Beyond cancer cells: Targeting the tumor microenvironment with gene therapy and armed oncolytic virus

Recent progress of iron-based nanomaterials in gene delivery and tumor gene therapy

Gene therapy aims to modify or manipulate gene expression and change the biological characteristics of living cells to achieve the purpose of treating diseases. The safe, efficient, and stable expression of exogenous genes in cells is crucial for the success of gene therapy, which is closely related to the vectors used in gene therapy. Currently, gene therapy vectors are mainly divided into two categories: viral vectors and non-viral vectors. Viral vectors are widely used due to the advantages of persistent and stable expression, high transfection efficiency, but they also have certain issues such as infectivity, high immunological rejection, randomness of insertion mutation, carcinogenicity, and limited vector capacity. Non-viral vectors have the advantages of non-infectivity, controllable chemical structure, and unlimited vector capacity, but the transfection efficiency is low. With the rapid development of nanotechnology, the unique physicochemical properties of nanomaterials have attracted increasing attention in the field of drug and gene delivery. Among many nanomaterials, iron-based nanomaterials have attracted much attention due to their superior physicochemical properties, such as Fenton reaction, magnetic resonance imaging, magnetothermal therapy, photothermal therapy, gene delivery, magnetically-assisted drug delivery, cell and tissue targeting, and so on. In this paper, the research progress of iron-based nanomaterials in gene delivery and tumor gene therapy is reviewed, and the future application direction of iron-based nanomaterials is further prospected.

DNMT3A promotes glioma growth and malignancy via TNF-α/NF-κB signaling pathway

Background

DNMT3A is the main molecule responsible for DNA methylation in cells. DNMT3A affects the progression of inflammation, degenerative diseases, and malignant tumors, and exhibits significant aberrantly expression in tumor tissues.

Methods

Transcriptome data and relevant clinical information were downloaded from The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), and Gene Expression Omnibus (GEO) datasets. Differential expression analysis and prognostic analysis were conducted based on above statistics. We constructed a clinical prognostic model and identified DNMT3A as an independent prognostic factor to accurately predict patient prognosis. Differential gene enrichment analysis revealed that DNMT3A affects the progression of glioma through multiple pathways, among which the tumor necrosis factor-α (TNF-α)/nuclear factor-kappa B (NF-κB) pathway shows a strong correlation. Immunological analysis also revealed a certain correlation between DNMT3A and tumor immunity. We demonstrated through gene editing that DNMT3A can affect the release of TNF-α in cells, thereby affecting the progression of glioma. Functional experiments have also demonstrated that DNMT3A plays a crucial role in tumors.

Results

RNA-sequencing and survival analyses of lower-grade glioma (LGG) patients in TCGA, CGGA, and GEO cohorts showed that high DNMT3A expression correlated with poor prognosis of LGG patients. Univariate and multivariate Cox regression analyses showed that DNMT3A expression was an independent prognostic indicator in LGG. The prognosis prediction nomogram with age, World Health Organization (WHO) grading, and DNMT3A expression showed reliable performance in predicting the 1-, 3-, and 5-year overall survival (OS) of LGG patients. Functional enrichment analysis, gene set enrichment analysis (GSEA), and ESTIMATE algorithm analyses showed that DNMT3A expression was associated with the tumor infiltration of immune cells and predicted response to immunotherapy in two immunotherapy cohorts of pan-cancer patients. Furthermore, short hairpin RNA (shRNA)-mediated knockdown of DNMT3A in the LGG cell lines suppressed proliferation, migration, and invasion of LGG cells by downregulating the TNF-α/NF-κB signaling pathway.

Conclusions

Our data showed that DNMT3A was a potential prognostic biomarker in glioma. DNMT3A promoted proliferation and malignancy of LGG cells through the TNF-α/NF-κB signaling pathway. DNMT3A is a promising therapeutic target for treating patients with LGG.

Cancer-associated fibroblasts: a versatile mediator in tumor progression, metastasis, and targeted therapy

Tumor microenvironment (TME) has been demonstrated to play a significant role in tumor initiation, progression, and metastasis. Cancer-associated fibroblasts (CAFs) are the major component of TME and exhibit heterogeneous properties in their communication with tumor cells. This heterogeneity of CAFs can be attributed to various origins, including quiescent fibroblasts, mesenchymal stem cells (MSCs), adipocytes, pericytes, endothelial cells, and mesothelial cells. Moreover, single-cell RNA sequencing has identified diverse phenotypes of CAFs, with myofibroblastic CAFs (myCAFs) and inflammatory CAFs (iCAFs) being the most acknowledged, alongside newly discovered subtypes like antigen-presenting CAFs (apCAFs). Due to these heterogeneities, CAFs exert multiple functions in tumorigenesis, cancer stemness, angiogenesis, immunosuppression, metabolism, and metastasis. As a result, targeted therapies aimed at the TME, particularly focusing on CAFs, are rapidly developing, fueling the promising future of advanced tumor-targeted therapy.

Immunotherapeutic Strategies for the Treatment of Glioblastoma: Current Challenges and Future Perspectives

Despite decades of research and the best up-to-date treatments, grade 4 Glioblastoma (GBM) remains uniformly fatal with a patient median overall survival of less than 2 years. Recent advances in immunotherapy have reignited interest in utilizing immunological approaches to fight cancer. However, current immunotherapies have so far not met the anticipated expectations, achieving modest results in their journey from bench to bedside for the treatment of GBM. Understanding the intrinsic features of GBM is of crucial importance for the development of effective antitumoral strategies to improve patient life expectancy and conditions. In this review, we provide a comprehensive overview of the distinctive characteristics of GBM that significantly influence current conventional therapies and immune-based approaches. Moreover, we present an overview of the immunotherapeutic strategies currently undergoing clinical evaluation for GBM treatment, with a specific emphasis on those advancing to phase 3 clinical studies. These encompass immune checkpoint inhibitors, adoptive T cell therapies, vaccination strategies (i.e., RNA-, DNA-, and peptide-based vaccines), and virus-based approaches. Finally, we explore novel innovative strategies and future prospects in the field of immunotherapy for GBM.

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.

Recent progress in combination therapy of oncolytic vaccinia virus

In recent years, oncolytic viruses have emerged as promising agents for treating various cancers. An oncolytic virus is a non-pathogenic virus that, due to genetic manipulation, tends to replicate in and cause lysis of cancerous cells while leaving healthy cells unaffected. Among these viruses, vaccinia virus is an attractive platform for use as an oncolytic platform due to its 190 Kb genome with a high capacity for encoding therapeutic payloads. Combining oncolytic VV therapy with other conventional cancer treatments has been shown to be synergistic and more effective than monotherapies. Additionally, OVV can be used as a vector to deliver therapeutic payloads, alone or in combination with other treatments, to increase overall efficacy. Here, we present a comprehensive analysis of preclinical and clinical studies that have evaluated the efficacy of oncolytic vaccinia viruses in cancer immunotherapy. We discuss the outcomes of these studies, including tumor regression rates, overall survival benefits, and long-term responses. Moreover, we provide insights into the challenges and limitations associated with oncolytic vaccinia virus- based therapies, including immune evasion mechanisms, potential toxicities, and the development of resistance.

Combination Immunotherapy of Oncolytic Flu-Vectored Virus and Programmed Cell Death 1 Blockade Enhances Antitumor Activity in Hepatocellular Carcinoma

Oncolytic viruses (OVs) are appealing anti-tumor agents. But it is limited in its effectiveness. In this study, we used combination therapy with immune checkpoint inhibitor to enhance the antitumor efficacy of OVs. Using reverse genetics technology, we rescued an oncolytic influenza virus with the name delNS1-GM-CSF from the virus. After identifying the hemagglutination and 50% tissue culture infectivedose (TCID50) of delNS1-GM-CSF, it was purified, and the viral morphology was observed under electron microscopy. Reverse transcription quantitative-polymerase chain reaction (RT-qPCR) was used to identify the level of GM-CSF expression in delNS1-GM-CSF, and the GM-CSF expression level was determined after infection with delNS1-GM-CSF by enzyme linked immunosorbent assay (ELISA). To study the tumor-killing effect of delNS1-GM-CSF, we utilized the hepatocellular carcinoma (HCC) tumor-bearing mouse model. To examine signaling pathways, we performed transcriptome sequencing on mouse tumor tissue and applied western blotting to confirm the results. Changes in T-cell infiltration in HCC tumors following treatment were analyzed using flow cytometry and immunohistochemistry. DelNS1-GM-CSF can target and kill HCCs without damaging normal hepatocytes. DelNS1-GM-CSF combined with programmed cell death 1 blockade therapy enhanced anti-tumor effects and significantly improved mouse survival. Further, we found that combination therapy had an antitumor impact via the janus kinase-signal transducer and activator of transcription (JAK2-STAT3) pathway as well as activated CD4+ and CD8+T cells. Interestingly, combined therapy also showed promising efficacy in distant tumors. DelNS1-GM-CSF is well targeted. Mechanistic investigation revealed that it functions through the JAK2-STAT3 pathway. Combination immunotherapies expected to be a novel strategy for HCC immunotherapy.

The role of lncRNA HCG18 in human diseases

A substantial number of long noncoding RNAs (lncRNAs) have been identified as potent regulators of human disease. Human leukocyte antigen complex group 18 (HCG18) is a new type of lncRNA that has recently been proven to play an important role in the occurrence and development of various diseases. Studies have found that abnormal expression of HCG18 is closely related to the clinicopathological characteristics of many diseases. More importantly, HCG18 was also found to promote disease progression by affecting a series of cell biological processes. This article mainly discusses the expression characteristics, clinical characteristics, biological effects and related regulatory mechanisms of HCG18 in different human diseases, providing a scientific theoretical basis for its early clinical application.

Ultrasound image-guided cancer gene therapy using iRGD dual-targeted magnetic cationic microbubbles

The gene therapy attracted more and more attention for the tumor therapy. To obtain a safe gene therapy system, the new gene vectors beyond the virus were developed for a high gene therapy efficiency. The ultrasound mediated gene therapy was safer and the plasmid DNA could be delivered by the microbubbles and combined with the ultrasound to increase the gene transfection efficiency. In this work, the cationic microbubbles decorated with Cyclo(Cys-Arg-Gly-Asp-Lys-Gly-Pro-AspCys) (iRGD peptides) and magnetic Fe3O4 nanoparticles (MBiM) was designed for targeted ultrasound contrast imaging guided gene therapy of tumors. The ultrasound image intensity was dramatically enhanced at the tumor site that received MBiM with the magnet applied, compared to those administrated the non-targeted microbubbles (MBb) or the microbubbles with only one target material on the surface (MBM and MBbi). The pGPU6/GFP/Neo-shAKT2 was used as a sample gene, which down regulate the AKT2 protein expression for the cancer therapy. It illustrated that MBiM/AKT2 had the highest gene transfection efficiency in the studied microbubbles mediated by the ultrasound, leading to the AKT2 protein expression downregulation and the strongest tumor killing effect in vitro and in vivo. In summary, a novel and biocompatible gene delivery platform via MBiM with both the endogenous and external targeting effects for breast cancer theranostics was developed.

A retrospective study on the efficacy and safety of Envafolimab, a PD-L1 inhibitor, in the treatment of advanced malignant solid tumors

Envafolimab, a PD-L1 inhibitor, has demonstrated potential in treating advanced malignant solid tumors (AMST). To study its' efficacy and safety in AMST, our retrospective study recruited 64 patients with various AMST, and treated with Envafolimab (400 mg every 3 weeks). We divided the patients into two cohorts: Cohort 1 (25 patients) receiving Envafolimab as first-line therapy, and Cohort 2 (39 patients) receiving it as second-line or subsequent therapy. Our analysis focused on Envafolimab's efficacy and safety. Over a median follow-up of 7.1 months, Cohort I reported a Disease Control Rate (DCR) of 72.0% and an Objective response rate (ORR) of 12.0%, while Cohort II had a DCR of 51.3% and an ORR of 5.1%. Notably, patients with more than four treatment cycles showed higher DCR and longer Progression-Free Survival (PFS) than those with fewer cycles. Adverse events were observed in 68.8% of patients, with severe events (CTCAE grade 3/4) in 14.1%. Most adverse events were mild, leading to treatment discontinuation in only 3.1% of patients, with no life-threatening events reported. In summary, Envafolimab is a safe and effective treatment for AMST, in both initial and later therapy stages, particularly with extended treatment duration, meriting further clinical trials.

An Engineered Influenza a Virus Expressing the Co-Stimulator OX40L as an Oncolytic Agent Against Hepatocellular Carcinoma

Background

Oncolytic virus (OV) therapy has emerged as a promising novel form of immunotherapy. Moreover, an increasing number of studies have shown that the therapeutic efficacy of OV can be further improved by arming OVs with immune-stimulating molecules.

Methods

In this study, we used reverse genetics to produce a novel influenza A virus, termed IAV-OX40L, which contained the immune-stimulating molecule OX40L gene in the influenza virus nonstructural (NS1) protein gene. The oncolytic effect of IAV-OX40L was explored on hepatocellular carcinoma (HCC)HCC cells in vitro and in vivo.

Results

Hemagglutination titers of the IAV-OX40L virus were stably 27-28 in specific-pathogen-free chicken embryos. The morphology and size distribution of IAV-OX40L are similar to those of the wild-type influenza. Expression of OX40L protein was confirmed by Western blot and immunofluorescence. MTS assays showed that the cytotoxicity of IAV-OX40L was higher in HCC cells (HepG2 and Huh7) than in normal liver cells (MIHA) in a time- and dose-dependent manner in vitro. We found that intratumoral injection of IAV-OX40L reduced tumor growth and increased the survival rate of mice compared with PR8-treated controls in vivo. In addition, the pathological results showed that IAV-OX40L selectively destroyed tumor tissues without harming liver and lung tissues. CD4+ and CD8+ T cells of the IAV-OX40L group were significantly increased in the splenic lymphocytes of mice. Further validation confirmed that IAV-OX40L enhanced the immune response mainly by activating Th1-dominant immune cells, releasing interferon-γ and interleukin-2.

Conclusion

Taken together, our findings demonstrate the novel chimeric influenza OV could provide a potential therapeutic strategy for combating HCC and improve the effectiveness of virotherapy for cancer therapy.

Improving the therapeutic efficacy of oncolytic viruses for cancer: targeting macrophages

Oncolytic viruses (OVs) for cancer treatment are in a rapid stage of development, and the direct tumor lysis and activation of a comprehensive host immune response are irreplaceable advantages of cancer immunotherapy. However, excessive antiviral immune responses also restrict the spread of OVs in vivo and the infection of tumor cells. Macrophages are functionally diverse innate immune cells that phagocytose tumor cells and present antigens to activate the immune response, while also limiting the delivery of OVs to tumors. Studies have shown that the functional propensity of macrophages between OVs and tumor cells affects the overall therapeutic effect of oncolytic virotherapy. How to effectively avoid the restrictive effect of macrophages on OVs and reshape the function of tumor-associated macrophages in oncolytic virotherapy is an important challenge we are now facing. Here, we review and summarize the complex dual role of macrophages in oncolytic virotherapy, highlighting how the functional characteristics of macrophage plasticity can be utilized to cooperate with OVs to enhance anti-tumor effects, as well as highlighting the importance of designing and optimizing delivery modalities for OVs in the future.

Design and selection of anti-PD-L1 single-domain antibody and tumor necrosis factor superfamily ligands for an optimal vectorization in an oncolytic virus

Arming oncolytic viruses with transgenes encoding immunomodulators improves their therapeutic efficacy by enhancing and/or sustaining the innate and adaptive anti-tumoral immune responses. We report here the isolation, selection, and vectorization of a blocking anti-human PDL1 single-domain antibody (sdAb) isolated from PDL1-immunized alpacas. Several formats of this sdAb were vectorized into the vaccinia virus (VV) and evaluated for their programmed cell death protein 1 (PD1)/PD1 ligand (PDL1) blocking activity in the culture medium of tumor cells infected in vitro. In those conditions, VV-encoded homodimeric sdAb generated superior PDL1 blocking activity compared to a benchmark virus encoding full-length avelumab. The sdAb was further used to design simple, secreted, and small tumor necrosis factor superfamily (TNFSF) fusions with the ability to engage their cognate receptors (TNFRSF) only in the presence of PDL1-positive cells. Finally, PDL1-independent alternatives of TNFRSF agonists were also constructed by fusing different variants of surfactant protein-D (SP-D) oligomerization domains with TNFSF ectodomains. An optimal SP-D-CD40L fusion with an SP-D collagen domain reduced by 80% was identified by screening with a transfection/infection method where poxvirus transfer plasmids and vaccinia virus were successively introduced into the same cell. However, once vectorized in VV, this construct had a much lower CD40 agonist activity compared to the SP-D-CD40L construct, which is completely devoid of the collagen domain that was finally selected. This latest result highlights the importance of working with recombinant viruses early in the payload selection process. Altogether, these results bring several complementary solutions to arm oncolytic vectors with powerful immunomodulators to improve their immune-based anti-tumoral activity.

Charting a killer course to the solid tumor: strategies to recruit and activate NK cells in the tumor microenvironment

The ability to expand and activate natural Killer (NK) cells ex vivo has dramatically changed the landscape in the development of novel adoptive cell therapies for treating cancer over the last decade. NK cells have become a key player for cancer immunotherapy due to their innate ability to kill malignant cells while not harming healthy cells, allowing their potential use as an "off-the-shelf" product. Furthermore, recent advancements in NK cell genetic engineering methods have enabled the efficient generation of chimeric antigen receptor (CAR)-expressing NK cells that can exert both CAR-dependent and antigen-independent killing. Clinically, CAR-NK cells have shown promising efficacy and safety for treating CD19-expressing hematologic malignancies. While the number of pre-clinical studies using CAR-NK cells continues to expand, it is evident that solid tumors pose a unique challenge to NK cell-based adoptive cell therapies. Major barriers for efficacy include low NK cell trafficking and infiltration into solid tumor sites, low persistence, and immunosuppression by the harsh solid tumor microenvironment (TME). In this review we discuss the barriers posed by the solid tumor that prevent immune cell trafficking and NK cell effector functions. We then discuss promising strategies to enhance NK cell infiltration into solid tumor sites and activation within the TME. This includes NK cell-intrinsic and -extrinsic mechanisms such as NK cell engineering to resist TME-mediated inhibition and use of tumor-targeted agents such as oncolytic viruses expressing chemoattracting and activating payloads. We then discuss opportunities and challenges for using combination therapies to extend NK cell therapies for the treatment of solid tumors.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

Oncolytic viruses and antibodies: are they more successful when delivered separately or when engineered as a single agent?

Oncolytic viruses (OVs) provide the promise of tumor-selective cytotoxicity coupled with amplification of the therapeutic agent (the virus) in situ within the tumor improving its therapeutic index. Despite this promise, however, single agent-treatments have not been as successful as combination therapies, particularly combining with checkpoint inhibitor antibodies. The antibodies may be delivered by two approaches, either encoded within the OV genome to restrict antibody production to sites of active virus infection or alternatively given alongside OVs as separate treatments. Both approaches have shown promising therapeutic outcomes, and this leads to an interesting question of whether one approach is potentially better than the other. In this review, we provide a brief summary of the combination OV-antibody therapies that target tumor cells, tumor microenvironment and immune cells to help define key parameters influencing which approach is superior, thereby improving insight into the rational design of OV treatment strategies.

Spatial metabolomics in head and neck tumors: a review

The joint analysis of single-cell transcriptomics, proteomics, lipidomics, metabolomics and spatial metabolomics is continually transforming our understanding of the mechanisms of metabolic reprogramming in tumor cells. Since head and neck tumor is the sixth most common tumor in the world, the study of the metabolic mechanism of its occurrence, development and prognosis is still undeveloped. In the past decade, this field has witnessed tremendous technological revolutions and considerable development that enables major breakthroughs to be made in the study of human tumor metabolism. In this review, a comprehensive comparison of traditional metabolomics and spatial metabolomics has been concluded, and the recent progress and challenges of the application of spatial metabolomics combined multi-omics in the research of metabolic reprogramming in tumors are reviewed. Furthermore, we also highlight the advances of spatial metabolomics in the study of metabolic mechanisms of head and neck tumors, and provide an outlook of its application prospects.

Cancer immune exclusion: breaking the barricade for a successful immunotherapy

Immunotherapy has changed the course of cancer treatment. The initial steps were made through tumor-specific antibodies that guided the setup of an antitumor immune response. A new and successful generation of antibodies are designed to target immune checkpoint molecules aimed to reinvigorate the antitumor immune response. The cellular counterpart is the adoptive cell therapy, where specific immune cells are expanded or engineered to target cancer cells. In all cases, the key for achieving positive clinical resolutions rests upon the access of immune cells to the tumor. In this review, we focus on how the tumor microenvironment architecture, including stromal cells, immunosuppressive cells and extracellular matrix, protects tumor cells from an immune attack leading to immunotherapy resistance, and on the available strategies to tackle immune evasion.

Recent advances in oncolytic virus therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly refractory cancer and the fourth leading cause of cancer-related mortality worldwide. Despite the development of a detailed treatment strategy for HCC, the survival rate remains unsatisfactory. Oncolytic virus has been extensively researched as a new cancer therapeutic agent in the treatment of HCC. Researchers have designed a variety of recombinant viruses based on natural oncolytic diseases, which can increase the targeting of oncolytic viruses to HCC and their survival in tumors, as well as kill tumor cells and inhibit the growth of HCC through a variety of mechanisms. The overall efficacy of oncolytic virus therapy is known to be influenced by anti-tumor immunity, toxic killing effect and inhibition of tumor angiogenesis, etc. Therefore, a comprehensive review of the multiple oncolytic mechanisms of oncolytic viruses in HCC has been conducted. So far, a large number of relevant clinical trials are under way or have been completed, and some encouraging results have been obtained. Studies have shown that oncolytic virus combined with other HCC therapies may be a feasible method, including local therapy, chemotherapy, molecular targeted therapy and immunotherapy. In addition, different delivery routes for oncolytic viruses have been studied so far. These studies make oncolytic virus a new and attractive drug for the treatment of HCC.

Local Delivery of Immunomodulatory Antibodies for Gastrointestinal Tumors

Cancer therapy has experienced a breakthrough with the use of immune checkpoint inhibitors (ICIs) based on monoclonal antibodies (mAbs), which are able to unleash immune responses against tumors refractory to other therapies. Despite the great advancement that ICIs represent, most patients with gastrointestinal tumors have not benefited from this therapy. In addition, ICIs often induce adverse effects that are related to their systemic use. Local administration of ICIs in tumors could concentrate their effect in the malignant tissue and provide a higher safety profile. A new and attractive approach for local delivery of ICIs is the use of gene therapy vectors to express these blocking antibodies in tumor cells. Several vectors have been evaluated in preclinical models of gastrointestinal tumors to express ICIs against PD-1, PD-L1, and CTLA-4, among other immune checkpoints, with promising results. Vectors used in these settings include oncolytic viruses, self-replicating RNA vectors, and non-replicative viral and non-viral vectors. The use of viral vectors, especially when they have replication capacity, provides an additional adjuvant effect that has been shown to enhance antitumor responses. This review covers the most recent studies involving the use of gene therapy vectors to deliver ICIs to gastrointestinal tumors.

Long noncoding RNA HCG18 Promotes Extracellular Matrix Degradation of Nucleus Pulposus Cells in Intervertebral Disc Degeneration by Regulating the miR-4306/EPAS1 Axis

BACKGROUND

Intervertebral disc degeneration is a very common disease worldwide and the leading cause of low back pain. Long noncoding RNAs are novel players in intervertebral disc degeneration and have multiple functions. This study explored the role of long noncoding RNA HCG18 in regulating extracellular matrix (ECM) degradation in nucleus pulposus cells (NPCs) during intervertebral disc degeneration.

METHODS

NPCs were subjected to interleukin-1β to induce a degenerative model of NPCs. Cell viability was assessed using Cell Counting Kit-8 assay. Messenger RNA and protein expressions were examined by real-time quantitative polymerase chain reaction and Western blot. The location of HCG18 was determined by nucleocytoplasmic separation assay. The binding relationships between HCG18, MIR4306, and EPAS1 were verified by dual luciferase reporter gene assay and/or RNA immunoprecipitation assay.

RESULTS

HCG18 was highly expressed in interleukin-1β-induced degenerated NPCs, which was associated with reduced collagen II and aggrecan expression and increased MMP-13 and ADAMTS-4 expression. HCG18 knockdown could remarkably inhibit ECM degradation in IL-1β-induced degenerated NPCs, while HCG18 overexpression had the opposite effect. Our molecular study further revealed that HCG18 could sponge MIR4306, and HCG18 knockdown could suppress ECM degradation in degenerated NPCs by elevating MIR4306 expression. In addition, EPAS1 was identified as the direct target of MIR4306. As expected, MIR4306 overexpression inhibited ECM degradation in degenerated NPCs by downregulating EPAS1.

CONCLUSIONS

HCG18 promoted ECM degradation in degenerated NPCs via regulation of the MIR4306/EPAS1 axis.

Novel technologies for applying immune checkpoint blockers

Cancer cells develop several ways to subdue the immune system among others via upregulation of inhibitory immune checkpoint (ICP) proteins. These ICPs paralyze immune effector cells and thereby enable unfettered tumor growth. Monoclonal antibodies (mAbs) that block ICPs can prevent immune exhaustion. Due to their outstanding effects, mAbs revolutionized the field of cancer immunotherapy. However, current ICP therapy regimens suffer from issues related to systemic administration of mAbs, including the onset of immune related adverse events, poor pharmacokinetics, limited tumor accessibility and immunogenicity. These drawbacks and new insights on spatiality prompted the exploration of novel administration routes for mAbs for instance peritumoral delivery. Moreover, novel ICP drug classes that are adept to novel delivery technologies were developed to circumvent the drawbacks of mAbs. We therefore review the state-of-the-art and novel delivery strategies of ICP drugs.

Synergistic efficacy of telomerase-specific oncolytic adenoviral therapy and histone deacetylase inhibition in human hepatocellular carcinoma

The telomerase-specific oncolytic adenovirus Telomelysin and the histone deacetylase inhibitor AR42 have demonstrated anticancer effects in preclinical models of human hepatocellular carcinoma (HCC). However, the clinical development of Telomelysin may be hindered by human antiviral immunity and tumor resistance. Combining oncolytic and epigenetic therapies is a viable approach for treating various cancers. This study investigated the potential synergism of Telomelysin and AR42 and the relevant underlying mechanisms. Telomelysin and AR42 exhibited synergistic antiproliferative effects in human HCC models in vitro and in vivo. Apoptosis induced by Telomelysin was significantly enhanced by AR42 in both PLC5 and Hep3B HCC cells. AR42 treatment unexpectedly attenuated the expression of the coxsackievirus and adenovirus receptor and the mRNA levels of human telomerase reverse transcriptase, which may be positively associated with the cytotoxicity of Telomelysin. Meanwhile, the cellular antiviral interferon response was not altered by AR42 treatment. Further, we found that Telomelysin enhanced Akt phosphorylation in HCC cells. AR42 reduced Telomelysin-induced phospho-Akt activation and enhanced Telomelysin-induced apoptosis. The correlation of Akt phosphorylation with drug-induced apoptosis was validated in HCC cells with upregulated or downregulated Akt signaling. Combination therapy with Telomelysin and AR42 demonstrated synergistic anti-HCC efficacy. Clinical trials investigating this new combination regimen are warranted.

Patient-derived xenograft model in colorectal cancer basic and translational research

Colorectal cancer (CRC) is one of the most popular malignancies globally, with 930 000 deaths in 2020. The evaluation of CRC-related pathogenesis and the discovery of potential therapeutic targets will be meaningful and helpful for improving CRC treatment. With huge efforts made in past decades, the systematic treatment regimens have been applied to improve the prognosis of CRC patients. However, the sensitivity of CRC to chemotherapy and targeted therapy is different from person to person, which is an important cause of treatment failure. The emergence of patient-derived xenograft (PDX) models shows great potential to alleviate the straits. PDX models possess similar genetic and pathological characteristics as the features of primary tumors. Moreover, PDX has the ability to mimic the tumor microenvironment of the original tumor. Thus, the PDX model is an important tool to screen precise drugs for individualized treatment, seek predictive biomarkers for prognosis supervision, and evaluate the unknown mechanism in basic research. This paper reviews the recent advances in constructed methods and applications of the CRC PDX model, aiming to provide new knowledge for CRC basic research and therapeutics.

An armed oncolytic virus enhances the efficacy of tumor-infiltrating lymphocyte therapy by converting tumors to artificial antigen-presenting cells in situ

The full potential of tumor-infiltrating lymphocyte (TIL) therapy has been hampered by the inadequate activation and low persistence of TILs, as well as inefficient neoantigen presentation by tumors. We transformed tumor cells into artificial antigen-presenting cells (aAPCs) by infecting them with a herpes simplex virus 1 (HSV-1)-based oncolytic virus encoding OX40L and IL12 (OV-OX40L/IL12) to provide local signals for optimum T cell activation. The infected tumor cells displayed increased expression of antigen-presenting cell-related markers and induced enhanced T cell activation and killing in coculture with TILs. Combining OV-OX40L/IL12 and TIL therapy induced complete tumor regression in patient-derived xenograft and syngeneic mouse tumor models and elicited an antitumor immunological memory. In addition, the combination therapy produced aAPC properties in tumor cells, activated T cells, and reprogrammed macrophages to a more M1-like phenotype in the tumor microenvironment. This combination strategy unleashes the full potential of TIL therapy and warrants further evaluation in clinical studies.

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.

Effect of Tertiary Lymphoid Structures on Prognosis of Patients with Hepatocellular Carcinoma and Preliminary Exploration of Its Formation Mechanism

Simple Summary

At present, research on tertiary lymphoid structures (TLSs) in hepatocellular carcinoma (HCC) has been limited to the prognostic impact. Our manuscript first validates previous studies using two databases and then initially explores the key molecules and mechanisms of TLS formation and immunotherapy implications for HCC patients by using the TCGA database. For example, LCK, a key molecule in the formation of TLSs, may affect the formation of TLSs by regulating the cytokine signalling pathway, chemokine signalling pathway, T-cell activation and P53 signalling pathway. Second, the expression level of LCK is another factor affecting the sensitivity of HCC patients to immune checkpoint inhibitors. In conclusion, our study provides a potential mechanism for further exploration of TLSs.

Abstract

Background: Tertiary lymphoid structures (TLSs) are formed by the aggregation of tumour-infiltrating lymphocytes (TILs), which is driven by chemokines or cytokines in the tumour microenvironment. Studies have shown that TLSs are associated with good prognosis in patients with various solid tumours and can improve patient responses to immunotherapy. However, the role of TLSs in hepatocellular carcinoma (HCC) remains controversial, and the underlying molecular mechanism is unclear. Methods: According to haematoxylin-eosin (HE) staining results, HCC patients in Xijing Hospital data and TCGA data were divided into TLS+ and TLS- groups, and Kaplan–Meier (KM) analysis was performed to assess overall survival (OS) and recurrence-free survival (RFS). Immunofluorescence (IF) and immunohistochemistry (IHC) were used to identify TILs in the TLS+ group. Lymphocyte-specific protein tyrosine kinase (LCK), a molecule involved in TLS formation, was explored in LinkedOmics. TILs were divided into two groups by drawing receiver operating characteristic (ROC) curves to calculate cut-off values. Spearman correlation analysis was used to calculate the correlation between LCK and TILs, and the molecular pathways by which LCK regulates immunotherapy were clarified through enrichment analysis. The half-maximal inhibitory concentration (IC50) distribution of sorafenib was observed in groups that varied in LCK expression. Results: According to the HE results, 61 cases in the Xijing Hospital cohort and 195 cases in the TCGA cohort had TLSs, while 89 cases and 136 cases did not. The KM results showed that TLSs had no effect on the OS of HCC patients but significantly affected RFS. The IF/IHC results showed that higher TIL numbers in TLSs were correlated with better prognosis in HCC patients. Spearman correlation analysis showed that LCK expression was positively correlated with TIL numbers. Enrichment analysis showed that upregulation of LCK expression mainly regulated the cytokine signalling pathway, the chemokine signalling pathway and T-cell activation. The IC50 scores of sorafenib in HCC patients with high LCK expression were lower, and the sensitivity was higher. Conclusion: TLSs mainly affected the early RFS of HCC patients but had no effect on OS. The high expression of the TLS formation-related gene LCK can increase the sensitivity of HCC patients to ICIs.

Strategies for Efficient Targeting of Tumor Collagen for Cancer Therapy

Simple Summary

The tumor microenvironment encompasses the cellular and extracellular matrix components that support and shape the three-dimensional framework in which solid tumors develop and grow. The extracellular matrix of the tumor is characterized by increased deposition and aberrant architecture of collagen fibers. Therefore, as a key mechanical component of the tumor microenvironment, collagen plays a critical role in cancer progression, metastasis, and therapeutic response. To boost the efficacy of current anticancer therapies, including immunotherapy, innovative approaches should take into account strategies directed against the dysregulated non-cancer cell stromal components. In the current review, we provide an overview of the principal approaches to target tumor collagen to provide therapeutic benefits.

Abstract

The tumor stroma, which comprises stromal cells and non-cellular elements, is a critical component of the tumor microenvironment (TME). The dynamic interactions between the tumor cells and the stroma may promote tumor progression and metastasis and dictate resistance to established cancer therapies. Therefore, novel antitumor approaches should combine anticancer and anti-stroma strategies targeting dysregulated tumor extracellular matrix (ECM). ECM remodeling is a hallmark of solid tumors, leading to extensive biochemical and biomechanical changes, affecting cell signaling and tumor tissue three-dimensional architecture. Increased deposition of fibrillar collagen is the most distinctive alteration of the tumor ECM. Consequently, several anticancer therapeutic strategies have been developed to reduce excessive tumor collagen deposition. Herein, we provide an overview of the current advances and challenges of the main approaches aiming at tumor collagen normalization, which include targeted anticancer drug delivery, promotion of degradation, modulation of structure and biosynthesis of collagen, and targeting cancer-associated fibroblasts, which are the major extracellular matrix producers.

Hydrogel-based co-delivery of CIK cells and oncolytic adenovirus armed with IL12 and IL15 for cancer immunotherapy

Intratumoral injection of various effector cells combined with oncolytic adenovirus expressing antitumor cytokines exert an effective antitumor immune effect by oncolysis and altering the tumor microenvironment. However, this combination therapy had certain limitations. When used in high concentrations, effector cells and oncolytic viruses can spread rapidly to surrounding non-target tissues. And because both therapies used in combination are immunogenic and exhibit shorter biological activity, multiple injections were required to attain an adequate therapeutic index. To overcome these drawbacks, we encapsulated gelatin-based hydrogel capable of co-deliver oncolytic adenovirus armed with IL12 and IL15 (CRAd-IL12-IL15) and CIK cells for enhancing and prolonging the antitumor effects of both therapies after a single intratumoral injection. The injectable and biodegradable hydrogel reduced the dispersion of high-dose oncolytic adenovirus and CIK cells from the injection site to the liver and other non-target tissues. In this study, a novel oncolytic adenoviral vector CRAd-IL12-IL15 was constructed to verify the cytokine expression and oncolytic ability, which can upregulate the expression levels of Bcl-2, Cish and Gzmb in tumor cells. The CRAd-IL12-IL15 + CIKs/gelatin treatment maintained sustained release of CRAd-IL12-IL15 and active CIK cells over a longer period of time, attenuating the antiviral immune response against adenovirus. In conclusion, the results suggested that hydrogel-mediated co-delivery of CRAd-IL12-IL15 and CIK cells might be a an approach to overcome limitations. Both treatments could be effectively retained in tumor tissue and sustained to induce potent anti-tumor immune responses with a single administration.

Dacarbazine-Loaded Targeted Polymeric Nanoparticles for Enhancing Malignant Melanoma Therapy

Dacarbazine (DTIC) dominates chemotherapy for malignant melanoma (MM). However, the hydrophobicity, photosensitivity, instability, and toxicity to normal cells of DTIC limit its efficacy in treating MM. In the present study, we constructed star-shaped block polymers nanoparticles (NPs) based on Cholic acid -poly (lactide-co-glycolide)-b-polyethylene glycol (CA-PLGA-b-PEG) for DTIC encapsulation and MM targeted therapy. DTIC-loaded CA-PLGA-b-PEG NPs (DTIC-NPs) were employed to increase the drug loading and achieve control release of DTIC, followed by further modification with nucleic acid aptamer AS1411 (DTIC-NPs-Apt), which played an important role for active targeted therapy of MM. In vitro, DTIC-NPs-Apt showed good pH-responsive release and the strongest cytotoxicity to A875 cells compared with DTIC-NPs and free DTIC. In vivo results demonstrated that the versatile DTIC-NPs-Apt can actively target the site of MM and exhibited excellent anti-tumor effects with no obvious side effects. Overall, this research provided multi-functional NPs, which endow a new option for the treatment of MM.

Cancer gene therapy goes viral: viral vector platforms come of age

Background

Since the advent of viral vector gene therapy in 1990s, cancer treatment with viral vectors promised to revolutionize the field of oncology. Notably, viral vectors offer a unique combination of efficient gene delivery and engagement of the immune system for anti-tumour response. Despite the early potential, viral vector-based cancer treatments are only recently making a big impact, most prominently as gene delivery devices in approved CAR-T cell therapies, cancer vaccines and targeted oncolytic therapeutics. To reach this broad spectrum of applications, a number of challenges have been overcome – from our understanding of cancer biology to vector design, manufacture and engineering. Here, we take an overview of viral vector usage in cancer therapy and discuss the latest advancements. We also consider production platforms that enable mainstream adoption of viral vectors for cancer gene therapy.

Conclusions

Viral vectors offer numerous opportunities in cancer therapy. Recent advances in vector production platforms open new avenues in safe and efficient viral therapeutic strategies, streamlining the transition from lab bench to bedside. As viral vectors come of age, they could become a standard tool in the cancer treatment arsenal.

BTBD10 is a Prognostic Biomarker Correlated With Immune Infiltration in Hepatocellular Carcinoma

Background: BTBD10 serves as an activator of Akt family members through decreasing the protein phosphatase 2A-mediated dephosphorylation. The present study attempted to investigate the prognostic value of BTBD10 in hepatocellular carcinoma (HCC), specially, its relationship with tumor-infiltrating lymphocytes (TILs).

Methods: BTBD10 expression was evaluated in HCC using The Cancer Genome Atlas (TCGA) and Xijing Hospital database, and verified in HCC cell lines. Cox analyses were performed to analyze independent prognostic risk factors for HCC. The optimal cut-off value of BTBD10 was calculated, by which all patients were divided into two groups to compare the overall survival (OS). The signaling pathways were predicted, by which BTBD10 may affect the progression of HCC. To investigate the impact of BTBD10 on HCC immunotherapy, correlations between BTBD10 and TILs, immune checkpoints, m6A methylation-related genes and ferroptosis-related genes were assessed. The distribution of half-maximal inhibitory concentration (IC50) of diverse targeted drugs was observed based on the differential expression of BTBD10.

Results: BTBD10 expression was higher in HCC tissues and cell lines than that of normal liver tissues and cells. The patients with high expression of BTBD10 showed a worse OS, as compared to that of BTBD10 low-expressing group. Cox analyses indicated that BTBD10 was an independent prognostic risk factor for HCC. Several molecular pathways of immune responses were activated in HCC patients with high-expressing of BTBD10. Furthermore, BTBD10 expression was demonstrated to be positively correlated with tumor-infiltrating B cells, T cells, macrophages, neutrophils and dendritic cells. Meanwhile, the expression of BTBD10 was synchronized with that of several m6A methylation-related genes, ferroptosis-related genes and immune checkpoints. The IC50 scores of Sorafenib, Navitoclax, Veliparib, Luminespib, and Imatinib were found to be lower in BTBD10 high-expressing HCC group.

Conclusion: BTBD10 negatively regulates tumor immunity in HCC and exhibits adverse effect on the prognosis of HCC, which could be a potential target for immunotherapy.

Oncolytic reovirus-mediated killing of mouse cancer-associated fibroblasts

Oncolytic viruses, which mediate tumor cell-specific infection, resulting in efficient tumor cell killing, have attracted much attention as a novel class of anti-cancer biopharmaceutical agents. Cancer-associated fibroblasts (CAFs) are an important component of the tumor microenvironment that strongly supports the growth, survival, and metastasis of tumor cells, suggesting that CAFs would have influence to the antitumor effects of oncolytic viruses; however, it remains to be fully evaluated whether oncolytic viruses affect the viabilities and properties of CAFs following treatment. Oncolytic reovirus, which is a non-enveloped virus that contains 10-segmented double-stranded RNA genome, shows efficient tumor cell lysis without apparent cytotoxicity to normal cells and has been tested worldwide in clinical trials against various types of tumors. In this study, we demonstrated that reovirus exhibited cytotoxicity against mouse primary CAFs isolated from subcutaneous tumors, but not against tail-tip fibroblasts. Infection with reovirus resulted in activation of caspase 3 and up-regulation of apoptosis-related gene expression, indicating that reovirus induced apoptosis of mouse primary CAFs. Intratumoral administration of reovirus induced apoptosis of mouse CAFs in the tumor. Taken together, these results indicate that reovirus has the potential to mediate antitumor effects by killing not only cancer cells but also CAFs.

Transferrin Receptor Targeted Polyplexes Completely Comprised of Sequence-Defined Components

Human transferrin protein (Tf) modified polyplexes have already displayed encouraging potential for receptor-mediated nucleic acid delivery into tumors. The use of a blood-derived targeting protein and polydisperse macromolecular cationic subunits however presents a practical challenge for pharmaceutical grade production. Here, Tf receptor (TfR) targeted small interfering RNA (siRNA) polyplexes are designed that are completely composed of synthetic, monodisperse, and sequence-defined subunits generated by solid-phase supported synthesis. An optimized cationizable lipo-oligoaminoamide (lipo-OAA) is used for siRNA core polyplex formation, and a retro-enantio peptide (reTfR) attached via a monodisperse polyethylene glycol (PEG) spacer via click chemistry is applied for targeting. Improved gene silencing is demonstrated in TfR-expressing KB and DU145 cells. Analogous plasmid DNA (pDNA) polyplexes are successfully used for receptor-mediated gene delivery in TfR-rich K562 cells and Neuro2a cells. Six lipo-OAAs differing in their lipidic domain and redox-sensitive attachment of lipid residues are tested in order to evaluate the impact of core polyplex stability on receptor-dependent gene transfer.

The role of NK cells in oncolytic viral therapy: a focus on hepatocellular carcinoma

Natural killer (NK) cells have a key role in host anti-tumour immune responses via direct killing of tumour cells and promotion of adaptive immune responses. They are therefore attractive targets to promote the anti-tumour efficacy of oncolytic viral therapies. However, NK cells are also potent components of the host anti-viral immune response, and therefore have the potential for detrimental anti-viral responses, limiting the spread and persistence of oncolytic viruses. Oncolytic viruses are currently being investigated for the treatment of hepatocellular carcinoma (HCC), a leading cause of cancer-related death with a high unmet clinical need. In this review, we highlight the role of NK cells in oncolytic virus therapy, their potential for improving treatment options for patients with HCC, and discuss current and potential strategies targeting NK cells in combination with oncolytic viral therapies.