The fumagillin analogue TNP-470 inhibits DNA synthesis of vascular smooth muscle cells stimulated by platelet-derived growth factor and insulin-like growth factor-I. Possible involvement of cyclin-dependent kinase 2.
The effect of an angiogenesis inhibitor, TNP-470, on DNA synthesis and its underlying signaling cascades stimulated by platelet-derived growth factor (PDGF)-BB and insulin-like growth factor (IGF)-I were examined in bovine vascular smooth muscle cells (SMCs). PDGF-BB (10 ng/mL)- and IGF-I (100 ng/mL)-stimulated increase in DNA synthesis was completely abolished by simultaneous treatment with TNP-470 (1.0 ng/mL). TNP-470 had no effects on PDGF receptor autophosphorylation or early signal transduction, such as activation of mitogen-activated protein kinase and immediate early gene expression. PDGF-BB induced an increase in mRNA levels of cyclin D1, cyclin-dependent kinase (cdk) 4, and cdk2, as well as the activity of cdk2, which preceded the G1/S boundary, as estimated by the kinetics of DNA synthesis. The PDGF-BB-induced activation of cdk2 was inhibited by TNP-470, which was correlated with decreased cdk2 mRNA levels. In contrast, TNP-470 had no or less marked effect on cyclin D1 and cdk4 mRNA levels induced by PDGF-BB. TNP-470 also inhibited a much smaller increase in cdk2 mRNA levels and activation stimulated by IGF-I. In conclusion, TNP-470 potently inhibits DNA synthesis of SMCs, and this inhibition is associated with decreased levels of cdk2 mRNA and activity.
Koyama
H
H
Second Department of Internal Medicine, Osaka City University Medical School, Japan.
Nishizawa
Y
Y
Hosoi
M
M
Fukumoto
S
S
Kogawa
K
K
Shioi
A
A
Morii
H
H
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D000077214:Becaplermin; D042846:CDC2-CDC28 Kinases; D002417:Cattle; D002478:Cells, Cultured; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D003510:Cyclohexanes; D004261:DNA Replication / Q000187:drug effects*; D004336:Drug Antagonism; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D000077609:O-(Chloroacetylcarbamoyl)fumagillol; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D020574:Proto-Oncogene Proteins c-sis; D012717:Sesquiterpenes / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*
D000903:Antibiotics, Antineoplastic; D003510:Cyclohexanes; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D012717:Sesquiterpenes; D000077214:Becaplermin; D007334:Insulin-Like Growth Factor I; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases; D000077609:O-(Chloroacetylcarbamoyl)fumagillol