EXPRESSION OF THE FLT4 VEGFR3 RECEPTOR TYROSINE KINASE-ENCODING GENE IN HEPATIC-TUMORS/

The FLT4/VEGFR3 tyrosine kinase receptor belongs to a class of recepto rs for growth factors of the vascular endothelial growth factor family and is important for the biology of lymphatic endothelium. It may pla y an important role in tumor growth. We have looked for the expression of the FLT4 gene in tumors of various origins. FLT4 expression was no t found except in some particular type of tumors: mouse hepatic tumors but not cell lines were shown to expressed Flt4 at a high frequency w hile Flt4 mRNA was absent or weakly expressed in normal liver, suggest ing that Flt4 de novo expression in liver nonparenchymal cells partici pates in tumor development of this tissue.