scholarly journals Knockdown of BCL6 Inhibited Malignant Phenotype and Enhanced Sensitivity of Glioblastoma Cells to TMZ through AKT Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Wen Song ◽  
Zhenling Wang ◽  
Pengcheng Kan ◽  
Zhuolin Ma ◽  
Yaru Wang ◽  
...  

Background. BCL6 was a critical prooncogene of human B-cell lymphomas which promoted tumor progress and contributed to malignant behavior in several kinds of cancers. This study was to detect the expression of BCL6 and its biological effect on glioma. Methods. RT-PCR and Western blot were used to detect the expression of BCL6 mRNA and protein in tissues and glioblastoma cell lines. The expression of BCL6 was knockdown in two glioblastoma cell lines (U87 and U251) using BCL6 shRNA. The CCK8, colony-formation, flow cytometry, Transwell, and wound-healing assays were used to evaluate the malignant phenotypic change of glioblastoma cells. Results. The expression of BCL6 was higher in glioma tissues and glioblastoma cell lines than normal tissues. Knockdown of BCL6 expression reduced the proliferation, migration, and invasion of glioblastoma cells. Moreover, knockdown of BCL6 changed expression of proteins related to malignant behaviors of glioblastoma cells. The suppression of BCL6 could increase chemosensitivity of U87 and U251 to temozolomide. Downregulation of BCL6 levels suppressed the expression of BCL2, cyclin D1, MMP2, and MMP9 proteins as well as two classic signaling pathway proteins p-AKT and p-ERK. Simultaneously, BAX and p21 protein levels were upregulated along with knockdown of BCL6. Conclusions. Our results indicated that BCL6 may be a tumor oncogene involved in the progression of glioma via affecting AKT and MAPK signaling pathways.

Author(s):  
Yihao Zhu ◽  
Handong Wang ◽  
Maoxing Fei ◽  
Ting Tang ◽  
Wenhao Niu ◽  
...  

AbstractSmarcd1 is a component of an evolutionary conserved chromatin remodeling complex—SWI/SNF, which is involved in transcription factor recruitment, DNA replication, recombination, and repair. Suppression of the SWI/SNF complex required for cellular differentiation and gene regulation may be inducible for cell proliferation and tumorigenicity. However, the inhibitory role of Smarcd1 in human glioblastoma cells has not been well illustrated. Both U87 and U251 human glioblastoma cell lines were employed in the present study. The lentivirus-mediated gene knockdown and overexpression approach was conducted to determine the function of Smarcd1. The protein levels were tested by western blot, and the relative mRNA contents were detected by quantitative real-time PCR. Cell viability was tested by CCK-8 and colony-forming assay. Transwell assays were utilized to evaluate the motility and invasive ability. Flow cytometry was employed to analyze cell cycle and apoptosis. SPSS software was used for statistical analysis. Low expression of Smarcd1 was observed in glioblastoma cell lines and in patients with high-grade glioma. Importantly, the depletion of Smarcd1 promoted cell proliferation, invasion, and chemoresistance, whereas enhanced expression of Smarcd1 inhibited tumor-malignant phenotypes. Mechanistic research demonstrated that overexpression of Smarcd1 decreased the expression of Notch1, while knockdown of Notch1 increased the expression of Smarcd1 through Hes1 suppression. Hence, the crosstalk between Smarcd1 and Notch1, which formed a feedback loop, was crucial in regulation of glioblastoma malignant phenotypes. Furthermore, targeting Smarcd1 could be a potential strategy for human glioblastoma treatment.


2019 ◽  
Author(s):  
jiang yongan ◽  
Liu Jia yu ◽  
Hong Wangwang ◽  
Fei Xiaowei ◽  
Liu ru'en

Abstract Arctigenin (ARG) is a natural lignan compound extracted from arctium lappa and has displayed anticancer functions and effective treatments in a variety of cancers.Studies had shown that Arctigenin(ARG) inhibits tumors through the AKT/MTOR pathway and mediates autophagy.However,the role in glioma cellshave not still fully understood.This study was designed to investigate whether Arctigenin(ARG) can mediateAKT/mTOR pathway in glioma to regulate autophagy,and affected glioma cells growth and survival.We found that the dose-dependent downregulation of Arctigenin(ARG),reducing cell proliferation,migration and invasion in two human glioblastoma cell lines (U87, T98G),These phenomena were reversed after the administration of the AKT agonist (SC79). Arctigenin(ARG) also affected other autophagy markers such as p62, LC3B.In addition, the apoptotic molecules cleaved-PARP,caspase-9, and cleaved-caspase3 were also dose-dependently altered.


2012 ◽  
Vol 318 (15) ◽  
pp. 1901-1912 ◽  
Author(s):  
Maria Grazia Cattaneo ◽  
Elisa Cappellini ◽  
Lucia M. Vicentini

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi47-vi48
Author(s):  
Beate Schmitt ◽  
Anne Boewe ◽  
Yuan Gu ◽  
Christoph Sippl ◽  
Steffi Urbschat ◽  
...  

Abstract Overexpression of NG2 in human glioblastoma cells is associated with an elevated drug resistance and thereby worsens clinical outcome. However, the regulatory mechanisms of NG2 expression are largely unknown. In this study, we identified miR-29b-3p as a posttranscriptional factor of NG2 expression. The basal mRNA levels of miR-29b-3p and NG2 were detected in the NG2-positive glioblastoma cell lines A1207 and U87 by qRT-PCR. The cells were transfected with miR-29b-3p-mimic or scrambled-miR (control) and the expression of NG2 was analyzed by qRT-PCR, flow cytometry and Western blot. Reporter gene analyses of the NG2 promotor region and 3’UTR were performed to study the effect of miR-29b-3p on NG2 expression. Finally, we analyzed the mRNA levels of NG2 and miR-29b-3p in samples from glioblastoma patients. We found that the two NG2-positive glioblastoma cell lines A1207 and U87 are positive for miR-29b-3p. Transfection with miR-29b-3p-mimic reduced NG2 mRNA levels in A1207 (29%±9.9; Mean±SD) and U87 (6%±2.8), resulting in a significantly decreased NG2 protein expression in A1207 (67%±6.4) and U87 (75%±4) when compared to controls. The analysis of the 3’UTR revealed that miR-29b-3p is a posttranscriptional regulator of NG2 expression. Moreover, miR-29b-3p affects the pretranscriptional NG2 expression by diminishing SP-1-dependent NG2 promotor activity. These results were confirmed by the analysis of glioblastoma patient-derived samples, demonstrating that a high NG2 expression is associated with low levels of miR-29b-3p. In conclusion, we identified miR-29b-3p as a crucial regulator of NG2 expression in glioblastoma. Hence, targeting NG2 expression by miR-29b-3p may provide a novel therapeutic strategy to overcome drug resistance in NG2-positive glioblastoma cells.


2020 ◽  
Vol 12 ◽  
pp. 175883592091530 ◽  
Author(s):  
Alja Zottel ◽  
Ivana Jovčevska ◽  
Neja Šamec ◽  
Jernej Mlakar ◽  
Jernej Šribar ◽  
...  

Background: Glioblastoma is a particularly common and very aggressive primary brain tumour. One of the main causes of therapy failure is the presence of glioblastoma stem cells that are resistant to chemotherapy and radiotherapy, and that have the potential to form new tumours. This study focuses on validation of eight novel antigens, TRIM28, nucleolin, vimentin, nucleosome assembly protein 1-like 1 (NAP1L1), mitochondrial translation elongation factor (EF-TU) (TUFM), dihydropyrimidinase-related protein 2 (DPYSL2), collapsin response mediator protein 1 (CRMP1) and Aly/REF export factor (ALYREF), as putative glioblastoma targets, using nanobodies. Methods: Expression of these eight antigens was analysed at the cellular level by qPCR, ELISA and immunocytochemistry, and in tissues by immunohistochemistry. The cytotoxic effects of the nanobodies were determined using AlamarBlue and water-soluble tetrazolium tests. Annexin V/propidium iodide tests were used to determine apoptotsis/necrosis of the cells in the presence of the nanobodies. Cell migration assays were performed to determine the effects of the nanobodies on cell migration. Results: NAP1L1 and CRMP1 were significantly overexpressed in glioblastoma stem cells in comparison with astrocytes and glioblastoma cell lines at the mRNA and protein levels. Vimentin, DPYSL2 and ALYREF were overexpressed in glioblastoma cell lines only at the protein level. The functional part of the study examined the cytotoxic effects of the nanobodies on glioblastoma cell lines. Four of the nanobodies were selected in terms of their specificity towards glioblastoma cells and protein overexpression: anti-vimentin (Nb79), anti-NAP1L1 (Nb179), anti-TUFM (Nb225) and anti-DPYSL2 (Nb314). In further experiments to optimise the nanobody treatment schemes, to increase their effects, and to determine their impact on migration of glioblastoma cells, the anti-TUFM nanobody showed large cytotoxic effects on glioblastoma stem cells, while the anti-vimentin, anti-NAP1L1 and anti-DPYSL2 nanobodies were indicated as agents to target mature glioblastoma cells. The anti-vimentin nanobody also had significant effects on migration of mature glioblastoma cells. Conclusion: Nb79 (anti-vimentin), Nb179 (anti-NAP1L1), Nb225 (anti-TUFM) and Nb314 (anti-DPYSL2) nanobodies are indicated for further examination for cell targeting. The anti-TUFM nanobody, Nb225, is particularly potent for inhibition of cell growth after long-term exposure of glioblastoma stem cells, with minor effects seen for astrocytes. The anti-vimentin nanobody represents an agent for inhibition of cell migration.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e13560-e13560
Author(s):  
Dorothee Gramatzki ◽  
Emese Szabo ◽  
Martin Gramatzki ◽  
Matthias Peipp ◽  
Michael Weller

e13560 Background: Glioblastoma is the most common primary malignant brain tumor with a poor prognosis. CD317 (HM1.24) is a transmembrane protein and may exist in differently spliced variants. It is highly expressed on plasma cells in multiple myeloma, as well as in certain solid tumor types. While several antibody drug conjugates are already in clinical practice, small immunotoxins with a different intracellular mode of action are only established in hairy cell leukemia. The immunotoxin HM1.24-ETA’ protein is a CD317 single chain Fv (scFv) antibody fused to a truncated version of Pseudomonas aeruginosa exotoxin A (ETA’). Methods: In vivo CD317 mRNA expression in human glioma of different grades and survival probabilities of glioblastoma patients based on CD317 mRNA expression were analyzed using the database of the Cancer Genome Atlas network (TCGA). CD317 protein expression was analyzed by immunohistochemistry in a human tissue microarray (TMA). In vitro CD317 mRNA expression was assessed by RT-PCR and CD317 protein levels by flow cytometry in several human glioblastoma cell lines. A cytotoxicity assay after treatment with HM1.24-ETA’ immunotoxin was performed in human glioblastoma cell lines. Results: Data on mRNA expression from the TCGA database demonstrated, that CD317 was upregulated in human glioblastomas compared to lower grade gliomas. In the group of glioblastoma patients increased CD317 mRNA expression was associated with decreased probability of survival ( p< 0.001). CD317 protein levels correlated directly with the tumor grade of astrocytic gliomas in the TMA. CD317 was expressed heterogeneously on mRNA and protein levels in the tested cell-lines in vitro. HM1.24-ETA’ induced cytotoxicity in CD317-positive glioblastoma cells in a concentration-dependent manner. Animal experiments currently performed suggest activity in glioblastoma xenografted mice. Conclusions: These data highlight CD317 as an interesting target antigen and HM1.24-ETA’ immunotoxin as a strategy for immunotherapy of glioblastoma patients.


2019 ◽  
Vol 78 (10) ◽  
pp. 939-948 ◽  
Author(s):  
Han Zhang ◽  
Danxia Qin ◽  
Zhixian Jiang ◽  
Jinning Zhang

Abstract Aerobic glycolysis is a characteristic in cancers that is important for cancer cell proliferation. Emerging evidence shows that long non-coding RNA (LncRNA) participates in glucose metabolism and cell proliferation in cancer. This study explored the effect of LncRNA: SNHG9 in glioblastoma. The mRNA expression of SNHG9 in human glioma tissues and glioblastoma cell lines was measured by qRT-PCR. Glioblastoma cell lines (U87 and U251) were transfected with miR-199a-5p or SNHG9-expressing plasmid and cell viability as well as concentrations of glucose and lactate were measured. The extracellular acidification was evaluated by glycolysis stress test. The Wnt2 levels were determined by qRT-PCR and Western blot. Results showed that the mRNA expression of SNHG9 was elevated in glioblastoma tissues. The elevated SNHG9 expression was related to lower survival rate in patients with glioma. SNHG9 could downregulate miR-199a-5p and upregulate Wnt2 in glioblastoma cells. Overexpression of SNHG9 in glioblastoma cells promoted aerobic glycolysis and cell proliferation, which could be attenuated by miR-199a-5p. Results of this study indicated an effect of SNHG9/miR-199a-5p/Wnt2 axis in regulating cell growth and aerobic glycolysis in glioblastoma.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Ian F Parney ◽  
Michael P Gustafson ◽  
Mary Solseth ◽  
Peggy Bulur ◽  
Timothy E Peterson ◽  
...  

Abstract Background Glioblastoma, the most common primary malignant brain tumor, is nearly universally fatal by 5 years. Dendritic cell vaccines are promising but often limited clinically by antigen choice, dendritic cell potency, and/or manufacturing yield. We optimized vaccine manufacture, generating potent mature autologous dendritic cells pulsed with allogeneic glioblastoma lysates. Methods Platelet lysate-based supplement was used to establish human glioblastoma cell lines. Phenotype and genotype were assessed. An improved culture technique to generate mature dendritic cells from glioblastoma patients’ monocytes was developed. The ability of T cells stimulated with autologous dendritic cells pulsed with allogeneic glioblastoma cell lysate to kill HLA-A2-matched glioblastoma cells was assessed. Results Glioblastoma cell lines established with platelet lysate supplement grew faster and expressed more stem-like markers than lines grown in neural stem cell media or in the presence of serum. They expressed a variety of glioma-associated antigens and had genomic abnormalities characteristic of glioblastoma stable up to 15 doublings. Unlike standard culture techniques, our optimized technique produced high levels of mature dendritic cells from glioblastoma patients’ monocytes. Autologous T cells stimulated with mature dendritic cells pulsed with allogeneic glioblastoma cell line lysate briskly killed HLA-A2-matched glioblastoma cells. Conclusions Our glioblastoma culture method provides a renewable source for a broad spectrum glioblastoma neoantigens while our dendritic cell culture technique results in more mature dendritic cells in glioblastoma patients than standard techniques. This broadly applicable strategy could be easily integrated into patient care.


2006 ◽  
Vol 81 (3) ◽  
pp. 1479-1491 ◽  
Author(s):  
Guido Wollmann ◽  
Michael D. Robek ◽  
Anthony N. van den Pol

ABSTRACT With little improvement in the poor prognosis for humans with high-grade glioma brain tumors, alternative therapeutic strategies are needed. As such, selective replication-competent oncolytic viruses may be useful as a potential treatment modality. Here we test the hypothesis that defects in the interferon (IFN) pathway could be exploited to enhance the selective oncolytic profile of vesicular stomatitis virus (VSV) in glioblastoma cells. Two green fluorescent protein-expressing VSV strains, recombinant VSV and the glioma-adapted recombinant VSV-rp30a, were used to study infection of a variety of human glioblastoma cell lines compared to a panel of control cells, including normal human astrocytes, oligodendrocyte precursor cells, and primary explant cultures from human brain tissue. Infection rate, cell viability, viral replication, and IFN-α/β-related gene expression were compared in the absence and presence of IFN-α or polyriboinosinic polyribocytidylic acid [poly(I:C)], a synthetic inducer of the IFN-α/β pathway. Both VSV strains caused rapid and total infection and death of all tumor cell lines tested. To a lesser degree, normal cells were also subject to VSV infection. In contrast, IFN-α or poly(I:C) completely attenuated the infection of all primary control brain cells, whereas most glioblastoma cell lines treated with IFN-α or poly(I:C) showed little or no sign of protection and were killed by VSV. Together, our results demonstrate that activation of the interferon pathway protects normal human brain cells from VSV infection while maintaining the vulnerability of human glioblastoma cells to viral destruction.


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