[show abstract][hide abstract] ABSTRACT: Glioma is the most common and fatal primary brain tumour with poor prognosis; however, the functional roles of miRNAs in glioma malignant progression are insufficiently understood. Here, we used an integrated approach to identify miRNA functional targets during glioma malignant progression by combining the paired expression profiles of miRNAs and mRNAs across 160 Chinese glioma patients, and further constructed the functional miRNA-mRNA regulatory network. As a result, most tumour-suppressive miRNAs in glioma progression were newly discovered, whose functions were widely involved in gliomagenesis. Moreover, three miRNA signatures, with different combinations of hub miRNAs (regulations≥30) were constructed, which could independently predict the survival of patients with all gliomas, high-grade glioma and glioblastoma. Our network-based method increased the ability to identify the prognostic biomarkers, when compared with the traditional method and random conditions. Hsa-miR-524-5p and hsa-miR-628-5p, shared by these three signatures, acted as protective factors and their expression decreased gradually during glioma progression. Functional analysis of these miRNA signatures highlighted their critical roles in cell cycle and cell proliferation in glioblastoma malignant progression, especially hsa-miR-524-5p and hsa-miR-628-5p exhibited dominant regulatory activities. Therefore, network-based biomarkers are expected to be more effective and provide deep insights into the molecular mechanism of glioma malignant progression.
Nucleic Acids Research 11/2013; · 8.28 Impact Factor
[show abstract][hide abstract] ABSTRACT: Isocitrate dehydrogenase (IDH) gene mutation is one of the most exciting new advances in these years. It has been reported that IDH gene frequently altered in grade II and grade III gliomas. We aimed to identify the mutation frequency of IDH genes in Chinese anaplastic glioma patients, the association of IDH gene mutation with other clinical and molecular pathological features and the prognostic value of it.
We performed polymerase chain reaction-based IDH gene mutation detection in 203 anaplastic glioma patients from China.
A total of 108 and 3 patients harbored IDH1 and IDH2 gene mutation, respectively. And there was a higher proportion of MGMT promoter methylation, frontal lobe location, and better outcome and lower proportion of temporal location in IDH-mutated samples. There were hardly any significant association between protein expression level of well-known markers and IDH mutation. Anaplastic oligoastrocytoma and anaplastic astrocytoma patients with IDH gene mutation showed similar prognosis with anaplastic oligodendroglioma patients with wild-type IDH gene.
IDH gene mutation is a good prognostic marker and a potential substratification factor for anaplastic glioma patients.
Journal of Cancer Research and Clinical Oncology 10/2013; · 2.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Ki-67 is an excellent indicator of glioma cell growth. However, limited information is available regarding the mechanisms underlying abnormal expression of Ki-67 in glioma tissue. The aim of this study is to identify Ki-67 specific miRNA-mRNA interactions on basis of miRNA and mRNA expression profilings. METHODS: We performed a large-scale miRNA (n=829) and mRNA (n=29421) expression profiling in primary glioblastoma multiforme (pGBM) and anaplastic astrocytoma (AA) tissues (with an aim to investigate Ki-67 related miRNAs and mRNAs. From target prediction databases, the targeting relationships between Ki-67 specific miRNAs and mRNAs were established, and functions of these mRNAs were analyzed by DAVID. The functional verifications of the candidate miRNA were also performed in LN229 cell line. RESULTS: High expression level of Ki-67 protein predicted a shorter survival time for patients with AA. Integrated analysis of profiling data from pGBM and AA revealed 4 Ki-67 positively and 5 negatively correlated miRNAs, along with the top 12 Ki-67 positively and 2 negatively correlated mRNAs. By means of target prediction, we found that the target mRNAs employed by miR-218 were the most significant among Ki-67 specific mRNAs. Up-regulation of miR-218 was further demonstrated to reduce Ki-67 expression, promote apoptosis, and induce G0/G1 phase cell cycle arrest in LN229 cells. CONCLUSIONS: Ki-67 protein may be regulated by specific miRNA-mRNA interactions which may contribute to the proliferation of glioma cells.
[show abstract][hide abstract] ABSTRACT: Background
Dysregulated zinc transport has been observed in many cancers. However, the status of zinc homeostasis and the expression profile of zinc transporters in brain and brain tumors have not been reported.Methods
The gene profiles of 14 zinc importers (ZIPs) and 10 zinc exporters (ZnTs) in patients with glioma were studied by investigating the association between the zinc transporters and brain tumor characteristics (tumor grade and overall survival time). Three independent cohorts were analyzed to cross-validate the findings: the Chinese Glioma Genome Atlas (CGCA) cohort (n = 186), the US National Cancer Institute Repository for Molecular Brain Neoplasia Data (REMBRANDT) cohort (n = 335), and The University of Texas (UT) cohort (n = 34).ResultsThe expression of ZIP3, 4, 8, 14, ZnT5, 6, and 7 were increased, and the expression of ZnT10 was decreased in grade IV gliomas, compared with grade II gliomas. Among all 24 zinc transporters, ZIP4 is most significantly associated with tumor grade and overall survival; this finding is consistent across 2 independent cohorts (CGCA and REMBRANDT) and is partially validated by the third cohort (UT). High ZIP4 expression was significantly associated with higher grade of gliomas and shorter overall survival (hazard ratio = 1.61, 95% confidence interval = 1.02-2.53, P = .040 in CGCA cohort; hazard ratio = 1.32, 95% confidence interval = 1.08-1.61, P = .007 in REMBRANDT cohort).Conclusions
Dysregulated expression of zinc transporters is involved in the progression of gliomas. Our results suggest that ZIP4 may serve as a potential diagnostic and prognostic marker for gliomas.
[show abstract][hide abstract] ABSTRACT: To analyze the clinical characteristics and prognostic factors in patients with glioma in an academic institute in China. From October 2004 to August 2010, total 1,285 patients were diagnosed as glioma at the Glioma Center of Beijing Tiantan Hospital. Clinical and molecular pathology features and survival rates were analyzed. The median overall survival (OS) times were 78.1, 37.6 and 14.4 months for low-grade glioma (WHO grade II), anaplastic glioma (WHO grade III) and glioblastoma (WHO grade IV), respectively. In patients with low-grade glioma, age, preoperative Karnofsky performance scale (KPS), pathological type, radiotherapy, O6-methylguanine-DNA methyltransferase (MGMT) expression and Ki-67 expression, were significantly associated with OS in multivariate analyses; and preoperative KPS and radiotherapy were significantly associated with progression-free survival (PFS). For anaplastic gliomas, age, preoperative KPS, pathological type, extent of resection, radiotherapy, p53 expression and phosphatase and tensin homolog (PTEN) expression were associated with OS. For glioblastomas, age, preoperative KPS, pathology type, extent of resection, radiotherapy and chemotherapy were associated with OS; and age, gender, preoperative KPS, extent of resection, radiotherapy and chemotherapy were associated with PFS. This is the largest survey for glioma management in China to date. We found significant differences in age, presenting symptoms and the expression of p53, MGMT, PTEN, and Ki-67 among patients with different types of glioma. Age, preoperative KPS, tumor grades, radiotherapy, chemotherapy and Ki-67 expression were significantly associated with clinical prognosis.
Journal of Neuro-Oncology 03/2013; · 3.12 Impact Factor
[show abstract][hide abstract] ABSTRACT: MicroRNAs (miRNAs) are single-stranded, 18- to 23-nt RNA molecules that function as regulators of gene expression. Previous studies have shown that microRNAs play important roles in human cancers, including gliomas. Here, we found that expression levels of miR-181b were decreased in gliomas, and we identified IGF-1R as a novel direct target of miR-181b. MiR-181b overexpression inhibited cell proliferation, migration, invasion, and tumorigenesis by targeting IGF-1R and its downstream signaling pathways, PI3K/AKT and MAPK/ERK1/2. Overexpression of IGF-1R rescued the inhibitory effects of miR-181b. In clinical specimens, IGF-1R was overexpressed, and its protein levels were inversely correlated with miR-181b expression. Taken together, our results indicate that miR-181b functions in gliomas to suppress growth by targeting the IGF-1R oncogene and that miR-181b may serve as a novel therapeutic target for gliomas.
[show abstract][hide abstract] ABSTRACT: High-grade gliomas (HGGs) account for the vast majority of all gliomas, including glioblastoma (World Health Organization (WHO) grade IV) and anaplasticgliomas (WHO grade III). Despite tremendous efforts in developing multimodal treatments, the overall prognosis remains poor; however, survival time varies considerably between patients. The nature of diffuse permeation into surrounding brain parenchyma poses dilemma for neurosurgeons between extensive surgical resection to eliminate as much as tumor cells as possible and adverse effects associated with brain function. Heterogeneity in both cytology and gene expression makes it difficult to coordinate an effective therapy which works for every patient. This article reviews recent advancements in the molecular mechanism, multimodal treatment and clinical management, and the updated view on the biomarkers in patients with HGG, both in primary and recurrent setting, with an emphasis on targeted therapies tailored to the patient.
[show abstract][hide abstract] ABSTRACT: The human Distal-less Homeobox (DLX) gene family encodes homeobox transcription factors involved in the control of morphogenesis and tissue homeostasis, which is primarily expressed in embryonic development. Recently, DLX gene family was reported to have essential roles in carcinogenesis. We have profiled whole genome expressed genes in 83 glioblastoma multiforme (GBM) patients from the Chinese Glioma Genome Atlas (CGGA) Group. Two major groups of samples were identified in mRNA expression profiles (referred to as Group 1 (G1) and Group 2 (G2)). We identified 7 out of the top 10 Gene Ontology terms in the G1 group were associated with differentiation and development of neuronal cell. The most significant prognostic gene was DLX2 (P<0.001, OR=1.744); overexpression of DLX2 indicated poor survival in the 83 GBM patients (low DLX2 vs. high DLX2, 77.6 vs. 44.7 weeks, P<0.001). Annotation of mRNA profiling data on GBM from The Cancer Genome Atlas and MD Anderson Cancer Center showed the proneural and neural subtypes highly correlated with low and high DLX2 expression, respectively. Knocking down of DLX2 in GBM cell line-LN229 results in decreased cyclin D1 expression and cell proliferation. Collectively, these data identified high expression of DLX2 as a poor prognostic marker to GBM patients.
Current Molecular Medicine 01/2013; · 4.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Background
Aberrant activation of beta-catenin/TCF4 and STAT3 signaling in glioblastoma multiforme (GBM) has been reported. However, the molecular mechanisms related to this process are still poorly understood.Methods
Genome-wide screening of the binding characteristics of the transcription factors TCF4 and STAT3 in GBM cells was performed by chromatin immunoprecipitation sequencing (ChIP-seq) assay. Hierarchical clustering was used to analyze the association of TCF4 and STAT3 coregulated genes with The Cancer Genome Atlas (TCGA) GBM subtypes (classical, mesenchymal, neural, and proneural). New molecular classification of GBM was proposed and validated in Western and Asian populations.ResultsWe identified 1250 overlapping putative target genes that were coregulated by TCF4 and STAT3. Further, the coregulated genes had the potential to guide TCGA GBM subtypes. Finally, we proposed a new molecular classification of GBM into 2 subtypes (proneural-like and mesenchymal-like) and showed that the new classification could be applied to both Western and Asian populations. In addition, the GBM response to temozolomide therapy differed depending on its subtype; mesenchymal-like GBM benefited, while there was no benefit for proneural-like GBM.Conclusions
This is the first comprehensive study to combine a ChIP-seq assay of TCF4 and STAT3 and data mining of patient cohorts to derive molecular subtypes of GBM.
[show abstract][hide abstract] ABSTRACT: To employ whole-genome messenger RNA profiling to identify the genes involved in malignant progression in glioma.
The whole genome expressed genes were profiled in 220 glioma patients from the Chinese Glioma Genome Atlas (97 LGGs and 123 HGGs). The differential expressed genes between LGG and HGG were identified by SAM analysis. Microarray data were validated by immunohistochemistry.
Among all the detected genes, the genes up-regulated mostly in high-grade glioma were IGFBP-2, CKLF, PTTG1, OSTCL and PTTG2 while those down-regulated mostly SEC31, RRP7B, HOOK3, SNRPN and CSMD3. Validation of IGFBP-2 with immunohistochemical staining showed a good correlation with the microarray data.
A panel of potential genes of malignant transformation may serve as future targets of gene therapy for glioma.
[show abstract][hide abstract] ABSTRACT: Objective. This study is to investigate the effects of bone marrow mesenchymal stem cell (BMSC) transplantation on acute liver failure (ALF). Methods. BMSCs were separated from rat bone marrow, cultured, and identified by flow cytometry. Rat model with ALF was established by injecting D-galactosamine and lipopolysaccharide. Rats were randomly divided into the control group and BMSC transplantation group. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured at 24 h, 120 h, and 168 h after BMSC transplantation. Apoptosis was detected by TUNEL assay. The expression of VEGF and AFP proteins was detected by immunofluorescence. Caspase-1 and IL-18 proteins and mRNA were detected by immunohistochemistry and RT-PCR. Results. Compared with the control group, levels of ALT, AST, caspase-1 and IL-18 proteins, and mRNA in the transplantation group were significantly lower at 120 h and 168 h after BMSCs transplantation. Apoptosis was inhibited by BMSCs transplantation. The VEGF protein levels were increased with the improvement of liver function, and the AFP protein levels were increased with the deterioration of the liver function after BMSCs transplantation. Conclusions. BMSCs transplantation can improve liver function and inhibit hepatocyte apoptosis as well as promote hepatocyte proliferation in rat model with ALF.
BioMed research international. 01/2013; 2013:251846.
[show abstract][hide abstract] ABSTRACT: MicroRNAs are strongly implicated as affecting glioma, but their specific roles and functions have yet to be fully elucidated. In this study, we defined the expression and function of miR-24, which we found to be upregulated in glioma samples and glioma cells by qRT-PCR. Downregulation of miR-24 in glioma cell lines inhibited proliferation and invasion and induced apoptosis. Using computational and expression analysis, ST7L was identified as a candidate target of miR-24. A reporter assay with the 3'UTR of ST7L cloned downstream of a luciferase gene showed increased luciferase activity in the absence of miR-24, providing strong evidence that miR-24 is a direct regulator of ST7L. Furthermore, we observed that restoration of ST7L activity resulted in effects that were similar to those from transfecting a miR-24 inhibitor into glioma cells. Mechanistic investigation revealed that the deletion of miR-24 suppressed β-catenin/Tcf-4 transcription activity by targeting ST7L. In conclusion, our study demonstrates that miR-24 upregulation is common in glioma and that suppression of miR-24 expression inhibits cell proliferation and invasion, suggesting that miR-24 may act as an oncogene in glioma.
[show abstract][hide abstract] ABSTRACT: Defining glioma subtypes based on objective genetic and molecular signatures may allow for a more rational, patient-specific approach to molecularly targeted therapy. However, prior studies attempting to classify glioma subtypes have given conflicting results. We aim to complement and validate the existing molecular classification system on a large number of samples from an East Asian population. A total of 225 samples from Chinese patients was selected for whole genome gene expression profiling. Consensus clustering was applied. Three major groups of gliomas were identified (referred to as G1, G2, and G3). The G1 subgroup correlates with a good clinical outcome, young age, and extremely high frequency of IDH1 mutations. Relative to the G1 subgroup, the G3 subgroup is correlated with a poorer clinical outcome, older age, and a very low rate of mutations in the IDH1 gene. Correlations of the G2 subgroup with respect to clinical outcome, age, and IDH1 mutation fall between the G1 and G3 subgroups. In addition, the G2 subtype was associated with a higher percentage of loss of 1p/19q when compared with G1 and G3 subtypes. Furthermore, our classification scheme was validated on 2 independent datasets derived from the cancer genome atlas (TCGA) and Rembrandt. With use of the TCGA classification system, proneural, neural, and mesenchymal, but not classical subtype, associated gene signatures were clearly defined. In summary, our results reveal that 3 main subtypes stably exist in Chinese patients with glioma. Our classification scheme may reflect the clinical and genetic alterations more clearly. Classical subtype-associated gene signature was not found in our dataset.
[show abstract][hide abstract] ABSTRACT: Abstract MSH6 (mutS homolog 6), one of the five key mismatch repair (MMR) genes, was found to play an important role in conferring resistance to alkylating agents - temozolomide (TMZ) in malignant glioma. This study aims to investigate whether genetic variations in MSH6 gene are associated with the survival outcomes in patients with malignant glioma. Each exon of the MSH6 gene was sequenced and single nucleotide polymorphism (SNP) analysis was performed using 74 tumor tissues from glioblastoma multiforme (GBM) patients. Among these patients, 54 patients received radiotherapy plus temozolomide (TMZ) treatment; 20 patients had radiotherapy only. The promoter methylation of O6-methylguanine methyltransferase (MGMT) was measured by MSP (methylation specific PCR). Literature mining and related data collection were done with NCBI and PubMed databases. Of the 74 GBM patients, 50% (n = 37) harbored MSH6 G268A polymorphism and no significant rates of other SNP or gene mutation across MSH6 exons were detected. The median OS was 15.6 months for who harbored the SNP and 12.6 months for SNP-negative patients (log-rank test: P = 0.324). The median OS for the MGMT promoter methylation group (n = 25) and non-methylation group (n = 29) of the 54 GBM patients treated with TMZ was 21.3 and 8.9 months respectively (P = 0.002). In conclusion, we identified a high frequency of MSH6 G268A polymorphism in MSH6 gene, which did not have a notable influence on survival for the malignant glioma patients with/without TMZ treatment.
The International journal of neuroscience 10/2012; · 0.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: To date, the aberrations in the DNA methylation patterns that are associated with different prognoses of G-CIMP- primary GBMs remain to be elucidated. Here, DNA methylation profiling of primary GBM tissues from 13 long-term survivors (LTS; overall survival ⩾18months) and 20 short-term survivors (STS; overall survival ⩽9months) was performed. Then G-CIMP+ samples were excluded. The differentially expressed CpG loci were identified between residual 18 STS and 9 LTS G-CIMP- samples. Methylation levels of 11 CpG loci (10genes) were statistically significantly lower, and 43 CpG loci (40genes) were statistically significantly higher in the tumor tissues of LTS than those of STS G-CIMP- samples (P<0.01). Of the 43 CpG loci that were hypermethylated in LTS G-CIMP- samples, 3 CpG loci localized in the promoter of ALDH1A3. Furthermore, using an independent validation cohort containing 37 primary GBM samples without IDH1 mutation and MGMT promoter methylation, the hypermethylation status of ALDH1A3 promoter predicted a better prognosis with an accompanied low expression of ALDH1A3 protein. Taken together, our results defined prognosis-related methylation signatures systematically for the first time in G-CIMP- primary GBMs. ALDH1A3 promoter methylation conferred a favorable prognosis in G-CIMP- primary GBMs.
[show abstract][hide abstract] ABSTRACT: Notch pathway plays critical role in stem cell maintenance and angiogenesis, as well as cell fate decisions of cancer. However, concrete mechanisms of notch pathway regulation in glioma were not well known, especially mediated by microRNAs. In this study, we identified a brain-specific miRNA, miR-524-5p, which was associated with the pathological grade and overall survival of gliomas. Restorated expression of miR-524-5p in glioma suppressed cell proliferation and invasion both in vitro and in vivo. Using bioinformatics and biological approaches, we found that Jagged-1 and Hes-1, two key components of notch pathway, were direct targets of miR-524-5p. Knocking down of Jagged-1 or Hes-1 partially phenocopied miR-524-5p re-expression, whereas forced expression of Jagged-1 or Hes-1 reversed the effects of miR-524-5p on proliferation and invasion of glioma. Moreover, miR-524-5p levels in glioma samples were inversely correlated with Jagged-1 and Hes-1 and their overexpressions were associated with poor survival. Thus, we have identified that miR-524-5p behaves as a tumor suppressor by negatively targeting Jagged-1 and Hes-1 and provides an additional option to inhibit this oncogene in gliomas.
[show abstract][hide abstract] ABSTRACT: The invasive behavior of glioblastoma multiforme (GBM) cells is one of the most important reasons for the poor prognosis of this cancer. For invasion, tumor cells must acquire an ability to digest the extracellular matrix and infiltrate the normal tissue bordering the tumor. Preventing this by altering effector molecules can significantly improve a patient's prognosis. Accumulating evidence suggests that miRNAs are involved in multiple biological functions, including cell invasion, by altering the expression of multiple target genes. The expression levels of miR-218 correlate with the invasive potential of GBM cells. In this study, we found that miR-218 expression was low in glioma tissues, especially in GBM. The data showed an inverse correlation in 60 GBM tissues between the levels of miR-218 and MMP mRNAs (MMP-2, -7 and -9). Additionally, ectopic expression of miR-218 suppressed the invasion of GBM cells whereas inhibition of miR-218 expression enhanced the invasive ability. Numerous members of the MMP family are downstream effectors of the Wnt/LEF1 pathway. Target prediction databases and luciferase data showed that LEF1 is a new direct target of miR-218. Importantly, western blot assays demonstrated that miR-218 can reduce protein levels of LEF1 and MMP-9. We, therefore, hypothesize that miR-218 directly targets LEF1, resulting in reduced synthesis of MMP-9. Results suggest that miR-218 is involved in the invasive behavior of GBM cells and by targeting LEF1 and blocking the invasive axis, miR-218-LEF1-MMPs, it may be useful for developing potential clinical strategies.
[show abstract][hide abstract] ABSTRACT: MET, the receptor for hepatocyte growth factor receptor (HGF), has been reported to trigger multiple and sometimes opposing cellular responses in various types of tumor cells. It has been implicated in the regulation of tumor-cell survival, proliferation, angiogenesis, invasion and metastasis. However, the MET regulatory mechanism in glioma is not well known. MicroRNAs are a class of small noncoding RNAs that play important roles in a variety of biological processes including human cancers. In this study, we used computational and expressional analysis to identify that the 'seed sequence' of miR-410 matched the 3' UTR of the MET mRNA. Besides, the expression of miR-410 was inversely associated with MET in human glioma tissues. Using luciferase and western blot assay, we certified that miR-410 directly targeted MET in glioma cells. While restoring expression of miR-410 led to proliferation inhibition and reduced invasive capability in glioma cells. Furthermore, we showed that miR-410 played an important role in regulating MET-induced AKT signal transduction. While downregulation of MET by RNAi, we observed that MET knockdown resulted in effects similar to that with miR-410 transfection in glioma cells. Our findings suggest that miR-410, a direct regulator of MET, may function as a tumor suppressor in human gliomas.
The international journal of biochemistry & cell biology 06/2012; 44(11):1711-7. · 4.89 Impact Factor