Immunotherapy for hepatocellular carcinoma patients: is it ready for prime time?

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.

A novel immune-related gene signature predicts the prognosis of hepatocellular carcinoma

Immune-related genes play a key role in regulating the cancer immune microenvironment, influencing the overall survival of patients with hepatocellular carcinoma (HCC). Along with the rapid development of immunotherapy, identifying immune-related genes with prognostic value in HCC has attracted increasing attention. Here, we aimed to develop a prognostic signature based on immune-related genes. By investigating the transcriptome landscape of 374 HCC and 160 non-HCC samples in silico, a total of 2251 differentially expressed genes were identified. Among which, 183 differentially expressed immune-related genes were subjected to a univariate Cox proportional hazard model to screen for genes with possible prognostic significance. A 10-gene prognostic signature, including HLA-G, S100A9, S100A10, DCK, CCL14, NRAS, EPO, IL1RN, GHR and RHOA, was generated employing a multivariate Cox proportional hazard model. Kaplan–Meier and Receiver Operator Characteristic (ROC) curves were used to evaluate the prognostic utility of the 10-gene signature. Moreover, the underlying mechanisms of these genes were analyzed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. According to the Tumor Immune Estimation Resource (TIMER) database, our prognostic signature was significantly associated with tumor-infiltrating B cells, CD4 T cells, dendritic cells, macrophages and neutrophils. Our study provides a novel prognostic signature based on immune-related genes associated with clinical outco mes of HCC.

Recent advances and applications of microspheres and nanoparticles in transarterial chemoembolization for hepatocellular carcinoma

Transarterial chemoembolization (TACE) is a recommended treatment for patients suffering from intermediate and advanced hepatocellular carcinoma (HCC). As compared to the conventional TACE, drug-eluting bead TACE demonstrates several advantages in terms of survival, treatment response, and adverse effects. The selection of embolic agents is critical to the success of TACE. Many studies have been performed on the modification of the structure, size, homogeneity, biocompatibility, and biodegradability of embolic agents. Continuing efforts are focused on efficient loading of versatile chemotherapeutics, controlled sizes for sufficient occlusion, real-time detection intra- and post-procedure, and multimodality imaging-guided precise treatment. Here, we summarize recent advances and applications of microspheres and nanoparticles in TACE for HCC. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Clinical Trials of Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

Introduction: Several immune checkpoint inhibitors (CPIs) are under clinical development in hepatocellular carcinoma (HCC) and the field is advancing rapidly. In this comprehensive review, we discuss published results and report on ongoing clinical trials. Methods: A literature search was carried out using PubMed and EMBASE; data reported at international meetings and clinicaltrials.gov were included as well. The search was updated 5 March 2021. We evaluated studies with monotherapy CPI's, combinations of CPI's and combinations of CPI's with other treatment modalities separately. Only studies with at least 10 included patients were considered. Results: We identified 2649 records published in the English language literature. After review, 29 studies remained, including 12 studies with preliminary data only. The obtained overall response rate of PD-1/PDL-1 monotherapy in phase II studies in the second-line setting was 15-20% with disease control in approximately 60% of patients. The responses were of long duration in a subset of patients. Furthermore, the safety profiles were manageable. However, a phase III study comparing nivolumab with sorafenib in the first-line setting and a phase III study evaluating pembrolizumab versus best supportive care in the second-line setting did not meet their prespecified endpoints. More recently, a phase I/II study of nivolumab and ipilimumab has resulted in a response rate of approximately 30% with a median OS of 22 months in the second-line setting. Multiple trials have been initiated to evaluate CPIs in combination with molecularly targeted drugs, especially anti-angiogenic drugs or local therapy. A phase III study investigating atezolizumab plus bevacizumab versus sorafenib in the first-line setting showed significantly increased survival in the combination arm. Conclusions: The combination of atezolizumab and bevacizumab represents a new standard of care in the first-line setting for fit patients with preserved liver function. CPIs can produce durable tumor remission and induce long-standing anti-tumor immunity in a subgroup of patients with advanced HCC. Although phase III trials of CPI monotherapy have been negative, the combination of PD-1/PD-L1 inhibitors with other anti-angiogenic drugs, CTLA-4 inhibitors or other modalities may result in new treatment options for patients with HCC. Research on predictive biomarkers is crucial for further development of CPIs in HCC.

LRP1B mutation: a novel independent prognostic factor and a predictive tumor mutation burden in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies globally and the second leading cause of cancer-related death. Low-density lipoprotein (LDL) receptor-related protein 1B (LRP1B) is one of the commonly mutated genes in HCC, but its role in HCC remains unclear. In this study, we analyzed the role of LRP1B mutation in HCC. The bioinformatics results show that LRP1B had a frequency of mutation in HCC patients, and LRP1B mutation was associated with a higher tumor mutation burden (TMB), and survival analysis proved that the prognosis of HCC patients with LRP1B mutation was poor. Univariate and multivariate COX regression analysis indicated that LRP1B mutation was an independent risk factor in evaluating HCC patients' prognosis. Correlation analysis showed that LRP1B mutation status was associated with the infiltration of 2 types of immune cells and higher expression of immune checkpoint gene human endogenous retrovirus-H long terminal repeat-associating protein 2 (HHLA2) in HCC patients. In summary, the results show that LRP1B mutation is associated with the higher TMB and poor prognosis of patients with HCC, and it was an independent risk factor for clinical outcomes of HCC patients. LRP1B gene mutations can serve as predictors in HCC patients with higher TMB and higher expression of HHLA2. The results of this study will be beneficial to future studies on targeted therapy and immunotherapy for HCC.

The Timing of Liver Transplantation Following Downstaging: Wait of Not to Wait?

PURPOSE

HCC is a complex disease that is diagnosed in advanced stage and on the background of cirrhosis. Locoregional therapies provide sufficient downstaging to enable patients suitable for radical procedures such liver transplantation. However, the interval between locoregional therapies and definitive therapy is still controversial. We performed a review of literature to evaluate the role of waiting period between locoregional therapies and liver transplantation or resection from the perspective of cure and recurrence rates.

METHODS

Thorough literature search was performed to evaluate the role of locoregional therapy and the interval to definitive therapies for the treatment of hepatocellular cancer.

RESULTS

Usually, small tumors with lower tumor burden, in other words, tumors within Milan criteria, can be transplanted with an acceptable overall and disease-free survival. However, treating patients with locally advanced tumors is currently a matter of extensive research. Currently, locoregional therapies are applied to downstage the patients. However, the duration of waiting is a crucial point that needs further research. There is a consensus that the waiting interval between down-staging and transplantation should be no less than 3 months. This is important for selection of favorable tumor biology as well as from the point of antitumor immune response.

CONCLUSION

Currently, there are no surrogate markers for surveillance of response to locoregional therapies as well as the antitumor immune response that develops as a result of down-staging.

Locoregional Therapy Approaches for Hepatocellular Carcinoma: Recent Advances and Management Strategies

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and third leading cause of cancer-related mortality worldwide. While surgical resection and transplantation are the standard first-line treatments for early-stage HCC, most patients do not fulfill criteria for surgery. Fortunately, catheter-directed and percutaneous locoregional approaches have evolved as major treatment modalities for unresectable HCC. Improved outcomes have been achieved with novel techniques which can be employed for diverse applications ranging from curative-intent for small localized tumors, to downstaging or bridging to resection and transplantation for early and intermediate disease, and locoregional control and palliation for advanced disease. This review explores recent advances in liver-directed techniques for HCC including bland transarterial embolization, chemoembolization, radioembolization, and ablative therapies, with a focus on patient selection, procedural technique, periprocedural management, and outcomes.

The Immune Modulation Effect of Locoregional Therapies and Its Potential Synergy with Immunotherapy in Hepatocellular Carcinoma

Locoregional therapies (LRTs) including radiofrequency ablation, surgical resection, and TACE, play a pivotal role in the treatment of early stage/locally advanced hepatocellular carcinoma (HCC). Besides their direct effect on tumor cells, LRTs also play an essential role in the immunomodulation of the tumor microenvironment which is of interest in the current era of cancer immunotherapy. In this review, we describe the HCC immune microenvironment and how it is affected by LRTs as described in multiple pre-clinical and clinical studies and provide the rationale for combining LRTs with immunotherapy.

Genetic Biomarkers For Hepatocellular Carcinoma In The Era Of Precision Medicine

Being one of the most lethal cancers that exhibit high levels of heterogeneity, hepatocellular carcinoma (HCC) is associated with diverse oncogenic pathways underpinned by varied driver genes. HCC can be induced by different etiological factors including virus infection, toxin exposure or metabolic disorders. Consequently, patients may display varied genetic profiles, and may respond differently to the treatments involving inhibition of target pathways. These DNA/RNA mutations, copy number variations, chromatin structural changes, aberrant expression of non-coding RNAs and epigenetic modifications were considered as biomarkers in the application of precision medication. To explore how genetic testing could contribute to early diagnosis, prognosis, treatment and postoperative monitoring of HCC, we conducted a systematic review of genetic markers associated with different pathologies. Moreover, we summarized on-going clinical trials for HCC treatment, including the trials for multiple kinase inhibitors and immune checkpoint blockade (ICB). The efficacy of ICB treatment in HCC is not as good as what was observed in lung cancer and melanoma, which might be due to the heterogeneity of the microenvironment of the liver.

Locoregional Therapy, Immunotherapy and the Combination in Hepatocellular Carcinoma: Future Directions

Image-guided locoregional therapies (LRTs) have long been a vital part of treatment regimens for hepatocellular carcinoma (HCC). Ablation, chemoembolization, and radioembolization are examples of commonly used treatment techniques for HCC. This review describes the various methods utilized to treat HCC in the field of interventional oncology and also focuses on new and novel treatment concepts being developed in the field including the use of novel immunotherapy agents and combination therapy of LRTs with immunotherapy.

The Expression of ILT4 in Myeloid Dendritic Cells in Patients with Hepatocellular Carcinoma

Immunoglobulin-like transcript (ILT) 4 is an inhibitory immune receptor of the immunoglobulin superfamily, which could deliver inhibitory signals and induce immunosuppression. The significance of the expression of ILT4 in mDCs subsets in patients with hepatocellular carcinoma (HCC) remains unclear. In this study, the frequency of mDCs subsets in the peripheral blood of 121 patients with HCC and 103 normal controls, and in the tumor and tumor free liver tissues (TFL) of 43 HCC patients was analyzed by flow cytometry. Then, the expressions of ILT4 in mDCs subsets in the microenvironment of liver cancer were also analyzed. Results showed that the percentage of CD1c⁺ subset was dramatically decreased in peripheral blood mononuclear cells (PBMCs) of HCC patients compared with normal controls, and also significantly decreased in tumor tissue compared with the TFL. The decreased of CD1c⁺ subset in blood could be a diagnostic factor for HCC with the area under the receiver operating characteristic curve 0.975 (P < 0.01). The percentage of ILT4⁺CD1c⁺ subset was dramatically increased in tumor than that of TFL and blood. There were significant correlations between the percentage of ILT4⁺ in CD1c⁺ subset in tumor and that of in blood. The percentage of ILT4⁺CD1c⁺ subset in tumor tissue was strongly associated with the Edmondson-Steiner stage in HCC (P = 0.03). Furthermore, the capacity of ILT4⁺CD1c⁺ subset producing IFN-γ was lower than ILT4^- CD1c subset in PBMC of HCC patients following Poly I:C stimulation. Taken together, the increased ILT4⁺CD1c⁺ subset in tumor tissue might play an important role in immune suppression for patients with HCC.

Splicing alterations contributing to cancer hallmarks in the liver: central role of dedifferentiation and genome instability

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. HCCs are molecularly heterogeneous tumors, and this complexity is to a great extent responsible for their poor response to conventional and targeted therapies. In this review we summarize recent evidence indicating that imbalanced expression of mRNA splicing factors can be a relevant source for this heterogeneity. We also discuss how these alterations may play a driver role in hepatocarcinogenesis by impinging on the general hallmarks of cancer. Considering the natural history of HCC, we focused on two pathogenic features that are characteristic of liver tumors: chromosomal instability and phenotypic de-differentiation. We highlight mechanisms connecting splicing derangement with these two processes and the enabling capacities acquired by liver cells along their neoplastic transformation. A thorough understanding of the alterations in the splicing machinery may also help to identify new HCC biomarkers and to design novel therapeutic strategies.

Disruption of PD-1 Enhanced the Anti-tumor Activity of Chimeric Antigen Receptor T Cells Against Hepatocellular Carcinoma

Cancer immunotherapy has made unprecedented breakthrough in the fields of chimeric antigen receptor-redirected T (CAR T) cell therapy and immune modulation. Combination of CAR modification and the disruption of endogenous inhibitory immune checkpoints on T cells represent a promising immunotherapeutic modality for cancer treatment. However, the potential for the treatment of hepatocellular carcinoma (HCC) has not been explored. In this study, the gene expressing the programmed death 1 receptor (PD-1) on the Glypican-3 (GPC3)-targeted second-generation CAR T cells employing CD28 as the co-stimulatory domain was disrupted using the CRISPR/Cas9 gene-editing system. It was found that, in vitro, the CAR T cells with the deficient PD-1 showed the stronger CAR-dependent anti-tumor activity against native programmed death 1 ligand 1-expressing HCC cell PLC/PRF/5 compared with the wild-type CAR T cells, and meanwhile, the CD4 and CD8 subsets, and activation status of CAR T cells were stable with the disruption of endogenous PD-1. Additionally, the disruption of PD-1 could protect the GPC3-CAR T cells from exhaustion when combating with native PD-L1-expressing HCC, as the levels of Akt phosphorylation and anti-apoptotic protein Bcl-xL expression in PD-1 deficient GPC3-CAR T cells were significantly higher than those in wild-type GPC3-CAR T cells after coculturing with PLC/PRF/5. Furthermore, the in vivo anti-tumor activity of the CAR T cells with the deficient PD-1 was investigated using the subcutaneous xenograft tumor model established by the injection of PLC/PRF/5 into NOD-scid-IL-2Rγ-/- (NSG) mice. The results indicated that the disruption of PD-1 enhanced the in vivo anti-tumor activity of CAR T cells against HCC, improved the persistence and infiltration of CAR T cells in the NSG mice bearing the tumor, and strengthened the inhibition of tumor-related genes expression in the xenograft tumors caused by the GPC3-CAR T cells. This study indicates the enhanced anti-tumor efficacy of PD-1-deficient CAR T cells against HCC and suggests the potential of precision gene editing on the immune checkpoints to enhance the CAR T cell therapies against HCC.

Vanadium complex: an appropriate candidate for killing hepatocellular carcinoma cancerous cells

Hepatocellular carcinoma (HCC) is a prevalent human malignancy which its drug resistance is increasing world-wide. This project was designed to assess the anti-cancer effects of 4-bromo-2-(((5-chloro-2-hydroxyphenyl) imino) methyl) phenol ([IV(L)] complex) on the HepG2 cell line and also L929 cells, as normal cells. HepG2 and L929 cells were cultured in RPMI culture medium and the survival rates of the cells were determined after 24 and 48 h using MTT assay to find IC50 concentration of vanadium m, [IV(L)] complex. The early apoptosis and necrosis/late apoptosis were determined by means of annexin V/PI apoptosis detection kit. The results revealed that vanadium m, [IV(L)] complex induce early apoptosis higher in HepG2 cell line than L929 cells. The rates of necrosis/late apoptosis were also induced in HepG2 cells more than L929 cells. Based on the results, vanadium m, [IV(L)] complex might be considered as a safe new drug for treatment of HCC with low side effects on control liver cells.

Emergence of immunotherapy as a novel way to treat hepatocellular carcinoma

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

Genome sequencing analysis of liver cancer for precision medicine

Liver cancer is the third leading cause of cancer-related death worldwide. Some thousands of liver cancer genome have been sequenced globally so far and most of driver genes/mutations with high frequency are established in liver cancer, including Wnt/β-catenin pathway, TP53/cell-cycle pathways, telomere maintenance, and chromatin regulators. HBV integration into cancer-related genes is also a driver event in hepatocarcinogenesis. These genes are affected by structural variants, copy-number alterations and virus integrations as well as point mutations. Etiological factors of liver cancer is most understood among common cancers, such as hepatitis, aflatoxin, alcohol, and metabolic diseases, and mutational signatures of liver cancer can provide evidence of the association between specific etiological factors and mutational signatures. Molecular classifications based on somatic mutations profiles, RNA expression profiles, and DNA methylation profiles are related with patient prognosis. For precision medicine, several actionable mutations with solid evidence such as targets of multi-kinase inhibitors is observed in liver cancer, but there is few molecular target therapy so far. It is possible that rare actionable mutations in liver cancer can guide other specific molecular therapy and immune therapy.