Linked Life Data

9345355

Source:http://linkedlifedata.com/resource/pubmed/id/9345355

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-11-25
pubmed:abstractText
Previous studies from this laboratory have shown that epidermal growth factor (EGF) and the tumor promoter, phorbol myristate acetate (PMA), are mitogenic in the endometrial cancer cell line HEC-1-A. Since the effects of EGF have been shown to be mediated by the protein kinase C (PKC) pathway transduction system, we examined the possibility that the EGF-responsive signal in the endometrial cancer cell line HEC-1-A involves protein kinase C activation. HEC-1-A cells were grown to confluency in 100-mm dishes and maintained in a serum-free medium for 24 hr prior to treatment. The cells were treated with EGF at varying time intervals (0.25 to 60 min) and concentrations (0.1 to 200 ng/ml). The cells were then lysed, homogenized, and centrifuged at 105,000g for 1 hr at 4 degrees C. The supernatant was chromatographed on DEAE-Sephacel columns. The membranous pellet was resuspended in 5 ml of lysis buffer containing 1% Nonidet P-40 and also chromatographed on DEAE-Sephacel columns separately. The eluates were collected and assayed for protein kinase C activity by determining the amount of 32P transferred from [gamma-32P]ATP onto histones in the presence of the phospholipids, phosphatidylserine, and diolein. Our results show that the cytoplasmic and membrane fraction of the HEC-1-A cell line contained phosphotransferase activity which displayed kinetic characteristics typical of the protein kinase C enzyme. The optimal incubation time for protein kinase C activation in the cytosol by EGF was 5 min (30-fold stimulation). The protein kinase C activity was increased when the cell lines were incubated with increasing concentrations of EGF. Enzyme saturation was seen at a concentration of 10 ng/ml of EGF (4.5-fold stimulation). Western blot analysis confirmed the presence of the PKC enzyme in the cytosol and membranes of our cancer cell line. These results suggest that EGF, at least partially, exerts its effects on the endometrial adenocarcinoma cell line by activating protein kinase C through increased breakdown of phosphatidyl inositol (PI). The PI cascade appears to be an important signal transduction system mediating the growth stimulatory effects of EGF on endometrial carcinoma.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0090-8258
pubmed:author
pubmed:issnType
Print
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
46-50
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:9345355-Blotting, Western, pubmed-meshheading:9345355-Cell Membrane, pubmed-meshheading:9345355-Cytosol, pubmed-meshheading:9345355-Diglycerides, pubmed-meshheading:9345355-Down-Regulation, pubmed-meshheading:9345355-Endometrial Neoplasms, pubmed-meshheading:9345355-Enzyme Activation, pubmed-meshheading:9345355-Epidermal Growth Factor, pubmed-meshheading:9345355-Female, pubmed-meshheading:9345355-Humans, pubmed-meshheading:9345355-Hypoglycemic Agents, pubmed-meshheading:9345355-Insulin, pubmed-meshheading:9345355-Insulin-Like Growth Factor I, pubmed-meshheading:9345355-Insulin-Like Growth Factor II, pubmed-meshheading:9345355-Kinetics, pubmed-meshheading:9345355-Protein Kinase C, pubmed-meshheading:9345355-Stimulation, Chemical, pubmed-meshheading:9345355-Tumor Cells, Cultured
pubmed:year
1997
pubmed:articleTitle
Epidermal growth factor activates protein kinase C in the human endometrial cancer cell line HEC-1-A.
pubmed:affiliation
Department of Obstetrics/Gynecology, University of Michigan, Ann Arbor 49109-0278, USA.
pubmed:publicationType
Journal Article