Immune Checkpoint Inhibitors in Hepatocellular Cancer: Current Understanding on Mechanisms of Resistance and Biomarkers of Response to Treatment

Understanding Gene Involvement in Hepatocellular Carcinoma: Implications for Gene Therapy and Personalized Medicine

Hepatocellular carcinoma (HCC) is the dominant type of liver cancers and is one of the deadliest health threats globally. The conventional therapeutic options for HCC are hampered by low efficiency and intolerable side effects. Gene therapy, however, now offers hope for the treatment of many disorders previously considered incurable, and gene therapy is beginning to address many of the shortcomings of conventional therapies. Herein, we summarize the involvement of genes in the pathogenesis and prognosis of HCC, with a special focus on dysregulated signaling pathways, genes involved in immune evasion, and non-coding RNAs as novel two-edged players, which collectively offer potential targets for the gene therapy of HCC. Herein, the opportunities and challenges of HCC gene therapy are discussed. These include innovative therapies such as genome editing and cell therapies. Moreover, advanced gene delivery technologies that recruit nanomedicines for use in gene therapy for HCC are highlighted. Finally, suggestions are offered for improved clinical translation and future directions in this area of endeavor.

Comparison of tumor response and outcomes of patients with hepatocellular carcinoma after multimodal treatment including immune checkpoint inhibitors - a systematic review and meta-analysis

BACKGROUND

The efficacy of immune checkpoint inhibitors (ICIs) combined with tyrosine kinase inhibitors (TKIs), trans-arterial chemoembolization (TACE), and radiotherapy to treat hepatocellular carcinoma (HCC) has not been well-defined. We performed a meta-analysis to characterize tumor response and survival associated with multimodal treatment of HCC.

METHODS

PubMed, Embase, Medline, Scopus, and CINAHL databases were searched (1990-2022). Random-effect meta-analysis was conducted to compare efficacy of treatment modalities. Odds ratios (OR) and standardized mean difference (SMD) were reported.

RESULTS

Thirty studies (4170 patients) met inclusion criteria. Triple therapy regimen (ICI + TKI + TACE) had the highest overall disease control rate (DCR) (87%, 95% CI 83-91), while ICI + radiotherapy had the highest objective response rate (ORR) (72%, 95% CI 54%-89%). Triple therapy had a higher DCR than ICI + TACE (OR 4.49, 95% CI 2.09-9.63), ICI + TKI (OR 3.08, 95% CI 1.63-5.82), and TKI + TACE (OR 2.90, 95% CI 1.61-5.20). Triple therapy demonstrated improved overall survival versus ICI + TKI (SMD 0.72, 95% CI 0.37-1.07) and TKI + TACE (SMD 1.13, 95% CI 0.70-1.48) (both p < 0.05). Triple therapy had a greater incidence of adverse events (AEs) compared with ICI + TKI (OR 0.59, 95% CI 0.29-0.91; p = 0.02), but no difference in AEs versus ICI + TACE or TKI + TACE (both p > 0.05).

CONCLUSION

The combination of ICIs, TKIs and TACE demonstrated superior tumor response and survival and should be considered for select patients with advanced HCC.

Mechanisms of drug resistance in HCC

HCC comprises ∼80% of primary liver cancer. HCC is the only major cancer for which death rates have not improved over the last 10 years. Most patients are diagnosed with advanced disease when surgical and locoregional treatments are not feasible or effective. Sorafenib, a multikinase inhibitor targeting cell growth and angiogenesis, was approved for advanced unresectable HCC in 2007. Since then, other multikinase inhibitors have been approved. Lenvatinib was found to be noninferior to sorafenib as a first-line agent. Regorafenib, cabozantinib, and ramucirumab were shown to prolong survival as second-line agents. Advances in immunotherapy for HCC have also added hope for patients, but their efficacy remains limited. A large proportion of patients with advanced HCC gain no long-term benefit from systemic therapy due to primary and acquired drug resistance, which, combined with its rising incidence, keeps HCC a highly fatal disease. This review summarizes mechanisms of primary and acquired resistance to therapy and includes methods for bypassing resistance. It addresses recent advancements in immunotherapy, provides new perspectives on the linkage between drug resistance and molecular etiology of HCC, and evaluates the role of the microbiome in drug resistance. It also discusses alterations in signaling pathways, dysregulation of apoptosis, modulations in the tumor microenvironment, involvement of cancer stem cells, changes in drug metabolism/transport, tumor hypoxia, DNA repair, and the role of microRNAs in drug resistance. Understanding the interplay among these factors will provide guidance on the development of new therapeutic strategies capable of improving patient outcomes.

Advances and considerations in the use of immunotherapies for primary hepato-biliary malignancies

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) comprise the two most common primary liver malignancies. Curative treatment options often include hepatectomy or liver transplantation; however, many patients present with advanced disease that is not amenable to surgical management. In turn, many patients are treated with systemic or targeted therapy. The tumor microenvironment (TME) is a complex network of immune cells and somatic cells, which can foster an environment for disease development and progression, as well as susceptibility and resistance to systemic therapeutic agents. In particular, the TME is comprised of both immune and non-immune cells. Immune cells such as T lymphocytes, natural killer (NK) cells, macrophages, and neutrophils reside in the TME and can affect tumorigenesis, disease progression, as well as response to therapy. Given the importance of the immune system, there are many emerging approaches for cancer immunotherapy. We herein provide a review the latest data on immunotherapy for primary HCC and BTC relative to the TME.

Analysis of Somatic Mutations in the TCGA-LIHC Whole Exome Sequence to Identify the Neoantigen for Immunotherapy in Hepatocellular Carcinoma

There are numerous clinically proven methods for treating cancer worldwide. Immunotherapy has been used to treat cancer with significant success in the current studies. The purpose of this work is to identify somatically altered target gene neoantigens and investigate liver cancer-related immune cell interaction and functional changes for potential immunotherapy in future clinical trials. Clinical patient data from the Cancer Genome Atlas (TCGA) database were used in this investigation. The R maf utility package was used to perform somatic analysis. The 17-mer peptide neoantigens were extracted using an in-house Python software called Peptide.py. Additionally, the epitope analysis was conducted using NetMHCpan4.1 program. Neopeptide immunogenicity was assessed using DeepCNN-Ineo, and tumor immune interaction, association with immune cells, correlation, and survival analysis were assessed using the TIMER web server. Based on somatic mutation analysis, we have identified the top 10 driver genes (TP53, TNN, CTNNB1, MUC16, ALB, PCLO, MUC4, ABCA13, APOB, and RYR2). From the superfamily of 20 HLA (Human leukocyte antigens) allele epitopes, we discovered 5653 neopeptides. Based on T cell receptor face hydrophobic analysis, these neopeptides were subjected to immunogenicity investigation. A mutation linked to tumor growth may have an impact on immune cells. According to this study's correlation and survival analysis, all driver genes may function as immune targets for liver cancer. These genes are recognized to be immune targets. In the future, immune checkpoint inhibitors may be developed to prolong patient survival times and prevent hepatocellular carcinoma (HCC) through immunotherapy.

A review of targeted therapy and immune checkpoint inhibitors for metastatic colorectal cancer

Surgical resection is the cornerstone of treatment for metastatic colorectal cancer (CRC) and offers the best chance at long-term survival. Unfortunately, most patients do not present with resectable metastatic disease and, among patients who do undergo curative-intent resection, many will develop recurrence. In turn, patients require a multi-disciplinary treatment approach with a combination of chemotherapy, surgery, radiation, and/or liver directed therapies that is guided by patient disease burden and clinical status. The development of targeted therapies has led to varying success in other cancers and has emerged as a treatment option for patients with metastatic CRC. While cytotoxic chemotherapy aims to kill cells as they replicate, targeted therapies are directed at biologic features of cancers, like angiogenesis or immune checkpoints. Targeted therapy can facilitate a more treatment tailored approach to the unique genomic alterations of the tumor and hopefully deliver more personalized therapy. We herein provide a systematic review of approved targeted therapies and immune checkpoint inhibitors for metastatic CRC and provide an overview of the current literature.

Concomitant Irradiation to Checkpoint Inhibitor Therapy of Hepatocellular Carcinoma Patients: A Systematic Retrospective, Single-Center Analysis

INTRODUCTION

Immunotherapy has been established as the standard treatment option for patients with advanced hepatocellular carcinoma (aHCC). Despite the increased efficacy, disease progression occurs in a relevant proportion of patients even after an objective response. Combination concepts with locoregional therapy are currently under investigation for hepatic disease but are also in discussion for the control of distant metastasis. Radiotherapy is a highly effective treatment modality for local tumor control. It is also thought to increase the efficacy of checkpoint inhibition and sensitize distant lesions to the effects of immunotherapy, but may potentially increase adverse effects. In our center, few patients with aHCC treated with immune checkpoint inhibitors (ICIs) received concomitant radiotherapy for symptom or disease control. The aim of this study was to retrospectively analyze adverse effects and efficacy of concomitant radiotherapy in patients with aHCC treated with checkpoint inhibition.

METHODS

To this aim, patients who received a combination of ICI and radiotherapy in our institution were retrospectively considered for analysis. The predefined inclusion criterion was radiotherapy after initiated checkpoint inhibition and continuation of ICI therapy for at least 8 weeks. Adverse effects and efficacy measurements were performed according to local standards.

RESULTS

The database search of 2016-2021 revealed six consecutive patients fulfilling the predefined criteria for concomitant ICI and radiotherapy. Three patients received high-dose-rate brachytherapy (15 Gy) to treat progredient hepatic lesions. Two patients received stereotactic body radiotherapy (SBRT) (25-30 Gy) for symptom control, and 1 patient received brachytherapy and SBRT to treat metastases. No severe adverse events were reported in the period (<6 months) after concomitant radiotherapy. In 5 out of 6 cases, long-term tumor control could be achieved by this therapeutic combination.

CONCLUSION

A good efficacy of concomitant radiotherapy and checkpoint inhibition has been achieved with no safety concerns. Further investigations should evaluate the safety, appropriate clinical context, and efficacy of this promising approach.

Immunotherapy for Advanced Hepatocellular Carcinoma-a Large Tertiary Center Experience

INTRODUCTION

Combination of immune-checkpoint inhibitor (ICI) and vascular endothelial growth factor (VEGF) antagonist has become the first line systemic treatment for advanced hepatocellular carcinoma (HCC). However, two-thirds of patients do not respond to ICI-based treatments and biomarkers for response remain elusive.

METHODS

Patients with advanced HCC who received Atezolizumab/Bevacizumab combination or Nivolumab during 2016-2022 were identified in our Liver Cancer Database. Retrospective review of their clinical data was performed to investigate parameters that could be predictive of immunotherapy response.

RESULTS

96 patients received Atezolizumab/Bevacizumab (n=60) or Nivolumab (n=36). Median age at diagnosis was 67.1 years. 70 patients had received treatment and 26 patients were treatment naïve before starting immunotherapy. Mean pre-treatment AFP was 9780.7 (±32035) ng/mL. Confirmed objective response (complete or partial) was seen in 29% of the population (n=27). Disease remained stable in 12% (n=11) and progressed in 60% (n=56). On univariate analysis, pre-treatment AFP>400 ng/mL was associated with objective response (OR=4.5, 95% CI:1.7-11.9, p=0.0015), while white race (OR=0.35, 95% CI:0.13-0.92, p=0.030) and prior radiotherapy (OR=0.14, 95% CI:0.01-1.1, p=0.033) or systemic therapy with TKIs (OR=0.25, 95% CI:0.08-0.81, p=0.017) were associated with poor response. On multivariate analysis only AFP>400 ng/mL remained associated with response (OR=3.7, 95% CI:1.3-10.5, p=0.014). Overall survival (OS) at one and three years was 86% and 43% in responders, and 45% and 29% in non-responders, respectively.

CONCLUSION

In our institutional experience, treatment naivety and pre-treatment AFP>400 ng/mL were associated with objective response. Prospective studies aimed at identifying factors associated with response to immunotherapy will aide patient selection.

SYVN1 ubiquitinates FoxO1 to induce β-catenin nuclear translocation, PD-L1-mediated metastasis, and immune evasion of hepatocellular carcinoma

BACKGROUND

A high incidence of hepatocellular carcinoma (HCC), the most frequently diagnosed form of liver cancer, is observed in Africa and Asia. SYVN1 is upregulated in HCC; however, the biological roles of SYVN1 in immune evasion remain unclear.

METHODS

RT-qPCR and western blot were employed to detect the expression levels of SYVN1 and the key molecules in HCC cells and tissues. Flow cytometry was used to determine the proportion of T cells, and an ELISA assay was used to determine the amount of IFN-γ secreted. Cell viability was monitored by CCK-8 and colony formation assays. The metastatic properties of HCC cells were detected by Transwell assays. Bioinformatics analysis, ChIP, and luciferase assays were used to study the transcriptional regulation of PD-L1. Co-IP was used to detect direct interaction between SYVN1 and FoxO1, as well as the ubiquitination of FoxO1. The in vitro findings were validated in xenograft and lung metastasis models.

RESULTS

In HCC cells and tissues, SYVN1 was upregulated while FoxO1 was downregulated. SYVN1 knockdown or FoxO1 overexpression reduced PD-L1 expression, and inhibited immune evasion, cell growth, and metastasis in HCC cells. Mechanistically, FoxO1 regulated PD-L1 transcription in a β-catenin-independent or -dependent manner. Functional studies further showed that SYVN1 promoted immune evasion, cell proliferation, migration and invasion via facilitating ubiquitin-proteasome-dependent degradation of FoxO1. In vivo investigations showed that silencing of SYVN1 inhibited immune evasion and metastasis of HCC cells, possible via the FoxO1/PD-L1 axis.

CONCLUSION

SYVN1 regulates FoxO1 ubiquitination to stimulate β-catenin nuclear translocation and promotes PD-L1-mediated metastasis and immune evasion in HCC.

Perspective on the Role of Gut Microbiome in the Treatment of Hepatocellular Carcinoma with Immune Checkpoint Inhibitors

Background and Objectives: Hepatocellular carcinoma (HCC) is the leading cause of liver cancer worldwide and has a high mortality rate. Its incidence has increased due to metabolic-associated liver disease (MAFLD) epidemics. Liver transplantation and surgery remain the most resolute measures. Despite the optimistic use of multi-kinase inhibitors, namely sorafenib, the co-existence of chronic liver disease made the response rate low in these patients. Immune checkpoint inhibitors (ICIs) have become a promising hope for certain advanced solid tumors and, also, for advanced HCC. Unfortunately, a large cohort of patients with HCC fail to respond to immunotherapy. Materials and Methods: We conducted a narrative search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials, and case series using the following keywords and acronyms and their associations: hepatocellular carcinoma, immunotherapy, checkpoint inhibitors, gut microbiota, and fecal microbiota transplantation. Results: ICIs are a promising and sufficiently safe treatment option for HCC. In detail, they have significantly improved survival and prognosis in these patients vs. sorafenib. Although there are several highlighted mechanisms of resistance, the gut microbiota signature can be used both as a response biomarker and as an effect enhancer. Practically, probiotic dose-finding and fecal microbiota transplantation are the weapons that can be used to increase ICI's treatment-response-reducing resistance mechanisms. Conclusion: Immunotherapy has been a significant step-up in HCC treatment, and gut microbiota modulation is an effective liaison to increase its efficacy.

Combined radiotherapy and immune checkpoint inhibition for the treatment of advanced hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is one of the most common cancers and a leading cause of cancer related death worldwide. Until recently, systemic therapy for advanced HCC, defined as Barcelona Clinic Liver Cancer (BCLC) stage B or C, was limited and ineffective in terms of long-term survival. However, over the past decade, immune check point inhibitors (ICI) combinations have emerged as a potential therapeutic option for patients with nonresectable disease. ICI modulate the tumor microenvironment to prevent progression of the tumor. Radiotherapy is a crucial tool in treating unresectable HCC and may enhance the efficacy of ICI by manipulating the tumor microenvironment and decreasing tumor resistance to certain therapies. We herein review developments in the field of ICI combined with radiotherapy for the treatment of HCC, as well as look at challenges associated with these treatment modalities, and review future directions of combination therapy.

Immune checkpoint inhibitors promising role in cancer therapy: clinical evidence and immune-related adverse events

The advent of immune checkpoint inhibitors (ICIs) has led to noteworthy progressions in the management of diverse cancer types, as evidenced by the pioneering "ipilimumab" medication authorized by US FDA in 2011. Importantly, ICIs agents have demonstrated encouraging potential in bringing about transformation across diverse forms of cancer by selectively targeting the immune checkpoint pathways that are exploited by cancerous cells for dodging the immune system, culminating in progressive and favorable health outcomes for patients. The primary mechanism of action (MOA) of ICIs involves blocking inhibitory immune checkpoints. There are three approved categories including Programmed Death (PD-1) inhibitors (cemiplimab, nivolumab, and pembrolizumab), Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) (Ipilimumab), and Programmed Death-Ligand 1 (PDL-1) (Avelumab). Although ICIs promisingly increase therapeutic response and cancer survival rates, using ICIs has demonstrated some limitations including autoimmune reactions and toxicities, requiring close monitoring. The present review endeavors to explicate the underlying principles of the MOA and pharmacokinetics of the approved ICIs in the realm of cancer induction, including an appraisal of their level of practice-based evidence.

Potential Effects of Regulating Intestinal Flora on Immunotherapy for Liver Cancer

The intestinal flora plays an important role in the occurrence and development of liver cancer, affecting the efficacy and side effects of conventional antitumor therapy. Recently, immunotherapy for liver cancer has been a palliative treatment for patients with advanced liver cancer lacking surgical indications. Representative drugs include immune checkpoint inhibitors, regulators, tumor vaccines, and cellular immunotherapies. The effects of immunotherapy on liver cancer vary because of the heterogeneity of the tumors. Intestinal flora can affect the efficacy and side effects of immunotherapy for liver cancer by regulating host immunity. Therefore, applying probiotics, prebiotics, antibiotics, and fecal transplantation to interfere with the intestinal flora is expected to become an important means of assisting immunotherapy for liver cancer. This article reviews publications that discuss the relationship between intestinal flora and immunotherapy for liver cancer and further clarifies the potential relationship between intestinal flora and immunotherapy for liver cancer.

Current Landscape of Immune Checkpoint Inhibitor Therapy for Hepatocellular Carcinoma

The liver maintains a balance between immune tolerance and activation in its role as a filtration system. Chronic inflammation disrupts this immune microenvironment, thereby allowing for the rise and progression of cancer. Hepatocellular carcinoma (HCC) is a liver tumor generally diagnosed in the setting of chronic liver disease. When diagnosed early, the primary treatment is surgical resection, liver transplantation, or liver directed therapies. Unfortunately, patients with HCC often present at an advanced stage or with poor liver function, thereby limiting options. To further complicate matters, most systemic therapies are relatively limited and ineffective among patients with advanced disease. Recently, the IMbrave150 trial demonstrated that the combination of atezolizumab and bevacizumab was associated with better survival compared to sorafenib among patients with advanced HCC. As such, atezolizumab and bevacizumab is now recommended first-line therapy for these patients. Tumor cells work to create an immunotolerant environment by preventing the activation of stimulatory immunoreceptors and upregulating expression of proteins that bind inhibitory immunoreceptors. ICIs work to block these interactions and bolster the anti-tumor function of the immune system. We herein provide an overview of the use of ICIs in the treatment of HCC.

Current and novel approaches in the pharmacological treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal malignant tumours worldwide. The mortality-to-incidence ratio is up to 91.6% in many countries, representing the third leading cause of cancer-related deaths. Systemic drugs, including the multikinase inhibitors sorafenib and lenvatinib, are first-line drugs used in HCC treatment. Unfortunately, these therapies are ineffective in most cases due to late diagnosis and the development of tumour resistance. Thus, novel pharmacological alternatives are urgently needed. For instance, immune checkpoint inhibitors have provided new approaches targeting cells of the immune system. Furthermore, monoclonal antibodies against programmed cell death-1 have shown benefits in HCC patients. In addition, drug combinations, including first-line treatment and immunotherapy, as well as drug repurposing, are promising novel therapeutic alternatives. Here, we review the current and novel pharmacological approaches to fight HCC. Preclinical studies, as well as approved and ongoing clinical trials for liver cancer treatment, are discussed. The pharmacological opportunities analysed here should lead to significant improvement in HCC therapy.

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.

Immunotherapeutic approaches in Hepatocellular carcinoma: Building blocks of hope in near future

Hepatocellular carcinoma (HCC) is the most common type of primary hepatic cancer and is among the major causes of mortality due to cancer. Due to the lack of efficient conventional therapeutic options for this cancer, particularly in advanced cases, novel treatments including immunotherapy have been considered. However, despite the encouraging clinical outcomes after implementing these innovative approaches, such as oncolytic viruses (OVs), adoptive cell therapies (ACT), immune checkpoint blockades (ICBs), and cancer vaccines, several factors have restricted their therapeutic effect. The main concern is the existence of an immunosuppressive tumor microenvironment (TME). Combination of different ICBs or ICBs plus tyrosine kinase inhibitors have shown promising results in overcoming these limiting factors to some extent. Combination of programmed cell death ligand-1 (PD-L1) antibody Atezolizumab and vascular endothelial growth factor (VEGF) antibody Bevacizumab has become the standard of care in the first-line therapy for untestable HCC, approved by regulatory agencies. This paper highlighted a wide overview of the direct and indirect immunotherapeutic strategies proposed for the treatment of HCC patients and the common challenges that have hindered their further clinical applications.

PEGylated Liposomes Loaded with Carbamate Inhibitor ANP0903 Trigger Apoptosis by Enhancing ER Stress in HepG2 Cancer Cells

Liver cancer is one of the most common causes of cancer death worldwide. In recent years, substantial progress has been made in the development of systemic therapies, but there is still the need for new drugs and technologies that can increase the survival and quality of life of patients. The present investigation reports the development of a liposomal formulation of a carbamate molecule, reported as ANP0903, previously tested as an inhibitor of HIV-1 protease and now evaluated for its ability to induce cytotoxicity in hepatocellular carcinoma cell lines. PEGylated liposomes were prepared and characterized. Small, oligolamellar vesicles were produced, as demonstrated by light scattering results and TEM images. The physical stability of the vesicles in biological fluids was demonstrated in vitro, alongside the stability during storage. An enhanced cellular uptake was verified in HepG2 cells treated with liposomal ANP0903, resulting in a greater cytotoxicity. Several biological assays were performed to elucidate the molecular mechanisms explaining the proapoptotic effect of ANP0903. Our results allow us to hypothesize that the cytotoxic action in tumor cells is probably due to the inhibition of the proteasome, resulting in an increase in the amount of ubiquitinated proteins within the cells, which in turn triggers activation of autophagy and apoptosis processes, resulting in cell death. The proposed liposomal formulation represents a promising approach to deliver a novel antitumor agent to cancer cells and enhance its activity.

Revamping the innate or innate-like immune cell-based therapy for hepatocellular carcinoma: new mechanistic insights and advanced opportunities

A cancerous tumour termed hepatocellular carcinoma (HCC) is characterized by inflammation and subsequently followed by end-stage liver disease and necrosis of the liver. The liver's continuous exposure to microorganisms and toxic molecules affects the immune response because normal tissue requires some immune tolerance to be safeguarded from damage. Several innate immune cells are involved in this process of immune system activation which includes dendritic cells, macrophages, and natural killer cells. The liver is an immunologic organ with vast quantities of innate and innate-like immune cells subjected to several antigens (bacteria, fungal or viral) through the gut-liver axis. Tumour-induced immune system engagement may be encouraged or suppressed through innate immunological systems, which are recognized promoters of liver disease development in pre-HCC conditions such as fibrosis or cirrhosis, ultimately resulting in HCC. Immune-based treatments containing several classes of drugs have transformed the treatment of several types of cancers in recent times. The effectiveness of such immunotherapies relies on intricate interactions between lymphocytes, tumour cells, and neighbouring cells. Even though immunotherapy therapy has already reported to possess potential effect to treat HCC, a clear understanding of the crosstalk between innate and adaptive immune cell pathways still need to be clearly understood for better exploitation of the same. The identification of predictive biomarkers, understanding the progression of the disease, and the invention of more efficient combinational treatments are the major challenges in HCC immunotherapy. The functions and therapeutic significance of innate immune cells, which have been widely implicated in HCC, in addition to the interplay between innate and adaptive immune responses during the pathogenesis, have been explored in the current review.

Potential Molecular Targeted Therapy for Unresectable Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancers, representing a serious worldwide health concern. The recurrence incidence of hepatocellular carcinoma (HCC) following surgery or ablation is as high as 70%. Thus, the clinical applicability of standard surgery and other locoregional therapy to improve the outcomes of advanced HCC is restricted and far from ideal. The registered trials did not identify a treatment that prolonged recurrence-free survival, the primary outcome of the majority of research. Several investigator-initiated trials have demonstrated that various treatments extend patients' recurrence-free or overall survival after curative therapies. In the past decade, targeted therapy has made significant strides in the treatment of advanced HCC. These targeted medicines produce antitumour effects via specific signals, such as anti-angiogenesis or advancement of the cell cycle. As a typical systemic treatment option, it significantly improves the prognosis of this fatal disease. In addition, the combination of targeted therapy with an immune checkpoint inhibitor is redefining the paradigm of advanced HCC treatment. In this review, we focused on the role of approved targeted medicines and potential therapeutic targets in unresectable HCC.

Immunotherapy for NAFLD and NAFLD-related hepatocellular carcinoma

The progression of non-alcoholic fatty liver disease (NAFLD), the most common liver disease, leads to non-alcoholic steatohepatitis and hepatocellular carcinoma. Despite the increasing incidence and prevalence of NAFLD, its therapeutic and preventive strategies to lower the disease burden is limited. In recent years, immunotherapy, including anti-programmed cell death 1/programmed cell death 1 ligand 1 treatment, has emerged as a potential approach to reach satisfactory modulation for the progression of NAFLD and treatment of NAFLD-related hepatocellular carcinoma. However, the effectiveness of immunotherapy against NAFLD and NAFLD-related hepatocellular carcinoma is in the early phase and it is yet not advanced. In addition, conflicting results are being reported regarding the prognosis of patients with NAFLD-related hepatocellular carcinoma and high expression of programmed cell death 1/programmed cell death 1 ligand 1. Herein, this review will discuss and elucidate the attempts and underlying mechanisms of immunotherapy against NAFLD and NAFLD-related hepatocellular carcinoma.

New Therapeutics for HCC: Does Tumor Immune Microenvironment Matter?

The incidence of liver cancer is continuously rising where hepatocellular carcinoma (HCC) remains the most common form of liver cancer accounting for approximately 80-90% of the cases. HCC is strongly prejudiced by the tumor microenvironment and being an inflammation-associated condition, the contribution of various immune mechanisms is critical in its development, progression, and metastasis. The tumor immune microenvironment is initially inflammatory which is subsequently replenished by the immunosuppressive cells contributing to tumor immune escape. Regardless of substantial advancement in systemic therapy, HCC has poor prognosis and outcomes attributed to the drug resistance, recurrence, and its metastatic behavior. Therefore, currently, new immunotherapeutic strategies are extensively targeted in preclinical and clinical settings in order to elicit robust HCC-specific immune responses and appear to be quite effective, extending current treatment alternatives. Understanding the complex interplay between the tumor and the immune cells and its microenvironment will provide new insights into designing novel immunotherapeutics to overcome existing treatment hurdles. In this review, we have provided a recent update on immunological mechanisms associated with HCC and discussed potential advancement in immunotherapies for HCC treatment.

Two Cases of Subsequent Hepatocellular Carcinoma in Immune Checkpoint Inhibitor-Responsive NSCLC: A Case Report

As novel therapeutic regimens continue to lead to increased survival of patients with lung cancer, it is imperative to remain mindful of the accompanying increase in the incidence of new primary malignancies. Although the most common secondary malignancies in patients with lung cancer have historically included colon, rectal, esophageal, and thyroid cancers, we report here two rare cases of new primary hepatocellular carcinomas in patients receiving immune checkpoint inhibitor therapy for NSCLC. In both cases, the diagnosis of hepatocellular carcinoma, rather than assuming a hepatic metastasis, was crucial for determining the appropriate approach for treatment. These cases thus underscore the importance of appropriate diagnostics to ensure that the proper therapeutics are chosen and present important considerations for the lung cancer community going forward.

Advances in Targeted Immunotherapy for Hepatobiliary Cancers

Cancer of the hepatobiliary system can be divided into primary liver cancer and biliary tract cancer (BTC), which includes hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), and gallbladder cancer (GBC). These aggressive cancers often present at an advanced stage or among patients with poorly preserved liver function. The primary treatment for HCC and BTC when diagnosed early is surgical resection, but given the high rate of recurrence and often advanced stage at diagnosis, many patients will require systemic therapy. Unfortunately, even with systemic therapy, long-term survival is poor. The immune system plays an important role in preventing cancer progression. The unique immune environment of the liver and subsequent alterations to the immune microenvironment by tumor cells to create a favorable microenvironment plays a key role in the progression of HCC and BTC. Due to the paucity of effective systemic therapies and distinctive immune environment of the liver, research and clinical trials are investigating the use of immunotherapy in HCC and BTC. This review will focus on current immunotherapies and emerging data for the treatment of HCC and BTC.

Artificial intelligence-based immunoprofiling serves as a potentially predictive biomarker of nivolumab treatment for advanced hepatocellular carcinoma

Immune checkpoint inhibitors (ICI) have been applied in treating advanced hepatocellular carcinoma (aHCC) patients, but few patients exhibit stable and lasting responses. Moreover, identifying aHCC patients suitable for ICI treatment is still challenged. This study aimed to evaluate whether dissecting peripheral immune cell subsets by Mann-Whitney U test and artificial intelligence (AI) algorithms could serve as predictive biomarkers of nivolumab treatment for aHCC. Disease control group carried significantly increased percentages of PD-L1+ monocytes, PD-L1+ CD8 T cells, PD-L1+ CD8 NKT cells, and decreased percentages of PD-L1+ CD8 NKT cells via Mann-Whitney U test. By recursive feature elimination method, five featured subsets (CD4 NKTreg, PD-1+ CD8 T cells, PD-1+ CD8 NKT cells, PD-L1+ CD8 T cells and PD-L1+ monocytes) were selected for AI training. The featured subsets were highly overlapping with ones identified via Mann-Whitney U test. Trained AI algorithms committed valuable AUC from 0.8417 to 0.875 to significantly separate disease control group from disease progression group, and SHAP value ranking also revealed PD-L1+ monocytes and PD-L1+ CD8 T cells exclusively and significantly contributed to this discrimination. In summary, the current study demonstrated that integrally analyzing immune cell profiling with AI algorithms could serve as predictive biomarkers of ICI treatment.

Highlighting novel targets in immunotherapy for liver cancer

INTRODUCTION

Alterations to the hepatic immune microenvironment can play a key role in the development and progression of cancer. This is especially true in the liver due to its evolutionarily conserved immunotolerant state. The presence of chronic inflammation can facilitate the development and progression of hepatocellular carcinoma (HCC) by disrupting the hepatic immune microenvironment. Recently, the addition of the immunotherapy atezolizumab (PD-L1 inhibitor) with bevacizumab (VEGF inhibitor) became the recommended first-line systemic treatment for advanced HCC.

AREAS COVERED

Given recent updates to the guidelines and emerging data on immunotherapy, we herein provide an overview of currently available and novel immunotherapy approaches for the treatment of HCC, including immune checkpoint inhibitors, adoptive cell therapy, and vaccine development. This review performed an extensive literature search to investigate benchwork, clinical research, and clinical trials that evaluate current immunotherapy and establish new targets. Literature was focused on the most up-to-date research and included ongoing clinical trials to better evaluate the obstacles and future direction of the field.

EXPERT OPINION

Given the heterogeneity of HCC tumors, improvement in outcomes will likely come from targeting multiple immune mechanisms. Continued research and clinical trials of combination immunotherapies are necessary to move the field forward.

Programmed death-ligand 1 (PD-L1) polymorphisms as predictive biomarkers for the development of liver cirrhosis and hepatocellular carcinoma in HCV Egyptian patients

BACKGROUND

Considering the immune evasion role of programmed death-ligand 1 (PD-L1) in cancer development, its genomic variations might be closely associated with disease development and cancer risks. Accordingly, this study was performed to investigate how the PD-L1 gene polymorphisms affect the susceptibility to hepatitis C virus (HCV)-induced liver cirrhosis and cancer development in the Egyptian population.

METHODOLOGY

Two single nucleotide polymorphisms of the PD-L1 gene; rs2297136 (A > G) and rs4143815 (C > G), were studied in 50 HCV, 51 liver cirrhosis, and 52 hepatocellular carcinoma (HCC) patients as well as 50 healthy subjects using real-time PCR.

RESULTS

The frequencies of PD-L1 rs2297136 AA and rs4143815 GG genotypes were significantly higher in the liver cirrhosis than the control and HCV groups. The rs4143815 CG and GG genotypes were linked to a higher risk of developing HCC and were positively associated with the clinicopathological features of HCC.

CONCLUSIONS

The PD-L1 rs2297136 AA and rs4143815 GG genotypes increase the susceptibility to liver cirrhosis. The rs4143815 CG and GG genotypes are positively associated with HCC risk and its clinicopathological characteristics. Therefore, HCV patients carrying the PD-L1 rs4143815 G-allele should be followed up on a regular basis to allow for early HCC management.

Biomarkers for response to immunotherapy in hepatobiliary malignancies

BACKGROUND

The advent of immune checkpoint inhibitors (ICIs) has revolutionized the therapeutic options of hepatobiliary malignancies. However, the clinical benefit provided by immunotherapy seems limited to a small subgroup of patients with hepatobiliary malignancies. The identification of reliable predictors of the response to immunotherapy is urgently needed.

DATA SOURCES

Literature search was conducted in PubMed for relevant articles published up to May 2022. Information of clinical trials was obtained from https://clinicaltrials.gov/.

RESULTS

Biomarkers for ICI response of hepatobiliary malignancies remain in the exploration stage and lack compelling evidence. Tumor programmed death-ligand 1 (PD-L1) expression is the most widely studied biomarker in hepatocellular carcinoma (HCC) and biliary tract cancers (BTCs), but there are conflicting results on its predictive potential. Tumor mutational burden (TMB) is generally low both in HCC and BTCs, and the clinical trials of TMB are rare in hepatobiliary malignancies. Promisingly, mismatch repair deficiency (dMMR)/high microsatellite instability (MSI-H) may be a predictive biomarker of response to anti-PD-1 therapy in BTCs. Furthermore, some emerging biomarkers, such as gut microbiota, show predictive potential in the preliminary studies. Radiomics and liquid-biopsy biomarkers, including circulating tumor cells, circulating tumor DNA (ctDNA) and exosomal PD-L1 provide a quick and non-invasive approach for monitoring the ICI response, showing a new promising direction.

CONCLUSIONS

Multiple potential biomarkers for predicting ICI response of hepatobiliary malignancies have been explored and tried to apply in clinic. Yet there is no robust evidence to prove their clinical value in predicting immunotherapeutic response for patients with hepatobiliary malignancies. The identification of predictors for response to ICIs is an urgent need and major challenge. Further studies are warranted to validate the role of emerging biomarkers in predicting immunotherapeutic responses.

A Comprehensive Evaluation of Prognostic Value and Immune Infiltration of KDM1 Family in Hepatocellular Carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies in the world. Previous studies indicated that the expression of the KDM1 genes (KDM1s), members of the amine oxidase superfamily, has prognostic value for breast and prostate cancer and malignant neuroblastoma. This study aimed to investigate the expression of KDM1s, their prognostic value, and their correlation with immune infiltration in patients with HCC.

METHODS

Multiomics analyses were utilized to analyze differential expression, prognostic value, genetic alteration, and immune cell infiltration of KDM1s in patients with HCC.

RESULTS

The high expression of KDM1A indicated poor overall survival (OS) and disease-free survival, whereas the high expression of KDM1B was significantly associated with poor OS. The genetic alterations and biological interaction network of KDM1s may provide detailed information for the dysregulated function of KDM1s in patients with HCC. KDM1-related signaling pathways and miRNA targets were explored and may provide value as therapeutic targets or tumor progression markers. The increased mRNA expression of KDM1s was significantly correlated with the infiltration of diverse immune cells in HCC.

CONCLUSIONS

This data-driven study indicates that KDM1s are promising prognostic biomarkers for survival and have the potential to become novel molecular targets in HCC treatments.

Response to PD-1 inhibitor after progression on PD-L1 inhibitor in advanced HCC

For hepatocellular carcinoma, the IMbrave150 trial demonstrated that combination atezolizumab and bevacizumab had significantly better overall survival compared with sorafenib in patients with unresectable disease. However, as more immune checkpoint inhibitors are approved as first-line agents in gastrointestinal cancers, there have been few reports on whether sequential PD-1/PD-L1 blockade is beneficial in the treatment of these diseases. We present a patient with hepatocellular carcinoma who had disease progression on atezolizumab, a PD-L1 inhibitor, but subsequently had a remarkable response to pembrolizumab, a PD-1 inhibitor.

Bias and inconsistency in the estimation of tumour mutation burden

BACKGROUND

Tumour mutation burden (TMB), defined as the number of somatic mutations per megabase within the sequenced region in the tumour sample, has been used as a biomarker for predicting response to immune therapy. Several studies have been conducted to assess the utility of TMB for various cancer types; however, methods to measure TMB have not been adequately evaluated. In this study, we identified two sources of bias in current methods to calculate TMB.

METHODS

We used simulated data to quantify the two sources of bias and their effect on TMB calculation, we down-sampled sequencing reads from exome sequencing datasets from TCGA to evaluate the consistency in TMB estimation across different sequencing depths. We analyzed data from ten cancer cohorts to investigate the relationship between inferred TMB and sequencing depth.

RESULTS

We found that TMB, estimated by counting the number of somatic mutations above a threshold frequency (typically 0.05), is not robust to sequencing depth. Furthermore, we show that, because only mutations with an observed frequency greater than the threshold are considered, the observed mutant allele frequency provides a biased estimate of the true frequency. This can result in substantial over-estimation of the TMB, when the cancer sample includes a large number of somatic mutations at low frequencies, and exacerbates the lack of robustness of TMB to variation in sequencing depth and tumour purity.

CONCLUSION

Our results demonstrate that care needs to be taken in the estimation of TMB to ensure that results are unbiased and consistent across studies and we suggest that accurate and robust estimation of TMB could be achieved using statistical models that estimate the full mutant allele frequency spectrum.

New 2-[(4-Amino-6-N-substituted-1,3,5-triazin-2-yl)methylthio]-N-(imidazolidin-2-ylidene)-4-chloro-5-methylbenzenesulfonamide Derivatives, Design, Synthesis and Anticancer Evaluation

In the search for new compounds with antitumor activity, new potential anticancer agents were designed as molecular hybrids containing the structures of a triazine ring and a sulfonamide fragment. Applying the synthesis in solution, a base of new sulfonamide derivatives 20–162 was obtained by the reaction of the corresponding esters 11–19 with appropriate biguanide hydrochlorides. The structures of the compounds were confirmed by spectroscopy (IR, NMR), mass spectrometry (HRMS or MALDI-TOF/TOF), elemental analysis (C,H,N) and X-ray crystallography. The cytotoxic activity of the obtained compounds toward three tumor cell lines, HCT-116, MCF-7 and HeLa, was examined. The results showed that some of the most active compounds belonged to the R¹ = 4-trifluoromethylbenzyl and R¹ = 3,5-bis(trifluoromethyl)benzyl series and exhibited IC₅₀ values ranging from 3.6 µM to 11.0 µM. The SAR relationships were described, indicating the key role of the R² = 4-phenylpiperazin-1-yl substituent for the cytotoxic activity against the HCT-116 and MCF-7 lines. The studies regarding the mechanism of action of the active compounds included the assessment of the inhibition of MDM2-p53 interactions, cell cycle analysis and apoptosis induction examination. The results indicated that the studied compounds did not inhibit MDM2-p53 interactions but induced G0/G1 and G2/M cell cycle arrest in a p53-independent manner. Furthermore, the active compounds induced apoptosis in cells harboring wild-type and mutant p53. The compound design was conducted step by step and assisted by QSAR models that correlated the activity of the compounds against the HCT-116 cell line with molecular descriptors.

Immune checkpoint inhibitors for solid organ transplant recipients: clinical updates

Transplant care continues to advance with increasing clinical experience and improvements in immunosuppressive therapy. As the population ages and long-term survival improves, transplant patient care has become more complex due to comorbidities, frailty, and the increased prevalence of cancer posttransplantation. Immune checkpoint inhibitors (ICIs) have become a standard treatment option for many cancers in non-transplant patients, but the use of ICIs in transplant patients is challenging due to the possibility of disrupting immune tolerance. However, over the past few years, ICIs have gradually started to be used in transplant patients as well. In this study, we review the current use of ICIs after all solid organ transplantation procedures (kidney, liver, heart, and lung). Increasing data suggest that the type and number of immunosuppressants may affect the risk of rejection after immunotherapy. Immunotherapy for cancer in transplant patients may be a feasible option for selected patients; however, prospective trials in specific organ transplant recipients are needed.

Encouraging specific biomarkers-based therapeutic strategies for hepatocellular carcinoma

The prevention, early discovery and effective treatment of patients with hepatocellular carcinoma (HCC) remain a global medical challenge. At present, HCC is still mainly treated by surgery, supplemented by vascular embolization, radio frequency, radiotherapy, chemotherapy and biotherapy. The application of multikinase inhibitor sorafenib, chimeric antigen receptor T cells, or PD-1/PD-L1 inhibitors can prolong the median survival of HCC patients. However, the treatment efficacy is still unsatisfactory due to HCC metastasis and postoperative recurrence. During the process of hepatocyte malignant transformation, HCC tissues can express and secrete many types of specific biomarkers, or oncogenic antigen molecules into blood, for example, alpha-fetoprotein, glypican-3, Wnt3a (one of the key signaling molecules in the Wnt/β-catenin pathway), insulin-like growth factor (IGF)-II or IGF-I receptor, vascular endothelial growth factor, secretory clusterin and so on. In addition, combining immunotherapy with non-coding RNAs might improve anti-cancer efficacy. These biomarkers not only contribute to HCC diagnosis or prognosis, but may also become molecular targets for HCC therapy under developing or clinical trials. This article reviews the progress in emerging biomarkers in basic research or clinical trials for HCC immunotherapy.

Cutting-Edge Platforms for Analysis of Immune Cells in the Hepatic Microenvironment-Focus on Tumor-Associated Macrophages in Hepatocellular Carcinoma

The role of tumor-associated macrophages (TAMs) in the pathogenesis of hepatocellular carcinoma (HCC) is poorly understood. Most studies rely on platforms that remove intrahepatic macrophages from the microenvironment prior to evaluation. Cell isolation causes activation and phenotypic changes that may not represent their actual biology and function in situ. State-of-the-art methods provides new strategies to study TAMs without losing the context of tissue architecture and spatial relationship with neighboring cells. These technologies, such as multispectral imaging (e.g., Vectra Polaris), mass cytometry by time-of-flight (e.g., Fluidigm CyTOF), cycling of fluorochromes (e.g., Akoya Biosciences CODEX/PhenoCycler-Fusion, Bruker Canopy, Lunaphore Comet, and CyCIF) and digital spatial profiling or transcriptomics (e.g., GeoMx or Visium, Vizgen Merscope) are being utilized to accurately assess the complex cellular network within the tissue microenvironment. In cancer research, these platforms enable characterization of immune cell phenotypes and expression of potential therapeutic targets, such as PDL-1 and CTLA-4. Newer spatial profiling platforms allow for detection of numerous protein targets, in combination with whole transcriptome analysis, in a single liver biopsy tissue section. Macrophages can also be specifically targeted and analyzed, enabling quantification of both protein and gene expression within specific cell phenotypes, including TAMs. This review describes the workflow of each platform, summarizes recent research using these approaches, and explains the advantages and limitations of each.

The predictive efficacy of tumor mutation burden in immunotherapy across multiple cancer types: A meta-analysis and bioinformatics analysis

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The FDA has approved pembrolizumab in all cancers with TMB > 10Mut/Mb based on the findings from the phase 2 KEYNOTE-158 study. However, predictive efficacy of TMB is greeted with many skepticisms.

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Cancer patients with high TMB have a better prognosis. Notably, there is no evidence shown whether the good prognosis is caused by the tumor itself or by immunotherapy.

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We compared the meta subgroup analysis by tumor types with non-ICIs from TCGA database and found that immunotherapy can increase, not reduce, cancer patients’ OS with high TMB.

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TMB is a promising therapeutic and prognostic biomarker for immunotherapy, which indicates a better ORR, DCB, OS and PFS.

Purpose

To explore the predictive efficacy of tumor mutation burden (TMB) as a potential biomarker for cancer patients treated with Immune checkpoint inhibitors (ICIs).

Methods

We systematically searched PubMed, Cochrane Library, Embase and Web of Science for clinical studies (published between Jan 1, 2014 and Aug 30, 2021) comparing immunotherapy patients with high TMB to patients with low TMB. Our main endpoints were objective response rate (ORR), durable clinical benefit (DCB), overall survival (OS) and progress-free Survival (PFS). Moreover, we downloaded simple nucleotide variation (SNV) data of 33 major cancer types from the TCGA database as non-ICIs group, and compared the high TMB patients’ OS between the non-ICIs group and meta-analysis results.

Results

Of 10,450 identified studies, 41 were eligible and were included in our analysis (7713 participants). Compared with low TMB patients receiving ICIs, high TMB yielded a better ORR (RR = 2.73; 95% CI: 2.31–3.22; P = 0.043) and DCB (RR = 1.93; 95% CI: 1.64–2.28; P = 0.356), and a significantly increased OS (HR =0.24; 95% CI: 0.21–0.28; P < 0.001) and PFS (HR = 0.38; 95% CI: 0.34–0.42; P < 0.001). Furthermore, compared with non-ICIs group from the TCGA database, immunotherapy can improve OS in some cancer types with high TMB and better prognosis, including colorectal cancer, gastric cancer, lung cancer, melanoma and pan-cancer.

Conclusion

TMB is a promising therapeutic and prognostic biomarker for immunotherapy, which indicates a better ORR, DCB, OS and PFS. If there is a standard for TMB assessment and cut-off, it could improve the management of different cancers.

The effects of immune checkpoint modulators on the clinical course of patients with resectable hepatocellular carcinoma

Background/Aim

Immune checkpoint proteins regulating T-cell mediated anti-tumor immunity have been reported to affect clinical outcomes in multiple malignancies. This study aimed to investigate the prognostic effect of histological expression of immune checkpoint proteins in patients with resected hepatocellular carcinoma (HCC).

Methods

A total of 221 patients with HCC who underwent curative resection were included. Expression of programmed-cell death ligand-1 (PD-L1) in tumor cells (tPD-L1) and tumor infiltrating mononuclear cells (TIMCs) (iPD-L1), programmed-cell death-1 in TIMCs (iPD-1), and cytotoxic T lymphocyte antigen-4 in TIMCs (iCTLA-4) were measured immunohistochemically.

Results

Histo-positivity for iCTLA-4, iPD-1, iPD-L1, and tPD-L1 was 32.1%, 42.5%, 35.3%, and 14.9%, respectively. Multivariate logistic analyses revealed that male sex and tumor >5 cm were variables related to iCTLA-4 positivity (odds ratio [OR], 0.46 and 1.94, respectively; P<0.05). Poor differentiation was related to PD-L1 expression in both tumor cells and TIMCs (OR, 2.88 and 3.46, respectively; P<0.05). Microvascular invasion was significantly associated only with iPD-L1 (OR, 2.24; P<0.05). In time-dependent outcome analyses, expression of immune checkpoint proteins in TIMCs (i.e., iCTLA-4, iPD-1, and iPD-L1) was significantly related to longer overall survival and non-cancer-related survival (all P<0.05), but not to time-to-recurrence or cancer-specific deaths. Concurrent activation of the PD-1:PD-L1 and CTLA-4 pathways predicted improved outcomes in terms of overall survival and non-cancer related survival (P=0.06 and P=0.03, respectively).

Conclusions

Immune checkpoint proteins upregulated in TIMCs in HCC tissues have individual and additive effects in prolonging the survival of patients, specifically in terms of survival not related to cancer recurrence.

The component with abundant immune-related cells in combined hepatocellular cholangiocarcinoma identified by cluster analysis

Combined hepatocellular cholangiocarcinoma (cHCC‐CCA) is a heterogeneous tumor sharing histological features with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). The tumor immune microenvironment (TIME) of cHCC‐CCA is unclear. We compared the TIME of cHCC‐CCA with that of HCC and iCCA. Twenty‐three patients with cHCC‐CCA after hepatectomy were evaluated in this study. Twenty‐three patients with iCCA and HCC were also included. iCCA was matched for size, and HCC was matched for size and hepatitis virus infection with cHCC‐CCA. Immune‐related cells among the iCCA‐component of cHCC‐CCA (C‐com), HCC‐component of cHCC‐CCA (H‐com), iCCA, and HCC were assessed using multiplex fluorescence immunohistochemistry. Among C‐com, H‐com, iCCA, and HCC, multiple comparisons and cluster analysis with k‐nearest neighbor algorithms were performed using immunological variables. Although HCC had more T lymphocytes and lower PD‐L1 expression than iCCA (P < 0.05), there were no significant differences in immunological variables between C‐com and H‐com. C‐com tended to have more T lymphocytes than iCCA (P = 0.09), and C‐com and H‐com had fewer macrophages than HCC (P < 0.05). In cluster analysis, all samples were classified into two clusters: one cluster had more immune‐related cells than the other, and 12 of 23 H‐com and eight of 23 C‐com were identified in this cluster. The TIME of C‐com and H‐com may be similar, and some immunological features in these components were different from those in HCC and some iCCA. Cluster analysis identified components with abundant immune‐related cells in cHCC‐iCCA.

Immunotherapies for hepatocellular carcinoma

Cases of hepatocellular carcinoma (HCC) are rapidly rising. This is particularly the case in the Western world, as a result of increasing rates of chronic liver disease, secondary to lifestyle-associated risk factors and the lack of an established screening programme for the general population. Traditionally, radical/curative treatment options for HCC, including liver transplantation and surgical resection are reserved for the minority of patients, presenting with an early stage cancer. For patients with advanced disease, Sorafenib and Lenvatinib were, until recently, the only licensed systemic treatments, and provided only limited survival benefits at the cost of a multitude of potential side effects. Recent scientific advances in the field of cancer immunotherapy have renewed significant interest in advanced HCC, in order to fulfil this apparent area of unmet clinical need. This has led to the success and recent regulatory approval of an Atezolizumab/Bevacizumab combination for the first-line treatment of advanced HCC following results from the IMbrave150 clinical trial in 2019, with further immune checkpoint inhibitors currently undergoing testing in advanced clinical trials. Furthermore, other cancer immunotherapies, including chimeric antigen receptor T-cells, dendritic cell vaccines and oncolytic viruses are also in early stage clinical trials, for the treatment of advanced HCC. This review will summarise the major approaches that have been and are currently in development for the systemic treatment of advanced HCC, their advantages, drawbacks, and predictions of where this revolutionary treatment field will continue to travel for the foreseeable future.

Targets of immunotherapy for hepatocellular carcinoma: An update

Hepatocellular carcinoma, the most common primary liver cancer, in an immunogenic tumor with a poor prognosis because these tumors are diagnosed at late stages. Although, surgical resection, ablation, liver transplant, and locoregional therapies are available for early stages; however, there are yet no effective treatment for advanced and recurrent tumors. Immune checkpoint inhibitor therapy and adoptive cell transfer therapy has gained the popularity with some positive results because these therapies overcome anergy and systemic immune suppression. However, still there is a lack of an effective treatment and thus there is an unmet need of a novel treatment. At present, the focus of the research is on oncolytic viral therapy and combination therapy where therapies including radiotherapy, immune checkpoint therapy, adoptive cell transfer therapy, and vaccines are combined to get an additive or synergistic effect enhancing the immune response of the liver with a cytotoxic effect on tumor cells. This review discusses the recent key development, the basis of drug resistance, immune evasion, immune tolerance, the available therapies based on stage of the tumor, and the ongoing clinical trials on immune checkpoint inhibitor therapy, adoptive cell transfer therapy, oncolytic viral vaccine therapy, and combination therapy.

Hepatocellular Carcinoma Cells Are Protected From Immunolysis by Mesenchymal Stromal Cells Through Indoleamine 2,3 Dioxygenase

B7 family proteins serve as checkpoint molecules that protect tumors from T cell mediated lysis. Tryptophan degrading enzymes indoleamine 2,3 dioxygenase (IDO) and tryptophan 2,3 dioxygenase (TDO) also induce T cell immune tolerance. However, little is known about the relative contribution of B7 molecules, tryptophan degrading enzymes, as well as the impact of tumor and stromal cell interactions to the development of immunosuppressive tumor microenvironment. To investigate such interactions, we used a tripartite model of human hepatocellular carcinoma cell line (HepG2) and mesenchymal stromal cells (MSCs) co-cultured with peripheral blood mononuclear cells (PBMCs). Co-culture of HepG2 cells and activated PBMCs demonstrate that HepG2 cells undergo PBMC mediated cytolysis, despite constitutive expression of B7-H3 and upregulation of PD-L1 by IFNγ. Knockdown of B7-H3, PD-L1 or IDO does not modulate PBMC mediated lysis of HepG2 cells. However, TNFα preactivation enhances lysis of HepG2 cells, and blocking of TNFα production from PBMCs protects HepG2 cells. On the other hand, MSCs protect HepG2 cells from PBMC mediated lysis, even in the presence of TNFα. Further investigation showed that MSC mediated protection is associated with the unique secretome profile of upregulated and downregulated cytokines and chemokines. IFNγ activated MSCs are superior to TNFα activated or control MSCs in protecting HepG2 cells. Blockade of IFNγ driven IDO activity completely abolishes the ability of MSCs to protect HepG2 cells from cytolysis by PBMCs. These results suggest that inhibition of IFNγ activation of IDO induction in stromal cells, combined with usage of TNFα, could be a novel immunotherapeutic strategy to induce regression of hepatocellular carcinoma.

Mechanisms of immune checkpoint inhibitor-mediated liver injury

The immune checkpoints, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death protein-1/ligand-1 (PD-1/PD-L1) are vital contributors to immune regulation and tolerance. Recently immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy; however, they come with the cost of immune related adverse events involving multiple organs such as the liver. Due to its constant exposure to foreign antigens, the liver has evolved a high capacity for immune tolerance, therefore, blockade of the immune checkpoints can result in aberrant immune activation affecting the liver in up to 20% of patients depending on the agent(s) used and underlying factors. This type of hepatotoxicity is termed immune mediated liver injury from checkpoint inhibitors (ILICI) and is more common when CTLA4 and PD-1/PD-L1 are used in combination. The underlying mechanisms of this unique type of hepatotoxicity are not fully understood; however, the contribution of CD8+ cytotoxic T lymphocytes, various CD4+ T cells populations, cytokines, and the secondary activation of the innate immune system leading to liver injury have all been suggested. This review summarizes our current understanding of the underlying mechanisms of liver injury in immunotherapy using animal models of ILICI and available patient data from clinical studies.

ERRFI1 induces apoptosis of hepatocellular carcinoma cells in response to tryptophan deficiency

Tryptophan metabolism is an essential regulator of tumor immune evasion. However, the effect of tryptophan metabolism on cancer cells remains largely unknown. Here, we find that tumor cells have distinct responses to tryptophan deficiency in terms of cell growth, no matter hepatocellular carcinoma (HCC) cells, lung cancer cells, or breast cancer cells. Further study shows that ERRFI1 is upregulated in sensitive HCC cells, but not in resistant HCC cells, in response to tryptophan deficiency, and ERRFI1 expression level positively correlates with HCC patient overall survival. ERRFI1 knockdown recovers tryptophan deficiency-suppressed cell growth of sensitive HCC cells. In contrast, ERRFI1 overexpression sensitizes resistant HCC cells to tryptophan deficiency. Moreover, ERRFI1 induces apoptosis by binding PDCD2 in HCC cells, PDCD2 knockdown decreases the ERRFI1-induced apoptosis in HCC cells. Thus, we conclude that ERRFI1-induced apoptosis increases the sensitivity of HCC cells to tryptophan deficiency and ERRFI1 interacts with PDCD2 to induce apoptosis in HCC cells.

Application of Immunotherapy in Hepatocellular Carcinoma

Hepatocellular carcinoma is one of the most common malignancies globally. It not only has a hidden onset but also progresses rapidly. Most HCC patients are already in the advanced stage of cancer when they are diagnosed, and have even lost the opportunity for surgical treatment. As an inflammation-related tumor, the immunosuppressive microenvironment of HCC can promote immune tolerance through a variety of mechanisms. Immunotherapy can activate tumor-specific immune responses, which brings a new hope for the treatment of HCC. At the present time, main immunotherapy strategies of HCC include immune checkpoint inhibitors, tumor vaccines, adoptive cell therapy, and so on. This article reviews the application and research progress of immune checkpoint inhibitors, tumor vaccines, and adoptive cell therapy in the treatment of HCC.

Immune Responses Following Locoregional Treatment for Hepatocellular Carcinoma: Possible Roles of Adjuvant Immunotherapy

Hepatocellular carcinoma (HCC) is a common cause of cancer-related deaths worldwide. Unlike other types of cancer, HCC can be treated with locoregional treatments (LRTs) such as radiofrequency ablation (RFA) or transarterial chemoembolization (TACE). However, recurrences following LRTs are common, and strategies to improve long-term outcomes need to be developed. The exhaustion of anti-tumor immunity in HCC has been well established in many reports and the immunomodulatory effects of LRTs (enhancement of tumor antigen-specific T cell responses after RFA, reduction of effector regulatory T cells after TACE) have also been reported in several previous studies. However, a comprehensive review of previous studies and the possible roles of immunotherapy following LRTs in HCC are not known. In this review, we discuss the immunological evidence of current clinical trials using LRTs and combined immunotherapies, and the possible role of this strategy.

Metabolic reprogramming of immune cells: Shaping the tumor microenvironment in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a typical inflammation‐induced cancer and displays a complex interaction between the tumor microenvironment and tumor development. Immune cells in the HCC microenvironment play both pro‐ and anti‐tumoral roles in HCC progression. An increasing number of findings indicate that metabolic reprogramming is essential for immune cell differentiation and function. In this review, we discuss the metabolic changes of different immune cells and correlate these findings to HCC progression.

Nuclear factor erythroid 2-related factor 2 and β-Catenin Coactivation in Hepatocellular Cancer: Biological and Therapeutic Implications

BACKGROUND AND AIMS

HCC remains a major unmet clinical need. Although activating catenin beta-1 (CTNNB1) mutations are observed in prominent subsets of HCC cases, these by themselves are insufficient for hepatocarcinogenesis. Coexpression of mutant CTNNB1 with clinically relevant co-occurrence has yielded HCCs. Here, we identify cooperation between β-catenin and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling in HCC.

APPROACH AND RESULTS

Public HCC data sets were assessed for concomitant presence of CTNNB1 mutations and either mutations in nuclear factor erythroid-2-related factor-2 (NFE2L2) or Kelch like-ECH-associated protein 1 (KEAP1), or Nrf2 activation by gene signature. HCC development in mice and similarity to human HCC subsets was assessed following coexpression of T41A-CTNNB1 with either wild-type (WT)-, G31A-, or T80K-NFE2L2. Based on mammalian target of rapamycin complex 1 activation in CTNNB1-mutated HCCs, response of preclinical HCC to mammalian target of rapamycin (mTOR) inhibitor was investigated. Overall, 9% of HCC cases showed concomitant CTNNB1 mutations and Nrf2 activation, subsets of which were attributable to mutations in NFE2L2/KEAP1. Coexpression of mutated CTNNB1 with mutant NFE2L2, but not WT-NFE2L2, led to HCC development and mortality by 12-14 weeks. These HCCs were positive for β-catenin targets, like glutamine synthetase and cyclin-D1, and Nrf2 targets, like NAD(P)H quinone dehydrogenase 1 and peroxiredoxin 1. RNA-sequencing and pathway analysis showed high concordance of preclinical HCC to human HCC subset showing activation of unique (iron homeostasis and glioblastoma multiforme signaling) and expected (glutamine metabolism) pathways. NFE2L2-CTNNB1 HCC mice were treated with mTOR inhibitor everolimus (5-mg/kg diet ad libitum), which led to >50% decrease in tumor burden.

CONCLUSIONS

Coactivation of β-catenin and Nrf2 is evident in 9% of all human HCCs. Coexpression of mutant NFE2L2 and mutant CTNNB1 led to clinically relevant HCC development in mice, which responded to mTOR inhibitors. Thus, this model has both biological and therapeutic implications.

Neoadjuvant Programmed Cell Death 1 (PD-1) Inhibitor Treatment in Patients With Hepatocellular Carcinoma Before Liver Transplant: A Cohort Study and Literature Review

Programmed cell death 1 (PD-1) blockade is considered contraindicated in liver transplant (LT) recipients due to potentially lethal consequences of graft rejection and loss. Though post-transplant PD-1 blockade had already been reported, pre-transplant use of PD-1 blockade has not been thoroughly investigated. This study explores the safety and efficacy of neoadjuvant PD-1 blockade in patients with hepatocellular carcinoma (HCC) after registration on the waiting list. Seven transplant recipients who underwent neoadjuvant PD-1 blockade combined with lenvatinib and subsequent LT were evaluated. The objective response rate (ORR) and disease control rate (DCR) was 71% and 85% according to the mRECIST criteria. Additionally, a literature review contained 29 patients were conducted to summarize the PD-1 blockade in LT for HCC. Twenty-two LT recipients used PD-1 inhibitors for recurrent HCC. 9.1% (2/22) and 4.5% (1/22) recipients achieved complete remission (CR) and partial remission (PR), respectively; 40.9% (9/22) recipients had progressive disease (PD). Allograft rejection occurred in 45% of patients. In total, seven patients from our center and three from the literature used pretransplant anti-PD-1 antibodies, eight patients (80%) had a PR, and the disease control rate was 100%. Biopsy-proven acute rejection (BPAR) incidence was 30% (3 in 10 patients), two patients died because of BPAR. This indicated that neoadjuvant PD-1-targeted immunotherapy plus tyrosine kinase inhibitors (TKI) exhibited promising efficacy with tolerable mortality in transplant recipients under close clinical monitoring.