Glioblastoma multiforme is one of the most deadly human solid tumors. The survival rate is less than 10% at 2 years, even with the best conventional therapy–resection followed by high-dose whole-brain external radiation (5,000–6,000 rad) and l, 3-bis (2-chlorethyl)-1-nitrosourea (BCNU) chemotherapy [24, 25]. These dismal statistics have prompted extensive efforts aimed at defining new therapeutic approaches to this malignant neoplasm. Testing of new immunotherapeutic and chemotherapeutic regimens requires in vitro or in vivo systems with characteristics that as closely as possible resemble those prevailing in the human glioma.

Induced tumor systems, such as the rat-avian sarcoma virus (ASV) model or transplantable models using nitrosourea-induced rat tumor lines (including C-6, 9L and RG-2) are useful for large-scale testing. However, cell lines established from human gliomas and human tumors transplanted into athymic nude mice offer the advantage that the neoplastic cells are human in origin.