Growth properties of SF188/V+ human glioma in rats in vivo observed by magnetic resonance imaging

SF188/V+ is a highly vascular human glioma model that is based on transfection of vascular endothelial growth factor (VEGF) cDNA into SF188/V-cells. This study aims to assess its growth and vascularity properties in vivo in a rat model. Thirty-two adult rats were inoculated with SF188/V+ tumor cells, and, for comparison, five were inoculated with SF188/V-tumor cells. Several conventional magnetic resonance imaging (MRI) sequences were acquired, and several quantitative structural (T₂ and T₁), functional [isotropic apparent diffusion coefficient (ADC) and blood flow], and molecular [protein and peptide-based amide proton transfer (APT)] MRI parameters were mapped on a 4.7 T animal scanner. In rats inoculated with SF188/V+ tumor cells, conventional T₂-weighted images showed a highly heterogeneous tumor mass, and post-contrast T₁-weighted images showed a heterogeneous, strong enhancement of the mass. There were moderate increases in T₂, T₁, and ADC, and large increases in blood flow and APT in the tumor, compared to contralateral brain tissue. Microscopic examination revealed prominent vascularity and hemorrhage in the VEGF-secreting xenografts as compared to controls, and immunohistochemical staining confirmed increased expression of VEGF in tumor xenografts. Our results indicate that the SF188/V+ glioma model exhibits some MRI and histopathology features that closely resemble human glioblastoma.