Using a pathway-focused approach, we aimed to provide a subgroup-specific basis for finding novel therapeutic strategies and further refinement of the risk stratification in pediatric ...medulloblastoma.
Based on genome-wide Cox regression and Gene Set Enrichment Analysis, we investigated prognosis-related signaling pathways and core genes in pediatric medulloblastoma subgroups using 530 patient data from Medulloblastoma Advanced Genomic International Consortium (MAGIC) project. We further examined the relationship between expression of the prognostic core genes and frequent chromosome aberrations using broad range copy number change data.
In SHH subgroup, relatively high expression of the core genes involved in p53, PLK1, FOXM1, and Aurora B signaling pathways are associated with poor prognosis, and their average expression synergistically increases with co-occurrence of losses of 17p, 14q, or 10q, or gain of 17q. In Group 3, in addition to high MYC expression, relatively elevated expression of PDGFRA, IGF1R, and FGF2 and their downstream genes in PI3K/AKT and MAPK/ERK pathways are related to poor survival outcome, and their average expression is increased with the presence of isochromosome 17q i(17q) and synergistically down-regulated with simultaneous losses of 16p, 8q, or 4q. In Group 4, up-regulation of the genes encoding various immune receptors and those involved in NOTCH, NF-κB, PI3K/AKT, or RHOA signaling pathways are associated with worse prognosis. Additionally, the expressions of Notch genes correlate with those of the prognostic immune receptors. Besides the Group 4 patients with previously known prognostic aberration, loss of chromosome 11, those with loss of 8q but without i(17q) show excellent survival outcomes and low average expression of the prognostic core genes whereas those harboring 10q loss, 1q gain, or 12q gain accompanied by i(17q) show bad outcomes. Finally, several metabolic pathways known to be reprogrammed in cancer cells are detected as prognostic pathways including glutamate metabolism in SHH subgroup, pentose phosphate pathway and TCA cycle in Group 3, and folate-mediated one carbon-metabolism in Group 4.
The results underscore several subgroup-specific pathways for potential therapeutic interventions: SHH-GLI-FOXM1 pathway in SHH subgroup, receptor tyrosine kinases and their downstream pathways in Group 3, and immune and inflammatory pathways in Group 4.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction
Modern understanding of the relation between the mutated cancer stem cell and its site of origin and of its interaction with the tissue environment is enhancing the importance of ...developmental anatomy in the diagnostic assessment of posterior fossa tumors in children. The aim of this review is to show how MR imaging can improve on the exact identification of the tumors in the brainstem and in the vicinity of the fourth ventricle in children, using both structural imaging data and a precise topographical assessment guided by the developmental anatomy.
Results
The development of the hindbrain results from complex processes of brainstem segmentation, ventro-dorsal patterning, multiple germinative zones, and diverse migration pathways of the neural progenitors. Depending on their origin in the brainstem,
gliomas
may be infiltrative or not, as well as overwhelmingly malignant (pons), or mostly benign (cervicomedullary, medullo-pontine tegmental, gliomas of the cerebellar peduncles). In the vicinity of the fourth ventricles, the prognosis of the
medulloblastomas
(MB) correlates the molecular subtyping as well as the site of origin: WNT MB develop from the Wnt-expressing lower rhombic lip and have a good prognosis; SHH MB develop from the Shh-modulated cerebellar cortex with an intermediate prognosis (dependent on age); recurrences are local mostly. The poor prognosis group 3 MB is radiologically heterogeneous: some tumors present classic features but are juxtaventricular (rather than intraventricular); others have highly malignant features with a small principal tumor and an early dissemination. Group 4 MB has classic features, but characteristically usually does not enhance; dissemination is common. Although there is as yet no clear molecular subgrouping of the
ependymomas
, their sites of origin and their development can be clearly categorized, as most develop in an exophytic way from the ventricular surface of the medulla in clearly specific locations: the obex region with expansion in the cistern magna, or the lateral recess region with expansion in the CPA and prepontine cisterns (cerebellar ependymomas, and still more intra-brainstem ependymomas are rare). Finally, almost all cerebellar gliomas are
pilocytic astrocytomas
.
Conclusions
A developmental and anatomic approach to the posterior fossa tumors in children (together with diffusion imaging data) provides a reliable pre-surgical identification of the tumor and of its aggressiveness.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, PRFLJ, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Many immunotherapies act by enhancing the ability of cytotoxic T cells to kill tumor cells. Killing depends on T cell recognition of antigens presented by class I major histocompatibility complex ...(MHC-I) proteins on tumor cells. In this study, we showed that medulloblastomas lacking the p53 tumor suppressor do not express surface MHC-I and are therefore resistant to immune rejection. Mechanistically, this is because p53 regulates expression of the peptide transporter Tap1 and the aminopeptidase Erap1, which are required for MHC-I trafficking to the cell surface. In vitro, tumor necrosis factor (TNF) or lymphotoxin-β receptor agonist can rescue expression of Erap1, Tap1 and MHC-I on p53-mutant tumor cells. In vivo, low doses of TNF prolong survival and synergize with immune checkpoint inhibitors to promote tumor rejection. These studies identified p53 as a key regulator of immune evasion and suggest that TNF could be used to enhance sensitivity of tumors to immunotherapy.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Sonic Hedgehog (SHH) medulloblastomas are brain tumours that arise in the posterior fossa. Cancer-propagating cells (CPCs) provide a reservoir of cells capable of tumour regeneration and relapse ...post-treatment. Understanding and targeting the mechanisms by which CPCs are maintained and expanded in SHH medulloblastoma could present novel therapeutic opportunities. We identified the aryl hydrocarbon receptor (AHR) pathway as a potent tumour suppressor in a SHH medulloblastoma mouse model. Ahr-deficient tumours and CPCs grown in vitro, showed elevated activation of the TGFβ mediator, SMAD3. Pharmacological inhibition of the TGFβ/SMAD3 signalling axis was sufficient to inhibit the proliferation and promote the differentiation of Ahr-deficient CPCs. Human SHH medulloblastomas with high expression of the AHR repressor (AHRR) exhibited a significantly worse prognosis compared to AHRR
tumours in two independent patient cohorts. Together, these findings suggest that reduced AHR pathway activity promotes SHH medulloblastoma progression, consistent with a tumour suppressive role for AHR. We propose that TGFβ/SMAD3 inhibition may represent an actionable therapeutic approach for a subset of aggressive SHH medulloblastomas characterised by reduced AHR pathway activity.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Introduction
Choroid Plexus Tumours (CPTs) account for 1–4% of all brain tumours in children. Atypical choroid plexus papillomas (aCPPs) are a subset of these tumours, defined over a decade ago, yet ...no consensus exists on the optimal approach to their management.
Methods
We conducted a retrospective analysis of all patients treated for CPTs at the Hospital for Sick Children between January 1, 2000, and December 31, 2018, and focused on patients with aCPP. Data extracted from the patient records for analysis included: demographic and clinical features, radiological imaging, surgical and adjuvant therapies, key pathological features, immunohistochemical staining for TP53 and tumour karyotype. Six of seven aCPP samples were profiled using Illumina HumanMethylationEPIC arrays and the top 10,000 most variably methylated probes were visualized using tSNE. Copy number inferencing was also performed.
Results
Twenty-nine patients were diagnosed with CPT, seven of whom had a diagnosis of aCPP as confirmed by histological review. Methylation profiling demonstrated that aCPPs clustered with both choroid plexus papillomas (CPPs) and choroid plexus carcinomas (CPCs). Complete resection of the tumour was pursued in all cases of aCPP and no patient received adjuvant therapy. All aCPP patients were alive at last follow up.
Conclusions
This limited case series suggests that paediatric aCPP can be successfully managed with surgical resection alone, followed by a ‘watch and wait’ approach thus avoiding adjuvant therapies. A deeper understanding of the biology of aCPP is required to identify objective markers which can help provide robust risk stratification and inform treatment strategies.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Recent incorporation of the four primary medulloblastoma subgroups into the WHO Classification of Central Nervous System Tumors necessitates globally accessible methods to discern subgroups. In this ...issue of Cancer Cell, Wang et al. develop a rapid and reliable machine learning workflow for pre-operative subgroup determination using routine magnetic resonance imaging.
Recent incorporation of the four primary medulloblastoma subgroups into the WHO Classification of Central Nervous System Tumors necessitates globally accessible methods to discern subgroups. In this issue of Cancer Cell, Wang et al. develop a rapid and reliable machine learning workflow for pre-operative subgroup determination using routine magnetic resonance imaging.
To determine whether the pattern of brain injury in term neonatal encephalopathy is associated with distinct prenatal and perinatal factors and to determine whether the pattern of injury is ...associated with 30-month neurodevelopmental outcome.
A total of 173 term newborns with neonatal encephalopathy from 2 centers underwent magnetic resonance imaging (MRI) at a median of 6 days of age (range, 1-24 days). Patterns of injury on MRI were defined on the basis of the predominant site of injury: watershed predominant, basal ganglia/thalamus predominant, and normal.
The watershed pattern of injury was seen in 78 newborns (45%), the basal ganglia/thalamus pattern was seen in 44 newborns (25%), and normal MRI studies were seen in 51 newborns (30%). Antenatal conditions such as maternal substance use, gestational diabetes, premature rupture of membranes, pre-eclampsia, and intra-uterine growth restriction did not differ across patterns. The basal ganglia/thalamus pattern was associated with more severe neonatal signs, including more intensive resuscitation at birth (
P
=
.001), more severe encephalopathy (
P
=
.0001), and more severe seizures (
P
=
.0001). The basal ganglia/thalamus pattern was associated with the most impaired motor and cognitive outcome at 30 months.
The patterns of brain injury in term neonatal encephalopathy are associated with different clinical presentations and neurodevelopmental outcomes. Measured prenatal risk factors did not predict the pattern of brain injury.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Medulloblastoma is the most common malignant brain tumor of childhood. Group 3 medulloblastoma, the most aggressive molecular subtype, frequently disseminates through the leptomeningeal cerebral ...spinal fluid (CSF) spaces in the brain and spinal cord. The mechanism of dissemination through the CSF remains poorly understood, and the molecular pathways involved in medulloblastoma metastasis and self-renewal are largely unknown. Here we show that NOTCH1 signaling pathway regulates both the initiation of metastasis and the self-renewal of medulloblastoma. We identify a mechanism in which NOTCH1 activates BMI1 through the activation of TWIST1. NOTCH1 expression and activity are directly related to medulloblastoma metastasis and decreased survival rate of tumor-bearing mice. Finally, medulloblastoma-bearing mice intrathecally treated with anti-NRR1, a NOTCH1 blocking antibody, present lower frequency of spinal metastasis and higher survival rate. These findings identify NOTCH1 as a pivotal driver of Group 3 medulloblastoma metastasis and self-renewal, supporting the development of therapies targeting this pathway.
Medulloblastoma (MB), which originates from embryonic neural stem cells (NSCs) or neural precursors in the developing cerebellum, is the most common malignant brain tumor of childhood. Recurrent and ...metastatic disease is the principal cause of death and may be related to resistance within cancer stem cells (CSCs). Chromatin state is involved in maintaining signaling pathways related to stemness, and inhibition of histone deacetylase enzymes (HDAC) has emerged as an experimental therapeutic strategy to target this cell population. Here, we observed antitumor actions and changes in stemness induced by HDAC inhibition in MB. Analyses of tumor samples from patients with MB showed that the stemness markers
BMI1
and
CD133
are expressed in all molecular subgroups of MB. The HDAC inhibitor (HDACi) NaB reduced cell viability and expression of
BMI1
and
CD133
and increased acetylation in human MB cells. Enrichment analysis of genes associated with
CD133
or
BMI1
expression showed mitogen-activated protein kinase (MAPK)/ERK signaling as the most enriched processes in MB tumors. MAPK/ERK inhibition reduced expression of the stemness markers, hindered MB neurosphere formation, and its antiproliferative effect was enhanced by combination with NaB. These results suggest that combining HDAC and MAPK/ERK inhibitors may be a novel and more effective approach in reducing MB proliferation when compared to single-drug treatments, through modulation of the stemness phenotype of MB cells.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Infant medulloblastoma represents an enormous challenge in neuro-oncology, due to their simultaneous high-risk of recurrence and high risk of severe neurodevelopmental sequelae with craniospinal ...irradiation. Currently infant medulloblastoma are treated with intensified protocols, either comprising intraventricular methotrexate or autologous transplant, both of which carry significant morbidity and are not feasible in the majority of the world. We sought to evaluate the molecular predictors of outcome in a cohort of infants homogeneously treated with induction chemotherapy, focal radiation and maintenance chemotherapy.
In a retrospective analysis, 29 young children treated with a craniospinal irradiation sparing strategy from Hospital Garrahan in Buenos Aires were profiled using Illumina HumanMethylationEPIC arrays, and correlated with survival.
Twenty-nine children (range, 0.3-4.6 y) were identified, comprising 17 sonic hedgehog (SHH), 10 Group 3/4, and 2 non-medulloblastomas. Progression-free survival (PFS) across the entire cohort was 0.704 (95% CI: 0.551-0.899). Analysis by t-distributed stochastic neighbor embedding revealed 3 predominant groups, SHHβ, SHHγ, and Group 3. Survival by subtype was highly prognostic with SHHγ having an excellent 5-year PFS of 100% (95% CI: 0.633-1) and SHHβ having a PFS of 0.56 (95% CI: 0.42-1). Group 3 had a PFS of 0.50 (95% CI: 0.25-1). Assessment of neurocognitive outcome was performed in 11 patients; the majority of survivors fell within the low average to mild intellectual disability, with a median IQ of 73.5.
We report a globally feasible and effective strategy avoiding craniospinal radiation in the treatment of infant medulloblastoma, including a robust molecular correlation along with neurocognitive outcomes.
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