Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-9-2
pubmed:abstractText
Because PRL has growth factor activities in several tissues, we have asked whether it also has autocrine growth factor activity in pituitary GH3 cells. GH3 cells were grown at increasing densities in the presence or absence of antirat PRL (polyclonal and monoclonal) or nonspecific antibodies. Cell proliferation increased with increasing cell density, as did the concentration of PRL in the medium. Antirat PRL, but not control antibody, markedly inhibited but did not eliminate cell proliferation, and this effect was diminished with increasing PRL concentration in the medium. PRL receptors were demonstrated on 40-50% of the cells by indirect immunofluorescence using a specific antirat PRL receptor monoclonal antibody. Cell surface PRL was colocalized to the same 40-50% of the cells and copatched or cocapped along with the receptors. Absence or presence of PRL receptors did not correlate with stage of the cell cycle, as judged by ethidium bromide dual labeling. Cell surface PRL was found to be on PRL-containing cells. These data have fulfilled four criteria necessary for establishment of a substance as a secreted autocrine growth factor: 1) the factor must be secreted; 2) in log growth phase, increased cell proliferation should occur at increased cell densities; 3) the cells must display a receptor for the factor; and 4) there must be a growth response to the factor. Thus we have established that PRL is an autocrine growth factor for at least 40-50% of the GH3 cell population. This, to our knowledge, is the first example of autocrine growth factor activity of a major hormone normotopically expressed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
131
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
595-602
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Prolactin isoform 2 as an autocrine growth factor for GH3 cells.
pubmed:affiliation
Division of Biomedical Sciences, University of California, Riverside 92521-0121.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't