INTRODUCTION: 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.
INTRODUCTION: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 meningiomasVEGF 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.
Authors: B Neyns; J Sadones; C Chaskis; M Dujardin; H Everaert; S Lv; J Duerinck; O Tynninen; N Nupponen; A Michotte; J De Greve Journal: J Neurooncol Date: 2010-09-25 Impact factor: 4.130
Authors: Sridharan Gururangan; Susan N Chi; Tina Young Poussaint; Arzu Onar-Thomas; Richard J Gilbertson; Sridhar Vajapeyam; Henry S Friedman; Roger J Packer; Brian N Rood; James M Boyett; Larry E Kun Journal: J Clin Oncol Date: 2010-05-17 Impact factor: 44.544
Authors: Benjamin M Ellingson; Timothy F Cloughesy; Albert Lai; Phioanh L Nghiemphu; Shadi Lalezari; Taryar Zaw; Kourosh Motevalibashinaeini; Paul S Mischel; Whitney B Pope Journal: J Neurooncol Date: 2011-06-25 Impact factor: 4.130
Authors: Csanad G Varallyay; Leslie L Muldoon; Seymur Gahramanov; Yingjen J Wu; James A Goodman; Xin Li; Martin M Pike; Edward A Neuwelt Journal: J Cereb Blood Flow Metab Date: 2009-01-14 Impact factor: 6.200