New insights into the pathogenesis and treatment of non-viral hepatocellular carcinoma: a balancing act between immunosuppression and immunosurveillance

Identification of CD8+ T-cell exhaustion signatures for prognosis in HBV-related hepatocellular carcinoma patients by integrated analysis of single-cell and bulk RNA-sequencing

BACKGROUND

HBV infection is the leading risk factor for HCC. HBV infection has been confirmed to be associated with the exhaustion status of CD8+ T cells and immunotherapeutic efficacy in HCC. In this study, we aimed to investigate the prognostic value of the CD8+ T-cell exhaustion signature and immunotherapy response in patients with HBV-related HCC.

METHODS

We identified different clusters of HBV-related HCC cells by single-cell RNA sequencing (scRNA-seq) and identified CD8+ T-cell exhaustion-related genes (TERGs) by pseudotime analysis. We conducted differential expression analysis and LASSO Cox regression to detect genes and construct a CD8+ T-cell exhaustion index (TEI). We next combined the TEI with other clinicopathological factors to design a prognostic nomogram for HCC patients. We also analysed the difference in the TEI between the non-responder and responder groups during anti-PD-L1 therapy. In addition, we investigated how HBV induces CD8+ T lymphocyte exhaustion through the inhibition of tyrosine metabolism in HCC using gene set enrichment analysis and RT‒qPCR.

RESULTS

A CD8+ T-cell exhaustion index (TEI) was established with 5 TERGs (EEF1E1, GAGE1, CHORDC1, IKBIP and MAGOH). An AFP level > 500 ng, vascular invasion, histologic grade (G3-G4), advanced TNM stage and poor five-year prognosis were related to a higher TEI score, while HBV infection was related to a lower TEI score. Among those receiving anti-PD-L1 therapy, responders had lower TEIs than non-responders did. The TEI also serves as an independent prognostic factor for HCC, and the nomogram incorporating the TEI, TNM stage, and vascular invasion exhibited excellent predictive value for the prognosis in HCC patients. RT‒qPCR revealed that among the tyrosine metabolism-associated genes, TAT (tyrosine aminotransferase) and HGD (homogentisate 1,2 dioxygenase) were expressed at lower levels in HBV-HCC than in non-HBV HCC.

CONCLUSION

Generally, we established a novel TEI model by comprehensively analysing the progression of CD8+ T-cell exhaustion, which shows promise for predicting the clinical prognosis and potential immunotherapeutic efficacy in HBV-related HCC patients.

Challenges and Solutions in the Management of Hepatocellular Carcinoma Associated with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has gained attention in the last few years due to its increasing prevalence worldwide becoming a global epidemic. The increasing incidence of NAFLD and the concurrent increase in the number of hepatocellular carcinoma (HCC) cases at a global level is a matter of concern. HCC has several risk factors, of which NAFLD and its associated metabolic disturbances-type 2 diabetes mellitus, obesity, and dyslipidemia-are of great interest due to their accelerating rise in incidence worldwide. There is a high amount of data derived from basic and clinical studies that reveal the molecular pathways that drive NAFLD-associated HCC. Based on these findings, new prevention, surveillance, and treatment strategies are emerging. However, current data on treatment modalities in NAFLD-associated HCC are still scarce, though the results from non-NAFLD HCC studies are promising and could provide a basis for a future research agenda to address NAFLD/NASH patients. Clinicians should carefully assess all the clinical and radiological parameters and establish a prognosis based on the Barcelona Clinic Liver Cancer classification and discuss in a multidisciplinary team the treatment strategy. The specific factors associated with NAFLD-associated HCC which can have a negative impact on survival even in patients with early HCC, such as cardiovascular disease, type 2 diabetes, and obesity, should be taken into consideration. This review aims to discuss the latest recommendations regarding the diagnosis and treatment of NAFLD-associated HCC and the remaining challenges.

NCOA5 Haploinsufficiency in Myeloid-Lineage Cells Sufficiently Causes Nonalcoholic Steatohepatitis and Hepatocellular Carcinoma

BACKGROUND & AIMS

The nuclear receptor coactivator 5 (NCOA5) is a putative type 2 diabetes susceptibility gene. NCOA5 haploinsufficiency results in the spontaneous development of nonalcoholic fatty liver disease (NAFLD), insulin resistance, and hepatocellular carcinoma (HCC) in male mice; however, the cell-specific effect of NCOA5 haploinsufficiency in various types of cells, including macrophages, on the development of NAFLD and HCC remains unknown.

METHODS

Control and myeloid-lineage-specific Ncoa5 deletion (Ncoa5ΔM/+) mice fed a normal diet were examined for the development of NAFLD, nonalcoholic steatohepatitis (NASH), and HCC. Altered genes and signaling pathways in the intrahepatic macrophages of Ncoa5ΔM/+ male mice were analyzed and compared with those of obese human individuals. The role of platelet factor 4 (PF4) in macrophages and the underlying mechanism by which PF4 affects NAFLD/NASH were explored in vitro and in vivo. PF4 expression in HCC patient specimens and prognosis was examined.

RESULTS

Myeloid-lineage-specific Ncoa5 deletion sufficiently causes spontaneous NASH and HCC development in male mice fed a normal diet. PF4 overexpression in Ncoa5ΔM/+ intrahepatic macrophages is identified as a potent mediator to trigger lipid accumulation in hepatocytes by inducing lipogenesis-promoting gene expression. The transcriptome of intrahepatic macrophages from Ncoa5ΔM/+ male mice resembles that of obese human individuals. High PF4 expression correlated with poor prognosis of HCC patients and increased infiltrations of M2 macrophages, regulatory T cells, and myeloid-derived suppressor cells in HCCs.

CONCLUSIONS

Our findings reveal a novel mechanism for the onset of NAFLD/NASH and HCC initiated by NCOA5-deficient macrophages, suggesting the NCOA5-PF4 axis in macrophages as a potential target for developing preventive and therapeutic interventions against NAFLD/NASH and HCC.

Angiotensin II receptor inhibition ameliorates liver fibrosis and enhances hepatocellular carcinoma infiltration by effector T cells

Although viral hepatocellular carcinoma (HCC) is declining, nonviral HCC, which often is the end stage of nonalcoholic or alcoholic steatohepatitis (NASH, ASH), is on an upward trajectory. Immune checkpoint inhibitors (ICIs) that block the T cell inhibitory receptor PD-1 were approved for treatment of all HCC types. However, only a minority of HCC patients show a robust and sustained response to PD-1 blockade, calling for improved understanding of factors that negatively impact response rate and duration and the discovery of new adjuvant treatments that enhance ICI responsiveness. Using a mouse model of NASH-driven HCC, we identified peritumoral fibrosis as a potential obstacle to T cell-mediated tumor regression and postulated that antifibrotic medications may increase ICI responsiveness. We now show that the angiotensin II receptor inhibitor losartan, a commonly prescribed and safe antihypertensive drug, reduced liver and peritumoral fibrosis and substantially enhanced anti-PD-1-induced tumor regression. Although losartan did not potentiate T cell reinvigoration, it substantially enhanced HCC infiltration by effector CD8+ T cells compared to PD-1 blockade alone. The beneficial effects of losartan correlated with blunted TGF-β receptor signaling, reduced collagen deposition, and depletion of immunosuppressive fibroblasts.

Angiotensin II receptor inhibition ameliorates liver fibrosis and enhances hepatocellular carcinoma infiltration by effector T cells

Although viral hepatocellular carcinoma (HCC) is declining, non-viral HCC, which often is the end-stage of non-alcoholic or alcoholic steatohepatitis (NASH, ASH), is on an upward trajectory. Immune checkpoint inhibitors (ICI) that block the T cell inhibitory receptor PD-1 were approved for treatment of all HCC types. However, only a small portion of HCC patients show a robust and sustained response to PD-1 blockade, calling for improved understanding of factors that negatively impact response rate and duration and the discovery of new adjuvant treatments that enhance ICI responsiveness. Using a mouse model of NASH-driven HCC, we identified peritumoral fibrosis as a potential obstacle to T cell mediated tumor regression and postulated that anti-fibrotic medications may increase ICI responsiveness. We now show that the angiotensin II receptor inhibitor losartan, a commonly prescribed and safe antihypertensive drug, reduced liver and peritumoral fibrosis and substantially enhanced anti-PD-1 induced tumor regression. Although losartan did not potentiate T cell reinvigoration, it substantially enhanced HCC infiltration by effector CD8 ⁺ T cells compared to PD-1 blockade alone. The beneficial effects of losartan correlated with inhibition of TGF-β receptor signaling, collagen deposition and depletion of immunosuppressive fibroblasts.

Significance

Immune checkpoint inhibitors are used in HCC treatment but overall response rates for single agent PD-1/PD-L1 blockers have remained stubbornly low. Using a mouse model of NASH-driven HCC, we show that co-treatment with the safe and inexpensive angiotensin II receptor inhibitor losartan substantially enhanced anti-PD-1 triggered HCC regression. Although losartan did not influence the reinvigoration of exhausted CD8 ⁺ T cells it considerably enhanced their intratumoral invasion, which we postulated to be compromised by peritumoral fibrosis. Indeed, the beneficial effect of losartan correlated with inhibition of TGF-β signaling and collagen deposition, and depletion of immunosuppressive fibroblasts. Losartan should be evaluated for its adjuvant activity in HCC patients undergoing PD-1/PD-L1 blocking therapy.

The benefit of immunotherapy in patients with hepatocellular carcinoma: a systematic review and meta-analysis

Background: A systemic review of the survival benefit of immune checkpoint inhibitors (ICIs) in phase III hepatocellular carcinoma (HCC) trials was conducted. Methods: Meta-analyses were performed with the generic inverse-variance method with a fixed-effects model. Results: In 10 trials encompassing 6123 patients, ICI-based therapy (monotherapy/combination) improved overall survival (OS) compared with the control arm (hazard ratio [HR]: 0.77; 95% CI: 0.70-0.84; p < 0.001). The survival benefit was consistent across variable treatment lines, Eastern Cooperative Oncology Group performance status and AFP levels. While the OS benefit was more pronounced in hepatitis B-related HCC (HR: 0.70; 95% CI: 0.63-0.77; p < 0.001), OS was improved in hepatitis C-related (HR: 0.83; 95% CI: 0.71-0.98) and nonviral HCC (HR: 0.86; 95% CI: 0.77-0.97). Conclusion: ICI-based therapies should be the standard for all patients with advanced HCC.

NAFLD-driven HCC: Safety and efficacy of current and emerging treatment options

In light of a global rise in obesity and type 2 diabetes, non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) represent an increasingly important underlying aetiology of hepatocellular carcinoma (HCC). HCCs arising from lipotoxicity-mediated chronic inflammation are characterised by several unique features: in contrast to virally driven HCC, up to 50% of NAFLD-HCC occurs in patients without cirrhosis and annual HCC incidence is comparatively low, complicating current surveillance strategies. On average, patients are older and are more frequently diagnosed at an advanced stage. While locoregional treatments are probably equally effective regardless of HCC aetiology, the picture is less clear for systemic therapy. Tyrosine kinase inhibitors are probably equally effective, while there have been initial signals that immune checkpoint inhibitors may be less effective in NAFLD-HCC than in viral HCC. Current international clinical practice guidelines for HCC do not consider aetiology, as there are insufficient data to draw specific conclusions or to recommend aetiology-specific modifications to the current management of patients with HCC. However, in light of the growing relevance of NAFLD-HCC, future clinical trials should assess whether HCC aetiology - and NAFLD/NASH in particular - influence the safety and efficacy of a given treatment.

Identification of PAFAH1B3 as Candidate Prognosis Marker and Potential Therapeutic Target for Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide. PAFAH1B3 plays an important role on occurrence and development in a variety tumor. However, the function of PAFAH1B3 in HCC remains unclear.

Methods

The TIMER, ONCOMINE, Human Protein Atlas (HPA), GEPIA, The Cancer Genome Atlas (TCGA), HCCDB, UALCAN and LinkedOmics database were used to analyze the prognostic value, co-expression genes and regulator networks of PAFAH1B3 in HCC. siRNA transfections and inhibitor of PAFAH1B3 P11 were used to verify the anti-tumor effect on HCC cell lines. Gene expression was detected by qRT-PCR. The functions of PAFAH1B3 downregulation in HCC cell lines were investigated using cell cycle analysis, apoptosis detection, CCK8 assay and transwell assay. Western blot was used to evaluate the role of PAFAH1B3 on metabolic pathways in HCC cells.

Results

Based on the data from databases, the expression of PAFAH1B3 was remarkably increased in HCC patients. High expression of PAFAH1B3 was associated with poorer overall survival (OS) and disease-free survival (DFS). And PAFAH1B3 was notably linked to age, sex, grade, stage, race, and TP53 mutational status. Then, the functional network analysis showed PAFAH1B3 may be involved in HCC through cell cycle, cell metabolism, spliceosome, and RNA transport. Furthermore, the mRNA expression of PAFAH1B3 was also increased in HCC cell lines. Flow cytometry analysis showed that PAFAH1B3 manipulated apoptosis and cell cycle regulation. CCK8 assay showed that PAFAH1B3 silencing or pharmacologic inhibitor of PAFAH1B3 inhibited the proliferation of HepG2, Huh7 and MHCC-97H cells. Transwell assay results showed that PAFAH1B3 silencing also significantly impaired the invasion and migratory ability of HCC cells. In addition, PAFAH1B3 silencing significantly downregulated the expression of glycolysis and lipid synthesis signaling pathways.

Conclusion

Our findings suggested that PAFAH1B3 plays a critical role in progression of HCC. PAFAH1B3 as a prognosis marker and potential target for HCC has prospective clinical significance.

Hepatobiliary malignancies have distinct peripheral myeloid-derived suppressor cell signatures and tumor myeloid cell profiles

Myeloid-derived suppressor cells (MDSCs) are immunosuppressive cells that are increased in patients with numerous malignancies including viral-derived hepatocellular carcinoma (HCC). Here, we report an elevation of MDSCs in the peripheral blood of patients with other hepatobiliary malignancies including non-viral HCC, neuroendocrine tumors (NET), and colorectal carcinoma with liver metastases (CRLM), but not cholangiocarcinoma (CCA). The investigation of myeloid cell infiltration in HCC, NET and intrahepatic CCA tumors further established that the frequency of antigen-presenting cells was limited compared to benign lesions, suggesting that primary and metastatic hepatobiliary cancers have distinct peripheral and tumoral myeloid signatures. Bioinformatics analysis of The Cancer Genome Atlas dataset demonstrated that a high MDSC score in HCC patients is associated with poor disease outcome. Given our observation that MDSCs are increased in non-CCA malignant liver cancers, these cells may represent suitable targets for effective immunotherapy approaches.

Synergistic anti-liver cancer effects of curcumin and total ginsenosides

BACKGROUND

Liver cancer is the sixth most frequently occurring cancer in the world and the fourth most common cause of cancer mortality. The pathogenesis of liver cancer is closely associated with inflammation and immune response in the tumor microenvironment. New therapeutic agents for liver cancer, which can control inflammation and restore cellular immunity, are required. Curcumin (Cur) is a natural anti-inflammatory drug, and total ginsenosides (TG) are a commonly used immunoregulatory drug. Of note, both Cur and TG have been shown to exert anti-liver cancer effects.

AIM

To determine the synergistic immunomodulatory and anti-inflammatory effects of Cur combined with TG in a mouse model of subcutaneous liver cancer.

METHODS

A subcutaneous liver cancer model was established in BALB/c mice by a subcutaneous injection of hepatoma cell line. Animals were treated with Cur (200 mg/kg per day), TG (104 mg/kg per day or 520 mg/kg per day), the combination of Cur (200 mg/kg per day) and TG (104 mg/kg per day or 520 mg/kg per day), or 5-fluorouracil combined with cisplatin as a positive control for 21 d. Tumor volume was measured and the protein expression of programmed cell death 1 and programmed cell death 1 ligand 1 (PD-L1), inflammatory indicators Toll like receptor 4 (TLR4) and nuclear factor-κB (NF-κB), and vascular growth-related factors nitric oxide synthases (iNOS) and matrix metalloproteinase 9 were analyzed by Western blot analysis. CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) were counted by flow cytometry.

RESULTS

The combination therapy of Cur and TG significantly inhibited the growth of liver cancer, as compared to vehicle-treated animals, and TG showed dose dependence. Cur combined with TG-520 markedly decreased the protein expression of PD-L1 (P < 0.0001), while CD4⁺CD25⁺Foxp3⁺ Tregs regulated by the PD-L1 signaling pathway exhibited a positive correlation with PD-L1. Cur combined with TG-520 also inhibited the cascade action mediated by NF-κB (P < 0.0001), thus inhibiting the TLR4/NF-κB signalling pathway (P = 0.0088, P < 0.0001), which is associated with inflammation and acts on PD-L1. It also inhibited the NF-κB-MMP9 signalling pathway (P < 0.0001), which is associated with tumor angiogenesis.

CONCLUSION

Cur combined with TG regulates immune escape through the PD-L1 pathway and inhibits liver cancer growth through NF-κB-mediated inflammation and angiogenesis.

Dendritic cell-based vaccine targeting aspartate-β-hydroxylas represents a promising therapeutic strategy for HCC

Background: Dendritic cells (DCs)-mediated immunotherapy has been considered as a promising antitumor method. Aspartate-β-hydroxylase (AAH) is a potential immunotherapeutic target for hepatocellular carcinoma (HCC). Materials & methods: C57BL/6 mice were immunized by AAH-DCs vaccine constructed ex vivo. Killing tumor cells effect of active T cells induced by AAH-DCs vaccine on HCC cells were measured in vitro and vivo. The underlying mechanism was preliminarily investigated. Results: T cells response when activated by AAH-DCs vaccine showed a significant inhibition effect on HCC cells in vitro and in tumor-bearing mice models when compared with controls. Additionally, compared with the control group, increased expressions of Caspase8, Caspase 3 and Bax, and declined expression of Bcl-2 were observed in AAH-DCs vaccine group. Conclusion: AAH-DCs vaccine could stimulate T cell responses against HCC, which was possibly achieved via pro-apoptosis mechanism.

Deranged hepatocyte intracellular Ca2+ homeostasis and the progression of non-alcoholic fatty liver disease to hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths in men, and the sixth in women. Non-alcoholic fatty liver disease (NAFLD) is now one of the major risk factors for HCC. NAFLD, which involves the accumulation of excess lipid in cytoplasmic lipid droplets in hepatocytes, can progress to non-alcoholic steatosis, fibrosis, and HCC. Changes in intracellular Ca²⁺ constitute important signaling pathways for the regulation of lipid and carbohydrate metabolism in normal hepatocytes. Recent studies of steatotic hepatocytes have identified lipid-induced changes in intracellular Ca²⁺, and have provided evidence that altered Ca²⁺ signaling exacerbates lipid accumulation and may promote HCC. The aims of this review are to summarise current knowledge of the lipid-induced changes in hepatocyte Ca²⁺ homeostasis, to comment on the mechanisms involved, and discuss the pathways leading from altered Ca²⁺ homeostasis to enhanced lipid accumulation and the potential promotion of HCC. In steatotic hepatocytes, lipid inhibits store-operated Ca²⁺ entry and SERCA2b, and activates Ca²⁺ efflux from the endoplasmic reticulum (ER) and its transfer to mitochondria. These changes are associated with changes in Ca²⁺ concentrations in the ER (decreased), cytoplasmic space (increased) and mitochondria (likely increased). They lead to: inhibition of lipolysis, lipid autophagy, lipid oxidation, and lipid secretion; activation of lipogenesis; increased lipid; ER stress, generation of reactive oxygen species (ROS), activation of Ca²⁺/calmodulin-dependent kinases and activation of transcription factor Nrf2. These all can potentially mediate the transition of NAFLD to HCC. It is concluded that lipid-induced changes in hepatocyte Ca²⁺ homeostasis are important in the initiation and progression of HCC. Further research is desirable to better understand the cause and effect relationships, the time courses and mechanisms involved, and the potential of Ca²⁺ transporters, channels, and binding proteins as targets for pharmacological intervention.