Immunotherapy in hepatocellular carcinoma

Combined immunotherapy for hepatocellular carcinoma: How to maximize immune checkpoint blockade synergic anti-tumor effect

Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer and has an increasing incidence worldwide. The management of HCC still has many restrictions, despite the fact that there are now numerous treatment options, including liver transplantation/resection, locoregional treatments (LRT), and systemic medication. As a turning point in the history of cancer treatment, the discovery of the immune checkpoints and the development of their inhibitors provide new hope for HCC patients. However, limited objective response rate and insignificant overall survival improvement are still urgent problems to be solved for immune checkpoint inhibitors (ICIs). Combination therapies are considered a solution for improving the effectiveness and response rate of ICIs, and several forms of combination treatments are currently being actively researched. In this review, we summarize the mainstream combination strategies, explain their theoretical basis, introduce several important and ongoing clinical trials, and suggest some potential future paths in this area at the conclusion of the review. AVAILABILITY OF DATA AND MATERIALS: Not applicable.

Proceedings of the Online Conference "Vaccines and Vaccination during and Post COVID Pandemics" (7-9 December 2022)

The COVID-19 pandemic put focus on various aspects of vaccine research and development. These include mass vaccination strategies, vaccination compliance and hesitancy, acceptance of novel vaccine approaches, preclinical and animal models used to assess vaccine safety and efficacy, and many other related issues. These issues were addressed by the international online conference "Vaccines and Vaccination During and Post COVID Pandemics" (VAC&VAC 2022) held on the platform of Riga Stradins University, Riga, Latvia. Conference was supported by the International Society for Vaccines, the National Cancer Institute "Fondazione Pascale" (Naples, Italy), and the scientific journal VACCINES (mdpi). VAC&VAC 2022 attracted nearly 150 participants from 14 countries. This report summarizes conference presentations and their discussion. Sessions covered the topics of (1) COVID-19 vaccine development, evaluation, and attitude towards these vaccines, (2) HPV and cancer vaccines, (3) progress and challenges of HIV vaccine development, (4) new and re-emerging infectious threats, and (5) novel vaccine vehicles, adjuvants, and carriers. Each session was introduced by a plenary lecture from renowned experts from leading research institutions worldwide. The conference also included sessions on research funding and grant writing and an early career researcher contest in which the winners received monetary awards and a chance to publish their results free of charge in the special issue of VACCINES covering the meeting.

Adoptive Cell Therapy in Hepatocellular Carcinoma: A Review of Clinical Trials

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Immune checkpoint inhibitors (ICIs) have become the new reference standard in first-line HCC treatment, replacing tyrosine kinase inhibitors (TKIs) such as sorafenib. Many clinical trials with different combinations are already in development to validate novel immunotherapies for the treatment of patients with HCC. Adoptive cell therapy (ACT), also known as cellular immunotherapy, with chimeric antigen receptors (CAR) or gene-modified T cells expressing novel T cell receptors (TCR) may represent a promising alternative approach to modify the immune system to recognize tumor cells with better clinical outcomes. In this review, we briefly discuss the overview of ACT as a promising treatment modality in HCC, along with recent updates of ongoing clinical trials.

Changing epidemiology of hepatocellular carcinoma in South America: A report from the South American liver research network

INTRODUCTION AND OBJECTIVES

Most epidemiological data on hepatocellular carcinoma (HCC) originate from resource-rich countries. We have previously described the epidemiology of HCC in South America through the South American Liver Research Network. Here, we provide an update on the changing epidemiology of HCC in the continent seven years since that report.

MATERIALS AND METHODS

We evaluated all cases of HCC diagnosed between 2019 to 2021 in centers from six countries in South America. A templated, retrospective chart review of patient characteristics at the time of HCC diagnosis, including basic demographic, clinical and laboratory data, was completed. Diagnosis of HCC was made radiologically or histologically for all cases via institutional standards.

RESULTS

Centers contributed to a total of 339 HCC cases. Peru accounted for 37% (n=125) of patients; Brazil 16% (n=57); Chile 15% (n=51); Colombia 14% (n=48); Argentina 9% (n=29); and Ecuador 9% (n=29). The median age at HCC diagnosis was 67 years (IQR 59-73) and 61% were male. The most common risk factor was nonalcoholic fatty liver disease (NAFLD, 37%), followed by hepatitis C (17%), alcohol use disorder (11%) and hepatitis B (12%). The majority of HCCs occurred in the setting of cirrhosis (80%). HBV-related HCC occurred at a younger age compared to other causes, with a median age of 46 years (IQR 36-64).

CONCLUSIONS

We report dramatic changes in the epidemiology of HCC in South America over the last decade, with a substantial increase in NAFLD-related HCC. HBV-related HCC still occurs at a much younger age when compared to other causes.

Overcoming the resistance of hepatocellular carcinoma to PD-1/PD-L1 inhibitor and the resultant immunosuppression by CD38 siRNA-loaded extracellular vesicles

Extracellular vesicles (EVs) are promising tools for drug delivery across different biological barriers. Here, we evaluated the potential of EVs-mediated delivery of CD38 siRNA on the immunosuppression of hepatocellular carcinoma (HCC). EVs were isolated from bone marrow mesenchymal stem cell culture medium and loaded with CD38 siRNA to prepare EVs/siCD38. Loss-of-function assays were conducted to investigate the biological functions of EVs/siCD38 in HCC cells. Xenograft mouse models were performed for further validation. High CD38 expression was found in HCC. EVs/siCD38 inhibited CD38 enzyme activity, decreased adenosine production, and promoted macrophage repolarization to M1 type, thus inhibiting HCC cell growth and metastasis in vitro as well as tumor growth in mice. Mechanistically, CD38 was upregulated in mice resistant to PD-1/PD-L1 inhibitor and EVs/siCD38 reversed the resistance of tumor to PD-1/PD-L1 inhibitor in vivo. Our results provide functional evidence for the use of EV-mediated delivery of CD38 siRNA to prevent immunosuppression feature of HCC.

ATP13A2 is a Prognostic Biomarker and Correlates with Immune Infiltrates in Hepatocellular Carcinoma

PURPOSE

To explore the expression and role of ATPase cation transporting 13A2 (ATP13A2) on hepatocellular carcinoma (HCC) progression and prognosis.

METHODS

The level of ATP13A2 in 63 HCC tissues was evaluated by quantitative real-time polymerase chain reaction, Western blot, and immunohistochemistry. Then, the prognostic value of ATP13A2 for HCC was explored. GO and KEGG pathway enrichments were performed to predict ATP13A2-mediated biological functions. Besides, the correlations between ATP13A2 and key regulators involved in cell cycle and metastasis, the status of different tumor-infiltrating immune cells was investigated.

RESULTS

ATP13A2 was frequently upregulated in 63 HCC tissues relatively to matched non-tumor tissues. The level of ATP13A2 significantly correlated with tumor stage and tumor grade. HCC patients with higher levels of ATP13A2 had a worse prognosis. Moreover, multivariate survival analysis supported ATP13A2 to be an independent prognostic factor for HCC. GO and KEGG analysis indicated a potential role of ATP13A2 on regulating cell cycle, metastasis, and immune infiltrates. Especially, the level of ATP13A2 was positively correlated with CCNB1, CCND3, CDC25B, CDK4, Vimentin, MMP9, MMP14, and LMNB2. A positive correlation was noticed between ATP13A2 and infiltration levels of B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages, neutrophils, dendritic cells, monocytes, M2 macrophages, and exhausted T cells in HCC.

CONCLUSION

Upregulation of ATP13A2 is a common feature as well as an independent prognostic biomarker for HCC. ATP13A2 are associated with key regulators involved in cell cycle, metastasis, and immune infiltrates in HCC, and may act as a potential immunotherapy target for HCC.

Prognosis-Related Molecular Subtypes and Immune Features Associated with Hepatocellular Carcinoma

Bioinformatics tools were used to identify prognosis-related molecular subtypes and biomarkers of hepatocellular carcinoma (HCC). Differential expression analysis of four datasets identified 3330 overlapping differentially expressed genes (DEGs) in the same direction in all four datasets. Those genes were involved in the cell cycle, FOXO signaling pathway, as well as complement and coagulation cascades. Based on non-negative matrix decomposition, two molecular subtypes of HCC with different prognoses were identified, with subtype C2 showing better overall survival than subtype C1. Cox regression and Kaplan-Meier analysis showed that 217 of the overlapping DEGs were closely associated with HCC prognosis. The subset of those genes showing an area under the curve >0.80 was used to construct random survival forest and least absolute shrinkage and selection operator models, which identified seven feature genes (SORBS2, DHRS1, SLC16A2, RCL1, IGFALS, GNA14, and FANCI) that may be involved in HCC occurrence and prognosis. Based on the feature genes, risk score and recurrence models were constructed, while a univariate Cox model identified FANCI as a key gene involved mainly in the cell cycle, DNA replication, and mismatch repair. Further analysis showed that FANCI had two mutation sites and that its gene may undergo methylation. Single-sample gene set enrichment analysis showed that Th2 and T helper cells are significantly upregulated in HCC patients compared to controls. Our results identify FANCI as a potential prognostic biomarker for HCC.

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.

Neoantigens and their clinical applications in human gastrointestinal cancers

Background

Tumor-specific neoantigens are ideal targets for cancer immunotherapy. As research findings have proved, neoantigen-specific T cell activity is immunotherapy’s most important determinant.

Main text

There is sufficient evidence showing the role of neoantigens in clinically successful immunotherapy, providing a justification for targeting. Because of the significance of the pre-existing anti-tumor immune response for the immune checkpoint inhibitor, it is believed that personalized neoantigen-based therapy may be an imperative approach for cancer therapy. Thus, intensive attention is given to strategies targeting neoantigens for the significant impact with other immunotherapies, such as the immune checkpoint inhibitor. Today, several algorithms are designed and optimized based on Next-Generation Sequencing and public databases, including dbPepNeo, TANTIGEN 2.0, Cancer Antigenic Peptide Database, NEPdb, and CEDAR databases for predicting neoantigens in silico that stimulates the development of T cell therapies, cancer vaccine, and other ongoing immunotherapy approaches.

Conclusions

In this review, we deliberated the current developments in understanding and recognition of the immunogenicity of newly found gastrointestinal neoantigens as well as their functions in immunotherapies and cancer detection. We also described how neoantigens are being developed and how they might be used in the treatment of GI malignancies.

CircSOD2 Contributes to Tumor Progression, Immune Evasion and Anti-PD-1 Resistance in Hepatocellular Carcinoma by Targeting miR-497-5p/ANXA11 Axis

Circular RNAs (circRNAs) can function as functional molecules in hepatocellular carcinoma (HCC). Herein, circRNA superoxide dismutase 2 (circSOD2) was researched in HCC progression and immune system. The real-time polymerase chain reaction (qRT-PCR) was used for quantification of circSOD2, microRNA-497-5p (miR-497-5p) and Annexin A11 (ANXA11). Cell assays were performed by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) and colony formation assays for proliferation, flow cytometry for apoptosis and cell cycle, wound healing assay for migration and transwell assay for migration/invasion. ANXA11 and metastatic protein levels were measured by western blot. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to analyze target binding. CD8⁺ T cell immunity was assessed by Immunohistochemistry (IHC) assay, and the effect of circSOD2 on programmed cell death 1 (PD-1) immune checkpoint inhibitors (anti-PD-1) therapy was evaluated by mice xenograft assay. CircSOD2 was upregulated in HCC tissues and cells. Knockdown of circSOD2 resulted in HCC cell growth inhibition, apoptosis promotion, cell cycle arrest and metastasis suppression. Mechanically, circSOD2 promoted HCC development by acting as a miR-497-5p sponge and miR-497-5p played a tumor-inhibitory role in HCC cells by targeting ANXA11. Moreover, circSOD2 induced upregulation of ANXA11 expression by interacting with miR-497-5p. Also, the promoting effects of circSOD2 on immune evasion and anti-PD-1 resistance were related to miR-497-5p/ANXA11 axis. This study elucidated the pivotal function of circSOD2 in HCC progression and immunosuppression by mediating miR-497-6p/ANXA11 axis. CircSOD2/miR-497-5p/ANXA11 axis was a novel view of circRNA research in HCC.

A ferroptosis-associated lncRNAs signature predicts the prognosis of hepatocellular carcinoma

BACKGROUND

Long noncoding RNAs (lncRNAs) have been implicated in the development of hepatocellular carcinoma (HCC). Mounting evidence shows that lncRNAs can be used as prognostic biomarkers of HCC. Here, we developed a multi-lncRNA prognostic signature comprising ferroptosis-related lncRNAs in HCC.

METHODS

Gene expression data and clinical information of HCC were obtained from the TCGA dataset. Differentially expressed genes of ferroptosis (DE-Ferrs) were screened. Correlation analysis was carried between lncRNAs and DE-Ferrs to identify ferroptosis-related lncRNAs. lncRNAs associated with prognosis and ferroptosis were identified using Univariate Cox analysis. Data from a TCGA dataset were randomly grouped into training and verification sets. The least absolute shrinkage and selection operator method analysis was carried out to identify lncRNAs with prognostic value. These lncRNAs were used to construct a prognostic signature using the training set. The signature was validated in the verification set.

RESULTS

A total of 90 DE-Ferrs-related lncRNAs were identified which were significantly correlated with HCC prognosis. Seven lncRNAs were used to construct a 7-lncRNA signature. The area under the curves for 1-, 3-, and 5-year overall survival (OS) were 0.748, 0.681, and 0.659 in the training set, and 0.791, 0.731, and 0.815 in the validation set, respectively. The results demonstrated that a high-risk score was significantly associated with a high tumor grade, high infiltration of macrophages and fibroblasts in the tumor, and high expression of m6A methylation regulatory factors. A nomogram was constructed using the risk score and clinical features for predicting the prognosis of HCC. The nomogram showed high prediction accuracy.

CONCLUSION

In conclusion, the established 7 ferroptosis-related lncRNAs signature can accurately predict HCC prognosis.

A stratification model of hepatocellular carcinoma based on expression profiles of cells in the tumor microenvironment

Background

A malignancy of the liver, hepatocellular carcinoma (HCC) is among the most common and second-leading causes of cancer-related deaths worldwide. A reliable prognosis model for guidance in choosing HCC therapies has yet to be established.

Methods

A consensus clustering approach was used to determine the number of immune clusters in the Cancer Genome Atlas and Liver Cancer-RIKEN, JP (LIRI_JP) datasets. The differentially expressed genes (DEGs) among these groups were identified based on RNA sequencing data. Then, to identify hub genes among signature genes, a co-expression network was constructed. The prognostic value and clinical characteristics of the immune clusters were also explored. Finally, the potential key genes for the immune clusters were determined.

Results

After conducting survival and correlation analyses of the DEGs, three immune clusters (C1, C2, and C3) were identified. Patients in C2 showed the longest survival time with the greatest abundance of tumor microenvironment (TME) cell populations. MGene mutations in Ffibroblast growth factor-19 (FGF19) and catenin (cadherin-associated protein),β1(CTNNB1) were mostly observed in C2 and C3, respectively. The signature genes of C1, C2, and C3 were primarily enriched in 5, 23, and 26 pathways, respectively.

Conclusions

This study sought to construct an immune-stratification model for the prognosis of HCC by dividing the expression profiles of patients from public datasets into three clusters and discovering the unique molecular characteristics of each. This stratification model provides insights into the immune and clinical characteristics of HCC subtypes, which is beneficial for the prognosis of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09647-5.

Phase I/II multicenter trial of a novel therapeutic cancer vaccine, HepaVac-101, for hepatocellular carcinoma

PURPOSE

Immunotherapy for hepatocellular carcinoma (HCC) shows considerable promise in improving clinical outcomes. HepaVac-101 represents a single-arm, first-in-man Phase I/II multicenter cancer vaccine trial for HCC (NCT03203005). It combines multi-peptide antigens (IMA970A) with the TLR7/8/RIG I agonist CV8102. IMA970A includes 5 HLA-A*24 and 7 HLA-A*02 as well as 4 HLA-DR restricted peptides selected after mass spectrometric identification in human HCC tissues or cell lines. CV8102 is an RNA-based immunostimulator inducing a balanced Th1/Th2 immune response.

EXPERIMENTAL DESIGN

82 patients with very early to intermediate stage HCCs were enrolled and screened for suitable HLA haplotypes and 22 put on study treatment. This consisted in a single infusion of low-dose cyclophosphamide followed by 9 intradermal coadministrations of IMA970A and CV8102. Only patients with no disease relapse after standard of care treatments were vaccinated. Primary endpoints of HepaVac-101 clinical trial were safety, tolerability and antigen-specific T-cell responses. Secondary or exploratory endpoints included additional immunological parameters and survival endpoints.

RESULTS

The vaccination showed a good safety profile. Transient mild-to-moderate injection-site reactions were the most frequent IMA970A/CV8102-related side effects. Immune responses against {greater than or equal to}1 vaccinated HLA class I tumor-associated peptide (TAA) and {greater than or equal to}1 vaccinated HLA class II TAA were respectively induced in 37% and 53% of the vaccinees.

CONCLUSION

Immunotherapy may provide a great improvement in treatment options for HCC. HepaVac-101 is a first-in-man clinical vaccine trial with multiple novel HLA class I- and class II-restricted TAAs against HCC. The results are initial evidence for safety and immunogenicity of the vaccine. Further clinical evaluations are warranted.

Antibody-drug conjugate as targeted therapeutics against hepatocellular carcinoma: preclinical studies and clinical relevance

An antibody-drug conjugate (ADC) is an advanced chemotherapeutic option with immense promises in treating many tumor. They are designed to selectively attack and kill neoplastic cells with minimal toxicity to normal tissues. ADCs are complex engineered immunoconjugates that comprise a monoclonal antibody for site-directed delivery and cytotoxic payload for targeted destruction of malignant cells. Therefore, it enables the reduction of off-target toxicities and enhances the therapeutic index of the drug. Hepatocellular carcinoma (HCC) is a solid tumor that shows high heterogeneity of molecular phenotypes and is considered the second most common cause of cancer-related death. Studies show enormous potential for ADCs targeting GPC3 and CD24 and other tumor-associated antigens in HCC with their high, selective expression and show potential outputs in preclinical evaluations. The review mainly highlights the preclinical evaluation of different antigen-targeted ADCs such as MetFab-DOX, Anti-c-Met IgG-OXA, Anti CD 24, ANC-HN-01, G7mab-DOX, hYP7-DCand hYP7-PC, Anti-CD147 ILs-DOX and AC133-vcMMAF against hepatocellular carcinoma and its future relevance.

Safety and efficacy of prophylactic and therapeutic vaccine based on live-attenuated Listeria monocytogenes in hepatobiliary cancers

Primary liver cancer (PLC) comprising hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) represents the third deadliest cancer worldwide with still insufficient treatment options. We have previously found that CD4 T helper 1 (Th1) response is indispensable for the protection against PLC. In the present research, we aimed to test the potent inducers of Th1 responses, live-attenuated Listeria monocytogenes ∆actA/∆inlB strain as preventive/therapeutic vaccine candidate in liver fibrosis, HCC, and CCA. Studies were performed using autochthonous models of HCC and CCA, highly reflecting human disease. L. monocytogenes ∆actA/∆inlB demonstrated strong safety/efficacy in premalignant and malignant liver diseases. The protective mechanism relied on the induction of strong tumor-specific immune responses that keep the development of hepatobiliary cancers under control. Combination therapy, comprising Listeria vaccination and a checkpoint inhibitor blockade significantly extended the survival of HCC-bearing mice even at the advanced stages of the disease. This is the first report on the safety and efficacy of Listeria-based vaccine in liver fibrosis, as well as the first proof of principle study on Listeria-based vaccines in CCA. Our study paves the way for the use of live-attenuated Listeria as safe and efficient vaccine and a potent inducer of protective immune responses in liver fibrosis and hepatobiliary malignancies.

Protective immune mechanism induced by live-attenuated double-deleted L. monocytogenes ∆actA/∆inlB vaccine strain delivering tumor antigens keeps hepatobiliary malignancies under control. Live-attenuated, double-deleted L. monocytogenes ∆actA/∆inlB strain expressing model tumor antigen was used in both, prophylactic and therapeutic vaccination settings. Vaccination was safe and led to: (i) induction of protective tumor-specific Th1 immune responses in premalignant and malignant stages and strong increase of tumor-specific IFN-ɣ⁺ CD4 and CD8 T cells; (ii) decrease of T regulatory cells; (iii) downregulation of several tumor-promoting ICI molecules (PD-1, CD160, LAG3, 4-1BBL) on CD4/CD8 T lymphocytes; (iv) decrease of tumor-specific IgG in serum, and (v) decrease of B lymphocytes, DC and MΦ locally in livers. iCCA, intrahepatic cholangiocarcinoma.

MicroRNA-15a/16-1 Prevents Hepatocellular Carcinoma by Disrupting the Communication Between Kupffer Cells and Regulatory T Cells

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is characterized by intratumoral accumulation of regulatory T cells (Tregs), which suppresses antitumor immunity. This study was designed to investigate how microRNAs regulate immunosuppression in HCC.

METHODS

FVB/NJ mice were hydrodynamically injected with AKT/Ras or c-Myc and Sleeping Beauty transposon to induce HCC. The Sleeping Beauty system was used to deliver microRNA-15a/16-1 into livers of mice. Flow cytometry and immunostaining were used to determine changes in the immune system.

RESULTS

Hydrodynamic injection of AKT/Ras or c-Myc into mice resulted in hepatic enrichment of Tregs and reduced cytotoxic T cells (CTLs) and HCC development. HCC impaired microRNA-15a/16-1 biogenesis in Kupffer cells (KCs) of AKT/Ras and c-Myc mice. Hydrodynamic injection of microRNA-15a/16-1 fully prevented HCC in AKT/Ras and c-Myc mice, while 100% of control mice died of HCC. Therapeutically, microRNA-15a/16-1 promoted a regression of HCC in both mouse models, impaired hepatic enrichment of Tregs, and increased hepatic CTLs. Mechanistically, a significant increase was observed in serum C-C motif chemokine 22 (CCL22) and transcription of Ccl22 in KCs of AKT/Ras and c-Myc mice. MicroRNA-15a/16-1 prevented KCs from overproducing CCL22 by inhibiting nuclear factor-κB that activates transcription of Ccl22. By reducing CCL22 binding to C-C chemokine receptor type 4 on Tregs, microRNA-15a/16-1 impaired Treg chemotaxis. Disrupting the interaction between microRNA-15a/16-1 and nuclear factor-κB impaired the ability of microRNA-15a/16-1 to prevent hepatic Treg accumulation and HCC. Depletion of cluster of differentiation 8⁺ T cells and additional treatment of CCL22 recovered growth of HCC that was fully prevented by microRNA-15a/16.

CONCLUSIONS

MicroRNA-15a/16-1 attenuates immunosuppression by disrupting CCL22-mediated communication between KCs and Tregs. MicroRNA-15a/16-1 represents a potential immunotherapy against HCC.

Advances in Nanoliposomes for the Diagnosis and Treatment of Liver Cancer

The mortality rate of liver cancer is gradually increasing worldwide due to the increasing risk factors such as fatty liver, diabetes, and alcoholic cirrhosis. The diagnostic methods of liver cancer include ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), among others. The treatment of liver cancer includes surgical resection, transplantation, ablation, and chemoembolization; however, treatment still faces multiple challenges due to its insidious development, high rate of recurrence after surgical resection, and high failure rate of transplantation. The emergence of liposomes has provided new insights into the treatment of liver cancer. Due to their excellent carrier properties and maneuverability, liposomes can be used to perform a variety of functions such as aiding in imaging diagnoses, combinatorial therapies, and integrating disease diagnosis and treatment. In this paper, we further discuss such advantages.

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.

Nano delivery of simvastatin targets liver sinusoidal endothelial cells to remodel tumor microenvironment for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) developed in fibrotic liver does not respond well to immunotherapy, mainly due to the stromal microenvironment and the fibrosis-related immunosuppressive factors. The characteristic of liver sinusoidal endothelial cells (LSECs) in contributing to fibrosis and orchestrating immune response is responsible for the refractory to targeted therapy or immunotherapy of HCC. We aim to seek a new strategy for HCC treatment based on an old drug simvastatin which shows protecting effect on LSEC.

METHOD

The features of LSECs in mouse fibrotic HCC model and human HCC patients were identified by immunofluorescence and scanning electron microscopy. The effect of simvastatin on LSECs and hepatic stellate cells (HSCs) was examined by immunoblotting, quantitative RT-PCR and RNA-seq. LSEC-targeted delivery of simvastatin was designed using nanotechnology. The anti-HCC effect and toxicity of the nano-drug was evaluated in both intra-hepatic and hemi-splenic inoculated mouse fibrotic HCC model.

RESULTS

LSEC capillarization is associated with fibrotic HCC progression and poor survival in both murine HCC model and HCC patients. We further found simvastatin restores the quiescence of activated hepatic stellate cells (aHSCs) via stimulation of KLF2-NO signaling in LSECs, and up-regulates the expression of CXCL16 in LSECs. In intrahepatic inoculated fibrotic HCC mouse model, LSEC-targeted nano-delivery of simvastatin not only alleviates LSEC capillarization to regress the stromal microenvironment, but also recruits natural killer T (NKT) cells through CXCL16 to suppress tumor progression. Together with anti-programmed death-1-ligand-1 (anti-PD-L1) antibody, targeted-delivery of simvastatin achieves an improved therapeutic effect in hemi-splenic inoculated advanced-stage HCC model.

CONCLUSIONS

These findings reveal an immune-based therapeutic mechanism of simvastatin for remodeling immunosuppressive tumor microenvironment, therefore providing a novel strategy in treating HCC.

Immunotherapy for Hepatocellular Carcinoma: New Prospects for the Cancer Therapy

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide. HCC patients may benefit from liver transplantation, hepatic resection, radiofrequency ablation, transcatheter arterial chemoembolization, and targeted therapies. The increased infiltration of immunosuppressive immune cells and the elevated expression of immunosuppressive factors in the HCC microenvironment are the main culprits of the immunosuppressive nature of the HCC milieu. The immunosuppressive tumor microenvironment can substantially attenuate antitumoral immune responses and facilitate the immune evasion of tumoral cells. Immunotherapy is an innovative treatment method that has been promising in treating HCC. Immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT), and cell-based (primarily dendritic cells) and non-cell-based vaccines are the most common immunotherapeutic approaches for HCC treatment. However, these therapeutic approaches have not generally induced robust antitumoral responses in clinical settings. To answer to this, growing evidence has characterized immune cell populations and delineated intercellular cross-talk using single-cell RNA sequencing (scRNA-seq) technologies. This review aims to discuss the various types of tumor-infiltrating immune cells and highlight their roles in HCC development. Besides, we discuss the recent advances in immunotherapeutic approaches for treating HCC, e.g., ICIs, dendritic cell (DC)-based vaccines, non-cell-based vaccines, oncolytic viruses (OVs), and ACT. Finally, we discuss the potentiality of scRNA-seq to improve the response rate of HCC patients to immunotherapeutic approaches.

Safflower yellow reduces DEN-induced hepatocellular carcinoma by enhancing liver immune infiltration through promotion of collagen degradation and modulation of gut microbiota

Safflower yellow (SY) is the main active ingredient isolated from the traditional Chinese medicine Carthamus tinctorius, which is a valuable natural edible pigment that is widely used to treat cerebrovascular and cardiovascular diseases. However, the effect of SY on hepatocellular carcinoma (HCC) remains unclear. In this study, we showed that SY decreased the degree of injury and inhibited the release of inflammatory factors in the liver of a diethylnitrosamine (DEN)-induced HCC mouse model. Flow cytometry and immunoblotting showed that SY increased the infiltration of CD8⁺ T cells and Gr-1⁺ macrophages to improve the immune microenvironment by affecting the expression of collagen fibers. Further cellular experiments showed that SY degraded the collagens in the liver cells through the TGF-β/Smad signalling pathway. SY also regulated the gut microbiota which may contribute to the immune microenvironment. In conclusion, SY exhibited a potent effect on the development of HCC by enhancing liver immune infiltration by promoting collagen degradation and modulating the gut microbiota. This study provides novel insights into the mechanism of SY as a candidate for the treatment of HCC in the future.

Immunotherapeutic treatments in hepatocellular carcinoma; achievements, challenges and future prospects

Hepatocellular carcinoma (HCC) is one of the most common and fatal malignancies with an alarming trend all around the world. Common therapeutic approaches in the early stage of disease are surgical resection, ablation, and liver transplantation. Due to the insidious identity of HCC, the majority of the patients are diagnosed at advanced stages, where tumor spreading, or distant metastasis unfortunately have already occurred. Immunotherapeutic options have elicited a promising approach in some malignancies with Food and Drug Administration (FDA) approving the first checkpoint inhibitor anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) ipilimumab for the treatment of melanoma ten years ago. In the past decade, many clinical trials have been investigating anti-CTLA-4 as well as anti-programmed cell death protein 1 (PD-1) therapies in various solid tumors, including HCC. In this mini-review we will discuss the latest clinical data from clinical trials for immune-checkpoint inhibitors for the treatment of HCC.

First-line immune checkpoint inhibitor-based combinations in unresectable hepatocellular carcinoma: current management and future challenges

INTRODUCTION

Immunotherapy has recently taken on an extremely important role in medical oncology, as first- or later-line treatment in several tumor types, and recent years have seen the emerging of clinical trials assessing immune checkpoint inhibitors (ICIs) in unresectable hepatocellular carcinoma (HCC).

AREAS COVERED

Herein, we provide an overview of recently published studies exploring the dual immune checkpoint blockade or the combination of ICIs plus biological treatments as first-line treatment in HCC patients with advanced disease, especially focusing on the biological rationale behind these therapeutic strategies, and ongoing active and recruiting clinical trials.

EXPERT OPINION

Results of studies on monotherapy with ICIs have suggested that this strategy could be beneficial only in a minority of patients; conversely, the recently published IMbrave150 study has reported an overall survival benefit in HCC receiving the combination of atezolizumab plus bevacizumab compared to sorafenib as first-line treatment. A wide number of clinical trials is evaluating ICI-based combinations in advanced HCC, a strategy which is supported by robust preclinical and early-phase clinical data, and results of these studies are highly awaited.

Immune Checkpoint Inhibitors in Hepatocellular Carcinoma: Current Progresses and Challenges

Hepatocellular carcinoma (HCC) is one of the most common malignant tumor in the world and its incidence is increasing in many countries. In recent years, with the deepening understanding of the immune and pathological mechanisms of HCC, immunotherapy based on the regulation of tumor immune microenvironment has become a new treatment choice for patients with HCC. Immune checkpoint inhibitors (ICIs) targeting programmed death protein-1, programmed death protein-ligand-1, or cytotoxic T-lymphocyte-associated antigen 4 are the most widely used. Instead of general immune-enhancing therapies, ICIs can reactivate anti-tumor immune responses by disrupting co-inhibitory T cell signaling. In this review, the research progress and existing problems of ICIs in the treatment of HCC in recent years are reviewed.

Xanthine dehydrogenase as a prognostic biomarker related to tumor immunology in hepatocellular carcinoma

Background

Xanthine dehydrogenase (XDH) is a critical enzyme involved in the oxidative metabolism of purines, pterin and aldehydes and a central component of the innate immune system. However, the prognostic value of XDH in predicting tumor-infiltrating lymphocyte abundance, the immune response, and survival in different cancers, including hepatocellular carcinoma (HCC), is still unclear.

Methods

XDH expression was analyzed in multiple databases, including Oncomine, the Tumor Immune Estimation Resource (TIMER), the Kaplan–Meier plotter database, the Gene Expression Profiling Interactive Analysis (GEPIA) database, and The Cancer Genome Atlas (TCGA). XDH-associated transcriptional profiles were detected with an mRNA array, and the levels of infiltrating immune cells were validated by immunohistochemistry (IHC) of HCC tissues. A predictive signature containing multiple XDH-associated immune genes was established using the Cox regression model.

Results

Decreased XDH mRNA expression was detected in human cancers originating from the liver, bladder, breast, colon, bile duct, kidney, and hematolymphoid system. The prognostic potential of XDH mRNA expression was also significant in certain other cancers, including HCC, breast cancer, kidney or bladder carcinoma, gastric cancer, mesothelioma, lung cancer, and ovarian cancer. In HCC, a low XDH mRNA level predicted poorer overall survival, disease-specific survival, disease-free survival, and progression-free survival. The prognostic value of XDH was independent of the clinical features of HCC patients. Indeed, XDH expression in HCC activated several immune-related pathways, including the T cell receptor, PI3K-AKT, and MAPK signaling pathways, which induced a cytotoxic immune response. Importantly, the microenvironment of XDH^high HCC tumors contained abundant infiltrating CD8 + T cells but not exhausted T cells. A risk prediction signature based on multiple XDH-associated immune genes was revealed as an independent predictor in the TCGA liver cancer cohort.

Conclusion

These findings suggest that XDH is a valuable prognostic biomarker in HCC and other cancers and indicate that it may function in tumor immunology. Loss of XDH expression may be an immune evasion mechanism for HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02173-7.

The Role of Immunotherapy in a Tolerogenic Environment: Current and Future Perspectives for Hepatocellular Carcinoma

In contrast to several tumors whose prognoses are radically affected by novel immunotherapeutic approaches and/or targeted therapies, the outcomes of advanced hepatocellular carcinoma (HCC) remain poor. The underlying cirrhosis that is frequently associated with it complicates medical treatment and often determines survival. The landscape of HCC treatment had included sorafenib as the only drug available for ten years, until 2018, when lenvatinib was approved for treatment. The second-line systemic treatments available for hepatocellular carcinoma include regorafenib, cabozantinib, ramucirumab, and, more recently, immune checkpoint inhibitors. However, the median survival remains below 15 months. The results obtained in clinics should be interpreted whilst considering the peculiar role of the liver as an immune organ. A healthy liver microenvironment ordinarily experiences stimulation by gut-derived antigens. This setup elucidates the response to chronic inflammation and the altered balance between tolerance and immune response in HCC development. This paper provides an overview of the mechanisms involved in HCC pathogenesis, with a special focus on the immune implications, along with current and future clinical perspectives.

Immunotherapy for cholangiocarcinoma: a 2021 update

Cholangiocarcinoma (CCA) is a rare malignancy with generally dismal prognosis. Immunotherapy has revolutionized the management of cancer patients during the last decade, offering durable responses with an acceptable safety profile, but there are still no significant advances regarding CCA. Novel immunotherapeutic methods, such as cancer vaccines, oncolytic viruses, adoptive cell therapy and combinations of immune checkpoint inhibitors with other agents are currently under investigation and may improve prognosis. Efforts to find robust biomarkers for response are also ongoing. In this review, we discuss the rationale for the use of immunotherapy in CCA and available clinical data. Ongoing trials will also be presented, as well as key findings from each study.

De novo prediction of cancer-associated T cell receptors for noninvasive cancer detection

The adaptive immune system recognizes tumor antigens at an early stage to eradicate cancer cells. This process is accompanied by systemic proliferation of the tumor antigen-specific T lymphocytes. While detection of asymptomatic early-stage cancers is challenging due to small tumor size and limited somatic alterations, tracking peripheral T cell repertoire changes may provide an attractive solution to cancer diagnosis. Here, we developed a deep learning method called DeepCAT to enable de novo prediction of cancer-associated T cell receptors (TCRs). We validated DeepCAT using cancer-specific or non-cancer TCRs obtained from multiple major histocompatibility complex I (MHC-I) multimer-sorting experiments and demonstrated its prediction power for TCRs specific to cancer antigens. We blindly applied DeepCAT to distinguish over 250 patients with cancer from over 600 healthy individuals using blood TCR sequences and observed high prediction accuracy, with area under the curve (AUC) ≥ 0.95 for multiple early-stage cancers. This work sets the stage for using the peripheral blood TCR repertoire for noninvasive cancer detection.

A review of cutting-edge therapies for hepatocellular carcinoma (HCC): Perspectives from patents

Rationale: Hepatocellular carcinoma (HCC) is a challenging disease due to its heterogenous etiology. Several breakthroughs have occurred in treatment of HCC, associated with an enormous number of patent publications for a variety of HCC treatment modalities. As patents can provide valuable information for academic research and commercial development, this study aims to unravel the cutting-edge therapies for HCC by using patents as an indicator. The outcome from this analysis may offer meaningful insights for respective policymaking, strategic plan and research and development (R&D) prioritization. Methods: Derwent Innovation platform was employed to collect the sample data of patents related to HCC treatment technologies worldwide as of December 31, 2019. Data inclusion, screening and exclusion were according to the rules of preferred reporting items for systematic reviews and meta-analyses (PRISMA). Technologies were classified based on Barcelona Clinic Liver Cancer (BCLC) staging system and recent clinical publications. Patent citation network analysis was carried out to identify and understand HCC therapeutic technology flow. Results: A dataset of 2543 patent documents and 528 patent families was generated. 11 technological categories were classified. Numerous researches were focalized on refinements in technologies and innovations within the field of HCC therapy, and the major achievements are technology advancement on molecular target therapy, chemotherapy, locoregional therapy, combination therapy and immunotherapy with demonstrated clinical benefits. In patent citation network, Notch pathway investigation, antibody drug conjugate (ADC) technology development and drug eluting beads trans artery chemoembolization (DEB-TACE) advancement are the major technological communities involving patents with the greatest future exploratory potential. Conclusion: Numerous emerging technologies have been identified in this study, in which exploring novel therapeutic targets in molecular target therapy, more localized and visible locoregional therapy and combination of immunotherapy with target therapy or other traditional therapies are highlighted as the future trends in treating HCC.

The Combination Immunotherapy of TLR9 Agonist and OX40 Agonist via Intratumoural Injection for Hepatocellular Carcinoma

Background

The response rate of immunotherapy via immune checkpoint blockade in hepatocellular carcinoma (HCC) is limited due to multiple immune evasion mechanisms. OX40 is a T cell co-stimulating molecule which suppresses the cancer immune evasion by activating effector T cells (Teffs) and counteracting regulatory T cells (Tregs). TLR9 belongs to the toll-like receptor superfamily which promotes tumour antigen presentation by stimulating the maturation of dendritic cells. Though the combination immunotherapy of TLR9 agonist (CpG) and OX40 agonist (anti-OX40 antibody) has shown encouraging efficacy in various tumours, its effect on HCC remains unknown.

Materials and Methods

Orthotopic and ectopic HCC models were constructed by implanting Hepa1-6 cells at different body sites of the mice. Immune agents were administrated via three ways, including intratumoural injection into one site of the tumour, intraperitoneal injection, and subcutaneous injection. The anti-tumour immune response was evaluated by the regression of both the local treated tumour and distant untreated tumour. The ratio and function of CD4+ T cells, CD8+ T cells, Tregs and myeloid-derived suppressor cells (MDSCs) were analyzed by flow cytometry.

Results

CpG via intratumoural injection remarkably upregulated the weakly expressed OX40 of intratumoural T cells. The combination immunotherapy of CpG and anti-OX40 antibody via intratumoural injection significantly inhibited the growth of local and distant tumours, and also effectively prevented their recurrence. Excitingly, drug administration via intratumoural injection, rather than via intraperitoneal or subcutaneous injections, induced potent anti-tumour immune response. Furthermore, we demonstrated that the combination immunotherapy promoted CD8+ and CD4+ T cells, and inhibited Tregs and myeloid-derived suppressor cells, contributing to the effective inhibition on HCC. Noteworthily, the combination immunotherapy also induced an immune memory response.

Conclusion

The intratumoural administration of combined CpG and anti-OX40 antibody serves as a promising immunotherapy against HCC.

A Review on Cancer Immunotherapy and Applications of Nanotechnology to Chemoimmunotherapy of Different Cancers

Clinically, different approaches are adopted worldwide for the treatment of cancer, which still ranks second among all causes of death. Immunotherapy for cancer treatment has been the focus of attention in recent years, aiming for an eventual antitumoral effect through the immune system response to cancer cells both prophylactically and therapeutically. The application of nanoparticulate delivery systems for cancer immunotherapy, which is defined as the use of immune system features in cancer treatment, is currently the focus of research. Nanomedicines and nanoparticulate macromolecule delivery for cancer therapy is believed to facilitate selective cytotoxicity based on passive or active targeting to tumors resulting in improved therapeutic efficacy and reduced side effects. Today, with more than 55 different nanomedicines in the market, it is possible to provide more effective cancer diagnosis and treatment by using nanotechnology. Cancer immunotherapy uses the body's immune system to respond to cancer cells; however, this may lead to increased immune response and immunogenicity. Selectivity and targeting to cancer cells and tumors may lead the way to safer immunotherapy and nanotechnology-based delivery approaches that can help achieve the desired success in cancer treatment.

Curative-Intent Treatment with Durvalumab in Early-Stage Cancers

The introduction of immunotherapy has fundamentally transformed the treatment landscape in cancer, providing long-term survival benefit for patients with advanced disease across multiple tumor types, including non-small cell lung cancer (NSCLC). In the placebo-controlled phase 3 PACIFIC trial, the PD-L1 inhibitor durvalumab demonstrated significant improvements in progression-free survival and overall survival in patients with unresectable, stage III NSCLC who had not progressed after platinum-based chemoradiotherapy (CRT). These findings have led to the widespread acceptance of the 'PACIFIC regimen' (durvalumab after CRT) as the standard of care in this setting. Moreover, the PACIFIC trial is the first study to demonstrate a proven survival advantage with an immunotherapy in a curative-intent setting, thereby providing a strong rationale for further investigation of durvalumab in early-stage cancers. Herein, we describe the extensive clinical development program for durvalumab across multiple tumor types in curative-intent settings, outlining the scientific rationale(s) for its use and highlighting the innovative research (e.g., personalized cancer monitoring) advanced by these trials.

Combined Inhibition of TGF-β1-Induced EMT and PD-L1 Silencing Re-Sensitizes Hepatocellular Carcinoma to Sorafenib Treatment

Hepatocellular carcinoma (HCC) is the most common type of primary hepatic malignancy. HCC is one of the leading causes of cancer deaths worldwide. The oral multi-tyrosine kinase inhibitor Sorafenib is the standard first-line therapy in patients with advanced unresectable HCC. Despite the significant survival benefit in HCC patients post treatment with Sorafenib, many patients had progressive disease as a result of acquiring drug resistance. Circumventing resistance to Sorafenib by exploring and targeting possible molecular mechanisms and pathways is an area of active investigation worldwide. Epithelial-to-mesenchymal transition (EMT) is a cellular process allowing epithelial cells to assume mesenchymal traits. HCC tumour cells undergo EMT to become immune evasive and develop resistance to Sorafenib treatment. Immune checkpoint molecules control immune escape in many tumours, including HCC. The aim of this study is to investigate whether combined inhibition of EMT and immune checkpoints can re-sensitise HCC to Sorafenib treatment. Post treatment with Sorafenib, HCC cells PLC/PRF/5 and Hep3B were monitored for induction of EMT and immune checkpoint molecules using quantitative reverse transcriptase (qRT)- PCR, western blot, immunofluorescence, and motility assays. The effect of combination treatment with SB431542, a specific inhibitor of the transforming growth factor (TGF)-β receptor kinase, and siRNA mediated knockdown of programmed cell death protein ligand-1 (PD-L1) on Sorafenib resistance was examined using a cell viability assay. We found that three days of Sorafenib treatment activated EMT with overexpression of TGF-β1 in both HCC cell lines. Following Sorafenib exposure, increase in the expression of PD-L1 and other immune checkpoints was observed. SB431542 blocked the TGF-β1-mediated EMT in HCC cells and also repressed PD-L1 expression. Likewise, knockdown of PD-L1 inhibited EMT. Moreover, the sensitivity of HCC cells to Sorafenib was enhanced by combining a blockade of EMT with SB431542 and knockdown of PD-L1 expression. Sorafenib-induced motility was attenuated with the combined treatment of SB431542 and PD-L1 knockdown. Our findings indicate that treatment with Sorafenib induces EMT and expression of immune checkpoint molecules, which contributes to Sorafenib resistance in HCC cells. Thus, the combination treatment strategy of inhibiting EMT and immune checkpoint molecules can re-sensitise HCC cells to Sorafenib.

Plasmodium infection prevents recurrence and metastasis of hepatocellular carcinoma possibly via inhibition of the epithelial‑mesenchymal transition

Postoperative recurrence causes a high mortality rate among patients with hepatocellular carcinoma (HCC). The current study aimed to determine the effects of Plasmodium infection on HCC metastasis and recurrence. The antitumor effects of Plasmodium infection were determined using two murine orthotopic HCC models: The non-resection model and the resection model. Tumour tissues derived from tumour-bearing mice treated with or without Plasmodium infection were harvested 15 days post-tumour inoculation. The expression levels of biomarkers related to epithelial-mesenchymal transition (EMT) and molecules associated with CC-chemokine receptor 10 (CCR10)-mediated PI3K/Akt/GSK-3β/Snail signalling were identified using reverse transcription-quantitative PCR and western blotting. The results demonstrated that Plasmodium infection significantly suppressed the progression, recurrence and metastasis of HCC in the two mouse models. The expression levels of E-cadherin were significantly higher in the Plasmodium-treated group compared with that in the control group, whereas the expression levels of Vimentin and Snail were significantly lower in the Plasmodium-treated group. Furthermore, Plasmodium infection inhibited the activation of Akt and GSK-3β in the tumour tissues by downregulating the expression levels of CCR10 and subsequently suppressing the accumulation of Snail, which may contribute to the suppression of EMT and the prevention of tumour recurrence and metastasis. In conclusion, the results of the present study demonstrated that Plasmodium infection inhibited the recurrence and metastasis and improved the prognosis of HCC by suppressing CCR10-mediated PI3K/Akt/GSK-3β/Snail signalling and preventing the EMT. These results may be important for the development of novel therapies for HCC recurrence and metastasis, especially for patients in the perioperative period.

Immunotherapy for Hepatocellular Carcinoma: Current Limits and Prospects

Although many approaches have been used to treat hepatocellular carcinoma (HCC), the clinical benefits remain limited, particularly for late stage HCC. In recent years, studies have focused on immunotherapy for HCC. Immunotherapies have shown promising clinical outcomes in several types of cancers and potential therapeutic effects for advanced HCC. In this review, we summarize the immune tolerance and immunotherapeutic strategies for HCC as well as the main challenges of current therapeutic approaches. We also present alternative strategies for overcoming these limitations.

Qualification of tumour mutational burden by targeted next-generation sequencing as a biomarker in hepatocellular carcinoma

BACKGROUND & AIMS

Tumour mutational burden (TMB) predicts improved response and survival to immunotherapy. In this pilot study, we optimized targeted next-generation sequencing (tNGS) to estimate TMB in hepatocellular carcinoma (HCC).

METHODS

We sequenced 48 non-paired samples (21 fresh-frozen [FF] and 27 paraffin-embedded [FFPE]), among which 11 FFPE samples were pretreated with uracil-DNA glycosylase (UDG). Thirty samples satisfied post-sequencing quality control. High/low TMB was defined by median number of mutations/Mb (Mut/Mb), across different minimum allele frequency (MAF) thresholds (≥0.05, ≥0.1 and ≥0.2).

RESULTS

Eligible patients (n = 29) were cirrhotic (84%) with TNM stage I-II HCC (75%). FFPE samples had higher TMB (median 958.39 vs 2.51 Mut/Mb, P < .0001), estimated deamination counts (median 1335.50 vs 0, P < .0001) and C > T transitions at CpG sites (median 60.3% vs 9.1%, P = .002) compared to FF. UDG-treated samples had lower TMB (median 4019.92 vs 353 Mut/Mb, P = .041) and deamination counts (median 6393.5 vs 328.5, P = .041) vs untreated FFPE. At 0.2 MAF threshold with UDG treatment, median TMB was 5.48 (range 1.68-16.07) and did not correlate with salient pathologic features of HCC, including survival.

CONCLUSION

While tNGS on fresh HCC samples appears to be the optimal source of tumour DNA, the low median TMB values observed may limit the role of TMB as a predictor of response to immunotherapy in HCC.

Human Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) is the fifth most common cancer and accounts for 8 [...].

Fibrinogen-like protein 2 promotes the accumulation of myeloid-derived suppressor cells in the hepatocellular carcinoma tumor microenvironment

The tumor microenvironment in hepatocellular carcinoma can be classified into cellular and non-cellular components. Myeloid-derived suppressor cells (MDSCs) are cellular components of this microenvironment that serve an important role in the progression of hepatocellular carcinoma. Fibrinogen-like protein 2 (FGL2) has been demonstrated to promote tumor progression by regulating cellular components of the tumor microenvironment in various types of malignant tumor. The present study aimed to determine the expression of FGL2 in hepatocellular carcinoma and its effect on the tumor microenvironment in order to determine novel targets for liver cancer treatment. Immunohistochemistry and reverse transcription quantitative PCR were performed to determine the expression level of FGL2 and the correlation with surface markers of human MDSCs in hepatocellular carcinoma. Furthermore, a mouse hepatocellular carcinoma cell line overexpressing FGL2 was established by stable transfection of a lentivirus expressing FGL2. In addition, fresh bone marrow cells extracted from mouse femurs were in vitro cultured using conditioned medium derived from the cell line overexpressing FGL2. An orthotopic hepatocellular carcinoma mouse model was also established. The results demonstrated that FGL2 expression level in hepatocellular carcinoma tissues was closely associated with tumor size. FGL2 level was positively correlated with the expression level of the MDSC surface markers CD11b and CD33 in hepatocellular carcinoma. The in vitro results demonstrated that FGL2 could maintain the undifferentiated state of bone marrow cells, therefore promoting MDSC accumulation. Furthermore, in the orthotopic hepatocellular carcinoma mouse model, we observed that overexpression of FGL2 could promote tumor growth and significantly increase the number of MDSCs in the tumors and spleen. Taken together, these findings suggested that FGL2 may promote hepatocellular carcinoma tumor growth by promoting the accumulation of MDSCs in the tumor microenvironment.

Regulatory T cell and activated natural killer cell infiltration in hepatocellular carcinoma: immune cell profiling using the CIBERSORT

BACKGROUND

Hepatocellular carcinoma (HCC) is understood to be an immunogenic tumor caused by chronic liver disease. Emerging research has indicated close interaction between various immune cells and tumor cells. Immunophenotyping, which has shown potential predictive value for the prognosis of various human malignancies, might allow responsive and non-responsive patients to be identified based on the extent and distribution of immune cell infiltration. Several novel immunotherapeutic approaches have been trialed and have shown promising efficacy. However, the efficacy of immunotherapies in HCC is limited by several factors. This study aimed to investigate tumor-infiltrating immune cells in HCC.

METHODS

Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) allows immune cell profiling analysis by deconvolution of gene expression microarray data. In this study, we analyzed the proportions of immune cells in 14 paired samples of HCC tissues obtained from GSE84402 in Gene Expression Omnibus (GEO) database.

RESULTS

In the 14 paired samples, HCC tissues showed significant infiltration by regulatory T cells (Tregs), activated natural killer (NK) cells, and M0 macrophages (P<0.001, P=0.007 and P=0.001, respectively), which were validated in CIBERSORT with the P value set at ≤0.05. In four paired samples identified from those selected by CIBERSORT, HCC tissues were found to have significant Treg and activated NK cell infiltration compared to non-tumor tissues (P=0.007 and P=0.015, respectively). Additionally, Pearson correlation analysis revealed Tregs to be positively correlated with activated NK cells (Correlation coefficient =0.41).

CONCLUSIONS

HCC tumor tissues were markedly infiltrated by Tregs and activated NK cells, which should be considered as candidate therapeutic targets in HCC multidisciplinary treatments.

Identification of immune landscape signatures associated with clinical and prognostic features of hepatocellular carcinoma

While cancer immunotherapy has been remarkably successful in some malignancies, some cancers derive limited benefit from current immunotherapies. Here, we combined immune landscape signatures with hepatocellular carcinoma clinical and prognostic features to classify them into distinct subtypes. The immunogenomic profiles, stromal cell features and immune cell composition of the subtypes were then systematically analyzed. Two independent prognostic indexes were established based on 6 immune-related genes and 17 differentially expressed genes associated with stromal cell content. These indexes were significantly correlated with tumor mutation burden, deficient DNA mismatch repair and microsatellite instability. In addition, tumor-infiltrating lymphocytes, including activated NK cells, resting memory CD4 T-cells, eosinophils, and activated mast cells were significantly correlated with hepatocellular carcinoma survival. In conclusion, we have comprehensively described the immune landscape signatures and identified prognostic immune-associated biomarkers of hepatocellular carcinoma. Our findings highlight potential novel avenues for improving responses to immunotherapy.

Immunotherapy for Hepatocellular Carcinoma: A 2021 Update

Hepatocellular carcinoma (HCC) is one of one of the most frequent liver cancers and the fourth leading cause of cancer-related mortality worldwide. Current treatment options such as surgery, neoadjuvant chemoradiotherapy, liver transplantation, and radiofrequency ablation will benefit only a very small percentage of patients. Immunotherapy is a novel treatment approach representing an effective and promising option against several types of cancer. The aim of our study is to present the currently ongoing clinical trials and to evaluate the efficacy of immunotherapy in HCC. In this paper, we demonstrate that combination of different immunotherapies or immunotherapy with other modalities results in better overall survival (OS) and progression-free survival (PFS) compared to single immunotherapy agent. Another objective of this paper is to demonstrate and highlight the importance of tumor microenvironment as a predictive and prognostic marker and its clinical implications in immunotherapy response.

Recent developments and ongoing trials in transplant oncology

Over the past two decades since the introduction of the Milan criteria, the field of transplant oncology has undergone a rapid development with a rising proportion of liver transplantations being performed for oncological indications. For many patients with liver tumours, transplantation represents the only chance for cure. However, many challenges remain, such as the adequate patient selection, management of post-transplant recurrence and refinement of neoadjuvant treatment protocols. This review provides an overview of the current state of the art of liver transplantation for oncological indications such as hepatocellular carcinoma, cholangiocarcinoma, colorectal liver metastasis and metastatic neuroendocrine tumours. We also summarize the ongoing research and explore future trends. Clinical trials are currently studying new diagnostic modalities, innovative pharmacological treatments, novel surgical techniques, downstaging regimens and new indications for liver transplantation. These emerging results will continue to shape the field of transplant oncology and provide us with the necessary tools to better select, treat and follow patients with liver tumours qualifying for liver transplantation.

Tumor microenvironment in primary liver tumors: A challenging role of natural killer cells

In the last years, several studies have been focused on elucidate the role of tumor microenvironment (TME) in cancer development and progression. Within TME, cells from adaptive and innate immune system are one of the main abundant components. The dynamic interactions between immune and cancer cells lead to the activation of complex molecular mechanisms that sustain tumor growth. This important cross-talk has been elucidate for several kind of tumors and occurs also in patients with liver cancer, such as hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). Liver is well-known to be an important immunological organ with unique microenvironment. Here, in normal conditions, the rich immune-infiltrating cells cooperate with non-parenchymal cells, such as liver sinusoidal endothelial cells and Kupffer cells, favoring self-tolerance against gut antigens. The presence of underling liver immunosuppressive microenvironment highlights the importance to dissect the interaction between HCC and iCCA cells with immune infiltrating cells, in order to understand how this cross-talk promotes tumor growth. Deeper attention is, in fact, focused on immune-based therapy for these tumors, as promising approach to counteract the intrinsic anti-tumor activity of this microenvironment. In this review, we will examine the key pathways underlying TME cell-cell communications, with deeper focus on the role of natural killer cells in primary liver tumors, such as HCC and iCCA, as new opportunities for immune-based therapeutic strategies.

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

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

Immunological Basis of Genesis of Hepatocellular Carcinoma: Unique Challenges and Potential Opportunities through Immunomodulation

A majority of hepatocellular carcinoma (HCC) develops in the setting of persistent chronic inflammation as immunological mechanisms have been shown to play a vital role in the initiation, growth and progression of tumours. The index review has been intended to highlight ongoing immunological changes in the hepatic parenchyma responsible for the genesis and progression of HCC. The in-situ vaccine effect of radiofrequency (RF) is through generation tumour-associated antigens (TAAs), following necrosis and apoptosis of tumour cells, which not only re-activates the antitumour immune response but can also act in synergism with checkpoint inhibitors to generate a superlative effect with intent to treat primary cancer and distant metastasis. An improved understanding of oncogenic responses of immune cells and their integration into signaling pathways of the tumour microenvironment will help in modulating the antitumour immune response. Finally, we analyzed contemporary literature and summarised the recent advances made in the field of targeted immunotherapy involving checkpoint inhibitors along with RF application with the intent to reinstate antitumour immunity and outline future directives in very early and early stages of HCC.

Elevated soluble TNFα levels and upregulated TNFα mRNA expression in purified peripheral blood monocyte subsets associated with high-grade hepatocellular carcinoma

BACKGROUND

Chronic inflammation is involved in the initiation and progression of various cancers, including liver cancer. The current study focuses on the characterization of the peripheral immune response in hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) patients, before and after surgical procedure, in order to assess the effect of tumor resection in the immune system homeostasis and to determine possible prognostic factors associated with high-grade tumors. We developed a whole-blood assay to monitor immune alterations and functional competence of peripheral monocytes in a group of 10 healthy individuals (HG), in 20 HCC patients and 8 CCA patients, by multi-color flow cytometry, qRT-PCR, and ELISA techniques.

RESULTS

The qRT-PCR analysis showed an upregulation of TNFα expression by classical and intermediate monocytes purified from HCC patients presenting tumors in grade G3-G4 as compared to G1-G2 HCC patients. Moreover, ELISA assay confirmed elevated serum levels of TNFα in G3-G4 compared to G1-G2 HCC patients. A significant decrease of circulating non-classical monocytes was detected in both CCA and HCC patients before and after surgical procedure. In addition, a functional defect in circulating classical and intermediate monocytes was observed in both groups of cancer patients when compared to the HG, with partial recovery after the surgical intervention.

CONCLUSIONS

This integrated analysis permitted the identification of altered functional competence of monocyte subsets in CCA and HCC patients. In addition, our results point to a potential role of TNFα as a prognostic peripheral biomarker in HCC patients, indicating the presence of high-grade tumors that should be further validated.

Integrative analysis of DNA methylation and gene expression reveals distinct hepatocellular carcinoma subtypes with therapeutic implications

We aimed to develop an HCC classification model based on the integrated gene expression and methylation data of methylation-driven genes. Genome, methylome, transcriptome, proteomics and clinical data of 369 HCC patients from The Cancer Genome Atlas Network were retrieved and analyzed. Consensus clustering of the integrated gene expression and methylation data from methylation-driven genes identified 4 HCC subclasses with significant prognosis difference. HS1 was well differentiated with a favorable prognosis. HS2 had high serum α-fetoprotein level that was correlated with its poor outcome. High percentage of CTNNB1 mutations corresponded with its activation in WNT signaling pathway. HS3 was well differentiated with low serum α-fetoprotein level and enriched in metabolism signatures, but was barely involved in immune signatures. HS3 also had high percentage of CTNNB1 mutations and therefore enriched in WNT activation signature. HS4 was poorly differentiated with the worst prognosis and enriched in immune-related signatures, but was barely involved in metabolism signatures. Subsequently, a prediction model was developed. The prediction model had high sensitivity and specificity in distributing potential HCC samples into groups identical with the training cohort. In conclusion, this work sheds light on HCC patient prognostication and prediction of response to targeted therapy.