Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1994-9-2
pubmed:abstractText
Parathyroid hormone-related protein (PTHrP) plays a prominent role in the pathogenesis of humoral hypercalcemia of malignancy. However, it is also expressed in various nonmalignant tissues, particularly during fetal organogenesis and tissue differentiation. Thus, PTHrP is synthesized in skin, placenta, and mammary gland during lactation. Little is known, however, about the regulation of PTHrP synthesis and release in nontumoral cells. We investigated the regulation of PTHrP production by epidermal growth factor (EGF), a factor of major importance in the development of lactating breast, in primary cultures of rat mammary epithelial cells. EGF stimulated the production of immunoreactive and bioactive PTHrP in a time- and concentration-dependent manner. A 12 h incubation with 10 ng/ml of EGF increased PTHrP production by 36.0 +/- 7.1% (n = 7 experiments, p < 0.01). This was accompanied by an increase in PTHrP mRNA steady-state levels. The production of PTHrP was stimulated by the protein kinase C (PKC) activator phorbol-12-myristate-13-acetate (PMA) by 82.9 +/- 9.7% (n = 4 experiments, p < 0.01). The effects of PMA and EGF were additive. The EGF-induced stimulation appeared to be independent of extracellular calcium concentration, prostaglandin, or cAMP synthesis, but may have involved tyrosine kinase-mediated mechanisms. These results indicate that EGF was capable of increasing the production of PTHrP by cultured mammary epithelial cells. They also suggest that factors activating the PKC pathway are involved in the upregulation of PTHrP expression in mammary epithelial cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0884-0431
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
639-44
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8053392-Animals, pubmed-meshheading:8053392-Calcium, pubmed-meshheading:8053392-Cells, Cultured, pubmed-meshheading:8053392-Culture Media, Conditioned, pubmed-meshheading:8053392-Cyclic AMP, pubmed-meshheading:8053392-Dose-Response Relationship, Drug, pubmed-meshheading:8053392-Epidermal Growth Factor, pubmed-meshheading:8053392-Female, pubmed-meshheading:8053392-Indomethacin, pubmed-meshheading:8053392-Lactation, pubmed-meshheading:8053392-Mammary Glands, Animal, pubmed-meshheading:8053392-Parathyroid Hormone-Related Protein, pubmed-meshheading:8053392-Prostaglandins, pubmed-meshheading:8053392-Protein Biosynthesis, pubmed-meshheading:8053392-Proteins, pubmed-meshheading:8053392-Rats, pubmed-meshheading:8053392-Rats, Wistar, pubmed-meshheading:8053392-Tetradecanoylphorbol Acetate, pubmed-meshheading:8053392-Up-Regulation
pubmed:year
1994
pubmed:articleTitle
Effects of epidermal growth factor on parathyroid hormone-related protein production by mammary epithelial cells.
pubmed:affiliation
Department of Medicine, University Hospital of Geneva, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't