Crosstalk between tumor-associated macrophages and neighboring cells in hepatocellular carcinoma

Liver cancer from the perspective of single-cell sequencing: a review combined with bibliometric analysis

BACKGROUND

Liver cancer (LC) is a prevalent malignancy and a leading cause of cancer-related mortality worldwide. Extensive research has been conducted to enhance patient outcomes and develop effective prevention strategies, ranging from molecular mechanisms to clinical interventions. Single-cell sequencing, as a novel bioanalysis technology, has significantly contributed to the understanding of the global cognition and dynamic changes in liver cancer. However, there is a lack of bibliometric analysis in this specific research area. Therefore, the objective of this study is to provide a comprehensive overview of the knowledge structure and research hotspots in the field of single-cell sequencing in liver cancer research through the use of bibliometrics.

METHOD

Publications related to the application of single-cell sequencing technology to liver cancer research as of December 31, 2023, were searched on the web of science core collection (WoSCC) database. VOSviewers, CiteSpace, and R package "bibliometrix" were used to conduct this bibliometric analysis.

RESULTS

A total of 331 publications from 34 countries, primarily led by China and the United States, were included in this study. The research focuses on the application of single cell sequencing technology to liver cancer, and the number of related publications has been increasing year by year. The main research institutions involved in this field are Fudan University, Sun Yat-Sen University, and the Chinese Academy of Sciences. Frontiers in Immunology and Nature Communications is the most popular journal in this field, while Cell is the most frequently co-cited journal. These publications are authored by 2799 individuals, with Fan Jia and Zhou Jian having the most published papers, and Llovet Jm being the most frequently co-cited author. The use of single cell sequencing to explore the immune microenvironment of liver cancer, as well as its implications in immunotherapy and chemotherapy, remains the central focus of this field. The emerging research hotspots are characterized by keywords such as 'Gene-Expression', 'Prognosis', 'Tumor Heterogeneity', 'Immunoregulation', and 'Tumor Immune Microenvironment'.

CONCLUSION

This is the first bibliometric study that comprehensively summarizes the research trends and developments on the application of single cell sequencing in liver cancer. The study identifies recent research frontiers and hot directions, providing a valuable reference for researchers exploring the landscape of liver cancer, understanding the composition of the immune microenvironment, and utilizing single-cell sequencing technology to guide and enhance the prognosis of liver cancer patients.

Intrahepatic IgA complex induces polarization of cancer-associated fibroblasts to matrix phenotypes in the tumor microenvironment of HCC

BACKGROUND AND AIMS

Cancer-associated fibroblasts (CAFs) play key roles in the tumor microenvironment. IgA contributes to inflammation and dismantling antitumor immunity in the human liver. In this study, we aimed to elucidate the effects of the IgA complex on CAFs in Pil Soo Sung the tumor microenvironment of HCC.

APPROACH AND RESULTS

CAF dynamics in HCC tumor microenvironment were analyzed through single-cell RNA sequencing of HCC samples. CAFs isolated from 50 HCC samples were treated with mock or serum-derived IgA dimers in vitro. Progression-free survival of patients with advanced HCC treated with atezolizumab and bevacizumab was significantly longer in those with low serum IgA levels ( p <0.05). Single-cell analysis showed that subcluster proportions in the CAF-fibroblast activation protein-α matrix were significantly increased in patients with high serum IgA levels. Flow cytometry revealed a significant increase in the mean fluorescence intensity of fibroblast activation protein in the CD68 + cells from patients with high serum IgA levels ( p <0.001). We confirmed CD71 (IgA receptor) expression in CAFs, and IgA-treated CAFs exhibited higher programmed death-ligand 1 expression levels than those in mock-treated CAFs ( p <0.05). Coculture with CAFs attenuated the cytotoxic function of activated CD8 + T cells. Interestingly, activated CD8 + T cells cocultured with IgA-treated CAFs exhibited increased programmed death-1 expression levels than those cocultured with mock-treated CAFs ( p <0.05).

CONCLUSIONS

Intrahepatic IgA induced polarization of HCC-CAFs into more malignant matrix phenotypes and attenuates cytotoxic T-cell function. Our study highlighted their potential roles in tumor progression and immune suppression.

Monocyte-to-High-Density Lipoprotein-Cholesterol Ratio Predicts Prognosis of Hepatocellular Carcinoma in Patients with Metabolic-Associated Fatty Liver Disease

Purpose

The incidence of non-B and non-C hepatocellular carcinoma (NBNC-HCC) is increasing globally. Metabolically associated fatty liver disease (MAFLD) has been a contributing factor to this rising trend in NBNC-HCC incidence. The monocyte-to-high-density lipoprotein-cholesterol ratio (MHR) is a new prognostic marker that connects systemic inflammation with disorders of lipid metabolism. Therefore, MHR may be a potential prognostic predictor of patients with MAFLD-related HCC (MAFLD-HCC). This study aims to investigate the relationship between the MHR and prognosis of patients with MAFLD-HCC and construct a novel prognostic prediction tool for MAFLD-HCC.

Patients and Methods

This retrospective study of patients with MAFLD-HCC included training (n = 112) and internal validation (n = 37) cohorts. Univariate and multivariate Cox proportional hazard regression analysis was conducted to identify independent risk factors of survival. A visual nomogram was constructed to assess the performance of the two groups. Furthermore, receiver operating characteristic (ROC) curves and calibration curves were used to verify the prognostic discriminative ability of this nomogram, even in the MHR, ALBI grade, and MHR-ALBI model.

Results

Univariate and multivariate analyses revealed that extrahepatic metastases, Vascular invasion, Barcelona staging B, C, D, elevated ALBI Grade 3, C-reactive protein (CRP), and MHR were independent risk factors for the prognosis of MAFLD-HCC. Moreover, calibration plots showed good discrimination and consistency when the significant factors were entered into the nomogram. Meanwhile, the MHR strongly correlated with the prognosis of cancer under a background of MAFLD-HCC, with a sensitivity of 88.89% and a specificity of 79.61%. Importantly, the performance of the MHR alone (AUC = 86.2) was not only superior to the ALBI grade (AUC = 63.8) but was comparable to the combination of MHR and ALBI (AUC = 88.5).

Conclusion

The novel nomogram demonstrated good value in predicting the overall survival of patients with MAFLD-HCC. The MHR may be a potential predictor of prognosis.

Characterizing ligand-receptor interactions and unveiling the pro-tumorigenic role of CCL16-CCR1 axis in the microenvironment of hepatocellular carcinoma

Background

The heterogeneity of the tumor microenvironment significantly influences the prognosis of hepatocellular carcinoma (HCC) patients, with cell communication through ligand-receptor complexes playing a central role.

Methods

We conducted single-cell transcriptomic analysis on ten HCC tissues to identify ligand-receptor genes involved in malignant HCC cell communication using CellChat. Leveraging RNA-Seq data from the TCGA Liver Cancer (TCGA-LIHC) and Liver Cancer - RIKEN, JP (LIRI-JP) cohorts, we employed Cox regression analysis to screen for prognosis-related genes. Prognostic risk models were constructed through unsupervised clustering and differential gene expression analysis. Subsequently, a co-culture system involving tumor cells and macrophages was established. A series of experiments, including Transwell assays, immunofluorescence staining, immunoprecipitation, flow cytometry, and immunohistochemistry, were conducted to elucidate the mechanism through which HCC cells recruit macrophages via the CCL16-CCR1 axis.

Results

Single-cell analysis unveiled significant interactions between malignant HCC cells and macrophages, identifying 76 related ligand-receptor genes. Patients were classified into three subtypes based on the expression patterns of eight prognosis-related ligand-receptor genes. The subtype with the worst prognosis exhibited reduced infiltration of T cell-related immune cells, downregulation of immune checkpoint genes, and increased M2-like tumor-associated macrophage scores. In vitro experiments confirmed the pivotal role of the CCL16-CCR1 axis in the recruitment and M2 polarization of tumor-associated macrophages. Clinical samples demonstrated a significant association between CCL16 protein expression levels and advanced stage, lymph node metastasis, and distant metastasis. Immunohistochemistry and immunofluorescence staining further confirmed the correlation between CCL16 and CCR1, CD68, and CD206, as well as CD68+CCR1+ macrophage infiltration.

Conclusions

Our study identified molecular subtypes, a prognostic model, and immune microenvironment features based on ligand-receptor interactions in malignant HCC cell communication. Moreover, we revealed the pro-tumorigenic role of HCC cells in recruiting M2-like tumor-associated macrophages through the CCL16-CCR1 axis.

Oxoaporphine Pr(III) complex inhibits hepatocellular carcinoma progression and metastasis by disrupting tumor cell-macrophage crosstalk

Tumor cells and macrophages communicate through the secretion of various cytokines to jointly promote the malignant development of cancers. We synthesized and characterized an oxoaporphine Pr(III) complex (PrL3(NO3)3) and found that it inhibits hepatocellular carcinoma (HCC) progression and metastasis by disrupting HCC cell-macrophage crosstalk. PrL3(NO3)3 treatment upregulated CD86, TNF-α, and IL-1β and downregulated CD163, CD206, CCL2, and VEGFA in macrophages. Our mRNA-Seq results demonstrated that PrL3(NO3)3 inhibited macrophage M2-like polarization by inhibiting the AMPK pathway and activating the NF-κB pathway by upregulating RelA/p65 Ser536 phosphorylation. This kind of macrophage polarization significantly inhibited HCC cell proliferation, migration, and invasion. In addition, PrL3(NO3)3 inhibited the migration, invasion, and chemotaxis of HCC cells by downregulating the expression of EMT-related markers and CCL2. hTFtarget database analysis revealed that PrL3(NO3)3 inhibited NF-κB nuclear translocation by upregulating RelA/p65 Ser536 phosphorylation in HCC cells, thereby downregulating the expression of Snail and CCL2. HCC tissue microarray analysis revealed that downregulation of RelA/p65 Ser536 phosphorylation is a driving event in HCC malignant progression. In conclusion, PrL3(NO3)3 effectively inhibits HCC cell-macrophage crosstalk by upregulating RelA/p65 Ser536 phosphorylation. This is the first report of a lanthanide complex exerting regulatory effects on both tumors and tumor-associated macrophages, providing a new strategy for the development of effective antitumor drugs.

The role of tumor-associated macrophages in hepatocellular carcinoma progression: A narrative review

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world, with complex etiology and mechanism, and a high mortality rate. Tumor-associated macrophages (TAMs) are an important part of the HCC tumor microenvironment. Studies in recent years have shown that TAMs are involved in multiple stages of HCC and are related to treatment and prognosis in HCC. The specific mechanisms between TAMs and HCC are gradually being revealed. This paper reviews recent advances in the mechanisms associated with TAMs in HCC, concentrating on an overview of effects of TAMs on drug resistance in HCC and the signaling pathways linked with HCC, providing clues for the treatment and prognosis determination of HCC.

Early C-reactive Protein Kinetics Predict Response to Immune Checkpoint Blockade in Unresectable Hepatocellular Carcinoma

Purpose

In recent years, a new therapeutic approach, known as immune checkpoint blockade (ICB), has been proposed as approach to improve outcomes in patients with intermediate stage (Barcelona Clinic Liver Cancer, BCLC B) or advanced stage (BCLC C) hepatocellular carcinoma (HCC). Unfortunately, only a select patients can benefit from ICB. Hence, biomarkers that can predict the success and survival of treatment are still necessary.

Patients and Methods

Between 2018 to 2021, 132 patients received ICB treatment for intermediate or advanced stage HCC. Based on the early kinetics of C-reactive protein (CRP), the patients were classified into three groups. The study endpoints were progression-free survival (PFS) and overall survival (OS).

Results

Our findings support the predictive power of early CRP kinetics in determining immunotherapy response for intermediate or advanced HCC. Objective response rates (ORR) were found in 41.2% of CRP flare-responders, 13.3% of CRP responders, and 3.5% of CRP non-responders (p<0.001). Disease control rates (DCR) in the three groups were substantially different (p<0.001). The improved PFS and OS were strongly correlated with the early kinetics of CRP. Compared to CRP non-responders, CRP responders, especially CRP flare-responders, had significantly longer PFS (median PFS: CRP flare-responders: 11.6 months vs CRP responders: 5.2 months vs CRP non-responders: 2.3 months, p<0.001).

Conclusion

The CRP flare response robustly predicts the immunotherapy response and outcomes in patients with HCC. Early CRP kinetics may be an inexpensive, easily implemented and non-invasive biomarker to anticipate response to ICB therapy in intermediate or advanced HCC, with the potential to optimize treatment monitoring.

Targeting the Heterogeneous Tumour-Associated Macrophages in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a prevalent and aggressive cancer that comprises a complex tumour microenvironment (TME). Tumour-associated macrophages (TAMs) are one of the most abundant immune cells present in the TME, and play a key role both in the development and in the progression of HCC. Thus, TAM-based immunotherapy has been presented as a promising strategy to complement the currently available therapies for HCC treatment. Among the novel approaches focusing on TAMs, reprogramming their functional state has emerged as a promising option for targeting TAMs as an immunotherapy in combination with the currently available treatment options. Nevertheless, a further understanding of the immunobiology of TAMs is still required. This review synthesizes current insights into the heterogeneous nature of TAMs in HCC and describes the mechanisms behind their pro-tumoural polarization focusing the attention on their interaction with HCC cells. Furthermore, this review underscores the potential involvement of TAMs' reprogramming in HCC therapy and highlights the urgency of advancing our understanding of these cells within the dynamic landscape of HCC.

Isolation and characterization of cancer-associated fibroblasts in the tumor microenvironment of hepatocellular carcinoma

BACKGROUND/AIM

Cancer-associated fibroblasts (CAFs) play an immunosuppressive role in the tumor microenvironment (TME) of human cancers; however, their characteristics and role in hepatocellular carcinoma (HCC) remain to be elucidated.

METHODS

Nine tumor and surrounding liver tissue samples from patients with HCC who underwent surgery were used to isolate patient-derived CAFs. Cell morphology was observed using an optical microscope after culture, and cell phenotypes were evaluated using flow cytometry and immunoblotting. Cytokines secreted by CAFs into culture medium were quantified using a multiplex cytokine assay.

RESULTS

CAFs were abundant in the TME of HCC and were adjacent to immune cells. After culture, the CAFs and non-tumor fibroblasts exhibited spindle shapes. We observed a robust expression of alpha-smooth muscle actin and fibroblast activation protein in CAFs, whereas alpha-fetoprotein, epithelial cell adhesion molecule, platelet/endothelial cell adhesion molecule-1, and E-cadherin were not expressed in CAFs. Furthermore, CAFs showed high secretion of various cytokines, namely C-X-C motif chemokine ligand 12, interleukin (IL)-6, IL-8, and C-C motif chemokine ligand 2.

CONCLUSIONS

CAFs are abundant in the TME of HCC and play a crucial role in tumor progression. These fibroblasts secrete cytokines that promote tumor growth and metastasis.

IL-8-induced CXCR2 down-regulation in circulating monocytes in hepatocellular carcinoma is partially dependent on MAGL

BACKGROUND

CXC-chemokine receptor 2 (CXCR2) expression was found to be down-regulated on circulating monocytes of cancer patients. Here, we analyze the percentage of CD14⁺CXCR2⁺ monocyte subsets in hepatocellular carcinoma (HCC) patients, and investigate the mechanisms that regulate CXCR2 surface expression on monocytes and its biological function.

METHODS

Flow cytometry was used to analyze the proportion of the CD14⁺CXCR2⁺ subset from the total circulating monocytes of HCC patients. Interleukin 8 (IL-8) levels were measured from serum and ascites, and their correlation with the CD14⁺CXCR2⁺ monocyte subset proportion was calculated. THP-1 cells were cultured in vitro and treated with recombinant human IL-8 and CXCR2 surface expression was analyzed. CXCR2 was knocked down to examine how it affects the antitumor activity of monocytes. Finally, a monoacylglycerol lipase (MAGL) inhibitor was added to analyze its effect on CXCR2 expression.

RESULTS

A decrease in the proportion of the CD14⁺CXCR2⁺ monocyte subset was observed in HCC patients compared with healthy controls. CXCR2⁺ monocyte subset proportion was associated with the AFP value, TNM stage, and liver function. Overexpression of IL-8 was observed in the serum and ascites of HCC patients, and negatively correlated with CXCR2⁺ monocyte proportion. IL-8 decreased CXCR2 expression in THP-1 cells, contributing to decreased antitumor activity toward HCC cells. MAGL expression in THP-1 cells was up-regulated after IL-8 treatment, and the MAGL inhibitor partially reversed the effects of IL-8 on CXCR2 expression.

CONCLUSIONS

Overexpression of IL-8 drives CXCR2 down-regulation on circulating monocytes of HCC patients, which could be partially reversed by a MAGL inhibitor.

Higher Number of Tumor-Infiltrating PD-L1+ Cells Is Related to Better Response to Multikinase Inhibitors in Hepatocellular Carcinoma

Multikinase inhibitors (MKIs) such as sorafenib and lenvatinib are first-line treatments for unresectable hepatocellular carcinoma (HCC) and are known to have immunomodulatory effects. However, predictive biomarkers of MKI treatment in HCC patients need to be elucidated. In the present study, thirty consecutive HCC patients receiving lenvatinib (n = 22) and sorafenib (n = 8) who underwent core-needle biopsy before treatment were enrolled. The associations of CD3, CD68, and programmed cell death-ligand-1 (PD-L1) immunohistochemistry with patient outcomes, including overall survival (OS), progression-free survival (PFS), and objective response rate (ORR), were evaluated. High and low subgroups were determined according to median CD3, CD68, and PD-L1 values. Median CD3 and CD68 counts were 51.0 and 46.0 per 20,000 µm², respectively. The median combined positivity score (CPS) of PD-L1 was 2.0. Median OS and PFS were 17.6 and 4.4 months, respectively. ORRs of the total, lenvatinib, and sorafenib groups were 33.3% (10/30), 12.5% (1/8), and 40.9% (9/22), respectively. The high CD68+ group had significantly better PFS than the low CD68+ group. The high PD-L1 group had better PFS than the low subgroup. When we analyzed the lenvatinib subgroup, PFS was also significantly better in the high CD68+ and PD-L1 groups. These findings suggest that high numbers of PD-L1-expressing cells within tumor tissue prior to MKI treatment can serve as a biomarker to predict favorable PFS in HCC patients.

Factors associated with the survival outcomes of patients with untreated hepatocellular carcinoma: An analysis of nationwide data

Introduction

In this study, we examined the natural course of untreated hepatocellular carcinoma (HCC) and identified predictors of survival in an area where hepatitis B is the predominant cause of HCC.

Methods

We identified 1,045 patients with HCC who did not receive HCC treatment and were registered in the Korean Primary Liver Cancer Registry between 2008 and 2014, and were followed-up up to December 2018. Thereafter, we analyzed the clinical characteristics of patients who survived for <12 or ≥12 months. A Cox proportional regression model was used to identify the variables associated with patient survival.

Results and discussion

The mean age of the untreated patients at HCC diagnosis was 59.6 years, and 52.1% of patients had hepatitis B. Most untreated patients (94.2%) died during the observation period. The median survival times for each Barcelona Clinic Liver Cancer (BCLC) stage were as follows: 31.0 months for stage 0/A (n = 123), 10.0 months for stage B (n = 96), 3.0 months for stage C (n = 599), and 1.0 month for stage D (n = 227). Multivariate Cox regression analysis demonstrated that BCLC stage D (hazard ratio, 4.282; P < 0.001), model for end-stage liver disease (MELD) score ≥10 (HR, 1.484; P < 0.001), and serum alpha-fetoprotein (AFP) level ≥1,000 ng/mL (HR, 1.506; P < 0.001) were associated with poor survival outcomes in patients with untreated HCC. In untreated patients with HCC, advanced stage BCLC, serum AFP level ≥1,000 ng/mL, and MELD score ≥10 were significantly associated with overall survival.

An Immunological Perspective on the Mechanism of Drug Induced Liver Injury: Focused on Drugs for Treatment of Hepatocellular Carcinoma and Liver Transplantation

The liver is frequently exposed to potentially toxic materials, and it is the primary site of clearance of foreign agents, along with many innate and adaptive immune cells. Subsequently, drug induced liver injury (DILI), which is caused by medications, herbs, and dietary supplements, often occurs and has become an important issue in liver diseases. Reactive metabolites or drug-protein complexes induce DILI via the activation of various innate and adaptive immune cells. There has been a revolutionary development of treatment drugs for hepatocellular carcinoma (HCC) and liver transplantation (LT), including immune checkpoint inhibitors (ICIs), that show high efficacy in patients with advanced HCC. Along with the high efficacy of novel drugs, DILI has become a pivotal issue in the use of new drugs, including ICIs. This review demonstrates the immunological mechanism of DILI, including the innate and adaptive immune systems. Moreover, it aims to provide drug treatment targets, describe the mechanisms of DILI, and detail the management of DILI caused by drugs for HCC and LT.

Blood-based biomarkers for immune-based therapy in advanced HCC: Promising but a long way to go

The introduction of immune checkpoint inhibitors (ICIs) represents a key shift in the management strategy for patients with hepatocellular carcinoma (HCC). However, there is a paucity of predictive biomarkers that facilitate the identification of patients that would respond to ICI therapy. Although several researchers have attempted to resolve the issue, the data is insufficient to alter daily clinical practice. The use of minimally invasive procedures to obtain patient-derived specimen, such as using blood-based samples, is increasingly preferred. Circulating tumor DNA (ctDNA) can be isolated from the blood of cancer patients, and liquid biopsies can provide sufficient material to enable ongoing monitoring of HCC. This is particularly significant for patients for whom surgery is not indicated, including those with advanced HCC. In this review, we summarize the current state of understanding of blood-based biomarkers for ICI-based therapy in advanced HCC, which is promising despite there is still a long way to go.

Multiplexed Digital Spatial Protein Profiling Reveals Distinct Phenotypes of Mononuclear Phagocytes in Livers with Advanced Fibrosis

Background and Aims: Intrahepatic mononuclear phagocytes (MPs) are critical for the initiation and progression of liver fibrosis. In this study, using multiplexed digital spatial protein profiling, we aimed to derive a unique protein signature predicting advanced liver fibrosis. Methods: Snap-frozen liver tissues from various chronic liver diseases were subjected to spatially defined protein-based multiplexed profiling (Nanostring GeoMX^TM). A single-cell RNA sequencing analysis was performed using Gene Expression Omnibus (GEO) datasets from normal and cirrhotic livers. Results: Sixty-four portal regions of interest (ROIs) were selected for the spatial profiling. Using the results from the CD68⁺ area, a highly sensitive and specific immune-related protein signature (CD68, HLA-DR, OX40L, phospho-c-RAF, STING, and TIM3) was developed to predict advanced (F3 and F4) fibrosis. A combined analysis of single-cell RNA sequencing data from GEO datasets (GSE136103) and spatially-defined, protein-based multiplexed profiling revealed that most proteins upregulated in F0-F2 livers in portal CD68⁺ cells were specifically marked in tissue monocytes, whereas proteins upregulated in F3 and F4 livers were marked in scar-associated macrophages (SAMacs) and tissue monocytes. Internal validation using mRNA expression data with the same cohort tissues demonstrated that mRNA levels for TREM2, CD9, and CD68 are significantly higher in livers with advanced fibrosis. Conclusions: In patients with advanced liver fibrosis, portal MPs comprise of heterogeneous populations composed of SAMacs, Kupffer cells, and tissue monocytes. This is the first study that used spatially defined protein-based multiplexed profiling, and we have demonstrated the critical difference in the phenotypes of portal MPs between livers with early- or late-stage fibrosis.

MiR-23b-3p suppresses epithelial-mesenchymal transition, migration, and invasion of hepatocellular carcinoma cells by targeting c-MET

Background

Aberrant expression of c-MET is known to be associated with tumor recurrence and metastasis by promoting cell proliferation, epithelial-mesenchymal transition (EMT), and migration in hepatocellular carcinoma (HCC). Recently, miR-23b-3p has been identified as a tumor suppressor, but detailed role of miR-23b-3p in HCC is still unclear. Our study aimed to investigate how miR-23b-3p is associated with the malignant potential of HCC cells.

Methods

HCC tissues and their adjacent non-tumor tissues were acquired from 30 patients with HCC. Expression of EMT- or stemness-related genes were examined in the two HCC cell lines. Migration of HCC cells was analyzed using transwell and wound healing assays.

Results

c-MET was overexpressed in HCC tissues compared to the adjacent non-tumor tissues. c-MET knockdown inhibited EMT and reduced migration and invasion of HCC cells. Furthermore, c-MET was a target of miR-23b-3p, and miR-23b-3p expression was decreased in HCC tissues compared to non-tumor tissues. Treatment of miR-23b-3p inhibitor in HCC cells promoted EMT, cell migration, and invasion. In contrast, miR-23b-3p overexpression suppressed EMT, cell migration, and invasion, concomitantly reducing c-MET expression. Transfection of miR-23b-3p inhibitor with concomitant c-MET knockdown mitigated the effects of miR-23b-3p inhibitor on EMT in HCC cells. In addition, transforming growth factor beta1 (TGF-β1) stimulation after miR-23b-3p overexpression induced neither the mesenchymal phenotype nor migratory property of HCC cells.

Conclusion

In this study, we confirmed that miR-23b-3p downregulation significantly increased EMT, migration, and invasion of HCC cells. In addition, c-MET was confirmed to be a target of miR-23b-3p in HCC cells and regulated the functional effects of miR-23b-3p. These results suggest that miR-23b-3p can be used as a prognostic biomarker and candidate target for HCC treatment.

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c-MET is a target of miR-23b-3p and overexpressed in HCC tissues.

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MiR-23b-3p expression was decreased in HCC tissues compared to non-tumor tissues.

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Inhibition of miR-23b-3p induced migration and invasion via EMT in HCC cells.

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MiR-23b-3p/c-MET axis may serve as a therapeutic target for HCC.

The hypoxia-driven crosstalk between tumor and tumor-associated macrophages: mechanisms and clinical treatment strategies

Given that hypoxia is a persistent physiological feature of many different solid tumors and a key driver for cancer malignancy, it is thought to be a major target in cancer treatment recently. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment (TME), which have a large impact on tumor development and immunotherapy. TAMs massively accumulate within hypoxic tumor regions. TAMs and hypoxia represent a deadly combination because hypoxia has been suggested to induce a pro-tumorigenic macrophage phenotype. Hypoxia not only directly affects macrophage polarization, but it also has an indirect effect by altering the communication between tumor cells and macrophages. For example, hypoxia can influence the expression of chemokines and exosomes, both of which have profound impacts on the recipient cells. Recently, it has been demonstrated that the intricate interaction between cancer cells and TAMs in the hypoxic TME is relevant to poor prognosis and increased tumor malignancy. However, there are no comprehensive literature reviews on the molecular mechanisms underlying the hypoxia-mediated communication between tumor cells and TAMs. Therefore, this review has the aim to collect all recently available data on this topic and provide insights for developing novel therapeutic strategies for reducing the effects of hypoxia.

Overcoming resistance to immune checkpoint inhibitors in hepatocellular carcinoma: Challenges and opportunities

Hepatocellular carcinoma is one of the leading causes of cancer mortality globally, and its incidence is increasing. Immune checkpoint therapy has revolutionized the treatment of hepatocellular carcinoma over the past few years. However, only a limited proportion of patients with hepatocellular carcinoma respond to immunotherapy. Despite the significant breakthroughs, the molecular mechanisms that drive immune responses and evasion are largely unresolved. Predicting tumor response and resistance to immune checkpoint inhibitors is a significant challenge. In this review, we focus on the current research progress of immune checkpoint inhibitors in hepatocellular carcinoma. Importantly, this review highlights the underlying mechanisms of resistance to immune checkpoint inhibitors and summarizes potential strategies to overcome the resistance to immune checkpoint inhibitors in hepatocellular carcinoma.

Multidisciplinary approach for hepatocellular carcinoma arising from cirrhotic liver with Budd-Chiari syndrome: a case report

Budd-Chiari syndrome (BCS) is defined by the obstruction of the hepatic venous outflow between the small hepatic veins and the junction of the inferior vena cava (IVC) with the right atrium. BCS with IVC obstruction occasionally progresses to hepatocellular carcinoma (HCC). Here, we report the case of a patient with HCC arising from a cirrhotic liver with BCS, in whom the hepatic portion of the IVC was obstructed, and who had a favorable outcome with a multidisciplinary approach and IVC balloon angioplasty.

The tumor microenvironment of hepatocellular carcinoma and its targeting strategy by CAR-T cell immunotherapy

Hepatocellular carcinoma (HCC) is the major subtype of liver cancer, which ranks sixth in cancer incidence and third in mortality. Although great strides have been made in novel therapy for HCC, such as immunotherapy, the prognosis remains less than satisfactory. Increasing evidence demonstrates that the tumor immune microenvironment (TME) exerts a significant role in the evolution of HCC and has a non-negligible impact on the efficacy of HCC treatment. In the past two decades, the success in hematological malignancies made by chimeric antigen receptor-modified T (CAR-T) cell therapy leveraging it holds great promise for cancer treatment. However, in the face of a hostile TME in solid tumors like HCC, the efficacy of CAR-T cells will be greatly compromised. Here, we provide an overview of TME features in HCC, discuss recent advances and challenges of CAR-T immunotherapy in HCC.

Intrahepatic inflammatory IgA+PD-L1high monocytes in hepatocellular carcinoma development and immunotherapy

Background

IgA neutralizes pathogens to prevent infection at mucosal sites. However, emerging evidence shows that IgA contributes to aggravating inflammation or dismantling antitumor immunity in human diseased liver. The aim of this study was to elucidate the roles of inflammation-induced intrahepatic inflammatory IgA⁺ monocytes in the development of hepatocellular carcinoma (HCC).

Methods

Patient cohorts including steatohepatitis cohort (n=61) and HCC cohort (n=271) were established. Patients’ surgical and biopsy specimens were analyzed using immunohistochemistry. Multicolor flow cytometry was performed with a subset of patient samples. Single-cell RNA-Seq analysis was performed using Gene Expression Omnibus (GEO) datasets. Additionally, we performed in vitro differentiation of macrophages, stimulation with coated IgA, and RNA sequencing. Hepa1-6 cells and C57BL/6N mice were used to obtain HCC syngeneic mouse models.

Results

Serum IgA levels were associated (p<0.001) with fibrosis progression and HCC development in patients with chronic liver diseases. Additionally, immunohistochemical staining of inflamed livers or HCC revealed IgA positivity in monocytes, with a correlation between IgA⁺ cell frequency and IgA serum levels. Compared with IgA⁻ monocytes, intrahepatic IgA⁺ monocytes expressed higher levels of programmed death-ligand 1 (PD-L1) in inflamed livers and in HCC tumor microenvironment. Single-cell RNA sequencing using NCBI GEO database indicated an upregulation in inflammation-associated genes in the monocytes of patients whose plasma cell IGHA1 expression was greater than or equal to the median value. Bulk RNA sequencing demonstrated that in vitro stimulation of M2-polarized macrophages using coated IgA complex induced PD-L1 upregulation via YAP-mediated signaling. In vivo blockade of IgA signaling decreased the number of tumor-infiltrating IgA⁺PD-L1^high macrophages and increased the number of CD69⁺CD8⁺ T cells to enhance antitumor effects in HCC mice models.

Conclusions

Overall, the findings of this study showed that serum IgA levels was correlated with intrahepatic and intratumoral infiltration of inflammatory IgA⁺PD-L1^high monocytes in chronic liver diseases and HCC, providing potential therapeutic targets.

A Unique Immune-Related Gene Signature Represents Advanced Liver Fibrosis and Reveals Potential Therapeutic Targets

Innate and adaptive immune responses are critically associated with the progression of fibrosis in chronic liver diseases. In this study, we aim to identify a unique immune-related gene signature representing advanced liver fibrosis and to reveal potential therapeutic targets. Seventy-seven snap-frozen liver tissues with various chronic liver diseases at different fibrosis stages (1: n = 12, 2: n = 12, 3: n = 25, 4: n = 28) were subjected to expression analyses. Gene expression analysis was performed using the nCounter PanCancer Immune Profiling Panel (NanoString Technologies, Seattle, WA, USA). Biological meta-analysis was performed using the CBS Probe PINGSTM (CbsBioscience, Daejeon, Korea). Using non-tumor tissues from surgically resected specimens, we identified the immune-related, five-gene signature (CHIT1_FCER1G_OSM_VEGFA_ZAP70) that reliably differentiated patients with low- (F1 and F2) and high-grade fibrosis (F3 and F4; accuracy = 94.8%, specificity = 91.7%, sensitivity = 96.23%). The signature was independent of all pathological and clinical features and was independently associated with high-grade fibrosis using multivariate analysis. Among these genes, the expression of inflammation-associated FCER1G, OSM, VEGFA, and ZAP70 was lower in high-grade fibrosis than in low-grade fibrosis, whereas CHIT1 expression, which is associated with fibrogenic activity of macrophages, was higher in high-grade fibrosis. Meta-analysis revealed that STAT3, a potential druggable target, highly interacts with the five-gene signature. Overall, we identified an immune gene signature that reliably predicts advanced fibrosis in chronic liver disease. This signature revealed potential immune therapeutic targets to ameliorate liver fibrosis.