NON-VIRAL GENE MODIFIED MESENCHYMAL STEM CELLS FOR GENE-DIRECTED ENZYME PRODRUG THERAPY

Abstract

Mesenchymal stem cells (MSCs) are attractive therapeutic vehicles in Gene-Directed Enzyme Prodrug Therapy (GDEPT) due to their immune-evasiveness and homing abilities. GDEPT mitigates high systemic toxicity of chemotherapy regimens. Currently, most protocols use viruses to modify MSCs but these are limited by safety, production cost, and scalability issues. Non-viral methods are seldom used as they are not effective. In this study, we developed a highly efficient non-viral platform to generate therapeutically modified MSCs at an unprecedented transfection efficiency of > 90%. Furthermore, this is agnostic to both AD- and UC-MSCs and is scalable on both flat-bed and on microcarriers. We utilized these MSCs in cytosine deaminase/ 5-fluorocytosine (CD/5-FC) prodrug system to target Temozolomide-resistant glioblastoma (TMZ-R GBM). CD-modified MSCs convert non-toxic 5-FC to toxic metabolites at tumour sites and mediate cellular toxicity through bystander effect. Here, we demonstrated CD-modified MSCs/5-FC were efficient in killing TMZ-R GBM in vitro and in vivo.