Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2002-8-22
pubmed:abstractText
Hepatocyte growth factor (HGF) and its receptor c-Met are expressed in inappropriately high abundance in gliomas and are further upregulated during the transition from low- to high-grade malignancy. In these cells HGF induces expression of c-Met via PKC, Ras and mitogen activated protein kinase (MAPK) pathway. Here we report that secretion and expression of HGF in U87 astrocytoma is increased by a PKC activator, PMA, an effect which is abolished by a PKC inhibitor, Go6976, specific for PKCalpha and PKCbeta1. Activating PKA by forskolin, on the other hand, had no effect. Furthermore, messenger molecule downstream of PKC, i.e. MEK mediates such effect of PKC as specific MEK inhibitors (PD98059 and U0126) abolished PMA induced HGF secretion by U87 cells. Accordingly, PMA induced rapid phosphorylation of MEK substrate, i.e. Erk1/2 (p42/44 MAPK). In addition, such effect of PKC is Ras-dependent as specific Ras inhibitor L-744,832 attenuated both PMA mediated induction of Erk 1/2 phosphorylation as well as HGF secretion. Moreover, a specific p38 MAPK inhibitor (SB203580) almost completely inhibited basal HGF secretion to an undetectable level. Increased secretion of HGF is most likely exerted at the transcriptional level since inhibitor of transcription, actinomycin D abolished such increase. Furthermore, when assessed by Northern blot analysis, PMA increased HGF transcripts while U0127 and SB203580 inhibited. Therefore, our data reveal that HGF secretion in U87 cells is regulated by Ras-dependent PKC, MEK cascade and in parallel by p38 MAPK pathway. Since the Raf-PKC-MEK cascade is used for HGF's signaling via its receptor in astrocytoma cells, our data revealing similar regulatory mechanism for HGF secretion in these cells would help to explain the feed forward nature of HGF action in glioma cells that would further accentuate its basal secretion, exacerbating its effects on the progression of gliomas in an autocrine fashion.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Hepatocyte Growth Factor, http://linkedlifedata.com/resource/pubmed/chemical/MAP Kinase Kinase 1, http://linkedlifedata.com/resource/pubmed/chemical/MAP2K1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase 1, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase..., http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase C, http://linkedlifedata.com/resource/pubmed/chemical/Protein Synthesis Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Tetradecanoylphorbol Acetate, http://linkedlifedata.com/resource/pubmed/chemical/p38 Mitogen-Activated Protein...
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0169-328X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
102
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
73-82
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:12191496-Astrocytoma, pubmed-meshheading:12191496-Cell Division, pubmed-meshheading:12191496-Cell Transformation, Neoplastic, pubmed-meshheading:12191496-Enzyme Inhibitors, pubmed-meshheading:12191496-Hepatocyte Growth Factor, pubmed-meshheading:12191496-Humans, pubmed-meshheading:12191496-MAP Kinase Kinase 1, pubmed-meshheading:12191496-Mitogen-Activated Protein Kinase 1, pubmed-meshheading:12191496-Mitogen-Activated Protein Kinase Kinases, pubmed-meshheading:12191496-Mitogen-Activated Protein Kinases, pubmed-meshheading:12191496-Neoplasm Invasiveness, pubmed-meshheading:12191496-Protein Kinase C, pubmed-meshheading:12191496-Protein Synthesis Inhibitors, pubmed-meshheading:12191496-Protein-Serine-Threonine Kinases, pubmed-meshheading:12191496-RNA, Messenger, pubmed-meshheading:12191496-Tetradecanoylphorbol Acetate, pubmed-meshheading:12191496-Tumor Cells, Cultured, pubmed-meshheading:12191496-p38 Mitogen-Activated Protein Kinases
pubmed:year
2002
pubmed:articleTitle
PKC, p42/44 MAPK and p38 MAPK regulate hepatocyte growth factor secretion from human astrocytoma cells.
pubmed:affiliation
Endocrine-Hypertension Division and Membrane Biology Program, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave., Boston, MA 02115, USA. nchattopadhyay@rics.bwh.harvard.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't