Invasion Of U251 Glioma Cells Research Articles

Retracted] miR‑218 inhibits the migration and invasion of glioma U87cells through the Slit2‑Robo1 pathway.

[This retracts the article DOI: 10.3892/ol.2015.2904.].

SP1 transcriptionally activates NLRP6 inflammasome and induces immune evasion and radioresistance in glioma cells

Glioma accounts for approximately 80% of all malignant brain tumors. This study aimed to investigate the interaction between specificity protein 1 (SP1) and NLR family pyrin domain containing 6 (NLRP6) and their roles in the activity of glioma cells. Differentially expressed genes in glioma were identified using transcriptome analysis tools, and a protein-protein-interaction network was performed based on the DEGs. SP1 and NLRP6 were abundantly expressed in glioma cells and indicated unfavorable prognosis of patients according to the GEO datasets. SP1could bind to the promoter of NLRP6 and induce its transcriptional activity. Downregulation of SP1 reduced proliferation, migration and invasion of glioma U87 cells in vitro as well as tumorigenesis in vivo. The malignancy of cells was restored after NLRP6 upregulation. Downregulation of SP1 in glioma cells also increased proliferation of CD8+ T cells and the immune activity in U87 cells, and it reduced the radioresistance of U87 cells. However, the immune evasion and radioresistance of glioma cells were restored upon NLRP6 upregulation. NLRP6 mediated the innate immune pathway through an ASC/caspase-1/IL-1β axis. To conclude, this study suggested that SP1 interacts with NLRP6 inflammasome to enhance malignant behaviors, immune evasion and radioresistance in glioma cells.

Abnormal expression of HOXD11 promotes the malignant behavior of glioma cells and leads to poor prognosis of glioma patients.

BackgroundHomeobox D11 (HOXD11) plays an important role in a variety of cancers, but its precise role in gliomas remains unclear. This study aimed to explore the relationship between HOXD11 and gliomas by combining bioinformatics methods with basic experimental validation.Materials and methodsObtain gene expression information and clinical information of glioma and non-tumor brain tissue samples from multiple public databases such as TCGA (666 glioma samples), CGGA (749 glioma samples), GEPIA(163 glioblastoma samples and 207 normal control samples), GEO (GSE4290 and GSE15824). Nine cases of glioma tissue and five cases of normal control brain tissue were collected from the clinical department of Henan Provincial People’s Hospital for further verification. A series of bioinformatic analysis methods were used to confirm the relationship between HOXD11 expression and overall survival and clinical molecular characteristics of patients with glioma. RT-qPCR was used to verify the change of expression level of HOXD11 in glioma cells and tissues. MTT assay, colony formation assay, wound-healing assay, immunofluorescence staining, flow cytometry and western blotting were used to detect the effect of HOXD11 on the biological behavior of glioma cell line U251.ResultsThe high expression of HOXD11 was significantly related to age, World Health Organization (WHO) grade, chemotherapy status, histological type, and even 1p19q codeletion data and isocitrate dehydrogenase (IDH) mutation. HOXD11, as an independent risk factor, reduces the overall survival of glioma patients and has diagnostic value for the prognosis of glioma. Gene Set Enrichment Analysis (GSEA) showed that HOXD11 was significantly enriched in cell signaling pathway such as cell cycle, DNA replication and so on. Finally, we confirmed that the knockout of HOXD11 can inhibit the proliferation and invasion of U251 glioma cells, and change the biological behavior of tumor cells by preventing the progression of cell cycle.ConclusionsHOXD11 may be used as a candidate biomarker for the clinical application of targeted drug and prognostic assessment treatment of glioma. In addition, This study will help to explore the pathological mechanism of glioma.

Mechanisms for propofol in inhibiting the proliferation and invasion of glioma U87 cells and its effect on miR-134 expression.

To investigate the effects of propofol on the proliferation and invasion of glioma U87 cells and to explore the possible anti-tumor mechanisms. The glioma U87 cells was divided into a blank group, a positive control group, and the propofol groups (1.00, 2.00 or 5.00 mmol/L). Cell counting kit-8 (CCK-8) was used to detect cell proliferation; Transwell method was used to detect the effect of propofol on invasion and migration of U87 cells; real-time PCR was used to detect the expression of microRNA-134 (miR-134); Western blotting was used to detect the expression levels of reproduction-related protein Ki-67, invasion-related protein metalloproteinase-2 (MMP-2), metalloproteinase-9 (MMP-9) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway-related protein. Compared with the blank group, the proliferation, invasion and migration capacity of U87 cells were reduced in the positive control group and the propofol groups after 48 hours (all P<0.05), along with the decreased expression of Ki-67, MMP-2 and MMP-9 and the ratio of p-PI3K/PI3K and p-Akt/Akt (all P<0.05), while the level of miR-134 was increased significantly (P<0.05). Compared with the positive control group and the 1.00 mmol/L propofol-treated group, the proliferation, invasion and migration capacity of U87 cells, the expression of Ki-67, MMP-2 and MMP-9, and the ratio of p-PI3K/PI3K and p-Akt/Akt was decreased significantly after 48 hours (all P<0.05), while the level of miR-134 was increased significantly in the 2.00 and 5.00 mmol/L propofol-treated groups (both P<0.05). Compared with the 2.00 mmol/L propofol-treated group, the proliferation, invasion and migration capacity of U87 cells, the expression of Ki-67, MMP-2 and MMP-9, and the ratio of p-PI3K/PI3K and p-Akt/Akt was decreased significantly after 48 hours in the 5.00 mmol/L propofol-treated group (all P<0.05), while the level of miR-134 was increased significantly (P<0.05). Propofol can decrease the proliferation rate, and the invasion and migration abilities of U87 cells, which may be achieved by up-regulation of miR-134 and suppression of PI3K/Akt signaling pathway.

Effect of lncRNA ZEB1-AS1 on proliferation, invasion and apoptosis of glioma U87 cells.

This study aimed to investigate the effect of LncRNA ZEB1-AS1 on the proliferation, invasion and apoptosis of human glioma U87 cells. U87 glioma cells were divided into three groups. The Si group was transfected with LncRNA ZEB1-AS1 specific SiRNA. The NC group was transfected with non-specific scramble siRNA, and untransfected glioma cells were used as the blank group. After 48 h of transfection, the proliferation of U87 cells was detected by MTT assay, apoptosis of U87 cells was detected by flow cytometry, and Transwell invasion assay was used to detect cell invasion. The expression of LncZEB1-AS1 in Si group was significantly lower than that in the NC and blank groups (P<0.01). There was no statistical difference in the OD 490 between the three groups at 24 h (P>0.05). At 48 h, the Si group was significantly lower than the NC group and the blank group (P<0.01). After 48 h, the three groups showed a gradually increasing trend, but at all the time points, the Si group was always lower than the NC and blank groups (P<0.01). The OD values of the blank and NC groups were significantly higher than the same group at the previous time point (P<0.01). The OD values of Si group at 48 and 96 h were significantly higher than those at the previous time point (P <0.05). Although there was an upward trend between 72 and 48 h, the difference was not significant (P>0.05). Flow cytometry detected apoptosis in each group and found that the apoptosis rate in the Si group was significantly higher than that in the NC and blank groups (P<0.01). Inhibition of LncRNA ZEB1-AS1 can inhibit the proliferation and invasion of glioma U87 cells and promote apoptosis. LncRNA ZEB1-AS1 is expected to become a new target for the treatment of glioma.

Human herpesvirus 6 U94 suppresses tumor cell proliferation and invasion by inhibiting Akt/GSK3β signaling in glioma

Background: Glioma is a highly malignant brain tumor with limited therapeutic options. We reported previously that the DNA and protein of human herpesvirus 6 (HHV-6) could be detected in glioma tumor tissues. However, the effects of HHV-6 U94, which is abundantly expressed during the virus’ latency period, on glioma progression remain unknown. In the present study, we aimed to determine on the roles of HHV-6 U94 in glioma progression. Methods: The ectopic expression of U94 in glioma U87 cells was achieved using lentivirus infection. The effects of HHV-6 U94 on cell proliferation, migration, and invasion were examined using cell counting kit-8 (CCK-8), colony formation, wound healing, Transwell migration, and invasion assays. The gene expression profiles of U94-expressing U87 cells were analyzed using microarray analysis and confirmed by quantitative RT-PCR and western blotting analysis. The effects of HHV-6 U94 on glioma tumor growth were evaluated using a xenograft nude mouse model. Results: We found that ectopic expression of U94 in glioma U87 cells dramatically inhibited colony formation and cell proliferation in vitro , and suppressed xenograft tumorigenesis in glioma-bearing nude mice. In addition, overexpression of U94 suppressed the migration and invasion of glioma U87 cells. Furthermore, enhanced expression of U94 in glioma cells downregulated ras-related protein rap-1A (RAP1A), solute carrier family 7 member 11 (SLC7A11), forkhead box P1 (FOXP1), and transcription factor 4 (TCF4) expression by inhibiting Akt kinase (AKT/glycogen synthase kinase 3 beta (GSK3β) signaling, which proteins are associated with the malignant phenotypes of glioma cells. Conclusions: Taken together, these data indicated that HHV-6 U94 could suppress tumor cell proliferation and invasion by inhibiting AKT/GSK3β signaling in glioma.

RETRACTED: Neferine inhibits proliferation, migration and invasion of U251 glioma cells by down-regulation of miR-10b

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Panels from Figures 2A, 2C and 5D appear similar to the “Migrated cell” panels from Figure 2E and the panels “Migrated cell/mimic NC + pEX” and “Invasive cell/miR-122 mimic + pEX” from Figure 7D of the article that was previously published by Daliang Kong and Yang Wang in the Journal of Cellular Biochemistry 119 (2018) 1050-1061 https://doi.org/10.1002/jcb.26273. Also, panels from Figures 2A and 2C appear similar to the panels “sh-FOXM1” from Figure 5D and “sh-HULC” from Figure 2E of the article that was published by Qiu Hong Rui, Jian Bo Ma, Yu Feng Liao, Jin Hua Dai and Zhen Yu Cai in the Brazilian Journal of Medical and Biological Research 52(4) (2019) e7728 https://doi.org/10.1590/1414-431X20197728. Although this article was published earlier than the article from the Brazilian Journal of Medical and Biological Research, the Editor decided to retract this article given concerns about the reliability of the data.

MicroRNA-130b promotes cell proliferation and invasion by inhibiting peroxisome proliferator-activated receptor-γ in human glioma cells.

MicroRNA-130b (miR-130b) is a novel tumor-related miRNA that has been found to be involved in several biological processes. However, there is limited evidence regarding the role of miR-130b in the tumorigenesis of human gliomas. In the present study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assays were used to quantify miR-130b expression levels in human glioma tissues and glioma cell lines (U251, U87, SNB19 and LN229). The expression level of miR-130b was found to be markedly higher in human glioma tissues than in non-neoplastic brain specimens. Specifically, higher expression levels of miR-130b were observed in the glioma cell lines, compared with those in normal human astrocytes (NHA). We also confirmed that miR-130b interacted with the 3′-untranslated region of peroxisome proliferator-activated receptor-γ (PPAR-γ), which negatively affected the protein levels of E-cadherin. Furthermore, its effects on cell proliferation and invasion were examined using CCK8, colony formation, cell cycle and Transwell assays. We found that the upregulation of miR-130b induced cell proliferation, decreased the percentage of cells in the G0/G1 phase and enhanced the invasiveness of U251 glioma cells whereas the downregulation of miR-130b exerted opposing effects. Moreover, it was demonstrated that the downregulation of miR-130b in U251 glioma cells restored the expression of PPAR-γ and E-cadherin, and inhibited the expression of β-catenin. Notably, PPAR-γ knockdown abolished the inhibitory effect of miR-130b inhibitor on the proliferation and invasivness of U251 cells. Taken together, these findings suggest that miR-130b promotes the proliferation and invasion of U251 glioma cells by inhibiting PPAR-γ.

Involvement of ROS-alpha v beta 3 integrin-FAK/Pyk2 in the inhibitory effect of melatonin on U251 glioma cell migration and invasion under hypoxia.

BackgroundMelatonin, a well-known antioxidant, has been shown to possess anti-invasive properties for glioma. However, little is known about the effect of melatonin on glioma cell migration and invasion under hypoxia, which is a crucial microenvironment for tumor progress. In addition, focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2) are closely associated with cell migration and invasion. Therefore, we investigated the possible role of these kinases and its related signaling in the regulation of human U251 glioma cells behavior by melatonin under hypoxia.MethodsThe abilities of migration and invasion of U251 glioma cells were determined by wound healing and transwell assay in vitro. The intracellular production of reactive oxygen species (ROS) was measured by using the fluorescent probe 6-carboxy-2′, 7′-dichorodihydrofluorescein diacetate (DCFH-DA). Immunofluorescence experiments and western blotting analysis were used to detect the expression level of protein. Small interfering RNAs (siRNA) was used to silence specific gene expression.ResultsThe pharmacologic concentration (1 mM) of melatonin significantly inhibited the migration and invasion of human U251 glioma cells under hypoxia. The inhibitory effect of melatonin was accompanied with the reduced phosphorylation of FAK and Pyk2, and decreased expression of alpha v beta 3 (αvβ3) integrin. Additionally, inhibition of αvβ3 integrin by siRNA reduced the phosphorylation of FAK/Pyk2 and demonstrated the similar anti-tumor effects as melatonin, suggesting the involvement of αvβ3 integrin- FAK/Pyk2 pathway in the anti-migratory and anti-invasive effect of melatonin. It was also found that melatonin treatment decreased the ROS levels in U251 glioma cells cultured under hypoxia. ROS inhibitor apocynin not only inhibited αvβ3 integrin expression and the phosphorylation levels of FAK and Pyk2, but also suppressed the migratory and invasive capacity of U251 glioma cells under hypoxia.ConclusionsThese results suggest that melatonin exerts anti-migratory and anti-invasive effects on glioma cells in response to hypoxia via ROS-αvβ3 integrin-FAK/Pyk2 signaling pathways. This provides evidence that melatonin may be a potential therapeutic molecule targeting the hypoxic microenvironment of glioma.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-015-0454-8) contains supplementary material, which is available to authorized users.

MiR-218 inhibits the migration and invasion of glioma U87 cells through the Slit2-Robo1 pathway.

Malignant gliomas are the most common primary brain tumors in adults and are associated with the highest mortality rate. Glioma invasion is one of the most notable causes of the poor prognosis of this cancer. Preventing the invasive behavior of malignant glioma cells by altering effector molecules can significantly improve the prognosis of a patient. microRNAs (miRNAs) are small noncoding RNAs, ~22 nucleotides in length, that are able to function as oncogenes or tumor suppressors in human cancer. In the present study, the expression level of miRNA 218 (miR-218) was found to be markedly downregulated in glioma cell lines and human primary glioma tissues. miR-218 upregulation was found to dramatically reduce the migratory speed and invasive ability of glioma cells. Furthermore, it was demonstrated that ectopic expression of miR-218 in glioma cells resulted in the downregulation of roundabout, axon guidance receptor, homolog 1 (Robo1), upregulation of Slit homolog 2 (Slit2) and the expression of associated proteins following Robo1 knockdown by small interfering RNA. In addition, it was demonstrated that miR-218 inactivated the Slit2-Robo1 pathway through downregulating Robo1 expression by directly targeting the 3′-untranslated region (3′-UTR) of Robo1. The present results indicate that miR-218 plays important roles in preventing the invasiveness of glioma cells, and reveals a novel mechanism of miRNA-mediated direct suppression of the Slit2-Robo1 pathway in glioma.

Nectin-like Molecule 1 Inhibits the Migration and Invasion of U251 Glioma Cells by Regulating the Expression of An Extracellular Matrix Protein Osteopontin

To investigate the molecular mechanism of nectin-like molecule 1 (NECL1) inhibiting the migration and invasion of U251 glioma cells. We infected U251 glioma cells with adeno-nectin-like molecule 1 (Ad-NECL1) or empty adenovirus (Ad). Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells. DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines. The differential expression of osteopontin (OPN), a gene related to migration and invasion, was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunohistochemistry. The restoration of NECL1 inhibited migration of U251 cells significantly (P<0.05). Altogether 195 genes were found differentially expressed by microarray, in which 175 were up-regulated and 20 down-regulated, including 9 extracellular matrix proteins involved in the migration of cells. Both mRNA and protein expressions of OPN, the most markedly reduced extracellular matrix protein, were found decreased in U251 cells after restoration of NECL1. Immunohistochemical assay also detected an increase of OPN in glioma tissues, related with the progressing of malignant grade. A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.

Differential expression and localization of TIMP-1 and TIMP-4 in human gliomas.

Studies have suggested that an imbalance of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may contribute to the malignant phenotype of gliomas. In this study, we have undertaken a detailed analysis of expression of the TIMP family in normal human brain and malignant gliomas at both the mRNA and protein level. Reverse transcription-PCR (RT-PCR) analyses of total RNA from surgical tumour specimens revealed unique expression patterns for the 4 members of the TIMP family, with TIMP-1 and -4 showing positive and negative correlations, respectively, with glioma malignancy. By RT-PCR, TIMP-2 and TIMP-3 expression did not change with tumour grade. In situ hybridization localized TIMP-1 to glial tumour cells and also to the surrounding tumour vasculature. TIMP-4 transcripts were predominantly localized to tumour cells, though minor expression was found in vessels. Recombinant TIMP-4 reduced invasion of U251 glioma cells through Matrigel, and U87 clones overexpressing TIMP-4 showed reduced invasive capacity in vitro. TIMP-4, but not TIMP-1, blocked Membrane Type-1-MMP-mediated progelatinase-A (MMP-2) activation in human umbilical vein endothelial cells. The differential expression and localization of individual TIMPs may contribute to the pathophysiology of human malignant gliomas, particularly with regard to tumour vascularization. © 2001 Cancer Research Campaign http://www.bjcancer.com