The effects of the neuN and neuT genes on differentiation and transformation of mammary epithelial cells

1994 ◽  
Vol 107 (10) ◽  
pp. 2919-2929
Author(s):  
E. Lucassen ◽  
A.C. Andres ◽  
E. Reichmann ◽  
A. Entwistle ◽  
M. Noble
Keyword(s):  
Extracellular Matrix ◽  
Tissue Culture ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Extracellular Matrix Proteins ◽  
Mammary Epithelial ◽  
Matrix Proteins ◽  
Tissue Culture Plastic ◽  
Anchorage Independent Growth ◽  
Beta Casein

Overexpression of the proto-oncogene product, p185neuN, in a non-tumorigenic mammary epithelial line (31E) facilitates aspects of lactogenic differentiation. Formation of branching cords and induction of beta-casein synthesis by 31E cells normally require co-culture of these cells with fibroblasts, or the presence of collagen or fibronectin. In contrast, 31E cells expressing p185neuN spontaneously form branching cords when grown on tissue culture plastic and can synthesize beta-casein in the absence of exogenous substrates or feeder layers. Under these conditions, the cells deposit laminin and fibronectin, indicating a possible role for p185neuN in the deposition of extracellular matrix proteins. Overexpression of the corresponding oncogene product, p185neuT, has markedly different effects. Expression of p185neuT does not facilitate the formation of branching cords or the synthesis of beta-casein when grown on tissue culture plastic, although these cells do deposit laminin and fibronectin. Confocal microscopy indicates a significant difference in the distribution of laminin and fibronectin in 31E cells expressing p185neuT compared to those expressing p185neuN. The effects of p185neuN and p185neuT expression on cell transformation depend on cell type. Expression of both p185neuN and p185neuT increases anchorage-independent growth of 31E cells, but only p185neuT induces anchorage-independent growth of NIH 3T3 fibroblasts. This lineage specificity in the action of p185neuN may be related to observations that overexpression of p185c-erbB-2 (the human homologue of p185neuN) is only associated with the development of human epithelial cancers. The effects of p185neuN on laminin deposition by 31E cells may be relevant to the transforming ability of p185neuN, since laminin can induce anchorage-independent growth of mouse mammary cells. These results suggest that p185neuN and p185neuT could exert their effects on differentiation and transformation of mammary epithelial cells in part by promoting the deposition of extracellular matrix proteins.

Tenascin-C inhibits extracellular matrix-dependent gene expression in mammary epithelial cells. Localization of active regions using recombinant tenascin fragments

1995 ◽  
Vol 108 (2) ◽  
pp. 519-527 ◽  
Author(s):  
P.L. Jones ◽  
N. Boudreau ◽  
C.A. Myers ◽  
H.P. Erickson ◽  
M.J. Bissell
Keyword(s):  
Gene Expression ◽  
Extracellular Matrix ◽  
Protein Synthesis ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Active Regions ◽  
Mammary Epithelial ◽  
Dependent Manner ◽  
Beta Casein ◽  
Casein Protein

The physiological role of tenascin in vivo has remained obscure. Although tenascin is regulated in a stage and tissue-dependent manner, knock-out mice appear normal. When tenascin expression was examined in the normal adult mouse mammary gland, little or none was present during lactation, when epithelial cells actively synthesize and secrete milk proteins in an extracellular matrix/lactogenic hormone-dependent manner. In contrast, tenascin was prominently expressed during involution, a stage characterized by the degradation of the extracellular matrix and the subsequent loss of milk production. Studies with mammary cell lines indicated that tenascin expression was high on plastic, but was suppressed in the presence of the laminin-rich, Engelbreth-Holm-Swarm (EHS) tumour biomatrix. When exogenous tenascin was added together with EHS to mammary epithelial cells, beta-casein protein synthesis and steady-state mRNA levels were inhibited in a concentration-dependent manner. Moreover, this inhibition by tenascin could be segregated from its effects on cell morphology. Using two beta-casein promoter constructs attached to the chloramphenicol acetyltransferase reporter gene we showed that tenascin selectively suppressed extracellular matrix/prolactin-dependent transcription of the beta-casein gene in three-dimensional cultures. Finally, we mapped the active regions within the fibronectin type III repeat region of the tenascin molecule that are capable of inhibiting beta-casein protein synthesis. Our data are consistent with a model where both the loss of a laminin-rich basement membrane by extracellular matrix-degrading enzymes and the induction of tenascin contribute to the loss of tissue-specific gene expression and thus the involuting process.

scholarly journals To grow mouse mammary epithelial cells in culture.

1984 ◽  
Vol 98 (3) ◽  
pp. 1026-1032 ◽  
Author(s):  
U K Ehmann ◽  
W D Peterson ◽  
D S Misfeldt
Keyword(s):  
Tissue Culture ◽  
Epithelial Cells ◽  
Normal Mouse ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Mammary Cells ◽  
Feeder Cells ◽  
Tissue Culture Plastic ◽  
Mouse Cells

Normal mouse mammary epithelial cells from Balb/c mice were successfully cultivated on tissue culture plastic with lethally irradiated LA7 feeder cells. The feeder cells also promoted colony formation from single mouse mammary cells, and the fraction of cells that formed colonies was proportional to the density of feeder cells. The mouse mammary cells could be passaged at least 8-12 times as long as new feeder cells were added at each passage. The cells now in culture have doubled in number at least 30 times, but the in vitro lifespan is not yet known. The cultures of mouse cells maintained by this technique never became overgrown with fibroblasts and numerous domes formed in the cultures.

Effect of the extracellular matrix on plasminogen activator isozyme activities of human mammary epithelial cells in culture

1983 ◽  
Vol 3 (6) ◽  
pp. 982-990
Author(s):  
N S Yang ◽  
C Park ◽  
C Longley ◽  
P Furmanski
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Plasminogen Activator ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Collagen Gels ◽  
Human Mammary Epithelial Cells ◽  
Human Mammary Epithelial ◽  
Normal Human ◽  
Mcf 7

Multiple molecular forms of plasminogen activator were detected in normal human mammary epithelial cells in culture. Cells derived from (normal) breast mammoplasty specimens and grown on the surface of collagen gels exhibited three major classes of plasminogen activator isozymes (Mr = 100,000 [100K], 75,000 [75K], and 55,000 [55K]). The activity of the 100K and 75K isozymes was greatly reduced when the cells were grown on conventional tissue-culture-grade plastic surfaces. MCF-7, a human mammary carcinoma cell line, exhibited predominantly or exclusively the 55K isozyme, irrespective of the cell growth substratum. The activity of the 55K isozyme was more than twofold higher for MCF-7 cells grown on collagen gels than for cells grown on plastic. Progesterone, diethylstilbestrol, and estrogen stimulated the activity of the 55K isozyme of MCF-7 cells, but only when the cells were grown on a plastic surface. The plasminogen activator activities of the normal human mammary epithelial cells were not stimulated by these hormones, irrespective of the growth substratum. These results show that the expression of plasminogen activator isozymes by human mammary epithelial cells is subject to modulation by the extracellular matrix. Normal and malignant cells may differ in their responsiveness to these effects.

Sign in / Sign up

Export Citation Format

Share Document