Oncolytic Therapy Research Articles

Abstract 7253: Oncolytic virus therapy with two-factor authentication shows robust safety and efficacy in liver cancer

Abstract Background: Humane Genomics is pioneering multi-factored authenticated oncolytic virotherapy (OVT) using glycoprotein receptor matching and aptazyme technology to positively control replication in cytoplasm. Using VSV as a platform the OVTs show excellent safety and remain highly lytic. Sindbis virus glycoprotein was mutated to eliminate natural infectivity and retargeted to GPC3 with a codon optimized nanobody. An aptazyme was used to regulate viral replication. As far as we are aware, this was the first report of a functional ON switch using a cancer biomarker. Methods: 293T cells were used for virus rescue and titration by TCID50. Identity was confirmed by Nanopore sequencing. We evaluated safety on off-target SK-Hep-1 and NCI-H28 cell lines, and efficacy on target HepG2 and patient derived HB17 cells. Cell health and GFP was measured at multiple timepoints up to 72 hours. Results: Safety testing of HGI498 on SK-Hep-1 (GPC3 negative) and NCI-H28 (GPC3 negative, biomarker negative) showed no virus induced cell cytopathic effects in a range of 0.01 ≤ MOI ≤1. HGI498’s efficacy testing on HepG2 and HB17 showed tumor cytotoxicity at MOI 0.01 (p<0.001). Endpoint dilution assay showed a 159-fold and 316-fold difference between off-target NCI-H28 and on-target HepG2 and HB17, respectively. We incorporated an optimized aptazyme with the GPC3 targeted glycoprotein (HGI572), which was similarly rescued, titered, and evaluated for selectivity. HGI572 demonstrated approximately 1000-fold higher titer on target HepG2 and HB17 cells than off-target cells. Initial in vivo MTD study shows that both HGI498 and HGI572 are well tolerated, and are currently being investigated in vivo for efficacy on Hep3B in NSG mice. HGI498 has shown no seroprevalence (in vitro) and is stable at cryostorage for a minimum of 11 months. Conclusion: We have successfully engineered a two-factor authentication enabled OVT to address an unmet need for a therapy for liver cancer. As far as we are aware, this is the first report of an ON switch using a cancer protein to control viral replication, and the ON/OFF control is the highest to date. Citation Format: Chad M. Moles, Peter Weijmarshausen, Rupsa Basu, Brenda Ho, Manal Farhat, Taylor Flaat, Bruce F. Smith, Michael Whitt, Sarah E. Woodfield, Sanjeev A. Vasudevan. Oncolytic virus therapy with two-factor authentication shows robust safety and efficacy in liver cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7253.

Abstract 6652: Advanced glioblastoma immunotherapy: Attenuated herpes oncolytic virus armed with anti-PD-1 antibody and IL-12

Abstract Background: Glioblastoma (GBM), the most common and deadly primary brain tumor in adults, has limited treatment options with poor outcomes. The urgent need for innovative treatments has spurred research into immunotherapy and oncolytic virus therapy as promising alternatives. Herein, we have developed a new generation oncolytic herpes simplex virus (oHSV) armed with IL-12 and anti-PD-1 antibody to provide a synergistic anti-GBM efficacy for immune-oncolytic therapy. Methods: MVR-C5252, a novel oHSV, was created by genetic engineering, which included the removal of a 15-kb internal repeat (IR) region and both copies of the γ34.5 genes, along with the insertion of two exogenous genes encoding the anti-PD-1 antibody and IL-12. MVR-C5252 was characterized and assessed for its anti-GBM activities through a series of experiments as follows: 1) Safety assessments, including evaluations of neurotoxicity and latency-reactivation characteristics, were conducted in Balb/C mice. 2) Anti-tumor activities were evaluated in cell cultures, subcutaneous and orthotopic xenograft mouse models, and immunocompetent mouse models. 3) Mechanistic studies were performed to uncover the mode of action of MVR-C5252, with a specific focus on its ability to induce cell death in GBM cells and activate the immune response in vivo. Results: 1) In vitro studies showed that MVR-C5252 is highly replication attenuated but with higher cell-killing activity in GBM cells compared to the first generation oHSV, R3616, which has γ34.5 deletions only. 2) Mechanistic studies showed that MVR-C5252 infection increased cell death by reducing CNTNRα expression, which typically prevents caspase 3 activation and has an anti-apoptotic effect in glioma cells. 3) Intracranial injection of MVR-C5252 revealed a remarkable safety profile, with over an 800-fold reduction in virulence compared to wild-type HSV-1. Furthermore, the mouse trigeminal ganglion (TG) infection model suggested that MVR-C5252 was unable to establish latency or reactivate in the TG. 4) In vivo subcutaneous and orthotopic xenograft mouse models showed that compared to the R3616 group, enhanced anti-tumor activity and extended survival were observed in the MVR-C5252 group. Additionally, in the syngeneic mice model, MVR-C5252 exhibited superior anti-tumor activity and immune activation over the backbone virus. Conclusions: With the unique combination of safety, potent anti-tumor activity, and immune-stimulatory properties, MVR-C5252 makes it a big potential candidate to address the pressing need for effective treatment strategies of GBM. Citation Format: Lei Wang, Xusha Zhou, Xiaoqing Chen, Yuanyuan Liu, Yanxin Zheng, Runbin Yan, Yonghong Liu, Jing Zhao, Grace Guoying Zhou. Advanced glioblastoma immunotherapy: Attenuated herpes oncolytic virus armed with anti-PD-1 antibody and IL-12 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6652.

New hopes for the breast cancer treatment: perspectives on the oncolytic virus therapy.

Oncolytic virus (OV) therapy has emerged as a promising frontier in cancer treatment, especially for solid tumours. While immunotherapies like immune checkpoint inhibitors and CAR-T cells have demonstrated impressive results, their limitations in inducing complete tumour regression have spurred researchers to explore new approaches targeting tumours resistant to current immunotherapies. OVs, both natural and genetically engineered, selectively replicate within cancer cells, inducing their lysis while sparing normal tissues. Recent advancements in clinical research and genetic engineering have enabled the development of targeted viruses that modify the tumour microenvironment, triggering anti-tumour immune responses and exhibiting synergistic effects with other cancer therapies. Several OVs have been studied for breast cancer treatment, including adenovirus, protoparvovirus, vaccinia virus, reovirus, and herpes simplex virus type I (HSV-1). These viruses have been modified or engineered to enhance their tumour-selective replication, reduce toxicity, and improve oncolytic properties.Newer generations of OVs, such as Oncoviron and Delta-24-RGD adenovirus, exhibit heightened replication selectivity and enhanced anticancer effects, particularly in breast cancer models. Clinical trials have explored the efficacy and safety of various OVs in treating different cancers, including melanoma, nasopharyngeal carcinoma, head and neck cancer, and gynecologic malignancies. Notably, Talimogene laherparepvec (T-VEC) and Oncorine have. been approved for advanced melanoma and nasopharyngeal carcinoma, respectively. However, adverse effects have been reported in some cases, including flu-like symptoms and rare instances of severe complications such as fistula formation. Although no OV has been approved specifically for breast cancer treatment, ongoing preclinical clinical trials focus on four groups of viruses. While mild adverse effects like low-grade fever and nausea have been observed, the effectiveness of OV monotherapy in breast cancer remains insufficient. Combination strategies integrating OVs with chemotherapy, radiotherapy, or immunotherapy, show promise in improving therapeutic outcomes. Oncolytic virus therapy holds substantial potential in breast cancer treatment, demonstrating safety in trials. Multi-approach strategies combining OVs with conventional therapies exhibit more promising therapeutic effects than monotherapy, signalling a hopeful future for OV-based breast cancer treatments.

Development of a robust cell-based potency assay for a coxsackievirus A21 oncolytic virotherapy

Oncolytic viruses (OV) are part of a burgeoning field of investigational oncolytic therapy (OT), in which lytic viruses dissolve advanced tumors productively and specifically. One such OT is a Coxsackievirus A21 (CVA21) based OV that is currently under clinical evaluation. A tissue culture infectious dose (TCID50) assay was used for CVA21 potency release and stability testing in early clinical development. The titer measured in this method was an extrapolated value from cytopathic effect (CPE) observed during the serial dilution but doesn't represent direct viral killing of cells. Moreover, the assay was not deemed to be optimal to carry into late phase clinical development due to limitations in assay precision, turn-around time, and sample throughput. To address these points, we developed a plaque assay to measure viral plaque forming units to measure the potency value for drug substance (DS), drug product (DP) and virus seed (master and working) stocks. In this manuscript, we describe the steps taken to develop this plaque assay for the late-stage clinical development, which include the assay qualification, validation, and robustness protocols, and describe statistical methods for data analysis. Moreover, the method was validated for linearity, accuracy, precision, and specificity. Furthermore, the plaque assay quantifies OV infectivity with better precision (32% vs 58%), with higher sample throughput (22 samples/week vs 3 samples/week) and shorter assay turnaround time (4 days vs 7 days) than the TCID50 method. This assay development strategy can provide guidance for the development of robust cell-based potency methods for OVs and other infectious viral products.

Clinical and Histological Response to Talimogene Laherparepvec Therapy in Advanced Melanoma: Impact on Overall Survival.

Talimogene laherparepvec (T-VEC) is an FDA-approved oncolytic herpesvirus therapy used for unresectable stage IIIB through IV metastatic melanoma. However, the correlation between clinical complete response (cCR) and pathologic complete response (pCR) in patients treated with T-VEC is understudied. We conducted a retrospective study from a prospectively maintained IRB-approved melanoma single-center database in patients treated with T-VEC from October 2015 to April 2022. Patients were categorized into 3 groups: cCR with pCR, cCR without pCR, and less than cCR. The primary endpoint was overall survival. We used descriptive statistics, chi-square tests, and Wilcoxon rank-sum tests to compare key covariates among exposure groups. We used survival analysis to compare survival curves and reported hazard ratio of death (95% CI) across exposure groups. We included 116 patients with a median overall survival (interquartile range) of 22.7 (14.8-39.3) months. The majority were men (69%) and White (97.4%), with a median age of 74.5 years. More than half of patients (n = 60, 51.6%) achieved cCR. Distribution among the groups was as follows: cCR with pCR (35.3%), cCR without pCR (16.3%), and less than cCR (48.4%). Median overall survival time (interquartile range) was 26.5 (18.6-36.0) months for cCR with pCR, 22.7 (14.4-35.5) months for cCR without pCR, and 17.8 (9.2-47.0) months for less than cCR (log-rank p value = 0.0033). Patients achieving cCR with pCR after T-VEC therapy have the most favorable overall survival outcomes, whereas those achieving cCR without pCR have inferior survival and those achieving less than cCR have the poorest overall survival outcomes. These findings emphasize the importance of histological confirmation and provide insights for optimizing T-VEC therapy in patients with advanced melanoma.

Abstract B054: Defective STING signaling in low-grade serous ovarian cancer: an opportunity for oncolytic viruses therapy

Abstract There are two serous ovarian cancer histotypes, low and high grade (LGSOC and HGSOC), which are distinct clinical and biological entities. LGSOC is a rare histotype with a relatively stable genome, while HGSC is more common and genomically unstable. Surprisingly LGSOC expresses high levels of the stimulator of the interferon genes (STING). The STING pathway recognizes cytoplasmic double-stranded DNA and mounts innate cellular immunity through interferon-beta type I production. Our objective is to investigate the aberrant STING signaling in LGSOC and test the effectiveness of oncolytic viruses against LGSOC. We used immunohistochemistry on tissue microarrays (TMAs) to assess STING protein expression in different ovarian cancer histotypes. Whole proteome analysis was applied to identify differentially expressed proteins in LGSOC and HGSOC patient samples (both n=9). Further, a semi-targeted proteomics approach was used to evaluate the expression levels of the STING pathway-related proteins in LGSOC, HGSOC, and LGSOC precursor tumors (each subtype, n=20). To evaluate the key transcription, phosphorylation, and translocation events in STING signaling, we treated LGSOC cell lines with an agonist (dsDNA90) and performed qPCR, immunoblotting, and immunofluorescence experiments, respectively. We tested the viability of the LGSOC cell lines in response to Vaccinia Virus (VV), and Vesicular Stomatitis Virus (VSV) based oncolytic vectors with or without immunostimulatory transgenes. Our results show that STING protein levels were consistently higher in LGSOC TMAs relative to other histotypes. Proteomics analysis showed that the half of the 16 most differentially expressed proteins were the effectors of STING signaling with unexpectedly lower expression in LGSOC, suggesting that despite the robust levels of STING in LGSOC tumors, the pathway is not fully active. Attenuated STING translocation and expression of IFNB1 and other cytokines in LGSOC cell lines confirm the aberrancy in the STING pathway. Semi-targeted proteomics revealed the considerable overexpression of STIM1 in LGSOC patient tumors, which has previously been shown to sequester STING in the endoplasmic reticulum. The treatment with VV and VSV oncolytic viruses significantly reduced the proliferation of LGSOC cell lines. In summary, we find attenuated STING signaling in LGSOC, possibly due to overexpression of STIM1 preventing STING translocation. Although oncolytic viruses show promising results in LGSOC cell lines, more research is needed to determine the optimal treatment strategy, testing oncolytic viruses expressing various transgenes and combination therapies. Citation Format: Almira Zhantuyakova, Dawn Cochrane, Gian Luca Negri, Sandra Spencer Miko, Taha Azad, Marta Llaurado Fernandez, Mark Carey, Gregg B. Morin, John Bell, David D. Huntsman. Defective STING signaling in low-grade serous ovarian cancer: an opportunity for oncolytic viruses therapy [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B054.

Mayana Zatz: Two critical questions take center stage – Which variants mitigate the impact of lethal mutations in severe conditions with mild phenotype? What factors contribute to the health and longevity of centenarians?

Mayana Zatz has been a Professor of Genetics at the Institute of Biosciences, University of São Paulo (USP), Brazil, since 1982. She became an assistant professor after a postdoc at the University of São Paulo and a second postdoc at the University of California, Los Angeles. Her current research is focused on neuromuscular disorders, aging, genomics, and, more recently, xenotransplantation and the use of the Zika virus as an oncolytic therapy against brain tumors. Functional studies are done in genetically engineered mouse and cell models. She is particularly interested in investigating protective mechanisms in rare patients with Duchenne dystrophy and a milder clinical course, as well as in centenarians' health determinants. Mayana Zatz is also involved in ethical aspects of genomic studies and government political decisions related to science. Professor Zatz is pleased to offer our readers insights into her personal and professional experiences.

The NP protein of Newcastle disease virus dictates its oncolytic activity by regulating viral mRNA translation efficiency.

Newcastle disease virus (NDV) has been extensively studied as a promising oncolytic virus for killing tumor cells in vitro and in vivo in clinical trials. However, the viral components that regulate the oncolytic activity of NDV remain incompletely understood. In this study, we systematically compared the replication ability of different NDV genotypes in various tumor cells and identified NP protein determines the oncolytic activity of NDV. On the one hand, NDV strains with phenylalanine (F) at the 450th amino acid position of the NP protein (450th-F-NP) exhibit a loss of oncolytic activity. This phenotype is predominantly associated with genotype VII NDVs. In contrast, the NP protein with a leucine amino acid at this site in other genotypes (450th-L-NP) can facilitate the loading of viral mRNA onto ribosomes more effectively than 450th-F-NP. On the other hand, the NP protein from NDV strains that exhibit strong oncogenicity interacts with eIF4A1 within its 366-489 amino acid region, leading to the inhibition of cellular mRNA translation with a complex 5' UTR structure. Our study provide mechanistic insights into how highly oncolytic NDV strains selectively promote the translation of viral mRNA and will also facilitate the screening of oncolytic strains for oncolytic therapy.

A Review of Current and Pipeline Drugs for Treatment of Melanoma.

Malignant melanoma is the most aggressive form of skin cancer. Standard treatment options include surgery, radiation therapy, systemic chemotherapy, targeted therapy, and immunotherapy. Combining these modalities often yields better responses. Surgery is suitable for localized cases, sometimes involving lymph node dissection and biopsy, to assess the spread of the disease. Radiation therapy may be sometimes used as a standalone treatment or following surgical excision. Systemic chemotherapy, while having low response rates, is utilized as part of combination treatments or when other methods fail. The development of resistance to systemic chemotherapies and associated side effects have prompted further research and clinical trials for novel approaches. In the case of advanced-stage melanoma, a comprehensive approach may be necessary, incorporating targeted therapies and immunotherapies that demonstrate significant antitumor activity. Targeted therapies, including inhibitors targeting BRAF, MEK, c-KIT, and NRAS, are designed to block the specific molecules responsible for tumor growth. These therapies show promise, particularly in patients with corresponding mutations. Combination therapy, including BRAF and MEK inhibitors, has been evidenced to improve progression-free survival; however, concerns about resistance and cutaneous toxicities highlight the need for close monitoring. Immunotherapies, leveraging tumor-infiltrating lymphocytes and CAR T cells, enhance immune responses. Lifileucel, an FDA-approved tumor-infiltrating lymphocyte therapy, has demonstrated improved response rates in advanced-stage melanoma. Ongoing trials continue to explore the efficacy of CAR T-cell therapy for advanced melanoma. Checkpoint inhibitors targeting CTLA-4 and PD-1 have enhanced outcomes. Emerging IL-2 therapies boost dendritic cells, enhancing anticancer immunity. Oncolytic virus therapy, approved for advanced melanoma, augments treatment efficacy in combination approaches. While immunotherapy has significantly advanced melanoma treatment, its success varies, prompting research into new drugs and factors influencing outcomes. This review provides insights into current melanoma treatments and recent therapeutic advances.

Combination of Oncolytic Virotherapy with Different Antitumor Approaches against Glioblastoma.

Glioblastoma is one of the most malignant and aggressive tumors of the central nervous system. Despite the standard therapy consisting of maximal surgical resection and chemo- and radiotherapy, the median survival of patients with this diagnosis is about 15 months. Oncolytic virus therapy is one of the promising areas for the treatment of malignant neoplasms. In this review, we have focused on emphasizing recent achievements in virotherapy, both as a monotherapy and in combination with other therapeutic schemes to improve survival rate and quality of life among patients with glioblastoma.

Are HPV oncogenic viruses involved in salivary glands tumorigenesis?

The association between different viruses and cancer is well acknowledged in human pathology. However, the precise understanding of how oncogenic viruses intervene in the development of cancer of salivary glands (SGs) remains incomplete. Our review aimed to explore the current literature regarding SGs cancer to evaluate the potential involvement of human papillomaviruses (HPVs) in their development. Our work hypothesis suggests that viruses may be involved in these tumors' immunogenicity. The literature analysis showed HPV-positive detection in different head and neck malignancies, added to variable risk factors and a constant increasing incidence rate. HPV tumorigenesis mechanism is complex, involving E6 and E7 HPV oncoproteins. Additionally, the reported findings generally support the relationship between SGs cancer and high oncogenic subtypes 16 and 18. However, the pathogenic contribution of HPV subtypes 11, 33, 45, 52, 56, and 59 is controversial and further research may clarify their potential involvement in the SG tumor's development. This literature review may enhance the understanding of the role of viral contribution as an etiopathogenic co-factor in SG carcinogenesis. Thus, these data may add value to innovative concepts and treatment strategies development, given that virus-induced tumors can be prevented by targeted immunization, added to oncolytic or viral therapy.

The Oncolytic Activity of Zika Viral Therapy in Human Neuroblastoma In Vivo Models Confers a Major Survival Advantage in a CD24-dependent Manner.

Sensitivity to the tumoricidal effect of ZIKV on high-risk neuroblastoma tumors is dependent on CD24 expression, offering a prognostic marker for this oncolytic therapy in an extensive array of CD24-expressing cancers.

An oncolytic circular RNA therapy.

An oncolytic circular RNA therapy.

Progression of oncolytic virus in liver cancer treatment.

The liver plays a crucrial role in detoxification, metabolism, and nutrient storage. Because liver cancer ranks among the top three leading causes of death globally, there is an urgent need for developing treatment strategies for liver cancer. Although traditional approaches such as radiation, chemotherapy, surgical removal, and transplantation are widely practiced, the number of patients with liver cancer continues to increase rapidly each year. Some novel therapeutics for liver cancer have been studied for many years. In the past decade, oncolytic therapy has emerged, in which viruses selectively infect and destroy cancer cells while sparing normal cells. However, oncolytic virotherapy for liver cancer remains relatively obscure due to the aggressive nature of the disease and the limited effectiveness of treatment. To keep pace with the latest developments in oncolytic tumor therapy for liver cancer, this review summarizes basic science studies and clinical trials conducted within 5 years, focusing on the efficacy and safety profiles of the five most commonly used oncolytic viruses: herpes simplex virus, adenovirus, influenza virus, vaccinia virus, and coxsackievirus.

Targeted Inhibition of p21 Promotes the Growth of Breast Cancer Cells and Impairs the Tumor-Killing Effect of the Vaccinia Virus.

Vaccinia virus is widely used as an oncolytic agent for human cancer therapy, and several versions of vaccinia virus have demonstrated robust antitumor effects in breast cancer. Most vaccinia viruses are modified by thymidine kinase (TK) deletion. The function of the cyclin-dependent kinase inhibitor p21 in breast cancer remains controversial. We explored the impact of p21 gene knockdown (KD) on breast cancer cells and whether p21 KD interferes with the antitumor effect of TK-negative vaccinia virus. p21 KD MDA-MB-231 and p21 KD MCF-7 cells were prepared, and cell proliferation and migration rates were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scratch healing assays. The tumor growth of xenografts originating from p21KD MDA-MB-231 cells and control cells was compared in a mouse model. The colony formation and sphere-forming abilities of p21 KD breast cancer cells were also determined using low-melting agarose and serum-free culture. The tumor-killing effect of the vaccinia virus was determined in breast cancer cells and mouse models using an MTT assay and tumor cell xenografts. p21 KD increased the growth and migration of MDA-MB-231 and MCF-7 cells and promoted the cell growth of MDA-MB-231 cells in mice, while decreasing the colony formation and sphere formation abilities. Expression of TK was reduced in p21 KD MDA-MB-231 cells. Oncolytic effects of both wild-type and TK-deleted vaccinia viruses were attenuated in p21KD MDA-MB-231 cells. The tumor-killing effect of TK-deleted vaccinia virus was also weakened in xenografted mice bearing p21 KD MDA-MB-231 cells. Targeted inhibition of p21 accelerates the proliferation and migration of breast cancer cells and impairs the tumor-killing effect of vaccinia virus, suggesting that p21 levels in cancer cells interfere with vaccinia virus oncolytic therapy.

Immunotherapy for canine cancer

Cancer in dogs is a serious and prevalent disease that has drawn significant attention in the field of veterinary medicine, representing the most common cause of death in adult dogs. Traditional treatments such as chemotherapy and surgery have many limitations and side effects and have not been able to completely eliminate cancer, and challenges still remain in improving the survival rate and life quality in dogs. The development of a new therapeutic methodology for canine cancer to improve treatment effectiveness and survival rate has become the focus of many scientists. Immunotherapy, as a new treatment strategy, is one of the important research directions in the field of cancer treatment in canine animals. Adoptive T-cell therapy, checkpoint inhibitors, and oncolytic virus therapy, as important immunotherapy approaches, have shown promising treatment effects. This article will introduce the background of canine cancer, the background of immunotherapy, and discuss the application prospects of adoptive T-cell therapy, checkpoint inhibitors, oncolytic virus therapy, and other related topics in the treatment of canine cancer.

Clinical challenges and strategies on delivery of Oncolytic Virus

Oncolytic Virus therapy, including HSV-1 and adenovirus, is a new type of tumour immunotherapy that uses specific viruses to directly kill tumour cells or to induce the body's intrinsic and acquired immunity to generate anti-tumour immune responses. In addition, Oncolytic Virus is capable of recruiting immune cells to improve the tumour microenvironment, so the development of The clinical significance of oncolytic virus therapy lies in its potential to enhance the efficacy of other immunotherapeutic approaches. However, the delivery of Oncolytic Virus in current clinical trials has huge defects, which greatly limits the benefits of Oncolytic Virus and even produces certain side effects. Therefore, this review discusses the definition and mechanism of Oncolytic Virus and focuses on the defects in Oncolytic Virus delivery, such as systemic delivery and intratumoural delivery. Further, this review also summarizes some improvement strategies against the challenges of intratumoural heterogeneity and vascular complexity.

The deletion of adenovirus E1B-19KD gene enhanced its cell killing ability against lung cancer cell line A549

Oncolytic Viruses immunotherapy is one of the most frequently used anti-cancer agents because it can significantly reverse local immune suppression and amplify antitumor immunity. Although drugs were already applied in cancer treatment, a new agent may open a new pathway for developing oncolytic therapy. This study intends to improve the adenoviral vector to increase its killing effect on tumor cells for effective and safe cancer gene therapy. We modified the pDC316 plasmid by adding TERT promoter, E1A, and E1B viral genes through homologous recombination and transfection. Then the virus was reassured of its stability through PCR analysis, Western blot, viral titer assays, and CPE assay. In the result, Ad-E1B 55k virus especially showed strong cytotoxicity of more than 50% of killing efficacy in vivo A549 cells. Cell viability in HepG2 is around 80% while in MRC5 cells, the viability is approximately 100%, which showed a tumor-specificity of the viruses. Moreover, only on day 4 has 20% of the efficacy of E1B 55k virus and the viability quickly returned to normal on the next day, which indicates the relative safety of the modified in MRC5 normal cells. In conclusion, the modified virus may serve as another starting point to design a potentially safer, better efficacy, and specificity in cancer immunotherapy. However, a further test of the vector in animal trials is recommended.

Molecular biology of canine parainfluenza virus V protein and its potential applications in tumor immunotherapy.

Canine parainfluenza virus (CPIV) is a zoonotic virus that is widely distributed and is the main pathogen causing canine infectious respiratory disease (CIRD), also known as "kennel cough," in dogs. The CPIV-V protein is the only nonstructural protein of the virus and plays an important role in multiple stages of the virus life cycle by inhibiting apoptosis, altering the host cell cycle and interfering with the interferon response. In addition, studies have shown that the V protein has potential applications in the field of immunotherapy in oncolytic virus therapy or self-amplifying RNA vaccines. In this review, the biosynthesis, structural characteristics and functions of the CPIV-V protein are reviewed with an emphasis on how it facilitates viral immune escape and its potential applications in the field of immunotherapy. Therefore, this review provides a scientific basis for research into the CPIV-V protein and its potential applications.

Systemic Administration with Bacteria-Inspired Nanosystems for Targeted Oncolytic Therapy and Antitumor Immunomodulation.

Malignant tumors represent a formidable global health challenge, compelling the pursuit of innovative treatment modalities. Oncolytic therapy has emerged as a promising frontier in antitumor strategies. However, both natural agents (such as oncolytic bacteria or viruses) and synthetic oncolytic peptides confront formidable obstacles in clinical trials, which include the delicate equilibrium between safety and efficacy, the imperative for systemic administration with targeted therapy, and the need to counteract oncolysis-induced immunosuppression. To overcome these dilemmas, we have developed biomimetic nanoengineering to create oncolytic bacteria-inspired nanosystems (OBNs), spanning from hierarchical structural biomimicry to advanced bioactive biomimicry. Our OBNs harbor inherent oncolytic potential, including functionalized oligosaccharides mimicking bacterial cell walls for optimal blood circulation and tumor targeting, tumor acidity-switchable decoration for tumor-specific oncolysis, stereospecific tryptophan-rich peptides for robust oncolytic activity, encapsulated tumor immunomodulators for enhanced immunotherapy, and innate multimodal imaging potential for biological tracing. This work elucidates the efficacy and mechanisms of OBNs, encompassing primary tumor suppression, metastasis prevention, and recurrence inhibition. Systemic administration of d-chiral OBNs has demonstrated superior oncolytic efficacy, surpassing intratumoral injections of clinical-grade oncolytic peptides. This work heralds an era in biomimetic engineering on oncolytic agents, promising the revolutionization of contemporary oncolytic therapy paradigms for clinical translation.