IDH1 mutations are common in malignant gliomas in older children, suggesting that a subset of these lesions may be biologically similar to malignant gliomas arising in younger adults and may be associated with a more favorable prognosis.
The interesting identification of an IDH1 mutation in a radiation-induced secondary malignant glioma raises the likelihood that these types of tumor may develop IDH1/2 mutations.
We investigated the expression of Sox11 in 132 diffuse astrocytomas in relation to the regulator cell marker nestin, c-Met and IDH1-R132H, which have shown to be differentially expressed among the molecular subgroups of malignant gliomas, as well as to an inducer of astrocytic differentiation, that is, signal transducer and activator of transcription (p-STAT-3), clinicopathological features and survival.
To determine the prognostic value of isocitrate dehydrogenase 1 (IDH1) mutation, O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, and 1p/19q co-deletion in Japanese patients with malignant gliomas.
Of 158 tumors with sufficient tissue, 110 (70 %) showed nuclear cMYC immunopositivity--most frequent (95 %, χ(2) p = 0.0248) and intense (mean 1.33, ANOVA p = 0.0179) in anaplastic astrocytomas versus glioblastomas (63 %) or low grade gliomas (74 %). cMYC expression associated with younger age as well as p53 immunopositivity (OR = 3.6, p = 0.0332) and mutant IDH1 (R132H) (OR = 7.4, p = 0.06) among malignant gliomas in our cohort.
Recently, mutations of the ATRX gene have been found in various subtypes and grades of gliomas and were shown to refine the prognosis of malignant gliomas in combination with IDH and 1p/19q status.
We identify miR148a as a novel, G-CIMP-associated miRNA whose methylation is tightly correlated with IDH1 mutation and associated with improved survival in patients with malignant glioma.
Classification based on IDH1/2 mutation status and Ki-67 expression level could be more convenient for clinical application and guide personalized treatment in malignant gliomas.
Recent investigations of malignant gliomas have identified additional genetic and chromosomal abnormalities which cluster with IDH1 mutations into two distinct subgroups.
The NRF2 activity is increased in a significant proportion of malignant gliomas in general but decreased in the majority of IDH1/2-mutant anaplastic gliomas.
Patient 2, with malignant glioma with primitive neuroectodermal tumor (MGPNET), had a secondary GBM with a noncanonical isocitrate dehydrogenase 1 (IDH1) mutation and 11-year-survival; autopsy showed encasement of the entire bilateral ventricular system by SVS.