Inhibited Glioma Cell Proliferation Research Articles

Mechanisms involved in the anti-tumor effects of Toosendanin in glioma cells

BackgroundToosendanin (TSN) is a triterpenoid compound mainly used as an ascaris repellant. Recent studies have shown that it possesses antitumor effects in many types of tumor cells. However, the effects of TSN on glioma cells have rarely been reported.MethodsDifferent assays were performed to investigate the effects of TSN on the different glioma cell lines including U87MG and LN18. The assays included colony formation, wound healing, and transwell assays. Furthermore, Hoechst 33342 staining, flow cytometry, and western blotting analysis were performed to investigate the apoptotic activities of TSN. Finally, the results were confirmed using a xenograft tumor model that comprised of nude mice.ResultsIn vitro, the CCK-8 and colony formation assays showed that TSN effectively inhibited glioma cell proliferation. Moreover, the inhibitory effects on glioma cell migration and invasion were demonstrated through the wound healing and transwell assays, respectively. Hoechst 33342 staining, flow cytometry, and western blotting assays demonstrated the significant effect of TSN in the apoptosis induction of glioma cells. Furthermore, the anti-glioma effect of TSN was exerted through the inhibition of the PI3K/Akt/mTOR signaling pathways as demonstrated by western blotting analysis. In addition, the effects of TSN on glioma cell viability, apoptosis, cell cycle arrest, migration, and invasion were reversed by 740Y-P, a PI3K activator. Finally, the mouse xenograft model confirmed the suppressive effect of TSN on tumor growth in vivo.ConclusionOur results suggest that TSN is a promising chemotherapeutic drug for patients with glioma.

Sevoflurane blocks glioma malignant development by upregulating circRELN through circRELN-mediated miR-1290/RORA axis

BackgroundSevoflurane (Sev) has been reported to inhibit cancer development, and sevoflurane treatment in cancers is implicated with the deregulation of specific non-coding RNAs (ncRNAs). This study aimed to investigate the relationship between sevoflurane and circular RNA reelin (circRELN) in glioma.MethodsThe expression of circRELN, microRNA-1290 (miR-1290) and RAR-related orphan receptor A (RORA) was measured by quantitative real-time PCR (qPCR). Cell proliferative capacity was assessed by cell counting kit-8 (CCK-8) and colony formation assays. Cell apoptosis and cell cycle distribution were monitored by flow cytometry assay. Cell migration was assessed by wound healing assay and transwell assay, and cell invasion was assessed by transwell assay. The protein levels of matrix metalloproteinase-2 (MMP2), MMP9 and RORA were quantified by western blot. Tumor growth in vivo was assessed by Xenograft models. The binding relationship between miR-1290 and circRELN or RORA was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.ResultsWe found that circRELN expression was declined in glioma tissues and cells, while Sev treatment enhanced circRELN expression. In function, Sev notably inhibited glioma cell proliferation, migration and invasion and promoted apoptosis and cell cycle arrest, while circRELN knockdown reversed these effects. MiR-1290 served as a target of circRELN, and glioma cell malignant phenotypes recovered by circRELN knockdown were partly repressed by miR-1290 deficiency. In addition, RORA was a target of miR-1290, and glioma cell malignant phenotypes promoted by miR-1290 restoration were partly blocked by RORA overexpression. CircRELN regulated RORA expression by targeting miR-1290. In Xenograft models, Sev inhibited tumor growth by upregulating circRELN.ConclusionSev blocked the progression of glioma by increasing circRELN expression, and circRELN played roles in glioma partly by regulating the miR-1290/RORA network.

LINC01087 inhibits glioma cell proliferation and migration, and increases cell apoptosis via miR-384/Bcl-2 axis.

Background: Long non-coding RNA (LncRNA) is associated with disease progression. It is reported that LINC01087 is highly expressed in cancer and participates in tumorigenesis. However, whether it regulates the development of glioma has not been studied. So, the goal of this research is to determine the role of LINC01087 in gliomas and to provide potential targets for clinical treatment.Methods: The gene expression was detected by quantitative reverse transcriptase polymerase chain reaction (QRT-PCR) and Western blotting (WB). Cell proliferation was analyzed by CCK8 and colony formation test, and apoptosis was detected by flow cytometry. Luciferase report experiment and RNA Binding Protein Immunoprecipitation confirmed the interaction between LINC01087, miR-384 and Bcl-2. The effect of regulating LINC01087 on the growth of glioma was confirmed in vitro.Results: The LINC01087 expression was up-regulated in clinical glioma samples (n = 35). Furthermore, LINC01087 silencing can obviously suppress the proliferation of glioma cells and induce apoptosis. Mechanically, we found that LINC01087 was the molecular sponge of miR-384. LINC01087 could inhibit the miR-384 expression and boost the Bcl-2 expression through sponge expression of miR-384. The repair of Bcl-2 effectively saved the proliferation and apoptosis of glioma cells lacking LINC01087.Conclusion: LINC01087 is highly expressed in glioma and can participate in the growth of glioma through miR-384/Bcl-2 axis. So, it is a potential therapeutic target.

Loss of FAM60A attenuates cell proliferation in glioma via suppression of PI3K/Akt/mTOR signaling pathways

BackgroundGlioma is a common malignant tumor of the central nervous system with a high incidence and mortality. Family with sequence similarity 60 member A (FAM60A) is a new subunit of the Sin3 deacetylase complex. The clinical significance and biologic role of FAM60A in glioma remain unclear. MethodsThe expression of FAM60A in normal glial cells, glioma cells, and five-paired gliomas, and adjacent noncancerous tissues was quantified using real-time polymerase chain reaction (PCR) and western blotting. FAM60A protein expression in 179 archived, paraffin-embedded glioma samples was analyzed using immunohistochemistry. The roles of FAM60A in glioma cell proliferation and tumorigenicity were explored in vitro and in vivo. The underlying molecular mechanisms were elucidated using Western blot assay. Serum exosomal FAM60A levels of glioma patients were detected using electron microscopy, western blot, and real-time PCR. ResultsFAM60A expression was significantly up-regulated in glioma tissues and cell lines and positively associated with a worse outcome in glioma. Knockdown of FAM60A could inhibit glioma cell proliferation and tumorigenicity in vitro and in vivo. Besides, FAM60A expression was detectable in extracted serum exosomes with a higher expression in the glioma cancer group than in the normal group. ConclusionsLoss of FAM60A attenuates cell proliferation in glioma by suppressing PI3K/Akt/mTOR signaling pathways. Therefore, FAM60A may act as a prognostic biomarker and therapeutic target for glioma.

Triptolide reverses epithelial-mesenchymal transition in glioma cells via inducing autophagy.

BackgroundTo observe the effects of triptolide (TP) on the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of glioma cells, and to explore the possible mechanisms of phenotypic changes in EMT.MethodsThe U87 and U251 glioma cell lines were treated TP. The Cell Counting Kit-8 (CCK-8) method was used to detect the half-maximal inhibitory concentration (IC50) of TP in these two cell lines and the inhibition of cell proliferation at the IC50 concentration. The wound-healing experiment and Transwell invasion assay were used to detect the cells’ migration and invasion abilities, respectively. Using western blot protocol, the expression levels of the EMT markers were analyzed, and the levels of the autophagy markers were also detected. The pEGFP-C2-LC3B plasmid was transfected into glioma cells, and the effect of TP on autophagy was detected by immunofluorescence. A subcutaneous tumor model in nude mice was established to observe the effect of TP on cell proliferation in vivo, and immunohistochemistry (IHC) was used to detect the expression levels of EMT markers in mouse tumor tissues.ResultsTP significantly inhibited the proliferation of U87 and U251 cells in a dose- and time-dependent manner. TP had a significant inhibitory effect on the migration and invasion of U87 and U251 cells. Western blot showed that TP reversed the process of EMT in glioma cells, which was evidenced by the upregulated expression of the epithelial marker E-cadherin, and the downregulated expression of the mesenchymal markers N-cadherin, Vimentin, ZEB1, Snail, and Slug. TP increased autophagy in glioma cells, increased the LC3B II/I ratio, and upregulated Beclin-1 and Atg-7 expression. Immunofluorescence showed that the number of autophagosomes increased significantly after TP was applied to cells. In the nude mouse subcutaneous tumor model, experiments revealed an inhibitory effect of TP on glioma cell proliferation in vivo. IHC confirmed that the expression of E-cadherin was upregulated in mouse tumor tissues, while the expression levels of N-Cadherin and Vimentin were downregulated.ConclusionsTP can inhibit glioma cell proliferation, migration, and invasion, and reverse EMT progression. The possible mechanism of EMT reversal in glioma cells is that TP induces autophagy.

LncRNA NEAT1 promotes glioma cancer progression via regulation of miR-98-5p/BZW1.

Background: Glioma is the most common malignant tumor in the human central nervous system. Long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) promotes oncogenesis in various tumors. In the present study, we aimed to examine the role of NEAT1 in altering the properties of gliomas.Methods: Quantitative real-time PCR technology was used to determine the expression levels of relevant genes in tumor tissues and cell lines. The protein expression levels were validated by Western blotting. Cell counting kit-8 (CCK-8) and colony formation assays were used to test the cell proliferation ability. A luciferase reporter assay was used to determine the interactions of the genes. Tumor xenografts were used to detect the role of NEAT1 in gliomas in vivo.Results: We demonstrated that NEAT1 up-regulated glioma cells and negatively correlated with miR-98-5p in glioma tissues. A potential binding region between NEAT1 and miR-98-5p was confirmed by dual-luciferase assays. NEAT1 knockdown inhibited glioma cell proliferation. The inhibition of miR-98-5p rescued the knockdown of NEAT1 in glioma cells. Basic leucine zipper and W2 domain containing protein 1 (BZW1) was identified as a direct target of miR-98-5p. We also identified that BZW1 was positively correlated with NEAT1 in glioma tissues. NEAT1 knockdown inhibited glioma cell proliferation in vivo via miR-98-5p/BZW1.Conclusion: Our results suggest that NEAT1 plays an oncogenic function in glioma progression. Targeting NEAT1/miR-98-5p/BZW1 may be a novel therapeutic treatment approach for glioma patients.

DNMT1 Mediated CAHM Repression Promotes Glioma Invasion via SPAK/JNK Pathway.

Gliomas are the most common and fatal brain tumors worldwide. Abnormal DNA promoter methylation is an important mechanism for gene loss of tumor suppressors. A long non-coding RNA colorectal adenocarcinoma hypermethylated (CAHM) has been reported to be nearly deleted in glioblastomas (GBMs). Nevertheless, the roles of CAHM in gliomas remain unknown up to now. In the present study, 969 glioma samples downloaded from the CGGA and Gravendeel databases were included. We found that CAHM expression was correlated with glioma grades, molecular subtype, IDH mutation status, and 1q/19p codel status. In glioma cells, CAHM is hypermethylated by DNA methyltransferase1 (DNMT1) and the loss of CAHM expression could be reversed by 5-Aza-2'-deoxycytidine (5-Aza), a specific inhibitor of DNA methyltransferases. Besides, the expression of CAHM was negatively associated with overall survival in both primary and recurrent gliomas. Moreover, the result of Gene Ontology (GO) analysis suggested that CAHM participated in negatively regulating cell development, nervous system development, neurogenesis, and integrin-mediated signaling pathway. Overexpression of CAHM inhibited glioma cell proliferation, clone formation, and invasion. Further exploring results showed that CAHM overexpression suppressed glioma migration and invasion through SPAK/MAPK pathway. Collectively, this study disclosed that CAHM might be a suppressor in gliomas.

PAICS is related to glioma grade and can promote glioma growth and migration.

Glioma is a common malignant tumour of the brain. In this study, we aimed to investigate diagnostic biomarkers and its role in glioma. Weighted gene co‐expression network analysis (WGCNA) and Cytoscape software were used to screen the marker genes in glioma. RT‐qPCR and Western blotting methods were performed to determine the expression of PAICS, ERCC1 and XPA genes in glioma tissues. Expression level of PAICS in different grades of glioma was examined by immunohistochemistry. CCK8 and Colony formation assays were used to detect cell proliferation. Cell adhesion assay was used to detect adhesion ability. Wound healing and transwell tests were used to detect cell migration ability. Flow cytometry was used to detect cell cycle and apoptosis. According to the predicted co‐expression network, we identified the hub gene PAICS. Furthermore, we observed that PAICS expression level was up‐regulated in glioma tissues compared with normal tissues, and the expression level was correlated with the grade of glioma. Moreover, we found PAICS can promote glioma cells proliferation and migration in vitro. Flow cytometry results showed that si‐PAICS cells were stalled at the G1 phase compared with the si‐NC cells and knocking down PAICS expression can increase apoptotic rate. PAICS can regulate the mRNA and protein levels of nucleotide excision repair pathway core genes ERCC1 and XPA. l‐aspartic acid can affect the expression of PAICS and then inhibit glioma cell proliferation. Our results indicated that PAICS can promote glioma proliferation and migration. PAICS may act as a potential diagnostic marker and a therapeutic target for glioma.

An E3 Ubiquitin Ligase RNF139 Serves as a Tumor-Suppressor in Glioma

Glioma is highly lethal because of its high malignancy. Ubiquitination, a type of ubiquitin-dependent protein modification, has been reported to play an oncogenic or tumor-suppressive role in glioma development, depending on the targets. Ring finger protein 139 (RNF139) is a membrane-bound E3 ubiquitin ligase serving as a tumor suppressor by ubiquitylation-dependently suppressing cell growth. Herein, we firstly confirmed the abnormal downregulation of RNF139 in glioma tissues and cell lines. In glioma cells, ectopic RNF139 overexpression could inhibit, whereas RNF139 knockdown could aggravate the aggressive behaviors of glioma cells, including hyperproliferation, migration, and invasion. Moreover, in two glioma cell lines, RNF139 overexpression inhibited, whereas RNF139 knockdown enhanced the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and AKT serine/threonine kinase 1 (AKT). In a word, we demonstrate the aberration in RNF139 expression in glioma tissue samples and cell lines. RNF139 serves as a tumor-suppressor in glioma by inhibiting glioma cell proliferation, migration, and invasion and promoting glioma cell apoptosis through regulating PI3K/AKT signaling.

Circ_0030018 promotes glioma proliferation and metastasis.

BackgroundCircular RNA (circRNA) plays an essential role in tumor progression, including glioma. circ_0030018 is a newly discovered circRNA that is highly expressed in glioma. However, its role and mechanism in glioma need to be further elucidated.MethodsThe expression of circ_0030018, microRNA (miR)-194-5p, and tripartite motif containing 44 (TRIM44) was examined using quantitative real-time PCR. Cell proliferation, migration, invasion, and apoptosis were determined using MTT assay, colony formation assay, transwell assay, and flow cytometry. Moreover, dual-luciferase reporter assay and RNA pull-down assay were used to verify the interactions among circ_0030018, miR-194-5p, and TRIM44. The protein expression of TRIM44 was assessed by western blot analysis. Animal experiments were conducted to explore the role of circ_0030018 in glioma tumor growth in vivo.Resultscirc_0030018 was overexpressed in glioma tissues and cells, and its silencing could inhibit glioma cell proliferation, migration, invasion, and accelerate apoptosis. miR-194-5p could be sponged by circ_0030018, and its overexpression could hinder the progression of glioma cells. Further experiments revealed that miR-194-5p inhibitor reversed the negative regulation of circ_0030018 knockdown on glioma cell progression. In addition, TRIM44 was a target of miR-194-5p, and its downregulation could repress glioma cell progression. Overexpressed TRIM44 reversed the inhibition effect of miR-194-5p on glioma cell progression. Animal experiments suggested that circ_0030018 knockdown could reduce glioma tumor growth through regulating miR-194-5p and TRIM44.ConclusionOur 8data showed that circ_0030018 enhanced glioma progression by sponging miR-194-5p to regulate TRIM44, indicating that circ_0030018 might be a potential treatment target for glioma.

Knockdown circular RNA circGFRA1 inhibits glioma cell proliferation and migration by upregulating microRNA-99a.

Glioma is the most widespread and malignant brain tumor in the central nervous system of adult, causing multiple cancer-associated deaths worldwide. Here, we identified the impact of circGFRA1 on glioma, and aimed to uncover the underlying molecular mechanism. The expression of circGFRA1 of glioma specimens was evaluated by using quantitative reverse transcription PCR. Cell viability, proliferation, colony formation, apoptosis and migration were estimated utilizing CCK-8, EdU staining, colony formation assay, TUNEL staining and Transwell assay, respectively. Bioinformatics analysis, luciferase assay and RNA co-immunoprecipitation was utilized for verification of direct binding between circGFRA1 and miR-99a. Western blot was applied to investigate protein expression in U251 cells. The results showed that circGFRA1 expression was overexpressed in glioma specimens. Knockdown circGFRA1 declined viability, colony formation, proliferation and migrative potential, but enhanced U251 cell apoptosis. Moreover, circGFRA1 acts as a microRNA sponge for miR-99a. Furthermore, miR-99a was involved in the circGFRA1-regulated glioma cell behaviors. Silencing circGFRA1 reduced p/t-AKT, p/t-FOXO1 and p/t-mTOR expression levels via upregulating miR-99a expression. In conclusion, our study demonstrated that knockdown circGFRA1 inhibits glioma cell proliferation and migration by upregulating microRNA-99a.

Sevoflurane suppresses glioma tumorigenesis via regulating circ_0079593/miR-633/ROCK1 axis

BackgroundSevoflurane is a common inhalational anesthetic, which has been revealed to have anticancer effect in glioma. However, the mechanisms of sevoflurane in glioma progression remain largely unclear. MethodsCell proliferation, cell cycle, apoptosis and metastasis were monitored by cell counting kit-8 (CCK-8), flow cytometry, Transwell and Western blot assays. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assays were used to examine the expression levels of circ_0079593, microRNA (miR)-633 and ROCK1 (Rho Associated Coiled-Coil Containing Protein Kinase 1). The dual-luciferase reporter assay was employed to confirm the targeting relationship between miR-633 and circ_0079593 or ROCK1. Animal experiment was conducted to explore the effect of sevoflurane in vivo. ResultsSevoflurane inhibited glioma cell proliferation, metastasis and induced apoptosis in vitro as well as impeded tumor growth in vivo. The expression of circ_0079593 was higher in glioma tissues and cells, and was decreased by sevoflurane treatment in glioma cells. Functional experiments showed that circ_0079593 overexpression in glioma cells reversed the inhibitory effects of sevoflurane on cell growth and metastasis. In a mechanism analysis, circ_0079593 acted as a sponge for miR-633 to elevate ROCK1 expression in glioma cells, and sevoflurane could regulate ROCK1 expression via circ_0079593/miR-633 axis. Besides that, circ_0079593/miR-633/ROCK1 axis mediated the protective effects of sevoflurane on glioma cell tumorigenesis. ConclusionSevoflurane repressed glioma tumorigenesis via regulating circ_0079593/miR-633/ROCK1 axis, suggesting a new insight into the application of sevoflurane in glioma therapy.

G-protein-coupled receptor GPR17 inhibits glioma development by increasing polycomb repressive complex 1-mediated ROS production

Glioma is the most common primary tumor in the central nervous system. However, the development of glioma and effective therapeutic strategies remain elusive. Here, we identify GPR17 as a potential target to treat glioma. Data mining with human LGG and GBM samples reveals that GPR17 is negatively correlated with glioma development. Overexpressing GPR17 inhibits glioma cell proliferation and induces apoptosis by raising ROS levels. GPR17-overexpressing glioma cells are less tumorigenic in the brain than in control cells. Mechanistically, GPR17 inhibits the transcription of RNF2, a key component in the PRC1 complex, through cAMP/PKA/NF-κB signaling, leading to reduced histone H2A monoubiquitination. ChIP-Seq and RNA-Seq analyses reveal KLF9 as a direct target of RNF2. KLF9 mediates the functions of GPR17 and RNF2 in glioma cells. Furthermore, activation of GPR17 by its agonist inhibits glioma formation. Our findings have thus identified GPR17 as a key regulator of glioma development and a potential therapeutic target for gliomas.

Mir-139-5p inhibits glioma cell proliferation and progression by targeting GABRA1

Glioma is an extremely aggressive malignant neoplasm of the central nervous system. MicroRNA (miRNA) are known to bind to specific target mRNA to regulate post-transcriptional gene expression and are, therefore, currently regarded as promising biomarkers for glioma diagnosis and prognosis. The aim of the present study was to examine the pathogenesis and potential molecular markers of glioma by comparing the differential expression of miRNA and mRNA between glioma tissue and peritumor brain tissue. We explored the impact of screened core miRNA and mRNA on cell proliferation, invasion, and migration of glioma. An miRNA expression profile dataset (GSE90603) and a transcriptome profile dataset (GSE90598) were downloaded from combined miRNA-mRNA microarray chips in the Gene Expression Omnibus (GEO) database. Overall, 59 differentially expressed miRNAs (DEMs) and 419 differentially expressed genes (DEGs) were identified using the R limma software package. FunRich software was used to predict DEM target genes and miRNA-gene pairs, and Perl software was used to find overlapping genes between DEGs and DEM target genes. There were 129 overlapping genes regulated by nine miRNAs between target genes of the DEMs and DEGs. The Chinese Glioma Genome Atlas(CGGA) was analyzed in order to identify miRNAs with diagnostic and prognostic significance. MiR-139-5p, miR-137, and miR-338-3p were validated to be significantly linked to prognosis in glioma patients. Finally, we validated that miR-139-5p affected glioma malignant biological behavior via targeting gamma-aminobutyric acid A receptor alpha 1(GABRA1) through rescue experiments. Low miR-139-5p expression was correlated with survival probability and World Health Organization (WHO) grade. MiR-139-5p overexpression inhibited cell proliferation, migration, and invasion of glioma in vitro. GABRA1 was identified as a functional downstream target of miR-139-5p. Decreased GABRA1 expression was related to similar biological roles as miR-139-5p overexpression while upregulation of GABRA1 effectively reversed the inhibition effects of miR-139-5p. These results demonstrate a novel axis for miR-139-5p/GABRA1 in glioma progression and provide potential prognostic predictors and therapeutic target for glioma patients.

Upregulation of lnc-ZNF281 Inhibits the Progression of Glioma via the AKT/GSK-3β/β-Catenin Signaling Pathway.

The purpose of this study is to elucidate the roles and potential underlying mechanisms of long noncoding RNA lnc-ZNF281 in glioma. We performed qRT-PCR to detect the expression levels of lnc-ZNF281 in glioma tissues. The effects of lnc-ZNF281 on the proliferative and migrative abilities of T98G and HS683 glioma cells were examined by cell proliferation assay, colony formation assay, wound-healing assay, and transwell assay. Also, the effects of lnc-ZNF281 on AKT/GSK-3β/β-catenin pathway were analyzed. The results showed that the expression of lnc-ZNF281 in glioma tissues was decreased compared with normal tissues. lnc-ZNF281 overexpression inhibited the proliferative and migrative abilities of glioma cells, while lnc-ZNF281 knockdown obtained the opposite findings. Besides, overexpression of lnc-ZNF281 in glioma cells inactivated the AKT/GSK-3β/β-catenin signaling pathway. Furthermore, β-catenin activation reversed the suppressive effects of lnc-ZNF281 on glioma cells. Taken together, lnc-ZNF281 inhibits glioma cell proliferation and migration via AKT/GSK-3β/β-catenin pathway and may serve as a potential target for glioma treatment.

Interfering with hyaluronic acid metabolism suppresses glioma cell proliferation by regulating autophagy

The tumor microenvironment plays an important role in tumor progression. Hyaluronic acid (HA), an important component of the extracellular matrix in the tumor microenvironment, abnormally accumulates in a variety of tumors. However, the role of abnormal HA accumulation in glioma remains unclear. The present study indicated that HA, hyaluronic acid synthase 3 (HAS3), and a receptor of HA named CD44 were expressed at high levels in human glioma tissues and negatively correlated with the prognosis of patients with glioma. Silencing HAS3 expression or blocking CD44 inhibited glioma cell proliferation in vitro and in vivo. The underlying mechanism was attributed to the inhibition of autophagy flux and maintaining glioma cell cycle arrest in G1 phase. More importantly, 4-methylumbelliferone (4-MU), a small competitive inhibitor of Uridine diphosphate (UDP) with the ability to penetrate the blood-brain barrier (BBB), also inhibited glioma cell proliferation in vitro and in vivo. Thus, approaches that interfere with HA metabolism by altering the expression of HAS3 and CD44 and the administration of 4-MU potentially represent effective strategies for glioma treatment.

Depletion of CIP2A inhibits the proliferation, migration, invasion and epithelial-mesenchymal transition of glioma cells

CIP2A is an oncoprotein that is overexpressed in multiple solid tumours and some malignant haematologic disorders. However, its function in glioma is poorly understood. In this study, our results demonstrated that the expression of CIP2A was higher in glioma tissues than in normal tissues. Using tissue microarrays for immunohistochemistry, we found that the intensity of CIP2A expression was higher in high-grade gliomas (grade III-IV) than in low-grade gliomas (grade I-II). In addition, we found that depletion of CIP2A inhibited glioma cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro. Taken together, our findings revealed that CIP2A was involved in glioma progression, indicating that CIP2A could be used as a potential therapeutic target in the future.

Knockdown of TRIM32 inhibits tumor growth and increases the therapeutic sensitivity to temozolomide in glioma in a p53-dependent and -independent manner

Tripartite motif protein 32 (TRIM32), an E3 ubiquitin ligase, has been reported to participate in many human cancers. However, the underlying role of TRIM32 in glioma remains largely unknown. Here, we aimed to explore the function of TRIM32 in glioma cells and the clinical implications and found that TRIM32 was upregulated in glioma tissues. Consistently, overexpression of TRIM32 promoted glioma U87 and U251 cell proliferation and conferred cell resistance to temozolomide (TMZ). Conversely, knockdown of TRIM32 inhibited glioma cells proliferation in vitro and in vivo and sensitized glioma cells to the treatment of TMZ in a p53-dependent and -independent manner. Mechanistically, knockdown of TRIM32 induced apoptosis of U87 an U251 cells. In addition, TRIM32 interacted with the antiapoptotic proteins BCL-xL and BCL-w, which antagonized the inhibitory effect of TRIM32 knockdown in U87 cells. Together, our study uncovered the role of TRIM32 in glioma and TRIM32 may be a potential therapeutic target for gliomas.

Gain of circBRAF Represses Glioma Progression by Regulating miR-1290/FBXW7 Axis.

Dysregulated circular RNAs (circRNAs) have been confirmed to partake in the modulation of the glioma progression. Here, we intended to explore the role of circBRAF in glioma and the possible action mechanism. The expression levels of circBRAF, microRNA (miR)-1290 and F-box and WD repeat domain containing 7 (FBXW7) were analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or western blot. Cell viability was assessed by 3-(4, 5)-dimethylthiazole-2-y1)-2, 5-biphenyl tetrazolium bromide (MTT) assay. Cell cycle distribution was determined by flow cytometry. Cell migration and invasion were evaluated through Trans-well assay. Related protein levels were detected by western blot. Targeted relation among circBRAF, miR-1290 and FBXW7 was validated by dual-luciferase reporter, RNA immunoprecipitation (RIP) and pull-down assays. Xenograft model was constructed to explore the function of circBRAF in vivo. Expression of circBRAF and FBXW7 was decreased in glioma tissues and cells. Upregulation of circBRAF inhibited glioma cell proliferation and metastasis in vitro. MiR-1290 was upregulated in glioma, which was sponged by circBRAF. Besides, circBRAF elevated FBXW7 expression by targeting miR-1290. Introduction of miR-1290 or FBXW7 knockdown could counteract the inhibitory effects of circBRAF upregulation on the malignant phenotypes of glioma cells. Overexpression of circBRAF repressed the tumor growth in vivo. Upregulation of circBRAF suppressed glioma evolvement in vitro and in vivo by regulating miR-1290/FBXW7 axis, broadening the cognition of glioma progression.

Collagen Type I α-1 Promotes Malignant Glioma Cell Proliferation and Is Associated with Glioma Prognosis

Collagen type I α-1 chain (COL1A1) is closely involved in the advancement of various tumors, yet the role of COL1A1 in the progression of glioma is not clear. Herein, we evaluated the effect of COL1A1 on glioma cell proliferation. The effect of COL1A1 on glioma cell proliferation was assessed through overexpression or knockdown of COL1A1. The CCK-8 and colony formation assays, as well as immunohistochemistry (IHC) were used to detect COL1A1 expression in different glioma grades. U-87MG as well as U-251MG cells were stably-inserted with lentivirus containing COL1A1 through transfection, we additionally used qRT-PCR as well as Western blot assay to validate their overexpression efficiencies. COL1A1 mRNA and protein levels were upregulated in the high-grade glioma (HGG) compared to the low-grade glioma (LGG). COL1A1 IHC score was remarkably higher in HGG than LGG. The staining index (SI) further showed that COL1A1 protein levels were higher in HGG than LGG. The Kaplan–Meier analysis showed that elevated COL1A1 mRNA levels were obviously correlated with lower overall survival (OS) and disease-free survival (DFS) for brain glioma patients. COL1A1 mRNA and protein levels were markedly upregulated in human glioma cell lines when compared with brain astrocyte cell lines. The high expression level of COL1A1 facilitated glioma cell proliferation. COL1A1 knockdown remarkably inhibited glioma cell proliferation. Thus, this research shows that COL1A1 promotes glioma cell proliferation and is closely related to glioma prognosis.