TMIC-58. THE CELLULAR AND MOLECULAR BASIS FOR MESENCHYMAL TRANSFORMATION IN GLIOMAS

Abstract Mesenchymal gliomas are the most aggressive tumors that carry the worst prognosis. The origins of mesenchymal cells within brain tumors, remains poorly understood. They could originate either from invading mesenchymal cells, from perivascular smooth muscle actin+ cells, or from a mesenchymal transformation of tumor cells. Identifying the origin and function of mesenchymal cells within gliomas is essential as these cells contribute to increased glioma aggressiveness and tumor progression. In this study we used human biopsies and implantable and genetically engineered mouse models (GEMM) of GBM to study tumor mesenchymal transformation. GBM implantable models were used to analyze the molecular landscape by laser microdissection followed by RNA-Seq and bioinformatics analysis. Time lapse confocal imagining was implemented to analyze GBM cells dynamics. Our results indicate the existence of a complex intratumoral and peritumoral dynamic organization of glioma cells (i.e., Oncostreams). Multicellular structures of elongated cells compatible with mesenchymal differentiation. These structures play important roles in intratumoral movements, peritumoral invasion of normal brain, and overall glioma progression. We also show that oncostreams are molecularly distinct and display increased expression of mesenchymal genes such as Col1a1. Knocking down of Col1a1 in a GEMM of aggressive gliomas reduced tumor progression and significantly increased animal survival. Histological examination confirmed absence of Col1a1, and absence of morphologically identifiable oncostreams. Our results show that tumor cells, especially within oncostreams, display a fibroblastic-like morphology and express proteins typical of mesenchymal cells. The knockout of Col1a1 from tumoral cells eliminated oncostreams from tumors and delayed tumor progression. These data suggest that tumor cells expressing mesenchymal genes regulate the organization of mesenchymal multicellular structures, and determine glioma progression. We propose that inhibiting mesenchymal transformation of glioma cells will assist in the treatment of glioblastoma.

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

Neuro-Oncology ◽

10.1093/neuonc/noz175.400 ◽

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.

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BIMG-18. ELEVATED CYSTATHIONINE IN MEDULLOBLASTOMA DEMONSTRATES TUMOR-SPECIFIC METHIONINE METABOLISM

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab024.017 ◽

2021 ◽

Vol 3 (Supplement_1) ◽

pp. i5-i5

Author(s):

Andrey Tikunov ◽

Elias Rosen ◽

Ben Babcock ◽

Seth Weir ◽

Stuart Parnham ◽

...

Keyword(s):

Tumor Cells ◽

Cellular Localization ◽

Cell Cycle Progression ◽

Desorption Electrospray Ionization ◽

2D Nmr ◽

Genetically Engineered ◽

Normal Brain ◽

Ms Imaging ◽

Order Of Magnitude

Abstract We investigated tumor-specific metabolism medulloblastoma using a non-biased MS-imaging screen and identified a pattern of methionine flux that may present a therapeutic opportunity. We studied brain tumors that form in mice genetically engineered to develop Sonic Hedgehog (SHH)-driven medulloblastoma. We subjected sagittal sections including brain and medulloblastoma to MS-imaging, generating concentration maps for hundreds of metabolites MW 100–400. We then confirmed results by analyzing tumor, brain and blood by LC-MS/MS, high-resolution NMR and 2D NMR-TOCSY, and used immunohistochemistry to determine the cellular localization of implicated enzymes. MS imaging, accomplished by matrix-assisted laser desorption electrospray ionization (MALDESI), detected cystathionine at an order of magnitude higher concentration in medulloblastomas compared to adjacent brain. No other metabolite showed such a strong, tumor-specific localization. LC-MS/MS and NMR methods confirmed cystathionine elevation. As cystathionine is the product of homocysteine and serine, catalyzed by cystathionine beta-synthase (CBS), we investigated CBS expression by IHC. Consistent with prior studies, we found that only astrocytes expressed CBS, both in the normal brain and within the tumors. ScRNA-seq confirmed Cbs only in astrocytes, and showed tumor cells express methionine-metabolizing enzymes Mat2a, Dnmt1, Ancy and Mtr. Together, these findings show that tumor cells generate and export homocysteine, which astrocytes convert to cystathionine. Tumor cystathionine generation responded to changes in methionine- cycle metabolites. In vivo, systemic administration of homocysteine increased tumor cystathionine which decreased in response to systemic folate, the methyl donor for homocysteine methyltransferase. Cystathionine itself was inert in tumors as tumor cells cultured in up to 8 mM cystathionine showed no change in cell cycle progression. Our studies show that medulloblastomas utilize methionine and generate homocysteine, but avoid folate-dependent homocysteine-methionine recycling by exporting homocysteine for detoxification by local astrocytes. This model suggests that treatments that impose methionine scarcity, folate scarcity or CBS inhibition may produce anti-tumor effects in medulloblastoma.

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A panel of synapse assembly genes as a biomarker for Gliomas

10.1101/19011114 ◽

2019 ◽

Author(s):

Xiangwen Ji ◽

Hongwei Zhang ◽

Qinghua Cui

Keyword(s):

Gene Expression ◽

Brain Metastasis ◽

Tumor Progression ◽

Tumor Cells ◽

Quantitative Method ◽

Glioma Cells ◽

Predictive Ability ◽

Predictive Performance ◽

Idh Mutation

AbstractGliomas are the most common primary brain cancers. In recent years, IDH mutation and 1p/19q codeletion have been suggested as biomarkers for the diagnosis, treatment and prognosis of gliomas. However, these biomarkers are only effective for a part of glioma patients and thus more biomarkers are still emergently needed. Recently, an electrochemical communication between normal neurons and glioma cells by neuro-glioma synapse has been reported. Moreover, it was discovered that breast-to-brain metastasis tumor cells have pseudo synapses with neurons and these synapses were indicated to promote tumor progression and metastasis. Based on the above observations, we first curated a panel of 66 SA genes and then proposed a metric, SA score, to quantify the synapseness for each sample of 12 glioma gene expression datasets from TCGA, CGGA, and GEO. Strikingly, SA score showed excellent predictive ability for the prognosis, diagnosis, and grading of gliomas. Moreover, being compared with the two established biomarkers, IDH mutation and 1p/19q codeletion, SA score was demonstrated independent and better predictive performance. In conclusion, this study revealed that SA genes contribute to glioma formation and development, and proposed a quantitative method, SA score, as an efficient biomarker for monitoring gliomas.

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TMIC-20. ELIMINATION OF SENESCENT ASTROCYTES IN THE BRAIN TUMOR MICROENVIRONMENT ATTENUATES GLIOBLASTOMA RECURRENCE AFTER RADIOTHERAPY

Neuro-Oncology ◽

10.1093/neuonc/noz175.1054 ◽

2019 ◽

Vol 21 (Supplement_6) ◽

pp. vi251-vi251

Author(s):

Eliot Fletcher-Sananikone ◽

Bipasha Mukherjee ◽

Sandeep Burma

Keyword(s):

Tumor Microenvironment ◽

Tumor Growth ◽

Tumor Cells ◽

Neutralizing Antibodies ◽

Glioma Cells ◽

Cell Types ◽

Normal Brain ◽

High Doses

Abstract Glioblastomas (GBM) are treated with high doses of ionizing radiation (IR) yet these tumors inevitably recur, and the recurrent tumors are highly therapy resistant. During GBM therapy, the surrounding brain tissue is irradiated along with the tumor. IR induces senescence in multiple cell types, and senescent stromal cells are known to promote the growth of neighboring tumor cells by secreting cytokines which create a senescence-associated secretory phenotype (SASP). We hypothesize that IR-induced senescence of normal brain cells in the tumor microenvironment is a powerful driver of GBM recurrence. We intra-cranially irradiated C57BL/6J mice, and found evidence of widespread senescence, with the astrocytic population being highly susceptible. Genomic analyses of irradiated brains revealed an altered transcriptomic profile which included upregulation of CDKN1A (p21), a key enforcer of senescence, and increased expression of SASP proteins including HGF, the ligand for the RTK Met. We orthotopically implanted mock-irradiated or irradiated mice with a limiting number of syngeneic glioma cells. Pre-irradiation of mouse brains resulted in a striking increase in tumor growth and invasion driven by Met activation in the tumor cells. Importantly, irradiated p21-/- mouse brains did not exhibit SASP and failed to promote tumor growth. Irradiated primary astrocytes underwent senescence in vitro and promoted the migration of glioma cells, and this could be attenuated with HGF-neutralizing antibodies or by the Met inhibitor Crizotinib. These findings indicate that SASP factors (like HGF) in the irradiated brain microenvironment could drive GBM recurrence after radiotherapy via the activation of RTKs (like MET) in the tumor cells. Significantly, we found that senolytic drugs can selectively kill senescent astrocytes both in vitro and in vivo resulting in attenuated growth of glioma cells. These results are of great translational significance as they indicate that adjuvant therapy with senolytic drugs might attenuate GBM recurrence after radiotherapy.

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Fyn tyrosine kinase, a downstream target of receptor tyrosine kinases, modulates antiglioma immune responses

Neuro-Oncology ◽

10.1093/neuonc/noaa006 ◽

2020 ◽

Vol 22 (6) ◽

pp. 806-818 ◽

Cited By ~ 4

Author(s):

Andrea Comba ◽

Patrick J Dunn ◽

Anna E Argento ◽

Padma Kadiyala ◽

Maria Ventosa ◽

...

Keyword(s):

Flow Cytometry ◽

Tyrosine Kinase ◽

Tumor Progression ◽

Molecular Mechanisms ◽

Glioma Cells ◽

Genetically Engineered ◽

Immune Reactivity ◽

Downstream Target ◽

Deficient Mice ◽

Fyn Tyrosine Kinase

Abstract Background High-grade gliomas are aggressive and immunosuppressive brain tumors. Molecular mechanisms that regulate the inhibitory immune tumor microenvironment (TME) and glioma progression remain poorly understood. Fyn tyrosine kinase is a downstream target of the oncogenic receptor tyrosine kinase pathway and is overexpressed in human gliomas. Fyn’s role in vivo in glioma growth remains unknown. We investigated whether Fyn regulates glioma initiation, growth and invasion. Methods We evaluated the role of Fyn using genetically engineered mouse glioma models (GEMMs). We also generated Fyn knockdown stem cells to induce gliomas in immune-competent and immune-deficient mice (nonobese diabetic severe combined immunodeficient gamma mice [NSG], CD8−/−, CD4−/−). We analyzed molecular mechanism by RNA sequencing and bioinformatics analysis. Flow cytometry was used to characterize immune cellular infiltrates in the Fyn knockdown glioma TME. Results We demonstrate that Fyn knockdown in diverse immune-competent GEMMs of glioma reduced tumor progression and significantly increased survival. Gene ontology (GO) analysis of differentially expressed genes in wild-type versus Fyn knockdown gliomas showed enrichment of GOs related to immune reactivity. However, in NSG and CD8−/− and CD4−/− immune-deficient mice, Fyn knockdown gliomas failed to show differences in survival. These data suggest that the expression of Fyn in glioma cells reduces antiglioma immune activation. Examination of glioma immune infiltrates by flow cytometry displayed reduction in the amount and activity of immune suppressive myeloid derived cells in the Fyn glioma TME. Conclusions Gliomas employ Fyn mediated mechanisms to enhance immune suppression and promote tumor progression. We propose that Fyn inhibition within glioma cells could improve the efficacy of antiglioma immunotherapies.

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Circ_0000020 elevates the expression of PIK3CA and facilitates the malignant phenotypes of glioma cells via targeting miR-142-5p

Cancer Cell International ◽

10.1186/s12935-021-01767-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Xu Wang ◽

Yaozu Zhu

Keyword(s):

Glioma Cell ◽

Glioma Cells ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Circular Rnas ◽

Normal Brain ◽

Loss Of Function ◽

Qrt Pcr ◽

Glioma Progression

Abstract Background Multiple circular RNAs (circRNAs) have been recently described as crucial oncogenic factors or tumor suppressors. This study aimed to investigate the role of circ_0000020 in glioma progression. Methods Circ_0000020 and miR-142-5p expressions in glioma samples were assessed through qRT-PCR, and then the association between pathological indexes and circ_0000020 expressions was analyzed. Functional experiment was performed with human glioma cell lines U251 and U87. Gain-of-function and loss-of-function models were established. CCK-8 assay was used to detect glioma cell proliferation. Transwell assay was used to examine glioma cell migration and invasion. The regulatory relationships among circ_0000020, miR-142-5p and phosphatidylinositol 3-kinase C (PIK3CA) were investigated by bioinformatics analysis, luciferase reporter assay, qRT-PCR and Western blot. In vivo tumorigenesis assay was performed with nude mice to further validate the demonstrations of in vitro experiments. Results Circ_0000020 expression in glioma samples was remarkably increased compared with that in normal brain tissues and its high expression was associated with unfavorable pathological indexes. Circ_0000020 overexpression remarkably accelerated proliferation, migration and invasion of glioma cells. Accordingly, circ_0000020 knockdown suppressed the malignant phenotypes of glioma cells. Circ_0000020 overexpression significantly reduced miR-142-5p expression by sponging it, and circ_0000020 could enhance the expression of PIK3CA, which was a target gene of miR-142-5p. Conclusions Circ_0000020 promotes glioma progression via miR-142-5p/PIK3CA axis.

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Interaction of Wharton’s Jelly Derived Fetal Mesenchymal Cells with Tumor Cells

Current Stem Cell Research & Therapy ◽

10.2174/1574888x09666140507153248 ◽

2014 ◽

Vol 9 (6) ◽

pp. 504-507 ◽

Cited By ~ 1

Author(s):

Chinnapandi Bharathiraja ◽

Raman Sukirtha ◽

Muthukalingan Krishnan ◽

Shanmugam Achiraman

Keyword(s):

Tumor Cells ◽

Mesenchymal Cells ◽

Wharton’S Jelly ◽

Wharton's Jelly

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EphA2 super-enhancer promotes tumor progression by recruiting FOSL2 and TCF7L2 to activate the target gene EphA2

Cell Death and Disease ◽

10.1038/s41419-021-03538-6 ◽

2021 ◽

Vol 12 (3) ◽

Author(s):

Shuang Cui ◽

Qiong Wu ◽

Ming Liu ◽

Mu Su ◽

ShiYou Liu ◽

...

Keyword(s):

Tumor Progression ◽

Tumor Cells ◽

Target Gene ◽

Super Enhancer ◽

Proliferation And Metastasis ◽

Active Transcription ◽

Hct 116 ◽

Large Clusters

AbstractSuper-enhancers or stretch enhancers (SEs) consist of large clusters of active transcription enhancers which promote the expression of critical genes that define cell identity during development and disease. However, the role of many super-enhancers in tumor cells remains unclear. This study aims to explore the function and mechanism of a new super-enhancer in various tumor cells. A new super-enhancer that exists in a variety of tumors named EphA2-Super-enhancer (EphA2-SE) was found using multiple databases and further identified. CRISPR/Cas9-mediated deletion of EphA2-SE results in the significant downregulation of its target gene EphA2. Mechanistically, we revealed that the core active region of EphA2-SE comprises E1 component enhancer, which recruits TCF7L2 and FOSL2 transcription factors to drive the expression of EphA2, induce cell proliferation and metastasis. Bioinformatics analysis of RNA-seq data and functional experiments in vitro illustrated that EphA2-SE deletion inhibited cell growth and metastasis by blocking PI3K/AKT and Wnt/β-catenin pathway in HeLa, HCT-116 and MCF-7 cells. Overexpression of EphA2 in EphA2-SE−/− clones rescued the effect of EphA2-SE deletion on proliferation and metastasis. Subsequent xenograft animal model revealed that EphA2-SE deletion suppressed tumor proliferation and survival in vivo. Taken together, these findings demonstrate that EphA2-SE plays an oncogenic role and promotes tumor progression in various tumors by recruiting FOSL2 and TCF7L2 to drive the expression of oncogene EphA2.

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Iron-Bound Lipocalin-2 from Tumor-Associated Macrophages Drives Breast Cancer Progression Independent of Ferroportin

Metabolites ◽

10.3390/metabo11030180 ◽

2021 ◽

Vol 11 (3) ◽

pp. 180

Author(s):

Christina Mertens ◽

Matthias Schnetz ◽

Claudia Rehwald ◽

Stephan Grein ◽

Eiman Elwakeel ◽

...

Keyword(s):

Breast Cancer ◽

Tumor Progression ◽

Tumor Cells ◽

Cancer Progression ◽

Lung Metastases ◽

Expression Profiles ◽

The Cancer Genome Atlas ◽

Lipocalin 2 ◽

Tumor Associated Macrophages

Macrophages supply iron to the breast tumor microenvironment by enforced secretion of lipocalin-2 (Lcn-2)-bound iron as well as the increased expression of the iron exporter ferroportin (FPN). We aimed at identifying the contribution of each pathway in supplying iron for the growing tumor, thereby fostering tumor progression. Analyzing the expression profiles of Lcn-2 and FPN using the spontaneous polyoma-middle-T oncogene (PyMT) breast cancer model as well as mining publicly available TCGA (The Cancer Genome Atlas) and GEO Series(GSE) datasets from the Gene Expression Omnibus database (GEO), we found no association between tumor parameters and Lcn-2 or FPN. However, stromal/macrophage-expression of Lcn-2 correlated with tumor onset, lung metastases, and recurrence, whereas FPN did not. While the total iron amount in wildtype and Lcn-2−/− PyMT tumors showed no difference, we observed that tumor-associated macrophages from Lcn-2−/− compared to wildtype tumors stored more iron. In contrast, Lcn-2−/− tumor cells accumulated less iron than their wildtype counterparts, translating into a low migratory and proliferative capacity of Lcn-2−/− tumor cells in a 3D tumor spheroid model in vitro. Our data suggest a pivotal role of Lcn-2 in tumor iron-management, affecting tumor growth. This study underscores the role of iron for tumor progression and the need for a better understanding of iron-targeted therapy approaches.

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Stromal CCL5 Promotes Breast Cancer Progression by Interacting with CCR3 in Tumor Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22041918 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1918

Author(s):

Mio Yamaguchi ◽

Kiyoshi Takagi ◽

Koki Narita ◽

Yasuhiro Miki ◽

Yoshiaki Onodera ◽

...

Keyword(s):

Breast Cancer ◽

Breast Carcinoma ◽

Tumor Progression ◽

Tumor Cells ◽

Cancer Progression ◽

Stromal Cells ◽

Human Breast Carcinoma ◽

Breast Cancer Patients ◽

Breast Carcinomas ◽

Human Breast

Chemokines secreted from stromal cells have important roles for interactions with carcinoma cells and regulating tumor progression. C-C motif chemokine ligand (CCL) 5 is expressed in various types of stromal cells and associated with tumor progression, interacting with C-C chemokine receptor (CCR) 1, 3 and 5 expressed in tumor cells. However, the expression on CCL5 and its receptors have so far not been well-examined in human breast carcinoma tissues. We therefore immunolocalized CCL5, as well as CCR1, 3 and 5, in 111 human breast carcinoma tissues and correlated them with clinicopathological characteristics. Stromal CCL5 immunoreactivity was significantly correlated with the aggressive phenotype of breast carcinomas. Importantly, this tendency was observed especially in the CCR3-positive group. Furthermore, the risk of recurrence was significantly higher in the patients with breast carcinomas positive for CCL5 and CCR3 but negative for CCR1 and CCR5, as compared with other patients. In summary, the CCL5-CCR3 axis might contribute to a worse prognosis in breast cancer patients, and these findings will contribute to a better understanding of the significance of the CCL5/CCRs axis in breast carcinoma microenvironment.

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