Search Results (84)

Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality. It usually arises in cirrhotic liver, where chronic inflammation and fibrosis create a tumor-permissive microenvironment. Dysregulation of microRNAs (miRNAs), particularly upregulation of the oncomiR miR-221 and loss of the tumor suppressor miR-199a-3p represent key drivers of liver carcinogenesis. The TG221 transgenic mouse, designed to overexpress miR-221 in hepatocytes, provides a relevant in vivo platform for mechanistic studies and for testing preventive and therapeutic approaches. The TG221 model recapitulates miR-221-driven tumorigenesis, including suppression of p27, p57 and Bmf. It is characterized by steatohepatitic injury and accelerated tumor formation after genotoxic challenge. In the cirrhotic CCl₄-induced background, TG221 mice develop fibrosis and cirrhosis followed by dysplastic and malignant lesions, mirroring the natural history of human HCC. Metformin administered during early fibrosis prevented macroscopic tumor formation and suppressed PI3K/AKT/mTOR signaling. Anti-miR-221 and miR-199a-3p mimics reduced tumor burden, restored tumor-suppressive pathways and improved liver integrity, thus indicating feasible chemopreventive strategies. From a therapeutic point of view, miR-199a-3p replacement synergized with palbociclib and overcame sorafenib resistance. A miR-199a-3p-responsive oncolytic adenovirus achieved tumor-selective replication with minimal toxicity. This review highlights the importance of the TG221 transgenic mouse as a powerful model for studying miRNA-driven hepatocarcinogenesis and enables preclinical evaluation of RNA-based chemopreventive and therapeutic approaches. Metformin, miRNA inhibition, miRNA replacement and miRNA-guided viral therapies emerge as promising approaches for advancing precision prevention and treatment strategies in HCC. Full article

The limited ability of the immune system to infiltrate solid tumors, attributed to the immunosuppressive tumor microenvironment (TME), remains a significant challenge in cancer therapy oncolytic adenovirus (OAd) that can directly kill tumor cells in addition to inducing both innate and adaptive immune responses. Therefore, the use of OAd to treat tumors is an appealing approach. In this study, we engineered an OAd armed with a human granulocyte–macrophage colony-stimulating factor (GM-CSF), controlled by the E2F promoter, Ad5/3-E2F-d24-GM-CSF (named OAd-Z1). The antitumor activity of OAd was tested in vitro and in vivo. These findings demonstrated that OAd expressed GM-CSF, replicated effectively in tumor cells, inhibited tumor growth, activated the de novo antitumor response, promoted apoptosis and immunogenic cell death in tumor cells, and increased cytokine and chemokine production both in vitro and in vivo. Additionally, OAd demonstrated an abscopal effect and stimulated T lymphocyte infiltration in vivo. Our findings demonstrate that OAd-Z1 represents promising immunotherapeutic candidates for lung cancer, with the potential to enhance systemic antitumor immunity. Full article

High-grade gliomas—particularly glioblastoma (GBM)—remain refractory to standard-of-care surgery followed by chemoradiation, with a median overall survival of ~15 months. Oncolytic viruses (OVs), which selectively infect and lyse tumor cells while engaging antitumor immunity, offer a mechanistically distinct therapeutic modality. This review synthesizes clinical progress of OVs in GBM, with emphasis on oncolytic herpes simplex virus (oHSV) and coverage of other vectors (adenovirus, reovirus, Newcastle disease virus, vaccinia virus) across phase I–III trials, focusing on efficacy and safety. Key observations include the encouraging clinical trajectory of oHSV exemplars—T-VEC (approved for melanoma) and G47Δ (approved in Japan for recurrent GBM)—the multi-center exploration of the adenovirus DNX-2401 combined with programmed death-1 (PD-1) blockade, and the early-stage status of reovirus (pelareorep) and Newcastle disease virus programs. Emerging evidence indicates that oHSV therapy augments immune infiltration within the tumor microenvironment and alleviates immunosuppression, with synergy when combined with chemotherapy or immune checkpoint inhibitors. Persistent challenges include GBM’s inherently immunosuppressive milieu, limitations imposed by the blood–brain barrier, intrapatient viral delivery and biodistribution, and concerns about viral shedding. Future directions encompass programmable vector design, optimization of systemic delivery, biomarker-guided patient selection, and rational combination immunotherapy. Collectively, OVs represent a promising immunotherapeutic strategy in GBM; further gains will hinge on vector engineering and precision combinations to translate mechanistic promise into durable clinical benefit. Full article

Background: Bladder cancer is the ninth most prevalent cancer globally. Most cases are urothelial carcinoma, classified as non-muscle invasive bladder cancer (NMIBC) or muscle invasive bladder cancer (MIBC); approximately 70% are diagnosed as NMIBC. Current standard of care for high-risk NMIBC includes transurethral tumour resection, followed by intravesical therapy with Bacillus Calmette-Guérin (BCG). However, significant unmet needs persist due to disease recurrence, BCG unresponsiveness, or progression to MIBC. Radical cystectomy is recommended after BCG unresponsiveness but may not be viable due to its invasiveness and morbidity. The paucity of treatment options for BCG-unresponsive NMIBC has driven research into alternatives such as gene therapy. The bladder’s anatomy allows direct vector–tumour contact, while urine and tissue samples allow for easy monitoring of therapeutic effects. Methods: This narrative review integrates findings from recent clinical and preclinical studies identified through comprehensive searches of peer-reviewed literature to provide an overview of the current landscape of gene therapy for BCG-unresponsive NMIBC. Results: Nadofaragene firadenovec, a recombinant adenovirus delivering interferon alpha-2b (IFNα2b), is the first FDA-approved gene therapy for BCG-unresponsive NMIBC with carcinoma in situ (CIS). A phase III nadofaragene firadenovec study (NCT02773849) demonstrated a 53% complete response (CR) rate at 3 months; and 43% of patients with CIS had bladder preservation at 60 months. Cretostimogene grenadenorepvec (CG0070), an oncolytic vector, demonstrated a 47% 6-month CR rate in a phase II study (NCT02365818). Detalimogene voraplasmid (EG-70), a nonviral gene therapy, demonstrated a 47% 6-month CR in a phase I/II study (NCT04752722). Future advances are likely to focus on patient selection, novel vectors, and combination strategies to improve treatment outcomes. Conclusions: Gene therapy represents a significant addition to the bladder cancer treatment landscape by offering bladder-sparing alternatives where conventional therapies are limited. Full article

Glioblastoma (GBM) is an aggressive and common form of central nervous system primary malignant tumor in adults. GBM accounts for about half of all gliomas. Despite maximal resection, radiotherapy, and temozolomide, median survival is still 12–15 months because of tumor heterogeneity, diffuse infiltration, and therapeutic resistance. Recurrence is nearly universal, underscoring the need for novel therapies. Oncolytic virotherapy demonstrates a promising strategy that combines direct tumor cell lysis with immune activation. Tumor-selective viruses replicate within malignant cells, induce cell death, and release tumor antigens, thereby reshaping the immunosuppressive microenvironment. Several viral backbones have advanced to clinical testing, including adenovirus (DNX-2401), herpes simplex virus (G47Δ, G207), poliovirus (PVS-RIPO), measles virus (MV-CEA), reovirus (pelareorep), vaccinia virus (Pexa-Vec), and vesicular stomatitis virus (VSV-GP). The approval of G47Δ in Japan for malignant glioma marks a milestone, with early trials demonstrating safety and signals of durable benefit, particularly in combination regimens. Current research emphasizes engineering viral genomes to enhance selectivity, immune stimulation, and resistance to clearance, while exploring synergistic combinations with radiotherapy, chemotherapy, immune checkpoint inhibitors, and tumor-treating fields. Advances in delivery, such as convection-enhanced infusion and blood–brain barrier modulation, are also under investigation. Despite obstacles, oncolytic virotherapy holds significant potential within multimodal GBM strategies. Full article

Glioblastoma (GBM) remains one of the most aggressive and treatment-resistant brain tumors, necessitating novel therapeutic approaches. Oncolytic treatments, particularly oncolytic viruses (OVs), have emerged as promising candidates by selectively infecting and lysing tumor cells while stimulating anti-tumor immunity. Various virus-based therapies are under investigation, including genetically engineered herpes simplex virus (HSV), adenovirus, poliovirus, reovirus, vaccinia virus, measles virus, and Newcastle disease virus, each exploiting unique tumor-selective mechanisms. While some, such as HSV-based therapies including G207 and Delytact^TM, have demonstrated clinical progress, significant challenges persist, including immune evasion, heterogeneity in patient response, and delivery barriers due to the blood–brain barrier. Moreover, combination strategies integrating OVs with immune checkpoint inhibitors, chemotherapy, and radiation are promising but require further clinical validation. Non-viral oncolytic approaches, such as tumor-targeting bacteria and synthetic peptides, remain underexplored. This review highlights current advancements while addressing critical gaps in the literature, including the need for optimized delivery methods, better biomarker-based patient stratification, and a deeper understanding of GBM’s immunosuppressive microenvironment. Future research should focus on enhancing OV specificity, engineering viruses to deliver therapeutic genes, and integrating OVs with precision medicine strategies. By identifying these gaps, this review provides a framework for advancing oncolytic therapies in GBM treatment. Full article

Background: While Bacillus Calmette-Guérin (BCG) remains the first-line therapy for high-risk bladder cancer, 30–40% of patients develop treatment resistance necessitating radical cystectomy, some are not suitable candidates for this procedure. This underscores the critical need for novel therapeutic approaches. Emerging clinical evidence has increasingly supported the therapeutic potential of oncolytic viruses in bladder cancer treatment. Based on this clinical foundation, we investigated the anti-tumor effects of KD01, a novel type 5 recombinant oncolytic adenovirus previously developed by our team engineered to express truncated BID (tBID), in bladder cancer. Methods: The cytotoxic effects and anti-tumor efficacy of KD01 were systematically evaluated across human bladder cancer cell lines, and cell death pathways were investigated by RNA sequencing and validated. Combination therapy studies with cisplatin employed cytotoxic testing. In the final stage, the safety of KD01 bladder instillation was evaluated. Results: KD01 induced bladder cancer cell death through multiple mechanisms, including oncolysis, immunogenic cell death, and mitochondrial apoptosis. At higher doses, KD01 combined with cisplatin synergistically inhibited cancer cell proliferation and induced apoptosis. Additionally, KD01 amplified damage-associated molecular patterns (DAMPs) release and immune activation; the combination with cisplatin further enhanced the process. Safety evaluations showed favorable tolerance to intravesical perfusion with KD01. Conclusions: The dual action of KD01 in directly killing tumor cells and activating anti-tumor immunity underscores its potential as a therapeutic agent. These findings highlight the preclinical efficacy and safety of KD01, informing the design of clinical trials. Full article

The delivery of biomolecules to target cells has been a longstanding challenge in biotechnology. DNA viruses naturally evolved the ability to deliver genetic material to cells and modulate cellular processes. As such, they inherently possess requisite characteristics that have led to their extensive study, engineering, and development as biotechnological tools. Here, we overview the application of DNA viruses to biotechnology, with specific implications in basic research, health, biomanufacturing, and agriculture. For each application, we review how an increasing understanding of virology and technological methods to genetically manipulate DNA viruses has enabled advances in these fields. Additionally, we highlight the remaining challenges to unlocking the full biotechnological potential of DNA viral technologies. Finally, we discuss the importance of balancing continued technological progress with ethical and biosafety considerations. Full article

Due to the minimal survival benefits of existing therapies for pediatric diffuse midline glioma (DMG) patients, new therapeutic modalities are being investigated. Immunotherapies such as CAR-T cells and oncolytic viruses (OVs) are part of these efforts, as evidenced by the increasing number of clinical trials. αβ T cells engineered with a high-affinity γ9δ2 T-cell receptor (TEGs) are immune cells designed to target metabolic changes in malignant or virally infected cells via BTN2A1 and BTN3A. Because the expression of BTN2A1 and BTN3A can be altered in tumor and infected cells, combining TEGs and OVs could potentially enhance the anti-tumor response. We investigated this hypothesis in the following study. We demonstrate that TEGs can indeed target DMG, which expresses BTN2A1 and BTN3A at varying levels, and that OVs can further enhance the expression of BTN3A—but not BTN2A1—in DMG. Functionally, TEGs killed DMG cell cultures, and this killing was further increased after OV infection of the DMGs with either adenovirus Δ24-RGD or reovirus R124 under suboptimal conditions. However, this additive effect was lost when γ9δ2 TCR–ligand interaction was boosted by pamidronate. This study demonstrates the additive effect of combining OVs and Vγ9Vδ2 TCR-engineered immune cells under suboptimal conditions and supports a combination strategy to enhance the efficacy of both therapeutic modalities. Full article

In this study, we present an oncolytic virus (OV) evaluation system established using microfluidic organ-on-a-chip (OOC) systems and patient-derived organoids (PDOs), which was used in the development of a novel oncolytic virus, AD4-GHPE. An OV offers advantages such as good targeting ability and minimal side effects, and it has achieved significant breakthroughs when combined with immunotherapy in recent clinical trials. The development of OVs has become an emerging research focus. PDOs can preserve the heterogeneity of in situ tumor tissues, whereas microfluidic OOC systems can automate and standardize various experimental procedures. These systems have been applied in cutting-edge drug screening and cell therapy experiments; however, their use in functionally complex oncolytic viruses remains to be explored. In this study, we constructed a novel recombinant oncolytic adenovirus, AD4-GHPE, and evaluated OOC systems and PDOs through various functional validations in hypopharyngeal and breast cancer organoids. The results confirmed that AD4-GHPE exhibits three antitumor mechanisms, namely, tumor-specific cytotoxicity, a reduction in programmed death ligand 1 (PD-L1) expression in tumor cells to increase CD8⁺ T-cell activity, and granulocyte–macrophage colony-stimulating factor (GM-CSF) secretion. The evaluation system combining OOC systems and PDOs was efficient and reliable, providing personalized OV treatment recommendations for patients and offering industrialized and standardized research ideas for the development of OVs. Full article

Cholangiocarcinoma (CCA), the second most common liver cancer, remains highly resistant to chemotherapy and radiotherapy, leaving patients with unresectable tumors in urgent need of innovative therapeutic approaches. Adenovirus type 6 (Ad6), a species C human adenovirus, offers significant potential for cancer therapy due to its low seroprevalence compared to Adenovirus type 5 (Ad5) and its ability to evade Kupffer cells during systemic delivery. In this study, we developed a novel oncolytic adenovirus vector based on the Ad6 engineered to express human GM-CSF (Ad6-d24-GM) and evaluated its therapeutic efficacy in a novel immunocompetent, replication-permissive Syrian hamster model of CCA. Intratumoral administration of Ad6-d24-GM significantly suppressed tumor growth and prolonged survival without evidence of toxicity, as indicated by stable body weights and normal liver enzyme levels. Both Ad6-d24-GM and wild-type Ad6 induced robust infiltration of CD4+ and CD8+ T cells, as well as CD68+ macrophages within tumors, demonstrating activation of antitumor immunity. Notably, the Ad6-d24-GM group exhibited a statistically significant increase in CD68+ cells compared to wild-type Ad6, highlighting the immunomodulatory effect of GM-CSF transgene. These results demonstrate the oncolytic and immunostimulatory potential of Ad6-based vectors for CCA treatment and validate the Syrian hamster syngeneic CCA-OF model as a valuable platform for studying oncolytic adenovirus therapies. Full article

Luciferase (luc) bioluminescence (BL) is the most used light-emitting protein that has been engineered to be expressed in multiple cancer cell lines, allowing for the detection of tumor nodules in vivo as it can penetrate most tissues. The goal of this study was to develop an oncolytic adenovirus (OAd)-resistant human triple-negative breast cancer (TNBC) that could express luciferase. Thus, when combining an OAd with chemotherapies or targeted therapies, we would be able to monitor the ability of these compounds to enhance OAd antitumor efficacy using BL in real time. The TNBC cell line HCC1937 was stably transfected with the plasmid pGL4.50[luc2/CMV/Hygro] (HCC1937/luc2). Once established, HCC1937/luc2 was orthotopically implanted in the 4th mammary gland fat pad of NSG (non-obese diabetic severe combined immunodeficiency disease gamma) female mice. Bioluminescence imaging (BLI) revealed that the HCC1937/luc2 cell line developed orthotopic breast tumor and lung metastasis over time. However, the integration of luc plasmid modified the HCC1937 phenotype, making HCC1937/luc2 more sensitive to OAdmCherry compared to the parental cell line and blunting the interferon (IFN) antiviral response. Testing two additional luc cell lines revealed that this was not a universal response; however, proper controls would need to be evaluated, as the integration of luciferase could affect the cells’ response to different treatments. Full article

Pancreatic cancer presents formidable challenges due to rapid progression and resistance to conventional treatments. Oncolytic viruses (OVs) selectively infect cancer cells and cause cancer cells to lyse, releasing molecules that can be identified by the host’s immune system. Moreover, OV can carry immune-stimulatory payloads such as interleukin-12, which when delivered locally can enhance immune system-mediated tumor killing. OVs are very well tolerated by cancer patients due to their ability to selectively target tumors without affecting surrounding normal tissues. OVs have recently been combined with other therapies, including chemotherapy and immunotherapy, to improve clinical outcomes. Several OVs including adenovirus, herpes simplex viruses (HSVs), vaccinia virus, parvovirus, reovirus, and measles virus have been evaluated in preclinical and clinical settings for the treatment of pancreatic cancer. We evaluated the safety and tolerability of a replication-competent oncolytic adenoviral vector carrying two suicide genes (thymidine kinase, TK; and cytosine deaminase, CD) and human interleukin-12 (hIL12) in metastatic pancreatic cancer patients in a phase 1 trial. This vector was found to be safe and well-tolerated at the highest doses tested without causing any significant adverse events (SAEs). Moreover, long-term follow-up studies indicated an increase in the overall survival (OS) in subjects receiving the highest dose of the OV. Our encouraging long-term survival data provide hope for patients with advanced pancreatic cancer, a disease that has not seen a meaningful increase in OS in the last five decades. In this review article, we highlight several preclinical and clinical studies and discuss future directions for optimizing OV therapy in pancreatic cancer. We envision OV-based gene therapy to be a game changer in the near future with the advent of newer generation OVs that have higher specificity and selectivity combined with personalized treatment plans developed under AI guidance. Full article

Primary bone malignancies, including osteosarcoma (OS), are rare but aggressive. Current OS treatment, involving surgical resection and chemotherapy, has improved survival for non-metastatic cases but remains ineffective for recurrent or metastatic OS. Oncolytic viral therapy (OVT) is a promising alternative, using naturally occurring or genetically modified viruses to selectively target and lyse cancer cells and induce a robust immune response against remaining OS cells. Various oncolytic viruses (OVs), such as adenovirus, herpes simplex virus, and measles virus, have demonstrated efficacy in preclinical OS models. Combining OVT with other therapeutics, such as chemotherapy or immunotherapy, may further improve outcomes. Despite these advances, challenges in reliability of preclinical models, safety, delivery, and immune response must be addressed to optimize OVT for clinical use. Future research should focus on refining delivery methods, exploring combination treatments, and clinical trials to ensure OVT’s efficacy and safety for OS. Overall, OVT represents a novel approach with the potential to drastically improve survival outcomes for patients with OS. Full article

Oncolytic virotherapy, using viruses such as vesicular stomatitis virus (VSVΔ51) and Herpes Simplex Virus-1 (HSV-1) to selectively attack cancer cells, faces challenges such as cellular resistance mediated by the interferon (IFN) response. Dimethyl fumarate (DMF) is used in the treatment of multiple sclerosis and psoriasis and is recognized for its anti-cancer properties and has been shown to enhance both VSVΔ51 and HSV-1 oncolytic activity. Tepilamide fumarate (TPF) is a DMF analog currently undergoing clinical trials for the treatment of moderate-to-severe plaque psoriasis. The aim of this study was to evaluate the potential of TPF in enhancing the effectiveness of oncolytic viruses. In vitro, TPF treatment rendered 786-0 carcinoma cells more susceptible to VSVΔ51 infection, leading to increased viral replication. It outperformed DMF in both increasing viral infection and increasing the killing of these resistant cancer cells and other cancer cell lines tested. Ex vivo studies demonstrated TPF’s selective boosting of oncolytic virus infection in cancer cells without affecting healthy tissues. Effectiveness was notably high in pancreatic and ovarian tumor samples. Our study further indicates that TPF can downregulate the IFN pathway through a similar mechanism to DMF, making resistant cancer cells more vulnerable to viral infection. Furthermore, TPF’s impact on gene therapy was assessed, revealing its ability to enhance the transduction efficiency of vectors such as lentivirus, adenovirus type 5, and adeno-associated virus type 2 across various cell lines. This data underscore TPF’s potential role in not only oncolytic virotherapy but also in the broader application of gene therapy. Collectively, these findings position TPF as a promising agent in oncolytic virotherapy, warranting further exploration of its therapeutic potential. Full article