Live attenuated measles viruses of the Edmonston lineage (MV-Edm) have potent anti-tumor activity but are not entirely tumor-specific owing to widespread distribution of their native receptors, CD46 and SLAM. We have therefore developed a pseudoreceptor system that allows rescue and propagation of fully retargeted viruses displaying single-chain antibody fragments. Viruses retargeted to tumor-selective CD38, epidermal growth factor receptor (EGFR) or EGFR mutant vIII (EGFRvIII) efficiently entered cells through their respective targeted receptors in vitro and in vivo, but not through CD46 and SLAM. When administered intratumorally or intravenously to mice bearing human CD38 or EGFR-positive human tumor xenografts, the targeted viruses demonstrated specific receptor-mediated anti-tumor activity. These data provide an in vivo demonstration of antibody-directed tumor destruction by retargeted oncolytic viruses.
The cellular tropisms of eukaryotic viruses are shaped by their need for entry receptors and intracellular transcription factors. Here we show that viral tropisms can also be regulated by tissue-specific microRNAs (miRNAs). Target sequences complementary to muscle-specific miRNAs were inserted into the 3' untranslated region (UTR) of an oncolytic picornavirus that causes lethal myositis in tumor-bearing mice. The recombinant virus still propagated in subcutaneous tumors, causing total regression and sustained viremia, but could not replicate in cells expressing complementary miRNAs and therefore did not cause myositis. This altered tropism was not due to insertional attenuation, as a control virus containing a 3' UTR insert with a disrupted miRNA target sequence fully retained its lethal myotropism. Tissue-specific destabilization of viral genomes by miRNA target insertion provides a potentially versatile new mechanism for controlling the tropism of replicating viruses for therapy and may serve as a new modality for attenuating viruses for vaccine purposes.
Multiple myeloma is a radiosensitive malignancy that is currently incurable. Here, we generated a novel recombinant vesicular stomatitis virus [VSV(⌬51) - IntroductionMultiple myeloma is a malignancy of antibody-secreting plasma cells that reside predominantly in bone and bone marrow and secrete a monoclonal immunoglobulin. 1 The disease responds initially to alkylating agents, corticosteroids, and thalidomide, but eventually becomes refractory. 2 Multiple myeloma remains incurable causing more than 10 000 deaths each year in the United States. 3 Although cultured myeloma cells are relatively resistant to radiotherapy in vitro, 4,5 the malignancy is highly radiosensitive and radiation therapy is routinely used for palliation of pain, neurologic compromise, or structural instability from focal myeloma deposits. Efforts to use radiation as a systemic modality for definitive therapy of myeloma, however, have been problematic because of collateral toxicity to normal tissues especially the bone marrow progenitor cells. 6,7 Developing novel therapies for multiple myeloma based on the targeted delivery of radioisotopes to sites of active disease may have important clinical implications for myeloma therapy.Gene transfer using the thyroidal sodium iodide symporter (NIS) gene offers a novel strategy for delivery of radionuclides to disseminated cancer cells. 8 NIS is a transmembrane protein in thyroid follicular cells that actively mediates iodide uptake to a concentration gradient more than 20 to 40-fold. 9 Cloning the human NIS cDNA has aided in imaging and therapy of dedifferentiated thyroid cancer and nonthyroid cancers such as glioma, neuroblastoma, melanoma, multiple myeloma, and ovarian, breast, cervix, lung, liver, and colon carcinoma. 10 Tissue-specific NIS expression has been achieved in various cancer xenografts with minimal toxicity to normal organs by using promoters and enhancers from genes encoding immunoglobulins, prostate-specific antigen, probasin, and mucin-1. [11][12][13][14][15][16] Cancer therapy using oncolytic viruses (oncolytic virotherapy) requires agents that amplify efficiently through replication and spread causing rapid tumor lysis, yet are safe causing minimal toxicity to normal tissue enabling systemic inoculations to treat metastatic cancers. 17,18 We previously engineered the NIS gene into a lymphotropic, replication-competent attenuated strain of measles virus (MV-NIS) 19 that was subsequently used for oncolytic virotherapy of myeloma xenografts. Intratumoral spread of MV-NIS could be monitored noninvasively by radioiodine imaging and virus-resistant tumors were ablated after administration of 131 I. 20 A phase I clinical trial to evaluate the targeting properties of MV-NIS in patients with recurrent or refractory myeloma is ongoing at our institution. Several RNA viruses other than measles virus, including reovirus, Newcastle disease virus, mumps virus, and vesicular stomatitis virus (VSV), are being developed as systemic oncolytic agents for cancer therapy. 18,21 Each of these viruses ...
Dexamethasone (Dex) and radiation therapy are established modalities in multiple myeloma. In this study, we propose a novel combination of Dex plus radiation that shows superior clonogenic cell killing and apoptosis of myeloma cells and selectively eliminates myeloma cells when cocultured with bone marrow stromal cells (BMSCs). Dex was found to inhibit the release of interleukin-6 from irradiated BMSCs, which is an established myeloma cell proproliferative cytokine. In 5TGM1 model, the combination of Dex with skeletal targeted radiotherapy (153-Sm-EDTMP) prolonged median survival time and inhibited radiation-induced myelosuppression. A two-cycle treatment of Dex plus 153-Sm-EDTMP was well tolerated and further improved median survival time. Mechanistically, Dex increased superoxide and hydrogen peroxide production and augmented radiation-induced oxidative stress and cell death of myeloma cells. In contrast, Dex inhibited radiation-induced increase in pro-oxidant levels and enhanced the clonogenic survival in normal hematopoietic stem and progenitor cells. Treatment with either N-acetylcysteine or the combination of polyethylene glycol (PEG)-conjugated copper, zinc-superoxide dismutase, and PEG-catalase significantly protected myeloma cells from Dex-induced clonogenic death. Overall, these results demonstrate that Dex in combination with radiotherapy enhances the killing of myeloma cells while protecting normal bone marrow hematopoiesis through a mechanism that involves selective increases in oxidative stress.
The oncolytic measles virus Edmonston strain (MV-Edm
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.