IGF2BP2 modulates autophagy and serves as a prognostic marker in glioma.

Glioma, a malignant brain tumor originating from neural glial cells, presents significant treatment challenges. However, the underlying mechanisms of glioma development are not fully understood, and effective targets are lacking. This study provides insights into the role of insulin-like growth factor 2 messenger RNA-binding protein 2 (IGF2BP2) in glioma progression and its therapeutic potential. Our analysis illustrated that elevated IGF2BP2 expression associated with significantly shorter survival among patients with low-grade glioma (LGG) in The Cancer Genome Atlas (TCGA) database. IGF2BP2 depletion led to compromised cell viability, G0/G1 phase arrest, and reduced colony-formation ability. Furthermore, ultrastructural analysis and mCherry-GFP-LC3 reporter assay revealed an increased abundance of autophagosomes upon IGF2BP2 knockdown. Western blot analysis corroborated these findings by showing reduced p62 levels coupled with increased LC3-ІІ/LC3-I ratio upon IGF2BP2 knockdown. A multicolor immunohistochemistry assay demonstrated the positive correlation between IGF2BP2 and p62 expression in glioma patient samples. Additionally, our analysis suggested a link between IGF2BP2 expression and drug-resistant markers in TCGA-LGG samples, and Cell Counting Kit-8 cell viability assay revealed that knockdown of IGF2BP2 sensitized cells to temozolomide treatment. This comprehensive exploration unveils the role of IGF2BP2 in glioma progression, shedding light on autophagy modulation and chemosensitization strategies for glioma therapy.

Depletion of the N6-Methyladenosine (m6A) reader protein IGF2BP3 induces ferroptosis in glioma by modulating the expression of GPX4.

Emerging evidence highlights the multifaceted contributions of m6A modifications to glioma. IGF2BP3, a m6A modification reader protein, plays a crucial role in post-transcriptional gene regulation. Though several studies have identified IGF2BP3 as a poor prognostic marker in glioma, the underlying mechanism remains unclear. In this study, we demonstrated that IGF2BP3 knockdown is detrimental to cell growth and survival in glioma cells. Notably, we discovered that IGF2BP3 regulated ferroptosis by modulating the protein expression level of GPX4 through direct binding to a specific motif on GPX4 mRNA. Strikingly, the m6A modification at this motif was found to be critical for GPX4 mRNA stability and translation. Furthermore, IGF2BP3 knockdown glioma cells were incapable of forming tumors in a mouse xenograft model and were more susceptible to phagocytosis by microglia. Our findings shed light on an unrecognized regulatory function of IGF2BP3 in ferroptosis. The identification of a critical m6A site within the GPX4 transcript elucidates the significance of post-transcriptional control in ferroptosis.

Opposite Mechanical Preference of Bone/Nerve Regeneration in 3D-Printed Bioelastomeric Scaffolds/Conduits Consistently Correlated with YAP-Mediated Stem Cell Osteo/Neuro-Genesis.

To systematically unveil how substrate stiffness, a critical factor in directing cell fate through mechanotransduction, correlates with tissue regeneration, novel biodegradable and photo-curable poly(trimethylene carbonate) fumarates (PTMCFs) for fabricating elastomeric 2D substrates and 3D bone scaffolds/nerve conduits, are presented. These substrates and structures with adjustable stiffness serve as a unique platform to evaluate how this mechanical cue affects the fate of human umbilical cord mesenchymal stem cells (hMSCs) and hard/soft tissue regeneration in rat femur bone defect and sciatic nerve transection models; whilst, decoupling from topographical and chemical cues. In addition to a positive relationship between substrate stiffness (tensile modulus: 90-990 kPa) and hMSC adhesion, spreading, and proliferation mediated through Yes-associated protein (YAP), opposite mechanical preference is revealed in the osteogenesis and neurogenesis of hMSCs as they are significantly enhanced on the stiff and compliant substrates, respectively. In vivo tissue regeneration demonstrates the same trend: bone regeneration prefers the stiffer scaffolds; while, nerve regeneration prefers the more compliant conduits. Whole-transcriptome analysis further shows that upregulation of Rho GTPase activity and the downstream genes in the compliant group promote nerve repair, providing critical insight into the design strategies of biomaterials for stem cell regulation and hard/soft tissue regeneration through mechanotransduction.

Choroid plexus mast cells drive tumor-associated hydrocephalus.

Tumor-associated hydrocephalus (TAH) is a common and lethal complication of brain metastases. Although other factors beyond mechanical obstructions have been suggested, the exact mechanisms are unknown. Using single-nucleus RNA sequencing and spatial transcriptomics, we find that a distinct population of mast cells locate in the choroid plexus and dramatically increase during TAH. Genetic fate tracing and intracranial mast-cell-specific tryptase knockout showed that choroid plexus mast cells (CPMCs) disrupt cilia of choroid plexus epithelia via the tryptase-PAR2-FoxJ1 pathway and consequently increase cerebrospinal fluid production. Mast cells are also found in the human choroid plexus. Levels of tryptase in cerebrospinal fluid are closely associated with clinical severity of TAH. BMS-262084, an inhibitor of tryptase, can cross the blood-brain barrier, inhibit TAH in vivo, and alleviate mast-cell-induced damage of epithelial cilia in a human pluripotent stem-cell-derived choroid plexus organoid model. Collectively, we uncover the function of CPMCs and provide an attractive therapy for TAH.

Dihydroartemisinin inhibits EMT of glioma via gene BASP1 in extrachromosomal DNA.

The mechanism of dihydroartemisinin (DHA) inhibiting the migration and invasion of glioma in an ROS-DSB-dependent manner has been revealed. Extrachromosomal DNAs (ecDNAs) which are generated by DNA damage have great potential in glioma treatment. However, the role of ecDNAs in DHA's pharmacological mechanisms in glioma is still unknown. In this study, DHA was found to inhibit proliferative activity, increase ROS levels and promote apoptosis in U87 and U251 cells. Migration and invasion have also been suppressed. ecDNA expression profiles were found in gliomas. EcDNA-BASP1 was found, by means of bioinformatics analysis, to be present in GBM tissues and positively correlated with patient prognosis. Proliferation, migration and invasion were upregulated after knockdown of ecDNA-BASP1. The expression of vimentin and N-cadherin also had the same tendency. Finally, we found that the ecDNA-BASP1 content in nude mouse transplant tumors was significantly increased after DHA treatment, which might exert a better suppressive effect on glioma. The upregulation of tumor suppressor ecDNA-BASP1 played an important role in the suppression of glioma progression induced by DHA. EcDNA-BASP1 may inhibit glioma migration and invasion through repressing epithelial-mesenchymal transition (EMT).

Identification of a copper metabolism-related gene signature for predicting prognosis and immune response in glioma.

BACKGROUND: Gliomas are highly refractory intracranial cancers characterized by genetic and transcriptional heterogeneity. However, therapeutic options are limited. In the last years, copper-induced cell death is becoming a prospective treatment strategy for gliomas and other solid tumors, but copper metabolism-related genes associated with cancer development remain unclear. METHODS: We first collected gene expression data from The Cancer Genome Atlas (TCGA) to identify significantly differentially expressed copper metabolism-related genes in gliomas. Using these genes, we performed COX regression and Least Absolute Shrinkage and Selection Operator (LASSO) regression to construct the prognostic model. The prognostic value of the model was further validated by CGGA testing set. Subsequently, functional analyses were carried out, including gene set enrichment analysis (GSEA), immune infiltration analysis, and mutation analysis. Finally, the expression levels of these genes were verified by immunohistochemical analysis. RESULTS: The prognostic model consisted of 7 genes: CDK1, LOXL2, LOXL3, NFE2L2, SLC31A1, SUMF1 and FDX1. According to this prognosis model, glioma patients could be split into the high-risk group or low-risk group, and the low-risk group showed significantly better prognostic survival (p < 0.001). Moreover, the high-risk group had higher levels of immune cell infiltration, immune checkpoint genes expression, and higher tumor mutational burden (TMB), which indicates that they might benefit more from immunotherapy. Finally, we confirmed the expression level of FDX1, SUMF1, and SLC31A1 protein as significantly different in glioblastoma, lower-grade glioma, and non-tumor brain tissues by immunohistochemical analysis, and the high expression of FDX1 and SLC31A1 protein was related to poor survival in glioma patients. CONCLUSIONS: Our study could contribute to the prognosis prediction and decision-making in patients with gliomas.

Artemisia annua Extract Improves the Cognitive Deficits and Reverses the Pathological Changes of Alzheimer's Disease via Regulating YAP Signaling.

Alzheimer's disease (AD) is a chronic neurodegenerative disease characterized by the occurrence of cognitive deficits. With no effective treatments available, the search for new effective therapies has become a major focus of interest. In the present study, we describe the potential therapeutic effect of Artemisia annua (A. annua) extract on AD. Nine-month-old female 3xTg AD mice were treated with A. annua extract for three months via oral administration. Animals assigned to WT and model groups were administrated with an equal volume of water for the same period. Treated AD mice significantly improved the cognitive deficits and exhibited reduced Aß accumulation, hyper-phosphorylation of tau, inflammatory factor release and apoptosis when compared with untreated AD mice. Moreover, A. annua extract promoted the survival and proliferation of neural progenitor cells (NPS) and increased the expression of synaptic proteins. Further assessment of the implicated mechanisms revealed that A. annua extract regulates the YAP signaling pathway in 3xTg AD mice. Further studies comprised the incubation of PC12 cells with Aß1-42 at a concentration of 8 µM with or without different concentrations of A. annua extract for 24 h. Obtained ROS levels, mitochondrial membrane potential, caspase-3 activity, neuronal cell apoptosis and assessment of the signaling pathways involved was performed using western blot and immunofluorescence staining. The obtained results showed that A. annua extract significantly reversed the Aß1-42-induced increase in ROS levels, caspase-3 activity and neuronal cell apoptosis in vitro. Moreover, either inhibition of the YAP signaling pathway, using a specific inhibitor or CRISPR cas9 knockout of YAP gene, reduced the neuroprotective effect of the A. annua extract. These findings suggest that A. annua extract may be a new multi-target anti-AD drug with potential use in the prevention and treatment of AD.

Protective effects of berberine against ß-amyloid-induced neurotoxicity in HT22 cells via the Nrf2/HO-1 pathway.

Neuronal apoptosis has been found to have a pivotal role in the course of Alzheimer's disease (AD). Berberine (BBR), a potent antioxidant, occurs in plants such as Berberis, Phellodendron chinense, and Hydrastis canadensis. In this study, a neuronal apoptotic model was established in vitro using HT22 cells induced by Aß25-35 to explore whether BBR contributes to protecting neurons against Aß25-35-induced neurotoxicity, as well as its potential mechanisms. BBR was applied to HT22 cells for 1 h prior to exposing the cells to Aß25-35 for 24 h. A CCK-8 assay was utilized to assess cell viability, and Annexin V - fluorescein isothiocyanate (FITC)/propidium iodide and Hoechst 33342 fluorescence staining were used to measure the rate of cell apoptosis. Existing scientific literature was also reviewed to further determine the effects of BBR on ROS production and mitochondrial function in HT22 cells. Furthermore, the expressions of proteins, including cytochrome C, cleaved caspase-3, p-p65, p65, and Nrf2/HO-1 antioxidant axis were assessed by Western blotting. The data indicated that BBR markedly improved cell viability, inhibited apoptosis and intracellular ROS levels, improved mitochondrial membrane potentials, decreased the rate of p-p65/p65, cytochrome C, and cleaved caspase-3, and intensified the activity of Nrf2/HO-1 antioxidants in HT22 cells. Overall, the findings indicated that BBR provides a certain level of neuroprotectiveness in HT22 cells exposed to Aß25-35 via relieving oxidative stress, as well as by restraining the mitochondrial pathway of cellular apoptosis. In addition, the restraint of NF-κB activity and sensitization of the Nrf2/HO-1 antioxidant axis, which together are intimately involved in the neuroprotection of BBR, may be possible mechanisms accounting for its effectiveness against Aß25-35in vitro.

VLA-4 suppression by senescence signals regulates meningeal immunity and leptomeningeal metastasis.

Leptomeningeal metastasis is associated with dismal prognosis and has few treatment options. However, very little is known about the immune response to leptomeningeal metastasis. Here, by establishing an immunocompetent mouse model of breast cancer leptomeningeal metastasis, we found that tumor-specific CD8+ T cells were generated in deep cervical lymph nodes (dCLNs) and played an important role in controlling leptomeningeal metastasis. Mechanistically, T cells in dCLNs displayed a senescence phenotype and their recruitment was impaired in mice bearing cancer cells that preferentially colonized in leptomeningeal space. Upregulation of p53 suppressed the transcription of VLA-4 in senescent dCLN T cells and consequently inhibited their migration to the leptomeningeal compartment. Clinically, CD8+ T cells from the cerebrospinal fluid of patients with leptomeningeal metastasis exhibited senescence and VLA-4 downregulation. Collectively, our findings demonstrated that CD8+ T cell immunosenescence drives leptomeningeal metastasis.

Development of a preoperative index-based nomogram for the prediction of hypokalemia in patients with pituitary adenoma: a retrospective cohort study.

OBJECTIVE: To develop and validate a preoperative index-based nomogram for the prediction of hypokalemia in patients with pituitary adenoma (PA). METHODS: This retrospective cohort study included 205 patients with PAs between January 2013 and April 2020 in the Sun Yat-sen Memorial Hospital, Guangzhou, China. The patients were randomly classified into either a training set (N = 143 patients) and a validation set (N = 62 patients) at a ratio of 7:3. Variables, which were identified by using the LASSO regression model were included for the construction of a nomogram, and a logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) in the training set. The area under the curve (AUC) was used to evaluate the performance of the nomogram for predicting hypokalemia. Multivariate logistic regression analysis with a restricted cubic spline analysis was conducted to identify a potential nonlinear association between the preoperative index and hypokalemia. RESULTS: The incidence of hypokalemia was 38.05%. Seven preoperative indices were identified for the construction of the nomogram: age, type of PA, weight, activated partial thromboplastin time, urea, eosinophil percentage, and plateletocrit. The AUCs of the nomogram for predicting hypokalemia were 0.856 (95% CI [0.796-0.915]) and 0.652 (95% CI [0.514-0.790]) in the training and validation sets, respectively. Restricted cubic splines demonstrated that there was no nonlinear association between hypokalemia and the selected variables. CONCLUSION: In this study, we constructed a preoperative indices-based nomogram that can assess the risk of hypokalemia after the surgical treatment of pituitary adenomas. This nomogram may also help to identify high risk patients who require close monitoring of serum potassium.

LncRNA TCONS_00004099-derived microRNA regulates oncogenesis through PTPRF in gliomas.

BACKGROUND: Glioblastoma is the most common and aggressive primary tumor in the central nervous system (CNS). Patients with glioblastomas have poor prognosis due to its aggressive clinical behavior and resistance to the chemotherapeutic agent temozolomide (TMZ). Aberrant long non-coding RNAs (lncRNAs) are involved in glioma progression and its regulatory mechanisms. Analysis of sequencing data identified a new lncRNA, named lncRNA TCONS_00004099, which could derive a new microRNA and was highly expressed in glioma. METHODS: To elucidate the role of lncRNA TCONS_00004099 in gliomas, Quantitative Real-time PCR (qPCR) was used to assess the differential expression of lncRNA TCONS_00004099 and its related miRNA in glioma tissues, normal brain tissues, glioma cell lines (U87 and U251 cells), and a normal human embryonic brain cell line (HEB). Cell Counting Kit-8 (CCK8) assays to assess cell proliferation, flow cytometry assays examining apoptosis and the cell cycle, colony formation assays, wound healing assay, transwell assays, and zebrafish xenograft models were performed to further clarify the effects of the lncRNA and the related miRNA. Finally, Western blots were carried out to verify the mechanisms related to PTPRF (Protein Tyrosine Phosphatase Receptor Type F). RESULTS: LncRNA TCONS_00004099 was significantly increased in glioma tissues and glioma cell lines. A novel miRNA (miRNA TCONS_00004099) derived from the lncRNA was identified by qPCR. Knockdown of this lncRNA suppressed cell proliferation, migration, invasion and enhanced TMZ-induced apoptosis in U87 and U251 cell lines in vitro and in vivo. The miRNA mimics or inhibitor of miRNA TCONS_00004099 was used to reverse the effects of knockdown or overexpression of lncRNA TCONS_00004099, respectively. Western Blot analyses verified that PTPRF is one of the downstream targets of lncRNA TCONS_00004099. CONCLUSIONS: These results demonstrated that lncRNA TCONS_00004099 promoted malignant behaviors in gliomas, including proliferation, metastasis, and anti-apoptosis. The effect of lncRNA TCONS_00004099 was mediated through miRNA TCONS_00004099 and its target PTPRF. Thus, the lncRNA TCONS_00004099/miRNA/PTPRF axis may be a potential therapeutic target for gliomas.

Hsa_circ_0080229 upregulates the expression of murine double minute-2 (MDM2) and promotes glioma tumorigenesis and invasion via the miR-1827 sponging mechanism.

BACKGROUND: Glioma is the most common and fatal primary cranial tumor. The epidermal growth factor receptor (EGFR) plays an important role in the occurrence and treatment of glioma, which might function through a circular ribonucleic acid (circRNA)-related mechanism. Hsa_circ_0080229 (circ_0080229) has been identified as a circRNA arising from an EGFR gene in gliomas; however, little is known about its molecular mechanism to date. METHODS: To address this question, a series of experiments were conducted to confirm the effect of circ_0080229 in gliomas and identify the downstream mechanism. A quantitative real-time polymerase chain reaction (qRT-PCR) analysis and in-situ hybridization/fluorescence in-situ hybridization (ISH/FISH) testing were performed to identify the expression of circ_0080229 in patient samples. Bioinformatic analysis was carried out to explore the possible mechanism. Next, a series of in-vitro functional assays and in-vivo assays with a xenograft subcutaneous glioma model was carried out to confirm the effect of circ_0080229. Finally, qRT-PCR analysis and a Western Blot analysis were performed to verify the related mechanism. RESULTS: The expression of circ_0080229 was upregulated in both glioma tissues and cell lines related to unfavorable clinicopathologic characteristics. The expression of circ_0080229 was found to be inversely correlated with miR-1827, a micro-ribonucleic acid (miRNA) targeting murine double minute-2 (MDM2). The downregulation of circ_0080229 inhibited gliomas in vivo and suppressed U87 and U251 cell lines in vitro, which the transfection of the miR-1827 inhibitor could reverse. Concerning the mechanism, a block of circ_0080229 decreased MDM2 expression, while the inhibition of miR-1827 reversed this effect. Thus, circ_0080229 appears to target the downstream miR-1827/MDM2 signaling pathway. CONCLUSIONS: Our results showed that the silencing of circ_0080229 upregulates the expression of miR-1827, which in turn resulted in the suppression of MDM2, and the mediation of the downstream P53 signaling pathway. Circ_0080229 exerted an effect in mediating tumor progression through the MDM2 signaling pathway by sponging miR-1827. Its importance as a potential prognostic biomarker in gliomas has thus been established.

Whole-exome sequencing identifies somatic mutations associated with lung cancer metastasis to the brain.

BACKGROUND: Lung cancer is the most aggressive cancer, resulting in one-quarter of all cancer-related deaths, and its metastatic spread accounts for >70% of these deaths, especially metastasis to the brain. Metastasis-associated mutations are important biomarkers for metastasis prediction and outcome improvement. METHODS: In this study, we applied whole-exome sequencing (WES) to identify potential metastasis-related mutations in 12 paired lung cancer and brain metastasis samples. RESULTS: We identified 1,702 single nucleotide variants (SNVs) and 6,131 mutation events among 1,220 genes. Furthermore, we identified several lung cancer metastases associated genes (KMT2C, AHNAK2). A mean of 3.1 driver gene mutation events per tumor with the dN/dS (non-synonymous substitution rate/synonymous substitution rate) of 2.13 indicating a significant enrichment for cancer driver gene mutations. Mutation spectrum analysis found lung-brain metastasis samples have a more similar Ti/Tv (transition/transversion) profile with brain cancer in which C to T transitions are more frequent while lung cancer has more C to A transversion. We also found the most important tumor onset and metastasis pathways, such as chronic myeloid leukemia, ErbB signaling pathway, and glioma pathway. Finally, we identified a significant survival associated mutation gene ERF in both The Cancer Genome Atlas (TCGA) (P=0.01) and our dataset (P=0.012). CONCLUSIONS: In summary, we conducted a pairwise lung-brain metastasis based exome-wide sequencing and identified some novel metastasis-related mutations which provided potential biomarkers for prognosis and targeted therapeutics.

Long noncoding RNA MEG3 silencing protects against hypoxia-induced pheochromocytoma-12 cell injury through inhibition of TIMP2 promoter methylation.

Hypoxia is a common pathological process caused by insufficient oxygen. Long noncoding RNAs (lncRNAs) have been proven to participate in this pathology. Hypoxia is reported to significantly reduce the secretion of tissue inhibitor of metalloproteinase 2 (TIMP2) and TIMP2 induces pheochromocytoma-12 (PC12) cell cycle arrest. Thus, our study aimed to explore the mechanism by which lncRNA maternally expressed gene 3 (MEG3) was implicated in hypoxia-induced PC12 cell injury through TIMP2 promoter methylation. To elucidate the potential biological significance of MEG3 and the regulatory mechanism between MEG3 and TIMP2, a hypoxia-induced PC12 cell injury model was generated. The hypoxia-exposed cells were subjected to a series of overexpression plasmids and short hairpin RNAs, followed by the measurement of levels of MEG3, TIMP2, lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS), Bcl-2-associated X protein, B-cell lymphoma-2, and caspase-3, as well as the changes in MMP, cell proliferation, apoptosis, and cell cycle progression. On the basis of the findings, MEG3 was upregulated in hypoxia-injured PC12 cells. MEG3 recruited methylation proteins DNMT3a, DNMT3b, and MBD1 and accelerated TIMP2 promoter methylation, which in turn inhibited its expression. Moreover, PC12 cells following MEG3 silencing and TIMP2 overexpression exhibited significantly decreased levels of LDH, MDA, and ROS along with cell apoptosis, yet increased SOD and MMP levels, as well as cell cycle entry to the S phase and cell proliferation. In conclusion, MEG3 silencing suppresses hypoxia-induced PC12 cell injury by inhibiting TIMP2 promoter methylation. This study may provide novel therapeutic targets for hypoxia-induced injury.

Acquired temozolomide resistance in MGMT-deficient glioblastoma cells is associated with regulation of DNA repair by DHC2.

The acquisition of temozolomide resistance is a major clinical challenge for glioblastoma treatment. Chemoresistance in glioblastoma is largely attributed to repair of temozolomide-induced DNA lesions by O6-methylguanine-DNA methyltransferase (MGMT). However, some MGMT-deficient glioblastomas are still resistant to temozolomide, and the underlying molecular mechanisms remain unclear. We found that DYNC2H1 (DHC2) was expressed more in MGMT-deficient recurrent glioblastoma specimens and its expression strongly correlated to poor progression-free survival in MGMT promotor methylated glioblastoma patients. Furthermore, silencing DHC2, both in vitro and in vivo, enhanced temozolomide-induced DNA damage and significantly improved the efficiency of temozolomide treatment in MGMT-deficient glioblastoma. Using a combination of subcellular proteomics and in vitro analyses, we showed that DHC2 was involved in nuclear localization of the DNA repair proteins, namely XPC and CBX5, and knockdown of either XPC or CBX5 resulted in increased temozolomide-induced DNA damage. In summary, we identified the nuclear transportation of DNA repair proteins by DHC2 as a critical regulator of acquired temozolomide resistance in MGMT-deficient glioblastoma. Our study offers novel insights for improving therapeutic management of MGMT-deficient glioblastoma.

Circular RNA hsa_circ_0076248 promotes oncogenesis of glioma by sponging miR-181a to modulate SIRT1 expression.

Glioma is one of the most common primary malignancies of the central nervous system, which has aggressive clinical behavior and a poorer prognosis. MicroRNAs (miRs) are a class of small noncoding RNAs that function as mediators of gene expression, which can be sponged by circRNA provided with a closed circular structure. Dysregulations of circular RNAs (circRNAs) and miRs have been implicated in the development and progression of glioma. In the current study, we investigated the role of circular RNA hsa_circ_0076248 in mediating the oncogenesis of glioma by sponging miR-181a to modulate silent information regulator 1 (SIRT1) expression in vitro and in vivo. The quantitative real-time polymerase chain reaction results showed that the expression of miR-181a was significantly decreased in glioma tissues and cell lines compared with normal brain tissues and normal gliocyte, respectively, and the expression of hsa_circ_0076248 and SIRT1 demonstrated the opposite. Bioinformatics analysis identified hsa_circ_0076248 could sponge miR-181a, and miR-181a could target the mRNA of SIRT1. Our results verified that downregulating hsa_circ_0076248 or upregulating miR-181a could depress the proliferation and invasion of glioma in vitro and in vivo. The experiment also showed that downregulating hsa_circ_0076248 or upregulating miR-181a could remarkably promote the temozolomide chemotherapy sensitivity. Furthermore, Western blot analysis testified that downregulating hsa_circ_0076248 or upregulating miR-181a could promote the expression of p53 and SIRT1. In summary, our study sheds light on the regulatory mechanism of hsa_circ_0076248 in glioma growth and invasion via sponging miR-181a, which downregulates the SIRT1 expression and also suggests that hsa_circ_0076248, miR-181a, and SIRT1 may serve as potential therapeutic targets for glioma.

Prospective Series of Nine Long Noncoding RNAs Associated with Survival of Patients with Glioblastoma.

OBJECTIVE: To analyze the long noncoding RNA (lncRNA) expression profile of glioblastoma multiforme (GBM) and identify prognosis-related lncRNAs, as well as their related protein-coding genes and functions. METHOD: The lncRNA expression profiles were obtained by microarray in six samples each of GBM and normal brain tissue. The lncRNAs expressed were significantly different between the two groups and used to detect their associations with patient survival time by downloading the related data from The Cancer Genome Atlas (TCGA). The total RNA-sequencing data of 152 patients diagnosed GBM level 3 with complete clinic information was downloaded. The survival time-dependent lncRNAs were identified by multivariate Cox regression analysis. For the survival time-dependent lncRNAs, we used the Pearson correlation coefficient and z test to search their associated protein-coding genes downloaded from TCGA. Functions of these genes were annotated by the Database for Annotation, Visualization, and Integrated Discovery (DAVID) for gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. RESULTS: More than 1,000 antisense lncRNAs and enhancer lncRNAs were selected for analysis in this study. Data from 152 cases with RNA-seq of GBM level 3 with complete information on GBM were downloaded from the TCGA database. Univariate Cox regression analysis revealed 19 lncRNAs with survival time dependency. These nine lncRNAs were used to construct our survival model via multivariate Cox regression analysis: TP73-AS1, AC078883.3, RP11-944L7.4, HAR1B, RP4-635E18.7, HOTAIR, SAPCD1-AS1, AC104653.1, and RP5-1172N10.2. The nine lncRNAs associated with them were inputted into the DAVID database for gene ontology and KEGG function enrichment analysis. The result showed these genes were enriched with ion binding, transport, cell-cell signaling, plasma membrane parts, and more, and they were mainly related to neuroactive ligand-receptor interaction pathway, calcium signaling pathway, and the mitogen-activated protein kinase signaling pathway. CONCLUSION: The nine lncRNAs were a set of biomarkers for the prognosis of patients with GBM, enabling a more accurate prediction of survival and revealing more biological functions.

The Surgical Treatment of Posttraumatic Skull Base Defects with Cerebrospinal Fluid Leak.

Objectives The objective was to explore further the surgical treatment of posttraumatic skull base defects with cerebrospinal fluid (CSF) leak and to identify the most common factors affecting the surgical treatment of posttraumatic skull base defect with CSF leak retrospectively. Materials and Methods This study included 144 patients with head trauma having skull base defect with CSF leak who had been surgically treated at Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University from 1998 to June 2016. There were 113 (78.5%) males and 31 (21.5%) females, with age ranging from 1 to 78 years and mean age of 26.58 ± 14.95 years. We explored the surgical approaches for the treatment of the skull base defect and the graft materials used and also measured the association among surgical approaches; location, size, and type of skull base defects; presence or absence of associated intracranial pathologies; postoperative complications; outcome; age; Glasgow outcome score (GOS) at discharge; and days of hospital stay. Results The location, size, and types of skull base defect and the presence of associated intracranial pathologies were the common factors identified not only for choosing the appropriate surgical approach but also for choosing the materials for defect repair, timing of the surgery, and the method used for the defect as well as leak repair. The statistically significant correlation with p < 0.001 was found in this study. Conclusion From this study, we could conclude that size, location, and types of the defect and the presence of associated intracranial injuries were the common factors that affected the surgical treatment of posttraumatic skull base defect with CSF leak. Hence, the importance of careful evaluation of these factors is essential for proper selection of the surgical approach and for avoiding unnecessary hassles.

Overexpression of COX7A2 is associated with a good prognosis in patients with glioma.

Cytochrome c oxidase subunit 7A2 (COX7A2) is a nuclear-encoded polypeptide involved in assembly and regulation of cytochrome c oxidase (COX). Changes in the respiratory chain as big complex are known to be associated with cancer, but little research has been performed to discover COX7A2 as a prognostic marker in glioma. In the present study, we investigated COX7A2 expression and its prognostic significance in glioma. Glioma surgical tissue samples were taken from 126 patients who had been followed up from 4 to 51 months. Immunohistochemistry were used to test COX7A2 expression in the 126 tumor samples. Eighty-six of 126 (68.3%) paraffin-embedded glioma biopsies showed high expression of COX7A2. Statistical analysis displayed that there was significant difference of COX7A2 expression level in patients categorized according to WHO classification. Kaplan-Meier survival analysis revealed that patients with higher COX7A2 expression had longer overall survival time and better prognosis. R2: microarray analysis based on Tumor Glioma French 284 database, Tumor Glioblastoma TCGA 540 database, and Tumor Glioma Kawaguchi 50 database testified that high expression of COX7A2 is associated with a good prognosis in patients with glioma. Multivariate analysis showed that COX7A2 high expression was an independent prognostic indicator for survival. Our results suggest that COX7A2 could be served as a valuable prognostic marker of glioma.

[MACF1 knockdown in glioblastoma multiforme cells increases temozolomide-induced cytotoxicity].

OBJECTIVE: To investigate the role of microtubule-actin crosslinking factor 1 (MACF1) in the response of glioma cells to temozolomide (TMZ). METHODS: TMZ was applied to a human gliomablastoma cell line (U87) and changes in the protein expression and cellular localization were determined with Western blot, RT-PCR, and immunofluorescence. The responses of the cells with MACF1 expression knockdown by RNA interference to TMZ were assessed. TMZ-induced effects on MACF1 expression were also assessed by immunohistochemistry in a nude mouse model bearing human glioblastoma xenografts. RESULTS: TMZ resulted in significantly increased MACF1 expression (by about 2 folds) and changes in its localization in the gliomablastoma cells both in vitro and in vivo (P<0.01). Knockdown of MACF1 reduced the proliferation (by 45%) of human glioma cell lines treated with TMZ (P<0.01). TMZ-induced changes in MACF1 expression was accompanied by cytoskeletal rearrangement. CONCLUSION: MACF1 may be a potential therapeutic target for glioblastoma.