Cold Tumors: A Therapeutic Challenge for Immunotherapy

Loss of Cadherin-11 in pancreatic ductal adenocarcinoma alters tumor-immune microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is one of the top five deadliest forms of cancer with very few treatment options. The 5-year survival rate for PDAC is 10% following diagnosis. Cadherin 11 (Cdh11), a cell-to-cell adhesion molecule, has been suggested to promote tumor growth and immunosuppression in PDAC, and Cdh11 inhibition significantly extended survival in mice with PDAC. However, the mechanisms by which Cdh11 deficiency influences PDAC progression and anti-tumor immune responses have yet to be fully elucidated. To investigate Cdh11-deficiency induced changes in PDAC tumor microenvironment (TME), we crossed p48-Cre; LSL-KrasG12D/+; LSL-Trp53R172H/+ (KPC) mice with Cdh11+/- mice and performed single-cell RNA sequencing (scRNA-seq) of the non-immune (CD45-) and immune (CD45+) compartment of KPC tumor-bearing Cdh11 proficient (KPC-Cdh11+/+) and Cdh11 deficient (KPC-Cdh11+/-) mice. Our analysis showed that Cdh11 is expressed primarily in cancer-associated fibroblasts (CAFs) and at low levels in epithelial cells undergoing epithelial-to-mesenchymal transition (EMT). Cdh11 deficiency altered the molecular profile of CAFs, leading to a decrease in the expression of myofibroblast markers such as Acta2 and Tagln and cytokines such as Il6, Il33 and Midkine (Mdk). We also observed a significant decrease in the presence of monocytes/macrophages and neutrophils in KPC-Cdh11+/- tumors while the proportion of T cells was increased. Additionally, myeloid lineage cells from Cdh11-deficient tumors had reduced expression of immunosuppressive cytokines that have previously been shown to play a role in immune suppression. In summary, our data suggests that Cdh11 deficiency significantly alters the fibroblast and immune microenvironments and contributes to the reduction of immunosuppressive cytokines, leading to an increase in anti-tumor immunity and enhanced survival.

Photothermally sensitive gold nanocage augments the antitumor efficiency of immune checkpoint blockade in immune "cold" tumors

Introduction

Immune checkpoint blockade (ICB) has revolutionized the therapy landscape of malignancy melanoma. However, the clinical benefits from this regimen remain limited, especially in tumors lacking infiltrated T cells (known as "cold" tumors). Nanoparticle-mediated photothermal therapy (PTT) has demonstrated improved outcomes in the ablation of solid tumors by inducing immunogenic cell death (ICD) and reshaping the tumor immune microenvironment. Therefore, the combination of PTT and ICB is a promising regimen for patients with "cold" tumors.

Methods

A second near-infrared (NIR-II) light-activated gold nanocomposite AuNC@SiO2@HA with AuNC as a kernel, silica as shell, and hyaluronic acid (HA) polymer as a targeting molecule, was synthesized for PTT. The fabricated AuNC@SiO2@HA nanocomposites underwent various in vitro studies to characterize their physicochemical properties, light absorption spectra, photothermal conversion ability, cellular uptake ability, and bioactivities. The synergistic effect of AuNC@SiO2@HA-mediated PTT and anti-PD-1 immunotherapy was evaluated using a mouse model of immune "cold" melanoma. The tumor-infiltrating T cells were assessed by immunofluorescence staining and flow cytometry. Furthermore, the mechanism of AuNC@SiO2@HA-induced T-cell infiltration was investigated through immunochemistry staining of the ICD-related markers, including HSP70, CRT, and HMGB1. Finally, the safety of AuNC@SiO2@HA nanocomposites was evaluated in vivo.

Results

The AuNC@SiO2@HA nanocomposite with absorption covering 1064 nm was successfully synthesized. The nano-system can be effectively delivered into tumor cells, transform the optical energy into thermal energy upon laser irradiation, and induce tumor cell apoptosis in vitro. In an in vivo mouse melanoma model, AuNC@SiO2@HA nanocomposites significantly induced ICD and T-cell infiltration. The combination of AuNC@SiO2@HA and anti-PD-1 antibody synergistically inhibited tumor growth via stimulating robust T lymphocyte immune responses.

Discussion

The combination of AuNC@SiO2@HA-mediated PTT and anti-PD-1 immunotherapy proposed a neoteric strategy for oncotherapy, which efficiently convert the immune "cold" tumors into "hot" ones.

Identification of pyroptosis-related lncRNA subtype and signature predicts the prognosis in bladder cancer

Pyroptosis is a new type of programmed cell death involved in all stages of tumorigenesis. Herein, a comprehensive study was conducted to evaluate the prognostic significance of pyroptosis-related lncRNAs in bladder cancer. Consensus clustering analysis was performed to identify the subclusters of bladder cancer. The prognostic pyroptosis-related lncRNA signature was constructed using LASSO Cox regression analysis. Consensus clustering identified 2 clusters of bladder cancer. Interestingly, significant differences in the ESTIMAE score, immune cell infiltration and immune checkpoint expression were obtained between the 2 clusters. A signature consisting of 11 pyroptosis-related lncRNAs was established and it had a good performance in predicting the overall survival rate of bladder cancer, with an AUC of 0.713. Moreover, pyroptosis-related lncRNA signature acted as a risk factor in bladder cancer. Bladder cancer patients with high-risk score had a higher tumor grade and higher clinical stage. A significant correlation was obtained between the risk score and immune cell infiltration. The expression of most checkpoints was higher in bladder cancer patients with high-risk score. A novel pyroptosis-related lncRNA signature was identified with prognostic value for bladder cancer patients. Pyroptosis-related lncRNAs have a potential role in cancer immunology and may serve as prognostic or therapeutic targets in bladder cancer.

Tumor microenvironment-responsive DNA-based nanomedicine triggers innate sensing for enhanced immunotherapy

Lack of proper innate sensing inside the tumor microenvironment could reduce both innate and adaptive immunity, which remains a critical cause of immunotherapy failure in various tumor treatments. Double-stranded DNA (dsDNA) has been evidenced to be a promising immunostimulatory agent to induce type I interferons (IFN-Is) production for innate immunity activation through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway, yet the unsatisfactory delivery and susceptibility to nuclease degradation hindered its feasibility for further clinical applications. Herein, we report on the constructed tumor microenvironment-responsive DNA-based nanomedicine loaded by dendritic mesoporous organosilica nanoparticles (DMONs), which provide efficient delivery of dsDNA to induce intratumoral IFN-Is production for triggering innate sensing for enhanced anti-tumor immunotherapy. Extensive in vitro and in vivo evaluations have demonstrated the dramatic IFN-Is production induced by dsDNA@DMONs in both immune cells and tumor cells, which facilitates dendritic cells (DCs) maturation and T cells activation for eliciting the potent innate immune and adaptive immune responses. Desirable biosafety and marked therapeutic efficacy with a tumor growth inhibition (TGI) of 51.0% on the murine B16-F10 melanoma model were achieved by the single agent dsDNA@DMONs. Moreover, dsDNA@DMONs combined with anti-PD-L1 antibody further enhanced the anti-tumor efficacy and led to almost complete tumor regression. Therefore, this work highlighted the immunostimulatory DNA-based nanomedicine as a promising strategy for overcoming the resistance to immunotherapy, by promoting the IFN-Is production for innate immunity activation and remodeling the tumor microenvironment.

GAS-STING: a classical DNA recognition pathways to tumor therapy

Cyclic GMP-AMP synthetase (cGAS), recognized as the primary DNA sensor within cells, possesses the capability to identify foreign DNA molecules along with free DNA fragments. This identification process facilitates the production of type I IFNs through the activator of the interferon gene (STING) which induces the phosphorylation of downstream transcription factors. This action characterizes the most archetypal biological functionality of the cGAS-STING pathway. When treated with anti-tumor agents, cells experience DNA damage that triggers activation of the cGAS-STING pathway, culminating in the expression of type I IFNs and associated downstream interferon-stimulated genes. cGAS-STING is one of the important innate immune pathways,the role of type I IFNs in the articulation between innate immunity and T-cell antitumour immunity.type I IFNs promote the recruitment and activation of inflammatory cells (including NK cells) at the tumor site.Type I IFNs also can promote the activation and maturation of dendritic cel(DC), improve the antigen presentation of CD4+T lymphocytes, and enhance the cross-presentation of CD8+T lymphocytes to upregulating anti-tumor responses. This review discussed the cGAS-STING signaling and its mechanism and biological function in traditional tumor therapy and immunotherapy.

Identification and validation of a cancer-associated fibroblasts-related scoring system to predict prognosis and immune landscape in hepatocellular carcinoma through integrated analysis of single-cell and bulk RNA-sequencing

BACKGROUND

Cancer-associated fibroblasts (CAFs) regulate the malignant biological behaviour of hepatocellular carcinoma (HCC) as a significant component of the tumour immune microenvironment (TIME). This study aimed to develop a CAFs-based scoring system to predict the prognosis and TIME of patients with HCC.

METHODS

Data for the TCGA-LIHC and GSE14520 cohorts were downloaded from The Cancer Genome Atlas and the Gene Expression Omnibus databases. Single-cell RNA-sequencing data for HCC samples were retrieved from the GSE166635 cohort. The Least Absolute Shrinkage and Selection Operator algorithm was employed to develop a CAFs-related scoring system (CAFRss). The predictive value of the CAFRss was determined using Kaplan-Meier, Cox regression and Receiver Operating Characteristic curves. Additionally, the TIMER platform, single sample Gene Set Enrichment Analysis and the Estimation of STromal and Immune cells in MAlignant Tumour tissues using Expression data algorithms were performed to determine the TIME landscape. Finally, the pRRophic algorithm was utilised for drug sensitivity analysis.

RESULTS

The evaluation of the CAFRss system demonstrated its superior ability to predict the clinical outcome of patients with HCC. Additionally, CAFRss effectively distinguished HCC populations with distinct TIME landscapes. Furthermore, CAFRss-based risk stratification identified individuals with immune 'hot tumours' and predicted the survival of patients treated with ICBs.

CONCLUSIONS

The developed CAFRss can serve as a predictive tool for determining the clinical outcome of HCC and differentiating populations with diverse TIME characteristics.

Angiopoietin-2 blockade suppresses growth of liver metastases from pancreatic neuroendocrine tumors by promoting T cell recruitment

Improving the management of metastasis in pancreatic neuroendocrine tumors (PanNETs) is critical, as nearly half of patients with PanNETs present with liver metastases, and this accounts for the majority of patient mortality. We identified angiopoietin-2 (ANGPT2) as one of the most upregulated angiogenic factors in RNA-Seq data from human PanNET liver metastases and found that higher ANGPT2 expression correlated with poor survival rates. Immunohistochemical staining revealed that ANGPT2 was localized to the endothelial cells of blood vessels in PanNET liver metastases. We observed an association between the upregulation of endothelial ANGPT2 and liver metastatic progression in both patients and transgenic mouse models of PanNETs. In human and mouse PanNET liver metastases, ANGPT2 upregulation coincided with poor T cell infiltration, indicative of an immunosuppressive tumor microenvironment. Notably, both pharmacologic inhibition and genetic deletion of ANGPT2 in PanNET mouse models slowed the growth of PanNET liver metastases. Furthermore, pharmacologic inhibition of ANGPT2 promoted T cell infiltration and activation in liver metastases, improving the survival of mice with metastatic PanNETs. These changes were accompanied by reduced plasma leakage and improved vascular integrity in metastases. Together, these findings suggest that ANGPT2 blockade may be an effective strategy for promoting T cell infiltration and immunostimulatory reprogramming to reduce the growth of liver metastases in PanNETs.

Targeting innate immune pathways for cancer immunotherapy

The innate immune system is critical for inducing durable and protective T cell responses to infection and has been increasingly recognized as a target for cancer immunotherapy. In this review, we present a framework wherein distinct innate immune signaling pathways activate five key dendritic cell activities that are important for T cell-mediated immunity. We discuss molecular pathways that can agonize these activities and highlight that no single pathway can agonize all activities needed for durable immunity. The immunological distinctions between innate immunotherapy administration to the tumor microenvironment versus administration via vaccination are examined, with particular focus on the strategies that enhance dendritic cell migration, interferon expression, and interleukin-1 family cytokine production. In this context, we argue for the importance of appreciating necessity vs. sufficiency when considering the impact of innate immune signaling in inflammation and protective immunity and offer a conceptual guideline for the development of efficacious cancer immunotherapies.

Natural polysaccharides exert anti-tumor effects as dendritic cell immune enhancers

With the development of immunotherapy, the process of tumor treatment is also moving forward. Polysaccharides are biological response modifiers widely found in plants, animals, fungi, and algae and are mainly composed of monosaccharides covalently linked by glycosidic bonds. For a long time, polysaccharides have been widely used clinically to enhance the body's immunity. However, their mechanisms of action in tumor immunotherapy have not been thoroughly explored. Dendritic cells (DCs) are a heterogeneous population of antigen presenting cells (APCs) that play a crucial role in the regulation and maintenance of the immune response. There is growing evidence that polysaccharides can enhance the essential functions of DCs to intervene the immune response. This paper describes the research progress on the anti-tumor immune effects of natural polysaccharides on DCs. These studies show that polysaccharides can act on pattern recognition receptors (PRRs) on the surface of DCs and activate phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT), mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), Dectin-1/Syk, and other signalling pathways, thereby promoting the main functions of DCs such as maturation, metabolism, antigen uptake and presentation, and activation of T cells, and then play an anti-tumor role. In addition, the application of polysaccharides as adjuvants for DC vaccines, in combination with adoptive immunotherapy and immune checkpoint inhibitors (ICIs), as well as their co-assembly with nanoparticles (NPs) into nano drug delivery systems is also introduced. These results reveal the biological effects of polysaccharides, provide a new perspective for the anti-tumor immunopharmacological research of natural polysaccharides, and provide helpful information for guiding polysaccharides as complementary medicines in cancer immunotherapy.

Integration of Protein Nanocage with CpG Motifs: A Virus-Mimicked Core-Shell Nanostructure to Ignite Antitumor Immunity

The tumor microenvironment typically possesses immunosuppressive properties that hinder the effectiveness of antitumor immune responses, even in the context of immunotherapies. However, it is observed that pathogenic microorganisms can trigger strong immune responses during infection, offering a potential means to counteract the immunosuppressive environment of tumors. In this study, a protein nanocage called CpG@HBc nanocages (NCs) is developed, which mimics the structure of the hepatitis B virus and combines with an immunostimulatory component known as cytosine phosphoguanosine oligonucleotide (CpG). By delivering these immunostimulatory agents, CpG@HBc NCs are able to effectively reverse the suppressive tumor microenvironment, resulting in the inhibition of poorly immunogenic tumors in mice. Through high-dimensional mass cytometry (CyTOF) analysis, remarkable alterations in immune responses is observed induced by CpG@HBc. Treatment with immunogenic CpG@HBc NCs, along with co-injection of an OX40 agonist, sensitized colorectal cancer tumors to T cell immune responses, resulting in significant impairment of tumor growth and robust immune activation. Furthermore, CpG@HBc NCs induced long-term antitumor immunological memory, protecting tumor-cured mice from tumor rechallenge. Overall, these findings highlight the potential of a virus-inspired protein nanocage to mimic anti-viral immunity and offer a unique therapeutic approach for cancer immunotherapy.

Virus-Like Nanotherapeutic for Spatiotemporally Enhancing Antigen Presentation and Cross-Presentation toward Potential Personalized Immunotherapy

One of the major causes of immunotherapy resistance is the loss of major histocompatibility complex class I (MHC-I) molecules in tumor cells or the downregulation of the class I antigen presentation pathway. In this study, a novel virus-like nanotherapeutic (siRNA@HCM) is developed via encapsulating nanosized siRNA nanoparticles in a hybrid membrane comprising a personalized tumor cell membrane and a universal 293T membrane expressing the mutant vesicular stomatitis virus glycoprotein (mVSV-G). Upon intravenous administration, siRNA@HCM accumulates at the tumor site and provides two potent driving forces for antitumor immunity. First, mVSV-G induces the fusion of siRNA@HCM with tumor cell membranes and directly injects siRNAs into the cytoplasm, significantly improving tumor intrinsic MHC-I antigen presentation. Moreover, mVSV-G can promote the maturation of dendritic cells, thereby achieving highly efficient antigen cross-presentation. The results demonstrate that spatiotemporally enhancing tumor intrinsic antigen presentation and cross-presentation via siRNA@HCM can achieve satisfactory antitumor efficacy and excellent biocompatibility. Immune infiltration analysis shows that siRNA@HCM treatment turns cold tumors into hot tumors. In addition, it significantly promotes the therapeutic effect of programmed death-1 inhibitor. In summary, virus-like nanotherapeutics present a promising approach to enhance the antitumor immune response, with distinct advantages for potential personalized therapy and clinical applications.

PD-1, PD-L1, IDO, CD70 and microsatellite instability as potential targets to prevent immune evasion in sarcomas

Background: Soft tissue and bone sarcomas are rare entities, hence, standardized therapeutic strategies are difficult to assess. Materials & methods: Immunohistochemistry was performed on 68 sarcoma samples to assess the expression of PD-1, PD-L1, IDO and CD70 in different tumor compartments and molecular analysis was performed to assess microsatellite instability status. Results: PD-1/PD-L1, IDO and CD70 pathways are at play in the immune evasion of sarcomas in general. Soft tissue sarcomas more often show an inflamed phenotype compared with bone sarcomas. Specific histologic sarcoma types show high expression levels of different markers. Finally, this is the first presentation of a microsatellite instability-high Kaposi sarcoma. Discussion/conclusion: Immune evasion occurs in sarcomas. Specific histologic types might benefit from immunotherapy, for which further investigation is needed.

Immune modulation of innate and adaptive responses restores immune surveillance and establishes anti-tumor immunological memory

Current immunotherapies have proven effective in strengthening anti-tumor immune responses but constant opposing signals from tumor cells and surrounding microenvironment eventually lead to immune escape. We hypothesize that in situ release of antigens and regulation of both the innate and adaptive arms of the immune system will provide a robust and long-term anti-tumor effect by creating immunological memory against the tumor. To achieve this, we developed CARG-2020, a virus-like-vesicle (VLV). It is a genetically modified and self-amplifying RNA with oncolytic capacity and encodes immune regulatory genes. CARG-2020 carries three transgenes: 1 ) the pleiotropic antitumor cytokine IL-12 in which the subunits (p35 and p40) are tethered together; 2) the extracellular domain (ECD) of the pro- tumor IL-17RA, which can serve as a dominant negative antagonist; and 3) shRNA for PD-L1. Using a mouse model of ovarian cancer, we demonstrate the oncolytic effect and immune modulatory capacities of CARG-2020. By enhancing IL-12 and blocking IL-17 and PD-L1, CARG-2020 successfully reactivates immune surveillance by promoting M1 instead of M2 macrophage differentiation, inhibiting MDSC expansion, and establishing a potent CD8+ T cell mediated anti-tumoral response. Furthermore, we demonstrate that this therapeutic approach provides tumor-specific and long-term protection preventing the establishment of new tumors. Our results provide rationale for the further development of this platform as a therapeutic modality for ovarian cancer patients to enhance the anti-tumor response and to prevent recurrence.

A glycosylation risk score comprehensively assists the treatment of bladder neoplasm in the real-world cohort, including the tumor microenvironment, molecular and clinical prognosis

Background: Bladder cancer is a common urological cancer associated high significant morbidity and mortality rates. Immunotherapy has emerged as a promising treatment option, although response rates vary among patients. Glycosylation has been implicated in tumorigenesis and immune regulation. However, our current comprehensive understanding of the role of glycosylation in bladder cancer and its clinical implications is limited. Methods: We constructed a training cohort based on the downloaded TCGA-BLCA dataset, while additional datasets (Xiangya cohort, GSE32894, GSE48075, GSE31684, GSE69795 and E-MTAB-1803) from Xiangya hospital, GEO and ArrayExpress database were obtained and used as validation cohorts. To identify glycosylation-related genes associated with prognosis, univariate Cox regression and LASSO regression were performed. A Cox proportional hazards regression model was then constructed to develop a risk score model. The performance of the risk score was assessed in the training cohort using Kaplan-Meier survival curves and ROC curves, and further validated in multiple validation cohorts. Results: We classified patients in the training cohort into two groups based on glycosylation-related gene expression patterns: Cluster 1 and Cluster 2. Prognostic analysis revealed that Cluster 2 had poorer survival outcomes. Cluster 2 also showed higher levels of immune cell presence in the tumor microenvironment and increased activation in key steps of the cancer immune response cycle. We developed an independent prognostic risk score (p < 0.001) and used it to construct an accurate prognostic prediction nomogram. The high glycosylation risk score group exhibited higher tumor immune cell infiltration, enrichment scores in immune therapy-related pathways, and a tendency towards a basal subtype. Conversely, the low-risk score group had minimal immune cell infiltration and tended to have a luminal subtype. These findings were consistent in our real-world Xiangya cohort. Conclusion: This multi-omics glycosylation score based on these genes reliably confirmed the heterogeneity of bladder cancer tumors, predicted the efficacy of immunotherapy and molecular subtypes, optimizing individual treatment decisions.

Small-molecule MHC-II inducers promote immune detection and anti-cancer immunity via editing cancer metabolism

Lack of MHC-II is emerging as a causal factor in cancer immune evasion, and the development of small-molecule MHC-II inducers is an unmet clinical need. Here, we identified three MHC-II inducers, including pristane and its two superior derivatives, that potently induce MHC-II expression in breast cancer cells and effectively inhibit the development of breast cancer. Our data suggest that MHC-II is central in promoting the immune detection of cancer to increase the tumor infiltration of T cells and enhance anti-cancer immunity. By discovering the malonyl/acetyltransferase (MAT) domain in fatty acid synthase (FASN) as the direct binding target of MHC-II inducers, we demonstrate that evasion of immune detection and cancer metabolic reprogramming are directly linked by fatty acid-mediated MHC-II silencing. Collectively, we identified three MHC-II inducers and illustrated that lack of MHC-II caused by hyper-activated fatty acid synthesis to limit immune detection is a potentially widespread mechanism underlying the development of cancer.

The interplay between neoantigens and immune cells in sarcomas treated with checkpoint inhibition

Introduction

Sarcomas are comprised of diverse bone and connective tissue tumors with few effective therapeutic options for locally advanced unresectable and/or metastatic disease. Recent advances in immunotherapy, in particular immune checkpoint inhibition (ICI), have shown promising outcomes in several cancer indications. Unfortunately, ICI therapy has provided only modest clinical responses and seems moderately effective in a subset of the diverse subtypes.

Methods

To explore the immune parameters governing ICI therapy resistance or immune escape, we performed whole exome sequencing (WES) on tumors and their matched normal blood, in addition to RNA-seq from tumors of 31 sarcoma patients treated with pembrolizumab. We used advanced computational methods to investigate key immune properties, such as neoantigens and immune cell composition in the tumor microenvironment (TME).

Results

A multifactorial analysis suggested that expression of high quality neoantigens in the context of specific immune cells in the TME are key prognostic markers of progression-free survival (PFS). The presence of several types of immune cells, including T cells, B cells and macrophages, in the TME were associated with improved PFS. Importantly, we also found the presence of both CD8+ T cells and neoantigens together was associated with improved survival compared to the presence of CD8+ T cells or neoantigens alone. Interestingly, this trend was not identified with the combined presence of CD8+ T cells and TMB; suggesting that a combined CD8+ T cell and neoantigen effect on PFS was important.

Discussion

The outcome of this study may inform future trials that may lead to improved outcomes for sarcoma patients treated with ICI.

Construction of a novel cancer-associated fibroblast-related signature to predict clinical outcome and immune response in colon adenocarcinoma

The interaction between the tumour and the surrounding microenvironment determines the malignant biological behaviour of the tumour. Cancer-associated fibroblasts (CAFs) coordinate crosstalk between cancer cells in the tumour immune microenvironment (TIME) and are extensively involved in tumour malignant behaviours, such as immune evasion, invasion and drug resistance. Here, we performed differential and prognostic analyses of genes associated with CAFs and constructed CAF-related signatures (CAFRs) to predict clinical outcomes in individuals with colon adenocarcinoma (COAD) based on machine learning algorithms. The CAFRs were further validated in an external independent cohort, GSE17538. Additionally, Cox regression, receiver operating characteristic (ROC) and clinical correlation analysis were utilised to systematically assess the CAFRs. Moreover, CIBERSORT, single sample Gene Set Enrichment Analysis (ssGSEA) and Estimation of Stromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) analysis were utilised to characterise the TIME in patients with COAD. Microsatellite instability (MSI) and tumour mutation burden were also analysed. Furthermore, Gene Set Variation Analysis (GSVA), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) elucidated the biological functions and signalling pathways involved in the CAFRs. Consensus clustering analysis was used for the immunological analysis of patients with COAD. Finally, the pRRophic algorithm was used for sensitivity analysis of common drugs. The CAFRs constructed herein can better predict the prognosis in COAD. The cluster analysis based on the CAFRs can effectively differentiate between immune 'hot' and 'cold' tumours, determine the beneficiaries of immune checkpoint inhibitors (ICIs) and provide insight into individualised treatment for COAD.

Innate immune response restarts adaptive immune response in tumors

The imbalance of immune response plays a crucial role in the development of diseases, including glioblastoma. It is essential to comprehend how the innate immune system detects tumors and pathogens. Endosomal and cytoplasmic sensors can identify diverse cancer cell antigens, triggering the production of type I interferon and pro-inflammatory cytokines. This, in turn, stimulates interferon stimulating genes, enhancing the presentation of cancer antigens, and promoting T cell recognition and destruction of cancer cells. While RNA and DNA sensing of tumors and pathogens typically involve different receptors and adapters, their interaction can activate adaptive immune response mechanisms. This review highlights the similarity in RNA and DNA sensing mechanisms in the innate immunity of both tumors and pathogens. The aim is to enhance the anti-tumor innate immune response, identify regions of the tumor that are not responsive to treatment, and explore new targets to improve the response to conventional tumor therapy and immunotherapy.

Emerging Roles of Using Small Extracellular Vesicles as an Anti-Cancer Drug

Small extracellular vesicles (sEVs) are emerging as a novel therapeutic strategy for cancer therapy. Tumor-cell-derived sEVs contain biomolecules that can be utilized for cancer diagnosis. sEVs can directly exert tumor-killing effects or modulate the tumor microenvironment, leading to anti-cancer effects. In this review, the application of sEVs as a diagnostic tool, drug delivery system, and active pharmaceutical ingredient for cancer therapy will be highlighted. The therapeutic efficacies of sEVs will be compared to conventional immune checkpoint inhibitors. Additionally, this review will provide strategies for sEV engineering to enhance the therapeutic efficacies of sEVs. As a bench-to-bedside application, we will discuss approaches to encourage good-manufacturing-practice-compliant industrial-scale manufacturing and purification of sEVs.

CTLA-4 blockade induces a microglia-Th1 cell partnership that stimulates microglia phagocytosis and anti-tumor function in glioblastoma

The limited efficacy of immunotherapies against glioblastoma underscores the urgency of better understanding immunity in the central nervous system. We found that treatment with αCTLA-4, but not αPD-1, prolonged survival in a mouse model of mesenchymal-like glioblastoma. This effect was lost upon the depletion of CD4+ T cells but not CD8+ T cells. αCTLA-4 treatment increased frequencies of intratumoral IFNγ-producing CD4+ T cells, and IFNγ blockade negated the therapeutic impact of αCTLA-4. The anti-tumor activity of CD4+ T cells did not require tumor-intrinsic MHC-II expression but rather required conventional dendritic cells as well as MHC-II expression on microglia. CD4+ T cells interacted directly with microglia, promoting IFNγ-dependent microglia activation and phagocytosis via the AXL/MER tyrosine kinase receptors, which were necessary for tumor suppression. Thus, αCTLA-4 blockade in mesenchymal-like glioblastoma promotes a CD4+ T cell-microglia circuit wherein IFNγ triggers microglia activation and phagocytosis and microglia in turn act as antigen-presenting cells fueling the CD4+ T cell response.

The future of affordable cancer immunotherapy

The treatment of cancer was revolutionized within the last two decades by utilizing the mechanism of the immune system against malignant tissue in so-called cancer immunotherapy. Two main developments boosted cancer immunotherapy: 1) the use of checkpoint inhibitors, which are characterized by a relatively high response rate mainly in solid tumors; however, at the cost of serious side effects, and 2) the use of chimeric antigen receptor (CAR)-T cells, which were shown to be very efficient in the treatment of hematologic malignancies, but failed to show high clinical effectiveness in solid tumors until now. In addition, active immunization against individual tumors is emerging, and the first products have reached clinical approval. These new treatment options are very cost-intensive and are not financially compensated by health insurance in many countries. Hence, strategies must be developed to make cancer immunotherapy affordable and to improve the cost-benefit ratio. In this review, we discuss the following strategies: 1) to leverage the antigenicity of "cold tumors" with affordable reagents, 2) to use microbiome-based products as markers or therapeutics, 3) to apply measures that make adoptive cell therapy (ACT) cheaper, e.g., the use of off-the-shelf products, 4) to use immunotherapies that offer cheaper platforms, such as RNA- or peptide-based vaccines and vaccines that use shared or common antigens instead of highly personal antigens, 5) to use a small set of predictive biomarkers instead of the "sequence everything" approach, and 6) to explore affordable immunohistochemistry markers that may direct individual therapies.

Optogenetic engineering of STING signaling allows remote immunomodulation to enhance cancer immunotherapy

The cGAS-STING signaling pathway has emerged as a promising target for immunotherapy development. Here, we introduce a light-sensitive optogenetic device for control of the cGAS/STING signaling to conditionally modulate innate immunity, called 'light-inducible SMOC-like repeats' (LiSmore). We demonstrate that photo-activated LiSmore boosts dendritic cell (DC) maturation and antigen presentation with high spatiotemporal precision. This non-invasive approach photo-sensitizes cytotoxic T lymphocytes to engage tumor antigens, leading to a sustained antitumor immune response. When combined with an immune checkpoint blocker (ICB), LiSmore improves antitumor efficacy in an immunosuppressive lung cancer model that is otherwise unresponsive to conventional ICB treatment. Additionally, LiSmore exhibits an abscopal effect by effectively suppressing tumor growth in a distal site in a bilateral mouse model of melanoma. Collectively, our findings establish the potential of targeted optogenetic activation of the STING signaling pathway for remote immunomodulation in mice.

Whole tumour cell-based vaccines: tuning the instruments to orchestrate an optimal antitumour immune response

Immunotherapy, particularly those based on immune checkpoint inhibitors (ICIs), has become a useful approach for many neoplastic diseases. Despite the improvements of ICIs in supporting tumour regression and prolonging survival, many patients do not respond or develop resistance to treatment. Thus, therapies that enhance antitumour immunity, such as anticancer vaccines, constitute a feasible and promising therapeutic strategy. Whole tumour cell (WTC) vaccines have been extensively tested in clinical studies as intact or genetically modified cells or tumour lysates, injected directly or loaded on DCs with distinct adjuvants. The essential requirements of WTC vaccines include the optimal delivery of a broad battery of tumour-associated antigens, the presence of tumour cell-derived molecular danger signals, and adequate adjuvants. These factors trigger an early and robust local innate inflammatory response that orchestrates an antigen-specific and proinflammatory adaptive antitumour response capable of controlling tumour growth by several mechanisms. In this review, the strengths and weaknesses of our own and others' experiences in studying WTC vaccines are revised to discuss the essential elements required to increase anticancer vaccine effectiveness.

Utility of Tumor Mutational Burden as a Biomarker for Response to Immune Checkpoint Inhibition in the VA Population

PURPOSE

Immune checkpoint inhibitors (ICIs) are used for an increasing number of indications across various tumor types, as well as several tumor-agnostic indications in patients with advanced cancer. Although many patients benefit from ICI therapy, others do not, highlighting a need for better predictive biomarkers. Tumor mutational burden (TMB) reflects the global number of mutations within a tumor and has been widely explored as a predictive biomarker of ICI response. The current tumor type-agnostic US Food and Drug Administration approval of pembrolizumab for metastatic solid tumors defines high TMB (TMB-H) as ≥10 mut/Mb as measured by FoundationOne CDx. This fixed cutoff may not be the ideal value across all solid tumors.

METHODS

We performed a retrospective analysis of the association of survival outcomes with TMB in patients treated with ICI for five major cancer types, using real-world data from the VA. Survival was measured from initiation of ICI, and Kaplan-Meier survival curves were compared by log-rank test.

RESULTS

Overall survival (OS) was significantly longer for patients with TMB-H versus TMB low tumors in non-small-cell lung cancer (NSCLC; n = 1,593), head and neck (H&N) cancer (n = 222), and urothelial cancer (n = 332). OS was not significantly different based on TMB status in melanoma (n = 207) or esophageal/gastric cancer (n = 248).

CONCLUSION

Consistent with previous studies, a predictive value of TMB ≥10 mut/Mb for ICI response was found in NSCLC and H&N, but not in esophageal/gastric cancer. Although inconclusive in the literature, significant association was found in urothelial cancer. The predictive value of TMB in melanoma was inconclusive. Our analysis does not support the use of a fixed threshold for TMB as a standalone predictive biomarker for ICI across all solid tumors.

Hypoxia effects on oncolytic virotherapy in Cancer: Friend or Foe?

Researchers have tried to find novel strategies for cancer treatment in the past decades. Among the utilized methods, administering oncolytic viruses (OVs) alone or combined with other anticancer therapeutic approaches has had promising outcomes, especially in solid tumors. Infecting the tumor cells by these viruses can lead to direct lysis or induction of immune responses. However, the immunosuppressive tumor microenvironment (TME) is considered a significant challenge for oncolytic virotherapy in treating cancer. Based on OV type, hypoxic conditions in the TME can accelerate or repress virus replication. Therefore, genetic manipulation of OVs or other molecular modifications to reduce hypoxia can induce antitumor responses. Moreover, using OVs with tumor lysis capability in the hypoxic TME may be an attractive strategy to overcome the limitations of the therapy. This review summarizes the latest information available in the field of cancer virotherapy and discusses the dual effect of hypoxia on different types of OVs to optimize available related therapeutic methods.

Construction of an efferocytosis-related long non-coding ribonucleic acid scoring system to predict clinical outcome and immunotherapy response in pancreatic adenocarcinoma

Background

Efferocytosis suppresses antitumour immune responses by inducing the release and secretion of cytokines. Long non-coding ribonucleic acids (lncRNAs) have various functions in different forms of programmed cell death and in immune regulation. This study aims to explore the potential role of efferocytosis-related lncRNAs as biomarkers in pancreatic adenocarcinoma (PAAD).

Methods

Transcriptome profiles, simple nucleotide variations and clinical data of patients with PAAD were extracted from The Cancer Genome Atlas (TCGA) database. Co-expression algorithms identified efferocytosis-related lncRNAs. The efferocytosis-related lncRNA scoring system (ERLncSys) was established using Cox regression and the Least Absolute Shrinkage and Selection Operator algorithm. Additionally, Kaplan-Meier (K-M) curves, Cox regression, receiver operating characteristic (ROC) curves and clinical parameter stratification analyses were used to evaluate ERlncSys. Moreover, ERlncSys was explored through Gene Set Variation Analysis, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Furthermore, the TIMER platform, ESTIMATE algorithm, single sample Gene Set Enrichment Analysis and immune checkpoint analysis were utilised to explore the predictive power of ERlncSys for the tumour immune microenvironment (TIME). Finally, a consensus clustering algorithm identified distinct molecular profiles among patients with PAAD, aiding in the identification of potential beneficiaries for immunotherapy.

Results

K-M, Cox regression and ROC analyses confirmed the robust prognostic efficacy of ERlncSys. Clinical stratification analysis indicated the broad applicability of ERlncSys in PAAD. Additionally, mmunological analyses indicated that ERlncSys can determine immune cell infiltration status in the TIME. Furthermore, consensus clustering analysis based on ERlncSys divided the TCGA-PAAD cohort into two clusters. Cluster 1 exhibited characteristics consistent with an immune 'hot tumour' compared to cluster 2, suggesting cluster 1 is a more suitable population for immune checkpoint inhibitor therapy.

Conclusion

The established ErlncSys aids in predicting the prognosis and understanding the TIME landscape of patients with PAAD. In turn, it facilitates the identification of optimal candidates for immunotherapy. This study introduces novel insights into the potential value of efferocytosis-related lncRNAs as biomarkers in PAAD.

Shaping the "hot" immunogenic tumor microenvironment by nanoparticles co-delivering oncolytic peptide and TGF-β1 siRNA for boosting checkpoint blockade therapy

Induction of potent immune responses toward tumors remains challenging in cancer immunotherapy, in which it only showed benefits in a minority of patients with "hot" tumors, which possess pre-existing effector immune cells within the tumor. In this study, we proposed a nanoparticle-based strategy to fire up the "cold" tumor by upregulating the components associated with T and NK cell recruitment and activation and suppressing TGF-β1 secretion by tumor cells. Specifically, LTX-315, a first-in-class oncolytic cationic peptide, and TGF-β1 siRNA were co-entrapped in a polymer-lipid hybrid nanoparticle comprising PLGA, DSPE-mPEG, and DSPE-PEG-conjugated with cRGD peptide (LTX/siR-NPs). The LTX/siR-NPs showed significant inhibition of TGF-β1 expression, induction of type I interferon release, and triggering immunogenic cell death (ICD) in treated tumor cells, indicated via the increased levels of danger molecules, an in vitro setting. The in vivo data showed that the LTX/siR-NPs could effectively protect the LTX-315 peptide from degradation in serum, which highly accumulated in tumor tissue. Consequently, the LTX/siR-NPs robustly suppressed TGF-β1 production by tumor cells and created an immunologically active tumor with high infiltration of antitumor effector immune cells. As a result, the combination of LTX/siR-NP treatment with NKG2A checkpoint inhibitor therapy remarkably increased numbers of CD8+NKG2D+ and NK1.1+NKG2D+ within tumor masses, and importantly, inhibited the tumor growth and prolonged survival rate of treated mice. Taken together, this study suggests the potential of the LTX/siR-NPs for inflaming the "cold" tumor for potentiating the efficacy of cancer immunotherapy.

Fulvestrant increases the susceptibility of enzalutamide-resistant prostate cancer cells to NK-mediated lysis

BACKGROUND

Enzalutamide, a next-generation antiandrogen agent, is approved for the treatment of metastatic castration-resistant prostate cancer (CRPC). While enzalutamide has been shown to improve time to progression and extend overall survival in men with CRPC, the majority of patients ultimately develop resistance to treatment. Immunotherapy approaches have shown limited clinical benefit in this patient population; understanding resistance mechanisms could help develop novel and more effective treatments for CRPC. One of the mechanisms involved in tumor resistance to various therapeutics is tumor phenotypic plasticity, whereby carcinoma cells acquire mesenchymal features with or without the loss of classical epithelial characteristics. This work investigated a potential link between enzalutamide resistance, tumor phenotypic plasticity, and resistance to immune-mediated lysis in prostate cancer.

METHODS

Models of prostate cancer resistant to enzalutamide were established by long-term exposure of human prostate cancer cell lines to the drug in culture. Tumor cells were evaluated for phenotypic features in vitro and in vivo, as well as for sensitivity to immune effector cell-mediated cytotoxicity.

RESULTS

Resistance to enzalutamide was associated with gain of mesenchymal tumor features, upregulation of estrogen receptor expression, and significantly reduced tumor susceptibility to natural killer (NK)-mediated lysis, an effect that was associated with decreased tumor/NK cell conjugate formation with enzalutamide-resistant cells. Fulvestrant, a selective estrogen receptor degrader, restored the formation of target/NK cell conjugates and increased susceptibility to NK cell lysis in vitro. In vivo, fulvestrant demonstrated antitumor activity against enzalutamide-resistant cells, an effect that was associated with activation of NK cells.

CONCLUSION

NK cells are emerging as a promising therapeutic approach in prostate cancer. Modifying tumor plasticity via blockade of estrogen receptor with fulvestrant may offer an opportunity for immune intervention via NK cell-based approaches in enzalutamide-resistant CRPC.

Dendritic Cell Vaccines: A Shift from Conventional Approach to New Generations

In the emerging era of cancer immunotherapy, immune checkpoint blockades (ICBs) and adoptive cell transfer therapies (ACTs) have gained significant attention. However, their therapeutic efficacies are limited due to the presence of cold type tumors, immunosuppressive tumor microenvironment, and immune-related side effects. On the other hand, dendritic cell (DC)-based vaccines have been suggested as a new cancer immunotherapy regimen that can address the limitations encountered by ICBs and ACTs. Despite the success of the first generation of DC-based vaccines, represented by the first FDA-approved DC-based therapeutic cancer vaccine Provenge, several challenges remain unsolved. Therefore, new DC vaccine strategies have been actively investigated. This review addresses the limitations of the currently most adopted classical DC vaccine and evaluates new generations of DC vaccines in detail, including biomaterial-based, immunogenic cell death-inducing, mRNA-pulsed, DC small extracellular vesicle (sEV)-based, and tumor sEV-based DC vaccines. These innovative DC vaccines are envisioned to provide a significant breakthrough in cancer immunotherapy landscape and are expected to be supported by further preclinical and clinical studies.

Factors impacting the benefits and pathogenicity of Th17 cells in the tumor microenvironment

Tumor development is closely associated with a complex tumor microenvironment, which is composed of tumor cells, blood vessels, tumor stromal cells, infiltrating immune cells, and associated effector molecules. T helper type 17 (Th17) cells, which are a subset of CD4+ T cells and are renowned for their ability to combat bacterial and fungal infections and mediate inflammatory responses, exhibit context-dependent effector functions. Within the tumor microenvironment, different molecular signals regulate the proliferation, differentiation, metabolic reprogramming, and phenotypic conversion of Th17 cells. Consequently, Th17 cells exert dual effects on tumor progression and can promote or inhibit tumor growth. This review aimed to investigate the impact of various alterations in the tumor microenvironment on the antitumor and protumor effects of Th17 cells to provide valuable clues for the exploration of additional tumor immunotherapy strategies.

Targeting KDM2A Enhances T-cell Infiltration in NSD1-Deficient Head and Neck Squamous Cell Carcinoma

In head and neck squamous cell carcinoma (HNSCC), a significant proportion of tumors have inactivating mutations in the histone methyltransferase NSD1. In these tumors, NSD1 inactivation is a driver of T-cell exclusion from the tumor microenvironment (TME). A better understanding of the NSD1-mediated mechanism regulating infiltration of T cells into the TME could help identify approaches to overcome immunosuppression. Here, we demonstrated that NSD1 inactivation results in lower levels of H3K36 dimethylation and higher levels of H3K27 trimethylation, the latter being a known repressive histone mark enriched on the promoters of key T-cell chemokines CXCL9 and CXCL10. HNSCC with NSD1 mutations had lower levels of these chemokines and lacked responses to PD-1 immune checkpoint blockade. Inhibition of KDM2A, the primary lysine demethylase that is selective for H3K36, reversed the altered histone marks induced by NSD1 loss and restored T-cell infiltration into the TME. Importantly, KDM2A suppression decreased growth of NSD1-deficient tumors in immunocompetent, but not in immunodeficient, mice. Together, these data indicate that KDM2A is an immunotherapeutic target for overcoming immune exclusion in HNSCC.

SIGNIFICANCE

The altered epigenetic landscape of NSD1-deficient tumors confers sensitivity to inhibition of the histone-modifying enzyme KDM2A as an immunotherapeutic strategy to stimulate T-cell infiltration and suppress tumor growth.

Membrane-localized neoantigens predict the efficacy of cancer immunotherapy

Immune checkpoint immunotherapy (ICI) can re-activate immune reactions against neoantigens, leading to remarkable remission in cancer patients. Nevertheless, only a minority of patients are responsive to ICI, and approaches for prediction of responsiveness are needed to improve the success of cancer treatments. While the tumor mutational burden (TMB) correlates positively with responsiveness and survival of patients undergoing ICI, the influence of the subcellular localizations of the neoantigens remains unclear. Here, we demonstrate in both a mouse melanoma model and human clinical datasets of 1,722 ICI-treated patients that a high proportion of membrane-localized neoantigens, particularly at the plasma membrane, correlate with responsiveness to ICI therapy and improved overall survival across multiple cancer types. We further show that combining membrane localization and TMB analyses can enhance the predictability of cancer patient response to ICI. Our results may have important implications for establishing future clinical guidelines to direct the choice of treatment toward ICI.

CD47 polymorphism for predicting nivolumab benefit in patients with advanced non‑small‑cell lung cancer

Immune checkpoint inhibitors (ICIs), such as nivolumab, play an essential role in non-small-cell lung cancer (NSCLC) treatment. Programmed death ligand-1 has been used as a predictive biomarker for the efficacy of ICI treatment in patients with NSCLC; however, its predictive value is considered insufficient. Therefore, there is an urgent need for better predictive biomarkers. The present study focused on the CD47 molecule, which is associated with macrophages and tumor immunity. The study aimed to investigate the association between CD47 single nucleotide polymorphism (SNP) and the therapeutic effect of nivolumab in patients with NSCLC. The CD47 SNP genotypes and clinical outcomes were retrospectively analyzed in 164 patients with NSCLC treated with nivolumab at Kyoto University Hospital (Kyoto, Japan). Patients with the G/G genotype of the CD47 SNP rs3804639 had significantly longer progression-free survival than those with the G/T or T/T genotypes [2.6 months vs. 2.1 months, hazard ratio (HR), 0.70; P=0.026]. Moreover, the G/G genotype of the CD47 SNP rs3804639 was associated with a significantly longer median overall survival than the G/T or T/T genotypes of the CD47 SNP rs3804639 (24.8 months vs. 12.0 months, HR, 0.64; P=0.021). In conclusion, CD47 polymorphism may be a novel predictive biomarker of nivolumab efficacy in patients with advanced NSCLC.

MHC class I loss is associated with biliary/progenitor cell features and "cold" tumor-immune microenvironment in hepatocellular carcinoma

Hepatocellular carcinomas (HCCs) with biliary/progenitor cell features frequently show increased programmed death-ligand 1 (PD-L1) expression, but their response to immunotherapy is not high. One possible explanation for this phenomenon could be the loss of major histocompatibility complex (MHC) class I expression on tumor cells, which impairs the presentation of tumor antigens to cytotoxic T cells. However, the potential correlation between MHC class I loss, biliary/progenitor cell features, and the tumor-immune microenvironment remains largely unexplored. Herein, we hypothesized that MHC class I loss could be associated with biliary/progenitor cell features and potentially impact the tumor-immune microenvironment. To evaluate this hypothesis and gain insight into the characteristics of tumor cells and the tumor-immune microenvironment in HCCs with MHC class I loss, we examined a consecutive series of 397 HCC cases. MHC class I loss was observed in 32 HCCs (8.1%). Lipid-less cytologic morphology was significantly associated with MHC class I loss (P = 0.02). CK19 expression and decreased ARG1 expression, both known as biliary/progenitor cell features, were significantly associated with MHC class I loss (P < 0.05). PD-L1 expression was irrelevant to the MHC class I status. HCCs with MHC class I loss exhibited significantly lower infiltration of CD8+, CD4+, CD20+, and FOXP3+ cells than those with intact MHC class I (all Ps < 0.01). Our study reveals an association between MHC class I loss, biliary/progenitor cell features, and a "cold" tumor-immune microenvironment in HCCs. These insights highlight the potential impact of MHC class I loss on tumor cells and the tumor-immune microenvironment.

Guanylate-binding proteins signature predicts favorable prognosis, immune-hot microenvironment, and immunotherapy response in hepatocellular carcinoma

BACKGROUND

The role of guanylate-binding proteins (GBPs) in various cancers has been elucidated recently. However, our knowledge of the clinical relevance and biological characteristics of GBPs in hepatocellular carcinoma (HCC) remains limited.

METHODS

A total of 955 HCC patients were enrolled from five independent public HCC cohorts. The role of GBP molecules in HCC was preliminarily investigated, and a GBP family signature, termed GBPs-score, was constructed by principal component analysis to combine the GBP molecule values. We revealed the effects of GBP genes and GBPs-score in HCC via well-established bioinformatics methods and validated GBP1-5 experimentally in a tissue microarray (TMA) cohort.

RESULTS

GBPs molecules were closely associated with the prognosis of patients with HCC, and a high GBPs-score highly inferred a favorable survival outcome. We also revealed high GBPs-score was related to anti-tumor immunity, the immune-hot tumor microenvironment (TME), and immunotherapy response. Among the GBPs members, GBP1-5 rather than GBP6/7 may be dominant in these fields. The TMA analysis based on immunohistochemistry showed positive correlations between GBP1-5 and the immune-hot TME with abundant infiltration of CD8+ T cells in HCC.

CONCLUSIONS

Our integrative study revealed the genetic and immunologic characterizations of GBPs in HCC and highlighted their potential values as promising biomarkers for prognosis and immunotherapy.

A small molecule inhibitor of PTP1B and PTPN2 enhances T cell anti-tumor immunity

The inhibition of protein tyrosine phosphatases 1B (PTP1B) and N2 (PTPN2) has emerged as an exciting approach for bolstering T cell anti-tumor immunity. ABBV-CLS-484 is a PTP1B/PTPN2 inhibitor in clinical trials for solid tumors. Here we have explored the therapeutic potential of a related small-molecule-inhibitor, Compound-182. We demonstrate that Compound-182 is a highly potent and selective active site competitive inhibitor of PTP1B and PTPN2 that enhances T cell recruitment and activation and represses the growth of tumors in mice, without promoting overt immune-related toxicities. The enhanced anti-tumor immunity in immunogenic tumors can be ascribed to the inhibition of PTP1B/PTPN2 in T cells, whereas in cold tumors, Compound-182 elicited direct effects on both tumor cells and T cells. Importantly, treatment with Compound-182 rendered otherwise resistant tumors sensitive to α-PD-1 therapy. Our findings establish the potential for small molecule inhibitors of PTP1B and PTPN2 to enhance anti-tumor immunity and combat cancer.

Induced Vascular Normalization-Can One Force Tumors to Surrender to a Better Microenvironment?

Immunotherapy has changed the way many cancers are being treated. Researchers in the field of immunotherapy and tumor immunology are investigating similar questions: How can the positive benefits achieved with immunotherapies be enhanced? Can this be achieved through combinations with other agents and if so, which ones? In our view, there is an urgent need to improve immunotherapy to make further gains in the overall survival for those patients that should benefit from immunotherapy. While numerous different approaches are being considered, our team believes that drug delivery methods along with appropriately selected small-molecule drugs and drug candidates could help reach the goal of doubling the overall survival rate that is seen in some patients that are given immunotherapeutics. This review article is prepared to address how immunotherapies should be combined with a second treatment using an approach that could realize therapeutic gains 10 years from now. For context, an overview of immunotherapy and cancer angiogenesis is provided. The major targets in angiogenesis that have modulatory effects on the tumor microenvironment and immune cells are highlighted. A combination approach that, for us, has the greatest potential for success involves treatments that will normalize the tumor's blood vessel structure and alter the immune microenvironment to support the action of immunotherapeutics. So, this is reviewed as well. Our focus is to provide an insight into some strategies that will engender vascular normalization that may be better than previously described approaches. The potential for drug delivery systems to promote tumor blood vessel normalization is considered.

SMYD3 represses tumor-intrinsic interferon response in HPV-negative squamous cell carcinoma of the head and neck

Cancers often display immune escape, but the mechanisms are incompletely understood. Herein, we identify SMYD3 as a mediator of immune escape in human papilloma virus (HPV)-negative head and neck squamous cell carcinoma (HNSCC), an aggressive disease with poor response to immunotherapy with pembrolizumab. SMYD3 depletion induces upregulation of multiple type I interferon (IFN) response and antigen presentation machinery genes in HNSCC cells. Mechanistically, SMYD3 binds to and regulates the transcription of UHRF1, encoding for a reader of H3K9me3, which binds to H3K9me3-enriched promoters of key immune-related genes, recruits DNMT1, and silences their expression. SMYD3 further maintains the repression of immune-related genes through intragenic deposition of H4K20me3. In vivo, Smyd3 depletion induces influx of CD8+ T cells and increases sensitivity to anti-programmed death 1 (PD-1) therapy. SMYD3 overexpression is associated with decreased CD8 T cell infiltration and poor response to neoadjuvant pembrolizumab. These data support combining SMYD3 depletion strategies with checkpoint blockade to overcome anti-PD-1 resistance in HPV-negative HNSCC.

Radiotherapy plus immune checkpoint inhibitor in prostate cancer

The immune checkpoint inhibitor (ICI) is a promising strategy for treating cancer. However, the efficiency of ICI monotherapy is limited, which could be mainly attributed to the tumor microenvironment of the "cold" tumor. Prostate cancer, a type of "cold" cancer, is the most common cancer affecting men's health. Radiotherapy is regarded as one of the most effective prostate cancer treatments. In the era of immune therapy, the enhanced antigen presentation and immune cell infiltration caused by radiotherapy might boost the therapeutic efficacy of ICI. Here, the rationale of radiotherapy combined with ICI was reviewed. Also, the scheme of radiotherapy combined with immune checkpoint blockades was suggested as a potential option to improve the outcome of patients with prostate cancer.

Attenuated Dengue virus PV001-DV induces oncolytic tumor cell death and potent immune responses

BACKGROUND

Viral therapies developed for cancer treatment have classically prioritized direct oncolytic effects over their immune activating properties. However, recent clinical insights have challenged this longstanding prioritization and have shifted the focus to more immune-based mechanisms. Through the potential utilization of novel, inherently immune-stimulating, oncotropic viruses there is a therapeutic opportunity to improve anti-tumor outcomes through virus-mediated immune activation. PV001-DV is an attenuated strain of Dengue virus (DEN-1 #45AZ5) with a favorable clinical safety profile that also maintains the potent immune stimulatory properties characterstic of Dengue virus infection.

METHODS

In this study, we utilized in vitro tumor killing and immune multiplex assays to examine the anti-tumor effects of PV001-DV as a potential novel cancer immunotherapy.

RESULTS

In vitro assays demonstrated that PV001-DV possesses the ability to directly kill human melanoma cells lines as well as patient melanoma tissue ex vivo. Importantly, further work demonstrated that, when patient peripheral blood mononuclear cells (PBMCs) were exposed to PV001-DV, a substantial induction in the production of apoptotic factors and immunostimulatory cytokines was detected. When tumor cells were cultured with the resulting soluble mediators from these PBMCs, rapid cell death of melanoma and breast cancer cell lines was observed. These soluble mediators also increased dengue virus binding ligands and immune checkpoint receptor, PD-L1 expression.

CONCLUSIONS

The direct in vitro tumor-killing and immune-mediated tumor cytotoxicity facilitated by PV001-DV contributes support of its upcoming clinical evaluation in patients with advanced melanoma who have failed prior therapy.

Generation and structure-activity relationships of novel imidazo-thienopyridine based TLR7 agonists: application as payloads for immunostimulatory antibody drug-conjugates

Pairing immunostimulatory small molecules with the targeting capability of an antibody has emerged as a novel therapeutic modality with the potential to treat a variety of solid tumors. A series of compounds based on an imidazo-thienopyridine scaffold were synthesized and tested for their ability to agonize the innate immune sensors toll-like receptor 7 and 8 (TLR7/8). Structure-activity relationship (SAR) studies revealed that certain simple amino-substituents could enable TLR7 agonism at low nanomolar concentrations. Drug-linkers containing either payload 1 or 20h were conjugated to the HER2-targeting antibody trastuzumab at the interchain disulfide cysteine residues using a cleavable valine-citrulline dipeptide linker and stochastic thiol-maleimide chemistry. In vitro, these immune-stimulating antibody drug-conjugates (ADCs) were found to induce cytokine release in a murine splenocyte assay when co-cultured with the HER2-high NCI-N87 cancer cell line. In vivo, tumor regression was observed with a single dose in an NCI-N87 gastric carcinoma xenograft model in BALB/c nude mice.

Prognostic analysis of lung adenocarcinoma based on cancer-associated fibroblasts genes using scRNA-sequencing

Cancer-associated fibroblasts (CAFs) are an important component of the tumor microenvironment (TME). CAFs can promote tumor occurrence and metastasis by promoting cancer cell proliferation, angiogenesis, extracellular matrix (ECM) remodeling, and drug resistance. Nevertheless, how CAFs are related to Lung adenocarcinoma (LUAD) has not yet been revealed, especially since the CAFs-related prediction model has yet to be established. We combined Single-cell RNA-sequencing (scRNA-seq) and Bulk-RNA data to develop a predictive model of 8 CAFs-associated genes. Our model predicted LUAD prognosis and immunotherapy efficacy. TME, mutation landscape and drug sensitivity differences were also systematically analyzed between the LUAD patients of high- and low-risk. Moreover, the model prognostic performance was validated in four independent validation cohorts in the Gene expression omnibus (GEO) and the IMvigor210 immunotherapy cohort.

Targeting LSD1 in tumor immunotherapy: rationale, challenges and potential

Lysine-specific demethylase 1 (LSD1) is an enzyme that removes lysine methylation marks from nucleosome histone tails and plays an important role in cancer initiation, progression, metastasis, and recurrence. Recent research shows that LSD1 regulates tumor cells and immune cells through multiple upstream and downstream pathways, enabling tumor cells to adapt to the tumor microenvironment (TME). As a potential anti-tumor treatment strategy, immunotherapy has developed rapidly in the past few years. However, most patients have a low response rate to available immune checkpoint inhibitors (ICIs), including anti-PD-(L)1 therapy and CAR-T cell therapy, due to a broad array of immunosuppressive mechanisms. Notably, inhibition of LSD1 turns "cold tumors" into "hot tumors" and subsequently enhances tumor cell sensitivity to ICIs. This review focuses on recent advances in LSD1 and tumor immunity and discusses a potential therapeutic strategy for combining LSD1 inhibition with immunotherapy.

Lighting Up the Fire in the Microenvironment of Cold Tumors: A Major Challenge to Improve Cancer Immunotherapy

Immunotherapy includes immune checkpoint inhibitors (ICI) such as antibodies targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or the programmed cell death protein/programmed death ligand 1 (PD-1/PD-L1) axis. Experimental and clinical evidence show that immunotherapy based on immune checkpoint inhibitors (ICI) provides long-term survival benefits to cancer patients in whom other conventional therapies have failed. However, only a minority of patients show high clinical benefits via the use of ICI alone. One of the major factors limiting the clinical benefits to ICI can be attributed to the lack of immune cell infiltration within the tumor microenvironment. Such tumors are classified as "cold/warm" or an immune "desert"; those displaying significant infiltration are considered "hot" or inflamed. This review will provide a brief summary of different tumor properties contributing to the establishment of cold tumors and describe major strategies that could reprogram non-inflamed cold tumors into inflamed hot tumors. More particularly, we will describe how targeting hypoxia can induce metabolic reprogramming that results in improving and extending the benefit of ICI.

TIGIT immune checkpoint blockade enhances immunity of human peripheral blood NK cells against castration-resistant prostate cancer

Castration-resistant prostate cancer (CRPC) patients have a 14-month median survival, emphasizing the need for alternative treatments. Previously, we demonstrated that expanded high-dose natural killer (NK) cells derived from human peripheral blood exhibit therapeutic efficacy against CRPC. However, which immune checkpoint blockade promotes NK cell antitumor immunity against CRPC remains unknown. Here, we explored immune checkpoint molecule expression in NK and CRPC cells during their interactions, and identified that the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) monoclonal antibody (mAb), vibostolimab, significantly enhanced NK cell cytotoxicity against CRPC cells and cytokine production in vitro, demonstrated by upregulation of degranulation marker CD107a and Fas-ligand (Fas-L) and increased interferon-gamma (IFN-γ) and tumor necrosis factor-alpha secretion. TIGIT blockade increased Fas-L expression and IFN-γ production via the NF-κB signaling pathway and restored degranulation via the mitogen-activated protein kinase ERK (extracellular signal-regulated kinase) kinase/ERK pathway in activated NK cells. Vibostolimab significantly enhanced NK cell antitumor effects against CRPC in two xenograft mouse models. Vibostolimab also increased T cell chemotaxis induced by activated NK cells in vitro and in vivo. Overall, blocking TIGIT/CD155 signaling enhances the antitumor effect of expanded NK cells against CRPC; this finding supports the translational application of TIGIT mAb and NK cell combination strategies from bench to bedside for CRPC treatment.

Mechanism-based pharmacokinetic and pharmacodynamic modeling for bispecific antibodies: challenges and opportunities

INTRODUCTION

Unlike conventional antibodies, bispecific antibodies (bsAbs) are engineered antibody- or antibody fragment-based molecules that can simultaneously recognize two different epitopes or antigens. Over the past decade, there has been an explosion of bsAbs being developed across therapeutic areas. Development of bsAbs presents unique challenges and mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) modeling has served as a powerful tool to optimize their development and realize their clinical utility.

AREAS COVERED

In this review, the guiding principles and case examples of how fit-for-purpose, mechanism-based PK/PD models have been applied to answer questions commonly encountered in bsAb development are presented. Such models characterize the key pharmacological elements of bsAbs, and they can be utilized for model-informed drug development. We also include the discussion of challenges, knowledge gaps and future direction for such models.

EXPERT OPINION

Mechanistic PK/PD modeling is a powerful tool to support the development of bsAbs. These models can be extrapolated to predict treatment outcomes based on mechanisms of action (MoA) and clinical observations to form positive learn-and-confirm cycles during drug development, due to their abilities to differentiate system- and drug-specific parameters. Meanwhile, the models should keep being adapted according to novel drug design and MoA, providing continuous opportunities for model-informed drug development.

Potential of Personalized Dendritic Cell-Based Immunohybridoma Vaccines to Treat Prostate Cancer

Prostate cancer (PCa) is the most commonly diagnosed cancer and the second most common cause of death due to cancer. About 30% of patients with PCa who have been castrated develop a castration-resistant form of the disease (CRPC), which is incurable. In the last decade, new treatments that control the disease have emerged, slowing progression and spread and prolonging survival while maintaining the quality of life. These include immunotherapies; however, we do not yet know the optimal combination and sequence of these therapies with the standard ones. All therapies are not always suitable for every patient due to co-morbidities or adverse effects of therapies or both, so there is an urgent need for further work on new therapeutic options. Advances in cancer immunotherapy with an immune checkpoint inhibition mechanism (e.g., ipilimumab, an anti-CTLA-4 inhibitor) have not shown a survival benefit in patients with CRPC. Other immunological approaches have also not given clear results, which has indirectly prevented breakthrough for this type of therapeutic strategy into clinical use. Currently, the only approved form of immunotherapy for patients with CRPC is a cell-based medicine, but it is only available to patients in some parts of the world. Based on what was gained from recently completed clinical research on immunotherapy with dendritic cell-based immunohybridomas, the aHyC dendritic cell vaccine for patients with CRPC, we highlight the current status and possible alternatives that should be considered in the future.

Immune checkpoint inhibition: a future guided by radiology

The limitation of the function of antitumour immune cells is a common hallmark of cancers that enables their survival. As such, the potential of immune checkpoint inhibition (ICI) acts as a paradigm shift in the treatment of a range of cancers but has not yet been fully capitalised. Combining minimally and non-invasive locoregional therapies offered by radiologists with ICI is now an active field of research with the aim of furthering therapeutic capabilities in medical oncology. In parallel to this impending advancement, the "imaging toolbox" available to radiologists is also growing, enabling more refined tumour characterisation as well as greater accuracy in evaluating responses to therapy. Options range from metabolite labelling to cellular localisation to immune checkpoint screening. It is foreseeable that these novel imaging techniques will be integrated into personalised treatment algorithms. This growth in the field must include updating the current standardised imaging criteria to ensure they are fit for purpose. Such criteria is crucial to both appropriately guide clinical decision-making regarding next steps of treatment, but also provide reliable prognosis. Quantitative approaches to these novel imaging techniques are also already being investigated to further optimise personalised therapeutic decision-making. The therapeutic potential of specific ICIs and locoregional therapies could be determined before administration thus limiting unnecessary side-effects whilst maintaining efficacy. Several radiological aspects of oncological care are advancing simultaneously. Therefore, it is essential that each development is assessed for clinical use and optimised to ensure the best treatment decisions are being offered to the patient. In this review, we discuss state of the art advances in novel functional imaging techniques in the field of immuno-oncology both pre-clinically and clinically.

Nanoengineered drug delivery in cancer immunotherapy for overcoming immunosuppressive tumor microenvironment

Almost like a living being in and of itself, tumors actively interact with and modify their environment to escape immune responses. Owing to the pre-formation of cancer-favorable microenvironment prior to anti-cancer treatment, the numerous attempts that followed propose limited efficacy in oncology. Immunogenicity by activation of immune cells within the tumor microenvironment or recruitment of immune cells from nearby lymph nodes is quickly offset as the immunosuppressive environment, rapidly converting immunogenic cells into immune suppressive cells, overriding the immune system. Tumor cells, as well as regulatory cells, namely M2 macrophages, Treg cells, and MDSCs, derived by the immunosuppressive environment, also cloak from potential anti-tumoral factors by directly or indirectly secreting cytokines, such as IL-10 and TGF-β, related to immune regulation. Enzymes and other metabolic or angiogenetic constituents - VEGF, IDO1, and iNOS - are also employed directed for anti-cancer immune cell malfunctioning. Therefore, the conversion of "cold" immunosuppressive environment into "hot" immune responsive environment is of paramount importance, bestowing the advances in the field of cancer immunotherapy the opportunity to wholly fulfill its intended purpose. This paper reviews the mechanisms by which tumors wield to exercise immune suppression and the nanoengineered delivery strategies being developed to overcome this suppression.

A transcriptome-informed QSP model of metastatic triple-negative breast cancer identifies predictive biomarkers for PD-1 inhibition

Triple-negative breast cancer (TNBC), a highly metastatic breast cancer subtype, has limited treatment options. While a small number of patients attain clinical benefit with single-agent checkpoint inhibitors, identifying these patients before the therapy remains challenging. Here, we developed a transcriptome-informed quantitative systems pharmacology model of metastatic TNBC by integrating heterogenous metastatic tumors. In silico clinical trial with an anti-PD-1 drug, pembrolizumab, predicted that several features, such as the density of antigen-presenting cells, the fraction of cytotoxic T cells in lymph nodes, and the richness of cancer clones in tumors, could serve individually as biomarkers but had a higher predictive power as combinations of two biomarkers. We showed that PD-1 inhibition neither consistently enhanced all antitumorigenic factors nor suppressed all protumorigenic factors but ultimately reduced the tumor carrying capacity. Collectively, our predictions suggest several candidate biomarkers that might effectively predict the response to pembrolizumab monotherapy and potential therapeutic targets to develop treatment strategies for metastatic TNBC.