Development of therapeutics for high grade gliomas using orthotopic rodent models.

To study novel treatments for high grade gliomas (WHO grade III and IV) we need animal models of those disorders. Orthotopic tumors in mouse or rats seem at present the most reliable in vivo glioma model in order to develop specific therapies. The orthotopic tumor characteristics should yet closely mimic the human glioma features (in particular infiltrating growth and neovascularization). In this regard, glioma cell lines with stem properties (glioma stem cells - GSC) may fulfill at best those needs. Orthotopic gliomas developed from some widely used, established non-stem cell lines showing poor infiltrating capacity are not suitable. Therapeutic and diagnostic procedures recently developed using orthotopic rodent glioma tumors along their potentialities and pitfalls are analyzed.