scholarly journals Long-range gene regulation network of the MGMT enhancer in modulating glioma cell sensitivity to temozolomide

2020 ◽  
Author(s):  
Anshun He ◽  
Bohan Chen ◽  
Jinfang Bi ◽  
Wenbin Wang ◽  
Jun Chen ◽  
...  
Keyword(s):  
Long Range ◽  
Glioma Cell ◽  
Target Genes ◽  
Acquired Resistance ◽  
Gene Promoter ◽  
Glioma Cells ◽  
Cell Sensitivity ◽  
Gene Regulation Network ◽  
Dna Repair Protein ◽  
Increased Sensitivity

AbstractAcquired resistance to temozolomide (TMZ) is a major obstacle in glioblastoma treatment. MGMT, a DNA repair protein, and the methylation at its gene promoter, plays an important role in TMZ resistance. However, some evidences have suggested a MGMT-independent mechanisms underlying TMZ resistance. Here, we used MGMT enhancer as a model and discovered that its deletion in glioma cells of low MGMT expression induced increased sensitivity to temozolomide. Analysis of a combination of RNA-seq and Capture Hi-C further suggested multiple long-range target genes regulated by the MGMT enhancer and that interactions may play important roles in glioma cell sensitivity to TMZ. This study reveals a novel mechanism of regulation of TMZ sensitivity in glioma cells.

scholarly journals A HOTAIR regulatory element modulates glioma cell sensitivity to temozolomide through long-range regulation of multiple target genes

2020 ◽  
Vol 30 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Lei Zhang ◽  
Anshun He ◽  
Bohan Chen ◽  
Jinfang Bi ◽  
Jun Chen ◽  
...  
Keyword(s):  
Long Range ◽  
Glioma Cell ◽  
Target Genes ◽  
Regulatory Element ◽  
Multiple Target ◽  
Cell Sensitivity

scholarly journals PUMA mediated afatinib-induced apoptosis in glioma cells

2021 ◽  
Author(s):  
Rongzhong Lu ◽  
Xinyue Sun ◽  
Yaping Ma ◽  
Rong Wang
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Glioma Cell ◽  
Glioma Cells ◽  
Wild Type ◽  
Glioma Cell Lines ◽  
Puma Expression ◽  
Increased Sensitivity ◽  
Induced Apoptosis

IntroductionAfatinib exhibits a tumor-inhibiting effect in different cancers by inducing apoptosis; however, its pro-apoptosis role in glioma cells is still not fully understood.Material and methodsIn the current study, two glioma cell lines (U373-MG and U87-MG) were treated with afatinib to measure their tolerance for afatinib-triggered cell death and apoptosis.ResultsWe found that afatinib treatment repressed both growth and proliferation and induced apoptosis in glioma cells. Moreover, it increased the expression of pro-apoptotic p53-upregulated modulator of apoptosis (PUMA). The influence of PUMA on afatinib-triggered apoptosis was assessed by PUMA overexpression and knockdown in glioma cell lines. PUMA overexpression resulted in an increased sensitivity of glioma cell lines toward afatinib, whereas its knockdown abated the effect of afatinib on apoptosis. Similarly, the in vivo potency of afatinib on U373-MG xenograft tumors in wild type (WT) and PUMA knockdown nude mice was measured. Afatinib treatment reduced the weight and volume of WT xenograft tumors but did not have the same effect on PUMA knockdown xenograft tumors. Afatinib also induced significant cell death and apoptosis in WT xenograft tumors but not in PUMA knockdown xenograft tumors.ConclusionsIn conclusion, afatinib induces apoptosis in glioma cells by mediating PUMA expression. This study warrants further investigation into the mechanism of afatinib in glioblastoma treatment.

Pisosterol Induces G2/M Cell Cycle Arrest and Apoptosis via the ATM/ATR Signaling Pathway in Human Glioma Cells

2020 ◽  
Vol 20 (6) ◽  
pp. 734-750
Author(s):  
Wallax A.S. Ferreira ◽  
Rommel R. Burbano ◽  
Claudia do Ó. Pessoa ◽  
Maria L. Harada ◽  
Bárbara do Nascimento Borges ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Signaling Pathway ◽  
Glioma Cell ◽  
Molecular Mechanisms ◽  
Glioma Cells ◽  
Dependent Manner ◽  
M Cell ◽  
Trypan Blue Exclusion ◽  
Cycle Arrest

Background: Pisosterol, a triterpene derived from Pisolithus tinctorius, exhibits potential antitumor activity in various malignancies. However, the molecular mechanisms that mediate the pisosterol-specific effects on glioma cells remain unknown. Objective: This study aimed to evaluate the antitumoral effects of pisosterol on glioma cell lines. Methods: The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue exclusion assays were used to evaluate the effect of pisosterol on cell proliferation and viability in glioma cells. The effect of pisosterol on the distribution of the cells in the cell cycle was performed by flow cytometry. The expression and methylation pattern of the promoter region of MYC, ATM, BCL2, BMI1, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, MDM2, p14ARF and TP53 was analyzed by RT-qPCR, western blotting and bisulfite sequencing PCR (BSP-PCR). Results: Here, it has been reported that pisosterol markedly induced G2/M arrest and apoptosis and decreased the cell viability and proliferation potential of glioma cells in a dose-dependent manner by increasing the expression of ATM, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, p14ARF and TP53 and decreasing the expression of MYC, BCL2, BMI1 and MDM2. Pisosterol also triggered both caspase-independent and caspase-dependent apoptotic pathways by regulating the expression of Bcl-2 and activating caspase-3 and p53. Conclusions: It has been, for the first time, confirmed that the ATM/ATR signaling pathway is a critical mechanism for G2/M arrest in pisosterol-induced glioma cell cycle arrest and suggests that this compound might be a promising anticancer candidate for further investigation.

scholarly journals CSIG-13. TRPM7 INDUCES TUMORIGENESIS AND STEMNESS THROUGH NOTCH ACTIVATION IN GLIOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii30-ii30
Author(s):  
Jingwei Wan ◽  
Alyssa Guo ◽  
Mingli Liu
Keyword(s):  
Notch Signaling ◽  
Glioma Cell ◽  
Glioma Cells ◽  
Inhibitory Effect ◽  
Notch Signaling Pathway ◽  
Normal Brain ◽  
Diffuse Astrocytoma ◽  
Notch1 Signaling ◽  
Signaling Activation ◽  
Proliferation And Invasion

Abstract Our group found that the inhibitory effect of TRPM7 on proliferation and invasion of human glioma cell is mediated by multiple mechanisms. TRPM7 regulates miR-28-5p expression, which suppresses cell proliferation and invasion in glioma cells by targeting Ras-related protein Rap1b. In particular, our group found that TRPM7 channels regulate glioma stem cell (GSC) growth/proliferation through STAT3 and Notch signaling. However, which Notch component(s) is crucial for its activity regulated by TRPM7, and its relationship with other GSC markers, such as CD133 and ALDH1, remain unclear. In the current project, we elucidate the mechanisms of TRMP7’s regulation of Notch signaling pathway that contribute to the development and progression of glioma and maintenance of self-renewal and tumorigenicity of GSC using multiple glioma cell lines (GC) with different molecular subtypes and GSCs derived from the GC lines. 1) We first analyzed TRPM7 expression using the Oncomine database (https://www.oncomine.org) and found that the TRPM7 mRNA expression is significantly increased in anaplastic astrocytoma, diffuse astrocytoma, and GBM patients compared to that in normal brain tissue controls. 2) TRPM7 is expressed in GBM, and its channel activity is correlated with Notch1 activation. Inhibition of TRPM7 downregulates Notch1 signaling, while upregulation of TRPM7 upregulates Notch1 signaling. 3) GSC markers, CD133 and ALDH1, are correlated with TRPM7 in GBM. 4) Targeting TRPM7 suppresses the growth and proliferation of glioma cells through G1/S arrests and apoptosis of glioma cells. 5) Targeting Notch1 suppresses the TRPM7-induced growth and proliferation of glioma cells, as well as the expression of GSC markers CD133 and ALDH1. In summary, TRPM7 is responsible for sustained Notch signaling activation, enhanced expression of GSC markers, and regulation of glioma stemness, which contribute to malignant glioma cell growth and invasion. Notch1 and ligand DII4 are key components that contribute GSC stemness.

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

2021 ◽  
Author(s):  
Xiaofeng Chen ◽  
Weiping Kuang ◽  
Yong Zhu ◽  
Bin Zhou ◽  
Xiaosong Li ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Cell Lines ◽  
Ubiquitin Ligase ◽  
Glioma Cell ◽  
Protein Modification ◽  
E3 Ubiquitin Ligase ◽  
Ring Finger ◽  
Glioma Cells ◽  
Migration And Invasion ◽  
Tissue Samples

AbstractGlioma 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.

scholarly journals In vitro expression of long and short ovine prolactin receptors: activation of Jak2/STAT5 pathway is not sufficient to account for prolactin signal transduction to the ovine beta-lactoglobulin gene promoter

1999 ◽  
Vol 23 (2) ◽  
pp. 125-136 ◽  
Author(s):  
C Bignon ◽  
N Daniel ◽  
L Belair ◽  
J Djiane
Keyword(s):  
Tyrosine Phosphorylation ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Gene Promoter ◽  
Janus Kinase ◽  
Prolactin Receptors ◽  
Milk Protein Gene ◽  
Prolactin Signaling ◽  
Beta Lactoglobulin

The recent finding that sheep had long (l-oPRLR) and short (s-oPRLR) prolactin receptors provided new tools to further explore prolactin signaling to target genes. Here we used CHO cells transfected with l-oPRLR or s-oPRLR cDNAs to compare the activation of known key steps of prolactin signaling by the two receptors. We found that prolactin stimulated l-oPRLR tyrosine phosphorylation, although it lacked the last tyrosine residue found in other long prolactin receptors. In addition, l-oPRLR and s-oPRLR both responded to prolactin stimulation by (1) Janus kinase 2 (Jak2) tyrosine phosphorylation, (2) DNA-binding activation of signal transducer and activator of transcription 5 (STAT5), (3) stimulation of transcription from a promoter made of six repeats of STAT5-responsive sequence. However, although it contains STAT5-binding consensus sequences, the ovine beta-lactoglobulin promoter (-4000 to +40) was transactivated by l-oPRLR, but not by s-oPRLR. Taken together, our results indicate that activation of Jak2/STAT5 pathway alone is not sufficient to account for prolactin-induced transcription of this milk protein gene, and that sequences of its promoter, other than STAT5-specific sequences, account for the opposite transcriptional activation capabilities of l-oPRLR and s-oPRLR.

Effect of GDM on the Expression of MT1-MMP and u-PA in Glioma Cells

2014 ◽  
Vol 1033-1034 ◽  
pp. 220-223
Author(s):  
Xue Mei Han ◽  
Li Bo Wang ◽  
Ni Ni Li ◽  
Song Yan Liu
Keyword(s):  
Normal Control ◽  
Glioma Cell ◽  
Fetal Bovine Serum ◽  
Glioma Cells ◽  
Normal Control Group ◽  
Control Group ◽  
Rt Pcr ◽  
Glioma Cell Lines ◽  
Fetal Bovine ◽  
Identify Gene Expression

To examine the effect of GDM on the expression of MT1-MMP and u-PA genes in glioma cells. Glioma cell lines U251 and U87 were cultured in DMEM medium supplemented with 10% fetal bovine serum. RT-PCR was used to identify gene expression level. The level of u-PA mRNA was up-regulated significantly in the HGF group compared with the normal control group (P<0.05). The expression of MT1-MMP and u-PA was significantly lower in the GDM group than in the normal control and HGF groups (P<0.05). The expression of u-PA in the HGF+GDM group was down-regulated significantly compared with the normal control and HGF groups (P<0.05).GDM can inhibit expression of both MT1-MMP and u-PA in glioma cells.

Enhancement of radiosensitivity of wild-type p53 human glioma cells by adenovirus-mediated delivery of the p53 gene

1998 ◽  
Vol 89 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Frederick F. Lang ◽  
W. K. Alfred Yung ◽  
Uma Raju ◽  
Floralyn Libunao ◽  
Nicholas H. A. Terry ◽  
...  
Keyword(s):  
Cell Line ◽  
Glioma Cell ◽  
Radiation Treatment ◽  
P53 Protein ◽  
Glioma Cells ◽  
Glioma Cell Line ◽  
Wild Type ◽  
Content Type ◽  
Infected Cells ◽  
Fine Print

Object. The authors sought to determine whether combining p53 gene transfer with radiation therapy would enhance the therapeutic killing of p53 wild-type glioma cells. It has been shown in several reports that adenovirus-mediated delivery of the p53 gene into p53 mutant gliomas results in dramatic apoptosis, but has little effect on gliomas containing wild-type p53 alleles. Therefore, p53 gene therapy alone may not be a clinically effective treatment for gliomas because most gliomas are composed of both p53 mutant and wild-type cell populations. One potential approach to overcome this problem is to exploit the role p53 plays as an important determinant in the cellular response to ionizing radiation. Methods. In vitro experiments were performed using the glioma cell line U87MG, which contains wild-type p53. Comparisons were made to the glioma cell line U251MG, which contains a mutant p53 allele. Monolayer cultures were infected with an adenovirus containing wild-type p53 (Ad5CMV-p53), a control vector (dl312), or Dulbecco's modified Eagle's medium (DMEM). Two days later, cultures were irradiated and colony-forming efficiency was determined. Transfection with p53 had only a minor effect on the plating efficiency of nonirradiated U87MG cells, reducing the plating efficiency from 0.23 ± 0.01 in DMEM to 0.22 ± 0.04 after addition of Ad5CMV-p53. However, p53 transfection significantly enhanced the radiosensitivity of these cells. The dose enhancement factor at a surviving fraction of 0.10 was 1.5, and the surviving fraction at 2 Gy was reduced from 0.61 in untransfected controls to 0.38 in p53-transfected cells. Transfection of the viral vector control (dl312) had no effect on U87MG radiosensitivity. In comparison, transfection of Ad5CMV-p53 into the p53 mutant cell line U251MG resulted in a significant decrease in the surviving fraction of these cells compared with controls, and no radiosensitization was detected. To determine whether Ad5CMV-p53—mediated radiosensitization of U87MG cells involved an increase in the propensity of these cells to undergo apoptosis, flow cytometric analysis of terminal deoxynucleotidyl transferase-mediated biotinylated-deoxyuridinetriphosphate nick-end labeling—stained cells was performed. Whereas the amount of radiation-induced apoptosis in uninfected and dl312-infected control cells was relatively small (2.1 ± 0.05% and 3.7 ± 0.5%, respectively), the combination of Ad5CMV-p53 infection and radiation treatment significantly increased the apoptotic frequency (18.6 ± 1.4%). To determine whether infection with Ad5CMV-p53 resulted in increased expression of functional exogenous p53 protein, Western blot analysis of p53 was performed on U87MG cells that were exposed to 9 Gy of radiation 2 days after exposure to Ad5CMV-p53, dl312, or DMEM. Infection with Ad5CMV-p53 alone increased p53 levels compared with DMEM- or dl312-treated cells. Irradiation of Ad5CMV-p53—infected cells resulted in a further increase in p53 that reached a maximum at 2 hours postirradiation. To determine whether exogenous p53 provided by Ad5CMV-p53 had transactivating activity, U87MG cells were treated as described earlier and p21 messenger RNA levels were determined. Infection of U87MG cells with Ad5CMV-p53 only resulted in an increase in p21 compared with DMEM- and dl312-treated cells. Irradiation of Ad5CMV-p53—infected cells resulted in an additional time-dependent increase in p21 expression. Conclusions. These data indicate that adenovirus-mediated delivery of p53 may enhance the radioresponse of brain tumor cells containing wild-type p53 and that this radiosensitization may involve converting from a clonogenic to the more sensitive apoptotic form of cell death. Although the mechanism underlying this enhanced apoptotic susceptibility is unknown, the Ad5CMV-p53—infected cells have a higher level of p53 protein, which increases further after irradiation, and this exogenous p53 is transcriptionally active. Thus, it is possible that the combination of Ad5CMV-p53 infection and radiation treatment increases p53 protein to a level that is sufficient to overcome at least partially the block in apoptosis existing in U87MG cells.

Inhibitory Effect of MicroRNA-376b-Overexpressing Bone Marrow Mesenchymal Stem Cells (BMSCs) on Malignant Characteristics of Glioma Cells Through Targeting Forkhead Box Protein P2 (FOXP2)

2022 ◽  
Vol 12 (5) ◽  
pp. 971-977
Author(s):  
Ruoyu Zhu ◽  
Zhonglin Wang
Keyword(s):  
Glioma Cell ◽  
Potential Role ◽  
Glioma Cells ◽  
Inhibitory Effect ◽  
Transwell Assay ◽  
Cell Behaviors ◽  
Forkhead Box ◽  
Marrow Mesenchymal Stem Cells ◽  
The Impact

This study investigated the impact of microRNA (miR)-376b derived from BMSCs on glioma progression. BMSCs were transfected with miR-376b mimic, miR-376b inhibitor or NC and then cocultured with glioma cells followed by measuring cell behaviors by MTT assay, Transwell assay and flow cytometry, FOXP2 and miR-376b expression by Western blot and RT-qPCR. After confirming the inhibitory and mimicking activity of transfection, we found that overexpression of miR-376b in BMSCs decreased glioma cell invasion, migration and proliferation but promoted cell apoptosis within 24 h and 48 h after transfection along with reduced number of cells in S-phase. Mechanically, miR-376b targeted miR-376b and up-regulation of miR-376b caused down-regulation of FOXP2 (p < 0.05). Overexpression of miR-376b in BMSCs decelerated glioma cell cycle and inhibitedmalignant behaviors of glioma cells by targeting FOXP2 expression. These evidence unveils the potential role of FOXP2 as a biomarker for the treatment of gliomas.

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