Immune mediators in the tumor microenvironment of prostate cancer

Prostate cancer tissue is composed of both cancer cells and host cells.The milieu of host components that compose the tumor is termed the tumor microenvironment(TME).Host cells can be those derived from the tissue in which the tumor originates(e.g.,fibroblasts and endothelial cells)or those recruited,through chemotactic or other factors,to the tumor(e.g.,circulating immune cells).Some immune cells are key players in the TME and represent a large proportion of non-tumor cells found within the tumor.Immune cells can have both anti-tumor and pro-tumor activity.In addition,crosstalk between prostate cancer cells and immune cells affects immune cell functions.In this review,we focus on immune cells and cytokines that contribute to tumor progression.We discuss T-regulatory and T helper17 cells and macrophages as key modulators in prostate cancer progression.In addition,we discuss the roles of interleukin-6 and receptor activator of nuclear factor kappa-B ligand in modulating prostate cancer progression.This review highlights the concept that immune cells and cytokines offer a potentially promising target for prostate cancer therapy.

Hematopoietic stem cell-derived adipocytes and fibroblasts in the tumor microenvironment

The tumor microenvironment(TME) is complex and constantly evolving. This is due, in part, to the crosstalk between tumor cells and the multiple cell types that comprise the TME, which results in a heterogeneous population of tumor cells and TME cells. This review will focus on two stromal cell types, the cancerassociated adipocyte(CAA) and the cancer-associated fibroblast(CAF). In the clinic, the presence of CAAs and CAFs in the TME translates to poor prognosis in multiple tumor types. CAAs and CAFs have an activated phenotype and produce growth factors, inflammatory factors, cytokines, chemokines, extracellular matrix components, and proteases in an accelerated and aberrant fashion. Through this activated state, CAAs and CAFs remodel the TME, thereby driving all aspects of tumor progression, including tumor growth and survival, chemoresistance, tumor vascularization, tumor invasion, and tumor cell metastasis. Similarities in the tumorpromoting functions of CAAs and CAFs suggest that a multipronged therapeutic approach may be necessary to achieve maximal impact on disease. While CAAs and CAFs are thought to arise from tissues adjacent to the tumor, multiple alternative origins for CAAs and CAFs have recently been identified. Recent studies from our lab and others suggest that the hematopoietic stem cell, through the myeloid lineage, may serve as a progenitor for CAAs and CAFs. We hypothesize that the multiple origins of CAAs and CAFs may contribute to the heterogeneity seen in the TME. Thus, a better understanding of the origin of CAAs and CAFs, how this origin impacts their functions in the TME, and thetemporal participation of uniquely originating TME cells may lead to novel or improved anti-tumor therapeutics.

Glycogen metabolism-mediated intercellular communication in the tumor microenvironment influences liver cancer prognosis

Glycogen metabolism plays a key role in the development of hepatoellular carcinoma(HCC),but the function of glycogen metabolism genes in the tumor microenvironment(TME)is still to be elucidated.Single cell RNA-seq data were obtained from ten HCC tumor samples totaling 64,545 cells and 65 glycogen metabolism genes were analyzed bya nonnegative matrix factorization(NMF).The prognosis and immune response of new glycogen TME cell dusters were predicted by using HCC and immunotherapy cohorts from public databases.HOC single cell analysis was divided into fibroblasts,NT T cells,macrophages,endothelial clls,and B cells,which were separately divided into new cell clusters by glycogen metabolism gene annotation.Pseudo temporal trajectory analysis demonstrated the temporal differentiation trajectory of different glycogen subtype cell dusters.Cellular communication analysis revealed extensive interactions between endothelial cells with glycogen metabolizing TME cell.related subtypes and diferent glycogen subtype cell clusters.SCENIC analysis of transcription factors upstream of TME cell clusters with different glycogen metabolism.In addition,TME cell dusters of glycogen metabolism were found to be enriched in expression in CAF subtypes,CD8 depleted,M1,and M2 types.Bulk seq analysis showed the prognostic signifcance of glycogen metabolism.mediated TME cell dusters in HCC,while a significant immune response was found in the immunotherapy cohort in patients treated with immune checkpoint blockade(ICB),especially for CAFs,T cells,and macrophages In summary,our study reveals for the first time that glycogen metabolism mediates intercellular communication in the hepatocellular carcinoma microenvironment while elucidating the anti-tumor mechanisms and immune prognostic responses of different subtypes of cell dusters.

Immune signature of small bowel adenocarcinoma and the role of tumor microenvironment

In this editorial we comment on the article published“Clinical significance of programmed cell death-ligand expression in small bowel adenocarcinoma is determined by the tumor microenvironment”.Small bowel adenocarcinoma(SBA)is a rare gastrointestinal neoplasm and despite the small intestine's significant surface area,SBA accounts for less than 3%of such tumors.Early detection is challenging and the reason arises from its asymptomatic nature,often leading to late-stage discovery and poor prognosis.Treatment involves platinum-based chemotherapy with a 5-fluorouracil combination,but the lack of effective chemotherapy contributes to a generally poor prognosis.SBAs are linked to genetic disorders and risk factors,including chronic inflammatory conditions.The unique characteristics of the small bowel,such as rapid cell renewal and an active immune system,contributes to the rarity of these tumors as well as the high intratumoral infiltration of immune cells is associated with a favorable prognosis.Programmed cell death-ligand 1(PD-L1)expression varies across different cancers,with potential discrepancies in its prognostic value.Microsatellite instability(MSI)in SBA is associated with a high tumor mutational burden,affecting the prognosis and response to immunotherapy.The presence of PD-L1 and programmed cell death 1,along with tumor-infiltrating lymphocytes,plays a crucial role in the complex microenvironment of SBA and contributes to a more favorable prognosis,especially in the context of high MSI tumors.Stromal tumor-infiltrating lymphocytes are identified as independent prognostic indicators and the association between MSI status and a favorable prognosis,emphasizes the importance of evaluating the immune status of tumors for treatment decisions.

Role of LAP^+CD4^+ T cells in the tumor microenvironment of colorectal cancer

AIM To investigate the abundance and potential functions of LAP^+CD4^+ T cells in colorectal cancer(CRC). METHODS Proportions of LAP^+CD4^+ T cells were examined in peripheral blood and tumor/paratumor tissues of CRC patients and healthy controls using flow cytometry. Expression of phenotypic markers such as forkhead box(Fox)p3, cytotoxic T-lymphocyte-associated protein(CTLA)-4, chemokine CC receptor (CCR)4 and CCR5 was measured using flow cytometry. LAP^-CD4^+ and LAP^+CD4^+ T cells were isolated using a magnetic cellsorting system and cell purity was analyzed by flow cytometry. Real-time quantitative polymerase chain reaction was used to measure expression of cytokines interleukin (IL)-10 and transforming growth factor(TGF)-β.RESULTS The proportion of LAP^+CD4^+ T cells was significantly higher in peripheral blood from patients (9.44% ± 3.18%) than healthy controls (1.49% ± 1.00%, P < 0.001). Among patients, the proportion of LAP^+CD4^+ T cells was significantly higher in tumor tissues(11.76% ± 3.74%) compared with paratumor tissues (3.87% ± 1.64%, P < 0.001). We also observed positive correlations between the proportion of LAP^+CD4^+ T cells and TNM stage(P < 0.001), distant metastasis(P < 0.001) and serum level of carcinoembryonic antigen(P < 0.05). Magnetic-activated cell sorting gave an overall enrichment of LAP^+CD4^+ T cells (95.02% ± 2.87%), which was similar for LAP^-CD4^+ T cells(94.75% ± 2.76%). In contrast to LAP^-CD4^+ T cells, LAP^+CD4^+ T cells showed lower Foxp3 expression but significantly higher levels of CTLA-4, CCR4 and CCR5(P < 0.01). LAP^+CD4^+ T cells expressed significantly larger amounts of IL-10 and TGF-β but lower levels of IL-2, IL-4, IL-17 and interferon-γ, compared with LAPCD4+ T cells.CONCLUSION LAP^+CD4^+ T cells accumulated in the tumor microenvironment of CRC patients and were involved in immune evasion mediated by IL-10 and TGF-β.

Interrelations Between Psychological Stress and Cancer-Deciphering Molecular Signals in the Tumor Microenvironment

Current research has revealed some links between psychological stress and cellular mutation,neoplastic proliferation and metastasis in patients with cancer.In stressful situations,the stress-related neuroendocrine mediators(e.g.,catecholamines,and glucocorticoids(GSs))are being secreted,via stimulation of the sympathetic nervous system(SNS),and the hypothalamic-pituitaryadrenocortical(HPA)axis.Catecholamine may affect the malignant progression,since they can regulate various cellular signaling pathways,via adrenergic receptors(ARs)that are expressed by different types of neoplastic cells.The ARs increase the proliferation and invasive potential of such cells,and change their“behavior”in the tumor microenvironment.Similarly,cortisol and its glucocorticoid receptors(GRs)can promote stress-induced malignant growth and metastasis.Maladaptation to stressful situations,often relevant to the cancer diagnosis and treatment,may accelerate tumor growth and spread(e.g.,via inflammation,angiogenesis,and migration).Studies have shown that psychological interventions can be helpful for adaptation to adverse circumstances during the therapeutic process in patients with cancer.This mini-review will address some interrelations between psychological stress and cancer.It will discuss how the receptor-mediated signaling pathways may lead to cancer initiation,propagation,and spread.In addition,it will describe a supportive role of the stress reduction strategies,for example,in patients with breast cancer(BC).

New roles of tumor-derived exosomes in tumor microenvironment

Throughout tumorigenesis, the co-evolution of tumor cells and their surrounding microenvironment leads to the development of malignant phenotypes. Cellular communication within the tumor microenvironment(TME) plays a critical role in influencing various aspects of tumor progression, including invasion and metastasis. The release of exosomes, a type of extracellular vesicle, by most cell types in the body, is an essential mediator of intercellular communication. A growing body of research indicates that tumor-derived exosomes(TDEs) significantly expedite tumor progression through multiple mechanisms, inducing epithelial-mesenchymal transition and macrophage polarization, enhancing angiogenesis, and aiding in the immune evasion of tumor cells. Herein, we describe the formation and characteristics of the TME, and summarize the contents of TDEs and their diverse functions in modulating tumor development. Furthermore, we explore potential applications of TDEs in tumor diagnosis and treatment.

Hypoxia-related bioinformatic signatures associated with prognosis and tumor microenvironment of pancreatic cancer:Current status,concerns,and future perspectives

Pancreatic cancer(PC),a highly lethal tumor with nearly identical incidence and mortality rates,has become the sixth leading cause of cancer-related deaths.Hypoxia is an important malignant factor in PC,as it regulates angiogenesis,metabolic reprogramming,tumor progression,and metastasis.Disrupting the hypoxic microenvironment can enhance the efficacy of antitumor therapy and improve the prognosis of patients with PC.With the advent of bioinformatics,hypoxia-related PC models have emerged in recent years.They provide a reference for estimating the prognosis and immune microenvironment of patients with PC and identify potential biomarkers for targeting hypoxic microenvironment.However,these findings based on bioinformatic analysis may not be completely reliable without further experimental evidence and clinical cohort validation.The application of these models and biomarkers in clinical practice to predict survival time and develop anti hypoxic therapeutic strategies for patients with PC remains in its infancy.In this editorial,we review the current status of hypoxia-related prognostic models in PC,analyze their similarities and differences,discuss several existing challenges,and provide potential solutions and directions for further studies.This editorial will facilitate the optimization,validation,and determination of the molecular mechanisms of related models.

Roles of the tumor microenvironment in the resistance to programmed cell death protein 1 inhibitors in patients with gastric cancer

Despite the continuous developments and advancements in the treatment of gastric cancer(GC),which is one of the most prevalent types of cancer in China,the overall survival is still poor for most patients with advanced GC.In recent years,with the progress in tumor immunology research,attention has shifted toward immunotherapy as a therapeutic approach for GC.Programmed cell death protein 1(PD-1)inhibitors,as novel immunosuppressive medications,have been widely utilized in the treatment of GC.However,many patients are still resistant to PD-1 inhibitors and experience recurrence in the advanced stages of PD-1 immunotherapy.To reduce the occurrence of drug resistance and recurrence in GC patients receiving PD-1 immunotherapy,to maximize the clinical activity of immunosuppressive drugs,and to elicit a lasting immune response,it is essential to research the tumor microenvironment mechanisms leading to PD-1 inhibitor resistance in GC patients.This article reviews the progress in studying the factors influencing the resistance to PD-1 inhibitors in the GC tumor microenvironment,aiming to provide insights and a basis for reducing resistance to PD-1 inhibitors for GC patients in the future.

Redefining the tumor microenvironment with emerging therapeutic strategies

The environment surrounding a tumor,known as the tumor microenvironment(TME),plays a role in how cancer progresses and responds to treatment.It poses both challenges and opportunities for improving cancer therapy.Recent progress in understanding the TME complexity and diversity has led to approaches for treating cancer.This perspective discusses the strategies for targeting the TME,such as adjusting networks using extracellular vesicles to deliver drugs and enhancing immune checkpoint inhibitors(ICIS)through combined treatments.Furthermore,it highlights adoptive cell transfer(ACT)therapies as an option for tumors.By studying how components of the TME interact and utilizing technologies like single-cell RNA sequencing and spatial transcriptomics,we can develop more precise and efficient treatments for cancer.This article emphasizes the need to reshape the TME to boost antitumor immunity and overcome resistance to therapy,providing guidance for research and clinical practices in precision oncology.

N6-methyladenosine methylation regulates the tumor microenvironment of Epstein-Barr virus-associated gastric cancer

BACKGROUND N6-methyladenosine(m6A)methylation modification exists in Epstein-Barr virus(EBV)primary infection,latency,and lytic reactivation.It also modifies EBV latent genes and lytic genes.EBV-associated gastric cancer(EBVaGC)is a distinctive molecular subtype of GC.We hypothesized EBV and m6A methylation regulators interact with each other in EBVaGC to differentiate it from other types of GC.AIM To investigate the mechanisms of m6A methylation regulators in EBVaGC to determine the differentiating factors from other types of GC.METHODS First,The Cancer Gene Atlas and Gene Expression Omnibus databases were used to analyze the expression pattern of m6A methylation regulators between EBVaGC and EBV-negative GC(EBVnGC).Second,we identified Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)functional enrichment of m6A-related differentially expressed genes.We quantified the relative abundance of immune cells and inflammatory factors in the tumor microenvironment(TME).Finally,cell counting kit-8 cell proliferation test,transwell test,and flow cytometry were used to verify the effect of insulin-like growth factor binding protein 1(IGFBP1)in EBVaGC cell lines.RESULTS m6A methylation regulators were involved in the occurrence and development of EBVaGC.Compared with EBVnGC,the expression levels of m6A methylation regulators Wilms tumor 1-associated protein,RNA binding motif protein 15B,CBL proto-oncogene like 1,leucine rich pentatricopeptide repeat containing,heterogeneous nuclear ribonucleoprotein A2B1,IGFBP1,and insulin-like growth factor 2 binding protein 1 were significantly downregulated in EBVaGC(P<0.05).The overall survival rate of EBVaGC patients with a lower expression level of IGFBP1 was significantly higher(P=0.046).GO and KEGG functional enrichment analyses showed that the immunity pathways were significantly activated and rich in immune cell infiltration in EBVaGC.Compared with EBVnGC,the infiltration of activated CD4+T cells,activated CD8+T cells,monocytes,activated dendritic cells,and plasmacytoid dendritic cells were significantly upregulated in EBVaGC(P<0.001).In EBVaGC,the expression level of proinflammatory factors interleukin(IL)-17,IL-21,and interferon-γ and immunosuppressive factor IL-10 were significantly increased(P<0.05).In vitro experiments demonstrated that the expression level of IGFBP1 was significantly lower in an EBVaGC cell line(SNU719)than in an EBVnGC cell line(AGS)(P<0.05).IGFBP1 overexpression significantly attenuated proliferation and migration and promoted the apoptosis levels in SNU719.Interfering IGFBP1 significantly promoted proliferation and migration and attenuated the apoptosis levels in AGS.CONCLUSION m6A regulators could remodel the TME of EBVaGC,which is classified as an immune-inflamed phenotype and referred to as a“hot”tumor.Among these regulators,we demonstrated that IGFBP1 affected proliferation,migration,and apoptosis.

Nanomaterials for refining tumor microenvironment and enhancing therapy in head and neck squamous cell carcinoma: a review

Head and neck squamous cell carcinoma (HNSCC) is a prevalent and lethal solid tumor with a high mortality rate. Conventional cancertreatments, including surgery, radiotherapy, and chemotherapy, primarily target cancer cell eradication. However, uncontrolled proliferation and metabolic activities of these cells result in abnormalities in nutrient levels, hypoxia, and immunosuppression within the tumor microenvironment (TME). These factors constrain the efficacy of traditional treatments by promoting drug resistance, recurrence, and metastasis. Nanomaterials (NMs), such as nanozymes, can exhibit enzymatic activity similar to that of natural enzymes and offer a promising avenuefor the direct modification of the TME through catalytic oxidation-reduction processes. Moreover, they can serve as sensitizers or drug deliverycarriers, enhancing the efficacy of traditional treatment methods. Recently, NMs have garnered significant attention from oncologists. Thisreview begins with an overview of the composition and unique characteristics of the TME. Subsequently, we comprehensively exploredthe application of NMs in the treatment of HNSCC. Finally, we discuss the potential prospects and challenges associated with usingNMs in biomedical research.

Immunosuppressive tumor microenvironment in gastric signet-ring cell carcinoma

Gastric signet-ring cell carcinoma(GSRCC)is a subtype of gastric cancer with distinct phenotype and high risk of peritoneal metastasis.Studies have shown that early GSRCC has a good prognosis,while advanced GSRCC is insensitive to radiotherapy,chemotherapy or immune checkpoint blockade therapy.With technological advancement of single-cell RNA sequencing analysis and cytometry by time of flight mass cytometry,more detailed atlas of tumor microenvironment(TME)in GSRCC and its association with prognosis could be investigated extensively.Recently,two single-cell RNA sequencing studies revealed that GSRCC harbored a unique TME,manifested as highly immunosuppressive,leading to high immune escape.The TME of advanced GSRCC was enriched for immunosuppressive factors,including the loss of CXCL13+-cluster of differentiation 8+-Tex cells and declined clonal crosstalk among populations of T and B cells.In addition,GSRCC was mainly infiltrated by follicular B cells.The increased proportion of SRCC was accompanied by a decrease in mucosaassociated lymphoid tissue-derived B cells and a significant increase in follicular B cells,which may be one of the reasons for the poor prognosis of GSRCC.By understanding the relationship between immunosuppressive TME and poor prognosis in GSRCC and the underlying mechanism,more effective immunotherapy strategies and improved treatment outcomes of GSRCC can be anticipated.

DCS, a novel classifier system based on disulfidptosis reveals tumor microenvironment heterogeneity and guides frontline therapy for clear cell renal carcinoma

Background: Emerging evidence suggests that cell deaths are involved in tumorigenesis and progression, which may be treated as a novel direction of cancers. Recently, a novel type of programmed cell death, disulfidptosis, was discovered. However, the detailed biological and clinical impact of disulfidptosis and related regulators remains largely unknown. Methods: In this work, we first enrolled pancancer datasets and performed multi-omics analysis, including gene expression, DNA methylation, copy number variation and single nucleic variation profiles. Then we deciphered the biological implication of disulfidptosis in clear cell renal cell carcinoma (ccRCC) by machine learning. Finally, a novel agent targeting at disulfidptosis in ccRCC was identified and verified. Results: We found that disulfidptosis regulators were dysregulated among cancers, which could be explained by aberrant DNA methylation and genomic mutation events. Disulfidptosis scores were depressed among cancers and negatively correlated with epithelial mesenchymal transition. Disulfidptosis regulators could satisfactorily stratify risk subgroups in ccRCC, and a novel subtype, DCS3, owning with disulfidptosis depression, insensitivity to immune therapy and aberrant genome instability were identified and verified. Moreover, treating DCS3 with NU1025 could significantly inhibit ccRCC malignancy. Conclusion: This work provided a better understanding of disulfidptosis in cancers and new insights into individual management based on disulfidptosis.

Effects of salidroside on glioma formation and growth inhibition together with improvement of tumor microenvironment

Objective：To test the effects of salidroside on formation and growth of glioma together with tumor microenvironment.Methods：Salidroside extracted from Rhodiola rosea was purified and treated on human glioma cells U251 at the concentration of 20 μg/mL.3-（4,5-dimethylthiazol-2-yl）-2,5-dephenyltetrazolium bromide （MTT） assay for cytotoxicity and flow cytometry （FCM） for cell cycle analysis were performed.Then for in vivo study,xenotransplantation tumor model in nude mice was generated and treated with salidroside at the concentration of 50 mg/kg.d for totally 20 d.Body weight and tumor size were detected every 2 d after the treatment.The levels of 8-isoprostane,superoxide dismutase （SOD） and malondialdehyde （MDA）,special markers for oxidative stress,were detected while immunofluoresence staining was performed for astrocyte detection.Results：For in vitro study,salidroside could decrease the viability of human glioma cells U251 and the growth of U251 cells at G0/G1 checkpoint during the cell cycle.For in vivo study,salidroside could also inhibit the growth of human glioma tissue in nude mice.The body weight of these nude mice treated with salidroside did not decrease as quickly as control group.In the tumor xenotransplantation nude mice model,mice were found of inhibition of oxidative stress by detection of biomarkers.Furthermore,overgrowth of astrocytes due to the stimulation of oxidative stress in the cortex of brain was inhibited after the treatment of salidroside.Conclusions：Salidroside could inhibit the formation and growth of glioma both in vivo and in vitro and improve the tumor microenvironment via inhibition of oxidative stress and astrocytes.

Construction and validation of a pancreatic cancer prognostic model based on genes related to the hypoxic tumor microenvironment

BACKGROUND Pancreatic cancer is one of the most lethal malignancies,characterized by poor prognosis and low survival rates.Traditional prognostic factors for pancreatic cancer offer inadequate predictive accuracy,often failing to capture the complexity of the disease.The hypoxic tumor microenvironment has been recognized as a significant factor influencing cancer progression and resistance to treatment.This study aims to develop a prognostic model based on key hypoxia-related molecules to enhance prediction accuracy for patient outcomes and to guide more effective treatment strategies in pancreatic cancer.AIM To develop and validate a prognostic model for predicting outcomes in patients with pancreatic cancer using key hypoxia-related molecules.METHODS This pancreatic cancer prognostic model was developed based on the expression levels of the hypoxia-associated genes CAPN2,PLAU,and CCNA2.The results were validated in an independent dataset.This study also examined the correlations between the model risk score and various clinical features,components of the immune microenvironment,chemotherapeutic drug sensitivity,and metabolism-related pathways.Real-time quantitative PCR verification was conducted to confirm the differential expression of the target genes in hypoxic and normal pancreatic cancer cell lines.RESULTS The prognostic model demonstrated significant predictive value,with the risk score showing a strong correlation with clinical features:It was significantly associated with tumor grade(G)(bP<0.01),moderately associated with tumor stage(T)(aP<0.05),and significantly correlated with residual tumor(R)status(bP<0.01).There was also a significant negative correlation between the risk score and the half-maximal inhibitory concentration of some chemotherapeutic drugs.Furthermore,the risk score was linked to the enrichment of metabolism-related pathways in pancreatic cancer.CONCLUSION The prognostic model based on hypoxia-related genes effectively predicts pancreatic cancer outcomes with improved accuracy over traditional factors and can guide treatment selection based on risk assessment.

Advances in research on tumor microenvironment of hepatocellular carcinoma

Modern medical research on cancer shows that hepatocellular carcinoma (HCC) is related to tumor microenvironment. Studying the relationship between tumor microenvironment and HCC can be used as a new research direction to provide more strategies and ideas for the prevention and treatment of HCC. This article describes the characteristics of tumor microenvironment, cytokines, related signaling pathways, the occurrence and development of traditional Chinese medicine and HCC, and treatment-related knowledge.

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.

Hypoxic tumor microenvironment:Destroyer of natural killer cell function

In recent years, immunotherapy has made remarkable progress in treating certain tumors and hematological malignancies. However, the efficacy of natural killer(NK) cells, which are an important subset of innate lymphocytes used in anticancer immunotherapy, remains limited. Hypoxia, a critical characteristic of the tumor microenvironment(TME), is involved in tumor development and resistance to radiotherapy, chemotherapy, and immunotherapy. Moreover, hypoxia contributes to the impairment of NK cell function and may be a significant factor that limits their therapeutic effects. Targeted hypoxia therapy has emerged as a promising research area for enhancing the efficacy of NK cell therapy. Therefore, understanding how the hypoxic TME influences NK cell function is crucial for improving antitumor treatment outcomes.

Multifaceted roles of lymphatic and blood endothelial cells in the tumor microenvironment of hepatocellular carcinoma:A comprehensive review

The tumor microenvironment is a complex network of cells,extracellular matrix,and signaling molecules that plays a critical role in tumor progression and metastasis.Lymphatic and blood vessels are major routes for solid tumor metastasis and essential parts of tumor drainage conduits.However,recent studies have shown that lymphatic endothelial cells(LECs)and blood endothelial cells(BECs)also play multifaceted roles in the tumor microenvironment beyond their structural functions,particularly in hepatocellular carcinoma(HCC).This comprehensive review summarizes the diverse roles played by LECs and BECs in HCC,including their involvement in angiogenesis,immune modulation,lymphangiogenesis,and metastasis.By providing a detailed account of the complex interplay between LECs,BECs,and tumor cells,this review aims to shed light on future research directions regarding the immune regulatory function of LECs and potential therapeutic targets for HCC.