In vivo establishment of T98G human glioblastoma

Human derived T98G glioblastoma has long been utilized as an in vitro model for epidermal growth factor receptor (EGFR)-mediated growth regulation. Recently, T98G has been employed to develop new types of therapy directed at limiting EGFR expression such as by administration of antisense oligonucleotides directed against EGFR encoding mRNA. A major limitation to extending this model for in vivo application is that T98G implanted s.c. or intracerebrally has been reported not to grow in nude mice. In an effort to extend this model to permit in vivo studies, we evaluated the use of Matrigel and orthotopic (intracranial) implantation techniques. When equal volumes of Matrigel were mixed with T98G cell suspensions, tumors developed at both flank and orthotopic locations. Four groups of nude mice were inoculated into the flanks with either 10⁵, 10⁶, 4 x 10⁶ or 10⁷ T98G cells in a 150 μl total volume with Matrigel. In 1/5, 3/5, 1/5 and 1/3 mice receiving 10⁵, 10⁶, 4 x 10⁶ and 10⁷ cells, respectively, tumors developed 11, 15, 15 and 15 weeks, respectively, following inoculation. Out of 4 mice inoculated orthotopically (intracranially into the frontal lobe) with only 4 x 10⁴ cells and Matrigel, 2 developed tumors. However, all mice (4/4) inoculated orthotopically with 4 x 10⁵ cells in a 10 μl total volume with Matrigel developed tumors. Two were identified histologically following a scheduled sacrifice at 36 and 60 days and two more at 103 and 118 days after sacrifice following abnormal behavior. The best tumor establishment efficacy combined orthotopic implantation of 4 x 10⁵ T98G cells with Matrigel. These techniques permit the use of T98G glioblastoma as an in vivo model for new forms of therapy.