Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 1
pubmed:dateCreated
2002-1-21
pubmed:abstractText
The signals that determine the correct polarity of breast epithelial structures in vivo are not understood. We have shown previously that luminal epithelial cells can be polarized when cultured within a reconstituted basement membrane gel. We reasoned that such cues in vivo may be given by myoepithelial cells. Accordingly, we used an assay where luminal epithelial cells are incorrectly polarized to test this hypothesis. We show that culturing human primary luminal epithelial cells within collagen-I gels leads to formation of structures with no lumina and with reverse polarity as judged by dual stainings for sialomucin, epithelial specific antigen or occludin. No basement membrane is deposited, and beta4-integrin staining is negative. Addition of purified human myoepithelial cells isolated from normal glands corrects the inverse polarity, and leads to formation of double-layered acini with central lumina. Among the laminins present in the human breast basement membrane (laminin-1, -5 and -10/11), laminin-1 was unique in its ability to substitute for myoepithelial cells in polarity reversal. Myoepithelial cells were purified also from four different breast cancer sources including a biphasic cell line. Three out of four samples either totally lacked the ability to interact with luminal epithelial cells, or conveyed only correction of polarity in a fraction of acini. This behavior was directly related to the ability of the tumor myoepithelial cells to produce alpha-1 chain of laminin. In vivo, breast carcinomas were either negative for laminin-1 (7/12 biopsies) or showed a focal, fragmented deposition of a less intensely stained basement membrane (5/12 biopsies). Dual staining with myoepithelial markers revealed that tumor-associated myoepithelial cells were either negative or weakly positive for expression of laminin-1, establishing a strong correlation between loss of laminin-1 and breast cancer. We conclude that the double-layered breast acinus may be recapitulated in culture and that one reason for the ability of myoepithelial cells to induce polarity is because they are the only source of laminin-1 in the breast in vivo. A further conclusion is that a majority of tumor-derived/-associated myoepithelial cells are deficient in their ability to impart polarity because they have lost their ability to synthesize sufficient or functional laminin-1. These results have important implications for the role of myoepithelial cells in maintenance of polarity in normal breast and how they may function as structural tumor suppressors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
115
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-50
pubmed:dateRevised
2011-4-11
pubmed:meshHeading
pubmed-meshheading:11801722-Basement Membrane, pubmed-meshheading:11801722-Biological Markers, pubmed-meshheading:11801722-Breast, pubmed-meshheading:11801722-Breast Neoplasms, pubmed-meshheading:11801722-Carcinoma, Intraductal, Noninfiltrating, pubmed-meshheading:11801722-Cell Differentiation, pubmed-meshheading:11801722-Cell Polarity, pubmed-meshheading:11801722-Collagen, pubmed-meshheading:11801722-Epithelial Cells, pubmed-meshheading:11801722-Extracellular Matrix, pubmed-meshheading:11801722-Female, pubmed-meshheading:11801722-Fluorescent Antibody Technique, pubmed-meshheading:11801722-Gels, pubmed-meshheading:11801722-Humans, pubmed-meshheading:11801722-Immunohistochemistry, pubmed-meshheading:11801722-Laminin, pubmed-meshheading:11801722-Microscopy, Confocal, pubmed-meshheading:11801722-Tumor Cells, Cultured
pubmed:year
2002
pubmed:articleTitle
Normal and tumor-derived myoepithelial cells differ in their ability to interact with luminal breast epithelial cells for polarity and basement membrane deposition.
pubmed:affiliation
Structural Cell Biology Unit, Institute of Medical Anatomy, The Panum Institute, DK-2200 Copenhagen N, Denmark.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't