JAK/STAT inhibition with ruxolitinib enhances oncolytic virotherapy in non-small cell lung cancer models

Resistance signatures to oncolytic vesiculoviruses in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) shows limited response to conventional therapies and immunotherapy due to dense stromal barriers and poor immunogenicity. Oncolytic vesiculoviruses hold therapeutic potential for PDAC by lysis of PDAC cells to release tumor-associated antigens, increasing tumor immunogenicity. We previously reported the efficacy of a chimeric vesicular stomatitis virus (VSV) expressing Morreton virus (MorV) glycoprotein in sarcoma. Here, we evaluated the oncolytic potency of MorV and chimeric virus, VMG, in PDAC models. VMG exhibited heterogeneous oncolysis across human PDAC cell lines and PDX cells, similar to parental viruses VSV and MorV. To evaluate potential signatures correlated with resistance to oncolytic vesiculoviruses, we compared transcriptomes of cell lines characterized as sensitive or resistant to oncolysis in vitro. We identified epithelial development and biological adhesion gene sets were significantly associated with vesiculovirus resistance. Additionally, escaped PDAC cells surviving two cycles of infection with VSV showed significant upregulation of stress keratins and downregulation of genes involved in retinoic acid metabolism and cell cycle. An overlapping 39 genes were higher in resistant cell lines at baseline as well as upregulated in escaped PDAC cells. Several resistance-associated genes are targets of anti-cancer therapies in development, offering potential combination approaches with oncolytic vesiculoviruses.

Rational strategies for designing next-generation oncolytic viruses based on transcriptome analysis of tumor cells infected with oncolytic herpes simplex virus-1

Introduction

Oncolytic herpes simplex viruses (oHSVs) are a type of biotherapeutic utilized in cancer therapy due to their ability to selectively infect and destroy tumor cells without harming healthy cells. We sought to investigate the functional genomic response and altered metabolic pathways of human cancer cells to oHSV-1 infection and to elucidate the influence of these responses on the relationship between the virus and the cancer cells.

Methods

Two datasets containing gene expression profiles of tumor cells infected with oHSV-1 (G207) and non-infected cells from the Gene Expression Omnibus (GEO) database were processed and normalized using the R software. Common differentially expressed genes between datasets were selected to identify hub genes and were further analyzed. Subsequently, the expression of hub genes was verified by real-time polymerase chain reaction (qRT-PCR) in MDA-MB-231 (a breast cancer cell line) infected with oHSV-1 and non-infected cells.

Results

The results of our data analysis indicated notable disparities in the genes associated with the proteasome pathway between infected and non-infected cells. Our ontology analysis revealed that the proteasome-mediated ubiquitin-dependent protein catabolic process was a significant biological process, with a p-value of 5.8E-21. Additionally, extracellular exosomes and protein binding were identified as significant cellular components and molecular functions, respectively. Common hub genes with degree and maximum neighborhood component (MNC) methods, including PSMD2, PSMD4, PSMA2, PSMD14, PSMD11, PSMC3, PSMC2, PSMD8, and PSMA4, were also identified. Analysis of gene expression by qRT-PCR and differential gene expression revealed that GADD45g genes can be effective genes in the proliferation of oncolytic HSV-1 virus.

Conclusion

The transcriptome changes in tumor cells infected by oHSV-1 may be utilized to predict oncolytic efficacy and provide rational strategies for designing next-generation oncolytic viruses.

The Small GTPase Ran Increases Sensitivity of Ovarian Cancer Cells to Oncolytic Vesicular Stomatitis Virus

Background/Objectives: Ovarian cancer is the deadliest gynecologic cancer, and with the majority of patients dying within the first five years of diagnosis, new therapeutic options are required. The small guanosine triphosphatase (GTPase) Ras-related nuclear protein (Ran) has been reported to be highly expressed in high-grade serous ovarian cancers (HGSOCs) and associated with poor outcomes. Blocking Ran function or preventing its expression were shown to be promising treatment strategies, however, there are currently no small molecule inhibitors available to specifically inhibit Ran function. Interestingly, a previous study suggested that the Vesicular stomatitis virus (VSV) could inhibit Ran activity. Given that VSV is an oncolytic virus (OV) and, therefore, has anti-cancer activity, we reasoned that oncolytic VSV (oVSV) might be particularly effective against ovarian cancer via Ran inhibition. Methods: We evaluated the sensitivity of patient-derived ovarian cancer cell lines to oVSV, as well as the impact of oVSV on Ran and vice versa, using overexpression systems, small interfering RNAs (siRNAs), and drug inhibition. Results: In this study, we evaluated the interplay between oVSV and Ran and found that, although oVSV does not consistently block Ran, increased Ran activation allows for better oVSV replication and tumor cell killing. Conclusions: Our study reveals a positive impact of Ran on oVSV sensitivity. Given the high expression of Ran in HGSOCs, which are particularly aggressive ovarian cancers, our data suggest that oVSV could be effective against the deadliest form of the disease.

Oncolytic vesicular stomatitis virus alone or in combination with JAK inhibitors is effective against ovarian cancer

Therapy-resistant ovarian cancers have a poor prognosis and novel effective treatment options are urgently needed. In this study, we evaluated the therapeutic efficacy of the oncolytic vesicular stomatitis virus (VSV) against a panel of patient-derived ovarian cancer cell lines of all epithelial subtypes. Notably, we found that most of the cell lines were sensitive to VSV virotherapy. With the objective of improving treatment efficacy for the oncolytic virus-resistant cell lines, we tested various combinations with ovarian cancer standard of care drugs: olaparib, carboplatin, paclitaxel, doxorubicin, cyclophosphamide, and gemcitabine. While none of these combinations revealed to be beneficial, further experiments demonstrated that the antiviral interferon pathway was functional in VSV-resistant cell lines. Given that interferons signal through Janus kinase (JAK)-STAT to mediate their antiviral function, we tested combinations of oncolytic VSV with clinically relevant JAK inhibitors. Our results show that combining VSV with various JAK inhibitors, including ruxolitinib, enhances VSV virotherapy and treatment efficacy. Altogether, we show that VSV, either as a stand-alone treatment or in combination with JAK inhibitors provides an effective therapeutic option for ovarian cancer patients.

A review exploring the fusion of oncolytic viruses and cancer immunotherapy: An innovative strategy in the realm of cancer treatment

Oncolytic viruses (OVs) are increasingly recognized as potent tools in cancer therapy, effectively targeting and eradicating oncogenic conditions while sparing healthy cells. They enhance antitumor immunity by triggering various immune responses throughout the cancer cycle. Genetically engineered OVs swiftly destroy cancerous tissues and activate the immune system by releasing soluble antigens like danger signals and interferons. Their ability to stimulate both innate and adaptive immunity makes them particularly attractive in cancer immunotherapy. Recent advancements involve combining OVs with other immune therapies, yielding promising results. Transgenic OVs, designed to enhance immunostimulation and specifically target cancer cells, further improve immune responses. This review highlights the intrinsic mechanisms of OVs and underscores their synergistic potential with other immunotherapies. It also proposes strategies for optimizing armed OVs to bolster immunity against tumors.

Fusogenic vesicular stomatitis virus combined with natural killer T cell immunotherapy controls metastatic breast cancer

BACKGROUND

Metastatic breast cancer is a leading cause of cancer death in woman. Current treatment options are often associated with adverse side effects and poor outcomes, demonstrating the need for effective new treatments. Immunotherapies can provide durable outcomes in many cancers; however, limited success has been achieved in metastatic triple negative breast cancer. We tested whether combining different immunotherapies can target metastatic triple negative breast cancer in pre-clinical models.

METHODS

Using primary and metastatic 4T1 triple negative mammary carcinoma models, we examined the therapeutic effects of oncolytic vesicular stomatitis virus (VSVΔM51) engineered to express reovirus-derived fusion associated small transmembrane proteins p14 (VSV-p14) or p15 (VSV-p15). These viruses were delivered alone or in combination with natural killer T (NKT) cell activation therapy mediated by adoptive transfer of α-galactosylceramide-loaded dendritic cells.

RESULTS

Treatment of primary 4T1 tumors with VSV-p14 or VSV-p15 alone increased immunogenic tumor cell death, attenuated tumor growth, and enhanced immune cell infiltration and activation compared to control oncolytic virus (VSV-GFP) treatments and untreated mice. When combined with NKT cell activation therapy, oncolytic VSV-p14 and VSV-p15 reduced metastatic lung burden to undetectable levels in all mice and generated immune memory as evidenced by enhanced in vitro recall responses (tumor killing and cytokine production) and impaired tumor growth upon rechallenge.

CONCLUSION

Combining NKT cell immunotherapy with enhanced oncolytic virotherapy increased anti-tumor immune targeting of lung metastasis and presents a promising treatment strategy for metastatic breast cancer.

The combination therapy of oncolytic virotherapy

Introduction: Compared to other cancer immunotherapies, oncolytic viruses possess several advantages, including high killing efficiency, excellent targeting capabilities, minimal adverse reactions, and multiple pathways for tumor destruction. However, the efficacy of oncolytic viruses as a monotherapy often falls short of expectations. Consequently, combining oncolytic viruses with traditional treatments to achieve synergistic effects has emerged as a promising direction for the development of oncolytic virus therapies. Methods: This article provides a comprehensive review of the current progress in preclinical and clinical trials exploring the combination therapies involving oncolytic viruses. Results: Specifically, we discuss the combination of oncolytic viruses with immune checkpoint inhibitors, chemotherapy, targeted therapy, and cellular therapy. Discussion: The aim of this review is to offer valuable insights and references for the further advancement of these combination strategies in clinical applications. Further research is necessary to refine the design of combination therapies and explore novel strategies to maximize the therapeutic benefits offered by oncolytic viruses.

Molecular Circuits of Immune Sensing and Response to Oncolytic Virotherapy

Oncolytic virotherapy is a promising immunotherapy approach for cancer treatment that utilizes viruses to preferentially infect and eliminate cancer cells while stimulating the immune response. In this review, we synthesize the current literature on the molecular circuits of immune sensing and response to oncolytic virotherapy, focusing on viral DNA or RNA sensing by infected cells, cytokine and danger-associated-signal sensing by neighboring cells, and the subsequent downstream activation of immune pathways. These sequential sense-and-response mechanisms involve the triggering of molecular sensors by viruses or infected cells to activate transcription factors and related genes for a breadth of immune responses. We describe how the molecular signals induced in the tumor upon virotherapy can trigger diverse immune signaling pathways, activating both antigen-presenting-cell-based innate and T cell-based adaptive immune responses. Insights into these complex mechanisms provide valuable knowledge for enhancing oncolytic virotherapy strategies.

Deciphering JAK/STAT signaling pathway: A multifaceted approach to tumorigenesis, progression and therapeutic interventions

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, essential for cellular communication, orchestrates a myriad of physiological and pathological processes. Recently, the intricate association between the pathway's dysregulation and the progression of malignant tumors has garnered increasing attention. Nevertheless, there is no systematic summary detailing the anticancer effects of molecules targeting the JAK/STAT pathway in the context of tumor progression. This review offers a comprehensive overview of pharmaceutical agents targeting the JAK/STAT pathway, encompassing phytochemicals, synthetic drugs, and biomolecules. These agents can manifest their anticancer effects through various mechanisms, including inhibiting proliferation, inducing apoptosis, suppressing tumor metastasis, and angiogenesis. Notably, we emphasize the clinical challenges of drug resistance while spotlighting the potential of integrating JAK/STAT inhibitors with other therapies as a transformative approach in cancer treatment. Moreover, this review delves into the avant-garde strategy of employing nanocarriers to enhance the solubility and bioavailability of anticancer drugs, significantly amplifying their therapeutic prowess. Through this academic exploration of the multifaceted roles of the JAK/STAT pathway in the cancer milieu, we aim to sketch a visionary trajectory for future oncological interventions.

Personalizing Oncolytic Immunovirotherapy Approaches

Development of successful cancer therapeutics requires exploration of the differences in genetics, metabolism, and interactions with the immune system among malignant and normal cells. The clinical observation of spontaneous tumor regression following natural infection with microorganism has created the premise of their use as cancer therapeutics. Oncolytic viruses (OVs) originate from viruses with attenuated virulence in humans, well-characterized vaccine strains of known human pathogens, or engineered replication-deficient viral vectors. Their selectivity is based on receptor expression level and post entry restriction factors that favor replication in the tumor, while keeping the normal cells unharmed. Clinical trials have demonstrated a wide range of patient responses to virotherapy, with subgroups of patients significantly benefiting from OV administration. Tumor-specific gene signatures, including antiviral interferon-stimulated gene (ISG) expression profile, have demonstrated a strong correlation with tumor permissiveness to infection. Furthermore, the combination of OVs with immunotherapeutics, including anticancer vaccines and immune checkpoint inhibitors [ICIs, such as anti-PD-1/PD-L1 or anti-CTLA-4 and chimeric antigen receptor (CAR)-T or CAR-NK cells], could synergistically improve the therapeutic outcome. Creating response prediction algorithms represents an important step for the transition to individualized immunovirotherapy approaches in the clinic. Integrative predictors could include tumor mutational burden (TMB), inflammatory gene signature, phenotype of tumor-infiltrating lymphocytes, tumor microenvironment (TME), and immune checkpoint receptor expression on both immune and target cells. Additionally, the gut microbiota has recently been recognized as a systemic immunomodulatory factor and could further be used in the optimization of individualized immunovirotherapy algorithms.

SOCS3 inhibiting JAK-STAT pathway enhances oncolytic adenovirus efficacy by potentiating viral replication and T-cell activation

Oncolytic viruses (OVs) are emerging as a potentially useful treatment for malignancies due to the capabilities of direct oncolysis and immune induction. Improving the replication of OVs is an effective approach to enhance the oncolytic effects. Here, we observed that cancer cells with deficiencies in JAK-STAT pathway showed greater sensitivity to oncolytic adenovirus (oAd), and JAK inhibitor could enhance the replication of oAd. Therefore, we constructed a novel oAd expressing SOCS3, a major negative regulator of JAK-STAT pathway, and confirmed that oAd-SOCS3 exhibited a more significant antitumor effect than oAd-Ctrl both in vitro and in vivo. Mechanistically, SOCS3 inhibited the activation of JAK-STAT pathway, resulting in stronger tumor selective replication of oAd and downregulated expression of PD-L1 on cancer cells as well. Both benefits could collectively awaken antitumor immunity. This study highlights the importance of JAK-STAT pathway in viral replication and confirms the treatment of oAd-SOCS3 in potential clinical applications.

Oncolytic viruses in lung cancer treatment: a review article

Lung cancer has a high morbidity rate worldwide due to its resistance to therapy. So new treatment options are needed to improve the outcomes of lung cancer treatment. This study aimed to evaluate the effectiveness of oncolytic viruses (OVs) as a new type of cancer treatment. In this study, 158 articles from PubMed and Scopus from 1994 to 2022 were reviewed on the effectiveness of OVs in the treatment of lung cancer. The oncolytic properties of eight categories of OVs and their interactions with treatment options were investigated. OVs can be applied as a promising immunotherapy option, as they are reproduced selectively in different types of cancer cells, cause tumor cell lysis and trigger efficient immune responses.

Oncolytic Virotherapy: A New Paradigm in Cancer Immunotherapy

Oncolytic viruses (OVs) are emerging as potential treatment options for cancer. Natural and genetically engineered viruses exhibit various antitumor mechanisms. OVs act by direct cytolysis, the potentiation of the immune system through antigen release, and the activation of inflammatory responses or indirectly by interference with different types of elements in the tumor microenvironment, modification of energy metabolism in tumor cells, and antiangiogenic action. The action of OVs is pleiotropic, and they show varied interactions with the host and tumor cells. An important impediment in oncolytic virotherapy is the journey of the virus into the tumor cells and the possibility of its binding to different biological and nonbiological vectors. OVs have been demonstrated to eliminate cancer cells that are resistant to standard treatments in many clinical trials for various cancers (melanoma, lung, and hepatic); however, there are several elements of resistance to the action of viruses per se. Therefore, it is necessary to evaluate the combination of OVs with other standard treatment modalities, such as chemotherapy, immunotherapy, targeted therapies, and cellular therapies, to increase the response rate. This review provides a comprehensive update on OVs, their use in oncolytic virotherapy, and the future prospects of this therapy alongside the standard therapies currently used in cancer treatment.

Potential applications of JAK inhibitors, clinically approved drugs against autoimmune diseases, in cancer therapy

Disturbances in immunoregulation may lead to both cancer and autoimmune diseases. Many therapeutic drugs for autoimmune diseases also display anti-tumor efficacy. The Janus kinase/signal transducer and activator of transcription signaling pathways are involved in the secretion of more than 50 distinct cytokines, which have critical roles in inducing autoimmune diseases and tumorigenesis. Thus, Janus kinases have become classical immunotherapeutic targets for immune disease. More than 70 Janus kinase inhibitors have been approved as immunomodulatory drugs for clinical use, of which 12 are used in the treatment of autoimmune diseases. This systematic review aims to elucidate the anti-tumor role of clinically approved Janus kinase inhibitors that were primarily designed for the treatment of autoimmune diseases and their potential for clinical translation as cancer treatments.

Cyclanoline Reverses Cisplatin Resistance in Bladder Cancer Cells by Inhibiting the JAK2/STAT3 Pathway

BACKGROUND

Cisplatin is a key therapeutic agent for bladder cancer, yet the emergence of cisplatin resistance presents a significant clinical challenge.

OBJECTIVE

This study aims to investigate the potential and mechanisms of cyclanoline (Cyc) in overcoming cisplatin resistance.

METHODS

Cisplatin-resistant T24 and BIU-87 cell models (T24/DR and BIU-87/DR) were established by increasing gradual concentration. Western Blot (WB) assessed the phosphorylation of STAT3, JAK2, and JAK3. T24/DR and BIU-87/DR cell lines were treated with selective STAT3 phosphorylation modulators, and cell viability was evaluated by CCK-8. Cells were subjected to cisplatin, Cyc, or their combination. Immunofluorescence (IHC) examined p-STAT3 expression. Protein and mRNA levels of apoptosis-related and cell cycle-related factors were measured. Changes in proliferation, invasion, migration, apoptosis, and cell cycle were monitored. In vivo, subcutaneous tumor transplantation models in nude mice were established, assessing tumor volume and weight. Changes in bladder cancer tissues were observed through HE staining, and the p-STAT3 was assessed via WB and IHC.

RESULTS

Cisplatin-resistant cell lines were successfully established, demonstrating increased phosphorylation of STAT3, JAK2, and JAK3. Cisplatin or Cyc treatment decreased p-STAT3, inhibited invasion and migration, and induced apoptosis and cell cycle arrest in the G0/G1 phase in vitro. In vivo, tumor growth was significantly suppressed, with extensive tumor cell death. IHC and WB consistently showed a substantial downregulation of STAT3 phosphorylation. These changes were more pronounced when cisplatin and Cyc were administered in combination.

CONCLUSION

Cyc reverses cisplatin resistance via JAK/STAT3 inhibition in bladder cancer, offering a potential clinical strategy to enhance cisplatin efficacy in treating bladder cancer.

Oncolytic Viruses in the Era of Omics, Computational Technologies, and Modeling: Thesis, Antithesis, and Synthesis

Oncolytic viruses (OVs) are the frontier therapy for refractory cancers, especially in integration with immunomodulation strategies. In cancer immunovirotherapy, the many available "omics" and systems biology technologies generate at a fast pace a challenging huge amount of data, where apparently clashing information mirrors the complexity of individual clinical situations and OV used. In this review, we present and discuss how currently big data analysis, on one hand and, on the other, simulation, modeling, and computational technologies, provide invaluable support to interpret and integrate "omic" information and drive novel synthetic biology and personalized OV engineering approaches for effective immunovirotherapy. Altogether, these tools, possibly aided in the future by artificial intelligence as well, will allow for the blending of the information into OV recombinants able to achieve tumor clearance in a patient-tailored way. Various endeavors to the envisioned "synthesis" of turning OVs into personalized theranostic agents are presented.

Roles of tissue-resident immune cells in immunotherapy of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common and lethal type of lung cancer, with limited treatment options and poor prognosis. Immunotherapy offers hope for improving the survival and quality of life of NSCLC patients, but its efficacy depends on the tumor immune microenvironment (TME). Tissue-resident immune cells are a subset of immune cells that reside in various tissues and organs, and play an important role in fighting tumors. In NSCLC, tissue-resident immune cells are heterogeneous in their distribution, phenotype, and function, and can either promote or inhibit tumor progression and response to immunotherapy. In this review, we summarize the current understanding on the characteristics, interactions, and roles of tissue-resident immune cells in NSCLC. We also discuss the potential applications of tissue-resident immune cells in NSCLC immunotherapy, including immune checkpoint inhibitors (ICIs), other immunomodulatory agents, and personalized cell-based therapies. We highlight the challenges and opportunities for developing targeted therapies for tissue-resident immune cells and optimizing existing immunotherapeutic approaches for NSCLC patients. We propose that tissue-resident immune cells are a key determinant of NSCLC outcome and immunotherapy response, and warrant further investigation in future research.

Therapeutic strategy for oncovirus-mediated oral cancer: A comprehensive review

Oral cancer is a neoplastic disorder of the oral cavities, including the lips, tongue, buccal mucosa, and lower and upper gums. Oral cancer assessment entails a multistep process that requires deep knowledge of the molecular networks involved in its progression and development. Preventive measures including public awareness of risk factors and improving public behaviors are necessary, and screening techniques should be encouraged to enable early detection of malignant lesions. Herpes simplex virus (HSV), human papillomavirus (HPV), Epstein-Barr virus (EBV), and Kaposi sarcoma-associated herpesvirus (KSHV) are associated with other premalignant and carcinogenic conditions leading to oral cancer. Oncogenic viruses induce chromosomal rearrangements; activate signal transduction pathways via growth factor receptors, cytoplasmic protein kinases, and DNA binding transcription factors; modulate cell cycle proteins, and inhibit apoptotic pathways. In this review, we present an up-to-date overview on the use of nanomaterials for regulating viral proteins and oral cancer as well as the role of phytocompounds on oral cancer. The targets linking oncoviral proteins and oral carcinogenesis were also discussed.

Lung cancer treatment potential and limits associated with the STAT family of transcription factors

Lung cancer is one of the mortal cancers and the leading cause of cancer-related mortality, with a cancer survival rate of fewer than 5% in developing nations. This low survival rate can be linked to things like late-stage detection, quick postoperative recurrences in patients receiving therapy, and chemoresistance developing against various lung cancer treatments. Signal transducer and activator of transcription (STAT) family of transcription factors are involved in lung cancer cell proliferation, metastasis, immunological control, and treatment resistance. By interacting with specific DNA sequences, STAT proteins trigger the production of particular genes, which in turn result in adaptive and incredibly specific biological responses. In the human genome, seven STAT proteins have been discovered (STAT1 to STAT6, including STAT5a and STAT5b). Many external signaling proteins can activate unphosphorylated STATs (uSTATs), which are found inactively in the cytoplasm. When STAT proteins are activated, they can increase the transcription of several target genes, which leads to unchecked cellular proliferation, anti-apoptotic reactions, and angiogenesis. The effects of STAT transcription factors on lung cancer are variable; some are either pro- or anti-tumorigenic, while others maintain dual, context-dependent activities. Here, we give a succinct summary of the various functions that each member of the STAT family plays in lung cancer and go into more detail about the advantages and disadvantages of pharmacologically targeting STAT proteins and their upstream activators in the context of lung cancer treatment.

Oncolytic virotherapy in lung cancer

Lung tumors are one of the most aggressive threats affecting humans. Current therapeutic approaches have improved patients' survival; however, further efforts are required to increase effectiveness and protection against tumor relapse and metastasis. Immunotherapy presents an alternative to previous treatments that focuses on stimulating of the patient's immune system to destroy tumor cells. Viruses can be used as part of the immune therapeutic approach as agents that could selectively infect tumor cells, triggering an immune response against the infection and against the tumor cells. Some viruses have been selected for specifically infecting and destroying cancer cells, activating the immune response, enhancing access, amplifying the cytotoxicity against the tumor cells, and improving the long-term memory that can prevent tumor relapse. Oncolytic virotherapy can then be used as a strategy to target the destruction of transformed cells at the tumor site and act in locations distant from the primary targeted tumor site. Some of the current challenges in lung cancer treatment can be addressed using traditional therapies combined with oncolytic virotherapy. Defining the best combination, including the choice of the right settings will be at the next frontier in lung cancer treatment.

Oncolytic virotherapy: basic principles, recent advances and future directions

Oncolytic viruses (OVs) have attracted growing awareness in the twenty-first century, as they are generally considered to have direct oncolysis and cancer immune effects. With the progress in genetic engineering technology, OVs have been adopted as versatile platforms for developing novel antitumor strategies, used alone or in combination with other therapies. Recent studies have yielded eye-catching results that delineate the promising clinical outcomes that OVs would bring about in the future. In this review, we summarized the basic principles of OVs in terms of their classifications, as well as the recent advances in OV-modification strategies based on their characteristics, biofunctions, and cancer hallmarks. Candidate OVs are expected to be designed as "qualified soldiers" first by improving target fidelity and safety, and then equipped with "cold weapons" for a proper cytocidal effect, "hot weapons" capable of activating cancer immunotherapy, or "auxiliary weapons" by harnessing tactics such as anti-angiogenesis, reversed metabolic reprogramming and decomposing extracellular matrix around tumors. Combinations with other cancer therapeutic agents have also been elaborated to show encouraging antitumor effects. Robust results from clinical trials using OV as a treatment congruously suggested its significance in future application directions and challenges in developing OVs as novel weapons for tactical decisions in cancer treatment.

Application of oncolytic virus in tumor therapy

Oncolytic viruses (OVs) can selectively kill tumor cells without affecting normal cells, as well as activate the innate and adaptive immune systems in patients. Thus, they have been considered as a promising measure for safe and effective cancer treatment. Recently, a few genetically engineered OVs have been developed to further improve the effect of tumor elimination by expressing specific immune regulatory factors and thus enhance the body's antitumor immunity. In addition, the combined therapies of OVs and other immunotherapies have been applied in clinical. Although there are many studies on this hot topic, a comprehensive review is missing on illustrating the mechanisms of tumor clearance by OVs and how to modify engineered OVs to further enhance their antitumor effects. In this study, we provided a review on the mechanisms of immune regulatory factors in OVs. In addition, we reviewed the combined therapies of OVs with other therapies including radiotherapy and CAR-T or TCR-T cell therapy. The review is useful in further generalize the usage of OV in cancer treatment.

Preclinical efficacy of oncolytic VSV-IFNβ in treating cancer: A systematic review

Background

Cancer incidence and mortality are increasing rapidly worldwide, necessitating further investigation into developing and optimizing emergent cancer therapies. Oncolytic viruses such as vesicular stomatitis virus encoding interferon β (VSV-IFNβ) have attracted considerable attention, as they offer great efficacy and safety profiles. This systematic review aimed to determine and compare the efficacy profile between VSV-IFNβ and non-treatment controls in preclinical cancer models.

Methodology

The Embase and Medline databases were systematically searched for relevant studies using related key terms and Medical Subject Headings (MeSH). Titles, abstracts, and full texts were screened, and data from eligible articles were extracted by two groups independently and in duplicate (two reviewers per group). Disagreements were resolved by a fifth independent reviewer. The included articles were all preclinical (translational) in vivo English studies that investigated and compared the efficacy profile between VSV-IFNβ and non-treatment controls in animal models. The risk of bias among the studies was assessed by two reviewers independently and in duplicate using SYRCLE’s risk-of-bias tool for animal studies; disparities were addressed by a third independent reviewer.

Results

After employing relevant MeSH and key terms, we identified 1598 articles. A total of 87 articles were either duplicates or conference proceedings and were thus excluded. Following title and abstract screening, 37 articles were included in the full-text assessment. Finally, 14 studies met the eligibility criteria. Forty-two experiments from the included studies examined the potential efficacy of VSV-IFNβ through different routes of administration, including intratumoral, intraperitoneal, and intravenous routes. Thirty-seven experiments reported positive outcomes. Meanwhile, five experiments reported negative outcomes, three and two of which examined intratumoral and intravenous VSV-IFNβ administration, respectively.

Conclusion

Although the majority of the included studies support the promising potential of VSV-IFNβ as an oncolytic virus, further research is necessary to ensure a safe and efficacious profile to translate its application into clinical trials.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022335418.

The Dilemma of HSV-1 Oncolytic Virus Delivery: The Method Choice and Hurdles

Oncolytic viruses (OVs) have emerged as effective gene therapy and immunotherapy drugs. As an important gene delivery platform, the integration of exogenous genes into OVs has become a novel path for the advancement of OV therapy, while the herpes simplex virus type 1 (HSV-1) is the most commonly used. However, the current mode of administration of HSV-1 oncolytic virus is mainly based on the tumor in situ injection, which limits the application of such OV drugs to a certain extent. Intravenous administration offers a solution to the systemic distribution of OV drugs but is ambiguous in terms of efficacy and safety. The main reason is the synergistic role of innate and adaptive immunity of the immune system in the response against the HSV-1 oncolytic virus, which is rapidly cleared by the body's immune system before it reaches the tumor, a process that is accompanied by side effects. This article reviews different administration methods of HSV-1 oncolytic virus in the process of tumor treatment, especially the research progress in intravenous administration. It also discusses immune constraints and solutions of intravenous administration with the intent to provide new insights into HSV-1 delivery for OV therapy.

Janus kinase/signal transducers and activator of transcription (JAK/STAT) and its role in Lung inflammatory disease

A key signaling channel for the signal transduction of several crucial cytokines implicated in sepsis is the JAK/STAT system. Once cytokines attach to the proper receptors, JAK kinases linked to them are activated and can selectively phosphorylate STATs. Activated STATs subsequently go to the nucleus, where they play a key role in the transcription of the target genes. Various biological activities use the JAK/STAT pathway, including hematopoiesis, immunological modulation, cell differentiation, and apoptosis. Inflammatory lung illnesses affect people worldwide and are a serious public health concern. Numerous common respiratory conditions, such as asthma, bronchiectasis, chronic obstructive pulmonary disease (COPD), and acute respiratory distress syndrome, are strongly influenced by inflammation. Microorganism infections or the destruction or demise of host cells are the causes of inflammation and the factors that perpetuate it. This review discusses the main elements of severe lung inflammation and how the JAK/STAT signaling pathway is essential for lung inflammation.

Janus Kinase-Signal Transducer and Activator of Transcription Inhibitors for the Treatment and Management of Cancer

According to the World Health Organization (WHO), cancer is the second-highest cause of mortality worldwide, killing nearly 9.6 million people annually. Despite the advances in diagnosis and treatment during the last couple of decades, it remains a serious concern due to the limitations of currently available cancer management strategies. Therefore, alternative strategies are highly required to overcome these glitches. In addition, many etiological factors such as environmental and genetic factors initiate the activation of the Janus kinase (JAK)-signal transducer and activator of the transcription (STAT) pathway. This aberrant activation of the JAK-STAT pathway has been reported in various disease states, including inflammatory conditions, hematologic malignancies, and cancer. For instance, many patients with myeloproliferative neoplasms carry the acquired gain-of-function JAK2 V617F somatic mutation. This knowledge has dramatically improved our understanding of pathogenesis and has facilitated the development of therapeutics capable of suppressing the constitutive activation of the JAK-STAT pathway. Our aim is not to be expansive but to highlight emerging ideas towards preventive therapy in a modern view of JAK-STAT inhibitors. A series of agents with different specificities against different members of the JAK family of proteins is currently undergoing evaluation in clinical trials. Here we give a summary of how JAK-STAT inhibitors function and a detailed review of current clinical drugs for managing cancer as a new therapeutic approach.

JAK/STAT pathway: Extracellular signals, diseases, immunity, and therapeutic regimens

Janus kinase/signal transduction and transcription activation (JAK/STAT) pathways were originally thought to be intracellular signaling pathways that mediate cytokine signals in mammals. Existing studies show that the JAK/STAT pathway regulates the downstream signaling of numerous membrane proteins such as such as G-protein-associated receptors, integrins and so on. Mounting evidence shows that the JAK/STAT pathways play an important role in human disease pathology and pharmacological mechanism. The JAK/STAT pathways are related to aspects of all aspects of the immune system function, such as fighting infection, maintaining immune tolerance, strengthening barrier function, and cancer prevention, which are all important factors involved in immune response. In addition, the JAK/STAT pathways play an important role in extracellular mechanistic signaling and might be an important mediator of mechanistic signals that influence disease progression, immune environment. Therefore, it is important to understand the mechanism of the JAK/STAT pathways, which provides ideas for us to design more drugs targeting diseases based on the JAK/STAT pathway. In this review, we discuss the role of the JAK/STAT pathway in mechanistic signaling, disease progression, immune environment, and therapeutic targets.

Modelling the spatial dynamics of oncolytic virotherapy in the presence of virus-resistant tumour cells

Oncolytic virotherapy is a promising form of cancer treatment that uses native or genetically engineered viruses to target, infect and kill cancer cells. Unfortunately, this form of therapy is not effective in a substantial proportion of cancer patients, partly due to the occurrence of infection-resistant tumour cells. To shed new light on the mechanisms underlying therapeutic failure and to discover strategies that improve therapeutic efficacy we designed a cell-based model of viral infection. The model allows us to investigate the dynamics of infection-sensitive and infection-resistant cells in tumour tissue in presence of the virus. To reflect the importance of the spatial configuration of the tumour on the efficacy of virotherapy, we compare three variants of the model: two 2D models of a monolayer of tumour cells and a 3D model. In all model variants, we systematically investigate how the therapeutic outcome is affected by the properties of the virus (e.g. the rate of viral spread), the tumour (e.g. production rate of resistant cells, cost of resistance), the healthy stromal cells (e.g. degree of resistance to the virus) and the timing of treatment. We find that various therapeutic outcomes are possible when resistant cancer cells arise at low frequency in the tumour. These outcomes depend in an intricate but predictable way on the death rate of infected cells, where faster death leads to rapid virus clearance and cancer persistence. Our simulations reveal three different causes of therapy failure: rapid clearance of the virus, rapid selection of resistant cancer cells, and a low rate of viral spread due to the presence of infection-resistant healthy cells. Our models suggest that improved therapeutic efficacy can be achieved by sensitizing healthy stromal cells to infection, although this remedy has to be weighed against the toxicity induced in the healthy tissue.

Current landscape and perspective of oncolytic viruses and their combination therapies

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Oncolytic virotherapy has become an important branch of cancer immunotherapy in clinical practice.

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Multiple viruses can be engineered to be OVs and armed with anticancer genes to enhance their efficacy.

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OVs can reshape TME and produce synergistic anticancer efficacy when combined with other therapies.

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Safety and effectiveness are the main direction of future research and development of OVs.

Oncolytic virotherapy has become an important strategy in cancer immunotherapy. Oncolytic virus (OV) can reshape the tumor microenvironment (TME) through its replication-mediated oncolysis and transgene-produced anticancer effect, inducing an antitumor immune response and creating favorable conditions for the combination of other therapeutic measures. Extensive preclinical and clinical data have suggested that OV-based combination therapy has definite efficacy and promising prospects. Recently, several clinical trials of oncolytic virotherapy combined with immunotherapy have made breakthroughs. This review comprehensively elaborates the OV types and their targeting mechanisms, the selection of anticancer genes armed in OVs, and the therapeutic modes of action and strategies of OVs to provide a theoretical basis for the better design and construction of OVs and the optimization of OV-based therapeutic strategies.

Improving cancer immunotherapy by rationally combining oncolytic virus with modulators targeting key signaling pathways

Oncolytic viruses (OVs) represent a new class of multi-modal immunotherapies for cancer, with OV-elicited antitumor immunity being key to their overall therapeutic efficacy. Currently, the clinical effectiveness of OV as monotherapy remains limited, and thus investigators have been exploring various combinations with other anti-cancer agents and demonstrated improved therapeutic efficacy. As cancer cells have evolved to alter key signaling pathways for enhanced cell proliferation, cancer progression and metastasis, these cellular and molecular changes offer promising targets for rational cancer therapy design. In this regard, key molecules in relevant signaling pathways for cancer cells or/and immune cells, such as EGFR-KRAS (e.g., KRAS^G12C), PI3K-AKT-mTOR, ERK-MEK, JAK-STAT, p53, PD-1-PD-L1, and epigenetic, or immune pathways (e.g., histone deacetylases, cGAS-STING) are currently under investigation and have the potential to synergize with OV to modulate the immune milieu of the tumor microenvironment (TME), thereby improving and sustaining antitumor immunity. As many small molecule modulators of these signaling pathways have been developed and have shown strong therapeutic potential, here we review key findings related to both OV-mediated immunotherapy and the utility of small molecule modulators of signaling pathways in immuno-oncology. Then, we focus on discussion of the rationales and potential strategies for combining OV with selected modulators targeting key cellular signaling pathways in cancer or/and immune cells to modulate the TME and enhance antitumor immunity and therapeutic efficacy. Finally, we provide perspectives and viewpoints on the application of novel experimental systems and technologies that can propel this exciting branch of medicine into a bright future.

The gamble between oncolytic virus therapy and IFN

Various studies are being conducted on oncolytic virotherapy which one of the mechanisms is mediating interferon (IFN) production by it exerts antitumor effects. The antiviral effect of IFN itself has a negative impact on the inhibition of oncolytic virus or tumor eradication. Therefore, it is very critical to understand the mechanism of IFN regulation by oncolytic viruses, and to define its mechanism is of great significance for improving the antitumor effect of oncolytic viruses. This review focuses on the regulatory mechanisms of IFNs by various oncolytic viruses and their combination therapies. In addition, the exerting and the producing pathways of IFNs are briefly summarized, and some current issues are put forward.

The association between PI3K, JAK/STAT pathways with the PDL-1 expression in prostate cancer

Programmed cell death protein-1/programmed death-ligand-1 (PD-1/PDL-1) signalling pathway has gained attention in prostate cancer. The relationship between pSTAT-1, pSTAT-3 expressions and PTEN loss with PDL-1 expression was assessed and the effects of the pathways on prostate cancer prognosis were evaluated. Patients who underwent radical prostatectomy between 2011 and 2017 were included in our study. Prostatectomy materials were evaluated using immunohistochemical staining of pSTAT-1, pSTAT-3, PTEN, and PDL-1. The relationship between PDL-1 and pSTAT-1, pSTAT-3 expressions and PTEN loss was evaluated. Additionally, factors affecting biochemical recurrence-free survival and clinical progression-free survival were analysed. Within100 patients, 9 of 11 patients with PDL-1 expression also had intermediate-high pSTAT-1 staining intensity, and those with PDL-1 expression had higher pSTAT-1 staining intensity than those without (81.9% vs. 56.2%, p = 0.014). In univariate analysis, pSTAT-1, pSTAT-3 and PDL-1 expressions had significant impact on biochemical recurrence-free and clinical progression-free survival. In multivariate analysis, pSTAT-1 staining intensity with radical prostatectomy ISUP grade in terms of biochemical recurrence-free survival and the pSTAT-1 H-score with radical prostatectomy ISUP grade in terms of clinical progression-free survival were independent risk factors. Moderate-high expression of pSTAT-1 was closely associated with PDL-1 expression, and pSTAT-1 was also a predictor of biochemical recurrence and clinical progression.

CDK4/6 inhibition enhances oncolytic virus efficacy by potentiating tumor-selective cell killing and T cell activation in refractory glioblastoma

Glioblastoma multiforme (GBM) is among the most aggressive human cancers. Although oncolytic virus (OV) therapy has been proposed as a potential approach to treat GBM, it frequently fails because GBM cells are usually nonpermissive to OV. Here, we describe a dual-step drug screen for identifying chemical enhancers of oncolytic virus in GBM. From a high-throughput screen of 1416 FDA-approved drugs, an inhibitor of CDK4/6 was identified as the top enhancer, selectively increasing potency of two OV strains, VSVΔ51 and Zika virus. Mechanistically, CDK4/6 inhibition promoted autophagic degradation of MAVS, resulting in impaired antiviral responses and enhanced tumor-selective replication of VSVΔ51 in vitro and in vivo. CDK4/6 inhibition cooperated with VSVΔ51 to induce severe DNA damage stress and amplify oncolysis. In GBM xenograft models, combined treatment with CDK4/6 inhibitor and VSVΔ51 significantly inhibited tumor growth and prolonged the survival of tumor-bearing mice. Further investigation revealed that CDK4/6 inhibitor and VSVΔ51 synergistically induced immunogenic cell death and boosted anti-tumor immunity. Together, this study features a promising approach of treating aggressive GBM through the combination of CDK4/6 inhibitor with OV.

Trial Watch: combination of tyrosine kinase inhibitors (TKIs) and immunotherapy

The past decades witnessed the clinical employment of targeted therapies including but not limited to tyrosine kinase inhibitors (TKIs) that restrain a broad variety of pro-tumorigenic signals. TKIs can be categorized into (i) agents that directly target cancer cells, (ii) normalize angiogenesis or (iii) affect cells of the hematologic lineage. However, a clear distinction of TKIs based on this definition is limited by the fact that many TKIs designed to inhibit cancer cells have also effects on immune cells that are being discovered. Additionally, TKIs originally designed to target hematological cancers exhibit bioactivities on healthy cells of the same hematological lineage. TKIs have been described to improve immune recognition and cancer immunosurveillance, providing the scientific basis to combine TKIs with immunotherapy. Indeed, combination of TKIs with immunotherapy showed synergistic effects in preclinical models and clinical trials and some combinations of TKIs normalizing angiogenesis with immune checkpoint blocking antibodies have already been approved by the FDA for cancer therapy. However, the identification of appropriate drug combinations as well as optimal dosing and scheduling needs to be improved in order to obtain tangible progress in cancer care. This Trial Watch summarizes active clinical trials combining TKIs with various immunotherapeutic strategies to treat cancer patients.

Self-replicating vehicles based on negative strand RNA viruses

Self-replicating RNA viruses have been engineered as efficient expression vectors for vaccine development for infectious diseases and cancers. Moreover, self-replicating RNA viral vectors, particularly oncolytic viruses, have been applied for cancer therapy and immunotherapy. Among negative strand RNA viruses, measles viruses and rhabdoviruses have been frequently applied for vaccine development against viruses such as Chikungunya virus, Lassa virus, Ebola virus, influenza virus, HIV, Zika virus, and coronaviruses. Immunization of rodents and primates has elicited strong neutralizing antibody responses and provided protection against lethal challenges with pathogenic viruses. Several clinical trials have been conducted. Ervebo, a vaccine based on a vesicular stomatitis virus (VSV) vector has been approved for immunization of humans against Ebola virus. Different types of cancers such as brain, breast, cervical, lung, leukemia/lymphoma, ovarian, prostate, pancreatic, and melanoma, have been the targets for cancer vaccine development, cancer gene therapy, and cancer immunotherapy. Administration of measles virus and VSV vectors have demonstrated immune responses, tumor regression, and tumor eradication in various animal models. A limited number of clinical trials have shown well-tolerated treatment, good safety profiles, and dose-dependent activity in cancer patients.

Targeting High-Risk Neuroblastoma Patient-Derived Xenografts with Oncolytic Virotherapy

Cancer is the leading cause of death by disease in children, and over 15% of pediatric cancer-related mortalities are due to neuroblastoma. Current treatment options for neuroblastoma remain suboptimal as they often have significant toxicities, are associated with long-term side effects, and result in disease relapse in over half of children with high-risk disease. There is a dire need for new therapies, and oncolytic viruses may represent an effective solution. Oncolytic viruses attack tumor cells in two ways: direct infection of tumor cells leading to cytolysis, and production of a debris field that stimulates an anti-tumor immune response. Our group has previously shown that M002, an oncolytic herpes simplex virus (oHSV), genetically engineered to express murine interleukin-12 (mIL-12), was effective at targeting and killing long term passage tumor cell lines. In the current study, we investigated M002 in three neuroblastoma patient-derived xenografts (PDXs). PDXs better recapitulate the human condition, and these studies were designed to gather robust data for translation to a clinical trial. We found that all three PDXs expressed viral entry receptors, and that the virus actively replicated in the cells. M002 caused significant tumor cell death in 2D culture and 3D bioprinted tumor models. Finally, the PDXs displayed variable susceptibility to M002, with a more profound effect on high-risk neuroblastoma PDXs compared to low-risk PDX. These findings validate the importance of incorporating PDXs for preclinical testing of oncolytic viral therapeutics and showcase a novel technique, 3D bioprinting, to test therapies in PDXs. Collectively, our data indicate that oHSVs effectively target high-risk neuroblastoma, and support the advancement of this therapy to the clinical setting.

Tumor metastasis: Mechanistic insights and therapeutic interventions

Cancer metastasis is responsible for the vast majority of cancer-related deaths worldwide. In contrast to numerous discoveries that reveal the detailed mechanisms leading to the formation of the primary tumor, the biological underpinnings of the metastatic disease remain poorly understood. Cancer metastasis is a complex process in which cancer cells escape from the primary tumor, settle, and grow at other parts of the body. Epithelial-mesenchymal transition and anoikis resistance of tumor cells are the main forces to promote metastasis, and multiple components in the tumor microenvironment and their complicated crosstalk with cancer cells are closely involved in distant metastasis. In addition to the three cornerstones of tumor treatment, surgery, chemotherapy, and radiotherapy, novel treatment approaches including targeted therapy and immunotherapy have been established in patients with metastatic cancer. Although the cancer survival rate has been greatly improved over the years, it is still far from satisfactory. In this review, we provided an overview of the metastasis process, summarized the cellular and molecular mechanisms involved in the dissemination and distant metastasis of cancer cells, and reviewed the important advances in interventions for cancer metastasis.

Anti-neoplastic pharmacophore benzophenone-1 coumarin (BP-1C) targets JAK2 to induce apoptosis in lung cancer

Reigning of the abnormal gene activation associated with survival signalling in lung cancer leads to the anomalous growth and therapeutic failure. Targeting specific cell survival signalling like JAK2/STAT3 nexus has become a major focus of investigation to establish a target specific treatment. The 2-bromobenzoyl-4-methylphenoxy-acetyl hydra acetyl Coumarin (BP-1C), is new anti-neoplastic agent with apoptosis inducing capacity. The current study was aimed to develop antitumor phramacophore, BP-1C as JAK2 specific inhibitor against lung neoplastic progression. The study validates and identifies the molecular targets of BP-1C induced cell death. Cell based screening against multiple cancer cell lines identified, lung adenocarcinoma as its specific target through promotion of apoptosis. The BP-1C is able to induce, specific hall marks of apoptosis and there by conferring anti-neoplastic activity. Validation of its molecular mechanism, identified, BP-1C specifically targets JAK2^Tyr1007/1008 phosphorylation, and inhibits its downstream STAT3^Tyr705 signalling pathway to induce cell death. As a consequence, modulation in Akt/Src survival signal and altered expression of interwoven apoptotic genes were evident. The results were reproducible in an in-vivo LLC tumor model and in-ovo xenograft studies. The computational approaches viz, drug finger printing confers, BP-1C as novel class JAK2 inhibitor and molecular simulations studies assures its efficiency in binding with JAK2. Overall, BP-1C is a novel JAK2 inhibitor with experimental evidence and could be effectively developed into a promising drug for lung cancer treatment.

Development of oncolytic viruses for cancer therapy

Oncolytic virotherapy is a therapeutic approach that uses replication-competent viruses to kill cancers. The ability of oncolytic viruses to selectively replicate in cancer cells leads to direct cell lysis and induction of anticancer immune response. Like other anticancer therapies, oncolytic virotherapy has several limitations such as viral delivery to the target, penetration into the tumor mass, and antiviral immune responses. This review provides an insight into the different characteristics of oncolytic viruses (natural and genetically modified) that contribute to effective applications of oncolytic virotherapy in preclinical and clinical trials, and strategies to overcome the limitations. The potential of oncolytic virotherapy combining with other conventional treatments or cancer immunotherapies involving immune checkpoint inhibitors and CAR-T therapy could form part of future multimodality treatment strategies.

Intrinsic Interferon Signaling Regulates the Cell Death and Mesenchymal Phenotype of Glioblastoma Stem Cells

Simple Summary

Interferon signaling is mostly studied in the context of immune cells. However, its role in glioma cancer cells is unclear. This study aimed to investigate the role of cancer-cell-intrinsic IFN signaling in tumorigenesis in glioblastoma (GBM). We found that GSCs and GBM tumors exhibited differential cell-intrinsic type I and type II IFN signaling, and the high IFN/STAT1 signaling was associated with mesenchymal phenotype and poor survival in glioma patients. IFN-β exposure induced cell death in GSCs with intrinsically high IFN/STAT1 signaling, and this effect was abolished by inhibition of IFN/STAT1 signaling. A subset of GBM patients with high IFN/STAT1 may benefit from the IFN-β therapy.

Abstract

Interferon (IFN) signaling contributes to stemness, cell proliferation, cell death, and cytokine signaling in cancer and immune cells; however, the role of IFN signaling in glioblastoma (GBM) and GBM stem-like cells (GSCs) is unclear. Here, we investigated the role of cancer-cell-intrinsic IFN signaling in tumorigenesis in GBM. We report here that GSCs and GBM tumors exhibited differential cell-intrinsic type I and type II IFN signaling, and high IFN/STAT1 signaling was associated with mesenchymal phenotype and poor survival outcomes. In addition, chronic inhibition of IFN/STAT1 signaling decreased cell proliferation and mesenchymal signatures in GSCs with intrinsically high IFN/STAT1 signaling. IFN-β exposure induced apoptosis in GSCs with intrinsically high IFN/STAT1 signaling, and this effect was abolished by the pharmacological inhibitor ruxolitinib and STAT1 knockdown. We provide evidence for targeting IFN signaling in a specific sub-group of GBM patients. IFN-β may be a promising candidate for adjuvant GBM therapy.

Resistance Mechanisms Influencing Oncolytic Virotherapy, a Systematic Analysis

Resistance to therapy is a frequently observed phenomenon in the treatment of cancer, and as with other cancer therapeutics, therapies based on oncolytic viruses also face the challenges of resistance, such as humoral and cellular antiviral responses, and tumor-associated interferon-mediated resistance. In order to identify additional mechanisms of resistance that may contribute to therapeutic failure, we developed a systematic search strategy for studies published in PubMed. We analyzed 6143 articles on oncolytic virotherapy and found that approximately 8% of these articles use resistance terms in the abstract and/or title. Of these 439 articles, 87 were original research. Most of the findings reported pertain to resistance mediated by tumor-cell-dependent interferon signaling. Yet, mechanisms such as epigenetic modifications, hypoxia-mediated inhibition, APOBEC-mediated resistance, virus entry barriers, and spatiotemporal restriction to viral spread, although not frequently assessed, were demonstrated to play a major role in resistance. Similarly, our results suggest that the stromal compartment consisting of, but not limited to, myeloid cells, fibroblasts, and epithelial cells requires more study in relation to therapy resistance using oncolytic viruses. Thus, our findings emphasize the need to assess the stromal compartment and to identify novel mechanisms that play an important role in conferring resistance to oncolytic virotherapy.

Oncolytic virotherapy - Forging its place in the immunomodulatory paradigm for Multiple Myeloma

The treatment focus for multiple myeloma (MM) has recently pivoted towards immune modulating strategies, with T-cell redirection therapies currently at the forefront of drug development. Yet, despite this revolution in treatment, MM remains without a sustainable cure. At the same time, tremendous advancement has been made in recombinant and gene editing techniques for oncolytic viruses (OV), which have increased their tumor specificity, improved safety, and enhanced the oncolytic and immunostimulatory potential. These breakthrough developments in oncolytic virotherapy have opened new avenues for OVs to be used in combination with other immune-based therapies such as checkpoint inhibitors, chimeric antigen receptor T-cells (CAR-T) and bispecific T-cell engagers. In this review, the authors place the spotlight on systemic oncolytic virotherapy as an adaptable immunotherapeutic for MM, highlight the unique mechanism of OVs in activating the immune-suppressive marrow microenvironment, and lastly showcase the OV platforms and the promising combination strategies in the pipeline for MM.

Targeting JAK/STAT Signaling Antagonizes Resistance to Oncolytic Reovirus Therapy Driven by Prior Infection with HTLV-1 in Models of T-Cell Lymphoma

Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that infects at least 10 million people worldwide and is associated with the development of T-cell lymphoma (TCL). The treatment of TCL remains challenging and new treatment options are urgently needed. With the goal of developing a novel therapeutic approach for TCL, we investigated the activity of the clinical formulation of oncolytic reovirus (Reolysin, Pelareorep) in TCL models. Our studies revealed that HTLV-1-negative TCL cells were highly sensitive to Reolysin-induced cell death, but HTLV-1-positive TCL cells were resistant. Consistent with these data, reovirus displayed significant viral accumulation in HTLV-1-negative cells, but failed to efficiently replicate in HTLV-1-positive cells. Transcriptome analyses of HTLV-1-positive vs. negative cells revealed a significant increase in genes associated with retroviral infection including interleukin-13 and signal transducer and activator of transcription 5 (STAT5). To investigate the relationship between HTLV-1 status and sensitivity to Reolysin, we infected HTLV-1-negative cells with HTLV-1. The presence of HTLV-1 resulted in significantly decreased sensitivity to Reolysin. Treatment with the JAK inhibitor ruxolitinib suppressed STAT5 phosphorylation and expression of the key anti-viral response protein MX1 and enhanced the anti-TCL activity of Reolysin in both HTLV-1-positive and negative cells. Our data demonstrate that the inhibition of the JAK/STAT pathway can be used as a novel approach to antagonize the resistance of HTLV-1-positive cells to oncolytic virus therapy.

Combining Oncolytic Viruses and Small Molecule Therapeutics: Mutual Benefits

The focus of treating cancer with oncolytic viruses (OVs) has increasingly shifted towards achieving efficacy through the induction and augmentation of an antitumor immune response. However, innate antiviral responses can limit the activity of many OVs within the tumor and several immunosuppressive factors can hamper any subsequent antitumor immune responses. In recent decades, numerous small molecule compounds that either inhibit the immunosuppressive features of tumor cells or antagonize antiviral immunity have been developed and tested for. Here we comprehensively review small molecule compounds that can achieve therapeutic synergy with OVs. We also elaborate on the mechanisms by which these treatments elicit anti-tumor effects as monotherapies and how these complement OV treatment.

Immunostimulatory bacterial antigen-armed oncolytic measles virotherapy significantly increases the potency of anti-PD1 checkpoint therapy

Clinical immunotherapy approaches are lacking efficacy in the treatment of glioblastoma (GBM). In this study, we sought to reverse local and systemic GBM-induced immunosuppression using the Helicobacter pylori neutrophil-activating protein (NAP), a potent TLR2 agonist, as an immunostimulatory transgene expressed in an oncolytic measles virus (MV) platform, retargeted to allow viral entry through the urokinase-type plasminogen activator receptor (uPAR). While single-agent murine anti-PD1 treatment or repeat in situ immunization with MV-s-NAP-uPA provided modest survival benefit in MV-resistant syngeneic GBM models, the combination treatment led to synergy with a cure rate of 80% in mice bearing intracranial GL261 tumors and 72% in mice with CT-2A tumors. Combination NAP-immunovirotherapy induced massive influx of lymphoid cells in mouse brain, with CD8+ T cell predominance; therapeutic efficacy was CD8+ T cell dependent. Inhibition of the IFN response pathway using the JAK1/JAK2 inhibitor ruxolitinib decreased PD-L1 expression on myeloid-derived suppressor cells in the brain and further potentiated the therapeutic effect of MV-s-NAP-uPA and anti-PD1. Our findings support the notion that MV strains armed with bacterial immunostimulatory antigens represent an effective strategy to overcome the limited efficacy of immune checkpoint inhibitor-based therapies in GBM, creating a promising translational strategy for this lethal brain tumor.

ECMarker: interpretable machine learning model identifies gene expression biomarkers predicting clinical outcomes and reveals molecular mechanisms of human disease in early stages

MOTIVATION

Gene expression and regulation, a key molecular mechanism driving human disease development, remains elusive, especially at early stages. Integrating the increasing amount of population-level genomic data and understanding gene regulatory mechanisms in disease development are still challenging. Machine learning has emerged to solve this, but many machine learning methods were typically limited to building an accurate prediction model as a 'black box', barely providing biological and clinical interpretability from the box.

RESULTS

To address these challenges, we developed an interpretable and scalable machine learning model, ECMarker, to predict gene expression biomarkers for disease phenotypes and simultaneously reveal underlying regulatory mechanisms. Particularly, ECMarker is built on the integration of semi- and discriminative-restricted Boltzmann machines, a neural network model for classification allowing lateral connections at the input gene layer. This interpretable model is scalable without needing any prior feature selection and enables directly modeling and prioritizing genes and revealing potential gene networks (from lateral connections) for the phenotypes. With application to the gene expression data of non-small-cell lung cancer patients, we found that ECMarker not only achieved a relatively high accuracy for predicting cancer stages but also identified the biomarker genes and gene networks implying the regulatory mechanisms in the lung cancer development. In addition, ECMarker demonstrates clinical interpretability as its prioritized biomarker genes can predict survival rates of early lung cancer patients (P-value < 0.005). Finally, we identified a number of drugs currently in clinical use for late stages or other cancers with effects on these early lung cancer biomarkers, suggesting potential novel candidates on early cancer medicine.

AVAILABILITYAND IMPLEMENTATION

ECMarker is open source as a general-purpose tool at https://github.com/daifengwanglab/ECMarker.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Flavopereirine Suppresses the Progression of Human Oral Cancer by Inhibiting the JAK-STAT Signaling Pathway via Targeting LASP1

Objective

Flavopereirine has been identified to be a potential anti-cancer agent in several types of human cancer. This study aimed to investigate the anti-cancer activity of flavopereirine in oral cancer.

Methods

The effect of flavopereirine on cell viability of human oral cancer cell lines (BcaCD885 and Tca8113) was evaluated by MTT assay and colony formation assay. Cell apoptosis and cell cycle distribution were detected by flow cytometry. Cell invasion and migration were evaluated by Transwell assay. The expression of LASP1, JAK2, p-JAK2, STST3, p-STST3, STST5 and p-STST5 was evaluated by qRT-PCR and Western blot. In addition, the xenograft mouse model was constructed to determine the anti-cancer role of flavopereirine in vivo.

Results

Flavopereirine significantly inhibited cell proliferation, invasion, migration and EMT process of BcaCD885 and Tca8113 cells, while promoted cell apoptosis in vitro. Flavopereirine markedly decreased the expression levels of p-JAK2, p-STST3 and p-STST5, while increased the expression levels of LASP1. In addition, downregulation of LASP1 significantly increased the expression levels of p-JAK2, p-STAT3 and p-STAT5 compared with si-NC in BcaCD885 cells. Moreover, flavopereirine was found to decrease tumor weight and volume of xenograft tumors in vivo.

Conclusion

Flavopereirine inhibited the progression of oral cancer through inactivating the JAK/STAT signaling pathway by upregulating LASP1, suggesting that flavopereirine might be a potential anti-cancer agent for oral cancer.

Evolving Role of Oncolytic Virotherapy: Challenges and Prospects in Clinical Practice

Selective oncotropism and cytolytic activity against tumors have made certain viruses subject to investigation as novel treatment modalities. However, monotherapy with oncolytic viruses (OVs) has shown limited success and modest clinical benefit. The capacity to genetically engineer OVs makes them a desirable platform to design complementary treatment modalities to overcome the existing treatment options' shortcomings. In recent years, our knowledge of interactions of the tumors with the immune system has expanded profoundly. There is a growing body of literature supporting immunomodulatory roles for OVs. The concept of bioengineering these platforms to induce the desired immune response and complement the current immunotherapeutic modalities to make immune-resistant tumors responsive to immunotherapy is under investigation in preclinical and early clinical trials. This review provides an overview of attempts to optimize oncolytic virotherapy as essential components of the multimodality anticancer therapeutic approach and discusses the challenges in translation to clinical practice.

Mutations in the IFNγ-JAK-STAT Pathway Causing Resistance to Immune Checkpoint Inhibitors in Melanoma Increase Sensitivity to Oncolytic Virus Treatment

PURPOSE

Next-generation sequencing studies and CRISPR-Cas9 screens have established mutations in the IFNγ-JAK-STAT pathway as an immune checkpoint inhibitor (ICI) resistance mechanism in a subset of patients with melanoma. We hypothesized ICI resistance mutations in the IFNγ pathway would simultaneously render melanomas susceptible to oncolytic virus (OV) therapy.

EXPERIMENTAL DESIGN

Cytotoxicity experiments were performed with a number of OVs on a matched melanoma cell line pair generated from a baseline biopsy and a progressing lesion with complete JAK2 loss from a patient that relapsed on anti-PD-1 therapy, in melanoma lines following JAK1/2 RNA interference (RNAi) and pharmacologic inhibition and in Jak2 knockout (KO) B16-F10 mouse melanomas. Furthermore, we estimated the frequency of genetic alterations in the IFNγ-JAK-STAT pathway in human melanomas.

RESULTS

The melanoma line from an anti-PD-1 progressing lesion was 7- and 22-fold more sensitive to the modified OVs, herpes simplex virus 1 (HSV1-dICP0) and vesicular stomatitis virus (VSV-Δ51), respectively, compared with the line from the baseline biopsy. RNAi, JAK1/2 inhibitor studies, and in vivo studies of Jak2 KOs B16-F10 melanomas revealed a significant increase in VSV-Δ51 sensitivity with JAK/STAT pathway inhibition. Our analysis of The Cancer Genome Atlas data estimated that approximately 11% of ICI-naïve cutaneous melanomas have alterations in IFNγ pathway genes that may confer OV susceptibility.

CONCLUSIONS

We provide mechanistic support for the use of OVs as a precision medicine strategy for both salvage therapy in ICI-resistant and first-line treatment in melanomas with IFNγ-JAK-STAT pathway mutations. Our study also supports JAK inhibitor-OV combination therapy for treatment-naïve melanomas without IFN signaling defects.See related commentary by Kaufman, p. 3278.