Role of tumor-associated macrophages in the progression of hepatocellular carcinoma

Construction of a Prognostic Model for Hepatocellular Carcinoma Based on Macrophage Polarization-Related Genes

Background

The progression of hepatocellular carcinoma (HCC) is related to macrophage polarization (MP). Our aim was to identify genes associated with MP in HCC patients and develop a prognostic model based on these genes.

Results

We successfully developed a prognostic model consisting of six MP-related genes (SCN4A, EBF3, ADGRB2, HOXD9, CLEC1B, and MSC) to calculate the risk score for each patient. Patients were then classified into high- and low-risk groups based on their median risk score. The performance of the MP-related prognostic model was evaluated using Kaplan-Meier and ROC curves, which yielded favorable results. Additionally, the nomogram demonstrated good clinical effectiveness and displayed consistent survival predictions with actual observations. Gene Set Enrichment Analysis (GSEA) revealed enrichment of pathways related to KRAS signaling downregulation, the G2M checkpoint, and E2F targets in the high-risk group. Conversely, pathways associated with fatty acid metabolism, xenobiotic metabolism, bile acid metabolism, and adipogenesis were enriched in the low-risk group. The risk score positively correlated with the number of invasion-related genes. Immune checkpoint expression differed significantly between the two groups. Patients in the high-risk group exhibited increased sensitivity to mitomycin C, cisplatin, gemcitabine, rapamycin, and paclitaxel, while those in the low-risk group showed heightened sensitivity to doxorubicin. These findings suggest that the high-risk group may have more invasive HCC with greater susceptibility to specific drugs. IHC staining revealed higher expression levels of SCN4A in HCC tissues. Furthermore, experiments conducted on HepG2 cells demonstrated that supernatants from cells with reduced SCN4A expression promoted M2 macrophage polarization marker, CD163 in THP-1 cells. Reduced SCN4A expression induced HCC-related genes, while increased SCN4A expression reduced their expression in HepG2 cells.

Conclusion

The MP-related prognostic model comprising six MPRGs can effectively predict HCC prognosis, infer invasiveness, and guide drug therapy. SCN4A is identified as a suppressor gene in HCC.

Statin therapy: a potential adjuvant to immunotherapies in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide and accounts for more than 90% of primary liver cancer. The advent of immune checkpoint inhibitor (ICI)-related therapies combined with angiogenesis inhibition has revolutionized the treatment of HCC in late-stage and unresectable HCC, as ICIs alone were disappointing in treating HCC. In addition to the altered immune microenvironment, abnormal lipid metabolism in the liver has been extensively characterized in various types of HCC. Stains are known for their cholesterol-lowering properties and their long history of treating hypercholesterolemia and reducing cardiovascular disease risk. Apart from ICI and other conventional therapies, statins are frequently used by advanced HCC patients with dyslipidemia, which is often marked by the abnormal accumulation of cholesterol and fatty acids in the liver. Supported by a body of preclinical and clinical studies, statins may unexpectedly enhance the efficacy of ICI therapy in HCC patients through the regulation of inflammatory responses and the immune microenvironment. This review discusses the abnormal changes in lipid metabolism in HCC, summarizes the clinical evidence and benefits of stain use in HCC, and prospects the possible mechanistic actions of statins in transforming the immune microenvironment in HCC when combined with immunotherapies. Consequently, the use of statin therapy may emerge as a novel and valuable adjuvant for immunotherapies in HCC.

Macrophage memory: Types, mechanisms, and its role in health and disease

On the basis of the mechanisms of action and characteristics of immune effects, immunity is commonly categorized into innate and adaptive immunity. Adaptive immunity is associated with the response to non-self-entities and is characterized by high specificity and memory properties. In contrast, innate immunity has traditionally been considered devoid of memory characteristics. However, an increasing number of studies have sought to challenge this conventional immunological dogma and shown that innate immune cells exhibit a more robust and rapid response to secondary stimulation, thus providing evidence of the immunological memory in innate immunity. Macrophages, which are among the most important innate immune cells, can also acquire memory phenotype that facilitates the mediation of recall responses. Macrophage memory is a relatively new concept that is revolutionizing our understanding of macrophage biology and immunological memory and could lead to a new class of vaccines and immunotherapies. In this review, we describe the characteristics and mechanisms of macrophage memory, as well as its essential roles in various diseases.

Hepatitis B Virus-Encoded MicroRNA (HBV-miR-3) Inhibits FIH-1 Expression to Promote Tumor Angiogenesis in HBV-Related Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) is a solid tumor with a rich blood supply, and anti-angiogenesis has important clinical significance. Hepatitis B Virus-Encoded MicroRNA 3 (HBV-miR-3) has recently been reported to be involved in HCC development. In this study, we aim to elucidate the role of HBV-miR-3 in promoting HBV-related HCC angiogenesis through Factor Inhibiting Hypoxia-inducible factor 1 (FIH-1).

Results

By analyzing HBV-related HCC tissue samples, we found that high expression of HBV-miR-3 was associated with poor overall survival and HBV-miR-3 expression was significantly correlated with VEGFR2 and FIH-1 expressions. In vitro, HBV-miR-3 agomir repressed FIH-1 expression and promoted HIF-1α/VEGFA signaling activation in HepG2 cells, resulting in increased HUVEC lumen formation in HepG2-HUVEC co-culture model. Conversely, HBV-miR-3 antagomir induced FIH-1 expression and inhibited HIF-1α/VEGFA signaling activation in HepG2.2.15 cells, resulting in decreased HUVEC lumen formation in HepG2.2.15-HUVEC co-culture model. The effect of HBV-miR-3 to HCC angiogenesis was also confirmed by a mouse tumor bearing model. We also confirmed that HBV-miR-3 repressed FIH-1 expression via targeting the 3'-UTR of FIH-1 mRNA by luciferase activity assay.

Conclusion

HBV-miR-3 was related to HCC patients' overall survival and it promoted angiogenesis by repressing FIH-1 expression. HBV-miR-3 may be a new marker for predicting prognosis and a novel target for anti-angiogenic treatment of HBV-related HCC.

M2 macrophage-secreted exosomes promote metastasis and increase vascular permeability in hepatocellular carcinoma

BACKGROUND

Metastasis is a key feature of malignant tumors and significantly contributes to their high mortality, particularly in hepatocellular carcinoma (HCC). Therefore, it is imperative to explore the mechanism of tumor metastasis. Recently, tumor-associated macrophages (TAMs) have been demonstrated to promote tumor progression, while TAM-derived molecules involved in HCC metastasis warrant further investigation.

METHODS

THP-1 was treated with IL-4 (Interleukin-4) and IL-13 (Interleukin-13) for M2 polarized macrophages. Exosomes derived from M2 macrophages were characterized. Then, HCC cells or human umbilical vein endothelial cells (HUVECs) were co-cultured with M2 macrophages or treated with M2 macrophage-secreted exosomes. Next, Transwell®, Scratch assay, tube formation, and endothelial permeability assays were performed. Moreover, RT-PCR, western blotting, immunofluorescence, and ELISA were used to assess mRNA and protein expression levels. Finally, the miRNA expression profiles of exosomes derived from M2 and M0 macrophages were analyzed.

RESULTS

M2 macrophage infiltration was correlated with metastasis and a poor prognosis in HCC patients. M2-derived exosomes were absorbed by HCC and HUVEC cells and promoted the epithelial-mesenchymal transition (EMT), vascular permeability, and angiogenesis. Notably, MiR-23a-3p levels were significantly higher in M2-derived exosomes and hnRNPA1 mediated miR-23a-3p packaging into exosomes. Phosphatase and tensin homolog (PTEN) and tight junction protein 1 (TJP1) were the targets of miR-23a-3p, as confirmed by luciferase reporter assays. Lastly, HCC cells co-cultured with M2-derived exosomes secreted more GM-CSF, VEGF, G-CSF, MCP-1, and IL-4, which in turn further recruited M2 macrophages.

CONCLUSIONS

Our findings suggest that M2 macrophage-derived miR-23a-3p enhances HCC metastasis by promoting EMT and angiogenesis, as well as increasing vascular permeability. Video Abstract.

Overexpression of miR-4669 Enhances Tumor Aggressiveness and Generates an Immunosuppressive Tumor Microenvironment in Hepatocellular Carcinoma: Its Clinical Value as a Predictive Biomarker

Accumulating evidence suggests the involvement of tumor-derived exosomes in the development and recurrence of hepatocellular carcinoma (HCC). We previously identified miR-4669 as a highly expressed microRNA in circulating exosomes obtained from patients with post-transplant HCC recurrence. This study aimed to explore how overexpression of miR-4669 affects HCC development and recurrence. The impact of miR-4669 overexpression in Hep3B cells on tumor cell behavior and the tumor microenvironment was evaluated in vitro. In addition, the clinical value of exosomal miR-4669 for the prediction of treatment response to HCC downstaging therapies and following post-transplant HCC recurrence was explored. Overexpression of miR-4669 enhanced migration ability and led to acquired sorafenib resistance with an elevation of sirtuin 1 and long noncoding RNA associated with microvascular invasion. Active release of tumor-derived exosomes and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) contributed to generating an immunosuppressive tumor microenvironment through the induction of M2 macrophage polarization. The retrospective analysis demonstrated the clinical value of exosomal miR-4669 for predicting treatment response to HCC downstaging therapies and for risk assessment of post-transplant HCC recurrence. In summary, the present data demonstrate the impact of exosomal miR-4669 on HCC recurrence through the enhancement of tumor aggressiveness and generation of an immunosuppressive tumor microenvironment.

Elevated Alfa-Fetoprotein and Des-Gamma-Carboxy Prothrombin Levels Predict Poor Outcomes After Liver Transplantation for Hepatocellular Carcinoma Beyond the Japan Criteria

AIM

The Japan criteria (Milan criteria + 5-5-500 rule) was established recently to select cirrhotic patients with hepatocellular carcinoma for liver transplantation. We evaluated factors associated with poor prognosis after liver transplantation and investigated whether a further extension of the criteria would be worthwhile.

METHODS

We retrospectively analyzed 86 patients who underwent liver transplantation for hepatocellular carcinoma at Kumamoto University Hospital since 2004; 69 patients (80.2%) met the Japan criteria (the JC^IN group), and 17 patients (19.8%) did not (the JC^OUT group).

RESULTS

The 5-year cancer-specific survival rates of the JC^IN group (92.2%) were significantly better than that of the JC^OUT group (39.2%; P < .001). In univariable analysis, alfa-fetoprotein and des-gamma-carboxy prothrombin were significant independent factors associated with cancer-specific survival rates. According to the receiver operating characteristic curves, the cutoff values of alfa-fetoprotein and des-gamma-carboxy prothrombin that predicted hepatocellular carcinoma recurrence after liver transplantation were 756 ng/mL and 1976 mAU/mL, respectively. The JC^OUT group was divided into 2 subgroups according to alfa-fetoprotein and des-gamma-carboxy prothrombin: low risk (alfa-fetoprotein level <756 ng/mL and des-gamma-carboxy prothrombin level <1976 mAU/mL) and high risk (alfa-fetoprotein level ≥756 ng/mL and/or des-gamma-carboxy prothrombin level ≥1976 mAU/mL). The 5-year cancer-specific survival rate in the low-risk group (67.5%) was significantly better than that in the high-risk group (0%; P < .001).

CONCLUSIONS

Alfa-fetoprotein levels of <756 ng/mL and des-gamma-carboxy prothrombin levels of <1976 mAU/mL may help identify cirrhotic patients with hepatocellular carcinoma who do not meet the Japan criteria but still benefit from liver transplantation.

Potential antiproliferative and apoptotic effects of pilocarpine combined with TNF alpha in chronic myeloid leukemia cells

Pilocarpine is a selective M₁/M₃ agonist of muscarinic acetylcholine receptor subtypes. Muscarinic acetylcholine receptors are G protein-coupled receptors. These receptors are different drug targets. The aim of the present work was to investigate the effect of pilocarpine on the expression of M₃ muscarinic acetylcholine receptor, the AChE activity, IL-8 release response, and proliferation in K562 cells, via muscarinic receptor activation. Human chronic myeloid leukemic cell cultures were incubated with drugs. Proliferation assays were performed by BrdU assay. Expression of M₃ muscarinic acetylcholine receptor and apoptosis proteins such as bcl, bax, cyt C, and caspases was assessed with the semiquantitative Western blotting method. Pilocarpine inhibits chronic myeloid cell proliferation and M₃ muscarinic acetylcholine receptor protein expression. Pilocarpine increases caspase-8 and -9 expression levels, upregulating the proapoptotic protein Bax and downregulating the expression levels of the antiapoptotic protein Bcl-2. The apoptotic activity of pilocarpine is associated with an increase in AChE activity. M₃ muscarinic acetylcholine receptors can activate multiple signal transduction systems and mediate inhibitory effects on chronic myeloid K562 cell proliferation depending on the presence of 1% FBS conditions. This apoptotic effect of pilocarpine may be due to the concentration of pilocarpine and the increase in AChE level. Our results suggest that inhibition of cell proliferation by inducing apoptosis of pilocarpine in K562 cells may be one of the targets. M₃ selective agonist may have therapeutic potential in chronic myeloid leukemia.

Acute respiratory distress syndrome enhances tumor metastasis into lungs: Role of BRD4 in the tumor microenvironment

Acute respiratory distress syndrome (ARDS) is associated with severe lung inflammation, edema, hypoxia, and high vascular permeability. The COVID-19-associated pandemic ARDS caused by SARS-CoV-2 has created dire global conditions and has been highly contagious. Chronic inflammatory disease enhances cancer cell proliferation, progression, and invasion. We investigated how acute lung inflammation activates the tumor microenvironment and enhances lung metastasis in LPS induced in vitro and in vivo models. Respiratory illness is mainly caused by cytokine storm, which further influences oxidative and nitrosative stress. The LPS-induced inflammatory cytokines made the conditions suitable for the tumor microenvironment in the lungs. In the present study, we observed that LPS induced the cytokine storm and promoted lung inflammation via BRD4, which further caused the nuclear translocation of p65 NF-κB and STAT3. The transcriptional activation additionally triggers the tumor microenvironment and lung metastasis. Thus, BRD4-regulated p65 and STAT3 transcriptional activity in ARDS enhances lung tumor metastasis. Moreover, LPS-induced ARDS might promote the tumor microenvironment and increase cancer metastasis into the lungs. Collectively, BRD4 plays a vital role in inflammation-mediated tumor metastasis and is found to be a diagnostic and molecular target in inflammation-associated cancers.

Predictive Factors for the Resectable Type of Hepatocellular Carcinoma Recurrence After Living Donor Liver Transplant

Recurrence of hepatocellular carcinoma (HCC) after living donor liver transplant (LDLT) is an essential factor defining prognosis, and surgical resection is the only curative treatment. However, the factors that define whether surgical resection is possible remain unclear. Here, we compared resectable and unresectable HCC recurrence cases after LDLT and examined factors that determine whether surgical resection is possible. Resectable (n = 17) and unresectable (n = 14) groups among 264 patients who underwent LDLT for HCC from January 1999 to March 2020 were compared and examined for recurrence type, prognosis, and clinicopathologic factors. Overall survival after LDLT (median, 8.5 vs 1.7 years, P < .01) was significantly longer in the resectable group. In univariate analysis, female recipient rate, lymphocyte to monocyte ratio (LMR) ≥2.75, and tumor size ≤5.0 cm were significantly higher in the resectable group. Younger donors, lower Model for End-Stage Liver Disease scores, lower graft volume, and lower graft volume to standard liver volume ratio were evident in the resectable group. In multivariate analysis, female recipient rate (P = .0034) and LMR ≥2.75 (P = .0203) were independent predictive factors for resectable HCC recurrence after LDLT. Female recipient and LMR ≥2.75 before transplant could predict the surgically resectable type of HCC recurrence after LDLT.

Development and verification of the glycolysis-associated and immune-related prognosis signature for hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) refers to the malignant tumor associated with a high mortality rate. This work focused on identifying a robust tumor glycolysis-immune-related gene signature to facilitate the prognosis prediction of HCC cases.

Methods: This work adopted t-SNE algorithms for predicting glycolysis status in accordance with The Cancer Genome Atlas (TCGA)-derived cohort transcriptome profiles. In addition, the Cox regression model was utilized together with LASSO to identify prognosis-related genes (PRGs). In addition, the results were externally validated with the International Cancer Genome Consortium (ICGC) cohort.

Results: Accordingly, the glycolysis-immune-related gene signature, which consisted of seven genes, PSRC1, CHORDC1, KPNA2, CDCA8, G6PD, NEIL3, and EZH2, was constructed based on TCGA-HCC patients. Under a range of circumstances, low-risk patients had extended overall survival (OS) compared with high-risk patients. Additionally, the developed gene signature acted as the independent factor, which was significantly associated with clinical stage, grade, portal vein invasion, and intrahepatic vein invasion among HCC cases. In addition, as revealed by the receiver operating characteristic (ROC) curve, the model showed high efficiency. Moreover, the different glycolysis and immune statuses between the two groups were further revealed by functional analysis.

Conclusion: Our as-constructed prognosis prediction model contributes to HCC risk stratification.

Associating resistance to immune checkpoint inhibitors with immunological escape in colorectal cancer

Colorectal cancer is a common malignant tumor that ranks third in incidence and second in mortality worldwide, and surgery in conjunction with chemotherapy and radiotherapy remains the most common treatment option. As a result of radiotherapy’s severe side effects and dismal survival rates, it is anticipated that more alternatives may emerge. Immunotherapy, a breakthrough treatment, has made significant strides in colorectal cancer over the past few years, overcoming specialized therapy, which has more selectivity and a higher survival prognosis than chemoradiotherapy. Among these, immune checkpoint inhibitor therapy has emerged as the primary immunotherapy for colorectal cancer nowadays. Nonetheless, as the use of immune checkpoint inhibitor has expanded, resistance has arisen inevitably. Immune escape is the primary cause of non-response and resistance to immune checkpoint inhibitors. That is the development of primary and secondary drug resistance. In this article, we cover the immune therapy-related colorectal cancer staging, the specific immune checkpoint inhibitors treatment mechanism, and the tumor microenvironment and immune escape routes of immunosuppressive cells that may be associated with immune checkpoint inhibitors resistance reversal. The objective is to provide better therapeutic concepts for clinical results and to increase the number of individuals who can benefit from colorectal cancer immunotherapy.

Exosomal miR-452-5p Induce M2 Macrophage Polarization to Accelerate Hepatocellular Carcinoma Progression by Targeting TIMP3

Background

Hepatocellular carcinoma (HCC) cell-derived exosomes have shown effects on inducing M2 macrophage polarization and promoting HCC progression. MiR-452-5p was reported by recent studies to promote malignancy progression as an exosomal microRNA that secreted by HCC cells, of which the underlying mechanism remains unclear. Here, we further explored how miR-452-5p functions in HCC.

Methods

MiR-452-5p expressions in HCC cells was examined by in situ hybridization. Next, HCC cell lines were transfected with the mimics or the inhibitor of miR-452-5p. Transfected cells' biological behavior were analyzed by CCK-8, flow cytometry, and Transwell assay. Then, exosomes were purified from miR-452-5p inhibited or overexpressed HCC cells and cocultured with macrophages to examine the role of miR-452-5p in macrophage polarization. To examine the role of exosomal miR-452-5p on macrophage polarization and tumor growth. We also performed the dual-luciferase assay to explore the targeting relationship between miR-452-5p and TIMP3.

Results

The upregulation of miR-452-5p was identified in HCC. The effects of HCC cell-derived exosomes on accelerating HCC migration and invasion and inducing M2 macrophage polarization were confirmed, which were further enhanced after overexpressing miR-452-5p but neutralized after silencing miR-452-5p. In addition, in vivo experiments demonstrated the effect of miR-452-5p on accelerating HCC growth and metastasis. Also, we identified that TIMP3 overexpression inhibited the promoted cell invasion and migration by HCC cell-derived exosomes.

Conclusion

Exosomal miR-452-5p secreted from HCC cells could induce polarization of M2 macrophage and therefore stimulating HCC progression by targeting TIMP3. Thus, miR-452-5p might be a potential biomarker for HCC prognosis.

Hepatic Stellate Cell Modulates the Immune Microenvironment in the Progression of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major cause of increases in the mortality rate due to cancer that usually develops in patients with liver fibrosis and impaired hepatic immunity. Hepatic stellate cells (HSCs) may directly or indirectly crosstalk with various hepatic cells and subsequently modulate extracellular remodeling, cell invasion, macrophage conversion, and cancer deterioration. In this regard, the tumor microenvironment created by activated HSC plays a critical role in mediating pathogenesis and immune escape during HCC progression. Herein, intermediately differentiated human liver cancer cell line (J5) cells were co-cultured with HSC-conditioned medium (HSC-CM); changes in cell phenotype and cytokine profiles were analyzed to assess the impact of HSCs on the development of hepatoma. The stage of liver fibrosis correlated significantly with tumor grade, and the administration of conditioned medium secreted by activated HSC (aHSC-CM) could induce the expression of N-cadherin, cell migration, and invasive potential, as well as the activity of matrix metalloproteinases in J5 cells, implying that aHSC-CM could trigger the epithelial-mesenchymal transition (EMT). Next, the HSC-CM was further investigated and network analysis indicated that specific cytokines and soluble proteins, such as activin A, released from activated HSCs could remarkably affect the tumor-associated immune microenvironment involved in macrophage polarization, which would, in turn, diminish a host’s immune surveillance and drive hepatoma cells into a more malignant phenotype. Together, our findings provide a novel insight into the integral roles of HSCs to enhance hepatocarcinogenesis through their immune-modulatory properties and suggest that HSC may serve as a potent target for the treatment of advanced HCC.

Preoperative inflammatory markers as prognostic predictors after hepatocellular carcinoma resection: data from a western referral center

Background

Recent studies from eastern centers have demonstrate an association between inflammatory response and long-term outcomes after hepatocellular carcinoma (HCC) resection. However, the prognostic impact of inflammatory markers in western patients, with distinct tumor and epidemiologic features, is still unknown.

Aim

To evaluate the prognostic impact of preoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR), as well as their impact according to tumor size (< 5 cm, 5–10 cm, > 10 cm) in patients undergoing HCC resection with curative intent.

Methods

Optimal cut-off values for NLR, PLR, and MLR were determined by plotting the receiver operator curves. Overall survival (OS) and disease-free survival (DFS) curves were calculated using the Kaplan–Meier method and compared using the log-rank test. The Cox method was used to identify independent predictors of OS and DFS.

Results

In total, 161 consecutive adult patients were included. A high NLR (> 1.715) was associated with worse OS (P = 0.018). High NLR (> 2.475; P = 0.047) and PLR (> 100.25; P = 0.028) were predictors of short DFS. In HCC < 5 cm, MLR (> 1.715) was associated with worse OS (P = 0.047). In the multivariate analysis, high PLR was an independent predictor of worse DFS [hazard ratio (HR) 3.029; 95%CI 1.499–6.121; P = 0.002].

Conclusion

Inflammatory markers are useful tools to predict long-term outcomes after liver resection in western patients, high NLR was able to stratify subgroups of patients with short OS and DFS, an increased PLR was an independent predictor of short DFS, while high MLR was associated with short OS in patients with early HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01779-6.

IL-1 receptor-associated kinase 1 participates in the modulation of the NLRP3 inflammasome by tumor-associated macrophages in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinomas (HCCs) occur frequently in the digestive system and are associated with high mortality. This current study examined the regulatory relationship between interleukin (IL)-1 receptor-associated kinase 1 (IRAK1), NLR family pyrin domain-containing 3 (NLRP3) inflammasomes, and tumor-associated macrophages (TAMs) in the growth and metastasis of HCC.

METHODS

The expression of IRAK1 and NLRP3 was assessed in tissues and cells via quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Immunohistology was performed to detect the macrophage markers CD68, CD163, and CD168 in tumor tissues. Small interfering (si)RNA targeting IRAK1 (si-IRAK1) was designed to silence IRAK1 expression. Following si-IRAK1 transfection and/or co-culture with TAMs, HCC cell viability, proliferation, migration, and invasion, as well as the expression of NLRP3 and pro-inflammatory cytokines IL-1 β, IL-18, and monocyte chemotactic protein 1 (MCP-1) were assessed.

RESULTS

HCC tissues showed elevated expression of IRAK1 and NLRP3, as well as increased expression of the macrophage markers CD68, CD163, and CD168, compared to adjacent healthy tissues. Silencing of IRAK1 expression in HepG2 and Huh7 cells resulted in suppression of cell proliferation, migration, and invasion, and also reduced expression of NLRP3 and the pro-inflammatory cytokines IL-1β, IL-18, and MCP-1. Moreover, TAMs promoted HepG2 and Huh7 cell proliferation, migration, and invasion, and elevated the expression of NLRP3, IL-1β, IL-18, and MCP-1. Furthermore, IRAK1 silencing reversed the effects of TAMs on HepG2 and Huh7 cells.

CONCLUSIONS

The expression of IRAK1 was associated with HCC growth and metastasis, as well as NLRP3 inflammasome activation. The ability of TAMs to promote HCC growth and metastasis may be activated by NLRP3 inflammasomes and regulated by IRAK1.

Matrix metalloproteinase-21 promotes metastasis via increasing the recruitment and M2 polarization of macrophages in HCC

MMP-21 is a newly identified member of the matrix metalloproteinase family and has been reported to regulate both embryonic development and tumor progression. However, the roles of MMP-21 in hemofiltrate C-C chemokine (HCC) remain largely unclear. In this study, we used western blot, qPCR and immunohistochemistry (IHC) to determine the upregulation of MMP-21 in HCC tissues, and showed that the increase in MMP-21 was associated with vascular invasion and poor prognosis. Although changing levels of MMP-21 in HCC cell lines had no significant effect on cell migration or invasion abilities in in vitro transwell tests, both IHC analysis and in vivo mouse models proved that upregulated MMP-21 promoted metastasis. Functional enrichments of MMP-21 using The Cancer Genome Atlas (TCGA) data suggested that MMP-21 might regulate metastasis via macrophages. Further experiments proved that MMP-21 enhanced macrophage recruitment by increasing CCL-14 levels and promoted M2-type polarization of macrophage by elevating the expression of CSF-1 and FGF-1. Taken together, this study revealed that MMP-21 controlled the tumor microenvironment remodeling and functional regulation of macrophages to regulate HCC metastasis.

Role of macrophages in tumor progression and therapy (Review)

The number and phenotype of macrophages are closely related to tumor growth and prognosis. Macrophages are recruited to (and polarized at) the tumor site thereby promoting tumor growth, stimulating tumor angiogenesis, facilitating tumor cell migration, and creating a favorable environment for subsequent colonization by (and survival of) tumor cells. These phenomena contribute to the formation of an immunosuppressive tumor microenvironment (TME) and therefore speed up tumor cell proliferation and metastasis and reduce the efficacy of antitumor factors and therapies. The ability of macrophages to remodel the TME through interactions with other cells and corresponding changes in their number, activity, and phenotype during conventional therapies, as well as the association between these changes and drug resistance, make tumor-associated macrophages a new target for antitumor therapies. In this review, advantages and limitations of the existing antitumor strategies targeting macrophages in Traditional Chinese and Western medicine were analyzed, starting with the effect of macrophages on tumors and their interactions with other cells and then the role of macrophages in conventional treatments was explored. Possible directions of future developments in this field from an all-around multitarget standpoint were also examined.

Hepatocellular Carcinoma: Molecular Pathogenesis and Therapeutic Advances

Hepatocellular carcinoma (HCC), the most common form of liver cancer, continues to be a serious medical problem with poor prognosis, without major therapeutic improvement for years and increasing incidence. Fortunately, advances in systemic treatment options are finally arriving for HCC patients. After a decade of sorafenib as a standard therapy for advanced HCC, several tyrosine kinase inhibitors (TKIs), antiangiogenic antibodies, and immune checkpoint inhibitors have reached the clinic. Although infections by hepatitis B virus and hepatitis C virus remain principal factors for HCC development, the rise of non- alcoholic steatohepatitis from diabetes mellitus or metabolic syndrome is impeding HCC decline. Knowledge of specific molecular mechanisms, based on the etiology and the HCC microenvironment that influence tumor growth and immune control, will be crucial for physician decision-making among a variety of drugs to prescribe. In addition, markers of treatment efficacy are needed to speed the movement of patients towards other potentially effective treatments. Consequently, research to provide scientific data for the evidence-based management of liver cancer is guaranteed in the coming years and discussed here.

EMT and Inflammation: Crossroads in HCC

Hepatocellular carcinoma is one of the major causes of cancer-related deaths worldwide and is associated with several inflammatory mediators, since 90% of HCCs occur based on chronic hepatitis B or C, alcoholism or increasingly metabolic syndrome-associated inflammation. EMT is a physiological process, with coordinated changes in epithelial gene signatures and is regulated by multiple factors, including cytokines and growth factors such as TGFβ, EGF, and FGF. Recent reports propose a strong association between EMT and inflammation, which is also correlated with tumor aggressiveness and poor outcomes. Cellular heterogeneity results collectively as an outcome of EMT, inflammation, and the tumor microenvironment, and it plays a fundamental role in the progression, complexity of cancer, and chemoresistance. In this review, we highlight recent developments concerning the association of EMT and inflammation in the context of HCC progression. Identifying potential EMT-related biomarkers and understanding EMT regulatory molecules will likely contribute to promising developments in clinical practice and will be a valuable tool for predicting metastasis in general and specifically in HCC.

Macrophages as key regulators of liver health and disease

Macrophages are a heterogeneous population of innate immune cells and key cellular components of the liver. Hepatic macrophages consist of embryologically-derived resident Kupffer cells (KC), recruited monocyte-derived macrophages (MDM) and capsular macrophages. Both the diversity and plasticity of hepatic macrophage subsets explain their different functions in the maintenance of hepatic homeostasis and in injury processes in acute and chronic liver diseases. In this review, we assess the evidence for macrophage involvement in regulating both liver health and injury responses in liver diseases including acute liver injury (ALI), chronic liver disease (CLD) (including liver fibrosis) and hepatocellular carcinoma (HCC). In healthy livers, KC display critical functions such as phagocytosis, danger signal recognition, cytokine release, antigen processing and the ability to orchestrate immune responses and maintain immunological tolerance. However, in most liver diseases there is a striking hepatic MDM expansion, which orchestrate both disease progression and regression. Single-cell approaches have transformed our understanding of liver macrophage heterogeneity, dynamics, and functions in both human samples and preclinical models. We will further discuss the new insights provided by these approaches and how they are enabling high-fidelity work to specifically identify pathogenic macrophage subpopulations. Given the important role of macrophages in regulating injury responses in a broad range of settings, there is now a huge interest in developing new therapeutic strategies aimed at targeting macrophages. Therefore, we also review the current approaches being used to modulate macrophage function in liver diseases and discuss the therapeutic potential of targeting macrophage subpopulations as a novel treatment strategy for patients with liver disorders.

Targeting macrophage-mediated tumor cell phagocytosis: An overview of phagocytosis checkpoints blockade, nanomedicine intervention, and engineered CAR-macrophage therapy

Immunotherapy has been developing at an unprecedented speed with promising therapeutic outcomes in the wide spectrum of cancers. Up until now, most immunotherapies have focused on adaptive immunity; however, investigating the potential of macrophage phagocytosis and consequent adaptive immune cross-priming has led to a growing interest in exploiting macrophages in cancer therapy. In light of the positive evidence from preclinical studies and early clinical data, targeting macrophage phagocytosis has become a promising therapeutic strategy. Here, we review therapies based on harnessing and amplifying macrophage phagocytosis, such as blocking phagocytosis checkpoints and exploiting nanoparticles as efficient approaches in elevating macrophages-mediated phagocytosis. The present study introduces CAR-macrophage as the state-of-the-art modality serving as the bridge between the innate and adaptive immune system to mount a superior anti-tumor response in the treatment of cancer. We also take a look at the recent reports of therapies based on CAR-engineered macrophages with the hope of providing a future research direction for expanding the application of CAR-macrophage therapy.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial–mesenchymal transition, and migration of cancer cells).

Current Trends in Non-Invasive Imaging of Interactions in the Liver Tumor Microenvironment Mediated by Tumor Metabolism

With the increasing understanding of resistance mechanisms mediated by the metabolic reprogramming in cancer cells, there is a growing clinical interest in imaging technologies that allow for the non-invasive characterization of tumor metabolism and the interactions of cancer cells with the tumor microenvironment (TME) mediated through tumor metabolism. Specifically, tumor glycolysis and subsequent tissue acidosis in the realms of the Warburg effect may promote an immunosuppressive TME, causing a substantial barrier to the clinical efficacy of numerous immuno-oncologic treatments. Thus, imaging the varying individual compositions of the TME may provide a more accurate characterization of the individual tumor. This approach can help to identify the most suitable therapy for each individual patient and design new targeted treatment strategies that disable resistance mechanisms in liver cancer. This review article focuses on non-invasive positron-emission tomography (PET)- and MR-based imaging techniques that aim to visualize the crosstalk between tumor cells and their microenvironment in liver cancer mediated by tumor metabolism.

Tumor-Associated Macrophages: Combination of Therapies, the Approach to Improve Cancer Treatment

Macrophages are one of the most important cells of the innate immune system and are known for their ability to engulf and digest foreign substances, including cellular debris and tumor cells. They can convert into tumor-associated macrophages (TAMs) when mature macrophages are recruited into the tumor microenvironment. Their role in cancer progression, metastasis, and therapy failure is of special note. The aim of this review is to understand how the presence of TAMs are both advantageous and disadvantageous in the immune system.

Prognostic Impact of Vessels that Encapsulate Tumor Cluster (VETC) in Patients who Underwent Liver Transplantation for Hepatocellular Carcinoma

BACKGROUND

There is limited published information about prognostic value of vessels that encapsulate tumor cluster (VETC) based on their involvement with immune cells in hepatocellular carcinoma (HCC). Our goal was to evaluate prognostic impact of VETC in patients who underwent living-donor liver transplantation (LDLT) for HCC, focusing on the involvement of VETC with immune status in tumor microenvironment (TME).

METHODS

Using a database of 150 patients who underwent LDLT for HCC, immunohistochemical staining of CD34 for VETC, angiopoietin-2 (Ang-2), CD3, and CD68, was reviewed with patients' clinicopathological factors.

RESULTS

A strong correlation between VETC pattern and malignant potential in HCC was observed; larger tumor size (P < 0.001), more numbers of tumors (P = 0.003), higher α-fetoprotein levels (P = 0.001), higher des-γ-carboxy prothrombin levels (P = 0.022), microvascular invasion (P < 0.001), and poor differentiation (P = 0.010). Overall survival (OS) of patients with VETC⁽⁺⁾ was significantly lower than those with VETC^(-) (P = 0.021; 5-year OS rates, 72.0% vs. 87.1%). Furthermore, the ratio of CD3⁽⁺⁾ cells was significantly lower in VETC⁽⁺⁾ group (P = 0.001), indicating that VETC activity may be strongly correlated with lymphocyte activity. Moreover, combination status of VETC⁽⁺⁾/CD3^low was an independent risk factor for mortality (hazard ratio 2.760, 95% confidence interval 1.183-6.439, P = 0.019). Additionally, the combination of VETC expression with immune status (low CD3 levels) enabled further classification of patients based on their clinical outcome.

CONCLUSIONS

Our results show the prognostic impact of VETC expression, tumor-infiltrating lymphocytes (TILs), and their combination in the setting of LDLT for HCC, which can be a novel prognostic biomarker for mortality after LDLT.

M2 Macrophage-Derived Exosomes Facilitate HCC Metastasis by Transferring αM β2 Integrin to Tumor Cells

BACKGROUND AND AIMS

The development and progression of hepatocellular carcinoma (HCC) is dependent on its local microenvironment. Tumor-associated macrophages (TAMs) are deemed a key factor for the tumor microenvironment and attribute to contribute to tumor aggressiveness. However, the detailed mechanism underlying the pro-metastatic effect of TAMs on HCC remains undefined.

APPROACH AND RESULTS

The present study proved that TAMs were enriched in HCC. TAMs were characterized by an M2-polarized phenotype and accelerated the migratory potential of HCC cells in vitro and in vivo. Furthermore, we found that M2-derived exosomes induced TAM-mediated pro-migratory activity. With the use of mass spectrometry, we identified that integrin, α_M β₂ (CD11b/CD18), was notably specific and efficient in M2 macrophage-derived exosomes (M2 exos). Blocking either CD11b and/or CD18 elicited a significant decrease in M2 exos-mediated HCC cell metastasis. Mechanistically, M2 exos mediated an intercellular transfer of the CD11b/CD18, activating the matrix metalloproteinase-9 signaling pathway in recipient HCC cells to support tumor migration.

CONCLUSIONS

Collectively, the exosome-mediated transfer of functional CD11b/CD18 protein from TAMs to tumor cells may have the potency to boost the migratory potential of HCC cells, thus providing insights into the mechanism of tumor metastasis.

Diagnostic and prognostic value of serum soluble CD163 in cirrhotic patients with hepatitis C virus-related hepatocellular carcinoma before and after locoregional therapy

Background

Tumor-associated macrophages (TAMs), inflammatory cells in tumor microenvironment, are crucial for the tumor occurrence and progression which in turn increase the expression of soluble CD163 (sCD163). Nevertheless, not much has been established regarding sCD163 and its connection to HCC diagnosis and prognosis. This study was conducted to evaluate the diagnostic and prognostic role of sCD163 in patients with HCC on top of HCV-related liver cirrhosis. Forty adult patients with HCV-related liver cirrhosis and HCC (HCC group) were randomly selected and subjected to locoregional therapies, either transarterial chemoembolization (TACE) or radiofrequency ablation (RFA). Four patients were excluded because of portal vein invasion. Another group of 20 patients with liver cirrhosis only served as controls (LC group). Routine laboratory studies and abdominal ultrasound were done for all. Alpha-fetoprotein (AFP) and sCD163 were measured twice, at baseline and 1-month post-intervention, using a commercially available enzyme-linked immunosorbent assay kit.

Results

At baseline, sCD163 showed an insignificant higher value in HCC group (p > 0.05). The best cutoff value for sCD163 and AFP was 6.2 mg/L and 195 ng/mL, respectively. AFP had a larger area under the curve (0.88 vs. 0.767). An overall significant decline was seen in sCD163 after treatment (6.5±1.5 to 3.1±2.5 mg/L; p < 0.001), while AFP showed an insignificant decrease (p > 0.05). Also, sCD163 decreased significantly in the eradicated cases (6.1±1.4 mg/L before intervention vs. 2.3±1.4 mg/L after intervention, p < 0.01), while there was a significant increase in the recurrent cases (8.4±0.4 mg/L before intervention vs. 10.3±1.6 after intervention; p < 0.05). Moreover, sCD163 showed a significant difference in its pre-intervention and post-intervention values between recurrent and eradicated HCC cases (p < 0.01).

Conclusions

It is concluded that sCD163 has a minor role as a diagnostic marker for HCC, yet it could be used as a good prognostic marker in predicting the tumor response to locoregional therapies.

Characterization of the inflammatory microenvironment and hepatic macrophage subsets in experimental hepatocellular carcinoma models

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. HCC typically develops on a background of chronic inflammation and fibrosis with tumor associated macrophages (TAMs) playing an important role in chronic inflammation-induced HCC and progression. However, the liver harbors unique macrophages, resident liver Kupffer cells (KCs) and monocyte-derived macrophages (Mo-Mφ), and their contribution to HCC and to the population of TAMs is incompletely known. Here, we characterized the tumor microenvironment and the proportion and transcriptional profile of hepatic macrophages (Mφ) in two commonly used HCC mouse models. A gradually increased expression of inflammatory, immune regulatory, fibrotic and cell proliferation pathways and markers was observed during diethylnitrosamine (DEN)- and non-alcoholic steatohepatitis (NASH)-induced HCC development. The transcriptional phenotypes of isolated hepatic Mφ subsets were clearly distinct and shifted during HCC development, with mixed pro-inflammatory and tumor-promoting expression profiles. There were marked differences between the models as well, with Mφ in NASH-HCC exhibiting a more immunomodulatory phenotype, in conjunction with an upregulation of lipid metabolism genes. Our data show that at least some infiltrated macrophages display expression of pro-tumoral markers, and that Kupffer cells are part of the population of TAMs and enhance tumor progression. These insights are useful to further unravel sequential pathogenic events during hepatocarcinogenesis and direct future development of new treatment strategies for HCC.

Identification and validation of redox-immune based prognostic signature for hepatocellular carcinoma

The intimate interaction between redox signaling and immunity has been widely revealed. However, the clinical application of relevant therapeutic is unavailable due to the absence of validated markers that stratify patients. Here, we identified novel biomarkers for prognosis prediction in hepatocellular carcinoma (HCC). Prognostic redox-immune-related genes for predicting overall survival (OS) of HCC were identified using datasets from TCGA, LIRI-JP, and GSE14520. LASSO Cox regression was employed to construct the signature model and generate a risk score in the TCGA cohort. The signature contained CDO1, G6PD, LDHA, GPD1L, PPARG, FABP4, CCL20, SPP1, RORC, HDAC1, STC2, HDGF, EPO, and IL18RAP. Patients in the high-risk group had a poor prognosis compared to the low-risk group. Univariate and multivariate Cox regressions identified this signature as an independent factor for predicting OS. Nomogram constructed by multiple clinical parameters showed good performance for predicting OS indicated by the c-index, the calibration curve, and AUC. GSEA showed that oxidoreductase activity and peroxisome-related metabolic pathways were enriched in the low-risk group, while glycolysis activity and hypoxia were higher in the high-risk group. Furthermore, immune profiles analysis showed that the immune score and stromal score were significantly decreased in the high-risk group in the TCGA cohort. There was a considerably lower infiltration of anti-tumor immune cells while a higher proportion of pro-tumor immune cells in silico. Immune markers were distinctly expressed between the subgroups, and redox-sensitive immunoregulatory biomarkers were at higher levels in the high-risk group. Altogether, we identified a redox-immune prognostic signature. A more severe redox perturbation-driven immunosuppressive environment in the high-risk group stratified by the signature may account for poor survival. This may provide a clue to the combined therapy targeting redox and immune in HCC.

Preoperative prognostic nutritional index predicts short- and long-term outcomes after liver resection in patients with hepatocellular carcinoma

The prognostic nutritional index (PNI) is one of the immune parameters calculated on the basis of the serum albumin and the total lymphocyte count. The aim of the present study was to investigate the prognostic significance of the PNI for short- and long-term outcomes after liver resection for patients with hepatocellular carcinoma (HCC). Data from 162 surgically treated patients with HCC (without any previous treatment) were retrospectively analyzed. The cutoff value of preoperative PNI was 45.0, which was calculated by a receiver operating characteristic curve for predicting the recurrence of HCC after liver resection. Patients were divided into low (n=86) and high (n=76) PNI groups. In short-term outcomes, patients in the low PNI group were more likely to experience postoperative complications compared with those in the high PNI group. The 5-year disease-free survival (DFS) rate in the low PNI group was significantly lower compared with that in the high PNI group (20.5% vs. 48.7%). In the multivariate analysis, a low PNI was an independent prognostic factor for DFS (HR, 1.65; 95% CI, 1.00-2.71). In conclusion, the preoperative PNI may be a prognostic factor for evaluating short- and long-term outcomes after liver resection in patients with HCC.

Near-infrared fluorescence imaging in immunotherapy

Near-infrared (NIR) light possesses many suitable optophysical properties for medical imaging including low autofluorescence, deep tissue penetration, and minimal light scattering, which together allow for high-resolution imaging of biological tissue. NIR imaging has proven to be a noninvasive and effective real-time imaging methodology that provides a high signal-to-background ratio compared to other potential optical imaging modalities. In response to this, the use of NIR imaging has been extensively explored in the field of immunotherapy. To date, NIR fluorescence imaging has successfully offered reliable monitoring of the localization, dynamics, and function of immune responses, which are vital in assessing not only the efficacy but also the safety of treatments to design immunotherapies optimally. This review aims to provide an overview of the current research on NIR imaging of the immune response. We expect that the use of NIR imaging will expand further in response to the recent success in cancer immunotherapy. We will also offer our insights on how this technology will meet rapidly growing expectations in the future.

Metformin and cancer immunity

The immune system plays an essential and central role in tumor cell differentiation, proliferation, angiogenesis, apoptosis, invasion, and metastasis. Over the past decade, cancer therapy has rapidly evolved from traditional approaches, such as surgery, chemotherapy, and radiotherapy, to revolutionary new treatment options with immunotherapy. This new era of cancer treatment options has now been clinically tested and applied to many forms of human malignancies, often with quite dramatic results. As we develop more effective combinations of cancer treatment, several agents have been recently investigated, putatively identified as anticancer agents, or immunostimulatory molecules. One such agent is metformin, originally developed as a fairly standard first-line therapy for patients with type-2 diabetes mellitus (T2DM). Given the underlying mechanisms of action, researchers began to examine the alternative functions and possible utility of metformin, finding that the cancer risk in patients with T2DM was reduced. It appears that metformin, at least in part, has an antitumor effect through activation of the 5' adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. Moreover, numerous studies have demonstrated that metformin interferes with key immunopathological mechanisms that are involved in the pathological processes or associated with malignant progression. Such insights may shed light on further analyzing whether metformin enhances the effectiveness of the immunotherapy and overcomes the immunotherapy resistance in the patients. Herein, we provide a comprehensive review of the literature examining the impact of metformin upon the host immune system and cancer immunity.

Granulocyte-macrophage colony-stimulating factor protects mice against hepatocellular carcinoma by ameliorating intestinal dysbiosis and attenuating inflammation

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. The gut microbiota can help maintain healthy metabolism and immunity. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a critical factor in promoting health and homeostasis; it promotes intestinal immunity, stimulates bone marrow precursors to generate macrophage colonies, and enhances the antibacterial and antitumor activity of circulating monocytes. As such, GM-CSF may protect against HCC development by regulating immunity as well as intestinal microecology.

AIM

To investigate the impact of GM-CSF on the gut microbiome and metabolic characteristics of HCC.

METHODS

Thirty-six male BALB/c nude mice were divided into three groups: Control (n = 10), HCC (n = 13), and HCC + GM-CSF (GM-CSF overexpression, n = 13). We utilized HCC cells to establish orthotopic transplantation tumor models of HCC with normal and over-expressing GM-CSF. Liver injury, immune inflammatory function and intestinal barrier function were evaluated. The fecal microbiome and metabolome were studied using 16S rRNA absolute quantification sequencing and gas chromatography-mass spectrometry.

RESULTS

GM-CSF overexpression significantly affected the gut microbiome of mice with HCC and resulted in a high abundance of organisms of the genera Roseburia, Blautia and Butyricimonass, along with a significant reduction in Prevotella, Parabacteroides, Anaerotruncus, Streptococcus, Clostridium, and Mucispirillum. Likewise, GM-CSF overexpression resulted in a substantial increase in fecal biotin and oleic acid levels, along with a prominent decrease in the fecal succinic acid, adenosine, fumaric acid, lipoic acid, and maleic acid levels. Correlation analysis revealed that the intestinal microbiota and fecal metabolites induced by GM-CSF were primarily involved in pathways related to reducing the inflammatory response, biotin metabolism, and intestinal barrier dysfunction.

CONCLUSION

GM-CSF can protect against HCC development by regulating immunity and modulating the abundance of specific intestinal microorganisms and their metabolites. This study provides new insights into the therapeutic approaches for HCC.

Blocking the Notch signal transduction pathway promotes tumor growth in osteosarcoma by affecting polarization of TAM to M2 phenotype

Background

Osteosarcoma is a primary malignant tumor that seriously affects the health and life of patients. It is of great clinical significance to explore the molecular mechanism of osteosarcoma development and develop the corresponding therapeutic targets. Th1/Th2 cytokines in the normal human body are in a state of dynamic balance. When this balance is destroyed, it is related to many diseases such as a tumor, autoimmune disease, microbial infection, transplant rejection, among many others.

Method

The model of mouse tumor-associated macrophage (TAM) was induced by being co-cultured with inducer granulocyte-macrophage colony stimulating factor (GM-CSF) and osteosarcoma S180 cells. The Notch1 knockout mice were obtained by gene targeting technology. The distribution of M1- and M2-type TAMs in the tumor was visualized by immunofluorescence staining. And the western-blot testing was used to detect and quantified the protein level of Notch1 and Th1/Th2-type cytokines.

Results

In this study, the polarization of TAMs to the M2 phenotype occurred after coculture with osteosarcoma S180 cells and secretion level Th1/Th2-type cytokines changed. Also, the expression level of Notch1 reduced significantly. Further, the critical transcription factor Notch1 of the Notch signaling pathway was knocked out in mice. The tumor volume of Notch1 knockout mice was significantly more extensive than of the control mice. The results of microstructural observation on tumor showed that M2-type TAMs infiltrated into tumor increased with increased expression of Th2-type cytokines, but M1-type TAMs reduced with reduced expression of Th1-type cytokines.

Conclusions

According to our results, the Notch signal transduction pathway participates in tumor occurrence and growth with a negative role by maintaining Th1/Th2 balance.

Construction of a lipid metabolism-related and immune-associated prognostic signature for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies. We aimed to identify a robust lipid metabolism-related signature associated with the HCC microenvironment to improve the prognostic prediction of HCC patients.

METHODS

We analyzed the gene expression profiles of lipid metabolism from Molecular Signatures Database and information of patients from The Cancer Genome Atlas. Gene set variation analysis (GSVA), gene set enrichment analysis (GSEA), and principal component analysis (PCA) were employed for functional annotation. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to verify the expression of model genes in HCC and adjacent tissues.

RESULTS

As a result, a lipid metabolism-related signature consisting of acyl-CoA synthetase long-chain family member 6 (ACSL6), lysophosphatidylcholine acyltransferase 1, phospholipase A2 group 1B, lecithin-cholesterol acyltransferase (LCAT), and sphingomyelin phosphodiesterase 4 (SMPD4) was identified among HCC patients. Lysophosphatidylcholine acyltransferase 1, PLA2G1B, and SMPD4 were proved significantly high expression while ACSL6 and LCAT were remarkably low expression in our 15 pairs of matched HCC and normal tissues by qRT-PCR. Under different conditions, the overall survival (OS) of patients in low-risk group was prolonged than that in high-risk group. Moreover, the as-constructed signature was an independent factor, which was remarkably associated with gender, histologic grade, and platelet level of HCC patients. In addition, the receiver operating characteristic (ROC) curve analysis confirmed the good potency of the model. Functional enrichment analysis further revealed that lower fatty acid (FA) oxidation and higher infiltration of immunocytes were detected in patients from the high-risk group compared with those in the low-risk group.

CONCLUSIONS

Our findings indicate that the lipid metabolism-related signature shows prognostic significance for HCC.

Modulating the Crosstalk between the Tumor and Its Microenvironment Using RNA Interference: A Treatment Strategy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with one of the highest mortality rates among solid cancers. It develops almost exclusively in the background of chronic liver inflammation, which can be caused by viral hepatitis, chronic alcohol consumption or an unhealthy diet. Chronic inflammation deregulates the innate and adaptive immune responses that contribute to the proliferation, survival and migration of tumor cells. The continuous communication between the tumor and its microenvironment components serves as the overriding force of the tumor against the body's defenses. The importance of this crosstalk between the tumor microenvironment and immune cells in the process of hepatocarcinogenesis has been shown, and therapeutic strategies modulating this communication have improved the outcomes of patients with liver cancer. To target this communication, an RNA interference (RNAi)-based approach can be used, an innovative and promising strategy that can disrupt the crosstalk at the transcriptomic level. Moreover, RNAi offers the advantage of specificity in comparison to the treatments currently used for HCC in clinics. In this review, we will provide the recent data pertaining to the modulation of a tumor and its microenvironment by using RNAi and its potential for therapeutic intervention in HCC.

Integrated analysis of single-cell RNA-seq and bulk RNA-seq unravels tumour heterogeneity plus M2-like tumour-associated macrophage infiltration and aggressiveness in TNBC

Triple-negative breast cancer (TNBC) is characterized by a more aggressive clinical course with extensive inter- and intra-tumour heterogeneity. Combination of single-cell and bulk tissue transcriptome profiling allows the characterization of tumour heterogeneity and identifies the association of the immune landscape with clinical outcomes. We identified inter- and intra-tumour heterogeneity at a single-cell resolution. Tumour cells shared a high correlation amongst stemness, angiogenesis, and EMT in TNBC. A subset of cells with concurrent high EMT, stemness and angiogenesis was identified at the single-cell level. Amongst tumour-infiltrating immune cells, M2-like tumour-associated macrophages (TAMs) made up the majority of macrophages and displayed immunosuppressive characteristics. CIBERSORT was applied to estimate the abundance of M2-like TAM in bulk tissue transcriptome file from The Cancer Genome Atlas (TCGA). M2-like TAMs were associated with unfavourable prognosis in TNBC patients. A TAM-related gene signature serves as a promising marker for predicting prognosis and response to immunotherapy. Two commonly used machine learning methods, random forest and SVM, were applied to find the genes that were mostly associated with M2-like TAM densities in the gene signature. A neural network-based deep learning framework based on the TAM-related gene signature exhibits high accuracy in predicting the immunotherapy response.

Predictor of outcome after living donor liver transplantation for patients with hepatocellular carcinoma beyond the Japan criteria

BACKGROUND

The Japan criteria (JC, maximum tumor size within 5 cm, within five tumor nodules, AFP within 500 ng/mL or within Milan criteria) have been applied to cadaveric liver transplantation (LT) for hepatocellular carcinoma (HCC) and will be used for living donor LT (LDLT) in Japan. The aim of this study was to verify the JC in LDLT and to clarify the risk factor of HCC recurrence and mortality after LDLT beyond the JC.

PATIENTS AND METHODS

Adult patients who underwent LDLT for end-stage liver disease with HCC until October 2019 were reviewed retrospectively (n = 246). Patients were divided into two groups according to whether they were within JC (n = 203) or beyond JC (n = 43). Recurrence-free or overall survival rates after LDLT were compared. Univariate and multivariate analyses were performed to identify risk factors of HCC recurrence and HCC-related mortality after LDLT for patients beyond the JC.

RESULTS

Patients beyond the JC had significantly poorer 5-year recurrence-free (50.3% vs 95.9%, P < .001) or overall (61.7% vs 98.1%, P < .001) survival rates compared with patients within the JC. A multivariate analysis revealed that des-gamma-carboxy prothrombin (DCP) ≥ 300 mAU/mL (hazard ratio 9.36, 95% CI; 2.41-36.4, P = .001) was an independent risk factor for HCC recurrence and HCC-related mortality (hazard ratio 13.8, 95% CI; 1.92-98.6, P = .01) after LDLT in patients beyond the JC.

CONCLUSION

The outcome of LDLT for patients within the JC was favorable. Patients beyond the JC with DCP ≥ 300 mAU/mL might be contraindicated for LDLT.

Prognostic role of immune cells in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), with rising incidence rates, is the most commonly occurring malignancy of the liver that exerts a heavy disease burden particularly in developing countries. A dynamic cross-talk between immune cells and malignant cells in tumor microenvironment governs the hepatocarcinogenesis. Monitoring immune contexture as prognostic markers is quite relevant and essential to evaluate clinical outcomes and to envisage response to therapy. In this review, we present an overview of the prognostic value of various tumor infiltrating immune cells and the continually evolving immune checkpoints as novel biomarkers during HCC. Tumor infiltration by immune cells such as T cells, NK cells and dendritic cells is linked with improved prognosis and favorable outcome, while the intra-tumoral presence of regulatory T cells (Tregs) or myeloid derived suppressor cells (MDSCs) on the other hand is associated with poor clinical outcome. In addition to these, the overexpression of negative regulatory molecules on tumor cells also provides inhibitory signals to T cells and is associated with poor prognosis. The limitation of a single marker can be overcome by advanced prognostication models and algorithms that evaluate multiple prognostic factors and ultimately aid the clinician in improving the disease free and overall survival of HCC patients.

Recent Advances: The Imbalance of Immune Cells and Cytokines in the Pathogenesis of Hepatocellular Carcinoma

Recent advancement in the immunological understanding of genesis of hepatocellular carcinoma (HCC) has implicated a decline in anti-tumour immunity on the background of chronic inflammatory state of liver parenchyma. The development of HCC involves a network of immunological activity in the tumour microenvironment involving continuous interaction between tumour and stromal cells. The reduction in anti-tumour immunity is secondary to changes in various immune cells and cytokines, and the tumour microenvironment plays a critical role in modulating the process of liver fibrosis, hepatocarcinogenesis, epithelial-mesenchymal transition (EMT), tumor invasion and metastasis. Thus, it is considered as one of primary factor behind the despicable tumour behavior and observed poor survival; along with increased risk of recurrence following treatment in HCC. The primary intent of the present review is to facilitate the understanding of the complex network of immunological interactions of various immune cells, cytokines and tumour cells associated with the development and progression of HCC.

Role of cellular, molecular and tumor microenvironment in hepatocellular carcinoma: Possible targets and future directions in the regorafenib era

Hepatocellular carcinoma (HCC) remains as one of the major causes of cancer-related mortality, despite the recent development of new therapeutic options. Regorafenib, an oral multikinase inhibitor, is the first systemic therapy that has a survival benefit for patients with advanced HCC that have a poor response to sorafenib. Even though regorafenib has been approved by the FDA, the clinical trial for regorafenib treatment does not show significant improvement in overall survival. The impaired efficacy of regorafenib caused by various resistance mechanisms, including epithelial-mesenchymal transitions, inflammation, angiogenesis, hypoxia, oxidative stress, fibrosis and autophagy, still needs to be resolved. In this review, we provide insight on regorafenib microenvironmental, molecular and cellular mechanisms and interactions in HCC treatment. The aim of this review is to help physicians select patients that would obtain the maximal benefits from regorafenib in HCC therapy.

Development of an immune-related prognostic index associated with hepatocellular carcinoma

Liver hepatocellular carcinoma (LIHC), an inflammation-associated cancer induced by a variety of etiological factors, is still one of the most prevalent and lethal cancers in human population. In this study, the expression profiles of immune-related genes (IRGs) were integrated with the overall survival (OS) of 378 LIHC patients based on the Cancer Genome Atlas (TCGA) dataset. Moreover, the differentially expressed and survival related IRGs among LIHC patients were predicted through the computational difference algorithm and COX regression analysis. As a result, 7 genes, including HSPA4, S100A10, FABP6, CACYBP, HDAC1, FCGR2B and SHC1, were retrieved to construct a predictive model associated with the overall survival (OS) of LIHC patients. Typically, the as-constructed model performed moderately in predicting prognosis, which was also correlated with tumor grade. Functional enrichment analysis revealed that the genes of high-risk group were actively involved in mRNA binding and the spliceosome pathway. Intriguingly, the prognostic index established based on IRGs reflected infiltration by multiple types of immunocytes. Our findings screen several IRGs with clinical significance, reveal the drivers of immune repertoire, and illustrate the importance of a personalized, IRG-based immune signature in LIHC recognition, surveillance, and prognosis prediction.

Tumour evolution in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common form of primary liver cancer, typically develops on the background of chronic liver disease and is an aggressive disease with dismal prognosis. Studies using next-generation sequencing of multiple regions of the same tumour nodule suggest different patterns of HCC evolution and confirm the high molecular heterogeneity in a subset of patients. Different hypotheses have been proposed to explain tumour evolution, including clonal selection or neutral and punctuated acquisition of genetic alterations. In parallel, data indicate a fundamental contribution of nonmalignant cells of the tumour microenvironment to cancer clonal evolution. Delineating these dynamics is crucial to improve the treatment of patients with HCC, and particularly to help understand how HCC evolution drives resistance to systemic therapies. A number of new minimally invasive techniques, such as liquid biopsies, could help track cancer evolution in HCC. These tools might improve our understanding of how systemic therapies affect tumour clonal composition and could facilitate implementation of real-time molecular monitoring of patients with HCC.

Extracellular vesicles from senescent hepatic stellate cells promote cell viability of hepatoma cells through increasing EGF secretion from differentiated THP-1 cells

Since the discovery of the senescence-associated secretory phenotype, the role of senescent hepatic stellate cells (HSCs) in hepatocellular carcinoma (HCC) development has gained increasing attention. Similar to cytokines, extracellular vesicles (EVs) are essential for intercellular communication. However, the function of EVs derived from senescent HSCs in HCC progression has not been extensively studied. The aims of the present study were to characterize the EVs derived from senescent HSCs and determine their role in the tumor microenvironment. Cellular senescence was induced in human hepatic stellate cells (HHSteCs) with various concentrations of etoposide. Induction was confirmed using EdU staining and 53BP1 and p21 immunostaining. EVs were isolated by ultracentrifugation and analyzed by nanoparticle tracking analysis. Multiplex immunoassays were used to compare the levels of growth factors secreted from hepatoma cell lines and macrophage cells pretreated with EVs derived from senescent HHSteCs (senescent EVs) with those pretreated with EVs derived from normal cultured HHSteCs (normal EVs). Treatment with 25 µM etoposide for 3 days was the most effective at inducing senescence in HHSteCs. This finding was confirmed by induction of irreversible cell-cycle arrest, upregulation of 53BP1 and p21 expression, and increased SA-β-gal staining. Senescent HHSteCs released increased quantities of EV particles compared with normally cultured HHSteCs. Multiplex analysis revealed that there was no difference between hepatoma cell lines treated with normal EVs and those treated with senescent EVs in growth factor secretion. In contrast, the secretion of epidermal growth factor (EGF) was increased by macrophage cells treated with senescent EVs compared with those treated with normal EVs. Furthermore, senescent EVs did not affect the viability of hepatoma cells but increased the viability of hepatoma cells co-cultured with macrophage cells. In conclusion, the release of EVs from senescent HSCs was higher compared with normal HSCs. Furthermore, senescent EVs promoted HCC development by upregulating EGF secretion from macrophages.

SIRT4 silencing in tumor-associated macrophages promotes HCC development via PPARδ signalling-mediated alternative activation of macrophages

Background

The activation of tumour-associated macrophages (TAMs) contributes to the progression of hepatocellular carcinoma (HCC). SIRT4 acts as a tumour suppressor of tumour growth by regulating cell metabolism, inflammation, and anti-tumourigenesis. However, the involvement of SIRT4 in the activation of TAMs is unknown. Based on previous findings, the expression of SIRT4 in distinct groups of TAMs as well as the effect of SIRT4 silencing on macrophage polarization was investigated.

Methods

The expression of SIRT4 in HCC tissues and peritumour tissues was tested by qRT-PCR, western blotting and histological analysis. A Kaplan-Meier survival curve was generated based on the expression of SIRT4 in the HCC samples. Next, immunofluorescence staining was used to evaluate distinct groups of TAMs in human HCC samples, and the expression of SIRT4 in M1 and M2 TAMs was examined by flow cytometry. A homograft mouse model was used to assess the effect of SIRT4 silencing in TAMs on the development of HCC cells.

Results

SIRT4 was significantly downregulated in HCC tumour tissues, and the expression of SIRT4 in peritumour tissues was positively associated with survival in patients. We further found that downregulation of SIRT4 was associated with increased macrophage infiltration and a high ratio of M2/M1 macrophages in HCC peritumour tissues. Using gene interference, we found that SIRT4 silencing in TAMs significantly modulated the alternative activation of macrophages and promoted in vitro and in vivo HCC cell growth. Mechanistically, we revealed that HCM restricted the expression of SIRT4 in macrophages and promoted alternative activation of macrophages via the FAO-PPARδ-STAT3 axis. Furthermore, we also revealed that elevated MCP-1 expression induced by SIRT4 downregulation was responsible for increased TAM infiltration in peritumour tissues.

Conclusions

Overall, our results demonstrate that downregulation of SIRT4 in TAMs modulates the alternative activation of macrophages and promotes HCC development via the FAO-PPARδ-STAT3 axis. These results could provide a new therapeutic target for the treatment of HCC.