Enhancing immunotherapy in cancer by targeting emerging immunomodulatory pathways

IDO1-mediated M2 macrophage polarization alleviates the progression of ankylosing spondylitis

Indoleamine 2,3-dioxygenase 1 (IDO1) plays an anti-inflammatory role in autoimmune disease. However, its specific function in ankylosing spondylitis (AS) remain unclear. This study aimed to investigate the potential role of IDO1 in AS. Immunofluorescence, RT-qPCR, and western blot assays were employed to measure gene expression, while ELISA was used to quantify the release of M1 macrophage and M2 macrophage markers. CCK-8, EdU, flow cytometry, ALP staining, and Alizarin red staining (ARS) assays were conducted for functional analysis. JASPAR predicted the binding sites between PPARγ and the promoter, which were further validated by luciferase and ChIP assays. Our findings revealed that the expression of IDO1 was markedly elevated in AS patients. IDO1 overexpression promoted the proliferation of THP-1 cells and M2 macrophage polarization. Conversely, IDO1 knockdown facilitated the osteogenic differentiation of BMSCs. Furthermore, IDO1-mediated upregulation of PPARγ modulated RUNX2 transcription. PPARγ overexpression counteracted the effects of IDO1 knockdown, thereby inhibiting the osteogenic differentiation of BMSCs. In conclusion, the IDO1/PPARγ/RUNX2 signaling pathway may protect against AS by promoting M2 macrophage polarization and inhibiting osteogenic differentiation.

Immune microenvironment of cancer bone metastasis

Bone is a common and frequent site of metastasis in cancer patients, leading to a significant reduction in quality of life and increased mortality. Bone marrow, the primary site of hematopoiesis, also serves as both a primary and secondary lymphoid organ. It harbors and supports a diverse array of immune cells, thereby creating a distinct immune microenvironment. These immune cells engage in a range of activities, including anti-tumor, pro-tumor, or a combination of both, which influence the development and progression of bone metastases. Rapid advances in cancer immunotherapy have underscored its potential to eradicate bone metastases. However, clinical outcomes have not yet met expectations. To improve the efficacy of immunotherapy, it is crucial to gain a comprehensive and in-depth understanding of the immune microenvironment within bone metastases. This review provides an overview of the current understanding of the role of different immune cells, their anti-tumor and pro-tumor activities, and their overall contribution to bone metastasis.

Single-Cell RNA Profiling of Ocular Adnexal Sebaceous Carcinoma Reveals a Complex Tumor Microenvironment and Identifies New Biomarkers

PURPOSE

Ocular adnexal sebaceous carcinoma (OaSC) is an aggressive malignancy that often necessitates orbital exenteration. Its tumor composition and transcriptional profile remain largely unknown, which poses a significant barrier to medical advances. Here, we report the first in-depth transcriptomic analysis of OaSC at the single-cell resolution and discern mechanisms underlying cancer progression for the discovery of potential globe-sparing immunotherapies, targeted therapies, and biomarkers to guide clinical management.

DESIGN

Laboratory investigation with a retrospective observational case series.

METHODS

Single-cell RNA sequencing was performed on six patient specimens: three primary tumors, two tumors with pagetoid spread, and a normal tarsus sample. Cellular components were identified via gene signatures. Molecular pathways underlying tumorigenesis and pagetoid spread were discerned via gene ontology analysis of the differentially expressed genes between specimens. CALML5 immunohistochemistry was performed on an archival cohort of OaSC, squamous cell carcinoma, ocular surface squamous neoplasia (OSSN), and basal cell carcinoma cases.

RESULTS

Analysis of 29,219 cells from OaSC specimens revealed tumor, immune, and stromal cells. Tumor-infiltrating immune cells include a diversity of cell types, including exhausted T-cell populations. In primary OaSC tumors, mitotic nuclear division and oxidative phosphorylation pathways are upregulated, while lipid biosynthesis and metabolism pathways are downregulated. Epithelial tissue migration pathways are upregulated in tumor cells undergoing pagetoid spread. Single-cell RNA sequencing analyses also revealed that CALML5 is upregulated in OaSC tumor cells. Diffuse nuclear and cytoplasmic CALML5 staining was present in 28 of 28 (100%) OaSC cases. Diffuse nuclear and membranous CALML5 staining was present in 5 of 25 (20%) squamous cell carcinoma and OSSN cases, while diffuse nuclear staining was present in 1 of 12 (8%) basal cell carcinoma cases.

CONCLUSIONS

This study reveals a complex OaSC tumor microenvironment and confirms that the CALML5 immunohistochemical stain is a sensitive diagnostic marker.

Programmable Porous Silicon Microparticles for Temporally Staged Drug Delivery in Combination Cancer Immunotherapy

Combination therapies using checkpoint inhibitors with immunostimulatory agonists have attracted great attention due to their synergistic therapeutic effects for cancer treatment. However, such combination immunotherapies require specific timing of doses to show sufficient antitumor efficacy. Sequential treatment usually requires multiple administrations of the individual drugs at specific time points, thus increasing the complexity of the drug regimen and compromising patient compliance. Here, we introduce an injectable porous silicon microparticle (pSiMP) for combination cancer immunotherapy where its multilayered nanopore structure was electrochemically programmed to achieve release of three distinct immunomodulatory drugs in the right sequence at the desired time. We find the optimal sequential treatment timeline of stimulator of interferon genes (STING) agonist, anti-OX40 antibody (aOX40), and anti-PD-1 antibody (aPD-1) for immunosuppressive tumors. We show that a single intratumoral injection of a cocktail of release-programmed pSiMPs coloaded with each antibody and a STING agonist significantly suppresses the tumor growth compared to conventional treatment involving sequential bolus injections, or an injection of pSiMPs configured to release all drugs at the same time, with no delay. With the timely release of immunomodulatory drugs, the programmable pSiMPs offer an effective treatment strategy for combination immunotherapy.

Emerging Delivery Systems for Enabling Precision Nucleic Acid Therapeutics

Nucleic acid therapeutics represent a highly promising treatment approach in modern medicine, treating diseases at the genetic level. However, these therapeutics face numerous challenges in practical applications, particularly regarding their stability, effectiveness, cellular uptake efficiency, and limitations in delivering them specifically to target tissues. To overcome these obstacles, researchers have developed various innovative delivery systems, including viral vectors, lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, protein carriers, exosomes, antibody oligonucleotide conjugates, and DNA nanostructure-based delivery systems. These systems enhance the therapeutic efficacy of nucleic acid drugs by improving their stability, targeting specificity, and half-life in vivo. In this review, we systematically discuss different types of nucleic acid drugs, analyze the major barriers encountered in their delivery, and summarize the current research progress in emerging delivery systems. We also highlight the latest advancements in the application of these systems for treating genetic diseases, infectious diseases, cancer, brain diseases, and wound healing. This review aims to provide a comprehensive overview of nucleic acid drug delivery systems' current status and future directions by integrating the latest advancements in nanotechnology, biomaterials science, and gene editing technologies, emphasizing their transformative potential in precision medicine.

Antimony Component Schottky Nanoheterojunctions as Ultrasound-Heightened Pyroptosis Initiators for Sonocatalytic Immunotherapy

Pyroptosis, an inflammatory modality of programmed cell death associated with the immune response, can be initiated by bioactive ions and reactive oxygen species (ROS). However, bioactive ion-induced pyroptosis lacks specificity, and further exploration of other ions that can induce pyroptosis in cancer cells is needed. Sonocatalytic therapy (SCT) holds promise due to its exceptional penetration depth; however, the rapid recombination of electron-hole (e--h+) pairs and the complex tumor microenvironment (TME) impede its broader application. Herein, we discovered that antimony (Sb)-based nanomaterials induced pyroptosis in cancer cells. Therefore, Schottky heterojunctions containing Sb component (Sb2Se3@Pt) were effectively designed and constructed via in situ growth of platinum (Pt) nanoparticles (NPs) on Sb2Se3 semiconductor with narrow band gaps, which were utilized as US-heightened pyroptosis initiators to induce highly effective pyroptosis in cancer cells to boost SCT-immunotherapy. Under US irradiation, excited electrons were transferred from Sb2Se3 nanorods (NRs) to the co-catalyst Pt via Schottky junctions, and band bending effectively prevented electron backflow and achieved efficient ROS generation. Moreover, the pores oxidized and depleted the overexpressed GSH in the TME, potentially amplifying ROS generation. The biological effects of the Sb2Se3@Pt nanoheterojunction itself combined with the sonocatalytic amplification of oxidative stress significantly induced Caspase-1/GSDMD-dependent pyroptosis in cancer cells. Therefore, SCT treatment with Sb2Se3@Pt not only effectively restrained tumor proliferation but also induced potent immune memory responses and suppressed tumor recurrence. Furthermore, the integration of this innovative strategy with immune checkpoint blockade (ICB) treatment elicited a systemic immune response, effectively augmenting therapeutic effects and impeding the growth of abscopal tumors. Overall, this study provides further opportunities to explore pyroptosis-mediated SCT-immunotherapy.

Self-Cascaded Pyroptosis-STING Initiators for Catalytic Metalloimmunotherapy

Gasdermin (GSDM)-mediated pyroptosis involves the induction of mitochondrial damage and the subsequent release of mitochondrial DNA (mtDNA), which is anticipated to activate the cGAS-STING pathway, thereby augmenting the antitumor immune response. However, challenges lie in effectively triggering pyroptosis in cancer cells and subsequently enhancing the cGAS-STING activation with specificity. Herein, we developed intelligent self-cascaded pyroptosis-STING initiators of cobalt fluoride (CoF2) nanocatalysts for catalytic metalloimmunotherapy. CoF2 nanocatalysts with a semiconductor structure and enzyme-like activity generated a substantial amount of reactive oxygen species (ROS) under stimulation by endogenous H2O2 and exogenous ultrasound. Importantly, we discovered that Co-based nanomaterials themselves induce pyroptosis in cancer cells. Therefore, CoF2 nanocatalysts initially acted as pyroptosis inducers, triggering caspase-1/GSDMD-dependent pyroptosis in cancer cells via Co2+ and ROS, leading to mtDNA release. Subsequently, CoF2 nanocatalysts were further utilized as intelligent STING agonists that were specifically capable of detecting mtDNA and augmenting the activation of the cGAS-STING pathway. These cascade events triggered a robust immune response, effectively modulating the immunosuppressive tumor microenvironment into an immune-supportive state, thereby providing favorable support for antitumor therapy. This innovative strategy not only significantly impeded the growth of the primary tumor but also elicited an immune response to further augment the efficacy of immune checkpoint inhibitors in preventing distant tumor progression. Overall, this study proposed a self-cascade strategy for activating and amplifying the cGAS-STING pathway with specificity mediated by pyroptosis, representing a valuable avenue for future cancer catalytic metalloimmunotherapy.

Pan-cancer analysis shows that TNFSF4 is a potential prognostic and immunotherapeutic biomarker for multiple cancer types including liver cancer

BACKGROUND

As a member of the tumor necrosis factor (TNF) superfamily, tumor necrosis factor superfamily member 4 (TNFSF4) is expressed on antigen-presenting cells and activated T cells by binding to its receptor TNFRSF4. However, tumorigenicity of TNFSF4 has not been studied in pan-cancer. Therefore, comprehensive bioinformatics analysis of pan-cancer was performed to determine the mechanisms through which TNFSF4 regulates tumorigenesis.

METHODS

RNA-seq data for 33 cancers were analyzed from UCSC XENA database. Online websites and databases were used to investigate TNFSF4's biological function, epigenetic modifications, genetic alterations, and tumor immunity. Furthermore, cell phenotype experiment and tumor xenotransplantation experiment were performed to determine the biological functions of TNFSF4.

RESULTS

The pan-cancer analysis showed that TNFSF4 was upregulated in several tumors. Significant relationships between TNFSF4 expression and single-cells data were also observed in numerous cancer types. TNFSF4 expression correlated with the expression of immune checkpoint genes and could influence various drug sensitivity. Vitro and vivo experiments showed that TNFSF4 could promote the development and progression of Hepatocellular Carcinoma (HCC).

CONCLUSIONS

TNFSF4 was upregulated in multiple cancer types and promoted the development and progression of cancers through several mechanisms including regulation of the tumor-infiltration of immune cells. Our study shows that TNFSF4 is a promising prognostic and immunotherapeutic biomarker in some malignant tumors.

A humanized anti-b7h3×4-1BB bispecific antibody exerts potent antitumour effects through the activation of innate and adaptive immunity

Agonistic monoclonal antibodies targeting 4-1BB have shown much preclinical promise, but their clinical development has been limited by obvious toxicity or unremarkable efficacy. Here, we generated two humanized anti-B7H3 × 4-1BB bsAbs (HK056-001/002) by fusing an anti-4-1BB scFv to the C-terminus of an anti-B7H3 with an intact Fc fragment from human IgG1 or IgG4. The two bsAbs were able to stimulate the 4-1BB signaling pathway, which was strictly dependent on B7H3 expression. In particular, HK056-001 retained Fc function and induced an ADCC effect in tumor cells, whereas HK056-002 did not. Strikingly, HK056-001 showed superior antitumour activity to HK056-002 both in vitro and in vivo. HK056-001 enhanced antitumour immunity and induced lasting antigen-specific immune memory to prevent tumor regrowth upon rechallenge, even at a dose as low as 2 mg/kg. Furthermore, HK056-001 did not induce nonspecific production of proinflammatory cytokines and had no apparent ability to induce ADA production. In addition, HK056-001 has no significant liver toxicity in human 4-1BB-KI BALB/c mice bearing CT26-B7H3 tumors. The optimal anti-B7H3 × 4-1BB bsAb HK056-001 exhibited synergistic antitumour effects by inducing an ADCC effect (innate immunity) and activating the 4-1BB signaling pathway (adaptive immunity) upon cross-bridging with B7H3 with no obvious toxicity, which could potentially provide a better therapeutic window compared to what is seen with 4-1BB agonists.

ETV7 limits the antiviral and antitumor efficacy of CD8+ T cells by diverting their fate toward exhaustion

Terminal exhaustion is a critical barrier to antitumor immunity. By integrating and analyzing single-cell RNA-sequencing and single-cell assay for transposase-accessible chromatin with sequencing data, we found that ETS variant 7 (ETV7) is indispensable for determining CD8+ T cell fate in tumors. ETV7 introduction drives T cell differentiation from memory to terminal exhaustion, limiting antiviral and antitumor efficacy in male mice. Mechanistically, ETV7 acts as a central transcriptional node by binding to specific memory genes and exhaustion genes and functionally skewing these transcriptional programs toward exhaustion. Clinically, ETV7 expression is negatively correlated with progression and responsiveness to immune checkpoint blockade in various human cancers. ETV7 depletion strongly enhances the antitumor efficacy of CD8+ T cells and engineered chimeric antigen receptor T cells in solid tumors. Thus, these findings demonstrate a decisive role for ETV7 in driving CD8+ T cell terminal exhaustion and reveal that ETV7 may be a promising target and biomarker for improving the efficacy of cancer immunotherapy.

Discovery of 1,2,4-benzotriazine derivatives as new hematopoietic progenitor kinase 1 (HPK1) inhibitors

Hematopoietic progenitor kinase 1 (HPK1), which negatively regulates immune signaling, has emerged as an attractive small-molecule drug target for tumor immunotherapy. Herein, we report the discovery of the 1,2,4-benzotriazine derivatives as new potent HPK1 inhibitors. Notably, compound A29 exhibited improved HPK1 inhibitory activity relative to compound 1 in the ADP-Glo kinase assay (IC50 = 2.70 and 13.6 nM, respectively). The pronounced inhibitory activity of A29 against downstream p-SLP76 in Jurkat T cells (IC50 = 8.1 nM) as well as the ability to induce the production of interleukin 2 (IL-2) in human peripheral blood mononuclear cells (PBMCs) confirmed its cellular target engagement and immune stimulatory effect. Consistently, this lead compound significantly enhanced T-cell killing ability against murine colon cancer cells CT26 or MC38 in a co-culture system. Furthermore, A29 was efficacious in a CT26 xenograft mouse model alone, and significantly enhanced the antitumor efficacy of an anti-PD-1 antibody. This work provides a promising lead for the development of effective HPK1 inhibitors for tumor immunotherapy.

Combination with oxaliplatin improves abscopal effect of oncolytic virotherapy through reorganization of intratumoral macrophages

Intratumoral administration is a widely used method for oncolytic virotherapy, as it enables immediate access of virus particles to the target tumor and potentially lead to the suppression of untreated distant tumors via in situ vaccination. However, because the injection volume and concentration of the virus solution are physically limited, the dose level cannot be increased. Additionally, efficacy in distant tumors needs improvement to prolong patient survival. Here, we demonstrate the benefit of oxaliplatin, with detailed mechanisms revealed through transcriptome analysis, which may provide a solution for the crucial deficiencies of oncolytic virotherapy. In virus-injected tumors, oxaliplatin improved virus retention through suppression of type I interferons. In distant virus-naive tumors, oxaliplatin induced alterations in the intratumoral macrophage characteristics, leading to the chemotaxis and recruitment of activated T cells and subsequently inducing an inflammatory state in the non-injected tumors. Our findings can be a trigger to change the therapeutic paradigm of oncolytic virotherapy for patients with systemic metastases.

Liposomal Nω-hydroxy-l-norarginine, a proof-of-concept: Arginase inhibitors can be incorporated in liposomes while retaining their therapeutic activity ex vivo

Cancer immunotherapy has evolved significantly over the last decade, with therapeutics targeting the adaptive immune system showing exciting effects in clinics. Yet, the modulation of the innate immune system, particularly the tumor-associated innate immune cells which are an integral part of immune responses in cancer, remains less understood. The arginase 1 (Arg1) pathway is a pivotal metabolic pathway that tumor-associated innate immune cells exploit to create an immunosuppressive tumor microenvironment, leading to the evasion of immune surveillance. The inhibition of Arg1 presents a therapeutic opportunity to reverse this immunosuppression, and Nω‑hydroxy-l-norarginine (nor-NOHA) has emerged as a potent arginase inhibitor with promising in vivo efficacy. However, the rapid systemic clearance of nor-NOHA poses a significant challenge for its therapeutic application. This study pioneers the encapsulation of nor-NOHA in liposomes, aiming to enhance its bioavailability and prolong its inhibitory activity against Arg1. Historically, the extensive interaction between innate immune cells and nanoparticles has been one of the biggest drawbacks in nanomedicine. Here we seek to utilize this effect and deliver liposomal nor-NOHA to the arginase 1 expressing innate immune cells. We systematically investigated the effect of lipid composition, acyl chain length, manufacturing and loading methodology on the encapsulation efficiency (EE%) and release profile of nor-NOHA. Our results indicate that while the manufacturing method and lipid acyl chain length do not significantly impact EE%, they crucially influence the release kinetics of nor-NOHA, with longer acyl chains demonstrating a more sustained release of nor-NOHA from liposomes enabling continuous inhibition of Arg1. Our findings suggest that liposomal nor-NOHA retains its functional inhibitory activity and could offer improved pharmacokinetic properties, making it a compelling base for iterations for further innovative cancer immunotherapeutic strategies in preclinical and clinical evaluations.

Development and characterisation of [18F]TTDP, a novel T cell immunoglobulin and ITIM domain tracer, in humanised mice and non-human primates

PURPOSE

The T cell immunoglobulin and ITIM domain (TIGIT) blockade immunotherapy response is directly associated with individual differences of TIGIT expression on tumour-infiltrating lymphocytes (TILs) in tumour immune microenvironment (TIME) of non-small cell lung cancer (NSCLC). Here, we developed a TIGIT-targeted PET tracer to evaluate its feasibility in predicting immunotherapy efficacy, aiming to manage NSCLC patients accurately.

METHODS

We synthesised a 18F-labeled TIGIT-targeted D-peptide, [18F]TTDP, and investigated the specificity of [18F]TTDP both to murine TIGIT and human TIGIT by a series of in vitro and in vivo assays. [18F]TTDP PET imaging was performed in humanised immune system (HIS) mice models bearing NSCLC patient-derived xenografts (PDXs) to evaluate the predictive value of FDA-approved combination immunotherapy of atezolizumab plus tiragolumab. Lastly, rhesus macaque was applied for [18F] TTDP PET to explore the tracer's in vivo distribution and translational potential in non-human primates.

RESULTS

[18F]TTDP showed high specificity for both murine TIGIT and human TIGIT in vitro and in vivo. The HIS NSCLC PDX platform was successfully established for [18F]TTDP PET imaging, and tumour uptake of [18F]TTDP was significantly correlated with the TIGIT expression of TILs in the TIME. [18F]TTDP PET imaging, in predicting treatment response to the combination immunotherapy in NSCLC HIS-PDX models, showed a sensitivity of 83.33% and a specificity of 100%. In addition, [18F]TTDP PET also showed cross-species consistency of the tracer biodistribution between non-human primate and murine animals, and no adverse events were observed.

CONCLUSION

The combined implementation of the [18F]TTDP and HIS-PDX model creates a state-of-the-art preclinical platform that will impact the identification and validation of TIGIT-targeted PET image-guided diagnosis, treatment response prediction, beneficial patient screening, novel immunotherapies, and ultimately the outcome of NSCLC patients. We first provided in vivo biodistribution of [18F]TTDP PET imaging in rhesus macaque, indicating its excellent translational potential in the clinic.

A Multiple Targeting Genome Editing System for Remodulation of Circulating Malignant Cells to Eliminate Cancer Immunosuppression and Restore Immune Responses

Cancer immunotherapy, which aims to eliminate cancer immunosuppression and reactivate anticancer immunity, holds great promise in oncology treatments. However, it is challenging to accurately study the efficacy of immunotherapy based on human-derived cells through animal experiments due to xenogeneic immune rejection. Herein, a personalized and precise strategy to evaluate the effectiveness of immunotherapy using the blood samples of cancer patients is presented. Through the utilization of multiple cancer-targeting delivery system decorated with the epidermal growth factor receptor (EGFR)-specific aptamer CL4 and the AXL-specific aptamer GL21.T to achieve superior efficiency in delivering the genome editing plasmid for MUC1 knockout, effective modulation on the behavior of circulating malignant cells (CMCs) is realized. After genome editing, both mucin 1 (MUC1) and programmed death-ligand 1 (PD-L1) are significantly downregulated in CMCs. The elimination of immunosuppression results in markedly enhanced secretion of pro-inflammatory anticancer cytokines encompassing interleukins 2, 12, and 15 and interferon-γ by immune cells. The study not only provides a strategy to overcome immunosuppression but also yields critical insights for personalized immunotherapy approaches.

Targeting immune evasion in hepatocellular carcinoma-initiating cells

Tumor-initiating cells (TICs) are particularly efficient at evading detection and elimination by the human immune system. Recent data from Yang and collaborators demonstrate that - at least in preclinical hepatocellular carcinoma models - the immunological privilege of CD49f+ TICs can be limited by targeting CD155, resulting in restored sensitivity to immune checkpoint inhibitors.

An antibody cocktail targeting two different CD73 epitopes enhances enzyme inhibition and tumor control

CD73, an ectoenzyme responsible for adenosine production, is often elevated in immuno-suppressive tumor environments. Inhibition of CD73 activity holds great promise as a therapeutic strategy for CD73-expressing cancers. In this study, we have developed a therapeutic anti-human CD73 antibody cocktail, HB0045. HB0045 is a 1:1 mixture of two humanized monoclonal IgG1 antibodies (mAbs), HB0038 and HB0039. The cocktail not only harnesses the advantages of its parental mAbs in enzyme inhibition but also shows a significantly greater capability of promoting T cell proliferation in vitro. Structural analyses show that HB0045 effectively locks the CD73 dimer in a "partially open" non-active conformation through a double lock mechanism. In various animal models of syngeneic and xenograft tumors, HB0045 inhibits tumor growth more potently than the single mAbs. Collectively, our findings provide functional and structural insights into the mechanism of a CD73-targeting antibody cocktail.

Nano-Armed Limosilactobacillus reuteri for Enhanced Photo-Immunotherapy and Microbiota Tryptophan Metabolism against Colorectal Cancer

Despite being a groundbreaking approach to treating colorectal cancer (CRC), the efficacy of immunotherapy is significantly compromised by the immunosuppressive tumor microenvironment and dysbiotic intestinal microbiota. Here, leveraging the superior carrying capacity and innate immunity-stimulating property of living bacteria, a nanomedicine-engineered bacterium, LR-S-CD/CpG@LNP, with optical responsiveness, immune-stimulating activity, and the ability to regulate microbiota metabolome is developed. Immunoadjuvant (CpG) and carbon dot (CD) co-loaded plant lipid nanoparticles (CD/CpG@LNPs) are constructed and conjugated to the surface of Limosilactobacillus reuteri (LR) via reactive oxygen species (ROS)-responsive linkers. The inherent photothermal and photodynamic properties of oral CD/CpG@LNPs induce in situ cytotoxic ROS generation and immunogenic cell death of colorectal tumor cells. The generated neoantigens and the released CpG function as a potent in situ vaccine that stimulates the maturation of immature dendritic cells. The mature dendritic cells and metabolites secreted by LR subsequently facilitated the tumor infiltration of cytotoxic T lymphocytes to eradicate colorectal tumors. The further in vivo results demonstrate that the photo-immunotherapy and intestinal microbial metabolite regulation of LR-S-CD/CpG@LNPs collectively suppressed the growth of orthotopic colorectal tumors and their liver metastases, presenting a promising avenue for synergistic treatment of CRC via the oral route.

Copper-coordination driven brain-targeting nanoassembly for efficient glioblastoma multiforme immunotherapy by cuproptosis-mediated tumor immune microenvironment reprogramming

Limited drug accumulation and an immunosuppressive microenvironment are the major bottlenecks in the treatment of glioblastoma multiforme (GBM). Herein, we report a copper-coordination driven brain-targeting nanoassembly (TCe6@Cu/TP5 NPs) for site-specific delivery of therapeutic agents and efficient immunotherapy by activating the cGAS-STING pathway and downregulating the expression of PD-L1. To achieve this, the mitochondria-targeting triphenylphosphorus (TPP) was linked to photosensitizer Chlorin e6 (Ce6) to form TPP-Ce6 (TCe6), which was then self-assembled with copper ions and thymopentin (TP5) to obtain TCe6@Cu/TP5 NPs. This nanoassembly effectively accumulated in tumor sites through the copper transport mechanism. Meanwhile, TCe6@Cu/TP5 could induce mitochondrial impairment by photodynamic therapy (PDT) mediated reactive oxygen species (ROS) accumulation and Cu2+ triggered cuproptosis, resulting in evoking the AMP-activated protein kinase (AMPK) pathway to degrade PD-L1, and activating the cGAS-STING pathway to enhance anti-tumor immunity. Moreover, TP5 significantly promoted the proliferation and differentiation of dendritic cells (DCs) and T lymphocytes to further amplify the cancer immunity cycle. Collectively, our TCe6@Cu/TP5 NPs effectively facilitate drug accumulation and activate systemic antitumor immunity in vitro and in vivo, providing an innovative solution across the BBB that potentiates GBM immunotherapy.

Current trends in sensitizing immune checkpoint inhibitors for cancer treatment

Immune checkpoint inhibitors (ICIs) have dramatically transformed the treatment landscape for various malignancies, achieving notable clinical outcomes across a wide range of indications. Despite these advances, resistance to immune checkpoint blockade (ICB) remains a critical clinical challenge, characterized by variable response rates and non-durable benefits. However, growing research into the complex intrinsic and extrinsic characteristics of tumors has advanced our understanding of the mechanisms behind ICI resistance, potentially improving treatment outcomes. Additionally, robust predictive biomarkers are crucial for optimizing patient selection and maximizing the efficacy of ICBs. Recent studies have emphasized that multiple rational combination strategies can overcome immune checkpoint resistance and enhance susceptibility to ICIs. These findings not only deepen our understanding of tumor biology but also reveal the unique mechanisms of action of sensitizing agents, extending clinical benefits in cancer immunotherapy. In this review, we will explore the underlying biology of ICIs, discuss the significance of the tumor immune microenvironment (TIME) and clinical predictive biomarkers, analyze the current mechanisms of resistance, and outline alternative combination strategies to enhance the effectiveness of ICIs, including personalized strategies for sensitizing tumors to ICIs.

PD-L1 antibody conjugated dihydrotanshinone I-loaded polymeric nanoparticle for targeted cancer immunotherapy combining PD-L1 blockade with immunogenic cell death

PURPOSE

Combination immune checkpoint inhibitors (ICI) with chemotherapeutic agents has proven to be highly promising in cancer therapy. However, low response rate, immune-related adverse events, and lack of effectively targeted co-delivery strategy are still major hurdles to overcome for this combination therapeutic regimen. Herein, programmed death-L1 (PD-L1) antibody modified and dihydrotanshinone I (DHT) loaded nanoparticle was prepared for tumor targeting drug delivery, thus achieving immune checkpoint blockade (ICB) and immunogenic cell death (ICD) synergistic anti-tumor effects.

METHODS

The DHT-loaded nanoparticle (DHT NP) was prepared by the emulsion solvent diffusion method. Atezolizumab (ATEZO) was thiolated with 2-iminothiolane and conjugated to the surface of DHT NP to prepare the ATEZO DHT NP. The drug encapsulation efficiency, drug loading, particle size and drug release were determined. The in vitro cellular uptake, cell proliferation inhibition and apoptosis were evaluated on the HGC-27 tumor cell. The in vivo tumor targeting, anti-tumor efficiency and immune regulation were assessed on tumor bearing mice.

RESULTS

The optimized ATEZO DHT NP was a spherical nanoparticle of about 250 nm with a continuous drug release profile. It was selectively taken up by the tumor cells through PD-L1 receptor-mediated endocytosis, which resulted in enhanced cytotoxicity and cell apoptosis. In vivo imaging further demonstrated its superior tumor tissue targeting ability. When tumor bearing mice were treated with the ATEZO DHT NP, its synergistic anti-tumor effect was much stronger than that of a single drug. Moreover, the tumor targeting delivery of DHT caused tumor necrosis and initiated ICD with release of tumor-associated antigens, which efficiently up-regulated the population of CD4+ and CD8+ T cells. Notably, there were no obvious system toxicity or tissue damage occur during the whole treatment period.

CONCLUSION

The ATEZO DHT NP could specifically target to tumor and enhance treatment efficiency through combination of PD-L1 blockade with ICD effect.

Insights into the Relationship Between the Gut Microbiome and Immune Checkpoint Inhibitors in Solid Tumors

Immunotherapy with immune checkpoint inhibitors represents a revolutionary approach to the treatment of solid tumors, including malignant melanoma, lung cancer, and gastrointestinal malignancies. Anti-CTLA-4 and anti-PD-1/PDL-1 therapies provide prolonged survival for cancer patients, but their efficacy and safety are highly variable. This review focuses on the crucial role of the gut microbiome in modulating the efficacy and toxicity of immune checkpoint blockade. Studies suggest that the composition of the gut microbiome may influence the response to immunotherapy, with specific bacterial strains able to promote an anti-tumor immune response. On the other hand, dysbiosis may increase the risk of adverse effects, such as immune-mediated colitis. Interventions aimed at modulating the microbiome, including the use of probiotics, prebiotics, fecal microbial transplantation, or dietary modifications, represent promising strategies to increase treatment efficacy and reduce toxicity. The combination of immunotherapy with the microbiome-based strategy opens up new possibilities for personalized treatment. In addition, factors such as physical activity and nutritional supplementation may indirectly influence the gut ecosystem and consequently improve treatment outcomes in refractory patients, leading to enhanced patient responses and prolonged survival.

Radiotherapy-resistant prostate cancer cells escape immune checkpoint blockade through the senescence-related ataxia telangiectasia and Rad3-related protein

BACKGROUND

The majority of patients with prostate cancer (PCa) exhibit intrinsic resistance to immune checkpoint blockade (ICB) following radiotherapy (RT). This resistance is generally attributed to the limited antigen presentation of heterogeneous cells within tumors. Here, we aimed to isolate and characterize these diverse subgroups of tumor post-RT to understand the molecular mechanisms of their resistance to ICB.

METHODS

Single-cell RNA-sequencing (scRNA-seq) was used to profile senescent cancer cell clusters induced by RT in LNCaP cells. The expression and phosphorylation levels of ataxia telangiectasia and Rad3-related protein (ATR) were assessed by immunohistochemistry in clinical samples from patients with or without RT. Co-immunoprecipitation, mutagenesis, and Western blotting were used to measure the interactions between proteins. Xenograft experiments were performed to assess the tumor immune response in the mice.

RESULTS

We identified a subset of PCa cells that exhibited resistance to RT, characterized by a reduced antigen presentation capability, which enhanced their ability to evade immune detection and resist cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade. scRNA-seq revealed that the senescent state was a transient phase of PCa cells post-RT, particularly in CTLA-4 blockade treatment-resistant cells. This state was marked by increased cytosolic ATR level. Cytosolic ATR phosphorylated CD86 in its cytosolic domain and enhanced the interaction between CD86 and its E3 ligase MARCH1 through electrostatic attraction. Depletion or inhibition of Atr increased the sensitivity to immune attack and improved responses to anti-Ctla-4 antibody treatment in a mouse model.

CONCLUSIONS

Our findings indicate that the activation of cytosolic ATR, which is associated with cellular senescence, impedes the effectiveness of combined RT and ICB treatments. This discovery may provide valuable insights for improving the efficacy of combined RT and ICB therapies in PCa.

Immune Checkpoint Blockade Combined with AbnobaViscum® Therapy Is Linked to Improved Survival in Advanced or Metastatic Non-Small-Cell Lung Cancer Patients: A Registry Study in Accordance with the ESMO Guidance for Reporting Real-World Evidence

Background: Recent advancements in cancer treatment have shown the potential of immune checkpoint blockade (ICB) plus Viscum album L. therapy in improving survival rates for patients with advanced or metastatic non-small-cell lung cancer (NSCLC). The objective of this study was to investigate factors associated with improved survival in NSCLC patients treated with a combination of ICB and abnobaViscum®. Methods: Patients with advanced or metastatic NSCLC from the accredited Network Oncology registry were included in this real-world data study adhering to ESMO-GROW criteria with ethics approval. Survival outcomes were compared between patients receiving ICB therapy alone versus those receiving combinational ICB plus abnobaViscum® therapy using Kaplan-Meier and multivariable Cox proportional hazard analysis. Results: Among 300 patients (median age 68 years; male/female ratio 1.19), 222 received ICB alone (CTRL group) and 78 received combinational therapy (COMB group). Overall survival was significantly prolonged in the COMB group by 7 months compared to CTRL (13.8 months vs. 6.8 months, p = 0.005) with a survival rate of 16.5% in the COMB group vs. 8.0% in the CTRL group. In programmed death-ligand 1 positive (≥1%) patients treated with first-line ICB, the addition of abnobaViscum® reduced the adjusted hazard of death by 75% (aHR: 0.25; 95%CI: 0.11-0.60, p = 0.02). Conclusions: The addition of abnobaViscum® to ICB is significantly associated with improved survival in patients with advanced or metastatic NSCLC patients, irrespective of age, stage, Eastern cooperative oncology group status, surgery, or radiation. Potential mechanisms include immune modulation, reduced primary ICB resistance, and tumor microenvironment modifications. The findings warrant further validation in randomized controlled trials or registry-based randomized controlled trials. Trial registration: The study was registered (DRKS00013335).

A STT3A-dependent PD-L1 glycosylation modification mediated by GMPS drives tumor immune evasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignant tumor characterized by rapid progression. To explore the regulatory mechanism of rapid tumor growth and metastasis, we conducted proteomic and scRNA-Seq analyses on advanced HCC tissues and identified a significant molecule, guanine monophosphate synthase (GMPS), closely associated with the immune evasion in HCC. We analyzed the immune microenvironment characteristics remodeled by GMPS using scRNA-Seq and found GMPS induced tumor immune evasion in HCC by impairing the tumor-killing function of CD8 + T cells. Further investigation revealed that GMPS increased PD-L1 expression by regulating its ubiquitination and glycosylation modification. Mechanistically, GMPS enhanced the bond between PD-L1 and the catalytic subunit STT3A of oligosaccharyltransferase (OST) by acting as an additional module connecting the Sec61 channel complex and STT3A, which aided in the translocation and modification of nascent peptides. Increased PD-L1 impaired the tumor-killing function of CD8 + T cells, leading to the immune evasion. Importantly, targeting GMPS with angustmycin A, an inhibitor of GMPS activity, significantly suppressed PD-L1 expression and tumor growth in HCC, which also increased the sensitivity to anti-CTLA-4 immunotherapy. These findings suggested the potential of targeting GMPS as a promising therapeutic approach for HCC.

Inhibition of JNK Signaling Overcomes Cancer-Associated Fibroblast-Mediated Immunosuppression and Enhances the Efficacy of Immunotherapy in Bladder Cancer

Currently, only 20% to 40% of patients with cancer benefit from immune checkpoint inhibitors. Understanding the mechanisms underlying the immunosuppressive tumor microenvironment (TME) and characterizing dynamic changes in the immunologic landscape during treatment are critical for improving responsiveness to immunotherapy. In this study, we identified JNK signaling in cancer-associated fibroblasts (CAF) as a regulator of the immunosuppressive TME. Single-cell RNA sequencing of bladder cancer samples treated with a JNK inhibitor revealed enhanced cytotoxicity and effector functions of CD8+ T cells. In untreated tumors, CAFs interacted frequently with CD8+ T cells and mediated their exhaustion. JNK inhibition abrogated the immunosuppression function of CAFs by downregulating the expression of thymic stromal lymphopoietin (TSLP), thereby restoring CD8+ T-cell cytotoxicity. In addition, blockade of CAF-derived TSLP in combination with anti-PD-1 treatment promoted tumor elimination by CD8+ T cells in vivo. Collectively, these results indicate that JNK signaling plays an important immunosuppressive role in the TME by promoting expression of TSLP in CAFs and suggest that inhibiting JNK signaling could be a promising immunotherapeutic strategy for cancer treatment. Significance: JNK signaling promotes the secretion of TSLP by bladder cancer-associated fibroblasts to impede CD8+ T-cell activity, which can be circumvented by combination treatment targeting JNK signaling and PD-1.

Exploring shared targets in cancer immunotherapy and cancer-induced bone pain: Insights from preclinical studies

Cancer casts a profound shadow on global health, with pain emerging as one of the dominant and severe complications, particularly in advanced stages. The effective management of cancer-induced pain remains an unmet need. Emerging preclinical evidence suggests that targets related to tumor immunotherapy may also modulate cancer-related pain pathways, thus offering a promising therapeutic direction. This review, focusing on more than ten molecular targets that link cancer immunotherapy and cancer-induced bone pain, underscores their potential to tackle both aspects in the context of comprehensive cancer care. Emphasizing factors such as types of cancer, drug administration methods, and sex differences in the analgesic efficacy of immunotherapeutic agents provides neuroscientific insights into personalized pain management for patients with cancer.

The Astragalus Membranaceus Herb Attenuates Leukemia by Inhibiting the FLI1 Oncogene and Enhancing Anti-Tumor Immunity

Astragalus membranaceus (AM) herb is a component of traditional Chinese medicine used to treat various cancers. Herein, we demonstrate a strong anti-leukemic effect of AM injected (Ai) into the mouse model of erythroleukemia induced by Friend virus. Chemical analysis combined with mass spectrometry of AM/Ai identified the compounds Betulinic acid, Kaempferol, Hederagenin, and formononetin, all major mediators of leukemia inhibition in culture and in vivo. Docking analysis demonstrated binding of these four compounds to FLI1, resulting in downregulation of its targets, induction of apoptosis, differentiation, and suppression of cell proliferation. Chemical composition analysis identified other compounds previously known having anti-tumor activity independent of the FLI1 blockade. Among these, Astragaloside-A (As-A) has marginal effect on cells in culture, but strongly inhibits leukemogenesis in vivo, likely through improvement of anti-tumor immunity. Indeed, both IDO1 and TDO2 were identified as targets of As-A, leading to suppression of tryptophane-mediated Kyn production and leukemia suppression. Moreover, As-A interacts with histamine decarboxylase (HDC), leading to suppression of anti-inflammatory genes TNF, IL1B/IL1A, TNFAIP3, and CXCR2, but not IL6. These results implicate HDC as a novel immune checkpoint mediator, induced in the tumor microenvironment to promote leukemia. Functional analysis of AM components may allow development of combination therapy with optimal anti-leukemia effect.

Impact of Serum GDF-15 and IL-6 on Immunotherapy Response in Cancer: A Prospective Study

BACKGROUND

Immunotherapy has transformed cancer treatment; however, predicting treatment response remains challenging. Serum biomarkers can help identify patients who are most likely to benefit from immunotherapy.

OBJECTIVE

This study evaluates the relationship between serum growth differentiation factor 15 (GDF-15) and interleukin-6 (IL-6) levels and treatment outcomes in cancer patients undergoing second-line immunotherapy.

METHODS

We conducted a prospective observational study involving 85 patients with non-small-cell lung cancer (NSCLC), renal cell carcinoma (RCC), or malignant melanoma treated with nivolumab. The baseline serum levels of GDF-15 and IL-6 were measured by using ELISA kits. The primary endpoints were progression-free survival (PFS) and overall survival (OS), with cachexia as a secondary outcome.

RESULTS

Elevated GDF-15 levels were significantly associated with shorter PFS (HR: 0.55, 95% CI: 0.32-0.96, p = 0.032) and OS (HR: 0.47, 95% CI: 0.25-0.90, p = 0.020). Higher IL-6 levels correlated with shorter PFS, though statistical significance was not achieved. Additionally, high GDF-15 levels were linked to increased cachexia incidence (p = 0.037).

CONCLUSION

Our findings indicate that GDF-15 could serve as a prognostic biomarker for immunotherapy response and may also be a target for cachexia management. Further studies should explore its potential to guide clinical decision making in oncology.

Immune-mediated liver injury from checkpoint inhibitors: mechanisms, clinical characteristics and management

Immunotherapy has changed the treatment landscape for patients with cancer in the past decade. Immune checkpoint inhibitor (ICI)-based therapies have proven effective in a range of malignancies, including liver and gastrointestinal cancers, but they can cause diverse off-target organ toxicities. With the increasingly wider application of these drugs, immune-mediated liver injury from ICIs has become a commonly encountered challenge in clinical hepatology and gastroenterology. In this Review, we discuss the evidence from human and animal studies on the immunological mechanisms of immune-mediated liver injury from ICIs and summarize its clinical features and practical considerations for its management.

Tumor Microenvironment-Responsive Nanoparticles Enhance IDO1 Blockade Immunotherapy by Remodeling Metabolic Immunosuppression

The clinical efficacy of immune checkpoint blockade (ICB) therapy is significantly compromised in the metabolically disordered tumor microenvironment (TME), posing a formidable challenge that cannot be ignored in current antitumor strategies. In this study, TME-responsive nanoparticles (HMP1G NPs) loaded with 1-methyltryptophan (1-MT; an indoleamine 2,3-dioxygenase 1 [IDO1] inhibitor,) and S-nitrosoglutathione (GSNO; a nitric oxide donor) is developed to enhance the therapeutic efficacy of 1-MT-mediated ICB. The HMP1G NPs responded to H+ and glutathione in the TME, releasing Mn2+, GSNO, and 1-MT. The released Mn2+ catalyzed the production of abundant reactive oxygen species and nitric oxide from hydrogen peroxide and GSNO, and the generated nitric oxide, synergistically with 1-MT, inhibited the accumulation of kynurenine mediated by IDO1 in the tumor. Mechanistically, HMP1G NPs downregulated tumor cell-derived IDO1 via the aryl hydrocarbon receptor/signal transducer and activator of transcription 3/interleukin signaling axis to improve kynurenine/tryptophan metabolism and immunosuppression. In a murine breast cancer model, treatment with HMP1G NPs elicited effective antitumor immunity and enhanced survival outcomes. This study highlights a novel nano-platform that simultaneously improves metabolism and enhances ICB efficacy to achieve a new and efficient antitumor strategy.

MAML3-fusions modulate vascular and immune tumour microenvironment and confer high metastatic risk in pheochromocytoma and paraganglioma

Pheochromocytomas and paragangliomas are rare neuroendocrine tumours. Around 20-25 % of patients develop metastases, for which there is an urgent need of prognostic markers and therapeutic stratification strategies. The presence of a MAML3-fusion is associated with increased metastatic risk, but neither the processes underlying disease progression, nor targetable vulnerabilities have been addressed. We have compiled a cohort of 850 patients, which has shown a 3.65 % fusion prevalence and represents the largest MAML3-positive series reported to date. While MAML3-fusions mainly cause single pheochromocytomas, we also observed somatic post-zygotic events, resulting in multiple tumours in the same patient. MAML3-tumours show increased expression of neuroendocrine-to-mesenchymal transition markers, MYC-targets, and angiogenesis-related genes, leading to a distinct tumour microenvironment with unique vascular and immune profiles. Importantly, our findings have identified MAML3-tumours specific vulnerabilities beyond Wnt-pathway dysregulation, such as a rich vascular network, and overexpression of PD-L1 and CD40, suggesting potential therapeutic targets.

Nanomaterial-assisted delivery of CpG oligodeoxynucleotides for boosting cancer immunotherapy

Cancer immunotherapy aims to improve immunity to not only eliminate the primary tumor but also inhibit metastasis and recurrence. It is considered an extremely promising therapeutic approach that breaks free from the traditional paradigm of oncological treatment. As the medical community learns more about the immune system's mechanisms that "turn off the brake" and "step on the throttle", there is increasingly successful research on immunomodulators. However, there are still more restrictions than countermeasures with immunotherapy related to immunomodulators, such as low responsiveness and immune-related adverse events that cause multiple adverse reactions. Therefore, medical experts and materials scientists attempted to the efficacy of immunomodulatory treatments through various methods, especially nanomaterial-assisted strategies. CpG oligodeoxynucleotides (CpG) not only act as an adjuvant to promote immune responses, but also induce autophagy. In this review, the enhancement of immunotherapy using nanomaterial-based CpG formulations is systematically elaborated, with a focus on the delivery, protection, synergistic promotion of CpG efficacy by nanomaterials, and selection of the timing of treatment. In addition, we also discuss and prospect the existing problems and future directions of research on nanomaterials in auxiliary CpG therapy.

Hydrogel activation of Mincle receptors for tumor cell processing: A novel approach in cancer immunotherapy

An obstacle in current tumor immunotherapies lies in the challenge of achieving sustained and tumor-targeting T cell immunity, impeded by the limited antigen processing and cross-presentation of tumor antigens. Here, we propose a hydrogel-based multicellular immune factory within the body that autonomously converts tumor cells into an antitumor vaccine. Within the body, the scaffold, formed by a calcium-containing chitosan hydrogel complex (ChitoCa) entraps tumor cells and attracts immune cells to establish a durable and multicellular microenvironment. Within this context, tumor cells are completely eliminated by antigen-presenting cells (APCs) and processed for cross-antigen presentation. The regulatory mechanism relies on the Mincle receptor, a cell-phagocytosis-inducing C-type lectin receptor specifically activated on ChitoCa-recruited APCs, which serves as a recognition synapse, facilitating a tenfold increase in tumor cell engulfment and subsequent elimination. The ChitoCa-induced tumor cell processing further promotes the cross-presentation of tumor antigens to prime protective CD8+ T cell responses. Therefore, the ChitoCa treatment establishes an immune niche within the tumor microenvironment, resulting in effective tumor regression either used alone or in combination with other immunotherapies. This hydrogel-induced immune factory establishes a functional organ-like multicellular colony for tumor-specific immunotherapy, paving the way for innovative strategies in cancer treatment.

Recent progress of porphyrin metal-organic frameworks for combined photodynamic therapy and hypoxia-activated chemotherapy

Nanoscale metal-organic frameworks integrated with porphyrins (Por-nMOFs) have emerged as efficient nanoplatforms for photodynamic therapy (PDT), which relies on the conversion of molecular oxygen into cytotoxic singlet oxygen. However, the hypoxic microenvironment within tumors significantly limits the efficacy of PDT. To address this challenge, researchers have explored various strategies to either alter or exploit the hypoxic conditions in tumors. One such strategy involves leveraging the porous structure of Por-nMOFs to load hypoxia-activated prodrugs (HAPs) like tirapazamine (TPZ), thereby utilizing the tumor's intrinsic hypoxic environment to trigger a chemotherapeutic effect that synergizes with PDT. Advances in nanoscience have enabled the development of porphyrin-based nMOFs capable of simultaneously loading both porphyrin photosensitizers and TPZ, ensuring effective release within cancer cells under high-phosphate conditions. The subsequent activation of co-loaded TPZ, by the tumor's own hypoxic microenvironment, and that created during PDT, facilitates a combined PDT and chemotherapy approach. This method not only enhances the suppression of cancer cell proliferation but also improves control over tumor metastasis while mitigating the negative impact of hypoxia on singular Por-nMOFs in PDT. This review summarizes recent advances in Por-nMOFs research, focusing on the design strategies for enhancing water dispersibility, circulatory stability, and targeting specificity through post-synthetic modifications. Additionally, this review highlights the bioapplication of Por-nMOFs by integrating TPZ chemotherapy and other therapeutic modalities to combat hypoxic and metastatic malignancies. We anticipate that this review will inspire further research into Por-nMOFs and advance their application in biomedicine.

The hallmarks of cancer immune evasion

According to the widely accepted "three Es" model, the host immune system eliminates malignant cell precursors and contains microscopic neoplasms in a dynamic equilibrium, preventing cancer outgrowth until neoplastic cells acquire genetic or epigenetic alterations that enable immune escape. This immunoevasive phenotype originates from various mechanisms that can be classified under a novel "three Cs" conceptual framework: (1) camouflage, which hides cancer cells from immune recognition, (2) coercion, which directly or indirectly interferes with immune effector cells, and (3) cytoprotection, which shields malignant cells from immune cytotoxicity. Blocking the ability of neoplastic cells to evade the host immune system is crucial for increasing the efficacy of modern immunotherapy and conventional therapeutic strategies that ultimately activate anticancer immunosurveillance. Here, we review key hallmarks of cancer immune evasion under the "three Cs" framework and discuss promising strategies targeting such immunoevasive mechanisms.

Multifunctional nanoparticles potentiate in-situ tumor vaccines via reversing insufficient Photothermal therapy by disrupting tumor vasculature

Photothermal therapy can trigger immunogenic cell death and release personalized in-situ tumor vaccine, activating immune responses to eliminate systemic tumors beyond the irradiated zone. However, the immune response of the in-situ tumor vaccines is often undermined by the residual tumor cells and their induced immunosuppressive tumor microenvironment (TME), which is attributed to insufficient photothermal effects stemming from the limited accumulation of photosensitizers. To overcome these limitations, we developed multi-functional nanoparticles (VI@Gd-NPs) that integrate a tumor vasculature-specific disrupting agent (Vadimezan, Phase III clinical drug), a photosensitizer (Indocyanine Green, ICG), and a magnetic resonance imaging contrast agent (Gadolinium, Gd) through chemical self-assembly. By selectively disrupting the tumor vasculature, these nanoparticles enhance the intratumoral delivery of photosensitizers (ICG and blood cells), and Gd. With the guidance of Gd-enhanced MRI, the improved delivery facilitates comprehensive photothermal ablation and regulates the TME, further initiating the in-situ tumor vaccine. Notably, this approach significantly enhances anti-tumor immune responses, improves survival rates, and reduces tumor recurrence and metastasis in various animal models. Moreover, depleting CD8+ T cells reverses these therapeutic benefits, highlighting the critical role of adaptive T cell immunity. Therefore, the VI@Gd-NPs treatment holds great potential for reigniting the in-situ tumor vaccine of photothermal therapy.

Efficacy and safety of camrelizumab, apatinib, and capecitabine combination therapy in advanced biliary tract cancer: a phase 2, nonrandomized, prospective study

BACKGROUND

Biliary tract cancer (BTC) is a highly malignant tumor, with limited therapy regimens and short response duration. In this study, we aim to assess the efficacy and safety of the combination of camrelizumab, apatinib, and capecitabine as the first- or second-line treatment in patients with advanced BTC.

METHODS

In this phase 2, nonrandomized, prospective study, eligible patients received camrelizumab (200 mg, d1, Q3W), apatinib (250 mg, qd, d1-d21, Q3W), and capecitabine (1000 mg/m², bid, d1-d14, Q3W) until trial discontinued. The primary endpoint was the objective response rate (ORR). The secondary endpoints were disease control rate, progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

From July 2019 to April 2023, we enrolled a total of 28 patients, of whom 14 patients were in the first-line treatment setting and 14 patients were in the second-line setting. At the data cutoff (April 30, 2023), the median follow-up duration was 18.03 months. Eight of 28 patients reached objective response (ORR: 28.57%), with an ORR of 50% and 7.1% for first-line and second-line treatment patients (P = .033). The median PFS was 6.30 months and the median OS was 12.80 months. Grade 3 or 4 adverse events (AEs) occurred in 9 (32.14%) patients, including elevated transaminase, thrombocytopenia, etc. No serious treatment-related AEs or treatment-related deaths occurred.

CONCLUSIONS

In this trial, the combination of camrelizumab, apatinib, and capecitabine showed promising antitumor activity and manageable toxicity in patients with advanced BTC, especially in the first-line setting.

CLINICAL TRIAL REGISTRATION

NCT04720131.

Cancer cell-intrinsic biosynthesis of itaconate promotes tumor immunogenicity

The Krebs cycle byproduct itaconate has recently emerged as an important metabolite regulating macrophage immune functions, but its role in tumor cells remains unknown. Here, we show that increased tumor-intrinsic cis-aconitate decarboxylase (ACOD1 or CAD, encoded by immune-responsive gene 1, Irg1) expression and itaconate production promote tumor immunogenicity and anti-tumor immune responses. Furthermore, we identify thimerosal, a vaccine preservative, as a specific inducer of IRG1 expression in tumor cells but not in macrophages, thereby enhancing tumor immunogenicity. Mechanistically, thimerosal induces itaconate production through a ROS-RIPK3-IRF1 signaling axis in tumor cells. Further, increased IRG1/itaconate upregulates antigen presentation-related gene expression via promoting TFEB nuclear translocation. Intratumoral injection of thimerosal induced itaconate production, activated the tumor immune microenvironment, and inhibited tumor growth in a T cell-dependent manner. Importantly, IRG1 deficiency markedly impaired tumor response to thimerosal treatment. Furthermore, itaconate induction by thimerosal potentiates the anti-tumor efficacy of adoptive T-cell therapy and anti-PD1 therapy in a mouse lymphoma model. Hence, our findings identify a new role for tumor intrinsic IRG1/itaconate in promoting tumor immunogenicity and provide a translational means to increase immunotherapy efficacy.

A Multi-Functional Nanoadjuvant Coupling Manganese with Toll-Like 9 Agonist Stimulates Potent Innate and Adaptive Anti-Tumor Immunity

The effectiveness of Toll-like 9 agonists (CpG) as an adjuvant for tumor immunotherapy is restricted due to their insufficient ability to activate anti-tumor immunity. To address that, the common nutrient metal ions are explored (Mn2+, Cu2+, Ca2+, Mg2+, Zn2+, Fe3+, and Al3+), identifying Mn2+ as a key enhancer of CpG to mediate immune activation by augmenting the STING-NF-κB pathway. Mn2+ and CpG are then self-assembled with epigallocatechin gallate (EGCG) into a nanoadjuvant MPN/CpG. Local delivery of MPN/CpG effectively inhibits tumor growth in a B16 melanoma-bearing mouse model, reshaping the tumor microenvironment (TME) by repolarizing M2-type tumor-associated macrophages (TAMs) to an M1-type and boosting intra-tumoral infiltration of CD8+/CD4+ T lymphocytes and DCs. Furthermore, compared to free CpG, MPN/CpG exhibits heightened accumulation in lymph nodes, enhancing CpG uptake and DC activation, consequently inducing significant antigen-specific cytotoxic CD8+ T cell immune response and humoral immunity. In a prophylactic tumor-bearing mouse model, MPN/CpG vaccination with OVA antigen significantly delays B16-OVA melanoma growth and extends mouse survival. These findings underscore the potential of MPN/CpG as a multifunctional adjuvant platform to drive powerful innate and adaptive immunity and regulate TME against tumors.

Ten-Year Outcome After Supracricoid Partial Laryngectomy in cT3M0 Laryngeal Squamous Cell Carcinoma-A STROBE Analysis

OBJECTIVES

The aim of this study was to document 10-year outcomes after supracricoid partial laryngectomy (SCPL) in selected cT3M0 laryngeal squamous cell carcinoma (SCC) patients.

METHODS

This real-life retrospective observational study analyzed an inception cohort of 168 patients with isolated, untreated, selected cT3M0 laryngeal SCC, that were consecutively managed by SCPL during the period 1973-2013, and followed up until death or for a minimum of 10 years in 92% of cases at a single French academic and tertiary referral care center. Prior induction chemotherapy, arytenoid cartilage removal, level II-IV neck dissection, and postoperative radiation therapy were performed on 148, 77, 136, and 27 patients, respectively. The main objective was to determine 10-year actuarial local control and laryngeal preservation estimates. Secondary objectives included 10-year actuarial survival and cause-of-death analysis, and assessment of correlations between endpoints and clinical variables. The significance threshold was set at p < 0.005.

RESULTS

Ten-year actuarial local control, laryngeal preservation, and survival estimates were 90%, 85%, and 52%, respectively. Salvage treatment resulted in an overall 99% local control rate. Metachronous second primary cancer, intercurrent disease without evidence of SCC, SCPL-related death, and uncontrolled local recurrence accounted for 31%, 26%, 7%, and 2% of causes of death. On univariate analysis, overall local recurrence and laryngeal preservation rates varied significantly, from 5% to 54% and 90% to 46% when resection margins were R0 and R1, respectively.

CONCLUSION

The present study highlighted successful 10-year outcomes after SCPL, providing further evidence in favor of its integration into the conservative armamentarium for endolaryngeal cT3 SCC.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:4557-4563, 2024.

Cell Identity and Spatial Distribution of PD-1/PD-L1 Blockade Responders

The programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) axis inhibits T cell activity, impairing anti-tumor immunity. Blocking this axis with therapeutic antibodies is one of the most promising anti-tumor immunotherapies. It has long been recognized that PD-1/PD-L1 blockade reinvigorates exhausted T (TEX) cells already present in the tumor microenvironment (TME). However, recent advancements in high-throughput gene sequencing and bioinformatic tools have provided researchers with a more granular and dynamic insight into PD-1/PD-L1 blockade-responding cells, extending beyond the TME and TEX populations. This review provides an update on the cell identity, spatial distribution, and treatment-induced spatiotemporal dynamics of PD-1/PD-L1 blockade responders. It also provides a synopsis of preliminary reports of potential PD-1/PD-L1 blockade responders other than T cells to depict a panoramic picture. Important questions to answer in further studies and the translational and clinical potential of the evolving understandings are also discussed.

Targeting the GTPase RAN by liposome delivery for tackling cancer stemness-emanated therapeutic resistance

Cancer therapeutic resistance as a common hallmark of cancer is often responsible for treatment failure and poor patient survival. Cancer stem-like cells (CSCs) are one of the main contributors to therapeutic resistance, cancer relapse and metastasis. Through screening from our in-house library of natural products, we found polyphyllin II (PPII) as a potent anti-CSC compound for triple-negative breast cancer (TNBC). To enhance anti-CSC selectivity and improve druggability of PPII, we leverage the liposome-mediated delivery technique for increasing solubility of PPII, and more significantly, attaining broader therapeutic window. Liposomal PPII demonstrates its marked potency to inhibit tumor growth, post-surgical recurrence and metastasis compared to commercial liposomal chemotherapeutics in the mouse models of CSC-enriched TNBC tumor. We further identify PPII as an inhibitor of the Ras-related nuclear (RAN) protein whose upregulated expression is correlated with poor clinical outcomes. The direct binding of PPII to RAN reduces TNBC stemness, thereby suppressing tumor progression. Our work offers a significance from drug discovery to drug delivery benefiting from liposome technique for targeted treatment of high-stemness tumor.

Biodegradable iridium coordinated nanodrugs potentiate photodynamic therapy and immunotherapy of lung cancer

Hypoxia, which is a common characteristic of most solid tumors, not only contributes to the immunosuppressive nature of the tumor microenvironment (TME) but also reduces the efficacy of many oxygen-depleting therapies, including photodynamic therapy (PDT). In this study, we developed acidity-responsive biodegradable iridium-coordinated (IPC) nanodrugs consisting of iridium ions, the photosensitizer chlorin e6 (Ce6), and polyvinylpyrrolidone to potentiate the effects of PDT and immunotherapy by modulating the TME. IPC nanodrugs that accumulate at high levels in tumors catalyze excess hydrogen peroxide to produce oxygen while depleting glutathione levels within cancer cells; thus, the released Ce6 is more efficient at producing reactive oxygen species (ROS) in response to laser irradiation. In addition, IPC nanodrugs alleviate tumor hypoxia, induce more immunogenic cell death by amplifying PDT responses, and synergistically inhibit tumor growth by initiating robust antitumor immunity and reversing the immunosuppressive nature of the TME. As a result, IPC nanodrugs exert pronounced combined therapeutic effects in vitro and in vivo, without obvious toxic effects due to acidity-responsive degradation. These iridium-coordinated nanodrugs have the potential to modulate the TME, amplify the effects of PDT, and substantially inhibit tumors, and they are expected to provide novel ideas for combination therapy of hypoxic cancer.

Targeting HLA-E-overexpressing cancers with a NKG2A/C switch receptor

BACKGROUND

Human leukocyte antigen (HLA)-E is overexpressed by a large proportion of solid tumors, including malignant glioblastoma, and acts as a major checkpoint for NKG2A+ CD8+ T cells and natural killer (NK) cells in the tumor microenvironment and circulation. This axis operates alongside PD-L1 to inhibit effector responses by T and NK cells.

METHODS

We engineered a chimeric A/C switch receptor, combining the high HLA-E binding affinity of the NKG2A receptor ectodomain with the activating signaling of the NKG2C receptor endodomain. The cytotoxic function of A/C switch-transduced NK and T cells was evaluated against tumor cells with varying levels of HLA-E expression. In vivo efficacy was assessed using a xenograft model of glioblastoma.

FINDINGS

A/C switch-transduced NK and T cells exhibited superior and specific cytotoxicity against tumor cells with medium to high HLA-E expression. A/C switch-expressing human T cells demonstrated enhanced anti-tumor function in a glioblastoma xenograft model. The activity of the modified T cells was governed by an equilibrium between A/C switch levels and HLA-E expression, creating a therapeutic window to minimize on-target, off-tumor toxicities. Normal cells remained insensitive to A/C switch T cells, even after interferon (IFN)-γ pretreatment to induce HLA-E expression.

CONCLUSIONS

The A/C switch receptor effectively targets tumor cells expressing high levels of HLA-E, either alone or in combination with other engineered specificities, to overcome the suppressive NKG2A/HLA-E checkpoint. This approach offers a promising therapeutic strategy with a favorable safety profile for targeting HLA-E-overexpressing tumors.

FUNDING

This work was funded by The Research Council of Norway, the Norwegian Cancer Society, and the National Cancer Institute.

Acetylcysteine synergizes PD-1 blockers against colorectal cancer progression by promoting TCF1+PD1+CD8+ T cell differentiation

BACKGROUND

Programmed cell death protein 1 (PD-1) blockade is essential in treating progressive colorectal cancer (CRC). However, some patients with CRC do not respond well to immunotherapy, possibly due to the exhaustion of CD8+ T cells in the tumor microenvironment. N-Acetylcysteine (NAC) can reduce CD8+ T cell exhaustion in vitro and induce their differentiation into long-lasting phenotypes, thus enhancing the anti-tumor effect of adoptive T cell transfer. However, whether NAC can be combined with PD-1 blockade in CRC treatment and how NAC regulates CD8+ T cell differentiation remain unclear. Hence, in this study, we aimed to investigate whether NAC has a synergistic effect with PD-1 blockers against CRC progression.

METHODS

We constructed a mouse CRC model to study the effect of NAC on tumors. The effect of NAC on CD8 + T cell differentiation and its potential mechanism were explored using cell flow assay and other studies in vitro and ex vivo.

RESULTS

We demonstrated that NAC synergized PD-1 antibodies to inhibit CRC progression in a mouse CRC model mediated by CD8+ T cells. We further found that NAC can induce TCF1+PD1+CD8+ T cell differentiation and reduce the formation of exhausted T cells in vitro and in vivo. Moreover, NAC enhanced the expression of Glut4 in CD8+ T cells, promoting the differentiation of TCF1+PD1+CD8+ T cells.

CONCLUSIONS

Our study provides a novel idea for immunotherapy for clinically progressive CRC and suggests that Glut4 may be a new immunometabolic molecular target for regulating CD8+ T cell differentiation.

Inhibition of PNCK inflames tumor microenvironment and sensitizes head and neck squamous cell carcinoma to immune checkpoint inhibitors

BACKGROUND

The landscape of the tumor microenvironment (TME) is intricately linked to the development of head and neck squamous cell carcinoma (HNSCC) and significantly influences immunotherapy efficacy. Recent research has underscored the pivotal role of PNCK in cancer progression, yet its relationship with immunotherapy remains elusive.

METHODS

We leveraged sequencing data from our cohort and public databases to evaluate PNCK expression, prognostic significance, and immune efficacy prediction. In vitro and in vivo experiments explored the role of PNCK in HNSCC progression. Animal models assessed the therapeutic effects and survival benefits of PNCK knockdown combined with immune checkpoint inhibitors (ICIs). Single-cell transcriptomics analyzed the impact of PNCK on the TME, and proteomic studies elucidated the mechanisms.

RESULTS

PNCK exerts multifaceted critical roles in the progression of HNSCC. Lower PNCK expression is associated with improved prognosis, enhanced immune cell infiltration, and increased responsiveness to ICIs. Conversely, PNCK promotes HNSCC cell migration, invasion, proliferation, colony formation, zebrafish angiogenesis, and tumor growth in mice. Moreover, targeting PNCK enhances sensitivity to ICIs and leads to significant alterations in the T-cell and B-cell ratios within the TME. These changes are attributed to the inhibition of nuclear transcription of PNCK-phosphorylated ZEB1, which restricts cytokine release and inflames the immune microenvironment to regulate the TME.

CONCLUSIONS

Inhibition of PNCK may be a potential strategy for treating HNSCC, as it may activate the immune response and improve the TME, thereby enhancing the efficacy of immunotherapy for HNSCC patients.

Inhibition of PRMT5 moderately suppresses prostate cancer growth in vivo but enhances its response to immunotherapy

Protein arginine methylation is a common post-translational modification (PTM) catalyzed by nine protein arginine methyltransferases (PRMTs). As the major symmetric arginine methyltransferase that methylates both histone and non-histone substrates, PRMT5 plays key roles in a number of biological processes critical for development and tumorigenesis. PRMT5 overexpression has been reported in multiple cancer types including prostate cancer (PCa), but the exact biological and mechanistic understanding of PRMT5 in aggressive PCa remains ill-defined. Here, we show that PRMT5 is upregulated in PCa, correlates with worse patient survival, promotes corrupted RNA splicing, and functionally cooperates with an array of pro-tumorigenic pathways to enhance oncogenesis. PRMT5 inhibition via either genetic knockdown or pharmacological inhibition reduces stemness with paralleled differentiation and arrests cell cycle progression without causing appreciable apoptosis. Strikingly, the severity of antitumor effect of PRMT5 inhibition correlates with disease aggressiveness, with AR+ PCa being less affected. Molecular characterization pinpoints MYC, but not (or at least to a lesser degree) AR, as the main partner of PRMT5 to form a positive feedback loop to exacerbate malignancy in both AR+ and AR- PCa cells. Inspired by the surprising finding that PRMT5 negatively correlates with tumor immune infiltration and transcriptionally suppresses an immune-gene program, we further show that although PRMT5 inhibitor (PRMT5i) EPZ015666 or anti-PD-1 immunotherapy alone exhibits limited antitumor effects, combination of PRMT5i with anti-PD-1 displays superior efficacy in inhibiting castration-resistant PCa (CRPC) in vivo. Finally, to expand the potential use of PRMT5i through a synthetic lethality concept, we also perform a global CRISPR/Cas9 knockout screen to unravel that many clinical-grade drugs of known oncogenic pathways can be repurposed to target CRPC when used in combination with PRMT5i at low doses. Collectively, our findings establish a rationale to exploit PRMT5i in combination with immunotherapy or other targeted therapies to treat aggressive PCa.

Synergistic immunotherapy with a calcium-based nanoinducer: evoking pyroptosis and remodeling tumor-associated macrophages for enhanced antitumor immune response

The challenges posed by low immunogenicity and the immunosuppressive tumor microenvironment (TME) significantly hinder the efficacy of cancer immunotherapy. Pyroptosis, characterized as a pro-inflammatory cell death pathway, emerges as a promising approach to augment immunotherapy by promoting immunogenic cell death (ICD). The predominance of M2 phenotype tumor-associated macrophages (TAMs) in the TME underscores the critical need for TAM reprogramming to mitigate this immunosuppression. Herein, we introduce a calcium-based, intelligent-responsive nanoinducer (CaZCH NPs), designed to concurrently initiate pyroptosis and remodel TAMs, thereby amplifying antitumor immunotherapy effects. Modified with hyaluronic acid, CaZCH NPs can target tumor cells. Once internalized, CaZCH NPs respond to the acidic environment, releasing Ca2+, curcumin and H2O2 to induce mitochondrial Ca2+ overload and oxidation stress, leading to caspase-3/GSDME-mediated cell pyroptosis. Concurrently, O2 produced by CaZCH and pro-inflammatory cytokines from pyroptotic cells work together to shift TAM polarization towards the M1 phenotype, effectively countering TME's immunosuppressive effect. Notably, the synergistic effect of Ca2+-mediated pyroptosis and TAM remodeling demonstrates superior antitumor efficiency in colorectal cancer models. The induced ICD, coupled with M1-type TAMs, effectively enhances immunogenicity and mitigates immunosuppression, promoting dendritic cell maturation and activating CD8+ T cell-dependent systemic antitumor immunity. Our study presents a promising synergistic strategy for achieving highly efficient immunotherapy using a simple calcium-based nanoinducer.

Immunologically effective biomaterials enhance immunotherapy of prostate cancer

Prostate cancer (PCa) is one of the most common malignant neoplasms affecting the male population. The onset of the disease is insidious and often associated with severe consequences, such as bone metastases at the time of initial diagnosis. Once it advances to metastatic castration-resistant PCa (mCRPC), conventional treatment methods become ineffective. As research on the mechanism of tumor therapy advances, immunotherapy has been evolving rapidly. However, PCa is a solid tumor type that primarily faces the challenges of poor immunogenicity and inhibitory tumor microenvironment (TME). Fortunately, the extensive use of biomaterials has led to continuous advancement in PCa immunotherapy. These innovative materials aim to address intractable issues, such as immune escape and immune desert, to inhibit tumor progression and metastasis. This detailed review focuses on the regulation of different aspects of tumor immunity by immunologically effective biomaterials, including modulating adaptive immunity, innate immunity, and the immune microenvironment, to enhance the efficacy of PCa immunotherapy. In addition, this review provides a perspective on the future prospects of immunotherapeutic nanoplatforms based on biomaterials in the treatment of PCa.