Abstract

Medulloblastoma is the most frequent childhood brain tumor. Medulloblastoma affects the cerebellum, the brain region that regulates motor coordination and is also involved in certain cognitive functions. Medulloblastoma is a heterogeneous tumor, and recent advances in high-throughput genomic techniques have allowed medulloblastoma to be classified into four molecularly distinct subgroups: the SHH-group, WNT-group, group 3, and group 4 medulloblastoma. Different medulloblastoma subgroups are characterized by distinct molecular alterations, are believed to originate from distinct types of neural progenitors, and have different clinical outcomes. WNT and SHH groups are relatively well understood and are named so because the WNT and SHH signaling pathways play a key role in their development. In contrast, molecular alterations and developmental mechanisms of group 3 and 4 medulloblastoma remain largely unknown. Although the survival of medulloblastoma patients has improved over the last 30 years, reaching the 5-year survival rate of 60-80%, treatment of this type of tumor is still associated with severe side effects. A deeper understanding of medulloblastoma biology and developing new pathway-specific therapies is urgently required for better treatment of medulloblastoma patients.

Keywords: Medulloblastoma; Cerebellum; Development; Medulloblastoma subgroups; Medulloblastoma pathways