STING agonist loaded lipid nanoparticles overcome anti-PD-1 resistance in melanoma lung metastasis via NK cell activation

Trends in the immunotherapy for glioblastoma: A two-decade bibliometric analysis

Glioblastoma is a life-threatening primary malignant brain tumor with an unfavorable prognosis. Contributing factors to its poor outcome include tumor heterogeneity, low mutational burden, and immunosuppression within the tumor microenvironment. Recognizing these challenges, immunotherapeutic strategies have emerged as a promising avenue for glioblastoma treatment. Although several dynamic research and scientific trend have increasingly taken pace in the immunotherapeutic approaches to glioblastoma, systematic bibliometric studies on such trends are few. On this note, this study explores a bibliometric analysis of the research hotspots and trends in glioblastoma immunotherapy. We conducted a search in the Web of Science Core Collection database for articles on glioblastoma immunotherapy published between 2004 and 2024. Using VOSviewer and CiteSpace software, we analyzed collected articles to explore aspects such as country of origin, journal of publication, affiliated institute, authorship, keywords, and citation patterns. As of May 1, 2024, we retrieved 3,729 papers on Glioblastoma Immunotherapy. In the field of glioblastoma immunotherapy, the United States stands out as the leading contributor, with 1,708 publications and a substantial 90,590 citations. Following closely, China has made significant contributions through 926 publications, earning 17,533 citations, while Germany adds to the body of knowledge with 349 publications and 16,355 citations. Furthermore, Authoritative journals in this field include Clinical Cancer Research and Neuro-Oncology. The top five keywords during this period were temozolomide, radiotherapy, dendritic cell, cytotoxic T lymphocyte, and vaccination. Moreover, Hotspots in the field include immune checkpoint inhibitors and chimeric antigen receptor T cell therapy.

Selective vascular disrupting therapy by lipid nanoparticle-mediated Fas ligand silencing and stimulation of STING

Although recent therapeutic developments have greatly improved the outcomes of patients with cancer, it remains on ongoing problem, particularly in relation to acquired drug resistance. Vascular disrupting agents (VDAs) directly damage tumor blood vessels, thus promoting drug efficacy and reducing the development of drug resistance; however, their low molecular weight and resulting lack of selectivity for tumor endothelial cells (TECs) lead to side effects that can hinder their practical use. Here, we report a novel tumor vascular disrupting therapy using nucleic acid-loaded lipid nanoparticles (LNPs). We prepared two LNPs: a small interfering RNA (siRNA) against Fas ligand (FasL)-loaded cyclic RGD modified LNP (cRGD-LNP) to knock down FasL in TECs and a stimulator of interferon genes (STING) agonist-loaded LNP to induce systemic type I interferon (IFN) production. The combination therapy disrupted the tumor vasculature and induced broad tumor cell apoptosis within 48 h, leading to rapid and strong therapeutic effects in various tumor models. T cells were not involved in these antitumor effects. Furthermore, the combination therapy demonstrated a significantly superior therapeutic efficacy compared with conventional anti-angiogenic agents and VDAs. RNA sequencing analysis suggested that reduced collagen levels may have been responsible for TEC apoptosis. These findings demonstrated a potential therapeutic method for targeting the tumor vasculature, which may contribute to the development of a new class of anti-cancer drugs.

A stimuli-responsive immunostimulant to activate chemo-immunotherapeutic effects by inducing DNA damage and STING activation

The integration of chemotherapy with systemic immune activation represents a promising approach to eradicate metastatic tumors. In this study, a stimuli-responsive immunostimulant nanoplatform (denoted as MV@Lip) was developed to synergistically activate antitumor immunity via chemotherapy-induced DNA damage and subsequent activation of the stimulator of interferon genes (STING) signaling pathway. The MV@Lip system encapsulates the chemotherapeutic agent mitoxantrone (Mit) and the STING agonist vadimezan (Vad) within a redox-responsive liposomal carrier. MV@Lip was indicated to enhance drug stability, while simultaneously promoting efficient co-delivery of both agents into tumor cells and suppressing tumor proliferation. Mechanistically, MV@Lip exerts its therapeutic efficacy through inducing DNA damage and triggering immunogenic cell death (ICD) to enhance tumor immunogenicity by releasing damage-associated molecular patterns (DAMPs). Concurrently, the released Vadimezan could activate the STING pathway, amplifying innate immune responses through the production of proinflammatory factors and the recruitment of immune effector cells. This concerted action facilitates the infiltration and activation of natural killer (NK) cells and T lymphocytes in the tumor microenvironment, ultimately leading to the suppression of both primary and metastatic tumors. These findings provide a compelling basis for advancing chemotherapeutic combinations as immune-stimulating strategies in the treatment of metastatic malignancies.

Tumor-associated macrophages remodel the suppressive tumor immune microenvironment and targeted therapy for immunotherapy

Despite the significant advances in the development of immune checkpoint inhibitors (ICI), primary and acquired ICI resistance remains the primary impediment to effective cancer immunotherapy. Residing in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play a pivotal role in tumor progression by regulating diverse signaling pathways. Notably, accumulating evidence has confirmed that TAMs interplay with various cellular components within the TME directly or indirectly to maintain the dynamic balance of the M1/M2 ratio and shape an immunosuppressive TME, consequently conferring immune evasion and immunotherapy tolerance. Detailed investigation of the communication network around TAMs could provide potential molecular targets and optimize ICI therapies. In this review, we systematically summarize the latest advances in understanding the origin and functional plasticity of TAMs, with a focus on the key signaling pathways driving macrophage polarization and the diverse stimuli that regulate this dynamic process. Moreover, we elaborate on the intricate interplay between TAMs and other cellular constituents within the TME, that is driving tumor initiation, progression and immune evasion, exploring novel targets for cancer immunotherapy. We further discuss current challenges and future research directions, emphasizing the need to decode TAM-TME interactions and translate preclinical findings into clinical breakthroughs. In conclusion, while TAM-targeted therapies hold significant promise for enhancing immunotherapy outcomes, addressing key challenges-such as TAM heterogeneity, context-dependent plasticity, and therapeutic resistance-remains critical to achieving optimal clinical efficacy.

Tumor-specific surface marker-independent targeting of tumors through nanotechnology and bioorthogonal glycochemistry

Biological targeting is crucial for effective cancer treatment with reduced toxicity but is limited by the availability of tumor surface markers. To overcome this, we developed a nanoparticle-based (NP-based), tumor-specific surface marker-independent (TRACER) targeting approach. Utilizing the unique biodistribution properties of NPs, we encapsulated Ac4ManNAz (Maz) to selectively label tumors with azide-reactive groups. Surprisingly, while NP-delivered Maz was cleared by the liver, it did not label macrophages, potentially reducing off-target effects. To exploit this tumor-specific labeling, we functionalized anti-4-1BB Abs with dibenzocyclooctyne to target azide-labeled tumor cells and activate the immune response. In syngeneic B16F10 melanoma and orthotopic 4T1 breast cancer models, TRACER enhanced the therapeutic efficacy of anti-4-1BB, increasing the median survival time. Immunofluorescence analyses revealed increased tumor infiltration of CD8+ T and NK cells with TRACER. Importantly, TRACER reduced the hepatotoxicity associated with anti-4-1BB, resulting in normal serum ALT and AST levels and decreased CD8+ T cell infiltration into the liver. Quantitative analysis confirmed a 4.5-fold higher tumor-to-liver ratio of anti-4-1BB accumulation with TRACER compared with conventional anti-4-1BB Abs. Our work provides a promising approach for developing targeted cancer therapies that circumvent limitations imposed by the paucity of tumor-specific markers, potentially improving efficacy and reducing off-target effects to overcome the liver toxicity associated with anti-4-1BB.

STING Agonists and How to Reach Their Full Potential in Cancer Immunotherapy

As cancer continues to rank among the leading causes of death, the demand for novel treatments has never been higher. Immunotherapy shows promise, yet many solid tumors such as pancreatic cancer or glioblastoma remain resistant. In these, the "cold" tumor microenvironment with low immune cell infiltration and inactive anti-tumoral immune cells leads to increased tumor resistance to these drugs. This resistance has driven the development of several drug candidates, including stimulators of interferon genes (STING) agonists to reprogram the immune system to fight off tumors. Preclinical studies demonstrated that STING agonists can trigger the cancer immunity cycle and increase type I interferon secretion and T cell activation, which subsequently induces tumor regression. Despite promising preclinical data, biological and physical challenges persist in translating the success of STING agonists into clinical trials. Nonetheless, novel combination strategies are emerging, investigating the combination of these agonists with other immunotherapies, presenting encouraging preclinical results. This review will examine these potential combination strategies for STING agonists and assess the benefits and challenges of employing them in cancer immunotherapy.

Exosomes as key mediators in immune and cancer cell interactions: insights in melanoma progression and therapy

Exosomes (30-150 nm) are small extracellular vesicles that are secreted by cells into the extracellular environment and are known to mediate cell-to-cell communication. Exosomes contain proteins, lipids, and RNA molecules in relative abundance, capable of modifying the activity of target cells. Melanoma-derived exosomes (MEXs) promote the transfer of oncogenic signals and immunosuppressive factors into immune cells, resulting in a bias of the immune response towards tumor-promoting processes. MEXs could suppress the activation and proliferation of T cells and dendritic cells and induce differentiation of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). They can induce apoptosis of antigen-specific CD8 + T cells and promote the transfer of tumor antigens, resulting in immune evasion. Specifically, MEXs can shuttle cytokines like interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) to immune cells or express programmed death-ligand 1 (PD-L1 or CD274), creating an immune-suppressive microenvironment that promotes tumorigenesis. Since exosomes preferentially accumulate in melanoma tissues, this targeted delivery could enhance the bioavailability of treatments while limiting side effects. Here, we review the molecular composition of melanoma-derived exosomes, their mechanisms of action, and their potential as therapeutic targets or biomarkers in melanoma. The summarizations of these mechanisms to appropriately influence exosome-mediated interactions could yield new tactics to elicit anti-melanoma immunity or augment the therapeutic effects of current therapies.

Intratumoral IL12 mRNA administration activates innate and adaptive pathways in checkpoint inhibitor resistant tumors resulting in complete responses

Despite the proven clinical activity of checkpoint inhibitors (ICIs) in several cancer indications, frequent occurrence of primary and secondary resistance reduces their overall effectiveness. Development of ICI resistance has been attributed mainly to genetic or epigenic alterations that affect the tumor antigen presentation machinery leading to diminished anti-tumor immune responses. There is an urgent need for new approaches which can either re-sensitize resistant tumors to the ICIs or engage alternate immune pathways to inhibit tumors. Intratumoral delivery of nanoparticle encapsulated murine IL-12 (mIL-12) mRNA induces powerful anti-tumor immune responses in murine tumor models and the human version of this drug results in objective responses in patients with advanced disease. Here, we tested the efficacy of mIL12 mRNA as a single agent and in combination with anti-PD-L1 antibodies in ICI sensitive Yummer1.7 melanoma and MC38 colorectal murine tumors and in ICI resistant, β2-microglobulin (B2M) knockout versions of these models. mIL12 mRNA monotherapy was sufficient to cause complete responses (CRs) in ≥ 60% of both ICI sensitive or resistant Yummer1.7 melanoma and MC38 colorectal carcinoma tumors. The mIL12 mRNA treatment resulted in potent upregulation of TH1 type cytokines and chemokines. A reduction in number of Tregs, increase in numbers and activation state of both cytotoxic T cells (CTLs) as well as tumor associated macrophages (TAMs) was observed indicating enhanced anti-tumor, cell-based immune responses in the tumor microenvironment. This mIL-12 induced concerted immune activation was associated with a robust killing and phagocytosis of tumor cells resulting in durable CRs. These observations suggest that intratumoral IL12mRNA therapy may benefit patients with ICI resistant cancers.

The impact of metabolic reprogramming on tertiary lymphoid structure formation: enhancing cancer immunotherapy

BACKGROUND

Cancer immunotherapy has achieved unprecedented success in the field of cancer therapy. However, its potential is constrained by a low therapeutic response rate.

MAIN BODY

Tertiary lymphoid structure (TLS) plays a crucial role in antitumor immunity and is associated with a good prognosis. Metabolic reprogramming, as a hallmark of the tumor microenvironment, can influence tumor immunity and promote the formation of follicular helper T cells and germinal centers. However, many current studies focus on the correlation between metabolism and TLS formation factors, and there is insufficient direct evidence to suggest that metabolism drives TLS formation. This review provided a comprehensive summary of the relationship between metabolism and TLS formation, highlighting glucose metabolism, lipid metabolism, amino acid metabolism, and vitamin metabolism.

CONCLUSIONS

In the future, an in-depth exploration of how metabolism affects cell interactions and the role of microorganisms in TLS will significantly advance our understanding of metabolism-enhanced antitumor immunity.

Combating cancer immunotherapy resistance: a nano-medicine perspective

Cancer immunotherapy offers renewed hope for treating this disease. However, cancer cells possess inherent mechanisms that enable them to circumvent each stage of the immune cycle, thereby evading anti-cancer immunity and leading to resistance. Various functionalized nanoparticles (NPs), modified with cationic lipids, pH-sensitive compounds, or photosensitizers, exhibit unique physicochemical properties that facilitate the targeted delivery of therapeutic agents to cancer cells or the tumor microenvironment (TME). These NPs are engineered to modify immune activity. The crucial signal transduction pathways and mechanisms by which functionalized NPs counteract immunotherapy resistance are outlined, including enhancing antigen presentation, boosting the activation and infiltration of tumor-specific immune cells, inducing immunogenic cell death, and counteracting immunosuppressive conditions in the TME. Additionally, this review summarizes current clinical trials involving NP-based immunotherapy. Ultimately, it highlights the potential of nanotechnology to advance cancer immunotherapy.

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.

Treatment of lung diseases via nanoparticles and nanorobots: Are these viable alternatives to overcome current treatments?

Challenges

Respiratory diseases remain challenging to treat, with current efforts primarily focused on managing symptoms rather than maintaining overall lung health. Traditional treatment methods, such as oral or parenteral administration of antiviral, antibacterial, and anti-inflammatory drugs, face limitations. These include difficulty in delivering therapeutic agents to pathogens residing deep in the airways and the risk of severe side effects due to high systemic drug concentrations. The growing threat of drug-resistant pathogens further complicates infection management.

Advancements

The lung's large surface area offers an attractive target for inhalation-based drug delivery. Nanoparticles (NP) enable uniform and sustained drug distribution across the alveolar network, overcoming challenges posed by complex lung anatomy. Recent breakthroughs in nanorobots (NR) have demonstrated precise navigation through biological environments, delivering therapies directly to affected lung areas with enhanced accuracy. Nanotechnology has also shown promise in treating lung cancer, with nanoparticles engineered to overcome biological barriers, improve drug solubility, and enable controlled drug release.

Future scope

This review explores the progress of NP and NR in addressing challenges in pulmonary drug delivery. These innovations allow targeted delivery of nucleic acids, drugs, or peptides to the pulmonary epithelium with unprecedented accuracy, offering significant potential for improving therapeutic effectiveness in respiratory disorders.

Design, Synthesis, and Biological Assessment of Novel Aminobenzidazole Agonists Targeting the Stimulator of Interferon Genes (STING) Receptor Signaling Pathway for Oncology Immunotherapy

The activation of the STING-mediated signaling pathway leads to the secretion of type I interferon (IFN) and the activation of tumor-specific T cells. STING, a pattern recognition receptor located on the endoplasmic reticulum membrane of immune cells, binds with endogenous cyclic dinucleotides. STING undergoes phosphorylation, triggering the STING-TBK1-IRF3 pathway and NF-κB pathway, resulting in the release of IFN-β and other pro-inflammatory cytokines, ultimately enhancing the activation of tumor-specific T cells. This mechanism serves to complement the limitations of immune checkpoint inhibitors and enhances the efficiency of the immune response. This study selected benzimidazole compounds GSK and SR-717, which exhibit promising potential as patented medicines, as our lead compounds. Aiming to address the challenges associated with the short half-life of benzimidazole compounds and the limited molecular activity of SR-717, we designed and synthesized a series of STING agonists (compounds 6~29). The compound 17 showed excellent agonistic activity on hSTING protein in vitro. The cytotoxicity tests of all the synthesized compounds were performed in vitro. Performed in vivo pharmacokinetic studies on the most promising compounds and conducted molecular docking analyses.

Progress Update on STING Agonists as Vaccine Adjuvants

Low antigen immunogenicity poses a significant challenge in vaccine development, often leading to inadequate immune responses and reduced vaccine efficacy. Therefore, the discovery of potent immune-enhancing adjuvants is crucial. STING (stimulator of interferon genes) agonists are a promising class of adjuvants which have been identified in various immune cells and are activated in response to DNA fragments, triggering a broad range of type-I interferon-dependent immune responses. Integrating STING agonists with vaccine components is an ideal strategy to bolster vaccine-induced immunity to infections and cancer cells. Several STING agonists are currently under investigation in preclinical studies and clinical trials; however, some have shown limited efficacy, while others exhibit off-target effects. To ensure safety, they are typically delivered with carriers that exhibit high biocompatibility and insolubility. In this review, we present the latest research on natural and synthetic STING agonists that have been effectively used in vaccine development, and summarize their application in adjuvant preventive and therapeutic vaccines. Additionally, we discuss the safety of STING agonists as vaccine adjuvants by reviewing potential delivery strategies. Overall, incorporating STING agonists into vaccine formulations represents a significant advancement in vaccine research with the potential to significantly enhance immune responses and improve vaccine efficacy. However, ongoing research is still required to identify the most effective and safe delivery strategies for STING agonists, as well as to evaluate their long-term safety and efficacy in clinical trials.

Targeting cGAS-STING pathway for reprogramming tumor-associated macrophages to enhance anti-tumor immunotherapy

The cyclic GMP-AMP synthase (cGAS)-stimulator interferon genes (STING) signaling pathway plays a crucial role in activating innate and specific immunity in anti-tumor immunotherapy. As the major infiltrating cells in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) could be polarized into either anti-tumor M1 or pro-tumor M2 types based on various stimuli. Accordingly, targeted reprogramming TAMs to restore immune balance shows promise as an effective anti-tumor strategy. In this review, we aim to target cGAS-STING pathway for reprogramming TAMs to enhance anti-tumor immunotherapy. We investigated the double-edged sword effects of cGAS-STING in regulating TME. The regulative roles of cGAS-STING pathway in TAMs and its impact on the TME were further revealed. More importantly, several strategies of targeting cGAS-STING for reprogramming TAMs were designed for enhancing anti-tumor immunotherapy. Taken together, targeting cGAS-STING pathway for reprogramming TAMs in TME might be a promising strategy to enhance anti-tumor immunotherapy.

STING in cancer immunoediting: Modeling tumor-immune dynamics throughout cancer development

Cancer immunoediting is a dynamic process of tumor-immune system interaction that plays a critical role in cancer development and progression. Recent studies have highlighted the importance of innate signaling pathways possessed by both cancer cells and immune cells in this process. The STING molecule, a pivotal innate immune signaling molecule, mediates DNA-triggered immune responses in both cancer cells and immune cells, modulating the anti-tumor immune response and shaping the efficacy of immunotherapy. Emerging evidence has shown that the activation of STING signaling has dual opposing effects in cancer progression, simultaneously provoking and restricting anti-tumor immunity, and participating in every phase of cancer immunoediting, including immune elimination, equilibrium, and escape. In this review, we elucidate the roles of STING in the process of cancer immunoediting and discuss the dichotomous effects of STING agonists in the cancer immunotherapy response or resistance. A profound understanding of the sophisticated roles of STING signaling pathway in cancer immunoediting would potentially inspire the development of novel cancer therapeutic approaches and overcome the undesirable protumor effects of STING activation.

Central nervous system and immune cells interactions in cancer: unveiling new therapeutic avenues

Cancer remains a leading cause of mortality worldwide. Despite significant advancements in cancer research, our understanding of its complex developmental pathways remains inadequate. Recent research has clarified the intricate relationship between the central nervous system (CNS) and cancer, particularly how the CNS influences tumor growth and metastasis via regulating immune cell activity. The interactions between the central nervous system and immune cells regulate the tumor microenvironment via various signaling pathways, cytokines, neuropeptides, and neurotransmitters, while also incorporating processes that alter the tumor immunological landscape. Furthermore, therapeutic strategies targeting neuro-immune cell interactions, such as immune checkpoint inhibitors, alongside advanced technologies like brain-computer interfaces and nanodelivery systems, exhibit promise in improving treatment efficacy. This complex bidirectional regulatory network significantly affects tumor development, metastasis, patient immune status, and therapy responses. Therefore, understanding the mechanisms regulating CNS-immune cell interactions is crucial for developing innovative therapeutic strategies. This work consolidates advancements in CNS-immune cell interactions, evaluates their potential in cancer treatment strategies, and provides innovative insights for future research and therapeutic approaches.

Application of nanoparticles with activating STING pathway function in tumor synergistic therapy

Although immunotherapy is currently one of the most promising methods for cancer treatment, its clinical application is limited due to issues such as excessive autoimmune responses and lack of specificity. Therefore, there is a need to improve immunotherapy by integrating emerging medical technologies with traditional treatments. The activation of the cGAS-STING pathway plays a crucial role in innate immunity and antiviral defense, making it highly promising for immunotherapy and attracting significant attention. In recent years, research on nanomaterials and immunotherapy has achieved groundbreaking progress in the medical field. Due to their unique size, shape, stiffness, surface effects, and quantum size effects, nanomaterials can either carry STING activators or directly activate the STING pathway, offering new opportunities for tumor-specific immunotherapy. These unique advantages of nanomaterials have opened up broader prospects for nanoparticle-based therapies targeting the STING pathway. This paper summarizes the current research on utilizing nanomaterials to activate the STING pathway, detailing the characteristics, classifications, and different approaches for targeting tumor cells. Additionally, it focuses on the latest advancements in combined nanotherapies based on cGAS-STING pathway activation, including the integration of nanomaterial-mediated STING pathway activation with immunotherapy, radiotherapy, chemotherapy, targeted therapy, and photodynamic therapy. This provides new ideas for nanoparticle-based combination therapies involving the STING pathway.

Nanocarrier-mediated modulation of cGAS-STING signaling pathway to disrupt tumor microenvironment

The cGAS-STING signaling plays an important role in the immune response in a tumor microenvironment (TME) of triple-negative breast cancer (TNBC). The acute and controlled activation of cGAS-STING signaling results in tumor suppression, while chronic activation of cGAS-STING signaling results in immune-suppressive TME that could result in tumor survival. There is a need, therefore, to develop therapeutic strategies for harnessing tumor suppressive effects of cGAS-STING signaling while minimizing the risks associated with chronic activation. Combination therapies and nanocarriers-based delivery of cGAS-STING agonists have emerged as promising strategies in immunotherapy for controlled modulation of cGAS-STING signaling in cancer. These approaches aim to optimize the tumor suppressive effects of the cGAS-STING pathway while minimizing the challenges associated with modulators of cGAS-STING signaling. In the present review, we discuss recent advancements and strategies in combination therapies and nanocarrier-based delivery systems for effectively controlling cGAS-STING signaling in cancer immunotherapy. Further, we emphasized the significance of nanocarrier-based approaches for effective targeting of the cGAS-STING signaling, tackling resistance mechanisms, and overcoming key challenges like immune suppression, tumor heterogeneity, and off-target effects.

Loss of RPN1 promotes antitumor immunity via PD-L1 checkpoint blockade in triple-negative breast cancer - experimental studies

BACKGROUND

RPN1, also known as ribophorin I (RPN1), is a type I transmembrane protein that plays an important role in glycosylation. However, the effects of RPN1 on cancer progression and immune evasion in breast cancer (BC) have not been identified.

MATERIALS AND METHODS

The expression of RPN1 was evaluated using RT-qPCR and immunohistochemistry (IHC). The effects of RPN1 on tumor cells were assessed using RT-qPCR, western blotting, flow cytometry, Cell Counting Kit 8 (CCK-8), colony formation assays, and in vivo experiments. The mechanism by which RPN1 modifies programmed death ligand-1 (PD-L1) and the tumor microenvironment was examined by RT-qPCR, western blotting, co-immunoprecipitation (Co-IP), and flow cytometry. The influence of the transcription factor YY1 on RPN1 expression was revealed using bioinformatics analysis, RT-qPCR, and dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assays.

RESULTS

RPN1 is aberrantly expressed in triple-negative breast cancer (TNBC) cells, correlating with increased proliferation and poor prognosis. RPN1 mediates the post-translational modification of PD-L1, enhancing its glycosylation and stability, thus facilitating PD-L1-mediated immune escape and tumor growth. The deletion of RPN1 improves the TNBC microenvironment and enhances the efficacy of anti-PD-1 therapy. Additionally, we uncovered a novel regulatory axis involving YY1/RPN1/YBX1 in PD-L1 regulation, affecting TNBC growth and metastasis.

CONCLUSIONS

Our preliminary study reveals that targeting RPN1 promotes immune suppression, providing a new potential immunotherapy strategy for TNBC. However, further research is necessary to fully elucidate and understand the specific mechanisms of RPN1 in TNBC and its potential for clinical application.

Novel Modifications and Delivery Modes of Cyclic Dinucleotides for STING Activation in Cancer Treatment

The microenvironment tends to be immunosuppressive during tumor growth and proliferation. Immunotherapy has attracted much attention because of its ability to activate tumor-specific immune responses for tumor killing. The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is an innate immune pathway that activates antitumor immunity by producing type I interferons. Cyclic dinucleotides (CDNs), produced by cGAS sensing cytoplasmic abnormal DNA, are major intermediate activating molecules in the STING pathway. Nowadays, CDNs and their derivatives have widely worked as powerful STING agonists in tumor immunotherapy. However, their clinical translation is hindered by the negative electrical properties, sensitivity to hydrolytic enzymes, and systemic toxicity. Recently, various CDN delivery systems have made significant progress in addressing these issues, either through monotherapy or in combination with other treatment modalities. This review details recent advances in CDNs-based pharmaceutical development or delivery strategies for enriching CDNs at tumor sites and activating the STING pathway.

Riluzole Enhancing Anti-PD-1 Efficacy by Activating cGAS/STING Signaling in Colorectal Cancer

Colorectal cancer is the second leading cause of cancer mortality in the United States. Although immune checkpoint blockade therapies including anti-PD-1/PD-L1 have been successful in treating a subset of patients with colorectal cancer, the response rates remain low. We have found that riluzole, a well-tolerated FDA-approved oral medicine for treating amyotrophic lateral sclerosis, increased intratumoral CD8+ T cells and suppressed tumor growth of colon cancer cells in syngeneic immune-competent mice. Riluzole-mediated tumor suppression was dependent on the presence of CD8+ T cells. Riluzole activates the cytosolic DNA sensing cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway in colon cancer cells, resulting in increased expression of IFNβ and IFNβ-regulated genes including CXCL10. Inhibition of ataxia telangiectasia mutated (ATM), but not ATM-related, resulted in a synergistic increase in IFNβ expression, suggesting that riluzole induces ATM-mediated damage response that contributes to cGAS/STING activation. Depletion of cGAS or STING significantly attenuated riluzole-induced expression of IFNβ and CXCL10 as well as increase of intratumoral CD8+ T cells and suppression of tumor growth. These results indicate that riluzole-mediated tumor infiltration of CD8+ T cells and attenuation of tumor growth is dependent on tumor cell-intrinsic STING activation. To determine whether riluzole treatment primes the tumor microenvironment for immune checkpoint modulation, riluzole was combined with anti-PD-1 treatment. This combination showed greater efficacy than either single agent and strongly suppressed tumor growth in vivo. Taken together, our studies indicate that riluzole activates cGAS/STING-mediated innate immune responses, which might be exploited to sensitize colorectal tumors to anti-PD-1/PD-L1 therapies.

Elucidating the expression and role of cGAS in pan-cancer using integrated bioinformatics and experimental approaches

cGAS plays an important role in regulating both tumor immune responses and DNA damage repair. Nevertheless, there was little research that comprehensively analyzed the correlation between cGAS and the tumor microenvironment, immune cell infiltration, and DNA damage repair in different cancers. In this study, The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia (CCLE) data were used to analyze the mRNA expression and genomic alterations of cGAS in pan-cancer. The HPA database was used to explore the protein levels of cGAS in normal tissues and cancers. Correlation analysis were performed to explore the role of cGAS in interferon expression, immune cell infiltrations, DNA damage repair, and predictive immune markers. The prognostic value of cGAS was analyzed using survival data from the TCGA, Kaplan-Meier plotter database, and PrognoScan database. Lastly, the role of cGAS in DNA damage repair signaling and interferon signaling was validated in NSCLC cell lines. The results showed that cGAS was widely expressed in human normal tissues and various cancers, and the expression of cGAS was significantly upregulated in almost all of the solid cancers. Genomic analysis indicated that the expression of cGAS was positively correlated with copy number levels, while negatively correlated with the methylation levels of cGAS promoter. In addition, the level of cGAS was positively correlated with type I interferons expression, infiltration levels of most immune cell types, TMB and MSI levels, stromal and immune scores, and DNA damage repair gene sets including nonhomologous end joining and homologous recombination pathway. Survival analysis indicated that cGAS levels were associated with patient prognosis in several cancers. Lastly, in vitro study showed knockdown of cGAS expression inhibits the DNA damage repair signaling pathway and interferon signaling in NSCLC. In conclusions, cGAS is wildly activated in human cancers, which might participate in regulating cancer immunity and DNA damage repair. cGAS could be used as an effective target for cancer treatment and might be a potential predictive immune marker.

Ginsenoside RG3 Synergizes With STING Agonist to Reverse Cisplatin Resistance in Gastric Cancer

This study investigates the synergistic inhibitory effects of combining the stimulator of interferon genes (STING) agonist cyclic diadenylate monophosphate (c-di-AMP) and ginsenoside RG3 on cisplatin (DDP)-resistant gastric cancer (GC) cells. The objective is to identify novel therapeutic targets and offers insights for the clinical management of DDP resistance. Various techniques were employed, including western blot, MTT assay, colony formation assay, scratch assay, transwell assay, tubule formation assay, flow cytometry, Hoechst 33342 fluorescence staining, and in vivo experiments, to investigate the potential mechanisms and effects of the combined application of the STING agonist and ginsenoside RG3 in reversing cisplatin resistance in gastric cancer. The combination markedly suppressed key malignant behaviors, including proliferation, migration, invasion, and angiogenesis of SGC-7901/DDP cells. Additionally, this treatment inhibited the epithelial-mesenchymal transition (EMT) process and stem cell-like characteristics of SGC-7901/DDP cells, while downregulating the expression of resistance-related proteins. The STING agonist effectively suppresses the growth and proliferation of gastric cancer cells. Ginsenoside RG3, well-documented for its multifaceted properties, including antioxidant, anti-aging, and anti-cancer effects, is widely used in cancer treatment and in managing chemotherapy-related side effects. Furthermore, RG3 enhances anti-tumor immunity by regulating signal transduction. This study comprehensively evaluated the efficacy of the STING agonist and RG3 combination through in vitro and in vivo experiments, demonstrating significant inhibition of malignant progression and reversal of drug resistance in gastric cancer. These findings offer a robust theoretical foundation for clinical applications and highlight new therapeutic targets for future research.

Stimulator of Interferon Genes Signal in Lung Cancer Regulates Differentiation of Myeloid-Derived Suppressor Cells in the Tumor Microenvironment Via the Interferon Regulatory Factor 3/NF-κB Pathway

Background: This study was designed to explore the action mechanism of stimulator of interferon genes (STING) on the differentiation of myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment of lung cancer. Methods: Bioinformatics analysis yielded a potential pathway for STING to regulate MDSC differentiation, the interferon regulatory factor 3 (IRF3)/NF-κB axis. The transfection efficiency of STING overexpression plasmid and small interfering RNA against IRF3 (siIRF3) was examined by quantitative real-time polymerase chain reaction (qRT-PCR). After transfection, A9 cells were co-cultured with extracted bone marrow cells (BMCs). MDSC differentiation, protein expression of the IRF3/NF-κB pathway, and changes in nuclear translocation of NF-κB were analyzed by flow cytometry, Western blot, and immunofluorescence staining experiments. A transplanted tumor mouse model was used for in vivo experiments. After cyclic diadenyl monophosphate (CDA; STING agonist) treatment, changes in MDSC differentiation and protein expression of the IRF3/NF-κB axis in transplanted tumors were verified by immunohistochemical staining, qRT-PCR, and Western blot. Results: Coculture of A9 cells and BMCs promoted MDSC differentiation, inhibited activation of IRF3/NF-κB signal in A9 cells, and boosted nuclear translocation of NF-κB. However, after the upregulation of STING, IRF3/NF-κB signal was activated, while MDSC differentiation and nuclear translocation of NF-κB were inhibited. SiIRF3 reversed the effects of STING overexpression. In vivo, CDA dampened MDSC differentiation and promoted protein expression of the IRF3/NF-κB axis. Conclusion: STING signal in lung cancer cells inhibits MDSC differentiation through activation of the IRF3/NF-κB pathway.

Lipid-Based Nanocarriers for Targeted Gene Delivery in Lung Cancer Therapy: Exploring a Novel Therapeutic Paradigm

Lung cancer is a significant cause of cancer-related death worldwide. It can be broadly categorised into small-cell lung cancer (SCLC) and Non-small cell lung cancer (NSCLC). Surgical intervention, radiation therapy, and the administration of chemotherapeutic medications are among the current treatment modalities. However, the application of chemotherapy may be limited in more advanced stages of metastasis due to the potential for adverse effects and a lack of cell selectivity. Although small-molecule anticancer treatments have demonstrated effectiveness, they still face several challenges. The challenges at hand in this context comprise insufficient solubility in water, limited bioavailability at specific sites, adverse effects, and the requirement for epidermal growth factor receptor inhibitors that are genetically tailored. Bio-macromolecular drugs, including small interfering RNA (siRNA) and messenger RNA (mRNA), are susceptible to degradation when exposed to the bodily fluids of humans, which can reduce stability and concentration. In this context, nanoscale delivery technologies are utilised. These agents offer encouraging prospects for the preservation and regulation of pharmaceutical substances, in addition to improving the solubility and stability of medications. Nanocarrier-based systems possess the notable advantage of facilitating accurate and sustained drug release, as opposed to traditional systemic methodologies. The primary focus of scientific investigation has been to augment the therapeutic efficacy of nanoparticles composed of lipids. Numerous nanoscale drug delivery techniques have been implemented to treat various respiratory ailments, such as lung cancer. These technologies have exhibited the potential to mitigate the limitations associated with conventional therapy. As an illustration, applying nanocarriers may enhance the solubility of small-molecule anticancer drugs and prevent the degradation of bio-macromolecular drugs. Furthermore, these devices can administer medications in a controlled and extended fashion, thereby augmenting the therapeutic intervention's effectiveness and reducing adverse reactions. However, despite these promising results, challenges remain that must be addressed. Multiple factors necessitate consideration when contemplating the application of nanoparticles in medical interventions. To begin with, the advancement of more efficient delivery methods is imperative. In addition, a comprehensive investigation into the potential toxicity of nanoparticles is required. Finally, additional research is needed to comprehend these treatments' enduring ramifications. Despite these challenges, the field of nanomedicine demonstrates considerable promise in enhancing the therapy of lung cancer and other respiratory diseases.

Discovery of an theranostic functional mAb for visualizing the sensitivity and effectiveness of PD-L1 checkpoint therapy

To address the challenges of inconsistent efficacy, low sensitivity, and subjective screening methods faced by PD-L1-targeted immune checkpoint therapies in the clinic. We propose to construct a therapeutic functional monoclonal antibody with tracking capability using tetrazolium-based bioorthogonal reaction turn-on fluorescence technology, focusing on the molecular biomarker PD-L1 for easy visualisation of therapeutic response. This therapeutic monoclonal antibody enables bioorthogonal reaction turn-on fluorescence to monitoring of tumors with varying degrees of PD-L1 expression, while preserving the activity of the PDL1 monoclonal antibody and improve the immune activation rate and achieve efficient anti-tumor effects. In conclusion, our proposed family of bio-orthogonal reaction-driven fluorescence turn-on methods can be used to identify therapeutic bifunctional monoclonal antibodies to PD-L1, which can be employed alongside the screening of PD-L1 antibodies for therapeutic effects. Abbreviations: CRT, Calreticulin; DCs, Dendritic cells; ELISA, Enzyme-linked immunosorbent assay; IFN-γ, Interferon-γ; IL-2, Interleukin-2; IHC, Immunohistochemistry; WB, Western blot.

Uncovering the Emerging Prospects of Lipid-based Nanoparticulate Vehicles in Lung Cancer Management: A Recent Perspective

Lung cancer, a leading cause of cancer-related deaths globally, is gaining research interest more than ever before. Owing to the burden of pathogenesis on the quality of life of patients and subsequently the healthcare system, research efforts focus on its management and amelioration. In an effort to improve bioavailability, enhance stability, minimize adverse effects and reduce the incidence of resistance, nanotechnological platforms have been harnessed for drug delivery and improving treatment outcomes. Lipid nanoparticles, in particular, offer an interesting clinical opportunity with respect to the delivery of a variety of agents. These include synthetic chemotherapeutic agents, immunotherapeutic molecules, as well as phytoconstituents with promising anticancer benefits. In addition to this, these systems are being studied for their usage in conjunction with other treatment strategies. However, their applications remain limited owing to a number of challenges, chiefly clinical translation. There is a need to address the scalability of such technologies, in order to improve accessibility. The authors aim to offer a comprehensive understanding of the evolution of lipid nanoparticles and their application in lung cancer, the interplay of disease pathways and their mechanism of action and the potential for delivery of a variety of agents. Additionally, a discussion with respect to results from preclinical studies has also been provided. The authors have also provided a well-rounded insight into the limitations and future perspectives. While the possibilities are endless, there is a need to undertake focused research to expedite clinical translation and offer avenues for wider applications in disease management.

The role of tumor types in immune-related adverse events

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that block inhibitors of T cell activation and function. With the widespread use of ICIs in cancer therapy, immune-related adverse events (irAEs) have gradually emerged as urgent clinical issues. Tumors not only exhibit high heterogeneity, and their response to ICIs varies, with "hot" tumors showing better anti-tumor effects but also a higher susceptibility to irAEs. The manifestation of irAEs displays a tumor-heterogeneous pattern, correlating with the tumor type in terms of the affected organs, incidence, median onset time, and severity. Understanding the mechanisms underlying the pathogenic patterns of irAEs can provide novel insights into the prevention and management of irAEs, guide the development of biomarkers, and contribute to a deeper understanding of the toxicological characteristics of ICIs. In this review, we explore the impact of tumor type on the therapeutic efficacy of ICIs and further elucidate how these tumor types influence the occurrence of irAEs. Finally, we assess key candidate biomarkers and their relevance to proposed irAE mechanisms. This paper also outlines management strategies for patients with various types of tumors, based on their disease patterns.

A comprehensive review of immune checkpoint inhibitors for cancer treatment

Immunology-based therapies are emerging as an effective cancer treatment, using the body's immune system to target tumors. Immune checkpoints, which regulate immune responses to prevent tissue damage and autoimmunity, are often exploited by cancer cells to avoid destruction. The discovery of checkpoint proteins like PD-1/PD-L1 and CTLA-4 was pivotal in developing cancer immunotherapy. Immune checkpoint inhibitors (ICIs) have shown great success, with FDA-approved drugs like PD-1 inhibitors (Nivolumab, Pembrolizumab, Cemiplimab), PD-L1 inhibitors (Atezolizumab, Durvalumab, Avelumab), and CTLA-4 inhibitors (Ipilimumab, Tremelimumab), alongside LAG-3 inhibitor Relatlimab. Research continues on new checkpoints like TIM-3, VISTA, B7-H3, BTLA, and TIGIT. Biomarkers like PDL-1 expression, tumor mutation burden, interferon-γ presence, microbiome composition, and extracellular matrix characteristics play a crucial role in predicting responses to immunotherapy with checkpoint inhibitors. Despite their effectiveness, not all patients experience the same level of benefit, and organ-specific immune-related adverse events (irAEs) such as rash or itching, colitis, diarrhea, hyperthyroidism, and hypothyroidism may occur. Given the rapid advancements in this field and the variability in patient outcomes, there is an urgent need for a comprehensive review that consolidates the latest findings on immune checkpoint inhibitors, covering their clinical status, biomarkers, resistance mechanisms, strategies to overcome resistance, and associated adverse effects. This review aims to fill this gap by providing an analysis of the current clinical status of ICIs, emerging biomarkers, mechanisms of resistance, strategies to enhance therapeutic efficacy, and assessment of adverse effects. This review is crucial to furthering our understanding of ICIs and optimizing their application in cancer therapy.

Prevalence of HPV in anal cancer: exploring the role of infection and inflammation

Anal cancer incidence is rising globally, driven primarily by human papillomavirus (HPV) infection. HPV, especially high-risk types 16 and 18, is considered a necessary cause of anal squamous cell carcinoma. Certain populations like people living with HIV, men who have sex with men, inflammatory bowel disease patients, smokers, and those with compromised immunity face elevated risk. Chronic inflammation facilitates viral persistence, cell transformation, and immune evasion through pathways involving the PD-1/PD-L1 axis. HIV coinfection further increases risk by impairing immune surveillance and epithelial integrity while promoting HPV oncogene expression. Understanding these inflammatory processes, including roles of CD8 + T cells and PD-1/PD-L1, could guide development of immunotherapies against anal cancer. This review summarizes current knowledge on inflammation's role in anal cancer pathogenesis and the interplay between HPV, HIV, and host immune factors.

Advances and prospects of precision nanomedicine in personalized tumor theranostics

Tumor, as the second leading cause of death globally, following closely behind cardiovascular diseases, remains a significant health challenge worldwide. Despite the existence of various cancer treatment methods, their efficacy is still suboptimal, necessitating the development of safer and more efficient treatment strategies. Additionally, the advancement of personalized therapy offers further possibilities in cancer treatment. Nanomedicine, as a promising interdisciplinary field, has shown tremendous potential and prospects in the diagnosis and treatment of cancer. As an emerging approach in oncology, the application of nanomedicine in personalized cancer therapy primarily focuses on targeted drug delivery systems such as passive targeting drug delivery, active targeting drug delivery, and environmentally responsive targeting drug delivery, as well as imaging diagnostics such as tumor biomarker detection, tumor cell detection, and in vivo imaging. However, it still faces challenges regarding safety, biocompatibility, and other issues. This review aims to explore the advances in the use of nanomaterials in the field of personalized cancer diagnosis and treatment and to investigate the prospects and challenges of developing personalized therapies in cancer care, providing direction for the clinical translation and application.

Triggering immunogenic death of cancer cells by nanoparticles overcomes immunotherapy resistance

Immunotherapy resistance poses a significant challenge in oncology, necessitating novel strategies to enhance the therapeutic efficacy. Immunogenic cell death (ICD), including necroptosis, pyroptosis and ferroptosis, triggers the release of tumor-associated antigens and numerous bioactive molecules. This release can potentiate a host immune response, thereby overcoming resistance to immunotherapy. Nanoparticles (NPs) with their biocompatible and immunomodulatory properties, are emerging as promising vehicles for the delivery of ICD-inducing agents and immune-stimulatory adjuvants to enhance immune cells tumoral infiltration and augment immunotherapy efficacy. This review explores the mechanisms underlying immunotherapy resistance, and offers an in-depth examination of ICD, including its principles and diverse modalities of cell death that contribute to it. We also provide a thorough overview of how NPs are being utilized to trigger ICD and bolster antitumor immunity. Lastly, we highlight the potential of NPs in combination with immunotherapy to revolutionize cancer treatment.

STING-activating dendritic cell-targeted nanovaccines that evoke potent antigen cross-presentation for cancer immunotherapy

Recently, nanovaccine-based immunotherapy has been robustly investigated due to its potential in governing the immune response and generating long-term protective immunity. However, the presentation of a tumor peptide-major histocompatibility complex to T lymphocytes is still a challenge that needs to be addressed for eliciting potent antitumor immunity. Type 1 conventional dendritic cell (cDC1) subset is of particular interest due to its pivotal contribution in the cross-presentation of exogenous antigens to CD8+ T cells. Here, the DC-derived nanovaccine (denoted as Si9GM) selectively targets cDC1s with marginal loss of premature antigen release for effective stimulator of interferon genes (STING)-mediated antigen cross-presentation. Bone marrow dendritic cell (BMDC)-derived membranes, conjugated to cDC1-specific antibody (αCLEC9A) and binding to tumor peptide (OVA257-264), are coated onto dendrimer-like polyethylenimine (PEI)-grafted silica nanoparticles. Distinct molecular weight-cargos (αCLEC9A-OVA257-264 conjugates and 2'3'-cGAMP STING agonists) are loaded in hierarchical center-radial pores that enables lysosome escape for potent antigen-cross presentation and activates interferon type I, respectively. Impressively, Si9GM vaccination leads to the upregulation of cytotoxic T cells, a reduction in tumor regulatory T cells (Tregs), M1/M2 macrophage polarization, and immune response that synergizes with αPD-1 immune checkpoint blockade. This nanovaccine fulfills a dual role for both direct T cell activation as an artificial antigen-presenting cell and DC subset maturation, indicating its utility in clinical therapy and precision medicine.

cGAS/STING in skin melanoma: from molecular mechanisms to therapeutics

Melanoma, recognized as the most aggressive type of skin cancer, has experienced a notable increase in cases, especially within populations with fair skin. This highly aggressive cancer is largely driven by UV radiation exposure, resulting in the uncontrolled growth and malignant transformation of melanocytes. The cGAS-STING pathway, an immune signaling mechanism responsible for detecting double-stranded DNA in the cytoplasm, is essential for mediating the immune response against melanoma. This pathway serves a dual purpose: it enhances antitumor immunity by activating immune cells, but it can also promote tumor growth when chronically activated by creating an immunosuppressive environment. This review comprehensively examines the multifaceted implication of the cGAS-STING pathway in melanoma pathogenesis and treatment. We explore its molecular mechanisms, including epigenetic regulation, interaction with signaling pathways such as AR signaling, and modulation by various cellular effectors like TG2 and activin-A. The therapeutic potential of modulating the cGAS-STING pathway is highlighted, with promising results from STING agonists, combination therapies with immune checkpoint inhibitors, and novel drug delivery systems, including nanoparticles and synthetic drugs. Our findings underscore the importance of the cGAS-STING pathway in melanoma, presenting it as a critical target for enhancing anti-tumor immunity. By leveraging this pathway, future therapeutic strategies can potentially convert 'cold' tumors into 'hot' tumors, making them more susceptible to immune responses.

Inflammation-Triggering Engineered Macrophages (MacTriggers) Enhance Reactivity of Immune Checkpoint Inhibitor Only in Tumor Tissues

Background: We have previously reported engineered macrophages (MacTriggers) that can accelerate the release of tumor necrosis factor-α in response to M2 polarization. MacTriggers are characterized by two original characteristics of macrophages: (1) migration to tumors; and (2) polarization to the M2 phenotype in tumors. Intravenously administered MacTriggers efficiently accumulated in the tumors and induced tumor-specific inflammation. This study reports a novel methodology for enhancing the anti-tumor effects of immune checkpoint inhibitors (ICIs). Results: In this study, we newly found that the intravenously administered MacTriggers in BALB/c mouse models upregulated the expression levels of immune checkpoint proteins, such as programmed cell death (PD)-1 in CD8+ T cells and PD-ligand 1 (PD-L1) in cancer cells and macrophages. Consequently, in two ICI-resistant tumor-inoculated mouse models, the combined administration of MacTrigger and anti-PD-1 antibody (aPD-1) synergistically inhibited tumor growth, whereas monotherapy with aPD-1 did not exhibit anti-tumor effects. This synergistic effect was mainly from aPD-1 enhancing the tumor-attacking ability of CD8+ T cells, which could infiltrate into the tumors following MacTrigger treatment. Importantly, no side effects were observed in normal tissues, particularly in the liver and spleen, indicating that the MacTriggers did not enhance the aPD-1 reactivity in normal tissues. This specificity was from the MacTriggers not polarizing to the M2 phenotype in normal tissues, thereby avoiding inflammation and increased PD-1/PD-L1 expression. MacTriggers could enhance aPD-1 reactivity only in tumors following tumor-specific inflammation induction. Conclusions: Our findings suggest that the MacTrigger and aPD-1 combination therapy is a novel approach for potentially overcoming the current low ICI response rates while avoiding side effects.

The cGAS-STING pathway drives neuroinflammation and neurodegeneration via cellular and molecular mechanisms in neurodegenerative diseases

Neurodegenerative diseases (NDs) are a type of common chronic progressive disorders characterized by progressive damage to specific cell populations in the nervous system, ultimately leading to disability or death. Effective treatments for these diseases are still lacking, due to a limited understanding of their pathogeneses, which involve multiple cellular and molecular pathways. The triggering of an immune response is a common feature in neurodegenerative disorders. A critical challenge is the intricate interplay between neuroinflammation, neurodegeneration, and immune responses, which are not yet fully characterized. In recent years, the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) pathway, a crucial immune response for intracellular DNA sensing, has gradually gained attention. However, the specific roles of this pathway within cellular types such as immune cells, glial and neuronal cells, and its contribution to ND pathogenesis, remain not fully elucidated. In this review, we systematically explore how the cGAS-STING signaling links various cell types with related cellular effector pathways under the context of NDs for multifaceted therapeutic directions. We emphasize the discovery of condition-dependent cellular heterogeneity in the cGAS-STING pathway, which is integral for understanding the diverse cellular responses and potential therapeutic targets. Additionally, we review the pathogenic role of cGAS-STING activation in Parkinson's disease, ataxia-telangiectasia, and amyotrophic lateral sclerosis. We focus on the complex bidirectional roles of the cGAS-STING pathway in Alzheimer's disease, Huntington's disease, and multiple sclerosis, revealing their double-edged nature in disease progression. The objective of this review is to elucidate the pivotal role of the cGAS-STING pathway in ND pathogenesis and catalyze new insights for facilitating the development of novel therapeutic strategies.

Blockade of CCR5+ T Cell Accumulation in the Tumor Microenvironment Optimizes Anti-TGF-β/PD-L1 Bispecific Antibody

In the previous studies, anti-TGF-β/PD-L1 bispecific antibody YM101 is demonstrated, with superior efficacy to anti-PD-L1 monotherapy in multiple tumor models. However, YM101 therapy can not achieve complete regression in most tumor-bearing mice, suggesting the presence of other immunosuppressive elements in the tumor microenvironment (TME) beyond TGF-β and PD-L1. Thoroughly exploring the TME is imperative to pave the way for the successful translation of anti-TGF-β/PD-L1 BsAb into clinical practice. In this work, scRNA-seq is employed to comprehensively profile the TME changes induced by YM101. The scRNA-seq analysis reveals an increase in immune cell populations associated with antitumor immunity and enhances cell-killing pathways. However, the analysis also uncovers the presence of immunosuppressive CCR5+ T cells in the TME after YM101 treatment. To overcome this hurdle, YM101 is combined with Maraviroc, a widely used CCR5 antagonist for treating HIV infection, suppressing CCR5+ T cell accumulation, and optimizing the immune response. Mechanistically, YM101-induced neutrophil activation recruits immunosuppressive CCR5+ T cells via CCR5 ligand secretion, creating a feedback loop that diminishes the antitumor response. Maraviroc then cleared these infiltrating cells and offset YM101-mediated immunosuppressive effects, further unleashing the antitumor immunity. These findings suggest selectively targeting CCR5 signaling with Maraviroc represents a promising and strategic approach to enhance YM101 efficacy.

Exploring resistance to immune checkpoint inhibitors and targeted therapies in melanoma

Melanoma is the most aggressive form of skin cancer, characterized by a poor prognosis, and its incidence has risen rapidly over the past 30 years. Recent therapies, notably immunotherapy and targeted therapy, have significantly improved the outcome of patients with metastatic melanoma. Previously dismal five-year survival rates of below 5% have shifted to over 50% of patients surviving the five-year mark, marking a significant shift in the landscape of melanoma treatment and survival. Unfortunately, about 50% of patients either do not respond to therapy or experience early or late relapses following an initial response. The underlying mechanisms for primary and secondary resistance to targeted therapies or immunotherapy and relapse patterns remain not fully identified. However, several molecular pathways and genetic factors have been associated with melanoma resistance to these treatments. Understanding these mechanisms paves the way for creating novel treatments that can address resistance and ultimately enhance patient outcomes in melanoma. This review explores the mechanisms behind immunotherapy and targeted therapy resistance in melanoma patients. Additionally, it describes the treatment strategies to overcome resistance, which have improved patients' outcomes in clinical trials and practice.

Low-Intensity Focused Ultrasound-Responsive Phase-Transitional Liposomes Loaded with STING Agonist Enhances Immune Activation for Breast Cancer Immunotherapy

Background: Pharmacologically targeting the STING pathway offers a novel approach to cancer immunotherapy. However, small-molecule STING agonists face challenges such as poor tumor accumulation, rapid clearance, and short-lived effects within the tumor microenvironment, thus limiting their therapeutic potential. To address the challenges of poor specificity and inadequate targeting of STING in breast cancer treatment, herein, we report the design and development of a targeted liposomal delivery system modified with the tumor-targeting peptide iRGD (iRGD-STING-PFP@liposomes). With LIFU irradiation, the liposomal system exploits acoustic cavitation, where gas nuclei form and collapse within the hydrophobic region of the liposome lipid bilayer (transient pore formation), which leads to significantly enhanced drug release. Methods: Transmission electron microscopy (TEM) was used to investigate the physicochemical properties of the targeted liposomes. Encapsulation efficiency and in vitro release were assessed using the dialysis bag method, while the effects of iRGD on liposome targeting were evaluated through laser confocal microscopy. The CCK-8 assay was used to investigate the toxicity and cell growth effects of this system on 4T1 breast cancer cells and HUVEC vascular endothelial cells. A subcutaneous breast cancer tumor model was established to evaluate the tumor-killing effects and therapeutic mechanism of the newly developed liposomes. Results: The liposome carrier exhibited a regular morphology, with a particle size of 232.16 ± 19.82 nm, as indicated by dynamic light scattering (DLS), and demonstrated low toxicity to both HUVEC and 4T1 cells. With an encapsulation efficiency of 41.82 ± 5.67%, the carrier exhibited a slow release pattern in vitro after STING loading. Targeting results indicated that iRGD modification enhanced the system's ability to target 4T1 cells. The iRGD-STING-PFP@liposomes group demonstrated significant tumor growth inhibition in the subcutaneous breast cancer mouse model with effective activation of the immune system, resulting in the highest populations of matured dendritic cells (71.2 ± 5.4%), increased presentation of tumor-related antigens, promoted CD8+ T cell infiltration at the tumor site, and enhanced NK cell activity. Conclusions: The iRGD-STING-PFP@liposomes targeted drug delivery system effectively targets breast cancer cells, providing a new strategy for breast cancer immunotherapy. These findings indicate that iRGD-STING-PFP@liposomes could successfully deliver STING agonists to tumor tissue, trigger the innate immune response, and may serve as a potential platform for targeted immunotherapy.

The complex role of immune cells in antigen presentation and regulation of T-cell responses in hepatocellular carcinoma: progress, challenges, and future directions

Hepatocellular carcinoma (HCC) is a prevalent form of liver cancer that poses significant challenges regarding morbidity and mortality rates. In the context of HCC, immune cells play a vital role, especially concerning the presentation of antigens. This review explores the intricate interactions among immune cells within HCC, focusing on their functions in antigen presentation and the modulation of T-cell responses. We begin by summarizing the strategies that HCC uses to escape immune recognition, emphasizing the delicate equilibrium between immune surveillance and evasion. Next, we investigate the specific functions of various types of immune cells, including dendritic cells, natural killer (NK) cells, and CD8+ T cells, in the process of antigen presentation. We also examine the impact of immune checkpoints, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and the pathways involving programmed cell death protein 1 (PD-1) and programmed death ligand 1 (PD-L1), on antigen presentation, while taking into account the clinical significance of checkpoint inhibitors. The review further emphasizes the importance of immune-based therapies, including cancer vaccines and CAR-T cell therapy, in improving antigen presentation. In conclusion, we encapsulate the latest advancements in research, propose future avenues for exploration, and stress the importance of innovative technologies and customized treatment strategies. By thoroughly analyzing the interactions of immune cells throughout the antigen presentation process in HCC, this review provides an up-to-date perspective on the field, setting the stage for new therapeutic approaches.

Nanomaterial-based cancer immunotherapy: enhancing treatment strategies

Cancer immunotherapy has emerged as a pivotal approach for treating various types of cancer, incorporating strategies such as chimeric antigen receptor T-cell (CAR-T) therapy, immune checkpoint blockade therapy, neoantigen peptides, mRNA vaccines, and small molecule modulators. However, the clinical efficacy of these therapies is frequently constrained by significant adverse effects and limited therapeutic outcomes. In recent years, the integration of nanotechnology into cancer immunotherapy has gained considerable attention, showcasing notable advantages in drug delivery, targeted accumulation, controlled release, and localized administration. This review focuses on nanomaterial-based immunotherapeutic strategies, particularly the development and application of nanocarriers such as liposomes, lipid nanoparticles, polymeric nanoparticles, and self-assembling scaffolds. We examine how these strategies can enhance the efficacy of cancer immunotherapy while minimizing adverse effects and analyze their potential for clinical translation.

Peripheral blood lymphocyte subpopulations as predictive biomarkers for first-line programmed death 1 inhibitors efficacy in esophageal squamous cell carcinoma: A retrospective study

Esophageal cancer (EC) poses a significant global health burden, necessitating effective treatment strategies. Immune checkpoint inhibitors have emerged as a promising therapeutic option for EC, but the identification of predictive biomarkers remains crucial for optimizing patient outcomes. We conducted a retrospective analysis of medical records from advanced esophageal squamous cell carcinoma patients treated with first-line programmed death 1 inhibitors. Peripheral blood lymphocyte subpopulations were evaluated using flow cytometry, while hematological tests provided data on neutrophil, lymphocyte, and monocyte counts. Cox regression and logistic regression analyses were employed to explore the association between lymphocyte subpopulations, baseline characteristics, and progression-free survival (PFS). Among the 100 initially included patients, 70 met eligibility criteria. Multivariate Cox regression analysis revealed a significant association between high CD16+CD56+ lymphocyte proportions and longer PFS, independent of other clinical variables. Similarly, a high CD4+/CD8+ ratio was correlated with prolonged PFS. Kaplan-Meier survival curves supported these findings. Logistic regression analysis indicated no significant differences in the CD4+/CD8+ ratio and CD16+CD56+ lymphocytes concerning baseline characteristics, suggesting their potential as independent prognostic markers. Our study highlights the predictive value of peripheral blood CD16+CD56+ lymphocytes and the CD4+/CD8+ ratio for the efficacy of programmed death 1 inhibitors in advanced esophageal squamous cell carcinoma patients. These findings underscore the importance of peripheral blood biomarkers in guiding personalized immunotherapy strategies and improving outcomes for EC patients.

Novel insights into immune cells modulation of tumor resistance

Tumor resistance poses a significant challenge to effective cancer treatment, making it imperative to explore new therapeutic strategies. Recent studies have highlighted the profound involvement of immune cells in the development of tumor resistance. Within the tumor microenvironment, macrophages undergo polarization into the M2 phenotype, thus promoting the emergence of drug-resistant tumors. Neutrophils contribute to tumor resistance by forming extracellular traps. While T cells and natural killer (NK) cells exert their impact through direct cytotoxicity against tumor cells. Additionally, dendritic cells (DCs) have been implicated in preventing tumor drug resistance by stimulating T cell activation. In this review, we provide a comprehensive summary of the current knowledge regarding immune cell-mediated modulation of tumor resistance at the molecular level, with a particular focus on macrophages, neutrophils, DCs, T cells, and NK cells. The targeting of immune cell modulation exhibits considerable potential for addressing drug resistance, and an in-depth understanding of the molecular interactions between immune cells and tumor cells holds promise for the development of innovative therapies. Furthermore, we explore the clinical implications of these immune cells in the treatment of drug-resistant tumors. This review emphasizes the exploration of novel approaches that harness the functional capabilities of immune cells to effectively overcome drug-resistant tumors.

A bispecific nanosystem activates endogenous natural killer cells in the bone marrow for haematologic malignancies therapy

Haematologic malignancies commonly arise from the bone marrow lesion, yet there are currently no effective targeted therapies against tumour cells in this location. Here we constructed a bone-marrow-targeting nanosystem, CSF@E-Hn, which is based on haematopoietic-stem-cell-derived nanovesicles adorned with gripper ligands (aPD-L1 and aNKG2D) and encapsulated with colony-stimulating factor (CSF) for the treatment of haematologic malignancies. CSF@E-Hn targets the bone marrow and, thanks to the gripper ligands, pulls together tumour cells and natural killer cells, activating the latter for specific tumour cell targeting and elimination. The therapeutic efficacy was validated in mice bearing acute myeloid leukaemia and multiple myeloma. The comprehensive assessment of the post-treatment bone marrow microenvironment revealed that the integration of CSF into a bone-marrow-targeted nanosystem promoted haematopoietic stem cell differentiation, boosted memory T cell generation and maintained bone homoeostasis, with long-term prevention of relapse. Our nanosystem represents a promising strategy for the treatment of haematologic malignancies.

Research progress and challenges of the PD-1/PD-L1 axis in gliomas

The emergence of programmed death-1 (PD-1) and programmed death ligand 1 (PD-L1) immunosuppressants provides new therapeutic directions for various advanced malignant cancers. At present, PD-1/PD-L1 immunosuppressants have made significant progress in clinical trials of some gliomas, but PD-1/PD-L1 inhibitors have not yet shown convincing clinical efficacy in gliomas. This article summarizes the research progress of the PD-1 /PD-L1 pathway in gliomas through the following three aspects. It mainly includes the complex expression levels and regulatory mechanisms of PD-1/PD-L1 in the glioma microenvironment, the immune infiltration in glioma immunosuppressive microenvironment, and research progress on the application of PD-1/PD-L1 immunosuppressants in clinical treatment trials for gliomas. This will help to understand the current treatment progress and future research directions better.

Evolving cancer resistance to anti-PD-1/PD-L1 antibodies in melanoma: Comprehensive insights with future prospects

Immunotherapy has transformed the treatment of advanced melanoma. However, up to two-thirds of patients experience disease progression after initially achieving a response to immunotherapy. Furthermore, most research has focused on cutaneous melanoma rather than acral or mucosal melanoma, although the latter predominates in Asian populations. In this review, we examine and summarize current definitions of resistance to immunotherapy and the epidemiology of resistance to PD-1 inhibition. We also review the available literature on molecular mechanisms of resistance, including how the tumor mutational landscape and tumor microenvironments of immunotherapy-resistant acral and mucosal melanomas may influence resistance. Finally, we review strategies for overcoming resistance to PD-1 inhibition and summarize completed studies and ongoing clinical trials. Our review highlights that improving the understanding of resistance mechanisms, optimizing existing therapies and further studying high-risk populations would maximize the potential of immunotherapy and result in optimized treatment outcomes for patients with melanoma.

Tumor eradication by triplet therapy with BRAF inhibitor, TLR 7 agonist, and PD-1 antibody for BRAF-mutated melanoma

Programmed death 1 (PD-1)/programmed death-ligand 1 inhibitors are commonly used to treat various cancers, including melanoma. However, their efficacy as monotherapy is limited, and combination immunotherapies are being explored to improve outcomes. In this study, we investigated a combination immunotherapy involving an anti-PD-1 antibody that blocks the major adaptive immune-resistant mechanisms, a BRAF inhibitor that inhibits melanoma cell proliferation, and multiple primary immune-resistant mechanisms, such as cancer cell-derived immunosuppressive cytokines, and a Toll-like receptor 7 agonist that enhances innate immune responses that promote antitumor T-cell induction and functions. Using a xenogeneic nude mouse model implanted with human BRAF-mutated melanoma, a BRAF inhibitor vemurafenib was found to restore T-cell-stimulatory activity in conventional dendritic cells by reducing immunosuppressive cytokines, including interleukin 6, produced by human melanoma. Additionally, intravenous administration of the Toll-like receptor 7 agonist DSR6434 enhanced tumor growth inhibition by vemurafenib through stimulating the plasmacytoid dendritic cells/interferon-α/natural killer cell pathways and augmenting the T-cell-stimulatory activity of conventional dendritic cells. In a syngeneic mouse model implanted with murine BRAF-mutated melanoma, the vemurafenib and DSR6434 combination synergistically augmented the induction of melanoma antigen gp100-specific T cells and inhibited tumor growth. Notably, only triplet therapy with vemurafenib, DSR6434, and the anti-PD-1 antibody resulted in complete regression of SIY antigen-transduced BRAF-mutated melanoma in a CD8 T-cell-dependent manner. These findings indicate that a triple-combination strategy targeting adaptive and primary resistant mechanisms while enhancing innate immune responses that promote tumor-specific T cells may be crucial for effective tumor eradication.

Strategies to enhance the therapeutic efficacy of anti-PD-1 antibody, anti-PD-L1 antibody and anti-CTLA-4 antibody in cancer therapy

Although immune checkpoint inhibitors (anti-PD-1 antibody, anti-PD-L1 antibody, and anti-CTLA-4 antibody) have displayed considerable success in the treatment of malignant tumors, the therapeutic effect is still unsatisfactory for a portion of patients. Therefore, it is imperative to develop strategies to enhance the effect of these ICIs. Increasing evidence strongly suggests that the key to this issue is to transform the tumor immune microenvironment from a state of no or low immune infiltration to a state of high immune infiltration and enhance the tumor cell-killing effect of T cells. Therefore, some combination strategies have been proposed and this review appraise a summary of 39 strategies aiming at enhancing the effectiveness of ICIs, which comprise combining 10 clinical approaches and 29 foundational research strategies. Moreover, this review improves the comprehensive understanding of combination therapy with ICIs and inspires novel ideas for tumor immunotherapy.

Mechanism insights and therapeutic intervention of tumor metastasis: latest developments and perspectives

Metastasis remains a pivotal characteristic of cancer and is the primary contributor to cancer-associated mortality. Despite its significance, the mechanisms governing metastasis are not fully elucidated. Contemporary findings in the domain of cancer biology have shed light on the molecular aspects of this intricate process. Tumor cells undergoing invasion engage with other cellular entities and proteins en route to their destination. Insights into these engagements have enhanced our comprehension of the principles directing the movement and adaptability of metastatic cells. The tumor microenvironment plays a pivotal role in facilitating the invasion and proliferation of cancer cells by enabling tumor cells to navigate through stromal barriers. Such attributes are influenced by genetic and epigenetic changes occurring in the tumor cells and their surrounding milieu. A profound understanding of the metastatic process's biological mechanisms is indispensable for devising efficacious therapeutic strategies. This review delves into recent developments concerning metastasis-associated genes, important signaling pathways, tumor microenvironment, metabolic processes, peripheral immunity, and mechanical forces and cancer metastasis. In addition, we combine recent advances with a particular emphasis on the prospect of developing effective interventions including the most popular cancer immunotherapies and nanotechnology to combat metastasis. We have also identified the limitations of current research on tumor metastasis, encompassing drug resistance, restricted animal models, inadequate biomarkers and early detection methods, as well as heterogeneity among others. It is anticipated that this comprehensive review will significantly contribute to the advancement of cancer metastasis research.