Human Glioma Cell Line U251 Research Articles

LncRNA MIR4435-2HG functions as a ceRNA against miR-125a-5p and promotes neuroglioma development by upregulating TAZ.

BackgroundExpression of the TAZ gene is closely related to the prognosis of glioma patients. We hoped to find long noncoding RNAs (lncRNAs) related to TAZ and a new target for glioma treatment.MethodsTAZ‐related genes were found by dual‐luciferase reporter gene assay, and the correlation of each gene was analyzed by the Pearson method. Human glioma cell lines U87 MG and U251 and glioma rats were used for cytology assays, and the related genes were transfected. We conducted immunohistochemistry, RT‐qPCR, Western blotting, CCK8 test, flow cytometry, transwell assays, clone formation analysis, and tumor weight measurements to verify the above relationship.ResultsWe found that miR‐125a‐5p was closely related to the TAZ gene, and the lncRNA MIR4435‐2HG was closely related to miR‐125a‐5p. Both MIR4435‐2HG‐OE and TAZ increased the expression of the TAZ gene, activated the Wnt signaling pathway, inhibited apoptosis, and promoted migration and proliferation in glioma cells. Besides, it also increased the tumor volume of gliomas in a rat model subcutaneously inoculated with glioma cells. We also found miR‐125a‐5p could block the effect of MIR4435‐2HG‐OE and TAZ.ConclusionsLncRNA MIR4435‐2HG obstructs the functions of miR‐125a‐5p and promotes neuroglioma development by upregulating the TAZ gene.

High-throughput and high-sensitivity capillary electrophoresis\u2013mass spectrometry method for sulfur-containing amino acids

Biological thiol amino acids have been suggested as biomarkers for pathological changes because they are reactive chemicals that participate in various physiological processes. In this study, multisegmented injection capillary electrophoresis–mass spectrometry with online sample preconcentration was used for analysis of thiol amino acids and intermediates of sulfur metabolism in human glioma cell line U-251 with high accuracy, throughput, and sensitivity. This was achieved using multiple, large-volume injections for online sample preconcentration. The 16 intermediates of sulfur metabolism had a good linear correlation coefficient range of 0.984–1 and the limit of detection range was 1.4–203.9 ng/mL. The recovery ranges of most amino acids were 88.1–114.5%, 89.0–104.3%, and 76.9–104.5% at 0.3, 0.75, and 1.5 μg/mL, respectively. The relative standard deviation ranges for the inter- and intra-day precision were 1.8–10.7% and 4.3–18.8%, respectively. Compared with the traditional injection method, the analytical time for compounds in sulfur metabolism was reduced to 4 min/sample, the method throughput was enhanced five times, and the sensitivity was increased 14.4–33.1 times. Customized injection sequences were applied in experimental optimization. The developed method simplified the experimental optimization to one injection and is suitable for the analysis of sulfur metabolites in biological samples and has high sensitivity, throughput, speed, and accuracy.

Establishment and Validation of the Detection of TERT Promoter Mutations by Human Gliomas U251 Cell Lines.

Gliomas are the most common type of primary brain tumor, yet the prognosis for glioma patients remains poor. Mutations in the promoter region of the telomerase reverse transcriptase gene (TERTp) are associated with diagnosis and poor prognosis in gliomas. Here, we developed a precise and rapid Sanger sequencing assay to screen or TERTp mutations. We established the Sanger sequencing approach for the detection of TERTp mutations based on human glioma cell lines U251 and assessed the analytical validation by determining the accuracy, sensitivity, precision, and specificity. In our study, we verified the accuracy of Sanger sequencing by the real-time polymerase chain reaction method. Our data showed that TERTp mutations were detected at an analytical sensitivity of 10% per mutant. The precision and specificity validation also showed the desired results. In total, 147 glioma patients were investigated for TERTp mutations, and of each patient, clinical data and molecular characteristics were analyzed. We found that anaplastic oligodendroglioma had the highest frequency of TERTp mutations (66.7%). No differences in TERTp mutation frequency were observed between frozen tissue specimens and formalin-fixed and paraffin-embedded tissue. TERTp mutations were associated with older patients (≥45 years), whereas isocitrate dehydrogenase (IDH) mutations were inclined to a younger age (<45 years), frontal location, and pathologic stage II-III patients. IDH mutations were significantly associated with O6-methylguanine-DNA methyltransferase (MGMT) methylation (P = 0.003) and lower Ki-67 protein expression (P = 0.011). Moreover, MGMT methylation was enriched in IDH-mutant/TERTp-mutant gliomas, and Ki-67 protein expression was the highest in the IDH-wild type/TERTp-mutant group. Taken together, the findings of this study indicate the establishment of a rapid, precise, and practical Sanger sequencing technique for TERTp mutations in gliomas that may show promising results in clinical applications.

Inhibition of glioma by adenovirus KGHV500 encoding anti-p21Ras scFv and carried by cytokine-induced killer cells.

Ras gene mutation or overexpression can lead to tumorigenesis in multiple kinds of cancer, including glioma. However, no drugs targeting Ras or its expression products have been approved for clinical application thus far. Adenoviral gene therapy is a promising method for the treatment of glioma. In this study, the human glioma cell line U251 was co-cultured with recombinant adenovirus KGHV500, and the anti-tumor effects of KGHV500 were determined by MTT, scratch test, Transwell invasion, and apoptosis assays. Then, KGHV500 was delivered via the intravenous injection of CIK cells into glioma xenografts. Tumor volume, ki67 proliferation index, apoptosis levels, and anti-p21Ras scFv expression were tested to evaluate targeting ability, anti-tumor efficacy, and safety. We found that the KGHV500 exhibited anti-tumor activity in U251 cells and increased the intracellular expression of anti-p21Ras scFv compared with that in the control groups. CIK cells delivered KGHV500 to U251 glioma cell xenografts and enhanced anti-tumor activity against glioma xenografts compared to that produced by the control treatment. In conclusion, targeting Ras is a useful therapeutic strategy for gliomas and other Ras-driven cancers, and the delivery of anti-p21Ras scFv by recombinant adenovirus and CIK cells may play an essential role in the therapy of Ras-driven cancers.

Circ_0000020 elevates the expression of PIK3CA and facilitates the malignant phenotypes of glioma cells via targeting miR-142-5p

BackgroundMultiple circular RNAs (circRNAs) have been recently described as crucial oncogenic factors or tumor suppressors. This study aimed to investigate the role of circ_0000020 in glioma progression.MethodsCirc_0000020 and miR-142-5p expressions in glioma samples were assessed through qRT-PCR, and then the association between pathological indexes and circ_0000020 expressions was analyzed. Functional experiment was performed with human glioma cell lines U251 and U87. Gain-of-function and loss-of-function models were established. CCK-8 assay was used to detect glioma cell proliferation. Transwell assay was used to examine glioma cell migration and invasion. The regulatory relationships among circ_0000020, miR-142-5p and phosphatidylinositol 3-kinase C (PIK3CA) were investigated by bioinformatics analysis, luciferase reporter assay, qRT-PCR and Western blot. In vivo tumorigenesis assay was performed with nude mice to further validate the demonstrations of in vitro experiments.ResultsCirc_0000020 expression in glioma samples was remarkably increased compared with that in normal brain tissues and its high expression was associated with unfavorable pathological indexes. Circ_0000020 overexpression remarkably accelerated proliferation, migration and invasion of glioma cells. Accordingly, circ_0000020 knockdown suppressed the malignant phenotypes of glioma cells. Circ_0000020 overexpression significantly reduced miR-142-5p expression by sponging it, and circ_0000020 could enhance the expression of PIK3CA, which was a target gene of miR-142-5p.ConclusionsCirc_0000020 promotes glioma progression via miR-142-5p/PIK3CA axis.

RNA Interference-Mediated Aurora Kinase A Gene Silencing Inhibits Human Glioma Cells Proliferation and Tumor Growth in Mice.

Objective: This study aims to explore the roles of Aurora Kinase A (Aurora A) in human glioma progression and relevant molecular mechanisms involved.Methods: RNA interference (RNAi) technology was performed to silence the Aurora A gene in human glioma cell line U251 and U87. Western blot and real-time PCR were used to determine the protein and mRNA expression levels of Aurora A. Flow cytometry was performed to analyze the cell cycle distribution and MTT was used to examine the cell viability. Annexin V/FITC double staining and Hoechst 33258 staining were carried out to examine cell apoptosis. Xenograft tumor model was established to examine the effect of Aurora A siRNA on tumor growth in vivo.Results: RNAi-mediated Aurora A gene silencing with specific short interfering RNA (siRNA) significantly decreased Aurora A protein and mRNA expression levels in human glioma cell line U251 and U87. Aurora A knockdown in glioma cells with siRNA strongly inhibited cell proliferation, along with the accumulation of cells in the G1, G2/M phase and decrease in S phase. Furthermore, the enhancement of cell apoptosis in vitro and the suppression of xenograft tumor growth in vivo were also observed after Aurora A silencing in U251 cell. In addition, Aurora A knockdown resulted in decreased expression of anti-apoptotic protein Bcl-2 and cell cycle protein Cyclin D1, while increased expression of pro-apoptotic factor caspase-3.Conclusion: Aurora A can be used as a candidate targeting gene and inhibition of Aurora A is a potentially promising therapy for glioblastoma.

Design and Synthesis of a Peptide-Based Glioma-Targeted Drug Delivery Vector gHope2.

In the current chapter, we are detailing the synthesis path of a tumor-targeted, CPP-functionalized chemotherapeutic drug, as well as in vitro validation of the targeting and cell penetrating functionalities of the construct. The design of targeted drug delivery vehicle is based on a new glioma-specific homing peptide that has been conjugated to doxorubicin. Further functionalization with an 18-amino acid cell penetrating peptide pVEC was achieved, a CPP that was chosen because of its high cell penetrating efficacy and low toxicity. The three elements were combined into one drug delivery construct gHope2, and its tumor-homing and cell penetrating activity was demonstrated in human glioma cell line U87.

NSun2 promotes cell migration through methylating autotaxin mRNA

NSun2 is an RNA methyltransferase introducing 5-methylcytosine into tRNAs, mRNAs, and noncoding RNAs, thereby influencing the levels or function of these RNAs. Autotaxin (ATX) is a secreted glycoprotein and is recognized as a key factor in converting lysophosphatidylcholine into lysophosphatidic acid (LPA). The ATX-LPA axis exerts multiple biological effects in cell survival, migration, proliferation, and differentiation. Here, we show that NSun2 is involved in the regulation of cell migration through methylating ATX mRNA. In the human glioma cell line U87, knockdown of NSun2 decreased ATX protein levels, whereas overexpression of NSun2 elevated ATX protein levels. However, neither overexpression nor knockdown of NSun2 altered ATX mRNA levels. Further studies revealed that NSun2 methylated the 3′-UTR of ATX mRNA at cytosine 2756 in vitro and in vivo. Methylation by NSun2 enhanced ATX mRNA translation. In addition, NSun2-mediated 5-methylcytosine methylation promoted the export of ATX mRNA from nucleus to cytoplasm in an ALYREF-dependent manner. Knockdown of NSun2 suppressed the migration of U87 cells, which was rescued by the addition of LPA. In summary, we identify NSun2-mediated methylation of ATX mRNA as a novel mechanism in the regulation of ATX.

Erinacerins, Novel Glioma Inhibitors from Hericium erinaceus, Induce Apoptosis of U87 Cells through Bax/Capase-2 Pathway.

Glioma is the most common tumor of the central nervous system. Hericium erinaceus, which has been reported to have a variety of pharmacological activities, is a widely used Traditional Chinese Medicine (TCM), and also a kind of delicious food accepted by the public. In this study, two new natural products, compounds 1 and 2, were isolated and identified from Hericium erinaceus. They were named erinacerin O and erinacerin P, respectively, after the structural identification, and their effects on human glioma cell line U87 were evaluated. Erinacerin P (2) exhibited obvious cytotoxicity on human glioma cell line U87. The IC50 value of 2 was 19.32μg/mL. The results showed that the apoptosis of U87 cells treated with 2 increased and the morphology of U87 cells altered significantly. Flow cytometry experiment showed that 2 could significantly increase the apoptosis rate of U87 cells and reduce DNA replication. Western blot results suggested the Bax/capase-3 pathway was involved in the U87 cell apoptosis induced by 2. Erinacerin O and Erinacerin P are novel compounds obtained from Hericium erinaceus and Erinacerin P could be a potential novel glioma inhibitor.

Identification of Gliotoxin isolated from marine fungus as a new pyruvate kinase M2 inhibitor

Pyruvate kinase M2 (PKM2) functions as an important rate-limiting enzyme of aerobic glycolysis that is involved in tumor initiation and progression. However, there are few studies on effective PKM2 inhibitors. Gliotoxin is a marine-derived fungal secondary metabolite with multiple biological activities, including immunosuppression, cytotoxicity, and et al. In this study, we found that Gliotoxin directly bound to PKM2 and inhibited its glycolytic activity in a dose-dependent manner accompanied by the decreases in glucose consumption and lactate production in the human glioma cell line U87. Moreover, Gliotoxin suppressed tyrosine kinase activity of PKM2, leading to a dramatic reduction in Stat3 phosphorylation in U87 cells. Furthermore, Gliotoxin suppressed cell viability in U87 cells, and cytotoxicity of Gliotoxin on U87 cells was obviously augmented under hypoxia condition compared to normal condition. Finally, Gliotoxin was demonstrated to induce cell apoptosis of U87 cells and synergize with temozolomide. Our findings identify Gliotoxin as a new PKM2 inhibitor with anti-tumor activity, which lays the foundation for the development of Gliotoxin as a promising anti-tumor drug in the future.

Pseudoceroximes A–E and Pseudocerolides A–E – Bromotyrosine Derivatives from a Pseudoceratina sp. Marine Sponge Collected in the South China Sea

15 new bromotyrosine‐derived compounds, pseudoceroximes A–E (1–5), pseudocerolides A–E (6–10), 13‐ketohemifistularin 3 (11), and ceratinines J–M (12–15), were isolated from a Pseudoceratina sp. marine sponge collected in the South China Sea. The planar structures of all compounds were established based on extensive NMR spectroscopic analyses and HRESIMS data. Their absolute configurations were assigned by a combination of modified Mosher's method, ECD calculations and a single‐crystal X‐ray diffraction experiment. Pseudoceroximes A–D (1–4) represent the first examples of the oxime‐type bromotyrosine derivatives possessing the 2‐oxazolidone ring. Pseudoceroximes A (1) and B (2) and pseudocerolide C (8) showed antibacterial activity against methicillin‐resistant Staphylococcus aureus ATCC 43300 with MIC values of 5.2–7.1 µm. Additionally, pseudoceroximes B (2) and D (4) exhibited moderate antiproliferative activity against two human glioma cell lines U87MG and U251.

Inhibition of Cathepsin D (CTSD) enhances radiosensitivity of glioblastoma cells by attenuating autophagy.

Postoperative radiotherapy combined with chemotherapy is a commonly used treatment for glioblastoma (GBM) but radiotherapy often fails to achieve the expected results mainly due to tumor radioresistance. In this study, we established a radioresistant subline from human glioma cell line U251 and found that Cathepsin D (CTSD), a gene closely related to the clinical malignancy and prognosis in glioma, had higher expression level in radioresistant clones than that in parental cells, and knocking down CTSD by small interfering RNA (siRNA) or its inhibitor Pepstatin-A increased the radiosensitivity. The level of autophagy was enhanced in the radioresistant GBM cells compared with its parent cells, and silencing autophagy by light chain 3 (LC3) siRNA significantly sensitized GBM cells to ionizing radiation (IR). Moreover, the protein expression level of CTSD was positively correlated with the autophagy marker LC3 II/I and negatively correlated with P62 after IR in radioresistant cells. As expected, through the combination of Western blot and immunofluorescence assays, inhibition of CTSD increased the formation of autophagosomes, while decreased the formation of autolysosomes, which indicating an attenuated autophagy level, leading to radiosensitization ultimately. Our results revealed for the first time that CTSD regulated the radiosensitivity of glioblastoma by affecting the fusion of autophagosomes and lysosomes. In significance, CTSD might be a potential molecular biomarker and a new therapeutic target in glioblastoma.

Total flavones of Dracocephalum moldavica L. protect astrocytes against H2O2-induced apoptosis through a mitochondria-dependent pathway

BackgroundThe active components of Dracocephalum moldavica L. (TFDM) can inhibit myocardial ischemia by inhibiting oxidative stress. However, the effects of TFDM on astrocytes have not been investigated in vitro. The current study aimed to explore whether TFDM protects astrocytes against H2O2-induced apoptosis through a mitochondria-dependent pathway.MethodsThe human glioma cell line U87 was used to investigate the ability of TFDM to protect astrocytes against H2O2-induced apoptosis. The cell counting kit-8 assay and flow cytometry were used to detect cell viability, apoptosis, MMP, Ca2+ influx and reactive oxygen species (ROS). Lactate dehydrogenase (LDH) and malonic dialdehyde (MDA) levels were measured by ELISA. In addition, protein and mRNA expression changes were detected by Western blotting and qRT-PCR.ResultsTFDM (0.78~200 μg/ml) had limited cytotoxic effects on the viability of U87 cells. Compared with the model group (treated with H2O2 only), cells treated with medium- and high-dose TFDM exhibited reduced MDA concentrations (P < 0.05) and ROS production (P < 0.05) and decreased MMP (P < 0.05) and reduced apoptosis (P < 0.05). The percentage of annexin V-FITC-stained cells was markedly suppressed by TFDM, confirming its anti-apoptotic properties. WB results showed that protein expression of Bcl-2-associated X protein (BAX), Caspase-3, Caspase-9, Caspase-12, and B-cell leukemia/lymphoma 2 (Bcl2) was reduced in the TFDM group compared with that in the model group (P < 0.05) and that expression of these proteins was normalized by TFDM treatment in a dose-dependent manner. According to RT-qPCR results, TFDM pretreatment resulted in reduced mRNA expression of BAX, Caspase-9, Caspase-12, p38MAPK, and CaMKII and increased mRNA expression of mTOR compared with the model group.ConclusionsThe current study revealed the protective effects of TFDM on U87 cells under oxidative stress conditions through the inhibition of a mitochondria-dependent pathway that is associated with the CaMKII/P38MAPK/ERK1/2 and PI3K/AKT/mTOR pathways.

Silencing lncRNA GIHCG increases radiosensitivity of glioma cells by up-regulating miR-146a-3p

Objective To investigate the effect of lncRNA GIHCG on the radiosensitivity of glioma cells and its mechanism. Methods The expression levels of GIHCG and miR-146a-3p in human brain normal glial cells HEB and glioma cell lines U251, A172, SHG139 and U87 were quantitatively measured by qRT-PCR assay. U251 and SHG139 cells were used for subsequent experiment. After silencing the expression of GIHCG or overexpressing miR-146a-3p in U251 and SHG139 cells, cell proliferation was detected by MTT assay, cell apoptosis was detected by flow cytometry, cell radiosensitivity was detected by colony formation assay and the expression levels of CDK1, CyclinD1, Bcl-2 and Bax proteins were measured by Western blot. The bioinformatics software predicted the presence of a binding site for GIHCG and miR-146a-3p. Dual luciferase reporter gene assay and qRT-PCR assay were adopted to verify the targeting relationship between GIHCG and miR-146a-3p. Results Compared with HEB cells, the expression of GIHCG was significantly up-regulated in glioma U87, U251, A172 and SHG139 cells (all P<0.05), whereas that of miR-146a-3p was remarkably down-regulated (P<0.05). Silencing GIHCG expression or overexpression of miR-146a-3p significantly decreased the U251 and SHG139 cell survival rate, survival fraction and the expression of CDK1, CyclinD1 and Bcl-2 proteins (all P<0.05), whereas considerably increased the apoptotic rate and expression of Bax protein (both P<0.05). GIHCG performed targeted negative regulation of miR-146a-3p expression in U251 and SHG139 cells and inhibition of miR-146a-3p expression reversed the effect of silencing GIHCG on proliferation, apoptosis and radiosensitivity of glioma cells. Conclusion Silencing GIHCG expression up-regulates the expression of miR-146a-3p, thereby enhancing the radiosensitivity of glioma cells. Key words: Glioma; lncRNA GIHCG; miR-146a-3p gene; Radiosensitivity

Inhibitory effect of Siwei Xiaoliuyin on glioma angiogenesis in nude mice.

Application of Siwei Xiaoliuyin in glioma mice. Explore the effect of Siwei Xiaoliuyin on angiogenesis of nude mice glioma and its mechanism. Establish human glioma cell line U87 tumor model. Mice were randomized to the saline group, the conventional dose of Siwei Xiaoliuyin, high dose group of Siwei Xiaoliuyin, TMZ group, combination therapy group, record the tumor volume. Using the method of Weidner counted the microvessel density. ELISA enzyme-linked adsorption method to detect the content of nude mice serum VEGF and ES. The difference was statistically significant (P<0.05). The tumor volume and MVD of conventional dose group, large dose group, Siwei Xiaoliuyin combined temozolomide group was smaller than the blank group，the difference was statistically significant (P<0.05). VEGF levels in three groups of nude mice were lower than the blank group and ES content is higher than blank group, the difference was statistically significant (P<0.05). Siwei Xiaoliuyin can inhibit glioma angiogenesis. Its mechanism of glioma angiogenesis inhibition may be through regulation VEGF and down-regulation of endostatin expression of vascular endothelial growth factor achieved. Down-regulation of endostatin expression of vascular endothelial growth factor achieved.

Lenalidomide Enhances CAR-T Cell Activity Against Solid Tumor Cells

Chimeric antigen receptor (CAR) T-cell immunotherapy still faces many challenges in the treatment of solid tumors, one of which is T-cell dysfunction or exhaustion. Immunomodulator lenalidomide may improve CAR T-cell function. In this study, the effects of lenalidomide on CAR T-cell functions (cytotoxicity, cytokine secretion, and cell proliferation) were investigated. Two different CAR T cells (CD133-specific CAR and HER2-specific CAR) were prepared, and the corresponding target cells including human glioma cell line U251 CD133-OE that overexpress CD133 and human breast cancer cell line MDA-MB-453 were used for functional assay. We found that lenalidomide promoted the killing of U251 CD133-OE by CD133-CAR T cells, the cytokine secretion, and the proliferation of CD133-CAR T cells. Lenalidomide also enhanced the cytotoxicity against MDA-MB-453 and the cytokine secretion of HER2-CAR T cells but did not affect their proliferation significantly. Furthermore, lenalidomide may regulate the function of CAR T cells by inducing the degradation of transcription factors Ikaros and Aiolos.

Glioma malignancy is linked to interdependent and inverse AMOG and L1 adhesion molecule expression

BackgroundGliomas account for the majority of primary human brain tumors and remain a challenging neoplasm for cure due to limited therapeutic options. Cell adhesion molecules play pivotal roles in the growth and progression of glial tumors. Roles of the adhesion molecules on glia (AMOG) and L1CAM (L1) in glioma cells have been shown to correlate with tumorigenesis: Increased expression of L1 and decreased expression of AMOG correlate with degree of malignancy.MethodsWe evaluated the interdependence in expression of these molecules by investigating the role of AMOG in vitro via modulation of L1 expression and analyzing apoptosis and cell senescence of glioma cells.ResultsImmunohistochemical staining of normal human cortical and glioma tissue microarrays demonstrated that AMOG expression was lower in human gliomas compared to normal tissue and is inversely correlated with the degree of malignancy. Moreover, reduction of AMOG expression in human glioblastoma cells elevated L1 expression, which is accompanied by decreased cell apoptosis as well as senescence.ConclusionAMOG and L1 interdependently regulate their expression levels not only in U-87 MG cells but also in U251 and SHG44 human glioma cell lines. The capacity of AMOG to reduce L1 expression suggests that methods for increasing AMOG expression may provide a therapeutic choice for the management of glial tumors with high expression of L1.

Curcumin suppresses invasiveness and migration of human glioma cells in vitro by inhibiting HDGF/β-catenin complex

To investigate the effect of curcumin on the invasion and migration of human glioma cells in vitro and explore the molecular mechanisms. MTT assay was used for screening the optimal curcumin concentrations. The effects of curcumin on the invasion and metastasis of human glioma cell lines U251 and LN229 were tested using Transwell assay, Boyden assay and wound-healing assays. The expression of the related proteins and their interactions were determined using Western blotting and coimmunoprecipitation assay. Curcumin at the concentration of 20 μmol/L for 48 h was used as the optimal condition for subsequent cell treatment. In the two glioma cell lines, curcumin significantly suppressed the invasion and migration of the cells (P &lt; 0.05) and lowered the expressions of hepatoma-derived growth factor (HDGF), Ncadherin, vimentin, Snail and Slug, but increased the expression of E-cadherin. Interference of HDGF in curcumin-treated glioma cells synergistically inhibited the epithelial-mesenchymal transition (EMT) signals, while overexpression of HDGF significantly reversed the inhibitory effect of curcumin on EMT; curcumin treatment could significantly reduce the binding of HDGF to β-catenin. Curcumin suppresses EMT signal by reducing HDGF/β-catenin complex and thereby lowers the migration and invasion abilities of human glioma cells in vitro.

Invasion and migration regulation of human glioma cells by long non-coding RNA linc00996

Objective To investigate the expression of long non-coding RNA linc00996 in glioma, its function in migration, invasion and its relationship with prognosis. Methods The differential expression of linc00996 in glioma patients and normal brain tissues was compared in TCGA database. 21 patients with glioma treated in our hospital were recruited. Tumor tissues and normal brain tissues were collected in the operation. The expression level of linc00996 in the above tissues was detected by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). Small interfering RNA targeting linc00996 sequence was synthesized and transfected into human glioma cell line U251. Wound healing and Transwell assay were used to detect the effect of down-regulation of linc00996 on migration and invasion of U251 cells respectively. In TCGA database, according to the median expression of linc00996 in glioma tissues, the patients were divided into two groups to compare the overall survival and disease-free survival of the linc00996 high and low expression groups. Statistical Analysis with STATA 12.0 Software. Results TCGA database showed that the expression level of linc00996 in glioma tissues was higher than that in normal brain tissues. In 21 cases of glioma, the expression level of linc00996 in tumor tissues was higher than that in normal tissues in 15 cases (71.4%). Small interfering RNA (si00996) could significantly down-regulate the expression of linc00996 in U251 cells (t=8.870, P<0.05). Wound healing assay showed that the cell migration ability decreased significantly after down-regulation of linc00996 expression. Transwell assay showed that the ability of U251 cells to penetrate membranes decreased after small interfering RNA silenced linc00996. Conclusion Linc00996 is highly expressed in glioma tissues and is associated with poor prognosis. Down-regulation of linc00996 expression can inhibit the migration and invasion of glioma cells. Key words: Glioma; Long non-coding RNA; Migration; Prognosis

Zika virus NS5 protein inhibits cell growth and invasion of glioma

Glioma is the most common primary brain tumor with high mortality. Given the poor outcomes with standard-of-care treatments, novel treatment strategies are needed. Oncolytic viral therapy for glioma has developed as an exciting therapeutic method in recent years. Zika virus, a member of flavivirus family, has oncolytic activity against glioma cells but the mechanism is unknown. Here, we aimed to determine which viral protein might play a critical role in mitigating glioma cell growth. We examined the tumor suppressor function of four nonstructural proteins NS1, NS3, NS4B and NS5 in human glioma cell line U87. As a result, we found that only NS5 significantly inhibited proliferation, migration and invasion of U87 cells. Moreover, expression of NS5 suppressed tumorigenicity of mouse GL261 glioma cell in vivo. Our findings provide some clues for further exploration of oncolytic Zika virus in the treatment of glioma.