(3):201-205
Summary A flow cytometric technique was developed to measure the relative concentration of whey protein and β-casein in individual
fixed and permeabilized bovine mammary epithelial cells. Primary bovine mammary epithelial cells were compared to mammary
cells isolated from explants after a 24-h incubation and a bovine mammary epithelial transfected cell line (MAC-T). Cells
were incubated with rabbit anti-bovine whey protein (α-lactalbumin + β-lactoglobulin) or β-casein primary antibodies followed
by a fluorescein-labeled goat anti-rabbit IgG second antibody. The number and intensity of fluorescing cells were measured
using an EPICS Profile Flow Cytometer. Primary and explant cells contained 3.3 and 2.8 times more whey protein than MAC-T
cells. Explant epithelial cells contained 2.9 and 5.1 times more β-casein than primary or MAC-T cells. The higher concentrations
of specific proteins within the cells was attributed to either greater synthesis or reduced secretion. These data show that
flow cytometry is capable of detecting differences in milk protein concentration in different mammary epithelial cell types. 相似文献
7.
8.
Kohtaro Miyazawa Tetsuya Hondo Takashi Kanaya Sachi Tanaka Ikuro Takakura Wataru Itani Michael T. Rose Haruki Kitazawa Takahiro Yamaguchi Hisashi Aso 《Histochemistry and cell biology》2010,133(1):125-134
Membranous epithelial cells (M cells) of the follicle-associated epithelium in Peyer’s patches have a high capacity for transcytosis
of several viruses and microorganisms. Here, we report that we have successfully established a bovine intestinal epithelial
cell line (BIE cells) and developed an in vitro M cell model. BIE cells have a cobblestone morphology and microvilli-like
structures, and strongly express cell-to-cell junctional proteins and cytokeratin, which is a specific intermediate filament
protein of epithelial cells. After co-culture with murine intestinal lymphocytes or treatment with supernatant from bovine
PBMC cultured with IL-2, BIE cells acquired the ability of transcytosis. Therefore, BIE cells have typical characteristics
of bovine intestinal epithelial cells and also have the ability to differentiate into an M cell like linage. In addition,
our results indicate that contact between immune cells and epithelial cells may not be absolutely required for the differentiation
of M cells. We think that BIE cells will be useful for studying the transport mechanisms of various pathogens and also the
evaluation of drug delivery via M cells. 相似文献
9.
Characterization of a myoepithelial cell line derived from a neonatal rat mammary gland 总被引:6,自引:2,他引:4
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《The Journal of cell biology》1981,91(3):827-836
A clonal, myoepithelial-like cell line has been obtained from a primary culture established from the mammary gland of a 7-d-old rat. In a number of respects, this cell line, termed Rama 401, resembles the myoepithelial cells of the mammary gland, especially when grown on floating collagen gels. The cells grow as multilayers on the gel surface and form branching structures that do not appear to contain a lumen. They are rather elongated, with irregular-shaped, flattened nuclei that contain large amounts of peripheral chromatin. Elongated processes project from the cell surface and numerous membrane pinocytotic vesicles can be seen. The cytoplasm is filled with linear arrays of 5- to 7-nm filaments with occasional dense foci. Cell junctions with associated 8- to 11-nm tonofilaments are also observed. Immunofluorescence techniques reveal actin and myosin filaments and also intermediate filaments of both prekeratin and vimentin types. Rama 401 cells secrete an amorphous material that, when an immunoperoxidase technique is used, stains with antibodies to basement membrane-specific type IV collagen. Localized densities of the cell membrane, which resemble hemidesmosomes, are located adjacent to these extracellular deposits. Immunofluorescence staining and immunoprecipitation techniques reveal that the cells also synthesize two other basement membrane proteins, laminin and fibronectin. The type IV collagen consists of two chains with molecular weights of 195,000 and 185,000. 相似文献
10.
《The International journal of biochemistry》1994,26(2):201-206
- 1.1. A non-radioisotopic method utilizing a biotin-avidin approach was used to characterize lactoferrin binding to the clonal MAC-T bovine mammary epithelial cell line.
- 2.2. Binding of lactoferrin to MAC-T cells and isolated membranes was specific and saturable.
- 3.3. Unlabeled lactoferrin competed for and displaced biotin-labeled lactoferrin from binding sites on mammary epithelial cells. In contrast, unlabeled transferrin did not compete.
- 4.4. Scatchard analysis of lactoferrin binding to MAC-T cell crude membranes was nonlinear, revealing two classes of binding sites with association constants (Ka) of 2.36 × 107 and 3.36 × 106M−1.
- 5.5. Binding of lactoferrin to MAC-T cells may be associated with the initial events which result in decreased MAC-T cell proliferation.
11.
Leukemia inhibitory factor induces apoptosis of the mammary epithelial cells and participates in mouse mammary gland involution 总被引:5,自引:0,他引:5
Schere-Levy C Buggiano V Quaglino A Gattelli A Cirio MC Piazzon I Vanzulli S Kordon EC 《Experimental cell research》2003,282(1):35-47
Leukemia inhibitory factor (LIF) is a multifunctional glycoprotein that displays multiple biological activities in different cell types, but to date there has been no report on its expression in the normal mammary gland. In this study we found that LIF is expressed at low but detectable levels in postpubertal, adult virgin, and pregnant mouse mammary glands. However, LIF expression drops after parturition to become almost undetectable in lactating glands. Interestingly, LIF expression shows a steep increase shortly after weaning that is maintained for the following 3 days. During this period, known as the first stage of mammary gland involution, the lack of suckling induces local factors that cause extensive epithelial cell death. It has been shown that Stat3 is the main factor in signaling the initiation of apoptosis, but the mechanism of its activation remains unclear. Herein, we show that LIF expression in the gland is induced by milk stasis and not by the decrease of circulating lactogenic hormones after weaning. Implantation of LIF containing pellets in lactating glands results in a significant increase in epithelium apoptosis. In addition, this treatment also induces Stat3 phosphorylation. We conclude that LIF regulated expression in the mouse mammary gland may play a relevant role during the first stage of mammary gland involution. Our results also show that LIF-induced mammary epithelium apoptosis could be mediated, at least partially, by Stat3 activation. 相似文献
12.
Brian W. Booth Corinne A. Boulanger Lucia Jimenez-Rojo Gilbert H. Smith 《Experimental cell research》2010,316(3):422-432
Amphiregulin (AREG), a ligand for epidermal growth factor receptor, is required for mammary gland ductal morphogenesis and mediates estrogen actions in vivo, emerging as an essential growth factor during mammary gland growth and differentiation. The COMMA-D β-geo (CDβgeo) mouse mammary cell line displays characteristics of normal mammary progenitor cells including the ability to regenerate a mammary gland when transplanted into the cleared fat pad of a juvenile mouse, nuclear label retention, and the capacity to form anchorage-independent mammospheres. We demonstrate that AREG is essential for formation of floating mammospheres by CDβgeo cells and that the mitogen activated protein kinase signaling pathway is involved in AREG-mediated mammosphere formation. Addition of exogenous AREG promotes mammosphere formation in cells where AREG expression is knocked down by siRNA and mammosphere formation by AREG−/− mammary epithelial cells. AREG knockdown inhibits mammosphere formation by duct-limited mammary progenitor cells but not lobule-limited mammary progenitor cells. These data demonstrate AREG mediates the function of a subset of mammary progenitor cells in vitro. 相似文献
13.
14.
Establishment and characterization of a lactating dairy goat mammary gland epithelial cell line 总被引:1,自引:0,他引:1
To study milk synthesis in dairy goat mammary gland, we had established an in vitro lactating dairy goat mammary epithelial
cell (DGMEC) line. Mammary tissues of Guan Zhong dairy goats at 35 d of lactation were dispersed and cultured in a medium
containing epithelial growth factor, insulin-like growth factor-1, insulin transferrin serum, and fetal bovine serum. Epithelial
cells were enriched by digesting with 0.25% trypsin repeatedly to remove fibroblast cells and were identified as epithelial
origin by staining with antibody against cytokeratine 18. The DGMECs displayed monolayer, cobble-stone, epithelial-like morphology,
and formed alveoli-like structures and island monolayer aggregates which were the typical characteristics of mammary epithelial
cells. A one-half logarithmically growth curve and cytoplasmic lipid droplets in these cells were observed. In this paper,
we also studied the lactating function of DGMECs. Results showed that DGMECs could secrete lactose and β-casein. Lactating
function of the cells had no obvious change after 48 h treated by insulin, while prolactin could obviously raise the secretion
of milk proteins and lactose. 相似文献
15.
Establishment and characterization of a bovine mammary epithelial cell line with unique properties 总被引:8,自引:0,他引:8
Boris Zavizion Marilyn van Duffelen Warren Schaeffer Ioannis Politis 《In vitro cellular & developmental biology. Animal》1996,32(3):138-148
Summary Clonal cell lines (BME-UV) were established from primary epithelial cells by stable transfection with a plasmid, carrying
the sequence of the simian virus 40 early region mutant tsA58, encoding the thermolabile large T antigen. The BME-UV cells
have undergone more than 300 population doublings and produce intranuclear large T antigen. At low confluency, growing islands
of cells are apparent exhibiting the characteristic cobblestone morphology of epithelial cells. The BME-UV cells expressed
functional markers such as microvilli and desmosomes and biochemical markers of mammary epithelial cells such as a repertoire
of cytokeratins. The BME-UV cells are capable of synthesizing low levels of α-lactalbumin and α8l (50 ng/ml of medium/24 h). One of the cell lines, BME-UV1 showed enhanced proliferation in the presence of epidermal growth
factor (EGF) and insulinlike growth factor I (IGF-I). The BME-UV1 cell line is the only known bovine mammary epithelial cell
line responsive to EGF. The BME-UV cells grown on collagen at low confluency are capable of developing very long projections
that most likely allow for communication between cells at a distance from each other. The BME-UV cells may become a valid
model system to examine bovine mammary epithelial proliferation and differentiation and cell-to-cell communication. 相似文献
16.
A cloned rat thymic epithelial cell line established from serum-free selective culture 总被引:6,自引:0,他引:6
Arthur Piltch Paul Naylor Jun Hayashi 《In vitro cellular & developmental biology. Plant》1988,24(4):289-293
Summary A serum-free system has been developed for selective growth and long-term culture of rat thymic epithelial cells. The growth
media is a modification of McKeehan's WAJC 404, plus insulin, cholera toxin, dexamethasone, and epidermal growth factor. Cultures
have been continuously passaged and maintained for over 6 mo., and a cloned cell line, TEA3A1, has been established. These
cells are epithelial, judging by morphology and ultrastructure, and are positive for A2B5 and thymosin α markers for thymic
endocrine cells.
This work was partly supported by grant PCM-834 0582 from the National Science Foundation, Washington, DC, and grant P01 CA
37589-2 from the National Cancer Institute, Bethesda, MD. 相似文献
17.
Joe D. Beckmann Hajime Takizawa Debra Romberger Mary Illig Lorene Claassen Kathleen Rickard Stephen I. Rennard 《In vitro cellular & developmental biology. Animal》1992,28(1):39-46
Summary Procedures for the serum-free culture of a density fractionated population of bovine bronchial epithelial cells have been
established. Epithelial cells dispersed by protease digestion were fractionated by density equilibrium centrifugation, followed
by plating of the small basal-like population on type I collagen-coated culture dishes. Two or three passages of 1:4 split
enriched for a population of actively dividing cells, which could be stored in liquid nitrogen for subsequent use. Clonal
growth assays revealed optimum proliferation using a 1:1 mixture of medium RPMI 1640 and LHC-9, a medium employed for human
bronchial epithelial cells. Cellular growth rate, which was 0.6 to 1.3 doublings per day depending on the cell preparation,
was conveniently decreased by supplementing LHC-9 medium with less than 50% RPMI. In contrast to airway epithelial cell cultures
from other species, serum stimulated the growth of bovine bronchial epithelial cells in this system. Transforming growth factorβ1, however, inhibited growth and induced differentiation into a squamous phenotype. Also in contrast with other systems, the
bovine cells were resistant to growth inhibition by 100 nM tetradecanoyl phorbol acetate or 1μM calcium ionophore A23187. Combination of phorbol ester with ionophore decreased mitotic activity, although induction of squamous
morphology was not observed. Therefore, growth inhibition and squamous differentiation were not tightly coupled in this system.
Finally, biologically synthesized matrix deposited by these cells stimulated growth rate. This culture system will therefore
be useful in assessing the activities of both soluble and matrix-associated factors in the absence of serum. 相似文献
18.
T W Keenan M Sasaki W N Eigel D J Mooré W W Franke I M Zulak A A Bushway 《Experimental cell research》1979,124(1):47-61
Fractions enriched in secretory vesicles were obtained from lactating bovine mammary tissue by a straightforward procedure involving gentle homogenization and centrifugation in isotonic milk salt solution containing Ficoll. Secretory vesicle-rich fractions could also be obtained from lactating rat mammary gland by this procedure. With rats, yields of vesicles were substantially increased by administration of colchicine or thioglucose to animals several hours before sacrifice. Isolated fractions were enriched in lactose and consisted predominantly of 0.2–1.2 μm diameter vesicles, many of which contained casein micelles. Enzymatic, compositional and morphological examination revealed vesicle preparations to be largely free of contamination by rough endoplasmic reticulum, mitochondria, nuclei, peroxisomes and lysosomes. Specific activity of several marker enzymes of the secretory vesicle fraction were similar to, or intermediate between, Golgi apparatus and milk lipid globule membranes. Amounts of cholesterol and gangliosides in vesicle fractions approached levels found in plasma membranes. In distribution of major phospholipids, secretory vesicles were intermediate between Golgi apparatus and milk lipid globule membranes. The pattern of polypeptides of secretory vesicle membrane was qualitatively similar to that of Golgi apparatus membranes. While there were similarities between these polypeptide patterns and that of lipid globule membranes, the latter contained relatively more of certain polypeptides, particularly the internal coat-associated polypeptides of the globule membrane. These observations are discussed in relation to the endomembrane hypothesis and the origin of the membrane of milk lipid globules. 相似文献
19.
Erika Schmid Werner W. Franke Christine Grund Dorothea L. Schiller Heiderose Kolb Neidhard Paweletz 《Experimental cell research》1983,146(2):309-328
Cells of a clonal line (BMGE + HM) selected from bovine mammary gland epithelial cell cultures are described which, after reaching confluence, do not assume typical epithelioid morphology, but form elongated cells with long slender processes extending over the surfaces of other cells. However, cells of this line which display non-epithelioid morphology and are exceptionally rich in actin microfilaments are identified as epithelial cells by their synthesis of cytokeratins and desmosomal plaque proteins, as demonstrated by immunofluorescence and immunoelectron microscopy and by gel electrophoresis of cytoskeletal proteins. The cells do not produce vimentin and desmin filaments. The specific cytokeratin polypeptides of these myoid cells are identical to those present in normal epithelioid BMGE + H cells but are arranged in unusual arrays of meshworks of finely dispersed, non-fasciated filaments and granular structures. Desmosomal plaque proteins, notably desmoplakins, are abundant, but the electron microscopic appearance of the desmosomes is abnormal in that most of them are associated with a second accessory plaque formed at a distance of 0.1-0.15 micron from the normal desmosomal plaque. Both cytokeratin filaments and desmosomal structures are found throughout the whole cytoplasm, including the extended cell processes. The existence of an epithelial cell line with such an unusual morphology demonstrates the importance of non-morphological criteria in identifying epithelium-derived cells. Our findings also indicate that dramatic differences of cell shape and organization of epithelial cells need not necessarily be associated with changes in the expression of specific cytoskeletal proteins. The possible origin of this cell line from myoepithelial cells is discussed. 相似文献
20.
Clonal characterization of mouse mammary luminal epithelial and myoepithelial cells separated by fluorescence-activated cell sorting 总被引:8,自引:0,他引:8
Matthew J. Smalley Jenny Titley Michael J. O’Hare 《In vitro cellular & developmental biology. Animal》1998,34(9):711-721
Summary Lineage analysis in vitro of heterogeneous tissues such as mammary epithelium requires the separation of constituent cell types and their growth as
clones. The separation of virgin mouse mammary luminal epithelial and myoepithelial cells by fluorescence-activated cell-sorting,
their growth at clonal density, and the phenotyping of the clones obtained with cell-type specific markers are described in
this paper. Epithelial cells were isolated by collagenase digestion followed by trypsinization, and the luminal and myoepithelial
cells were flow-sorted with the rat monoclonal antibodies 33A10 and JB6, respectively. Sorted cells were cloned under, using
low oxygen conditions (<5% vol/vol), in medium containing cholera toxin and insulin, with an irradiated feeder layer of 3T3-L1
cells. Clones were characterized morphologically, and antigenically by multiple immunofluorescence with a panel of antibodies
to cytoskeletal antigens specific to either luminal epithelial or myoepithelial cells in situ. Whereas sorted myoepithelial cells gave a single clone type, sorted luminal cells gave three morphological clone types,
two of which grew rapidly. All myoepithelially derived clones showed a limited proliferative capacity in vitro, in contrast to their rat and human counterparts, as shown in previous studies. The present results with sorted mouse cells
have also allowed the stability of the differentiated phenotype in mouse, rat, and human mammary luminal epithelial and myoepithelial
cells in primary clonal culture to be compared. They show that the mouse mammary cells are the least stable in terms of expression
of differentiation-specific cytoskeletal markers in vitro. 相似文献