The relevance of cell proliferation, vascular endothelial growth factor, and basic fibroblast growth factor production to angiogenesis and tumorigenicity in human glioma cell lines

Tumor growth is partially dependent on angiogenesis, a process that relies on angiogenic factors, Tumorigenicity of cancer cells is thought to be asso ciated with the production of various angiogenic factors that stimulate or inhibit the rate of endothelial cell migration and proliferation. However, the relative importance of specific individual factors originally studied i n cancer cell lines has yet to be determined in vivo. In this study, we exa mined seven human glioma cell lines for dynamic changes of two major angiog enic factors, basic fibroblast growth factor (bFGF) and vascular endothelia l growth factor (VEGF), and for doubling time and tumorigenicity in nude mi ce. Various correlation studies demonstrated that in these glioma cell line s, VEGF expression correlated well with RBC density in tumor sections (r(2) = 0.804) and with average tumor weight (r(2) = 0.987). In contrast, bFGF e xpression in the observed glioma cell lines did not correlate with tumorige nicity (r(2) = 0.001) or with VEGF expression (r(2) = 0.255). Furthermore, there was no correlation between doubling time and tumorigenicity in these cell lines (r(2) = 0.160). Taken together, these results suggest that VEGF plays a major role in glioma formation and that down-regulation of VEGF, ra ther than bFGF, would be a more effective choice for glioma gene therapy.