Treatment of Human Glioblastoma with a Live Attenuated Zika Virus Vaccine Candidate

Practical immunomodulatory landscape of glioblastoma multiforme (GBM) therapy

Glioblastoma multiforme (GBM) is the most common harmful high-grade brain tumor with high mortality and low survival rate. Importantly, besides routine diagnostic and therapeutic methods, modern and useful practical techniques are urgently needed for this serious malignancy. Correspondingly, the translational medicine focusing on genetic and epigenetic profiles of glioblastoma, as well as the immune framework and brain microenvironment, based on these challenging findings, indicates that key clinical interventions include immunotherapy, such as immunoassay, oncolytic viral therapy, and chimeric antigen receptor T (CAR T) cell therapy, which are of great importance in both diagnosis and therapy. Relatively, vaccine therapy reflects the untapped confidence to enhance GBM outcomes. Ongoing advances in immunotherapy, which utilizes different methods to regenerate or modify the resistant body for cancer therapy, have revealed serious results with many different problems and difficulties for patients. Safe checkpoint inhibitors, adoptive cellular treatment, cellular and peptide antibodies, and other innovations give researchers an endless cluster of instruments to plan profoundly in personalized medicine and the potential for combination techniques. In this way, antibodies that block immune checkpoints, particularly those that target the program death 1 (PD-1)/PD-1 (PD-L1) ligand pathway, have improved prognosis in a wide range of diseases. However, its use in combination with chemotherapy, radiation therapy, or monotherapy is ineffective in treating GBM. The purpose of this review is to provide an up-to-date overview of the translational elements concentrating on the immunotherapeutic field of GBM alongside describing the molecular mechanism involved in GBM and related signaling pathways, presenting both historical perspectives and future directions underlying basic and clinical practice.

Zika virus and brain cancer: Can Zika be an effective treatment for brain cancer? A systematic review

INTRODUCTION

Many studies have highlighted the use of oncolytic viruses as a new class of therapeutic agents for central nervous system (CNS) tumors, especially glioblastomas (GMB). Zika Virus (ZIKV) proteins targeted to specific stem cells have been studied in vitro and animal models with promising results.

MATERIALS AND METHODS

A systematic review was evaluated the efficacy and safety of the ZIKV use for CNS tumors treatment. Data were extracted and the in vivo studies were evaluated using the Robins-I tool. We assessed bias in each study using criteria such as selection bias, performance bias, detection bias, attrition bias, reporting bias, and others. According to Cochrane guidelines, bias was classified as high, low, or uncertain. High bias occurred when studies did not meet the criteria. Low bias was assigned when criteria were clearly met. Uncertain bias reflected insufficient information for a clear classification.

RESULTS

The 14 included studies shown that ZIKV reduced cell viability or inhibited the growth, proliferation of glioma stem cells (GSCs), and Bcl2 expression - which could potentially enhance the effect of chemotherapy/radiotherapy; caused cytopathic effects, induced tumor cell damage, manifested oncolytic properties, and even selectively safely killed GSCs; ultimately, it led to significant tumor remission and enhanced long-term survival through enhanced T-cell response.

CONCLUSIONS

Although current evidence suggests ZIKV as a promising treatment for CNS tumors and may improve survival when combined with surgery and radiotherapy. Despite limited human evidence, it shows potential benefits. Further research is needed to confirm safety, efficacy, and optimize treatment in humans.

Harnessing ZIKV NS2A RNA for alleviating acute hepatitis and cytokine release storm by targeting translation machinery

BACKGROUND AND AIMS

Hyperactivated inflammatory responses induced by cytokine release syndrome are the primary causes of tissue damage and even death. The translation process is precisely regulated to control the production of proinflammatory cytokines. However, it is largely unknown whether targeting translation can effectively limit the hyperactivated inflammatory responses during acute hepatitis and graft-versus-host disease.

APPROACH AND RESULTS

By using in vitro translation and cellular overexpression systems, we have found that the nonstructural protein gene NS2A of Zika virus functions as RNA molecules to suppress the translation of both ectopic genes and endogenous proinflammatory cytokines. Mechanistically, results from RNA pulldown and co-immunoprecipitation assays have demonstrated that NS2A RNA interacts with the translation initiation factor eIF2α to disrupt the dynamic balance of the eIF2/eIF2B complex and translation initiation, which is the rate-limiting step of translation. In the acetaminophen-induced, lipopolysaccharide/D-galactosamine-induced, viral infection-induced acute hepatitis, and graft-versus-host disease mouse models, mice with myeloid cell-specific knock-in of NS2A show decreased levels of serum proinflammatory cytokines and reduced tissue damage.

CONCLUSIONS

Zika virus NS2A dampens the production of proinflammatory cytokines and alleviates inflammatory injuries by interfering translation process as RNA molecules, which suggests that NS2A RNA is potentially used to treat numerous acute inflammatory diseases characterized by cytokine release syndrome.

Oncolytic virotherapy improves immunotherapies targeting cancer stemness in glioblastoma

Despite advances in cancer therapies, glioblastoma (GBM) remains the most resistant and recurrent tumor in the central nervous system. GBM tumor microenvironment (TME) is a highly dynamic landscape consistent with alteration in tumor infiltration cells, playing a critical role in tumor progression and invasion. In addition, glioma stem cells (GSCs) with self-renewal capability promote tumor recurrence and induce therapy resistance, which all have complicated eradication of GBM with existing therapies. Oncolytic virotherapy is a promising field of therapy that can kill tumor cells in a targeted manner. Manipulated oncolytic viruses (OVs) improve cancer immunotherapy by directly lysis tumor cells, infiltrating antitumor cells, inducing immunogenic cell death, and sensitizing immune-resistant TME to an immune-responsive hot state. Importantly, OVs can target stemness-driven GBM progression. In this review, we will discuss how OVs as a therapeutic option target GBM, especially the GSC subpopulation, and induce immunogenicity to remodel the TME, which subsequently enhances immunotherapies' efficiency.

Prognostic relevance and validation of ARPC1A in the progression of low-grade glioma

Low-grade glioma (LGG) is a grade II-III glioma accompanied by distinct clinical and molecular characteristics and the studies related to its prognosis are still unclear. The objective of this study is to explore the involvement of mitochondrial-related genes SLBP, COMMD7, LSM4, TOMM34, RPP40, FKBP1A, ARPC1A, and TBCA for the prognosis of LGG. We detected differences in the expression of some of the genes by analyzing the bioinformatics dataset and combining it with RT-PCR experiments. Subsequently, a nomogram was constructed and validated for the clinical relevance of risk factors such as age, WHO grade, IDH mutation status, Ch.1p19q co-deletion status, and high and low expression of ARPC1A to predict the 1-, 3-, 5-year overall survival and prognostic relevance of ARPC1A. Gene set enrichment analysis was performed for the relevant datasets pertinent to the expression of ARPC1A to elucidate the cancer-promoting pathways involved in the LGG through KEGG and GO analysis. Transfection assays, CCK-8 assays, and flow cytometry were used to determine the proliferation rate, and apoptosis rate of the HS683 and SW1783 cell lines respectively. Western blotting was used to examine the involvement of the cancer-promoting activity of ARPC1A through MAPK signaling. In this study, the prognostic value of ARPC1A in LGG was found by bioinformatics analysis combined with experimental approach analysis and may be a significant independent risk factor. ARPC1A fosters a higher LGG proliferation rate that may control the MAP kinase signaling and could be a prominent biomarker for LGG. Future studies are warranted to explore its clinical implications.

Improvement of current immunotherapies with engineered oncolytic viruses that target cancer stem cells

The heterogeneity of the solid tumor microenvironment (TME) impairs the therapeutic efficacy of standard therapies and also reduces the infiltration of antitumor immune cells, all of which lead to tumor progression and invasion. In addition, self-renewing cancer stem cells (CSCs) support tumor dormancy, drug resistance, and recurrence, all of which might pose challenges to the eradication of malignant tumor masses with current therapies. Natural forms of oncolytic viruses (OVs) or engineered OVs are known for their potential to directly target and kill tumor cells or indirectly eradicate tumor cells by involving antitumor immune responses, including enhancement of infiltrating antitumor immune cells, induction of immunogenic cell death, and reprogramming of cold TME to an immune-sensitive hot state. More importantly, OVs can target stemness factors that promote tumor progression, which subsequently enhances the efficacy of immunotherapies targeting solid tumors, particularly the CSC subpopulation. Herein, we describe the role of CSCs in tumor heterogeneity and resistance and then highlight the potential and remaining challenges of immunotherapies targeting CSCs. We then review the potential of OVs to improve tumor immunogenicity and target CSCs and finally summarize the challenges within the therapeutic application of OVs in preclinical and clinical trials.

Zika Virus: A Neurotropic Warrior against High-Grade Gliomas-Unveiling Its Potential for Oncolytic Virotherapy

Gliomas account for approximately 75-80% of all malignant primary tumors in the central nervous system (CNS), with glioblastoma multiforme (GBM) considered the deadliest. Despite aggressive treatment involving a combination of chemotherapy, radiotherapy, and surgical intervention, patients with GBM have limited survival rates of 2 to 5 years, accompanied by a significant decline in their quality of life. In recent years, novel management strategies have emerged, such as immunotherapy, which includes the development of vaccines or T cells with chimeric antigen receptors, and oncolytic virotherapy (OVT), wherein wild type (WT) or genetically modified viruses are utilized to selectively lyse tumor cells. In vitro and in vivo studies have shown that the Zika virus (ZIKV) can infect glioma cells and induce a robust oncolytic activity. Consequently, interest in exploring this virus as a potential oncolytic virus (OV) for high-grade gliomas has surged. Given that ZIKV actively circulates in Colombia, evaluating its neurotropic and oncolytic capabilities holds considerable national and international importance, as it may emerge as an alternative for treating highly complex gliomas. Therefore, this literature review outlines the generalities of GBM, the factors determining ZIKV's specific tropism for nervous tissue, and its oncolytic capacity. Additionally, we briefly present the progress in preclinical studies supporting the use of ZIKV as an OVT for gliomas.

Molecular insights and promise of oncolytic virus based immunotherapy

Discovering a therapeutic that can counteract the aggressiveness of this disease's mechanism is crucial for improving survival rates for cancer patients and for better understanding the most different types of cancer. In recent years, using these viruses as an anticancer therapy has been thought to be successful. They mostly work by directly destroying cancer cells, activating the immune system to fight cancer, and expressing exogenous effector genes. For the treatment of tumors, oncolytic viruses (OVs), which can be modified to reproduce only in tumor tissues and lyse them while preserving the healthy non-neoplastic host cells and reinstating antitumor immunity which present a novel immunotherapeutic strategy. OVs can exist naturally or be created in a lab by altering existing viruses. These changes heralded the beginning of a new era of less harmful virus-based cancer therapy. We discuss three different types of oncolytic viruses that have already received regulatory approval to treat cancer as well as clinical research using oncolytic adenoviruses. The primary therapeutic applications, mechanism of action of oncolytic virus updates, future views of this therapy will be covered in this chapter.

Repurposing of Zika virus live-attenuated vaccine (ZIKV-LAV) strains as oncolytic viruses targeting human glioblastoma multiforme cells

Glioblastoma multiforme (GBM) is the most common malignant primary brain cancer affecting the adult population. Median overall survival for GBM patients is poor (15 months), primarily due to high rates of tumour recurrence and the paucity of treatment options. Oncolytic virotherapy is a promising treatment alternative for GBM patients, where engineered viruses selectively infect and eradicate cancer cells by inducing cell lysis and eliciting robust anti-tumour immune response. In this study, we evaluated the oncolytic potency of live-attenuated vaccine strains of Zika virus (ZIKV-LAV) against human GBM cells in vitro. Our findings revealed that Axl and integrin αvβ5 function as cellular receptors mediating ZIKV-LAV infection in GBM cells. ZIKV-LAV strains productively infected and lysed human GBM cells but not primary endothelia and terminally differentiated neurons. Upon infection, ZIKV-LAV mediated GBM cell death via apoptosis and pyroptosis. This is the first in-depth molecular dissection of how oncolytic ZIKV infects and induces death in tumour cells.

Advances in oncolytic herpes simplex virus and adenovirus therapy for recurrent glioma

Recurrent glioma treatment is challenging due to molecular heterogeneity and treatment resistance commonly observed in these tumors. Researchers are actively pursuing new therapeutic strategies. Oncolytic viruses have emerged as a promising option. Oncolytic viruses selectively replicate within tumor cells, destroying them and stimulating the immune system for an enhanced anticancer response. Among Oncolytic viruses investigated for recurrent gliomas, oncolytic herpes simplex virus and oncolytic adenovirus show notable potential. Genetic modifications play a crucial role in optimizing their therapeutic efficacy. Different generations of replicative conditioned oncolytic human adenovirus and oncolytic HSV have been developed, incorporating specific modifications to enhance tumor selectivity, replication efficiency, and immune activation. This review article summarizes these genetic modifications, offering insights into the underlying mechanisms of Oncolytic viruses' therapy. It also aims to identify strategies for further enhancing the therapeutic benefits of Oncolytic viruses. However, it is important to acknowledge that additional research and clinical trials are necessary to establish the safety, efficacy, and optimal utilization of Oncolytic viruses in treating recurrent glioblastoma.

Differential Susceptibility of Ex Vivo Primary Glioblastoma Tumors to Oncolytic Effect of Modified Zika Virus

Glioblastoma (GBM), the most common primary malignant brain tumor, is a highly lethal form of cancer with a very limited set of treatment options. High heterogeneity in the tumor cell population and the invasive nature of these cells decrease the likely efficacy of traditional cancer treatments, thus requiring research into novel treatment options. The use of oncolytic viruses as potential therapeutics has been researched for some time. Zika virus (ZIKV) has demonstrated oncotropism and oncolytic effects on GBM stem cells (GSCs). To address the need for safe and effective GBM treatments, we designed an attenuated ZIKV strain (ZOL-1) that does not cause paralytic or neurological diseases in mouse models compared with unmodified ZIKV. Importantly, we found that patient-derived GBM tumors exhibited susceptibility (responders) and non-susceptibility (non-responders) to ZOL-1-mediated tumor cell killing, as evidenced by differential apoptotic cell death and cell viability upon ZOL-1 treatment. The oncolytic effect observed in responder cells was seen both in vitro in neurosphere models and in vivo upon xenograft. Finally, we observed that the use of ZOL-1 as combination therapy with multiple PI3K-AKT inhibitors in non-responder GBM resulted in enhanced chemotherapeutic efficacy. Altogether, this study establishes ZOL-1 as a safe and effective treatment against GBM and provides a foundation to conduct further studies evaluating its potential as an effective adjuvant with other chemotherapies and kinase inhibitors.

The Present and Future of Optic Pathway Glioma Therapy

Optic pathway gliomas (OPGs) encompass two distinct categories: benign pediatric gliomas, which are characterized by favorable prognosis, and malignant adult gliomas, which are aggressive cancers associated with a poor outcome. Our review aims to explore the established standards of care for both types of tumors, highlight the emerging therapeutic strategies for OPG treatment, and propose potential alternative therapies that, while originally studied in a broader glioma context, may hold promise for OPGs pending further investigation. These potential therapies encompass immunotherapy approaches, molecular-targeted therapy, modulation of the tumor microenvironment, nanotechnologies, magnetic hyperthermia therapy, cyberKnife, cannabinoids, and the ketogenic diet. Restoring visual function is a significant challenge in cases where optic nerve damage has occurred due to the tumor or its therapeutic interventions. Numerous approaches, particularly those involving stem cells, are currently being investigated as potential facilitators of visual recovery in these patients.

Development of Zika Virus E Variants for Pseudotyping Retroviral Vectors Targeting Glioblastoma Cells

A fundamental idea for targeting glioblastoma cells is to exploit the neurotropic properties of Zika virus (ZIKV) through its two outer envelope proteins, prM and E. This study aimed to develop envelope glycoproteins for pseudotyping retroviral vectors that can be used for efficient tumor cell infection. Firstly, the retroviral vector pNLlucAM was packaged using wild-type ZIKV E to generate an E-HIVluc pseudotype. E-HIVluc infection rates for tumor cells were higher than those of normal prME pseudotyped particles and the traditionally used vesicular stomatitis virus G (VSV-G) pseudotypes, indicating that protein E alone was sufficient for the formation of infectious pseudotyped particles. Secondly, two envelope chimeras, E41.1 and E41.2, with the E wild-type transmembrane domain replaced by the gp41 transmembrane and cytoplasmic domains, were constructed; pNLlucAM or pNLgfpAM packaged with E41.1 or E41.2 constructs showed infectivity for tumor cells, with the highest rates observed for E41.2. This envelope construct can be used not only as a tool to further develop oncolytic pseudotyped viruses for therapy, but also as a new research tool to study changes in tumor cells after the transfer of genes that might have therapeutic potential.

Flaviviruses in AntiTumor Therapy

Oncolytic viruses offer a promising approach to tumor treatment. These viruses not only have a direct lytic effect on tumor cells but can also modify the tumor microenvironment and activate antitumor immunity. Due to their high pathogenicity, flaviviruses have often been overlooked as potential antitumor agents. However, with recent advancements in genetic engineering techniques, an extensive history with vaccine strains, and the development of new attenuated vaccine strains, there has been a renewed interest in the Flavivirus genus. Flaviviruses can be genetically modified to express transgenes at acceptable levels, and the stability of such constructs has been greatly improving over the years. The key advantages of flaviviruses include their reproduction cycle occurring entirely within the cytoplasm (avoiding genome integration) and their ability to cross the blood-brain barrier, facilitating the systemic delivery of oncolytics against brain tumors. So far, the direct lytic effects and immunomodulatory activities of many flaviviruses have been widely studied in experimental animal models across various types of tumors. In this review, we delve into the findings of these studies and contemplate the promising potential of flaviviruses in oncolytic therapies.

Recombinant measles virus vaccine rMV-Hu191 exerts an oncolytic effect on esophageal squamous cell carcinoma via caspase-3/GSDME-mediated pyroptosis

Oncolytic viruses have recently been proven to be an effective and promising cancer therapeutic strategy, but there is rare data about oncolytic therapy in esophageal squamous cell carcinoma (ESCC), especially oncolytic measles virotherapy. Therefore, this study aimed to explore whether the recombinant measles virus vaccine strain rMV-Hu191 has an oncolytic effect against ESCC cells in vitro and in vivo and elucidate the underlying mechanisms. Our results showed that rMV-Hu191 could efficiently replicate in and kill ESCC cells through caspase-3/GSDME-mediated pyroptosis. Mechanistically, rMV-Hu191 triggers mitochondrial dysfunction to induce pyroptosis, which is mediated by BAK (BCL2 antagonist/killer 1) or BAX (BCL2 associated X). Further analysis revealed that rMV-Hu191 activates inflammatory signaling in ESCC cells, which may enhance the oncolytic efficiency. Moreover, intratumoral injection of rMV-Hu191 induced dramatic tumor regression in an ESCC xenograft model. Collectively, these findings imply that rMV-Hu191 exhibits an antitumor effect through BAK/BAX-dependent caspase-3/GSDME-mediated pyroptosis and provides a potentially promising new therapy for ESCC treatment.

Modeling glioblastoma complexity with organoids for personalized treatments

Glioblastoma (GBM) remains a fatal diagnosis despite the current standard of care of maximal surgical resection, radiation, and temozolomide (TMZ) therapy. One aspect that impedes drug development is the lack of an appropriate model representative of the complexity of patient tumors. Brain organoids derived from cell culture techniques provide a robust, easily manipulatable, and high-throughput model for GBM. In this review, we highlight recent progress in developing GBM organoids (GBOs) with a focus on generating the GBM microenvironment (i.e., stem cells, vasculature, and immune cells) recapitulating human disease. Finally, we also discuss the use of organoids as a screening tool in drug development for GBM.

Recent Developments in Glioblastoma Therapy: Oncolytic Viruses and Emerging Future Strategies

Glioblastoma is the most aggressive form of malignant brain tumor. Standard treatment protocols and traditional immunotherapy are poorly effective as they do not significantly increase the long-term survival of glioblastoma patients. Oncolytic viruses (OVs) may be an effective alternative approach. Combining OVs with some modern treatment options may also provide significant benefits for glioblastoma patients. Here we review virotherapy for glioblastomas and describe several OVs and their combination with other therapies. The personalized use of OVs and their combination with other treatment options would become a significant area of research aiming to develop the most effective treatment regimens for glioblastomas.

Attenuated WNV-poly(A) exerts a broad-spectrum oncolytic effect by selective virus replication and CD8+ T cell-dependent immune response

As an emerging tumor therapy, ideal oncolytic viruses preferentially replicate in malignant cells, reverse the immunosuppressive tumor microenvironment, and eventually can be eliminated by the patient. It is of great significance for cancer treatment to discover new excellent oncolytic viruses. Here, we found that WNV live attenuated vaccine WNV-poly(A) could be developed as a novel ideal oncolytic agent against several types of cancers. Mechanistically, due to its high sensitivity to type Ι interferon (IFN-Ι), WNV-poly(A) could specifically kill tumor cells rather than normal cells. At the same time, WNV-poly(A) could activate Dendritic cells (DCs) and trigger tumor antigen specific response mediated by CD8 + T cell, which contributed to inhibit the propagation of original and distal tumor cells. Like intratumoral injection, intravenous injection with WNV-poly(A) also markedly delays Huh7 hepatic carcinoma (HCC) transplanted tumor progression. Most importantly, in addition to an array of mouse xenograft tumor models, WNV-poly(A) also has a significant inhibitory effect on many different types of patient-derived tumor tissues and HCC patient-derived xenograft (PDX) tumor models. Our studies reveal that WNV-poly(A) is a potent and excellent oncolytic agent against many types of tumors and may have a role in metastatic and recurrent tumors.

Unraveling the Metabolic Alterations Induced by Zika Infection in Prostate Epithelial (PNT1a) and Adenocarcinoma (PC-3) Cell Lines

The outbreak of Zika virus infection in 2016 led to the identification of its presence in several types of biofluids, including semen. Later discoveries associated Zika infection with sexual transmission and persistent replication in cells of the male reproductive tract. Prostate epithelial and carcinoma cells are favorable to virus replication, with studies pointing to transcriptomics alterations of immune and inflammation genes upon persistence. However, metabolome alterations promoted by the Zika virus in prostate cells are unknown. Given its chronic effects and oncolytic potential, we aim to investigate the metabolic alterations induced by the Zika virus in prostate epithelial (PNT1a) and adenocarcinoma (PC-3) cells using an untargeted metabolomics approach and high-resolution mass spectrometry. PNT1a cells were viable up to 15 days post ZIKV infection, in contrast to its antiproliferative effect in the PC-3 cell lineage. Remarkable alterations in the PNT1a cell metabolism were observed upon infection, especially regarding glycerolipids, fatty acids, and acylcarnitines, which could be related to viral cellular resource exploitation, in addition to the over-time increase in oxidative stress metabolites associated with carcinogenesis. The upregulation of FA20:5 at 5 dpi in PC-3 cells corroborates the antiproliferative effect observed since this metabolite was previously reported to induce PC-3 cell death. Overall, Zika virus promotes extensive lipid alterations on both PNT1a and PC-3 cells, promoting different outcomes based on the cellular metabolic state.

Live-attenuated Japanese encephalitis virus inhibits glioblastoma growth and elicits potent antitumor immunity

Glioblastomas (GBMs) are highly aggressive brain tumors that have developed resistance to currently available conventional therapies, including surgery, radiation, and systemic chemotherapy. In this study, we investigated the safety of a live attenuated Japanese encephalitis vaccine strain (JEV-LAV) virus as an oncolytic virus for intracerebral injection in mice. We infected different GBM cell lines with JEV-LAV to investigate whether it had growth inhibitory effects on GBM cell lines in vitro. We used two models for evaluating the effect of JEV-LAV on GBM growth in mice. We investigated the antitumor immune mechanism of JEV-LAV through flow cytometry and immunohistochemistry. We explored the possibility of combining JEV-LAV with PD-L1 blocking therapy. This work suggested that JEV-LAV had oncolytic activity against GBM tumor cells in vitro and inhibited their growth in vivo. Mechanistically, JEV-LAV increased CD8+ T cell infiltration into tumor tissues and remodeled the immunosuppressive GBM microenvironment that is non-conducive to immunotherapy. Consequently, the results of combining JEV-LAV with immune checkpoint inhibitors indicated that JEV-LAV therapy improved the response of aPD-L1 blockade therapy against GBM. The safety of intracerebrally injected JEV-LAV in animals further supported the clinical use of JEV-LAV for GBM treatment.

Interfer(on)ing with Zika virus

In this issue of Neuron, Bulstrode et al.¹ demonstrate that glioblastoma slice cultures, unlike neural progenitors, are refractory to Zika virus infection. The anti-infective mechanism is myeloid-lineage cell-secreted interferon beta. These studies have implications for therapeutics in both glioblastoma and Zika virus infections.

Myeloid cell interferon secretion restricts Zika flavivirus infection of developing and malignant human neural progenitor cells

Zika virus (ZIKV) can infect human developing brain (HDB) progenitors resulting in epidemic microcephaly, whereas analogous cellular tropism offers treatment potential for the adult brain cancer, glioblastoma (GBM). We compared productive ZIKV infection in HDB and GBM primary tissue explants that both contain SOX2+ neural progenitors. Strikingly, although the HDB proved uniformly vulnerable to ZIKV infection, GBM was more refractory, and this correlated with an innate immune expression signature. Indeed, GBM-derived CD11b+ microglia/macrophages were necessary and sufficient to protect progenitors against ZIKV infection in a non-cell autonomous manner. Using SOX2+ GBM cell lines, we found that CD11b+-conditioned medium containing type 1 interferon beta (IFNβ) promoted progenitor resistance to ZIKV, whereas inhibition of JAK1/2 signaling restored productive infection. Additionally, CD11b+ conditioned medium, and IFNβ treatment rendered HDB progenitor lines and explants refractory to ZIKV. These findings provide insight into neuroprotection for HDB progenitors as well as enhanced GBM oncolytic therapies.

2-Deoxyglucose, an Inhibitor of Glycolysis, Enhances the Oncolytic Effect of Coxsackievirus

Glioblastoma multiforme (GBM) is one of the most common types of brain tumor. Despite intensive research, patients with GBM have a poor prognosis due to a very high rate of relapse and significant side effects of the treatment, with a median survival of 14.6 months. Oncolytic viruses are considered a promising strategy to eliminate GBM and other types of cancer, and several viruses have already been introduced into clinical practice. However, identification of the factors that underly the sensitivity of tumor species to oncolytic viruses or that modulate their clinical efficacy remains an important target. Here, we show that Coxsackievirus B5 (CVB5) demonstrates high oncolytic potential towards GBM primary cell species and cell lines. Moreover, 2-deoxyglucose (2DG), an inhibitor of glycolysis, potentiates the cytopathic effects of CVB5 in most of the cancer cell lines tested. The cells in which the inhibition of glycolysis enhanced oncolysis are characterized by high mitochondrial respiratory activity and glycolytic capacity, as determined by Seahorse analysis. Thus, 2-deoxyglucose and other analogs should be considered as adjuvants for oncolytic therapy of glioblastoma multiforme.

Overcoming the blood-brain barrier for the therapy of malignant brain tumor: current status and prospects of drug delivery approaches

Besides the broad development of nanotechnological approaches for cancer diagnosis and therapy, currently, there is no significant progress in the treatment of different types of brain tumors. Therapeutic molecules crossing the blood-brain barrier (BBB) and reaching an appropriate targeting ability remain the key challenges. Many invasive and non-invasive methods, and various types of nanocarriers and their hybrids have been widely explored for brain tumor treatment. However, unfortunately, no crucial clinical translations were observed to date. In particular, chemotherapy and surgery remain the main methods for the therapy of brain tumors. Exploring the mechanisms of the BBB penetration in detail and investigating advanced drug delivery platforms are the key factors that could bring us closer to understanding the development of effective therapy against brain tumors. In this review, we discuss the most relevant aspects of the BBB penetration mechanisms, observing both invasive and non-invasive methods of drug delivery. We also review the recent progress in the development of functional drug delivery platforms, from viruses to cell-based vehicles, for brain tumor therapy. The destructive potential of chemotherapeutic drugs delivered to the brain tumor is also considered. This review then summarizes the existing challenges and future prospects in the use of drug delivery platforms for the treatment of brain tumors.

Glioblastoma microenvironment and its reprogramming by oncolytic virotherapy

Glioblastoma (GBM), a highly aggressive form of brain tumor, responds poorly to current conventional therapies, including surgery, radiation therapy, and systemic chemotherapy. The reason is that the delicate location of the primary tumor and the existence of the blood-brain barrier limit the effectiveness of traditional local and systemic therapies. The immunosuppressive status and multiple carcinogenic pathways in the complex GBM microenvironment also pose challenges for immunotherapy and single-targeted therapy. With an improving understanding of the GBM microenvironment, it has become possible to consider the immunosuppressive and highly angiogenic GBM microenvironment as an excellent opportunity to improve the existing therapeutic efficacy. Oncolytic virus therapy can exert antitumor effects on various components of the GBM microenvironment. In this review, we have focused on the current status of oncolytic virus therapy for GBM and the related literature on antitumor mechanisms. Moreover, the limitations of oncolytic virus therapy as a monotherapy and future directions that may enhance the field have also been discussed.

Does covid-19 impair endogenous neurogenesis?

Endogenous neural stem cells are thought to continue to generate new neurons throughout life in the human brain. Endogenous neurogenesis has been proposed to contribute to physiological roles in maintaining and regenerating olfaction, as well as promoting normal cognition, learning and memory. Specific impairments in these processes in COVID-19 - impaired olfaction and cognition - may implicate the SARS-CoV-2 virus in attenuating neurogenesis. Furthermore, neurogenesis has been linked with neuroregeneration; and impaired neuroregeneration has previously been linked with neurodegenerative diseases. Emerging evidence supports an association between COVID-19 infection and accelerated neurodegeneration. Also, structural changes indicating global reduction in brain size and specific reduction in the size of limbic structures - including orbitofrontal cortex, olfactory cortex and parahippocampal gyrus - as a result of SARS-CoV-2 infection have been demonstrated. This paper proposes the hypothesis that SARS-CoV-2 infection may impair endogenous neural stem cell activity. An attenuation of neurogenesis may contribute to reduction in brain size and/or neurodegenerative processes following SARS-CoV-2 infection. Furthermore, as neural stem cells are thought to be the cell of origin in glioma, better understanding of SARS-CoV-2 interaction with tumorigenic stem cells is indicated, with a view to informing therapeutic modulation. The subacute and chronic implications of attenuated endogenous neurogenesis are explored in the context of long COVID. Modulating endogenous neurogenesis may be a novel therapeutic strategy to address specific neurological manifestations of COVID-19 and potential applicability in tumour virotherapy.

Emerging therapies for glioblastoma: current state and future directions

Glioblastoma (GBM) is the most common high-grade primary malignant brain tumor with an extremely poor prognosis. Given the poor survival with currently approved treatments for GBM, new therapeutic strategies are urgently needed. Advances in decades of investment in basic science of glioblastoma are rapidly translated into innovative clinical trials, utilizing improved genetic and epigenetic profiling of glioblastoma as well as the brain microenvironment and immune system interactions. Following these encouraging findings, immunotherapy including immune checkpoint blockade, chimeric antigen receptor T (CAR T) cell therapy, oncolytic virotherapy, and vaccine therapy have offered new hope for improving GBM outcomes; ongoing studies are using combinatorial therapies with the aim of minimizing adverse side-effects and augmenting antitumor immune responses. In addition, techniques to overcome the blood-brain barrier (BBB) for targeted delivery are being tested in clinical trials in patients with recurrent GBM. Here, we set forth the rationales for these promising therapies in treating GBM, review the potential novel agents, the current status of preclinical and clinical trials, and discuss the challenges and future perspectives in glioblastoma immuno-oncology.

Gospel of malignant Glioma: Oncolytic virus therapy

Glioma accounts for nearly 80% of all intracranial malignant tumors. It is a major challenge to society as it is causes to impaired brain function in many patients. Currently, gliomas are mainly treated with surgery, postoperative radiotherapy, and chemotherapy. However, the curative effects of these treatments are not satisfactory. Oncolytic virus (OV) is a novel treatment which works by activating the immune functions and inducing apoptosis of tumor cells. The OV propagates indefinitely in the host cell, eventually leading to the death of host cell. Subsequently, a large number of antigens and signal molecules are released which exert antitumor immunity. Several preclinical and clinical studies have shown that G207, DNX2401, Zika and other viruses have important roles in malignant tumors. For example, these viruses can reduce the growth of tumor cells without causing severe complications. However, the known OVs have not been clearly classified. Herein, we divided OVs into neurotropic and non-neurophilic OVs based on whether the OVs are naturally neurotropic or not. The therapeutic effects of each group were compared. Finally, challenges encountered in the clinical application of OVs in the treatment of malignant gliomas were summarized.

Oncolytic Zika virus promotes intratumoral T cell infiltration and improves immunotherapy efficacy in glioblastoma

Glioblastoma (GBM) is the deadliest primary brain tumor and is generally resistant to immunotherapy because of severe dysfunction of T cells. Novel treatment options are critically needed to overcome the immunotherapy resistance of GBM. Here we demonstrate that Zika virus (ZIKV) treatment improves the efficacy of anti-PD ligand 1 (PD-L1) immunotherapy in GBM. We found that ZIKV induces a strong pro-inflammatory response and increases CD4⁺ and CD8⁺ T cell intratumoral infiltration and activation in GBM mouse models. ZIKV treatment of mice bearing GBM tumors inhibits tumor growth and prolongs survival. These therapeutic effects of ZIKV on GBM tumors are negated in mice depleted of T cells. Moreover, ZIKV dramatically promotes activation of the type I interferon signaling pathway in GBM cells. ZIKV treatment potently sensitizes GBM to PD-L1 blockade and provides significant and durable survival benefits. Our findings reveal that ZIKV overcomes the resistance of GBM to immune checkpoint blockade, which may lead to therapeutic applications of ZIKV in individuals with GBM receiving immunotherapy.

Intracranial delivery of synthetic mRNA to suppress glioblastoma

Owing to messenger RNA's unique biological advantages, it has received increasing attention to be used as a therapeutic, known as mRNA-based gene therapy. It is critical to have an ideal strategy of mRNA gene therapy for glioma, which grows in a special environment. In the present study, we screened out a safe and efficient transfection reagent for intracranial delivery of synthetic mRNA in mouse brain. First, in order to analyze the effect of different transfection reagents on the intracranial delivery of mRNA, the synthetic luciferase mRNA was wrapped with two different transfection reagents and microinjected into the brain at the fixed point. The expression status of delivered mRNA was monitored by a small animal imaging system. The possible reagent-induced biological toxicity was evaluated by behavioral and blood biochemical measurements. Then, to test the therapeutic effect of our intracranial delivery mRNA model on glioma, synthetic modified tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA was used as an example of therapeutic application. This model demonstrated that synthetic mRNA could be successfully delivered into the brain using commercially available transfection reagents, and TransIT-mRNA showed better results than in vivo-jetPEI kit. This model can be applied in precise targeting and personalized gene therapy of glioma.

Apoptosis during ZIKA Virus Infection: Too Soon or Too Late?

Cell death by apoptosis is a major cellular response in the control of tissue homeostasis and as a defense mechanism in the case of cellular aggression such as an infection. Cell self-destruction is part of antiviral responses, aimed at limiting the spread of a virus. Although it may contribute to the deleterious effects in infectious pathology, apoptosis remains a key mechanism for viral clearance and the resolution of infection. The control mechanisms of cell death processes by viruses have been extensively studied. Apoptosis can be triggered by different viral determinants through different pathways as a result of virally induced cell stresses and innate immune responses. Zika virus (ZIKV) induces Zika disease in humans, which has caused severe neurological forms, birth defects, and microcephaly in newborns during the last epidemics. ZIKV also surprised by revealing an ability to persist in the genital tract and in semen, thus being sexually transmitted. Mechanisms of diverting antiviral responses such as the interferon response, the role of cytopathic effects and apoptosis in the etiology of the disease have been widely studied and debated. In this review, we examined the interplay between ZIKV infection of different cell types and apoptosis and how the virus deals with this cellular response. We illustrate a duality in the effects of ZIKV-controlled apoptosis, depending on whether it occurs too early or too late, respectively, in neuropathogenesis, or in long-term viral persistence. We further discuss a prospective role for apoptosis in ZIKV-related therapies, and the use of ZIKV as an oncolytic agent.

AXL receptor is required for Zika virus strain MR-766 infection in human glioblastoma cell lines

Recent reports have shown that Zika virus (ZIKV) has oncolytic potential against human glioblastoma (GBM); however, the mechanisms underlying its tropism and cell entry are not completely understood. The receptor tyrosine kinase AXL has been identified as an entry receptor for ZIKV in a cell-type-specific manner. Interestingly, AXL is frequently overexpressed in GBM patients. Using commercially available GBM cell lines, we first show that cells expressing AXL are permissive for ZIKV infection, while cells that do not express AXL are not. Furthermore, inhibition of AXL kinase using R428 and antibody blockade of AXL receptor strongly attenuated virus entry in GBM cell lines. Additionally, CRISPR knockout of the AXL gene in GBM cell lines completely abolished ZIKV infection, significantly inhibited viral replication, and significantly reduced apoptosis compared with parental lines. Lastly, introduction of AXL receptor into non-expressing cell lines renders the cells susceptible to ZIKV infection. Together, these findings demonstrate that ZIKV entry into GBM cells in vitro is mediated by the AXL receptor and that following cell entry, productive infection is cytotoxic. Thus, ZIKV is a potential oncolytic virus for GBM.

Nanotherapeutics Overcoming the Blood-Brain Barrier for Glioblastoma Treatment

Glioblastoma (GBM) is the most common malignant primary brain tumor with a poor prognosis. The current standard treatment regimen represented by temozolomide/radiotherapy has an average survival time of 14.6 months, while the 5-year survival rate is still less than 5%. New therapeutics are still highly needed to improve the therapeutic outcome of GBM treatment. The blood-brain barrier (BBB) is the main barrier that prevents therapeutic drugs from reaching the brain. Nanotechnologies that enable drug delivery across the BBB hold great promise for the treatment of GBM. This review summarizes various drug delivery systems used to treat glioma and focuses on their approaches for overcoming the BBB to enhance the accumulation of small molecules, protein and gene drugs, etc. in the brain.

Oncolytic Viro-Immunotherapy: An Emerging Option in the Treatment of Gliomas

The prognosis of malignant gliomas remains poor, with median survival fewer than 20 months and a 5-year survival rate merely 5%. Their primary location in the central nervous system (CNS) and its immunosuppressive environment with little T cell infiltration has rendered cancer therapies mostly ineffective, and breakthrough therapies such as immune checkpoint inhibitors (ICIs) have shown limited benefit. However, tumor immunotherapy is developing rapidly and can help overcome these obstacles. But for now, malignant gliomas remain fatal with short survival and limited therapeutic options. Oncolytic virotherapy (OVT) is a unique antitumor immunotherapy wherein viruses selectively or preferentially kill tumor cells, replicate and spread through tumors while inducing antitumor immune responses. OVTs can also recondition the tumor microenvironment and improve the efficacy of other immunotherapies by escalating the infiltration of immune cells into tumors. Some OVTs can penetrate the blood-brain barrier (BBB) and possess tropism for the CNS, enabling intravenous delivery. Despite the therapeutic potential displayed by oncolytic viruses (OVs), optimizing OVT has proved challenging in clinical development, and marketing approvals for OVTs have been rare. In June 2021 however, as a genetically engineered OV based on herpes simplex virus-1 (G47Δ), teserpaturev got conditional and time-limited approval for the treatment of malignant gliomas in Japan. In this review, we summarize the current state of OVT, the synergistic effect of OVT in combination with other immunotherapies as well as the hurdles to successful clinical use. We also provide some suggestions to overcome the challenges in treating of gliomas.

New Immunotherapeutic Approaches for Glioblastoma

Glioblastoma (GBM) is the most common primary malignant brain tumor with a high mortality rate. The current treatment consists of surgical resection, radiation, and chemotherapy; however, the median survival rate is only 12-18 months despite these alternatives, highlighting the urgent need to find new strategies. The heterogeneity of GBM makes this tumor difficult to treat, and the immunotherapies result in an attractive approach to modulate the antitumoral immune responses favoring the tumor eradication. The immunotherapies for GMB including monoclonal antibodies, checkpoint inhibitors, vaccines, and oncolytic viruses, among others, have shown favorable results alone or as a multimodal treatment. In this review, we summarize and discuss promising immunotherapies for GBM currently under preclinical investigation as well as in clinical trials.

Immune Microenvironment Landscape in CNS Tumors and Role in Responses to Immunotherapy

Despite the important evolution of immunotherapeutic agents, brain tumors remain, in general, refractory to immune therapeutics. Recent discoveries have revealed that the glioma microenvironment includes a wide variety of immune cells in various states that play an important role in the process of tumorigenesis. Anti-tumor immune activity may be occurring or induced in immunogenic hot spots or at the invasive edge of central nervous system (CNS) tumors. Understanding the complex heterogeneity of the immune microenvironment in gliomas will likely be the key to unlocking the full potential of immunotherapeutic strategies. An essential consideration will be the induction of immunological effector responses in the setting of the numerous aspects of immunosuppression and evasion. As such, immune therapeutic combinations are a fundamental objective for clinical studies in gliomas. Through immune profiling conducted on immune competent murine models of glioma and ex vivo human glioma tissue, we will discuss how the frequency, distribution of immune cells within the microenvironment, and immune modulatory processes, may be therapeutically modulated to lead to clinical benefits.

Molecular Mechanisms of Drug Resistance in Glioblastoma

Glioblastoma multiforme (GBM) is the most common and fatal primary brain tumor, is highly resistant to conventional radiation and chemotherapy, and is not amenable to effective surgical resection. The present review summarizes recent advances in our understanding of the molecular mechanisms of therapeutic resistance of GBM to already known drugs, the molecular characteristics of glioblastoma cells, and the barriers in the brain that underlie drug resistance. We also discuss the progress that has been made in the development of new targeted drugs for glioblastoma, as well as advances in drug delivery across the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB).

Immune cells enhance Zika virus-mediated neurologic dysfunction in brain of mice with humanized immune systems

Zika virus (ZIKV) can generate a number of neurological dysfunctions in infected humans. Here, we tested the potential of human immune cells to protect against ZIKV infection in genetically humanized MISTRG mice. FACS analysis showed robust reconstitution of the mouse spleen with human T cells. Peripheral ZIKV inoculation resulted in infection within the brains of MISTRG mice. Mice that were reconstituted with human peripheral blood mononuclear cells (PBMC) showed a more rapid lethal response to ZIKV than the control mice lacking these immune cells. Immunocytochemical analysis of T cell markers CD3, CD45, or CD8 showed strong T cell presence in the brain, together with robust infection by ZIKV particularly in the excitatory pyramidal and granule neurons of the hippocampus. Infection was also found in cortex, striatum, the dopamine neurons of the substantia nigra, and other brain loci. Infection was considerably less in other regions such as the septum and hypothalamus. These data support the perspective that, rather than exerting a protective function, T cells may underlie some ZIKV-mediated neuropathology in the brain.

The Dual Regulation of Apoptosis by Flavivirus

Apoptosis is a form of programmed cell death, which maintains cellular homeostasis by eliminating pathogen-infected cells. It contains three signaling pathways: death receptor pathway, mitochondria-mediated pathway, and endoplasmic reticulum pathway. Its importance in host defenses is highlighted by the observation that many viruses evade, hinder or destroy apoptosis, thereby weakening the host’s immune response. Flaviviruses such as Dengue virus, Japanese encephalitis virus, and West Nile virus utilize various strategies to activate or inhibit cell apoptosis. This article reviews the research progress of apoptosis mechanism during flaviviruses infection, including flaviviruses proteins and subgenomic flaviviral RNA to regulate apoptosis by interacting with host proteins, as well as various signaling pathways involved in flaviviruses-induced apoptosis, which provides a scientific basis for understanding the pathogenesis of flaviviruses and helps in developing an effective antiviral therapy.

Microfluidic Organoids-on-a-Chip: Quantum Leap in Cancer Research

Organ-like cell clusters, so-called organoids, which exhibit self-organized and similar organ functionality as the tissue of origin, have provided a whole new level of bioinspiration for ex vivo systems. Microfluidic organoid or organs-on-a-chip platforms are a new group of micro-engineered promising models that recapitulate 3D tissue structure and physiology and combines several advantages of current in vivo and in vitro models. Microfluidics technology is used in numerous applications since it allows us to control and manipulate fluid flows with a high degree of accuracy. This system is an emerging tool for understanding disease development and progression, especially for personalized therapeutic strategies for cancer treatment, which provide well-grounded, cost-effective, powerful, fast, and reproducible results. In this review, we highlight how the organoid-on-a-chip models have improved the potential of efficiency and reproducibility of organoid cultures. More widely, we discuss current challenges and development on organoid culture systems together with microfluidic approaches and their limitations. Finally, we describe the recent progress and potential utilization in the organs-on-a-chip practice.

Oncolytic Virotherapy in Solid Tumors: The Challenges and Achievements

Oncolytic virotherapy (OVT) is a promising approach in cancer immunotherapy. Oncolytic viruses (OVs) could be applied in cancer immunotherapy without in-depth knowledge of tumor antigens. The capability of genetic modification makes OVs exciting therapeutic tools with a high potential for manipulation. Improving efficacy, employing immunostimulatory elements, changing the immunosuppressive tumor microenvironment (TME) to inflammatory TME, optimizing their delivery system, and increasing the safety are the main areas of OVs manipulations. Recently, the reciprocal interaction of OVs and TME has become a hot topic for investigators to enhance the efficacy of OVT with less off-target adverse events. Current investigations suggest that the main application of OVT is to provoke the antitumor immune response in the TME, which synergize the effects of other immunotherapies such as immune-checkpoint blockers and adoptive cell therapy. In this review, we focused on the effects of OVs on the TME and antitumor immune responses. Furthermore, OVT challenges, including its moderate efficiency, safety concerns, and delivery strategies, along with recent achievements to overcome challenges, are thoroughly discussed.

Clinically Explored Virus-Based Therapies for the Treatment of Recurrent High-Grade Glioma in Adults

As new treatment modalities are being explored in neuro-oncology, viruses are emerging as a promising class of therapeutics. Virotherapy consists of the introduction of either wild-type or engineered viruses to the site of disease, where they exert an antitumor effect. These viruses can either be non-lytic, in which case they are used to deliver gene therapy, or lytic, which induces tumor cell lysis and subsequent host immunologic response. Replication-competent viruses can then go on to further infect and lyse neighboring glioma cells. This treatment paradigm is being explored extensively in both preclinical and clinical studies for a variety of indications. Virus-based therapies are advantageous due to the natural susceptibility of glioma cells to viral infection, which improves therapeutic selectivity. Furthermore, lytic viruses expose glioma antigens to the host immune system and subsequently stimulate an immune response that specifically targets tumor cells. This review surveys the current landscape of oncolytic virotherapy clinical trials in high-grade glioma, summarizes preclinical experiences, identifies challenges associated with this modality across multiple trials, and highlights the potential to integrate this therapeutic strategy into promising combinatory approaches.

Zika virus oncolytic activity requires CD8+ T cells and is boosted by immune checkpoint blockade

Glioblastoma multiforme (GBM) is a fatal human cancer in part because GBM stem cells are resistant to therapy and recurrence is inevitable. Previously, we demonstrated Zika virus (ZIKV) targets GBM stem cells and prevents death of mice with gliomas. Here, we evaluated the immunological basis of ZIKV-mediated protection against GBM. Introduction of ZIKV into the brain tumor increased recruitment of CD8⁺ T and myeloid cells to the tumor microenvironment. CD8⁺ T cells were required for ZIKV-dependent tumor clearance because survival benefits were lost with CD8⁺ T cell depletion. Moreover, while anti–PD-1 antibody monotherapy moderately improved tumor survival, when coadministered with ZIKV, survival increased. ZIKV-mediated tumor clearance also resulted in durable protection against syngeneic tumor rechallenge, which also depended on CD8⁺ T cells. To address safety concerns, we generated an immune-sensitized ZIKV strain, which was effective alone or in combination with immunotherapy. Thus, oncolytic ZIKV treatment can be leveraged by immunotherapies, which may prompt combination treatment paradigms for adult patients with GBM.

Novel modulators of p53-signaling encoded by unknown genes of emerging viruses

The p53 transcription factor plays a key role both in cancer and in the cell-intrinsic response to infections. The ORFEOME project hypothesized that novel p53-virus interactions reside in hitherto uncharacterized, unknown, or hypothetical open reading frames (orfs) of human viruses. Hence, 172 orfs of unknown function from the emerging viruses SARS-Coronavirus, MERS-Coronavirus, influenza, Ebola, Zika (ZIKV), Chikungunya and Kaposi Sarcoma-associated herpesvirus (KSHV) were de novo synthesized, validated and tested in a functional screen of p53 signaling. This screen revealed novel mechanisms of p53 virus interactions and two viral proteins KSHV orf10 and ZIKV NS2A binding to p53. Originally identified as the target of small DNA tumor viruses, these experiments reinforce the notion that all viruses, including RNA viruses, interfere with p53 functions. These results validate this resource for analogous systems biology approaches to identify functional properties of uncharacterized viral proteins, long non-coding RNAs and micro RNAs.

New viruses are constantly emerging. The ORFEOME project was based on the hypothesis that every virus, regardless of its molecular makeup and biology should encode functions that intersect the p53 signaling network, since p53 guards the cell from genomic insults, of which depositing a foreign, viral nucleic acid is one. The result of the ORFEOME screen of proteins without any known function, of predicted open reading frames and of suspected non-coding RNAs is the identification of two viral proteins that interact with p53. The first one, orf10, is encoded by Kaposi Sarcoma-associated herpesvirus and the second one, NS2A, is encoded by the Zika virus.

Impact of Zika virus on the human type I interferon osteoimmune response

BACKGROUND

The developing field of osteoimmunology supports importance of an interferon (IFN) response pathway in osteoblasts. Clarifying osteoblast-IFN interactions is important because IFN is used as salvage anti-tumor therapy but systemic toxicity is high with variable clinical results. In addition, osteoblast response to systemic bursts and disruptions of IFN pathways induced by viral infection may influence bone remodeling. ZIKA virus (ZIKV) infection impacts bone development in humans and IFN response in vitro. Consistently, initial evidence of permissivity to ZIKV has been reported in human osteoblasts.

HYPOTHESIS

Osteoblast-like Saos-2 cells are permissive to ZIKV and responsive to IFN.

METHODS

Multiple approaches were used to assess whether Saos-2 cells are permissive to ZIKV infection and exhibit IFN-mediated ZIKV suppression. Proteomic methods were used to evaluate impact of ZIKV and IFN on Saos-2 cells.

RESULTS

Evidence is presented confirming Saos-2 cells are permissive to ZIKV and support IFN-mediated suppression of ZIKV. ZIKV and IFN differentially impact the Saos-2 proteome, exemplified by HELZ2 protein which is upregulated by IFN but non responsive to ZIKV. Both ZIKV and IFN suppress proteins associated with microcephaly/pseudo-TORCH syndrome (BI1, KI20A and UBP18), and ZIKV induces potential entry factor PLVAP.

CONCLUSIONS

Transient ZIKV infection influences osteoimmune state, and IFN and ZIKV activate distinct proteomes in Saos-2 cells, which could inform therapeutic, engineered, disruptions.

Zika virus NS2A protein induces the degradation of KPNA2 (karyopherin subunit alpha 2) via chaperone-mediated autophagy

KPNA2/importin-alpha1 (karyopherin subunit alpha 2) is the primary nucleocytoplasmic transporter for some transcription factors to activate cellular proliferation and differentiation. Aberrant increase of KPNA2 level is identified as a prognostic marker in a variety of cancers. Yet, the turnover mechanism of KPNA2 remains unknown. Here, we demonstrate that KPNA2 is degraded via the chaperone-mediated autophagy (CMA) and that Zika virus (ZIKV) enhances the KPNA2 degradation. KPNA2 contains a CMA motif, which possesses an indispensable residue Gln109 for the CMA-mediated degradation. RNAi-mediated knockdown of LAMP2A, a vital component of the CMA pathway, led to a higher level of KPNA2. Moreover, ZIKV reduced KPNA2 via the viral NS2A protein, which contains an essential residue Thr100 for inducing the CMA-mediated KPNA2 degradation. Notably, mutant ZIKV with T100A alteration in NS2A replicates much weaker than the wild-type virus. Also, knockdown of KPNA2 led to a higher ZIKV viral yield, which indicates that KPNA2 mediates certain antiviral effects. These data provide insights into the KPNA2 turnover and the ZIKV-cell interactions.

SLC39A1 contribute to malignant progression and have clinical prognostic impact in gliomas

BACKGROUND

Gliomas are one of the most common primary tumors of the central nervous system, and have an unfavorable prognosis. SLC39A1 is a zinc ion transport protein which inhibits the progression of prostate cancer. By studying the role and mechanism of SLC39A1 in the progression of gliomas, perhaps a new therapeutic target can be provided for their treatment.

METHOD

The TCGA, CCGA, GSE16011, GSE44971 and GSE11260 data sets were employed to evaluate the expression level of SLC39A1 in paracancerous and glioma tissues. In addition, Kaplan-Meier analysis, Cox analysis, and the ESTIMATE and CIBERSORT algorithms were used to analyze its prognostic value and immune infiltration correlation. A CCK-8 and flow cytometer were used to measure the effects of SLC39A1 on U87 cell proliferation or apoptosis; RT-qPCR and western blot were used to detect its effects on the expression of MMP2\MMP9.

RESULTS

SLC39A1 has up-regulated expression in glioma tissues. High SLC39A1 expression predicted significantly worse survival. Univariate and multivariate analysis show that SLC39A1 independently indicated poor prognosis in patients with gliomas. The expression of SLC39A1 is significantly correlated with clinical pathological parameters such as Grade, IDH mutation status, and 1p19q codeletion status. In vitro experimental results show that SLC39A1 promotes proliferation of glioma cells, inhibits their apoptosis, and promotes expression of MMP2\MMP9. In addition, it may affect infiltration of immune cells into the glioma microenvironment.

CONCLUSION

SLC39A1 may serve as a new prognostic biomarker and potential target for treatment of gliomas.

Oncolytic Viruses as a Platform for the Treatment of Malignant Brain Tumors

Malignant brain tumors remain incurable diseases. Although much effort has been devoted to improving patient outcome, multiple factors such as the high tumor heterogeneity, the strong tumor-induced immunosuppressive microenvironment, and the low mutational burden make the treatment of these tumors especially challenging. Thus, novel therapeutic strategies are urgent. Oncolytic viruses (OVs) are biotherapeutics that have been selected or engineered to infect and selectively kill cancer cells. Increasingly, preclinical and clinical studies demonstrate the ability of OVs to recruit T cells and induce durable immune responses against both virus and tumor, transforming a “cold” tumor microenvironment into a “hot” environment. Besides promising clinical results as a monotherapy, OVs can be powerfully combined with other cancer therapies, helping to overcome critical barriers through the creation of synergistic effects in the fight against brain cancer. Although many questions remain to be answered to fully exploit the therapeutic potential of OVs, oncolytic virotherapy will clearly be part of future treatments for patients with malignant brain tumors.