TRLS-16. RAPID GENERATION OF EPENDYMOMA MOUSE MODELS FOR PRE-CLINICAL STUDIES

Pediatric Ependymomas are the leading cause of cancer death among children & adolescents with the 5-year progression free survival (PFS)rate being < 30%. Despite this poor prognosis there has been less success in development of targeted therapies. A major drawback in developing new therapeutics is lack of proper models of disease. Objective of out work has been to develop orthogonal models of various distinct groups of ependymoma to enable understanding of tumor microenvironment thus leading to strategies targeting potential therapeutic sites. In this regard we have developed two models of ZFTA-RELA Ependymoma: 1) In Utero Electroporation Model: DNA plasmids are transfected into developing forebrain, 2) Allograft Model: Primary tumor derived or in vitro transducer cells are allografted into various regions of brain. Further we have shown that these models molecularly resemble patient-derived tumors using RNA sequencing. Using these ZFTA-RELA mouse models we have shown that NSG mice (n=8/treatment group) treated with Selinexor (an XPO1 inhibitor) in combination with chemotherapy have lower tumor volumes by 40% as compared to vehicle or chemotherapy alone treated mice (P<0.05). Furthermore the combination therapy treated mice have improved survival by 28 days as compared to vehicle mice. In conclusion, we have shown that our novel models of ependymomas not only closely resemble disease in patients, but can also be used to develop effective targeted therapies.