title: P2Y(AC)(-)-receptor agonists enhance the proliferation of rat C6 glioma cells through activation of the p42/44 mitogen-activated protein kinase.
abstract: 1. Extracellularly added P(1),P(3)-di(adenosine-5') triphosphate (Ap(3)A), P(1),P(4)-di(adenosine-5') tetraphosphate (Ap(4)A), ATP, ADP, AMP and adenosine are growth inhibitory for rat C6 glioma cells. Analysis of nucleotide hydrolysis and the use of nucleotidase inhibitors demonstrated that the latter inhibition is due to hydrolysis of the nucleotides to adenosine. 2. Agonists of the P2Y(AC)(-)-receptor enhance the growth of C6 cells if their hydrolysis to adenosine is inhibited by pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). In these conditions, the potency to stimulate cell growth parallels the ranking of the receptor agonists, i.e. 2-methylthioadenosine-5'-diphosphate (2MeSADP)>Ap(3)A>Ap(4)A. ATP and ADP are still hydrolysed in the presence of PPADS and have no proliferative effect on C6 cells. 3. The enhanced growth is due to a P2Y(AC)(-)-receptor-mediated activation of p42/44 mitogen-activated protein kinase (MAPK) as shown by immunoblotting and protein kinase assays for active MAPK and the use of the MAPK/extracellular signal-regulated kinase kinase (MEK) inhibitor PD98059. 4. The UTP-induced enhancement of the growth of C6 cells is due to activation of MAPK by a PPADS sensitive nucleotide receptor. 5. In conclusion, the effect of nucleotides on the growth of C6 cells is determined by ecto-nucleotidases and by activation of nucleotide receptors. Hydrolysis of nucleotides to adenosine induces growth inhibition while inhibition of the hydrolysis of agonists of the P2Y(AC)(-)-receptor enhances cell growth by activation of MAPK.
authors.affiliation: Department of Biochemistry, Cellular Biochemistry, University of Antwerp, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Claes
authors.forename: B
authors.initials: B
authors.lastname: Grobben
authors.forename: K
authors.initials: K
authors.lastname: Van Kolen
authors.forename: D
authors.initials: D
authors.lastname: Roymans
authors.forename: H
authors.initials: H
authors.lastname: Slegers
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000378:metabolism / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D002455:Cell Division / Q000187:drug effects*; D015226:Dinucleoside Phosphates / Q000378:metabolism / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005910:Glioma / Q000201:enzymology / Q000473:pathology; D006868:Hydrolysis; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects* / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects* / Q000378:metabolism; D058910:Purinergic P2 Receptor Agonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000502:physiology; D013873:Thionucleotides / Q000494:pharmacology; D013997:Time Factors; D014227:Triazines / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D015226:Dinucleoside Phosphates; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D013873:Thionucleotides; D014227:Triazines; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; C002480:methylthio-ADP; D000249:Adenosine Monophosphate; C020733:diadenosine tetraphosphate; C011440:diadenosine triphosphate; C012842:Cibacron Blue F 3GA; D011732:Pyridoxal Phosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D000241:Adenosine