Neuroblastoma and Ewing's Sarcoma Associated with ROR1 Expression Can Be Effectively Targeted with NK Cells Modified to Express an Anti ROR1 Chimeric Antigen Receptor

Metastatic solid tumors, especially neuroblastoma (NB) and Ewing's sarcoma (ES) have dismal prognosis (Perkins et al, PLoS One, 2014). Targeted cellular therapy with T or NK cells modified with chimeric antigen receptors (CAR) is a novel approach to chemo-resistant childhood solid tumors (Grupp SA, Clin Cancer Res, 2012; Mackall C, Front Oncol, 2012). NK cells can be significantly expanded by co-culture with genetically engineered K562 cells overexpressing mb-IL21 (Lee D, PLOS, 2012). Riddell and colleagues have identified ROR1 as a novel target on B cell tumors in which CARs can be developed and utilized for targeted cellular therapy (Riddell S, Blood, 2010).