We identified novel ALK fusions in a neuroblastoma (BEND5-ALK) and an astrocytoma (PPP1CB-ALK), novel BRAF fusions in an astrocytoma (BCAS1-BRAF) and a ganglioglioma (TMEM106B-BRAF), and a novel PAX3-GLI2 fusion in a rhabdomyosarcoma.
Moreover, experiments using primary cultured astrocytoma cells indicate that astrocytoma patients with a low expression of SIX3 and mutant p53 are more sensitive to treatment with aurora kinase inhibitors.
Thus, loss of ATRX immunoexpression, shown for the first time in these tumors, along with immunopositivity for p53 and IDH1, indicates that these tumors are molecular astrocytomas, and their clinical behaviour is likely to recapitulate that of ATRX-mutant and IDH-mutant diffuse astrocytomas of the same grade.
Similar to previously reported findings on E-GBM associated with low-grade glioma, this case suggested that low-grade astrocytic glioma with BRAFV600E mutation progressed to E-GBM.
Routine IHC can be used for evaluation of ATRX loss, p53 protein accumulation and IDH1R132H mutation, which may allow a means of classification of astrocytoma outcome.
In addition, p-CREB expression correlated with higher Ki-67 labeling index (P = .049) and p53 overexpression (P < .0001) as well as with the histologic grade of astrocytomas (P = .044).
An institutional cohort of 105 brain tumors (51 dysembryoplastic neuroepithelial tumors (DNTs), 14 subependymal giant cell astrocytomas (SEGAs), 12 glioblastoma with neuronal marker expression (GBM-N), and 28 pleomorphic xanthoastrocytomas (PXAs)) from 100 patients were investigated for the presence of BRAF(V600E) by direct sequencing.
We analyzed markers, including IDH mutation(IDHmut), 1p19q codeletion(1p19qcodel), ATRX expression loss(ATRX loss) and p53 overexpression, and outcomes in 159 patients with WHO grade II oligodendroglioma, oligoastrocytoma, and astrocytoma (2003-2012).
The results demonstrate that increased expression and activity of LOX, BMP1 and HIF1A were positively correlated with the malignant grade of astrocytomas.
Among many molecular abnormalities, BRAF mutation and mTOR activation in pilocytic astrocytomas and subependymal giant cell astrocytomas are actionable targets sensitive to vemurafenib and everolimus, respectively.
These findings suggest that CDKN2A testing may provide further clinical aid in lower-grade glioma substratification beyond IDH mutation and 1p19q codeletion status, particularly in IDH/TP53 mutated astrocytomas.
Several investigations have searched a correlation between the BRAF gene fusions alterations and mutations at IDH1 and IDH2 genes in low grade pediatric astrocytomas.
The algorithm measured significant increase in F-actin at cell edges with concomitant decrease in internal punctate actin in astrocytoma cells lacking functional neurofibromin and p53 when treated with three structurally-distinct anticancer small molecules: OSW1, Schweinfurthin A (SA) and a synthetic marine compound 23'-dehydroxycephalostatin 1.
All xenograft-producing gliomas harbored "lineage-defining" mutations in CIC (oligodendroglioma) or TP53 (astrocytoma), and 6 of 8 additionally had activating mutations in PIK3CA or amplification of PDGFRA, MET, or N-MYC.
We found that oligoastrocytomas harbored mutations in TP53 (80%, 12/15) and ATRX (60%, 9/15) at frequencies similar to pure astrocytic tumors, suggesting that oligoastrocytomas and astrocytomas may represent a single genetic or biological entity. p53 protein expression correlated with mutation status and showed significant increases in astrocytomas and oligoastrocytomas compared to oligodendrogliomas, a finding that also may facilitate accurate classification.
To study the putative expression patterns and clinical significance of Hsp27, we assessed the associations between Hsp27, R132H mutation of Isocitrate dehydrogenase1 (IDH1-R132H), Hypoxia-inducible factor subunit alpha (HIF-1 alpha), Carbonic anhydrase IX (CA IX), and patient prognosis in astrocytic gliomas.