Abstract 4336: Oncolytic reovirus as a novel therapy for neuroblastoma

Abstract

Abstract Background: Neuroblastoma (NB), a tumour of neurocrest progenitor cells of the sympathetic nervous system, is the most common extracranial pediatric tumour and accounts for approximately 15 percent of childhood cancer mortality. Even with surgery, radiation therapy, aggressive cytotoxic chemotherapy including autologous stem cell transplantation and more recently immunotherapy, high risk neuroblastoma has only a 30 percent predicted survival rate. Reovirus, a double-stranded RNA virus, has been shown to be effective against a myriad of cancers through its ability to preferentially lyse cancer cells with aberrant Ras pathway signaling. In this study, we investigate the potential of reovirus (serotype 3, strain Dearing) as a novel treatment for neuroblastoma and neuroblastoma tumour initiating cells (nbTIC). Experimental Design/Results: Reovirus induces dramatic cytotoxic effects at a multiplicity of infection (MOI) of 40 within 48h as assessed by WST-1 viability assays for the IMR-32, IMR-5, SK-N-AS, SK-N-SH, LAN-1, LAN-5, and SHEP human neuroblastoma cell lines in vitro. Interestingly the human neuroblastoma tumor-initiating cell lines, NB-12, NB88 and NB122 (kind gift from Dr David Kaplan) were also found to be very sensitive to reovirus-induced cytotoxicity, suggesting a role for reovirus treatment of refractory neuroblastoma. In order to further study reovirus, immunotherapy and neuroblastoma, a syngeneic, immunocompetent murine model (Neuro2a, A/J neuroblastoma model) was utilized to test reovirus-induced cytotoxicity and RV-directed immunotherapy of Neuro2A in vitro and in vivo. Preliminary data suggest that the Neuro2a cells are exquisitely sensitive to reovirus in vitro. Updated results will be presented. Conclusion: These preclinical results suggest that reovirus holds promise as a novel therapeutic for neuroblastoma and that it warrants further investigation in early phase clinical trials. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4336. doi:10.1158/1538-7445.AM2011-4336