TMOD-23. LENTIVIRAL-INDUCED BRAIN GLIOMAS IN RAT MODEL

Abstract High-grade gliomas are the most common type of malignant intracranial tumor with dismal five-year prognostic outcomes despite developments in chemoradiotherapy and surgical intervention. Distinct oncogenes associated with tumorigenesis and progression have been identified, providing targets for potential therapeutic interventions and modeling efforts. In this study, we evaluated the efficacy of vectors targeting EGFR and PTEN, individually and in combination to produce high-grade brain gliomas. Four groups of rats underwent intracranial stereotaxic injection of lentiviral vector into the forceps minor of the corpus callosum. All animals were weighed and monitored for behavioral deficits three times per week for 90 days. Upon signs of clinical morbidity or at 90 days post-inoculation, tissues were harvested and analyzed using hematoxylin and eosin and immunohistochemical staining. Rats injected with the combination of the EGFR and the sh-PTEN vectors exhibited declines in weight, survival, and motor function compared to the control. The combination of the EGFR and sh-PTEN vectors was the only condition to induce tumorigenesis with histopathological confirmation of high-grade identity as confirmed by immunohistochemistry showing the most positivity for GFAP and SOX2 compared to the control. Significant increases in Ki-67 characterized combination tumors as highly proliferative. Increased oxidative stress and angiogenesis were supported by significant increases in 4HNE, SMA, and HIF-1α in the tumors compared to other treatment groups. Thus, the present model of high-grade rat brain glioma provides a potential model to assess pathogenic pathways and evaluate therapeutic strategies.