RESUMO
Histone H3.3 mutations are a hallmark of pediatric gliomas, but their core oncogenic mechanisms are not well-defined. To identify major effectors, we used CRISPR-Cas9 to introduce H3.3K27M and G34R mutations into previously H3.3-wildtype brain cells, while in parallel reverting the mutations in glioma cells back to wildtype. ChIP-seq analysis broadly linked K27M to altered H3K27me3 activity including within super-enhancers, which exhibited perturbed transcriptional function. This was largely independent of H3.3 DNA binding. The K27M and G34R mutations induced several of the same pathways suggesting key shared oncogenic mechanisms including activation of neurogenesis and NOTCH pathway genes. H3.3 mutant gliomas are also particularly sensitive to NOTCH pathway gene knockdown and drug inhibition, reducing their viability in culture. Reciprocal editing of cells generally produced reciprocal effects on tumorgenicity in xenograft assays. Overall, our findings define common and distinct K27M and G34R oncogenic mechanisms, including potentially targetable pathways.
Assuntos
Biomarcadores Tumorais/metabolismo , Edição de Genes , Regulação Neoplásica da Expressão Gênica , Glioma/patologia , Histonas/genética , Mutação , Receptores Notch/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Proliferação de Células , Criança , Feminino , Glioma/genética , Glioma/metabolismo , Glicina/química , Glicina/genética , Histonas/química , Humanos , Lisina/química , Lisina/genética , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptores Notch/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: The objective of this article is to evaluate the utility of fetal lung mass imaging for predicting neonatal respiratory distress. METHOD: Pregnancies with fetal lung masses between 2009 and 2014 at a single center were analyzed. Neonatal respiratory distress was defined as intubation and mechanical ventilation at birth, surgery before discharge, or extracorporeal membrane oxygenation (ECMO). The predictive utility of the initial as well as maximal lung mass volume and congenital pulmonary airway malformation volume ratio by ultrasound (US) and magnetic resonance imaging (MRI) was analyzed. RESULTS: Forty-seven fetal lung mass cases were included; of those, eight (17%) had respiratory distress. The initial US was performed at similar gestational ages in pregnancies with and without respiratory distress (26.4 ± 5.6 vs 22.3 ± 3 weeks, p = 0.09); however, those with respiratory distress had higher congenital volume ratio at that time (1.0 vs 0.3, p = 0.01). The strongest predictors of respiratory distress were maximal volume >24.0 cm3 by MRI (100% sensitivity, 91% specificity, 60% positive predictive value, and 100% negative predictive value) and maximal volume >34.0 cm3 by US (100% sensitivity, 85% specificity, 54% positive predictive value, and 100% negative predictive value). CONCLUSION: Ultrasound and MRI parameters can predict neonatal respiratory distress, even when obtained before 24 weeks. Third trimester parameters demonstrated the best positive predictive value. © 2017 John Wiley & Sons, Ltd.