Project description:<p><strong>INTRODUCTION:</strong> Neuronal activity regulated by synaptic communication exerts an important role in tumorigenesis and progression in brain tumors. Genes for soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) annotated with the function ‘vesicle’ about synaptic connectivity were identified and one of these proteins, synaptosomal-associated protein 25 (SNAP25), was found to have discrepant expression levels in neuropathies. However, the specific mechanism and prognostic value of SNAP25 during glioma progression remain unclear. </p><p><strong>METHODS:</strong> Using RNA sequencing data from The Cancer Genome Atlas (TCGA) database, the differential synaptosis-related genes between LGG and GBM were identified as highly correlated. Cox proportional hazards regression analysis and survival analysis indicated that the candidate gene SNAP25 could differentiate the outcome of low- and high-risk patients, and the Chinese Glioma Genome Atlas (CGGA) cohort was used for validation of the data set. RT-qPCR, western blot, and immunohistochemistry assays were performed to examine the expression level of SNAP25 in glioma cells and samples. Functional assays were performed to identify the effects of SNAP25 knockdown and overexpression on cell viability, migration, and invasion. Then, an immunofluorescence assay of the xenograft tissue was applied to evaluate the expression of the neuronal dendron formation marker-MAP2. Liquid chromatography-high re solution mass spectrometry (LC-MS)-based metabolomics approach was presented for identifying crucial metabolic disturbances in glioma cells. In situ mouse xenograft model was used to investigate the role of SNAP25 in vivo.</p><p><strong>RESULTS:</strong> SNAP25 was down expressed in glioma tissues and cell lines and low-level SNAP25 indicated an unfavorable prognosis of glioma patients. SNAP25 inhibited cell proliferation, migration, invasion and fostered glutamate metabolism of glioma cells, exerting a tumor suppressor role. SNAP25 overexpression expressed lower expression of MAP2, indicating poor neuronal plasticity and connectivity. SNAP25 could interact with glutaminase(GLS)and GLS knockdown could rescue the anti-tumor effect of SNAP25 in glioma cells. Moreover, upregulation of SNAP25 also decreased tumor volume and prolonged the overall survival (OS) of the xenograft mouse.</p><p><strong>CONCLUSION:</strong> SNAP25 inhibited carcinogenesis of glioma via sponging glutamate metabolism by regulating GLS expression, as well as inhibiting dendritic formation, which could be considered as a molecular target for glioma diagnosis and therapy.</p>
Project description:Background: we preliminarily outlined the expression of hsa_circ_0008922 in glioma and explored its biological functions. Methods:with RNA sequencing of a panel of glioma tissues and normal brain tissues, The 10 tissues were divided into two groups:C (normal brain tissue, n = 5) and T (tumor tissue, n = 5). With the hsa_circ_0008922 downregulated cells, a series of assays were carried out as follows. Results:We found that the expression of hsa_circ_0008922 in glioma tissues was 3.4 times higher than that in normal tissues. And the expression of has_circ_0008922 was correlated with WHO tumor grade. After down-regulating the expression of hsa_circ_0008922, malignant biological behavior of glioma cells was inhibited, such as cell proliferation, colony formation, migration, and invasion.
Project description:This study demonstrated the effects of lncRNA HOTAIR knockdown on the glioma proteomics. An abnormally high expression of the lncRNA HOTAIR has been previously demonstrated in glioma cells. HOTAIR regulates genes by anchoring epigenetic modification proteins and causes abnormalities in multiple signaling pathways. We knocked down HOTAIR in glioma cells by siRNA with SILAC labeling, and then total protein was extracted for proteome mass spectrometry.
Project description:BackgroundA glioma is a tumor originating from glial cells in the central nervous system. Although significant progress has been made in diagnosis and treatment, most high-grade glioma patients are prone to recurrence. Therefore, molecular targeted therapy may become a new direction for adjuvant therapy in glioma. In recent years, many studies have revealed that circular RNA (circRNA) may play an important role in the occurrence and development of many tumors including gliomas. Our previous study found that the expression of hsa_circ_0008922 was up-regulated in glioma tissues upon RNA sequencing. The biological mechanism of circ_0008922 is still unreported in gliomas. Therefore, in this study, we preliminarily outlined the expression of hsa_circ_0008922 in glioma and explored its biological functions.MethodsThe expression of hsa_circ_0008922 in forty glioma tissues and four glioma cell lines (A172, U251, SF763 and U87) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The correlation between hsa_circ_0008922 expression and clinicopathological features of glioma patients was evaluated by Fisher's exact test. To understand the potential function of hsa_circ_0008922 in glioma, we constructed small interfering RNA (siRNA) to hsa_circ_0008922 to downregulate its expression in glioma cell lines A172 and U251. With these hsa_circ_0008922 downregulated cells, a series of assays were carried out as follows. Cell proliferation was detected by CCK8 assay, migration and invasion were determined by wound healing assay and transwell assay, respectively. Colony formation ability was evaluated by plate clonogenic assay. Moreover, flow cytometry combined with Western blot was performed to analyze apoptosis status and the expression of apoptotic related proteins (caspase 3 and caspase 9). Finally, the possible biological pathways and potential miRNA targets of hsa_circ_0008922 were predicted by bioinformatics.ResultsWe found that the expression of hsa_circ_0008922 in glioma tissues was 3.4 times higher than that in normal tissues. The expression of has_circ_0008922 was correlated with WHO tumor grade. After down-regulating the expression of hsa_circ_0008922, malignant biological behavior of glioma cells was inhibited, such as cell proliferation, colony formation, migration, and invasion. At the same time, it also induced apoptosis of glioma cells. Predicted analysis by bioinformatics demonstrated that hsa_circ_0008922 may be involved in tumor-related pathways by acting as a molecular sponge for multiple miRNAs (hsa-let-7e-5p, hsa-miR-506-5p, hsa-let-7b-5p, hsa-let-7c-5p and hsa-let-7a-5p). Finally, we integrated our observation to build a circRNA-miRNA-mRNA predictive network.
Project description:Transcriptional profiling of human glioma cells to elucidate the role of chronophin (CIN/PDXP) for glioma pathogenesis three-condition experiment: control cells vs. knockdown and knockdown vs. rescue
Project description:Insulin-like growth factor-binding protein 2 (IGFBP2) is increasingly recognized as a glioma oncogene, emerging as a target for therapeutic intervention. In this study, we used an integrative approach to characterizing the IGFBP2 network, combining transcriptional profiling of human glioma with validation in glial cells and the replication competent ASLV long terminal repeat with a splice acceptor/tv-a glioma mouse system. We demonstrated that IGFBP2 expression is closely linked to genes in the integrin and integrin-linked kinase (ILK) pathways and that these genes are associated with prognosis. We further showed that IGFBP2 activates integrin ?1 and down- stream invasion pathways, requires ILK to induce cell motility, and activates NF-?B. Most significantly, the IGFBP2/integrin/ILK/NF-?B network functions as a physiologically active signaling pathway in vivo by driving glioma progression; interfering with any point in the pathway markedly inhibits progression. The results of this study reveal a signaling pathway that is both targetable and highly relevant to improving the survival of glioma patients. We performed cDNA microarray analysis to compare two stably expressing cell lines originating from SNB19; two clones expressing a mutant form of IGFBP2 that cannot bind integrin (RGD ? RGE point mutation; referred to as RGE mutant); and two clones expressing wild-type IGFBP2. SNB19 clones transfected with empty vector were placed in the reference channel in each hybridization.