Integrative Multi-Omics and Functional Validation Reveal the Role of the TACE Refractoriness-Associated Gene ATP1B3 in Hepatocellular Carcinoma

B56ε is a regulatory subunit of the serine/threonine protein phosphatase 2A, which is abnormally expressed in tumors and regulates various tumor cell functions. At present, the application of B56ε in pan-cancer lacks a comprehensive analysis, and its role and mechanism in hepatocellular carcinoma (HCC) are still unclear. To analyze B56ε in pan-cancer, and explore its role and mechanism in HCC. The Cancer Genome Atlas, Genotype-Tissue Expression, Gene Expression Profiling Interactive Analysis, and Tumor Immune Estimation Resource databases were used to analyze B56ε expression, prognostic mutations, somatic copy number alterations, and tumor immune characteristics in 33 tumors. The relationships between B56ε expression levels and drug sensitivity, immunotherapy, immune checkpoints, and human leukocyte antigen (HLA)-related genes were further analyzed. Gene Set Enrichment Analysis (GSEA) was performed to reveal the role of B56ε in HCC. The Cell Counting Kit-8, plate cloning, wound healing, and transwell assays were conducted to assess the effects of B56ε interference on the malignant behavior of HCC cells. In most tumors, B56ε expression was upregulated, and high B56ε expression was a risk factor for adrenocortical cancer, HCC, pancreatic adenocarcinoma, and pheochromocytoma and paraganglioma (all P < 0.05). B56ε expression levels were correlated with a variety of immune cells, such as T helper 17 cells, B cells, and macrophages. There was a positive correlation between B56ε expression levels with immune checkpoint genes and HLA-related genes (all P < 0.05). The expression of B56ε was negatively correlated with the sensitivity of most chemotherapy drugs, but a small number showed a positive correlation (all P < 0.05). GSEA analysis showed that B56ε expression was related to the cancer pathway, p53 downstream pathway, and interleukin-mediated signaling in HCC. Knockdown of B56ε expression in HCC cells inhibited the proliferation, migration, and invasion capacity of tumor cells. B56ε is associated with the microenvironment, immune evasion, and immune cell infiltration of multiple tumors. B56ε plays an important role in HCC progression, supporting it as a prognostic marker and potential therapeutic target for HCC.

BackgroundDespite breakthroughs in immune checkpoint blockade (ICB) for advanced hepatocellular carcinoma (HCC), tumor immune evasion remains a major limitation to immunotherapy efficacy. PTEN-induced putative kinase 1 (PINK1) has highlighted roles in immune system regulation and tumor progression, but its specific role in HCC and impact on ICB response remains unclear. This study aimed to elucidate how PINK1 dysfunction enables HCC adaptation to ICB-induced immune attacks and identify potential therapeutic targets.MethodsOnline patient dataset analyses were performed to evaluate the impact of reduced PINK1 expression on clinical prognosis in HCC. An orthotopic HCC tumor cell mouse model was established. Single-cell RNA sequencing and flow cytometry were employed to explore the immune characteristics and remodeling of the tumor microenvironment in PINK1-deficient HCC. Neutrophils and T cells were isolated, stimulated, and/or cultured for ex vivo functional assays. Gene Expression Omnibus database analyses were performed to identify key genes involved in HCC resistance to ICB.ResultsWe identified PINK1 as a key mediator of ICB resistance in HCC. We found that PINK1 expression was significantly reduced in ICB-resistant HCC and a reduced PINK1 signature was associated with poorer clinical outcomes in patients with HCC. Importantly, PINK1 deficiency serves as a predictive biomarker for diminished responsiveness to immunotherapy. Function experiments have revealed that PINK1 regulates HCC progression and infiltration and activation of neutrophils and T cells. Mechanistically, the tumor cell-intrinsic downregulation of PINK1 activated the production of chemokines involved in neutrophil recruitment, and tumor-infiltrating neutrophils inhibited T cell activity. Additionally, a neutrophil-depleting antibody resensitized tumors to antiprogrammed death-ligand 1 therapy in orthotopic HCC models, further demonstrating that neutrophils are the primary population responsible for the adaptation of cancer cells with reduced PINK1 to ICB-induced immune attacks.ConclusionsOur study uncovered PINK1 as both a predictor of the ICB response and a key mediator of immune evasion by promoting neutrophil infiltration. These results highlight that the therapeutic targeting of neutrophils may represent a viable strategy to overcome ICB resistance in HCC.

623 Background: The EpiSwitch Checkpoint Inhibitor Response Test (CiRT) is a blood-based assay that analyzes DNA conformations in immune cells to predict responses to immune checkpoint inhibitors (ICIs) targeting PD-L1/PD-1. CiRT has demonstrated superior predictive accuracy compared to traditional biomarkers, such as tumor mutational burden (TMB) and PD-L1 immunohistochemistry (IHC), for predicting responses in urothelial cancer (ESMO 2022). However, its role in hepatocellular carcinoma (HCC) and other gastrointestinal (GI) tumors remains unclear. As immunotherapy becomes more common in these cancers, identifying reliable predictive biomarkers is essential to optimize treatment outcomes. Methods: This retrospective study evaluates CiRT-predicted immunotherapy responses and clinical outcomes in patients with HCC and GI tumors, including cholangiocarcinoma, pancreatic adenocarcinoma, and gastric cancer. All patients received one or more lines of immunotherapy. CiRT responses were categorized into high probability (HP) and low probability (LP). Treatment response was assessed per RECIST 1.1 criteria. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), overall survival (OS), and progression-free survival (PFS) were analyzed. Results: 43 patients (24 HP, 19 LP) were included. HCC patients (n = 33) received varied immunotherapy regimens, such as combinations of bevacizumab with atezolizumab, tremelimumab with durvalumab, and nivolumab with ipilimumab. Non-HCC patients (n = 10) received combinations of immunotherapy and chemotherapy such as durvalumab with cisplatin and gemcitabine and nivolumab with oxaliplatin and capecitabine. Across all patients, CiRT revealed a sensitivity of 73.91%, a specificity of 65%, a PPV of 70.83%, and an NPV of 68.42%. In HCC, sensitivity was 70.59% and specificity was 68.75%. In non-HCC, sensitivity was 83.33% and specificity 50%. HP responders showed better treatment outcomes compared to LP responders, with higher rates of complete response (CR: 12.5% vs 0%), partial response (PR: 29.2% vs 21.1%), and stable disease (SD: 29.2% vs 10.5%), and a lower rate of progressive disease (PD: 29.2% vs 68.4%) (p = 0.0467). Overall, 70.83% of HP achieved CR, PR, or SD vs. 31.58% of LP (p = 0.0098). PFS was significantly better in HP (p = 0.044, Log-rank test; median PFS = 2.0 months for the LP group, mPFS not reached for the HP group). No statistically significant OS difference was noted due to the lack of events in the HP group. Conclusions: CiRT HP status was associated with improved response rates to immunotherapy, longer PFS, and better treatment outcomes in HCC and GI tumors. HP responders experienced notably better outcomes, suggesting that CiRT could serve as a promising predictive biomarker for immunotherapy response, addressing a critical unmet need for reliable biomarkers to treat HCC and other GI tumors.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, with metabolic reprogramming playing a critical role in its progression. Bile acid metabolism has emerged as a key pathway in hepatocarcinogenesis, yet its comprehensive role in HCC remains poorly understood. This study aims to systematically investigate the dysregulation of bile acid metabolism in HCC and its clinical implications. We performed gene set enrichment analysis (GSEA), genomic alteration analysis, transcriptional profiling, and DNA methylation analysis using transcriptomic and genomic data from the TCGA cohort. A bile acid metabolism signature was developed using single-sample GSEA (ssGSEA), and its prognostic value was assessed through Kaplan-Meier survival and Cox regression analyses. Immune cell infiltration and associations with immunotherapy and chemotherapy response were also evaluated. Using training data from 368 HCC patients and validation cohorts (n = 221), significant dysregulation of bile acid metabolism was observed, with distinct pathway activation across clinical subgroups (P < 0.05). Genomic alterations, including mutations and copy number variations, were identified in key bile acid metabolism-related genes. The bile acid metabolism signature was strongly associated with overall survival and tumor stage (P < 0.05). Immune cell infiltration patterns varied significantly between high and low bile acid metabolism groups, suggesting a role in shaping the tumor immune microenvironment. However, no significant association was found between the signature and immunotherapy response. This study highlights the critical role of bile acid metabolism in HCC progression, with potential implications for prognosis and therapeutic targeting. The bile acid metabolism signature serves as a robust prognostic indicator, offering insights into personalized treatment strategies.

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide and shows significant heterogeneity. Cadherin 13 (CDH13) is abnormally expressed in various malignancies, but its role in HCC and the tumor microenvironment remains unclear. This study aimed to systematically explore the expression, regulatory mechanisms, and potential functions of CDH13 in HCC using a multi-omics strategy. We integrated transcriptomics, proteomics, spatial transcriptomics, single-cell RNA sequencing (scRNA-seq), immunohistochemistry (IHC), clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) gene editing, chromatin immunoprecipitation sequencing (ChIP-seq), weighted gene co-expression network analysis (WGCNA), gene set variation analysis (GSVA), immune infiltration analysis, molecular docking, phenotypic analysis, and survival analysis. In multiple cohorts, CDH13 mRNA was significantly upregulated in 5145 HCC samples (standardized mean difference (SMD) = 1.17) and associated with poor prognosis (hazard ratio (HR) = 2.06). Protein levels were elevated in 165 public and 476 clinical paired samples (361 from Guangxi Medical University, 115 from Yulin Red Cross Hospital; SMD = 2.48), mainly localized to the cytoplasm and membrane. Spatial transcriptomics showed CDH13 enrichment in tumor regions and spatial association with endothelial cells, which was confirmed in an independent HCC tissue section. Focusing on cell function, CRISPR/Cas9 knockout of CDH13 significantly inhibited proliferation in HCC cell lines such as SNU182, SNU739, HUH7, etc. Further analysis showed CDH13 was expressed in hepatocytes, endothelial cells, and hepatitis B virus (HBV)-infected regions; pseudotime analysis indicated late-stage upregulation in endothelial cells and activation of the macrophage migration inhibitory factor (MIF) pathway. IHC confirmed moderate CDH13 positivity in tumor cells and strong positivity in microvascular endothelial cells. CDH13-high endothelial cells were enriched in pyrimidine metabolism, oxidative phosphorylation, and propanoate metabolism. WGCNA and GSVA linked CDH13-related genes to angiogenesis, invasion, and metabolic reprogramming. ChIP-seq identified binding of Forkhead box A1 (FOXA1) to CDH13 regulatory regions. Clinically, CDH13 negatively correlated with regulatory T cells (Tregs, R = -0.311) and γδ T cells (R = -0.206), and positively with stromal scores (R = 0.400). High CDH13 predicted poor immunotherapy response (Area Under the Curve (AUC) = 0.745-0.795) and prognosis. Molecular docking shows a binding with docetaxel (-7.6kcal/mol), while phenotypic analysis showed no obvious physiological toxicity. CDH13 is highly expressed in HCC and may promote angiogenesis, immune evasion, and metabolic reprogramming via the FOXA1-CDH13 axis, suggesting its potential as a therapeutic target.

BackgroundSTRIP2 is a key regulator of cytoskeletal dynamics, yet its precise role in hepatocellular carcinoma (HCC) remains unclear. This study aimed to elucidate the mechanistic function of STRIP2 in HCC progression.MethodsSTRIP2 expression was analyzed using public databases. The prognostic significance and predictive value of STRIP2 were assessed through Kaplan-Meier survival analysis, receiver operating characteristic (ROC) curves, univariate and multivariate Cox regression, and nomogram models. Enrichment analysis was performed to explore STRIP2-related signaling pathways. Immune infiltration analysis was conducted to examine the relationship between STRIP2 and the tumor immune microenvironment. Tumor Immune Dysfunction and Exclusion (TIDE) scores and drug sensitivity analyses were used to evaluate the therapeutic relevance of STRIP2. Finally, immunohistochemistry (IHC) and immunofluorescence (IF) staining were performed to validate STRIP2 expression and its prognostic significance in a clinical cohort, while its functional role in HCC cells was investigated through knockout experiments.ResultsSTRIP2 expression was found to be significantly upregulated in HCC tissues based on public database analysis, enrichment and immune infiltration analyses indicated that high STRIP2 expression was linked to an immunosuppressive tumor microenvironment, characterized by increased Th2 cell infiltration and reduced CD8+ T-cell activity. Mechanistically, STRIP2 may regulate ion channel activity to mediate cytoskeletal remodeling and cell adhesion, thereby enhancing HCC cell migration and invasion. Additionally, elevated STRIP2 expression was associated with reduced sensitivity to immunotherapy, as indicated by higher TIDE scores. Immunohistochemical and IF staining demonstrated that STRIP2 is predominantly localized in the cytoplasm of HCC cells. In clinical cohort analysis, STRIP2 overexpression was associated with poor prognosis in HCC patients. Cox regression analyses confirmed that it was an independent prognostic factor for HCC. Functional experiments further revealed that STRIP2 knockout significantly inhibited HCC cell proliferation, migration, and invasion.ConclusionsSTRIP2 functions as a tumor-promoting factor in HCC, facilitating tumor progression, immune evasion, and therapy resistance. STRIP2 may serve as a novel biomarker and a promising target for precision treatment in HCC.

Hepatocellular carcinoma (HCC) is a highly lethal malignancy associated with poor prognosis due to late-stage diagnosis and high recurrence rates. The MEX3 family genes has been implicated in various cancers; however, their roles in HCC remain largely unexplored. This study aims to systematically analyze the expression patterns, prognostic significance, and immune-related functions of MEX3A, MEX3B, MEX3C, and MEX3D in HCC using comprehensive bioinformatics approaches. We conducted a multi-level bioinformatics analysis to investigate the expression, prognostic significance, clinicopathological correlations, genetic alterations, immune associations, and functional mechanisms of MEX3 family members in HCC. Transcriptomic data from TCGA and GEO databases, along with experimental validation via qRT-PCR and Western blotting, were used to assess expression profiles. Kaplan-Meier, ROC curve, and Cox regression analyses were employed for prognostic evaluation. Co-expression, enrichment, and immune infiltration analyses further elucidated the functional and immunological relevance of MEX3 family genes. A prognostic model based on co-expressed genes was constructed and validated using LASSO and time-dependent ROC analyses. MEX3A, MEX3B, MEX3C, and MEX3D were significantly upregulated in HCC tissues compared to normal liver tissues (P < 0.05). ROC curve analysis demonstrated high diagnostic accuracy, particularly for MEX3A (AUC = 0.915). Kaplan-Meier survival analysis indicated that elevated MEX3A and MEX3C expression was associated with poorer overall survival (OS) and disease-specific survival (DSS) (P < 0.05). Mutation analysis revealed that MEX3A exhibited the highest alteration frequency (11%), primarily through gene amplifications. Immune infiltration analysis demonstrated significant correlations between MEX3 expression and multiple immune cell populations, including regulatory T cells (Tregs), cytotoxic T cells, and macrophages. Moreover, MEX3B, MEX3C, and MEX3D expression correlated with key immune checkpoint genes, including PDCD1, CD274, and CTLA4. Functional enrichment analysis revealed that MEX3 co-expressed genes were significantly involved in RNA metabolism, immune response regulation, and oncogenic signaling pathways. A 17-gene MEX3 co-expression-based prognostic model stratified patients into high- and low-risk groups with significantly different survival outcomes (AUC = 0.791 at 1 year). This study highlights the oncogenic potential of MEX3 family members in HCC and their associations with immune regulation. The findings suggest that MEX3 family genes could serve as potential biomarkers for HCC prognosis and immunotherapy responsiveness. Further experimental validation is warranted to elucidate the mechanistic roles of MEX3 family genes in HCC progression and immune evasion.

Transcatheter arterial chemoembolization (TACE) is a standard therapy for the treatment of intermediate-stage hepatocellular carcinoma (HCC). In this study, we tried to elucidate the possibility of using radiofrequency ablation (RFA) as an alternative treatment of intermediate-stage HCC. Among 246 patients who were initially diagnosed with intermediate-stage HCC, 76 who were treated with TACE (TACE group) and 91 who were treated with RFA (RFA group) were enrolled in this study. The risk for survival was analyzed with the Cox Proportional Hazard Model, and the survival rates were compared using propensity score matching. About half (50.6%) of the intermediate-stage HCC patients in the RFA group were diagnosed with Barcelona Clinic Liver Cancer substage-B1 (BCLC-B1) compared with only 19.7% of the patients in the TACE group. Survival of the RFA group was longer than that of TACE group in patients with BCLC-B1 and BCLC-B2. In contrast, no difference between groups was observed in patients with BCLC-B3/4. Multivariate analysis revealed that large tumor size (>30 mm, hazard ratio = 1.685, P = 0.043), high des-γ-carboxyprothrombin (>100 mAU/mL, hazard ratio = 1.920, P = 0.012), and TACE group (hazard ratio = 1.896, P = 0.016) were significant risk factors for survival. Overall 3-year survival of the patients in the RFA group (69.5%) was significantly longer than that of patients in the TACE group (51.5%) after propensity score matching (P = 0.032). No significant adverse events were observed in either group. RFA was useful for the treatment of less advanced intermediate-stage HCC and could be an alternative to TACE in selected cases.

The immunobiology of hepatocellular carcinoma in humans and mice: Basic concepts and therapeutic implications

Background: Lactylation is closely involved in cancer progression, but its role in hepatocellular carcinoma (HCC) is unclear. The present work set out to develop a lactylation-related gene (LRG) signature for HCC. Methods: The lactylation score of tumor and normal groups was calculated using the gene set variation analysis (GSVA) package. The single-cell RNA sequencing (scRNA-seq) analysis of HCC was performed in the "Seurat" package. Prognostic LRGs were selected by performing univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses to develop and validate a Riskscore model. Functional enrichment analysis was conducted by gene set enrichment analysis (GSEA) using the "clusterProfiler" package. Genomic characteristics between different risk groups were compared, and tumor mutational burden (TMB) was calculated by the "Maftools" package. Immune cell infiltration was assessed by algorithms of cell-type identification by estimating relative subsets of RNA transcript (CIBERSORT), microenvironment cell populations-counter (MCP-counter), estimating the proportions of immune and cancer cells (EPIC), tumor immune estimation resource (TIMER), and single-sample gene set enrichment analysis (ssGSEA). Immunotherapy response was predicted by the tumor immune dysfunction and exclusion (TIDE) algorithm. Drug sensitivity was analyzed using the "pRRophetic" package. A nomogram was established using the "rms" package. The expressions of the prognostic LRGs in HCC cells were verified by in vitro test, and cell counting kit-8 (CCK-8), wound healing, and transwell assays were carried out to measure the viability, migration, and invasion of HCC cells. Results: The lactylation score, which was higher in the tumor group than in the normal group, has been confirmed as an independent factor for the prognostic evaluation in HCC. Six prognostic LRGs, including two protective genes (FTCD and APCS) and four risk genes (LGALS3, C1orf43, TALDO1, and CCT5), were identified to develop a Riskscore model with a strong prognostic prediction performance in HCC. The scRNA-seq analysis revealed that LGALS3 was largely expressed in myeloid cells, while APCS, FTCD, TALDO1, CCT5, and C1orf43 were mainly expressed in hepatocytes. The high-risk group was primarily enriched in the pathways involved in tumor occurrence and development, with higher T cell infiltration. Moreover, the high-risk group was found to be less responsive to immunotherapy but was more sensitive to chemotherapeutic drugs. By integrating Riskscore and clinical features, a nomogram with a high predictive accuracy was developed. Additionally, C1orf43, CCT5, TALDO1, and LGALS3 were highly expressed in HCC cells. Silencing CCT5 inhibited the viability, migration, and invasion of HCC cells. Conclusion: The present work developed a novel LRG gene signature that could be considered a promising therapeutic target and biomarker for HCC.

Tumor heterogeneity of immune infiltration of cells plays a decisive role in hepatocellular carcinoma (HCC) therapy response and prognosis. This study investigated the effect of different subtypes of CD8+T cells on the HCC tumor microenvironment about its prognosis. Single-cell RNA sequencing, transcriptome, and single-nucleotide variant data from LUAD patients were obtained based on the GEO, TCGA, and HCCD18 databases. CD8+ T cells-associated subtypes were identified by consensus clustering analysis, and genes with the highest correlation with prognostic CD8+ T cell subtypes were identified using WGCNA. The ssGSEA and ESTIMATE algorithms were used to calculate pathway enrichment scores and immune cell infiltration levels between different subtypes. Finally, the TIDE algorithm, CYT score, and tumor responsiveness score were utilized to predict patient response to immunotherapy. We defined 3 CD8+T cell clusters (CD8_0, CD8_1, CD8_2) based on the scRNA- seq dataset (GSE149614). Among, CD8_2 was prognosis-related risk factor with HCC. We screened 30 prognosis genes from CD8_2, and identified 3 molecular subtypes (clust1, clust2, clust3). Clust1 had better survival outcomes, higher gene mutation, and enhanced immune infiltration. Furthermore, we identified a 12 genes signature (including CYP7A1, SPP1, MSC, CXCL8, CXCL1, GCNT3, TMEM45A, SPP2, ME1, TSPAN13, S100A9, and NQO1) with excellent prediction performance for HCC prognosis. In addition, High-score patients with higher immune infiltration benefited less from immunotherapy. The sensitivity of low-score patients to multiple drugs including Parthenolide and Shikonin was significantly higher than that of high-score patients. Moreover, high-score patients had increased oxidative stress pathways scores, and the RiskScore was closely associated with oxidative stress pathways scores. And the nomogram had good clinical utility. To predict the survival outcome and immunotherapy response for HCC, we developed a 12-gene signature based on the heterogeneity of the CD8+ T cells.

BackgroundUbiquitin-specific protease 32 (USP32) is a highly conserved gene that promotes cancer progression. However, its role in hepatocellular carcinoma (HCC) is not well understood. The aim of this project is to explore the clinical significance and functions of USP32 in HCC.MethodsThe expression of USP32 in HCC was evaluated using data from TCGA, GEO, TISCH, tissue microarray, and human HCC samples from our hospital. Survival analysis, PPI analysis and GSEA analysis were performed to evaluate USP32-related clinical significance, key molecules and enrichment pathways. Using the ssGSEA algorithm and TIMER, we investigated the relationships between USP32 and immune infiltrates in the TME. Univariate and multivariate Cox regression analyses were then used to identify key USP32-related immunomodulators and constructed a USP32-related immune prognostic model. Finally, CCK8, transwell and colony formation assays of HCC cells were performed and an HCC nude mouse model was established to verify the oncogenic role of USP32.ResultsUSP32 is overexpressed in HCC and its expression is an independent predictive factor for outcomes of HCC patients. USP32 is associated with pathways related to cell behaviors and cancer signaling, and its expression is significantly correlated with the infiltration of immune cells in the TME. We also successfully constructed a USP32-related immune prognostic model using 5 genes. Wet experiments confirmed that knockdown of USP32 could repress the proliferation, colony formation and migration of HCC cells in vitro and inhibit tumor growth in vivo.ConclusionUSP32 is highly expressed in HCC and closely correlates with the TME of HCC. It is a potential target for improving the efficacy of chemotherapy and developing new strategies for targeted therapy and immunotherapy in HCC.

Liver inflammation plays a critical role in hepatocellular carcinoma (HCC) etiology. Damage-associated molecular patterns (DAMP), such as high-mobility group box 1 (HMGB1), and dysregulated miRNAs involved in inflammatory disease states, such as miR-21, may participate in the link between inflammation and cancer. We sought to determine the role of HMGB1 signaling in HCC tumor progression. We first document the concordant expression increase of HMGB1 and miR-21 in HCC cell lines and primary HCC tumor samples and subsequently show that HMGB1 stimulation results in overexpression of miR-21. These changes were found to be dependent on the IL6/STAT3 signaling axis. Invasion and migration of HCC cells in vitro were inhibited by both STAT3 and miR-21 antagonists, suggesting a role for this pathway in HCC tumor progression. We verified that HMGB1-induced expression of miR-21 in HCC provides a posttranscriptional repression of the matrix metalloproteinase (MMP) inhibitors RECK and TIMP3, which are known to impact HCC progression and metastases. Finally, we found that inhibition of miR-21 in murine HMGB1-overexpressing HCC xenografts led to reduced tumor MMP activity through released repression of the miR-21 targets RECK and TIMP3, which ultimately impeded tumor progression. The prototypical DAMP, HMGB1, is released during liver inflammation and provides a favorable environment for HCC growth. HMGB1 signaling increases miR-21 expression to mediate the enhanced activity of MMPs through RECK and TIMP3. These findings provide a novel mechanism for HMGB1-mediated HCC progression through the IL6/Stat3-miR-21 axis.

&lt;div&gt;Abstract&lt;p&gt;Liver inflammation plays a critical role in hepatocellular carcinoma (HCC) etiology. Damage-associated molecular patterns (DAMP), such as high-mobility group box 1 (HMGB1), and dysregulated miRNAs involved in inflammatory disease states, such as miR-21, may participate in the link between inflammation and cancer. We sought to determine the role of HMGB1 signaling in HCC tumor progression. We first document the concordant expression increase of HMGB1 and miR-21 in HCC cell lines and primary HCC tumor samples and subsequently show that HMGB1 stimulation results in overexpression of miR-21. These changes were found to be dependent on the IL6/STAT3 signaling axis. Invasion and migration of HCC cells &lt;i&gt;in vitro&lt;/i&gt; were inhibited by both STAT3 and miR-21 antagonists, suggesting a role for this pathway in HCC tumor progression. We verified that HMGB1-induced expression of miR-21 in HCC provides a posttranscriptional repression of the matrix metalloproteinase (MMP) inhibitors RECK and TIMP3, which are known to impact HCC progression and metastases. Finally, we found that inhibition of miR-21 in murine HMGB1-overexpressing HCC xenografts led to reduced tumor MMP activity through released repression of the miR-21 targets RECK and TIMP3, which ultimately impeded tumor progression. The prototypical DAMP, HMGB1, is released during liver inflammation and provides a favorable environment for HCC growth. HMGB1 signaling increases miR-21 expression to mediate the enhanced activity of MMPs through RECK and TIMP3. These findings provide a novel mechanism for HMGB1-mediated HCC progression through the IL6/Stat3-miR-21 axis. &lt;i&gt;Cancer Res; 75(8); 1645–56. ©2015 AACR&lt;/i&gt;.&lt;/p&gt;&lt;/div&gt;

&lt;div&gt;Abstract&lt;p&gt;Liver inflammation plays a critical role in hepatocellular carcinoma (HCC) etiology. Damage-associated molecular patterns (DAMP), such as high-mobility group box 1 (HMGB1), and dysregulated miRNAs involved in inflammatory disease states, such as miR-21, may participate in the link between inflammation and cancer. We sought to determine the role of HMGB1 signaling in HCC tumor progression. We first document the concordant expression increase of HMGB1 and miR-21 in HCC cell lines and primary HCC tumor samples and subsequently show that HMGB1 stimulation results in overexpression of miR-21. These changes were found to be dependent on the IL6/STAT3 signaling axis. Invasion and migration of HCC cells &lt;i&gt;in vitro&lt;/i&gt; were inhibited by both STAT3 and miR-21 antagonists, suggesting a role for this pathway in HCC tumor progression. We verified that HMGB1-induced expression of miR-21 in HCC provides a posttranscriptional repression of the matrix metalloproteinase (MMP) inhibitors RECK and TIMP3, which are known to impact HCC progression and metastases. Finally, we found that inhibition of miR-21 in murine HMGB1-overexpressing HCC xenografts led to reduced tumor MMP activity through released repression of the miR-21 targets RECK and TIMP3, which ultimately impeded tumor progression. The prototypical DAMP, HMGB1, is released during liver inflammation and provides a favorable environment for HCC growth. HMGB1 signaling increases miR-21 expression to mediate the enhanced activity of MMPs through RECK and TIMP3. These findings provide a novel mechanism for HMGB1-mediated HCC progression through the IL6/Stat3-miR-21 axis. &lt;i&gt;Cancer Res; 75(8); 1645–56. ©2015 AACR&lt;/i&gt;.&lt;/p&gt;&lt;/div&gt;