YC-1 inhibits proliferation of human vascular endothelial cells through a cyclic GMP-independent pathway.
This study was designed to investigate the effect of YC-1, 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole, in human umbilical vein endothelial cells (HUVECs) proliferation and its underlying mechanism. YC-1 at a range of concentrations (5-50 microM) inhibited DNA synthesis and decreased cell number in cultured HUVEC in a dose- and time-dependent manner. YC-1 was not cytotoxic at these concentrations. [3H]thymidine incorporation and flow cytometry analyses revealed that YC-1 treatment decreased DNA synthesis and arrested the cells at the G0/G1 phase of the cell cycle. Western blot analysis demonstrated that YC-1 (5-50 microM) increased the levels of cyclin-dependent kinase (CDK)-inhibitory proteins (CKIs), p21 and p27, but did not induce any significant changes of cyclins and CDKs. In the YC-1-treated HUVEC, the formation of CDK2-p21 complex, but not CDK2-p27 complex, was increased and the assayable CDK2 kinase activity was decreased. These changes were in a dose-dependent manner. In contrast, the formations of CDK4-p21 and CDK4-p27 complex were slightly increased and the assayable CDK4 kinase activity was slightly decreased (if there were any changes). Pretreatment with guanylyl cyclase inhibitors, 1H-(1,2,4)oxadiazolo[4,3-a]quinozalin-1-one (ODQ) and methylene blue, inhibited the YC-1-induced increase of cyclic GMP level, but did not change significantly the magnitude of the YC-1-induced inhibition of thymidine incorporation and cell number in HUVEC. These results indicate that YC-1-induced cell cycle arrest in HUVEC occurred when the cyclin-CDK system was inhibited just as p21 and p27 protein levels were augmented. This YC-1-induced antiproliferation effect in HUVEC is via a cyclic GMP-independent pathway.
Hsu
Hun-Kung
HK
Graduate Institute of Medical Sciences, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan, ROC.
Juan
Shu-Hui
SH
Ho
Pei-Yin
PY
Liang
Yu-Chih
YC
Lin
Chien-Huang
CH
Teng
Che-Ming
CM
Lee
Wen-Sen
WS
D002455:Cell Division / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism*; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D016193:G1 Phase / Q000187:drug effects; D006801:Humans; D007191:Indazoles / Q000494:pharmacology*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
D007191:Indazoles; D010975:Platelet Aggregation Inhibitors; D014316:Tritium; C090937:3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole; D004247:DNA; D006152:Cyclic GMP; D013936:Thymidine