Biology of angiogenesis and invasion in glioma

Treatment of adult brain tumors, in particular glioblastoma, remains a significant clinical challenge, despite modest advances in surgical technique, radiation, and chemotherapeutics. The formation of abnormal, dysfunctional tumor vasculature and glioma cell invasion along white matter tracts are believed to be major components of the inability to treat these tumors effectively. Recent insight into the fundamental processes governing glioma angiogenesis and invasion provide a renewed hope for development of novel strategies aimed at reducing the morbidity of this uniformly fatal disease. In this review, we discuss background biology of the blood brain barrier and its pertinence to blood vessel formation and tumor invasion. We will then focus our attention on the biology of glioma angiogenesis and invasion, and the key mediators of these processes. Last, we will briefly discuss recent and ongoing clinical trials targeting mediators of angiogenesis or invasion in glioma patients. The findings provide a renewed hope for those endeavoring to improve treatment of patients with glioma by providing a novel set of rational targets for translational drug discovery.