Immune checkpoint inhibition: prospects for prevention and therapy of hepatocellular carcinoma

Pentapeptide cRGDfK-Surface Engineered Nanostructured Lipid Carriers as an Efficient Tool for Targeted Delivery of Tyrosine Kinase Inhibitor for Battling Hepatocellular Carcinoma

Background

Antitumor research aims to efficiently target hepatocarcinoma cells (HCC) for drug delivery. Nanostructured lipid carriers (NLCs) are promising for active tumour targeting. Cell-penetrating peptides are feasible ligands for targeted cancer treatment.

Methods

In this study, we optimized gefitinib-loaded NLCs (GF-NLC) for HCC treatment. The NLCs contained cholesterol, oleic acid, Pluronic F-68, and Phospholipon 90G. The NLC surface was functionalized to enhance targeting with the cRGDfK-pentapeptide, which binds to the αvβ3 integrin receptor overexpressed on hepatocarcinoma cells.

Results

GF-NLC formulation was thoroughly characterized for various parameters using differential scanning calorimetry and X-ray diffraction analysis. In-vitro and in-vivo studies on the HepG2 cell line showed cRGDfK@GF-NLC's superiority over GF-NLC and free gefitinib. cRGDfK@GF-NLC exhibited significantly higher cytotoxicity, growth inhibition, and cellular internalization. Biodistribution studies demonstrated enhanced tumour site accumulation without organ toxicity. The findings highlight cRGDfK@GF-NLC as a highly efficient carrier for targeted drug delivery, surpassing non-functionalized NLCs. These functionalized NLCs offer promising prospects for improving hepatocarcinoma therapy outcomes by specifically targeting HCC cells.

Conclusion

Based on these findings, cRGDfK@GF-NLC holds immense potential as a highly efficient carrier for targeted drug delivery of anticancer agents, surpassing the capabilities of non-functionalized NLCs. This research opens up new avenues for effective treatment strategies in hepatocarcinoma.

c(RGDfK) anchored surface manipulated liposome for tumor-targeted Tyrosine Kinase Inhibitor (TKI) delivery to potentiate liver anticancer activity

Current anticancer drug research includes tumor-targeted administration as a critical component because it is the best strategy to boost efficacy and decrease toxicity. Low drug concentration in cancer cells, nonspecific distribution, rapid clearance, multiple drug resistance, severe side effects, and other factors contribute to the disappointing results of traditional chemotherapy. As an innovative technique of treatments for hepatocellular carcinoma (HCC) in recent years, nanocarrier-mediated targeted drug delivery systems can overcome the aforesaid limitations via enhanced permeability and retention effect (EPR) and active targeting. Epidermal growth factor receptor (EGFR) inhibitor Gefitinib (Gefi) has dramatic effects on hepatocellular carcinoma. Herein, we developed and assessed an α_vβ₃ integrin receptor targeted c(RGDfk) surface modified liposomes for better targeting selectivity and therapeutic efficacy of Gefi on HCC cells. The conventional and modified Gefi loaded liposomes, i.e., denoted as Gefi-L and Gefi-c(RGDfK)-L, respectively, were prepared through the ethanol injection method and optimized via Box Behnken design (BBD). The FTIR and ¹H-NMR spectroscopy verified that the c(RGDfK) pentapeptides had formed an amide bond with the liposome surface. In addition, the particle size, Polydispersity index, zeta potential, encapsulation efficiency, and in-vitro Gefi release of the Gefi-L and Gefi-c(RGDfK)-L were measured and analyzed. As indicated by the MTT assay on HepG2 cells, Gefi-c(RGDfK)-L displayed considerably higher cytotoxicity than Gefi-L or Gefi alone. Throughout the incubation period, HepG2 cells took up significantly more Gefi-c(RGDfK)-L than Gefi-L. According to the in vivo biodistribution analysis, Gefi-c(RGDfK)-L accumulated more strongly at the tumor site than Gefi-L and free Gefi. Furthermore, HCC-bearing rats treated with Gefi-c(RGDfK)-L showed a substantial drop in liver marker enzymes (alanine transaminase, alkaline phosphatase, aspartate transaminase, and total bilirubin levels) compared to the disease control group. Gefi-c(RGDfK)-L suppresses tumour growth more effectively than Gefi-L and free Gefi, according to an in vivo analysis of their anticancer activities. Thus, c(RGDfk)-surface modified liposomes, i.e., Gefi-c(RGDfK)-L may serve as an efficient carrier for the targeted delivery of anticancer drugs.

Hepatocellular carcinoma (HCC) immunotherapy by anti-PD-1 monoclonal antibodies: A rapidly evolving strategy

Hepatocellular carcinoma (HCC) is one of the deadliest cancers in the world, with a high relapse rate. Delayed symptom onset observed in 70-80% of patients leads to diagnosis in advanced stages commonly associated with chronic liver disease. Programmed cell death protein 1 (PD-1) blockade therapy has recently emerged as a promising therapeutic option in the clinical management of several advanced malignancies, including HCC, due to the activation of exhausted tumor-infiltrating lymphocytes and improved outcomes of T-cell function. However, many people with HCC do not respond to PD-1 blockade therapy, and the diversity of immune-related adverse events (irAEs) restricts their clinical utility. Therefore, numerous effective combinatory strategies, including combinations with anti-PD-1 antibodies and other therapeutic methods ranging from chemotherapy to targeted therapies, are evolving to improve therapeutic outcomes and evoke synergistic anti-tumor impressions in patients with advanced HCC. Unfortunately, combined therapy may have more side effects than single-agent treatment. Nonetheless, identifying appropriate predictive biomarkers can aid in managing potential immune-related adverse events by distinguishing patients who respond best to PD-1 inhibitors as single agents or in combination strategies. In the present review, we summarize the therapeutic potential of PD-1 blockade therapy for advanced HCC patients. Besides, a glimpse of the pivotal predictive biomarkers influencing a patient's response to anti-PD-1 antibodies will be provided.

Peripheral immune characteristics of hepatitis B virus-related hepatocellular carcinoma

Background

Liver cancer is the sixth most common cancer worldwide and the third leading cause of cancer-related death. As a chronic liver disease, many studies have shown that the immune response plays a key role in the progression of liver cancer. Chronic hepatitis B virus (HBV) infection is one of the high-risk factors for HCC, accounting for 50%–80% of HCC cases worldwide, and little is known about the immune status of HBV associated hepatocellular carcinoma (HBV-HCC), therefore, we aimed to explore the changes in peripheral immunity in patients with HBV-HCC.

Methods

In this study, patients with HBV-HCC (n=26), patients with hepatitis B-related cirrhosis (HBV-LC) (n=31) and healthy volunteers (n=49) were included. The lymphocytes and their subpopulation phenotypes in peripheral blood were characterized. In addition, we explored the effect of viral replication on peripheral immunity in patients with HCC and analyzed the circulating immunophenotypic characteristics at different stages of HCC with flow cytometry.

Results

Firstly, our results showed that the percentages of total αβ T cells in the peripheral blood of HBV-HCC patients was significantly decreased compared to healthy subjects. Secondly, we found that naïve CD4+ T cells in HBV-HCC patients were significantly reduced, terminally differentiated CD8+ T cells, homing memory CD8+ T cells and Th2 cells were increased in peripheral circulation in HBV-HCC patients. Moreover, in the peripheral blood of HBV-HCC patients, expression of TIGIT on CD4+ T cells and PD-1 on the surface of Vδ 1 T cells was increased. In addition, we found that sustained viral replication resulted in up-regulation of TIM3 expression on CD4+ T cells, and TIM3+ γδ T cells increased in peripheral circulation in patients with advanced HBV-HCC.

Conclusion

Our study showed that circulating lymphocytes in HBV-HCC patients exhibited features of immune exhaustion, especially in HCC patients with persistent viral replication and in patients with intermediate and advanced HBV-HCC, including decreased frequency of T cells and elevated expression of inhibitory receptors including TIGIT and TIM3 on CD4+ T cells and γδ T cells. Meanwhile, our research suggests that the combination of CD3+ T cell and CD8+HLADR+CD38+ T cell may be a potential diagnostic indicator for HBV-HCC. These findings could help us to better understand the immune characteristics of HBV-HCC and explore the immune mechanisms and immunotherapy strategies for HBV-HCC.

Vascular endothelial growth factor A is a potential prognostic biomarker and correlates with immune cell infiltration in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths among cancer patients. Vascular endothelial growth factor A (VEGFA) is involved in regulating biological processes, such as angiogenesis and vascular permeability, and is very closely related to the pathogenesis of various tumours, especially vascular-rich, solid tumours. Clinical data of patients with HCC and other tumours were analysed through public databases, such as the TCGA database, Gene Expression Omnibus database, Human Protein Atlas database, STRING, Tumour Immune Estimation Resource and Kaplan-Meier Plotter. The tumour tissues and adjacent normal tissues of patients with HCC from Hunan Provincial People's Hospital were collected to verify the expression of VEGFA by immunohistochemistry, immunofluorescence, Western blotting and qPCR. VEGFA expression is elevated in multiple tumour types and correlates with the prognosis of tumour patients. VEGFA is involved in regulating the tumour microenvironment and immune cell function in tumour development. Inhibition of VEGFA reduces proliferation, invasion, and migration and promotes apoptosis in HCC cells. VEGFA is a potential predictive biomarker for the diagnosis and prognosis of HCC.

The mononuclear phagocyte system in hepatocellular carcinoma

The mononuclear phagocyte system (MPS) consists of monocytes, dendritic cells and macrophages, which play vital roles in innate immune defense against cancer. Hepatocellular carcinoma (HCC) is a complex disease that is affected or initiated by many factors, including chronic hepatitis B virus infection, hepatitis C virus infection, metabolic disorders or alcohol consumption. Liver function, tumor stage and the performance status of patients affect HCC clinical outcomes. Studies have shown that targeted treatment of tumor microenvironment disorders may improve the efficacy of HCC treatments. Cytokines derived from the innate immune response can regulate T-cell differentiation, thereby shaping adaptive immunity, which is associated with the prognosis of HCC. Therefore, it is important to elucidate the function of the MPS in the progression of HCC. In this review, we outline the impact of HCC on the MPS. We illustrate how HCC reshapes MPS cell phenotype remodeling and the production of associated cytokines and characterize the function and impairment of the MPS in HCC.

Targeted Therapies for Hepatocellular Carcinoma Treatment: A New Era Ahead-A Systematic Review

Hepatocellular carcinoma (HCC) remains one of the most common malignancies and the third cause of cancer-related death worldwide, with surgery being the best prognostic tool. Among the well-known causative factors of HCC are chronic liver virus infections, chronic virus hepatitis B (HBV) and chronic hepatitis virus C (HCV), aflatoxins, tobacco consumption, and non-alcoholic liver disease (NAFLD). There is a need for the development of efficient molecular markers and alternative therapeutic targets of great significance. In this review, we describe the general characteristics of HCC and present a variety of targeted therapies that resulted in progress in HCC therapy.

Intravenous administration of viral vectors expressing prostate cancer antigens enhances the magnitude and functionality of CD8+ T cell responses

BACKGROUND

The use of immunotherapeutic vaccination in prostate cancer is a promising approach that likely requires the induction of functional, cytotoxic T cells . The experimental approach described here uses a well-studied adenovirus-poxvirus heterologous prime-boost regimen, in which the vectors encode a combination of prostate cancer antigens, with the booster dose delivered by either the intravenous or intramuscular (IM) route. This prime-boost regimen was investigated for antigen-specific CD8+ T cell induction.

METHODS

The coding sequences for four antigens expressed in prostate cancer, 5T4, PSA, PAP, and STEAP1, were inserted into replication-incompetent chimpanzee adenovirus Oxford 1 (ChAdOx1) and into replication-deficient modified vaccinia Ankara (MVA). In four strains of mice, ChAdOx1 prime was delivered intramuscularly, with an MVA boost delivered by either IM or intravenous routes. Immune responses were measured in splenocytes using ELISpot, multiparameter flow cytometry, and a targeted in vivo killing assay.

RESULTS

The prime-boost regimen was highly immunogenic, with intravenous administration of the boost resulting in a sixfold increase in the magnitude of antigen-specific T cells induced and increased in vivo killing relative to the intramuscular boosting route. Prostate-specific antigen (PSA)-specific responses were dominant in all mouse strains studied (C57BL/6, BALBc, CD-1 and HLA-A2 transgenic).

CONCLUSION

This quadrivalent immunotherapeutic approach using four antigens expressed in prostate cancer induced high magnitude, functional CD8+ T cells in murine models. The data suggest that comparing the intravenous versus intramuscular boosting routes is worthy of investigation in humans.

Advances in Immune Checkpoint Inhibitors for Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is usually diagnosed in an advanced stage and has become the second deadliest type of cancer worldwide. The systemic treatment of advanced HCC has been a challenge, and for decades was limited to treatment with tyrosine kinase inhibitors (TKIs) until the application of immune checkpoint inhibitors (ICIs) became available. Due to drug resistance and unsatisfactory therapeutic effects of monotherapy with TKIs or ICIs, multi-ICIs, or the combination of ICIs with antiangiogenic drugs has become a novel strategy to treat advanced HCC. Antiangiogenic drugs mostly include TKIs (sorafenib, lenvatinib, regorafenib, cabozantinib and so on) and anti-vascular endothelial growth factor (VEGF), such as bevacizumab. Common ICIs include anti-programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1), including nivolumab, pembrolizumab, durvalumab, and atezolizumab, and anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4), including tremelimumab and ipilimumab. Combination therapies involving antiangiogenic drugs and ICIs or two ICIs may have a synergistic action and have shown greater efficacy in advanced HCC. In this review, we present an overview of the current knowledge and recent clinical developments in ICI-based combination therapies for advanced HCC and we provide an outlook on future prospects.

Silybum marianum total extract, silymarin and silibinin abate hepatocarcinogenesis and hepatocellular carcinoma growth via modulation of the HGF/c-Met, Wnt/β-catenin, and PI3K/Akt/mTOR signaling pathways

Hepatocellular carcinoma (HCC) has been identified as one of the most deadly malignancies with limited therapeutic efficacy worldwide. However, understanding the molecular mechanisms of crosstalk between signaling pathways in HCC and predicting cancer cell responses to targeted therapeutic interventions remain to be challenge. Thus, in this study, we aimed to evaluate the anticancerous efficacy of Silybum marianum total extract (STE), silymarin (Sm), and silibinin (Sb) against experimentally-induced HCC in rats. In vitro investigations were also performed and the anticancer effects against HCC cell lines (HepG2 and Huh7) were confirmed. Wistar rats were given diethylnitrosamine (DEN)/2-acetylaminofluorene (AAF)/carbon tetrachloride (CCl4) and were orally treated with STE (200 mg/kg body weight (bw)), Sm (150 mg/kg bw), and Sb (5 mg/kg bw) every other day from the 1st or 16th week to the 25th week of DEN/AAF/CCl4 injection. Treatment with STE, Sm, and Sb inhibited the growth of cancerous lesions in DEN/AAF/CCl4-treated rats. This inhibition was associated with inhibition of Ki-67 expression and repression of HGF/cMet, Wnt/β-catenin, and PI3K/Akt/mTOR signaling pathways. STE, Sm, and Sb improved liver function biomarkers and tumor markers (AFP, CEA, and CA19.9) and increased total protein and albumin levels in serum. STE, Sm, and Sb treatment was also noted to reduce the hepatic production of lipid peroxides, increase hepatic glutathione content, and induce the activities of hepatic antioxidant enzymes in DEN/AAF/CCl4-treated rats. These results indicate that STE, Sm, and Sb exert anti-HCC effects through multiple pathways, including suppression of Ki-67 expression and HGF/cMet, Wnt/β-catenin, and PI3K/Akt/mTOR pathways and enhancement of antioxidant defense mechanisms.

In vitro evidence of oncofetal antigen and TLR-9 agonist co-delivery by alginate nanovaccine for liver cancer immunotherapy

Liver cancer is the most common malignant tumor and liver cancer immunotherapy has been one of the research hotspots. To induce antigen-specific antitumor immune responses against liver cancer, we developed...

Emerging Role of PD-1/PD-L1 Inhibitors in Chronic Liver Diseases

Programmed cell death protein 1 (PD-1)/PD-ligand (L)1, the immune checkpoint inhibitors have emerged as a promising strategy for the treatment of various diseases including chronic liver diseases (CLDs) such as hepatitis, liver injury and hepatocellular carcinoma (HCC). The role of PD-1/PD-L1 has been widely inspected in the treatment of viral hepatitis and HCC. PD-1 is known to play a crucial role in inhibiting immunological responses and stimulates self-tolerance by regulating the T-cell activity. Further, it promotes apoptosis of antigen-specific T-cells while preventing apoptosis of Treg cells. PD-L1 is a trans-membrane protein which is recognized as a co-inhibitory factor of immunological responses. Both, PD-1 and PD-L1 function together to downregulate the proliferation of PD-1 positive cells, suppress the expression of cytokines and stimulate apoptosis. Owing to the importance of PD-1/PD-L1 signaling, this review aims to summarize the potential of PD-1/PD-L1 inhibitors in CLDs along with toxicities associated with them. We have enlisted some of the important roles of PD-1/PD-L1 in CLDs, the clinically approved products and the pipelines of drugs under clinical evaluation.

The Role of Immune Checkpoint Blockade in the Hepatocellular Carcinoma: A Review of Clinical Trials

The prevalence of primary liver cancer is rapidly rising all around the world. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Unfortunately, the traditional treatment methods to cure HCC showed poor efficacy in patients who are not candidates for liver transplantation. Until recently, tyrosine kinase inhibitors (TKIs) were the front-line treatment for unresectable liver cancer. However, rapidly emerging new data has drastically changed the landscape of HCC treatment. The combination treatment of atezolizumab plus bevacizumab (immunotherapy plus anti-VEGF) was shown to provide superior outcomes and has become the new standard first-line treatment for unresectable or metastatic HCC. Currently, ongoing clinical trials with immune checkpoint blockade (ICB) have focused on assessing the benefit of antibodies against programmed cell death 1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte- associated antigen 4 (CTLA-4) as monotherapies or combination therapies in patients with HCC. In this review, we briefly discuss the mechanisms underlying various novel immune checkpoint blockade therapies and combination modalities along with recent/ongoing clinical trials which may generate innovative new treatment approaches with potential new FDA approvals for HCC treatment in the near future.

A Somatic Mutation-Derived LncRNA Signature of Genomic Instability Predicts Prognosis for Patients With Liver Cancer

Background: Genomic instability is considered as one of the hallmarks of hepatocellular carcinoma (HCC) and poses a significant challenge to the clinical treatment. The emerging evidence has revealed the roles of long non-coding RNAs (lncRNAs) in the maintenance of genomic instability. This study is aimed to develop a genomic instability-related lncRNA signature for determining HCC prognosis and the suitability of patients for immunotherapy. Methods: In this study, data related to transcriptome profiling, clinical features, and the somatic mutations of patients with HCC were downloaded from The Cancer Genomic Atlas (TCGA). Bioinformatics analysis was performed to identify and construct a somatic mutation-derived genomic instability-associated lncRNA signature (GILncSig). Single-sample gene set enrichment analysis (ssGSEA) was applied to estimate the levels of immune cell infiltration. A nomogram was constructed, and calibration was performed to assess the effectiveness of the model. Results: In the study, seven genomic instability-related lncRNAs were identified and used to define a prognostic signature. Patients with HCC were stratified into high- and low-risk groups with significant differences in the survival (median survival time = 1.489, 1.748 year; p = 0.006) based on the optimal cutoff value (risk score = 1.010) of the risk score in the training group. In addition, GILncSig was demonstrated to be an independent risk factor for the patients with HCC when compared to the clinical parameters (p < 0.001). According to the receiver operating characteristic (ROC) curve, nomogram, and calibration plot, the signature could predict the survival rate for the patients with HCC in the 1st, 3rd, and 5th years. Furthermore, ssGSEA revealed the potential of the signature in guiding decisions for administering clinical treatment. Conclusions: In this study, we developed a novel prognostic model based on the somatic mutation-derived lncRNAs and validated it using an internal dataset. The independence of the GILncSig was estimated using univariate and follow-up multivariate analyses. Immunologic analysis was used to evaluate the complex factors involved in the HCC progression.

A highly stable multifunctional aptamer for enhancing antitumor immunity against hepatocellular carcinoma by blocking dual immune checkpoints

T-lymphocytes play a potent role in cancer immunotherapy; while, limited tumor infiltrating lymphocytes (TILs) combined with severe immunosuppression always significantly hinder their antitumor immune responses, especially in solid tumors such as hepatocellular carcinoma (HCC). Here, we prepared a highly stable multifunctional aptamer for strengthening antitumor immunity against HCC solid tumors through a dual immune checkpoint blockade of CTLA-4 and PD-L1. The engineered multifunctional aptamer (termed P1/C4-bi-apt) can block both CTLA-4/B7 and PD-1/PD-L1 signaling pathways and thus enhance the antitumor immune responses. Furthermore, it can direct CTLA-4-positive T cells to infiltrate into tumors to further enhance the antitumor efficacy compared to a single blockage of CTLA-4 or PD-L1. As a result, the multifunctional aptamer can significantly inhibit tumor growth and thus improve the long-term survival of HCC-bearing mice. The designed multifunctional aptamer is simple, stable and easy to prepare, and it can significantly strengthen the functionality of T cells, holding great potential for HCC immunotherapy.

Construction of TME and Identification of crosstalk between malignant cells and macrophages by SPP1 in hepatocellular carcinoma

Liver cancer accounts for 6% of all malignancies causing death worldwide, and hepatocellular carcinoma (HCC) is the most common histological type. HCC is a heterogeneous cancer, but how the tumour microenvironment (TME) of HCC contributes to the progression of HCC remains unclear. In this study, we investigated the immune microenvironment by multiomics analysis. The tumour immune infiltration characteristics of HCC were determined at the genomic, epigenetic, bulk transcriptome and single-cell levels by data from The Cancer Genome Atlas portal and the Gene Expression Omnibus (GEO). An epigenetic immune-related scoring system (EIRS) was developed to stratify patients with poor prognosis. SPP1, one gene in the EIRS system, was identified as an immune-related predictor of poor survival in HCC patients. Through receptor-ligand pair analysis in single-cell RNA-seq, SPP1 was indicated to mediate the crosstalk between HCC cells and macrophages via SPP1-CD44 and SPP1-PTGER4 association. In vitro experiments further validate SPP1 can trigger the polarization of macrophages to M2-phenotype tumour-associated macrophages (TAMs).

Natural Bioactive Compounds as Adjuvant Therapy for Hepatitis C Infection

Background:

Hepatitis C virus infection is a significant global health burden, which causes acute or chronic hepatitis. Acute hepatitis C is generally asymptomatic and progresses to cure, while persistent infection can progress to chronic liver disease and extrahepatic manifestations. Standard treatment is expensive, poorly tolerated, and has variable sustained virologic responses amongst the different viral genotypes. New therapies involve direct acting antivirals; however, it is also very expensive and may not be accessible for all patients worldwide. In order to provide a complementary approach to the already existing therapies, natural bioactive compounds are investigated as to their several biologic activities, such as direct antiviral properties against hepatitis C, and effects on mitigating chronic progression of the disease, which include hepatoprotective, antioxidant, anticarcinogenic and anti-inflammatory activities; additionally, these compounds present advantages, as chemical diversity, low cost of production and milder or inexistent side effects.

Objective:

To present a broad perspective on hepatitis C infection, the chronic disease, and natural compounds with promising anti-HCV activity. Methods: This review consists of a systematic review study about the natural bioactive compounds as a potential therapy for hepatitis C infection.

Results:

The quest for natural products has yielded compounds with biologic activity, including viral replication inhibition in vitro, demonstrating antiviral activity against hepatitis C.

Conclusion:

One of the greatest advantages of using natural molecules from plant extracts is the low cost of production, not requiring chemical synthesis, which can lead to less expensive therapies available to low and middle-income countries.

Absence of association between pretransplant serum soluble programmed death protein-1 level and prognosis following living donor liver transplantation in patients with hepatocellular carcinoma

ABSTRACT

Programmed death protein 1 (PD-1) pathway is one of the most critical mechanisms in tumor biology of hepatocellular carcinoma (HCC). The study aimed to assess the prognostic influence of pretransplant serum soluble PD-1 (sPD-1) in patients undergoing liver transplantation for treatment of HCC.Data from 229 patients with HCC who underwent living donor liver transplantation between January 2010 and December 2015 were retrospectively evaluated. Stored serum samples were used to measure sPD-1 concentrations.Overall survival (OS) and disease-free survival (DFS) rates were 94.3% and 74.5% at 1 year; 78.2% and 59.2% at 3 years; and 75.4% and 55.5% at 5 years, respectively. Prognostic analysis using pretransplant serum sPD-1 with a cut-off of 93.6 μg/mL (median value of the study cohort) did not have significant prognostic influence on OS (P = .69) and DFS (P = .26). Prognostic analysis using sPD-1 with a cut-off of 300 μg/mL showed similar OS (P = .46) and marginally lower DFS (P = .070). Combination of Milan criteria and sPD-1 with a cutoff of 300 μg/mL showed similar outcomes of OS and DFS in patients within and beyond Milan criteria. Multivariate analysis revealed that only Milan criteria was an independent prognostic for OS and DFS, but pretransplant sPD1 with a cut-off of 300 μg/mL did not become a prognostic factor.The results of this study demonstrate that pretransplant serum sPD-1 did not show significant influences on post-transplant outcomes in patients with HCC. Further large-scale, multicenter studies are necessary to clarify the role of serum sPD-1 in liver transplantation recipients.

Managing viral hepatitis in cancer patients under immune checkpoint inhibitors: should we take the risk?

More patients with chronic hepatitis B and C infection are being exposed to immune checkpoint inhibitors (ICIs), but the safety and efficacy of ICIs in patients with chronic viral hepatitis are still poorly described. To explore this interaction, we identified eight studies of cancer patients with viral hepatitis treated with one or more ICIs, formally assessed tumor responses and safety by grading liver dysfunction. ICIs appear to be relatively safe in HBV/HCV-infected patients, and hepatitis related to viral reactivation is rare. In some patients, viral load regressed during ICI treatment, so immune checkpoints may play a role in viral clearance. HBV/HCV do not appear to be a contraindication to ICIs, although careful clinical and biochemical follow-up is recommended and, whenever necessary, antiviral therapy commenced.

Radiation-induced abscopal effect and its enhancement by programmed cell death 1 blockade in the hepatocellular carcinoma: A murine model study

BACKGROUND/AIMS

The abscopal effect, a rare phenomenon induced by radiation, can be reinforced by immunotherapy. Although radiation therapy and immunotherapy are increasingly being utilized for the treatment of hepatocellular carcinoma (HCC), whether immunotherapy could boost the abscopal effect remains unclear. In this study, we aimed to elucidate the immunological mechanisms underlying the abscopal effect induced by the combination of irradiation and immunotherapy in a murine HCC model.

METHODS

A syngeneic HCC mouse model was established by transplanting murine Hepa 1-6 HCC cells into both hind legs of immunocompetent C57BL/6 mice. The tumors on the right hind legs were irradiated, and abscopal effects were observed in the non-irradiated tumors on the left hind leg with or without the coadministration of anti-programmed cell death 1 (PD-1) antibodies. Flow cytometric analyses were performed to analyze the distributions of immune cells infiltrating both irradiated and non-irradiated tumors and the tumor-draining lymph nodes (TDLNs).

RESULTS

Administration of 16 Gy in two fractions more effectively inhibited the growth of both irradiated and nonirradiated tumors with higher tumor infiltration of cytotoxic T cells than 8 Gy did in a single fraction. The higher dose also increased activated dendritic cells in TDLNs, which had higher expression of the programmed cell death ligand 1. Coadministration of anti-PD-1 antibodies significantly enhanced the abscopal effect and increased infiltration of activated cytotoxic T cells in both irradiated and non-irradiated tumors.

CONCLUSION

Our findings show that adding anti-PD-1 therapy to radiation enhanced the abscopal effect in a syngeneic murine model of HCC.

Lymphocyte Landscape after Chronic Hepatitis C Virus (HCV) Cure: The New Normal

Chronic HCV (CHC) infection is the only chronic viral infection for which curative treatments have been discovered. These direct acting antiviral (DAA) agents target specific steps in the viral replication cycle with remarkable efficacy and result in sustained virologic response (SVR) or cure in high (>95%) proportions of patients. These treatments became available 6–7 years ago and it is estimated that their real impact on HCV related morbidity, including outcomes such as cirrhosis and hepatocellular carcinoma (HCC), will not be known for the next decade or so. The immune system of a chronically infected patient is severely dysregulated and questions remain regarding the immune system’s capacity in limiting liver pathology in a cured individual. Another important consequence of impaired immunity in patients cleared of HCV with DAA will be the inability to generate protective immunity against possible re-infection, necessitating retreatments or developing a prophylactic vaccine. Thus, the impact of viral clearance on restoring immune homeostasis is being investigated by many groups. Among the important questions that need to be answered are how much the immune system normalizes with cure, how long after viral clearance this recalibration occurs, what are the consequences of persisting immune defects for protection from re-infection in vulnerable populations, and does viral clearance reduce liver pathology and the risk of developing hepatocellular carcinoma in individuals cured with these agents. Here, we review the recent literature that describes the defects present in various lymphocyte populations in a CHC patient and their status after viral clearance using DAA treatments.

Expression of Inhibitory Receptors on T and NK Cells Defines Immunological Phenotypes of HCV Patients with Advanced Liver Fibrosis

Chronic HCV can result in advanced liver disease, including cirrhosis. Patients with advanced fibrosis experience poor clinical outcomes and increased risk for hepatocellular carcinoma (HCC). These outcomes are, in part, a consequence of immune dysfunction. Increased inhibitory receptor and Galectin-9 (GAL-9) expression is a possible mechanism promoting lymphocyte dysfunction. In this study, we measured the expression of inhibitory receptors and GAL-9 on T/NK cells of patients with chronic HCV with no to moderate fibrosis (F0-F2) and advanced fibrosis (F3-F4). To analyze their co-expression, we employed t-SNE analysis. Notably, we found that F3-F4 patients had higher frequencies of >3 inhibitory receptor co-expression on NK cells. Moreover, F3-F4 patients manifest a higher frequency of NK cells co-expressing TIGIT and TIM-3, and CD4/NK cells co-expressing LAG-3 and GAL-9. In conclusion, we identified phenotypes of immune dysregulation that could explain the increased susceptibility to infection and HCC in patients with chronic HCV with advanced fibrosis.

Immunologic Features of Patients With Advanced Hepatocellular Carcinoma Before and During Sorafenib or Anti-programmed Death-1/Programmed Death-L1 Treatment

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Today, a promising treatment strategy is focused on the enhancement of antitumor immune responses by immune checkpoint modification. However, as only 20% of patients with HCC are responders, identification of predictive factors is urgently required. Therefore, for the first time, the features of the intrahepatic and circulating immune system in patients with advanced-stage HCC, before and during the treatment, were analyzed.

METHODS

We collected fresh HCC biopsies, along with adjacent tumor-free liver tissues and peripheral blood samples, from 21 patients with advanced HCC. Furthermore, we performed an extensive immunomonitoring of patients with HCC treated with sorafenib or programmed death (PD)-1/PD-L1 pathway blockade using multiparametric flow cytometry.

RESULTS

We observed that regardless of the treatment, low baseline intratumoral CD4/CD8 T-cell ratio was associated with better overall survival (P = 0.0002). The baseline frequency of intratumoral PD-1 CD8 T cells was significantly lower in patients responding to sorafenib treatment than in the nonresponders (P = 0.0117), and the frequency of circulating PD-1 T cells increased with tumor progression (P = 0.0329). By contrast, responders to PD-1/PD-L1 pathway blockade showed a trend of high baseline frequency of intratumoral PD-1 CD8 T cells. Moreover, we observed a trend of LAG3 and TIM3 upregulation on circulating T cells in nonresponding patients to PD-1/PD-L1 pathway blockade.

DISCUSSION

Immunosuppressive state, characterized by an enhanced intratumoral CD4/CD8 T-cell ratio, was associated with poor prognosis. Additionally, our results suggest that the frequency of intratumoral PD-1 CD8 T cells may serve as a biomarker to identify which individuals will benefit from which treatment and support the use of combination strategies.

Overview of Current Progress in Immune Checkpoint Inhibitor Therapy for Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) remains to a common cause of tumor mortality worldwide and represents the most common type of lethal hepatic malignancy. The incidence of HCC is swiftly increasing in western countries and southeast Asia. Despite poor prognosis, traditional treatments for advanced HCC appear to be minimally effective or even useless since patients are usually diagnosed in the advanced stage of disease. In recent years, immune checkpoint blockade has shown promising results in multiple pre-clinical and clinical trials of different solid tumors, including advanced HCC. Novel drugs targeting immune checkpoints, such as nivolumab (anti-PD-1), durvalumab (anti-PD-L1), and tremelimumab (anti-CTLA-4) have been shown to be highly effective and relatively safe in monotherapy or in combination treatment of advanced liver cancer. Unlike other immunotherapies, this approach can rouse human anti-tumor immunity by relieving T-cell exhaustion and inhibiting the evasion of HCC by blocking co-inhibitory signaling transduction accurately. In this review, we will provide current knowledge of several major immune checkpoints and summarize recent data from clinical trials that applied immune checkpoint inhibitors alone or in combination. In addition, this review will discuss the limitations and future prospective of immune checkpoint-targeted therapy for advanced HCC.

Differential expression of Tim-3, PD-1, and CCR5 on peripheral T and B lymphocytes in hepatitis C virus-related hepatocellular carcinoma and their impact on treatment outcomes

BACKGROUND AND OBJECTIVE

Activation of the immune checkpoints and expression of chemokines and chemokine receptors have been reported to promote HCC progression. This study aimed to assess the differential expression of Tim-3, PD-1, and CCR5 on peripheral blood lymphocytes from patients with HCV-related HCC and correlate their expression with the treatment outcomes.

PATIENTS AND METHODS

The study incorporated 40 patients with chronic HCV-related HCC and 40 healthy controls. Patients were radiologically assessed for hepatic focal lesions and portal vein thrombosis. Response to HCC treatment and overall survival (OS) outcomes were determined. The expression of Tim-3, PD-1, and CCR5 among CD19⁺, CD4⁺, and CD8⁺ lymphocytes was assessed by flow cytometry.

RESULTS

Higher frequencies of CD4⁺ and CD8⁺ cells expressing each of Tim-3 and PD-1 and PD-1⁺CD19⁺ cells were observed in the HCV-related HCC patients in comparison with controls. The highest expression of Tim-3 and PD-1 was by the CD8⁺ cells. Strong relations were detected among PD-1⁺CD19⁺, PD-1⁺CD4⁺ and PD-1⁺CD8⁺ cells. Elevated levels of PD-1⁺ lymphocytes were significantly associated with poor treatment response and shorter OS.

CONCLUSION

Modulation of the expression of immune checkpoints as Tim-3 and PD-1, and of CCR5 on T cells is somehow related to HCC. CD8⁺ T cells expressing PD-1 were the most relevant to HCC prognosis (OS and treatment response) and could represent a promising target for immune therapy against HCC. Future studies need to focus on exploring PD-1⁺ B cells and Tim-3⁺CD4⁺ cells, which seem to play a significant role in the pathogenesis of HCC.

Direct-acting antiviral treatment downregulates immune checkpoint inhibitor expression in patients with chronic hepatitis C

Chronic hepatitis C (CHC) infection is associated with increased TIM-3, PD-1 immune checkpoint receptors expression that inhibits adaptive T cells and increases NK cell cytotoxicity against T helper cells, both resulting T cell exhaustion. Elimination of the virus with direct-acting antivirals (DAAs) may modify host immune response via altering these immune checkpoint receptors’ expression. We conducted a prospective study to analyze changes in TIM-3, PD-1 and their ligands galectin-9, PD-L1 expression by peripheral blood T cell subpopulations, NK cell subpopulations, and monocytes by multicolor flow cytometry in 14 CHC patients successfully treated with 12 weeks of dasabuvir, ombitasvir, and paritaprevir/ritonavir plus ribavirin. Blood samples were collected before, at the end of treatment, and 12 and 24 weeks later. Sustained virological response (SVR) was associated with increased percentage of peripheral blood CD3+ T and CD8+ cytotoxic T lymphocytes and decreased percentage of NKbright cells. After DAA treatment, decreased TIM-3 expression by CD4+ T cells, by NKbright, and by NKT cells was found. Expression of immune checkpoint molecules’ ligand PD-L1 by NK cells and by regulatory T cells and galectin-9 by NK cells and monocytes also decreased significantly at SVR. Our data suggest that DAA treatment not only inhibits viral replication but may alter host adaptive and innate immune responses. A decrease in immune checkpoint molecules and their ligands expression both on adaptive and on innate immune cells may contribute to the recovery of exhausted adaptive immune responses and to sustained virological response.

Implications of driver genes associated with a high tumor mutation burden identified using next-generation sequencing on immunotherapy in hepatocellular carcinoma

Immune checkpoint blockade (ICB) therapy is a treatment strategy for hepatocellular carcinoma (HCC); however, its clinical efficacy is limited to a select subset of patients. Next-generation sequencing has identified the value of tumor mutation burden (TMB) as a predictor for ICB efficacy in multiple types of tumor, including HCC. Specific driver gene mutations may be indicative of a high TMB (TMB-H) and analysis of such mutations may provide novel insights into the underlying mechanisms of TMB-H and potential therapeutic strategies. In the present study, a hybridization-capture method was used to target 1.45 Mb of the genomic sequence (coding sequence, 1 Mb), analyzing the somatic mutation landscape of 81 HCC tumor samples. Mutations in five genes were significantly associated with TMB-H, including mutations in tumor protein 53 (TP53), Catenin^®1 (CTNNB1), AT-rich interactive domain-containing protein 1A (ARID1A), myeloid/lymphoid or mixed-lineage leukemia (MLL) and nuclear receptor co-repressor 1 (NCOR1). Further analysis using The Cancer Genome Atlas Liver Hepatocellular Carcinoma database showed that TP53, CTNNB1 and MLL mutations were positively correlated with TMB-H. Meanwhile, mutations in ARID1A, TP53 and MLL were associated with poor overall survival of patients with HCC. Overall, TMB-H and associated driver gene mutations may have potential as predictive biomarkers of ICB therapy efficacy for treatment of patients with HCC.

Association of TIM-3 with BCLC Stage, Serum PD-L1 Detection, and Response to Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma

Considering the increasing importance of immune checkpoints in tumor immunity we investigated the clinical relevance of serum T-cell immunoglobulin and mucin domain-3 (TIM-3) in patients with hepatocellular carcinoma (HCC). Serum TIM-3 levels were measured and their association with HCC stage and the detection of serum programmed death ligand-1 (PD-L1) were assessed. In patients submitted to transarterial chemoembolization (TACE), pre- and 1-week post-treatment TIM-3 levels were also evaluated. We studied 53 HCC patients with BCLC stages: 0 (5.7%), A (34%), B (32.1%), C (22.6%), and D (5.7%). The patients with advanced HCC (BCLC C) had significantly higher TIM-3 levels than patients with BCLC A (p = 0.009) and BCLC B (p = 0.019). TIM-3 levels were not associated with HCC etiology (p = 0.183). PD-L1 detection (9/53 patients) correlated with TIM-3 levels (univariate analysis, p = 0.047). In 33 patients who underwent TACE, post-treatment TIM-3 levels (231 pg/mL, 132–452) were significantly higher than pre-TACE levels (176 pg/mL, 110–379), (p = 0.036). Complete responders had higher post-TACE TIM-3 levels (534 pg/mL, 370–677) than partial responders (222 pg/mL, 131–368), (p = 0.028). Collectively, TIM-3 may have a role in anti-tumor immunity following TACE, setting a basis for combining immunotherapy and chemoembolization.

Programmed Cell Death Protein-1 (PD-1)-Targeted Immunotherapy for Advanced Hepatocellular Carcinoma in Real World

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignant solid tumors. Its incidence is increasing worldwide due to the dissemination of hepatitis B infection, HCV infection and nonalcoholic steatohepatitis-related HCC. For patients with advanced HCC, the available treatments are extremely limited and the prognosis is very poor. Therefore, it is urgent to discover new innovative approaches. Programmed cell death protein-1-targeted immunotherapy has shown promising results in multicenter clinical trials.

AIM

To evaluate the effectiveness and safety of anti-PD-1 agent in patients with advanced primary hepatocellular carcinoma.

METHODS

A retrospective analysis of 55 patients with advanced primary hepatocellular carcinoma who had been administered anti-PD-1 agent. Tumor response was assessed according to the modified Response Evaluation Criteria in Solid Tumors and any adverse events were recorded.

RESULTS

The median overall survival (OS) was 15 months. The median progression-free survival (PFS) was 10 months. No patient had complete response (CR) and 12 (22%) participants achieved partial response (PR), resulting in an overall response rate (ORR) of 22%. Thirty-seven (67%) patients showed stable disease (SD) and 6 (11%) subjects had progressive disease (PD) at first radiological evaluation. The disease control rate (DCR) was 89%. The total side effect rate was 61.8% and most were relieved after treatment.

CONCLUSION

Programmed cell death protein-1-targeted immunotherapy is a safe and effective treatment for advanced primary hepatocellular carcinoma.

Timp3 deficiency affects the progression of DEN-related hepatocellular carcinoma during diet-induced obesity in mice

AIM

Obesity and low-grade inflammation are associated with an increased risk of hepatocellular carcinoma (HCC), a leading cause of cancer-related death worldwide. The tissue inhibitor of metalloproteinase (TIMP) 3, an endogenous inhibitor of protease activity that represents a key mediator of inflammation, is reduced in inflammatory metabolic disorders and cancer. In contrast, Timp3-deficient mice (Timp3^-/-) are highly resistant to developing HCC in response to a diethylnitrosamine (DEN); therefore, we aimed to elucidate the biological role of genetic loss of Timp3 in obesity-related hepatocarcinogenesis.

METHODS

Fourteen-day-old male wild-type (wt) and Timp3^-/- mice were injected with 25 mg/kg DEN or an equal volume of saline. After 4 weeks, mice were randomized into two dietary groups and fed either normal or high-fat diet and allowed to grow until 32 weeks of age. Liver histological features were analyzed, and differentially expressed genes in the liver were quantified.

RESULTS

In Timp3^-/- mice fed with the obesogenic diet, despite the increase in liver steatosis and inflammation, both the number of tumors and the total tumor size are significantly reduced 30 weeks post-DEN injection, compared to control mice. Moreover, Timp3 deletion in hepatocarcinogenesis during obesity is associated with a reduction in FoxM1 transcriptional activity through H19/miR-675/p53 pathway.

CONCLUSIONS

This study suggests that Timp3 ablation leads to cell cycle perturbation, at least in part by repressing FoxM1 transcriptional activity through H19/miR-675/p53 pathway.

Role of regulatory T cells and checkpoint inhibition in hepatocellular carcinoma

Immune checkpoint inhibition suggests promising progress for the treatment of advanced hepatocellular carcinoma (HCC). However, the underlying cellular mechanisms remain unclear because liver cancer cells apparently do not upregulate inhibitory checkpoint molecules. Here, we analysed whether regulatory T cells (Tregs) can alternatively trigger checkpoint inhibition pathways in HCC. Using flow cytometry we analysed expression of checkpoint molecules (PD-1, PD-L1, CTLA-4, GITR, Tim-3) on peripheral CD4⁺CD25⁺Foxp3⁺ Tregs and their secretion of inhibitory mediators (IL-10, IL-35, TGF-beta, galectin-9) in 116 individuals (50 patients with HCC, 41 non-tumour bearing liver disease controls, 25 healthy controls). Functional activity of Tregs on T effector cells (IFN-gamma production, cytotoxicity) was characterized in vitro using a lectin-dependent cellular cytotoxicity (LDCC) assay against checkpoint inhibitor-negative P815 target cells. Unlike liver patients without malignancy and healthy controls, the frequency of checkpoint inhibitor-positive Tregs inversely correlated to age of patients with HCC (PD-L1, p = 0.0080; CTLA-4, p = 0.0029) and corresponded to enhanced numbers of Tregs producing IL-10 and IL-35 (p < 0.05 each). Tregs inhibited IFN-gamma secretion and cytotoxicity of CD8⁺ T cells when added to LDCC against P815 cells. Treg-induced inhibition of IFN-gamma secretion could be partially blocked by neutralizing PD-1 and PD-L1 antibodies specifically in HCC patients. In HCC peripheral Tregs upregulate checkpoint inhibitors and contribute to systemic immune dysfunction and antitumoural activity by several inhibitory pathways, presumably facilitating tumour development at young age. Blocking PD-L1/PD-1 interactions in vitro selectively interfered with inhibitory Treg -T effector cell interactions in the patients with HCC and resulted in improved antitumoural activity also against checkpoint inhibitor-negative tumour cells.

Predictive Factors for Response to PD-1/PD-L1 Checkpoint Inhibition in the Field of Hepatocellular Carcinoma: Current Status and Challenges

Immunotherapies targeting immune checkpoints are fast-developing therapeutic approaches adopted for several tumor types that trigger unprecedented rates of durable clinical responses. Immune checkpoint programmed cell death protein 1 (PD-1), expressed primarily by T cells, and programmed cell death ligand 1 (PD-L1), expressed mainly by tumor cells, macrophages, and dendritic cells, are molecules that impede immune function, thereby allowing tumor cells to proliferate, grow and spread. PD-1/PD-L1 checkpoint inhibitors have emerged as a promising treatment strategy of hepatocellular carcinoma (HCC). However, only a minority of HCC patients benefit from this therapy. To find a niche for immune checkpoint inhibition in HCC patients, future strategies might require predictive factor-based patient selection, to identify patients who are likely to respond to the said therapy and combination strategies in order to enhance anti-tumor efficacy and clinical success. This review provides an overview of the most recent data pertaining to predictive factors for response to PD-1/PD-L1 checkpoint inhibition in the field of HCC.

Relaxin gene delivery mitigates liver metastasis and synergizes with check point therapy

Activated hepatic stellate cell (aHSC)-mediated liver fibrosis is essential to the development of liver metastasis. Here, we discover intra-hepatic scale-up of relaxin (RLN, an anti-fibrotic peptide) in response to fibrosis along with the upregulation of its primary receptor (RXFP1) on aHSCs. The elevated expression of RLN serves as a natural regulator to deactivate aHSCs and resolve liver fibrosis. Therefore, we hypothesize this endogenous liver fibrosis repair mechanism can be leveraged for liver metastasis treatment via enforced RLN expression. To validate the therapeutic potential, we utilize aminoethyl anisamide-conjugated lipid-calcium-phosphate nanoparticles to deliver plasmid DNA encoding RLN. The nanoparticles preferentially target metastatic tumor cells and aHSCs within the metastatic lesion and convert them as an in situ RLN depot. Expressed RLN reverses the stromal microenvironment, which makes it unfavorable for established liver metastasis to grow. In colorectal, pancreatic, and breast cancer liver metastasis models, we confirm the RLN gene therapy results in significant inhibition of metastatic progression and prolongs survival. In addition, enforced RLN expression reactivates intra-metastasis immune milieu. The combination of the RLN gene therapy with PD-L1 blockade immunotherapy further produces a synergistic anti-metastatic efficacy. Collectively, the targeted RLN gene therapy represents a highly efficient, safe, and versatile anti-metastatic modality, and is promising for clinical translation.

Optimizing radiotherapy with immune checkpoint blockade in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer, and its incidence is rapidly increasing in North America and Western Europe as well as South-East Asia. Patients with advanced stage HCC have very poor outcomes; therefore, the discovery of new innovative approaches is urgently needed. Cancer immunotherapy has become a game-changer and revolutionized cancer treatment. A comprehensive understanding of tumor-immune interactions led to the development of immune checkpoint inhibitors (ICIs) as new therapeutic tools, which have been used with great success. Targeting immune checkpoint molecules such as programmed cell death-1 (PD-1) and cytotoxic T lymphocyte-associated protein-4 (CTLA-4) reinvigorates anti-tumor immunity by restoring exhausted T cells. Despite their effectiveness in several types of cancer, of the many immune suppressive mechanisms limit the efficacy of ICI monotherapy. Radiation therapy (RT) is an essential local treatment modality for a broad range of malignancies, and it is currently gaining extensive attention as a promising combination partner with ICIs because of its ability to trigger immunogenic cell death. The efficacy of combination approaches using RT and ICIs has been well documented in numerous preclinical and clinical studies on various types of cancers but not HCC. The application of ICIs has now expanded to HCC, and RT is recognized as a promising modality in HCC. This review will highlight the current roles of PD-1 and CTLA-4 therapies and their combination with RT in the treatment of cancers, including HCC. In addition, this review will discuss the future perspectives of the combination of ICIs and RT in HCC treatment.

Anemoside B4 exerts anti-cancer effect by inducing apoptosis and autophagy through inhibiton of PI3K/Akt/mTOR pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide and novel therapeutic approaches are urgently required. Anemoside B4 (AB4) is a compound extracted from Pulsatilla chinensis (P. chinensis). Previous studies have indicated that P. chinensis extract P. chinensis saponins has anti-cancer activity. However, the pharmacological effect of AB4 in cancer is largely unknown. In this study, we investigated the anti-cancer efficacy of AB4 in HCC. We used CCK-8 assay and colony formation assay to evaluate the cytotoxicity of AB4 and found that this agent markedly inhibited SMMC7721 cell proliferation. By using a panel of morphological and molecular experiments, we reported that AB4 induced HCC SMMC7721 cell apoptosis and autophagy. Notably, AB4 treatment acts on the Bcl-2-caspase-3 pathway and Beclin-1-LC3-p62 pathway, thereby regulates both apoptosis and autophagy. Finally, we showed that AB4-induced apoptosis and autophagy converges at the PI3K/Akt/mTOR signaling. AB4 treatment inhibits this signaling transduction pathway and leads to HCC cell death. Collectively, our study highlighted the anti-cancer efficacy of AB4 and suggested that AB4 might be a novel way to treat HCC.

IL-25 protects against high-fat diet-induced hepatic steatosis in mice by inducing IL-25 and M2a macrophage production

Interleukin (IL)-25 is a cytokine that has previously been shown to have a protective role against nonalcoholic fatty liver disease (NAFLD), which is associated with the induction of M2 macrophage differentiation. However, the direct relationships between IL-25 expression regulation, M2 induction and NAFLD remain unknown. In this study, we demonstrate that IL-25 promotes hepatic macrophage differentiation into M2a macrophages both in vivo and in vitro via the IL-13/STAT6 pathway. M2 macrophages that were differentiated in vitro were able to ameliorate high-fat diet HFD-induced hepatic steatosis. Furthermore, we found that IL-25 treatment, both in vitro and in vivo, promotes direct binding of STAT6 to the IL-25 gene promoter region. This binding of STAT6 in response to IL-25 treatment also resulted in the increase of IL-25 expression in hepatocytes. Together, these findings identify IL-25 as a protective factor against HFD-induced hepatic steatosis by inducing an increase of IL-25 expression in hepatocytes and through promotion of M2a macrophage production.

Fecal microbiota transplantation: a promising strategy in preventing the progression of non-alcoholic steatohepatitis and improving the anti-cancer immune response

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) has the potential to progress to hepatocellular carcinoma (HCC). However, limited therapies are currently available for the treatment of advanced HCC, and one must strive to search for novel strategies.

AREAS COVERED

We provide insight on current knowledge related to gut microbiota and NAFLD, summarize the sequence linking obesity to HCC and highlight gut dysbiosis in obesity and its consequences on the liver. We detail the impact of the gut microbiota on immune checkpoint inhibitors, and speculate on the role of fecal microbiota transplantation (FMT) in NAFLD and in improving anti-neoplastic immune response.

EXPERT OPINION

Manipulation of the gut microbiota seems promising in the secondary prevention of NAFLD/NASH and/or in potentiating anti-cancer immune response, notably by a global 'resetting' using FMT. However, the composition of a 'harmful' gut microbiome in HCC still needs to be characterized, and the impact of FMT on HCC growth needs to be assessed.

IL-6 augments IL-4-induced polarization of primary human macrophages through synergy of STAT3, STAT6 and BATF transcription factors

Macrophages in the tumor microenvironment respond to complex cytokine signals. How these responses shape the phenotype of tumor-associated macrophages (TAMs) is incompletely understood. Here we explored how cytokines of the tumor milieu, interleukin (IL)-6 and IL-4, interact to influence target gene expression in primary human monocyte-derived macrophages (hMDMs). We show that dual stimulation with IL-4 and IL-6 synergistically modified gene expression. Among the synergistically induced genes are several targets with known pro-tumorigenic properties, such as CC-chemokine ligand 18 (CCL18), transforming growth factor alpha (TGFA) or CD274 (programmed cell death 1 ligand 1 (PD-L1)). We found that transcription factors of the signal transducer and activator of transcription (STAT) family, STAT3 and STAT6 bind regulatory regions of synergistically induced genes in close vicinity. STAT3 and STAT6 co-binding further induces the basic leucine zipper ATF-like transcription factor (BATF), which participates in synergistic induction of target gene expression. Functional analyses revealed increased MCF-7 and MDA-MB 231 tumor cell motility in response to conditioned media from co-treated hMDMs compared to cells incubated with media from single cytokine-treated hMDMs. Flow cytometric analysis of T cell populations upon co-culture with hMDMs polarized by different cytokines indicated that dual stimulation promoted immunosuppressive properties of hMDMs in a PD-L1-dependent manner. Analysis of clinical data revealed increased expression of BATF together with TAM markers in tumor stroma of breast cancer patients as compared to normal breast tissue stroma. Collectively, our findings suggest that IL-4 and IL-6 cooperate to alter the human macrophage transcriptome, endowing hMDMs with pro-tumorigenic properties.

Decreased CRHBP expression is predictive of poor prognosis in patients with hepatocellular carcinoma

Corticotropin releasing hormone binding protein (CRHBP) mediates the reaction between corticotropin releasing hormone (CRH) and corticotropin releasing hormone receptors (CRHRs). It is expressed in a number of organs, and the expression of CRHBP is associated with tumorigenesis and cancer progression. The aim of the present study was to investigate CRHBP expression levels in hepatocellular carcinoma (HCC) and its association with patient clinicopathological characteristics as well as prognosis. The expression of CRHBP was examined by immunohistochemistry in 169 HCC tissues and 151 adjacent non-tumorous tissues. The results were validated by western blotting using patient tissues and liver cancer cell lines. The association of CRHBP expression with clinicopathological patient characteristics and survival rate was analyzed statistically. Expression of CRHBP was detected in 142/151 (94.0%) non-tumorous liver tissues, and 84/169 (49.7%) HCC tissues (P<0.001). The expression of CRHBP was negatively associated with tumor size (P=0.013), Edmondson Grade (P=0.002), hepatitis B virus antigen (P=0.020), and α-fetoprotein levels (P=0.014). Patients exhibiting low CRHBP expression were associated with shorter survival time compared with those exhibiting high CRHBP expression (P=0.012). The results of western blotting analysis suggest that reduced CRHBP expression is frequently observable in patients with HCC. Low CRHBP expression in HCC tissues may be a predictor of clinical prognosis and a potential therapeutic target for HCC.

Hepatotoxicity of immune checkpoint inhibitors: An evolving picture of risk associated with a vital class of immunotherapy agents

Immune checkpoint inhibitors (ICIs) block CTLA-4, PD-1 and PD-L1, or other molecules that control antitumour activities of lymphocytes. These products are associated with a broad array of immune-related toxicities affecting a variety of organs, including the liver. ICI-associated immune-mediated hepatitis (IMH) ranges in severity between mild and life-threatening and is marked by findings that bear both similarities as well as differences with idiopathic autoimmune hepatitis. Hepatotoxic events are often detected in clinical trials of ICIs that are powered for efficacy. Risk levels for ICI-induced liver injury may be impacted by the specific checkpoint molecule targeted for treatment, the ICI dose levels, and the presence of a pre-existing autoimmune diathesis, chronic infection or tumour cells which infiltrate the liver parenchyma. When patients develop liver injury during ICI treatment, a prompt assessment of the cause of injury, in conjunction with the application of measures to optimally manage the adverse event, should be made. Strategies to manage the risk of IMH include the performance of pretreatment liver tests with regular monitoring during and after ICI treatment and patient education. Using Common Terminology Criteria for Adverse Events developed at the National Cancer Institute to measure the severity level of liver injury, recommended actions may include continued ICI treatment with close patient monitoring, ICI treatment suspension or discontinuation and/or administration of corticosteroids or, when necessary, a non-steroidal immunosuppressive agent. The elucidation of reliable predictors of tumour-specific ICI treatment responses, as well as an increased susceptibility for clinically serious immune-related adverse events, would help optimize treatment decisions for individual patients.

Emergence of immunotherapy as a novel way to treat hepatocellular carcinoma

Tumor immunity proceeds through multiple processes, which consist of antigen presentation by antigen presenting cells (APCs) to educate effector cells and destruction by the effector cytotoxic cells. However, tumor immunity is frequently repressed at tumor sites. Malignantly transformed cells rarely survive the attack by the immune system, but cells that do survive change their phenotypes to reduce their immunogenicity. The resultant cells evade the attack by the immune system and form clinically discernible tumors. Tumor microenvironments simultaneously contain a wide variety of immune suppressive molecules and cells to dampen tumor immunity. Moreover, the liver microenvironment exhibits immune tolerance to reduce aberrant immune responses to massively-exposed antigens via the portal vein, and immune dysfunction is frequently associated with liver cirrhosis, which is widespread in hepatocellular carcinoma (HCC) patients. Immune therapy aims to reduce tumor burden, but it is also expected to prevent non-cancerous liver lesions from progressing to HCC, because HCC develops or recurs from non-cancerous liver lesions with chronic inflammatory states and/or cirrhosis and these lesions cannot be cured and/or eradicated by local and/or systemic therapies. Nevertheless, cancer immune therapy should augment specific tumor immunity by using two distinct measures: enhancing the effector cell functions such as antigen presentation capacity of APCs and tumor cell killing capacity of cytotoxic cells, and reactivating the immune system in immune-suppressive tumor microenvironments. Here, we will summarize the current status and discuss the future perspective on immune therapy for HCC.