Brain Tumor Cells Research Articles

Abstract 6133: Growth response and migration of brain cancer cell lines to treatment with agents targeting different members of the HER family, CDKs and other signalling pathways

Abstract Glioblastoma (GB) is one of the most frequent primary brain tumors in adults with an extremely poor prognosis and a very high demand for novel therapies. Poor prognosis has been linked to its complex biology, tumor heterogeneity and an increased activation of signaling pathways through various growth factor receptors signaling pathway. In particular, aberrant expression and activation of epidermal growth factor receptor (EGFR) expression has been found to be common in patients with GBM. However, no EGFR inhibitor has yet been approved for the treatment of patients with brain tumor and there is currently no comprehensive study of all members of the HER family in the progression brain tumors. The aim of this study was to investigate the role of all members of the HER family (EGFR, HER2 HER3 and HER4), other growth factor receptors (e.g., C-MET) and downstream cell signaling pathways in the growth of a panel of human brain cancer cell lines (HBCCLs) and response to therapeutic interventions. Using Sulforhodamine B colorimetric assay, the growth response of four HBCCLs to treatment with 18 agents targeting different members of the HER family and other growth receptors (e.g. C-met/ALK 7, PDGFRs, FGFRs, C-kit), cyclin dependent kinases inhibitors (e.g. CDKs 1/2/5/9, CDK4/6) and downstream signaling molecules (e.g. STAT3, Src, Abl) was examined. We determined the expression level of all members of the HER family in brain cancer cells by flow cytometry and Western blot and the effect of these agents on migration of brain cancer cells were determined using Incucyte. Of the targeted agents examined, the CDK 1/2/5/9 inhibitor dinaciclib was the most potent and inhibited growth for all four HBCCLs with an IC50 below 10nM. Of the HER inhibitors, neratinib and afatinib were more effective than erlotinib and lapatinib and inhibiting the growth of all HBCCLs at IC50 values below 700nM and 1.9 µM, respectively. Treatment with Src/Abl/c-kit inhibitor dasatinib, STAT3 inhibitor static, Abl/PDGFRα/VEGFR2/FGFR1 inhibitor Ponatinib and the TRK/ROS/ALK inhibitor entrecitinb also inhibited the growth of HBCCLs with IC50 value ranging from 0.06 - 2.96 µM, 1 - 3.8µM, 0.19- 0.42 μM and 2.85- 3.47μM, respectively. Interestingly, these agents were more effective in inhibiting growth of HBCCLs when proliferating at a slower rate. In addition to inhibiting the proliferation of HBCCLs, treatment with neratinib, dinaciclib, dasatanib, static and trametinib inhibited the migration of brain tumor cells. Finally, treatment with neratinib in combination with Palbociclib, AZD4547, trametinib and miransertib inhibited the growth of HBCCLs synergistically. Taken together, our results support further investigation on the therapeutic potential of irreversible pan HER in combination with the CDK inhibitor dinaciclib and other targeted agents in brain cancer. Citation Format: Ermira Mulliqi, Said A. Khelwatty, Anna L. Morgan, Keyoumars Ashkan, Helmout Modjtahedi. Growth response and migration of brain cancer cell lines to treatment with agents targeting different members of the HER family, CDKs and other signalling pathways. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6133.

Distinct gene expression patterns of SOX2 and SOX2OT variants in different types of brain tumours

Numerous investigations have been recently published on the dysregulated expression of long-noncoding RNAs (lncRNAs) in various cancer types, emphasizing that abnormal lncRNA expression is a major contributor to tumourigenesis. A broad spectrum of lncRNAs is expressed in the central nervous system, where these RNAs seem to play key roles in brain development and function. In addition to expressing SOX2, a master regulator of pluripotency that lies within its third intron, lncRNA SOX2OT has a proposed role in regulating neural development. Based on our previous studies, alternative splicing of SOX2OT generates two alternatively spliced variants (SOX2OT-S1 and SOX2OT-S2). The present study investigated the expression patterns of SOX2OT variants and SOX2 in three principal types of brain tumours (gliomas, meningiomas and pituitary adenomas) and in four brain tumour cell lines (U87-MG, 1321N1, A172 and DAOY). Total RNAwas extracted from 34 human brain tumour specimens, and the expression profile of target genes was measured using a real-time reverse transcription PCR approach. Our data revealed distinct expression patterns for SOX2OT variants and SOX2 in the brain tumour samples, indicating their potential involvement in brain tumourigenesis. Moreover, our results highlighted the potential usefulness of SOX2OT-S1, SOX2OT-S2, and SOX2 in molecular diagnosis and brain tumour classification.

Spatial landscape of the tumor immune microenvironment

Two recent studies published in Nature by Karimi et al. and Sorin et al. applied multiplexed imaging mass cytometry (IMC) to characterize the single-cell tumor immune landscapes covering millions of cells in brain tumors and lung adenocarcinomas (LUAD). They identified specific cell subtypes and cell–cell interactions that correlate with distinct clinical outcomes, thus providing valuable insights into tumor biology and prognostic prediction based on spatial architecture.

Co-delivery of paclitaxel and etoposide prodrug by human serum albumin and PLGA nanoparticles: synergistic cytotoxicity in brain tumour cells

The aims of this study were to develop co-delivery systems of paclitaxel (PTX) and etoposide prodrug (4’-O-benzyloxycarbonyl-etoposide, ETP-cbz) based on non-cross-linked human serum albumin (HSA) and poly(lactide-co-glycolide) nanoparticles and to evaluate the synergistic potential of these drugs in vitro. The nanoformulations were prepared by the high-pressure homogenisation technique and characterised using DLS, TEM, SEM, AFM, HPLC, CZE, in-vitro release, and cytotoxicity in human and murine glioma cells. All nanoparticles had 90-150 nm in size and negative ζ-potentials. The Neuro2A cells were the most sensitive to both HSA- and PLGA-based co-delivery systems (IC50 0.024 µM and 0.053 µM, respectively). The drugs’ synergistic effect (combination index < 0.9) was observed in the GL261 cells for both types of co-delivery formulations and in the Neuro2A cells for the HSA-based system. These nanodelivery systems may be useful to improve combination chemotherapy for brain tumour treatment. To our knowledge, this is the first report describing the non-cross-linked HSA-based co-delivery nanosuspension which was prepared using nab™ technology.

A whole‐genome scan for Artemisinin cytotoxicity reveals a novel therapy for human brain tumors

The natural compound Artemisinin is the most widely used antimalarial drug worldwide. Based on its cytotoxicity, it is also used for anticancer therapy. Artemisinin and its derivates are endoperoxides that damage proteins in eukaryotic cells; their definite mechanism of action and host cell targets, however, have remained largely elusive. Using yeast and haploid stem cell screening, we demonstrate that a single cellular pathway, namely porphyrin (heme) biosynthesis, is required for the cytotoxicity of Artemisinins. Genetic or pharmacological modulation of porphyrin production is sufficient to alter its cytotoxicity in eukaryotic cells. Using multiple model systems of human brain tumor development, such as cerebral glioblastoma organoids, and patient‐derived tumor spheroids, we sensitize cancer cells to dihydroartemisinin using the clinically approved porphyrin enhancer and surgical fluorescence marker 5‐aminolevulinic acid, 5‐ALA. A combination treatment of Artemisinins and 5‐ALA markedly and specifically killed brain tumor cells in all model systems tested, including orthotopic patient‐derived xenografts in vivo. These data uncover the critical molecular pathway for Artemisinin cytotoxicity and a sensitization strategy to treat different brain tumors, including drug‐resistant human glioblastomas.

Modeling interaction of Glioma cells and CAR T-cells considering multiple CAR T-cells bindings

Chimeric antigen receptor (CAR) T-cell based immunotherapy has shown its potential in treating blood cancers, and its application to solid tumors is currently being extensively investigated. For glioma brain tumors, various CAR T-cell targets include IL13Rα2, EGFRvIII, HER2, EphA2, GD2, B7-H3, and chlorotoxin. In this work, we are interested in developing a mathematical model of IL13Rα2 targeting CAR T-cells for treating glioma. We focus on extending the work of Kuznetsov et al. (1994) by considering binding of multiple CAR T-cells to a single glioma cell, and the dynamics of these multi-cellular conjugates. Our model more accurately describes experimentally observed CAR T-cell killing assay data than the models which do not consider multi-cellular conjugates. Moreover, we derive conditions in the CAR T-cell expansion rate that determines treatment success or failure. Finally, we show that our model captures distinct CAR T-cell killing dynamics from low to high antigen receptor densities in patient-derived brain tumor cells.

Natural killer cell therapy potentially enhances the antitumor effects of bevacizumab plus irinotecan in a glioblastoma mouse model.

Various combination treatments have been considered to attain the effective therapy threshold by combining independent antitumor mechanisms against the heterogeneous characteristics of tumor cells in malignant brain tumors. In this study, the natural killer (NK) cells associated with bevacizumab (Bev) plus irinotecan (Iri) against glioblastoma multiforme (GBM) were investigated. For the experimental design, NK cells were expanded and activated by K562 cells expressing the OX40 ligand and membrane-bound IL-18 and IL-21. The effects of Bev and Iri on the proliferation and NK ligand expression of GBM cells were evaluated through MTT assay and flow cytometry. The cytotoxic effects of NK cells against Bev plus Iri-treated GBM cells were also predicted via the LDH assay in vitro. The therapeutic effect of different injected NK cell routes and numbers combined with the different doses of Bev and Iri was confirmed according to tumor size and survival in the subcutaneous (s.c) and intracranial (i.c) U87 xenograft NOD/SCID IL-12Rγnull mouse model. The presence of injected-NK cells in tumors was detected using flow cytometry and immunohistochemistry ex vivo. As a result, Iri was found to affect the proliferation and NK ligand expression of GBM cells, while Bev did not cause differences in these cellular processes. However, the administration of Bev modulated Iri efficacy in the i.c U87 mouse model. NK cells significantly enhanced the cytotoxic effects against Bev plus Iri-treated GBM cells in vitro. Although the intravenous (IV) injection of NK cells in combination with Bev plus Iri significantly reduced the tumor volume in the s.c U87 mouse model, only the direct intratumorally (IT) injection of NK cells in combination with Bev plus Iri elicited delayed tumor growth in the i.c U87 mouse model. Tumor-infiltrating NK cells were detected after IV injection of NK cells in both s.c and i.c U87 mouse models. In conclusion, the potential therapeutic effect of NK cells combined with Bev plus Iri against GBM cells was limited in this study. Accordingly, further research is required to improve the accessibility and strength of NK cell function in this combination treatment.

Genomic study and lipidomic bioassay of Leeuwenhoekiella parthenopeia: A novel rare biosphere marine bacterium that inhibits tumor cell viability.

The fraction of low-abundance microbiota in the marine environment is a promising target for discovering new bioactive molecules with pharmaceutical applications. Phenomena in the ocean such as diel vertical migration (DVM) and seasonal dynamic events influence the pattern of diversity of marine bacteria, conditioning the probability of isolation of uncultured bacteria. In this study, we report a new marine bacterium belonging to the rare biosphere, Leeuwenhoekiella parthenopeia sp. nov. Mr9T, which was isolated employing seasonal and diel sampling approaches. Its complete characterization, ecology, biosynthetic gene profiling of the whole genus Leeuwenhoekiella, and bioactivity of its extract on human cells are reported. The phylogenomic and microbial diversity studies demonstrated that this bacterium is a new and rare species, barely representing 0.0029% of the bacterial community in Mediterranean Sea metagenomes. The biosynthetic profiling of species of the genus Leeuwenhoekiella showed nine functionally related gene cluster families (GCF), none were associated with pathways responsible to produce known compounds or registered patents, therefore revealing its potential to synthesize novel bioactive compounds. In vitro screenings of L. parthenopeia Mr9T showed that the total lipid content (lipidome) of the cell membrane reduces the prostatic and brain tumor cell viability with a lower effect on normal cells. The lipidome consisted of sulfobacin A, WB 3559A, WB 3559B, docosenamide, topostin B-567, and unknown compounds. Therefore, the bioactivity could be attributed to any of these individual compounds or due to their synergistic effect. Beyond the rarity and biosynthetic potential of this bacterium, the importance and novelty of this study is the employment of sampling strategies based on ecological factors to reach the hidden microbiota, as well as the use of bacterial membrane constituents as potential novel therapeutics. Our findings open new perspectives on cultivation and the relationship between bacterial biological membrane components and their bioactivity in eukaryotic cells, encouraging similar studies in other members of the rare biosphere.

Deciphering the Role of microRNA Mediated Regulation of Coronin 1C in Glioblastoma Development and Metastasis.

Glioblastoma multiforme (GBM) is a highly heterogenic and malignant brain tumour with a median survival of 15 months. The initial identification of primary glioblastomas is often challenging. Coronin 1C (CORO1C) is a key player in actin rearrangement and cofilin dynamics, as well as enhancing the processes of neurite overgrowth and migration of brain tumour cells. Different bioinformatic databases were accessed to measure CORO1C expression at the mRNA and protein level in normal and malignant brains. CORO1C expression was observed in brain regions which have retained high synaptic plasticity and myelination properties. CORO1C was also expressed mainly within the hippocampus formation, including the Cornu Ammonis (CA) fields: CA1-CA4. Higher expression was also noticed in paediatric GBM in comparison to their adult counterparts. Pediatric cell populations were observed to have an increased log2 expression of CORO1C. Furthermore, 62 miRNAs were found to target the CORO1C gene. Of these, hsa-miR-34a-5p, hsa-miR-512-3p, hsa-miR-136-5p, hsa-miR-206, hsa-miR-128-3p, and hsa-miR-21-5p have shown to act as tumour suppressors or oncomiRs in different neoplasms, including GBM. The elevated expression of CORO1C in high grade metastatic brain malignancies, including GBM, suggests that this protein could have a clinical utility as a biomarker linked to an unfavorable outcome.

Understanding radiation response and cell cycle variation in brain tumour cells using Raman spectroscopy.

Radiation therapy is currently utilised in the treatment of approximately 50% of cancer patients. A move towards patient tailored radiation therapy would help to improve the treatment outcome for patients as the inter-patient and intra-patient heterogeneity of cancer leads to large differences in treatment responses. In radiation therapy, a typical treatment outcome is cell cycle arrest which leads to cell cycle synchronisation. As treatment is typically given over multiple fractions it is important to understand how variation in the cell cycle can affect treatment response. Raman spectroscopy has previously been assessed as a method for monitoring radiation response in cancer cells and has shown promise in detecting the subtle biochemical changes following radiation exposure. This study evaluated Raman spectroscopy as a potential tool for monitoring cellular response to radiation in synchronised versus unsynchronised UVW human glioma cells in vitro. Specifically, it was hypothesised that the UVW cells would demonstrate a greater radiation resistance if the cell cycle phase of the cells was synchronised to the G1/S boundary prior to radiation exposure. Here we evaluated whether Raman spectroscopy, combined with cell cycle analysis and DNA damage and repair analysis (γ-H2AX assay), could discriminate the subtle cellular changes associated with radiation response. Raman spectroscopy combined with principal component analysis (PCA) was able to show the changes in radiation response over 24 hours following radiation exposure. Spectral changes were assigned to variations in protein, specifically changes in protein signals from amides as well as changes in lipid expression. A different response was observed between cells synchronised in the cell cycle and unsynchronised cells. After 24 hours following irradiation, the unsynchronised cells showed greater spectral changes compared to the synchronised cells demonstrating that the cell cycle plays an important role in the radiation resistance or sensitivity of the UVW cells, and that radiation resistance could be induced by controlling the cell cycle. One of the main aims of cancer treatment is to stop the proliferation of cells by controlling or halting progression through the cell cycle, thereby highlighting the importance of controlling the cell cycle when studying the effects of cancer treatments such as radiation therapy. Raman spectroscopy has been shown to be a useful tool for evaluating the changes in radiation response when the cell cycle phase is controlled and therefore highlighting its potential for assessing radiation response and resistance.

Brain tumor detection using CNN, AlexNet &amp;amp; GoogLeNet ensembling learning approaches

&lt;abstract&gt; &lt;p&gt;The detection of neurological disorders and diseases is aided by automatically identifying brain tumors from brain magnetic resonance imaging (MRI) images. A brain tumor is a potentially fatal disease that affects humans. Convolutional neural networks (CNNs) are the most common and widely used deep learning techniques for brain tumor analysis and classification. In this study, we proposed a deep CNN model for automatically detecting brain tumor cells in MRI brain images. First, we preprocess the 2D brain image MRI image to generate convolutional features. The CNN network is trained on the training dataset using the GoogleNet and AlexNet architecture, and the data model's performance is evaluated on the test data set. The model's performance is measured in terms of accuracy, sensitivity, specificity, and AUC. The algorithm performance matrices of both AlexNet and GoogLeNet are compared, the accuracy of AlexNet is 98.95, GoogLeNet is 99.45 sensitivity of AlexNet is 98.4, and GoogLeNet is 99.75, so from these values, we can infer that the GooGleNet is highly accurate and parameters that GoogLeNet consumes is significantly less; that is, the depth of AlexNet is 8, and it takes 60 million parameters, and the image input size is 227 × 227. Because of its high specificity and speed, the proposed CNN model can be a competent alternative support tool for radiologists in clinical diagnosis.&lt;/p&gt; &lt;/abstract&gt;

Experimental evaluation of the antioxidant and antitumor activities of thyme and basil essential oils and their phenolic constituents: theoretical antioxidant evaluation

BackgroundIdentifying specific biological activities of natural products are of the main concerns worldwide for the use in safe functional food manufacture; essential oils and their components are good candidates in this respect. The present work aims to evaluate the biological activities of basil and thyme oils as well as their phenolic constituents. Using computational methods to predict biological activities are currently effective tools in minimizing and explaining experimental works.ResultsChemical composition of thyme and basil oils were determined using GC–MS. The identified phenolic components were thymol (28.21%) and carvacrol (0.47%) in thyme oil and eugenol (11.37%) in basil oil. The antioxidant activity of both oils and their phenolic constituents as expressed by EC50 value were 535.01, 134.37, 176.57, 407.89 and 2.29 µg/mL against DPPH and 131.95, 56.65, 57.15, 82.71and 32.80 µg/mL against hydrogen peroxide, respectively. The order of activity is basil oil > thyme oil while phenolic compound order is eugenol > thymol > carvacrol; reducing power showed the same order. Basil oil showed also higher and good antitumor activity where it reduces the surviving fraction to 38.4% of brain tumor cells (U251) and 61.3% of liver tumor cells (HEPG2) at concentration 10 µg/mL. The antioxidant activity were evaluated theoretically according to the main three mechanisms, Hydrogen-Atom-Transfer (HAT), Single Electron Transfer–Proton Transfer (SET-PT) and the Sequential Proton Loss Electron-Transfer (SPLET); the results proved the experimental order of antioxidant and biological activities, and explained the remarkably higher activities of basil oil and its main phenolic component, eugenol.ConclusionTheoretical calculation can be used successfully to explain and predict the experimental biological activity results. Basil oil and its main phenolic component, eugenol, were found effective as antioxidants. Basil oil was also efficient in reducing the surviving fraction of liver and brain cancer cells where it reduces brain cells even lower than cells treated by doxorubicin, a known anti-cancer agent; thus, basil oil and its main phenolic components, eugenol, can be used safely in food preservation and functional food production.Graphical

Regulatory role of endoplasmic reticulum resident chaperone protein ERp29 in anti-murine β-coronavirus host cell response

Gap junctional intercellular communication (GJIC) involving astrocytes is important for proper CNS homeostasis. As determined in our previous studies, trafficking of the predominant astrocyte GJ protein, Connexin43 (Cx43), is disrupted in response to infection with a neurotropic murine β-coronavirus (MHV-A59). However, how host factors are involved in Cx43 trafficking and the infection response is not clear. Here, we show that Cx43 retention due to MHV-A59 infection was associated with increased ER stress and reduced expression of chaperone protein ERp29. Treatment of MHV-A59-infected astrocytes with the chemical chaperone 4-sodium phenylbutyrate increased ERp29 expression, rescued Cx43 transport to the cell surface, increased GJIC, and reduced ER stress. We obtained similar results using an astrocytoma cell line (delayed brain tumor) upon MHV-A59 infection. Critically, delayed brain tumor cells transfected to express exogenous ERp29 were less susceptible to MHV-A59 infection and showed increased Cx43-mediated GJIC. Treatment with Cx43 mimetic peptides inhibited GJIC and increased viral susceptibility, demonstrating a role for intercellular communication in reducing MHV-A59 infectivity. Taken together, these results support a therapeutically targetable ERp29-dependent mechanism where β-coronavirus infectivity is modulated by reducing ER stress and rescuing Cx43 trafficking and function.

Autonomous rhythmic activity in glioma networks drives brain tumour growth

Diffuse gliomas, particularly glioblastomas, are incurable brain tumours1. They are characterized by networks of interconnected brain tumour cells that communicate via Ca2+ transients2-6. However, the networks' architecture and communication strategy and how these influence tumour biology remain unknown. Here we describe how glioblastoma cell networks include a small, plastic population of highly active glioblastoma cells that display rhythmic Ca2+ oscillations and are particularly connected to others. Their autonomous periodic Ca2+ transients preceded Ca2+ transients of other network-connected cells, activating the frequency-dependent MAPK and NF-κB pathways. Mathematical network analysis revealed that glioblastoma network topology follows scale-free and small-world properties, with periodic tumour cells frequently located in network hubs. This network design enabled resistance against random damage but was vulnerable to losing its key hubs. Targeting of autonomous rhythmic activity by selective physical ablation of periodic tumour cells or by genetic or pharmacological interference with the potassium channel KCa3.1 (also known as IK1, SK4 or KCNN4) strongly compromised global network communication. This led to a marked reduction of tumour cell viability within the entire network, reduced tumour growth in mice and extended animal survival. The dependency of glioblastoma networks on periodic Ca2+ activity generates a vulnerability7 that can be exploited for the development of novel therapies, such as with KCa3.1-inhibiting drugs.

Efficacy of molecular and nano-therapies on brain tumor models in microfluidic devices

The three-dimensional (3D) organization of cells affects their mobility, proliferation, and overall response to treatment. Spheroids, organoids, and microfluidic chips are used in cancer research to reproduce in vitro the complex and dynamic malignant microenvironment. Herein, single- and double-channel microfluidic devices are used to mimic the spatial organization of brain tumors and investigate the therapeutic efficacy of molecular and nano anti-cancer agents. Human glioblastoma multiforme (U87-MG) cells were cultured into a Matrigel matrix embedded within the microfluidic devices and exposed to different doses of free docetaxel (DTXL), docetaxel-loaded spherical polymeric nanoparticles (DTXL-SPN), and the aromatic N-glucoside N-(fluorenylmethoxycarbonyl)-glucosamine-6-phosphate (Fmoc-Glc6P). We observed that in the single-channel microfluidic device, brain tumor cells are more susceptible to DTXL treatment as compared to conventional cell monolayers (50-fold lower IC50 values). In the double-channel device, the cytotoxicity of free DTXL and DTXL-SPN is comparable, but significantly lowered as compared to the single-channel configuration. Finally, the administration of 500 μM Fmoc-Glc6P in the double-channel microfluidic device shows a 50 % U87-MG cell survival after only 24 h, and no deleterious effect on human astrocytes over 72 h. Concluding, the proposed microfluidic chips can be used to reproduce the 3D complex spatial arrangement of solid tumors and to assess the anti-cancer efficacy of therapeutic compounds administrated in situ or systemically.

CSIG-29. EMPLOYING THE ZIKA VIRUS AS ONCOLYTIC VIROTHERAPY AGAINST PAEDIATRIC NERVOUS SYSTEM CANCER CELLS

Abstract BACKGROUND Malignant paediatric nervous system tumours, such as medulloblastoma, ATRT and high-risk neuroblastoma commonly harbour tumour cells with stem-like features which are highly tumorigenic and resistant to conventional therapies. These tumours can exhibit high lethality and may result in severe sequelae that significantly affect paediatric patients' quality of life. Oncolytic virotherapy exploits viruses that preferentially infect and destroy tumour cells. These viruses present a unique advantage in targeting highly heterogeneous cancers as they possess a secondary mechanism of action, through which they induce an anti-tumoral immune response. The Zika virus (ZIKV) is capable of infecting and destroying aggressive human paediatric brain tumour and neuroblastoma cells in vitro. ZIKV effectively reduces brain tumour size in mice (xenograft model) and canines (naturally occurring) and can induce an immune response against canine brain tumours. METHODS Employing global expression omics profiling of ZIKV infection and mapping of viral protein-host protein interactions, we aim to elucidate the mechanisms which underpin ZIKVs therapeutic properties, both at the molecular and cellular pathway levels. RESULTS Through extensive transcriptome profiling of ZIKV-infected paediatric brain tumour, neuroblastoma and NPCs, we have identified a variety of pathways which are involved in the ZIKV oncolytic response in the tumour cells and its neuro-dysregulation of NPCs. Despite both brain tumour and neuroblastoma cells undergoing ZIKV-induced oncolysis, we observed there to be a heterogeneous response within these different tumour cells at the molecular level to lead to oncolysis. Additionally, the infected tumour cells demonstrate elevated immune system profiles which alludes to the immune response that ZIKV may raise within the patient’s body against the paediatric tumour. Analysing our findings alongside the neuro-dysregulation we observe in our ZIKV-infected NPCs is allowing us to build a safety profile for employing a ZIKV-based therapy, whilst contributing to the growing knowledge of Congenital ZIKV Syndrome.

IMMU-06. REDUCTION OF CD4+ T CELLS NEGATIVELY AFFECTS SURVIVAL IN OLD BUT NOT YOUNG MICE WITH GLIOBLASTOMA

Abstract OBJECTIVE Previous work indicates poorer survival outcomes for older glioblastoma (GBM) patients ≥ 65 years of age as compared to younger patients &amp;lt; 65 years of age. The cellular mechanisms associated with this age-dependent survival difference remain elusive. Here we evaluated the overall survival of young and old immunocompetent mice with intracranial brain tumors that were depleted for specific immune cell populations. METHODS Young 6-8 weeks of age vs old 80+ weeks of age C57BL/6 mice were treated for up to 3 weeks with either IgG isotype control antibodies or with depleting antibodies against murine CD4, CD8, or NK1.1, beginning at 3 days prior to- and every 3 days post-intracranial injection of the mouse brain tumor cell lines, GL261 or CT-2A. Overall survival was compared between groups. Additionally, absolute peripheral blood mononuclear cell (PBMC) counts for CD3+ T cells, CD4+ T cells, and CD8+ T cells were analyzed between aneurysm control- and GBM-patients. RESULTS Older adult mice, but not younger mice, with either intracranial GL261 or CT-2A cell-based brain tumors have a significantly decreased overall survival when depleted for CD4+ T cells as compared to the IgG control-treated group, as well as groups depleted for CD8+ T- or NK-cells (P &amp;lt; 0.05). Coincidently, older GBM patients have fewer CD4+ T cells as compared to younger GBM patient counterparts (P &amp;lt; 0.05). CONCLUSIONS The data suggest that the levels of CD4+ T cells play more important roles in the survival of old subjects with GBM than in the younger subjects. A mechanistic understanding for this CD4+ T cell-dependent survival benefit is ongoing.

DNA damage in IDH-mutant gliomas: mechanisms and clinical implications.

Since the discovery of IDH mutations in glioma over a decade ago, significant progress has been made in determining how these mutations affect epigenetic, transcriptomic, and metabolic programs in brain tumor cells. In this article, we summarize current understanding of how IDH mutations influence DNA damage in glioma and discuss clinical implications of these findings. We performed a thorough review of peer-reviewed publications and provide an overview of key mechanisms by which IDH mutations impact response to DNA damage in gliomas, with an emphasis on clinical implications. The effects of mutant IDH on DNA damage largely fall into four overarching categories: Gene Expression, Sensitivity to Alkylating Agents, Homologous Recombination, and Oxidative Stress. From a mechanistic standpoint, we discuss how mutant IDH and the oncometabolite (R)-2HG affect each of these categories of DNA damage. We also contextualize these mechanisms with respect to ongoing clinical trials. Studies are underway that incorporate current standard-of-care therapies, including radiation and alkylating agents, in addition to novel therapeutic agents that exert genotoxic stress specifically in IDH-mutant gliomas. Lastly, we discuss key unanswered questions and emerging data in this field that have important implications for our understanding of glioma biology and for the development of new brain tumor therapies. Mounting preclinical and clinical data suggest that IDH mutations alter DNA damage sensing and repair pathways through distinct mechanisms. Future studies are needed to deepen our understanding of these processes and provide additional mechanistic insights that can be leveraged for therapeutic benefit.

The LncRNA MIAT is identified as a regulator of stemness-associated transcript in glioma.

Myocardial infarction-associated transcript (MIAT) is a long non-coding RNA (lncRNA) with altered expression in different diseases and malignancies. In this study, the potential expression and function of lncRNA MIAT in intuition and progression of brain cancer was investigated. At first, TCGA data analysis demonstrated that lncRNA MIAT is significantly upregulated in various malignancies, especially its expression is dramatically elevated in brain tumors. In line with the data, we further evaluated the expression of MIAT in a series of brain tumor tissue, and our results revealed that the expression of MIAT was noticeably overexpressed in glioblastoma (p = < 0.0001). We further found that the expression of MIAT was markedly upregulated in low-grade brain tumors rather than high-grade ones. To further investigate the biological function of MIAT in brain cancer cells, its expression was suppressed by si-RNA-mediated knocking down. Inhibition of MIAT resulted in reduced proliferation of brain tumor cells followed by cell cycle arrest at the G1 phase, and significant induction of apoptosis, and senescence, but limited the migration ability and epithelial-mesenchymal-transition (EMT). Moreover, knocking-down of MIAT reduced the expression of stemness factors, followed by upregulation of their downstream miRNAs (micro RNAs), let-7a-5p, and miR-29b-3p. Altogether, our data demonstrated that lncRNA MIAT could control proliferation, migration, and metastasis of brain cancer cells via regulating the Nanog/ Sox2 / let-7a-5p / miR-29b-3p axis. This data could introduce lncRNA MIAT as a novel oncogene in brain cancer pathogenesis.

Miniature NIR-II Nanoprobes for Active-Targeted Phototheranostics of Brain Tumors.

Nanoprobes (NPs) in the second near-infrared biowindow (NIR-II, 1000-1700nm) are developed and widely used in cancer phototheranostics. However, most NIR-II NPs exhibit low phototheranostic efficiency due to their tedious synthetic routes, large particle sizes (>20nm), and lack of active targeting properties. Here, miniature NIR-II NPs, named HSA-ICG-iRGD, for active-targeted NIR-II phototheranostics of brain tumors are reported. The HSA-ICG-iRGD probes are designed based on hydrophobic interactions as well as hydrogen bonds between albumin and indocyanine green derivatives (ICG-iRGD) via molecular docking. The as-prepared NPs have a compact size of 10nm and show tumor-targeting ability by specifically binding to αv β3 integrin receptors which are highly expressed on the surface of brain tumor cells via iRGD peptides. The HSA-ICG-iRGD NPs are then applied to perform active-targeted NIR-II fluorescence imaging, resulting in a signal-to-background ratio of 6.85 in orthotopic glioma mouse models. Under the selected laser irradiation of 808nm, the photothermal effect of HSA-ICG-iRGD extends the survival of the tumor-bearing mice to 55 days, significantly longer than that of the control group (30 days). These results highlight the potential of miniature NPs for active-targeted NIR-II fluorescence imaging and phototherapy of brain tumors.