Search

Medulloblastoma is the most-common form of paediatric brain cancer. Advances in our understanding of the molecular basis of medulloblastoma indicate that it is not a single disease, but a collection of four distinct molecular tumour subtypes. This knowledge has important implications for medulloblastoma research and treatment. In this Review, the characteristic demographic, clinical and genetic features of the four molecular subtypes of medulloblastoma are described, and the implications of molecular distinctions on therapy are discussed.

Characterization of medulloblastoma tissues using single-cell transcriptomics shows that the different molecular subtypes consist of distinct developmental phenotypes.

Medulloblastomas are the most common malignant childhood brain tumours and are thought to arise from the cerebellum. There is substantial heterogeneity among medulloblastomas and some are thought to arise following aberrant Sonic Hedgehog pathway activation. It is now shown that a distinct subtype of medulloblastoma arises from the dorsal brainstem and is associated with altered WNT signalling. Distinct molecular and clinical profiles of the subtypes have implications for future treatment.

Ependymoma is a type of neural tumour that arises throughout the central nervous system. Using comparative transcriptomics in mouse and human tumours, these authors home in on mutations that are specific to individual tumour subgroups. In doing so, they generate the first mouse model of ependymoma and demonstrate the power of interspecific genomic comparisons to interrogate cancer subgroups.

The survival rate of patients with pediatric cancer has increased considerably due to improved understanding of the biology of cancer subtypes, and the development of targeted therapies. This Review analyzes the recent findings that link pharmacogenomic variations with drug exposure, adverse effects, and efficacy of the emerging new treatments in pediatric oncology.

Patient-derived xenografts provide a resource for basic and translational cancer research. Here, the authors generate multiple pediatric high-grade glioma xenografts, use omics technologies to show that they are representative of primary tumours and use them to assess therapeutic response.

Germline mutations in the Elongator complex gene ELP1 predispose individuals to the development of childhood medulloblastoma.

At least two-thirds of supratentorial ependymomas contain oncogenic fusions between RELA, the principal effector of nuclear factor-κB (NF-κB) signalling, and uncharacterized gene C11orf95; C11orf95–RELA fusion proteins translocate spontaneously to the nucleus to activate NF-κB target genes, and rapidly transform neural stem cells to form tumours in mice

Whole-genome sequencing of medulloblastoma samples reveals several recurrent mutations in genes not previously implicated in the disease, many of which affect components of the epigenetic machinery in different disease subgroups.

Multi-omic mapping shows that group 3 and group 4 medulloblastomas have a common, human-specific developmental origin in the cerebellar rhombic lip, providing a basis for their ambiguous molecular features and overlapping anatomical location, and for the difficulty of modelling these tumours in mice.

An online approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups has been developed to help to improve current diagnostic standards.

Genomic analysis of 491 medulloblastoma samples, including methylation profiling of 1,256 cases, effectively assigns candidate drivers to most tumours across all molecular subgroups.

Focusing on two ill-characterized subtypes of medulloblastoma (group 3 and group 4), this study identifies prevalent genomic structural variants that are restricted to these two subtypes and independently bring together coding regions of GFI1 family proto-oncogenes with active enhancer elements, leading to their mutually exclusive oncogenic activation.

Suzanne Baker and colleagues sequenced the whole genomes of seven pediatric brainstem glioblastomas and matched normal tissue. They found that 78% of diffuse intrinsic pontine gliomas and 22% of non-brainstem pediatric glioblastomas contained a mutation in H3F3A, encoding histone H3.3, or in the related HIST1H3B, encoding histone H3.1, causing a p.Lys27Met amino acid substitution in each protein.

Jun Yang, Clinton Stewart and colleagues report the results of a genome-wide association study of cisplatin-induced ototoxicity among children undergoing treatment for brain tumors. They identify common variants in ACYP2 strongly associated with cisplatin-induced hearing loss and ototoxicity severity.

David Ellison and colleagues report whole-genome sequencing of pediatric low-grade gliomas, the most common pediatric brain tumor. They identify a range of genomic alterations, including recurrent and mutually exclusive duplications of the FGFR1 region encoding the tyrosine kinase domain and rearrangements of MYB.

Brain cancer encompasses a diverse range of complex malignancies, many of which are associated with a poor prognosis and require more effective treatments. In this Position Paper, an international panel of clinicians and laboratory-based scientists convened by Cancer Research UK identify and discuss seven challenges that must be overcome if we are to cure all patients with a brain tumour.

This Primer by Pfister and colleagues reviews the molecular genetics, diagnosis and management of medulloblastoma and touches upon the quality of life of patients and future outlooks.

Suzanne Baker, Jinghui Zhang and colleagues report the identification of recurrent somatic mutations in the bone morphogenetic protein (BMP) receptor ACVR1 in 32% of diffuse intrinsic pontine gliomas.

Cell-free DNA (cfDNA) profiling as liquid biopsy is of clinical utility in carcinomas of adult-onset. However, its application in childhood cancers, including brain tumors, has not been as extensively studied. In this article, we review the current status of applying cfDNA analysis for pediatric central nervous system neoplasms. Technical challenges, evidence for utility based on current literature, and potential future developments are discussed.