Prognostic Biomarker In Glioblastoma Research Articles

Pre-operative apparent diffusion coefficient values and tumour region volumes as prognostic biomarkers in glioblastoma: correlation and progression-free survival analyses

ObjectivesGlioblastoma (GB) contains diverse histologic regions. Apparent diffusion coefficient (ADC) values are surrogates for the degree of number of cells within the tumour regions. Because an assessment of ADC values and volumes within tumour sub-compartments of GB is missing in the literature, we aimed to evaluate these associations.MethodsA retrospective cohort of 48 patients with GB underwent segmentation to calculate tumour region volumes (in cubic centimetre) and ADC values in tumour regions: normal tissue, enhancing tumour, proximal oedema, distal oedema, and necrosis. Correlation, Kaplan-Meier, and Cox hazard regression analyses were performed.ResultsWe found a statistically significant difference among ADC values for tumour regions: F (4, 220) = 166.71 and p ≤ .001 and tumour region volumes (necrosis, enhancing tumour, peritumoural oedema): F (2, 141) = 136.3 and p ≤ .001. Post hoc comparisons indicated that the only significantly different mean score was the peritumoural volume in oedema region (p < .001). We observed a positive significant correlation between ADC of distal oedema and peritumoural volume, r = .418, df = 34, and p = .011. Cox proportional hazards regression analysis considering only tumour region volumes provided an almost significant model: − 2 log-likelihood = 146.066, χ2 (4) = 9.303, and p = .054 with a trend towards significance of the hazard function: p = .067 and HR = 1.077 for the non-enhancing tumour volume.ConclusionsADC values together with volumes of oedema region might have a role as predictors of progression-free survival (PFS) in patients with GB; we recommend a routine MRI assessment with the calculation of these biomarkers in GB.

MicroRNA-562 negatively regulated c-MET/AKT pathway in the growth of glioblastoma cells.

BackgroundMicroRNA-562 (miR-562) has been found to possess anti-cancer function in certain tumors. However, the function of miR-562 in glioblastoma (GBM) is still not fully understood.PurposeThe aim at present study is to analyze the function of miR-562 and its possible target in GBM cells.Patients and methodsIn the present study, a total of 80 GBM samples and 16 adjacent noncancerous tissues were used to examine the expression of miR-562 and c-MET. In order to gain a deep insight into the molecular network of miR-562 and c-MET in GBM, the miR-562 mimic and inhibitor were transfected into two GBM cell lines (U251 and U87), respectively. Meanwhile, lentiviral vector was used to mediate overexpression of c-MET. Cell proliferation was examined via Cell Counting Kit-8 (CCK-8) assays. Meanwhile, cell apoptosis was analyzed by Annexin V-FTTC/PI staining assay.ResultsOur results indicated that the level of miR-562 was downregulated in GBM tissues and the expression of c-MET was upregulated in tumors. Cell proliferation analysis indicated that miR-562 was an anti-proliferation effector in GBM cells. Moreover, cell apoptosis analysis suggested the pro-apoptosis function of miR-562 in GBM cells.ConclusionOur results demonstrated that miR-562 negatively regulated the c-MET/AKT signal pathway. In addition, caspase-3 might also serve as another target for miR-562 in GBM cells. This research not only obtained a deep understanding of miR-562 but also provided evidence in terms of developing new prognostic biomarker for GBM.

CSIG-24. miR-575 IS ASSOCIATED WITH WORSE SURVIVAL OF GBM PATIENTS AND ACTS AS A NOVEL ONCOGENE THROUGH TARGETING p27/CDKN1B AND BLID/BRCC2

Glioblastoma (GBM) patients currently face poor survival outcomes with an average survival period of less than 15 months, while only 3–5% of patients survive longer than 36 months. Although the mechanisms of tumorigenesis are still being elucidated, miRNAs are promising candidates to explore as novel and prognostic biomarkers in GBM. Here, we determined the correlation between miR-575 expression in GBM tumors and overall survival (OS) of patients and undertook functional studies to unfold the contribution of this miR to GBM tumorigenesis. Total RNAs were isolated from 268 FFPE GBM tumor samples and miR expression was assayed (simultaneously) using NanoString Technologies, and univariable and multivariable cox regression analyses were performed. Cell proliferation, colony formation, migration assay, qPCR, immunoblotting, and luciferase assay were conducted to define the function of miR-575 in GBM. Our survival analysis (n=268) show that miR-575 is associated with worse OS of GBM patients (HR=1.5, p-value=5.77E-05) by continuous UVA. miR-575 was also found to be significantly associated with OS, independent of age, gender, treatment, and KPS in a MVA (HR=1.208, p=0.012). Since miR-575 was found to be negatively associated with OS, we hypothesized that miR-575 overexpression would increase tumor progression. Our functional studies indicate that overexpression of miR-575 significantly increased the proliferation and motility of LN229 and U251 GBM cells in vitro. Consistent with the result found in LN229 and U251 cells, inhibition of miR-575 in U87 cells significantly decreased their proliferation and motility. Subsequent in silico and mechanistic studies identified p27/CDKN1B and BLID/BRCC2 aspotential target genes of miR-575 in GBM. Overexpression of miR-575 in GBM cells reduced the expression of both BLID and p27 at both mRNA and protein levels. miR-575 has prognostic value in GBM, with higher expression correlating with worse OS of patients, and contributes to GBM tumorigenesis by inhibiting expression of p27 and BLID.

Identification of a panel of genes as a prognostic biomarker for glioblastoma.

BackgroundGlioblastoma multiforme (GBM) is a fatal disease without effective therapy. Identification of new biomarkers for prognosis would enable more rational selections of strategies to cure patients with GBM and prevent disease relapse.MethodsSeven datasets derived from GBM patients using microarray or next generation sequencing in R2 online database (http://r2.amc.nl) were extracted and then analyzed using JMP software. The survival distribution was calculated according to the Kaplan-Meier method and the significance was determined using log-rank statistics. The sensitivity of a panel of GBM cell lines in response to temozolomide (TMZ), salinomycin, celastrol, and triptolide treatments was evaluated using MTS and tumor-sphere formation assay.FindingsWe identified that CD44, ATP binding cassette subfamily C member 3 (ABCC3), and tumor necrosis factor receptor subfamily member 1A (TNFRSF1A) as highly expressed genes in GBMs are associated with patients' poor outcomes and therapy resistance. Furthermore, these three markers combined with MGMT, a conventional GBM marker, can classify GBM patients into five new subtypes with different overall survival time in response to treatment. The four-gene signature and the therapy response of GBMs to a panel of therapeutic compounds were confirmed in a panel of GBM cell lines.InterpretationThe data indicate that the four-gene panel can be used as a therapy response index for GBM patients and potential therapeutic targets. These results provide important new insights into the early diagnosis and the prognosis for GBM patients and introduce potential targets for GBM therapeutics.FundBaylor Scott & White Health Startup Fund (E.W.); Collaborative Faculty Research Investment Program (CFRIP) of Baylor University, Baylor Scott & White Health, and Baylor College of Medicine (E.W., T.S., J.H.H.); NIH R01 NS067435 (J.H.H.); Scott & White Plummer Foundation Grant (J.H.H.); National Natural Science Foundation of China 816280007 (J.H.H. and Fu.W.).

Bioinformatics analyses of significant genes, related pathways and candidate prognostic biomarkers in glioblastoma.

Glioblastoma (GBM) is the most common type of malignant tumor of the central nervous system. The prognosis of patients with GBM is very poor, with a survival time of ~15 months. GBM is highly heterogeneous and highly aggressive. Surgical removal of intracranial tumors does provide a good advantage for patients as there is a high rate of recurrence. The understanding of this type of cancer needs to be strengthened, and the aim of the present study was to identify gene signatures present in GBM and uncover their potential mechanisms. The gene expression profiles of GSE15824 and GSE51062 were downloaded from the Gene Expression Omnibus database. Normalization of the data from primary GBM samples and normal samples in the two databases was conducted using R software. Then, joint analysis of the data was performed. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, and the protein-protein interaction (PPI) network of the differentially expressed genes (DEGs) was constructed using Cytoscape software. Identification of prognostic biomarkers was conducted using UALCAN. In total, 9,341 DEGs were identified in the GBM samples, including 9,175 upregulated genes and 166 downregulated genes. The top 1,000 upregulated DEGs and all of the downregulated DEGs were selected for GO, KEGG and prognostic biomarker analyses. The GO results showed that the upregulated DEGs were significantly enriched in biological processes (BP), including immune response, cell division and cell proliferation, and the downregulated DEGs were also significantly enriched in BP, including cell growth, intracellular signal transduction and signal transduction by protein phosphorylation. KEGG pathway analysis showed that the upregulated DEGs were enriched in circadian entrainment, cytokine-cytokine receptor interaction and maturity onset diabetes of the young, while the downregulated DEGs were enriched in the TGF-β signaling pathway, MAPK signaling pathway and pathways in cancer. All of the downregulated genes and the top 1,000 upregulated genes were selected to establish the PPI network, and the sub-networks revealed that these genes were involved in significant pathways, including olfactory transduction, neuroactive ligand-receptor interaction and viral carcinogenesis. In total, seven genes were identified as good prognostic biomarkers. In conclusion, the identified DEGs and hub genes contribute to the understanding of the molecular mechanisms underlying the development of GBM and they may be used as diagnostic and prognostic biomarkers and molecular targets for the treatment of patients with GBM in the future.

Long noncoding RNA H19, and not microRNA miR-326, is over-expressed and predicts survival in glioblastoma.

Glioblastoma (GB) represents the most common malignant brain tumor, which, despite extensive research, remains of poor prognosis. The focus of recent studies of GB pathogenesis has shifted to the study of the role of noncoding RNAs (ncRNAs). In this study, we examined the expression levels of the microRNA miR-326 and the long ncRNA H19 (on which a miR-326 putative binding site was found by in-silico analysis) in brain tumor tissue from GB patients as compared to cancer-free brain tissue. Relative expression levels of miR-326 were not found to be significantly altered in GB patients. By comparison, H19 was consistently over-expressed in all GB patients (p < 0.001), and correlated with poorer overall survival (OS) and progression-free survival (PFS) (p = 0.026 and p = 0.045, respectively). At a cutoff value of 5.27, H19 up-regulation could predict OS in GB patients, with a 71.4% sensitivity and 59.6% specificity (p = 0.026). The current GB patients were clustered by the multivariate analysis into 4 groups based on miR-326 and H19 expression profiles, age at diagnosis, and PFS. Our data suggest a role for H19 in the pathogenesis of GB and could be a potential prognostic biomarker for GB.

Identification of a Panel of Genes as a Prognostic Biomarker for Glioblastoma

Glioblastoma multiforme (GBM) is a fatal disease without effective therapy. Identification of new biomarkers for prognosis would enable more rational selections of strategies to cure patients with GBM and prevent relapse. We analyzed a large amount of gene expression profiling data derived from GBM patients. We identified CD44, ATP binding cassette subfamily C member 3 (ABCC3), and TNRSF1A as highly expressed genes in GBMs. Furthermore, the expression of these three genes is closely associated with patient's short survival time and therapy resistance. Moreover, these three markers combining with MGMT, a conventional GBM marker, can classify GBM patients into 5 new subgroups with different overall survival time in response to treatment. The four-gene signature was then evaluated in a panel of GBM cell lines treated with traditional therapeutic compounds and the data indicate that the four-gene panel can be used as a therapy response index for GBM patients and potential therapeutic targets. These results provide important new insights into the early detections and prognosis for GBM patients and introduce potential targets for GBM therapeutics. Funding: This study is, in part, supported by NovoCure Inc, 160280 (E.F. and F.W.); Baylor Scott and White Startup funds (E.W.); NIH R01 NS067435 (J.H.H.), Scott & White Plummer Foundation Grant (J.H.H.); National Science Foundation in China 816280007 (J.H.H. and Fu. W.); Jiangsu Nature Foundation BK20151565, Jiangsu Traditional Chinese Medicine Foundation ZD201501, Jiangsu Six Talent Peak Project 2015YY006 (Fu. W.). Declaration of Interest: The authors declare that they have no competing interests. Ethical Approval: Ethical approval of our experiments was given by the ethics committee of Baylor Scott and White Health.

Abstract 2459: Clinicopathological subgroups of glioblastoma patients are characterized by specific lncRNA expression patterns

Abstract Introduction: Glioblastoma (GBM) is the most frequent primary brain tumor of astrocytic origin. The prognosis is unfavourable with the median overall survival (OS) being between 12 and 15 months from diagnosis. Identification of new therapeutic targets, as well as new prognostic and predictive biomarkers for more accurate stratification of patients presents significant unmet medical needs. Long non-coding RNAs (lncRNAs) are regulators of gene expression playing important roles in the molecular pathology of GBM, indicating their potential as biomarkers and therapeutics targets. Material and Methods: Our study included 80 GBM patients treated with Stupp protocol and 16 patients with non-dominant anterior temporal cortexes resected during surgery for intractable epilepsy. Informed consent approved by the local Ethical Commission was obtained from each patient. IDH1 mutations and MGMT methylation status were evaluated in all GBMs. RNA (RIN &amp;gt; 8) from 96 specimens was used for next-generation RNA sequencing (RNAseq). rRNA depletion and cDNA library preparation were performed with RiboCop rRNA Depletion Kit V1.2 (Lexogen) and NEBNext Ultra II Directional RNA Library Prep Kit for Illumina (NEB), respectively. RNAseq was done using NextSeq 500 High Output Kit and NextSeq 500 instrument (both Illumina). 24,087 protein-coding and 8,414 non-coding RNAs and their sequential variants with non-zero RPKM at least in one sample underwent statistical evaluation. CLC genomic workbench was used for the alignment and target counts. Results: Statistical analysis revealed 84 (P &amp;lt; 0.001) dysregulated lncRNAs in GBMs compared to non-tumor brain tissue samples. The results also showed 485 dysregulated protein-coding RNAs with P &amp;lt; 0.001 and 24 protein-coding RNAs with P &amp;lt; 0.000001. 35 lncRNAs showed significant dysregulation when lncRNA profiles of GBM tissues with methylated MGMT promoter (≥ 25% methylation) were compared to those with unmethylated promoter (P &amp;lt; 0.01). When lncRNA patterns of GBM samples with mutated IDH1 were compared to those with wild-type IDH1, 60 lncRNAs were found to be significantly dysregulated (P &amp;lt; 0.001). Correlating lncRNA expression patterns with OS uncovered 6 lncRNA signature which enabled identifying patients with significantly worse prognosis (OS &amp;lt; 6 months). Conclusion: We described significant dysregulation of lncRNAs and protein-coding RNAs in GBM tissue compared to non-tumor brain tissue and specific lncRNA patterns linked to MGMT methylation and IDH1 mutation status. We also identified 6 lncRNA signature allowing sensitive prognostic stratification of GBM patients. Our study indicates that lncRNAs could serve as promising diagnostic and prognostic biomarkers in GBM. This work was supported by Ministry of Health of the Czech Republic, grant nr. 15-33158A, 15-34553A, 15-31627A, 15-34678A, 16-31314A, 16-31765A and by grant of Czech Grant Agency nr. 16-18257S. Citation Format: Marek Vecera, Romana Butova, Radim Lipina, Stefan Reguli, Martin Smrcka, Radim Jancalek, Michal Filip, Marketa Hermanova, Leos Kren, Pavol Mojak, Jaroslav Juracek, Tana Machackova, Natalia A. Gablo, Jiri Sana, Ondrej Slaby. Clinicopathological subgroups of glioblastoma patients are characterized by specific lncRNA expression patterns [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2459.

P53 and miR-210 regulated NeuroD2, a neuronal basic helix-loop-helix transcription factor, is downregulated in glioblastoma patients and functions as a tumor suppressor under hypoxic microenvironment.

The factors involved in cell differentiation have recently garnered interest for their role in inhibition of pathogenesis in various tumors. However, their role in glioblastoma (GBM) remains poorly understood. We analyzed The Cancer Genome Atlas (TCGA) GBM data and found significant downregulation of neurogenic differentiation factor NeuroD2 in GBM patients. Low levels of NeuroD2 were found to be correlated with poor overall survival of GBM patients in TCGA dataset as well as in our cohort. Interestingly, NeuroD2 was shown to be transcriptionally induced by p53 and post-transcriptionally targeted by hypoxia- inducible miRNA, miR-210. NeuroD2 overexpression diminished GBM aggressiveness by inhibiting cell proliferation, migration and promoting apoptosis under hypoxia. NeuroD2 overexpressing GBM cells failed to form three-dimensional (3D)-tumor spheroids and displayed reduced migration in a 3D gelatin matrix. NeuroD2 gene signature was enriched in pathways belonging to cytokine-cytokine receptor interaction, TNF-signaling, PI3K-AKT signaling, focal adhesion and ECM-receptor interaction. Overall, our study identifies a novel role of NeuroD2 as a tumor suppressor and prognostic biomarker in GBM the levels of which are tightly regulated by p53 and miR-210. Overexpressing NeuroD2 may potentially be a simple and efficient therapeutic strategy to inhibit the malignant phenotype of GBM cells.

Long noncoding RNA lncHERG promotes cell proliferation, migration and invasion in glioblastoma.

Long noncoding RNAs have recently been proven to regulate tumorgenesis in many cancers. However, their biological functions in glioblastoma remain largely unknown. Here we found an uncharacteristic lncRNA lncHERG that is highly expressed in human glioblastoma (GBM). We found that lncHERG knockdown inhibited cell proliferation, migration and invasion in glioblastoma in vitro and in vivo. Moreover, the higher expression of lncHERG in patients with glioblastoma indicated lower survival rate and poorer prognosis. Mechanistically, we found that lncHERG can serve as a sponge for miR-940 which is a tumor suppressor in cervical cancer and whose function has not been defined in glioblastoma. We showed that miR-940 was down-regulated in glioblastoma tissues compared to peritumor tissues. LncHERG knockdown impaired cell proliferation, migration and invasion while inhibition of miR-940 in the meantime reversed this trend. In conclusion, our study highlights the essential role of lncHERG in glioblastoma by acting as a competing endogenous RNA of miR-940, which may serve as a new prognostic biomarker in glioblastoma.

MicroRNA-141 is a tumor regulator and prognostic biomarker in human glioblastoma.

Human glioblastoma is one of the most malignant types of brain tumor in the world. In the present study, the functional mechanisms of microRNA-141 (miR-141) were assessed, and the potential role of miR-141 as a prognostic biomarker in glioblastoma was examined. The gene expression of miR-141 in glioblastoma cell lines and glioblastoma tumors was assessed by reverse transcription-quantitative polymerase chain reaction. Glioblastoma LN229 and U89 cell lines were transfected with synthetic miR-141 mimics to upregulate endogenous miR-141. The subsequent effect on glioblastoma proliferation was assessed by MTT assay. In human glioblastoma, miR-141 expression was compared between patients with tumors of different pathological grades. Statistical analyses were performed to assess the correlation between miR-141 and the clinicopathological properties and overall survival rates (OS) of the patients. In addition, a Cox regression model was used to examine whether miR-141 was a potential biomarker of glioblastoma. miR-141 was aberrantly downregulated in glioblastoma cell lines and human glioblastoma tumors. Forced miR-141 upregulation in glioblastoma LN229 and U89 cell lines suppressed cancer proliferation. In patients with glioblastoma, miR-141 downregulation was closely associated with an advanced disease stage, poor clinicopathological properties and a shorter OS time. The multivariate Cox regression model demonstrated that low miR-141 expression was an effective prognostic biomarker for patients with glioblastoma. Overall, the present study showed that miR-141 may be a functional cancer regulator and a prognostic biomarker for glioblastoma.

Chemokine receptor CXCR7 is an independent prognostic biomarker in glioblastoma.

Glioblastoma (GBM) is the most common and most fatal primary brain cancer in adults. Due to the complex nature of GBM, its pathogenesis still remain unclear. Accumulating evidence suggest that chemokine receptor CXCR7 contribute to the development of various types of tumors. We aim to examine the prognostic significance of CXCR7 in GBM. CXCR7 were first detected by Immunohistochemistry. The association between CXCR7 and overall survival (OS) were examined. Moreover, multivariate analyses were conducted to evaluate the prognostic factors in GBM. Of all 146 GBM patients recruited, 77 were in the high-expression subgroup, the rest 69 were in low-expression subgroup. There are no differences between these two subgroups in terms of age, gender, family history of cancer, extent of surgery, chemotherapy, radiotherapy, KPS, MGMT methylation status and tumor size. However, high CXCR7 expression was robustly correlated with poor OS in GBM. Multivariate analysis confirmed age, KPS scores, chemotherapy, IDH1 mutation, MGMT methylation and CXCR7 were independent factors in survival prognosis. CXCR7 may involve in the clinical GBM progression, and CXCR7 could be a valuable prognostic marker in the treatment of GBM.

Abstract 5726: A novel tumor-promoting role for miR-4516 in glioblastoma

Abstract Background: Glioblastomas are the most aggressive high-grade brain tumors, which are often life-threatening due to their location and rapid growth. Although survival rates differ depending on a variety of genetic and environmental factors, the average survival rate for a glioblastoma (GBM) patient is less than 15 months. Although the mechanisms of tumorigenesis are still being elucidated, miRNAs are promising candidates to explore as novel and prognostic biomarkers in GBM. Here we demonstrate a novel role for miR-4516 in promoting growth and migration of GBM and establish the molecular mechanisms mediating these functions. Methods: Formalin-fixed, paraffin-embedded tissue blocks (n=268) were collected for all patients and total RNA was isolated. miRNAs were analyzed simultaneously using the nCounter human miRNA v2 assay (NanoString Technologies; Seattle,WA). Functional characterization studies were conducted in vitro and in vivo. The effect of miR-4516 on GBM cell growth and motility were evaluated by cell proliferation assay, migration and invasion assay, and Annexin-V assay. Realtime PCR, immunoblotting, and 3’ untranslated region luciferase assays were used to analyze miR-4516 targets and signaling pathways. Intracranial injection will be performed to investigate the role of miR-4516 in tumor growth in vivo. Results: Univariate analysis showed that miR-4516 expression in GBM patients was inversely correlated with overall survival (FDR=0.002, p=1.02E-05). Knockdown of miR-4516 blocked tumor growth and induced cell apoptosis. Tumor cell growth, migration and invasion were induced in both transient miR-4516 overexpressed GBM cells (LN229, LN18, and U87) and stable miR-4516 overexpressed GBM cells (U87-EGFRvIII). These miR-4516 tumor-promoting effects were mediated in part via direct targeting PTPN14 and CDKN1A. Investigation of the other miR-4516 targets and in vivo functional study are in process. Conclusion: Taken together, these results suggest that miR-4516 acts as a prognostic biomarker for GBM patients. Funding Information: 1R01CA169368 (PI: Houghton; Co-I:Chakravarti); 1R01CA11522358 Multiple-PI R01: Chakravarti (PI); Xia (PI); 1R01CA1145128 Baroukhim (PI); Chakravarti (Co-PI) 7/2015-6/2020; R01CA108633 (PI:Chakravarti); 1RC2CA148190 (Scientific PI: Chakravarti) Citation Format: Tiantian Cui, Ashley Gray, Ziyan Liu, Marjolein Geurts, Pierre Robe, Joseph McElroy, Erica Hlavin Bell, Arnab Chakravarti. A novel tumor-promoting role for miR-4516 in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5726. doi:10.1158/1538-7445.AM2017-5726

Prognostic implications of the subcellular localization of survivin in glioblastomas treated with radiotherapy plus concomitant and adjuvant temozolomide.

OBJECTIVE Currently, the standard treatment protocol for patients with newly diagnosed glioblastoma (GBM) includes surgery, radiotherapy, and concomitant and adjuvant temozolomide (TMZ). Various prognostic biomarkers for GBM have been described, including survivin expression. The aim of this study was to determine whether the subcellular localization of survivin correlates with GBM prognosis in patients who received the standard treatment protocol. METHODS The authors retrospectively examined the subcellular localization of survivin (nuclear, cytoplasmic, or both) using immunohistochemistry in 50 patients with GBM who had received the standard treatment. The relationship between survivin localization and overall survival (OS) was assessed with uni- and multivariate analyses including other clinicopathological factors (age, sex, Karnofsky Performance Scale [KPS] score, extent of resection, the use of second-line bevacizumab, O6-methylguanine-DNA methyltransferase [MGMT] status, and MIB-1 labeling index). RESULTS Log-rank tests revealed that patient age, KPS score, extent of resection, MGMT status, and survivin localization (p < 0.0001) significantly correlated with OS. Multivariate analysis indicated that patient age, MGMT status, and survivin localization significantly correlated with OS. Patients with nuclear localization of survivin had a significantly shorter OS than those in whom survivin expression was exclusively cytoplasmic (median OS 19.5 vs 31.7 months, respectively, HR 5.690, 95% CI 2.068-17.612, p = 0.0006). There was no significant difference in OS between patents whose survivin expression was exclusively nuclear or nuclear/cytoplasmic. CONCLUSIONS Nuclear expression of survivin is a factor for a poor prognosis in GBM patients. Subcellular localization of survivin can help to predict OS in GBM patients treated with the standard protocol.

Identification of prognostic biomarkers in glioblastoma using a long non-coding RNA-mediated, competitive endogenous RNA network.

Glioblastoma multiforme (GBM) is a highly malignant brain tumor associated with a poor prognosis. Cross-talk between competitive endogenous RNAs (ceRNAs) plays a critical role in tumor development and physiology. In this study, we present a multi-step computational approach to construct a functional GBM long non-coding RNA (lncRNA)-mediated ceRNA network (LMCN) by integrating genome-wide lncRNA and mRNA expression profiles, miRNA-target interactions, functional analyses, and clinical survival analyses. LncRNAs in the LMCN exhibited specific topological features consistent with a regulatory association with coding mRNAs across GBM pathology. We determined that the lncRNA MCM3AP-AS was involved in RNA processing and cell cycle-related functions, and was correlated with patient survival. MCM3AP-AS and MIR17HG acted synergistically to regulate mRNAs in a network module of the competitive LMCN. By integrating the expression profile of this module into a risk model, we stratified GBM patients in both the The Cancer Genome Atlas and an independent GBM dataset into distinct risk groups. Finally, survival analyses demonstrated that the lncRNAs and network module are potential prognostic biomarkers for GBM. Thus, ceRNAs could accelerate biomarker discovery and therapeutic development in GBM.

SEMA6A is a prognostic biomarker in glioblastoma.

Glioblastoma multiforme (GBM) is one of the most aggressive tumors in the central nervous system. SEMA6A, the first identified class 6 semaphorin, is contributed to regulate vascular development and adult angiogenesis. However, the function of SEMA6A in GBM is still undefined. In the present study, we investigated the expression of SEMA6A protein in 200 GBM tissues using immunohistochemistry (IHC). SEMA6A expression was associated with time to progression (P = 0.001) and mean tumor diameter (P = 0.038). Kaplan-Meier analysis revealed that patients expressing high SEMA6A protein levels had a significantly longer overall survival (OS, P = 0.013) and progression-free survival (PFS, P = 0.005) compared to those with low SEMA6A expression level. Cox multivariate regression analysis confirmed that low SEMA6A expression was an independent unfavorable prognostic factors for PFS (HR, 1.896; 95% CI, 1.147-2.768; P = 0.009) and OS (HR, 1.712; 95% CI, 1.011-2.657; P = 0.012). Furthermore, in vitro experiments showed that SEMA6A could inhibit proliferation, migration, and invasion in different glioma cell lines. In conclusion, our findings indicated that SEMA6A may be a potential prognostic biomarker in the treatment of GBM.

Prognostic Impact of MGMT Promoter Methylation in Glioblastoma - A Systematic Review

MGMT promoter methylation is currently considered the main prognostic biomarker in glioblastoma, yet some concerns remain about its actual impact on outcome. The aim of the present study was to analyze literature data on this topic. Therefore, a systematic review and analysis of recently published glioblastoma cohorts examining the relationship between MGMT methylation and prognosis was performed. We found that only 19/28 studies (68%) confirmed the prognostic value of MGMT methylation and/or its role in predicting response to temozolomide. In these studies, however, the population showed significantly lower rates of unfavorable prognosticators as compared with studies where MGMT methylation was not prognostic/predictive. Moreover, studies demonstrating a better prognosis for MGMT methylated cases had significantly lower rates of deaths at 3 and 6 months. Multivariate analysis showed that the 3-month and 6-month deaths are significantly associated with the prognostic/predictive value of MGMT methylation, and that the percent of MGMT methylated tumors and of patients treated with alkylating drugs trend towards statistical significance if modeled with the 6-month but not with the 3-month mortality rate. These results suggest that the paucity of short-term survivors may represent a bias in studies focusing on MGMT methylation and prognosis, and that a temporal threshold may be necessary in order to demonstrate the clinical benefit of MGMT promoter methylation.

Progranulin overexpression predicts overall survival in patients with glioblastoma

Despite multimodal treatment, patients with astrocytoma still face a poor survival, and identification of valuable prognostic factors is crucial to yield effective individual therapy strategies. The aim of this study was to investigate progranulin (PGRN) expression in astrocytomas and explore its association with tumor grade and overall patient survival by scoring the PGRN immunoreactivity of both tumor cells and blood vessels. About 210 astrocytoma samples with different WHO grades and 14 normal brain tissues were studied by immunohistochemistry for PGRN. Semi-quantitative RT-PCR and Western blot were carried out to confirm its expression in 35 tumor specimens. Serum levels of PGRN in glioblastoma were examined by enzyme immunometric assay. PGRN expression was almost undetectable in the normal brain tissues by immunohistochemistry but increased in both astrocytoma cells and tumor blood vessels with pathological grading. Sera in glioblastoma were significantly higher than in healthy control. In grade II astrocytoma, strong vascular PGRN expression was closely related to tumor recurrence. In glioblastoma, high total PGRN expression, strong vascular PGRN expression, and strong tumor cellular PGRN expression all correlated with decreased patient survival in univariate analysis. However, only total PGRN expression as well as vascular PGRN expression status was independently associated with patient's survival in the multivariate analysis. These results suggest that PGRN, involved in astrocytoma progression, may serve as a prognostic biomarker for glioblastoma.