BACKGROUND: Mixed gliomas, such as oligoastrocytomas (OA), anaplastic oligoastrocytomas, and glioblastomas (GBMs) with an oligodendroglial component (GBMO) are defined as tumors composed of a mixture of two distinct neoplastic cell types, astrocytic and oligodendroglial. Recently, mutations ATRX and TP53, and codeletion of 1p/19q are shown to be genetic hallmarks of astrocytic and oligodendroglial tumors, respectively. Subsequent molecular analyses of mixed gliomas preferred the reclassification to either oligodendroglioma or astrocytoma. This study was designed to apply genetically integrated diagnostic criteria to mixed gliomas and determine usefulness and prognostic value of new classification in Korean patients. METHODS: Fifty-eight cases of mixed OAs and GBMOs were retrieved from the pathology archives of Seoul National University Hospital from 2004 to 2015. Reclassification was performed according to genetic and immunohistochemical properties. Clinicopathological characteristics of each subgroup were evaluated. Overall survival was assessed and compared between subgroups. RESULTS: We could reclassify all mixed OAs and GBMOs into either astrocytic or oligodendroglial tumors. Notably, 29 GBMOs could be reclassified into 11 cases of GBM, IDH-mutant, 16 cases of GBM, IDH-wildtype, and two cases of anaplastic oligodendroglioma, IDH mutant. Overall survival was significantly different among these new groups (p<.001). Overall survival and progression-free survival were statistically better in gliomas with IDH mutation, ATRX mutation, no microscopic necrosis, and young patient age (cut off, 45 years old). CONCLUSIONS: Our results strongly suggest that a genetically integrated diagnosis of glioma better reflects prognosis than former morphology-based methods.
Astrocytoma ; Classification ; Diagnosis ; Disease-Free Survival ; Genetics ; Glioblastoma ; Glioma ; Humans ; Necrosis ; Oligodendroglioma ; Pathology ; Prognosis ; Seoul

OBJECTIVE: This study aims to determine whether gamma knife radiosurgery (GKR) improves survival in patients with recurrent highgrade gliomas.METHODS: Twenty nine patients with recurrent high-grade glioma underwent 38 GKR. The male-to-female ratio was 10 : 19, and the median age was 53.8 years (range, 20–75). GKR was performed in 11 cases of recurrent anaplastic oligodendrogliomas, five anaplastic astrocytomas, and 22 glioblastomas. The median prescription dose was 16 Gy (range, 10–24), and the median target volume was 7.0 mL (range, 1.1–15.7). Of the 29 patients, 13 (44.8%) received concurrent chemotherapy. We retrospectively analyzed the progression-free survival (PFS) and overall survival (OS) after GKR depending on the Eastern Cooperative Oncology Group (ECOG) performance status (PS), pathology, concurrent chemotherapy, radiation dose, and target tumor volume.RESULTS: Starting from when the patients underwent GKR, the median PFS and OS were 5.0 months (range, 1.1–28.1) and 13.0 months (range, 1.1–75.1), respectively. On univariate analysis, the median PFS was significantly long in patients with anaplastic oligodendroglioma, ECOG PS 1, and target tumor volume less than 10 mL (p < 0.05). Meanwhile, on multivariate analysis, patients with ECOG PS 1 and target tumor volume less than 10 mL showed improved PFS (p=0.043 and p=0.007, respectively). The median OS was significantly increased in patients with ECOG PS 1 and tumor volume less than 10 mL on univariate and multivariate analyses (p < 0.05).CONCLUSION: GKR could be an additional treatment option in recurrent high-grade glioma, particularly in patients with good PS and limited tumor volume.
Astrocytoma ; Disease-Free Survival ; Drug Therapy ; Glioblastoma ; Glioma ; Humans ; Multivariate Analysis ; Oligodendroglioma ; Pathology ; Prescriptions ; Radiosurgery ; Recurrence ; Retrospective Studies ; Tumor Burden

The current World Health Organization classification system of primary brain tumors is solely based on morphologic criteria. However, there is accumulating evidence that tumors with similar histology have distinct molecular signatures that significantly impact treatment response and survival. Recent practice-changing clinical trials have defined a role for routine assessment of O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastoma patients, especially in the elderly, and 1p and 19q codeletions in patients with anaplastic glial tumors. Recently discovered molecular alterations including mutations in IDH-1/2, epidermal growth factor receptor (EGFR), and BRAF also have the potential to become targets for future drug development. This article aims to summarize current knowledge on the molecular biology of high-grade gliomas relevant to daily practice.
Aged ; Brain Neoplasms ; genetics ; metabolism ; pathology ; Chromosome Deletion ; DNA Methylation ; DNA Modification Methylases ; genetics ; metabolism ; DNA Repair Enzymes ; genetics ; metabolism ; Glioblastoma ; genetics ; metabolism ; pathology ; Glioma ; genetics ; metabolism ; pathology ; Humans ; Isocitrate Dehydrogenase ; genetics ; metabolism ; Neoplasm Grading ; Oligodendroglioma ; genetics ; metabolism ; pathology ; Point Mutation ; Promoter Regions, Genetic ; Receptor, Epidermal Growth Factor ; metabolism ; Tumor Suppressor Proteins ; genetics ; metabolism

Alpha-internexin (INA) is a proneuronal gene-encoding neurofilament interacting protein. INA is overexpressed mostly in oligodendroglial phenotype gliomas, is related to 1p/19q codeletion, and is a favorable prognostic marker. We studied INA expression in oligodendrogliomas (ODGs) and glioblastomas (GBMs) to verify its association with several molecular phenotypes, 1p/19q codeletion, and epidermal growth-factor-receptor (EGFR) amplification. A total of 230 low- and high-grade ODG and GBM cases was analyzed for INA expression by immunohistochemical staining; and 1p/19q and EGFR gene status was examined by fluorescence in-situ hybridization. INA was positive in 80.3% of ODGs and in 34.3% of GBMs. 1p/19q codeletion was detected in 77.0% of ODGs and 5.5% of GBMs. INA and 1p/19q codeletion were strongly correlated (P < 0.001). The specificity of INA expression for 1p/19q codeletion was 70.8%, while sensitivity was 100%; positive predictive value was 72.5%, and negative predictive value was 29.2% in all 228 tumors. INA expression was correlated with better progression-free survival (PFS) and overall survival (OS) (P = 0.001). In conclusion, INA expression has high specificity and sensitivity to predict 1p/19q codeletion, and it is well correlated with PFS of both ODGs and GBMs. Therefore, INA expression could be a simple, reliable, and favorable prognostic and surrogate marker for 1p/19q codeletion and long term survival.
Adult ; Brain Neoplasms/*metabolism/mortality/pathology ; Chromosomes, Human, Pair 1 ; Chromosomes, Human, Pair 19 ; Female ; Gene Deletion ; Glioblastoma/*metabolism/mortality/pathology ; Humans ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; Intermediate Filament Proteins/genetics/*metabolism ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Oligodendroglioma/*metabolism/mortality/pathology ; Phenotype ; Predictive Value of Tests ; Prognosis ; Receptor, Epidermal Growth Factor/genetics/metabolism

Antigens, Nuclear ; metabolism ; Cordotomy ; methods ; Diagnosis, Differential ; Ependymoma ; metabolism ; pathology ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Nerve Tissue Proteins ; metabolism ; Neurocytoma ; metabolism ; pathology ; surgery ; Oligodendroglioma ; S100 Proteins ; metabolism ; Spinal Cord Neoplasms ; metabolism ; pathology ; surgery ; Synaptophysin ; metabolism

Allelic loss of the short arm of chromosome 1 has been observed frequently in a wide spectrum of cancers, most frequently in oligodendroglioma. In our previous studies, we evaluated 177 oligodendroglial tumor samples and identified the AJAP1 gene (formerly Shrew1) in the consensus region of deletion. AJAP1 is a transmembrane protein found in adheren junctions and functions to inhibit glioma cell adhesion and migration. Whereas a putative tumor suppressor gene, we did not detect AJAP1 gene mutations. In subsequent studies, we found that AJAP1 was underexpressed in oligodendrogliomas relative to normal brain tissues. Bioinformatic analysis revealed the presence of CpG islands in the promoter of AJAP1. Methylation analysis of the AJAP1 promoter identified hypermethylation in 21% of oligodendrogliomas (n =27), and the degree of methylation correlated with low levels of AJAP1 expression (P = 0.045). The AJAP1 promoter was also highly methylated in a wide spectrum of cell lines (n = 22), including cell lines of glioblastoma. Analysis of the National Cancer Institute's REMBRANDT dataset, which contains 343 glioma samples, indicated that low AJAP1 gene expression was associated with decreased survival. Thus, both genetic (gene deletion) and epigenetic alterations (promoter methylation) are likely mechanisms that inactivate the putative tumor suppressor AJAP1 in gliomas, which contributes to poor prognosis.
Astrocytoma ; genetics ; metabolism ; pathology ; Cell Adhesion Molecules ; genetics ; metabolism ; Cell Line, Tumor ; Central Nervous System Neoplasms ; genetics ; metabolism ; pathology ; CpG Islands ; genetics ; DNA Methylation ; Down-Regulation ; Gene Deletion ; Glioblastoma ; genetics ; metabolism ; pathology ; Humans ; Oligodendroglioma ; genetics ; metabolism ; pathology ; Promoter Regions, Genetic ; genetics ; Survival Rate

Adolescent ; Adult ; Aged ; Diagnosis, Differential ; Ependymoma ; pathology ; Female ; Follow-Up Studies ; Humans ; Immunohistochemistry ; Magnetic Resonance Imaging ; Male ; Meningeal Neoplasms ; diagnostic imaging ; metabolism ; pathology ; surgery ; Meningioma ; diagnostic imaging ; metabolism ; pathology ; surgery ; Mucin-1 ; metabolism ; Oligodendroglioma ; pathology ; Tomography, X-Ray Computed ; Vimentin ; metabolism ; Young Adult

OBJECTIVETo study the correlation of loss of heterozygosity (LOH) on chromosome 1p and 19q with the expression of MGMT, p53 and Ki-67 proteins in gliomas.

METHODSOne hundred and forty six cases of gliomas (45 oligodendrogliomas, 42 oligodendroastrocytomas, and 59 astrocytomas) were included in this study. Their tissue and blood samples were retrospectively analyzed by PCR-denaturing high-performance liquid chromatography (DHPLC) for 1p and 19q status and by immunohistochemistry for MGMT, p53 and Ki-67 expression patterns. The correlation among them and with clinicopathological characteristics were analyzed by chi-square test and t-test.

RESULTSIn the oligodendrogliomas, the positive rate of 1p LOH was 59.8%, significantly higher than 33.9% in astrocytomas (P = 0.002), and 1p and 19q LOH was 42.5%, significantly higher than 16.9% in astrocytomas (P = 0.001). Combined with LOH on 1p and 19q, low MGMT expression (65.5%), and high Ki-67 expression (54%) were more frequent in oligodendrogliomas, whereas high p53 expression was more frequent in astrocytomas and mixed tumors (75.2%). 1p LOH (72.5%) and low MGMT (87.5%) expressions were more frequent in grade II oligodendrogliomas, whereas high expressions of p53 (83.0%) and Ki-67 (76.6%) were more frequent in grade III oligodendrogliomas. In addition, high Ki-67 expression was more frequent in grade III astrocytomas. LOH on 1p and 19q LOH was more frequent in nontemporal oligodendrogliomas (55.6%) than that in temporal ones (22.2%, P = 0.002). Non-random associations were found between LOH 1p and 19q LOH, MGMT and p53 protein expressions, and MGMT and Ki-67 protein expressions (all P < 0.05), whereas mutual exclusions were found between LOH on 1p and 19q and p53 expression, and LOH 1p and Ki-67 expression.

CONCLUSIONSThere is a significant interrelationship of the investigated molecular markers and clinicopathological features of gliomas, which support a promising role of molecular markers in guiding diagnostic assessment and clinical management of gliomas.

Adolescent ; Adult ; Aged ; Astrocytoma ; genetics ; metabolism ; pathology ; Brain Neoplasms ; genetics ; metabolism ; pathology ; Child ; Chromosomes, Human, Pair 1 ; genetics ; Chromosomes, Human, Pair 19 ; genetics ; Female ; Glioma ; genetics ; metabolism ; pathology ; Humans ; Ki-67 Antigen ; metabolism ; Loss of Heterozygosity ; Male ; Middle Aged ; O(6)-Methylguanine-DNA Methyltransferase ; metabolism ; Oligodendroglioma ; genetics ; metabolism ; pathology ; Retrospective Studies ; Tumor Suppressor Protein p53 ; metabolism ; Young Adult

Astrocytoma ; blood supply ; pathology ; Capillaries ; pathology ; Central Nervous System Neoplasms ; blood supply ; pathology ; Diagnosis, Differential ; Ependymoma ; blood supply ; pathology ; Glioblastoma ; blood supply ; pathology ; Hemangioblastoma ; blood supply ; pathology ; Humans ; Hyperplasia ; Microvessels ; pathology ; Neoplasms, Neuroepithelial ; blood supply ; pathology ; Oligodendroglioma ; blood supply ; pathology ; Paraganglioma ; blood supply ; pathology

OBJECTIVESTo investigate the relationship between the expression of miR-218 and CDK6 in glioma cells, and their biological impacts on the tumor cell proliferation and apoptosis.

METHODSExpression levels of miR-218 as well as CDK6 and Ki-67 proteins were analyzed in 60 cases of gliomas with various grades and 10 control brain tissue samples by tissue microarray, locked oligonucleotide probe in situ hybridization and immunohistochemistry. Glioblastoma multiform cell line (U87MG) was transfected with miR-218 mimics (mimics group) and a control sequence (control group), followed by qRT-PCR detection of miR-218 and immunocytochemical stain of CDK6 and Ki-67, respectively. Single cell gel electrophoresis was used to detect the presence of apoptotic cell.

RESULTSThe miR-218 labeling indexes (LI) were statistically different (P<0.05) among all groups including control (22.45 +/- 0.59) and various glioma groups (grades I - II 4.00 +/- 1.07, grade III 1.87 +/- 1.06 and grade IV 0.94 +/- 0.78, respectively). The CDK6 LI of the four groups was 7.25 +/- 1.20, 16.71 +/- 0.80, 24.43 +/- 0.62 and 32.05 +/- 0.43, respectively. Significant differences existed between the control group and the glioma groups, and between grade IV and grades I - II glioma groups (P<0.01). Ki-67 positive cell densities of the above four groups (0.00 +/- 0.00, 9.30 +/- 3.48, 31.15 +/- 9.44 and 60.15 +/- 13.60) were significantly different from one and another (P<0.01). The expression of miR-218 negatively correlated with CDK-6 LI (r = -0.480, P<0. 01) and Ki-67 positive cell density (r = - 0.534, P<0.01), while the latter two positively correlated with each other (r = 0.530, P<0.01). U87MG transfection experiment showed that the miR-218 level of the mimics group was significantly higher than that of the control group (P<0.01). CDK6 and Ki-67 LI of the mimics group (14.74 +/- 1.19 and 30.88 +/- 3.31) were significantly lower than those of the control group (79.06 +/- 2.07 and 64.94 +/- 3.96, P<0.01), whilst its apoptotic index (AI) (68.44 +/- 7.05) was significantly higher than that of the control group (13.04 +/- 0.97, P<0.01).

CONCLUSIONSThe expression level of miR-218 is an important reference indicator for the assessment of the grade of gliomas. An aberrant decrease of its expression may lead to an increase of the CDK6 expression and proliferative activity of giloma cells. Introducing exogenous miR-218 may effectively down-regulate the CDK6 expression, inhibit cell proliferation and induce apoptosis of malignant giloma cells. These findings imply that miR-218 may serve as a therapeutic agent against malignant glioma.

Adolescent ; Adult ; Apoptosis ; Astrocytoma ; metabolism ; pathology ; Brain Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Child ; Cyclin-Dependent Kinase 6 ; metabolism ; Ependymoma ; metabolism ; pathology ; Female ; Glioblastoma ; metabolism ; pathology ; Glioma ; metabolism ; pathology ; Humans ; Ki-67 Antigen ; metabolism ; Male ; MicroRNAs ; metabolism ; Middle Aged ; Neoplasm Grading ; Oligodendroglioma ; metabolism ; pathology ; Transfection ; Young Adult