Syk Inhibition Reprograms Tumor-Associated Macrophages and Overcomes Gemcitabine-Induced Immunosuppression in Pancreatic Ductal Adenocarcinoma

Overcoming immunotherapy resistance in colorectal cancer through nano-selenium probiotic complexes and IL-32 modulation

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) is a major global health burden, with immunotherapy often limited by immune tolerance and resistance. This study introduces an innovative approach using Selenium Nanoparticles-Loaded Extracellular Vesicles combined with Interleukin-32 and Engineered Probiotic Escherichia coli Nissle 1917 (SeNVs@NE-IL32-EcN) to enhance CD8+ T cell-mediated immune responses and overcome immunotherapy resistance.

METHODS

Single-cell RNA sequencing (scRNA-seq) and transcriptomic analyses were performed to identify key immune cells and regulators involved in CRC immunotherapy resistance, focusing on CD8+ T cells and the regulatory factor IL32. A humanized xenograft mouse model was used to evaluate the impact of IL32 and SeNVs@NE-IL32-EcN on tumor growth and immune responses. The SeNVs@NE-IL32-EcN complex was synthesized through a reverse micelle method and functionalized using extracellular vesicles. Its morphology, size, antioxidant activity, and safety were characterized using electron microscopy, dynamic light scattering (DLS), and in vitro co-culture assays.

RESULTS

Single-cell analyses revealed a significant reduction in CD8+ T cell infiltration in immunotherapy-resistant CRC patients. IL32 was identified as a key regulator enhancing CD8+ T cell cytotoxic activity through granzyme B and IFN-γ secretion. Treatment with SeNVs@NE-IL32-EcN significantly improved the proliferation and activity of CD8+ T cells and reduced tumor progression in humanized mouse models. In vitro and in vivo results demonstrated the complex's biocompatibility, antioxidant properties, and ability to enhance CRC immunotherapy while mitigating immune tolerance.

CONCLUSION

SeNVs@NE-IL32-EcN offers a novel nano-biomaterial strategy that integrates nanotechnology and probiotic therapy to enhance CD8+ T cell-mediated immunity and overcome CRC immunotherapy resistance. This study lays the foundation for future therapeutic applications in cancer treatment by advancing immune-modulating biomaterials.

Spleen tyrosine kinase aggravates intestinal inflammation through regulating inflammatory responses of macrophage in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a persistent chronic, non-specific inflammatory disease, and macrophages play a crucial role in its pathogenesis. Spleen tyrosine kinase (Syk) is strongly associated with the pathogenesis of several inflammatory diseases. However, the role of Syk in the pathogenesis of UC is still obscure.

METHODS

Syk expression was analyzed in peripheral blood mononuclear cells (PBMCs) and colonic tissues of UC patients using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunofluorescence. A public database was used to analyze the expression of selected signature genes of interest in UC patients with different expressions of Syk. R788, a small molecule inhibitor of Syk, was used to treat macrophages from mice. The functions of macrophages were assessed using qRT-PCR, flow cytometry, and fluorescence microscopy. Dextran sodium sulfate (DSS)-induced colitis mice model was established to determine the role of Syk in UC.

RESULTS

The Syk levels were markedly increased in PBMCs, colonic tissues, and colonic mucosa lamina propria macrophages from UC patients, and positively related to disease activity. Inhibition of Syk with R788 decreased pro-inflammatory genes expression and increased anti-inflammatory genes expression in peritoneal macrophages and bone marrow macrophages. Blockade of Syk enhanced phagocytosis and bactericidal ability of macrophages. Syk promoted the production of reactive oxygen species of macrophages and M1-type macrophage polarization. Furthermore, inhibition of Syk alleviated intestinal mucosal inflammation in DSS-induced colitis model.

CONCLUSIONS

Syk plays a vital role in intestinal inflammation by regulating inflammatory responses of macrophages in UC. Targeting Syk may be a promising therapeutic approach for UC.

Targeting spleen tyrosine kinase (SYK): structure, mechanisms and drug discovery

Spleen tyrosine kinase (SYK) is a crucial non-receptor tyrosine kinase involved in signaling pathways that regulate various cellular processes. It is primarily expressed in hematopoietic cells and myeloid cells, which are crucial for B-cell development, maturation and antibody production, and it is a key therapeutic target for autoimmune and allergic diseases. Overexpression of SYK is also associated with cancer and cardiovascular, cerebrovascular and neurodegenerative diseases, contributing to their initiation and progression. SYK is a promising target for drug development, and several inhibitors have already been reported. This review covers the structure and regulatory pathways of SYK, as well as its links to various diseases. It also highlights key small-molecule SYK inhibitors, their design strategies and their potential therapeutic benefits, aiming to enhance our understanding and aid in the discovery of more-effective SYK inhibitors.

Platelet signaling in immune landscape: comprehensive mechanism and clinical therapy

Platelets are essential for blood clotting and maintaining normal hemostasis. In pathological conditions, platelets are increasingly recognized as crucial regulatory factors in various immune-mediated inflammatory diseases. Resting platelets are induced by various factors such as immune complexes through Fc receptors, platelet-targeting autoantibodies and other platelet-activating stimuli. Platelet activation in immunological processes involves the release of immune activation stimuli, antigen presentation and interaction with immune cells. Platelets participate in both the innate immune system (neutrophils, monocytes/macrophages, dendritic cells (DCs) and Natural Killer (NK) cells and the adaptive immune system (T and B cells). Clinical therapeutic strategies include targeting platelet activation, platelet-immune cell interaction and platelet-endothelial cell interaction, which display positive development prospects. Understanding the mechanisms of platelets in immunity is important, and developing targeted modulations of these mechanisms will pave the way for promising therapeutic strategies.

Development of anti-cancer drugs for tumor-associated macrophages: a comprehensive review and mechanistic insights

This review provides an in-depth summary of the development of anti-cancer drugs for tumor-associated macrophages (TAMs), with a particular focus on the development and tissue specialization of macrophages, and factors influencing the polarization of M1 and M2 macrophages, and mechanistic insights underlying the targeting therapeutic approaches. TAMs, pivotal in the tumor microenvironment, exhibit notable plasticity and diverse functional roles. Influenced by the complex milieu, TAMs polarize into M1-type, which suppresses tumors, and M2-type, which promotes metastasis. Notably, targeting M2-TAMs is a promising strategy for tumor therapy. By emphasizing the importance of macrophages as a therapeutic target of anti-cancer drugs, this review aims to provide valuable insights and research directions for clinicians and researchers.

A hypoxia-derived gene signature to suggest cisplatin-based therapeutic responses in patients with cervical cancer

Cervical cancer remains a significant global public health concern, often exhibits cisplatin resistance in clinical settings. Hypoxia, a characteristic of cervical cancer, substantially contributes to cisplatin resistance. To evaluate the therapeutic efficacy of cisplatin in patients with cervical cancer and to identify potential effective drugs against cisplatin resistance, we established a hypoxia-inducible factor-1 (HIF-1)-related risk score (HRRS) model using clinical data from patients treated with cisplatin. Cox and LASSO regression analyses were used to stratify patient risks and prognosis. Through qRT-PCR, we validated nine potential prognostic HIF-1 genes that successfully predict cisplatin responsiveness in patients and cell lines. Subsequently, we identified fostamatinib, an FDA-approved spleen tyrosine kinase inhibitor, as a promising drug for targeting the HRRS-high group. We observed a positive correlation between the IC50 values of fostamatinib and HRRS in cervical cancer cell lines. Moreover, fostamatinib exhibited potent anticancer effects on high HRRS groups in vitro and in vivo. In summary, we developed a hypoxia-related gene signature that suggests cisplatin response prediction in cervical cancer and identified fostamatinib as a potential novel treatment approach for resistant cases.

Expression of variant isoforms of the tyrosine kinase SYK differentially regulates cervical cancer progression through PI3K/AKT pathway

Invasion and metastasis are the main reasons for the poor prognosis of patients with cervical cancer(CC). SYK is closely related to tumor development. However, the functions of its two isoforms, SYK (L) or SYK (S), are not fully understood to date. In this study, we investigated their biologic functions and possible prognostic values in CC. qRT-PCR was performed to detect the expression of SYK and two variant isoforms in cervical cancer tissues and cells. The association of SYK(L) and SYK(S) with Clinical pathological parameters were evaluated. The migration and invasion was detected by scratch assay and transwell. Western blot was conducted to measure the changes of epithelial mesenchymal transition (EMT)-related markers and PI3K/AKT signaling pathway proteins in cervical cancer cells. LY294002 (inhibitor of PI3K/AKT pathway) and IGF-1 (activator of PI3K/AKT pathway) were applied to evaluate the contribution of PI3K/AKT signaling pathway in cervical cancer cells. The expression of SYK(S) in cervical cancer tissues was significantly higher than that of SYK(L). SYK(L) and SYK(S) were correlated with muscular infiltration, SYK(L) high expression had a better prognosis, whereas SYK(S) high expression predicted a worse disease outcome. Cox multivariate regression analysis demonstrated that SYK(L) expression was an independent prognostic factor. SYK(L) significantly inhibited the proliferation, migration and invasion, while SYK(S) showed the opposite effects. LY294002 blocked SYK (L) knockdown-induced enhancement of migration and invasion as well as the expression EMT-related markers, whereas IGF-1 rescued the decreased migration, invasion and EMT induced by SYK (S) knockdown. The results suggest that SYK(L) and SYK(S) are involved in the progression of cervical cancer through PI3K/AKT signaling pathway, and may serve as potential targets for clinical treatment of advanced cervical cancer.

GL-V9 Promotes Autophagy-Mediated YAP1 Degradation and Activates Mitochondrial Apoptosis in PDAC Cells

Background: Pancreatic ductal adenocarcinoma (PDAC) is among the most aggressive forms of pancreatic cancer with a poor prognosis. YAP1 expression is markedly elevated in PDAC, but how it works is not clear. GL-V9, a derivative of the natural compound wogonin, effectively fights a variety of tumors; however, its effect on PDAC has not yet been studied. Methods: TCGA database analysis, Western blots, immunofluorescence, and real-time PCR were used to evaluate GL-V9's effect on YAP1 expression and mRNA levels. Immunofluorescence was used to examine the co-location of YAP1 with LAMP2 and p62. Co-immunoprecipitation was used to assess the binding of YAP1 to ubiquitin, p62, and TEAD1. A PDAC graft tumor model was used to test GL-V9's pharmacological effects. Western blots and immunohistochemistry were used to measure apoptosis- and autophagy-related protein expression. Results: GL-V9 effectively promoted the degradation of YAP1, reduced YAP1 nuclear localization, and induced mitochondrial apoptosis in PDAC cells. YAP1 overexpression led to the upregulation of Bcl-2 and attenuated the caspase cascade induced by GL-V9. Furthermore, we demonstrated that GL-V9 induced autophagosome-lysosome fusion via the AKT/mTOR/TFEB pathway, leading to mitochondrial apoptosis in PDAC cells. In vivo studies also confirmed that GL-V9 exerts anti-tumor effects by suppressing YAP1 expression, while also activating autophagy and inducing mitochondrial apoptosis in BXPC-3-bearing BALB/c nude mice. Conclusions: Our findings underscore the importance of autophagy-mediated YAP1 degradation in PDAC, providing a novel molecular rationale (GL-V9) as a promising treatment for this disease.

New insights into SYK targeting in solid tumors

Spleen tyrosine kinase (SYK) is predominantly expressed in hematopoietic cells and has been extensively studied for its pivotal role in B cell malignancies and autoimmune diseases. In epithelial solid tumors, SYK shows a paradoxical role, acting as a tumor suppressor in some cancers while driving tumor growth in others. Recent preclinical studies have identified the role of SYK in the tumor microenvironment (TME), revealing that SYK signaling in immune cells, especially B cells, and myeloid cells, promote immunosuppression, tumor growth, and metastasis across various solid tumors. This review explores the emerging roles of SYK in solid tumors, the mechanisms of SYK activation, and findings from preclinical and clinical studies of SYK inhibitors as either standalone treatments or in combination with immunotherapy or chemotherapy for solid tumors.

Unveiling the contribution of tumor-associated macrophages in driving epithelial-mesenchymal transition: a review of mechanisms and therapeutic Strategies

Tumor-associated macrophages (TAMs), fundamental constituents of the tumor microenvironment (TME), significantly influence cancer development, primarily by promoting epithelial-mesenchymal transition (EMT). EMT endows cancer cells with increased motility, invasiveness, and resistance to therapies, marking a pivotal juncture in cancer progression. The review begins with a detailed exposition on the origins of TAMs and their functional heterogeneity, providing a foundational understanding of TAM characteristics. Next, it delves into the specific molecular mechanisms through which TAMs induce EMT, including cytokines, chemokines and stromal cross-talking. Following this, the review explores TAM-induced EMT features in select cancer types with notable EMT characteristics, highlighting recent insights and the impact of TAMs on cancer progression. Finally, the review concludes with a discussion of potential therapeutic targets and strategies aimed at mitigating TAM infiltration and disrupting the EMT signaling network, thereby underscoring the potential of emerging treatments to combat TAM-mediated EMT in cancer. This comprehensive analysis reaffirms the necessity for continued exploration into TAMs' regulatory roles within cancer biology to refine therapeutic approaches and improve patient outcomes.

Enhancing cancer immunotherapy: Nanotechnology-mediated immunotherapy overcoming immunosuppression

Immunotherapy is an important cancer treatment method that offers hope for curing cancer patients. While immunotherapy has achieved initial success, a major obstacle to its widespread adoption is the inability to benefit the majority of patients. The success or failure of immunotherapy is closely linked to the tumor's immune microenvironment. Recently, there has been significant attention on strategies to regulate the tumor immune microenvironment in order to stimulate anti-tumor immune responses in cancer immunotherapy. The distinctive physical properties and design flexibility of nanomedicines have been extensively utilized to target immune cells (including tumor-associated macrophages (TAMs), T cells, myeloid-derived suppressor cells (MDSCs), and tumor-associated fibroblasts (TAFs)), offering promising advancements in cancer immunotherapy. In this article, we have reviewed treatment strategies aimed at targeting various immune cells to regulate the tumor immune microenvironment. The focus is on cancer immunotherapy models that are based on nanomedicines, with the goal of inducing or enhancing anti-tumor immune responses to improve immunotherapy. It is worth noting that combining cancer immunotherapy with other treatments, such as chemotherapy, radiotherapy, and photodynamic therapy, can maximize the therapeutic effects. Finally, we have identified the challenges that nanotechnology-mediated immunotherapy needs to overcome in order to design more effective nanosystems.

The Pivotal Role of Macrophages in the Pathogenesis of Pancreatic Diseases

The pancreas is an organ with both exocrine and endocrine functions, comprising a highly organized and complex tissue microenvironment composed of diverse cellular and non-cellular components. The impairment of microenvironmental homeostasis, mediated by the dysregulation of cell-to-cell crosstalk, can lead to pancreatic diseases such as pancreatitis, diabetes, and pancreatic cancer. Macrophages, key immune effector cells, can dynamically modulate their polarization status between pro-inflammatory (M1) and anti-inflammatory (M2) modes, critically influencing the homeostasis of the pancreatic microenvironment and thus playing a pivotal role in the pathogenesis of the pancreatic disease. This review aims to summarize current findings and provide detailed mechanistic insights into how alterations mediated by macrophage polarization contribute to the pathogenesis of pancreatic disorders. By analyzing current research comprehensively, this article endeavors to deepen our mechanistic understanding of regulatory molecules that affect macrophage polarity and the intricate crosstalk that regulates pancreatic function within the microenvironment, thereby facilitating the development of innovative therapeutic strategies that target perturbations in the pancreatic microenvironment.

Nanoparticles in tumor microenvironment remodeling and cancer immunotherapy

Cancer immunotherapy and vaccine development have significantly improved the fight against cancers. Despite these advancements, challenges remain, particularly in the clinical delivery of immunomodulatory compounds. The tumor microenvironment (TME), comprising macrophages, fibroblasts, and immune cells, plays a crucial role in immune response modulation. Nanoparticles, engineered to reshape the TME, have shown promising results in enhancing immunotherapy by facilitating targeted delivery and immune modulation. These nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles further enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells such as dendritic cells. Moreover, exosomes, whether naturally secreted by cells in the body or bioengineered, have been explored to regulate the TME and immune-related cells to affect cancer immunotherapy. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, exhibit the potential to accelerate immunotherapy. The co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-tumor immunity. With their ability to induce long-term immunity, nanoarchitectures are promising structures in vaccine development. This review underscores the critical role of nanoparticles in overcoming current challenges and driving the advancement of cancer immunotherapy and TME modification.

Breaking the stromal barrier in pancreatic cancer: Advances and challenges

Pancreatic cancer (PC) remains a leading cause of mortality worldwide due to the absence of early detection methods and the low success rates of traditional therapeutic strategies. Drug resistance in PC is driven by its desmoplastic stroma, which creates a barrier that shields cancer niches and prevents the penetration of drugs. The PC stroma comprises heterogeneous cellular populations and non-cellular components involved in aberrant ECM deposition, immunosuppression, and drug resistance. These components can influence PC development through intricate and complex crosstalk with the PC cells. Understanding how stromal components and cells interact with and influence the invasiveness and refractoriness of PC cells is thus a prerequisite for developing successful stroma-modulating strategies capable of remodeling the PC stroma to alleviate drug resistance and enhance therapeutic outcomes. In this review, we explore how non-cellular and cellular stromal components, including cancer-associated fibroblasts and tumor-associated macrophages, contribute to the immunosuppressive and tumor-promoting effects of the stroma. We also examine the signaling pathways underlying their activation, tumorigenic effects, and interactions with PC cells. Finally, we discuss recent pre-clinical and clinical work aimed at developing and testing novel stroma-modulating agents to alleviate drug resistance and improve therapeutic outcomes in PC.