Immunosuppressive CD10+ALPL+ neutrophils promote resistance to anti-PD-1 therapy in HCC by mediating irreversible exhaustion of T cells

Integrative Analysis of scRNA-Seq and Bulk RNA-Seq Identifies Plasma Cell Related Genes and Constructs a Prognostic Model for Hepatocellular Carcinoma

Purpose

The complexity and heterogeneity of the tumor immune microenvironment (TIME) are linked to the development and poor prognosis of hepatocellular carcinoma (HCC). However, the cell type within the TIME that is most closely associated with HCC development remains unclear. Herein, we aimed to identify cell clusters that significantly contribute to HCC development and their underlying mechanisms.

Method and Results

Using single-cell RNA sequencing (scRNA-seq), we analyzed changes in the TIME of normal and tumor tissues, identifying plasma cells as the key cluster in HCC development. Based on plasma cell-related genes (PCRGs), we constructed and validated an eight-gene prognostic model (ST6GALNAC4, SEC61A1, SSR3, RPN2, PRDX4, TRAM1, SPCS2, CD79A) using internal and external datasets and a nomogram. Functional enrichment, miRNA network construction, and transcriptional regulation analyses were performed to explore underlying mechanisms. TIDE scores and the GDSC database were used to predict immunotherapy and chemotherapy sensitivity in different risk groups. Finally, SSR3's biological function was validated in vitro in HCC cell lines.

Conclusion

Plasma cells are key clusters in HCC development. A prognostic model based on the PCRGs can accurately predict the prognosis of patients with HCC and guide clinical treatment.

Distinct immunophenotypic profiles and neutrophil heterogeneity in colorectal cancer

Colorectal cancer (CRC) exhibits significant molecular and immunological heterogeneity. Neutrophil infiltration patterns play a crucial yet poorly understood role in tumor progression and patient outcomes. This study presents a comprehensive single-cell atlas of the CRC tumor microenvironment (TME), integrating transcriptomic data from 388,511 cells across 98 samples from 63 patients. Employing advanced computational methods, we stratified patients based on their immune cell infiltration profiles, revealing distinct immunophenotypes with potential therapeutic implications. Our analysis focused on tissue-resident neutrophils (TRNs) and uncovered previously uncharacterized subpopulations with diverse functional states. Trajectory inference analysis revealed a dynamic differentiation path from normal-associated neutrophils to tumor-associated neutrophils, highlighting the remarkable plasticity of these cells within the tumor environment. By integrating single-cell data with bulk transcriptomic and clinical information, we identified specific neutrophil-derived gene signatures associated with poor prognosis in CRC, suggesting their potential as novel prognostic biomarkers. This study not only provides unprecedented insights into neutrophil heterogeneity in CRC but also identifies potential targets for immunomodulatory therapies. Our findings lay the groundwork for developing more nuanced, personalized immunotherapeutic strategies for CRC, potentially improving treatment efficacy for patients who currently show a limited response to existing immunotherapies.

Engineered oncolytic virus coated with anti-PD-1 and alendronate for ameliorating intratumoral T cell hypofunction

BACKGROUND

Glioblastoma is a highly aggressive and devastating primary brain tumor that is resistant to conventional therapies. Oncolytic viruses represent a promising therapeutic approach for glioblastoma by selectively lysing tumor cells and eliciting an anti-tumor immune response. However, the clinical efficacy of oncolytic viruses is often hindered by challenges such as short persistence, host antiviral immune responses, and T cell dysfunction.

METHODS

We have developed a novel therapeutic strategy by "dressing" oncolytic viruses with anti-PD-1 antibodies and alendronate (PD-1/Al@OV) to prevent premature clearance of the oncolytic viruses and enhance T cell function, thereby improving immunotherapy outcomes against glioma.

RESULTS

We found that in the high reactive oxygen species environment of the tumor, PD-1/Al@OV disassembled to release oncolytic viruses, anti-PD-1, and alendronate. The released anti-PD-1 blocked the PD-1/PD-L1 pathway, activating T cells; the alendronate eliminated tumor-associated macrophages, increasing the concentration of oncolytic viruses; and the oncolytic viruses directly lysed cancer cells, enhancing intratumoral T cell infiltration.

CONCLUSION

This approach effectively improved the immunosuppressive microenvironment of glioblastoma and achieved a robust anti-tumor effect. Consequently, this study presents a novel strategy for immune combination therapy and the improvement of the glioblastoma immune microenvironment, thereby offering new prospects for the clinical application of oncolytic viruses.

Harnessing nanoparticles for reshaping tumor immune microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers, characterized by high morbidity and mortality rates. Recently, immunotherapy has emerged as a crucial treatment modality for HCC, following surgery, locoregional therapies, and targeted therapies. This approach harnesses the body's immune system to target and eliminate cancer cells, potentially resulting in durable antitumor responses. However, acquired resistance and the tumor immunosuppressive microenvironment (TIME) significantly hinder its clinical application. Recently, advancements in nanotechnology, coupled with a deeper understanding of cancer biology and nano-biological interactions, have led to the development of various nanoparticles aimed at enhancing therapeutic efficacy through specific targeting of tumor tissues. These nanoparticles increase the accumulation of immunotherapeutic drugs within the tumor microenvironment, thereby transforming the TIME. In this review, we provide a concise overview of the fundamental principles governing the TIME landscape in HCC and discuss the rationale for and applications of nanoparticles in this context. Additionally, we highlight existing challenges and potential opportunities for the clinical translation of cancer nanomedicines.

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.

Loss of SGK1 supports metastatic colonization in hepatocellular carcinoma by promoting resistance to T cell-mediated immunity

BACKGROUND & AIMS

Immune evasion by tumor cells is a principal obstacle to effectively targeting metastasis in hepatocellular carcinoma (HCC). However, the specific molecular mechanisms facilitating immune escape during metastatic seeding are not fully elucidated.

METHODS

Utilizing in vivo CRISPR library screening in murine HCC metastasis models under conditions of both intact and depleted T cell immunity, we identified genes critical to tumor immune evasion during metastatic colonization, and investigated intrinsic mechanisms by several experimental approaches.

RESULTS

Our screens identified Sgk1 as an essential suppressor of metastatic colonization under T cell immunosurveillance. Sgk1-deficient tumor cells displayed significantly enhanced metastatic capacity in the presence of CD8+ T cells, underscoring the role of Sgk1 in regulating immune escape. Clinical analyses corroborated these findings, showing markedly lower SGK1 expression in circulating tumor cells and metastatic lesions relative to matched primary tumors in HCC patients, with low SGK1 expression associating with compromised T cell function and poorer clinical outcomes. Mechanistically, Sgk1 inactivation in tumor cells attenuated CD8+ T cell-mediated, RIPK1-dependent necroptosis-a cell death pathway essential for cytotoxic T cell-mediated restriction of metastasis. Loss of Sgk1 consequently enabled tumor cells to circumvent T cell-induced cytotoxicity, thereby promoting metastatic colonization. Furthermore, the outgrowth of Sgk1-deficient metastatic cells induced a microenvironmental shift toward terminal T cell exhaustion, establishing conditions conducive to sustained immune evasion.

CONCLUSIONS

These findings establish SGK1 as a crucial regulator of immune-mediated control over metastatic growth in HCC. SGK1 expression in metastatic lesions may serve as a predictive biomarker for response to immune checkpoint inhibitors, presenting new avenues for therapeutic intervention to overcome immune resistance in metastatic HCC.

IMPACT AND IMPLICATIONS

Despite metastasis is a common occurrence and lethal determinant in cancers, the mechanism underlying tumor immune evasion during metastatic seeding is unclear. Our study reveals that loss of Sgk1 renders metastatic tumor cells survival advantages against antitumor immune response by abrogating CD8+ T cell-induced RIPK1-dependent necroptosis. Growth of Sgk1-silenced metastasis led to infiltration of terminally exhausted CD8+ T cells, which could be reversed by immune checkpoint inhibitors administered at early stage of metastatic seeding. These findings provide valuable insights into potential therapeutic strategies targeting resistance to T cell immunity in cancer metastasis.

T-cell Receptor Repertoire Analysis in the Context of Transarterial Chemoembolization Synergy with Systemic Therapy for Hepatocellular Carcinoma

T-cell receptor (TCR) sequencing provides a novel platform for insight into and characterization of intricate T-cell profiles, advancing the understanding of tumor immune heterogeneity. Recently, transarterial chemoembolization (TACE) combined with systemic therapy has become the recommended regimen for advanced hepatocellular carcinoma. The regulation of the immune microenvironment after TACE and its impact on tumor progression and recurrence has been a focus of research. By examining and tracking fluctuations in the TCR repertoire following combination treatment, novel perspectives on the modulation of the tumor microenvironment post-TACE and the underlying mechanisms governing tumor progression and recurrence can be gained. Clarifying the distinctive metrics and dynamic alterations of the TCR repertoire within the context of combination therapy is imperative for understanding the mechanisms of anti-tumor immunity, assessing efficacy, exploiting novel treatments, and further advancing precision oncology in the treatment of hepatocellular carcinoma. In this review, we initially summarized the fundamental characteristics of TCR repertoire and depicted immune microenvironment remodeling after TACE. Ultimately, we illustrated the prospective applications of TCR repertoires in TACE combined with systemic therapy.

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.

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.

Neutrophils in cancer drug resistance: Roles and therapeutic opportunities

The tumor microenvironment (TME) is closely associated with the therapeutic response and clinical outcome of cancer drug therapies, which mainly include immunotherapy, chemotherapy and targeted therapy. Neutrophils that infiltrate tumors, also known as tumor-associated neutrophils (TANs), constitute a primary part of the TME. However, the functional importance of TANs in cancer drug therapy has long been overlooked because of their relatively short life span. Recent studies have shown that TANs play crucial protumoral or antitumoral roles in cancer drug treatment, largely because of their diversity and plasticity. This review describes the development, heterogeneity and recruitment of neutrophils in the context of cancer and emphasizes the role and mechanisms of TANs in cancer drug resistance. Additionally, several potential neutrophil-targeted strategies are discussed.

Pinpointing the integration of artificial intelligence in liver cancer immune microenvironment

Liver cancer remains one of the most formidable challenges in modern medicine, characterized by its high incidence and mortality rate. Emerging evidence underscores the critical roles of the immune microenvironment in tumor initiation, development, prognosis, and therapeutic responsiveness. However, the composition of the immune microenvironment of liver cancer (LC-IME) and its association with clinicopathological significance remain unelucidated. In this review, we present the recent developments related to the use of artificial intelligence (AI) for studying the immune microenvironment of liver cancer, focusing on the deciphering of complex high-throughput data. Additionally, we discussed the current challenges of data harmonization and algorithm interpretability for studying LC-IME.

Potential crosstalk between Naïve CD4+ T cells and SPP1+ Macrophages is associated with clinical outcome and therapeutic response in hepatocellular carcinoma

BACKGROUND

The highly heterogeneity of the tumor microenvironment (TME) in hepatocellular carcinoma (HCC) results in diverse clinical outcomes and therapeutic responses. This study aimed to investigate potential intercellular crosstalk and its impact on clinical outcomes and therapeutic responses.

METHODS

Single-cell RNA sequencing (scRNA-seq), spatial transcriptomics (ST) and bulk RNA sequencing (RNA-seq) datasets were integrated to comprehensively analyze the intercellular interactions within the TME. Multiplex immunohistochemistry was conducted to validate the intercellular interactions. A machine learning-based integrative procedure was used in bulk RNA-seq datasets to generate a risk model to predict prognosis and therapeutic responses.

RESULTS

Survival analyses based on the bulk RNA-seq datasets revealed the negative impact of the naïve Cluster of Differentiation 4+ (CD4) T cells and Secreted Phosphoprotein 1+ (SPP1) macrophages on prognosis. Furthermore, their intricate intercellular crosstalk and spatial colocalization were also observed by scRNA-seq and ST analyses. Based on this crosstalk, a machine learning model, termed the naïve CD4+ T cell and SPP1+ macrophage prognostic score (TMPS), was established in the bulk-RNA seq datasets for prognostic prediction. The TMPS achieved C-index values of 0.785, 0.715, 0.692 and 0.857, respectively, across 4 independent cohorts. A low TMPS was associated with a significantly increased survival rates, improved response to immunotherapy and reduced infiltration of immunosuppressive cells, such as. regulatory T cells. Finally, 8 potential sensitive drugs and 6 potential targets were predicted for patients based on their TMPS.

CONCLUSION

The crosstalk between naïve CD4+ T cells and SPP1+ macrophages play a crucial role in the TME. TMPS can reflect this crosstalk and serve as a valuable tool for prognostic stratification and guiding clinical decision-making.

Machine Learning Integration with Single-Cell Transcriptome Sequencing Datasets Reveals the Impact of Tumor-Associated Neutrophils on the Immune Microenvironment and Immunotherapy Outcomes in Gastric Cancer

The characteristics of neutrophils play a crucial role in defining the tumor inflammatory environment. However, the function of tumor-associated neutrophils (TANs) in tumor immunity and their response to immune checkpoint inhibitors (ICIs) remains incompletely understood. By analyzing single-cell RNA sequencing data from over 600,000 cells in gastric cancer (GSE163558 and GSE183904), colorectal cancer (GSE205506), and lung cancer (GSE207422), we identified neutrophil subsets in primary gastric cancer that are associated with the treatment response to ICIs. Specifically, we focused on neutrophils with high expression of CD44 (CD44_NEU), which are abundant during tumor progression and exert significant influence on the gastric cancer immune microenvironment. Machine learning analysis revealed 22 core genes associated with CD44_NEU, impacting inflammation, proliferation, migration, and oxidative stress. In addition, multiple immunofluorescence staining and gastric cancer spatial transcriptome data (GSE203612) showed a correlation between CD44_NEU and T-cell infiltration in gastric cancer tissues. A risk score model derived from seven essential genes (AQP9, BASP1, BCL2A1, PLEK, PDE4B, PROK2, and ACSL1) showed better predictive capability for patient survival compared to clinical features alone, and integrating these scores with clinical variables resulted in a prognostic nomogram. Overall, this study highlights the heterogeneity of TANs, particularly the CD44_NEU critical influence on immunotherapy outcomes, paving the way for personalized treatment strategies.

Integrated single-cell transcriptome and TCR profiles of hepatocellular carcinoma highlight the convergence on interferon signaling during immunotherapy

BACKGROUND

Despite the success of immune checkpoint inhibitor (ICI)-based combination therapies in hepatocellular carcinoma (HCC), its effectiveness remains confined to a subset of patients. The development of reliable, predictive markers is important for accurate patient stratification and further mechanistic understanding of therapy response.

METHODS

We comprehensively analyzed paired single-cell RNA transcriptome and T-cell repertoire profiles from 14 HCC ascites samples, collected from 7 patients before and after treatment with the combination of sintilimab (anti-PD-1) and bevacizumab (anti-VEGF).

RESULTS

We identify a widespread convergence on interferon (IFN) signaling across various immune cell lineages in treatment-responsive patients with HCC, indicating a common transcriptional state transition in the immune microenvironment linked to immunotherapy response in HCC. Strong IFN signaling marks CD8+ T cells with larger clonal expansion and enhanced cytotoxicity, macrophages toward M1-like polarization and strong T-cell recruitment ability, dendritic cells with increased antigen presentation capacity, as well as highly cytotoxic natural killer cells and activated B cells. By translating our finding to cohorts of patients with HCC, we demonstrate the specificity of IFN-signaling in the prognosis of patients with HCC and its ability to predict immunotherapy response.

CONCLUSIONS

This study provides a unique single-cell resource with clonal and longitudinal resolution during ICI therapy and reveals IFN signaling as a biomarker of immunotherapy response in HCC, suggesting a beneficial effect by combining IFN inducers with ICIs for patients with HCC.

Reverse resistance to immune checkpoint inhibitor in a patient with recurrent cardia cancer by intratumoral injection of recombinant human adenovirus type 5: a case report and literature review

Advanced metastatic cardia cancer is an intractable malignance with poor prognosis. It is often accompanied by upper digestive tract obstruction, which seriously affects the quality of patients. Therefore, effective relief of eating obstruction is an important goal in the treatment of cardia cancer. Immune checkpoint inhibitors (ICIs) have shown significant efficacy in cardia cancer, but only a small percentage of patients will benefit from them due to immune resistance. Oncolytic viruses have been shown to enhance the efficacy of ICIs by altering the immune microenvironment. This indicates that oncolytic virus has the potential value of overcoming the immune resistance of cardia cancer. Here, we present a case with local recurrent and multiple metastatic cardia cancer accompanied by eating obstruction. After 4 cycles of chemotherapy plus ICI therapy, the patient´s metastases were significant shrink, but the recurrent carida lesion were almost unchanged. Then we implemented exploratory local injection of recombinant human adenovirus type 5(H101) into recurrent cardia lesion by painless gastroscopy. Surprisingly, the cardia lesion shrank significantly, and the eating obstruction was greatly relieved. We also observed a significant increase of infiltrated CD4+T cells in biopsy tissues after H101 treatment. Our study not only conformed the value of oncolytic viruses to reverse ICI resistance in patients with gastric cancer, but also revealed its underlying impact on immune microenvironment.

The regulatory role of mitotic catastrophe in hepatocellular carcinoma drug resistance mechanisms and its therapeutic potential

This review focuses on the role and underlying mechanisms of mitotic catastrophe (MC) in the regulation of drug resistance in hepatocellular carcinoma (HCC). HCC is one of the leading causes of cancer-related mortality worldwide, posing significant treatment challenges due to its high recurrence rates and drug resistance. Research suggests that MC, as a mechanism of cell death, plays a crucial role in enhancing the efficacy of HCC treatment by disrupting the replication and division mechanisms of tumor cells. The present review summarizes the molecular mechanisms of MC and its role in HCC drug resistance and explores the potential of combining MC with existing cancer therapies to improve treatment outcomes. Future research should focus on the in-depth elucidation of the molecular mechanisms of MC and its application in HCC therapy, providing new insights for the development of more effective treatments.

Multifaceted roles of neutrophils in tumor microenvironment

Neutrophils, the most abundant leukocyte population in circulation, play a crucial role in detecting and responding to foreign cells, such as pathogens and tumor cells. However, the impact of neutrophils on cancer pathogenesis has been overlooked because of their short lifespan, terminal differentiation, and limited transcriptional activity. Within the tumor microenvironment (TME), neutrophils can be influenced by tumor cells or other stromal cells to acquire either protumor or antitumor properties via the cytokine environment. Despite progress in neutrophil-related research, a comprehensive understanding of tissue-specific neutrophil diversity and adaptability in the TME is still lacking, which poses a significant obstacle to the development of neutrophil-based cancer therapies. This review evaluated the current studies on the dual roles of neutrophils in cancer progression, emphasizing their importance in predicting clinical outcomes, and explored various approaches for targeting neutrophils in cancer treatment, including their potential synergy with cancer immunotherapy.

Qizhu anticancer prescription enhances immunosurveillance of liver cancer cells by regulating p21-dependent secretory phenotypes

ETHNOPHARMACOLOGICAL RELEVANCE

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide, largely due to the limitations of available therapeutic strategies. The traditional Chinese medicine Qizhu Anticancer Prescription (QZACP) can improve the quality of life and prolong the survival time of patients with HCC. However, the precise mechanisms underlying the anti-cancer properties of QZACP remain unclear.

PURPOSE

This study examined the anti-hepatocarcinogenic properties of QZACP, with a specific focus on its influence on the p21-activated secretory phenotype (PASP)-mediated immune surveillance, to elucidate the underlying molecular pathways involved in HCC.

MATERIALS AND METHODS

Cell proliferation was measured using the Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, and clonogenic assays. The cell cycle was evaluated using flow cytometry, and senescence was identified by staining with senescence-associated beta-galactosidase (SA-β-gal). A primary liver cancer model produced by diethylnitrosamine was established in C57 BL/6 mice to assess the tumor-inhibitory effect of QZACP. The liver's pathological characteristics were examined using hematoxylin and eosin staining. PASP screening was performed using GeneCards, DisGeNet, Online Mendelian Inheritance in Man, and The Cancer Genome Atlas databases. Western blot analysis, enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining, and Transwell migration assays were performed.

RESULTS

Serum containing QZACP enhanced p21 expression, triggered cell cycle arrest, accelerated cell senescence, and suppressed cell proliferation in Huh7 and MHCC-97H liver cancer cells. QZACP reduced the quantity and dimensions of liver tumor nodules and enhanced p21 protein expression, SA-β-Gal staining in tumor lesions, and cytotoxic CD8+ T cell infiltration. Bioinformatic analyses indicated that PASP factors, including hepatocyte growth factor, decorin (DCN), dermatopontin, C-X-C motif chemokine ligand 14 (CXCL14), and Wnt family member 2 (WNT2), play an important role in the development of HCC. In addition, these factors are associated with the presence of natural killer cells and CD8+ T cells within tumors. Western blotting and ELISA confirmed that QZACP increased DCN, CXCL14, and WNT2 levels in tumor tissues and peripheral blood.

CONCLUSIONS

QZACP's suppression of HCC progression may involve cell senescence mediated via p21 upregulation, DCN, CXCL14, and WNT2 secretion, and reversal of the immunosuppressive microenvironment. This study provides insights that can be used in the development of new treatment strategies for HCC.

Hepatocellular Carcinoma Immunotherapy: Predictors of Response, Issues, and Challenges

Immune checkpoint inhibitors (ICIs), such as durvalumab, tremelimumab, and atezolizumab, have emerged as a significant therapeutic option for the treatment of hepatocellular carcinoma (HCC). In fact, the efficacy of ICIs as single agents or as part of combination therapies has been demonstrated in practice-changing phase III clinical trials. However, ICIs confront several difficulties, including the lack of predictive biomarkers, primary and secondary drug resistance, and treatment-related side effects. Herein, we provide an overview of current issues and future challenges in this setting.

Innate immune cells in tumor microenvironment: A new frontier in cancer immunotherapy

Innate immune cells, crucial in resisting infections and initiating adaptive immunity, play diverse and significant roles in tumor development. These cells, including macrophages, granulocytes, dendritic cells (DCs), innate lymphoid cells, and innate-like T cells, are pivotal in the tumor microenvironment (TME). Innate immune cells are crucial components of the TME, based on which various immunotherapy strategies have been explored. Immunotherapy strategies, such as novel immune checkpoint inhibitors, STING/CD40 agonists, macrophage-based surface backpack anchoring, ex vivo polarization approaches, DC-based tumor vaccines, and CAR-engineered innate immune cells, aim to enhance their anti-tumor potential and counteract cancer-induced immunosuppression. The proximity of innate immune cells to tumor cells in the TME also makes them excellent drug carriers. In this review, we will first provide a systematic overview of innate immune cells within the TME and then discuss innate cell-based therapeutic strategies. Furthermore, the research obstacles and perspectives within the field will also be addressed.

SLAM family-mediated crosstalk between tumor and immune cells in the tumor microenvironment: a promising biomarker and a potential therapeutic target for immune checkpoint therapies

Immune cells infiltrating the tumor microenvironment are physiologically important in controlling cancers. However, emerging studies have shown that cancer cells can evade immune surveillance and establish a balance in which these immune cells support tumor progression and therapeutic resistance. The signaling lymphocytic activation molecule family members have been recognized as mediators of tumor microenvironment interactions, and a promising therapeutic target for cancer immunotherapy. This review is focused on the role of SLAM family in tumor and immune cell interactions and discusses how such crosstalk affects tumor behavior. This will shed insight into the next step toward improving cancer immunotherapy.

Neutrophil extracellular traps promote immune escape in hepatocellular carcinoma by up-regulating CD73 through Notch2

Immune escape is the main reason that immunotherapy is ineffective in hepatocellular carcinoma (HCC). Here, this study illustrates a pathway mediated by neutrophil extracellular traps (NETs) that can promote immune escape of HCC. Mechanistically, we demonstrated that NETs up-regulated CD73 expression through activating Notch2 mediated nuclear factor kappa B (NF-κB) pathway, promoting regulatory T cells (Tregs) infiltration to mediate immune escape of HCC. In addition, we found the similar results in mouse HCC models by hydrodynamic plasmid transfection. The treatment of deoxyribonuclease I (DNase I) could inhibit the action of NETs and improve the therapeutic effect of anti-programmed cell death protein 1 (PD-1). In summary, our results revealed that targeting of NETs was a promising treatment to improve the therapeutic effect of anti-PD-1.

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.

From MASLD to HCC: What's in the middle?

Metabolic dysfunction associated steatotic liver disease (MASLD) is a progressive pathological condition characterized by the accumulation of triglycerides within hepatocytes that causes histological changes, which, in the long run, might compromise liver functional capacities. MASLD predisposes to metabolic dysfunction-associated steatohepatitis (MASH), in which the persistence of inflammatory reactions perpetuates tissue injury and induces alterations of the extracellular matrix, leading to liver fibrosis and cirrhosis. Furthermore, these processes are also fertile ground for the development of hepatocellular carcinoma (HCC). In this latter respect, growing evidence suggests that chronic inflammation not only acts as the primary stimulus for hepatocellular malignant transformation, cell proliferation and cancer cell progression but also reshapes the immune landscape, inducing immune system exhaustion and favoring the loss of cancer immune surveillance. Therefore, a thorough understanding of the cellular and molecular mechanisms orchestrating hepatic inflammatory responses may open the way for fine-tuning therapeutic interventions that could, from one side, counteract MASLD progression and, on the other one, effectively treat HCCs.

Advances in hepatocellular carcinoma drug resistance models

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Surgery has been the major treatment method for HCC owing to HCC's poor sensitivity to radiotherapy and chemotherapy. However, its effectiveness is limited by postoperative tumour recurrence and metastasis. Systemic therapy is applied to eliminate postoperative residual tumour cells and improve the survival of patients with advanced HCC. Recently, the emergence of various novel targeted and immunotherapeutic drugs has significantly improved the prognosis of advanced HCC. However, targeted and immunological therapies may not always produce complete and long-lasting anti-tumour responses because of tumour heterogeneity and drug resistance. Traditional and patient-derived cell lines or animal models are used to investigate the drug resistance mechanisms of HCC and identify drugs that could reverse the resistance. This study comprehensively reviewed the established methods and applications of in-vivo and in-vitro HCC drug resistance models to further understand the resistance mechanisms in HCC treatment and provide a model basis for possible individualised therapy.

Applications of single-cell multi-omics in liver cancer

Primary liver cancer, more specifically hepatocellular carcinoma (HCC), remains a significant global health problem associated with increasing incidence and mortality. Clinical, biological, and molecular heterogeneity are well-known hallmarks of cancer and HCC is considered one of the most heterogeneous tumour types, displaying substantial inter-patient, intertumoural and intratumoural variability. This heterogeneity plays a pivotal role in hepatocarcinogenesis, metastasis, relapse and drug response or resistance. Unimodal single-cell sequencing techniques have already revolutionised our understanding of the different layers of molecular hierarchy in the tumour microenvironment of HCC. By highlighting the cellular heterogeneity and the intricate interactions among cancer, immune and stromal cells before and during treatment, these techniques have contributed to a deeper comprehension of tumour clonality, hematogenous spreading and the mechanisms of action of immune checkpoint inhibitors. However, major questions remain to be elucidated, with the identification of biomarkers predicting response or resistance to immunotherapy-based regimens representing an important unmet clinical need. Although the application of single-cell multi-omics in liver cancer research has been limited thus far, a revolution of individualised care for patients with HCC will only be possible by integrating various unimodal methods into multi-omics methodologies at the single-cell resolution. In this review, we will highlight the different established single-cell sequencing techniques and explore their biological and clinical impact on liver cancer research, while casting a glance at the future role of multi-omics in this dynamic and rapidly evolving field.

Efficacy and safety of lenvatinib combined with PD‑1/PD‑L1 inhibitors in the treatment of hepatocellular carcinoma: A meta‑analysis and systematic review

A meta-analysis of the clinical survival indicators, adverse reactions and safety of lenvatinib combined with programmed death-1 (PD-1) inhibitors in treating liver cancer was conducted, providing objective and effective evidence for clinical use. The present study is anticipated to guide the clinical application of lenvatinib. In the current meta-analysis, the PubMed, Embase and Cochrane Library databases were searched from inception to September 2023. Randomized controlled trials (RCTs), non-RCTs and single-arm trial studies related to the combined treatment of lenvatinib and PD-1/PD-ligand 1 (L1) inhibitors for hepatocellular carcinoma (HCC) were included, while published and unpublished literature on other study types, literature with incomplete or inadequate information, animal experiments, literature reviews and systematic studies were excluded. Data were processed using STATA 15.1. The pooled results showed that the objective response rate [ORR; odds ratio (OR), 3.36; 95% confidence interval (CI), 2.13-5.30; P<0.001], disease control rate (DCR; OR, 1.62; 95% CI, 1.03-2.57; P=0.038) and partial response (PR; OR, 3.81; 95% CI, 2.17-6.70; P<0.001) of combined lenvatinib and PD-1/PD-L1 inhibitor therapy were significantly higher than those of lenvatinib monotherapy. Additionally, subgroup analysis results showed that the DCR of combination therapy using lenvatinib and nivolumab was significantly higher than that of lenvatinib monotherapy (OR, 2.20; 95% CI; 1.07-4.51; P=0.032). The difference between combination therapy using lenvatinib and camrelizumab, and lenvatinib monotherapy was not significant. However, the complete response, stable disease, progression disease and incidence rate of adverse events between combination therapy and lenvatinib monotherapy were not significantly different. Compared with lenvatinib alone, lenvatinib combined with PD-1/PD-L1 inhibitors significantly improved ORR, mainly PR, and DCR in patients with HCC. At present, lenvatinib is mainly combined with nivolumab to increase the DCR of lenvatinib monotherapy for HCC. In addition, the incidence rate of adverse reactions between combination therapy and lenvatinib monotherapy was not significantly different for HCC.

NETscape or NEThance: tailoring anti-cancer therapy

Neutrophils, major regulators of innate immunity, have recently emerged as key components of the tumor microenvironment. The role of neutrophils in cancer has been linked to their ability to form neutrophil extracellular traps (NETs), structures composed of decondensed DNA decorated with enzymes that are released into the extracellular space. Here, we discuss the pivotal roles of NETs in influencing responses to anticancer therapies such as chemotherapy, radiotherapy, immunotherapy, and targeted therapy. Highlighting recent insights, we delve into the dual nature of NETs in the context of anticancer treatments, examining their potential to either counteract or enhance treatment outcomes. Strategic targeting of NETs may be a promising avenue for crafting combination therapies to counteract resistance or enhance anticancer treatments' efficacy.

Engineering and Targeting Neutrophils for Cancer Therapy

Neutrophils are the most abundant white blood cells in the circulation and act as the first line of defense against infections. Increasing evidence suggests that neutrophils possess heterogeneous phenotypes and functional plasticity in human health and diseases, including cancer. Neutrophils play multifaceted roles in cancer development and progression, and an N1/N2 paradigm of neutrophils in cancer is proposed, where N1 neutrophils exert anti-tumor properties while N2 neutrophils display tumor-supportive and immune-suppressive functions. Selective activation of beneficial neutrophil population and targeted inhibition or re-polarization of tumor-promoting neutrophils has shown an important potential in tumor therapy. In addition, due to the natural inflammation-responsive and physical barrier-crossing abilities, neutrophils and their derivatives (membranes and extracellular vesicles (EVs)) are regarded as advanced drug delivery carriers for enhanced tumor targeting and improved therapeutic efficacy. In this review, the recent advances in engineering neutrophils for drug delivery and targeting neutrophils for remodeling tumor microenvironment (TME) are comprehensively presented. This review will provide a broad understanding of the potential of neutrophils in cancer therapy.

Beyond binary: bridging neutrophil diversity to new therapeutic approaches in NSCLC

Neutrophils represent the most abundant myeloid cell subtype in the non-small-cell lung cancer (NSCLC) tumor microenvironment (TME). By anti- or protumor polarization, they impact multiple aspects of tumor biology and affect sensitivity to conventional therapies and immunotherapies. Single-cell RNA sequencing (scRNA-seq) analyses have unraveled an extensive neutrophil heterogeneity, helping our understanding of their pleiotropic role. In this review we summarize recent data and models on tumor-associated neutrophil (TAN) biology, focusing on the diversity that evolves in response to tumor-intrinsic cues. We categorize available transcriptomic profiles from different cancer entities into a defined set of neutrophil subclusters with distinct phenotypic properties, to step beyond the traditional binary N1/2 classification. Finally, we discuss potential ways to exploit these neutrophil states in the setting of anticancer therapy.

Heterogeneity in Liver Cancer Immune Microenvironment: Emerging Single-Cell and Spatial Perspectives

Primary liver cancer is a solid malignancy with a high mortality rate. The success of immunotherapy has shown great promise in improving patient care and highlights a crucial need to understand the complexity of the liver tumor immune microenvironment (TIME). Recent advances in single-cell and spatial omics technologies, coupled with the development of systems biology approaches, are rapidly transforming the landscape of tumor immunology. Here we review the cellular landscape of liver TIME from single-cell and spatial perspectives. We also discuss the cellular interaction networks within the tumor cell community in regulating immune responses. We further highlight the challenges and opportunities with implications for biomarker discovery, patient stratification, and combination immunotherapies.

Immunosuppressive tumor microenvironment and immunotherapy of hepatocellular carcinoma: current status and prospectives

Hepatocellular carcinoma (HCC) is a major health concern worldwide, with limited therapeutic options and poor prognosis. In recent years, immunotherapies such as immune checkpoint inhibitors (ICIs) have made great progress in the systemic treatment of HCC. The combination treatments based on ICIs have been the major trend in this area. Recently, dual immune checkpoint blockade with durvalumab plus tremelimumab has also emerged as an effective treatment for advanced HCC. However, the majority of HCC patients obtain limited benefits. Understanding the immunological rationale and exploring novel ways to improve the efficacy of immunotherapy has drawn much attention. In this review, we summarize the latest progress in this area, the ongoing clinical trials of immune-based combination therapies, as well as novel immunotherapy strategies such as chimeric antigen receptor T cells, personalized neoantigen vaccines, oncolytic viruses, and bispecific antibodies.

Beyond host defense and tissue injury: the emerging role of neutrophils in tissue repair

Neutrophils, the most abundant immune cells in human blood, play a fundamental role in host defense against invading pathogens and tissue injury. Neutrophils carry potentially lethal weaponry to the affected site. Inadvertent and perpetual neutrophil activation could lead to nonresolving inflammation and tissue damage, a unifying mechanism of many common diseases. The prevailing view emphasizes the dichotomy of their function, host defense versus tissue damage. However, tissue injury may also persist during neutropenia, which is associated with disease severity and poor outcome. Numerous studies highlight neutrophil phenotypic heterogeneity and functional versatility, indicating that neutrophils play more complex roles than previously thought. Emerging evidence indicates that neutrophils actively orchestrate resolution of inflammation and tissue repair and facilitate return to homeostasis. Thus, neutrophils mobilize multiple mechanisms to limit the inflammatory reaction, assure debris removal, matrix remodeling, cytokine scavenging, macrophage reprogramming, and angiogenesis. In this review, we will summarize the homeostatic and tissue-reparative functions and mechanisms of neutrophils across organs. We will also discuss how the healing power of neutrophils might be harnessed to develop novel resolution and repair-promoting therapies while maintaining their defense functions.

Novel molecular hepatocellular carcinoma subtypes and RiskScore utilizing apoptosis-related genes

Hepatocellular carcinoma (HCC) is the third leading cause of global cancer-related deaths. Despite immunotherapy offering hope for patients with HCC, only some respond to it. However, it remains unclear how to pre-screen eligible patients. Our study aimed to address this issue. In this study, we identified 13 prognostic genes through univariate Cox regression analysis of 87 apoptosis-related genes. Subsequently, these 13 genes were analyzed using ConsensusClusterPlus, and patients were categorized into three molecular types: C1, C2, and C3. A prognostic model and RiskScore were constructed using Lasso regression analysis of 132 significant genes identified between C1 and C3. We utilized quantitative polymerase chain reaction to confirm the model's transcript level in Huh7 and THLE2 cell lines. Both molecular subtypes and RiskScores effectively predicted patients benefiting from immunotherapy. Cox regression analysis revealed RiskScore as the most significant prognosis factor, suggesting its clinical application potential and providing a foundation for future experimental research.

Precision treatment in advanced hepatocellular carcinoma

The past decade has witnessed significant advances in the systemic treatment of advanced hepatocellular carcinoma (HCC). Nevertheless, the newly developed treatment strategies have not achieved universal success and HCC patients frequently exhibit therapeutic resistance to these therapies. Precision treatment represents a paradigm shift in cancer treatment in recent years. This approach utilizes the unique molecular characteristics of individual patient to personalize treatment modalities, aiming to maximize therapeutic efficacy while minimizing side effects. Although precision treatment has shown significant success in multiple cancer types, its application in HCC remains in its infancy. In this review, we discuss key aspects of precision treatment in HCC, including therapeutic biomarkers, molecular classifications, and the heterogeneity of the tumor microenvironment. We also propose future directions, ranging from revolutionizing current treatment methodologies to personalizing therapy through functional assays, which will accelerate the next phase of advancements in this area.