SPDR-2 DEVELOPMENT OF A NOVEL THERAPEUTIC STRATEGY AGAINST MEDULLOBLASTOMA TARGETING MYC

Medulloblastoma (MB) is the most common pediatric malignant brain tumor, with aggressive behavior and central nervous system dissemination. Standard of care for medulloblastoma include surgery, chemotherapy with platinum agent, and craniospinal radiation. If patients survived with these intensive treatments, frequently faced treatment-related adverse events. Therefore, development of novel therapeutic strategy is an important issue. Driver mutation underlying MB pathogenesis have been discovered, and molecular profiling led to the identification of subgroups; Wingless (WNT), Sonic Hedgehog(SHH), Group3, and Group4. Group 3, especially the group with MYC/MYCN amplification/overexpression confer a poor prognosis. Myc is attracting as a therapeutic target, however, to date, no drugs have been developed that target myc. We had found that N-myc downstream regulated gene-1 (NDRG1) protein expression is a good prognostic factor in glioblastoma, a representative of adult malignant brain tumors, and that Differentiation inducing factor-1 (DIF-1) increased NDRG1 expression. We reported that DIF-1 crossed the Blood-Brain Barrier and could be an effective treatment for GBM in vivo. In this research process, we found that DIF-1 markedly reduced Myc expression in patient-derived glioblastoma stem cells with MYC/MYCN amplification. Based on this result, we found that DIF-1 decreased Myc expression and inhibited cell survival/proliferation even in medulloblastoma cell lines with MYC/MYCN amplification. In this presentation, we will present the results obtained in the research of a novel Myc-targeted therapy using DIF-1 for MB with MYC/MYCN amplification.