[Diagnostic and prognostic values of 1p and 19q deletions in adult gliomas: critical review of the literature and implications in daily clinical practice]

New targets for cancer promotion and therapy in gliomas: Scinderin

Glioma is one of the most common primary intracranial tumors, characterized by invasive growth and poor prognosis. Actin cytoskeletal rearrangement is an essential event in tumor cell migration. Scinderin (SCIN), an actin severing and capping protein that regulates the actin cytoskeleton, is involved in the proliferation and migration of certain cancer cells. However, its biological role and molecular mechanism in glioma remain unclear. Lin et al explored the role and mechanism of SCIN in gliomas. The results showed that SCIN mechanically affected cytoskeleton remodeling and inhibited the formation of lamellipodia via RhoA/FAK signaling pathway. This study identifies the cancer-promoting role of SCIN and provides a potential therapeutic target for SCIN in glioma treatment.

Prognostic factors influencing clinical outcomes of malignant glioblastoma multiforme: clinical, immunophenotypic, and fluorescence in situ hybridization findings for 1p19q in 816 chinese cases

Malignant glioblastoma multiforme (GBM) is the most malignant brain tumor and despite recent advances in diagnostics and treatment prognosis remains poor. In this retrospective study, we assessed the clinical and radiological parameters, as well as fluorescence in situ hybridization (FISH) of 1p19q deletion, in a series of cases. A total of 816 patients with GBM who received surgery and radiation between January 2010 and May 2014 were included in this study. Kaplan-Meier survival analysis and Cox regression analysis were used to find the factors independently influencing patient progression free survival (PFS) and overall survival (OS). Age at diagnosis, preoperative Karnofsky Performance Scale (KPS) score, KPS score change at 2 weeks after operation, neurological deficit symptoms, tumor resection extent, maximal tumor diameter, involvement of eloquent cortex or deep structure, involvement of brain lobe, Ki-67 and MMP9 expression level and adjuvant chemotherapy were statistically significant factors (p<0.05) for both PFS and OS in the univariate analysis. Cox proportional hazards modeling revealed that age ≤50 years, preoperative KPS score ≥80, KPS score change after operation ≥0, involvement of single frontal lobe, deep structure involvement, low Ki-67 and MMP9 expression and adjuvant chemotherapy were independent favorable factors (p<0.05) for patient clinical outcomes.

Prognostic impact of molecular phenotype in patients with recurrent anaplastic glioma treated with prolonged administration of temozolomide

We retrospectively investigated the prognostic impact of molecular phenotypes in patients with recurrent anaplastic glioma treated with prolonged administration of temozolomide (TMZ). Malignant gliomas have a dismal prognosis despite the available multimodal treatments. We reviewed 87 patients who were diagnosed with recurrent anaplastic gliomas between March 2004 and June 2010, and 58 were enrolled for analysis. In the cohort, 21 patients had anaplastic oligodendrogliomas, 18 anaplastic oligoastrocytomas and 19 anaplastic astrocytomas. All patients were initially treated with surgical resection or biopsy followed by involved-field radiotherapy. At recurrence, patients were treated with 150-200mg/m(2) of TMZ on days 1-5 in 28 day cycles until disease progression. We evaluated the association of molecular phenotypes, including 1p19q deletion, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status, isocitrate dehydrogenase-1 (IDH1) mutation and other clinico-histopathological findings with treatment outcome. During the mean follow-up period of 34.6 months, 33 patients were still alive (56.9%). Median survival from recurrence was 39.7 months (95% confidence interval [CI] 22.7-56.7). Time to progression from administration of TMZ was 6.4 months (95% CI 5.0-7.8). Univariate analysis demonstrated that the presence of the IDH1 mutation was closely associated with treatment response (8.4 versus 3.8 months; p=0.015). Oligodendroglial lineage, 1p19q deletion status and MGMT promoter methylation status were not independent variables for determining the TMZ treatment outcome. In recurrent anaplastic gliomas, TMZ treatment is an effective modality regardless of MGMT methylation status or histological type. The IDH1 mutation has the most powerful prognostic impact on overall patient survival.

Identification of a novel population in high-grade oligodendroglial tumors not deleted on 1p/19q using array CGH

Oligodendroglial tumors (ODTs) are primary tumors of the central nervous system that show recurrent codeletion of whole chromosome arms 1p and 19q. Non-1p/19q-deleted high-grade ODTs can present other genetic aberrations, CDKN2A deletion (9p21.3), EGFR amplification (7p11.2) and/or chromosome 10 loss, which are associated with a poor prognosis. The identification of these abnormalities allowed drafting a histo-molecular classification. The aim of this study was to precisely identify, using array CGH, the genomic hallmarks of these tumors, particularly those that are not deleted on 1p/19q. We studied 14 formalin-fixed paraffin-embedded high-grade ODTs using pangenomic oligonucleotide array CGH with an average resolution of 22.3 kb. The 1p/19q codeletion was found in five anaplastic oligodendrogliomas. The three genomic aberrations carrying a poor prognosis were found, most often associated, in five out of nine tumors not deleted on 1p/19q. In addition, four recurrent copy number alterations, involving genes that participate to cell growth and cycle, were found to be strongly associated in five tumors not deleted on 1p/19q: gain or amplification at 1q32.1 (MDM4, PIK3C2B genes), 12q14.1 (CDK4 gene), 12q14.3-q15 (MDM2 gene) and homozygous deletion at 22q13.1 (APOBEC3B gene). MDM2, MDM4, CDK4 and PIK3C2B are known for potentially being amplified or overexpressed in high-grade gliomas. However, the involvement of APOBEC3B, coding for mRNA edition enzyme, is described here for the first time. Our results show a strong association between these four alterations. Therefore, this can open a perspective for a novel subgroup in high-grade ODTs not deleted on 1p/19q.

Hypoxia-inducible factor-1-regulated protein expression and oligodendroglioma patient outcome: comparison with established biomarkers and preoperative UCSF low-grade scoring system

Methods for predicting outcome for patients with oligodendrogliomas and anaplastic oligodendrogliomas (AOs) are limited. Hypoxia-inducible factor-1α (HIF-1α) controls many proteins involved in glycolysis and angiogenesis including VEGF, Glut-1, and CA-IX. We examined whether expression of HIF-1α and other hypoxia-regulated molecules (HRM) can predict overall (OS) and progression-free (PFS) survival. We correlated these data with more established biomarkers and a published preoperative scoring system. We prospectively collected tissue samples and followed outcomes of 50 patients with oligodendrogliomas and 32 with AOs. Tumor tissues were stained for measures of proliferative index, microvascular density, IDH-1 mutational status, and HRMs. We retrospectively analyzed preoperative imaging and clinical data based on the UCSF Scoring System (good prognostic indicators: Karnofsky Performance Scale (KPS) score > 80, age < 50 years, tumor diameter < 4 cm, noneloquent tumor location) and correlated these with immunohistochemical markers, 1p19q chromosomal status, and compared both with patient PFS and OS. Mean follow-up was 85.6 ± 41.4 months. HRMs showed higher expression in AOs than in oligodendrogliomas. Both 1p19q codeletion and IDH-1 mutation predict outcome of patients with both oligodendroglioma and AO. The UCSF score is a strong predictor for oligodendrogliomas patient outcome and is strengthened by IDH-1 and 1p19q status. Glut-1 may be useful in predicting PFS in AOs. Proliferation index >5 for oligodendrogliomas and KPS ≤ 80 for AOs predict a worse prognosis. Immunohistochemical markers of HRMs show a significantly higher expression in anaplastic variants of oligodendrogliomas and may contribute to the prediction of survival in these patients.

Oncogene addiction in gliomas: implications for molecular targeted therapy

Oncogene addiction is a phenomenon that the survival of cancer cells depends on an activated oncogene or inactivation of tumor suppressor gene, and is regarded as the 'Achilles heel' of the successful molecular targeted therapies in cancer. However, the role of oncogene addiction in gliomas has not been elucidated systematically. In this review, we summarize the current experimental and clinical evidence for the concept of oncogene addiction and describe the mechanisms explaining oncogene addiction in gliomas. And the clinical implications for oncogene addiction in molecular targeted therapy are further emphasized. In addition, we discuss future direction for defining complex "oncogene addiction network" through the integrated analysis of multiple platforms in the flow of genetic information in gliomagenesis.

p14ARF promoter region methylation as a marker for gliomas diagnosis

Methylation in the promoter region is one of the mechanisms through which tumor suppressors are inactivated, resulting in tumorigenesis and/or tumor progression. Herein, we studied the methylation status in the promoter region of the p14ARF tumor suppressor gene in 33 brain tissues isolated from glioma patients (astrocytomas) and compared to 12 brain tissues isolated from autopsy donors using methylation-specific polymerase chain reaction (MSP). The correlation between the expression of P14 and P53 was investigated using immunohistochemistry (IHC). The average percentage of methylation in the promoter region of p14ARF gene in brain samples from glioma patients is 39.4%, while 0 from autopsy donors. No difference in the methylation level between low-grade and high-grade gliomas was detected. The methylation status has no correlation with the prognosis in glioma patients. A significant correlation between the expression of mutant form of TP53 and the grade of the glioma was established. Furthermore, there was a negative correlation between methylation of the p14ARF promoter and the expression of the mutant form of TP53. Therefore, our data suggest that methylation in the promoter region of the p14ARF gene may be used as a biomarker for the diagnosis of gliomas.