Differential expression of VEGF isoforms and VEGF receptors in cartilaginous tumors.

Vascular endothelial growth factor (VEGF), which is known to have at least five isoforms and four receptors, is integral to tumor-induced neovascularization. In order to determine whether VEGF signaling is modulated in the development of cartilaginous tumors, we analyzed osteochondrogenic tumors for the expression of VEGF isoforms and VEGF receptors using the reverse transcription-polymerase chain reaction method. Although mRNA for VEGF121, VEGF165, VEGFR-1 and NRP-2 was widely expressed, mRNA expression for VEGF189, VEGFR-2 and NRP-1 was linked to a malignant phenotype such as local invasion. These results indicated that VEGF signaling was fine-tuned by the differential expression of the VEGF isoforms and VEGF receptors.