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.

IGH Complementarity Determining Region-3-Cytomegalovirus Protein Chemical Complementarity Linked to Better Overall Survival Probabilities for Glioblastoma.

Cytomegalovirus (CMV) has long been thought to have an association with glioblastoma multiforme (GBM), although the exact role of CMV and any subsequent implications for treatment have yet to be fully understood. This study addressed whether IGH complementarity determining region-3 (CDR3)-CMV protein chemical complementarity, with IGH CDR3s representing both tumor resident and blood-sourced IGH recombinations, was associated with overall survival (OS) distinctions. IGH recombination sequencing reads were obtained from (a) the Clinical Proteomic Tumor Analysis Consortium, tumor RNAseq files; and (b) the cancer genome atlas, blood exome-derived files. The Adaptive Match web tool was used to calculate chemical complementarity scores (CSs) based on hydrophobic interactions, and those scores were used to group GBM cases and assess survival probabilities. We found a higher OS probability for cases whose hydrophobic IGH CDR3-CMV protein chemical complementarity scores (Hydro CSs) were in the upper 50th percentile for several CMV proteins, including UL99 and UL123, as well as for CSs based on known B cell epitopes representing these proteins. We also identified multiple immune signature genes, including CD79A and TNFRSF17, for which higher RNA expression was associated with higher Hydro CSs. Results were consistent with the idea that stronger immunoglobulin responses to CMV are associated with better OS probabilities for GBM.

Electrophysiological Impact of SARS-CoV-2 Envelope Protein in U251 Human Glioblastoma Cells: Possible Implications in Gliomagenesis?

SARS-CoV-2 is the causative agent of the COVID-19 pandemic, the acute respiratory disease which, so far, has led to over 7 million deaths. There are several symptoms associated with SARS-CoV-2 infections which include neurological and psychiatric disorders, at least in the case of pre-Omicron variants. SARS-CoV-2 infection can also promote the onset of glioblastoma in patients without prior malignancies. In this study, we focused on the Envelope protein codified by the virus genome, which acts as viroporin and that is reported to be central for virus propagation. In particular, we characterized the electrophysiological profile of E-protein transfected U251 and HEK293 cells through the patch-clamp technique and FURA-2 measurements. Specifically, we observed an increase in the voltage-dependent (Kv) and calcium-dependent (KCa) potassium currents in HEK293 and U251 cell lines, respectively. Interestingly, in both cellular models, we observed a depolarization of the mitochondrial membrane potential in accordance with an alteration of U251 cell growth. We, therefore, investigated the transcriptional effect of E protein on the signaling pathways and found several gene alterations associated with apoptosis, cytokines and WNT pathways. The electrophysiological and transcriptional changes observed after E protein expression could explain the impact of SARS-CoV-2 infection on gliomagenesis.

First parechovirus reported case in Saudi Arabia in hospitalized immunocompromised adult patient.

Human parechovirus, a member of the Picornaviridae family (PeVs), can lead to severe infections, including severe meningitis, meningoencephalitis, and sepsis-like syndrome. We report a case of human parechovirus-related encephalitis in a 52-year-old woman diagnosed with glioblastoma multiforme. She underwent surgical resection in June 2022. Unfortunately, her disease recurred, and she underwent a second resection in August 2022, followed by radiation therapy and Temozolomide therapy. She presented to the hospital with acute confusion followed by seizures, necessitating intubation for airway support. A cerebrospinal fluid (CSF) sample was obtained and processed using the Biofire FilmArray, which reported the detection of HSV-1. Despite being on Acyclovir, the patient did not show signs of improvement. Consequently, a second CSF sample was obtained and sent for next-generation sequencing (NGS), which returned a positive result for Parechovirus. In this presented case, the patient exhibited symptoms of an unknown infectious cause. The utilization of NGS and metagenomic analysis helped identify Parechovirus as the primary pathogen present, in addition to previously identified HSV. This comprehensive approach facilitated a thorough assessment of the underlying infection and guided targeted treatment. In conclusion, the application of NGS techniques and metagenomic analysis proved instrumental in identifying the root cause of the infection.

Noninvasive therapy of brain cancer using a unique systemic delivery methodology with a cancer terminator virus.

Primary, glioblastoma, and secondary brain tumors, from metastases outside the brain, are among the most aggressive and therapeutically resistant cancers. A physiological barrier protecting the brain, the blood-brain barrier (BBB), functions as a deterrent to effective therapies. To enhance cancer therapy, we developed a cancer terminator virus (CTV), a unique tropism-modified adenovirus consisting of serotype 3 fiber knob on an otherwise Ad5 capsid that replicates in a cancer-selective manner and simultaneously produces a potent therapeutic cytokine, melanoma differentiation-associated gene-7/interleukin-24 (MDA-7/IL-24). A limitation of the CTV and most other viruses, including adenoviruses, is an inability to deliver systemically to treat brain tumors because of the BBB, nonspecific virus trapping, and immune clearance. These obstacles to effective viral therapy of brain cancer have now been overcome using focused ultrasound with a dual microbubble treatment, the focused ultrasound-double microbubble (FUS-DMB) approach. Proof-of-principle is now provided indicating that the BBB can be safely and transiently opened, and the CTV can then be administered in a second set of complement-treated microbubbles and released in the brain using focused ultrasound. Moreover, the FUS-DMB can be used to deliver the CTV multiple times in animals with glioblastoma  growing in their brain thereby resulting in a further enhancement in survival. This strategy permits efficient therapy of primary and secondary brain tumors enhancing animal survival without promoting harmful toxic or behavioral side effects. Additionally, when combined with a standard of care therapy, Temozolomide, a further increase in survival is achieved. The FUS-DMB approach with the CTV highlights a noninvasive strategy to treat brain cancers without surgery. This innovative delivery scheme combined with the therapeutic efficacy of the CTV provides a novel potential translational therapeutic approach for brain cancers.

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.

ScRNA-seq reveals novel immune-suppressive T cells and investigates CMV-TCR-T cells cytotoxicity against GBM.

BACKGROUND: Glioblastoma (GBM) is a fatal primary brain malignancy in adults. Previous studies have shown that cytomegalovirus (CMV) is a risk factor for tumorigenesis and aggressiveness for glioblastoma. However, little is known about how CMV infection affects immune cells in the tumor microenvironment of GBM. Furthermore, there has been almost no engineered T-cell receptor (TCR)-T targeting CMV for GBM research to date. METHODS: We evaluated the CMV infection status of patients with GBM's tumor tissue by immune electron microscopy, immunofluorescence, and droplet digital PCR. We performed single-cell RNA sequencing for CMV-infected GBM to investigate the effects of CMV on the GBM immune microenvironment. CellChat was applied to analyze the interaction between cells in the GBM tumor microenvironment. Additionally, we conducted single-cell TCR/B cell receptor (BCR) sequencing and Grouping of Lymphocyte Interactions with Paratope Hotspots 2 algorithms to acquire specific CMV-TCR sequences. Genetic engineering was used to introduce CMV-TCR into primary T cells derived from patients with CMV-infected GBM. Flow cytometry was used to measure the proportion and cytotoxicity status of T cells in vitro. RESULTS: We identified two novel immune cell subpopulations in CMV-infected GBM, which were bipositive CD68+SOX2+ tumor-associated macrophages and FXYD6+ T cells. We highlighted that the interaction between bipositive TAMs or cancer cells and T cells was predominantly focused on FXYD6+ T cells rather than regulatory T cells (Tregs), whereas, FXYD6+ T cells were further identified as a group of novel immunosuppressive T cells. CMV-TCR-T cells showed significant therapeutic effects on the human-derived orthotopic GBM mice model. CONCLUSIONS: These findings provided an insight into the underlying mechanism of CMV infection promoting the GBM immunosuppression, and provided a novel potential immunotherapy strategy for patients with GBM.

Generation of glioblastoma in mice engrafted with human cytomegalovirus-infected astrocytes.

Mounting evidence is identifying human cytomegalovirus (HCMV) as a potential oncogenic virus. HCMV has been detected in glioblastoma multiforme (GB). Herewith, we present the first experimental evidence for the generation of CMV-Elicited Glioblastoma Cells (CEGBCs) possessing glioblastoma-like traits that lead to the formation of glioblastoma in orthotopically xenografted mice. In addition to the already reported oncogenic HCMV-DB strain, we isolated three HCMV clinical strains from GB tissues that transformed HAs toward CEGBCs and generated spheroids from CEGBCs that resulted in the appearance of glioblastoma-like tumors in xenografted mice. These tumors were nestin-positive mostly in the invasive part surrounded by GFAP-positive reactive astrocytes. The glioblastoma immunohistochemistry phenotype was confirmed by EGFR and cMet gene amplification in the tumor parallel to the detection of HCMV IE and UL69 genes and proteins. Our results fit with an HCMV-induced glioblastoma model of oncogenesis in vivo which will open the door to new therapeutic approaches and assess the anti-HCMV treatment as well as immunotherapy in fighting GB which is characterized by poor prognosis.

Effects of HSV-G47Δ Oncolytic Virus on Telomerase and Telomere Length Alterations in Glioblastoma Multiforme Cancer Stem Cells Under Hypoxia and Normoxia Conditions.

BACKGROUND: Due to the existence of tumor stem cells with tumorigenicity properties and resistance patterns, treatment of glioblastoma is not easy. Hypoxia is a major concern in glioblastoma therapy. Telomerase activity and telomere length alterations have been known to play a critical role in glioblastoma progression and invasion. OBJECTIVE: This study aimed to investigate the effects of HSV-G47Δ oncolytic virus on telomerase and telomere length alterations in U251GBMCSCs (U251-Glioblastoma cancer stem cells) under hypoxia and normoxia conditions. METHODS: U251-CSCs were exposed to the HSV-G47Δ virus in optimized MOI (Multiplicity of infection= 1/14 hours). An absolute telomere length and gene expression of telomerase subunits were determined using an absolute human telomere length quantification PCR assay. Furthermore, a bioinformatics pathway analysis was carried out to evaluate physical and genetic interactions between dysregulated genes with other potential genes and pathways. RESULTS: Data revealed that U251CSCs had longer telomeres when exposed to HSV-G47Δ in normoxic conditions but had significantly shorter telomeres in hypoxic conditions. Furthermore, hTERC, DKC1, and TEP1 genes were significantly dysregulated in hypoxic and normoxic microenvironments. The analysis revealed that the expression of TERF2 was significantly reduced in both microenvironments, and two critical genes from the MRN complex, MER11 and RAD50, were significantly upregulated in normoxic conditions. RAD50 showed a significant downregulation pattern in the hypoxic niche. Our results suggested that repair complex in the telomeric structure could be targeted by HSV-G47Δ in both microenvironments. CONCLUSION: In the glioblastoma treatment strategy, telomerase and telomere complex could be potential targets for HSV-G47Δ in both microenvironments.

Phosphorylation of ERK-Dependent NF-κB Triggers NLRP3 Inflammasome Mediated by Vimentin in EV71-Infected Glioblastoma Cells.

Enterovirus 71 (EV71) is a dominant pathogenic agent that may cause severe central nervous system (CNS) diseases among infants and young children in the Asia-pacific. The inflammasome is closely implicated in EV71-induced CNS injuries through a series of signaling pathways. However, the activation pathway of NLRP3 inflammasome involved in EV71-mediated CNS injuries remains poorly defined. In the studies, EV71 infection, ERK1/2 phosphorylation, and activation of NLRP3 are abolished in glioblastoma cells with low vimentin expression by CRISPR/Cas9-mediated knockdown. PD098059, an inhibitor of p-ERK, remarkably blocks the vimentin-mediated ERK1/2 phosphorylation in EV71-infected cells. Nuclear translocation of NF-κB p65 is dependent on p-ERK in a time-dependent manner. Moreover, NLRP3 activation and caspase-1 production are limited in EV71-infected cells upon the caffeic acid phenethyl ester (CAPE) administration, an inhibitor of NF-κB, which contributes to the inflammasome regulation. In conclusion, these results suggest that EV71-mediated NLRP3 inflammasome could be activated via the VIM-ERK-NF-κB pathway, and the treatment of the dephosphorylation of ERK and NF-κB inhibitors is beneficial to host defense in EV71-infected CNS.

Metabolic Reprogramming of Glioblastoma Cells during HCMV Infection Induces Secretome-Mediated Paracrine Effects in the Microenvironment.

Glioblastoma (GBM) is an aggressive primary central nervous system neoplasia with limited therapeutic options and poor prognosis. Following reports of cytomegalovirus (HCMV) in GBM tumors, the anti-viral drug Valganciclovir was administered and found to significantly increase the longevity of GBM patients. While these findings suggest a role for HCMV in GBM, the relationship between them is not clear and remains controversial. Treatment with anti-viral drugs may prove clinically useful; however, their results do not explain the underlying mechanism between HCMV infection and GBM progression. We hypothesized that HCMV infection would metabolically reprogram GBM cells and that these changes would allow for increased tumor progression. We infected LN-18 GBM cells and employed a Seahorse Bioanalyzer to characterize cellular metabolism. Increased mitochondrial respiration and glycolytic rates were observed following infection. These changes were accompanied by elevated production of reactive oxygen species and lactate. Due to lactate's numerous tumor-promoting effects, we examined the impact of paracrine signaling of HCMV-infected GBM cells on uninfected stromal cells. Our results indicated that, independent of viral transmission, the secretome of HCMV-infected GBM cells was able to alter the expression of key metabolic proteins and epigenetic markers. This suggests a mechanism of action where reprogramming of GBM cells alters the surrounding tumor microenvironment to be permissive to tumor progression in a manner akin to the Reverse-Warburg Effect. Overall, this suggests a potential oncomodulatory role for HCMV in the context of GBM.

Molecular Investigation of Human Cytomegalovirus and Epstein-Barr virus in Glioblastoma Brain Tumor: A Case-Control Study in Iran

Background: Glioblastoma multiforme is the most invasive and lethal form of brain cancer with unclear etiology. Our study aimed to investigate the molecular prevalence of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) infections in patients with glioblastoma multiforme (GBM). Methods: This case-control study was conducted on 42 FFPE brain tumor samples from GBM patients and 42 brain autopsies from subjects without neurological disorders. The presence of EBV and HCMV DNA was determined, using PCR and nested-PCR assays, respectively. Results: HCMV DNA was detected in 3 out of 42 (7.1%) of GBM samples and was absent from the control group (p = 0.07). Importantly, EBV DNA was detected in 9 out of 42 (21.4%) brain tissue specimens of GBM subjects, but again in none of the control group (p = 0.001). Conclusion: Our findings indicate that infection with EBV is associated with GBM.

High accumulation of Mx2 renders limited multiplication of oncolytic herpes simplex virus-1 in human tumor cells.

Increasing studies demonstrated that oncolytic activities of oHSV-1 are limited to the capacity of virus replicating in tumors. In order to potentiate the oHSV-1 oncolytic activity and expand the application of oHSV-1 treatment in multiple types of tumors, it is critical to explore the potential factors or mechanisms mediating tumor resistance to oHSV-1 infection. Here we evaluated the levels of oHSV-1 multiplication in various tumor cell lines and showed that glioblastoma cell line A172 had the lowest virus yields but intrinsically accumulated the highest levels of Mx2 protein. Subsequently we demonstrated that genetic depletion of Mx2 specifically enhanced oHSV-1 productive replication in A172 cells through promoting the nuclear translocation of uncoated viral genomic DNA and down-regulating innate antiviral response. In the further investigation, we found that Mx2 knockdown could alter the intrinsic mRNA accumulation of diverse sets innate immune genes in A172 cells, in particular DHX36 and MyD88. Mx2 depletion led to a decrease in mRNA levels of MyD88 and DHX36 in A172 cells and MyD88/DHX36 knockdown increased virus yield in A172 cells and decreased the production of IFNα, activation of IRF3 activity and NF-κB signaling in A172 cells. This shed new lights on understanding the roles of some intrinsic antiviral genes in oHSV-1 resistance, facilitating to offer potential targets to improve oHSV-1 oncolytic efficacy and develop candidates of biomarkers to predict the efficiency of oHSV-1 multiplication in tumors.

Zika virus replication in glioblastoma cells: electron microscopic tomography shows 3D arrangement of endoplasmic reticulum, replication organelles, and viral ribonucleoproteins.

Structural changes of two patient-derived glioblastoma cell lines after Zika virus infection were investigated using scanning transmission electron tomography on high-pressure-frozen, freeze-substituted samples. In Zika-virus-infected cells, Golgi structures were barely visible under an electron microscope, and viral factories appeared. The cytosol outside of the viral factories resembled the cytosol of uninfected cells. The viral factories contained largely deranged endoplasmic reticulum (ER), filled with many so-called replication organelles consisting of a luminal vesicle surrounded by the ER membrane. Viral capsids were observed in the vicinity of the replication organelles (cell line #12537 GB) or in ER cisternae at large distance from the replication organelles (cell line #15747 GB). Near the replication organelles, we observed many about 100-nm-long filaments that may represent viral ribonucleoprotein complexes (RNPs), which consist of the RNA genome and N protein oligomers. In addition, we compared Zika-virus-infected cells with cells infected with a phlebovirus (sandfly fever Turkey virus). Zika virions are formed in the ER, whereas phlebovirus virions are assembled in the Golgi apparatus. Our findings will help to understand the replication cycle in the virus factories and the building of the replication organelles in glioblastoma cells.

Viral targeting of glioblastoma stem cells with patient-specific genetic and post-translational p53 deregulations.

Cancer therapy urges targeting of malignant subsets within self-renewing heterogeneous stem cell populations. We dissect the genetic and functional heterogeneity of human glioblastoma stem cells (GSCs) within patients by their innate responses to non-pathogenic mouse parvoviruses that are tightly restrained by cellular physiology. GSC neurospheres accumulate assembled capsids but restrict viral NS1 cytotoxic protein expression by an innate PKR/eIF2α-P response counteractable by electric pulses. NS1 triggers a comprehensive DNA damage response involving cell-cycle arrest, neurosphere disorganization, and bystander disruption of GSC-derived brain tumor architecture in rodent models. GSCs and cancer cell lines permissive to parvovirus genome replication require p53-Ser15 phosphorylation (Pp53S15). NS1 expression is enhanced by exogeneous Pp53S15 induction but repressed by wtp53. Consistently, patient-specific GSC subpopulations harboring p53 gain-of-function mutants and/or Pp53S15 are selective viral targets. This study provides a molecular foundation for personalized biosafe viral therapies against devastating glioblastoma and other cancers with deregulated p53 signaling.

Oncolytic H-1 parvovirus binds to sialic acid on laminins for cell attachment and entry.

H-1 parvovirus (H-1PV) is a promising anticancer therapy. However, in-depth understanding of its life cycle, including the host cell factors needed for infectivity and oncolysis, is lacking. This understanding may guide the rational design of combination strategies, aid development of more effective viruses, and help identify biomarkers of susceptibility to H-1PV treatment. To identify the host cell factors involved, we carry out siRNA library screening using a druggable genome library. We identify one crucial modulator of H-1PV infection: laminin γ1 (LAMC1). Using loss- and gain-of-function studies, competition experiments, and ELISA, we validate LAMC1 and laminin family members as being essential to H-1PV cell attachment and entry. H-1PV binding to laminins is dependent on their sialic acid moieties and is inhibited by heparin. We show that laminins are differentially expressed in various tumour entities, including glioblastoma. We confirm the expression pattern of laminin γ1 in glioblastoma biopsies by immunohistochemistry. We also provide evidence of a direct correlation between LAMC1 expression levels and H-1PV oncolytic activity in 59 cancer cell lines and in 3D organotypic spheroid cultures with different sensitivities to H-1PV infection. These results support the idea that tumours with elevated levels of γ1 containing laminins are more susceptible to H-1PV-based therapies.

Evidence for residual SARS-CoV-2 in glioblastoma tissue of a convalescent patient.

Since coronavirus disease 2019 (COVID-19) swept all over the world, several studies have shown the susceptibility of a patient with cancer to COVID-19. In this case, the removed glioblastoma multiforme (GBM)-adjacent (GBM-A), GBM-peritumor and GBM-central (GBM-C) tissues from a convalescent patient of COVID-19, who also suffered from glioblastoma meanwhile, together with GBM-A and GBM tissues from a patient without COVID-19 history as negative controls, were used for RNA ISH, electron microscopy observing and immunohistochemical staining of ACE2 and the virus antigen (N protein). The results of RNA ISH, electron microscopy observing showed that SARS-CoV-2 directly infects some cells within human GBM tissues and SARS-CoV-2 in GBM-C tissue still exists even when it is cleared elsewhere. Immunohistochemical staining of ACE2 and N protein showed that the expressions of ACE2 are significantly higher in specimens, including GBM-C tissue from COVID-19 patient than other types of tissue. The unique phenomenon suggests that the surgical protection level should be upgraded even if the patient is in a convalescent period and the pharyngeal swab tests show negative results. Furthermore, more attention should be paid to confirm whether the shelter-like phenomenon happens in other malignancies due to the similar microenvironment and high expression of ACE2 in some malignancies.

Cytomegalovirus infection of glioblastoma cells leads to NF-κB dependent upregulation of the c-MET oncogenic tyrosine kinase.

Cytomegalovirus (CMV) is widespread in humans and has been implicated in glioblastoma (GBM) and other tumors. However, the role of CMV in GBM remains poorly understood and the mechanisms involved are not well-defined. The goal of this study was to identify candidate pathways relevant to GBM that may be modulated by CMV. Analysis of RNAseq data after CMV infection of patient-derived GBM cells showed significant upregulation of GBM-associated transcripts including the MET oncogene, which is known to play a role in a subset of GBM patients. These findings were validated in vitro in both mouse and human GBM cells. Using immunostaining and RT-PCR in vivo, we confirmed c-MET upregulation in a mouse model of CMV-driven GBM progression and in human GBM. siRNA knockdown showed that MET upregulation was dependent on CMV-induced upregulation of NF-κB signaling. Finally, proneural GBM xenografts overexpressing c-MET grew much faster in vivo than controls, suggesting a mechanism by which CMV infection of tumor cells could induce a more aggressive mesenchymal phenotype. These studies implicate the CMV-induced upregulation of c-MET as a potential mechanism involved in the effects of CMV on GBM growth.

Susceptibility of neuroblastoma and glioblastoma cell lines to SARS-CoV-2 infection.

Modelling cell infection in-a-dish can represent a useful tool to understand the susceptibility of different cell types towards severe acute respiratory coronavirus-2 (SARS-CoV-2) and to decipher its neurotropism. In this perspective, retinoic acid (RA)-differentiated neuroblastoma cell lines, SH-SY5Y and SK-N-BE(2) and glioblastoma cell lines, U-87 MG and U-373 MG, were infected with a SARS-CoV-2 strain, at various multiplicity-of-infection (MOI). We first demonstrated that the common entry genes - needed for invading epithelial cells - were expressed. RA-differentiation induced an upregulation of ace2 and tmprss2 gene expression while inducing downregulation of ctsb and ctsl. Using in situ hybridization and confocal analysis, SARS-CoV-2 gene S RNA was detected intracellularly at MOI 5.0, and localized in both soma and neuritic-like or glial-like processes. The infection was confirmed by quantification of viral gene E RNA and showed a dose-dependency, with few infected cells at MOI 0.1. After 24 h of infection, no cytopathic effect was observed in SH-SY5Y abilities to maintain neuritic processes or in U-373 MG for the uptake of glutamate. Unlike the permissive Vero E6 cells, no significant apoptosis death was detected following SARS-CoV-2 infection of neuroblastoma or glioblastoma cells. This study demonstrates the susceptibility of neuronal- and glial-like cell lines towards SARS-CoV-2 infection at high MOIs. Once inside the cells, the virus does not seem to rapidly replicate nor exert major cytopathic effect. Overall, our results strengthen the idea that SARS-CoV-2 has a tropism for nervous cells that express commonly described entry genes.