Differing roles of protein kinase C on the signal transduction of tumour necrosis factor-alpha and -beta on PANC-1 cells: in vitro autoradiographic investigation.
We investigated alterations in protein kinase C (PKC) activity of PANC-1 cells following treatment with tumour necrosis factor (TNF)-alpha or TNF-beta by an in vitro autoradiographic method. Binding studies performed on whole cells using [3H]phorbol-12,13-dibutyrate (PDBu) as a ligand revealed strong activation of PKC by TNFs within 30 min. The effect was similar to that seen after 30 min treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA). After treatment for 24 h, TNF-beta caused a marked down-regulation of PKC similar to that seen after 24 h treatment with TPA; significant activation persisted, however, in the cells treated for 24 h with TNF-alpha. Our data suggest that PKC activation may play a more important role in the TNF-alpha signal transduction pathway than in that of TNF-beta.
Matsubara
N
N
First Department of Surgery, Okayama University Medical School, Japan.
Mizukawa
K
K
Iwagaki
H
H
Fuchimoto
S
S
Kimura
Y
Y
Orita
K
K
D001345:Autoradiography; D004790:Enzyme Induction; D006801:Humans; D066298:In Vitro Techniques; D008233:Lymphotoxin-alpha / Q000494:pharmacology*; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D011493:Protein Kinase C / Q000096:biosynthesis*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha; D011493:Protein Kinase C