Oncolytic Research Articles

Synergistic anti-tumor effects of oncolytic virus and anti-programmed cell death protein 1 antibody combination therapy: For suppression of lymph node and distant metastasis in a murine melanoma model

Synergistic anti-tumor effects of oncolytic virus and anti-programmed cell death protein 1 antibody combination therapy: For suppression of lymph node and distant metastasis in a murine melanoma model

Vaccinia virus-mediated oncolytic immunotherapy: emerging strategies for gastrointestinal cancer treatment at dawn

Vaccinia virus-mediated oncolytic immunotherapy: emerging strategies for gastrointestinal cancer treatment at dawn

Oncolytic virus and CAR-T cell therapy in solid tumors.

Adoptive immunotherapy with T cells, genetically modified to express a tumor-reactive chimeric antigen receptor (CAR), is an innovative and rapidly developing life-saving treatment for cancer patients without other therapeutic opportunities. CAR-T cell therapy has proven effective only in hematological malignancies. However, although by now only a few clinical trials had promising outcomes, we predict that CAR-T therapy will eventually become an established treatment for several solid tumors. Oncolytic viruses (OVs) can selectively replicate in and kill cancer cells without harming healthy cells. They can stimulate an immune response against the tumor, because OVs potentially stimulate adaptive immunity and innate components of the host immune system. Using CAR-T cells along with oncolytic viruses may enhance the efficacy of CAR-T cell therapy in destroying solid tumors by increasing the tumor penetrance of T cells and reducing the immune suppression by the tumor microenvironment. This review describes recent advances in the design of oncolytic viruses and CAR-T cells while providing an overview of the potential combination of oncolytic virotherapy with CAR-T cells for solid cancers. In this review, we will focus on the host-virus interaction in the tumor microenvironment to reverse local immunosuppression and to develop CAR-T cell effector function.

Oncolytic viruses: a potential breakthrough immunotherapy for multiple myeloma patients.

Oncolytic virotherapy represents an innovative and promising approach for the treatment of cancer, including multiple myeloma (MM), a currently incurable plasma cell (PC) neoplasm. Despite the advances that new therapies, particularly immunotherapy, have been made, relapses still occur in MM patients, highlighting the medical need for new treatment options. Oncolytic viruses (OVs) preferentially infect and destroy cancer cells, exerting a direct and/or indirect cytopathic effect, combined with a modulation of the tumor microenvironment leading to an activation of the immune system. Both naturally occurring and genetically modified viruses have demonstrated significant preclinical effects against MM cells. Currently, the OVs genetically modified measles virus strains, reovirus, and vesicular stomatitis virus are employed in clinical trials for MM. Nevertheless, significant challenges remain, including the efficiency of the virus delivery to the tumor, overcoming antiviral immune responses, and the specificity of the virus for MM cells. Different strategies are being explored to optimize OV therapy, including combining it with standard treatments and targeted therapies to enhance efficacy. This review will provide a comprehensive analysis of the mechanism of action of the different OVs, and preclinical and clinical evidence, focusing on the role of oncolytic virotherapy as a new possible immunotherapeutic approach also in combination with the current therapeutic armamentarium and underlying the future directions in the context of MM treatments.

Perceptions of Cancer Through the Ages—From Hippocratic Oncology to Precision Cancer Medicine

The unravelling of the human genome created new perceptions of the origin and evolution of diseases, and for cancer in particular, it established the notion that neoplasia has been a companion of life since its appearance on Earth. It is not surprising that neoplasms, in various forms, develop in numerous species of animals and even in plants. Unmistakable accounts of cancer with clinical features as are understood today begin in the 5th c. B.C. The principles and practice of the Hippocratic and Galenic tradition dominated cancer care virtually into the 20th century. Advanced sequencing technologies at the dawn of the 21st century generated new therapeutic opportunities with immunotherapy, oncolytic virotherapy, and gene transfer, with the latter especially being used in cases of hereditary cancer.

The Application of CRISPR/Cas9 in Cancer Immunotherapy

Currently, Cancer is the number one killer of human health. The death rate from cancer is increasing year over year as the population ages and grows, particularly since 2019, when there were almost 10 million cases globally recorded by the World Health Organization every year. In light of this trend, it is imperative to continue developing medications and to update and iterate on anti-cancer therapeutic technologies. CAR-T cell therapy, microphage-based therapy, oncolytic virotherapy, and checkpoint blockade therapy are the most popular cancer treatments, but a few patients still cannot tolerate these therapies. A post-optimized strategy is to use gene editing to alter the characteristics of cancer treatment. New therapeutic options for the treatment of complex disorders have become available with the development of CRISPR/Cas9 gene editing technology in recent years. This method is widely used in market research for gene knockdown, endogenous gene expression, and chromosome locus markers because of its accuracy and efficiency in processing harmful gene fragments. Also, it is extremely valuable from a medical standpoint when researching immunomodulator resistance. Despite its great potential, there remain concerns over the technology’s usefulness and efficacy and negative prognostic reactions. This review primarily focuses on the current use of CRISPR/Cas9 in cancer immunotherapies.

Advances in Cancer Treatment: Harnessing Antibody-Drug Conjugates and Oncolytic Viruses for Targeted Therapy

Effective cancer treatment remains a major challenge due to its heterogeneity and complexity. However, emerging therapies such as antibody-drug conjugates (ADCs) and oncolytic viruses show great potential in leveraging the body's natural defenses to selectively target and destroy cancer cells. These promising treatments have demonstrated encouraging results in clinical trials, and ongoing research and development are expected to further enhance their efficacy and improve patient outcomes.

Novel Immunotherapeutics for the Treatment of Non-Small Cell Lung Cancer (NSCLC) Resistant to PD-1/PD-L1 Inhibitors.

Immunotherapy with PD-1/PD-L1 inhibitors is the standard method of care for the treatment of newly diagnosed advanced or metastatic NSCLC, with or without chemotherapy. Many tumors, however, develop resistance to these immunotherapy agents. There is a need to develop more effective therapies for patients with metastatic NSCLC in the second-line setting and beyond. In this review, we present an overview of novel immunotherapies being investigated regarding the treatment of these patients. We summarize completed, as well as ongoing, trials investigating these therapies as monotherapy or in combination with PD-1/PD-L1 inhibitors. These include immune co-stimulatory antibodies, T-cell agonists, oncolytic viruses, vaccines, TIL therapies, and CAR-T therapies.

Therapeutic advances in hepatocellular carcinoma: an update from the 2024 ASCO annual meeting.

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related deaths worldwide. Recent advances in immunotherapies, targeted therapies, and combination treatments have significantly improved outcomes for many patients with HCC. This review summarizes key findings from the 2024 ASCO Annual Meeting, focusing on emerging therapies, including immune checkpoint inhibitors (ICIs), CAR-T cell therapies, oncolytic viruses, and locoregional treatments like transarterial chemoembolization (TACE) and hepatic arterial infusion chemotherapy (HAIC). ICIs, particularly when combined with other agents, have shown promising efficacy, though challenges such as immune-related adverse events and resistance mechanisms remain. CAR-T cell therapies and oncolytic viruses offer novel therapeutic avenues for advanced HCC, but their long-term efficacy in solid tumors is still under investigation. Locoregional therapies, especially in combination with systemic treatments, continue to play a critical role in managing unresectable HCC and improving conversion rates to surgical resection. Additionally, the potential of biomarkers, such as hypoxia scores and CTNNB1 mutations, is being explored to better personalize treatment and predict patient responses. These biomarkers could pave the way for more targeted and effective therapeutic strategies. Overall, the recent studies presented at the ASCO meeting highlight progress in HCC treatment, underscoring the importance of continued innovation. Future research should focus on overcoming resistance mechanisms, optimizing combination therapies, and integrating biomarker-driven approaches to improve patient outcomes and enhance personalized treatment strategies.

Enhanced Antitumor Efficacy of Oncolytic Vaccinia Virus Therapy Through Keratin-Mediated Delivery in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) represents an aggressive subtype characterized by high rates of recurrence and metastasis, necessitating the exploration of alternative treatment strategies. Oncolytic vaccinia virus (OVV) therapy has emerged as a promising approach, selectively infecting and destroying tumor cells. However, its efficacy is often hampered by inadequate viral distribution within the tumor microenvironment. Here, we investigate the potential of keratin (KTN) as a carrier for OVV delivery to enhance viral distribution and antitumor efficacy. In vitro assays revealed that KTN significantly improves OVV stability, leading to increased tumor cell apoptosis and necrosis. Furthermore, KTN effectively inhibits cancer cell migration by suppressing the epithelial-mesenchymal transition (EMT) process and downregulating metastasis-related proteins. These findings are corroborated in a syngeneic TNBC mouse model, where KTN-mediated OVV delivery enhances cytotoxic T cell-mediated antitumor immune responses without compromising the anti-angiogenic effects of the virus. Notably, KTN alone exhibits antitumor effects by suppressing tumor growth and metastasis, underscoring its potential as a standalone therapeutic agent. In conclusion, our study underscores the promise of KTN-mediated OVV delivery as a promising therapeutic strategy for TNBC. By improving viral distribution, suppressing EMT, and enhancing antitumor immunity, this approach holds significant potential for enhancing patient outcomes in TNBC treatment. Further investigation is warranted to explore the broader utility of KTN in various cancer therapy approaches.

Oral reovirus reshapes the gut microbiome and enhances antitumor immunity in colon cancer

The route of oncolytic virotherapy is pivotal for immunotherapeutic efficacy in advanced cancers. In this preclinical study, an oncolytic reovirus (RC402) is orally administered to induce antitumor immunity. Oral reovirus treatment shows no gross toxicities and effectively suppresses multifocal tumor lesions. Orally administered reovirus interacts with the host immune system in the Peyer’s patch of the terminal ileum, increases IgA+ antibody-secreting cells in the lamina propria through MAdCAM-1+ blood vessels, and reshapes the gut microbiome. Oral reovirus promotes antigen presentation, type I/II interferons, and T cell activation within distant tumors, but does not reach or directly infect tumor cells beyond the gastrointestinal tract. In contrast to intratumoral reovirus injection, the presence of the gut microbiome, Batf3+ dendritic cells, type I interferons, and CD8+ T cells are indispensable for orally administered reovirus-induced antitumor immunity. Oral reovirus treatment is most effective when combined with αPD-1(L1) and/or αCTLA-4, leading to complete colon tumor regression and protective immune memory. Collectively, oral reovirus virotherapy is a feasible and effective immunotherapeutic strategy in preclinical studies.

Entry of Newcastle disease virus into host cells: an interplay among viral and host factors.

Newcastle disease (ND) is a major burden for the poultry industry worldwide, especially in developing countries. The virus that causes this disease, Newcastle disease virus (NDV), is also an effective vector for the development of novel human and animal vaccines and a promising oncolytic virus for cancer therapy. The mechanism of entry of NDV into host cells is of particular interest because it has a significant impact on the infectivity, host range, and pathogenicity of the virus. Here, we present an overview of the entry of NDV into cells, focusing on the interplay among viral and host factors involved in this process. In particular, recent research revealing novel features of NDV attachment to cells, the identification of viral and cellular components that regulate binding of the virus to cells, and the emerging role of novel cellular routes of NDV entry are discussed. More importantly, some of the remaining gaps in our understanding of NDV entry and some fundamental questions for research efforts in the future are also highlighted.

Oncolytic Coxsackievirus B3 Strain PD-H Is Effective Against a Broad Spectrum of Pancreatic Cancer Cell Lines and Induces a Growth Delay in Pancreatic KPC Cell Tumors In Vivo

Pancreatic cancer is one of the deadliest cancers globally, with limited success from existing therapies, including chemotherapies and immunotherapies like checkpoint inhibitors for patients with advanced pancreatic ductal adenocarcinoma (PDAC). A promising new approach is the use of oncolytic viruses (OV), a form of immunotherapy that has been demonstrated clinical effectiveness in various cancers. Here we investigated the potential of the oncolytic coxsackievirus B3 strain (CVB3) PD-H as a new treatment for pancreatic cancer. In vitro, PD-H exhibited robust replication, as measured by plaque assays, and potent lytic activity, as assessed by XTT assays, in most pancreatic tumor cell lines, outperforming two other coxsackievirus strains tested, H3N-375/1TS and CVA21. Thus, H3N-375/1TS showed efficient replication and lytic efficiency in distinctly fewer tumor cell lines, while most tumor cells were resistant to CVA21. The oncolytic efficiency of the three OV largely correlated with mRNA expression levels of viral receptors and their ability to induce apoptosis, as measured by cleaved caspase 3/7 activity in the tumor cells. In a syngeneic mouse model with subcutaneous pancreatic tumors, intratumoral administration of PD-H significantly inhibited tumor growth but did not completely stop tumor progression. Importantly, no virus-related side effects were observed. Although pancreatic tumors respond to PD-H treatment, its therapeutic efficacy is limited. Combining PD-H with other treatments, such as those aiming at reducing the desmoplastic stroma which impedes viral infection and spread within the tumor, may enhance its efficacy.

Genetic Factors Associated with Clinical Response in Melanoma Patients Treated with Talimogene Laherparapvec: A Single-Institution Retrospective Analysis.

Talimogene laherparapvec (T-VEC) is a modified herpes simplex virus type 1 (HSV-1) and the first oncolytic virus to be approved for the treatment of unresectable melanoma. We assessed whether there are tumor-intrinsic genetic factors that are associated with tumor control. A single-institution, retrospective analysis of melanoma patients treated with T-VEC was performed. Demographics, histopathologic reports, treatment history, clinical outcomes, and tumor genomic analysis of approximately 100 genes were collected. Ninety-three patients who had received T-VEC were identified, of whom 84 (91%) were diagnosed with cutaneous melanoma. Sixty-nine (69) patients received more than one dose of T-VEC and had sufficient data available for clinical analysis. Of these patients 30.0% (n=21) had evidence of a complete response, defined as complete regression of all lesions without the need for additional treatment or procedures. Stage III disease (p<0.001), absence of macroscopic nodal disease (p<0.001), and absence of visceral/central nervous system metastases (p=0.004) were all associated with evidence of any clinical response or local control by univariate analysis. At the time of analysis, 54 patients had tumor genetic data available. Sixty genes were mutated in at least one patient, and all but one patient had at least one gene mutation identified. Presence of TERT promotor mutation was associated with evidence of any clinical response (p=0.043) or local control (p=0.039) by multivariate analysis. This work describes the experience using T-VEC in melanoma at a single institution and highlights the presence of TERT promotor mutations as a possible driver of clinical response.

Generalized Hamiltonian and Lagrangian aspects of a model for virus–tumor interaction in oncolytic virotherapy

We analyze the generalized Hamiltonian structure of a system of first‐order ordinary differential equations for the Jenner et al. system (Letters in Biomathematics 5 (2018), no. S1, S117–S136). The system of equations is used for modeling the interaction of an oncolytic virus with a tumor cell population. Our analysis is based on the existence of a Jacobi last multiplier and a time‐dependent first integral. Suitable conditions on the model parameters allow for the reduction of the problem to a planar system of equations, and the time‐dependent Hamiltonian flows are described. The geometry of the Hamiltonian flows is also investigated using the symplectic and cosymplectic methods.

Oncolytic Viruses as Reliable Adjuvants in CAR-T Cell Therapy for Solid Tumors

Although impactful scientific advancements have recently been made in cancer therapy, there remains an opportunity for future improvements. Immunotherapy is perhaps one of the most cutting-edge categories of therapies demonstrating potential in the clinical setting. Genetically engineered T cells express chimeric antigen receptors (CARs), which can detect signals expressed by the molecules present on the surface of cancer cells, also called tumor-associated antigens (TAAs). Their effectiveness has been extensively demonstrated in hematological cancers; therefore, these results can establish the groundwork for their applications on a wide range of requirements. However, the application of CAR-T cell technology for solid tumors has several challenges, such as the existence of an immune-suppressing tumor microenvironment and/or inadequate tumor infiltration. Consequently, combining therapies such as CAR-T cell technology with other approaches has been proposed. The effectiveness of combining CAR-T cell with oncolytic virus therapy, with either genetically altered or naturally occurring viruses, to target tumor cells is currently under investigation, with several clinical trials being conducted. This narrative review summarizes the current advancements, opportunities, benefits, and limitations in using each therapy alone and their combination. The use of oncolytic viruses offers an opportunity to address the existing challenges of CAR-T cell therapy, which appear in the process of trying to overcome solid tumors, through the combination of their strengths. Additionally, utilizing oncolytic viruses allows researchers to modify the virus, thus enabling the targeted delivery of specific therapeutic agents within the tumor environment. This, in turn, can potentially enhance the cytotoxic effect and therapeutic potential of CAR-T cell technology on solid malignancies, with impactful results in the clinical setting.

Transcriptome profiling of Canine Parvovirus 2 Nonstructural gene 1(CPV2.NS1) transfected 4T1 mice mammary tumor cells to elucidate its oncolytic effects

Oncolytic viral gene therapy is a directed approach to target cancer cells without affecting healthy cells of the body. Canine parvovirus (CPV2) is an oncolytic virus that precisely targets and destroys neoplastic cells by causing DNA damage, mitochondrial damage, and apoptosis. Non-structural gene 1 (NS1) of CPV, concerned with viral DNA replication is a key mediator of cytotoxicity of CPV and can specifically cause tumor cell lysis. In the present study, by using the transcriptomics approach, we tried to identify molecular pathways and key genes involved in CPV2.NS1 mediated 4T1 mice mammary tumor cell death. We identified necroptosis and mitochondrial damage-mediated apoptosis as major cell death pathways leading to CPV2.NS1 transfected 4T1 cancer cell death. Various DEGs identified in our study play an important role in pathways like the PI3K/AKT pathway, diverse metabolic pathways, MAPK signaling pathway, and FGF signaling pathway, whichare mostly dysregulated in cancerous conditions. Histone variant H2A.X genes, Capn2, and Mapk10/JNK are predicted as key genes that play a role in causing endoplasmic reticulum stress and mitochondrial damage, thereby leading to necroptosis and apoptosis. This study is a preliminary work done to identify key genes and molecular pathways involved in CPV2.NS1 mediated 4T1 cancer cells death which need to be further validated to establish this viral gene as a potent oncolytic agent.

Interleukin-12 Delivery Strategies and Advances in Tumor Immunotherapy.

Interleukin-12 (IL-12) is considered to be a promising cytokine for enhancing an antitumor immune response; however, recombinant IL-12 has shown significant toxicity and limited efficacy in early clinical trials. Recently, many strategies for delivering IL-12 to tumor tissues have been developed, such as modifying IL-12, utilizing viral vectors, non-viral vectors, and cellular vectors. Previous studies have found that the fusion of IL-12 with extracellular matrix proteins, collagen, and immune factors is a way to enhance its therapeutic potential. In addition, studies have demonstrated that viral vectors are a good platform, and a variety of viruses such as oncolytic viruses, adenoviruses, and poxviruses have been used to deliver IL-12-with testing previously conducted in various cancer models. The local expression of IL-12 in tumors based on viral delivery avoids systemic toxicity while inducing effective antitumor immunity and acting synergistically with other therapies without compromising safety. In addition, lipid nanoparticles are currently considered to be the most mature drug delivery system. Moreover, cells are also considered to be drug carriers because they can effectively deliver therapeutic substances to tumors. In this article, we will systematically discuss the anti-tumor effects of IL-12 on its own or in combination with other therapies based on different delivery strategies.

Anticancer effect of the oncolytic Newcastle disease virus harboring the PTEN gene on glioblastoma.

Glioblastoma (GBM) is one of the most lethal types of human brain cancer and is characterized by rapid growth, an aggressive nature and a poor prognosis. GBM is highly heterogeneous, and often involves several genetic mutations and abnormalities. Genetic disorders or low expression of phosphatase and tensin homolog (PTEN) are associated with GBM occurrence, progression and poor prognosis of patients with GBM. However, effective delivery of PTEN for expression in GBM cells within the brain remains challenging. The aim of the present study was to develop a therapeutic strategy to restore PTEN expression in GBM cells by utilizing a recombinant Newcastle disease virus (rNDV) vector expressing the human PTEN gene (rNDV-PTEN). Methods included infection of U87-MG cells with rNDV-PTEN, followed by assessments of PTEN expression, and cell proliferation, migration and apoptosis. Additionally, an orthotopic GBM mouse model was used to evaluate the in vivo efficacy of rNDV-PTEN. Infection with recombinant rNDV-PTEN treatment increased PTEN protein expression in the cytoplasm of the U87-MG cells, reduced cell proliferation and migration, and induced apoptosis by inhibiting the AKT/mTOR signaling pathway. In the orthotopic GBM mouse model, rNDV-PTEN significantly reduced tumor size and improved survival rates. Magnetic resonance imaging and in vivo imaging analyses confirmed the targeted delivery and efficacy of rNDV-PTEN. These findings highlight the usefulness of rNDV-PTEN as a promising therapeutic agent for GBM, representing a potential advancement in treatment, especially for patients with PTEN deficiency.

A bibliometric analysis of oncolytic virotherapy combined with immunotherapy

ABSTRACT Oncolytic virotherapy in combination with immunotherapy has demonstrated significant survival benefits in some types of cancer. Here, we summarized the development, research hotpots and potential trends of the combination therapy using visual bibliometric analysis. A total of 712 articles were retrieved on June 21, 2023. The USA was the top contributors of any country (325, 45.65%), and the Rluk Research Libraries UK ranked first (43, 6.03%) of any institutions. The Journal for ImmunoTherapy of Cancer was with the largest publications (60, 8.43%). ‘Tumor microenvironment’ and ‘delivery’ were citation keywords with the strongest ongoing bursts. Research fronts in the future may focus on the methods of virus delivery and tumor microenvironment modulation. Futhermore, the most extensively studied cancer were melanoma, glioma and hepatocellular carcinoma.