MODL-09. Exploring the Role of Magmas (Mitochondria-Associated Protein Involved in Granulocyte-Macrophage Colony-Stimulating Factor Signal Transduction) Inhibition As a Potential Therapeutic Intervention in Medulloblastoma

Abstract BACKGROUND: Brain tumors are the second most common type of pediatric cancer and the leading cause of all cancer-related deaths in children. Medulloblastoma (MB) is the most common type of malignant pediatric brain tumor and has a five-year overall survival ranging from 40-75%, depending on the patient’s age and other prognostic features. There are various anti-cancer therapies against medulloblastoma, but the treatment of recurrent and refractory disease remains a challenge. As a result, the need for new and novel therapies remain a top priority. One area of interest in CNS tumors are targets within mitochondria. Magmas overexpression has been reported in multiple types of metabolically active tissue and cancer cells, including prostate cancer, pituitary adenoma, and glioma. Some new data suggest that specific subgroups of medulloblastoma may also overexpress Magmas. This ongoing study aims to examine whether Magmas inhibition by compound “BT9” could be beneficial in the treatment of medulloblastoma. METHODS: We continue to study the ability of a Magmas inhibitor (BT#9) as a therapeutic agent in stable medulloblastoma cell lines and patient-derived primary cultures by performing MTT assays, tunnel assays, flow cytometry, migration assays, and invasion assays. RESULTS: Similar to the adult GBM studies, Magmas inhibition by BT#9 had significant cytotoxic effects, causing both decreased cell proliferation, increased apoptosis, and blocked cell migration in medulloblastoma cell lines DAOY, D283, and D425. IC50s determined for each during different time points demonstrated an average range 2-5μM compared to the average range seen in adult glioblastoma cell cultures which could range up to 10 μM. These findings suggest that the inhibition of Magmas could potentially optimize clinical outcomes in recurrent/refractory medulloblastoma and warrants further investigation. Our future studies will include the determination of IC50s for primary cell cultures and in vitro testing with patient-derived xenograft models.