|
|
||||||||
Departments of 1 Internal Medicine and 2 Biochemistry, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
Although vascular
endothelial growth factor (VEGF) plays a role in the growth of
hypervascular tumors, mechanisms for paracrine regulation of its
receptor expression on vascular endothelial cells remain unknown. This
study aimed to investigate whether VEGF released from hypoxia-exposed
Hep G2 cells alters expression of the two distinct receptors, kinase
insert domain-containing receptor (KDR) and
fms-like tyrosine kinase 1 (flt-1), in human umbilical venous endothelial cells
(HUVEC). Hep G2 cells were cultured in 20% or 1%
O2 for 16 h to examine induction
of VEGF mRNA and its protein expression. Conditioned medium from Hep G2 cells (CM) was applied to HUVEC under normoxic conditions, and expression of mRNA for the VEGF receptors was determined by
RT-PCR. In response to the hypoxic challenge, Hep G2 cells
upregulated VEGF mRNA and the release of VEGF. Hypoxia-CM
preferentially stimulated the mRNA expression of
flt-1 but not that of KDR in HUVEC.
When the VEGF release from hypoxia-exposed Hep G2 cells was blocked by
its antisense oligodeoxynucleotide, the endothelial
flt-1 mRNA upregulation elicited by
the hypoxia-CM was still maintained. These results suggest that
hypoxia-exposed Hep G2 cells not only produce VEGF but also evolve
paracrine induction of flt-1 through VEGF-independent mechanisms.
reverse transcription-polymerase chain reaction; flt-1; kinase insert domain-containing receptor; antisense oligodeoxynucleotide
This article has been cited by other articles:
![]() |
Y. Yokoyama, R. Baveja, N. Sonin, M. G. Clemens, and J. X. Zhang Hepatic neovascularization after partial portal vein ligation: novel mechanism of chronic regulation of blood flow Am J Physiol Gastrointest Liver Physiol, January 1, 2001; 280(1): G21 - G31. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Wang, D. B. Donner, and R. S. Warren Homeostatic Modulation of Cell Surface KDR and Flt1 Expression and Expression of the Vascular Endothelial Cell Growth Factor (VEGF) Receptor mRNAs by VEGF J. Biol. Chem., May 19, 2000; 275(21): 15905 - 15911. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |