THE EFFECT OF SILENCING THE WILMS' TUMOR 1 GENE ON THE RADIATION SENSITIVITY OF GLIOBLASTOMA CELLS

Abstract

THE EFFECT OF SILENCING THE WILMS' TUMOR 1 GENE ON THE RADIATION SENSITIVITY OF GLIOBLASTOMA CELLS By Dana C. Chan A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University. Virginia Commonwealth University, 2006. Advisor: William C. Broaddus, M.D., Ph.D. Associate Professor, Department of Neurosurgery Associate Professor, Department of Anatomy and Neurobiology Glioblastomas are among the most devastating of human cancers with a median survival of only 9-12 months. This type of brain tumor is incurable, largely due its remarkable proliferative capacity and resistance to current treatments. High levels of the Wilms' Tumor 1 (WTI) gene have been identified in glioblastomas, suggesting an oncogenic function. Moreover, known WT? target genes have been implicated in resistance to radiation. To determine the role of WT1 in radiation resistance, two glioblastoma cell lines expressing WT1 were treated with siRNAs to si.lence this gene. Confirmation of WT1 knockdown was achieved through real-time PCR and Western blot. After treatment with siRNA, cells were irradiated, and cell survival was assessed using a luminescent ATP assay and clonogenic survival assay. We demonstrate that treatment with WT1 siRNA increased the radiation sensitivity in both cell lines. These findings suggest that WT1 functions to protect glioblastoma cells from radiation-induced death. CHAPTER