Development Of Human Glioma Research Articles

Ultrafast Detection of Monoamine Oxidase A in Live Cells and Clinical Glioma Tissues Using an Affinity Binding‐Based Two‐Photon Fluorogenic Probe

AbstractAbnormal expression of monoamine oxidase A (MAO−A) has been implicated in the development of human glioma, making MAO−A a promising target for therapy. Therefore, a rapid determination of MAO−A is critical for diagnosis. Through in silico screening of two‐photon fluorophores, we discovered that a derivative of N,N‐dimethyl‐naphthalenamine (pre‐mito) can effectively fit into the entrance of the MAO−A cavity. Substitutions on the N‐pyridine not only further explore the MAO−A cavity, but also enable mitochondrial targeting ability. The aminopropyl substituted molecule, CD1, showed the fastest MAO−A detection (within 20 s), high MAO−A affinity and selectivity. It was also used for in situ imaging of MAO−A in living cells, enabling a comparison of the MAO−A content in human glioma and paracancerous tissues. Our results demonstrate that optimizing the affinity binding‐based fluorogenic probes significantly improves their detection rate, providing a general approach for rapid detection probe design and optimization.

Ultrafast Detection of Monoamine Oxidase A in Live Cells and Clinical Glioma Tissues Using an Affinity Binding-Based Two-Photon Fluorogenic Probe.

Abnormal expression of monoamine oxidase A (MAO-A) has been implicated in the development of human glioma, making MAO-A a promising target for therapy. Therefore, a rapid determination of MAO-A is critical for diagnosis. Through in-silico screening of two-photon fluorophores, we discovered that a derivative of N,N-dimethyl-naphthalenamine (pre-mito) can effectively fit into the entrance of MAO-A cavity. Substitutions on the N-pyridine not only further explore the MAO-A cavity, but also enable mitochondrial targeting ability. The aminopropyl substituted molecule, CD1, showed the fastest MAO-A detection (within 20 s), high MAO-A affinity and selectivity. It was also used for in situ imaging of MAO-A in living cells, enabling a comparison of the MAO-A content in human glioma and paracancerous tissues. Our results demonstrate that optimizing the affinity binding-based fluorogenic probes significantly improves their detection rate, providing a general approach for rapid detection probe design and optimization.

MicroRNA-542 suppressed the proliferation of human glioma cells by targeting talin-2 (TLN2)

Purpose: To investigate the effect of miR-542 in the development of human glioma.
 Methods: The expressions of miR-542 and TLN2 in glioma cells and normal human astrocytes were determined using qRT-PCR, while MTT and colony formation assays were used to determine cell proliferation. Western blotting was used to determine protein expression.
 Results: It was revealed that miR-542 was significantly downregulated in glioma cells. Overexpression of miR-542 inhibited the proliferation and clonogenicity of glioma cells via induction of apoptosis. The percentage of apoptotic U87 cells increased from 5.32 in control to 26.76 upon miR-542 overexpression. Moreover, TLN2 was identified as the functional regulatory target of miR542 in glioma. The expression of TLN2 was markedly upregulated in human glioma cells. However, overexpression of miR-542 suppressed TLN2 expression. Silencing of TLN2 mimicked the tumor-suppressive effects of miR-542 in glioma cells, but this effect was blocked by TLN2 over-expression.
 Conclusion: These results suggest that miR-542 exerted glioma-suppressive effect, with TLN2 as its functional regulatory target.
 Keywords: Glioma; Proliferation; Micro-RNA; Tumorigenesis; MiR-542; Apoptosis; Prognosis; talin-2; Oncogene

Expression Profiles and Bioinformatics Analysis of Full-length circRNA Isoforms in Gliomas

Background: Circular RNAs (circRNAs) are a newly discovered type of non-coding RNA, which have been demonstrated to act as microRNA (miRNA) “sponges” to modulate gene expression. Emerging evidence has confirmed that circRNAs take part in many biological processes in a variety of malignant tumors, including gliomas, suggesting that they could serve as biomarkers or therapeutic targets for tumors. The purpose of this study was to explore the roles of circRNAs in gliomas and to provide valuable clues for clinical diagnosis and treatment. Methods: RNA-seq data with poly(A)-/RNase R treatment was employed to investigate the expression profiles of circRNAs in tumor and paracancerous tissues derived from glioma patients. CircAST was used for full-length circRNA reconstruction and quantification. Bioinformatics analyses, including GO enrichment and KEGG pathway analyses, were performed to reveal the potential biological process and pathways of their host genes. A circRNA-miRNA interaction network was constructed to depict the interactions of the dysregulated circRNA transcripts with miRNAs. Results: A total of 20,474 circular transcripts that originated from 16,022 circRNAs were successfully reconstructed in the samples. We detected 646 upregulated and 112 downregulated circular transcripts in tumor tissues compared with paracancerous tissues. GO analysis revealed that their host genes may be related to positive regulation of GTPase activity, regulation of synaptic transmission, and glutamatergic and dendrite morphogenesis in the cytoplasm and cytosol. KEGG pathway analysis showed that the glutamatergic synapse, neurotrophin signaling pathway, and ErbB signaling pathway may be linked to the occurrence and development of gliomas. Conclusion: Our study revealed a comprehensive profile of differentially expressed circRNA transcripts in gliomas, indicating that aberrantly expressed circRNAs might play important roles in the occurrence and development of human gliomas.

Designing optimal combination therapy for personalised glioma treatment

Like it happens in other tumours, glioma cells co-evolve in a microenvironment consisting of bona fide tumour cells as well as a range of parenchymal cells, which produces numerous signalling molecules. Recently, the results of an in silico experiment suggested that a combination therapy that would target multiple key cytokines at the same time may be more effective for suppressing the growth of a tumour. The in silico experiments also showed that the optimal combination therapy is very much dependent on a patient’s molecular profile. In this work, we employ evolutionary algorithms for designing optimal combination therapy tailored to the patient’s tumour microenvironment. Experiments were performed using a state-of-the-art glioma microenvironment model, capable of imitating many characteristics of human glioma development, and many virtual patient profiles. Results show that the therapies designed by the presented memetic algorithm were very effective in impeding tumour growth and were tailored to the patient’s personal tumour microenvironment.

Roles of long non-coding RNAs in the hallmarks of glioma.

Glioma is one of the most common types of tumor of the central nervous system. Due to the aggressiveness and invasiveness of high-level gliomas, the survival time of patients with these tumors is short, at ~15 months, even after combined treatment with surgery, radiotherapy and/or chemotherapy. Recently, a number of studies have demonstrated that long non-coding RNA (lncRNAs) serve crucial roles in the multistep development of human gliomas. Gliomas acquire numerous biological abilities during multistep development that collectively constitute the hallmarks of glioma. Thus, in this review, the roles of lncRNAs associated with glioma hallmarks and the current and future prospects for their development are summarized.

GALE Promotes the Proliferation and Migration of Glioblastoma Cells and Is Regulated by miR-let-7i-5p.

PurposeGlioma is the most common and lethal type of brain tumor. While GALE (UDP-galactose-4-epimerase) has been shown to be overexpressed in some kinds of cancers, its expression in gliomas has not been reported. MicroRNAs (miRNAs) function as tumor suppressors in many cancers, and online datasets can be used to predict whether GALE is regulated by miR-let-7i-5p. In this investigation, we explored the effect and regulatory mechanisms of GALE on glioblastoma growth via miR-let-7i-5p.MethodsWe used a Cox proportional hazards model and publicly available datasets to examine the relationship between GALE and the survival rates of glioma patients. Bioinformatics predicted the targeting of GALE by miR-let-7i-5p. The proliferation, migration, cell cycle and apoptosis of human glioblastoma cells were assessed by relevant assays. We also demonstrated the effect of GALE on glioblastoma multiforme [GBM] tumor growth using an in vivo orthotopic xenograft model.ResultsGALE was upregulated in human gliomas, especially in high-grade gliomas (e.g., GBM). An obvious decline in GALE expression was observed in human glioblastoma cell lines (U87 and U251) following treatment with a small interfering RNA (siRNA) targeting GALE or miR-let-7i-5p mimics. Knockdown of GALE or overexpression of miR-let-7i-5p (with miR-let-7i-5p mimics) inhibited U87 and U251 cell growth. miR-let-7i-5p significantly restrained the migration ability of human glioblastoma cells in vascular mimic (VM), wound healing and transwell assays, and GALE promoted glioblastoma growth in vivo.ConclusionOur findings confirm that GALE plays an important role in promoting the development of human glioma and that GALE can be regulated by miR-let-7i-5p to inhibit human glioblastoma growth.Implications for cancer survivorsOur data show that cancer survivors have low GALE expression, which indicates that GALE may be a diagnostic biomarker and a promising therapeutic target in glioblastoma.

P11.52 Reduced expression of proteolipid protein 2 increases ER-stress-induced apoptosis and autophagy in glioblastoma

Abstract BACKGROUND The PLP2 gene encodes for the Proteolipid protein 2 (PLP2) which is an integral ion channel membrane protein of the endoplasmic reticulum. The protein has been shown to be involved in several human cancers, but the importance of PLP2 in gliomas is poorly understood. In the present study, we therefore investigated the role of PLP2 in human glioma development. MATERIAL AND METHODS Immunohistochemistry was carried out for paraffin-embedded glioma samples, and changes in protein level were detected by western blot analysis. Small interfering RNA transfections were used for knockdown of specific genes. Cell viability and proliferation was then assessed by CCK-8 assay and EdU assay. Transmission electron microscopy was used to observe the ultrastructure of the cells and flow cytometry for the evaluation of apoptosis. Finally, U87 and U251 cells were treated with lentiviral transduction to obtain stably PLP2-knockdown cell lines, which were used for an in vivo study. RESULTS Data from publicly available datasets (Rembrandt, TCGA and CGGA) showed a correlation between up-regulation of PLP2 levels and increased malignancy. This was confirmed by IHC staining of sections from our own clinical glioma samples. Mechanistically, down-regulation of PLP2 in U87 and U251 glioma cell lines decreased the proliferation and increased apoptosis and autophagy, mediated by ER-stress. In PLP2 knockdown U87 and U251 cells, autophagy inhibition by chloroquine (CQ) augmented apoptotic cell death. Finally, orthotopic U87-shPLP2 and U251-shPLP2 intracranial xenograft models revealed that down-regulating of PLP2 inhibited glioma development in vivo. CONCLUSION In conclusion, the results indicate that PLP2 expression is related to glioma progression, and could be a potential target for future treatment strategies.

Ubiquitin ligase RNF5 serves an important role in the development of human glioma

The ubiquitin ligase ring finger protein 5 (RNF5) has previously been associated with the development of breast cancer. Patients with breast cancer and high RNF5 expression have been demonstrated to have a shorter survival time compared with patients with low RNF5 expression. However, the role of RNF5 in human glioma has not been determined. The present study analyzed the role of RNF5 in gliomas using bioinformatics analysis. The results revealed that RNF5 was differentially expressed in non-cancerous brain tissues and different grades of glioma. Furthermore, a high RNF5 expression in patients with glioma was associated with an improved prognosis compared with patients with low expression. Gene Set Enrichment Analysis revealed that RNF5 was particularly associated with ‘Wnt signaling pathway’, ‘apoptosis’, ‘focal adhesion’ and ‘cytokine-cytokine receptor interaction’ in patients with glioma. Additionally, 4 potential ubiquitination substrates for RNF5 were predicted, including sorting nexin 10, proprotein convertase subtilisin/kexin type 1, leucine rich glioma inactivated 1 and solute carrier family 39 member 12. These findings provided the basis for further investigation on the role of RNF5 in tumors.

Knockdown of PEBP4 inhibits human glioma cell growth and invasive potential via ERK1/2 signaling pathway.

Phosphatidylethanolamine (PE)-binding protein 4 (PEBP4) is an antiapoptotic protein that is aberrantly expressed in various malignancies. We previously demonstrated that PEBP4 expression is dramatically induced in human gliomas and positively correlated with tumor grade and patient survival. However, the function of PEBP4 in human glioma development and underlying mechanisms remain largely unknown. By stable lentiviral vector-mediated silencing of PEBP4, we examined the effects of PEBP4 knockdown on the growth, apoptosis, and invasion of U251 and U373 human glioma cell lines using MTT, Transwell, colony formation, and flow cytometric assays. We examined the in vivo role of PEBP4 in tumor growth by inoculation of BALB/c nu/nu male mice with PEBP4-deficient U251 and U373 cells. The expression of cell cycle- and apoptosis-related proteins was analyzed by Western blotting and immunostaining. Knockdown of PEBP4 significantly reduced the proliferation and invasion of human glioma cells while inducing cell apoptosis by altering the expression of cell cycle- and apoptosis-related proteins. Mechanistically, PEBP4 knockdown led to activation of the extracellular signal-regulated kinases 1/2 (ERK1/2) pathway, an effect that could be reversed by U0126, a selective inhibitor of MEK1/2 (upstream of ERK1/2), suggesting involvement of ERK1/2 signaling in the regulation of glioma development and progression by PEBP4. We identified PEBP4 as a novel regulator mediating human glioma cell proliferation, invasion, and apoptosis as well as tumor formation and growth. Therefore, PEBP4 may be a potential therapeutic target in human glioma treatment.

Six-Transmembrane Epithelial Antigen of Prostate 3 Predicts Poor Prognosis and Promotes Glioblastoma Growth and Invasion

Recent evidence suggests that dysregulation of iron regulatory factors may play essential roles in cancer pathophysiology. Six-transmembrane epithelial antigen of prostate 3 (STEAP3) is a metalloreductase, which is vital for cellular iron uptake and homeostasis. However, the clinical significance and function of STEAP3 in the development of human gliomas remain unclear. Through analysis of publicly available databases, we found that STEAP3 was highly expressed in malignant gliomas, especially in the mesenchymal glioma molecular subtype and isocitrate dehydrogenase 1/2 (IDH1/2) wild-type gliomas. Expression levels of STEAP3 in gliomas correlated inversely with patient overall survival (OS) and served as an independent prognostic marker by multivariate Cox regression analysis. In functional assays performed with RNA knockdown, loss of STEAP3 attenuated aggressive phenotypes in glioma cells, including cell proliferation, invasion, and sphere formation in vitro and tumor growth in vivo. Finally, STEAP3 drives these activities by inducing mesenchymal transition, promoting transferrin receptor (TfR) expression, and activating STAT3-FoxM1 axis signaling. Taken together, these results indicate that STEAP3 functions as an oncogenic mediator in glioma progression and is thus a potential therapeutic target for the treatment of the disease.

TAGLN2 is a candidate prognostic biomarker promoting tumorigenesis in human gliomas

BackgroundTransgelin-2 (TAGLN2) is a member of the calponin family of actin-bundling proteins that is involved in the regulation of cell morphology, motility, and cell transformation. Here, the clinical significance and potential function of TAGLN2 in malignant gliomas were investigated.MethodsMolecular and clinical data was obtained from The Cancer Genome Atlas (TCGA) database. Gene ontology and pathway analysis was used to predict potential functions of TAGLN2. RNA knockdown was performed using siRNA or lentiviral contructs in U87MG and U251 glioma cell lines. Cells were characterized in vitro or implanted in vivo to generate orthotopic xenografts in order to assess molecular status, cell proliferation/survival, and invasion by Western blotting, flow cytometry, and 3D tumor spheroid invasion assay, respectively.ResultsIncreased TAGLN2 expression was associated with increasing tumor grade (P < 0.001), the mesenchymal molecular glioma subtype and worse prognosis in patients (P < 0.001). Immunohistochemistry performed with anti-TAGLN2 on an independent cohort of patients (n = 46) confirmed these results. Gene silencing of TAGLN2 in U87MG and U251 significantly inhibited invasion and tumor growth in vitro and in vivo. Western blot analysis revealed that epithelial-mesenchymal transition (EMT) molecular markers, such as N-cadherin, E-cadherin, and Snail, were regulated in a manner corresponding to suppression of the EMT phenotype in knockdown experiments. Finally, TAGLN2 was induced ~ 2 to 3-fold in U87MG and U251 cells by TGFβ2, which was also elevated in GBM and highly correlated with TAGLN2 mRNA levels (P < 0.001).ConclusionsOur findings indicate that TAGLN2 exerts a role in promoting the development of human glioma. The regulation and function of TAGLN2 therefore renders it as a candidate molecular target for the treatment of GBM.

A novel serum microRNA-based identification and classification biomarker of human glioma.

Malignant glioma is one of the most common primary brain tumors that develop via multiple pathways and gene deregulation. MicroRNAs are involved in human cancer development and progression, and their serum expression profiles of glioma patients may be useful for classifying cancers. However, the profile and molecular mechanism of serum microRNAs for human glioma are poorly understood. Thus, it is crucial to analyze microRNA expression in human glioma serum to identify molecular subclasses and early stage of glioma. In this study, we performed microRNA alteration that contributes to glioma profile via analysis of The Cancer Genome Atlas RNA sequencing data and other independent Gene Expression Omnibus microarray data. We identified the glioma-associated novel microRNA as a key regulator of human glioma development and progression. The putative novel miR-1825 was validated by real-time polymerase chain reaction and its expression was significantly decreased in the serum of glioma patients compared with healthy controls. Patients with high miR-1825 expression had a longer survival rate. Interestingly, we found that miR-1825 expression levels were dependent on tumor size and pathological grading in glioma patients, but not associated with other factors including age and T classification. MicroRNA-Gene Ontology network indicated that miR-1825 may play an important role in the development of human glioma including apoptosis, cell proliferation, and invasion. In vitro assays of miR-1825 inhibit U87 cell proliferation and invasion and induce apoptosis. Furthermore, we provide evidence that the tumor-suppressive microRNA miR-1825 controls KLF2 expression. Reporter gene analyses revealed that both microRNAs directly targeted the 3'-untranslated region of KLF2 messenger RNA. These data demonstrated that miR-1825 expression in serum of human glioma was associated with tumorigenesis and miR-1825 may be used as a biomarker for identification of the pathological grade of glioma.

PP75. DROSOPHILA MELANOGASTER AS A MODEL ORGANISM TO STUDY GLIOMA: LOCATION AND IDENTIFICATION OF FOLLISTATIN

Gliomas are the most common, malignant brain tumour found in the central nervous system. The main characteristics of gliomas is their rapid proliferation, resistance to current chemotherapies and their ability to infiltrate the brain. Brain tumours have a low survival rate due to the lack of available treatments. In the UK between 2010 and 2011, the survival rate was 14% for 10 or more year. The mortality rates for malignant brain and CNS tumours have increased by up to 24% in the UK between 1970 and 2012. As there is difficulty obtaining glioma samples, it is important to identify a suitable model organism. The main signalling pathways seen to be activated in human glioma development are the epithelial growth factor receptor (EGFR) and phosphatidylinositol-3 kinase (PI3K) pathways. The homologous EFGR and PI3K pathways have been studied greatly in drosophila, and show that there must be co-activation of the EGFR and PI3K pathways for cancer development to occur; leading to an increase in glial cell numbers by 50-100x fold. Follistatin is a protein which has been identified as a biomarker in malignant gliomas; by comparing normal serum to glioma serum it has shown that there is an overexpression of follistatin. Gliomas can be replicated in drosophila as there has been a high level of homology identified in human diseased states and in neural development. Follistatin studies have shown it has important roles in development and differentiation of tissues and organs. It acts as an inhibitor, binding to activin, bone morphogenetic proteins and other proteins which can be found in vertebrates. Follistatin has been identified within a number of different cancer types (such as prostate and ovarian), and plays an important role in cancer metastasis and angiogenesis. Serum studies have revealed follistatin is present in the early stages of cancer development; however the location and role of follistatin in cancer development has not been identified. Drosophila contain a homolog of follistatin, which will allow studies of follistatin in cancer within drosophila. By using drosophila as a model organism it will allow the location of follistatin and its involvement in glioma development to be identified. Immunohistochemistry is used to identify the location and distribution of a protein within a tissue or an organ. It is commonly used to identify which proteins are present in specific types of cancer. Follistatin has been identified to play a role in the early stages of glioma development. Therefore by using immunohistochemistry follistatin can be identified throughout the different stages of glioma development and possibly identify its role in this development. The aim of the research is to identify and locate the protein follistatin in drosophila by using immunohistochemistry. Using different larval instar stages, this will identify the distribution of follistatin in different stages of neural development. The hypothesis would be that follistatin is involved in the early stages of glial development and the distribution is important in glioma development compared to normal neural development.

C-Terminal Binding Protein is Involved in Promoting to the Carcinogenesis of Human Glioma.

C-terminal binding protein (CtBP) is responsible for regulating the pathogenesis of a lot of cancer types. However, whether CtBP1/2 is involved in regulating the growth and development of human glioma is still obscure. In the present study presented here, our results firstly reveal that CtBP1/2 deficiency, induced by siRNA interference, disrupts the functional integrity of the MRN complex that is responsible for DNA repair in human glioma cells. The dysfunction of the MRN complex further contributes to the up-regulation of ATM and Rad3-related kinase (ATR) and Chk1 signaling pathway, which inhibits cell cycle progression mediated by CDK2, preparing for the initiation of DNA repair. Under the condition of hypoxia, hypoxia-inducible factor-1α (HIF-1α) can be directly regulated by CDK2 on protein level, playing coordinately regulatory role in the carcinogenesis of human glioma cells. Overall, our findings reveal that CtBP1/2 is essential to promote to human glioma cell growth through maintaining the DNA stability regulated by the MRN/ATR/Chk1/CDK2/HIF-1α signaling pathway.

Loss of Diacylglycerol Kinase-Ζ Inhibits Cell Proliferation and Survival in Human Gliomas.

Diacylglycerol kinases ζ (DGKζ) is a critical lipid kinase which is involved in phosphatidic acid (PA) generation via diacylglycerol (DAG) phosphorylation. DGKζ is highly expressed in central nervous system and essential for brain development. Studies have indicated that DGKζ is associated with colon cancer invasion and metastasis. However, the involvement of DGKζ in human glioma development remains elusive. Here, we explored the impact and possible mechanisms of DGKζ knockdown on the proliferation and survival of glioma cells. The relationship between DGKζ expression status and human glioma stages was explored in 111 specimens of human gliomas via immunohistochemistry technology. Then the impact of DGKζ on cell proliferation, cell cycle, survival, and colony formation ability was determined in U-87 MG glioma cell lines via lentiviral-mediated small interfering (shRNA) strategy. The influence of DGKζ knockdown on global gene expression in U-87 MGglioma cell lines was further analyzed by microarray platform to reveal the possible molecular mechanisms underlying DGKζ-mediated glioma development and progression. Immunohistochemistry analysis revealed that DGKζ expression is positively correlated with human gliomagrade. Lentiviral-mediated small interfering (shRNA) strategyefficiently reduced DGKζ expression and DGKζ knockdown impaired cell proliferation, inhibited colony formation ability, and induced cell cycle arrest and cell apoptosis in U-87 MG glioma cells. Finally, microarray analysis revealed that multiple cancer-associated pathways and oncogenes were regulated by DGKζ knockdown, which provides insights into underlying mechansims of DGKζ-associated glioma development and progression. Our results established the positive correlation between DGKζ expression and gliomagrade. Furthermore, DGKζ knockdown in human glioma cell lines U-87 MG impaired cell proliferation, inhibited colony formation ability, and induced cell cycle arrest and apoptosis which microarray analysis showed that DGKζ knockdown interrupted multiple oncogenes and cancer-associated pathways. Taken together, we provided confidential evidence for the causal role of DGKζ in glioma development and progression.

GCN5 Potentiates Glioma Proliferation and Invasion via STAT3 and AKT Signaling Pathways.

The general control of nucleotide synthesis 5 (GCN5), which is one kind of lysine acetyltransferases, regulates a number of cellular processes, such as cell proliferation, differentiation, cell cycle and DNA damage repair. However, its biological role in human glioma development remains elusive. In the present study, we firstly reported that GCN5 was frequently overexpressed in human glioma tissues and GCN5 was positively correlated with proliferation of cell nuclear antigen PCNA and matrix metallopeptidase MMP9. Meanwhile, down-regulation of GCN5 by siRNA interfering inhibited glioma cell proliferation and invasion. In addition, GCN5 knockdown reduced expression of p-STAT3, p-AKT, PCNA and MMP9 and increased the expression of p21 in glioma cells. In conclusion, GCN5 exhibited critical roles in glioma development by regulating cell proliferation and invasion, which suggested that GCN5 might be a potential molecular target for glioma treatment.

Do relevant markers of cancer stem cells CD133 and Nestin indicate a poor prognosis in glioma patients? A systematic review and meta-analysis.

BackgroundCD133 and Nestin, as the markers of cancer stem cells, have recently been reported frequently in the pathogenesis and development of human gliomas. However, the prognostic role of CD133 and Nestin in gliomas still remains controversial. In this study, we aimed to evaluate the association between the expression of CD133 and Nestin and the outcome of glioma patients by conducting a systematic review and meta-analysis.MethodsWe performed systematically electronic and manual searches through the database of Pubmed and embase (until to December 25, 2014) for titles and abstracts which investigated the relationships between CD133 and Nestin expression and outcome of glioma patients. A systematic review and meta-analysis was executed to generate Pooled hazard ratios (HRs) with 95 % confidence intervals (CIs) for overall survival (OS) and progression-free survival (PFS).ResultsA total of 1,490 patients from 32 studies (13 articles) were included in the analysis. 19 studies and 13 studies investigated correlation between CD133 expression or Nestin and survival in gliomas, respectively. Our results showed that high CD133 expression in patients with glioma was associated with poor prognosis in terms of OS (HR 1.69; 95 % CI, 1.16–2.47; P =0.0060) and PFS (HR, 1.64; 95 % CI, 1.12–2.39; P = 0.010). In addition, high Nestin expression were associated with worse OS (HR 1.751; 95 % CI, 1.19–2.58, p = 0.004) but has no significant association with PFS (HR 1.55; 95 % CI, 0.96–2.51, p = 0.074). Even more important, the results of the subgroup meta-analyses show that that high CD133 expression was associated with worse prognosis in terms of OS and PFS in patients with WHO IV glioma but not WHO II-III. On the other hand, Nestin high expression was associated with worse prognosis in terms of OS and PFS in patients with WHO II-III glioma but not WHO IV.ConclusionHigh level of CD133 expression trends to correlate with a worse OS and PFS in glioma patients, especially WHO IV gliomas and Nestin high expression trends to correlate with a worse OS in glioma patients especially WHO II–III, revealing both the markers of cancer stem cells may as the potential pathological prognostic markers for glioma patients.

Adenovirus encoding Smad4 suppresses glioma cell proliferation and increases apoptosis through cell cycle arrest at G1 phase

Mothers against decapentaplegic homologue 4 (Smad4) is associated with several human cancers. However, the exact mechanism of Smad4 in human glioma is still unknown. In this study, we constructed a recombinant adenovirus encoding Smad4 and transduced it into glioma cells. The results demonstrated that the overexpression of Smad4 not only suppressed glioma cell proliferation but also increased cell apoptosis by promoting cell cycle arrest at G1 phase. Furthermore, an adenovirus encoding Smad4 suppressed tumor formation in nude mice. These findings clearly demonstrate that Smad4 plays an important role in human glioma development by regulating cell proliferation. Moreover, Smad4 may represent a potential therapeutic target in glioma.

Efficient inhibition of human glioma development by RNA interference-mediated silencing of PAK5.

Glioma is the most common type of primary intracranial tumor and is highly lethal due to its pathogenetic location, high invasiveness, and poor prognosis. Even combined surgery and chemoradiotherapy do not effectively rescue glioma patients. Molecular target therapy is considered a safe and promising therapy for glioma. The identification of a novel, effective target protein in gliomas is of great interest. We found that PAK5 was highly expressed in the tumor tissues of glioma patients and human glioma cell lines. We then used a lentivirus-delivered short hairpin RNA to stably silence PAK5 expression in glioma cells and explore its influence. The results showed that the inhibition of PAK5 reduced cell viability and delayed the cell cycle at the G0/G1 phase in the glioma cells with PAK5 high expression. In addition, silencing PAK5 expression in U87 cells weakened their colony formation ability and in vivo tumorigenesis ability. Further studies demonstrated that PAK5 inhibition led to an increase in cleaved caspase 3 and a decrease in β-catenin. In conclusion, our results suggest that the inhibition of PAK5 by RNA interference might efficiently suppress tumor development of glioma cells with PAK5 high expression. This finding provides a novel, promising therapeutic target for glioma treatment.