THER-15. DEVELOPING TUMOR-HOMING CYTOTOXIC HUMAN INDUCED NEURAL STEM CELL THERAPY FOR BRAIN METASTASES

INTRODUCTION: Non-small cell lung cancer (NSCLC) and breast cancer are the most common cancers that metastasize to the brain. New therapies are needed to seek out and eradicate metastases. Genetically engineered neural stem cells (NSCs) have shown unique tumor-homing capacity, allowing them to deliver cytotoxic proteins directly to tumors. An ideal NSC drug carrier would be readily available and autologous. We have transdifferentiated human fibroblasts into induced NSCs (hiNSCs) that home to tumors and engineered the hiNSCs to release the cytotoxic protein TRAIL. Here we used intracerebroventricular (ICV) injections to deliver hiNSCs to metastatic foci. METHODS: We performed an in vitro efficacy co-culture assay, used in vivo studies to determine the migration, persistence, and efficacy of therapeutic hiNSCs against H460 NSCLC and triple-negative breast cancer MB231-Br tumors in the brain. Following the establishment of tumors in the brains of nude mice, hiNSCs were injected directly into the tumor or the ventricle contralateral to the site of tumor. The migration and persistence of hiNSCs was investigated by following the bioluminescence of the hiNSCs. The therapeutic efficacy of the hiNSCs was determined by following the bioluminescece of the tumor. RESULTS/CONCLUSION: Co-culture results demonstrated that hiNSC therapy reduced the viability of H460 and MB231-Br up to 75% and 99.8% respectively compared to non-treated controls. ICV-administered hiNSC serial imaging show that cells persisted for more than one week. Fluorescent analysis of tissue sections showed that hiNSCs co-localized with lateral and a contralateral tumors within 7 days. Using H460 and MB231-Br models, kinetic tracking of intracranial tumor volumes showed intratumoral or ICV-injected therapeutic hiNSCs reduced the growth rate of brain tumors by 31-fold and 3-fold, respectively. This work demonstrates for the first time that we can effectively deliver personalized cytotoxic tumor-homing cells through the ventricles to target brain metastases.