Linked Life Data

10497309

Source:http://linkedlifedata.com/resource/pubmed/id/10497309

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-11-1
pubmed:abstractText
Mammary epithelial cells cultured on Engelbreth-Holm-Swarm (EHS) matrix form multicellular structures termed mammospheres, in which cells and matrix become arranged around a central luminal space. In the presence of lactogenic hormones, cells within mammospheres become polarized, form tight intercellular junctions, and secrete milk proteins vectorially into the luminal space. This study examined the mechanism of lumen formation. Histological examination of developing mammospheres showed that cavitation was associated spatially and temporally with the appearance of fragmented nuclear material in apoptotic bodies, and with the presence of cells positively labeled by terminal deoxynucleotide transferase-mediated deoxyuridine nick end-labeling (TUNEL). Analysis of [(32)P]-deoxynucleotide end-labeled genomic DNA by electrophoresis and autoradiography showed DNA laddering indicative of apoptosis. A transient increase in laddering coincided with both lumen formation and the presence of TUNEL-positive cells. Lumen formation, DNA laddering, and detection of TUNEL-positive cells were all accelerated when matrix composition was altered. They were also impaired coordinately when caspase inhibitor was present during the first two days of culture. Therefore, lumen formation in mammosphere cultures is due to selective apoptosis of centrally located cells. Mammosphere cavitation was accompanied by redistribution of matrix constituents to the mammosphere periphery. Western blotting and Western ligand blotting of culture medium showed that lumen formation was also associated with a transient increase in insulin-like growth factor binding protein-5 (IGFBP5), a factor implicated in mammary apoptosis in vivo. We propose that epithelial cell survival during mammosphere development is induced selectively through stabilization by basement membrane constituents, which may act directly on the epithelial cell or confer protection against autocrine apoptotic factors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9541
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:volume
181
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
304-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Influence of microenvironment on mammary epithelial cell survival in primary culture.
pubmed:affiliation
Hannah Research Institute, Ayr, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't