title: Molecular MRI assessment of vascular endothelial growth factor receptor-2 in rat C6 gliomas.
abstract: Angiogenesis is essential to tumour progression and a precise evaluation of angiogenesis is important for tumour early diagnosis and treatment. The quantitative and dynamic in vivo assessment of tumour angiogenesis can be achieved by molecular magnetic resonance imaging (mMRI). Vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) are the main regulatory systems in angiogenesis and have been used as hot targets for radionuclide-based molecular imaging. However, little research has been accomplished in targeting VEGF/VEGFRs by mMRI. In our study, we aimed to assess the expression of VEGFR2 in C6 gliomas by using a specific molecular probe with mMRI. The differential uptake of the probe conjugated to anti-VEGFR2 monoclonal antibody, shown by varied increases in T(1) signal intensity during a 2 hr period, demonstrated the heterogeneous expression of VEGFR2 in different tumour regions. Microscopic fluorescence imaging, obtained for the biotin group in the probe with streptavidin-Cy3, along with staining for cellular VEGFR2 levels, laminin and CD45, confirmed the differential distribution of the probe which targeted VEGFR2 on endothelial cells. The angiogenesis process was also assessed using magnetic resonance angiography, which quantified tumour blood volume and provided a macroscopic view and a dynamic change of the correlation between tumour vasculature and VEGFR2 expression. Together these results suggest mMRI can be very useful in assessing and characterizing the expression of specific angiogenic markers in vivo and help evaluate angiogenesis associated with tumour progression.
authors.affiliation: Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
authors.forename: Ting
authors.initials: T
authors.lastname: He
authors.forename: Nataliya
authors.initials: N
authors.lastname: Smith
authors.forename: Debra
authors.initials: D
authors.lastname: Saunders
authors.forename: Sabrina
authors.initials: S
authors.lastname: Doblas
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Jessica
authors.initials: J
authors.lastname: Hoyle
authors.forename: Robert
authors.initials: R
authors.lastname: Silasi-Mansat
authors.forename: Florea
authors.initials: F
authors.lastname: Lupu
authors.forename: Megan
authors.initials: M
authors.lastname: Lerner
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Brackett
authors.forename: Rheal A
authors.initials: RA
authors.lastname: Towner
mesh_terms: D000818:Animals; D001710:Biotin / Q000378:metabolism; D015153:Blotting, Western; D045744:Cell Line, Tumor; D005910:Glioma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D007150:Immunohistochemistry; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D057054:Molecular Imaging / Q000379:methods*; D015335:Molecular Probes / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000378:metabolism; D004369:Pentetic Acid / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
chemical_list: D015335:Molecular Probes; C513815:biotin-BSA-GdDTPA; D012710:Serum Albumin, Bovine; D001710:Biotin; D004369:Pentetic Acid; D040301:Vascular Endothelial Growth Factor Receptor-2