Liver-infiltrating CD8(+) lymphocytes as prognostic factor for tumour recurrence in hepatitis C virus-related hepatocellular carcinoma

AI-based tumor-infiltrating lymphocyte scoring system for assessing HCC prognosis in patients undergoing liver resection

Background & Aims

Tumor-infiltrating lymphocytes (TILs), particularly CD8+ TILs, are key prognostic markers in many cancers. However, their prognostic value in hepatocellular carcinoma (HCC) remains controversial, with different evidence. Given the heterogeneous outcomes in patients with HCC undergoing liver resection, this study aims to develop an AI-based system to quantify CD8+ TILs and assess their prognostic value for patients with HCC.

Methods

We conducted a retrospective multicenter study on patients undergoing liver resection across three cohorts (N = 514). We trained a deep neural network and a random forest model to segment tumor regions and locate CD8+ TILs in H&E and CD8-stained whole-slide images. We quantified CD8+ TIL density and established an Automated CD8+ Tumor-infiltrating Lymphocyte Scoring (ATLS-8) system to assess its prognostic value.

Results

In the discovery cohort, the 5-year overall survival (OS) rates were 34.05% for ATLS-8 low-score and 65.03% for ATLS-8 high-score groups (hazard ratio [HR] 2.40; 95% CI, 1.37-4.19; p = 0.015). These findings were confirmed in validation cohort 1, which had 5-year OS rates of 28.57% and 68.73% (HR 3.38; 95% CI, 1.27-9.02; p = 0.0098), and validation cohort 2, which had 59.26% and 81.48% (HR 2.74; 95% CI, 1.05-7.15; p = 0.031). ATLS-8 improved the prognostic model based on clinical variables (C-index 0.770 vs. 0.757; 0.769 vs. 0.727; 0.712 vs. 0.642 in three cohorts).

Conclusions

We developed an automated system using CD8-stained whole-slide images to assess immune infiltration (ATLS-8). In patients with HCC undergoing resection, higher CD8+ TIL density correlates with better OS, as per ATLS-8 assessment. This system is a promising tool for advancing clinical immune microenvironment assessment and outcome prediction.

Impact and implications

CD8+ tumor-infiltrating lymphocytes (TILs) have been identified as a prognostic factor associated with many cancers. In this study, CD8+ TILs were identified as an independent prognostic factor for overall survival in patients with hepatocellular carcinoma who undergoing liver resection. Therefore, ATLS-8, a novel digital biomarker based on whole-slide image-level CD8+ TILs, could play an important role in the prognostic assessment of patients with HCC and could be integrated into clinicopathological models to participate in the decision-making and prognostic assessment of patients. The scoring system combined with artificial intelligence is essential for automated, quantitative, whole-slide image-level assessment of TILs, which can be widely applied to quantify the immune profile of multi-cancer disease types with the discussion of subsequent immunotherapy.

Low CD8+ Density Variation and R1 Surgical Margin as Independent Predictors of Early Post-Resection Recurrence in HCC Patients Meeting Milan Criteria

Our study included 41 patients fulfilling the Milan criteria preoperatively and aimed to identify individuals at high risk of post-resection HCC relapse, which occurred in 18 out of 41 patients (43.9%), retrospectively. We analyzed whole slide images of CD8 immunohistochemistry with automated segmentation of tissue classes and detection of CD8+ lymphocytes. The image analysis outputs were subsampled using a hexagonal grid-based method to assess spatial distribution of CD8+ lymphocytes with regards to the epithelial edges. The CD8+ lymphocyte density indicators, along with clinical, radiological, post-surgical and pathological variables, were tested to predict HCC relapse. Low standard deviation of CD8+ density along the tumor edge and R1 resection emerged as independent predictors of shorter recurrence-free survival (RFS). In particular, patients presenting with both adverse predictors exhibited 100% risk of relapse within 200 days. Our results highlight the potential utility of integrating CD8+ density variability and surgical margin to identify a high relapse-risk group among Milan criteria-fulfilling HCC patients. Validation in cohorts with core biopsy could provide CD8+ distribution data preoperatively and guide preoperative decisions, potentially prioritizing liver transplantation for patients at risk of incomplete resection (R1) and thereby improving overall treatment outcomes significantly.

Overall Survival Prediction by Tumor Microenvironment Lymphocyte Distribution in Hepatocellular Carcinoma After Liver Transplantation

INTRODUCTION

Our previous research demonstrated that CD8+ cell density profiling using a hexagonal grid-based digital image analysis method provides predictors of patient outcomes after liver resection due to hepatocellular carcinoma (HCC). Continuing our study, we have further investigated the applicability of the methodology to patients receiving a liver transplant for HCC.

METHODS

The retrospective study enrolled patients with HCC who underwent liver transplantation (LT) at the Vilnius University Hospital Santaros Clinics between 2007 and 2020. We determined the density profiles of CD8+ lymphocytes at the interface between HCC and stroma and the interface between the perineoplastic liver parenchyma and stroma. Both digital image analysis and the hexagonal grid-based immunogradient method were applied to CD8+ immunohistochemistry images. Survival statistics based on clinicopathological, peripheral blood analysis, and surgical data determined the prognostic value of these indicators.

RESULTS

Univariate clinicopathological predictors of worse OS after LT included: patient's age at the time of the transplantation, a higher number of HCC nodules, lower platelet count, longer activated thromboplastin time, lower serum albumin, higher serum total bilirubin, and lower serum creatinine levels. The two independent predictors of overall survival were mean CD8+ cell density at the epithelial edge of the explanted liver parenchyma-stroma interface and peripheral blood platelet count.

CONCLUSIONS

Our model discloses that preoperative peripheral blood platelet count and mean CD8+ cell density at the epithelial edge of nonmalignant interface in the explanted liver parenchyma are independent predictors of OS for HCC after LT.

Key oncogenic signaling pathways affecting tumor-infiltrating lymphocytes infiltration in hepatocellular carcinoma: basic principles and recent advances

The incidence of hepatocellular carcinoma (HCC) ranks first among primary liver cancers, and its mortality rate exhibits a consistent annual increase. The treatment of HCC has witnessed a significant surge in recent years, with the emergence of targeted immune therapy as an adjunct to early surgical resection. Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) has shown promising results in other types of solid tumors. This article aims to provide a comprehensive overview of the intricate interactions between different types of TILs and their impact on HCC, elucidate strategies for targeting neoantigens through TILs, and address the challenges encountered in TIL therapies along with potential solutions. Furthermore, this article specifically examines the impact of oncogenic signaling pathways activation within the HCC tumor microenvironment on the infiltration dynamics of TILs. Additionally, a concise overview is provided regarding TIL preparation techniques and an update on clinical trials investigating TIL-based immunotherapy in solid tumors.

The molecular mechanism of actions and clinical utilities of tumor infiltrating lymphocytes in gastrointestinal cancers: a comprehensive review and future prospects toward personalized medicine

Gastrointestinal (GI) cancers remain a significant global health burden, accounting for a substantial number of cases and deaths. Regrettably, the inadequacy of dependable biomarkers hinders the precise forecasting of patient prognosis and the selection of appropriate therapeutic sequencing for individuals with GI cancers, leading to suboptimal outcomes for numerous patients. The intricate interplay between tumor-infiltrating lymphocytes (TILs) and the tumor immune microenvironment (TIME) has been shown to be a pivotal determinant of response to anti-cancer therapy and consequential clinical outcomes across a multitude of cancer types. Therefore, the assessment of TILs has garnered global interest as a promising prognostic biomarker in oncology, with the potential to improve clinical decision-making substantially. Moreover, recent discoveries in immunotherapy have progressively changed the landscape of cancer treatment and significantly prolonged the survival of patients with advanced cancers. Nonetheless, the response rate remains constrained within solid tumor sufferers, even when TIL landscapes appear comparable, which calls for the development of our understanding of cellular and molecular cross-talk between TIME and tumor. Hence, this comprehensive review encapsulates the extant literature elucidating the TILs' underlying molecular pathogenesis, prognostic significance, and their relevance in the realm of immunotherapy for patients afflicted by GI tract cancers. Within this review, we demonstrate that the type, density, and spatial distribution of distinct TIL subpopulations carries pivotal implications for the prediction of anti-cancer treatment responses and patient survival. Furthermore, this review underscores the indispensable role of TILs in modulating therapeutic responses within distinct molecular subtypes, such as those characterized by microsatellite stability or programmed cell death ligand-1 expression in GI tract cancers. The review concludes by outlining future directions in TIL-based personalized medicine, including integrating TIL-based approaches into existing treatment regimens and developing novel therapeutic strategies that exploit the unique properties of TILs and their potential as a promising avenue for personalized cancer treatment.

Overexpression of TRIM28 predicts an unfavorable prognosis and promotes the proliferation and migration of hepatocellular carcinoma

Objectives

Previous studies have shown that tripartite motif-containing 28 (TRIM28) might be a latent target for cancer therapy. However, the detailed roles and mechanisms of TRIM28 in hepatocellular carcinoma (HCC) remain ambiguous.

Methods

We systematically analyzed TRIM28 mRNA expression and protein levels in HCC tissues based on large-scale data and publicly available immunohistochemistry images. We estimated the prognostic capacity of TRIM28 in HCC. Additionally, we performed gene enrichment, immune infiltration, and drug sensitivity analyses to further explore the roles of TRIM28 in HCC. To determine the effect of TRIM28 expression on HCC cell proliferation and migration, successful transfection of siRNAs was conducted in MHCC97-L and Huh7 cells, followed by cell functional assays.

Results

We verified the overexpression of TRIM28 in HCC at the mRNA and protein levels. The summary receiver operating characteristics curve with the area under curve of 0.84 (95 % CI: 0.81–0.87) indicated the high accuracy of increasing TRIM28 expression for discriminating HCC from non-HCC tissues. According to The Cancer Genome Atlas datasets, TRIM28 mRNA expression was significantly related to age, grade, stage, and pathologic T (p<0.05). Increased TRIM28 expression levels were significant correlated to poor survival in HCC patients. An enrichment analysis suggested that TRIM28-reated genes primarily participated in the spliceosome signaling pathway, with hub genes including SNRPA1, SNRPF, SNRPD1, SF3B2, SNRPB, SNRPE, and EFTUD2. TRIM28 expression was correlated with the infiltration of five immune cells. Higher TRIM28 expression was linked to better sensitivity of tumor cells to pluripotin. Molecular docking showed that pluripotin could bind to TRIM28. Further, knockdown of TRIM28 inhibited the proliferation and migration of HCC cells.

Conclusions

TRIM28 is highly expressed in HCC and contribute to the proliferation and migration of HCC cells, leading to unfavorable outcomes. These findings indicate TRIM28 promise as a novel prognostic indicator.

A comprehensive survival and prognosis analysis of GPR55 expression in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common subtype, accounting for about 90% of all primary liver cancers. The liver is rich in a large number of immune cells, thus forming a special immune microenvironment, which plays a key role in the occurrence and development of hepatocellular carcinoma. Nowadays, tumor immunotherapy has become one of the most promising cancer treatment methods. Immune checkpoint inhibitors (ICIs) combined with VEGF inhibitors are listed as first-line treatment options for advanced HCC. Therefore, the search for a potential biomarker to predict the response to immunotherapy in HCC patients is urgently needed. The G protein-coupled receptor 55 (GPR55), a lysophosphatidylinositol (LPI) receptor, has recently emerged as a potential new target for anti-tumor therapy. Previous studies have found that GPR55 is highly expressed in breast cancer, pancreatic cancer, skin cancer and cholangiocarcinoma, and is involved in tumor proliferation and migration. However, the role and mechanism of GPR55 in HCC has not been elucidated. Therefore, this article discusses the clinical significance of GPR55 in HCC and its correlation with the immune response of HCC patients, so as to provide theoretical basis for improving the prognosis of HCC.

Comprehensive DNA methylation profiling of COVID-19 and hepatocellular carcinoma to identify common pathogenesis and potential therapeutic targets

BACKGROUND & AIMS

The effects of SARS-CoV-2 infection can be more complex and severe in patients with hepatocellular carcinoma (HCC) as compared to other cancers. This is due to several factors, including pre-existing conditions such as viral hepatitis and cirrhosis, which are commonly associated with HCC.

METHODS

We conducted an analysis of epigenomics in SARS-CoV-2 infection and HCC patients, and identified common pathogenic mechanisms using weighted gene co-expression network analysis (WGCNA) and other analyses. Hub genes were identified and analyzed using LASSO regression. Additionally, drug candidates and their binding modes to key macromolecular targets of COVID-19 were identified using molecular docking.

RESULTS

The epigenomic analysis of the relationship between SARS-CoV-2 infection and HCC patients revealed that the co-pathogenesis was closely linked to immune response, particularly T cell differentiation, regulation of T cell activation and monocyte differentiation. Further analysis indicated that CD4⁺ T cells and monocytes play essential roles in the immunoreaction triggered by both conditions. The expression levels of hub genes MYLK2, FAM83D, STC2, CCDC112, EPHX4 and MMP1 were strongly correlated with SARS-CoV-2 infection and the prognosis of HCC patients. In our study, mefloquine and thioridazine were identified as potential therapeutic agents for COVID-19 in combined with HCC.

CONCLUSIONS

In this research, we conducted an epigenomics analysis to identify common pathogenetic processes between SARS-CoV-2 infection and HCC patients, providing new insights into the pathogenesis and treatment of HCC patients infected with SARS-CoV-2.

Effects of gene silencing of indoleamine 2,3-dioxygenase 1 combined with rosmarinic acid on tumor immune microenvironment in H22 tumor-bearing mice

Rosmarinic acid (RA) is a natural polyphenolic compound with several pharmacological activities, including immunomodulation and anti-tumor effect. Indoleamine 2,3-dioxygenase-1 (IDO1), the rate-limiting enzyme that metabolizes tryptophan into kynurenine, is an important negative immune regulator. This study aimed to explore the effect of combined action of IDO1 gene silencing and RA on tumor immune microenvironment. H22 tumor-bearing mice were treated with combination therapy with RA and IDO1-shRNA. The percentages and apoptosis of T-cells and subsets of splenic regulatory T-cells (Tregs) were detected by flow cytometry. Levels of tumor necrosis factor (TNF-α), Interferon-γ (IFN-γ), interleukin-2 (IL-2) and interleukin-10 (IL-10) were measured by enzyme linked immunosorbent assay (ELISA). Treatment with RA + IDO1-shRNA significantly increased the percentage of CD4+ T cells, ratio of CD4⁺/CD8⁺ and the levels of IFN-γ and IL-2, while decreased CD8+ apoptosis, the proportion of splenic Tregs and the levels of TNF-α and IL-10. The present study demonstrated that combination therapy with RA and IDO1-shRNA had anti-tumor effects on HCC. The mechanism might be related to regulating immune response and immunocytokines, as well as alleviating immunosuppression induced by Tregs in the tumor immune microenvironment.

Prognostic Value of CD8+ Lymphocytes in Hepatocellular Carcinoma and Perineoplastic Parenchyma Assessed by Interface Density Profiles in Liver Resection Samples

Hepatocellular carcinoma (HCC) often emerges in the setting of long-standing inflammatory liver disease. CD8 lymphocytes are involved in both the antitumoral response and hepatocyte damage in the remaining parenchyma. We investigated the dual role of CD8 lymphocytes by assessing density profiles at the interfaces of both HCC and perineoplastic liver parenchyma with surrounding stroma in whole-slide immunohistochemistry images of surgical resection samples. We applied a hexagonal grid-based digital image analysis method to sample the interface zones and compute the CD8 density profiles within them. The prognostic value of the indicators was explored in the context of clinicopathological, peripheral blood testing, and surgery data. Independent predictors of worse OS were a low standard deviation of CD8+ density along the tumor edge, high mean CD8+ density within the epithelial aspect of the perineoplastic liver-stroma interface, longer duration of surgery, a higher level of aspartate transaminase (AST), and a higher basophil count in the peripheral blood. A combined score, derived from these five independent predictors, enabled risk stratification of the patients into three prognostic categories with a 5-year OS probability of 76%, 40%, and 8%. Independent predictors of longer RFS were stage pT1, shorter duration of surgery, larger tumor size, wider tumor-free margin, and higher mean CD8+ density in the epithelial aspect of the tumor-stroma interface. We conclude that (1) our computational models reveal independent and opposite prognostic impacts of CD8+ cell densities at the interfaces of the malignant and non-malignant epithelium interfaces with the surrounding stroma; and (2) together with pathology, surgery, and laboratory data, comprehensive prognostic models can be constructed to predict patient outcomes after liver resection due to HCC.

Recent progress in molecular mechanisms of postoperative recurrence and metastasis of hepatocellular carcinoma

Hepatectomy is currently considered the most effective option for treating patients with early and intermediate hepatocellular carcinoma (HCC). Unfortunately, the postoperative prognosis of patients with HCC remains unsatisfactory, predominantly because of high postoperative metastasis and recurrence rates. Therefore, research on the molecular mechanisms of postoperative HCC metastasis and recurrence will help develop effective intervention measures to prevent or delay HCC metastasis and recurrence and to improve the long-term survival of HCC patients. Herein, we review the latest research progress on the molecular mechanisms underlying postoperative HCC metastasis and recurrence to lay a foundation for improving the understanding of HCC metastasis and recurrence and for developing more precise prevention and intervention strategies.

Biomarkers for the Detection and Management of Hepatocellular Carcinoma in Patients Treated with Direct-Acting Antivirals

Simple Summary

Chronic Hepatitis C virus (HCV) represents the main etiological factor for hepatocellular carcinoma (HCC) in developed countries. The introduction of direct-acting antivirals (DAAs) improved the eradication of the hepatitis C virus (HCV) but not the reduction in the incidence of HCV-associated HCC. Some patients still develop HCC, even after reaching a sustained virological response (SVR). This review is a summary of pre-clinical studies that investigated predictive biomarkers for HCC occurrence and recurrence in HCV-infected patients treated with DAAs. The presented biomarkers are found dysregulated in serum or tissue at specific time points (before, during, after DAA treatment or post SVR) and correlated with HCC-predisposing conditions. Thus, this review aims to improve the management of patients developing HCV-induced HCC.

Abstract

Hepatocellular carcinoma (HCC) is the sixth-most common type of cancer worldwide and chronic Hepatitis C virus (HCV) represents the main etiological factor in developed countries. HCV promotes hepatocarcinogenesis through persistent liver inflammation and dysregulation of cell signaling pathways. The introduction of direct-acting antivirals (DAAs) resulted in a significant improvement in the eradication of the virus, with an expected reduction of HCC incidence. However, the risk of HCC development can persist after DAA treatment. Recent studies have investigated the potential use of molecular biomarkers that predict HCC occurrence or recurrence helping the stratification of patients under surveillance. This review aimed to summarize all pre-clinical exploration of predictive biomarkers to identify DAA-treated patients at risk for HCC development. Dysregulated microRNAs, lncRNAs, histone modifications, cytokines, proteins, and sphingolipids represent various classes of HCC risk predictors identified in two different biological sources (tissue and serum). The non-invasive serum markers can provide a more accessible means to perform clinical monitoring and predict the risk of HCC. In addition, conditions like cirrhosis, predisposing to HCC, strongly correlate with most of the molecular predictors identified, supporting the value of these molecules as possible biomarkers of HCC in DAA-treated patients.

Innate and Adaptive Immunopathogeneses in Viral Hepatitis; Crucial Determinants of Hepatocellular Carcinoma

Viral hepatitis B (HBV) and hepatitis C (HCV) infections remain the most common risk factors for the development of hepatocellular carcinoma (HCC), and their heterogeneous distribution influences the global prevalence of this common type of liver cancer. Typical hepatitis infection elicits various immune responses within the liver microenvironment, and viral persistence induces chronic liver inflammation and carcinogenesis. HBV is directly mutagenic but can also cause low-grade liver inflammation characterized by episodes of intermittent high-grade liver inflammation, liver fibrosis, and cirrhosis, which can progress to decompensated liver disease and HCC. Equally, the absence of key innate and adaptive immune responses in chronic HCV infection dampens viral eradication and induces an exhausted and immunosuppressive liver niche that favors HCC development and progression. The objectives of this review are to (i) discuss the epidemiological pattern of HBV and HCV infections, (ii) understand the host immune response to acute and chronic viral hepatitis, and (iii) explore the link between this diseased immune environment and the development and progression of HCC in preclinical models and HCC patients.

Patient stratification in hepatocellular carcinoma: impact on choice of therapy

INTRODUCTION

HCC comprises around 60 to 80% of all primary liver cancers and exhibits wide geographical variability. Appropriate treatment allocation needs to include both patient and tumor characteristics.

AREAS COVERED

Current HCC classification systems to guide therapy are either liver function-centric and evaluate physiologic liver function to guide therapy or prognostic stratification classification systems broadly based on tumor morphologic parameters, patient performance status, and liver reserve assessment. This review focuses on different classification systems for HCC, their strengths, and weaknesses as well as the use of artificial intelligence in improving prognostication in HCC.

EXPERT OPINION

Future HCC classification systems will need to incorporate clinic-pathologic data from a multitude of sources and emerging therapies to develop patient-specific treatment plans targeting a patient's unique tumor profile.

T- and B-Cells in the Inner Invasive Margin of Hepatocellular Carcinoma after Resection Associate with Favorable Prognosis

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world, which frequently recurs after curative resection. Several options to predict recurrence of HCC have been proposed, however, their prognostic ability is limited. This study aimed to test the hypothesis that distribution and numbers of T- and B-lymphocytes in different regions of the resected tumor may have different prognostic significance. Different subregions of HCC demonstrated uneven lymphocyte infiltration. CD20+ B-lymphocytes and CD8+ T-lymphocytes, or their combination in the inner tumor invasive margin and inner/outer margin ratios, convey the best prediction for time to recurrence and disease-free survival. The results offer a novel approach to the stratification of the risk of early tumor recurrence after curative liver resection.

Abstract

In this retrospective study on 67 patients with hepatocellular carcinoma (HCC), after tumor resection, we evaluated the significance of CD3+ and CD8+ T-lymphocytes and CD20+ B-lymphocytes in tumor and non-tumor liver for time to recurrence (TTR), disease-free survival (DFS) and overall survival. After immunohistochemical staining, the density of nucleated lymphocyte profiles (Q_A) was estimated stereologically in the tumor center (TC), inner margin (inn M), outer margin (out M), peritumor and non-tumor liver. In TC, intermediate and high Q_A of CD8+ cells predicted longer TTR, whereas CD3+ and CD20+ were predictive only at high Q_A. DFS was predicted by high Q_A of CD3+, CD8+ and CD20+ cells in TC. The inn M harbored smaller Q_A of CD3+, CD8+ and CD20+ lymphocytes than out M. In contrast to out M, high T-cells’ Q_A and intermediate and high B-cell Q_A in inn M predicted longer TTR and DFS. High inn M/out M Q_A ratios of CD3+ and CD20+ cells were associated with longer TTR and DFS, whereas high inn M/out M Q_A ratio of CD8+ was predictive only for DFS. Patients with intermediate-high Q_A of combined CD8+ and CD20+ cells in inn M showed longer TTR and DFS, compared to CD8+-high or CD20+-high alone. Our findings highlight overall heterogeneity of the tumor invasive margin, the importance of inn M, and the predictive role of B-cells.

Downregulation of ACE2 is associated with advanced pathological features and poor prognosis in clear cell renal cell carcinoma

Aims: The aim of this study was to explore the alteration in ACE2 expression and correlation between ACE2 expression and immune infiltration in clear cell renal cell carcinoma (ccRCC). Methods: The authors first analyzed the expression profiles and prognostic value of ACE2 in ccRCC patients using The Cancer Genome Atlas public database. The authors used ESTIMATE and CIBERSORT algorithms to analyze the correlation between ACE2 expression and tumor microenvironment in ccRCC samples. Results: ACE2 was correlated with sex, distant metastasis, clinical stage, tumor T stage and histological grade. Moreover, downregulation of ACE2 was correlated with unfavorable prognosis. In addition, ACE2 expression was associated with different immune cell subtypes. Conclusion: The authors' analyses suggest that ACE2 plays an important role in the development and progression of ccRCC and may serve as a potential prognostic biomarker in ccRCC patients.

Progression on the Roles and Mechanisms of Tumor-Infiltrating T Lymphocytes in Patients With Hepatocellular Carcinoma

Primary liver cancer (PLC) is one of the most common malignancies in China, where it ranks second in mortality and fifth in morbidity. Currently, liver transplantation, hepatic tumor resection, radiofrequency ablation, and molecular-targeted agents are the major treatments for hepatocellular carcinoma (HCC). Overall, HCC has a poor survival rate and a high recurrence rate. Tumor-infiltrating lymphocytes (TILs) have been discovered to play essential roles in the development, prognosis, and immunotherapy treatment of HCC. As the major component cells of TILs, T cells are also proved to show antitumor and protumor effects in HCC. Foxp3+, CD8+, CD3+, and CD4+ T lymphocytes are the broadly studied subgroups of TILs. This article reviews the roles and mechanisms of different tumor-infiltrating T lymphocyte subtypes in HCC.

Possible spontaneous regression of hepatocellular carcinoma with unique histopathological features confirmed by surgical resection: a case report

Background

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare event, and its clinicopathological features and underlying mechanism are not fully understood.

Case presentation

An 84-year-old female with hepatitis C virus infection and diabetes mellitus was referred to our hospital for further examination. Abdominal ultrasonography showed a 3.4-cm solid tumor with a heterogeneous irregular center and no fibrous capsule in liver segment 8 (S8). An enhanced computed tomography (CT) scan revealed a tumor in S8 with heterogeneous enhancement in the arterial phase and washed out insufficiently in the portal and equilibrium phase. The enhanced pattern on magnetic resonance imaging was similar to that of CT. Although the imaging findings were not typical for HCC, liver resection (S8) was performed with HCC as the most probable diagnosis. Histopathological examination of the resected specimen showed that the tumor was well to moderately differentiated HCC with unique features. Approximately half of the tumor was composed of well-differentiated HCC that was focally accompanied by dense lymphocyte infiltration. The other half of the tumor was fibrotic tissue that resembled an inflammatory pseudotumor. Several foci of moderately differentiated HCC were scattered within the tumor with a nodule-in-nodule appearance, and the foci totally showed coagulative necrosis. On immunostaining, lymphocytes in the tumor stroma were positive for CD8 and programmed death 1. The expression of programmed death-ligand 1 was observed in carcinoma cells and macrophages specifically within the lymphocyte-rich area of HCC.

Conclusions

We consider this case representative of spontaneous regression of HCC, and the immune response against HCC might contribute to tumor regression, leading to complex histopathological appearances. This case may provide insight into the mechanism of spontaneous regression of HCC.

Tumor Immune Microenvironment and Immunosuppressive Therapy in Hepatocellular Carcinoma: A Review

Liver cancer has the fourth highest mortality rate of all cancers worldwide, with hepatocellular carcinoma (HCC) being the most prevalent subtype. Despite great advances in systemic therapy, such as molecular-targeted agents, HCC has one of the worst prognoses due to drug resistance and frequent recurrence and metastasis. Recently, new therapeutic strategies such as cancer immunosuppressive therapy have prolonged patients' lives, and the combination of an immune checkpoint inhibitor (ICI) and VEGF inhibitor is now positioned as the first-line therapy for advanced HCC. Since the efficacy of ICIs depends on the tumor immune microenvironment, it is necessary to elucidate the immune environment of HCC to select appropriate ICIs. In this review, we summarize the findings on the immune microenvironment and immunosuppressive approaches focused on monoclonal antibodies against cytotoxic T lymphocyte-associated protein 4 and programmed cell death protein 1 for HCC. We also describe ongoing treatment modalities, including adoptive cell transfer-based therapies and future areas of exploration based on recent literature. The results of pre-clinical studies using immunological classification and animal models will contribute to the development of biomarkers that predict the efficacy of immunosuppressive therapy and aid in the selection of appropriate strategies for HCC treatment.

Imaging features of gadoxetic acid-enhanced MR imaging for evaluation of tumor-infiltrating CD8 cells and PD-L1 expression in hepatocellular carcinoma

BACKGROUND

Tumor-infiltrating CD8 cells and expression of programmed cell death ligand 1 (PD-L1) are immune checkpoint markers in patients with hepatocellular carcinoma (HCC). We aimed to determine the ability of preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI) findings to predict CD8 cell density and PD-L1 expression in HCC.

METHODS

A total of 120 patients with HCC who underwent 3.0-T gadoxetic acid-enhanced MRI before curative resection from January 2016 to June 2020 were enrolled and divided into a training set (n = 84) and a testing set (n = 36). Thirty-four patients with advanced stage HCC who received anti-PD-1 inhibitor between January 2017 and April 2020 and underwent pretreated gadoxetic acid-enhanced MRI scans were enrolled in an independent validation set. PD-L1 expression and CD8 cell infiltration were assessed with immunohistochemical staining, respectively. Two radiologists blinded to pathology results evaluated the pretreated MR features in consensus. Logistic regression and the receiver operating characteristic curve (ROC) analyses were used to determine the value of image features to predict high CD8 cell density, PD-L1 positivity and the combination of high CD8 cell density and PD-L1 positivity in HCC in the training set and validated the findings in the testing set. The associations of MRI predictors with the objective response to immunotherapy were assessed in the independent validation.

RESULTS

In the training set, the independent MRI predictors were irregular tumor margin (ITM, P = 0.008) and peritumoral low signal intensity (PLSI) on hepatobiliary phase (HBP) images (P < 0.001) for PD-L1 positivity, absence of an enhancing capsule (AEC, P = 0.001) and PLSI on HBP images (P = 0.025) for high CD8 cell density, and PLSI on HBP images (P = 0.001) and ITM (P = 0.023) for the both. The area under the curves (AUCs) of the predictive models for evaluating PD-L1 positivity, high CD8 cell density and the combination of high CD8 cell density and PD-L1 positivity were 0.810 and 0.809, 0.740 and 0.728, and 0.809 and 0.874 in the training and testing set, respectively. The objective response was demonstrated to be associated with the combination of PLSI on HBP images and ITM (PHI, P = 0.004), and the combination of PLSI on HBP images and AEC (PHA, P = 0.012) in the independent validation set.

CONCLUSIONS

Pretreated MRI features have the potential to identify patients with HCC in an immune-activated state and predict outcomes of immunotherapy. Trial registration The study was retrospectively registered on March 5, 2020 with registration no. [2020] 02-012-01.

Risk factors for early postoperative recurrence in single and small hepatitis B virus-associated primary hepatocellular carcinoma

Objective

To investigate the risk factors of early postoperative recurrence in patients with single and small (≤3 cm) hepatitis B virus-associated primary hepatocellular carcinoma (HBV-HCC).

Methods

This retrospective study analyzed patients with single and small HBV-HCC. All patients were followed up for 1 year after surgery.

Results

Among 182 patients, 54 patients had early recurrence within 1 year. The recurrence group had higher proportions of men, drinking history, Child–Turcotte–Pugh (CTP) class C, patients who underwent transarterial chemoembolization (TACE), and serum alpha-fetoprotein (AFP) >10 ng/mL as well as higher gamma-glutamyl transpeptidase (GGT) levels and lower total protein (TP) and CD8⁺ T lymphocyte levels than the no recurrence group. Cox multivariate regression analysis demonstrated that drinking history (HR, 1.312; 95% CI, 1.042–1.652), CTP class C (HR, 1.236; 95% CI, 1.037–1.473), TACE treatment (HR, 1.241; 95% CI, 1.026–1.501), GGT (HR, 1.138; 95% CI, 1.042–1.243), TP (HR, 0.729; 95% CI, 0.555–0.957), and AFP (HR, 2.519; 95% CI, 1.343–4.726) were independently associated with early postoperative recurrence.

Conclusion

Drinking history, CTP class C, TACE, serum AFP, GGT, and TP levels were independently associated with early postoperative recurrence in patients with single and small HBV-HCC.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

The Profile and Role of Tumor-infiltrating Lymphocytes in Hepatocellular Carcinoma: An Immunohistochemical Study

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Tumor-infiltrating lymphocytes (TILs) are a class of cells that form the tumor microenvironment and thus have an effect on carcinogenesis. The aim of this study was to investigate the immunohistochemical expression of CD8, CD4, cytotoxic T lymphocyte-associated protein-4 (CTLA-4), and granzyme B in HCC and their correlation with clinicopathologic parameters and prognosis. This study was carried out on 112 cases of HCC. High percentage of CD8+ TILs was associated with large tumors and adjacent noncirrhotic liver. High percentage of CD4+ TILs and high CD4 to CD8 ratio were associated with nonviral etiology, low alpha fetoprotein, and direct acting antiviral treatment. High percentage of CTLA-4-positive TILs tended to be associated with high-grade HCC, while a high percentage of CTLA-4 in tumor cells was associated with multiple lesions and low tumor grade. High percentage of granzyme B+ TILs was associated with low grade, early stage, and absence of tumor recurrence. High CD4 percentage and high CD4/CD8 ratio affected patients' overall survival. There is a dynamic interaction between the different subsets of lymphocytes in the environment of HCC manifested by coparallel expression of CD4 and CD8 augmenting the expression of CTLA-4, and only CD8 augments the expression of granzyme B. This opens the gate for the beneficial role of immunotherapy in the management of HCC, reducing recurrence and improving survival.

Prognostic role of immune cells in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), with rising incidence rates, is the most commonly occurring malignancy of the liver that exerts a heavy disease burden particularly in developing countries. A dynamic cross-talk between immune cells and malignant cells in tumor microenvironment governs the hepatocarcinogenesis. Monitoring immune contexture as prognostic markers is quite relevant and essential to evaluate clinical outcomes and to envisage response to therapy. In this review, we present an overview of the prognostic value of various tumor infiltrating immune cells and the continually evolving immune checkpoints as novel biomarkers during HCC. Tumor infiltration by immune cells such as T cells, NK cells and dendritic cells is linked with improved prognosis and favorable outcome, while the intra-tumoral presence of regulatory T cells (Tregs) or myeloid derived suppressor cells (MDSCs) on the other hand is associated with poor clinical outcome. In addition to these, the overexpression of negative regulatory molecules on tumor cells also provides inhibitory signals to T cells and is associated with poor prognosis. The limitation of a single marker can be overcome by advanced prognostication models and algorithms that evaluate multiple prognostic factors and ultimately aid the clinician in improving the disease free and overall survival of HCC patients.

Hepatocellular Carcinoma Mechanisms Associated with Chronic HCV Infection and the Impact of Direct-Acting Antiviral Treatment

Hepatitis C virus (HCV) infection is the major risk factor for liver cirrhosis and hepatocellular carcinoma (HCC). The mechanisms of HCC initiation, growth, and metastasis appear to be highly complex due to the decade-long interactions between the virus, immune system, and overlapping bystander effects of host metabolic liver disease. The lack of a readily accessible animal model system for HCV is a significant obstacle to understand the mechanisms of viral carcinogenesis. Traditionally, the primary prevention strategy of HCC has been to eliminate infection by antiviral therapy. The success of virus elimination by antiviral treatment is determined by the SVR when the HCV is no longer detectable in serum. Interferon-alpha (IFN-α) and its analogs, pegylated IFN-α (PEG-IFN-α) alone with ribavirin (RBV), have been the primary antiviral treatment of HCV for many years with a low cure rate. The cloning and sequencing of HCV have allowed the development of cell culture models, which accelerated antiviral drug discovery. It resulted in the selection of highly effective direct-acting antiviral (DAA)-based combination therapy that now offers incredible success in curing HCV infection in more than 95% of all patients, including those with cirrhosis. However, several emerging recent publications claim that patients who have liver cirrhosis at the time of DAAs treatment face the risk of HCC occurrence and recurrence after viral cure. This remains a substantial challenge while addressing the long-term benefit of antiviral medicine. The host-related mechanisms that drive the risk of HCC in the absence of the virus are unknown. This review describes the multifaceted mechanisms that create a tumorigenic environment during chronic HCV infection. In addition to the potential oncogenic programming that drives HCC after viral clearance by DAAs, the current status of a biomarker development for early prediction of cirrhosis regression and HCC detection post viral treatment is discussed. Since DAAs treatment does not provide full protection against reinfection or viral transmission to other individuals, the recent studies for a vaccine development are also reviewed.

Reliability of a single-region sample to evaluate tumor immune microenvironment in hepatocellular carcinoma

BACKGROUND & AIMS

Intratumor heterogeneity has frequently been reported in patients with hepatocellular carcinoma (HCC). Thus, the reliability of single-region tumor samples for evaluation of the tumor immune microenvironment is also debatable. We conducted a prospective study to analyze the similarity in tumor immune microenvironments among different regions of a single tumor.

METHODS

Multi-region sampling was performed on newly resected tumors. The tumor immune microenvironment was evaluated by immunohistochemical staining of PD-L1, CD4, CD8, CD20, FoxP3, DC-LAMP (or LAMP3), CD68, MPO, and tertiary lymphoid structures (TLSs). PD-L1 expression was manually quantified according to the percentage of PD-L1-stained tumor or stromal cells. The densities (number/mm²) of immune cells and the number of TLSs per sample were determined by whole-section counting. RNA-sequencing was applied in selected samples. Similarities in tumor immune microenvironments within each tumor were evaluated by multivariate Mahalanobis distance analyses.

RESULTS

Thirteen tumors were collected from 12 patients. The median diameter of tumors was 9 cm (range 3-16 cm). A median of 6 samples (range 3-12) were obtained from each tumor. Nine (69.2%) tumors exhibited uniform expression of PD-L1 in all regions of the tumor. Out of 13 tumors analyzed by immunohistochemical staining, 8 (61.5%) tumors displayed a narrow Mahalanobis distance for all regions within the tumor; while 8 (66.7%) of the 12 tumors analyzed by RNA-sequencing displayed a narrow Mahalanobis distance. Immunohistochemistry and RNA-sequencing had a high concordance rate (83.3%; 10 of 12 tumors) for the evaluation of similarities between tumor immune microenvironments within a tumor.

CONCLUSIONS

A single-region tumor sample might be reliable for the evaluation of tumor immune microenvironments in approximately 60-70% of patients with HCC.

LAY SUMMARY

Heterogeneity in the regional immune microenvironments of tumors has been reported in patients with hepatocellular carcinoma. This heterogeneity could be an obstacle when trying to reliably evaluate the immune microenvironment of an entire tumor using only a single-region tumor sample, which may be the only option in patients with more advanced disease. Our study utilized both immunohistochemical and transcriptomic analyses to demonstrate that a single-region sample is reliable for evaluation of tumor immune microenvironments in 60-70% of patients with hepatocellular carcinoma.

Effects of rosmarinic acid on immunoregulatory activity and hepatocellular carcinoma cell apoptosis in H22 tumor-bearing mice

Rosmarinic acid (RA) is a natural polyphenolic compound that exists in many medicinal species of Boraginaceae and Lamiaceae. The previous studies have revealed that RA had therapeutic effects on hepatocellular carcinoma (HCC) in the H22-xenograft models by inhibiting the inflammatory cytokines and NF-κB p65 pathway in the tumor microenvironment. However, its molecular mechanisms of immunoregulation and pro-apoptotic effect in HCC have not been fully explored. In the present study, RA at 75, 150, and 300 mg/kg was given to H22 tumor-bearing mice via gavage once a day for 10 days. The results showed that RA can effectively inhibit the tumor growth through regulating the ratio of CD4⁺/CD8⁺ and the secretion of interleukin (IL)-2 and interferon-γ, inhibiting the expressions of IL-6, IL-10 and signal transducer and activator of transcription 3, thereby up-regulating Bax and Caspase-3 and down-regulating Bcl-2. The underlying mechanisms involved regulation of immune response and induction of HCC cell apoptosis. These results may provide a more comprehensive perspective to clarify the anti-tumor mechanism of RA in HCC.

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

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

Immunologic Correlates of Pathologic Complete Response to Preoperative Immunotherapy in Hepatocellular Carcinoma

In hepatocellular carcinoma (HCC), surgical resection is associated with high recurrence rate, and no effective adjuvant therapy currently exists. We initiated a pilot randomized trial of perioperative immunotherapy with nivolumab and ipilimumab for resectable HCC. Here, we provide an illustrative report of a case that achieved a complete response and report immunologic correlates of this complete pathologic response to perioperative immunotherapy. Clinical response was correlated with an increase in CD8⁺ T-cell infiltration, with an increase in two effector T-cell clusters. This study is ongoing, and the final results may contribute to a paradigm shift in the perioperative treatment of HCC, leading to the incorporation of immunotherapy in the curative setting.

Clinicopathologic and prognostic significance of tumor-infiltrating CD8+ T cells in patients with hepatocellular carcinoma: A meta-analysis

BACKGROUND

In patients with hepatocellular carcinoma (HCC), the clinicopathologic and prognostic roles of tumor-infiltrating CD8+ T cells for survival are still controversial. A meta-analysis was performed to resolve this issue.

METHODS

We identified studies from PubMed, Embase, and the Cochrane Library to evaluate the clinicopathologic and prognostic value of tumor-infiltrating CD8+ T cells in patients with HCC. A meta-analysis was conducted to estimate clinicopathologic characteristics, overall survival (OS), and disease-free survival. The hazard ratio (HR) and 95% confidence interval (CI) were calculated employing fixed-effect or random-effect models depending on the heterogeneity of the included trials.

RESULTS

A total of 3509 patients from 21 observational studies were enrolled. The meta-analysis revealed that high levels of intratumoral CD8+ tumor-infiltrating lymphocytes (TILs) were associated with better OS (OS; HR = 0.676, P = .001) and disease-free survival (disease-free survival [DFS]; HR = 0.712, P = .002). The pooled analysis also demonstrated high density of infiltration of CD8+ TILs in margin of tumor (MT) was statistically significant associated with better OS (HR = 0.577; P <.001). Moreover, the patients with low CD8+ TILs infiltration had negative HBSAg (OR = 1.67, P = .02), large tumor size (OR = 1.74, P <.01), and later TNM stage (OR = 1.70, P <.01).

CONCLUSIONS

Our findings suggested that low levels of CD8+ TILs predict large tumor size, later TNM stage and might be a promising prognostic factor of HCC especially for Asian patients. High-quality randomized controlled trials are needed to determine if CD8+ TILs could serve as targets for immunotherapy in hepatocellular carcinoma.

Prognostic value of tumor-infiltrating lymphocytes in hepatocellular carcinoma: A meta-analysis

BACKGROUND

In patients with hepatocellular carcinoma (HCC), the prognostic role of tumor-infiltrating lymphocytes (TILs) for survival is still controversial. A meta-analysis was performed to investigate the prognostic effect of TILs in HCC.

METHODS

We identify studies from PubMed, Embase, and the Cochrane Library to evaluate the prognostic value of TILs in patients with HCC. A meta-analysis was conducted to estimate overall survival and disease-free survival. The hazard ratio (HR) and 95% confidence interval (CI) were calculated employing fixed-effect or random-effect models depending on the heterogeneity of the included trials.

RESULTS

A total of 7905 patients from 46 observational studies were enrolled. For TILs subsets, the density of CD8+, FOXP3+, CD3+, and Granzyme B+ lymphocytes was significantly associated with improved survival (P < .05). The density of FOXP3+ TILs in intratumor (IT) was the most significant prognostic marker (pooled HR = 1.894; 95% CI = 1.659-2.164; P < .001). Patients with high infiltration of CD8+ TILs in IT (pooled HR = 0.676; 95% CI = 0.540-0.845; P = .001) or in margin of tumor (MT) (pooled HR = 0.577; 95% CI = 0.437-0.760; P < .001) had better OS. The pooled analysis revealed that high density of Granzyme B+ T-lymphocytes in IT was statistically significant associated with better OS (pooled HR = 0.621; 95% CI = 0.516-0.748; P < .001) and DFS (pooled HR = 0.678; 95% CI = 0.563-0.815; P < .001). It was interesting that high density of CD3+ in IT foreboded worse OS (pooled HR = 1.008; 95% CI = 1.000-1.015; P = .037), but better DFS (pooled HR = 0.596; 95% CI = 0.374-0.948; P = .029).

CONCLUSION

Our findings suggested that some TIL subsets could serve as prognostic biomarkers in HCC. High-quality randomized controlled trials are needed to determine if these TILs could serve as targets for immunotherapy in HCC.

Hepatocellular carcinoma after direct-acting antiviral drug treatment in patients with hepatitis C virus

Background and Aim

Given the use of direct‐acting antivirals (DAAs) to treat hepatitis C virus (HCV), their effects on hepatocarcinogenesis should be determined.

Methods

This study enrolled 349 patients with HCV who underwent DAA treatment at our hospital between 2014 and 2018. Their median age was 65 years, and 184 were male; 301 cases were of HCV serotype 1, and 48 were of serotype 2. The DAA treatment was daclatasvir/asunaprevir in 107 cases, sofosbuvir (SOF)/ledipasvir in 147 cases, ritonavir‐boosted ombitasvir/paritaprevir in 28 cases, elbasvir/grazoprevir in 19 cases, and SOF/ribavirin in 48 cases. The patients’ histories included hepatocellular carcinoma (HCC) in 45 cases, liver transplant (LT) in 10 cases, and kidney transplant (KT) in 17 cases.

Results

Sustained virological responses occurred in 335 cases (96%). DAA treatment was initiated a median of 16.3 months after HCC treatment. After DAA treatment, 15 cases (33%) had recurrence of HCC after a median of 11.6 months, and 3 cases (1%) developed de novo HCC. Six LT patients and one KT patient had HCC; however, no HCC was observed after DAA. The incidence of HCC was significantly higher in patients with multiple HCC treatments in the Cox hazard model (hazard ratio 1.664, 95% confidence interval 1.134–2.441, P < 0.01). Surgical resection or LT reduced the risk of HCC.

Conclusions

DAA did not increase the rate of HCC, even in immunosuppressed patients. However, careful follow‐up for HCC recurrence is required in previously treated cases.

Molecular Mechanisms of Hepatocarcinogenesis Following Sustained Virological Response in Patients with Chronic Hepatitis C Virus Infection

Despite the success of direct-acting antiviral (DAA) agents in treating chronic hepatitis C virus (HCV) infection, the number of cases of HCV-related hepatocellular carcinoma (HCC) is expected to increase over the next five years. HCC develops over the span of decades and is closely associated with fibrosis stage. HCV both directly and indirectly establishes a pro-inflammatory environment favorable for viral replication. Repeated cycles of cell death and regeneration lead to genomic instability and loss of cell cycle control. DAA therapy offers >90% sustained virological response (SVR) rates with fewer side effects and restrictions than interferon. While elimination of HCV helps to restore liver function and reverse mild fibrosis, post-SVR patients remain at elevated risk of HCC. A series of studies reporting higher than expected rates of HCC development among DAA-treated patients ignited debate over whether use of DAAs elevates HCC risk compared to interferon. However, recent prospective and retrospective studies based on larger patient cohorts have found no significant difference in risk between DAA and interferon therapy once other factors are taken into account. Although many mechanisms and pathways involved in hepatocarcinogenesis have been elucidated, our understanding of drivers specific to post-SVR hepatocarcinogenesis is still limited, and lack of suitable in vivo and in vitro experimental systems has hampered efforts to examine etiology-specific mechanisms that might serve to answer this question more thoroughly. Further research is needed to identify risk factors and biomarkers for post-SVR HCC and to develop targeted therapies based on more complete understanding of the molecules and pathways implicated in hepatocarcinogenesis.

The Paradoxical Role of NKG2D in Cancer Immunity

The activating receptor NKG2D and its ligands are recognized as a potent immune axis that controls tumor growth and microbial infections. With regards to cancer surveillance, various studies have demonstrated the antitumor function mediated by NKG2D on natural killer cells and on conventional and unconventional T cells. The use of NKG2D-deficient mice established the importance of NKG2D in delaying tumor development in transgenic mouse models of cancer. However, we recently demonstrated an unexpected, flip side to this coin, the ability for NKG2D to contribute to tumor growth in a model of inflammation-driven liver cancer. With a focus on the liver, here, we review current knowledge of NKG2D-mediated tumor surveillance and discuss evidence supporting a dual role for NKG2D in cancer immunity. We postulate that in certain advanced cancers, expression of ligands for NKG2D can drive cancer progression rather than rejection. We propose that the nature of the microenvironment within and surrounding tumors impacts the outcome of NKG2D activation. In a form of autoimmune attack, NKG2D promotes tissue damage, mostly in the inflamed tissue adjacent to the tumor, facilitating tumor progression while being ineffective at rejecting transformed cells in the tumor bed.

Molecular basis of hepatocellular carcinoma induced by hepatitis C virus infection

Present study outlines a comprehensive view of published information about the underlying mechanisms operational for progression of chronic hepatitis C virus (HCV) infection to development of hepatocellular carcinoma (HCC). These reports are based on the results of animal experiments and human based studies. Although, the exact delineated mechanism is not yet established, there are evidences available to emphasize the involvement of HCV induced chronic inflammation, oxidative stress, insulin resistance, endoplasmic reticulum stress, hepato steatosis and liver fibrosis in the progression of HCV chronic disease to HCC. Persistent infection with replicating HCV not only initiates several liver alterations but also creates an environment for development of liver cancer. Various studies have reported that HCV acts both directly as well as indirectly in promoting this process. Whereas HCV related proteins, like HCV core, E1, E2, NS3 and NS5A, modulate signal pathways dysregulating cell cycle and cell metabolism, the chronic infection produces similar changes in an indirect way. HCV is an RNA virus and does not integrate with host genome and therefore, HCV induced hepatocarcinogenesis pursues a totally different mechanism causing imbalance between suppressors and proto-oncogenes and genomic integrity. However, the exact mechanism of HCC inducement still needs a full understanding of various steps involved in this process.

The immunoreceptor NKG2D promotes tumour growth in a model of hepatocellular carcinoma

Inflammation is recognized as one of the drivers of cancer. Yet, the individual immune components that possess pro- and anti-tumorigenic functions in individual cancers remain largely unknown. NKG2D is a potent activating immunoreceptor that has emerged as an important player in inflammatory disorders besides its well-established function as tumour suppressor. Here, we provide genetic evidence of an unexpected tumour-promoting effect of NKG2D in a model of inflammation-driven liver cancer. Compared to NKG2D-deficient mice, NKG2D-sufficient mice display accelerated tumour growth associated with, an increased recruitment of memory CD8⁺T cells to the liver and exacerbated pro-inflammatory milieu. In addition, we show that NKG2D contributes to liver damage and consequent hepatocyte proliferation known to favour tumorigenesis. Thus, the NKG2D/NKG2D-ligand pathway provides an additional mechanism linking chronic inflammation to tumour development in hepatocellular carcinoma. Our findings expose the need to selectively target the types of cancer that could benefit from NKG2D-based immunotherapy.

Expression of NKG2D immunoreceptor ligands on tumour cells is believed to inhibit tumour growth through engaging NKG2D-expressing immune cells. Here, the authors show that in a model of liver cancer the NKG2D/NKG2D-ligand pathway can also promote tumour formation by sustaining an inflammatory environment.

Progression of fibrosis in patients with chronic viral hepatitis is associated with IL-17(+) neutrophils

BACKGROUND & AIMS

The pro-inflammatory cytokine IL-17 plays a crucial role in liver diseases associated with hepatic fibrosis and increased risk of cancer development. Nevertheless, the cellular source of this cytokine has never been characterized in patients with liver fibrosis.

METHODS

In this study, we investigated liver biopsies from 49 patients with chronic viral hepatitis at different stages of liver fibrosis. We monitored IL-17 production by intracellular flow cytometry, immunofluorescence and immunohistochemical in situ stainings, allowing a precise quantification, characterization and localization of IL-17(+) cells.

RESULTS

Density of IL-17(+) cells increased with the stage of liver fibrosis specifically in fibrotic septa and portal areas (correlation coefficient r = 0.7373; P < 0.0001). Data clearly show that the frequency of intrahepatic IL-17(+) lymphocytes (including T, NKT and NK cells) was independent on stage of liver fibrosis, and we observed no statistical differences in number of IL-17(+) macrophages during progression of fibrosis. On the other hand, the number of IL-17(+) neutrophils in fibrotic septa and portal areas strongly correlated with the stages of fibrosis (correlation coefficient r = 0.6986; P < 0.0001), contributing significantly to total IL-17 production in liver tissue.

CONCLUSIONS

Our data indicate that neutrophils represent an important source of IL-17 in the human liver, especially in late fibrosis stages. Inhibition of this specific harmful subset of neutrophils may offer therapeutic opportunities in fibrotic liver.

Molecular mechanisms of hepatitis C virus-induced hepatocellular carcinoma

Hepatitis C virus (HCV) is a major leading cause of hepatocellular carcinoma (HCC). HCV-induced hepatocarcinogenesis is a multistep process resulting from a combination of pathway alterations that are either caused directly by viral factors or immune mediated as a consequence of a chronic state of inflammation. Host genetic variation is now emerging as an additional element that contribute to increase the risk of developing HCC. The advent of direct-acting antiviral agents foresees a rapid decline of HCC rate in HCV patients. However, a full understanding of the HCV-mediated tumourigenic process is required to elucidate if pro-oncogenic signatures may persist after virus clearance, and to identify novel tools for HCC prevention and therapy. In this review, we summarize the current knowledge of the molecular mechanisms responsible for HCV-induced hepatocarcinogenesis.

Liver-infiltrating CD11b-CD27- NK subsets account for NK-cell dysfunction in patients with hepatocellular carcinoma and are associated with tumor progression

Natural killer (NK) cells have a vital role in killing hepatocellular carcinoma (HCC) cells; however, the mechanism underlying tumor-infiltrating NK (TINK)-cell dysfunction remains poorly understood. Using flow cytometry staining, we precisely characterized the frequency, phenotype and function of NK subsets distinguished by CD27 and CD11b in 30 patients with HCC in comparison to 30 healthy controls. Interestingly, we found a substantial proportion of liver-infiltrating CD11b⁻CD27⁻ (DN) NK subsets in tumor tissue from HCC patients. Remarkably, these relatively expanded DN NK subsets exhibited an inactive and immature phenotype. By detecting the expression of CD107a and interferon-gamma (IFN-γ) on NK subsets and NK cells, we demonstrated that DN NK subsets exhibited a poor cytotoxic capacity and deficient potential to produce IFN-γ in comparison to the other three subsets, which contributed to the dysfunction of TINK cells in HCC patients. In addition, we found that the presence of DN NK cells was closely associated with the clinical outcomes of HCC patients, as the frequency of DN NK cells among TINK cells was positively correlated with tumor stage and size. A large percentage of DN NK cells among TINK cells was an independent prognostic factor for lower survival in the 60-month follow-up period. In conclusion, a substantial proportion of CD11b⁻CD27⁻NK subsets among TINK cells accounts for NK-cell dysfunction in patients with HCC and is associated with tumor progression. Our study may provide a novel therapeutic target for the treatment of patients with HCC.