Expression of VEGF and its receptors in different brain tumors.
BACKGROUND
Vascular endothelial growth factor (VEGF) and its receptors VEGFR-1 and -2 are considered to play a major in tumor angiogenesis, which is a prerequisite for growth of solid tumors. Glioblastoma multiforme is a prominent example of VEGF-induced tumor vascularization; however, little is known about VEGF and in particular VEGFR expression in other types of brain tumors.


METHODS
VEGFR mRNA was quantified by real time RT-PCR in 12 different types of brain tumors and compared to VEGF protein content measured by ELISA. VEGF splice variants were determined by an RT-PCR method.


RESULTS
VEGF protein was highest in glioblastoma and metastatic kidney tumors. In all types of tumors the diffusible splice forms VEGF(121) and VEGF(165) were expressed; VEGF(189) was minor in a few tumors. Expression of VEGF receptors did not necessarily correlate with VEGF content. Both were highly expressed in glioblastomas, but in meningiomas VEGF was low and VEGFR high, and in metastatic tumors the reverse. With few exceptions, in particular oligodendrogliomas, VEGFR-1 expression was parallel to VEGFR-2 expression. Interestingly, for the astrocytic gliomas, the expression of VEGFR correlated well to the tumor malignancy, even better than VEGF content.


CONCLUSIONS
These results show that VEGF and VEGFR expression in various types of brain tumors differ and are not necessarily parallel.
Huang
Hongguang
H
Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
Held-Feindt
Janka
J
Buhl
Ralf
R
Mehdorn
Hubertus M
HM
Mentlein
Rolf
R
D015152:Blotting, Northern / Q000379:methods; D001932:Brain Neoplasms / Q000145:classification / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004806:Ependymoma / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D014644:Genetic Variation; D005909:Glioblastoma / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007680:Kidney Neoplasms / Q000378:metabolism; D008545:Melanoma / Q000378:metabolism; D009837:Oligodendroglioma / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2