Engineering of an Immunogenic pre‐Trans‐splicing RNA (iPTR) to Block Growth and Express a Glioblastoma Specific Epitope

Abstract

The most common and lethal malignancy of the central nervous system (CNS) is glioblastoma multiforme (GBM). Due to the blood brain barrier and the relatively immunologically privileged status of the CNS, clinical strategies have not improved the standard of care. Epidermal growth factor receptor (EGFR), a type of tyrosine kinase receptor, has been found to be overexpressed in as much as 60% of GBM tumors. Upon binding of its cognate ligand, EGFR promotes tumor growth and proliferation. The cytokine, interleukin‐13 receptor alpha variant 2 (IL13Rα2) is an isoform selectively expressed in GBM. It is highly immunogenic, attracting cytotoxic T‐cells to the tumor microenvironment. Therapeutically, this cytokine has the potential reactivate the immune system toward GBM. In the current study, we have designed and cloned an immunogenic pre‐trans splicing RNA molecule (iPTR) against EGFR. The iPTR has the potential to synergistically block growth and reactivate the immune system toward the tumor microenvironment by generation of a GBM‐specific epitope. In a GBM tissue culture model, we use RT‐PCR to detect changes in IL13Rα2 peptide expression. In addition, we use western blot and ELISA to measure changes in EGFR protein localization. Genetic delivery of our highly immunogenic IL13Rα2 peptide using the iPTR has the potential to redirect the immune system to recognize and induce apoptosis in GBM cells.Support or Funding InformationMonmouth University School of Science Research, Bristol‐Meyers Squibb, Johnson and Johnson, and the Independent College Fund of New Jersey