ADENO-ASSOCIATED VIRUS INTRAVENTRICULAR INJECTION ALLOWS THE RESTRICTED TRANSDUCTION OF GLIOBLASTOMA CELLS NESTED IN THE PERI- AND SUB-VENTRICULAR ZONE IN A PATIENT-DERIVED ORTHOTOPIC XENOGRAFT MODEL

Abstract INTRODUCTION: Glioblastoma (GBM) seems to arise from cells nested in the subventricular zone (SVZ), a neurogenic zone in the adult brain. After striatal engraftment of patient-derived GBM cells in mice, we showed that some tumor cells escape the tumor mass to colonize the SVZ. We aimed to determine if the SVZ-nested GBM cells could be highlighted by the intraventricular injection of a viral vector. MATERIALS AND METHODS: We determined the optimal Adeno-Associated Virus (AAV) serotype to transduce patient-derived GBM cells cultured in 3D (GB1). We studied the spreading of the virus 4 weeks after intraventricular injection in mice. We realized striatal engraftment with GB1 cells, previously transfected with a lentiviral construction in order to express the Red-Fluorescent-Protein (RFP) spontaneously, while they express Green-Fluorescent-Protein (eGFP) only in presence of Cre-recombinase. 10 weeks after engraftment, an AAV expressing Cre-Recombinase was injected in the lateral ventricle and mice were perfused at 14 weeks. RESULTS: AAV serotype DJ (AAVDJ) efficiently transduced GB1 cells. 4 weeks after intraventricular injection, the AAVDJ transduced cells in the SVZ and the medial part of the caudoputamen (mCP). The median of the longest distance between the right ventricle and the transduced cells in the mCP was 293.8µm [245 – 376.5]. In 5 mice, the median of the shortest distance between RFP-positive GBM cells and right ventricle was 580.1µm [535 – 785.1]. SVZ was not colonized and eGFP signal was not found. In the 4 other mice, SVZ was invaded and eGFP signal was detected. The median of the longest distance between the right ventricle and eGFP-positive tumor cells was 240.5µm [195.7 – 372.5]. The median of the eGFP volume was 9 499 404µm3. CONCLUSION: It is possible to transduce GBM cells nested in the peri- and sub-ventricular zone thanks to AAV intraventricular injection.