Human Glioma Cell Line U251 Research Articles

Monocarboxylate transporter dependent mechanism is involved in proliferation, migration, and invasion of human glioblastoma cell lines via activation of PI3K/Akt signaling pathway.

Glioblastoma multiforme is one of the most common primary tumors of the central nervous system, with a very poor prognosis. Cancer cells have been observed to upregulate pH regulators, such as monocarboxylate transporters (MCTs), with an increase in MCT4 expression being observed in several malignancies. MCT4/ recombinant cluster of differentiation 147 (CD147) transporter complex was reported to stimulate vascular endothelial growth factor (VEGF) via the phosphatidylinositol 3 kinase (PI3K) /protein kinase B (Akt) pathway, which has been proven to mediate glioblastoma invasion and migration. The present study aimed to clarify the role of the MCT4/CD147 transporter complex in glioblastoma cell proliferation, migration, and invasion. In this work, lentiviral vectors were used to overexpress MCT4/CD147 and small interfering RNA (siRNA) was used to silence MCT4/CD147 in the human glioma cell lines U87 and U251, respectively. The effects on cell proliferation, migration and invasiveness, as well as the protein expression levels of MCT4 and CD147, extracellular lactate content and Akt activation were assessed by MTT, wound-healing and invasion assays, western blotting and colorimetric method, respectively. The analysis results suggested that cell proliferation, migration, invasion, and Akt activation were decreased by siRNA in all cell lines, but were increased by lentivirus-mediated MCT4 overexpression. These findings suggest that inhibiting the activity and expression of the MCT4/CD147 transporter complex via metabolic-targeting drugs, particularly in cells with a high rate of glycolysis, should be explored as a novel strategy for glioblastoma treatment.

Effect of gold-conjugated resveratrol nanoparticles on glioma cells and its underlying mechanism.

Glioblastoma is the most aggressive brain tumor with poor prognosis. Although Resveratrol (Rsv) is known to have therapeutic effects on glioma, the effects of gold-conjugated resveratrol nanoparticles (Rsv-AuNPs) on glioma cells are rarely reported. We aimed to investigate the effects of Rsv-AuNPs on glioma cells and its underlying mechanism. Human glioma cell line U87 was treated with different concentrations of Rsv-AuNPs. CCK-8, transwell, and wound healing assay were performed to measure the effects of Rsv-AuNPs on cell proliferation, invasion, and migration ability, respectively. Flow cytometry assay was used to detect the effects of Rsv-AuNPs on apoptosis. Changes of protein expressions related to proliferation, invasion, migration, and apoptosis were measured by Western blot assay. In addition, the inhibitory role of Rsv-AuNPs in the PI3K/AKT/mTOR signaling pathway was verified by using PI3K inhibitor LY294002. Rsv-AuNPs treatment significantly suppressed proliferation, migration, and invasion of U87 cells (allP <0.05) and increased the apoptosis rate (P <0.05). The changes of proteins related to proliferation, migration, invasion and apoptosis were consistent (allP <0.05). Moreover, Rsv-AuNPs treatment significantly inhibited the phosphorylation of PI3K, AKT and mTOR proteins in U87 cells (P <0.05). The present study found that Rsv-AuNPs inhibited the proliferation, migration, and invasion of U87 cells and induced apoptosis by inhibiting the activation of PI3K/AKT/mTOR signaling pathway. In the future, Rsv-AuNPs might be applied to the clinical treatment of glioma through more in-depth animal and clinical research.

Borneol promotes autophagic degradation of HIF-1α and enhances chemotherapy sensitivity in malignant glioma.

Gliomas are characterized by high mortality rates and resistance. Even with conventional chemotherapy the prognosis of glioblastoma remains poor. Many medications are not optimally effective due to limited bioavailability. The bioavailability of medicine can be enhanced by borneol, a monoterpenoid substance. In this study, we investigated the effect of borneol, a commonly used Chinese medicine, on chemosensitivity in C6 glioma and U251 human glioma cell lines and elucidated its therapeutic molecular targets. The chemosensitivity-inducing effects of borneol in C6 and U251 cells were examined using CCK8 and clonal formation assays. The mechanism underlying the effect of borneol was evaluated through immunohistochemistry and western blotting assays. Further, the number of autophagosomes was determined via transmission electron microscopy. Finally, the chemical sensitization effect of borneol was evaluated in SD rats after C6 orthotopic tumor transplantation. Borneol increased cytotoxicity in C6 and U251 cells in response to temozolomide (TMZ). In addition, through transmission electron microscopy, western blotting, and immunohistochemical tests, we found that borneol combined with TMZ significantly increased the level of autophagy and that hypoxia inducible factor-1(HIF-1α) is a candidate target through which borneol enhances the cytotoxic effect of TMZ. Borneol's ability to enhance HIF-1α degradation was counteracted following the administration of autophagy inhibitors. In vivo, borneol treatment was found to enhance the anticancer effect of TMZ and delay tumor progression, and this effect was closely related to its ability to promote the autophagic degradation of HIF-1α. HIF-1α might be a valid therapeutic target of borneol, which can be potentially applied as a chemosensitizing drug used for glioma treatment.

Retracted] Effect of CCL2 siRNA on proliferation and apoptosis in the U251 human glioma cell line.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the VEGF western blotting data shown in Fig.4A on p.3392 were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes. Owing to the fact that the contentious data in the above article had already been published elsewhere prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office never received a reply.The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 16: 3387‑3394, 2017; DOI: 10.3892/mmr.2017.6995].

Expression profiles and function prediction of tRNA-derived fragments in glioma

BackgroundGlioblastoma (GBM) is the most aggressive malignant primary brain tumor. The transfer RNA-derived fragments (tRFs) are a new group of small noncoding RNAs, which are dysregulated in many cancers. Until now, the expression and function of tRFs in glioma remain unknown.MethodsThe expression profiles of tRF subtypes were analyzed using the Cancer Genome Atlas (TCGA)-low-grade gliomas (LGG)/GBM dataset. The target genes of tRFs were subjected to Gene Ontology, Kyoto Encyclopedia and Gene set enrichment analysis of Genes and Genomes pathway enrichment analysis. The protein-protein interaction enrichment analysis was performed by STRING. QRT-PCR was performed to detect the expressions of tRFs in human glioma cell lines U87, U373, U251, and human astrocyte cell line SVG p12. Western blot assay was used to detect to the expression of S100A11. The interaction between tRF-19-R118LOJX and S100A11 mRNA 3’UTR was detected by dual-luciferase reporter assay. The effects of tRF-19-R118LOJX, tRF-19-6SM83OJX and S100A11 on the glioma cell proliferation, migration and in vitro vasculogenic mimicry formation ability were examined by CCK-8 proliferation assay, EdU assay, HoloMonitor cell migration assay and tube formation assay, respectively.ResultstRF-19-R118LOJX and tRF-19-6SM83OJX are the most differentially expressed tRFs between LGG and GBM groups. The functional enrichment analysis showed that the target genes of tRF-19-R118LOJX and tRF-19-6SM83OJX are enriched in regulating blood vessel development. The upregulated target genes are linked to adverse survival outcomes in glioma patients. tRF-19-R118LOJX and tRF-19-6SM83OJX were identified to suppress glioma cell proliferation, migration, and in vitro vasculogenic mimicry formation. The mechanism of tRF-19-R118LOJX might be related to its function as an RNA silencer by targeting the S100A11 mRNA 3’UTR.ConclusiontRFs would become novel diagnostic biomarkers and therapeutic targets of glioma, and the mechanism might be related to its post-transcriptionally regulation of gene expression by targeting mRNA 3’UTR.

Curcumol reverses temozolomide resistance in glioma cells by regulating the UTX/MGMT axis

To explore the mechanism through which curcumol reverses primary drug resistance in glioma cells. The inhibitory effect of 10, 20, and 40 μg/mL curcumol were observed in human glioma cell lines A172 and U251. UTX-overexpressing glioma cells constructed by lentiviral transfection were treated with curcumol (40 μg/mL), temozolomide (TMZ; 10 μg/mL), or both, and the changes in cell viability, clone formation capacity and apoptosis were assessed using MTT assay, cell clone formation experiment, and flow cytometry; UTX activity in the cells was determined using a UTX detection kit, and the enrichment of UTX and H3K27me3 in the MGMT promoter region was detected with ChiP-qPCR. The protein expressions in glioma cells were detected using Western blotting and immunohistochemistry. In a nude mouse model bearing glioma xenografts, the effects of curcumol (20 mg/kg), TMZ (20 mg/kg) and their combination on tumor growth and expressions of UTX, H3K27me3 and MGMT were evaluated. Curcumol significantly inhibited the proliferation (P<0.05) and promoted apoptosis of cultured glioma cells (P<0.01). Curcumol, but not TMZ, produced significant inhibitory effect on tumor growth in the tumor-bearing mice (P<0.01). Curcumol significantly inhibited UTX activity and increased the expression level of H3K27me3 protein in the glioma cells. UTX overexpression obviously decreased H3K27me3 protein expression and reversed the effects of curcumol on glioma cell proliferation and apoptosis (P<0.01). Curcumol reduced the enrichment of UTX and H3K27me3 in the MGMT promoter region (P<0.05) and decreased MGMT protein expression, which was reversed by UTX overexpression. In both the in vivo and in vitro experiments, curcumol combined with TMZ significantly increased H3K27me3 protein expression in the glioma cells, reduced the expression of its downstream target gene MGMT, and enhanced TMZ sensitivity of the glioma cells. Curcumol can enhance glioma cell sensitivity to TMZ by regulating the UTX/MGMT axis.

Modulating Wnt/β-Catenin Signaling Pathway on U251 and T98G Glioblastoma Cell Lines Using a Combination of Paclitaxel and Temozolomide, A Molecular Docking Simulations and Gene Expression Study.

One of the most lethal cancers, glioblastoma (GBM), affects 14.5% of all central nervous system (CNS) tumors. Patients diagnosed with GBM have a meager median overall survival (OS) of 15 months. Extensive genetic analysis has shown that many dysregulated pathways, including the Wnt/β-catenin signaling system, contribute to the pathogenicity of GBM. Paclitaxel (PTX) and temozolomide (TMZ) are recognized to have therapeutic potential in several types of cancer, including GBM. This work aimed to examine the impact of PTX and TMZ on the human glioma cell lines U251 and T98G using molecular docking simulations and gene expression profiles in the Wnt/β-catenin signaling pathway. Standard procedure for Molecular Docking simulation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay, and Flow Cytometry assay was used. Genes implicated in the Wnt/β-catenin signaling pathway, including Dvl, Axin, APC, β-catenin, and glycogen synthase kinase3-β (GSK3β), were subjected to real-time PCR. The estimated parameters for targets revealed that the average binding energy and inhibition constant (Ki) for the DVL, β-Catenin, and GSK3β, when targeted by PTX, were - 5.01 kcal/mol, - 5.4 kcal/mol, and - 9.06 kcal/mol, respectively. This energy range was - 6.34 kcal/mol for DVL, - 5.52 kcal/mol for β-Catenin, and - 5.66 kcal/mol for GSK3β as a result of TMZ's inhibitory actions. Gene expression analyses indicated that PTX and PTX/TMZ suppressed GSK3β (p < 0.05). GSK3β from the Wnt/β-catenin signaling pathway was significantly targeted by PTX alone, and adding TMZ to PTX may improve the efficacy of glioblastoma treatment. In addition, the GSK3β gene may help GBM therapy strategies as a potential PTX target.

Treatment activity of the injectable hydrogels loaded with dexamethasone In(iii) complex on glioma by inhibiting the VEGF signaling pathway

Abstract In this work, a novel In(iii) coordination polymer, i.e., {[In(L)(im)(H2O)](H2O)} n (1) was produced from the synthetic reactions in water and dimethylformamide mixed solvents and using methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylic acid (H2L) and imidazole (Him) as the co-ligands, and then successfully loaded with dexamethasone. The injectable hydrogels were prepared from natural polysaccharide hyaluronic acid with good biocompatibility and successfully loaded with In(iii) complex. The suppressive inhibitory effect of hydrogels toward U251 human glioma cell line viability was assessed using the Cell Counting Kit-8 assay kit, and the relatively expressed levels of the vascular endothelial growth factor signaling pathway were determined by real-time RT-PCR.

Piroctone olamine disrupts mitochondrial dynamics in glioma cells through the PI3K/AKT pathway

To investigate the growth-inhibitory and pro-apoptotic effects of piroctone olamine (PO) on glioma cells and explore the underlying mechanism. Human glioma cell lines U251 and U373 were treated with PO and the changes in cell proliferation were detected using CCK-8 assay and EdU assay. Clone formation assay and flow cytometry were used to examine the changes in clone formation ability and apoptosis of the treated cells. Mitochondrial membrane potential of the cells and morphological changes of the mitochondria were detected using JC-1 staining and a fluorescence probe, respectively. The expressions of mitochondrial fission protein DRP1 and the fusion protein OPA1 were determined with Western blotting. Transcriptome sequencing and differential gene enrichment analysis was performed, and the expression levels of PI3K, AKT and p-AKT in the treated cells were verified using Western blotting. CCK-8 assay showed that PO significantly inhibited the proliferation of U251 and U373 cells in a time- and dose-dependent manner (P < 0.001). EdU test showed that the proliferative activity of PO-treated cells was significantly decreased, and the number of cell colonies also decreased significantly (P < 0.01). PO treatment significantly increased apoptotic rates (P < 0.01), decreased mitochondrial membrane potential and caused obvious changes in mitochondrial morphology of the cells. Pathway enrichment analysis showed that the down-regulated genes were significantly enriched in the PI3K/AKT pathway, which was verified by Western blotting showing significantly down-regulated expression levels of PI3K, AKT and p-AKT in PO-treated cells (P < 0.05). PO interferes with mitochondrial fusion and fission function through the PI3K/AKT pathway, thereby inhibiting the proliferation and increasing apoptosis of glioma cells.

AQP8 may affect glioma proliferation and growth by regulating GSK‐3β phosphorylation and nuclear transport of β‐catenin

The purpose of this work is to examine the impact of AQP8 on the proliferation and development of human glioma cell lines A172 and U251 and to determine if aquaporin 8 (AQP8) is associated with GSK-3β phosphorylation and nuclear transport of β-catenin in the Wnt signaling pathway. AQP8 knockdown cell lines were constructed using a CRISPR/Cas9 double vector lentivirus infection. SAM/dCas9 was used to construct AQP8 overexpression cell lines and the CV084 lentivirus vector was used to construct AQP8 rescue cell lines. AQP8 and its mRNA, and phosphorylated GSK-3β, β-catenin, and other related proteins, were detected using western blot and qRT-PCR. Glioma cell apoptosis was detected using Hoechst 33342 dye. The migration of glioma cells was discovered using a wound healing assay. β-catenin localization in cells was detected using immunofluorescence staining. The proliferative and migratory capacities of A172 and U251 cells were significantly enhanced after AQP8 overexpression. The Wnt signaling pathways appeared to have higher levels of phosphorylated GSK-3β and β-catenin, and a rise in the fluorescence intensity ratio of β-catenin in the nucleus and cytoplasm, which suggests that β-catenin translocated into the nucleus, while AQP8 knockdown produced the opposite effect. Further, overexpression of AQP8 in AQP8 knockdown cell lines rescued the reduction of related protein levels caused by AQP8 knockdown. High AQP8 expression promotes proliferation and growth of glioma cells, a process associated with phosphorylation of GSK-3β and nuclear translocation of β-catenin.

A novel prognostic related lncRNA signature associated with amino acid metabolism in glioma.

Glioma is one of the deadliest malignant brain tumors in adults, which is highly invasive and has a poor prognosis, and long non-coding RNAs (lncRNAs) have key roles in the progression of glioma. Amino acid metabolism reprogramming is an emerging hallmark in cancer. However, the diverse amino acid metabolism programs and prognostic value remain unclear during glioma progression. Thus, we aim to find potential amino-related prognostic glioma hub genes, elaborate and verify their functions, and explore further their impact on glioma. Glioblastoma (GBM) and low-grade glioma (LGG) patients' data were downloaded from TCGA and CCGA datasets. LncRNAs associated with amino acid metabolism were discriminated against via correlation analysis. LASSO analysis and Cox regression analysis were conducted to identify lncRNAs related to prognosis. GSVA and GSEA were performed to predict the potential biological functions of lncRNA. Somatic mutation data and CNV data were further built to demonstrate genomic alterations and the correlation between risk scores. Human glioma cell lines U251 and U87-MG were used for further validation in vitro experiments. There were eight amino-related lncRNAs in total with a high prognostic value that were identified via Cox regression and LASSO regression analyses. The high risk-score group presented a significantly poorer prognosis compared with the low risk-score group, with more clinicopathological features and characteristic genomic aberrations. Our results provided new insights into biological functions in the above signature lncRNAs, which participate in the amino acid metabolism of glioma. LINC01561 is one of the eight identified lncRNAs, which was adopted for further verification. In in vitro experiments, siRNA-mediated LINC01561 silencing suppresses glioma cells' viability, migration, and proliferation. Novel amino-related lncRNAs associated with the survival of glioma patients were identified, and a lncRNA signature can predict glioma prognosis and therapy response, which possibly has vital roles in glioma. Meanwhile, it emphasized the importance of amino acid metabolism in glioma, particularly in providing deeper research at the molecular level.

TB-3 A GINGER EXTRACT COMPOUND A REVEALED ANTITUMOR ACTIVITY AGAINST GLIOMA

Abstract Purpose Malignant neoplasms arising in the brain and central nervous system have a poor prognosis and present with symptoms such as headache, epileptic seizures, and paralysis of the arms and legs. Treatment of glioma, the most frequent primary brain tumor, is based on surgical removal of the tumor, radiation therapy, and chemotherapy. However, since gliomas grow invasively, surgical removal of the entire tumor is considered difficult. In addition, the standard treatment, temozolomide, possesses the problem of resistance. Therefore, the risk of recurrence is high, and the development of noble therapeutic agents for Glioma is required. We have screened for compounds with anti-tumor activity against Glioma from our natural compound library and focused on ginger extract, Compound A. In this study, we investigated the effect of Compound A on Glioma cell lines. Methods and Results To evaluate the antitumor activity of Compound A on Glioma in vitro , MTT assay was performed. Human glioma cell lines U87-MG and U251 cells were treated with Compound A. After 96 hours, cell viability was evaluated using CCK-8. The IC50 value of Compound A in U87-MG cells was calculated to be 16.3 μM. The IC50 of Compound A in U251 cells was 10.8 μM. Next, to examine the effect of Compound A on normal cells, we performed the same MTT assay using primary cultured rat astrocytes. The MTT assay showed no decrease in cell viability in primary cultured rat astrocytes at 15 μM, whereas an antitumor effect was observed in a human glioma cell line. Discussion In this study, Compound A showed antitumor activity against Glioma without affecting normal cells. In the future, we will examine the effects of Compound A in an immunocompromised mouse brain in which U87-MG-RFP cells are implanted, which may lead to the development of therapeutic agents against Glioma.

Irreversible Electroporation Mediates Glioma Apoptosis via Upregulation of AP-1 and Bim: Transcriptome Evidence.

The heat-sink effect and thermal damage of conventional thermal ablative technologies can be minimized by irreversible electroporation (IRE), which results in clear ablative boundaries and conservation of blood vessels, facilitating maximal safe surgical resection for glioblastoma. Although much comparative data about the death forms in IRE have been published, the comprehensive genetic regulatory mechanism for apoptosis, among other forms of regulatory cell death (RCD), remains elusive. We investigated the electric field intensity threshold for apoptosis/necrosis (YO-PRO-1/PI co-staining) of the U251 human malignant glioma cell line with stepwise increased uniform field intensity. Time course samples (0-6 h) of apoptosis induction and sham treatment were collected for transcriptome sequencing. Sequencing showed that transcription factor AP-1 and its target gene Bim (Bcl2l11), related to the signaling pathway, played a major role in the apoptosis of glioma after IRE. The sequencing results were confirmed by qPCR and Western blot. We also found that the transcription changes also implicated three other forms of RCD: autophagy, necroptosis, and immunogenic cell death (ICD), in addition to apoptosis. These together imply that IRE possibly mediates apoptosis by the AP-1-Bim pathway, causes mixed RCD simultaneously, and has the potential to aid in the generation of a systemic antitumor immune response.

Effect of glioma-derived immunoglobulin on biological function of glioma cells

IntroductionGlioma is the most common and most invasive primary central nervous system tumour, and it is urgent to develop new specific therapeutic targets. Studies have confirmed that epithelial-derived tumour cells promote tumour cell proliferation and metastasis by secreting a large number of immunoglobulins (Igs), but the role of tumour-derived Igs in glioma has never been reported. MethodsThe Gene Expression Profiling Interactive Analysis and Chinese Glioma Genome Atlas databases were used to analyse the Ig transcription and its correlation with the prognosis of patients with glioma. Immunohistochemistry and immunofluorescence were used to detect the protein expression of IgG and IgM in the glioma tissues of patients and glioma cell lines. When IgG was knocked down by small interfering RNA or knocked out by CRISPR-Cas9, the function of proliferation and migration of glioma cells were analysed by CCK-8, clone formation, wound healing, and transwell assays. Changes in proteins and their phosphorylation in signalling pathways were detected by western blotting. The nude mouse subcutaneous tumour-bearing model was established to analyse the effect of IgG in vivo. ResultsThe transcriptional level of IgG was pretty high in glioma tissues and was positively correlated with high WHO grade, recurrence, and poor prognosis. The expression of IgG and IgM was found in tumour tissues and human glioma cell lines U87 and U251, and the main expression form was secreted. Decreased IgG inhibited the proliferation and migration of glioma cells. Knockout or knockdown of IgG downregulated the phosphorylation of the key molecules in the MAPK and PI3K/Akt pathway through the HGF/SF-Met or FAK/Src pathway. In vivo tumourigenesis mouse model confirmed that reduced IgG expression inhibited glioma growth. ConclusionIg was expressed in glioma tissues and cell lines, and a high expression level predicted a poor prognosis of patients. Glioma-derived IgG promoted glioma cell proliferation and migration through the HGF/SF-Met or FAK/Src pathway.

BR2 cell penetrating peptide effectively delivers anti-p21Ras scFv to tumor cells with ganglioside expression for therapy of ras-driven tumor

PurposeCell membrane penetrating peptide BR2 can bind with ganglioside and introduce foreign drugs into tumor cells. In this study, we employed BR2 to carry the broad-spectrum anti-p21Ras scFv prepared in our laboratory into ganglioside expressing tumor cells for therapy of ras-driven tumors.MethodsBR2-p21Ras scFv gene was cloned to prokaryotic expression vector and expressed in E. coli BL21, then the fusion protein was purified with HisPur Ni-NTA. The immunoreactivity of the fusion protein with p21Ras was detected by ELISA and western blotting. The membrane-penetrating and immune co-localization with p21Ras of the fusion protein were determined by immunofluorescence. The antitumor activity was investigated using MTT, wound healing, colone formation, and apoptosis assays in vitro.ResultsBR2-p21Ras scFv fusion protein was successfully expressed and purified. We found that the fusion protein could specifically penetrate into human tumor cell lines which express ganglioside including human neuroblastoma cell line SK-N-SH, human colon cancer cell line HCT116 and human glioma cell line U251. After entering tumor cells the fusion protein bonded specifically with p21Ras. In vitro experiments revealed that it could significantly inhibit the proliferation, migration, and colone formation of HCT116, SK-N-SH, and U251 cells and promote the apoptosis of these tumor cells.ConclusionsBR2-p21Ras scFv can penetrate ganglioside expressing tumor cells and inhibit the growth of ras-driven tumor by binding with p21Ras, and producing an inhibitory effect. It is suggested that BR2-p21Ras scFv is a potential ras-driven tumor therapeutic antibody.

Salvianolic acid A (Sal A) suppresses malignant progression of glioma and enhances temozolomide (TMZ) sensitivity via repressing transgelin-2 (TAGLN2) mediated phosphatidylinositol-3-kinase (PI3K) / protein kinase B (Akt) pathway

ABSTRACT Glioma originated from excessively proliferative and highly invaded glial cells is a common intracranial malignant tumor with poor prognosis. Resistance to temozolomide (TMZ) is a clinical challenge in glioma treatment due to the fact that chemoresistance remains a main obstacle in the improvement of drug efficacy. Salvianolic acid A (Sal A), originated from traditional Chinese herbal medicine Salvia miltiorrhiza, possesses anti-tumor effects and could facilitate the delivery of drugs to brain tumor tissues. In the present work, effects of Sal A on the viability, proliferation, migration, invasion and apoptosis of human glioma cell line U87 cells as well as influence of Sal A on TMZ resistance were measured, so as to identify the biological function of Sal A in the malignant behaviors and chemoresistance of glioma cells. Additionally, activation of TAGLN2/PI3K/Akt pathway in glioma cells was also detected to investigate whether Sal A could regulate TAGLN2/PI3K/Akt to manipulate the progression of glioma and TMZ resistance. Results discovered that Sal A treatment reduced the viability, repressed the proliferation, migration and invasion of glioma cells as well as promoted the apoptosis of glioma cells. Besides, Sal A treatment suppressed TAGLN2/PI3K/Akt pathway in glioma cells. Sal A treatment strengthened the suppressing effect of TMZ on glioma cell proliferation and reinforced the promoting effect of TMZ on glioma cell apoptosis, which were abolished by upregulation of TAGLN2. To conclude, Sal A treatment could suppress the malignant behaviors of glioma cells and improve TMZ sensitivity through inactivating TAGLN2/PI3K/Akt pathway.

Long Chain Non Coding RNA Targeting miR Signal Axis Regulates the Mechanism of Apoptosis and Invasion and Migration of Glioma U251 Cells.

The occurrence of glioma is gradually promoted by various factors, and it has gone through multiple stages of development, involving abnormal expression of multiple genes. One of the important reasons for the development of gliomas is the interaction of genetic factors and the environment. Non-coding transcripts can also form this high-level structure, and the formation of binding sites for interactions between lncRNA and proteins, DNA, and other RNA molecules may be related to their structural diversity. Due to the importance of glioma-related research and the potential effectiveness of lncRNA, this paper focuses on the mechanism of long-chain non-coding RNA targeting the Mir signal axis to regulate apoptosis, invasion and migration of glioma U251 cells. In this paper, human glioma cell line U251 was used as experimental material for simulation analysis. The results showed that after miR simulation, the pass rate of U251 stem cells through the filter was 17.3%, which was significantly less than 85.4% of group C; compared with 77.6% of the negative control group, the cell penetration rate of the miR inhibitor group was significantly improved. 92.5%. The miR expression level can affect the invasion ability of U251 stem cells, and can negatively regulate the expression of fzd4 to inhibit the invasion and metastasis of glioma U251 cells.

Propofol inhibits proliferation and migration of glioma cells by up-regulating lncRNA GAS5

Propofol has been documented to exhibit anti-tumor effects in cancers. However, the underlying mechanisms of its inhibition remain unclear. We conducted this study to investigate the effect of propofol on lncRNA GAS5 in glioma cells, and to probe the role of GAS5 in the anti-tumor effects of propofol. Human glioma cell line U251 were treated with propofol. Cell proliferation, migration, invasion, cell cycle and apoptosis were evaluated, and the expression of GAS5 was measured. After that, we knockdown the expression of GAS5 in U251 cells by using siRNA and treated them with propofol, detected above indicators again and measured the expression of GAS5-related proteins. We found that propofol significantly reduced U251 cells proliferation, migration and invasion, induced cell cycle arrest and apoptosis while promoted GAS5 expression. These affects could be attenuated when GAS5 was down-regulated. Moreover, propofol increases the expression of P21, decreases the expression of c-Myc and GSTM3 through elevating GAS5 expression. In total, the anti-tumor activity of propofol on glioma cells was verified in this study. One possible mechanism involved was preliminary revealed: propofol up-regulates the expression of GAS5, thus stimulating P21 pathway, blocking c-Myc and GSTM3 pathways.

PLOD1 acts as a tumor promoter in glioma via activation of the HSF1 signaling pathway.

Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) is a collagen-related lysyl hydroxylase and its prognostic value in glioma patients was verified. However, its biological function in glioma has yet to be fully investigated. The PLOD1 mRNA status and clinical significance in gliomas were assessed via the GEPIA database. Overexpression or targeted depletion of PLOD1 was carried out in the human glioma cell line U87 and verified by western blotting. CCK8 and colony formation assays were implemented to examine the impact of PLOD1 on the proliferative and colony-forming phenotypes of U87 cells. Luciferase reporter assays and HSF1-specific pharmacologic inhibitors (KRIBB11) were employed to determine the regulatory relationship between PLOD1 and heat shock factor 1 (HSF1). High expression of PLOD1 was observed in tissue samples of glioblastoma multiforme (GBM) and brain lower-grade glioma (LGG). GEPIA overall survival further demonstrated that both GBM and LGG patients with high PLOD1 displayed worse clinical outcomes compared with those with low PLOD1. Overexpression and targeted depletion of PLOD1 enhanced and suppressed U87 cell proliferation and colony formation, respectively. Luciferase reporter assays showed that PLOD1 significantly enhanced the transcriptional activity of HSF1 in HEK293T cells. PLOD1 deficiency in U87 cells inhibited HSF1-induced survivin accumulation, whereas KRIBB11 also blocked the PLOD1-overexpressing induced survivin expression. An inhibitor of HSF1 signaling events abolishedthe increased clonogenic potential caused by PLOD1 overexpression in U87 cells. High expression of PLOD1 can increase the proliferation and colony formation of U87 cells by activating the HSF1 signaling pathway. This study suggested PLOD1/HSF1 as an effective therapeutic target for gliomas.

Microglial-stimulation of glioma invasion involves the EGFR ligand amphiregulin.

High grade glioma is one of the deadliest human cancers with a median survival rate of only one year following diagnosis. The highly motile and invasive nature of high grade glioma makes it difficult to completely remove surgically. Therefore, increasing our knowledge of the mechanisms glioma cells use to invade normal brain is of critical importance in designing novel therapies. It was previously shown by our laboratory that tumor-associated microglia (TAMs) stimulate glioma cell invasion and this process is dependent on CSF-1R signaling. In this study, we seek to identify pro-invasive factors that are upregulated in microglia in a CSF-1R-dependent manner. We assayed cDNA and protein from microglia treated with conditioned media from the murine glioma cell line GL261, and discovered that several EGFR ligands including amphiregulin (AREG) are strongly upregulated. This upregulation is blocked by addition of a pharmacological CSF-1R inhibitor. Using RNA interference, we show that AREG-depleted microglia are less effective at promoting invasion of GL261 cells into Matrigel-coated invasion chambers. In addition, an AREG blocking antibody strongly attenuates the ability of THP-1 macrophages to activate human glioma cell line U87 invasion. Furthermore, we have identified a signaling pathway which involves CSF-1 signaling through ERK to upregulate AREG expression in microglia. Interfering with ERK using pharmacological inhibitors prevents AREG upregulation in microglia and microglia-stimulated GL261 invasion. These data highlight AREG as a key factor in produced by tumor associated microglia in promoting glioma invasion.