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PubMed2026

Long-Term Outcomes and Paired Immune and Genomic Exploratory Analyses After Neoadjuvant Dose-Dense MVAC in Muscle-Invasive Bladder Cancer: A Single-Centre Case Series.

Background/Objectives: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy has been the standard of care for muscle-invasive bladder cancer (MIBC) for two decades, yet a substantial proportion of patients derive no benefit. As antibody-drug conjugates and immune checkpoint inhibitors reshape perioperative treatment, it is unclear which patients retain meaningful benefit from platinum. We describe long-term outcomes and exploratory paired immune and genomic analyses in a single-centre cohort treated with dose-dense MVAC (dd-MVAC). Methods: We retrospectively identified 54 consecutive patients with MIBC treated with neoadjuvant dd-MVAC between November 2013 and November 2019. Forty-two underwent radical cystectomy and are assessable for pathologic response. Immunohistochemistry for CD3, CD8, FOXP3, PD-1, PD-L1, PD-L2, and NY-ESO-1 was evaluable in 31 baseline specimens and 22 paired specimens; paired genomic profiling was evaluable in 12 cases, with paired tumour mutational burden (TMB) in 10 by whole-exome sequencing and 7 by TSO-500. Paired analyses necessarily exclude patients achieving a pathologic complete response (pCR), who have no residual tumour, and most early progressors. Results: pCR was achieved in 11/42 operated patients (26%, 95% CI 15-41). Median follow-up was 87 months (IQR 24-104). Hydronephrosis was the only baseline factor associated with absence of pCR (p = 0.016). Within the operated cohort, pCR was associated with longer recurrence-free survival (log-rank p = 0.017), but the difference in overall survival did not reach significance (p = 0.121). NAC reduced intratumoral FOXP3 (q = 0.001), NY-ESO-1 (q = 0.013), PD-L2 (q = 0.013), and CD3 (q = 0.043) after correction for multiple comparisons, whereas TMB showed no significant change (TSO-500 p = 0.67; WES p = 0.86). No statistically significant association was detected between any baseline immune marker, including PD-L1, and pCR. The mutational landscape was largely concordant before and after NAC. Conclusions: This study was exploratory and was not powered to validate predictive biomarkers. In this long-term cohort, dd-MVAC was associated with measurable depletion of intratumoral immune populations in chemoresistant tumours, while paired genomic profiles remained broadly concordant. No pre-treatment biomarker identified platinum-refractory patients, but the small evaluable subsets mean these are hypothesis-generating rather than negative findings, and prospective studies with pre-specified biomarker endpoints are required.

chemoresistance↗
PubMed2025

The Proteomic Landscape of CTNNB1 Mutated Low-Grade Early-Stage Endometrial Carcinomas.

Endometrial carcinoma is the most frequent gynecologic malignancy in western countries. In recent years, mutations in CTNNB1 have been associated with worse prognosis in low-risk carcinomas. However, there is a lack of understanding of the proteomic implications of CTNNB1 mutations in this type of tumor. In this study, we performed shotgun proteomics using Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples of CTNNB1 mutated and wild-type low-risk endometrial carcinomas. A publicly available proteomic and transcriptomic database was used to validate results. Differential protein expression and Gene Set Enrichment Analysis revealed dysregulation of pathways associated with cell keratinization, immune response modulation, and intracellular calcium regulation. CTNNB1 mutated tumors showed immune dysregulation at multiple levels including cytokine secretion, cell adhesion, and lymphocyte activation. These results were supported by tissue multiplex immunofluorescence analysis, demonstrating reduced CD8 tumor-infiltrating lymphocytes and different immune spatial interaction patterns. Intracellular calcium dysfunction was associated with key transcript dysregulation. We found an increased expression of CAMK2A and ROR2, suggesting a potential role for non-canonical Wnt pathway activation in CTNNB1 mutated tumors.

Humans↗
PubMed2026

Unraveling the Enigma of Melanoma Brain Metastasis: New Molecular Insights and Therapeutic Directions.

Melanoma, a highly aggressive and metastatic cancer, poses significant challenges due to its propensity to spread to distant organs, with brain metastasis representing a particularly devastating complication. This review synthesizes preclinical and clinical evidence on the molecular, cellular, and microenvironmental mechanisms driving melanoma metastasis, emphasizing mechanisms of blood-brain barrier traversal, tumor-stroma co-option, and brain-specific genomic and transcriptional programs. We summarize advances in therapeutic strategies to combat melanoma brain metastasis including novel small molecules, immunotherapies, and combination approaches tailored for brain metastases. The review also highlights the immunological landscape of the brain, translational models, and multidisciplinary clinical management strategies. Finally, we identify critical research gaps, including the need for brain metastasis-specific clinical trials, AI-driven predictive models, and preventive strategies, to guide future efforts in improving outcomes for patients with melanoma brain metastasis.

Humans↗
PubMed1998

Immune cells in the tumor microenvironment. Mechanisms responsible for functional and signaling defects.

Lymphocytes recovered from human tumors or the peripheral blood of patients with advanced malignancies are functionally compromised. Abnormalities in signaling via the T cell receptor (TcR) in T cells and Fc gamma RIII in NK cells obtained from cancer patients include significantly decreased expression of the receptor-associated zeta chains, decreased Ca++ flux as well as impaired kinase activity following triggering with anti-CD3 or anti-CD16 antibodies, respectively, and altered expression of downstream protein tyrosine kinase p56lck. Some of these defects were demonstrable in situ, in T cells infiltrating tumor tissues. Post-translational modifications of the zeta protein were responsible for its low levels, since near normal levels of mRNA were present in situ in the patients' T cells. LNL in tumor-involved LN or mononuclear cells in solid tumors were shown to contain numerous apoptotic (TUNEL+) CD3+ lymphocytes. Co-incubation of normal activated T cells or Jurkat cells with tumor targets (either freshly isolated or tumor cell lines) induced degradation of the zeta chain as well as apoptosis in a proportion of lymphocytes. Both fresh and cultured human tumors were shown to express FasL, and T cells in tumors were found to be Fas+. Therefore, the Fas-FasL pathway is, at least in part, responsible for signaling defects and apoptosis induced by the tumor in lymphocytes found in its milieu. Preliminary data indicate that immunotherapy with cytokines might normalize zeta expression in T cells and partly restore their antitumor functions.

Apoptosis↗
PubMed2000

Adaptive response of thymocyte apoptosis and cell cycle progression induced by low dose X-ray irradiation in mice.

The dose-effect of adaptive response of thymocyte apoptosis and cell cycle progression induced by whole-body X-ray irradiation (WBI) was studied in male Kunming mice. The inductive doses (D1) were 25, 50, 75, 100 or 200 mGy 6 h before the challenging doses (D2) of 1.0, 1.5 or 2.0 Gy. The changes in the percentages of the thymocyte apoptotic bodies (TAB) and the cells in different phases of cell cycle were measured with flow cytometry. The percentages of TAB decreased, the arrests of G1 and G2 + M phases diminished, and the cells of DNA synthesis of S phase increased when the D1 + D2 groups was compared with the D2 groups. When D1 was 200 mGy, the adaptive response of thymocyte apoptosis and cell cycle progression were no longer induced by low dose radiation (LDR). In addition, the extracellular fluid from the splenocytes were cultured with Con A for 48 h in vitro 24 h after 75 mGy WBI was placed in the murine thymocyte suspension from mice irradiated with 2.0 Gy WBI and co-incubated. The thymocyte apoptosis decreased. Especially, noteworthy was that the percentages of TAB after the incubation for 72 h were significantly lower than those in 2.0 Gy irradiated thymocytes (P < 0.05). These results indicate that when the mice were irradiated with 25-100 mGy (D1, 12.5 mGy/min) 6 h before 1.0-2.0 Gy (D2, 0.287 Gy/min) exposure, an adaptive response of thymocyte apoptosis and cell cycle progression may be induced under the condition of WBI, and LDR (75 mGy) may change the microenvironment of immune cells and decrease the thymocyte apoptosis.

Animals↗
PubMed2003

Pathogenesis and treatment of HIV-associated renal diseases: lessons from clinical and animal studies, molecular pathologic correlations, and genetic investigations.

HIV infection is associated with several renal syndromes, including acute renal failure. Chronic renal failure directly linked to HIV infection includes thrombotic microangiopathic renal diseases, immune-mediated glomerulonephritides, and HIV-associated nephropathy. A renal biopsy may be necessary for diagnosis. The development of HIV-associated nephropathy has been definitively linked to renal cellular infection, but the disease affects only a minority of patients, typically men of African descent. Therefore, factors determining disease expression in infected patients must now be emphasized. The pathogenic mechanisms involved in HIV-associated renal disease remain obscure. Genetic factors, as well as renal cellular responses, mediated by HIV proteins (including an immune-activated microenvironment) capable of presenting antigen in susceptible hosts probably explain most cases. HIV-associated nephropathy has a characteristic pathologic phenotype, including glomerular, tubular, and interstitial changes, and ultrastructural findings. Infection of the glomerular epithelial cell, or podocyte, and consequent structural and biochemical changes may be pivotal in pathogenesis. The HIV-1 transgenic mouse is an important model for understanding disease pathogenesis, particularly the role of HIV proteins in mediating renal tissue injury. Rigorously controlled randomized trials have not evaluated treatment, but corticosteroids and angiotensin-converting enzyme inhibitors have been used. Highly active antiretroviral therapy seems to have decreased the incidence of end-stage renal disease related to HIV infection and, in case reports, to have improved renal functional and pathologic outcomes of HIV-associated nephropathy. Outcomes in patients undergoing hemodialysis and peritoneal dialysis have improved, and current research focuses on renal transplantation for treatment of HIV-infected patients.

Animals↗
PubMedDate not supplied

The use of the hu-PBL-SCID mouse model to study lymphocyte homing and responsiveness to recall antigens.

SCID mice were injected intraperitoneally with human peripheral blood lymphocytes (PBL) that had been previously stimulated with pokeweed mitogen (PWM) for two days to generate activated B cells. After two weeks, serum and gut washes obtained from SCID mice reconstituted with human PBL (hu-PBL-SCID mice) contained human IgA, IgG, and IgM indicating the successful survival of human lymphoid cell grafts in both mucosal and nonmucosal tissues of the SCID mice. Human IgA plasma cells could be detected by immunofluorescence microscopy in the lamina propria of the small intestine, while IgM plasma cells predominated in the spleen. The results suggested that PWM-activated plasma cell precursors homed to the spleen and the lamina propria of the SCID mouse where they differentiated into plasma cells. In vivo stimulation of hu-PBL-SCID mice with diphtheria and tetanus toxoids (DT/TT) elicited a primary (IgM) immune response pattern rather than a secondary (IgG) response. Antigen-specific antibody-secreting cells were found in the spleen and lamina propria after immunization. The microenvironment of the hu-PBL-SCID mice may select virgin B cells subsets over memory B cell clones.

Animals↗
PubMed2026

IL1RAP Is Associated With an Inflammation-Immunity-Related State in Skin Cutaneous Melanoma: Integrative Evidence From Pan-Cancer Data and Melanoma Immunotherapy Cohorts.

BACKGROUND: The crosstalk between inflammation and immunity plays a central role in tumor progression, immune evasion, and therapeutic response. Interleukin-1 receptor accessory protein (IL1RAP) is a key adaptor in inflammatory signaling, yet its immunological relevance and clinical implications in skin cutaneous melanoma (SKCM) remain largely unexplored. METHODS: We performed an integrative analysis combining pan-cancer and melanoma-focused datasets. Bulk transcriptomic, single-cell, spatial transcriptomic, genomic alteration, pharmacogenomic, and clinical survival data were obtained from TCGA, GTEx, GEO, ENA, and other public resources. IL1RAP expression was evaluated across cancer types in relation to diagnostic performance, immune subtypes, survival outcomes, functional pathway activity, immune-genomic states, somatic alterations, and drug-response metrics. Melanoma-focused analyses examined immune infiltration, methylation-derived tumor-infiltrating lymphocyte (MeTIL) scores, and exploratory survival associations in five treatment cohorts; the survival groups were defined using cohort-specific optimal cutoffs rather than median splits. RESULTS: IL1RAP expression differed between tumor and normal tissues in multiple cancers, although the direction and magnitude varied by cancer type. Pan-cancer survival associations were likewise context dependent. Single-cell and spatial transcriptomic resources indicated cell-type and spatial heterogeneity of IL1RAP expression within tumor microenvironments. Pathway, immune-genomic, and pharmacogenomic analyses identified exploratory associations with functional states, genomic features, and drug-response metrics. In SKCM, IL1RAP expression was associated with several immune-infiltration estimates and higher MeTIL scores. Across five melanoma immunotherapy cohorts, the direction and magnitude of the overall survival associations varied substantially. CONCLUSIONS: This retrospective integrative analysis suggests that IL1RAP may mark an inflammation-immunity-related state in SKCM. The heterogeneous associations across cancers and melanoma treatment cohorts support further validation but do not establish IL1RAP as a causal regulator, a treatment-response predictor, or a therapeutic target.

IL1RAP↗
PubMed2006

Immune resistance orchestrated by the tumor microenvironment.

It is now little disputed that most if not all cancer cells express antigens that can be recognized by specific CD8(+) T lymphocytes. However, a central question in the field of anti-tumor immunity is why such antigen-expressing tumors are not spontaneously eliminated by the immune system. While in some cases, this lack of rejection may be due to immunologic ignorance, induction of anti-tumor T-cell responses in many patients has been detected in the peripheral blood, either spontaneously or in response to vaccination, without accompanying tumor rejection. These observations argue for the importance of barriers downstream from initial T-cell priming that need to be addressed to translate immune responses into clinical tumor regression. Recent data suggest that the proper trafficking of effector T cells into the tumor microenvironment may not always occur. T cells that do effectively home to tumor metastases are often found to be dysfunctional, pointing toward immunosuppressive mechanisms in the tumor microenvironment. T-cell anergy due to insufficient B7 costimulation, extrinsic suppression by regulatory cell populations, inhibition by ligands such as programmed death ligand-1, metabolic dysregulation by enzymes such as indoleamine-2,3-dioxygenase, and the action of soluble inhibitory factors such as transforming growth factor-beta have all been clearly implicated in generating this suppressive microenvironment. Identification of these downstream processes points to new therapeutic targets that should be manipulated to facilitate the effector phase of anti-tumor immune responses in concert with vaccination or T-cell adoptive transfer.

Animals↗
PubMed2006

Cytokine-based therapy and biochemotherapy for advanced melanoma.

A variety of immunotherapeutic approaches have shown activity in patients with metastatic melanoma with the best results being observed with interleukin 2 (IL-2). Follow-up data through 2004 confirm the durability of responses produced by the Food and Drug Administration-approved high-dose IL-2 regimen in this patient population. Efforts to develop more tolerable and/or effective IL-2-based treatment regimens by either prolonged administration of lower doses or the combination of IL-2 with other cytokines, monoclonal antibodies, or vaccines have yet to produce results superior to those seen with high-dose IL-2 alone. Recent investigations have suggested that, in some patients, IL-2 may expand regulatory T-cell populations leading to immune tolerance rather than antitumor immunity. Efforts to shift this balance in favor of immune rejection by reducing the confounding effects of regulatory T cells on IL-2 therapy or the use of novel and potentially more purely immunostimulatory cytokines are ongoing. Despite promising phase 2 data, phase 3 studies have failed to show meaningful clinical benefit for the combination of cytokines with cytotoxic chemotherapy, so-called "biochemotherapy." Nonetheless, recent investigations with biochemotherapy followed by maintenance immunotherapy suggest that biochemotherapy may still have a role as a "bridge to immunotherapy" in some patients with rapidly progressive disease. Given the low number of patients achieving durable benefit with cytokine-based immunotherapy, considerable recent effort has focused on identifying predictors of therapeutic response. Investigations suggest that immune responsiveness may be predetermined by a tumor microenvironment conducive to immune recognition and the host propensity to develop autoimmunity. Efforts to understand and further define pretreatment predictors of response through the use of gene expression and proteomic techniques are ongoing and raise the potential for eventually limiting cytokine-based immunotherapy to those most likely to benefit.

Animals↗
PubMed2002

Prospective molecular profiling of melanoma metastases suggests classifiers of immune responsiveness.

We amplified RNAs from 63 fine needle aspiration (FNA) samples from 37 s.c. melanoma metastases from 25 patients undergoing immunotherapy for hybridization to a 6108-gene human cDNA chip. By prospectively following the history of the lesions, we could correlate transcript patterns with clinical outcome. Cluster analysis revealed a tight relationship among autologous synchronously sampled tumors compared with unrelated lesions (average Pearson's r = 0.83 and 0.7, respectively, P < 0.0003). As reported previously, two subgroups of metastatic melanoma lesions were identified that, however, had no predictive correlation with clinical outcome. Ranking of gene expression data from pretreatment samples identified approximately 30 genes predictive of clinical response (P < 0.001). Analysis of their annotations denoted that approximately half of them were related to T-cell regulation, suggesting that immune responsiveness might be predetermined by a tumor microenvironment conducive to immune recognition.

Adult↗
PubMedDate not supplied

Immunobiology of gestational trophoblastic diseases.

Gestational trophoblastic diseases (GTDs) comprise a group of interrelated diseases characterized by development after gestation, widespread metastases, and high curability with chemotherapy. The good prognosis of GTDs is considered partly a result of the host immune response to paternal antigens expressed on trophoblastic cells. In this study, we review current understanding of the immunobiology of GTDs. First of all, we describe the microenvironment between trophoblastic cells and subpopulation of immune cells. Second, immunogenetics, immune microenvironment around abnormal trophoblast, and mechanism of GTDs escaping from maternal immune system surveillance were also discussed. Third, we propose the possible immunotherapy for persistent GTDs, particularly the vaccine designed on human chorionic gonadotrophin, which is generally accepted as a tumor marker for GTDs diagnosis. Due to the low incidence of GTDs and high response to chemotherapy, there have been few literatures about immunobiologic characteristics of GTDs compared with the other gynecologic malignancies, such as ovarian cancer, but the immunologic behavior of GTDs should be explored for further understanding of the etiology of these diseases and to help designing immunotherapeutic strategies for persistent GTDs.

Antigens, Neoplasm↗
PubMed2026

Glutathione reductase deficiency potentiates the immunogenicity of ferroptosis and cuproptosis via amplified reactive oxygen species accumulation and cGAS-STING pathway activation.

BACKGROUND: Cancer remains a major therapeutic challenge due to drug resistance and metastasis, processes driven by oxidative stress and redox imbalance. Targeting this vulnerability through ferroptosis (iron-dependent lipid peroxidation) and cuproptosis (copper-driven mitochondrial dysfunction), two ROS-mediated cell death pathways, offers a promising therapeutic strategy. However, clinical translation is hindered by incomplete understanding of their redox regulation and limited immunogenicity. METHODS: A genome-wide CRISPR knockout screen was performed to identify key regulators of ferroptosis. Genetic depletion or pharmacological inhibition of candidate genes was evaluated across multiple cancer cell lines for sensitivity to ferroptosis inducer RSL3 and the cuproptosis inducer elesclomol (Es). Antitumor efficacy was assessed in xenograft, orthotopic, metastatic, and syngeneic mouse models, alone or combined with immune checkpoint inhibitors. Mechanistic studies also examined ROS production, mitochondrial stress, mitochondrial DNA release, cGAS-STING activation, and immune responses within the tumor microenvironment. RESULTS: Glutathione reductase (GSR), a central enzyme maintaining reduced glutathione (GSH) homeostasis, was identified as the top suppressor of ferroptosis. GSR knockout or pharmacological inhibition markedly sensitized diverse cancer cell lines to RSL3-induced ferroptosis, while GSR overexpression conferred resistance. Strikingly, GSR depletion also enhanced sensitivity to cuproptosis triggered by the copper ionophore Es. In multiple in vivo tumor models, GSR inhibition synergizes with RSL3 or Es to suppress tumor growth, inhibit lung metastasis, and prolong survival. Mechanistically, GSR deficiency amplified ROS production, induced mitochondrial stress, and triggered the cytosolic mitochondrial DNA release under ferroptotic or cuproptotic stress, activating the cGAS-STING pathway in vitro and in vivo. This increased inflammatory cytokine production, promoted immunogenic cell death, and enhanced the release of damage-associated molecular patterns (DAMPs), including HMGB1. Together, GSR inhibition combined with a ferroptosis or cuproptosis inducer transformed the tumor microenvironment into a highly immune stimulatory state, thereby enhancing the efficacy of immune checkpoint blockade through increased dendritic cell activation and T-cell infiltration and activation. CONCLUSIONS: GSR represents a key molecular node connecting and modulating ferroptosis and cuproptosis through redox regulation. Targeting GSR amplifies ROS-mediated immunogenic cell death, triggers cGAS-STING activation in cancer cells, and enhances the efficacy of cancer immunotherapy, providing a promising redox-based therapeutic strategy.

Ferroptosis↗
PubMed1993

Immune privilege as the result of local tissue barriers and immunosuppressive microenvironments.

As the cellular and molecular bases of immune privilege are elucidated experimentally, the phenomenon emerges as an active and dynamic exercise in immune regulation. Local tissue factors play a key role in the establishment and maintenance of privilege, particularly tissue cytokines and mediators within the local microenvironment, which modify both the induction and expression of immunity to antigens that are introduced into, or arise within, privileged sites.

Animals↗
PubMed2026

Expression of PIEZO1 in lung adenocarcinoma correlates with PD-L1 expression, cell migration, and poor prognosis: an exploratory study.

BACKGROUND AND AIMS: Lung adenocarcinoma (LUAD) treatment is challenging process. and the function of PIEZO1, a mechanically sensitive ion channel has not been systematically determined. In this study we aimed to explore the expression, potential associations, and clinical significance of PIEZO1 in LUAD. METHODS AND AIMS: A comprehensive bioinformatics analysis was performed using data from the Cancer Genome Atlas (TCGA) database, the Gene Expression Omnibus (GEO) database and other databases. Experimental validation was performed to confirm the expression patterns and preliminarily examine the associations of PIEZO1 in LUAD cell lines. RESULTS: PIEZO1 expression was significantly lower in LUAD tissues than in normal lung tissues (P&#x2009;<&#x2009;0.05). Its expression was correlated with advanced pathological stage, lymph node involvement, and distant metastasis. High PIEZO1 expression was associated with a distinct immune-related tumor microenvironment, characterized by correlations with the expression levels of multiple immune checkpoint molecules, and was identified as an independent factor associated with poor overall survival (HR&#x2009;=&#x2009;1.49; 95% CI 1.11-2; P&#x2009;<&#x2009;0.007). In vitro experiments confirmed the downregulated PIEZO1 expression in LUAD cell lines, and functional knockdown experiments revealed its association with cell migration and PD-L1 expression. CONCLUSION: This exploratory study revealed that PIEZO1 expression in LUAD cell lines correlated with the expression of immune-related features and EMT-related genes, as well as poor prognosis. In vitro, PIEZO1 knockdown is associated with reduced cell migration and decreased PD-L1 expression. These findings provide a basis for future investigations into the potential role of PIEZO1 in LUAD.

Gene expression↗
PubMed2005

Inducible immune regulation following autoimmune disease in the immune-privileged eye.

The immune-privileged eye has the potential to induce regulatory immunity along with local mechanisms of immunosuppression. Rodent models of human autoimmune uveoretinitis [experimental autoimmune uveoretinitis (EAU)] recover without spontaneous recurrence of uveitis, which differs from uveitis in some humans. This raises the possibility that the mechanism of immune privilege in the rodent eye can reimpose itself during autoimmune uveoretinitis and re-establish tolerance to autoantigen. To investigate this possibility, we examined the spleens of EAU-recovered mice for regulatory immunity. We detected regulatory immunity when we adoptively transferred post-EAU spleen cells into other mice immunized for EAU. We could not detect this regulatory immunity in enucleated mice nor in naive mice. Moreover, unlike the mechanisms of anterior chamber-associated immune deviation, the suppression was only mediated by post-EAU CD4+ T cells, which required activation with autoantigen presented by post-EAU spleen antigen-presenting cells (APC). Our results demonstrate that when the immune-privileged ocular microenvironment recovers from an autoimmune response, it has influenced systemic immunity to retinal autoantigen by affecting APC and mediating induction of potential regulatory CD4+ T cells laying in wait in the post-EAU spleen for restimulation.

Animals↗
PubMed2026

Multi-omics and spatial transcriptomics reveal that S100A10 drives CD8+ T-cell exhaustion and immune evasion in hepatocellular carcinoma through cPLA2-5-LOX-mediated arachidonic acid metabolism and ferroptosis.

Immune evasion in hepatocellular carcinoma (HCC) represents a major biological barrier limiting the efficacy of immunotherapy, yet its molecular basis remains incompletely understood. Increasing evidence indicates that tumor metabolic reprogramming and ferroptosis-related signaling play critical roles in shaping an immunosuppressive tumor microenvironment (TME); however, the specific regulatory factors involved remain unclear. This study aims to systematically elucidate the functional role of S100 calcium-binding protein A10 (S100A10) in immune evasion in HCC, with a particular focus on the molecular mechanisms by which S100A10 regulates CD8+ T-cell exhaustion through arachidonic acid (AA) metabolism and ferroptosis, as well as its potential therapeutic implications. To this end, data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) cohort are integrated to analyze the expression patterns of S100A10, its prognostic value, and its association with the immune microenvironment. S100A10 overexpression and knockout models are established in HCCLM3 and MHCC97L cell lines, and S100A10-mediated metabolic pathway reprogramming is characterized using transcriptomic profiling, untargeted metabolomics, and ferroptosis-related functional assays. In parallel, single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics are employed to delineate the cell-type specificity and spatial distribution of S100A10. Furthermore, human CD8+ T-cell co-culture systems and orthotopic mouse HCC models are used to evaluate the impact of S100A10 on immune function and responsiveness to anti-programmed cell death protein 1 (anti-PD-1) therapy. The results demonstrate that S100A10 is significantly upregulated in HCC and is closely associated with poor prognosis and an immunosuppressive state. Mechanistically, S100A10 activates cytosolic phospholipase A2-arachidonate 5-lipoxygenase (cPLA2-5-LOX)-mediated AA oxidative metabolism, leading to the accumulation of lipid peroxidation products and ferroptosis-associated signals, thereby driving CD8+ T-cell exhaustion and promoting immune evasion. Significantly, inhibition of S100A10 reshapes the tumor immune microenvironment (TIME) and enhances the therapeutic efficacy of anti-PD-1 treatment. Collectively, these findings identify S100A10 as a critical regulator of metabolic-immune coupling in HCC and provide a theoretical basis for combinatorial strategies targeting metabolism and immunotherapy.

Arachidonic acid metabolism↗