The cGAS-STING pathway and cancer

In situ non-canonical activation and sensitization of cGAS-STING pathway with manganese telluride nanosheets

Immune checkpoint blockade (ICB) has achieved encouraging outcome in various malignant tumors. However, the low immunogenicity and insufficient infiltration of T cells within tumors severely limit the curative effects. Herein, we reported synthesis and experimental evaluation of H2O2-responsive MnTe2 nanosheets (NSs) for improving anti-tumor immune responses. Within the tumor microenvironment characterized by high level of H2O2, the MnTe2 NSs were degraded to release Mn2+ and TeO42- which subsequently induced cellular endoplasmic reticulum (ER) stress and non-canonically activated the cGAS-STING pathway. Moreover, the cellular Mn2+ ions enhanced the sensitivity of cGAS-STING pathway and the maturation of dendritic cells (DCs) concurrently. Ultimately, the MnTe2 NSs exhibited favorable in vivo anti-tumor immune effects, especially in combination with PD-L1 checkpoint inhibitors. These findings provided compelling evidence for exploration and utilization of nanomedicine to leverage innate immune system for better tumor immunotherapy.

Photochemical bomb: Precision nuclear targeting to activate cGAS-STING pathway for enhanced bladder cancer immunotherapy

Activating the cGAS-STING pathway presents a promising strategy to enhance the innate immunity and combat the immunosuppressive tumor microenvironment. One key mechanism for triggering this pathway involves the release of damaged DNA fragments caused by nuclear DNA damage. However, conventional cGAS-STING agonists often suffer from limited nucleus-targeting efficiency and potential biotoxicity. In this study, we develop a novel nucleus-targeting theranostic nanoplatform designed to synergistically activate the cGAS-STING pathway through the combination of photodynamic therapy (PDT) and cisplatin chemotherapy for orthotopic bladder cancer treatment. The nanoplatform integrates a new high-performance type-I photosensitizer with near-infrared-II emission, a TATSA peptide for enhanced nuclear targeting, and a biosafe platinum (IV) cisplatin prodrug. Upon NIR laser irradiation, the nanoagent delivers synergistic nucleus-targeted PDT and chemotherapy, causing substantial DNA damage and the release of double-stranded DNA, which subsequently activates the cGAS-STING pathway and triggers potent immunomodulation. This activation promotes dendritic cells maturation, enhances cytotoxic T infiltration, and facilitates the formation of memory T cells, leading to immune microenvironment remodeling, and long-lasting immune memory, thus effectively inhibiting orthotopic bladder tumors and reducing the risk of metastasis. These findings highlight the substantial potential of this strategy to overcome the limitations of current immunotherapies by leveraging nucleus-targeted PDT to activate the cGAS-STING pathway for cancer treatment.

Conjugated STING agonists

An innate immune system is the first line of defense and prevents the host from infection and attacks the invading pathogens. Stimulator of interferon genes (STING) plays a vital role in the innate immune system. STING activation by STING agonists leads to phosphorylation of TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) with the release of type I interferons and proinflammatory cytokines, further promoting the adaptive immune response and activating T cells by increased antigen presentation. Natural STING agonist cyclic dinucleotides (CDNs) encounter many defects such as high polarity by negative charges, low stability and circulative half-life, off-target systemic toxicity, and low response efficacy in clinical trials. To overcome these challenges, massive efforts have addressed chemical modifications of CDNs, development of non-CDN STING agonists, and delivery of these STING agonists either by conjugation or liposomes/nanoparticles. Considering there have been a great number of reports regarding nanosystem-aided delivery, here, we examine the development of STING agonists, especially for non-CDNs and their delivery specifically by conjugation strategy, with a focus on the STING agonists in clinical trials and current challenges of their potential in cancer immunotherapy.

Microbiota mechanisms in cancer progression and therapy

The composition of the microbiota in patients has been shown to correlate with cancer progression and response to therapy, highlighting unique opportunities to improve patient outcomes. In this review, we discuss the challenges and advancements in understanding the chemical mechanisms of specific microbiota species, pathways, and molecules involved in cancer progression and treatment. We also describe the modulation of cancer and immunotherapy by the microbiota, along with approaches for investigating microbiota enzymes and metabolites. Elucidating these specific microbiota mechanisms and molecules should offer new opportunities for developing enhanced diagnostics and therapeutics to improve outcomes for cancer patients. Nonetheless, many microbiota mechanisms remain to be determined and require innovative chemical genetic approaches.

STING pathway activation with cisplatin polyprodrug nanoparticles for chemo-immunotherapy in ovarian cancer

Cisplatin serves as the cornerstone medication in ovarian cancer (OC) chemotherapy; however, numerous resistance factors exist, resulting in unsatisfactory clinical treatment outcomes. Concurrently, OC frequently establishes an immunosuppressive microenvironment, which further exacerbates the challenges of cisplatin chemotherapy. Hence, it is particularly significant to explore a therapeutic approach capable of overcoming cisplatin resistance while reversing the immunosuppressive microenvironment of OC. Here, we synthesized a novel cisplatin polyprodrug (PTP) containing thioketal units, which self-assembled with a stimulator of interferon genes (STING) small-molecule agonist (SR-717) to form redox-smart-responsive PTP@SR-717 nanoparticles (NPs), enabling synergistic chemo-immunotherapy. Specifically, PTP@SR-717 NPs enhanced the anti-tumor effect of cisplatin through three key mechanisms: (i) Pre-target factors: Enhancing intracellular cisplatin uptake and reducing GSH-mediated detoxification to promote platinum accumulation. (ii) On-target factors: Utilizing molecular damage-associated molecular patterns (DAMPs) triggered by cisplatin to activate the STING pathway, thereby synergistically amplifying the STING-TBK1-IRF3 signaling and efficiently triggering an immune response. (iii) Post-target factors: Combining chemotherapy and immunotherapy to harness the immune system for tumor eradication. In conclusion, this study presents an effective approach to addressing the challenges associated with cisplatin in the clinical treatment of OC.

Targeting of COPⅠ elicits CD8+ T cell-mediated anti-tumor immunity and suppresses growth of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) possesses the immunosuppressive tumor microenvironment (TME) that limits the effectiveness of immunotherapy. Genetic alterations of the coat protein complex Ⅰ (COPⅠ) lead to STING activation and inflammatory immune response. This study aims to address whether targeting COPⅠ can be exploited as a strategy to elicit immune response and inhibit iCCA progression. Here, we demonstrated that the COPⅠ subunits were highly expressed in human and mouse iCCA tissues. Genetic and pharmacological inhibition of COPⅠ suppressed growth of the mouse autochthonous iCCAs driven by activated oncogenes. Disruption of COPⅠ increased T cell presence in tumor environment and elicited anti-tumor T cell response through activating STING-type-I interferon (IFN-I) pathway. Neutralizing CD8+ T cell or STING deletion efficiently counteracted the suppression of iCCA growth by targeting COPⅠ. In addition, the Wnt/β-catenin signaling was dramatically attenuated in tumor cells by STING activation in the context of COPⅠ disruption. Notably, targeting COPⅠ markedly potentiates the therapeutic efficacy of anti-PD-1 in suppressing iCCA growth. In conclusion, our study reveals that targeting COPⅠ effectively suppresses tumor growth by enhancing T cell presence and function in mouse iCCA. STING activation by COPⅠ inhibition dedicates the T cell control of iCCA growth. COPⅠ is a potential target for iCCA treatment.

Deciphering cGAS-STING signaling: implications for tumor immunity and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent form of primary liver cancer and poses a significant global health challenge due to its rising incidence and associated mortality. Recent advancements in understanding the cytosolic DNA sensing, the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway have illuminated its critical role in the immune response to HCC. This narrative review deciphers the multifaceted involvement of cGAS-STING in HCC, mainly its function in detecting cytosolic DNA and initiating type I interferon (IFN-I) responses, which are pivotal for antitumor immunity. This immune response is crucial for combating pathogens and can play a role in tumor surveillance. In the context of HCC, the tumor microenvironment (TME) can exhibit immune resistance, which complicates the effectiveness of therapies like immune checkpoint blockade. However, activation of the cGAS-STING pathway has been shown to stimulate antitumor immune responses, enhancing the activity of dendritic cells and cytotoxic T lymphocytes. There is ongoing research into STING agonists as a treatment strategy for HCC, with some studies indicating promising results in prolonging survival and enhancing the immune response against tumors. By summarizing current knowledge and identifying research gaps, this review aims to provide a comprehensive overview of cGAS-STING signaling in HCC and its future directions, emphasizing its potential as a therapeutic target in the fight against HCC. Understanding these mechanisms could pave the way for innovative immunotherapeutic approaches that enhance the efficacy of existing treatments and improve patient prognosis.

Melatonin alleviates sepsis-induced acute lung injury by inhibiting necroptosis via reducing circulating mtDNA release

BACKGROUND

Sepsis is a life-threatening condition that often leads to severe complications, including acute lung injury (ALI), which carries high morbidity and mortality in critically ill patients. Melatonin (Mel) has shown significant protective effects against sepsis-induced ALI, but its precise mechanism remains unclear.

METHODS

A cecal ligation and puncture (CLP) model was used to induce sepsis in male C57BL/6 mice, which were divided into four groups: Control, Sham, CLP, and CLP + Mel. ALI severity was evaluated via hematoxylin and eosin (H&E) staining, lung wet/dry ratio, and serum biomarkers (SP-D, sRAGE). Inflammatory cytokines (IL-1β, IL-6, TNF-α) were measured in serum and bronchoalveolar lavage fluid using ELISA. Circulating mitochondrial DNA (mtDNA) subtypes (D-loop, mt-CO1, mMito) were quantified by real-time PCR. TUNEL staining was performed to assess lung cell apoptosis. Necroptosis and STING pathway activation were analyzed via Western blot and immunofluorescence.

RESULTS

Sepsis led to increased circulating mtDNA levels and activation of necroptosis signaling pathways. Melatonin treatment alleviated sepsis-induced ALI, improving survival, reducing inflammatory cytokines and mtDNA release, and suppressing necroptosis. Intraperitoneal injection of mtDNA in mice activated necroptosis, while RIP1 inhibitor Nec-1 counteracted mtDNA-induced lung damage and necroptosis in sepsis-induced ALI. Additionally, melatonin significantly inhibited STING pathway activation. Further experiments revealed that STING modulation influenced necroptosis protein expression and mediated melatonin's protective effects in sepsis-induced ALI.

CONCLUSION

Melatonin mitigates sepsis-induced ALI by suppressing necroptosis through inhibition of STING activation and reduction of mtDNA release. These findings suggest melatonin as a potential therapeutic strategy for sepsis-induced ALI.

STING rs7380824 Polymorphism Contributes to the Susceptibility of Colorectal Cancer in Chinese Population

STING, an endoplasmic reticulum-localized protein with multiple transmembrane domains, has been implicated in colorectal cancer (CRC) development. This study investigated the association between STING rs7380824 polymorphism and CRC susceptibility using both bioinformatics analysis and a case-control study. Bioinformatics predictions from SIFT and PolyPhen indicated that the rs7380824 variant, which results in an amino acid substitution from arginine (R) to glutamine (Q) at position 293, is likely to be deleterious, with a SIFT score of 0.000 and a PolyPhen score of 0.999. A total of 870 CRC patients and 870 healthy controls were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Logistic regression analysis demonstrated that individuals carrying the CT and TT genotypes had an increased risk of CRC with OR (95% CI) of 1.564 (1.115-2.192) and 1.551 (1.271-1.893), respectively. Stratified analysis showed that the rs7380824 C > T variant increased CRC risk in all age and gender groups. Furthermore, non-smokers with the CT or TT genotype had a higher CRC risk (OR = 1.661, 95% CI: 1.333-2.071, p < 0.001), while no significant association was observed among smokers (p = 0.238). Similarly, non-drinkers carrying the CT or TT genotype showed an increased CRC risk (OR = 1.746, 95% CI: 1.395-2.185, p < 0.001), whereas no significant difference was detected among drinkers (p = 0.265). This study identifies STING rs7380824 polymorphism as a significant contributor to CRC susceptibility, with bioinformatics predictions and case-control analysis confirming its deleterious impact and the association with increased CRC risk. In addition, these findings underscore the interplay between genetic and environmental factors in CRC development, highlighting STING's potential as a genetic biomarker for CRC risk assessment in the Chinese population.

PCK1 inhibits cGAS-STING activation by consumption of GTP to promote tumor immune evasion

Hypoxia induces immunosuppressive phenotypes in tumor cells even in the presence of cytosolic DNA accumulation. The mechanisms by which tumor cells suppress hypoxia-induced cGAS-STING activation for immune evasion remain largely unclear. Here, we demonstrate that hypoxic stimulation induces JNK1/2-mediated S151 phosphorylation of phosphoenolpyruvate carboxykinase 1 (PCK1), a rate-limiting enzyme in gluconeogenesis. This phosphorylation triggers the interaction between PCK1 and cGAS. The PCK1 associated with cGAS competitively consumes GTP, a substrate shared by both PCK1 and cGAS. Consequently, PCK1 inhibits GTP-dependent cGAS activation and subsequent STING-promoted immune cell infiltration and activation in the tumor microenvironment, leading to promoted tumor growth in mice. The blockade of PCK1 function, in combination with anti-PD-1 antibody treatment, exhibits an additive therapeutic effect on tumor growth. Additionally, PCK1 S151 phosphorylation is inversely correlated with cGAS-STING activation in human breast cancer specimens and patient survival. These findings reveal a novel regulation of cGAS-STING pathway and uncover the metabolic control of immune response in tumor cells.

cGAS mRNA-Based Immune Agonist Promotes Vaccine Responses and Antitumor Immunity

mRNA vaccines are a potent tool for immunization against viral diseases and cancer. However, the lack of a vaccine adjuvant limits the efficacy of these treatments. In this study, we used cGAS mRNA, which encodes the DNA innate immune sensor, complexed with lipid nanoparticles (LNP), to boost the immune response. By introducing specific mutations in human cGAS mRNA (hcGASK187N/L195R), we significantly enhanced cGAS activity, resulting in a more potent and sustained stimulator of interferon gene (STING)-mediated IFN response. cGAS mRNA-LNPs exhibited stimulatory effects on maturation, antigen engulfment, and antigen presentation by antigen-presenting cells, both in vitro and in vivo. Moreover, the hcGASK187N/L195R mRNA-LNP combination demonstrated a robust adjuvant effect and amplified the potency of mRNA and protein vaccines, which was a result of strong humoral and cell-mediated responses. Remarkably, the hcGASK187N/L195R mRNA-LNP complex, either alone or in combination with antigens, demonstrated exceptional efficacy in eliciting antitumor immunity. In addition to its immune-boosting properties, hcGASK187N/L195R mRNA-LNP exerted antitumor effects with IFNγ directly on tumor cells, further promoting tumor restriction. In conclusion, we developed a cGAS mRNA-based immunostimulatory adjuvant compatible with various vaccine forms to boost the adaptive immune response and cancer immunotherapies.

STING-∆C, a novel splice isoform of STING, inhibits DNA virus-induced innate immunity and autophagy

Stimulator of interferon genes (STING) plays a critical role in the innate immune response to cytosolic DNA, primarily activating type I interferons (IFNs). Although alternative splicing is known to modulate immune pathways, the influence of STING splice isoforms requires further exploration. Here, we identified STING-∆C, a novel splice isoform of STING generated by retention of intron 6, resulting in a truncated C-terminus. While STING-∆C shares its N-terminal domain with full-length STING, it contains a unique C-terminal sequence. STING-∆C acts as a dominant negative regulator of cGAS-STING signaling pathway by suppressing cGAS-, 2'3'-cGAMP-, and STING-mediated activation of the IFN response. Gain- and loss-of-function experiments showed that STING-∆C inhibited IFN production in response to double-stranded DNA and DNA virus, including HSV-1 and HPV. Furthermore, STING-∆C promoted HSV-1 replication and reduces STING-induced autophagy. Mechanistically, STING-∆C interacts with full-length STING, preventing its oligomerization and assembly with TBK1, a vital component of the STING-TBK1-IRF3 signalsome. This interaction blocks IRF3 phosphorylation and nuclear translocation, thereby halting IFN production. STING-∆C thus represents a newly identified splice isoform that negatively regulates cGAS-STING signaling. These findings broaden our understanding of STING's regulatory mechanisms and may guide therapeutic strategies for autoimmune diseases and viral infections linked to excessive STING activation.

Mitigating Doxorubicin-Induced Cardiotoxicity and Enhancing Anti-Tumor Efficacy with a Metformin-Integrated Self-Assembled Nanomedicine

Doxorubicin (Dox) is a potent chemotherapeutic agent commonly used in cancer treatment. However, cardiotoxicity severely limited its clinical application. To address this challenge, a novel self-assembled nanomedicine platform, PMDDH, is developed for the co-delivery of Dox and metformin, an antidiabetic drug with cardioprotective and anti-tumor properties. PMDDH integrates metformin into a polyethyleneimine-based bioactive excipient (PMet), with Dox intercalated into double-stranded DNA and a hyaluronic acid (HA) coating to enhance tumor targeting. The PMDDH significantly improves the pharmacokinetics and tumor-targeting capabilities of Dox, while metformin enhances the drug's anti-tumor activity by downregulating programmed cell death ligand 1 (PD-L1) and activating the AMP-activated protein kinase (AMPK) signaling pathway. Additionally, the DNA component stimulates the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, which synergizes with Dox-induced immunogenic cell death (ICD) to promote a robust anti-tumor immune response. PMDDH markedly reduces Dox-induced cardiotoxicity by preserving mitochondrial function, reducing reactive oxygen species (ROS) production, and inducing protective autophagy in cardiomyocytes. These findings position PMDDH as a promising dual-function nanomedicine that enhances the anti-tumor efficacy of Dox while minimizing its systemic toxicity, offering a safer and more effective alternative for cancer therapy.

The carcinogenic metabolite acetaldehyde impairs cGAS activity to negatively regulate antiviral and antitumor immunity

The cGAS-MITA/STING pathway plays critical roles in both host defense against DNA virus and intrinsic antitumor immunity by sensing viral genomic DNA or dis-located mitochondrial/cellular DNA. Whether carcinogenic metabolites can target the cGAS-MITA axis to promote tumorigenesis is unknown. In this study, we identified acetaldehyde, a carcinogenic metabolite, as a suppressor of the cGAS-MITA pathway. Acetaldehyde inhibits the DNA virus herpes simplex virus 1 (HSV-1)- and transfected DNA-triggered but not cGAMP-induced activation of downstream components and induction of downstream effector genes. Mechanistically, acetaldehyde impairs the binding of cGAS to DNA as well as the phase separation of the cGAS-DNA complex in cells. In mouse models, acetaldehyde inhibits antiviral cytokine production, promotes viral replication and lethality upon HSV-1 infection. In a colorectal tumor xenograft model, acetaldehyde promotes tumor growth and inhibits CD8+ T cell infiltration by targeting cGAS in both the tumor cells and immune cells in mice. Bioinformatic analysis indicates that expression of acetaldehyde dehydrogenase 2 (ALDH2), which converts acetaldehyde to acetic acid, is negatively correlated with stimulatory immune signatures in clinical colorectal tumors, and higher ALDH2 expression exhibits better prognosis of colorectal cancer patients. Collectively, our results suggest that acetaldehyde impairs cGAS activity to inhibit the cGAS-MITA axis, which contributes to its effects on carcinogenesis.

The role of cGAS-STING in remodeling the tumor immune microenvironment induced by radiotherapy

The activation of the cGAS-STING pathway occurs when tumor cell DNA is damaged by ionizing radiation. Once triggered, this pathway reshapes the tumor immune microenvironment by promoting the maturation, activation, polarization, and immune-killing capacity of immune cells, as well as by inducing the release of interferons and the expression of immune-related genes. In addition, the gut microbiota and various mechanisms of programmed cell death interact with the cGAS-STING pathway, further influencing its function in remodeling the immune microenvironment after radiotherapy. Therefore, investigating the mechanisms of the cGAS-STING pathway in reshaping the tumor immune microenvironment post-radiotherapy can not only optimize the efficacy of combined radiotherapy and immunotherapy but also provide new research directions and potential targets for cancer treatment.

Smart Organic-Inorganic Copolymer Nanoparticles Distinguish Between Microglia and Cancer Cells for Synergistic Immunotherapy in Glioma

The stimulator of interferon genes (STING) pathway has emerged as a new immunotherapy strategy with potent local stimulation specificity, showing promising potential to counteract the immunosuppression in glioma. Herein, a tumor microenvironment (TME) responsive nanoagonists are developed based on an organic-inorganic copolymer composed of the polymer PC6AB coupled with manganous phosphate ionic oligomers (MnP). The degradation of nanoagonists into PC6AB and MnP in the acidic TME enables spatiotemporal control of their delivery to tumor cells and immune cells, respectively. PC6AB with membranolytic activity selectively interacts with tumor cell membranes to induce immunogenic cell death, while manganese metal can activate the STING pathway in immune cells and trigger downstream immunostimulatory signals. Nanoagonists can stimulate robust antitumor immunity after local injection into the brain extracellular space (ECS), showing significant therapeutic efficacy in mouse glioma. Nanoagonists can achieve spatiotemporal orchestration of STING activation in response to TME and enhance immune response against "cold" solid tumors, providing a promising approach for clinical immunotherapy.

Mechanistic study of Liquiritigenin inhibiting bladder cancer cell proliferation and migration by regulating STING1

BACKGROUND

Bladder cancer (BLCA) is the most common malignant tumor in the urinary system, with a significantly higher incidence in men than in women, severely impacting quality of life. The STING1 gene (stimulator of interferon genes 1) plays a critical role in innate immunity by recognizing abnormal DNA and activating immune signaling pathways, promoting the expression of type I interferons and pro-inflammatory cytokines, thereby enhancing anti-tumor immune responses. Liquiritigenin (LQG), a flavonoid compound extracted from licorice, exhibits anti-inflammatory, antioxidant, and anti-cancer properties, capable of inhibiting tumor cell proliferation and invasion while regulating autophagy. This study aims to evaluate the role of LQG in regulating the STING1 gene and its anti-cancer mechanisms in bladder cancer.

METHODS

This study employed a multidimensional approach, combining bioinformatics analysis with both in vitro and in vivo experimental validation. Bioinformatics was utilized to assess the expression, function, and immune-related analyses of the STING1 gene. In vitro experiments included CCK-8 assays and colony formation assays to evaluate cell proliferation; Transwell migration assays and wound healing assays to assess migratory capacity; flow cytometry to analyze apoptosis; and immunofluorescence to observe the accumulation of autophagosomes. Additionally, molecular docking analysis was conducted to explore the interaction between LQG and the STING protein, while Western blotting was used to elucidate key molecular pathways. In vivo studies employed a mouse xenograft tumor model to systematically evaluate the anti-tumor effects and safety of LQG.

RESULTS

The results showed that STING1 expression was significantly lower in bladder cancer tissues compared to normal tissues. Functional enrichment analysis indicated a close relationship between STING1 and immune response regulation. High STING1 expression was positively associated with different types of immune cells and important immune checkpoints. Analysis of immunotherapy indicated that high STING1 expression was associated with favorable clinical responses. Molecular docking confirmed that LQG directly targets the STING protein. Experimental results demonstrated that LQG inhibits tumor cell survival by targeting STING and blocking autophagic flux. Additionally, LQG downregulated the expression of MMP2 and MMP9, inhibiting migration and invasion, while enhancing apoptosis by modulating Bcl-2, Bax, and caspase-3 levels.

CONCLUSION

These findings underscore the critical role of STING1 in the immunobiology of bladder cancer, indicating its potential as a therapeutic target and biomarker for immunotherapy. The novel STING agonist LQG has multiple anti-tumor effects, including the modulation of apoptosis, inhibition of invasion, and enhancement of immune responses. This paves the way for future STING-targeted therapies in bladder cancer treatment.

STING and metabolism-related diseases: Roles, mechanisms, and applications

The stimulator of interferon genes (STING) pathway plays a critical role in innate immunity, acting as a central mediator that links cytosolic DNA sensing to inflammatory signaling. STING not only responds to cellular metabolic states but also actively regulates key metabolic processes, including glycolysis, lipid metabolism, and redox balance. This bidirectional interaction underscores the existence of a dynamic feedback mechanism between STING signaling and metabolic pathways, which is essential for maintaining cellular homeostasis. This review provides a comprehensive analysis, beginning with an in-depth overview of the classical STING signaling pathway, followed by a detailed examination of its reciprocal regulation of various metabolic pathways. Additionally, it explores the role and mechanisms of STING signaling in metabolic disorders, including obesity, diabetes, and atherosclerosis. By integrating these insights into the mutual regulation between STING and its metabolism, novel therapeutic strategies targeting this pathway in metabolic diseases have been proposed.

Tumor microenvironment-driven resistance to immunotherapy in non-small cell lung cancer: strategies for Cold-to-Hot tumor transformation

Non-small cell lung cancer (NSCLC) represents a formidable challenge in oncology due to its molecular heterogeneity and the dynamic suppressive nature of its tumor microenvironment (TME). Despite the transformative impact of immune checkpoint inhibitors (ICIs) on cancer therapy, the majority of NSCLC patients experience resistance, necessitating novel approaches to overcome immune evasion. This review highlights shared and subtype-specific mechanisms of immune resistance within the TME, including metabolic reprogramming, immune cell dysfunction, and physical barriers. Beyond well-characterized components such as regulatory T cells, tumor-associated macrophages, and myeloid-derived suppressor cells, emerging players - neutrophil extracellular traps, tertiary lymphoid structures, and exosomal signaling networks - underscore the TME's complexity and adaptability. A multi-dimensional framework is proposed to transform cold, immune-excluded tumors into hot, immune-reactive ones. Key strategies include enhancing immune infiltration, modulating immunosuppressive networks, and activating dormant immune pathways. Cutting-edge technologies, such as single-cell sequencing, spatial transcriptomics, and nanomedicine, are identified as pivotal tools for decoding TME heterogeneity and personalizing therapeutic interventions. By bridging mechanistic insights with translational innovations, this review advocates for integrative approaches that combine ICIs with metabolic modulators, vascular normalizers, and emerging therapies such as STING agonists and tumor vaccines. The synergistic potential of these strategies is poised to overcome resistance and achieve durable antitumor immunity. Ultimately, this vision underscores the importance of interdisciplinary collaboration and real-time TME profiling in refining precision oncology for NSCLC, offering a blueprint for extending these advances to other malignancies.

USP28-Based Deubiquitinase-Targeting Chimeras for Cancer Treatment

Deubiquitinase-targeting chimeras (DUBTACs) are an emerging class of therapeutics that can stabilize tumor suppressors by hijacking a deubiquitinase (DUB), thereby offering a strategic pivot from conventional approaches to target tumor suppressors. However, only OTUB1 and USP7 have been harnessed for DUBTAC development to date. Here, we show for the first time that USP28 can be leveraged for developing DUBTACs. Utilizing a USP28 noncovalent ligand, we crafted USP28-recruiting DUBTACs that effectively stabilized the ΔF508-CFTR mutant protein, with comparable effectiveness to the previously reported OTUB1- and USP7-recruiting CFTR DUBTACs. Furthermore, we developed USP28-recruiting cGAS DUBTACs that effectively stabilized cGAS, elevated the cGAS-STING signaling pathway, and elicited an antiproliferative effect. We also developed first-in-class PPARγ DUBTACs to target cancer metabolism pathways. Our lead PPARγ DUBTACs effectively stabilized PPARγ and suppressed cancer cell proliferation, thus providing a new potential anticancer therapeutic approach. Hence, this work advances the targeted protein stabilization field.

An off-target effect of class A CpG-oligonucleotides on suppressing the cyclic GMP-AMP synthase signaling in fibroblastic reticular cells

Background

Class A CpG-oligonucleotides (ODNs), a Toll-like receptor 9 (TLR9) agonist, have been applied for treating inflammatory diseases and cancer in preclinical studies and clinical trials. A recent study has reported that class A ODNs can activate the Cyclic GMP-AMP synthase (cGAS) signaling to regulate the inflammatory response in human monocytes. However, it remains unknown whether class A ODNs can activate the cGAS pathways in other cell types, such as fibroblastic reticular cells (FRC), which play critical roles in modulating the immune environments during inflammatory diseases and cancer.

Methods

To understand the role of class A ODN in regulating the cGAS signaling in FRC, we treated mouse FRC and human fibroblast with class A ODN, a cGAS agonist (HT-DNA), and combined class A and HT-DNA.

Results

Unexpectedly, we found that class A ODNs suppress the cGAS level and downstream signaling in human and murine FRC. The class A ODN-induced suppression effect on cGAS is limited in FRC, but not other immune cell types, and is independent of TLR9. Performing pulldown assay and Mass spectrum, we found that class A ODNs regulate the cGAS level post translationally by interacting with cGAS and ZNF598, an E3 ubiquitin ligase.

Conclusion

Our data reveal an unrecognized off-target effect of class A ODN on suppressing the cGAS signaling in FRCs, which should be considered when designing class A ODN regimens for inflammatory diseases and cancer.

Oxaliplatin accelerates immunogenic cell death by activating the cGAS/STING/TBK1/IRF5 pathway in gastric cancer

Immunogenic cell death is a tumor cell death involving both innate and adaptive immune responses. Given the published findings that oxaliplatin causes the secretion of high mobility group box 1 (HMGB1) from cancer cells, which is necessary for the initiation of immunogenic cell death, we investigated whether oxaliplatin plays an anticancer role in gastric cancer by inducing immunogenic cell death and further explored its mechanism. We found that oxaliplatin inhibited viability and induced pyroptosis, immunogenic cell death, the production of reactive oxygen species, mitochondrial permeability transition pore (mPTP) opening, and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) axis activation in gastric cancer cells. Suppressing mPTP opening (cyclosporine treatment), depleting mitochondrial DNA (mtDNA; ethidium bromide treatment), or STING downregulation (H151 or si-STING treatment) reversed cGAS/STING pathway activation and the increased immunogenic cell death induced by oxaliplatin in MKN-45 and AGS cells. Moreover, oxaliplatin induced immunogenic cell death via activating the cGAS/STING/TANK-binding kinase 1 (TBK1; also known as serine/threonine-protein kinase TBK1)/interferon regulatory factor 5 (IRF5) pathway. In conclusion, oxaliplatin treatment could induce immunogenic cell death and mPTP opening and activate the cGAS/STING/TBK1/IRF5 pathway in gastric cancer cells.

TFEB and TFE3 regulate STING1-dependent immune responses by controlling type I interferon signaling

STING1 is an essential component of the innate immune defense against a wide variety of pathogens. Whereas induction of type I interferon (IFN) responses is one of the best-defined functions of STING1, our transcriptomic analysis revealed IFN-independent activities of STING1 in macrophages, including transcriptional upregulation of numerous lysosomal and autophagic genes. This upregulation was mediated by the STING1-induced activation of the transcription factors TFEB and TFE3, and led to increased autophagy, lysosomal biogenesis, and lysosomal acidification. TFEB and TFE3 also modulated IFN-dependent STING1 signaling by controlling IRF3 activation. IFN production and cell death were increased in TFEB- and TFE3-depleted iBMDMs. Conversely, TFEB overexpression led to reduced IRF3 activation and an almost complete inhibition of IFN synthesis and secretion, resulting in decreased CASP3 activation and increased cell survival. Our study reveals a key role of TFEB and TFE3 as regulators of STING1-mediated innate antiviral immunity.Abbreviation: ACOD1/IRG1, aconitate decarboxylase 1; cGAMP, cyclic guanosine monophosphate-adenosine monophosphate; CGAS, cyclic GMP-AMP synthase; DMXAA, 5,6-dimethylxanthenone-4-acetic acid; EIF4EBP1, eukaryotic translation initiation factor 4E binding protein 1; GABARAP, GABA type A receptor-associated protein; HSV-1, herpes simplex virus type; iBMDMs, immortalized bone marrow-derived macrophages; IFN, type I interferon; IFNB, interferon beta; IKBKE, inhibitor of nuclear factor kappa B kinase subunit epsilon; IRF3, interferon regulatory factor 3; LAMP1, lysosomal associated membrane protein 1; LAMP2, lysosomal associated membrane protein 2; MTORC1, mechanistic target of rapamycin kinase complex 1; RPS6, ribosomal protein S6; STING1, stimulator of interferon response cGAMP interactor 1; TBK1, TANK binding kinase 1; TFE3, transcription factor binding to IGHM enhancer 3; TFEB, transcription factor EB.

Excision repair cross complementation group 1 gene exon 3 skipping isoform presents selective cGAS-STING activation in platinum-sensitive lung adenocarcinoma

Platinum-based chemotherapy is widely used as a frontline therapy for lung adenocarcinoma, while its efficacy is limited by agent resistance and severe toxicity. Recently the immunotherapy represents an alternative or complement to Platinum-based chemotherapy. Interestingly, the sensitivity to platinum is known as a relevant phenotypical biomarker of valid immunotherapy due to the defects in DNA damage response (DDR) in cancer cells. The cGAS/STING pathway detects cytosolic DNA to activate innate immune response, which seems to become a bridge linking DDR and cancer immunogenicity. This study aimed to investigate the effect of ERCC1 splicing isoforms on the cGAS/STING pathway. Besides, the association of ERCC1 splicing isoforms with cGAS/STING signaling in cisplatin-treated cells was analyzed, and the modulation of PRPF8 on ERCC1 exon skipping splicing was elucidated by RNA immunoprecipitation. Finally, we also explored the potential role of an herbal extract β-elemene as chemosensitizer and activator of cGAS/STING signaling. We demonstrated that ERCC1 exon 3 inclusion was of equal importance to exon 8 and endowed ERCC1 with an elevated DNA repair activity, which was linked with cisplatin resistance and cGAS-STING suppression. Mechanistically, PRPF8 was identified to be directly interacted with modulating ERCC1 exon 3 skipping, while β-elemene was found to be involved in the activation of cGAS-STING signaling as an inhibitor of PRPF8. Our data reveal that the ERCC1 exon 3 skipping isoform is associated with DDR and the cGAS/STING innate immune pathway, which provide preclinical rationale for using alternative or complement immunotherapy in Platinum-sensitive NSCLC patients.

Ferroptosis as a key player in the pathogenesis and intervention therapy in liver injury: focusing on drug-induced hepatotoxicity

Globally, drug-induced hepatotoxicity or drug-induced liver injury (DILI) is a serious clinical concern. Knowing the processes and patterns of cell death is essential for finding new therapeutic targets since there are not many alternatives to therapy for severe liver lesions. Excessive lipid peroxidation is a hallmark of ferroptosis, an iron-reliant non-apoptotic cell death linked to various liver pathologies. When iron is pathogenic, concomitant inflammation may exacerbate iron-mediated liver injury, and the hepatocyte necrosis that results is a key element in the fibrogenic response. The idea that dysregulated metabolic pathways and compromised iron homeostasis contribute to the development of liver injury by ferroptosis is being supported by new data. Various ferroptosis-linked genes and pathways have been linked to liver injury, although the molecular processes behind ferroptosis's pathogenicity are not well known. Here, we delve into the features of ferroptosis, the processes governing ferroptosis, and our current knowledge of iron metabolism. We also provide an overview of ferroptosis's involvement in the pathophysiology of liver injury, particularly DILI. Lastly, the therapeutic possibilities of ferroptosis targeting for liver injury management have been provided. Natural products, nanoparticles (NPs), mesenchymal stem cell (MSC), and their exosomes have attracted increasing attention among such therapeutics.

Stimulator of Interferon Genes Agonist Synergistically Amplifies Programmed Cell Death Protein-1 Blockade and Radiation-Induced Systemic Antitumor Responses via Tumor Microenvironment Enrichment

PURPOSE

The effectiveness of immune checkpoint inhibitors in solid tumors is limited and heavily dependent on the tumor microenvironment (TME). Radiation therapy (RT) reshapes the TME, promoting T cell infiltration. We explored the combined antitumor effects of the stimulator of interferon genes (STING) agonist with low-dose RT and immunotherapy.

METHODS AND MATERIALS

Tumor cell lines (PRM-SCLC, MC38, and LL2) were treated with the STING agonist diABZI (0.001-10 µM) to assess cytotoxicity. The mRNA expression levels of chemokines and cytokines in tumor cells were quantitatively analyzed in conjunction with RT to assess immune activation. Flow cytometry assessed bone marrow-derived dendritic cell and macrophage maturation. Subcutaneous tumor-bearing mouse models (PRM-SCLC, MC38, LL2) were used to monitor tumor volume, body weight, and survival. Tumor samples were collected for flow cytometry, immunofluorescence, immunohistochemistry, and transcriptome sequencing. Bilateral tumor models assessed the abscopal effect, with tumor and tumor-draining lymph node samples collected.

RESULTS

The STING agonist diABZI did not directly inhibit tumor cell proliferation at tested concentrations. However, when combined with RT, diABZI significantly upregulated chemokines and IFN-β mRNA levels in tumor cells, while mitigating the RT-induced rise in TGF-β levels. In vitro, bone marrow-derived dendritic cells and macrophages treated with STING agonist + RT showed increased maturation. In tumor-bearing mice, the STING agonist enhanced the efficacy of RT, chemotherapy, and immunotherapy. Adding STING agonist to low-dose RT + αPD-1 activated tumor-infiltrating CD45+, CD8+, CD4+ T cells, natural killer cells, and dendritic cells, and promoted M1 macrophage polarization. Transcriptome analysis showed enhanced antigen presentation and T cell activation. In bilateral tumor models, triple therapy reduced both primary and distant tumor volumes, with increased T cell infiltration and a higher presence of TCF1+ PD-1+ TSL cells in tumor-draining lymph nodes.

CONCLUSIONS

STING agonist boosts immune activation and cell recruitment in the TME, enhancing immunotherapy response. It also amplifies the abscopal effect of RT, promoting systemic antitumor immunity with clinical translational potential.

Harnessing single-cell and multi-omics insights: STING pathway-based predictive signature for immunotherapy response in lung adenocarcinoma

Background

Lung adenocarcinoma is the most prevalent type of small-cell carcinoma, with a poor prognosis. For advanced-stage patients, the efficacy of immunotherapy is suboptimal. The STING signaling pathway plays a pivotal role in the immunotherapy of lung adenocarcinoma; therefore, further investigation into the relationship between the STING pathway and lung adenocarcinoma is warranted.

Methods

We conducted a comprehensive analysis integrating single-cell RNA sequencing (scRNA-seq) data with bulk transcriptomic profiles from public databases (GEO, TCGA). STING pathway-related genes were identified through Genecard database. Advanced bioinformatics analyses using R packages (Seurat, CellChat) revealed transcriptomic heterogeneity, intercellular communication networks, and immune landscape characteristics. We developed a STING pathway-related signature (STINGsig) using 101 machine learning frameworks. The functional significance of ERRFI1, a key component of STINGsig, was validated through mouse models and multicolor flow cytometry, particularly examining its role in enhancing antitumor immunity and potential synergy with α-PD1 therapy.

Results

Our single-cell analysis identified and characterized 15 distinct cell populations, including epithelial cells, macrophages, fibroblasts, T cells, B cells, and endothelial cells, each with unique marker gene profiles. STING pathway activity scoring revealed elevated activation in neutrophils, epithelial cells, B cells, and T cells, contrasting with lower activity in inflammatory macrophages. Cell-cell communication analysis demonstrated enhanced interaction networks in high-STING-score cells, particularly evident in fibroblasts and endothelial cells. The developed STINGsig showed robust prognostic value and revealed distinct immune microenvironment characteristics between risk groups. Notably, ERRFI1 knockdown experiments confirmed its significant role in modulating antitumor immunity and enhancing α-PD1 therapy response.

Conclusion

The STING-related pathway exhibited distinct expression levels across 15 cell populations, with high-score cells showing enhanced tumor-promoting pathways, active immune interactions, and enrichment in fibroblasts and IFI27+ inflammatory macrophages. In contrast, low-score cells were associated with epithelial phenotypes and reduced immune activity. We developed a robust STING pathway-related signature (STINGsig), which identified key prognostic genes and was linked to the immune microenvironment. Through in vivo experiments, we confirmed that knockdown of ERRFI1, a critical gene within the STINGsig, significantly enhances antitumor immunity and synergizes with α-PD1 therapy in a lung cancer model, underscoring its therapeutic potential in modulating immune responses.

cGAS-STING signaling in melanoma: regulation and therapeutic targeting

Melanocytes are the source of the skin cancer known as melanoma. It usually affects the viscera, mucous membranes, and skin. Even so, melanoma only makes for 7% of all skin cancer occurrences. By triggering the generation of type I interferons (IFN-I) and inflammatory cytokines upon identifying microbial DNA, the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway promotes anti-microbial innate immunity. A growing body of research indicates that antitumor immunity depends on the cGAS-STING axis being activated. The cGAS-STING-regulated downstream cytokines, particularly IFN-I, act as linkages between adaptive and innate immunity. As a result, an increasing amount of research has concentrated on the synthesis and screening of agonists of the STING pathway. As a result, an increasing amount of research has concentrated on the synthesis and screening of agonists of the STING pathway. The many implications of the cGAS-STING pathway in the pathophysiology and therapy of melanoma are thoroughly examined in this study. Our research highlights the significance of the cGAS-STING pathway in melanoma and identifies it as a key target for boosting immunity against tumors.

Cancer Cell-Intrinsic Type I Interferon Signaling Promotes Antitumor Immunity in Head and Neck Squamous Cell Carcinoma

Background: The cyclic GMP-AMP synthase (cGAS)-type I interferon (IFN-I) pathway detects cytoplasmic DNA and triggers immune responses. Cancer cells often suppress this pathway to evade immune surveillance; however, its therapeutic potential remains unclear. Methods: Mouse oral squamous cell carcinoma models, representing a prominent subtype of head and neck squamous cell carcinoma (HNSCC), were employed in this study. Flow cytometry, Western blot, ELISA, and PCR were used for analysis. Results: We found that immune-unresponsive MOC2 tumors exhibited a deficiency of antigen-presenting cells and cytotoxic T lymphocytes, along with a significant suppression of the cGAS-IFN-I pathway, compared to immune-responsive MOC1 tumors. An MOC2-conditioned medium impaired the differentiation of bone marrow-derived cells into dendritic cells (DCs), reducing the expression of DC markers as well as class I and II major histocompatibility complex (MHC) molecules. The activation of the cGAS-IFN-I pathway in MOC2 cells, either through exogenous DNA or direct IFN-I expression, enhanced class I MHC expression and antigen presentation on MOC2 cells. Furthermore, IFNB1 expression in MOC2 cells induced apoptosis and upregulated chemokines, such as CXCL9 and CXCL10, which recruit immune cells. In immunocompetent mice, IFNB1 expression suppressed MOC2 tumor growth by attracting DCs and T cells, an effect amplified by co-expressing the granulocyte-macrophage colony-stimulating factor. Conclusions: These findings highlight the potential of enhancing cancer cell-intrinsic cGAS-IFN-I signaling to improve tumor immune surveillance and control the progression of immune-cold HNSCC tumors.

Deubiquitinase-Targeting Chimeras (DUBTACs) as a Potential Paradigm-Shifting Drug Discovery Approach

Developing proteolysis-targeting chimeras (PROTACs) is well recognized through target protein degradation (TPD) toward promising therapeutics. While a variety of diseases are driven by aberrant ubiquitination and degradation of critical proteins with protective functions, target protein stabilization (TPS) rather than TPD is emerging as a unique therapeutic modality. Deubiquitinase-targeting chimeras (DUBTACs), a class of heterobifunctional protein stabilizers consisting of deubiquitinase (DUB) and protein-of-interest (POI) targeting ligands conjugated with a linker, can rescue such proteins from aberrant elimination. DUBTACs stabilize the levels of POIs in a DUB-dependent manner, removing ubiquitin from polyubiquitylated and degraded proteins. DUBTACs can induce a new interaction between POI and DUB by forming a POI-DUBTAC-DUB ternary complex. Herein, therapeutic benefits of TPS approaches for human diseases are introduced, and recent advances in developing DUBTACs are summarized. Relevant challenges, opportunities, and future perspectives are also discussed.

Biopolymer-based bone scaffold for controlled Pt (IV) prodrug release and synergistic photothermal-chemotherapy and immunotherapy in osteosarcoma

Achieving bone defect repair while preventing tumor recurrence after osteosarcoma surgery has consistently posed a clinical challenge. Local treatment with 3D-printed scaffolds loaded with chemotherapeutic drugs can exert certain effects in tumor inhibition and bone regeneration. However, the non-specific activation of chemotherapeutic drugs leads to high local toxic side effects and the formation of an immunosuppressive tumor microenvironment, thereby limiting their clinical application and therapeutic efficacy. To address this, we designed a Pt (IV) prodrug with low toxicity and minimal side effects, which releases Pt (II) in response to glutathione. This prodrug was grafted onto polydopamine (PDA) through an amidation reaction, resulting in a composite nanomaterial (PDA@Pt) that possesses both photothermal synergistic chemotherapy and immuno-oncological properties. Subsequently, we innovatively employed selective laser sintering technology to incorporate PDA@Pt into a poly (L-lactic acid)/bioactive glass matrix, successfully constructing a composite scaffold with dual anti-tumor and bone repair capabilities. The study revealed that the composite scaffold significantly inhibited the growth of osteosarcoma cells and activated the cGAS-STING pathway by inducing DNA damage, ultimately converting the 'cold tumor' into a 'hot tumor.' Additionally, the composite scaffold could induce osteogenic differentiation of bone marrow mesenchymal stem cells and exhibited excellent bone repair capabilities in vivo.

OAS cross-activates RNase L intercellularly through cell-to-cell transfer of 2-5A to spread innate immunity

The 2',5'-oligoadenylate synthetase (OAS)-RNase L pathway is a classical antiviral innate immune pathway. Upon sensing dsRNA, OAS produces 2',5'-oligoadenylate (2-5A) as a second messenger to activate RNase L. Whether 2-5A can be transported to extend the reach of innate immune signaling has not been established. Here, we showed that 2-5A was transferred from cell to cell through connexin (CX43/CX45) gap junctions. 2-5A was also transferred through importers and exporters, allowing OAS to remotely activate RNase L and protect neighboring cells from viral infection. We identified ABCC10 as a 2-5A exporter. Loss of ABCC10 had no effect on 2-5A production but reduced 2-5A export and protection of neighboring cells. Furthermore, OAShi tumors such as MC38 naturally produced 2-5A in vivo, which was secreted via ABCC10 to activate host-not tumor-RNase L-mediated antitumor response. Therefore, 2-5A is an immunotransmitter that mediates short-range communication between cells in infection and cancer.

Unveiling the crossroads of STING signaling pathway and metabolic reprogramming: the multifaceted role of the STING in the TME and new prospects in cancer therapies

The cGAS-STING signaling pathway serves as a critical link between DNA sensing and innate immunity, and has tremendous potential to improve anti-tumor immunity by generating type I interferons. However, STING agonists have shown decreasing biotherapeutic efficacy in clinical trials. Tumor metabolism, characterized by aberrant nutrient utilization and energy production, is a fundamental hallmark of tumorigenesis. And modulating metabolic pathways in tumor cells has been discovered as a therapeutic strategy for tumors. As research concerning STING progressed, emerging evidence highlights its role in metabolic reprogramming, independent its immune function, indicating metabolic targets as a strategy for STING activation in cancers. In this review, we delve into the interplay between STING and multiple metabolic pathways. We also synthesize current knowledge on the antitumor functions of STING, and the metabolic targets within the tumor microenvironment (TME) that could be exploited for STING activation. This review highlights the necessity for future research to dissect the complex metabolic interactions with STING in various cancer types, emphasizing the potential for personalized therapeutic strategies based on metabolic profiling.

The cGAS‒STING pathway in cancer immunity: mechanisms, challenges, and therapeutic implications

Innate immunity represents the body's first line of defense, effectively countering the invasion of external pathogens. Recent studies have highlighted the crucial role of innate immunity in antitumor defense, beyond its established function in protecting against external pathogen invasion. Enhancing innate immune signaling has emerged as a pivotal strategy in cancer therapy. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway is a key innate immune signal that activates the immune response and exerts antitumor effects; this is primarily attributed to the DNA receptor function of cGAS, which recognizes exogenous DNA to activate downstream STING signaling. This, in turn, promotes the activation of downstream targets such as IRF-3(Interferon Regulatory Factor 3) and NF-κB, leading to the secretion of type I interferons and proinflammatory cytokines, thereby increasing cellular immune activity. The activation of the cGAS-STING pathway may thus play a crucial role in enhancing anticancer immunity. In this paper, we reviewed the role of cGAS-STING signaling in anticancer immunity and its molecular mechanisms. Additionally, we briefly discuss the current applications of the cGAS-STING pathway in cancer immunity, summarize recent developments in STING agonists, and address the challenges facing the use of the cGAS-STING pathway in cancer therapy. Finally, we provide insights into the role of the cGAS‒STING pathway in cancer and propose new directions for cancer immunotherapy.

Albumin-targeted oxaliplatin(iv) prodrugs bearing STING agonists

The anticancer platinum complex oxaliplatin exerts its activity through DNA damage and immune-stimulatory mechanisms, but is associated with adverse treatment side effects. Platinum(iv) complexes represent a promising prodrug strategy to improve tolerability and to enhance antitumor efficacy via attachment of additional bioactive ligands or tumor-targeting moieties. In the present study, oxaliplatin(iv) complexes containing immune-stimulatory STING agonists SR-717 or MSA-2 were synthesized and their biological properties were studied. Whereas the Pt-SR-717 compound was fast reduced, Pt-MSA-2 complexes displayed significantly higher reductive stability reflected by low in vitro cytotoxicity. Although the platinum(iv) complexes activated interferon regulatory factor (IRF) and NF-κB signaling pathways less effectively compared to the free STING agonists, reducing conditions elevated cytotoxicity and STING downstream signaling, particularly for MSA-2-containing prodrugs. Rapid albumin binding of a maleimide-containing Pt-MSA-2 derivative resulted in elevated plasma levels, prolonged blood circulation, and enhanced tumor accumulation of platinum in CT-26 tumor-bearing mice. The Pt-MSA-2 complexes triggered immune activation and cytokine secretion without hematotoxicity usually associated with free oxaliplatin. The albumin-targeted Pt-MSA-2 drug significantly inhibited tumor growth after intravenous application, while the non-maleimide complex was effective only when applied peritumorally. However, the effects were not enhanced compared to mono-treatment with oxaliplatin or MSA-2, indicating a lack of synergism between the two simultaneously released agents. Our results demonstrate that oxaliplatin(iv) complexes represent a valuable strategy for enhanced tumor-targeting and adverse effect reduction, but question the simultaneous release of STING agonists and free oxaliplatin as a potent strategy towards synergistic antineoplastic activity.

Chromosomal Instability and Clonal Heterogeneity in Breast Cancer: From Mechanisms to Clinical Applications

BACKGROUND

Chromosomal instability (CIN) and clonal heterogeneity (CH) are fundamental hallmarks of breast cancer that drive tumor evolution, disease progression, and therapeutic resistance. Understanding the mechanisms underlying these phenomena is essential for improving cancer diagnosis, prognosis, and treatment strategies.

METHODS

In this review, we provide a comprehensive overview of the biological processes contributing to CIN and CH, highlighting their molecular determinants and clinical relevance.

RESULTS

We discuss the latest advances in detection methods, including single-cell sequencing and other high-resolution techniques, which have enhanced our ability to characterize intratumoral heterogeneity. Additionally, we explore how CIN and CH influence treatment responses, their potential as therapeutic targets, and their role in shaping the tumor immune microenvironment, which has implications for immunotherapy effectiveness.

CONCLUSIONS

By integrating recent findings, this review underscores the impact of CIN and CH on breast cancer progression and their translational implications for precision medicine.

DNA Nanostructures-Based In Situ Cancer Vaccines: Mechanisms and Applications

Current tumor vaccines suffer from inadequate immune responsive due to the insufficient release of tumor antigens, low tumor infiltration, and immunosuppressive microenvironment. DNA nanostructures with their ability to precisely engineer, controlled release, biocompatibility, and the capability to augment the immunogenicity of tumor microenvironment, have gained significant attention for their potential to revolutionize vaccine designing. This review summarizes various applications of DNA nanostructures in the construction of in situ cancer vaccines, which can generate tumor-associated antigens directly from damaged tumors for cancer immune-stimulation. The mechanisms and components of cancer vaccines are listed, the specific strategies for constructing in situ vaccines using DNA nanostructures are explored and their underlying mechanisms of action are elucidated. The immunogenic cell death (ICD) induced by chemotherapeutic agents, photothermal therapy (PTT), photodynamic therapy (PDT), and radiation therapy (RT) and the related cancer vaccines building strategies are systematically summarized. The applications of different DNA nanostructures in various cancer immunotherapy are elaborated, which exerts precise, long-lasting, and robust immune responses. The current challenges and future prospectives are proposed. This review provides a holistic understanding of the evolving role of DNA nanostructures for in situ vaccine development.

Regulation of the cGAS-STING Pathway

The cGAS-cGAMP-STING pathway is essential for immune defense against pathogens. Upon binding DNA, cGAS synthesizes cGAMP, which activates STING, leading to potent innate immune effector responses. However, lacking specific features to distinguish between self and nonself DNA, cGAS-STING immunity requires precise regulation to prevent aberrant activation. Several safeguard mechanisms acting on different levels have evolved to maintain tolerance to self DNA and ensure immune homeostasis under normal conditions. Disruption of these safeguards can lead to erroneous activation by self DNA, resulting in inflammatory conditions but also favorable antitumor immunity. Insights into structural and cellular checkpoints that control and terminate cGAS-STING signaling are essential for comprehending and manipulating DNA-triggered innate immunity in health and disease.

STING Activation in Various Cell Types in Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND

During the hepatic histological progression in metabolic dysfunction-associated steatotic liver disease (MASLD), the immunological mechanisms play a the pivotal role, especially when progressing to metabolic dysfunction-associated steatohepatitis (MASH). The discovery of the stimulator of interferon genes (STING) marked a significant advancement in understanding the immune system.

METHODS

We searched literature on STING involved in MASLD in PubMed to summarise the role of intrahepatic or extrahepatic STING signal pathways and the potential agonists or inhibitors of STING in MASLD.

RESULTS

Besides inflammation and type I interferon response induced by STING activation in the intrahepatic or extrahepatic immune cells, STING activation in hepatocytes leads to protein aggregates and lipid deposition. STING activation in hepatic macrophages inhibits autophagy in hepatocytes and promotes hepatic stellate cells (HSCs) activation. STING activation in HSCs promotes HSC activation and exacerbates liver sinusoidal endothelial cells (LSECs) impairment. However, it was also reported that STING activation in hepatic macrophages promotes lipophagy in hepatocytes and STING activation in HSCs leads to HSC senescence. STING activation in LSEC, inhibits angiogenesis. For extrahepatic tissue, STING signalling participates in the regulation of the intestinal permeability, intestinal microecology and insulin action in adipocytes, which were all involved in the pathogenesis of MASLD.

CONCLUSION

There're plenty of STING ligands in MASLD. How STING activation affects the intercellular conversation in MASLD deserves thorough investigation.

Pyrithione zinc alters mismatch repair to trigger tumor immunogenicity

Mismatch repair deficiency (dMMR) cancers are highly sensitive to immunotherapy, but only account for a small fraction of cancer patients. How to increase immunotherapy efficacy on MMR-proficient (pMMR) cancer is still a major challenge. This study demonstrates that pyrithione zinc (PYZ), an FDA-approved drug, can enhance tumor immunogenicity via altering MMR and activating STING signaling. Mechanistically, PYZ elevates levels of ROS, leading to the upregulation of HIF-1α and DNA damage, while also inhibiting the expression of DNA mismatch repair proteins MSH2 and MSH6, together promoting DNA damage accumulation. Therefore, the administration of PYZ results in the accumulation of DNA damage, leading to the activation of STING signaling, which enhances tumor immunogenicity. Knockout of Sting diminishes the activation of IFN-I signaling induced by PYZ and reduces tumor immunogenicity. Furthermore, in vivo administration of PYZ promotes the infiltration of CD8+ T cells into the tumor and inhibits tumor growth, an effect that is attenuated in Nude mice or mice with CD8+ T cell depletion or deficiency of Ifnar. Overall, our findings showed that pyrithione zinc could trigger tumor immunogenicity by downregulating MMR machinery and activating STING pathway in tumor cells, and provide a translational approach to improve immunotherapy on pMMR cancer.

A Hybrid Manganese Nanoparticle Simultaneously Eliminates Cancer Stem Cells and Activates STING Pathway to Potentiate Cancer Immunotherapy

Current immunotherapies such as immune checkpoint blockades (ICBs) have revolutionized oncotherapy regime; however, their responsiveness and efficiencies among patients with head and neck squamous cell carcinoma (HNSCC) remain quite limited. The existence of therapeutic-refractory cancer stem cells (CSCs) and inadequate activation of the cyclic guanosine monophosphate-adenosine monophosphate synthase/interferon gene stimulator (cGAS/STING) signaling pathway greatly contribute to immune evasion and immunotherapeutic resistance. Herein, we sought to develop a nanocomplex for HNSCC therapy by simultaneous CSCs eradication and STING activation. PTC209/MnO2@BSA (bovine serum albumin) nanoparticles (PMB NPs) synthesized via a facile and green process are reported, wherein the released manganese (Mn) ions under acidic tumor microenvironment significantly enhance cGAS-STING signals and facilitate the dendritic cells maturation to unleash the T-cell-mediated immune response. Meanwhile, PTC209 released from PMB NPs targets BMI1+ CSCs to suppress cancer stemness and epithelial-mesenchymal transition (EMT) and elicits apoptosis to further potentiate Mn-based metalloimmunotherapy. Both in vitro and in vivo experiments elucidate that PMB NPs function as designed, exerting powerful immunotherapeutic and chemotherapeutic impacts to impede HNSCC growth and metastasis as well as bolster anti-PD-1-based ICB. Collectively, our findings provide a promising therapeutic strategy against HNSCC by combinational CSCs elimination and STING activation via metalloimmunotherapy.

Engineering innate immune cells for cancer immunotherapy

Innate immune cells, including natural killer cells, macrophages and γδ T cells, are gaining prominence as promising candidates for cancer immunotherapy. Unlike conventional T cells, these cells possess attributes such as inherent antitumor activity, rapid immune responses, favorable safety profiles and the ability to target diverse malignancies without requiring prior antigen sensitization. In this Review, we examine the engineering strategies used to enhance their anticancer potential. We discuss challenges associated with each cell type and summarize insights from preclinical and clinical work. We propose strategies to address existing barriers, providing a perspective on the advancement of innate immune engineering as a powerful modality in anticancer treatment.

Enhanced cGAS-STING Activation and Immune Response by LPDAM Platform-Based Lapachone-Chemical-Photothermal Synergistic Therapy for Colorectal Cancer

The cGAS-STING signaling pathway is a pivotal immune response mechanism that bridges tumor and immune cell interactions. This study describes a multifunctional LPDAM nanoplatform integrating Lapachone, polydopamine (PDA), and Mn2+, which synergistically kills tumor cells and activates the cGAS-STING pathway, thereby inducing DC maturation and T cell activation to achieve potent antitumor immunity. In the tumor microenvironment, Lapachone generates H2O2 via the NAD(P)H:quinone oxidoreductase 1 (NQO1 enzyme), while Mn2+ catalyze H2O2 conversion into •OH through chemodynamic effects (CDT). The photothermal effects (PTT) of PDA further amplify this cascade reaction, producing reactive oxygen species (ROS) that damage tumor mitochondria and release mitochondrial DNA (mtDNA). The released mtDNA activates the cGAS-STING pathway, while Mn2+ enhances the sensitivity of cGAS to mtDNA, leading to robust antitumor immunity. Concurrently, photothermal-induced immunogenic cell death (ICD) promotes dendritic cells (DCs) maturation, further strengthening immune responses. Moreover, Mn2⁺ also serves as a contrast agent for T1-weighted magnetic resonance imaging (MRI), offering precise tumor visualization. This study demonstrates that the LPDAM nanoplatform facilitates Lapachone/CDT/PTT synergistic therapy under MRI guidance, showcasing its potential as an innovative strategy for combined immunotherapy in clinical oncology.

The Proimmunomodulatory and Anti-immunomodulatory Effects of Radiotherapy in Oncologic Care

The abscopal effect in radiotherapy (RT) refers to the phenomenon where localized radiation treatment causes regression of distant, nonirradiated tumors. Although rare, recent research shows that combining radiation with immunotherapies, such as immune checkpoint inhibitors, can enhance this effect. The interaction between radiation-induced cell death, immune responses, and the tumor microenvironment manifests in competing biologic mechanisms resulting in complex immunologic outcomes. In order to maximize the therapeutic advantages of the immunogenic effect of RT in the future, further studies are needed to fully understand its biologic underpinnings.

Dendritic cell maturation in cancer

Dendritic cells (DCs) are specialized antigen-presenting cells that are present at low abundance in the circulation and tissues; they serve as crucial immune sentinels by continually sampling their environment, migrating to secondary lymphoid organs and shaping adaptive immune responses through antigen presentation. Owing to their ability to orchestrate tolerogenic or immunogenic responses to a specific antigen, DCs have a pivotal role in antitumour immunity and the response to immune checkpoint blockade and other immunotherapeutic approaches. The multifaceted functions of DCs are acquired through a complex, multistage process called maturation. Although the role of inflammatory triggers in driving DC maturation was established decades ago, less is known about DC maturation in non-inflammatory contexts, such as during homeostasis and in cancer. The advent of single-cell technologies has enabled an unbiased, high-dimensional characterization of various DC states, including mature DCs. This approach has clarified the molecular programmes associated with DC maturation and also revealed how cancers exploit these pathways to subvert immune surveillance. In this Review, we discuss the mechanisms by which cancer disrupts DC maturation and highlight emerging therapeutic opportunities to modulate DC states. These insights could inform the development of DC-centric immunotherapies, expanding the arsenal of strategies to enhance antitumour immunity.

Dual-modality immune nano-activator harnessing Mn2⁺ and quercetin to potentiate the cGAS-STING pathway for advanced cancer metalloimmunotherapy

Manganese ions (Mn2+) have emerged as promising activators of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. However, their clinical application was hindered by low bioavailability and limited immune activation pathways, which impaired their ability to trigger robust immune responses and achieve significant antitumor effects. To address these challenges, we developed a dual-modality immune nano-activator by coordinating manganese ions with quercetin. This strategy was designed to enhance the cGAS-STING pathway activation and elicit the immunogenic cell death, thereby strengthening the antitumor immune response. The engineered nano-activator demonstrated superior tumor-targeting ability and efficient cellular internalization. Upon exposure to near-infrared irradiation, the system harnessed photothermal effects to induce apoptosis in tumor cells while simultaneously accelerating the release of manganese ions and quercetin. The released manganese ions facilitated the generation of reactive oxygen species, which in conjunction with quercetin-induced apoptosis, amplified photothermal-induced DNA damage. This DNA damage further promoted the release of cytosolic DNA, which in turn activated the cGAS-STING pathway, thereby intensifying immune activation. Notably, the nano-activator also triggered immunogenic cell death, which synergized with the cGAS-STING activation to promote dendritic cell maturation and activate antigen-specific T-cell, significantly enhancing the immune response against the tumor. Both in vitro and in vivo studies confirmed that this nano-activator effectively inhibited tumor growth, with particularly pronounced effects when combined with anti-CTLA-4 antibodies.

Orally Bioavailable and Site-Selective Covalent STING Inhibitor Derived from a Macrocyclic Marine Diterpenoid

Pharmacological inhibition of the cGAS-STING-controlled innate immune pathway is an emerging therapeutic strategy for a myriad of inflammatory diseases. Here, we report GHN105 as an orally bioavailable covalent STING inhibitor. Late-stage diversification of the briarane-type diterpenoid excavatolide B allowed the installation of solubility-enhancing functional groups while enhancing its activity as a covalent STING inhibitor against multiple human STING variants, including the S154 variant responsible for a genetic autoimmune disease. Selectively engaging the membrane-proximal Cys91 residue of STING, GHN105 dose-dependently inhibited cGAS-STING signaling and type I interferon responses in cells and in vivo. Moreover, orally administered GHN105 exhibited on-target engagement in vivo and markedly reversed key pathological features in a delayed treatment of the acute colitis mouse model. Our study provided proof of concept that the synthetic briarane analog GHN105 serves as a safe, site-selective, and orally active covalent STING inhibitor and devises a regimen that allows long-term systemic administration.

Reprogramming the Tolerogenic Immune Response Against Pancreatic Cancer Metastases by Lipid Nanoparticles Delivering a STING Agonist Plus Mutant KRAS mRNA

We demonstrate reprogramming of the tolerogenic immune environment in the liver for mounting an effective immune response against often-fatal pancreatic cancer metastases. This was achieved by engineering a lipid nanoparticle (LNP) to deliver mRNA encoding the KRAS G12D neoantigenic epitope along with cGAMP, a dinucleotide agonist of the stimulator of the interferon genes (STING) pathway, capable of activating a type I interferon response. cGAMP/mKRAS/LNP were synthesized by a microfluidics approach involving nanoprecipitation of mRNA and cGAMP by an ionizable lipid, MC3. Controls included nanoparticles delivering individual components or a wild-type RAS sequence. The dual delivery carrier successfully activated the type I interferon pathway in vitro as well as in vivo, with reprogramming of costimulatory receptor (CD80 and CD86) and MHC-I expression on liver antigen-presenting cells (APC). This allowed the generation of IFN-γ producing cytotoxic T cells, capable of mounting an effective immune response in the metastatic KRAS pancreatic cancer (KPC) mouse model. Noteworthy, intravenous injection of cGAMP/mKRAS/LNP suppressed metastatic growth significantly and prolonged animal survival, both prophylactically and during treatment of established metastases. The protective immune response was mediated by the generation of perforin-releasing CD8+ cytotoxic T cells, engaged in pancreatic cancer cell killing. Importantly, the immune response could also be adoptively transferred by injecting splenocytes (containing memory T cells) from treated into nontreated recipient mice. This study demonstrates that reprogramming the immune-protective niche for metastatic pancreatic cancer can be achieved by the delivery of a STING agonist and mutant KRAS mRNA via ionizable LNPs, offering both prophylactic and therapeutic advantages.

Targeting tumor monocyte-intrinsic PD-L1 by rewiring STING signaling and enhancing STING agonist therapy

STING is an important DNA sensing machinery in initiating immune response, yet therapies targeting STING have shown poor outcomes in clinical trials. Here, we reveal that STING signaling induces PD-L1hi tumor monocytes (Tu.Mons) that dominate the resistance against STING agonist therapy. Cell-intrinsic PD-L1, induced by the STING-IRF3-IFN-I axis, is identified as the driving factor for protumoral PD-L1hi Tu.Mons. Notably, TLR2-activated Tu.Mons resist STING-induced upregulation of cell-intrinsic PD-L1 and the associated protumoral functions. Mechanistically, TLR2 stimulation remodels STING signaling by facilitating STING and TRAF6 interaction, which suppresses the IRF3-IFN-I response and enhances NF-κB activation. Moreover, we demonstrate that combining STING agonists with TLR2 agonist pretreatment significantly improves antitumor efficacy in murine syngeneic and humanized models. Our findings uncover a protumoral aspect of STING activation mediated by cell-intrinsic PD-L1 and propose a promising strategy to boost antitumor immunity by fine-tuning STING signaling outputs.

Supramolecular polyrotaxane-based nano-theranostics enable cancer-cell stiffening for enhanced T-cell-mediated anticancer immunotherapy

Despite the tremendous therapeutic promise of activating stimulators of interferon genes (STING) enable to prime robust de novo T-cell responses, biomechanics-mediated immune inhibitory pathways hinder the cytotoxicity of T cells against tumor cells. Blocking cancer cell biomechanics-mediated evasion provides a feasible strategy for augmenting STING activation-mediated anti-tumor therapeutic efficacy. Here, we fabricate a redox-responsive Methyl-β-cyclodextrin (MeβCD)-based supramolecular polyrotaxanes (MSPs), where the amphiphilic diselenide-bridged axle polymer loads MeβCD by the host-guest interaction and end-caping with two near-infrared (NIR) fluorescence probes IR783. The MSPs self-assemble with STING agonists diABZIs into nanoparticles (RDPNs@diABZIs), which enable simultaneous release of MeβCD and diABZIs in the redox tumor microenvironment. After the released diABZIs activate STING on antigen-presenting cells (APCs), de novo T-cell responses are initiated. Meanwhile, the released MeβCD depletes membrane cholesterol to overcome cancer-cell mechanical softness, which enhances the CTL-mediated killing of cancer cells. In the female tumor-bearing mouse model, we demonstrate that RDPNs@diABZIs lead to effective tumor regression and generate long-term immunological memory. Furthermore, RDPNs@diABZIs can achieve significant tumor eradication, with these mice remaining survival for at least 2 months.