Cancer-associated fibroblasts induce PDL1+ neutrophils through the IL6-STAT3 pathway that foster immune suppression in hepatocellular carcinoma. Cell Death Dis. 2018;9:422. [PMID: 29556041 PMCID: PMC5859264 DOI: 10.1038/s41419-018-0458-4]

Unraveling the complex role of tumor-associated neutrophils within solid tumors

Neutrophils are integral to the frontline defense against pathogenic bacterial and fungal invasions. Beyond their traditional roles, these cells are increasingly recognized for their dualistic contributions to the pathology of autoimmune and inflammatory diseases, as well as their complex involvement in cancer progression. Neutrophils interact with different disease states, highlighting their potential as therapeutic targets. Within tumor microenvironment (TME), tumor-associated neutrophils (TANs) exhibit a functional dichotomy, capable of either fostering or impeding tumor growth and metastasis. This binary functional potential of TANs, under certain conditions, suggests a reversible state that could transition from tumor-promoting to tumor-eradicating phenotypes. Despite the critical implications of such functional plasticity, systematic studies of TAN behavioral shifts in the context of cancer immunotherapy remain scarce. Herein, we review recent advancements in the understanding of TANs within the TME, highlighting their binary regulatory effects on solid tumors. Leveraging the latest insights from experimental and clinical research, this review elucidates the complex roles of TANs in tumor development and explores their molecular interactions as potential therapeutic targets. The elucidation of these mechanisms holds promise for novel cancer treatment strategies, aiming to improve patient outcomes by manipulating the tumor-promoting or -suppressing functions of TANs.

Pathogenesis and Systemic Treatment of Hepatocellular Carcinoma: Current Status and Prospects

Hepatocellular carcinoma (HCC) remains one of the major threats to human health worldwide. The emergence of systemic therapeutic options has greatly improved the prognosis of patients with HCC, particularly those with advanced stages of the disease. In this review, we discussed the pathogenesis of HCC, genetic alterations associated with the development of HCC, and alterations in the tumor immune microenvironment. Then, important indicators and emerging technologies related to the diagnosis of HCC are summarized. Also, we reviewed the major advances in treatments for HCC, offering insights into future prospects for next-generation managements.

Unlocking the crucial role of cancer-associated fibroblasts in tumor metastasis: Mechanisms and therapeutic prospects

BACKGROUND

Tumor metastasis represents a stepwise progression and stands as a principal determinant of unfavorable prognoses among cancer patients. Consequently, an in-depth exploration of its mechanisms holds paramount clinical significance. Cancer-associated fibroblasts (CAFs), constituting the most abundant stromal cell population within the tumor microenvironment (TME), have garnered robust evidence support for their pivotal regulatory roles in tumor metastasis.

AIM OF REVIEW

This review systematically explores the roles of CAFs at eight critical stages of tumorigenic dissemination: 1) extracellular matrix (ECM) remodeling, 2) epithelial-mesenchymal transition (EMT), 3) angiogenesis, 4) tumor metabolism, 5) perivascular migration, 6) immune escape, 7) dormancy, and 8) premetastatic niche (PMN) formation. Additionally, we provide a compendium of extant strategies aimed at targeting CAFs in cancer therapy.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review delineates a structured framework for the interplay between CAFs and tumor metastasis while furnishing insights for the potential therapeutic developments. It contributes to a deeper understanding of cancer metastasis within the TME, facilitating the utilization of CAF-targeting therapies in anti-metastatic approaches.

Neutrophils in cancer: At the crucial crossroads of anti-tumor and pro-tumor

Neutrophils are important components of the immune system and play a key role in defending against pathogenic infections and responding to inflammatory cues, including cancer. Their dysregulation indicates potential disease risk factors. However, their functional importance in disease progression has often been underestimated due to their short half-life, especially as there is limited information on the role of intratumoral neutrophils. Recent studies on their prominent role in cancer have led to a paradigm shift in our understanding of the functional diversity of neutrophils. These studies highlight that neutrophils have emerged as key components of the tumor microenvironment, where they can play a dual role in promoting and suppressing cancer. Moreover, several approaches to therapeutically target neutrophils have emerged, and clinical trials are investigating their efficacy. In this review, we discussed the involvement of neutrophils in cancer initiation and progression. We summarized recent advances in therapeutic strategies targeting neutrophils and, most importantly, suggested future research directions that could facilitate the manipulation of neutrophils for therapeutic purposes in cancer patients.

Revisiting the role of cancer-associated fibroblasts in tumor microenvironment

Cancer-associated fibroblasts (CAFs) are integral components of the tumor microenvironment playing key roles in tumor progression, metastasis, and therapeutic resistance. However, challenges persist in understanding their heterogeneity, origin, and functional diversity. One major obstacle is the lack of standardized naming conventions for CAF subpopulations, with current systems failing to capture their full complexity. Additionally, the identification of CAFs is hindered by the absence of specific biomarkers, limiting the precision of diagnostic and therapeutic strategies. In vitro culture conditions often fail to maintain the in vivo characteristics of CAFs, which complicates their study and the translation of findings to clinical practice. Although current detection methods, such as antibodies, mRNA probes, and single-cell transcriptomics, offer insights into CAF biology, they lack standardization and fail to provide reliable quantitative measures. Furthermore, the dynamic interactions between CAFs, tumor cells, and immune cells within the TME remain insufficiently understood, and the role of CAFs in immune evasion and therapy resistance is an area of ongoing research. Understanding how CAFs influence drug resistance and the immune response is essential for developing more effective cancer therapies. This review aims to provide an in-depth analysis of the challenges in CAF research, propose future research directions, and emphasize the need for improved CAF-targeted therapeutic strategies. By addressing these gaps, it seeks to highlight the potential of CAFs as targets for overcoming therapeutic resistance and enhancing the efficacy of cancer treatments.

Immunocytes in the tumor microenvironment: recent updates and interconnections

The tumor microenvironment (TME) is a complex, dynamic ecosystem where tumor cells interact with diverse immune and stromal cell types. This review provides an overview of the TME's evolving composition, emphasizing its transition from an early pro-inflammatory, immune-promoting state to a later immunosuppressive milieu characterized by metabolic reprogramming and hypoxia. It highlights the dual roles of key immunocytes-including T lymphocytes, natural killer cells, macrophages, dendritic cells, and myeloid-derived suppressor cells-which can either inhibit or support tumor progression based on their phenotypic polarization and local metabolic conditions. The article further elucidates mechanisms of immune cell plasticity, such as the M1/M2 macrophage switch and the balance between effector T cells and regulatory T cells, underscoring their impact on tumor growth and metastasis. Additionally, emerging therapeutic strategies, including checkpoint inhibitors and chimeric antigen receptor (CAR) T and NK cell therapies, as well as approaches targeting metabolic pathways, are discussed as promising avenues to reinvigorate antitumor immunity. By integrating recent molecular insights and clinical advancements, the review underscores the importance of deciphering the interplay between immunocytes and the TME to develop more effective cancer immunotherapies.

Role of Neutrophils in Anti-Tumor Activity: Characteristics and Mechanisms of Action

As one of the leading components in the immune system, neutrophils in the tumor microenvironment (TME) have received considerable attention in recent years. The tumor-killing effects of neutrophils in a variety of tumors have been reported. However, the functions of neutrophils in tumors remain to be completely elucidated, and both anti-tumor and tumor-promotion activities have been reported. This review focuses on the characteristics of neutrophils and their mechanisms of action in the TME, with an emphasis on their anti-tumor activity, including reactive oxygen species (ROS)-induced tumor killing, cytotoxic T lymphocytes (CTLs)-induced tumor killing, trogocytosis, cytotoxic enzymes, and trained immunity. Furthermore, the possible targets and methods of tumor treatment regimens for neutrophils are explored, with the aim of exploring the use of neutrophils in the future as a potential anti-tumor treatment strategy.

Extracellular matrix stiffness: mechanisms in tumor progression and therapeutic potential in cancer

Tumor microenvironment (TME) is a complex ecosystem composed of both cellular and non-cellular components that surround tumor tissue. The extracellular matrix (ECM) is a key component of the TME, performing multiple essential functions by providing mechanical support, shaping the TME, regulating metabolism and signaling, and modulating immune responses, all of which profoundly influence cell behavior. The quantity and cross-linking status of stromal components are primary determinants of tissue stiffness. During tumor development, ECM stiffness not only serves as a barrier to hinder drug delivery but also promotes cancer progression by inducing mechanical stimulation that activates cell membrane receptors and mechanical sensors. Thus, a comprehensive understanding of how ECM stiffness regulates tumor progression is crucial for identifying potential therapeutic targets for cancer. This review examines the effects of ECM stiffness on tumor progression, encompassing proliferation, migration, metastasis, drug resistance, angiogenesis, epithelial-mesenchymal transition (EMT), immune evasion, stemness, metabolic reprogramming, and genomic stability. Finally, we explore therapeutic strategies that target ECM stiffness and their implications for tumor progression.

Roles of the gut microbiota in hepatocellular carcinoma: from the gut dysbiosis to the intratumoral microbiota

Hepatocellular carcinoma (HCC) is closely linked to alterations in the gut microbiota. This dysbiosis is characterized by significant changes in the microbial population, which correlate with the progression of HCC. Gut dysbiosis ultimately promotes HCC development in several ways: it damages the integrity of the gut-vascular barrier (GVB), alters the tumor microenvironment (TME), and even affects the intratumoral microbiota. Subsequently, intratumoral microbiota present a characteristic profile and play an essential role in HCC progression mainly by causing DNA damage, mediating tumor-related signaling pathways, altering the TME, promoting HCC metastasis, or through other mechanisms. Both gut microbiota and intratumoral microbiota have dual effects on HCC progression; a comprehensive understanding of their complex biological roles will provide a theoretical foundation for potential clinical applications in HCC treatment.

Cancer-associated fibroblasts in hepatocellular carcinoma: heterogeneity, mechanisms and therapeutic targets

Hepatocellular carcinoma (HCC) is one of the common malignant cancers worldwide. Although immunotherapy has improved the treatment outcome in HCC, a significant percentage of patients with advanced HCC still cannot benefit from immunotherapy. Therefore, developing new targets or combination therapeutic strategies to improve the efficacy of immunotherapy is urgently needed. A deeper understanding of the mechanisms underlying immune regulation may help in this regard. The tumor microenvironment (TME) consists of a diverse set of components modulating the efficacy of immunotherapy. Cancer-associated fibroblasts (CAFs) are critical components of the TME and can regulate both tumor and immune cells through secreted cytokines and exosomes that impact various signaling pathways in target cells. CAF-derived cytokines can also participate in extracellular matrix (ECM) remodeling, thereby impacting cancer progression and tumor responsiveness to immunotherapy among other effects. A thorough understanding of the phenotypic and functional profile dynamism of CAFs may lead the way for new treatment strategies and/or better treatment outcomes in HCC patients. In this review, we outline the biomarkers and functional heterogeneity of CAFs in HCC and elaborate on molecular mechanisms of CAFs, including anti-programmed cell death protein 1 (PD-1)/PD-ligand 1 (PD-L1) immunotherapy. We also examine current clinical implications of CAFs-related targets as potential therapeutic candidates in HCC.

Neutrophils in Type 1 Diabetes: Untangling the Intricate Web of Pathways and Hypothesis

Neutrophils are increasingly recognized as key contributors to the pathogenesis of Type 1 Diabetes (T1D), yet their precise mechanistic role in disease onset and progression remains incompletely understood. While these innate immune cells reside in pancreatic tissue and support tissue homeostasis under physiological conditions, they can also drive tissue damage by triggering innate immune responses and modulating inflammation. Within the inflammatory milieu, neutrophils establish complex, bidirectional interactions with various immune cells, including macrophages, dendritic cells, natural killer cells, and lymphocytes. Once activated, they may enhance the innate immune response through direct or indirect crosstalk with immune cells, antigen presentation, and β-cell destruction or dysfunction. These mechanisms underscore the multifaceted and dynamic role of neutrophils in T1D, shaped by their intricate immunological interactions. Further research into the diverse functional capabilities of neutrophils is crucial for uncovering novel aspects of their involvement in T1D, potentially revealing new therapeutic targets to modulate disease progression.

Cancer associated fibroblasts in cancer development and therapy

Cancer-associated fibroblasts (CAFs) are key players in cancer development and therapy, and they exhibit multifaceted roles in the tumor microenvironment (TME). From their diverse cellular origins, CAFs undergo phenotypic and functional transformation upon interacting with tumor cells and their presence can adversely influence treatment outcomes and the severity of the cancer. Emerging evidence from single-cell RNA sequencing (scRNA-seq) studies have highlighted the heterogeneity and plasticity of CAFs, with subtypes identifiable through distinct gene expression profiles and functional properties. CAFs influence cancer development through multiple mechanisms, including regulation of extracellular matrix (ECM) remodeling, direct promotion of tumor growth through provision of metabolic support, promoting epithelial-mesenchymal transition (EMT) to enhance cancer invasiveness and growth, as well as stimulating cancer stem cell properties within the tumor. Moreover, CAFs can induce an immunosuppressive TME and contribute to therapeutic resistance. In this review, we summarize the fundamental knowledge and recent advances regarding CAFs, focusing on their sophisticated roles in cancer development and potential as therapeutic targets. We discuss various strategies to target CAFs, including ECM modulation, direct elimination, interruption of CAF-TME crosstalk, and CAF normalization, as approaches to developing more effective treatments. An improved understanding of the complex interplay between CAFs and TME is crucial for developing new and effective targeted therapies for cancer.

The fibroinflammatory response in cancer

Fibroinflammation refers to the highly integrated fibrogenic and inflammatory responses mediated by the concerted function of fibroblasts and innate immune cells in response to tissue perturbation. This process underlies the desmoplastic remodelling of the tumour microenvironment and thus plays an important role in tumour initiation, growth and metastasis. More specifically, fibroinflammation alters the biochemical and biomechanical signalling in malignant cells to promote their proliferation and survival and further supports an immunosuppressive microenvironment by polarizing the immune status of tumours. Additionally, the presence of fibroinflammation is often associated with therapeutic resistance. As such, there is increasing interest in targeting this process to normalize the tumour microenvironment and thus enhance the treatment of solid tumours. Herein, we review advances made in unravelling the complexity of cancer-associated fibroinflammation that can inform the rational design of therapies targeting this.

STAT3 orchestrates immune dynamics in hepatocellular carcinoma: A pivotal nexus in tumor progression

Hepatocellular carcinoma (HCC) presents a formidable challenge in oncology, attributed to its association with chronic liver diseases and global prevalence. The immune microenvironment profoundly influences HCC progression, balancing immune suppression and antitumor responses. The Signal Transducer and Activator of Transcription 3 (STAT3) is central to this equilibrium, orchestrating immune dynamics and intertwining tumor progression with immune evasion mechanisms. Dysregulated STAT3 signaling, activated by various stimuli, including cytokines and growth factors, promotes an immunosuppressive milieu within HCC tumors, fostering tumor survival and proliferation while hindering immune surveillance. Non-coding RNAs and other molecules regulate this process, modulating STAT3 activity and influencing immune cell function. Moreover, therapeutic interventions targeting the STAT3 pathway, alongside advancements in radiotherapy, cancer vaccines, and diabetes-related drugs, offer promising strategies in HCC management. Integrating natural compounds with immunotherapy emerges as a novel approach, leveraging their ability to enhance antitumor immunity and counter immune evasion strategies. Understanding the multifaceted role of STAT3 and its interactions within the immune landscape of HCC is paramount for devising effective therapeutic interventions and improving patient outcomes.

Navigating heme pathways: the breach of heme oxygenase and hemin in breast cancer

Breast cancer remains a significant global health challenge, with diverse subtypes and complex molecular mechanisms underlying its development and progression. This review comprehensively examines recent advances in breast cancer research, with a focus on classification, molecular pathways, and the role of heme oxygenases (HO), heme metabolism implications, and therapeutic innovations. The classification of breast cancer subtypes based on molecular profiling has significantly improved diagnosis and treatment strategies, allowing for tailored approaches to patient care. Molecular studies have elucidated key signaling pathways and biomarkers implicated in breast cancer pathogenesis, shedding light on potential targets for therapeutic intervention. Notably, emerging evidence suggests a critical role for heme oxygenases, particularly HO-1, in breast cancer progression and therapeutic resistance, highlighting the importance of understanding heme metabolism in cancer biology. Furthermore, this review highlights recent advances in breast cancer therapy, including targeted therapies, immunotherapy, and novel drug delivery systems. Understanding the complex interplay between breast cancer subtypes, molecular pathways, and innovative therapeutic approaches is essential for improving patient outcomes and developing more effective treatment strategies in the fight against breast cancer.

Hepatic Stellate Cells Functional Heterogeneity in Liver Cancer

Hepatic stellate cells (HSCs) are the liver's pericytes, and play key roles in liver homeostasis, regeneration, fibrosis, and cancer. Upon injury, HSCs activate and are the main origin of myofibroblasts and cancer-associated fibroblasts (CAFs) in liver fibrosis and cancer. Primary liver cancer has a grim prognosis, ranking as the third leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) being the predominant type, followed by intrahepatic cholangiocarcinoma (iCCA). Moreover, the liver hosts 35% of all metastatic lesions. The distinct spatial distribution and functional roles of HSCs across these malignancies represent a significant challenge for universal therapeutic strategies, requiring a nuanced and tailored understanding of their contributions. This review examines the heterogeneous roles of HSCs in liver cancer, focusing on their spatial localization, dynamic interactions within the tumor microenvironment (TME), and emerging therapeutic opportunities, including strategies to modulate their activity, and harness their potential as targets for antifibrotic and antitumor interventions.

Vitamin D impedes eosinophil chemotaxis via inhibiting glycolysis-induced CCL26 expression in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is likely to relapse due to aberrant eosinophil infiltration. The deficiency of Vitamin D (VD) is associated with increased eosinophil infiltration in eosinophilic oesophagitis. However, the role of VD in eosinophilic CRSwNP (ECRSwNP) remains unclear. This study aims to explore the effects of VD on eosinophil chemotaxis in ECRSwNP and the underlying mechanisms.

METHODS

Human nasal mucosal tissues were collected from the control group, patients with non-ECRSwNP and those with ECRSwNP. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of VD and CCL26 in the nasal mucosa, plasma, or human primary nasal epithelial cells (hNECs). hNECs and eosinophils from patients were cultured to investigate the effect of VD on eosinophil chemotaxis and CCL26 expression via eosinophil migration assay, Western blot, and ELISA. Transcriptome sequencing, pathway enrichment analysis, Western blot and immunohistochemical staining were used to determine the key signaling pathway involved in eosinophil chemotaxis.

RESULTS

A significant decrease in VD levels was observed in the nasal mucosa of patients with ECRSwNP, which correlated with increased local eosinophil infiltration. Furthermore, pathway enrichment analysis suggested that glycolysis signaling was promoted in the ECRSwNP group, verified by enhanced expression of glycolytic key enzymes that were positively correlated with eosinophil infiltration in nasal mucosa from patients with ECRSwNP. VD suppressed eosinophil chemotaxis in vitro by inhibiting CCL26 expression. Glycolysis regulated CCL26 expression via the ERK pathway and lactate, which promoted the expression and stability of CCL26 protein. VD attenuated glycolysis, leading to decreased production of lactate and inactivation of the ERK pathway. The decrease in lactate production suppressed eosinophil chemotaxis. Moreover, the ERK pathway activator reversed the inhibitory effect of VD on eosinophil chemotaxis.

CONCLUSIONS

VD impedes eosinophil chemotaxis by inhibiting glycolysis - induced CCL26 expression via attenuating the activation of the ERK pathway and reducing lactate production. VD supplementation may be a novel strategy to treat ECRSwNP.

Cancer-associated fibroblasts promote pro-tumor functions of neutrophils in pancreatic cancer via IL-8: potential suppression by pirfenidone

BACKGROUND

The mechanisms by which neutrophils acquire pro-tumor properties remain poorly understood. In pancreatic cancer, cancer-associated fibroblasts (CAFs) may interact with neutrophils, directing them to promote tumor progression.

METHODS

To validate the association between CAFs and neutrophils, the localization of neutrophils was examined in clinically resected pancreatic cancer specimens. CAFs were produced by culturing in cancer-conditioned media, and the effects of these CAFs on neutrophils were examined. In vitro migration and invasion assays assess the effect of CAF-activated neutrophils on cancer cells. The factors secreted by the activated neutrophils were also explored. Finally, pirfenidone (PFD) was tested to determine whether it could suppress the pro-tumor functions of activated neutrophils.

RESULTS

In pancreatic cancer specimens, neutrophils tended to co-localize with IL-6-positive CAFs. Neutrophils co-cultured with CAFs increased migratory capacity and prolonged life span. CAF-affected neutrophils enhance the migratory and invasive activities of pancreatic cancer cells. IL-8 is the most upregulated cytokine secreted by the neutrophils. PFD suppresses IL-8 secretion from CAF-stimulated neutrophils and mitigates the malignant traits of pancreatic cancer cells.

CONCLUSION

CAFs activate neutrophils and enhance the malignant phenotype of pancreatic cancer. The interactions between cancer cells, CAFs, and neutrophils can be disrupted by PFD, highlighting a potential therapeutic approach.

Inflammation and Immunity in Liver Neoplasms: Implications for Future Therapeutic Strategies

Over the past two decades, the "hallmarks of cancer" have revolutionized cancer research and highlighted the crucial roles of inflammation and immunity. Protumorigenic inflammation promotes cancer development along with inhibition of antitumor immunity, shaping the tumor microenvironment (TME) toward a tumor-permissive state and further enhancing the malignant potential of cancer cells. This immunosuppressive TME allows tumors to evade immunosurveillance. Thus, understanding the complex interplay between tumors and the immune system within the TME has become pivotal, especially with the advent of immunotherapy. Although immunotherapy has achieved notable success in many malignancies, primary liver cancer, particularly hepatocellular carcinoma, presents unique challenges. The hepatic immunosuppressive environment poses obstacles to the effectiveness of immunotherapy, along with high mortality rates and limited treatment options for patients with liver cancer. In this review, we discuss current understanding of the complex immune-mediated mechanisms underlying liver neoplasms, focusing on hepatocellular carcinoma and liver metastases. We describe the molecular and cellular heterogeneity within the TME, highlighting how this presents unique challenges and opportunities for immunotherapy in liver cancers. By unraveling the immune landscape of liver neoplasms, this review aims to contribute to the development of more effective therapeutic interventions, ultimately improving clinical outcomes for patients with liver cancer.

Targeting Deltex E3 Ubiquitin Ligase 2 Inhibits Tumor-associated Neutrophils and Sensitizes Hepatocellular Carcinoma Cells to Immunotherapy

Several E3 ligases have been found to affect the immune microenvironment of hepatocellular carcinoma (HCC) and lead to the resistance of immunotherapy. In this study, genes of E3 ligases are screened based on The Cancer Genome Atlas (TCGA) dataset. Through cytometry by time of flight (CyTOF), flow cytometry, and further experiments, Deltex E3 ubiquitin ligase 2 (DTX2) in HCC cells is identified to promote the infiltration and polarization of tumor-associated neutrophils (TANs) with a protumor phenotype, thus attenuating the infiltration and cytotoxicity of CD8+ T cells partially through C-X-C motif chemokine 2 (CXCL2) and C-X-C motif chemokine 6 (CXCL6). Mechanistically, DTX2 can interact with histone H2B and promote its monoubiquitination at lysine120 (H2BK120ub1), thereby increasing CXCL2 and CXCL6 transcription through histone epigenetic regulation. Different tumor models in vivo demonstrated that DTX2 inhibitor treatment inhibited tumor growth and sensitized HCC cells to the therapeutic effects of programmed cell death protein 1 (PD-1) antibody. In summary, this study identifies DTX2 as a potential target for HCC immunotherapy.

Evaluation of S100A8/A9 and neutrophils as prognostic markers in metastatic melanoma patients under immune-checkpoint inhibition

Immune-checkpoint inhibitors (ICIs) have revolutionized melanoma treatment, yet approximately half of patients do not respond to these therapies. Identifying prognostic biomarkers is crucial for treatment decisions. Our retrospective study assessed liquid biopsies and tumor tissue analyses for two potential biomarkers: danger-associated molecular pattern (DAMP) S100A8/A9 and its source, neutrophils. In 43 metastatic unresected stage III/IV melanoma patients, elevated serum levels of S100A8/A9 and neutrophils before and during ICI treatment correlated with worse outcomes. Furthermore, in 113 melanoma patients, neutrophil expression in the tumor microenvironment (TME) was associated with relapse and reduced survival. Measuring S100A8/A9 and neutrophils could enhance immunotherapy monitoring by predicting impaired clinical outcomes and non-response to ICIs. Serum S100A8/A9 levels and neutrophil counts at baseline (T0) and during treatment (T3) correlated with reduced progression-free survival (PFS). Elevated S100A8/A9 levels at T0 and T3 negatively impacted overall survival (OS). Notably, neutrophil infiltration was more prevalent in primary melanomas than in nevi and metastases, and its presence in primary melanomas was linked to poorer survival. S100A8/A9 serum levels, neutrophil counts, and tumor-associated neutrophil infiltration represent promising biomarkers for predicting treatment response and clinical outcomes in melanoma patients receiving ICIs. SIGNIFICANCE: These findings underscore the critical need for reliable biomarkers in melanoma research, particularly for predicting responses to immune-checkpoint inhibitors (ICIs). Identifying S100A8/A9 levels and neutrophil infiltration as potential indicators of treatment outcomes offers valuable insights for personalized therapy decisions. By enhancing monitoring and prognosis assessment, these biomarkers contribute to refining treatment strategies, ultimately improving patient care and outcomes. This research bridges gaps in understanding melanoma response mechanisms and highlights avenues for further investigation into immune-related markers, fostering advancements in precision medicine for melanoma patients.

Cancer-associated fibroblasts as therapeutic targets for cancer: advances, challenges, and future prospects

Research into cancer treatment has been mainly focused on developing therapies to directly target cancer cells. Over the past decade, extensive studies have revealed critical roles of the tumour microenvironment (TME) in cancer initiation, progression, and drug resistance. Notably, cancer-associated fibroblasts (CAFs) have emerged as one of the primary contributors in shaping TME, creating a favourable environment for cancer development. Many preclinical studies have identified promising targets on CAFs, demonstrating remarkable efficacy of some CAF-targeted treatments in preclinical models. Encouraged by these compelling findings, therapeutic strategies have now advanced into clinical evaluation. We aim to provide a comprehensive review of relevant subjects on CAFs, including CAF-related markers and targets, their multifaceted roles, and current landscape of ongoing clinical trials. This knowledge can guide future research on CAFs and advocate for clinical investigations targeting CAFs.

Spatial heterogeneity of the hepatocellular carcinoma microenvironment determines the efficacy of immunotherapy

Hepatocellular carcinoma (HCC) remains a global health challenge owing to its widespread incidence and high mortality. HCC has a specific immune tolerance function because of its unique physiological structure, which limits the efficacy of chemotherapy, radiotherapy, and molecular targeting. In recent years, new immune approaches, including adoptive cell therapy, tumor vaccines, and oncolytic virus therapy, have shown great potential. As the efficacy of immunotherapy mainly depends on the spatial heterogeneity of the tumor immune microenvironment, it is necessary to elucidate the crosstalk between the composition of the liver cancer immune environment, from which potential therapeutic targets can be selected to provide more appropriate individualized treatment programs. The role of spatial heterogeneity of immune cells in the microenvironment of HCC in the progression and influence of immunotherapy on improving the treatment and prognosis of HCC were comprehensively analyzed, providing new inspiration for the subsequent clinical treatment of liver cancer.

Up-regulated ITGB4 promotes hepatocellular carcinoma metastasis by activating hypoxia-mediated glycolysis and cancer-associated fibroblasts

The pre-metastatic niche constructed by cancer-associated fibroblasts (CAFs) plays a key role in the hypoxic tumor microenvironment (TME), promoting hepatocellular carcinoma (HCC) metastasis. Integrin, which is involved in cell-to-cell or cell-to-matrix interactions and TME regulation, affects tumor metastasis. However, the complex interactions between integrin-mediated HCC cells and CAFs remain unclear. Co-culture experiments were used to assess the behaviors of HCC cells and CAFs, demonstrating HCC metastatic traits and CAFs activation in vitro. Transcriptome sequencing analysis and molecular detection identified key genes, with overexpression and knockdown experiments further confirming their roles in HCC progression. Xenograft models validated these findings in vivo. We showed that HCC cells induced the conversion of normal hepatic stellate cells (HSCs) into CAFs and recruit additional CAFs, driven by lactate produced by HCC. Integrin beta 4 (ITGB4) was identified as a key gene in the process. Inhibiting ITGB4 reduced lactate secretion, reversed CAFs activation and recruitment, and decreased HCC metastasis, while overexpressing ITGB4 significantly enhanced these malignant phenotypes. ITGB4 influences glycolysis and HCC metastasis through the AKT/HK2 signaling pathway, and CAFs activation and recruitment through the TGF-β/Smads signaling pathway. Compared to tumors derived from control cells, ITGB4-knockdown tumors showed fewer and smaller intrahepatic metastatic nodules, reduced lactate production and CAFs formation, along with inhibition of AKT/HK2 and TGF-β/Smads signaling pathways. Our findings highlighted the impact of hypoxia on HCC progression, revealing the roles of ITGB4-mediated glycolysis and lactate-induced CAFs in the pre-metastatic niche on HCC metastasis.

The role of transcription factors in the crosstalk between cancer-associated fibroblasts and tumor cells

BACKGROUND

Transcription factors (TFs) fulfill a critical role in the formation and maintenance of different cell types during the developmental process as well as disease. It is believed that cancer-associated fibroblasts (CAFs) are activation status of tissue-resident fibroblasts or derived from form other cell types via transdifferentiation or dedifferentiation. Despite a subgroup of CAFs exhibit anti-cancer effects, most of them are reported to exert effects on tumor progression, further indicating their heterogeneous origin.

AIM OF REVIEW

This review aimed to summarize and review the roles of TFs in the reciprocal crosstalk between CAFs and tumor cells, discuss the emerging mechanisms, and their roles in cell-fate decision, cellular reprogramming and advancing our understanding of the gene regulatory networks over the period of cancer initiation and progression.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This manuscript delves into the key contributory factors of TFs that are involved in activating CAFs and maintaining their unique states. Additionally, it explores how TFs play a pivotal and multifaceted role in the reciprocal crosstalk between CAFs and tumor cells. This includes their involvement in processes such as epithelial-mesenchymal transition (EMT), proliferation, invasion, and metastasis, as well as metabolic reprogramming. TFs also have a role in constructing an immunosuppressive microenvironment, inducing resistance to radiation and chemotherapy, facilitating angiogenesis, and even 'educating' CAFs to support the malignancies of tumor cells. Furthermore, this manuscript delves into the current status of TF-targeted therapy and considers the future directions of TFs in conjunction with anti-CAFs therapies to address the challenges in clinical cancer treatment.

Heterogeneity of tumor-associated neutrophils in hepatocellular carcinoma

Neutrophils are the most abundant cell type in human blood and play a crucial role in the immune system and development of tumors. This review begins with the generation and development of neutrophils, traces their release from the bone marrow into the bloodstream, and finally discusses their role in the hepatocellular carcinoma (HCC) microenvironment. It elaborates in detail the mechanisms by which tumor-associated neutrophils (TANs) exert antitumor or protumor effects under the influence of various mediators in the tumor microenvironment. Neutrophils can exert antitumor effects through direct cytotoxic action. However, they can also accelerate the formation and progression of HCC by being recruited and infiltrated, promoting tumor angiogenesis, and maintaining an immunosuppressive microenvironment. Therefore, based on the heterogeneity and plasticity of neutrophils in tumor development, this review summarizes the current immunotherapies targeting TANs, discusses potential opportunities and challenges, and provides new insights into exploring more promising strategies for treating HCC.

Neutrophils in cancer: from biology to therapy

The view of neutrophils has shifted from simple phagocytic cells, whose main function is to kill pathogens, to very complex cells that are also involved in immune regulation and tissue repair. These cells are essential for maintaining and regaining tissue homeostasis. Neutrophils can be viewed as double-edged swords in a range of situations. The potent killing machinery necessary for immune responses to pathogens can easily lead to collateral damage to host tissues when inappropriately controlled. Furthermore, some subtypes of neutrophils are potent pathogen killers, whereas others are immunosuppressive or can aid in tissue healing. Finally, in tumor immunology, many examples of both protumorigenic and antitumorigenic properties of neutrophils have been described. This has important consequences for cancer therapy, as targeting neutrophils can lead to either suppressed or stimulated antitumor responses. This review will discuss the current knowledge regarding the pro- and antitumorigenic roles of neutrophils, leading to the concept of a confused state of neutrophil-driven pro-/antitumor responses.

Effect of neutrophils on tumor immunity and immunotherapy resistance with underlying mechanisms

Neutrophils are key mediators of the immune response and play essential roles in the development of tumors and immune evasion. Emerging studies indicate that neutrophils also play a critical role in the immunotherapy resistance in cancer. In this review, firstly, we summarize the novel classification and phenotypes of neutrophils and describe the regulatory relationships between neutrophils and tumor metabolism, flora microecology, neuroendocrine and tumor therapy from a new perspective. Secondly, we review the mechanisms by which neutrophils affect drug resistance in tumor immunotherapy from the aspects of the immune microenvironment, tumor antigens, and epigenetics. Finally, we propose several promising strategies for overcoming tumor immunotherapy resistance by targeting neutrophils and provide new research ideas in this area.

Neutrophil diversity and function in health and disease

Neutrophils, the most abundant type of granulocyte, are widely recognized as one of the pivotal contributors to the acute inflammatory response. Initially, neutrophils were considered the mobile infantry of the innate immune system, tasked with the immediate response to invading pathogens. However, recent studies have demonstrated that neutrophils are versatile cells, capable of regulating various biological processes and impacting both human health and disease. Cytokines and other active mediators regulate the functional activity of neutrophils by activating multiple receptors on these cells, thereby initiating downstream signal transduction pathways. Dysfunctions in neutrophils and disruptions in neutrophil homeostasis have been implicated in the pathogenesis of numerous diseases, including cancer and inflammatory disorders, often due to aberrant intracellular signaling. This review provides a comprehensive synthesis of neutrophil biological functions, integrating recent advancements in this field. Moreover, it examines the biological roles of receptors on neutrophils and downstream signaling pathways involved in the regulation of neutrophil activity. The pathophysiology of neutrophils in numerous human diseases and emerging therapeutic approaches targeting them are also elaborated. This review also addresses the current limitations within the field of neutrophil research, highlighting critical gaps in knowledge that warrant further investigation. In summary, this review seeks to establish a comprehensive and multidimensional model of neutrophil regulation, providing new perspectives for potential clinical applications and further research.

Pan-cancer analysis of STAT3 indicates its potential prognostic value and correlation with immune cell infiltration in prostate cancer

BACKGROUND

Targeting the STAT3 signaling pathway is a promising therapeutic approach for cancer patients. However, the association between STAT3 expression, the tumor immune microenvironment, and genetic variation remains unclear across human cancers, especially prostate cancer.

METHODS

We used R software and other tools to analyze pan-cancer and mutation data from publicly available databases statistically. A comprehensive investigation was performed to assess the genetic heterogeneity and clinical relevance of STAT3 in various malignancies, with a specific focus on its role in the immune landscape and prognostic significance in prostate cancer. The findings were validated through immunohistochemistry (IHC) and multiplex immunofluorescence (mIF).

RESULTS

STAT3 expression is abnormal in the majority of cancer tissues, which is strongly correlated with these patients' prognosis. Eight measures of tumor heterogeneity and six measures of tumor stemness of multiple tumor types showed a strong correlation with STAT3 expression. Furthermore, in individuals with prostate cancer, STAT3 expression indicated the degree of immune cell infiltration and the advancement of the disease. IHC analysis revealed that STAT3 was down-regulated in prostate tumor tissues, while mIF analysis demonstrated that STAT3 signaling (p-STAT3) was extensively active in tumor tissues and positive lymph node tissues.

CONCLUSION

STAT3 may serve as a valuable prognostic biomarker and therapeutic target across various cancers, with particular relevance to prostate cancer.

The role of neutrophils in osteosarcoma: insights from laboratory to clinic

Osteosarcoma, a highly aggressive malignant bone tumor, is significantly influenced by the intricate interactions within its tumor microenvironment (TME), particularly involving neutrophils. This review delineates the multifaceted roles of neutrophils, including tumor-associated neutrophils (TANs) and neutrophil extracellular traps (NETs), in osteosarcoma's pathogenesis. TANs exhibit both pro- and anti-tumor phenotypes, modulating tumor growth and immune evasion, while NETs facilitate tumor cell adhesion, migration, and immunosuppression. Clinically, neutrophil-related markers such as the neutrophil-to-lymphocyte ratio (NLR) predict patient outcomes, highlighting the potential for neutrophil-targeted therapies. Unraveling these complex interactions is crucial for developing novel treatment strategies that harness the TME to improve osteosarcoma management.

CTC-neutrophil interaction: A key driver and therapeutic target of cancer metastasis

Circulating tumor cells (CTCs) are cancer cells that detach from the primary tumor and enter the bloodstream, where they can seed new metastatic lesions in distant organs. CTCs are often associated with white blood cells (WBCs), especially neutrophils, the most abundant and versatile immune cells in the blood. Neutrophils can interact with CTCs through various mechanisms, such as cell-cell adhesion, cytokine secretion, protease release, and neutrophil extracellular traps (NETs) formation. These interactions can promote the survival, proliferation, invasion, and extravasation of CTCs, as well as modulate the pre-metastatic niche and the tumor microenvironment. Therefore, inhibiting CTC-neutrophils interaction could be a potential strategy to reduce tumor metastasis and improve the prognosis of cancer patients. In this review, we summarize the current literature on CTC-neutrophils interaction' role in tumor metastasis and discuss the possible therapeutic approaches to target this interaction.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

Drug resistance and tumor immune microenvironment: An overview of current understandings (Review)

The use of antitumor drugs represents a reliable strategy for cancer therapy. Unfortunately, drug resistance has become increasingly common and contributes to tumor metastasis and local recurrence. The tumor immune microenvironment (TME) consists of immune cells, cytokines and immunomodulators, and collectively they influence the response to treatment. Epigenetic changes including DNA methylation and histone modification, as well as increased drug exportation have been reported to contribute to the development of drug resistance in cancers. In the past few years, the majority of studies on tumors have only focused on the development and progression of a tumor from a mechanistic standpoint; few studies have examined whether the changes in the TME can also affect tumor growth and drug resistance. Recently, emerging evidence have raised more concerns regarding the role of TME in the development of drug resistance. In the present review, it was discussed how the suppressive TME adapts to drug resistance characterized by the cooperation of immune cells, cytokines, immunomodulators, stromal cells and extracellular matrix. Furthermore, it was reviewed how these immunological or metabolic changes alter immuno‑surveillance and thus facilitate tumor drug resistance. In addition, potential targets present in the TME for developing novel therapeutic strategies to improve individualized therapy for cancer treatment were revealed.

Predictive value of CXCL1+_FAP+ phenotype in CAFs for distant metastasis and its correlation with PD-L1 expression in locoregionally advanced nasopharyngeal carcinoma patients

OBJECTIVE

There is a lack of effective biomarkers for predicting the distant metastasis in nasopharyngeal carcinoma (NPC). We aimed to explore the expression of FAP+Cancer-associated fibroblasts (CAFs) derived CXCL1 in NPC and its predictive values for distant metastasis and correlation with PD-L1 expression.

MATERIALS AND METHODS

A total of 345 patients with locoregionally advanced NPC were retrospectively enrolled (the training cohort: the validation cohort = 160:185). Co-expression of CXCL1 and FAP and the expression of PD-L1 were detected by multi-immunofluorescence staining and immunohistochemistry, respectively. The primary end-point was distant metastasis-free survival (DMFS). The Kaplan-Meier method was used to calculate the survival. The Cox proportional hazards model was used to assess prognostic risk factors.

RESULTS

A novel CXCL1+_FAP+ phenotype in CAFs was identified in NPC and then used to divide patients into low and high risk groups. Both in the training cohort and validation cohort, patients in the high risk group had poorer DMFS, overall survival (OS), progression-free survival (PFS) and locoregional relapse-free survival (LRFS) than patients in the low risk group. Multivariate analysis revealed CXCL1+_FAP+ phenotype was an independent prognostic factor for DMFS, OS, PFS and LRFS. Further results showed patients in the high risk group had higher PD-L1 expression than those in the low risk group.

CONCLUSION

Our study showed CXCL1+_FAP+ phenotype in CAFs could effectively classified locoregionally advanced NPC patients into different risk groups for distant metastasis and might be a potential biomarker for anti-PD-1/PD-L1 immunotherapy.

Global research trends in the tumor microenvironment of hepatocellular carcinoma: insights based on bibliometric analysis

Objective

This study aimed to use visual mapping and bibliometric analysis to summarize valuable information on the tumor microenvironment (TME)-related research on hepatocellular carcinoma (HCC) in the past 20 years and to identify the research hotspots and trends in this field.

Methods

We screened all of the relevant literature on the TME of HCC in the Web of Science database from 2003 to 2023 and analysed the research hotspots and trends in this field via VOSviewer and CiteSpace.

Results

A total of 2,157 English studies were collected. According to the prediction, the number of papers that were published in the past three years will be approximately 1,394, accounting for 64.63%. China published the most papers (n=1,525) and had the highest total number of citations (n=32,253). Frontiers In Immunology published the most articles on the TME of HCC (n=75), whereas, Hepatology was the journal with the highest total number of citations (n=4,104) and average number of citations (n=91). The four clusters containing keywords such as "cancer-associated fibroblasts", "hepatic stellate cells", "immune cells", "immunotherapy", "combination therapy", "landscape", "immune infiltration", and "heterogeneity" are currently hot research topics in this field. The keywords "cell death", "ferroptosis", "biomarkers", and "prognostic features" have emerged relatively recently, and these research directions are becoming increasingly popular.

Conclusions

We identified four key areas of focus in the study of the TME in HCC: the main components and roles in the TME, immunotherapy, combination therapy, and the microenvironmental landscape. Moreover, the result of our study indicate that effect of ferroptosis on the TME in HCC may become a future research trend.

Heterogeneity and interplay: the multifaceted role of cancer-associated fibroblasts in the tumor and therapeutic strategies

The journey of cancer development is a multifaceted and staged process. The array of treatments available for cancer varies significantly, dictated by the disease's type and stage. Cancer-associated fibroblasts (CAFs), prevalent across various cancer types and stages, play a pivotal role in tumor genesis, progression, metastasis, and drug resistance. The strategy of concurrently targeting cancer cells and CAFs holds great promise in cancer therapy. In this review, we focus intently on CAFs, delving into their critical role in cancer's progression. We begin by exploring the origins, classification, and surface markers of CAFs. Following this, we emphasize the key cytokines and signaling pathways involved in the interplay between cancer cells and CAFs and their influence on the tumor immune microenvironment. Additionally, we examine current therapeutic approaches targeting CAFs. This article underscores the multifarious roles of CAFs within the tumor microenvironment and their potential applications in cancer treatment, highlighting their importance as key targets in overcoming drug resistance and enhancing the efficacy of tumor therapies.

FAP positive cancer-associated fibroblasts promote tumor progression and radioresistance in esophageal squamous cell carcinoma by transferring exosomal lncRNA AFAP1-AS1

Cancer-associated fibroblasts (CAFs) are abundant and heterogeneous stromal cells in the tumor microenvironment, which play important roles in regulating tumor progression and therapy resistance by transferring exosomes to cancer cells. However, how CAFs modulate esophageal squamous cell carcinoma (ESCC) progression and radioresistance remains incompletely understood. The expression of fibroblast activation protein (FAP) in CAFs was evaluated by immunohistochemistry in 174 ESCC patients who underwent surgery and 78 pretreatment biopsy specimens of ESCC patients who underwent definitive chemoradiotherapy. We sorted CAFs according to FAP expression, and the conditioned medium (CM) was collected to culture ESCC cells. The expression levels of several lncRNAs that were considered to regulate ESCC progression and/or radioresistance were measured in exosomes derived from FAP+ CAFs and FAP- CAFs. Subsequently, cell counting kit-8, 5-ethynyl-2'-deoxyuridine, transwell, colony formation, and xenograft assays were performed to investigate the functional differences between FAP+ CAFs and FAP- CAFs. Finally, a series of in vitro and in vivo assays were used to evaluate the effect of AFAP1-AS1 on radiosensitivity of ESCC cells. FAP expression in stromal CAFs was positively correlated with nerve invasion, vascular invasion, depth of invasion, lymph node metastasis, lack of clinical complete response and poor survival. Culture of ESCC cells with CM/FAP+ CAFs significantly increased cancer proliferation, migration, invasion and radioresistance, compared with culture with CM/FAP- CAFs. Importantly, FAP+ CAFs exert their roles by directly transferring the functional lncRNA AFAP1-AS1 to ESCC cells via exosomes. Functional studies showed that AFAP1-AS1 promoted radioresistance by enhancing DNA damage repair in ESCC cells. Clinically, high levels of plasma AFAP1-AS1 correlated with poor responses to dCRT in ESCC patients. Our findings demonstrated that FAP+ CAFs promoted radioresistance in ESCC cells through transferring exosomal lncRNA AFAP1-AS1; and may be a potential therapeutic target for ESCC treatment.

Complex role of neutrophils in the tumor microenvironment: an avenue for novel immunotherapies

Neutrophils, which originate from the bone marrow and are characterized by a segmented nucleus and a brief lifespan, have a crucial role in the body's defense against infections and acute inflammation. Recent research has uncovered the complex roles of neutrophils as regulators in tumorigenesis, during which neutrophils exhibit a dualistic nature that promotes or inhibits tumor progression. This adaptability is pivotal within the tumor microenvironment (TME). In this review, we provide a comprehensive characterization of neutrophil plasticity and heterogeneity, aiming to illuminate current research findings and discuss potential therapeutic avenues. By delineating the intricate interplay of neutrophils in the TME, this review further underscores the urgent need to understand the dual functions of neutrophils with particular emphasis on the anti-tumor effects to facilitate the development of effective therapeutic strategies against cancer.

SFRP1 mediates cancer-associated fibroblasts to suppress cancer cell proliferation and migration in head and neck squamous cell carcinoma

BACKGROUND

Cancer-associated fibroblasts (CAFs), as key cell populations in the tumor microenvironment (TME), play a crucial role in tumor regulation. Previous studies on a prognostic signature of 8 CAF-related genes in head and neck squamous cell carcinoma (HNSCC) revealed that Secreted frizzled-related protein 1 (SFRP1) is one of the hub genes closely related to CAFs. SFRP1 is deficiently expressed in numerous types of cancer and is classified as a tumor suppressor gene. However, the role of SFRP1 in TME regulation in HNSCC remains unclear. This study aimed to explore the role of SFRP1 in the proliferation and migration of HNSCC cells by mediating CAFs and their regulatory mechanisms.

METHODS

The expression differences, prognosis, and immune infiltration of SFRP1 in HNSCC were analyzed using the TIMER and GEPIA2 databases. The expression of SFRP1 in HNSCC tumor tissues, as well as the expression and secretion of SFRP1 in CAFs and tumor cells, were examined. An indirect co-culture system was constructed to detect the proliferation, migration, and apoptosis of HNSCC cells, and to clarify the effect of SFRP1 on tumor cells by mediating CAFs. Furthermore, the expression and secretion of 10 cytokines derived from CAFs that act on immune cells were verified.

RESULTS

SFRP1 was differently expressed in HNSCC tumor tissues and highly expressed in CAFs. SFRP1 inhibited the proliferation and migration of tumor cells and promoted apoptosis by mediating CAFs. The detection of CAFs-derived factors suggested that the mechanism of action of SFRP1 was associated with the regulation of immune cells.

CONCLUSION

SFRP1 inhibits the proliferation and migration of HNSCC cells by mediating CAFs, and the mechanism of action is related to the regulation of immune cells, which may provide new research directions and therapeutic targets for HNSCC.

From bioinformatics to clinical applications: a novel prognostic model of cuproptosis-related genes based on single-cell RNA sequencing data in hepatocellular carcinoma

OBJECTIVE AND METHODS

To ascertain the connection between cuproptosis-related genes (CRGs) and the prognosis of hepatocellular carcinoma (HCC) via single-cell RNA sequencing (scRNA-seq) and RNA sequencing (RNA-seq) data, relevant data were downloaded from the GEO and TCGA databases. The differentially expressed CRGs (DE-CRGs) were filtered by the overlaps in differentially expressed genes (DEGs) between HCC patients and normal controls (NCs) in the scRNA-seq database, DE-CRGs between high- and low-CRG-activity cells, and DEGs between HCC patients and NCs in the TCGA database.

RESULTS

Thirty-three DE-CRGs in HCC were identified. A prognostic model (PM) was created employing six survival-related genes (SRGs) (NDRG2, CYB5A, SOX4, MYC, TM4SF1, and IFI27) via univariate Cox regression analysis and LASSO. The predictive ability of the model was validated via a nomogram and receiver operating characteristic curves. Research has employed tumor immune dysfunction and exclusion as a means to examine the influence of PM on immunological heterogeneity. Macrophage M0 levels were significantly different between the high-risk group (HRG) and the low-risk group (LRG), and a greater macrophage level was linked to a more unfavorable prognosis. The drug sensitivity data indicated a substantial difference in the half-maximal drug-suppressive concentrations of idarubicin and rapamycin between the HRG and the LRG. The model was verified by employing public datasets and our cohort at both the protein and mRNA levels.

CONCLUSION

A PM using 6 SRGs (NDRG2, CYB5A, SOX4, MYC, TM4SF1, and IFI27) was developed via bioinformatics research. This model might provide a fresh perspective for assessing and managing HCC.

Cancer associated fibroblasts and metabolic reprogramming: unraveling the intricate crosstalk in tumor evolution

Metabolic reprogramming provides tumors with an energy source and biofuel to support their survival in the malignant microenvironment. Extensive research into the intrinsic oncogenic mechanisms of the tumor microenvironment (TME) has established that cancer-associated fibroblast (CAFs) and metabolic reprogramming regulates tumor progression through numerous biological activities, including tumor immunosuppression, chronic inflammation, and ecological niche remodeling. Specifically, immunosuppressive TME formation is promoted and mediators released via CAFs and multiple immune cells that collectively support chronic inflammation, thereby inducing pre-metastatic ecological niche formation, and ultimately driving a vicious cycle of tumor proliferation and metastasis. This review comprehensively explores the process of CAFs and metabolic regulation of the dynamic evolution of tumor-adapted TME, with particular focus on the mechanisms by which CAFs promote the formation of an immunosuppressive microenvironment and support metastasis. Existing findings confirm that multiple components of the TME act cooperatively to accelerate the progression of tumor events. The potential applications and challenges of targeted therapies based on CAFs in the clinical setting are further discussed in the context of advancing research related to CAFs.

Cancer-associated fibroblasts: a versatile mediator in tumor progression, metastasis, and targeted therapy

Tumor microenvironment (TME) has been demonstrated to play a significant role in tumor initiation, progression, and metastasis. Cancer-associated fibroblasts (CAFs) are the major component of TME and exhibit heterogeneous properties in their communication with tumor cells. This heterogeneity of CAFs can be attributed to various origins, including quiescent fibroblasts, mesenchymal stem cells (MSCs), adipocytes, pericytes, endothelial cells, and mesothelial cells. Moreover, single-cell RNA sequencing has identified diverse phenotypes of CAFs, with myofibroblastic CAFs (myCAFs) and inflammatory CAFs (iCAFs) being the most acknowledged, alongside newly discovered subtypes like antigen-presenting CAFs (apCAFs). Due to these heterogeneities, CAFs exert multiple functions in tumorigenesis, cancer stemness, angiogenesis, immunosuppression, metabolism, and metastasis. As a result, targeted therapies aimed at the TME, particularly focusing on CAFs, are rapidly developing, fueling the promising future of advanced tumor-targeted therapy.

The role of neutrophils in autoimmune diseases

Historically, neutrophils have been primarily regarded as short-lived immune cells that act as initial responders to antibacterial immunity by swiftly neutralizing pathogens and facilitating the activation of adaptive immunity. However, recent evidence indicates that their roles are considerably more complex than previously recognized. Neutrophils comprise distinct subpopulations and can interact with various immune cells, release granular proteins, and form neutrophil extracellular traps. These functions are increasingly recognized as contributing factors to tissue damage in autoimmune diseases. This review comprehensively examines the physiological functions and heterogeneity of neutrophils, their interactions with other immune cells, and their significance in autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, antiphospholipid syndrome, antineutrophil cytoplasmic antibody-associated vasculitis, multiple sclerosis, and others. This review aims to provide a deeper understanding of the function of neutrophils in the development and progression of autoimmune disorders.

Targeting Gsk3a reverses immune evasion to enhance immunotherapy in hepatocellular carcinoma

BACKGROUND

Immune escape is an important feature of hepatocellular carcinoma (HCC). The overall response rate of immune checkpoint inhibitors (ICIs) in HCC is still limited. Revealing the immune regulation mechanisms and finding new immune targets are expected to further improve the efficacy of immunotherapy. Our study aims to use CRISPR screening mice models to identify potential targets that play a critical role in HCC immune evasion and further explore their value in improving immunotherapy.

METHODS

We performed CRISPR screening in two mice models with different immune backgrounds (C57BL/6 and NPG mice) and identified the immunosuppressive gene Gsk3a as a candidate for further investigation. Flow cytometry was used to analyze the impact of Gsk3a on immune cell infiltration and T-cell function. RNA sequencing was used to identify the changes in neutrophil gene expression induced by Gsk3a and alterations in downstream molecules. The therapeutic value of the combination of Gsk3a inhibitors and anti-programmed cell death protein-1 (PD-1) antibody was also explored.

RESULTS

Gsk3a, as an immune inhibitory target, significantly promoted tumor growth in immunocompetent mice rather than immune-deficient mice. Gsk3a inhibited cytotoxic T lymphocytes (CTLs) function by inducing neutrophil chemotaxis. Gsk3a promoted self-chemotaxis of neutrophil expression profiles and neutrophil extracellular traps (NETs) formation to block T-cell activity through leucine-rich α-2-glycoprotein 1 (LRG1). A significant synergistic effect was observed when Gsk3a inhibitor was in combination with anti-PD-1 antibody.

CONCLUSIONS

We identified a potential HCC immune evasion target, Gsk3a, through CRISPR screening. Gsk3a induces neutrophil recruitment and NETs formation through the intermediate molecule LRG1, leading to the inhibition of CTLs function. Targeting Gsk3a can enhance CTLs function and improve the efficacy of ICIs.

MYC and KRAS cooperation: from historical challenges to therapeutic opportunities in cancer

RAS and MYC rank amongst the most commonly altered oncogenes in cancer, with RAS being the most frequently mutated and MYC the most amplified. The cooperative interplay between RAS and MYC constitutes a complex and multifaceted phenomenon, profoundly influencing tumor development. Together and individually, these two oncogenes regulate most, if not all, hallmarks of cancer, including cell death escape, replicative immortality, tumor-associated angiogenesis, cell invasion and metastasis, metabolic adaptation, and immune evasion. Due to their frequent alteration and role in tumorigenesis, MYC and RAS emerge as highly appealing targets in cancer therapy. However, due to their complex nature, both oncogenes have been long considered "undruggable" and, until recently, no drugs directly targeting them had reached the clinic. This review aims to shed light on their complex partnership, with special attention to their active collaboration in fostering an immunosuppressive milieu and driving immunotherapeutic resistance in cancer. Within this review, we also present an update on the different inhibitors targeting RAS and MYC currently undergoing clinical trials, along with their clinical outcomes and the different combination strategies being explored to overcome drug resistance. This recent clinical development suggests a paradigm shift in the long-standing belief of RAS and MYC "undruggability", hinting at a new era in their therapeutic targeting.

Exploring the role of the immune microenvironment in hepatocellular carcinoma: Implications for immunotherapy and drug resistance

Hepatocellular carcinoma (HCC), the most common type of liver tumor, is a leading cause of cancer-related deaths, and the incidence of liver cancer is still increasing worldwide. Curative hepatectomy or liver transplantation is only indicated for a small population of patients with early-stage HCC. However, most patients with HCC are not candidates for radical resection due to disease progression, leading to the choice of the conventional tyrosine kinase inhibitor drug sorafenib as first-line treatment. In the past few years, immunotherapy, mainly immune checkpoint inhibitors (ICIs), has revolutionized the clinical strategy for HCC. Combination therapy with ICIs has proven more effective than sorafenib, and clinical trials have been conducted to apply these therapies to patients. Despite significant progress in immunotherapy, the molecular mechanisms behind it remain unclear, and immune resistance is often challenging to overcome. Several studies have pointed out that the complex intercellular communication network in the immune microenvironment of HCC regulates tumor escape and drug resistance to immune response. This underscores the urgent need to analyze the immune microenvironment of HCC. This review describes the immunosuppressive cell populations in the immune microenvironment of HCC, as well as the related clinical trials, aiming to provide insights for the next generation of precision immunotherapy.

Immunotherapy for hepatocellular carcinoma

ABSTRACT

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Its high recurrence rate and lack of effective control drugs result in a 5-year survival rate of only about 10%. HCC is a tumor regulated by the immune system. Significant breakthroughs have occurred in treating solid tumors with immunotherapy in recent years. Various immunotherapies, such as immune checkpoint inhibitors (ICIs), including combination therapies, have demonstrated promising therapeutic effects in both clinical applications and research. Other immunotherapies, such as adoptive cell therapies and oncolytic viruses, are also emerging, offering hope for addressing long-term survival issues in HCC. This article reviews current commonly used immunotherapy strategies and the latest research findings for reference.