Interactive regulation of signalling pathways in bone cells: possible modulation of PGE2-stimulated adenylyl cyclase activity by protein kinase C.
We have reported previously that tumour-promoting phorbol esters modulate both basal and vasoactive intestinal polypeptide (VIP)-stimulated adenylyl cyclase activity in GH3 (an established pituitary cell line). Here, we probe the receptor and cell specificity of this response. Experiments were performed in the presence of isobutylmethylxanthine. Unlike the response in GH3 cells, the tumour-promoting phorbol ester (tetradecanoyl phorbol acetate (TPA] did not affect either basal adenylyl cyclase activity nor VIP-stimulated activity in the rat osteosarcoma subclones UMR 106-01 and UMR 106-06. In addition, the cyclase responses to parathyroid hormone (PTH), and, in the case of UMR 106-06, to calcitonin were unaffected by tumour-promoting phorbol ester. However, prostaglandin E2-stimulated cyclase activity in both of these subclones was attenuated in a dose-dependent manner.
Dobson
P R
PR
Department of Human Metabolism and Clinical Biochemistry, University of Sheffield Medical School, U.K.
Brown
B L
BL
Michelangeli
V P
VP
Short
A D
AD
Moseley
J M
JM
Russell
R G
RG
Martin
T J
TJ
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D015232:Dinoprostone / Q000008:administration & dosage / Q000494:pharmacology*; D012516:Osteosarcoma / Q000188:drug therapy / Q000201:enzymology*; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D012474:Salmon; D015398:Signal Transduction / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology
D014660:Vasoactive Intestinal Peptide; D011493:Protein Kinase C; D000262:Adenylyl Cyclases; D015232:Dinoprostone; D013755:Tetradecanoylphorbol Acetate