Expression of the FLT4/VEGFR3 receptor tyrosine kinase encoding gene in hepatic tumors

The FLT4/VEGFR3 tyrosine kinase receptor belongs to a class of receptors for growth factors of the vascular endothelial growth factor family and is important for the biology of lymphatic endothelium. It may play an important role in tumor growth. We have looked for the expression of the FLT4 gene in tumors of various origins. FLT4 expression was not found except in some particular type of tumors: mouse hepatic tumors but not cell lines were shown to expressed Flt4 at a high frequency while Flt4 mRNA was absent or weakly expressed in normal liver, suggesting that Flt4 de novo expression in liver nonparenchymal cells participates in tumor development of this tissue.