High expression of TIG3 predicts poor survival in patients with primary glioblastoma.

TIG3 (tazarotene-induced gene 3) has been reported to suppress the progression of several malignancies, where this gene is universally downregulated. However, the expression of TIG3 in primary glioblastoma and its relevance to patient's prognosis have not been elaborated. Thus, this study was aimed to evaluate TIG3 expression level in primary glioblastoma and investigate the prognostic value of TIG3 for patients. The Cancer Genome Atlas database was first utilized to analyze the expression and prognostic potential of TIG3 in 528 glioblastoma cases. Compared with control group, glioblastoma showed significantly elevated TIG3 expression (p < 0.001). Log-rank analysis revealed that higher expression of TIG3 was associated with shorter overall survival (358vs 383 days, p = 0.039). Furthermore, TIG3 protein expression detected by immunohistochemistry confirmed positive correlation of TIG3 expression and glioma grade and upregulation of TIG3 in our cohort of 101 primary glioblastoma patients compared to 16 normal brains. Finally, Kaplan-Meier analysis and Cox regression analysis identified high TIG3 expression as an independent risk factor for overall survival of primary glioblastoma patients (overall survival, 10 vs 13 months, p = 0.033; hazard ratio = 1.542, p = 0.046). Together, this study indicated that increased expression of TIG3 in primary glioblastoma is a novel biomarker for predicting poor outcome of patients. We then hypothesize that TIG3 may function in a different pattern in glioblastoma.

Overexpression of G-protein-coupled receptors 65 in glioblastoma predicts poor patient prognosis.

OBJECTIVE: G-protein-coupled receptors 65 (GPR65), identified as an acid-sensing receptor, is overexpressed in several malignancies and promote tumor development. Our aim was to investigate the expression and prognostic value of GPR65 in glioblastoma. MATERIALS AND METHODS: We determined the expression of GPR65 protein using immunohistochemistry in tissue microarrays containing 11 Grade I, 107 Grade II, 47 Grade III, and 102 Grade IV gliomas and 16 normal brains. Then we evaluated its association with pathological grades, prognosis, and recurrence. The Cancer Genome Atlas (TCGA) group (N=528) was further employed to examine transcriptional level of GPR65 in glioblastoma and the correlation between GPR65 expression and clinical outcome. RESULTS: In our cohort, GPR65 expression was positively related to glioma pathological grade (p<0.01) and elevated in glioblastoma (p<0.01). High expression of GPR65 was associated with significantly short overall survival (OS) (p=0.013) and progression-free survival (PFS) (p=0.029), and could be identified as an independent risk factor for OS of glioblastoma patients (Hazard Ratio [HR]=1.596, p=0.037). As an aiding evidence, increased GPR65 mRNA expression was also found in TCGA glioblastoma group (p<0.001) and its high level predicted a poor clinical outcome (OS, p=0.003; PFS, p=0.001). CONCLUSION: Our findings suggest that GPR65 is overexpressed in glioblastoma and its high expression predicts unfavorable clinical outcome for patients. Targeting GPR65 may serve as a potential therapy for treating glioblastoma.

The E3 ubiquitin ligase CHIP/miR-92b/PTEN regulatory network contributes to tumorigenesis of glioblastoma.

Glioblastoma (GBM) is the most frequent, aggressive and fatal tumor in the central nervous system, while PTEN signaling is frequently deregulated in human GBM. We previously reported the up-regulation of the carboxyl terminal of Hsp70-interacting protein (CHIP) in GBM, however, the causal link between its dysregulation and tumorigenesis has not been established. Using miRNA microarrays and quantitative RT-PCR (qRT-PCR), we found activation of CHIP leads to increased transcription of miR-92b. Further studies in T98G and LN229 cells showed overexpression of miR-92b elicited reduction of PTEN and efficiently rescued glioma development in CHIP knock-down cells. The core pathway, PI3K/Akt pathway, was then upregulated, which promoted GBM cell proliferation. Meanwhile, genetic ablation of miR-92b could restore PTEN expression and inhibit glioma growth. These data demonstrate that the CHIP/miR-92b/PTEN axis serves as a new mechanism underlying GBM tumorigenesis, providing potential new therapeutic targets.

High expression of WDR1 in primary glioblastoma is associated with poor prognosis.

Primary glioblastoma always has a fatal outcome despite maximal therapy. Identification and validation of prognostic biomarkers and novel therapeutics will be potentially powerful to transform the care of glioblastoma patients. In this study, we constructed Affymetrix gene microarrays with 14 glioma samples to screen for genes with potential prognostic value by hieratical clustering, and 83 genes including WD-repeat containing protein 1 (WDR1) were filtered out. WDR1 is a major co-factor collaborating with cofilin in actin cytoskeletal dynamics, which may play vital role in glioma proliferation and invasion. Further, The Cancer Genome Atlas (TCGA) database was utilizedto verify the expression of WDR1 and its prognostic implicationin 528 glioblastoma specimens. Survival and correlation analyses showed WDR1 expression was highly expressed and related to the prognosis of glioblastoma and the expression of signal transducer and activator of transcription 3 (STAT3), respectively (p<0.05). Finally, WDR1 expression was detected in our large cohort containing 258 glioma patients (including 100 primary glioblastomas).And univariate and multivariate analyses confirmed that high WDR1 expression was an independent prognostic factor for a shorter progression-free survival (PFS) and overall survival (OS) in primary glioblastoma patients at our center [hazard ratio (HR)=1.844, p=0.005 and HR=2.085, p=0.001, respectively]. Together, WDR1 is significantly over-expressed in primary glioblastoma. High expression of WDR1 can independently predict unfavorable clinical outcome for primary glioblastoma patients. This study identifies a novel prognostic biomarker and a potential therapeutic target for glioblastoma.

The challenges and the promise of molecular targeted therapy in malignant gliomas.

Malignant gliomas are the most common malignant primary brain tumors and one of the most challenging forms of cancers to treat. Despite advances in conventional treatment, the outcome for patients remains almost universally fatal. This poor prognosis is due to therapeutic resistance and tumor recurrence after surgical removal. However, over the past decade, molecular targeted therapy has held the promise of transforming the care of malignant glioma patients. Significant progress in understanding the molecular pathology of gliomagenesis and maintenance of the malignant phenotypes will open opportunities to rationally develop new molecular targeted therapy options. Recently, therapeutic strategies have focused on targeting pro-growth signaling mediated by receptor tyrosine kinase/RAS/phosphatidylinositol 3-kinase pathway, proangiogenic pathways, and several other vital intracellular signaling networks, such as proteasome and histone deacetylase. However, several factors such as cross-talk between the altered pathways, intratumoral molecular heterogeneity, and therapeutic resistance of glioma stem cells (GSCs) have limited the activity of single agents. Efforts are ongoing to study in depth the complex molecular biology of glioma, develop novel regimens targeting GSCs, and identify biomarkers to stratify patients with the individualized molecular targeted therapy. Here, we review the molecular alterations relevant to the pathology of malignant glioma, review current advances in clinical targeted trials, and discuss the challenges, controversies, and future directions of molecular targeted therapy.

VSIG4 is highly expressed and correlated with poor prognosis of high-grade glioma patients.

The high-grade glioma (HGG) remains as the greatest challenge for cancer management worldwide. Identification of novel therapeutics and diagnostic method is in urgent need. The V-set and immunoglobulin domain-containing protein 4 (VSIG4) is a complement receptor for C3b/iC3b and inhibits cytotoxic T lymphocytes activation, which may play important roles in glioma oncogenesis. In this study, we performed immunohistochemistry in tissue microarray to determine the expression of VSIG4 in malignant glioma and normal brain. We then applied univariate and multivariate analyses to evaluate the expression of VSIG4 and correlated with prognosis of glioma patients. We have shown that VSIG4 was significantly elevated in high-grade glioma compared with those of normal brain tissues (P<0.001). We have also found that high VSIG4 expression was an independent prognostic factor for a shorter progression-free survival (PFS) and overall survival (OS) in high-grade glioma patients [hazard ratio (HR) =1.786, P=0.011 and HR=2.199, P=0.001, respectively]. Patients with low VSIG4 expression had a significantly longer median OS and PFS than those with high VSIG4 expression. Subgroup analysis stratifying HGG patients by both VSIG4 expression and tumor grade further confirmed the independent prognostic role of VSIG4 in HGG patients, while no adjuvant radiotherapy, small extent of resection and higher tumor grade were other three independent risk factors for HGG poor prognosis. Similar findings were also obtained using data from Cancer Genome Atlas (TCGA). Together, our results support that VISG4 can be used as a prognostic factor and potentially an immunotherapeutic target for glioma.