The inflammatory microenvironment of HCC - the plot becomes complex

Decoding Immune Signature to Detect the Risk for Early-Stage HCC Recurrence

Hepatocellular carcinoma (HCC) is often recognized as an inflammation-linked cancer, which possesses an immunosuppressive tumor microenvironment. Curative treatments such as surgical resection, liver transplantation, and percutaneous ablation are mainly applicable in the early stage and demonstrate significant improvement of survival rate in most patients. However, 70-80% of patients report HCC recurrence within 5 years of curative treatment, representing an important clinical issue. However, there is no effective recurrence marker after surgical and locoregional therapies, thus, tumor size, number, and histological features such as cancer cell differentiation are often considered as risk factors for HCC recurrence. Host immunity plays a critical role in regulating carcinogenesis, and the immune microenvironment characterized by its composition, functional status, and density undergoes significant alterations in each stage of cancer progression. Recent studies reported that analysis of immune contexture could yield valuable information regarding the treatment response, prognosis and recurrence. This review emphasizes the prognostic value of tumors associated with immune factors in HCC recurrence after curative treatment. In particular, we review the immune landscape and immunological factors contributing to early-stage HCC recurrence, and discuss the immunotherapeutic interventions to prevent tumor recurrence following curative treatments.

Strategies for improving the efficacy of immunotherapy in hepatocellular carcinoma

Primary liver cancer, mainly hepatocellular carcinoma (HCC), is the sixth most diagnosed cancer and third leading cause of cancer-related death globally. Recently, immunotherapies such as immune checkpoint inhibitors (ICIs) have made great progress in the systemic treatment of HCC. However, anti-PD-1 therapy with pembrolizumab or nivolumab as a single agent did not meet their predefined end points of overall survival in the KEYNOTE-240 and CheckMate 459 trials. It is urgent to understand the immunological rationale and explore novel ways to improve the efficacy of immunotherapy. The combination of ICIs with other therapies, such as tyrosine kinase inhibitors (TKIs), monoclonal antibodies, or local therapy, has been demonstrated to improve overall response rate and survival. In addition, modulating tumor microenvironment is a potential way to overcome the primary and secondary resistance to immunotherapies. In this review, we summarized the latest findings in the immune microenvironment, the mechanisms of their synergistic effects when combined with anti-VEGF agents or TKIs, as well as other kinds of immune treatment.

Detection and Quantification of Hepatitis B Virus Genomes in Peripheral Blood Mononuclear Cells of Chronic Hepatitis B Virus Infection, Cirrhosis, and Hepatocellular Carcinoma Patients

Background: Several studies have revealed that the hepatitis B virus (HBV) exists in peripheral blood mononuclear cells (PBMCs). It remains poorly understood whether HBV DNA and covalently closed circular DNA (cccDNA) can emerge in PBMCs of patients with different stages of HBV infection. Objectives: This study aimed to compare the detection of HBV DNA and quantification and presence of cccDNA within PBMC from patients with chronic hepatitis B (CHB), cirrhosis, and hepatocellular carcinoma (HCC). Methods: The present study was conducted on 120 participants (30 CHB patients, 30 cirrhosis patients, 30 HCC patients, and 30 healthy controls) from Tehran, Iran. HBV serological markers were tested by enzyme-linked immunosorbent assay (ELISA). PBMCs of all individuals were assayed for HBV DNA detection, quantification, and the presence of cccDNA. Results: Of 90 HBV patients, 58 (64.4%) were positive for HBV DNA in PBMCs. HBV DNA was detected in PBMCs isolated from 13/30 CHB, 20/30 cirrhosis, and 25/30 HCC patients. In addition, 6 (20%) CHB, 13 (43.3%) cirrhosis, and 16 (15.3%) HCC patients were cccDNA positive. The HBV viral loads in serums were statistically higher than the HBV viral loads of PBMCs (P < 0.001). A positive correlation was found between HBV DNA loads in serums and PBMCs of patients. Moreover, HBV DNA quantity of serums and PBMCs showed a significant association in terms of hepatitis B e antigen (HBeAg) status. Conclusions: HBV quantity in PBMCs correlated with serum HBV viral loads. HBV genomes in PBMCs may be a risk factor for HBV disease progression.

Immunity as Cornerstone of Non-Alcoholic Fatty Liver Disease: The Contribution of Oxidative Stress in the Disease Progression

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome and has become the major cause of chronic liver disease, especially in western countries. NAFLD encompasses a wide spectrum of hepatic histological alterations, from simple steatosis to steatohepatitis and cirrhosis with a potential development of hepatocellular carcinoma. Non-alcoholic steatohepatitis (NASH) is characterized by lobular inflammation and fibrosis. Several studies reported that insulin resistance, redox unbalance, inflammation, and lipid metabolism dysregulation are involved in NAFLD progression. However, the mechanisms beyond the evolution of simple steatosis to NASH are not clearly understood yet. Recent findings suggest that different oxidized products, such as lipids, cholesterol, aldehydes and other macromolecules could drive the inflammation onset. On the other hand, new evidence indicates innate and adaptive immunity activation as the driving force in establishing liver inflammation and fibrosis. In this review, we discuss how immunity, triggered by oxidative products and promoting in turn oxidative stress in a vicious cycle, fuels NAFLD progression. Furthermore, we explored the emerging importance of immune cell metabolism in determining inflammation, describing the potential application of trained immune discoveries in the NASH pathological context.

Predictive value of preoperative and postoperative peripheral lymphocyte difference in hepatitis B virus-related hepatocellular cancer patients: Based on the analysis of dynamic nomogram

BACKGROUND

Inflammation plays an important role in the progression and prognosis of hepatocellular carcinoma (HCC). Our aim is to explore the prognostic value of preoperative and postoperative peripheral lymphocyte differences and to develop a dynamic prognosis nomogram in hepatitis B virus-related HCC patients.

METHODS

Important indicators related to overall survival (OS) are screened out by Cox proportional hazard models. The receiver operating characteristic curves, decision curve analysis curves, net reclassification improvement, and integrated discrimination improvement were used to evaluate the performance of the model.

RESULTS

Lymphocyte (L) difference was an independent risk factor. It was further verified that the performance of the nomogram was significantly improved after the L difference was incorporated into the nomogram. The nomogram generated had the area under curves of 0.779, 0.775, and 0.793 at 3, 5, and 7 years after surgery, respectively. Our nomogram models showed significantly better performance in predicting the HCC prognosis compared to other models. And online webserver and scoring system table was built based on the proposed nomogram for convenient clinical use.

CONCLUSIONS

It is newly found that L difference is an effective predictor of OS, and the nomogram based on this indicator can accurately predict the prognosis of HCC patients.

Molecular Mechanisms and Targets of Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. HCC develops through a multistep process that involves the local tumor microenvironment, intracellular signaling pathways, and altered metabolic system that allows the cancer proliferation. Understanding the mechanisms of tumor development and progression is critical to developing improved therapies aimed at better survival. This article reviews the molecular mechanisms of HCC development and highlights the potential therapeutic targets for treatments.

Gene copy number variations in the leukocyte genome of hepatocellular carcinoma patients with integrated hepatitis B virus DNA

Integration of hepatitis B virus (HBV) DNA into the human liver cell genome is believed to promote HBV-related carcinogenesis. This study aimed to quantify the integration of HBV DNA into the leukocyte genome in hepatocellular carcinoma (HCC) patients in order to identify potential biomarkers for HBV-related diseases. Whole-genome comparative genomic hybridization (CGH) chip array analyses were performed to screen gene copy number variations (CNV) in the leukocyte genome, and the results were confirmed by quantitative polymerase chain reaction (qPCR). The commonly detected regions included chromosome arms 19p, 5q, 1q and 15p, where 200 copy number gain events and 270 copy number loss events were noted. In particular, gains were observed in 5q35.3 (OR4F3) and 19p13.3 (OR4F17) in 90% of the samples. Successful homologous recombination of OR4F3 and the HBV P gene was demonstrated, and the amplification at 5q35.3 is potentially associated with the integration of HBV P gene into natural killer cells isolated from peripheral blood mononuclear cells (PBMCs). Receiver operating characteristic (ROC) curve analysis indicated that the combination of OR4F3 and OR4F17 a novel potential biomarker of HBV-related diseases.

Impact of non-neoplastic vs intratumoural hepatitis B viral DNA and replication on hepatocellular carcinoma recurrence

Background:

This study aims to determine the impact of intracellular hepatitis B virus (HBV) DNA, covalently closed circular DNA (cccDNA) and viral replicative activity in both tumour and non-neoplastic liver on prognosis and to determine the relationship of viral replicative activity and Ishak fibrosis in predicting outcome following resection.

Methods:

A total of 99 prospectively enrolled patients treated with primary liver resection for HBV-HCC are included. Intracellular HBV DNA and cccDNA were quantitated by real-time PCR. The RNA-sequencing (RNA-seq) was performed in a subset of 21 patients who had either minimal liver fibrosis (Ishak stages 0–2) or end-stage fibrosis (Ishak stage 6).

Results:

Tumour tissue contained a lower cccDNA copy number compared with paired non-neoplastic liver, and larger tumours (>3 cm) had less cccDNA compared with small tumours (⩽3 cm). High viral replicative activity in non-neoplastic liver was associated with higher HCC recurrence rate independent of Ishak fibrosis stage. Genes correlated with viral replicative activity in non-neoplastic liver (620 genes) were distinct from those associated with end-stage fibrosis (1226 genes). Genes associated with viral replicative activity were preferentially distributed in regions on chr3, chr16 and chr19.

Conclusions:

Viral replicative activity in non-neoplastic liver is associated with HCC recurrence through mechanisms that are distinct from and independent of Ishak fibrosis stage.

The impact of inflammatory cells in malignant ascites on small intestinal ICCs' morphology and function

Malignant ascites is one of the common complication at the late stage of abdominal cancers, which may deteriorate the environment of abdominal cavity and lead to potential damage of functional cells. Interstitial cells of Cajal (ICCs) are mesoderm-derived mesenchymal cells that function normal gastrointestinal motility. The pathological changes of ICCs or the reduced number may lead to the motility disorders of gastrointestinal tract. In this study, through analysis of malignant ascites which were obtained from cancer patients, we found that inflammatory cells, including tumour-infiltrating lymphocytes, accounted for 17.26 ± 1.31% and tumour-associated macrophages, occupied 19.06 ± 2.27% of total cells in the ascites, suggesting these inflammatory cells, in addition to tumour cells, may exert important influence on the tumour environment of abdominal cavity. We further demonstrated that the number of mice ICCs were significant decreased, as well as morphological and functional damage when ICCs were in the simulated tumour microenvironment in vitro. Additionally, we illustrated intestinal myoelectrical activity reduced and irregular with morphological changes of ICCs using the mice model of malignant ascites. In conclusion, our data suggested that inflammatory cells in malignant ascites may damage ICCs of the small intestine and lead to intestinal motility disorders.

Inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma

AIM: To study the inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma (HCC) in nude mice.

METHODS: CBRH-7919 HCC cells were injected into the subcutaneous region of nude mice. Beginning two weeks after the challenge, tumor growth was measured every week for six weeks. The stromal microenvironment and inflammatory cell infiltration was assessed by immunohistochemistry in paired tumor and adjacent peritumoral samples, and macrophage phenotype was assessed using double-stain immunohistochemistry incorporating expression of an intracellular enzyme. A chemokine PCR array, comprised of 98 genes, was used to screen differential gene expressions, which were validated by Western blotting. Additionally, expression of identified chemokines was knocked-down by RNA interference, and the effect on tumor growth was assessed.

RESULTS: Inflammatory cell infiltrates are a key feature of adjacent peritumoral tissues with increased macrophage, neutrophil, and T cell (specifically helper and activated subsets) infiltration. Macrophages within adjacent peritumoral tissues express inducible nitric oxide synthase, suggestive of a proinflammatory phenotype. Fifty-one genes were identified in tumor tissues during the progression period, including 50 that were overexpressed (including CXCL1, CXCL2 and CXCL3) and three that were underexpressed (CXCR1, Ifg and Actb). RNA interference of CXCL1 in the CBRH-7919 cells decreased the growth of tumors in nude mice and inhibited expression of CXCL2, CXCL3 and interleukin-1β protein.

CONCLUSION: These findings suggest that CXCL1 plays a critical role in tumor growth and may serve as a potential molecular target for use in HCC therapy.

Angiogenin secretion from hepatoma cells activates hepatic stellate cells to amplify a self-sustained cycle promoting liver cancer

Hepatocellular carcinoma (HCC) frequently develops in a pro-inflammatory and pro-fibrogenic environment with hepatic stellate cells (HSCs) remodeling the extracellular matrix composition. Molecules secreted by liver tumors contributing to HSC activation and peritumoral stromal transformation remain to be fully identified. Here we show that conditioned medium from HCC cell lines, Hep3B and HepG2, induced primary mouse HSCs transdifferentiation, characterized by profibrotic properties and collagen modification, with similar results seen in the human HSC cell line LX2. Moreover, tumor growth was enhanced by coinjection of HepG2/LX2 cells in a xenograft murine model, supporting a HCC-HSC crosstalk in liver tumor progression. Protein microarray secretome analyses revealed angiogenin as the most robust and selective protein released by HCC compared to LX2 secreted molecules. In fact, recombinant angiogenin induced in vitro HSC activation requiring its nuclear translocation and rRNA transcriptional stimulation. Moreover, angiogenin antagonism by blocking antibodies or angiogenin inhibitor neomycin decreased in vitro HSC activation by conditioned media or recombinant angiogenin. Finally, neomycin administration reduced tumor growth of HepG2-LX2 cells coinjected in mice. In conclusion, angiogenin secretion by HCCs favors tumor development by inducing HSC activation and ECM remodeling. These findings indicate that targeting angiogenin signaling may be of potential relevance in HCC management.

Role of innate immunity in the development of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of liver cancer worldwide. It is caused by a variety of risk factors, most common ones being infection with hepatitis viruses, alcohol, and obesity. HCC often develops in the background of underlying cirrhosis, and even though a number of interventional treatment methods are currently in use, recurrence is fairly common among patients who have had a resection. Therefore, whole liver transplantation remains the most practical treatment option for HCC. Due to the growing incidence of HCC, intense research efforts are being made to understand cellular and molecular mechanisms of the disease so that novel therapeutic strategies can be developed to combat liver cancer. In recent years, it has become clear that innate immunity plays a critical role in the development of a number of liver diseases, including HCC. In particular, the activation of Toll-like receptor signaling results in the generation of immune responses that often results in the production of pro-inflammatory cytokines and chemokines, and could cause acute inflammation in the liver. In this review, the current knowledge on the role of innate immune responses in the development and progression of HCC is examined, and emerging therapeutic strategies based on molecular mechanisms of HCC are discussed.

Cellular and molecular mechanisms of hepatocellular carcinoma: an update

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor that accounts for ~80 % of all liver cancer cases worldwide. It is a multifactorial disease caused by a variety of risk factors and often develops in the background of underlying cirrhosis. A number of cellular phenomena, such as tumor microenvironment, inflammation, oxidative stress, and hypoxia act in concert with various molecular events to facilitate tumor initiation, progression, and metastasis. The emergence of microRNAs and molecular-targeted therapies adds a new dimension in our efforts to combat this deadly disease. Intense research in this multitude of areas has led to significant progress in our understanding of cellular processes and molecular mechanisms that occur during multistage events that lead to hepatocarcinogenesis. In this review, we discuss the current knowledge of HCC, focusing mainly on advances that have occurred during the past 5 years and on the development of novel therapeutics for liver cancer.

Inflammatory immune responses in tumor microenvironment and metastasis of hepatocellular carcinoma

Metastasis is a multistage process that requires cancer cells to escape from the primary tumor, survive in the circulation, seed at distant sites and grow. Each of these processes involves rate-limiting steps that are influenced by non-malignant cells of the tumor microenvironment. There are growing evidences that tumors are sustained and promoted by inflammatory signals from the surrounding microenvironment. This review describes experimental data demonstrating the role of the inflammatory immune responses of microenvironment in metastases of hepatocellular carcinoma (HCC), points out the prospective areas for future research and possible new therapeutic approaches to control the metastasis of HCC.