Synthetic enforcement of STING signaling in cancer cells appropriates the immune microenvironment for checkpoint inhibitor therapy

GRP78 Nanobody-Directed Immunotoxin Activates Innate Immunity Through STING Pathway to Synergize Tumor Immunotherapy

The lack of targetable antigens poses a significant challenge in developing effective cancer-targeted therapies. Cell surface translocation of endoplasmic reticulum (ER) chaperones, such as glucose-regulated protein 78 (GRP78), during malignancy, drug resistance, and ER stress induced by therapies, offers a promising pan-cancer target. To target GRP78, nanobody C5, identified from a phage library and exhibiting high affinity for human and mouse GRP78, is utilized to develop the Pseudomonas exotoxin (PE) immunotoxin C5-PE38. C5-PE38 induced ER stress, apoptosis and immunogenic cell death in targeted cells and showed antitumor efficacy against colorectal cancer and melanoma models without obvious toxicity. Mechanistically, transcriptome profiling showed that C5-PE38 reshaped the tumor immune microenvironment with enhanced innate and adaptive immune response and response to interferon beta. Moreover, C5-PE38-induced cell death could trans-activate STING pathway in dendritic cells and macrophages, promoting CD8+ T cell infiltration. It also sensitizes both primary and metastatic melanomas to anti-PD1 therapy, partly through STING activation. Overall, this study unveils a feasible GRP78 nanobody-directed therapy strategy for single or combinatorial cancer intervention. This work finds that C5-PE38-induced cell death stimulates STING-dependent cytosolic DNA release to promote antitumor immunity, a mechanism not previously reported for PE38, providing valuable insights for its clinical use.

Intratumoral or Subcutaneous MK-2118, a Noncyclic Dinucleotide STING Agonist, with or without Pembrolizumab, for Advanced or Metastatic Solid Tumors or Lymphomas

PURPOSE

We evaluated the noncyclic dinucleotide stimulator of IFN genes agonist MK-2118 ± pembrolizumab in participants with advanced solid tumors or lymphomas.

PATIENTS AND METHODS

This first-in-human study (NCT03249792) enrolled participants with refractory, advanced solid tumors or lymphomas. Participants received intratumoral (IT) MK-2118 100 to 20,000 μg (arm 1), IT MK-2118 900 to 15,000 μg plus intravenous (IV) pembrolizumab 200 mg every 3 weeks (arm 2), or subcutaneous (SC) MK-2118 5,000 to 150,000 μg plus IV pembrolizumab 200 mg every 3 weeks (arm 4); arm 3 (visceral injection of MK-2118) was not pursued. IT dosing used an accelerated titration design and modified toxicity probability interval method; SC dosing (arm 4) was started subsequent to arms 1 and 2. The primary objectives were safety/tolerability. MK-2118 pharmacokinetics was a secondary endpoint; objective responses and biomarkers were exploratory endpoints.

RESULTS

A total of 140 participants were enrolled (arm 1, n = 27; arm 2, n = 57; arm 4, n = 56). Grade 3/4 treatment-related adverse events occurred in 22%, 23%, and 11% of participants, respectively, but no maximum tolerated dose was identified up to MK-2118 20,000, 15,000, and 150,000 μg across the three arms. Dose-dependent increases in MK-2118 systemic exposure were observed following IT and subcutaneous administration. Objective responses were seen in 0%, 6%, and 4% of participants, respectively. IT MK-2118 led to dose-dependent changes in stimulator of interferon genes-based blood RNA expression levels, IFNγ, IFNγ-induced protein 10, and IL6; SC MK-2118 did not generate dose-related immune responses.

CONCLUSIONS

IT MK-2118 ± pembrolizumab and SC MK-2118 plus pembrolizumab had manageable toxicity and limited antitumor activity. IT but not SC administration demonstrated systemic immune effects.

Reciprocal regulation between ferroptosis and STING-type I interferon pathway suppresses head and neck squamous cell carcinoma growth through dendritic cell maturation

Head and neck squamous cell carcinoma (HNSCC) presents a serious clinical challenge mainly due to its resistance to conventional therapies and its complex, immunosuppressive tumor microenvironment. While recent studies have identified ferroptosis as a new therapeutic option, its impact on the immune microenvironment in HNSCC remains controversial, which may hinder its translational application. Although the role of the stimulator of interferon genes (STING)-type I interferon (IFN-I) pathway in antitumor immune responses has been widely investigated, its relationship with ferroptosis in HNSCC has not been fully explored. In this study, we discovered that ferroptosis in HNSCC inhibited tumor growth, activated STING-IFN-I pathway and subsequently improved recruitment and maturation of dendritic cells. We further demonstrated that IFN-I could enhance ferroptosis by inhibiting xCT-glutathione peroxidase 4 (GPX4) antioxidant system. To harness this positive feedback loop, we treated HNSCC tumors with both ferroptosis inducer and STING agonist, resulting in significant tumor suppression, elevated ferroptosis levels and enhanced dendritic cell infiltration. Overall, our findings reveal a mutually regulatory relationship between ferroptosis and the intrinsic STING-IFN-I pathway, providing novel insights into immune-mediated tumor suppression and suggesting its potential as therapeutic approach in HNSCC.

EXOTLR1/2-STING: A Dual-Mechanism Stimulator of Interferon Genes Activator for Cancer Immunotherapy

As natural agonists of the stimulator of interferon genes (STING) protein, cyclic dinucleotides (CDNs) can activate the STING pathway, leading to the expression of type I interferons and various cytokines. Efficient activation of the STING pathway in antigen-presenting cells (APCs) and tumor cells is crucial for antitumor immune response. Tumor-derived exosomes can be effectively internalized by APCs and tumor cells and have excellent potential to deliver CDNs to the cytoplasm of APCs and tumor cells. Here, we leverage tumor exosomes as a delivery platform, designing an EXOTLR1/2-STING loaded with CDNs. To achieve efficient loading of CDNs onto exosomes, we chemically conjugated CDNs with Pam3CSK4, a compound featuring multiple fatty acid chains, resulting in Pam3CSK4-CDGSF. Utilizing the high lipophilicity of Pam3CSK4, Pam3CSK4-CDGSF could be efficiently loaded onto the exosomes through simple incubation. Moreover, as an agonist for Toll-like receptor 1/2, Pam3CSK4 also exhibits robust immunological synergistic effects in conjunction with CDNs. EXOTLR1/2-STING effectively induced the activation of APCs and triggered tumor cell death, producing a favorable antitumor therapeutic effect. It also demonstrated significant synergistic effects with immune checkpoint therapies.

Inhalable nanovesicles loaded with a STING agonist enhance CAR-T cell activity against solid tumors in the lung

Suppression of chimeric antigen receptor-modified T (CAR-T) cells by the immunosuppressive tumor microenvironment remains a major barrier to their efficacy against solid tumors. To address this, we develop an anti-PD-L1-expressing nanovesicle loaded with the STING agonist cGAMP (aPD-L1 NVs@cGAMP) to remodel the tumor microenvironment and thereby enhance CAR-T cell activity. Following pulmonary delivery, the nanovesicles rapidly accumulate in the lung and selectively deliver STING agonists to PD-L1-overexpressing cells via the PD-1/PD-L1 interaction. This targeted delivery effectively avoids the systemic inflammation and poor cellular uptake that plague free STING agonists. Internalized STING agonists trigger STING signaling and induce interferon responses, which diminish immunosuppressive cell populations such as myeloid-derived suppressor cells in the tumor microenvironment and promote CAR-T cell infiltration. Importantly, the anti-PD-L1 single chain variable fragment on the nanovesicle surface blocks PD-L1 upregulation induced by STING agonists and prevents CAR-T cell exhaustion. In both orthotopic lung cancer and lung metastasis model, combined therapy with CAR-T cells and aPD-L1 NVs@cGAMP potently inhibits tumor growth and prevents recurrence. Therefore, aPD-L1 NVs@cGAMP is expected to serve as an effective CAR-T cell enhancer to improve the efficacy of CAR-T cells against solid tumors.

From Images to Genes: Radiogenomics Based on Artificial Intelligence to Achieve Non-Invasive Precision Medicine in Cancer Patients

With the increasing demand for precision medicine in cancer patients, radiogenomics emerges as a promising frontier. Radiogenomics is originally defined as a methodology for associating gene expression information from high-throughput technologies with imaging phenotypes. However, with advancements in medical imaging, high-throughput omics technologies, and artificial intelligence, both the concept and application of radiogenomics have significantly broadened. In this review, the history of radiogenomics is enumerated, related omics technologies, the five basic workflows and their applications across tumors, the role of AI in radiogenomics, the opportunities and challenges from tumor heterogeneity, and the applications of radiogenomics in tumor immune microenvironment. The application of radiogenomics in positron emission tomography and the role of radiogenomics in multi-omics studies is also discussed. Finally, the challenges faced by clinical transformation, along with future trends in this field is discussed.

cGAS/STING pathway and gastrointestinal cancer: Mechanisms and diagnostic and therapeutic targets (Review)

The health of individuals is seriously threatened by intestinal cancer, which includes pancreatic, colorectal, esophageal, gastric and gallbladder cancer. Most gastrointestinal cancers do not have typical and specific early symptoms, and lack specific and effective diagnostic markers and treatment methods. It is critical to understand the etiology of gastrointestinal cancer and develop more efficient methods of diagnosis and treatment. The cyclic GMP‑AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway serves a crucial role in the occurrence, progression and treatment of gastrointestinal cancer. The present review focuses on the latest progress regarding the role and mechanism of the cGAS/STING pathway in gastrointestinal cancer, and discusses treatment approaches and related applications based on the cGAS/STING signaling pathway. In order to improve the knowledge of the connection between the cGAS/STING pathway and gastrointestinal cancer, aid the diagnosis and treatment of gastrointestinal cancer, and lessen the burden on patients and society, the present review also discusses future research directions and existing challenges regarding cGAS/STING in the study of gastrointestinal cancer.

Effect of colorectal cancer stem cells on the development and metastasis of colorectal cancer

The relevant mechanism of tumor-associated macrophages (TAMs) in the treatment of colorectal cancer patients with immune checkpoint inhibitors (ICIs) is discussed, and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related studies. As a class of drugs widely used in clinical tumor immunotherapy, ICIs can act on regulatory molecules on cells that play an inhibitory role - immune checkpoints - and kill tumors in the form of an immune response by activating a variety of immune cells in the immune system. The sensitivity of patients with different types of colorectal cancer to ICI treatment varies greatly. The phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of ICIs. ICIs can regulate the phenotypic function of TAMs, and TAMs can also affect the tolerance of colorectal cancer to ICI therapy. TAMs play an important role in ICI resistance, and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

Genomic instability as a driver and suppressor of anti-tumor immunity

Genomic instability is a driver and accelerator of tumorigenesis and influences disease outcomes across cancer types. Although genomic instability has been associated with immune evasion and worsened disease prognosis, emerging evidence shows that genomic instability instigates pro-inflammatory signaling and enhances the immunogenicity of tumor cells, making them more susceptible to immune recognition. While this paradoxical role of genomic instability in cancer is complex and likely context-dependent, understanding it is essential for improving the success rates of cancer immunotherapy. In this review, we provide an overview of the underlying mechanisms that link genomic instability to pro-inflammatory signaling and increased immune surveillance in the context of cancer, as well as discuss how genomically unstable tumors evade the immune system. A better understanding of the molecular crosstalk between genomic instability, inflammatory signaling, and immune surveillance could guide the exploitation of immunotherapeutic vulnerabilities in cancer.

Vasoactive intestinal peptide promotes secretory differentiation and mitigates radiation-induced intestinal injury

BACKGROUND

Vasoactive intestinal peptide (VIP) is a neuronal peptide with prominent distribution along the enteric nervous system. While effects of VIP on intestinal motility, mucosal vasodilation, secretion, and mucosal immune cell function are well-studied, the direct impact of VIP on intestinal epithelial cell turnover and differentiation remains less understood. Intestinal stem and progenitor cells are essential for the maintenance of intestinal homeostasis and regeneration, and their functions can be modulated by factors of the stem cell niche, including neuronal mediators. Here, we investigated the role of VIP in regulating intestinal epithelial homeostasis and regeneration following irradiation-induced injury.

METHODS

Jejunal organoids were derived from male and female C57Bl6/J, Lgr5-EGFP-IRES-CreERT2 or Lgr5-EGFP-IRES-CreERT2/R26R-LSL-TdTomato mice and treated with VIP prior to analysis. Injury conditions were induced by exposing organoids to 6 Gy of irradiation (IR). To investigate protective effects of VIP in vivo, mice received 12 Gy of abdominal IR followed by intraperitoneal injections of VIP.

RESULTS

We observed that VIP promotes epithelial differentiation towards a secretory phenotype predominantly via the p38 MAPK pathway. Moreover, VIP prominently modulated epithelial proliferation as well as the number and proliferative activity of Lgr5-EGFP+ progenitor cells under homeostatic conditions. In the context of acute irradiation injury in vitro, we observed that IR injury renders Lgr5-EGFP+ progenitor cells more susceptible to VIP-induced modulations, which coincided with the strong promotion of epithelial regeneration by VIP. Finally, the observed effects translate into an in vivo model of abdominal irradiation, where VIP showed to prominently mitigate radiation-induced injury.

CONCLUSIONS

VIP prominently governs intestinal homeostasis by regulating epithelial progenitor cell proliferation and differentiation and promotes intestinal regeneration following acute irradiation injury.

KDM3A Ablation Activates Endogenous Retrovirus Expression to Stimulate Antitumor Immunity in Gastric Cancer

The success of immunotherapy for cancer treatment is limited by the presence of an immunosuppressive tumor microenvironment (TME); Therefore, identifying novel targets to that can reverse this immunosuppressive TME and enhance immunotherapy efficacy is essential. In this study, enrichment analysis based on publicly available single-cell and bulk RNA sequencing data from gastric cancer patients are conducted, and found that tumor-intrinsic interferon (IFN) plays a central role in TME regulation. The results shows that KDM3A over-expression suppresses the tumor-intrinsic IFN response and inhibits KDM3A, either genomically or pharmacologically, which effectively promotes IFN responses by activating endogenous retroviruses (ERVs). KDM3A ablation reconfigures the dsRNA-MAVS-IFN axis by modulating H3K4me2, enhancing the infiltration and function of CD8 T cells, and simultaneously reducing the presence of regulatory T cells, resulting in a reshaped TME in vivo. In addition, combining anti-PD1 therapy with KDM3A inhibition effectively inhibited tumor growth. In conclusions, this study highlights KDM3A as a potential target for TME remodeling and the enhancement of antitumor immunity in gastric cancer through the regulation of the ERV-MAVS-IFN axis.

Mechanism of immune activation mediated by genomic instability and its implication in radiotherapy combined with immune checkpoint inhibitors

Various genetic and epigenetic changes associated with genomic instability (GI), including DNA damage repair defects, chromosomal instability, and mitochondrial GI, contribute to development and progression of cancer. These alterations not only result in DNA leakage into the cytoplasm, either directly or through micronuclei, but also trigger downstream inflammatory signals, such as the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. Apart from directly inducing DNA damage to eliminate cancer cells, radiotherapy (RT) exerts its antitumor effects through intracellular DNA damage sensing mechanisms, leading to the activation of downstream inflammatory signaling pathways. This not only enables local tumor control but also reshapes the immune microenvironment, triggering systemic immune responses. The combination of RT and immunotherapy has emerged as a promising approach to increase the probability of abscopal effects, where distant tumors respond to treatment due to the systemic immunomodulatory effects. This review emphasizes the importance of GI in cancer biology and elucidates the mechanisms by which RT induces GI remodeling of the immune microenvironment. By elucidating the mechanisms of GI and RT-induced immune responses, we aim to emphasize the crucial importance of this approach in modern oncology. Understanding the impact of GI on tumor biological behavior and therapeutic response, as well as the possibility of activating systemic anti-tumor immunity through RT, will pave the way for the development of new treatment strategies and improve prognosis for patients.

High levels of tumor cell-intrinsic STING signaling are associated with increased infiltration of CD8+ T cells in dMMR/MSI-H gastric cancer

Mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) gastric cancer (GC) exhibits an immune-active tumor microenvironment (TME) compared to MMR proficient (pMMR)/microsatellite stable/Epstein-Barr virus-negative [EBV (-)] GC. The tumor cell-intrinsic cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been considered a key regulator of immune cell activation in the TME. However, its significance in regulating the immune-active TME in dMMR/MSI-H GC remains unclear. Here, we demonstrated that tumor cell-intrinsic cGAS-STING was highly expressed in dMMR GC compared to pMMR/EBV (-) GC. The expression of tumor cell-intrinsic STING was significantly and positively associated with the number of CD8+ tumor-infiltrating lymphocytes in GC. Analysis of TCGA datasets revealed that the expression of interferon-stimulated genes and STING downstream T-cell attracting chemokines was significantly higher in MSI-H GC compared to other subtypes of GC with EBV (-). These results suggest that tumor cell-intrinsic STING signaling plays a key role in activating immune cells in the dMMR/MSI-H GC TME and might serve as a novel biomarker predicting the efficacy of immunotherapy for GC treatment.

PTPRT loss enhances anti-PD-1 therapy efficacy by regulation of STING pathway in non-small cell lung cancer

With the revolutionary progress of immune checkpoint inhibitors (ICIs) in non-small cell lung cancer, identifying patients with cancer who would benefit from ICIs has become critical and urgent. Here, we report protein tyrosine phosphatase receptor type T (PTPRT) loss as a precise and convenient predictive marker independent of PD-L1 expression for anti-PD-1/PD-L1 axis therapy. Anti-PD-1/PD-L1 axis treatment markedly increased progression-free survival in patients with PTPRT-deficient tumors. PTPRT-deficient tumors displayed cumulative DNA damage, increased cytosolic DNA release, and higher tumor mutation burden. Moreover, the tyrosine residue 240 of STING was identified as a direct substrate of PTPRT. PTPRT loss elevated phosphorylation of STING at Y240 and thus inhibited its proteasome-mediated degradation. PTPRT-deficient tumors released more IFN-β, CCL5, and CXCL10 by activation of STING pathway and increased immune cell infiltration, especially of CD8 T cells and natural killer cells, ultimately enhancing the efficacy of anti-PD-1 therapy in multiple subcutaneous and orthotopic tumor mouse models. The response of PTPRT-deficient tumors to anti-PD-1 therapy depends on the tumor-intrinsic STING pathway. In summary, our findings reveal the mechanism of how PTPRT-deficient tumors become sensitive to anti-PD-1 therapy and highlight the biological function of PTPRT in innate immunity. Considering the prevalence of PTPRT mutations and negative expression, this study has great value for patient stratification and clinical decision-making.

Colorectal medullary carcinoma: a pathological subtype with intense immune response and potential to benefit from immune checkpoint inhibitors

INTRODUCTION

Different pathological types of colorectal cancer have distinguished immune landscape, and the efficacy of immunotherapy will be completely different. Colorectal medullary carcinoma, accounting for 2.2-3.2%, is characterized by massive lymphocyte infiltration. However, the attention to the immune characteristics of colorectal medullary carcinoma is insufficient.

AREA COVERED

We searched the literature about colorectal medullary carcinoma on PubMed through November 2023to investigate the hallmarks of colorectal medullary carcinoma's immune landscape, compare medullary carcinoma originating from different organs and provide theoretical evidence for precise treatment, including applying immunotherapy and BRAF inhibitors.

EXPERT OPINION

Colorectal medullary carcinoma is a pathological subtype with intense immune response, with six immune characteristics and has the potential to benefit from immunotherapy. Mismatch repair deficiency, ARID1A missing and BRAF V600E mutation often occurs. IFN-γ pathway is activated and PD-L1 expression is increased. Abundant lymphocyte infiltration performs tumor killing function. In addition, BRAF mutation plays an important role in the occurrence and development, and we can consider the combination of BRAF inhibitors and immunotherapy in patients with BRAF mutant. The exploration of colorectal medullary carcinoma will arouse researchers' attention to the correlation between pathological subtypes and immune response, and promote the process of precise immunotherapy.

The cGAS/STING Pathway-A New Potential Biotherapeutic Target for Gastric Cancer?

Gastric cancer ranks among the top five deadliest tumors worldwide, both in terms of prevalence and mortality rates. Despite mainstream treatments, the efficacy in treating gastric cancer remains suboptimal, underscoring the urgency for novel therapeutic approaches. The elucidation of tumor immunosuppressive microenvironments has shifted focus towards cancer biotherapeutics, which leverage the patient's immune system or biologics to target tumor cells. Biotherapy has emerged as a promising alternative for tumors resistant to traditional chemotherapy, radiation, and immunotherapy. Central to this paradigm is the cGAS-STING pathway, a pivotal component of the innate immune system. This pathway recognizes aberrant DNA, such as that from viral infections or tumor cells, and triggers an immune response, thereby reshaping the immunosuppressive tumor microenvironment into an immune-stimulating milieu. In the context of gastric cancer, harnessing the cGAS-STING pathway holds significant potential for biotherapeutic interventions. This review provides a comprehensive overview of the latest research on cGAS-STING in gastric cancer, including insights from clinical trials involving STING agonists. Furthermore, it assesses the prospects of targeting the cGAS-STING pathway as a novel biotherapeutic strategy for gastric cancer.

The balance of STING signaling orchestrates immunity in cancer

Over the past decade, it has become clear that the stimulator of interferon genes (STING) pathway is critical for a variety of immune responses. This endoplasmic reticulum-anchored adaptor protein has regulatory functions in host immunity across a spectrum of conditions, including infectious diseases, autoimmunity, neurobiology and cancer. In this Review, we outline the central importance of STING in immunological processes driven by expression of type I and III interferons, as well as inflammatory cytokines, and we look at therapeutic options for targeting STING. We also examine evidence that challenges the prevailing notion that STING activation is predominantly beneficial in combating cancer. Further exploration is imperative to discern whether STING activation in the tumor microenvironment confers true benefits or has detrimental effects. Research in this field is at a crossroads, as a clearer understanding of the nuanced functions of STING activation in cancer is required for the development of next-generation therapies.

Role of vascular endothelial growth factor D in lung adenocarcinoma immunotherapy response

OBJECTIVE

To identify key genes associated with tumor-associated macrophages (TAMs), tumor immunotherapy, in the prognosis of lung adenocarcinoma (LUAD).

METHODS

The mRNA expression profiles of LUAD samples were obtained from The Cancer Genome Atlas (TCGA) database. The "CIBERSORT" R package was employed to calculate the proportion of innate immune cell infiltration in both tumor and adjacent normal tissues. TAM-associated genes in LUAD were identified to construct a prognostic risk model using weighted gene correlation network analysis (WGCNA), Least Absolute Shrinkage and Selection Operator (LASSO), and multivariate Cox regression analyses (COX). The IMvigor210 cohort was utilized to validate the roles of these genes as predictors of immunotherapy response. Tissue microarrays, immunofluorescence staining, and mRNA level detection methods were used to determine the correlation of risk factors in LUAD tissues.

RESULTS

CIBERSORT analysis revealed significant differences in innate immune cells between tumor and adjacent tissues. Seventy-four differential genes linked to these cells were identified from WGCNA. Four hub genes (endothelin receptor type B, vascular endothelial growth factor D (VEGFD), latent transforming growth factor beta binding protein 4 (LTBP4), and fibroblast growth factor receptor 4 (FGFR4)) in the TAM prognostic model were identified as independent prognostic risk factors (P < 0.05). VEGFD expression was identified as a low-risk factor for LUAD prognosis prediction (P < 0.05). Moreover, low-risk patients exhibited higher sensitivity to anti-PD-L1 therapy compared to high-risk patients (P < 0.05). VEGFD levels were negatively correlated with programmed cell death 1 (PD-1) levels (r = -0.363; P < 0.05), suggesting that VEGFD may serve as a predictor for anti-PD-1 treatment.

CONCLUSIONS

VEGFD is associated with innate immunity in LUAD, it can predict LUAD prognosis, and therefor may be a potential predictor for anti-PD-1 treatment in patients with LUAD.

Biophysical and biochemical aspects of immune cell-tumor microenvironment interactions

The tumor microenvironment (TME), composed of and influenced by a heterogeneous set of cancer cells and an extracellular matrix, plays a crucial role in cancer progression. The biophysical aspects of the TME (namely, its architecture and mechanics) regulate interactions and spatial distributions of cancer cells and immune cells. In this review, we discuss the factors of the TME-notably, the extracellular matrix, as well as tumor and stromal cells-that contribute to a pro-tumor, immunosuppressive response. We then discuss the ways in which cells of the innate and adaptive immune systems respond to tumors from both biochemical and biophysical perspectives, with increased focus on CD8+ and CD4+ T cells. Building upon this information, we turn to immune-based antitumor interventions-specifically, recent biophysical breakthroughs aimed at improving CAR-T cell therapy.

Enhancing immunotherapy outcomes by targeted remodeling of the tumor microenvironment via combined cGAS-STING pathway strategies

Immune checkpoint inhibitors (ICIs) represent a groundbreaking advance in the treatment of malignancies such as melanoma and non-small cell lung cancer, showcasing substantial therapeutic benefits. Nonetheless, the efficacy of ICIs is limited to a small subset of patients, primarily benefiting those with "hot" tumors characterized by significant immune infiltration. The challenge of converting "cold" tumors, which exhibit minimal immune activity, into "hot" tumors to enhance their responsiveness to ICIs is a critical and complex area of current research. Central to this endeavor is the activation of the cGAS-STING pathway, a pivotal nexus between innate and adaptive immunity. This pathway's activation promotes the production of type I interferon (IFN) and the recruitment of CD8+ T cells, thereby transforming the tumor microenvironment (TME) from "cold" to "hot". This review comprehensively explores the cGAS-STING pathway's role in reconditioning the TME, detailing the underlying mechanisms of innate and adaptive immunity and highlighting the contributions of various immune cells to tumor immunity. Furthermore, we delve into the latest clinical research on STING agonists and their potential in combination therapies, targeting this pathway. The discussion concludes with an examination of the challenges facing the advancement of promising STING agonists in clinical trials and the pressing issues within the cGAS-STING signaling pathway research.

Role of STING in the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a prevalent form of lung cancer. Patients with advanced NSCLC are currently being treated with various therapies, including traditional radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. However, a considerable proportion of advance patients who cannot benefit from them. Consequently, it is essential to identify a novel research target that offers an encouraging perspective. The stimulator of interferon genes (STING) has emerged as such a target. At present, it is confirmed that activating STING in NSCLC tumor cells can impede the proliferation and metastasis of dormant tumor cells. This review focuses on the role of STING in NSCLC treatment and the factors influencing its activation. Additionally, it explores the correlation between STING activation and diverse therapy modalities for NSCLC, such as radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. Furthermore, it proposes the prospect of innovative therapy methods involving nanoparticles, with the aim of using the features of STING to develop more strategies for NSCLC therapy.

DNA Damage-driven Inflammatory Cytokines: Reprogramming of Tumor Immune Microenvironment and Application of Oncotherapy

DNA damage occurs across tumorigenesis and tumor development. Tumor intrinsic DNA damage can not only increase the risk of mutations responsible for tumor generation but also initiate a cellular stress response to orchestrate the tumor immune microenvironment (TIME) and dominate tumor progression. Accumulating evidence documents that multiple signaling pathways, including cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) and ataxia telangiectasia-mutated protein/ataxia telangiectasia and Rad3-related protein (ATM/ATR), are activated downstream of DNA damage and they are associated with the secretion of diverse cytokines. These cytokines possess multifaced functions in the anti-tumor immune response. Thus, it is necessary to deeply interpret the complex TIME reshaped by damaged DNA and tumor-derived cytokines, critical for the development of effective tumor therapies. This manuscript comprehensively reviews the relationship between the DNA damage response and related cytokines in tumors and depicts the dual immunoregulatory roles of these cytokines. We also summarize clinical trials targeting signaling pathways and cytokines associated with DNA damage and provide future perspectives on emerging technologies.

Immunogenic PANoptosis-Initiated Cancer Sono-Immune Reediting Nanotherapy by Iteratively Boosting Cancer Immunity Cycle

The cancer-immune cycle conceptualized the mechanisms of driving T cell responses to tumors, but w as limited by immunological ignorance elicited by tumor inherent immunoediting, which failed to initiate and maintain adaptive immunity. Targeting specific vulnerabilities of cell death patterns may provide unique opportunities to boost T cell antitumor immunological effects. Here an ultrasound nanomedicine-triggered tumor immuno-reediting therapeutic strategy using nano/genetically engineered extracellular vesicles, which can induce tumor highly immunogenic PANoptosis and iteratively start-up the energization of cancer innate immunity cycle by repeatedly liberating damage-associated molecular patterns, thereby priming sufficient antigen-specific T cells and shaping protective immune response through activating cGAS-STING signaling pathways, is reported. Aided by immune checkpoint blockade, the reprogramming of immune microenvironment further facilitated a prompt bridging of innate and adaptive immunity, and remarkably suppressed metastatic and rechallenged tumor growth. Thus, targeting PANoptotic cell death provides a catcher against immune escape and a positive-feedback immune activation gateway for overcoming immune resistance to intractable cancers.

At the Crossroads of the cGAS-cGAMP-STING Pathway and the DNA Damage Response: Implications for Cancer Progression and Treatment

The evolutionary conserved DNA-sensing cGAS-STING innate immunity pathway represents one of the most important cytosolic DNA-sensing systems that is activated in response to viral invasion and/or damage to the integrity of the nuclear envelope. The key outcome of this pathway is the production of interferon, which subsequently stimulates the transcription of hundreds of genes. In oncology, the situation is complex because this pathway may serve either anti- or pro-oncogenic roles, depending on context. The prevailing understanding is that when the innate immune response is activated by sensing cytosolic DNA, such as DNA released from ruptured micronuclei, it results in the production of interferon, which attracts cytotoxic cells to destroy tumors. However, in tumor cells that have adjusted to significant chromosomal instability, particularly in relapsed, treatment-resistant cancers, the cGAS-STING pathway often supports cancer progression, fostering the epithelial-to-mesenchymal transition (EMT). Here, we review this intricate pathway in terms of its association with cancer progression, giving special attention to pancreatic ductal adenocarcinoma and gliomas. As the development of new cGAS-STING-modulating small molecules and immunotherapies such as oncolytic viruses involves serious challenges, we highlight several recent fundamental discoveries, such as the proton-channeling function of STING. These discoveries may serve as guiding lights for potential pharmacological advancements.

The complementarity of DDR, nucleic acids and anti-tumour immunity

Immune checkpoint blockade (ICB) immunotherapy is a first-line treatment for selected cancers, yet the mechanisms of its efficacy remain incompletely understood. Furthermore, only a minority of patients with cancer benefit from ICB, and there is a lack of fully informative treatment response biomarkers. Selectively exploiting defects in DNA damage repair is also a standard treatment for cancer, spurred by enhanced understanding of the DNA damage response (DDR). DDR and ICB are closely linked-faulty DDR produces immunogenic cancer neoantigens that can increase the efficacy of ICB therapy, and tumour mutational burden is a good but imperfect biomarker for the response to ICB. DDR studies in ICB efficacy initially focused on contributions to neoantigen burden. However, a growing body of evidence suggests that ICB efficacy is complicated by the immunogenic effects of nucleic acids generated from exogenous DNA damage or endogenous processes such as DNA replication. Chemotherapy, radiation, or selective DDR inhibitors (such as PARP inhibitors) can generate aberrant nucleic acids to induce tumour immunogenicity independently of neoantigens. Independent of their functions in immunity, targets of immunotherapy such as cyclic GMP-AMP synthase (cGAS) or PD-L1 can crosstalk with DDR or the DNA repair machinery to influence the response to DNA-damaging agents. Here we review the rapidly evolving, multifaceted interfaces between DDR, nucleic acid immunogenicity and immunotherapy efficacy, focusing on ICB. Understanding these interrelated processes could explain ICB treatment failures and reveal novel exploitable therapeutic vulnerabilities in cancers. We conclude by addressing major unanswered questions and new research directions.