Long-term complications such as radiation-induced second malignancies occur in a subset of patients following radiation-therapy, particularly relevant in pediatric patients due to the long follow-up period in case of survival. Radiation-induced gliomas (RIGs) have been reported in patients after treatment with cranial irradiation for various primary malignancies such as acute lymphoblastic leukemia (ALL) and medulloblastoma (MB). We perform comprehensive (epi-) genetic and expression profiling of RIGs arising after cranial irradiation for MB (n = 23) and ALL (n = 9). Our study reveals a unifying molecular signature for the majority of RIGs, with recurrent PDGFRA amplification and loss of CDKN2A/B and an absence of somatic hotspot mutations in genes encoding histone 3 variants or IDH1/2, uncovering diagnostic markers and potentially actionable targets.

• MeSH
• amplifikace genu * MeSH
• chromozomální delece MeSH
• dítě MeSH
• dospělí MeSH
• genetická transkripce MeSH
• genom lidský MeSH
• genová přestavba genetika   MeSH
• gliom genetika   patologie   MeSH
• inhibitor p15 cyklin-dependentní kinasy metabolismus   MeSH
• inhibitor p16 cyklin-dependentní kinasy metabolismus   MeSH
• Kaplanův-Meierův odhad MeSH
• lidé středního věku MeSH
• lidé MeSH
• lokální recidiva nádoru patologie   MeSH
• metylace DNA genetika   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• regulace genové exprese u nádorů MeSH
• růstový faktor odvozený z trombocytů - receptor alfa genetika   metabolismus   MeSH
• shluková analýza MeSH
• záření MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• CDKN2A protein, human MeSH Prohlížeč
• CDKN2B protein, human MeSH Prohlížeč
• inhibitor p15 cyklin-dependentní kinasy MeSH
• inhibitor p16 cyklin-dependentní kinasy MeSH
• růstový faktor odvozený z trombocytů - receptor alfa MeSH

BACKGROUND: Malignant astrocytic gliomas in children show a remarkable biological and clinical diversity. Small in-frame insertions or missense mutations in the epidermal growth factor receptor gene (EGFR) have recently been identified in a distinct subset of pediatric-type bithalamic gliomas with a unique DNA methylation pattern. METHODS: Here, we investigated an epigenetically homogeneous cohort of malignant gliomas (n = 58) distinct from other subtypes and enriched for pediatric cases and thalamic location, in comparison with this recently identified subtype of pediatric bithalamic gliomas. RESULTS: EGFR gene amplification was detected in 16/58 (27%) tumors, and missense mutations or small in-frame insertions in EGFR were found in 20/30 tumors with available sequencing data (67%; 5 of them co-occurring with EGFR amplification). Additionally, 8 of the 30 tumors (27%) harbored an H3.1 or H3.3 K27M mutation (6 of them with a concomitant EGFR alteration). All tumors tested showed loss of H3K27me3 staining, with evidence of overexpression of the EZH inhibitory protein (EZHIP) in the H3 wildtype cases. Although some tumors indeed showed a bithalamic growth pattern, a significant proportion of tumors occurred in the unilateral thalamus or in other (predominantly midline) locations. CONCLUSIONS: Our findings present a distinct molecular class of pediatric-type malignant gliomas largely overlapping with the recently reported bithalamic gliomas characterized by EGFR alteration, but additionally showing a broader spectrum of EGFR alterations and tumor localization. Global H3K27me3 loss in this group appears to be mediated by either H3 K27 mutation or EZHIP overexpression. EGFR inhibition may represent a potential therapeutic strategy in these highly aggressive gliomas.

• Klíčová slova
• EGFR mutation, (bi)thalamic, H3 K27M mutation, K27me3, pediatric-type high-grade glioma,
• MeSH
• dítě MeSH
• erbB receptory genetika   MeSH
• geny erbB-1 MeSH
• gliom * genetika   MeSH
• histony genetika   MeSH
• lidé MeSH
• metylace DNA MeSH
• mutace MeSH
• nádory mozku * genetika   MeSH
• thalamus MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• EGFR protein, human MeSH Prohlížeč
• erbB receptory MeSH
• histony MeSH

Diffuse gliomas with K27M histone mutations (H3K27M glioma) are generally characterized by a fatal prognosis, particularly affecting the pediatric population. Based on the molecular heterogeneity observed in this tumor type, personalized treatment is considered to substantially improve therapeutic options. Therefore, clinical evidence for therapy, guided by comprehensive molecular profiling, is urgently required. In this study, we analyzed feasibility and clinical outcomes in a cohort of 12 H3K27M glioma cases treated at two centers. Patients were subjected to personalized treatment either at primary diagnosis or disease progression and received backbone therapy including focal irradiation. Molecular analyses included whole-exome sequencing of tumor and germline DNA, RNA-sequencing, and transcriptomic profiling. Patients were monitored with regular clinical as well as radiological follow-up. In one case, liquid biopsy of cerebrospinal fluid (CSF) was used. Analyses could be completed in 83% (10/12) and subsequent personalized treatment for one or more additional pharmacological therapies could be recommended in 90% (9/10). Personalized treatment included inhibition of the PI3K/AKT/mTOR pathway (3/9), MAPK signaling (2/9), immunotherapy (2/9), receptor tyrosine kinase inhibition (2/9), and retinoic receptor agonist (1/9). The overall response rate within the cohort was 78% (7/9) including one complete remission, three partial responses, and three stable diseases. Sustained responses lasting for 28 to 150 weeks were observed for cases with PIK3CA mutations treated with either miltefosine or everolimus and additional treatment with trametinib/dabrafenib in a case with BRAFV600E mutation. Immune checkpoint inhibitor treatment of a case with increased tumor mutational burden (TMB) resulted in complete remission lasting 40 weeks. Median time to progression was 29 weeks. Median overall survival (OS) in the personalized treatment cohort was 16.5 months. Last, we compared OS to a control cohort (n = 9) showing a median OS of 17.5 months. No significant difference between the cohorts could be detected, but long-term survivors (>2 years) were only present in the personalized treatment cohort. Taken together, we present the first evidence of clinical efficacy and an improved patient outcome through a personalized approach at least in selected cases of H3K27M glioma.

• Klíčová slova
• H3K27M, comprehensive molecular profiling, diffuse midline glioma, pediatric oncology, precision medicine,
• Publikační typ
• časopisecké články MeSH

Ependymal tumors across age groups are currently classified and graded solely by histopathology. It is, however, commonly accepted that this classification scheme has limited clinical utility based on its lack of reproducibility in predicting patients' outcome. We aimed at establishing a uniform molecular classification using DNA methylation profiling. Nine molecular subgroups were identified in a large cohort of 500 tumors, 3 in each anatomical compartment of the CNS, spine, posterior fossa, supratentorial. Two supratentorial subgroups are characterized by prototypic fusion genes involving RELA and YAP1, respectively. Regarding clinical associations, the molecular classification proposed herein outperforms the current histopathological classification and thus might serve as a basis for the next World Health Organization classification of CNS tumors.

• MeSH
• adaptorové proteiny signální transdukční genetika   MeSH
• dítě MeSH
• dospělí MeSH
• ependymom klasifikace   genetika   patologie   MeSH
• fosfoproteiny genetika   MeSH
• fúze genů MeSH
• genetická transkripce MeSH
• genová dávka MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádory centrálního nervového systému klasifikace   genetika   patologie   MeSH
• předškolní dítě MeSH
• senioři MeSH
• signální proteiny YAP MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory MeSH
• věkové faktory * 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
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• fosfoproteiny MeSH
• signální proteiny YAP MeSH
• transkripční faktory MeSH
• YAP1 protein, human MeSH Prohlížeč