Project description:Despite the proven safety of oncolytic viruses (OV) in clinical trials for glioblastoma (GBM), their efficacy has been hindered by suboptimal spreading within the tumor. We show that hyaluronan or hyaluronic acid (HA), an important component of extracellular matrix (ECM), is highly expressed in a majority of tumor xenografts established from patient-derived GBM lines that present both invasive and nodular phenotypes. Intratumoral injection of a conditionally replicating adenovirus expressing soluble hyaluronidase (ICOVIR17) into nodular GBM, mediated HA degradation and enhanced viral spread, resulting in a significant antitumor effect and mice survival. In an effort to translate OV-based therapeutics into clinical settings, we encapsulated human adipose-derived mesenchymal stem cells (MSC) loaded with ICOVIR17 in biocompatible synthetic extracellular matrix (sECM) and tested their efficacy in a clinically relevant mouse model of GBM resection. Compared with direct injection of ICOVIR17, sECM-MSC loaded with ICOVIR17 resulted in a significant decrease in tumor regrowth and increased mice survival. This is the first report of its kind revealing the expression of HA in GBM and the role of OV-mediated HA targeting in clinically relevant mouse model of GBM resection and thus has clinical implications.
Project description:BackgroundHuman papillomavirus (HPV)-associated malignancy remain a main cause of cancer in men and women. Cancer immunotherapy has represented great potential as a new promising cancer therapeutic approach. Here, we report Mesenchymal stem cells (MSCs) as a carrier for the delivery of oncolytic Newcastle disease virus (NDV) for the treatment of HPV-associated tumor.MethodsFor this purpose, MSCs obtained from the bone marrow of C57BL mice, then cultured and characterized subsequently by the flow cytometry analysis for the presence of cell surface markers. In this study, we sought out to determine the impacts of MSCs loaded with oncolytic NDV on splenic T cell and cytokine immune responses, caspase-3 and -9 expression, and myeloid and myeloid-derived suppressor cells (MDSCs) by histological and immunohistochemical studies in the tumor microenvironment (TME).ResultsOur findings proved that MSCs possess both migratory capacity and tumor tropism toward transplanted tumor tissue after peritumoral administration. Tumor therapy experiments indicated that oncolytic NDV delivered by MSCs-engineered system significantly reduces tumor growth, which is associated with the enhancement of E7-specific lymphocyte proliferation, CD8+ T cell cytolysis responses, and splenic IFN-?, IL-4 and IL-12 responses compared with control groups. Moreover, the treatment upregulated the concentration of apoptotic proteins (caspase 9) and increased infiltration of tumor microenvironment with CD11b?+?myeloid and Gr1?+?MDSCs cells.ConclusionsOur data suggest MSCs carrying oncolytic NDV as a potentially effective strategy for cancer immunotherapy through inducing splenic Th1 immune responses and apoptosis in the tumor microenvironment.
Project description:Oncolytic viruses (OV) are promising forms of immunotherapy that have demonstrated clinical benefit in difficult-to-treat cancers such as metastatic melanoma. However, their adoption in other malignancies has been limited, in part, due to poorly understood mechansims of therapeutic resistance. Here, bulk RNA-seq was performed on oncolytic vaccinia virus-sensitive and -resistant murine head and neck squamous cell carcinomas (MEERvvS and MEERvvR, respectively) to explore potential means of OV resistance. These results corroborated a potential role for TGF-beta mediated stabilization of immunosuppressive regulatory T cells in the tumor microenvironment of OV-resistant MEERvvR-bearing mice. Subsequently, treatment with oncolytic vaccinia virus engineered to expess a dominant negative TGF-β signaling inhibitor (VVtgfbi) restored sensitivity to OV-mediated cell death among MEERvvR tumors. Single-cell RNA seq performed on CD45+ immune cells isolated from tumors suggests TGF-β inhibition may also reduce the presence and activity of myeloid-derived suppressor cell populations within the tumor microenvironment.
Project description:Cancer stem cells (CSCs) represent a distinct subpopulation of cancer cells which are shown to be relatively resistant to conventional anticancer therapies and have been correlated to disease recurrence. Oncolytic viruses utilize methods of cell killing that differ from traditional therapies and thus are able to elude the typical mechanisms that CSCs use to resist current chemotherapies and radiotherapies. Moreover, genetically engineered oncolytic viruses may further augment the oncolytic effects. Here we review the recent data regarding the ability of several oncolytic viruses to eradicate CSCs.
Project description:Only a subset of cancer patients inoculated with oncolytic herpes simplex virus (oHSV) type-1 has shown objective response in phase 1 and 2 clinical trials. This has raised speculations whether resistance of tumor cells to oHSV therapy may be a limiting factor. In this study, we have identified established and patient derived primary glioblastoma multiforme (GBM) stem cell lines (GSC) resistant to oHSV and also to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) that has recently shown promise in preclinical and initial clinical studies. We created a recombinant oHSV bearing a secretable TRAIL (oHSV-TRAIL) and hypothesized that oHSV-TRAIL could be used as a cancer therapeutic to target a broad spectrum of resistant tumors in a mechanism-based manner. Using the identified resistant GBM lines, we show that oHSV-TRAIL downregulates extracellular signal-regulated protein kinase (ERK)-mitogen-activated protein kinase (MAPK) and upregulates c-Jun N-terminal kinase (JNK) and p38-MAPK signaling, which primes resistant GBM cells to apoptosis via activation of caspase-8, -9, and -3. We further show that oHSV-TRAIL inhibits tumor growth and invasiveness and increases survival of mice bearing resistant intracerebral tumors without affecting the normal tissues. This study sheds new light on the mechanism by which oHSV and TRAIL function in concert to overcome therapeutic-resistance, and provides an oncolytic virus based platform to target a broad spectrum of different cancer types.
Project description:Glioblastoma is a highly lethal brain cancer that frequently recurs in proximity to the original resection cavity. We explored the use of oncolytic virus therapy against glioblastoma with Zika virus (ZIKV), a flavivirus that induces cell death and differentiation of neural precursor cells in the developing fetus. ZIKV preferentially infected and killed glioblastoma stem cells (GSCs) relative to differentiated tumor progeny or normal neuronal cells. The effects against GSCs were not a general property of neurotropic flaviviruses, as West Nile virus indiscriminately killed both tumor and normal neural cells. ZIKV potently depleted patient-derived GSCs grown in culture and in organoids. Moreover, mice with glioblastoma survived substantially longer and at greater rates when the tumor was inoculated with a mouse-adapted strain of ZIKV. Our results suggest that ZIKV is an oncolytic virus that can preferentially target GSCs; thus, genetically modified strains that further optimize safety could have therapeutic efficacy for adult glioblastoma patients.
Project description:Pediatric high-grade glioma (pHGG) and diffuse intrinsic pontine glioma (DIPG) are invasive tumors with poor survival. Oncolytic virotherapy, initially devised as a direct cytotoxic treatment, is now also known to act via immune-mediated mechanisms. Here we investigate a previously unreported mechanism of action: the inhibition of migration and invasion in pediatric brain tumors. We evaluated the effect of oncolytic herpes simplex virus 1716 (HSV1716) on the migration and invasion of pHGG and DIPG both in vitro using 2D (scratch assay, live cell imaging) and 3D (spheroid invasion in collagen) assays and in vivo using an orthotopic xenograft model of DIPG invasion. HSV1716 inhibited migration and invasion in pHGG and DIPG cell lines. pHGG cells demonstrated reduced velocity and changed morphology in the presence of virus. HSV1716 altered pHGG cytoskeletal dynamics by stabilizing microtubules, inhibiting glycogen synthase kinase-3, and preventing localized clustering of adenomatous polyposis coli (APC) to the leading edge of cells. HSV1716 treatment also reduced tumor infiltration in a mouse orthotopic xenograft DIPG model. Our results demonstrate that HSV1716 targets the migration and invasion of pHGG and DIPG and indicates the potential of an oncolytic virus (OV) to be used as a novel anti-invasive treatment strategy for pediatric brain tumors.
Project description:Celyvir (autologous mesenchymal cells -MSCs- that carry an oncolytic adenovirus) is a new therapeutic strategy for metastatic tumors developed by our research group over the last decade. There are limitations for studying the immune effects of human oncolytic adenoviruses in murine models since these viruses do not replicate naturally in these animals. The use of xenografts in immunodeficient mice prevent assessing important clinical aspects of this therapy such as the antiadenoviral immune response or the possible intratumoral immune changes, both of tumor infiltrating leukocytes and of the microenvironment. In our strategy, the presence of MSCs in the medicinal product adds an extra level of complexity. We present here a murine model that overcomes many of these limitations. We found that carrier cells outcompeted intravenous administration of naked particles in delivering the oncolytic virus into the tumor masses. The protection that MSCs could provide to the oncolytic adenovirus did not preclude the development of an antiadenoviral immune response. However, the presence of circulating antiadenoviral antibodies did not prevent changes detected at the tumor masses: increased infiltration and changes in the quality of immune cells per unit of tumor volume, and a less protumoral and more inflammatory profile of the tumor microenvironment. We believe that the model described here will enable the study of crucial events related to the immune responses affecting both the medicinal product and the tumor.
Project description:In preclinical studies, neural stem cell (NSC)-based delivery of oncolytic virus has shown great promise in the treatment of malignant glioma. Ensuring the success of this therapy will require critical evaluation of the spatial distribution of virus after NSC transplantation. In this study, the patient-derived GBM43 human glioma line was established in the brain of athymic nude mice, followed by the administration of NSCs loaded with conditionally replicating oncolytic adenovirus (NSC-CRAd-S-pk7). We determined the tumor coverage potential of oncolytic adenovirus by examining NSC distribution using magnetic resonance (MR) imaging and by three-dimensional reconstruction from ex vivo tissue specimens. We demonstrate that unmodified NSCs and NSC-CRAd-S-pk7 exhibit a similar distribution pattern with most prominent localization occurring at the tumor margins. We were further able to visualize the accumulation of these cells at tumor sites via T2-weighted MR imaging as well as the spread of viral particles using immunofluorescence. Our analyses reveal that a single administration of oncolytic virus-loaded NSCs allows for up to 31% coverage of intracranial tumors. Such results provide valuable insights into the therapeutic potential of this novel viral delivery platform.