scholarly journals A nuclear function for an oncogenic microRNA as a modulator of snRNA and splicing

2022 ◽  
Vol 21 (1) ◽  
Author(s):  
Rachid El Fatimy ◽  
Yanhong Zhang ◽  
Evgeny Deforzh ◽  
Mahalakshmi Ramadas ◽  
Harini Saravanan ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
Northern Blotting ◽  
Small Gtpase ◽  
Nuclear Function ◽  
Mediated Effects ◽  
U6 Snrna ◽  
Rna Immunoprecipitation ◽  
Direct Binding

Abstract Background miRNAs are regulatory transcripts established as repressors of mRNA stability and translation that have been functionally implicated in carcinogenesis. miR-10b is one of the key onco-miRs associated with multiple forms of cancer. Malignant gliomas exhibit particularly striking dependence on miR-10b. However, despite the therapeutic potential of miR-10b targeting, this miRNA’s poorly investigated and largely unconventional properties hamper the clinical translation. Methods We utilized Covalent Ligation of Endogenous Argonaute-bound RNAs and their high-throughput RNA sequencing to identify miR-10b interactome and a combination of biochemical and imaging approaches for target validation. They included Crosslinking and RNA immunoprecipitation with spliceosomal proteins, a combination of miRNA FISH with protein immunofluorescence in glioma cells and patient-derived tumors, native Northern blotting, and the transcriptome-wide analysis of alternative splicing. Results We demonstrate that miR-10b binds to U6 snRNA, a core component of the spliceosomal machinery. We provide evidence of the direct binding between miR-10b and U6, in situ imaging of miR-10b and U6 co-localization in glioma cells and tumors, and biochemical co-isolation of miR-10b with the components of the spliceosome. We further demonstrate that miR-10b modulates U6 N-6-adenosine methylation and pseudouridylation, U6 binding to splicing factors SART3 and PRPF8, and regulates U6 stability, conformation, and levels. These effects on U6 result in global splicing alterations, exemplified by the altered ratio of the isoforms of a small GTPase CDC42, reduced overall CDC42 levels, and downstream CDC42 -mediated effects on cell viability. Conclusions We identified U6 snRNA, the key RNA component of the spliceosome, as the top miR-10b target in glioblastoma. We, therefore, present an unexpected intersection of the miRNA and splicing machineries and a new nuclear function for a major cancer-associated miRNA.

scholarly journals A nuclear function for an oncogenic microRNA as a modulator of snRNA and splicing

2021 ◽  
Author(s):  
Rachid EL FATIMY ◽  
Yanhong Zhang ◽  
Evgeny Deforzh ◽  
Mahalakshmi Ramadas ◽  
Harini Saravanan ◽  
...  
Keyword(s):  
Glioma Cells ◽  
Small Gtpase ◽  
Splicing Factors ◽  
Core Component ◽  
Nuclear Function ◽  
Mediated Effects ◽  
U6 Snrna ◽  
Tumor Tissues ◽  
Direct Binding

miRNAs are regulatory transcripts established as repressors of mRNA stability and translation. Here we demonstrate that a key onco-miRNA, miR-10b, binds to U6 snRNA, a core component of the spliceosomal machinery. We provide evidence of direct binding between miR-10b and U6, in situ visualizations of miR-10b and U6 co-localization in glioma cells and patient-derived tumor tissues, and biochemical co-isolation of miR-10b with the components of the spliceosome. We further demonstrate that miR-10b modulates U6 N-6-adenosine methylation and pseudouridylation, U6 binding to splicing factors SART3 and PRPF8, and regulates U6 stability, conformation, and levels. These effects on U6 result in splicing alterations, illustrated by the altered ratio of the isoforms of a small GTPase CDC42, reduced overall CDC42 levels, and downstream CDC42 -mediated effects on cell viability. We, therefore, present an unexpected intersection of the miRNA and splicing machineries and a new nuclear function for a major cancer-associated miRNA.

Effects of Extracellular Vesicles Derived from Mesenchymal Stem/Stromal Cells on Liver Diseases

2019 ◽  
Vol 14 (5) ◽  
pp. 442-452 ◽  
Author(s):  
Wenjie Zheng ◽  
Yumin Yang ◽  
Russel Clive Sequeira ◽  
Colin E. Bishop ◽  
Anthony Atala ◽  
...  
Keyword(s):  
Regenerative Medicine ◽  
Extracellular Vesicles ◽  
Stromal Cells ◽  
Liver Diseases ◽  
Therapeutic Potential ◽  
Mechanisms Of Action ◽  
Therapeutic Effects ◽  
Chronic Liver Injury ◽  
Mediated Effects ◽  
Therapeutic Benefits

Therapeutic effects of Mesenchymal Stem/Stromal Cells (MSCs) transplantation have been observed in various disease models. However, it is thought that MSCs-mediated effects largely depend on the paracrine manner of secreting cytokines, growth factors, and Extracellular Vesicles (EVs). Similarly, MSCs-derived EVs also showed therapeutic benefits in various liver diseases through alleviating fibrosis, improving regeneration of hepatocytes, and regulating immune activity. This review provides an overview of the MSCs, their EVs, and their therapeutic potential in treating various liver diseases including liver fibrosis, acute and chronic liver injury, and Hepatocellular Carcinoma (HCC). More specifically, the mechanisms by which MSC-EVs induce therapeutic benefits in liver diseases will be covered. In addition, comparisons between MSCs and their EVs were also evaluated as regenerative medicine against liver diseases. While the mechanisms of action and clinical efficacy must continue to be evaluated and verified, MSCs-derived EVs currently show tremendous potential and promise as a regenerative medicine treatment for liver disease in the future.

scholarly journals EXTH-70. ENHANCEMENT OF ANTITUMOR ACTIVITY BY USING 5-ALA–MEDIATED SONODYNAMIC THERAPY TO INDUCE APOPTOSIS AND NECROSIS IN A MOUSE GLIOMA MODEL

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi97-vi97
Author(s):  
Satoshi Suehiro ◽  
Takanori Ohnishi ◽  
Akihiro Inoue ◽  
Daisuke Yamashita ◽  
Masahiro Nishikawa ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
High Intensity Focused Ultrasound ◽  
Control Group ◽  
Normal Brain ◽  
Sonodynamic Therapy ◽  
Cytotoxic Effects

Abstract OBJECTIVE High invasiveness of malignant gliomas frequently causes local tumor recurrence. To control such recurrence, novel therapies targeted toward infiltrating glioma cells are required. Here, we examined cytotoxic effects of sonodynamic therapy (SDT) combined with a sonosensitizer, 5-aminolevulinic acid (5-ALA), on malignant gliomas both in vitro and in vivo. METHODS In vitro cytotoxicity of 5-ALA-SDT was evaluated in U87 and U251 glioma cells and in U251Oct-3/4 glioma stemlike cells. Treatment-related apoptosis was analyzed using flow cytometry. Intracellular reactive oxygen species (ROS) were measured and the role of ROS in treatment-related cytotoxicity was examined. Effects of 5-ALA-SDT with high-intensity focused ultrasound (HIFU) on tumor growth, survival of glioma-transplanted mice, and histological features of the mouse brains were investigated. RESULTS The 5-ALA-SDT inhibited cell growth and changed cell morphology. Flow cytometric analysis indicated that 5-ALA-SDT induced apoptotic cell death. The 5-ALA-SDT generated higher ROS than in the control group, and inhibition of ROS generation completely eliminated the cytotoxic effects of 5-ALA-SDT. In the in vivo study, 5-ALA-SDT with HIFU greatly prolonged survival of the tumor-bearing mice compared with that of the control group (p < 0.05). Histologically, 5-ALA-SDT produced mainly necrosis of the tumor tissue in the focus area and induced apoptosis of the tumor cells in the perifocus area around the target of the HIFU-irradiated field. Normal brain tissues around the ultrasonic irradiation field of HIFU remained intact. CONCLUSIONS The 5-ALA-SDT was cytotoxic toward malignant gliomas. Generation of ROS by the SDT was thought to promote apoptosis of glioma cells. The 5-ALA-SDT with HIFU induced tumor necrosis in the focus area and apoptosis in the perifocus area of the HIFU-irradiated field. These results suggest that 5-ALA-SDT with HIFU may present a less invasive and tumor-specific therapy, not only for a tumor mass but also for infiltrating tumor cells in malignant gliomas.

Soluble CD70: a novel immunotherapeutic agent for experimental glioblastoma

2010 ◽  
Vol 113 (2) ◽  
pp. 280-285 ◽  
Author(s):  
James Miller ◽  
Guenter Eisele ◽  
Ghazaleh Tabatabai ◽  
Steffen Aulwurm ◽  
Gabriele von Kürthy ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Malignant Gliomas ◽  
Ectopic Expression ◽  
Glioma Cells ◽  
Interferon Γ ◽  
Soluble Form ◽  
Immune Effector ◽  
Effector Cells ◽  
Immune Effector Cells

Object Given the overall poor outcome with current treatment strategies in malignant gliomas, immunotherapy has been considered a promising experimental approach to glioblastoma for more than 2 decades. A cell surface molecule, CD70, may induce potent antitumor immune responses via activation of the costimulatory receptor CD27 expressed on immune effector cells. There is evidence that a soluble form of CD70 (sCD70) may exhibit biological activity, too. A soluble costimulatory ligand is attractive because it may facilitate immune activation and may achieve a superior tissue distribution. Methods To test the antiglioma effect of sCD70, the authors genetically modified SMA-560 mouse glioma cells to secrete the extracellular domain of CD70. They assessed the immunogenicity of the transfected cells in cocultures with immune effector cells by the determination of immune cell proliferation and the release of interferon-γ. Syngeneic VM/Dk mice were implanted orthotopically with control or sCD70-releasing glioma cells to determine a survival benefit mediated by sCD70. Depletion studies were performed to identify the cellular mediators of prolonged survival of sCD70-releasing glioma-bearing mice. Results The authors found that ectopic expression of sCD70 enhanced the proliferation and interferon-γ release of syngeneic splenocytes in vitro. More importantly, sCD70 prolonged the survival of syngeneic VM/Dk mice bearing intracranial SMA-560 gliomas. The survival rate at 60 days increased from 5 to 45%. Antibody-mediated depletion of CD8-positive T cells abrogates the survival advantage conferred by sCD70. Conclusions These data suggest that sCD70 is a potent stimulator of antiglioma immune responses that depend critically on CD8-positive T cells. Soluble CD70 could be a powerful adjuvant for future immunotherapy trials for glioblastoma.

Administration of interleukin-12 and -18 enhancing the antitumor immunity of genetically modified dendritic cells that had been pulsed with Semliki Forest virus—mediated tumor complementary DNA

2002 ◽  
Vol 97 (5) ◽  
pp. 1184-1190 ◽  
Author(s):  
Ryuya Yamanaka ◽  
Naoki Yajima ◽  
Naoto Tsuchiya ◽  
Junpei Honma ◽  
Ryuichi Tanaka ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Antitumor Immunity ◽  
Semliki Forest Virus ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
Antitumor Effects ◽  
Content Type ◽  
Immunogene Therapy ◽  
Fine Print

Object. Immunogene therapy for malignant gliomas was further investigated in this study to improve its therapeutic efficacy. Methods. Dendritic cells (DCs) were isolated from bone marrow and pulsed with phosphate-buffered saline or Semliki Forest virus (SFV)—mediated 203 glioma complementary (c)DNA with or without systemic administration of interleukin (IL)-12 and IL-18 to treat mice bearing the 203 glioma. To study the immune mechanisms involved in tumor regression, the authors investigated tumor growth of an implanted 203 glioma model in T cell subset—depleted mice and in interferon (IFN) γ—neutralized mice. To examine the protective immunity produced by tumor inoculation, a repeated challenge of 203 glioma cells was given by injecting the cells into the left thighs of surviving mice and the growth of these cells was monitored. The authors demonstrated that the combined administration of SFV-cDNA, IL-12, and IL-18 produced significant antitumor effects against the growth of murine glioma cells in vivo and also can induce specific antitumor immunity. The synergic effects of the combination of SFV-cDNA, IL-12, and IL-18 in vivo were also observed to coincide with markedly augmented IFNγ production. The antitumor effects of this combined therapy are mediated by CD4+ and CD8+ T cells and by NK cells. These results indicate that the use of IL-18 and IL-12 in DC-based immunotherapy for malignant glioma is beneficial. Conclusions. Immunogene therapy combined with DC therapy, IL-12, and IL-18 may be an excellent candidate in the development of a new treatment protocol. The self-replicating SFV system may therefore provide a novel approach for the treatment of malignant gliomas.

scholarly journals Membrane-type 1 Matrix Metalloprotease (MT1-MMP) Enables Invasive Migration of Glioma Cells in Central Nervous System White Matter

1999 ◽  
Vol 144 (2) ◽  
pp. 373-384 ◽  
Author(s):  
Ann T.J. Beliën ◽  
Paolo A. Paganetti ◽  
Martin E. Schwab
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
White Matter ◽  
Plasma Membranes ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
Glioblastoma Cells

Invasive glioma cells migrate preferentially along central nervous system (CNS) white matter fiber tracts irrespective of the fact that CNS myelin contains proteins that inhibit cell migration and neurite outgrowth. Previous work has demonstrated that to migrate on a myelin substrate and to overcome its inhibitory effect, rat C6 and human glioblastoma cells require a membrane-bound metalloproteolytic activity (C6-MP) which shares several biochemical and pharmacological characteristics with MT1-MMP. We show now that MT1-MMP is expressed on the surface of rat C6 glioblastoma cells and is coenriched with C6-MP activity. Immunodepletion of C6-MP activity is achieved with an anti–MT1-MMP antibody. These data suggest that MT1-MMP and the C6-MP are closely related or identical. When mouse 3T3 fibroblasts were transfected with MT1-MMP they acquired the ability to spread and migrate on the nonpermissive myelin substrate and to infiltrate into adult rat optic nerve explants. MT1-MMP–transfected fibroblasts and C6 glioma cells were able to digest bNI-220, one of the most potent CNS myelin inhibitory proteins. Plasma membranes of both MT1-MMP–transfected fibroblasts and C6 glioma cells inactivated inhibitory myelin extracts, and this activity was sensitive to the same protease inhibitors. Interestingly, pretreatment of CNS myelin with gelatinase A/MMP-2 could not inactivate its inhibitory property. These data imply an important role of MT1-MMP in spreading and migration of glioma cells on white matter constituents in vitro and point to a function of MT1-MMP in the invasive behavior of malignant gliomas in the CNS in vivo.

scholarly journals OLIG2 maintenance is not essential for diffuse intrinsic pontine glioma cell line growth but regulates tumor phenotypes

2021 ◽  
Author(s):  
Yunfei Liao ◽  
Zaili Luo ◽  
Yaqi Deng ◽  
Feng Zhang ◽  
Rohit Rao ◽  
...  
Keyword(s):  
Cell Growth ◽  
Cell Line ◽  
Therapeutic Potential ◽  
Malignant Gliomas ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Glioma Cell Line ◽  
Egfr Signaling ◽  
Pontine Glioma ◽  
Genomic Landscape ◽  
Genome Bisulfite Sequencing

Abstract Background Diffuse intrinsic pontine glioma (DIPG) is a pediatric lethal high-grade brainstem glioma with no effective therapies. OLIG2 was reported to be critical for the growth of a DIPG cell line CCHMC-DIPG-1. Surprisingly, we found that the CCHMC-DIPG-1 cells express little OLIG2 and exhibit a mesenchymal phenotype, which raised a question regarding the role of OLIG2 in the growth of DIPG cells. Methods We evaluated the function of OLIG2 in different DIPG cell lines through molecular and genetic approaches and performed transcriptomic and genomic landscape profiling including whole-genome bisulfite-sequencing, RNA-seq, ATAC-seq, and ChIP-seq. shRNA-mediated knockdown and CRISPR-Cas9-mediated knockout approaches were utilized to assess OLIG2 functions in DIPG cell growth. Results We found that DIPG cells are phenotypically heterogeneous and exhibit the characteristics of distinct malignant gliomas including proneural, classical, and mesenchymal subtypes. OLIG2 knockdown did not impact the growth of CCHMC-DIPG-1 cells, wherein OLIG2 is epigenetically silenced. Moreover, OLIG2 deletion did not substantially impair OLIG2-expressing proneural-like DIPG growth but led to an upregulation of HIPPO-YAP1 and EGFR signaling and a tumor phenotype shift. Targeting HIPPO-YAP1 and EGFR signaling in OLIG2-deficient DIPG cells inhibited tumor cell growth. Conclusions Our data indicate that OLIG2 is dispensable for DIPG growth but regulates the phenotypic switch of DIPG tumor cells. OLIG2 downregulation leads to deregulation of adaptive YAP1 and EGFR signaling. Targeting YAP1 and EGFR pathways inhibits the growth of OLIG2-deficient DIPG cells, pointing to a therapeutic potential by targeting adaptive signaling to treat DIPG tumors with nominal OLIG2 expression.

scholarly journals Nuclear magnetic resonance metabolic fingerprint of bevacizumab in mutant IDH1 glioma cells

2018 ◽  
Vol 52 (4) ◽  
pp. 392-398 ◽  
Author(s):  
Tanja Mesti ◽  
Nadia Bouchemal ◽  
Claire Banissi ◽  
Mohamed N. Triba ◽  
Carole Marbeuf-Gueye ◽  
...  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
Magic Angle Spinning ◽  
Idh1 Mutation ◽  
Metabolic Effects ◽  
Metabolic Phenotype ◽  
Magic Angle ◽  
Metabolic Fingerprint ◽  
U87 Cells

AbstractBackgroundMalignant gliomas are rapidly growing tumours that extensively invade the brain and have bad prognosis. Our study was performed to assess the metabolic effects of bevacizumab on the glioma cells carrying the IDH1 mutation, a mutation, associated with better prognosis and treatment outcome. Bevacizumab is known to inhibit tumour growth by neutralizing the biological activity of vascular endothelial growth factor (VEGF). However, the direct effects of bevacizumab on tumour cells metabolism remain poorly known.Materials and methodsThe immunoassay and MTT assay were used to assess the concentration of secreted VEGF and cell viability after bevacizumab exposure. Metabolomic studies on cells were performed using high resolution magic angle spinning spectroscopy (HRMAS).ResultsmIDH1-U87 cells secreted VEGF (13 ng/mL). Regardless, bevacizumab had no cytotoxic effect, even after a 72h exposure and with doses as high as 1 mg/mL. Yet, HRMAS analysis showed a significant effect of bevacizumab (0.1 mg/mL) on the metabolic phenotype of mIDH1-U87 cells with elevation of 2-hydroxyglutarate and changes in glutamine group metabolites (alanine, glutamate, glycine) and lipids (polyunsaturated fatty acids [PUFA], glycerophosphocholine, and phosphocholine).ConclusionsIn mIDH1-U87 cells, changes in glutamine group metabolites and lipids were identified as metabolic markers of bevacizumab treatment. These data support the possibility of a functional tricarboxylic acid cycle that runs in reductive manner, as a probable mechanism of action of bevacizumab in IDH1 mutated gliomas and propose a new target pathway for effective treatment of malignant gliomas.

scholarly journals LncRNA DANCR functions as a competing endogenous RNA to regulate RAB1A expression by sponging miR-634 in glioma

2018 ◽  
Vol 38 (1) ◽  
Author(s):  
Dawei Xu ◽  
Jian Yu ◽  
Guojun Gao ◽  
Guangjian Lu ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Cell Lines ◽  
Noncoding Rna ◽  
Molecular Mechanisms ◽  
Glioma Cells ◽  
Tumor Grade ◽  
Underlying Mechanism ◽  
Luciferase Reporter ◽  
Biological Functions ◽  
Advanced Tumor ◽  
Rna Immunoprecipitation

Long noncoding RNA (lncRNA) differentiation antagonizing nonprotein coding RNA (DANCR) plays important regulatory roles in many solid tumors. However, the effect of DANCR in glioma progression and underlying molecular mechanisms were not entirely explored. In the present study, we determined the expression of DANCR in glioma tissues and cell lines using qRT-PCR and further defined the biological functions. Furthermore, we used luciferase reporter assay, Western blot, and RNA immunoprecipitation (RIP) to explore the underlying mechanism. Our results showed that DANCR was significantly up-regulated in glioma tissues and cell lines (U251, U118, LN229, and U87MG). High DANCR expression was correlated with advanced tumor grade. Inhibition of DANCR suppressed the glioma cells proliferation and induced cells arrested in the G0/G1 phase. In addition, we verified that DANCR could directly interact with miR-634 in glioma cells and this interaction resulted in the inhibition of downstream of RAB1A expression. The present study demonstrated that DANCR/miR-634/RAB1A axis plays crucial roles in the progression of glioma, and DANCR might potentially serve as a therapeutic target for the treatment of glioma patients.

scholarly journals GITRL-armed Delta-24-RGD oncolytic adenovirus prolongs survival and induces anti-glioma immune memory

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Yisel Rivera-Molina ◽  
Hong Jiang ◽  
Juan Fueyo ◽  
Teresa Nguyen ◽  
Dong Ho Shin ◽  
...  
Keyword(s):  
T Cells ◽  
Functional Characterization ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
Immune Memory ◽  
Anticancer Effect ◽  
Memory Cd8 T Cells ◽  
In Vivo Experiments ◽  
Immunocompetent Mice

Abstract Background Viroimmunotherapy is evolving as a strong alternative for the standard treatment of malignant gliomas. Promising results from a recent clinical trial testing the anticancer effect of Delta-24-RGD in patients with glioblastoma suggested the induction of antitumoral immunity after viral administration. To further enhance the anti-glioma immune effect, we have armed Delta-24-RGD with the costimulatory ligand GITRL (Delta-24-GREAT [Glucocorticoid Receptor Enhanced Activity of T cells]). Methods We tested the infectivity and replication of Delta-24-GREAT, and the expression of ectopic GITRL in human and murine glioma cell lines. In vivo experiments involved the intracranial implantation of glioma cells into an immunocompetent model to study the anticancer effect, and rechallenging experiments to study long-term protection. Phenotypic and functional characterization of lymphocyte populations were performed by FACS and ELISA for Th1 cytokines expression, respectively. Results Our results showed that Delta-24-GREAT infects and induces the expression of GITRL. Delta-24-GREAT prolonged the survival of glioma-bearing immunocompetent mice and resulted in both anti-viral and anti-glioma immune responses, including increased frequency of central memory CD8+ T cells. Rechallenging the surviving mice with a second implantation of glioma cells did not lead to tumor growth; however, the surviving mice developed lethal tumors when B16/F10 melanoma cells were implanted intracranially, strongly indicating that the immune response was specific for glioma antigens. Conclusions GITRL-armed Delta-24-RGD treatment results in an antigen-restricted antitumor memory, an enhanced anti-glioma effect, and the generation of central immune memory. Our results strongly indicate that this strategy represents a vertical advance in virotherapy designed to treat patients with malignant brain tumors.

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