title: Coexpression of flt-1, flt-4 and KDR in freshly isolated and cultured human endothelial cells.
abstract: Vascular endothelial cell growth factors (VEGF) are key modulators of endothelial cell growth and function. The class III receptor tyrosine kinases KDR and Flt-1 are high affinity receptors for VEGF, while Flt-4 is a receptor for the recently identified VEGF-C. We have examined the expression of flt-1, flt-4 and KDR in human microvascular and large vessel endothelial cells and in a variety of other cell types in vitro. Endothelial cells proliferated and exhibited increased procoagulant activity in response to VEGF. Flt-1, flt-4 and KDR were detected in both freshly isolated endothelial cells, and in sparse and confluent endothelial cell cultures by RT-PCR. Attempts to modulate receptor expression by culturing cells at reduced oxygen tensions (2%) did not induce consistent changes in flt-1, flt-4 or KDR expression. Incubation with tumor-conditioned medium or co-culture of endothelial cells with a range of breast and small cell lung carcinoma cell lines did not reproducibly alter receptor mRNA expression. However, flt-1, flt-4 and KDR transcript levels were enhanced following treatment with tetradecanoylphorbol acetate.
authors.affiliation: University of Nottingham Laboratory of Molecular Oncology, CRC Dept. of Clinical Oncology, City Hospital, United Kingdom.
authors.forename: P W
authors.initials: PW
authors.lastname: Hewett
authors.forename: J C
authors.initials: JC
authors.lastname: Murray
mesh_terms: D001483:Base Sequence; D002478:Cells, Cultured; D017931:DNA Primers; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D017978:Receptors, Growth Factor / Q000235:genetics*
chemical_list: D017931:DNA Primers; D017978:Receptors, Growth Factor; D020794:Receptor Protein-Tyrosine Kinases