Medulloblastoma (MB) comprises a group of heterogeneous paediatric embryonal neoplasms of the hindbrain with strong links to early development of the hindbrain1-4. Mutations that activate Sonic hedgehog signalling lead to Sonic hedgehog MB in the upper rhombic lip (RL) granule cell lineage5-8. By contrast, mutations that activate WNT signalling lead to WNT MB in the lower RL9,10. However, little is known about the more commonly occurring group 4 (G4) MB, which is thought to arise in the unipolar brush cell lineage3,4. Here we demonstrate that somatic mutations that cause G4 MB converge on the core binding factor alpha (CBFA) complex and mutually exclusive alterations that affect CBFA2T2, CBFA2T3, PRDM6, UTX and OTX2. CBFA2T2 is expressed early in the progenitor cells of the cerebellar RL subventricular zone in Homo sapiens, and G4 MB transcriptionally resembles these progenitors but are stalled in developmental time. Knockdown of OTX2 in model systems relieves this differentiation blockade, which allows MB cells to spontaneously proceed along normal developmental differentiation trajectories. The specific nature of the split human RL, which is destined to generate most of the neurons in the human brain, and its high level of susceptible EOMES+KI67+ unipolar brush cell progenitor cells probably predisposes our species to the development of G4 MB.
- MeSH
- antigen Ki-67 metabolismus MeSH
- buněčná diferenciace * genetika MeSH
- buněčný rodokmen MeSH
- histondemethylasy MeSH
- lidé MeSH
- meduloblastom * klasifikace genetika patologie MeSH
- metencephalon * embryologie patologie MeSH
- mozeček embryologie patologie MeSH
- mutace MeSH
- nádory mozečku * klasifikace genetika patologie MeSH
- proteiny hedgehog metabolismus MeSH
- proteiny T-boxu metabolismus MeSH
- represorové proteiny MeSH
- svalové proteiny MeSH
- transkripční faktory Otx nedostatek genetika MeSH
- transkripční faktory PEBP2A genetika MeSH
- transkripční faktory MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- antigen Ki-67 MeSH
- CBFA2T2 myeloid-transforming gene-related protein MeSH Prohlížeč
- CBFA2T3 protein, human MeSH Prohlížeč
- core binding factor alpha MeSH Prohlížeč
- EOMES protein, human MeSH Prohlížeč
- histondemethylasy MeSH
- KDM6A protein, human MeSH Prohlížeč
- OTX2 protein, human MeSH Prohlížeč
- PRDM6 protein, human MeSH Prohlížeč
- proteiny hedgehog MeSH
- proteiny T-boxu MeSH
- represorové proteiny MeSH
- svalové proteiny MeSH
- transkripční faktory Otx MeSH
- transkripční faktory PEBP2A MeSH
- transkripční faktory MeSH
Sonic hedgehog medulloblastoma encompasses a clinically and molecularly diverse group of cancers of the developing central nervous system. Here, we use unbiased sequencing of the transcriptome across a large cohort of 250 tumors to reveal differences among molecular subtypes of the disease, and demonstrate the previously unappreciated importance of non-coding RNA transcripts. We identify alterations within the cAMP dependent pathway (GNAS, PRKAR1A) which converge on GLI2 activity and show that 18% of tumors have a genetic event that directly targets the abundance and/or stability of MYCN. Furthermore, we discover an extensive network of fusions in focally amplified regions encompassing GLI2, and several loss-of-function fusions in tumor suppressor genes PTCH1, SUFU and NCOR1. Molecular convergence on a subset of genes by nucleotide variants, copy number aberrations, and gene fusions highlight the key roles of specific pathways in the pathogenesis of Sonic hedgehog medulloblastoma and open up opportunities for therapeutic intervention.
- MeSH
- dítě MeSH
- dospělí MeSH
- genetická variace MeSH
- genové regulační sítě MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- meduloblastom genetika MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nádory mozečku genetika MeSH
- předškolní dítě MeSH
- proteiny hedgehog genetika MeSH
- regulace genové exprese u nádorů * MeSH
- signální transdukce genetika MeSH
- transkriptom * MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- proteiny hedgehog MeSH
- SHH protein, human MeSH Prohlížeč
While the preponderance of morbidity and mortality in medulloblastoma patients are due to metastatic disease, most research focuses on the primary tumor due to a dearth of metastatic tissue samples and model systems. Medulloblastoma metastases are found almost exclusively on the leptomeningeal surface of the brain and spinal cord; dissemination is therefore thought to occur through shedding of primary tumor cells into the cerebrospinal fluid followed by distal re-implantation on the leptomeninges. We present evidence for medulloblastoma circulating tumor cells (CTCs) in therapy-naive patients and demonstrate in vivo, through flank xenografting and parabiosis, that medulloblastoma CTCs can spread through the blood to the leptomeningeal space to form leptomeningeal metastases. Medulloblastoma leptomeningeal metastases express high levels of the chemokine CCL2, and expression of CCL2 in medulloblastoma in vivo is sufficient to drive leptomeningeal dissemination. Hematogenous dissemination of medulloblastoma offers a new opportunity to diagnose and treat lethal disseminated medulloblastoma.
- Klíčová slova
- brain tumors, circulating tumor cells, medulloblastoma, metastases, pediatric cancer,
- MeSH
- alografty MeSH
- chemokin CCL2 metabolismus MeSH
- lidé MeSH
- lidské chromozomy, pár 10 genetika MeSH
- meduloblastom krevní zásobení genetika patologie MeSH
- meningeální nádory krevní zásobení sekundární MeSH
- myši SCID MeSH
- nádorové buněčné linie MeSH
- nádorové cirkulující buňky MeSH
- parabióza MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- CCL2 protein, human MeSH Prohlížeč
- chemokin CCL2 MeSH
The development of targeted anti-cancer therapies through the study of cancer genomes is intended to increase survival rates and decrease treatment-related toxicity. We treated a transposon-driven, functional genomic mouse model of medulloblastoma with 'humanized' in vivo therapy (microneurosurgical tumour resection followed by multi-fractionated, image-guided radiotherapy). Genetic events in recurrent murine medulloblastoma exhibit a very poor overlap with those in matched murine diagnostic samples (<5%). Whole-genome sequencing of 33 pairs of human diagnostic and post-therapy medulloblastomas demonstrated substantial genetic divergence of the dominant clone after therapy (<12% diagnostic events were retained at recurrence). In both mice and humans, the dominant clone at recurrence arose through clonal selection of a pre-existing minor clone present at diagnosis. Targeted therapy is unlikely to be effective in the absence of the target, therefore our results offer a simple, proximal, and remediable explanation for the failure of prior clinical trials of targeted therapy.
- MeSH
- buněčné klony účinky léků metabolismus patologie MeSH
- cílená molekulární terapie metody MeSH
- Drosophila melanogaster cytologie genetika MeSH
- genom lidský genetika MeSH
- kraniospinální iradiace MeSH
- lidé MeSH
- lokální recidiva nádoru genetika patologie terapie MeSH
- meduloblastom genetika patologie radioterapie chirurgie terapie MeSH
- modely nemocí na zvířatech MeSH
- mutační analýza DNA MeSH
- myši MeSH
- nádory mozečku genetika patologie radioterapie chirurgie terapie MeSH
- radioterapie řízená obrazem MeSH
- selekce (genetika) účinky léků MeSH
- signální transdukce MeSH
- xenogenní modely - testy antitumorózní aktivity MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
