Liver iron excess in patients with hepatocellular carcinoma developed on non-alcoholic steato-hepatitis

Targeting the regulation of iron homeostasis as a potential therapeutic strategy for nonalcoholic fatty liver disease

With aging and the increasing incidence of obesity, nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. NAFLD mainly includes simple hepatic steatosis, nonalcoholic steatohepatitis (NASH), liver fibrosis and hepatocellular carcinoma (HCC). An imbalance in hepatic iron homeostasis is usually associated with the progression of NAFLD and induces iron overload, reactive oxygen species (ROS) production, and lipid peroxide accumulation, which leads to ferroptosis. Ferroptosis is a unique type of programmed cell death (PCD) that is characterized by iron dependence, ROS production and lipid peroxidation. The ferroptosis inhibition systems involved in NAFLD include the solute carrier family 7 member 11 (SLC7A11)/glutathione (GSH)/glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1)/coenzyme Q10 (CoQ10)/nicotinamide adenine dinucleotide phosphate (NADPH) regulatory axes. The main promotion system involved is the acyl-CoA synthetase long-chain family (ACSL4)/arachidonic lipoxygenase 15 (ALOX15) axis. In recent years, an increasing number of studies have focused on the multiple roles of iron homeostasis imbalance and ferroptosis in the progression of NAFLD. This review highlights the latest studies about iron homeostasis imbalance- and ferroptosis-associated NAFLD, mainly including the physiology and pathophysiology of hepatic iron metabolism, hepatic iron homeostasis imbalance during the development of NAFLD, and key regulatory molecules and roles of hepatic ferroptosis in NAFLD. This review aims to provide innovative therapeutic strategies for NAFLD.

STEAP2 promotes hepatocellular carcinoma progression via increased copper levels and stress-activated MAP kinase activity

Six Transmembrane Epithelial Antigen of Prostate 2 (STEAP2) belongs to a family of metalloreductases, which indirectly aid in uptake of iron and copper ions. Its role in hepatocellular carcinoma (HCC) remains to be characterized. Here, we report that STEAP2 expression was upregulated in HCC tumors compared with paired adjacent non-tumor tissues by RNA sequencing, RT-qPCR, Western blotting, and immunostaining. Public HCC datasets demonstrated upregulated STEAP2 expression in HCC and positive association with tumor grade. Transient and stable knockdown (KD) of STEAP2 in HCC cell lines abrogated their malignant phenotypes in vitro and in vivo, while STEAP2 overexpression showed opposite effects. STEAP2 KD in HCC cells led to significant alteration of genes associated with extracellular matrix organization, cell adhesion/chemotaxis, negative enrichment of an invasiveness signature gene set, and inhibition of cell migration/invasion. STEAP2 KD reduced intracellular copper levels and activation of stress-activated MAP kinases including p38 and JNK. Treatment with copper rescued the reduced HCC cell migration due to STEAP2 KD and activated p38 and JNK. Furthermore, treatment with p38 or JNK inhibitors significantly inhibited copper-mediated cell migration. Thus, STEAP2 plays a malignant-promoting role in HCC cells by driving migration/invasion via increased copper levels and MAP kinase activities. Our study uncovered a novel molecular mechanism contributing to HCC malignancy and a potential therapeutic target for HCC treatment.

Transferrin Receptor is Associated with Sensitivity to Ferroptosis Inducers in Hepatocellular Carcinoma

PURPOSE

Transferrin receptor (TFR), a membrane protein that has a critical role in the transport of iron into cells, is known to be a ferroptosis-related marker. Although TFR is reported to be abundantly expressed in tumor cells, its relationship with ferroptosis inducers in hepatocellular carcinoma (HCC) remains unclear.

METHODS

The authors performed immunohistochemical staining of TFR and divided 350 HCC patients into two groups according to its expression. They analyzed the association between TFR expression and prognosis or clinicopathologic factors. In addition, the regulation of malignant activity and its effect on the efficacy of ferroptosis inducers were investigated in vitro.

RESULTS

For this study, 350 patients were divided into TFR-positive (n =180, 51.4%) and TFR-negative (n = 170, 48.6%) groups. The TFR-positive group had more hepatitis B surface antigen (HBs-Ag) (p = 0.0230), higher α-fetoprotein (AFP) levels (p = 0.0023), higher des-gamma-carboxyprothrombin (DCP) levels (p = 0.0327), a larger tumor size (p = 0.0090), greater proportions of Barcelona Clinic Liver Cancer (BCLC) stage B or C (p = 0.0005), poor differentiation (p < 0.0001), and microscopic intrahepatic metastasis (p = 0.0066). In the multivariate analyses, TFR expression was an independent prognostic factor in disease-free survival (p = 0.0315). In vitro, TFRC knockdown decreased cell motility. In addition, TFRC knockdown abolished artesunate (AS)-, lenvatinib-, and sorafenib-induced ferroptosis in HCC cell lines. The study demonstrated that simultaneous treatment of AS with multi-kinase inhibitor augmented the ferroptosis-inducing effects of AS in HCC cell lines.

CONCLUSION

TFR expression is a poor prognostic factor in HCC, but its expression increases sensitivity to ferroptosis-inducing agents.

Pathology and Pathogenesis of Metabolic Dysfunction-Associated Steatotic Liver Disease-Associated Hepatic Tumors

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive fat accumulation in the livers of patients without a history of alcohol abuse. It is classified as either simple steatosis (nonalcoholic fatty liver) or nonalcoholic steatohepatitis (NASH), which can progress to liver cirrhosis and hepatocellular carcinoma (HCC). Recently, it was suggested that the terms "metabolic dysfunction-associated steatotic liver disease (MASLD)" and "metabolic dysfunction-associated steatohepatitis (MASH)" should replace the terms "nonalcoholic fatty liver disease (NAFLD)" and "nonalcoholic steatohepatitis (NASH)", respectively, with small changes in the definitions. MASLD, a hepatic manifestation of metabolic syndrome, is rapidly increasing in incidence globally, and is becoming an increasingly important cause of HCC. Steatohepatitic HCC, a histological variant of HCC, is characterized by its morphological features resembling non-neoplastic steatohepatitis and is closely associated with underlying steatohepatitis and metabolic syndrome. Variations in genes including patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily 2 (TM6SF2), and membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7) are associated with the natural history of MASLD, including HCC development. The mechanisms of HCC development in MASLD have not been fully elucidated; however, various factors, including lipotoxicity, inflammation, reactive oxygen species, insulin resistance, and alterations in the gut bacterial flora, are important in the pathogenesis of MASLD-associated HCC. Obesity and MASLD are also recognized as risk factors for hepatocellular adenomas, and recent meta-analyses have shown an association between MASLD and intrahepatic cholangiocarcinoma. In this review, we outline the pathology and pathogenesis of MASLD-associated liver tumors.

Relationship between iron overload caused by abnormal hepcidin expression and liver disease: A review

Iron is essential to organisms, the liver plays a vital role in its storage. Under pathological conditions, iron uptake by the intestine or hepatocytes increases, allowing excess iron to accumulate in liver cells. When the expression of hepcidin is abnormal, iron homeostasis in humans cannot be regulated, and resulting in iron overload. Hepcidin also regulates the release of iron from siderophores, thereby regulating the concentration of iron in plasma. Important factors related to hepcidin and systemic iron homeostasis include plasma iron concentration, body iron storage, infection, inflammation, and erythropoietin. This review summarizes the mechanism and regulation of iron overload caused by hepcidin, as well as related liver diseases caused by iron overload and treatment.

Non-alcoholic Fatty Liver Disease (NAFLD), Type 2 Diabetes, and Non-viral Hepatocarcinoma: Pathophysiological Mechanisms and New Therapeutic Strategies

In recent years, the incidence of non-viral hepatocellular carcinoma (HCC) has increased dramatically, which is probably related to the increased prevalence of metabolic syndrome, together with obesity and type 2 diabetes mellitus (T2DM). Several epidemiological studies have established the association between T2DM and the incidence of HCC and have demonstrated the role of diabetes mellitus as an independent risk factor for the development of HCC. The pathophysiological mechanisms underlying the development of Non-alcoholic fatty liver disease (NAFLD) and its progression to Non-alcoholic steatohepatitis (NASH) and cirrhosis are various and involve pro-inflammatory agents, oxidative stress, apoptosis, adipokines, JNK-1 activation, increased IGF-1 activity, immunomodulation, and alteration of the gut microbiota. Moreover, these mechanisms are thought to play a significant role in the development of NAFLD-related hepatocellular carcinoma. Early diagnosis and the timely correction of risk factors are essential to prevent the onset of liver fibrosis and HCC. The purpose of this review is to summarize the current evidence on the association among obesity, NASH/NAFLD, T2DM, and HCC, with an emphasis on clinical impact. In addition, we will examine the main mechanisms underlying this complex relationship, and the promising strategies that have recently emerged for these diseases' treatments.

Iron as a therapeutic target in chronic liver disease

It was clearly realized more than 50 years ago that iron deposition in the liver may be a critical factor in the development and progression of liver disease. The recent clarification of ferroptosis as a specific form of regulated hepatocyte death different from apoptosis and the description of ferritinophagy as a specific variation of autophagy prompted detailed investigations on the association of iron and the liver. In this review, we will present a brief discussion of iron absorption and handling by the liver with emphasis on the role of liver macrophages and the significance of the iron regulators hepcidin, transferrin, and ferritin in iron homeostasis. The regulation of ferroptosis by endogenous and exogenous mod-ulators will be examined. Furthermore, the involvement of iron and ferroptosis in various liver diseases including alcoholic and non-alcoholic liver disease, chronic hepatitis B and C, liver fibrosis, and hepatocellular carcinoma (HCC) will be analyzed. Finally, experimental and clinical results following interventions to reduce iron deposition and the promising manipulation of ferroptosis will be presented. Most liver diseases will be benefited by ferroptosis inhibition using exogenous inhibitors with the notable exception of HCC, where induction of ferroptosis is the desired effect. Current evidence mostly stems from in vitro and in vivo experimental studies and the need for well-designed future clinical trials is warranted.

Recent advances in the application of ionomics in metabolic diseases

Trace elements and minerals play a significant role in human health and diseases. In recent years, ionomics has been rapidly and widely applied to explore the distribution, regulation, and crosstalk of different elements in various physiological and pathological processes. On the basis of multi-elemental analytical techniques and bioinformatics methods, it is possible to elucidate the relationship between the metabolism and homeostasis of diverse elements and common diseases. The current review aims to provide an overview of recent advances in the application of ionomics in metabolic disease research. We mainly focuses on the studies about ionomic or multi-elemental profiling of different biological samples for several major types of metabolic diseases, such as diabetes mellitus, obesity, and metabolic syndrome, which reveal distinct and dynamic patterns of ion contents and their potential benefits in the detection and prognosis of these illnesses. Accumulation of copper, selenium, and environmental toxic metals as well as deficiency of zinc and magnesium appear to be the most significant risk factors for the majority of metabolic diseases, suggesting that imbalance of these elements may be involved in the pathogenesis of these diseases. Moreover, each type of metabolic diseases has shown a relatively unique distribution of ions in biofluids and hair/nails from patients, which might serve as potential indicators for the respective disease. Overall, ionomics not only improves our understanding of the association between elemental dyshomeostasis and the development of metabolic disease but also assists in the identification of new potential diagnostic and prognostic markers in translational medicine.

The Emerging Role of Tumor Microenvironmental Stimuli in Regulating Metabolic Rewiring of Liver Cancer Stem Cells

Primary liver cancer (PLC) is one of the most devastating cancers worldwide. Extensive phenotypical and functional heterogeneity is a cardinal hallmark of cancer, including PLC, and is related to the cancer stem cell (CSC) concept. CSCs are responsible for tumor growth, progression, relapse and resistance to conventional therapies. Metabolic reprogramming represents an emerging hallmark of cancer. Cancer cells, including CSCs, are very plastic and possess the dynamic ability to constantly shift between different metabolic states depending on various intrinsic and extrinsic stimuli, therefore amplifying the complexity of understanding tumor heterogeneity. Besides the well-known Warburg effect, several other metabolic pathways including lipids and iron metabolism are altered in PLC. An increasing number of studies supports the role of the surrounding tumor microenvironment (TME) in the metabolic control of liver CSCs. In this review, we discuss the complex metabolic rewiring affecting liver cancer cells and, in particular, liver CSCs. Moreover, we highlight the role of TME cellular and noncellular components in regulating liver CSC metabolic plasticity. Deciphering the specific mechanisms regulating liver CSC-TME metabolic interplay could be very helpful with respect to the development of more effective and innovative combinatorial therapies for PLC treatment.

Iron and liver cancer: an inseparable connection

Iron is an essential element for all organisms. Iron-containing proteins play critical roles in cellular functions. The biological importance of iron is largely attributable to its chemical properties as a transitional metal. However, an excess of 'free' reactive iron damages the macromolecular components of cells and cellular DNA through the production of harmful free radicals. On the contrary, most of the body's excess iron is stored in the liver. Not only hereditary haemochromatosis but also some liver diseases with mild-to-moderate hepatic iron accumulation, such as chronic hepatitis C, alcoholic liver disease and nonalcoholic steatohepatitis, are associated with a high risk for liver cancer development. These findings have attracted attention to the causative and promotive roles of iron in the development of liver cancer. In the last decade, accumulating evidence regarding molecules regulating iron metabolism or iron-related cell death programmes such as ferroptosis has shed light on the relationship between hepatic iron accumulation and hepatocarcinogenesis. In this review, we briefly present the current molecular understanding of iron regulation in the liver. Next, we describe the mechanisms underlying dysregulated iron metabolism depending on the aetiology of liver diseases. Finally, we discuss the causative and promotive roles of iron in cancer development.

On the Core Prescriptions and Their Mechanisms of Traditional Chinese Medicine in Hepatitis B, Liver Cirrhosis, and Liver Cancer Treatment

Background

As a frequent cause of death in cancer patients, liver cancer usually occurs in hepatitis B and cirrhosis. In China, Chinese people have been using traditional Chinese medicine (TCM) in treating various chronic liver diseases, which could effectively improve the symptoms and slow down the progression of liver diseases. However, due to the complexity rules of TCM prescription, their action mechanisms are still not clearly understood, which may affect the popularization of effective prescriptions. This study aims to identify the core TCM herbs in the treatment of hepatitis B, liver cirrhosis, and liver cancer so as to clarify the mechanism of action of the core herb networks.

Methods

There were 1,673 prescriptions for chronic liver diseases collected in this study, of which 854 were hepatic B prescriptions, 530 were for liver cirrhosis, and 289 were for liver cancer. The basic characteristics of herbal medicine were firstly explained via descriptive analysis, then the core prescriptions of herbal medicine were analyzed through association rule, and finally, the mechanism of core prescriptions was explored with the help of systematic network pharmacology and by applying such databases as TCMIP, HERB, OMIM, GeneCards, KEGG, and software like RStudio and Cytoscape.

Results

The rule of the core prescriptions in these cases was characterized by the application of herbs with both cold and warm properties, in which bitter herbs with cold property took priority. Tonifying deficiency, clearing heat, and activating blood circulations to remove stasis were common treatment principles for the three liver diseases. Turmeric Root Tuber (YuJin), White Peony Root (BaiShao), Bupleurum (ChaiHu), Salvia miltiorrhiza (DanShen), and Astragali Radix (HuangQi) were prescribed the most in hepatitis B treatment to invigorate the spleen and soothe the liver. Astragali Radix (HuangQi), Tuckahoe (FuLing), Atractylodis Macrocephalae Rhizoma (BaiZhu), Fructus Polygoni Orientalis (ShuiHongHuaZi), and Curcumae Rhizome (EZhu) were most frequently applied in liver cirrhosis treatment to replenish qi and activate blood. Oldenlandia (BaiHuaSheSheCao), Bearded Scutellaria (BanZhiLian), Curcumae Rhizome (EZhu), and Cardamom (DouKou) were most frequently prescribed to eliminate cancer toxin, invigorate the spleen, and activate blood. These core herbs mainly act through signal transduction and immune system pathways, in which the PI3K-Akt pathway plays a key role. The core prescription for liver cirrhosis regulated more endocrine system pathways than the hepatitis B prescription, and liver cancer prescription regulated more nervous system-related pathways.

Conclusion

Three core prescriptions for hepatitis B, liver cirrhosis, and liver cancer treatment were identified, which acted mainly through signal transduction and immune system pathways to regulate immunity and cell growth and participate in inflammation inhibition, in which liver cancer prescription regulated more pathways, especially more nervous system-related pathways than the other two.

Suppressed farnesoid X receptor by iron overload in mice and humans potentiates iron-induced hepatotoxicity

BACKGROUND AND AIMS

Iron overload (IO) is a frequent finding in the general population. As the major iron storage site, the liver is subject to iron toxicity. Farnesoid X receptor (FXR) regulates bile acid metabolism and is implicated in various liver diseases. We aimed to determine whether FXR plays a role in regulating iron hepatotoxicity.

APPROACH AND RESULTS

Human and mouse hepatocytes were treated with ferric ammonium citrate or iron dextran (FeDx). Mice were orally administered ferrous sulfate or injected i.p. with FeDx. Wild-type and Fxr^-/- mice were fed an iron-rich diet for 1 or 5 weeks. Mice fed an iron-rich diet were coadministered the FXR agonist, GW4064. Forced expression of FXR was carried out with recombinant adeno-associated virus 1 week before iron-rich diet feeding. Serum levels of bile acids and fibroblast growth factor 19 (FGF19) were quantified in adults with hyperferritinemia and children with β-thalassemia. The data demonstrated that iron suppressed FXR expression and signaling in human and mouse hepatocytes as well as in mouse liver and intestine. FXR deficiency potentiated iron hepatotoxicity, accompanied with hepatic steatosis as well as dysregulated iron and bile acid homeostasis. FXR negatively regulated iron-regulatory proteins 1 and 2 and prevented hepatic iron accumulation. Forced FXR expression and ligand activation significantly suppressed iron hepatotoxicity in iron-fed mice. The FXR agonist, GW4064, almost completely restored dysregulated bile acid signaling and metabolic syndrome in iron-fed mice. Conjugated primary bile acids were increased and FGF19 was decreased in serum of adults with hyperferritinemia and children with β-thalassemia.

CONCLUSIONS

FXR plays a pivotal role in regulating iron homeostasis and protects mice against iron hepatotoxicity. Targeting FXR may represent a therapeutic strategy for IO-associated chronic liver diseases.

Identification of Ferroptosis-related molecular model and immune subtypes of hepatocellular carcinoma for individual therapy

BACKGROUND

Excessive iron accumulation and lipid peroxidation are primary characteristics of ferroptosis in hepatocellular carcinoma (HCC). Ferroptosis inducer combined with immunotherapy has become a new hope for HCC patients. Therefore, the construction and validation of subtype-specific sensitivity to ferroptosis inducer will be helpful for hierarchical management and precise individual therapy.

METHODS

RNA-seq transcriptome and clinical data of HCC patients were extracted from International Cancer Genome Consortium (ICGC) dataset and The Cancer Genome Atlas (TCGA) dataset. Consistency matrix and data clustering of the both cohorts were constructed by 'ConsensusClusterPlus' package. Single-sample gene set enrichment analysis (ssGSEA) analysis was performed to evaluate immune infiltration. Cox analysis was utilized to construct a ferroptosis phenotype-related prognostic model (FRPM) in HCC. The predictive efficiency of the constructed FRPM was evaluated through Kaplan Meier (K-M) survival analyses and Receiver Operating Characteristic (ROC) curves. The expression levels of candidate genes were detected and validated by Real-Time PCR between liver cancer tissues and adjacent non-tumor liver tissues.

RESULTS

45 differentially expressed ferroptosis-related genes (FRGs) were identified between HCC tissues and non-tumor liver tissues. Furthermore, four ferroptosis-associated clusters (FACs) of HCC were established via consensus clustering. Subsequently, we established a FRPM, consisting of four prognostic genes (SLC7A11, SLC1A5, GCLM and SAT1), to evaluate the survival of HCC patients, based on which, patients were divided into high-risk group and low-risk group. The high-risk group exhibited worse survival compared to low-risk group (p < 0.0001 both in TCGA and ICGC cohorts). Patients belong to different FACs or different risk scores showed distinct clinical characteristics. Moreover, in the validation experiment, the transcriptional expression levels of the four prognostic genes were consistent with the results drew from datasets.

CONCLUSION

We revealed a novel FRGs signature, which may provide the molecular characteristic data for effectively prognostic evaluation and potential personalized therapy for HCC patients.

Iron-Induced Hepatocarcinogenesis—Preventive Effects of Nutrients

The liver is a primary organ that stores body iron, and plays a central role in the regulation of iron homeostasis. Hepatic iron overload (HIO) is a prevalent feature among patients with chronic liver diseases (CLDs), including alcoholic/nonalcoholic liver diseases and hepatitis C. HIO is suggested to promote the progression toward hepatocellular carcinoma because of the pro-oxidant nature of iron. Iron metabolism is tightly regulated by various factors, such as hepcidin and ferroportin, in healthy individuals to protect the liver from such deteriorative effects. However, their intrinsic expressions or functions are frequently compromised in patients with HIO. Thus, various nutrients have been reported to regulate hepatic iron metabolism and protect the liver from iron-induced damage. These nutrients are beneficial in HIO-associated CLD treatment and eventually prevent iron-mediated hepatocarcinogenesis. This mini-review aimed to discuss the mechanisms and hepatocarcinogenic risk of HIO in patients with CLDs. Moreover, nutrients that hold the potential to prevent iron-induced hepatocarcinogenesis are summarized.

Magnetic resonance imaging metrics and the predictability of adverse outcomes in on-treatment Asian chronic hepatitis B

BACKGROUND AND AIM

Liver fibrosis and steatosis are important factors affecting chronic hepatitis B (CHB) disease outcome. Multiparametric magnetic resonance (MR) imaging of the liver measures fibroinflammation, fat, and iron through iron-corrected T1 relaxation time (cT1), proton density fat fraction (PDFF), and T2*-weighted imaging, respectively. We assessed the utility of MR metrics for prognostication in CHB.

METHODS

Chronic hepatitis B patients receiving nucleos(t)ide analogs with advanced fibrosis documented by vibration-controlled transient elastography were recruited. Paired multiparametric MR liver and transient elastography were performed at baseline and after at least 2 years. Adverse outcomes including death, hepatocellular carcinoma (HCC), and liver decompensation were monitored.

RESULTS

One hundred and ninety-two patients (mean age 60.3 ± 8.5 years; 76.0% male) were recruited. Eight patients (4.2%) developed HCC after 11.6 (8.8-22.8) months, and increased baseline liver iron independently predicted HCC (hazard ratio 2.329 [1.030-5.266]; P = 0.042). Liver MR metrics were not predictive of death or hepatic decompensation. Among 150 patients with follow-up liver MR at 30.3 (25.2-35.6) months, longitudinal liver PDFF increase was associated with liver cT1 increase (odds ratio 1.571 [1.217-2.029]; P = 0.001). Ninety patients received simultaneous multiparametric MR pancreas during the follow-up MR. Pancreatic PDFF correlated with liver PDFF (r = 0.501, P < 0.001), while pancreatic T1 had no correlation with liver cT1 (r = -0.092, P = 0.479). Pancreatic T1 and PDFF were not associated with adverse outcomes.

CONCLUSION

Among CHB patients with advanced disease, liver iron level on MR predicts HCC. Multiparametric MR can also simultaneously assess the pancreas and the liver. Multiparametric MR should be further studied as a one-stop option for monitoring and prognosticating CHB.

Iron Activates cGAS-STING Signaling and Promotes Hepatic Inflammation

Iron deposition and chronic inflammation are associated with chronic liver diseases, such as alcoholic liver disease, nonalcoholic fatty liver disease, and chronic hepatitis B and C. However, the relationship between iron deposition and chronic inflammation in these diseases is still unclear. In the current study, we aimed to investigate the effect of iron on chronic inflammation in HepG2 cells and mice liver. We demonstrated that iron treatment enhanced the expression of cGAS, STING, and their downstream targets, including TBK1, IRF-3, and NF-κB in HepG2 cells and mice liver. We also found that treatment of HepG2 cells and mice with ferric ammonium citrate increased the expression of inflammatory cytokines, such as IFN-β. Finally, we found that genes involved in iron metabolism and the STING signaling pathway were up-regulated in liver cancer tissues, and the survival time of patients with high expression of these genes in tumor tissues was significantly shortened. These results suggest that iron overload may promote the progress of the chronic liver disease by activating cGAS-STING-mediated chronic inflammation, which provides a new idea for the development of drugs for the treatment of the chronic liver disease.

Genetic effects of iron levels on liver injury and risk of liver diseases: A two-sample Mendelian randomization analysis

Background and aims

Although iron homeostasis has been associated with liver function in many observational studies, the causality in this relationship remains unclear. By using Mendelian Randomization analyses, we aimed to evaluate the genetic effects of increased systemic iron levels on the risk of liver injury and various liver diseases. Moreover, in light of the sex-dependent iron regulation in human beings, we further estimated the sex-specific effect of iron levels in liver diseases.

Methods

Independent single nucleotide polymorphisms associated with systemic iron status (including four indicators) at the genome-wide significance level from the Genetics of Iron Status (GIS) Consortium were selected as instrumental variables. Summary data for six liver function biomarkers and five liver diseases were obtained from the UK Biobank, the Estonian Biobank, the eMERGE network, and FinnGen consortium. Mendelian Randomization assessment of the effect of iron on liver function and liver diseases was conducted.

Results

Genetically predicted iron levels were positively and significantly associated with an increased risk of different dimensions of liver injury. Furthermore, increased iron status posed hazardous effects on non-alcoholic fatty liver disease, alcoholic liver disease, and liver fibrosis/cirrhosis. Sex-stratified analyses indicated that the hepatoxic role of iron might exist in NAFLD and liver fibrosis/cirrhosis development among men. No significantly causal relationship was found between iron status and viral hepatitis.

Conclusion

Our study adds to current knowledge on the genetic role of iron in the risk of liver injury and related liver diseases, which provides clinical and public health implications for liver disease prevention as iron status can be modified.

ENO1 suppresses cancer cell ferroptosis by degrading the mRNA of iron regulatory protein 1

α-Enolase 1 (ENO1) is a critical glycolytic enzyme whose aberrant expression drives the pathogenesis of various cancers. ENO1 has been indicated as having additional roles beyond its conventional metabolic activity, but the underlying mechanisms and biological consequences remain elusive. Here, we show that ENO1 suppresses iron regulatory protein 1 (IRP1) expression to regulate iron homeostasis and survival of hepatocellular carcinoma (HCC) cells. Mechanistically, we demonstrate that ENO1, as an RNA-binding protein, recruits CNOT6 to accelerate the messenger RNA decay of IRP1 in cancer cells, leading to inhibition of mitoferrin-1 (Mfrn1) expression and subsequent repression of mitochondrial iron-induced ferroptosis. Moreover, through in vitro and in vivo experiments and clinical sample analysis, we identified IRP1 and Mfrn1 as tumor suppressors by inducing ferroptosis in HCC cells. Taken together, this study establishes an important role for the ENO1-IRP1-Mfrn1 pathway in the pathogenesis of HCC and reveals a previously unknown connection between this pathway and ferroptosis, suggesting a potential innovative cancer therapy.

Genetics, Immunity and Nutrition Boost the Switching from NASH to HCC

Nonalcoholic fatty liver disease (NAFLD) is the leading contributor to the global burden of chronic liver diseases. The phenotypic umbrella of NAFLD spans from simple and reversible steatosis to nonalcoholic steatohepatitis (NASH), which may worsen into cirrhosis and hepatocellular carcinoma (HCC). Notwithstanding, HCC may develop also in the absence of advanced fibrosis, causing a delayed time in diagnosis as a consequence of the lack of HCC screening in these patients. The precise event cascade that may precipitate NASH into HCC is intricate and it entails diverse triggers, encompassing exaggerated immune response, endoplasmic reticulum (ER) and oxidative stress, organelle derangement and DNA aberrancies. All these events may be accelerated by both genetic and environmental factors. On one side, common and rare inherited variations that affect hepatic lipid remodeling, immune microenvironment and cell survival may boost the switching from steatohepatitis to liver cancer, on the other, diet-induced dysbiosis as well as nutritional and behavioral habits may furtherly precipitate tumor onset. Therefore, dietary and lifestyle interventions aimed to restore patients' health contribute to counteract NASH progression towards HCC. Even more, the combination of therapeutic strategies with dietary advice may maximize benefits, with the pursuit to improve liver function and prolong survival.

Non-alcoholic fatty liver disease and hematologic manifestations (Review)

Non-alcoholic fatty liver disease (NAFLD) is a multisystem disease, and it is associated with numerous extra-hepatic manifestations or additional co-occurring diseases. The aim of the present review was the identification and management of the hematologic manifestations of NAFLD. One of the triggers is considered to be iron abnormalities. Increased ferritin levels, hepatic iron deposits and iron overload are associated with NAFLD. The iron overload degree and severity are associated with the level of liver fibrosis and with the risk for hepatocellular carcinoma. Excess iron deposits refers to the dysmetabolic iron overload syndrome (DIOS) and it is characterized by steatosis associated with moderate tissue iron deposition and increased levels of serum ferritin, while the serum transferrin saturation was normal. Further prospective studies are necessary to determine whether NAFLD has an independent risk for hematologic symptoms, besides the known risk factors. Future studies are also needed in order to assess the increasing impact of NAFLD on the micro- and macro-vascular complications of this systemic disease.

Serum Biomarkers of Iron Status and Risk of Hepatocellular Carcinoma Development in Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become a major contributor to the rising incidence of hepatocellular carcinoma (HCC) in the United States and other developed countries. Iron, an essential metal primarily stored in hepatocytes, may play a role in the development of NAFLD-related HCC. Epidemiologic data on iron overload without hemochromatosis in relation to HCC are sparse. This study aimed to examine the associations between serum biomarkers of iron and the risk of HCC in patients with NAFLD.

METHODS

We identified 18,569 patients with NAFLD using the University of Pittsburgh Medical Center electronic health records from 2004 through 2018. After an average 4.34 years of follow-up, 244 patients developed HCC. Cox proportional hazard regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) of HCC incidence associated with elevated levels of iron biomarkers with adjustment for age, sex, race, body mass index, history of diabetes, and tobacco smoking.

RESULTS

The HRs (95% CIs) of HCC for clinically defined elevation of serum iron and transferrin saturation were 2.91 (1.34-6.30) and 2.02 (1.22-3.32), respectively, compared with their respective normal range. No statistically significant association was observed for total iron-binding capacity or serum ferritin with HCC risk.

CONCLUSIONS

Elevated levels of serum iron and transferrin saturation were significantly associated with increased risk of HCC among patients with NAFLD without hemochromatosis or other major underlying causes of chronic liver diseases.

IMPACT

Clinical surveillance of serum iron level may be a potential strategy to identify patients with NAFLD who are at high risk for HCC.

Management of Cardiometabolic Complications in Patients With Nonalcoholic Fatty Liver Disease: A Review of the Literature With Recommendations

Nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of liver conditions characterized by significant lipid deposition within hepatocytes. As an overarching diagnosis, NAFLD contains a continuum of progressive liver diseases ranging from isolated liver steatosis to necroinflammatory states leading to end-stage liver disease. Nonalcoholic fatty liver and nonalcoholic steatohepatitis are distinguished by their histologic patterns, with the former exhibiting steatosis without fibrosis or inflammation. This important distinction provides clinicians a timeline within the NAFLD staging to target appropriate interventions against modifiable risk factors. NAFLD is likely formed in response to metabolic imbalances that damage the livers adaptive capacity. Metabolic conditions leading to steatosis mirror common cardiovascular risk factors, including dyslipidemia, diabetes mellitus, and obesity. Acknowledging the common risk factors for development and progression of NAFLD, it is unsurprising the first-line management focuses on the treatment of metabolic syndrome with an emphasis on weight reduction in obese populations. The purpose of this review is to provide a detailed summary of the literature as well as outline the current treatment recommendations for patients with NAFLD with a detailed focus on pharmacologic antiobesity interventions.

PPAR agonist fenofibrate attenuates iron-induced liver injury in mice by modulating the Sirt3 and -catenin signaling

Iron accumulation is frequently associated with chronic liver diseases. However, our knowledge on how iron contributes to the liver injury is limited. Aberrant Wnt/β-catenin signaling is a hallmark of several hepatic pathologies. We recently reported that peroxisome proliferator-activated receptor α (PPARα) agonist, fenofibrate, prevents iron-induced oxidative stress and β-catenin signaling by chelating the iron. Sirtuin3 (Sirt3), a type of NAD+-dependent deacetylase, that plays a critical role in metabolic regulation was found to prevent ischemia reperfusion injury (IRI) by normalizing the Wnt/β-catenin pathway. In the present study, we explored if fenofibrate prevents iron-induced liver injury by regulating the Sirt3 and β-catenin signaling. In vitro and in vivo iron treatment resulted in the downregulation of PPARα, Sirt3, active β-catenin, and its downstream target gene c-Myc in the mouse liver. Pharmacological activation of Sirt3, both in vitro and in vivo, by Honokiol (HK), a known activator of Sirt3, abrogated the inhibitory effect of iron overload on active β-catenin expression and prevented the iron-induced upregulation of α smooth muscle actin (αSMA) and TGFβ expression. Intrinsically, PPARα knockout mice showed significant downregulation of hepatic Sirt3 levels. In addition, treatment of iron overload mice with PPARα agonist fenofibrate reduced hepatic iron accumulation and prevented iron-induced downregulation of liver Sirt3 and active β-catenin, mitigating the progression of fibrosis. Thus, our results establish a novel link between hepatic iron and PPARα, Sirt3, and β-catenin signaling. Further exploration on the mechanisms by which fenofibrate ameliorates iron-induced liver injury likely has significant therapeutic impact on iron-associated chronic liver diseases.NEW & NOTEWORTHY Hepatic intracellular iron accumulation has been implicated in the pathophysiology of chronic liver diseases. In this study, we identified a novel mechanism involved in the progression of fibrosis. Excess iron accumulation in liver caused downregulation of PPARα-Sirt3-Wnt signaling leading to fibrosis. This work has significant translational potential as PPARα agonist fenofibrate could be an attractive therapeutic drug for the treatment of liver disorders associated with iron overload.

Iron at the Interface of Hepatocellular Carcinoma

Cancer incidence and mortality are rapidly growing, with liver cancer being the sixth most diagnosed cancer worldwide and the third leading cause of cancer death in 2020. A number of risk factors have been identified that trigger the progression to hepatocellular carcinoma. In this review, we focus on iron as a potential risk factor for liver carcinogenesis. Molecules involved in the regulation of iron metabolism are often upregulated in cancer cells, in order to provide a supply of this essential trace element for all stages of tumor development, survival, proliferation, and metastasis. Thus, cellular and systemic iron levels must be tightly regulated to prevent or delay liver cancer progression. Disorders associated with dysregulated iron metabolism are characterized with increased susceptibility to hepatocellular carcinoma. This review discusses the association of iron with metabolic disorders such as hereditary hemochromatosis, non-alcoholic fatty liver disease, obesity, and type 2 diabetes, in the background of hepatocellular carcinoma.

Transferrin receptor regulates malignancies and the stemness of hepatocellular carcinoma-derived cancer stem-like cells by affecting iron accumulation

BACKGROUND

Iron metabolism is essential because it plays regulatory roles in various physiological and pathological processes. Disorders of iron metabolism balance are related to various cancers, including hepatocellular carcinoma. Cancer stem-like cells (CSCs) exert critical effects on chemotherapy failure, cancer metastasis, and subsequent disease recurrence and relapse. However, little is known about how iron metabolism affects liver CSCs. Here, we investigated the expression of transferrin receptor 1 (TFR1) and ferroportin (FPN), two iron importers, and an upstream regulator, iron regulatory protein 2 (IRP2), in liver hepatocellular carcinoma (LIHC) and related CSCs.

METHODS

The expression levels of TFR1, FPN and IRP2 were analysed using the GEPIA database. CSCs were derived from parental LIHC cells cultured in serum-free medium. After TFR1 knockdown, ROS accumulation and malignant behaviours were measured. The CCK-8 assay was performed to detect cell viability after TFR1 knockdown and erastin treatment.

RESULTS

TFR1 expression was upregulated in LIHC tissue and CSCs derived from LIHC cell lines, prompting us to investigate the roles of TFR1 in regulating CSCs. Knockdown of TFR1 expression decreased iron accumulation and inhibited malignant behaviour. Knockdown of TFR1 expression decreased reactive oxygen species (ROS) accumulation induced by erastin treatment and maintained mitochondrial function, indicating that TFR1 is critical in regulating erastin-induced cell death in CSCs. Additionally, knockdown of TFR1 expression decreased sphere formation by decreasing iron accumulation in CSCs, indicating a potential role for TFR1 in maintaining stemness.

CONCLUSION

These findings, which revealed TFR1 as a critical regulator of LIHC CSCs in malignant behaviour and stemness that functions by regulating iron accumulation, may have implications to improve therapeutic approaches.

Clinical heterogeneity in patients with non-alcoholic fatty liver disease-associated hepatocellular carcinoma

INTRODUCTION

The indisputable increase in nonalcoholic Fatty Liver Disease (NAFLD) prevalence (25% of population) has consequently led to an increase in Hepatocellular Carcinoma (HCC) and liver-related mortality worldwide. The characteristics of patients with HCC, secondary to NAFLD, are older age, large tumors due to late diagnosis, often without cirrhosis and high prevalence of the metabolic syndrome components, leading to an increased mortality rate. Although the mechanisms of disease remain partially obscure, insulin resistance, oxidative stress, apoptosis, iron overload, and excessive local and systemic inflammation are identified as culprits for hepatocarcinogenesis in the presence of NAFLD.

AREA COVERED

In this review, the authors report that there are no uniform guidelines for surveillance and early diagnosis in this patient group. Barcelona Clinic Liver Cancer staging is generally applicable to HCC due to NAFLD and management depends on liver function, tumor characteristics, and cardiovascular comorbidity. Evidence suggests that HCC due to NAFLD can be associated with worse survival due to late diagnosis.

EXPERT OPINION

The need for effective early diagnosis and management of NAFLD is urgent, considering the galloping incidence of the obesity and the fact that liver cirrhosis and HCC due to NAFLD will become the first indication for liver transplantation in foreseeable future.

Regulatory Connections between Iron and Glucose Metabolism

Iron is essential for energy metabolism, and states of iron deficiency or excess are detrimental for organisms and cells. Therefore, iron and carbohydrate metabolism are tightly regulated. Serum iron and glucose levels are subjected to hormonal regulation by hepcidin and insulin, respectively. Hepcidin is a liver-derived peptide hormone that inactivates the iron exporter ferroportin in target cells, thereby limiting iron efflux to the bloodstream. Insulin is a protein hormone secreted from pancreatic β-cells that stimulates glucose uptake and metabolism via insulin receptor signaling. There is increasing evidence that systemic, but also cellular iron and glucose metabolic pathways are interconnected. This review article presents relevant data derived primarily from mouse models and biochemical studies. In addition, it discusses iron and glucose metabolism in the context of human disease.

The Burden and Trends of Primary Liver Cancer Caused by Specific Etiologies from 1990 to 2017 at the Global, Regional, National, Age, and Sex Level Results from the Global Burden of Disease Study 2017

BACKGROUND

Liver cancer is one of the leading causes of cancer-related deaths worldwide. The primary causes of liver cancer include hepatitis B virus (HBV), hepatitis C virus (HCV), alcohol consumption, nonalcoholic fatty liver disease, and other factors.

AIMS

The objective of this study was to evaluate the global and sex-, age-, region-, country-, and etiology-related liver cancer burden, as well as the trends in liver cancer caused by different etiologies.

METHODS

The causes of liver cancer from 1990 to 2017, including global, regional, and national liver cancer incidence, mortality, and etiology, were collected from the Global Burden of Disease study 2017, and the time-dependent change in the trends of liver cancer burden was evaluated by annual percentage change.

RESULTS

The global liver cancer incidence and mortality have been increasing. There were 950,000 newly-diagnosed liver cancer cases and over 800,000 deaths in 2017, which is more than twice the numbers recorded in 1990. HBV and HCV are the major causes of liver cancer. HBV is the major risk factor of liver cancer in Asia, while HCV and alcohol abuse are the major risk factors in the high sociodemographic index and high human development index regions. The mean onset age and incidence of liver cancer with different etiologies have gradually increased in the past 30 years.

CONCLUSIONS

The global incidence is still rising and the causes have national, regional, or population specificities. More targeted prevention strategies must be developed for the different etiologic types in order to reduce liver cancer burden.

Hepatic STAMP2 mediates recombinant FGF21-induced improvement of hepatic iron overload in nonalcoholic fatty liver disease

Although previous studies have shown that the administration of fibroblast growth factor 21 (FGF21) reverses hepatic steatosis, the mechanism by which FGF21 exerts a therapeutic effect on nonalcoholic fatty liver disease (NAFLD) is not yet entirely understood. We previously demonstrated that hepatic six transmembrane protein of prostate 2 (STAMP2) may represent a suitable target for NAFLD. We investigated the mechanism underlying the therapeutic effect of recombinant FGF21 on NAFLD, focusing on the involvement of hepatic STAMP2. In this study, we used human nonalcoholic steatosis patient pathology samples, C57BL/6 mice for a high-fat diet (HFD)-induced in vivo NAFLD model, and used human primary hepatocytes and HepG2 cells for oleic acid (OA)-induced in vitro NAFLD model. We observed that recombinant FGF21 treatment ameliorated hepatic steatosis and insulin resistance through the upregulation of STAMP2 expression. We further observed hepatic iron overload (HIO) and reduced iron exporter, ferroportin expression in the liver samples obtained from human NAFLD patients, and HFD-induced NAFLD mice and in OA-treated HepG2 cells. Importantly, recombinant FGF21 improved HIO through the hepatic STAMP2-mediated upregulation of ferroportin expression. Our data suggest that hepatic STAMP2 may represent a suitable therapeutic intervention target for FGF21-induced improvement of NAFLD accompanying HIO.

Molecular Mechanisms Regulating Obesity-Associated Hepatocellular Carcinoma

Obesity is a global, intractable issue, altering inflammatory and stress response pathways, and promoting tissue adiposity and tumorigenesis. Visceral fat accumulation is correlated with primary tumor recurrence, poor prognosis and chemotherapeutic resistance. Accumulating evidence highlights a close association between obesity and an increased incidence of hepatocellular carcinoma (HCC). Obesity drives HCC, and obesity-associated tumorigenesis develops via nonalcoholic fatty liver (NAFL), progressing to nonalcoholic steatohepatitis (NASH) and ultimately to HCC. The better molecular elucidation and proteogenomic characterization of obesity-associated HCC might eventually open up potential therapeutic avenues. The mechanisms relating obesity and HCC are correlated with adipose tissue remodeling, alteration in the gut microbiome, genetic factors, ER stress, oxidative stress and epigenetic changes. During obesity-related hepatocarcinogenesis, adipokine secretion is dysregulated and the nuclear factor erythroid 2 related factor 1 (Nrf-1), nuclear factor kappa B (NF-κB), mammalian target of rapamycin (mTOR), phosphatidylinositol-3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt, and Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways are activated. This review captures the present trends allied with the molecular mechanisms involved in obesity-associated hepatic tumorigenesis, showcasing next generation molecular therapeutic strategies and their mechanisms for the successful treatment of HCC.

Iron Status and Cancer Risk in UK Biobank: A Two-Sample Mendelian Randomization Study

We conducted a two-sample Mendelian randomization study to explore the associations of iron status with overall cancer and 22 site-specific cancers. Single-nucleotide polymorphisms for iron status were obtained from a genome-wide association study of 48,972 European-descent individuals. Summary-level data for breast and other cancers were obtained from the Breast Cancer Association Consortium and UK Biobank. Genetically predicted iron status was positively associated with liver cancer and inversely associated with brain cancer but not associated with overall cancer or the other 20 studied cancer sites at p < 0.05. The odds ratios of liver cancer were 2.45 (95% CI, 0.81, 7.45; p = 0.11), 2.11 (1.16, 3.83; p = 0.02), 10.89 (2.44, 48.59; p = 0.002) and 0.30 (0.17, 0.53; p = 2 × 10-5) for one standard deviation increment of serum iron, transferrin saturation, ferritin and transferrin levels, respectively. For brain cancer, the corresponding odds ratios were 0.69 (0.48, 1.00; p = 0.05), 0.75 (0.59, 0.97; p = 0.03), 0.41 (0.20, 0.88; p = 0.02) and 1.49 (1.04, 2.14; p = 0.03). Genetically high iron status was positively associated with liver cancer and inversely associated with brain cancer.

Extra-Hepatic Manifestations of Nonalcoholic Fatty Liver Disease: A Review

Nonalcoholic fatty liver disease (NAFLD) is now the leading cause of chronic liver disease worldwide with a strong association with metabolic syndrome. NAFLD is truly a systemic disease and is associated with a plethora of extra-hepatic manifestations or comorbidities. These are either related to secondary effects of associated obesity or from pathophysiological effects of insulin resistance in NAFLD. Three most common causes of increased morbidity and mortality associated with NAFLD are cardiovascular disease, liver disease, and cancer. In this narrative review, we will discuss comprehensively on cardiovascular disease, type 2 diabetes mellitus, and chronic kidney disease and will also highlight on malignancy especially colorectal cancer, pulmonary disorders including obstructive sleep apnea, endocrine disorders such as hypothyroidism and polycystic ovarian syndrome, dermatological disorders especially psoriasis, and hematological associations including iron overload and susceptibility to thrombosis. In addition to focusing on pathogenesis of these extrahepatic manifestations, we will highlight their clinical implications for physicians in routine clinical practice. Further, there remains an unmet need for safe and effective therapies and examining their benefits on these extra-hepatic manifestations among patients with NAFLD.

Non-alcoholic fatty liver disease associated with hepatocellular carcinoma: An increasing concern

Hepatocellular carcinoma (HCC) is the sixth most common cancer in world and third largest cause of cancer-related deaths. The last few decades have witnessed the emergence of non-viral causes of HCC, the most important being non-alcoholic fatty liver disease (NAFLD). NAFLD ranges from simple steatosis in the absence of excessive alcohol intake to non-alcoholic steatohepatitis (NASH) with or without cirrhosis. About 3-15 per cent of the obese patients with NASH progress to cirrhosis and about 4-27 per cent of NASH with cirrhosis patients transform to HCC. It is also known that HCC can develop de novo in patients with NASH without the presence of cirrhosis. Yearly cumulative incidence of NASH-related HCC is low (2.6%) compared to four per cent of viral-HCC. NAFLD has been associated with risk factors such as metabolic syndrome, insulin resistance, altered gut flora and persistent inflammation. Due to alarming rise in metabolic diseases, both in the developing as well as the developed world, it is expected that the incidence of NAFLD/NASH-HCC would rise manifold in future. No definite guidelines have been drawn for surveillance and management of NAFLD/NASH-associated HCC. It is thus important to discuss the entity of HCC in NAFLD at length with special focus on its epidemiology, risk factors, pathophysiology, diagnosis, clinical presentation and prevention.

Hepatocellular carcinoma in alcoholic and non-alcoholic fatty liver disease-one of a kind or two different enemies?

Hepatocellular cancer (HCC) is a cancer with an overall poor prognosis and an alarming globally rising incidence. While viral etiology of chronic liver disease and HCC is down-trending, alcohol and excess calorie intake have emerged as major culprits. Alcohol related liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) share similar pathogenetic mechanism of hepatic injury and in promoting development of HCC; yet some genetic and epigenetic features are distinct and may promise clinical utility. Population based intervention are urgently needed to reduce alcohol use and improve metabolic factors such as obesity and diabetes. The goal is to identify at-risk patients, to link these patients to care and to provide effective management of chronic liver disease and HCC. This review focuses on the epidemiology, pathophysiology including genetic and epigenetic altercation as well as clinical aspects of ALD and NAFLD associated HCC.

Association between dietary iron and zinc intake and development of ulcerative colitis: A case-control study in Japan

BACKGROUND AND AIM

The prevalence of ulcerative colitis (UC) has been increasing in Japan. Trace elements, such as iron, zinc, magnesium, and copper, can cause digestive symptoms where there is a deficiency or excess. We focused on the dietary intake of trace elements and their associations with UC development.

METHODS

A multicenter, hospital-based case-control study was conducted in Japan. Cases were 127 newly diagnosed UC patients, and 171 age-matched and sex-matched hospital controls were recruited. We considered that UC patients had potentially changed their dietary habits due to disease symptoms. The dietary habits were investigated using a self-administered diet history questionnaire to analyze the dietary intakes and frequencies at two points, the previous 1 month and 1 year before.

RESULTS

In the assessment of dietary habits 1 year before, the highest intake of iron showed an increased odds ratio (OR) for UC on multivariate analysis (OR = 4.05, 95% confidence interval, 1.46-11.2, P < 0.01). The highest intake of zinc 1 year before showed a decreased OR for UC (OR = 0.39, 95% confidence interval, 0.18-0.85, P = 0.01). Intakes of magnesium and copper had no significant association with UC. Because most UC cases had experienced the first symptom of UC within the previous 11 months, these intakes at 1 year before represented an association with pre-illness dietary habits.

CONCLUSION

A high intake of iron has some effect on the development of UC. In contrast, a high intake of zinc has a protective effect on the development of UC.

Genetic studies of abdominal MRI data identify genes regulating hepcidin as major determinants of liver iron concentration

BACKGROUND & AIMS

Excess liver iron content is common and is linked to the risk of hepatic and extrahepatic diseases. We aimed to identify genetic variants influencing liver iron content and use genetics to understand its link to other traits and diseases.

METHODS

First, we performed a genome-wide association study (GWAS) in 8,289 individuals from UK Biobank, whose liver iron level had been quantified by magnetic resonance imaging, before validating our findings in an independent cohort (n = 1,513 from IMI DIRECT). Second, we used Mendelian randomisation to test the causal effects of 25 predominantly metabolic traits on liver iron content. Third, we tested phenome-wide associations between liver iron variants and 770 traits and disease outcomes.

RESULTS

We identified 3 independent genetic variants (rs1800562 [C282Y] and rs1799945 [H63D] in HFE and rs855791 [V736A] in TMPRSS6) associated with liver iron content that reached the GWAS significance threshold (p <5 × 10-8). The 2 HFE variants account for ∼85% of all cases of hereditary haemochromatosis. Mendelian randomisation analysis provided evidence that higher central obesity plays a causal role in increased liver iron content. Phenome-wide association analysis demonstrated shared aetiopathogenic mechanisms for elevated liver iron, high blood pressure, cirrhosis, malignancies, neuropsychiatric and rheumatological conditions, while also highlighting inverse associations with anaemias, lipidaemias and ischaemic heart disease.

CONCLUSION

Our study provides genetic evidence that mechanisms underlying higher liver iron content are likely systemic rather than organ specific, that higher central obesity is causally associated with higher liver iron, and that liver iron shares common aetiology with multiple metabolic and non-metabolic diseases.

LAY SUMMARY

Excess liver iron content is common and is associated with liver diseases and metabolic diseases including diabetes, high blood pressure, and heart disease. We identified 3 genetic variants that are linked to an increased risk of developing higher liver iron content. We show that the same genetic variants are linked to higher risk of many diseases, but they may also be associated with some health advantages. Finally, we use genetic variants associated with waist-to-hip ratio as a tool to show that central obesity is causally associated with increased liver iron content.

Mouse models of hereditary hemochromatosis do not develop early liver fibrosis in response to a high fat diet

Hepatic iron overload, a hallmark of hereditary hemochromatosis, triggers progressive liver disease. There is also increasing evidence for a pathogenic role of iron in non-alcoholic fatty liver disease (NAFLD), which may progress to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis and hepatocellular cancer. Mouse models of hereditary hemochromatosis and NAFLD can be used to explore potential interactions between iron and lipid metabolic pathways. Hfe-/- mice, a model of moderate iron overload, were reported to develop early liver fibrosis in response to a high fat diet. However, this was not the case with Hjv-/- mice, a model of severe iron overload. These data raised the possibility that the Hfe gene may protect against liver injury independently of its iron regulatory function. Herein, we addressed this hypothesis in a comparative study utilizing wild type, Hfe-/-, Hjv-/- and double Hfe-/-Hjv-/- mice. The animals, all in C57BL/6J background, were fed with high fat diets for 14 weeks and developed hepatic steatosis, associated with iron overload. Hfe co-ablation did not sensitize steatotic Hjv-deficient mice to liver injury. Moreover, we did not observe any signs of liver inflammation or fibrosis even in single steatotic Hfe-/- mice. Ultrastructural studies revealed a reduced lipid and glycogen content in Hjv-/- hepatocytes, indicative of a metabolic defect. Interestingly, glycogen levels were restored in double Hfe-/-Hjv-/- mice, which is consistent with a metabolic function of Hfe. We conclude that hepatocellular iron excess does not aggravate diet-induced steatosis to steatohepatitis or early liver fibrosis in mouse models of hereditary hemochromatosis, irrespectively of the presence or lack of Hfe.

Mechanisms of hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. It is the second leading cause of cancer-related deaths worldwide, with a very poor prognosis. In the United States, there has been only minimal improvement in the prognosis for HCC patients over the past 15 years. Details of the molecular mechanisms and other mechanisms of HCC progression remain unclear. Consequently, there is an urgent need for better understanding of these mechanisms. HCC is often diagnosed at advanced stages, and most patients will therefore need systemic therapy, with sorafenib being the most common at the present time. However, sorafenib therapy only minimally enhances patient survival. This review provides a summary of some of the known mechanisms that either cause HCC or contribute to its progression. Included in this review are the roles of viral hepatitis, non-viral hepatitis, chronic alcohol intake, genetic predisposition and congenital abnormalities, toxic exposures, and autoimmune diseases of the liver. Well-established molecular mechanisms of HCC progression such as epithelial-mesenchymal transition, tumor-stromal interactions and the tumor microenvironment, cancer stem cells, and senescence bypass are also discussed. Additionally, we discuss the roles of circulating tumor cells, immunomodulation, and neural regulation as potential new mechanisms of HCC progression. A better understanding of these mechanisms could have implications for the development of novel and more effective therapeutic and prognostic strategies, which are critically needed.

Transferrin receptor 1 overexpression is associated with tumour de-differentiation and acts as a potential prognostic indicator of hepatocellular carcinoma

AIM

Hepatocellular carcinoma (HCC) is the second leading cause of cancer mortality worldwide. An excess of iron in liver tissue causes oxidative stress, leading to hepatocellular carcinogenesis. Iron metabolism, which is regulated by a complex mechanism, is important for cancer cell survival. The aim of this study is to clarify the role of iron regulatory protein in the progression of HCC and in patient outcome.

METHODS AND RESULTS

We first investigated the mRNA level of iron metabolism-related genes, including hepcidin, ferroportin 1 (FPN-1) and transferrin receptor (TFR)-1/2. TFR-1/2 protein expression was then evaluated in surgical specimens from 210 cases using immunohistochemistry, and we compared clinicopathological factors with TFR-1/2 expression. The mRNA expression levels of TFR-1 were significantly increased in HCC tissues compared with adjacent non-cancerous tissues (P = 0.0013), but there were no differences in other genes. High expression of TFR-1 in HCC was associated with the absence of alcohol abuse (P = 0.0467), liver cirrhosis (P < 0.0001), higher alpha-fetoprotein (AFP; P < 0.0001), smaller tumour size (P = 0.0022), poor histological differentiation (P < 0.0001) and morphological features (P < 0.0001). In contrast, high expression of TFR-2 in HCC was associated with lower AFP (P < 0.0001), well-differentiated histological grade (P < 0.0001) and morphological features (P = 0.0010). Multivariate analysis for both overall survival and recurrence-free survival indicated that high TFR-1 expression was a significant prognostic factor for poor outcome.

CONCLUSIONS

We found an inverse correlation of TFR-1 and TFR-2 expression in AFP and tumour differentiation. TFR-1 overexpression suggests a higher risk of recurrence and death in HCC patients following liver resection.

Disruption of FBXL5-mediated cellular iron homeostasis promotes liver carcinogenesis

Hepatocellular iron overload elicited by ablation of the iron-sensing ubiquitin ligase FBXL5 promotes liver carcinogenesis induced by exposure to a chemical carcinogen or hepatitis virus, suggesting that FBXL5 is a previously unrecognized oncosuppressor in liver carcinogenesis in mice.

Hepatic iron overload is a risk factor for progression of hepatocellular carcinoma (HCC), although the molecular mechanisms underlying this association have remained unclear. We now show that the iron-sensing ubiquitin ligase FBXL5 is a previously unrecognized oncosuppressor in liver carcinogenesis in mice. Hepatocellular iron overload elicited by FBXL5 ablation gave rise to oxidative stress, tissue damage, inflammation, and compensatory proliferation of hepatocytes and to consequent promotion of liver carcinogenesis induced by exposure to a chemical carcinogen. The tumor-promoting outcome of FBXL5 deficiency in the liver was also found to be effective in a model of virus-induced HCC. FBXL5-deficient mice thus constitute the first genetically engineered mouse model of liver carcinogenesis promoted by iron overload. In addition, dysregulation of FBXL5-mediated cellular iron homeostasis was found to be associated with poor prognosis in human HCC, suggesting that FBXL5 plays a key role in defense against hepatocarcinogenesis.

The role of iron in hepatic inflammation and hepatocellular carcinoma

Iron is an essential for organisms and the liver plays a major role in its storage. In pathologic conditions, where iron absorption from the intestine or iron uptake into the hepatocytes is increased, excess iron accumulates in the hepatocytes, leading to hepatocyte injury through the production of free radicals. Iron exerts its toxicity by catalyzing the generation of reactive oxygen species (ROS). ROS causes cell injury by inducing damage to the lysosomal, cytoplasmic, nuclear and mitochondrial membranes, apoptosis through activation of the caspase cascade, and hyperoxidation of fatty chains. In this manuscript, we reviewed the articles regarding role of iron in hepatic inflammation and hepatocellular carcinoma.

miR-148a regulates expression of the transferrin receptor 1 in hepatocellular carcinoma

Transferrin receptor 1 (TFR1) is a transmembrane glycoprotein that allows for transferrin-bound iron uptake in mammalian cells. It is overexpressed in various cancers to satisfy the high iron demand of fast proliferating cells. Here we show that in hepatocellular carcinoma (HCC) TFR1 expression is regulated by miR-148a. Within the TFR1 3′UTR we identified and experimentally validated two evolutionarily conserved miRNA response elements (MREs) for miR-148/152 family members, including miR-148a. Interestingly, analyses of RNA sequencing data from patients with liver hepatocellular carcinoma (LIHC) revealed a significant inverse correlation of TFR1 mRNA levels and miR-148a. In addition, TFR1 mRNA levels were significantly increased in the tumor compared to matched normal healthy tissue, while miR-148a levels are decreased. Functional analysis demonstrated post-transcriptional regulation of TFR1 by miR-148a in HCC cells as well as decreased HCC cell proliferation upon either miR-148a overexpression or TFR1 knockdown. We hypothesize that decreased expression of miR-148a in HCC may elevate transferrin-bound iron uptake, increasing cellular iron levels and cell proliferation.

Trends in hepatocellular carcinoma due to non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and is associated with hepatocellular carcinoma (HCC), the most frequent malignant liver tumor. The increasing prevalence of obesity and diabetes is influencing the epidemiology of HCC with the most dramatic increases in NAFLD-related HCC seen in Western countries. Although cirrhosis is the major risk factor for HCC in NAFLD, there is increasing recognition that NAFLD-HCC occurs in the absence of cirrhosis. Areas covered: The epidemiology of NAFLD related HCC and its impact on changing the incidence of HCC globally. We overview risk factors for NAFLD-HCC in the presence and absence of cirrhosis and examine trends in liver transplantation (LT) related to NAFLD-HCC. Expert commentary: The incidence of NAFLD-related cirrhosis will continue to rise globally in parallel with risk factors of obesity and diabetes. Consequently, NAFLD-related HCC will become an increasingly important cause of liver-related morbidity and mortality and a common indication for LT worldwide. Further identification of risk factors for NAFLD-HCC and effective treatments for NAFLD are required to reduce this future burden of disease.

Measurement of liver iron by magnetic resonance imaging in the UK Biobank population

The burden of liver disease continues to increase in the UK, with liver cirrhosis reported to be the third most common cause of premature death. Iron overload, a condition that impacts liver health, was traditionally associated with genetic disorders such as hereditary haemochromatosis, however, it is now increasingly associated with obesity, type-2 diabetes and non-alcoholic fatty liver disease. The aim of this study was to assess the prevalence of elevated levels of liver iron within the UK Biobank imaging study in a cohort of 9108 individuals. Magnetic resonance imaging (MRI) was undertaken at the UK Biobank imaging centre, acquiring a multi-echo spoiled gradient-echo single-breath-hold MRI sequence from the liver. All images were analysed for liver iron and fat (expressed as proton density fat fraction or PDFF) content using LiverMultiScan. Liver iron was measured in 97.3% of the cohort. The mean liver iron content was 1.32 ± 0.32 mg/g while the median was 1.25 mg/g (min: 0.85 max: 6.44 mg/g). Overall 4.82% of the population were defined as having elevated liver iron, above commonly accepted 1.8 mg/g threshold based on biochemical iron measurements in liver specimens obtained by biopsy. Further analysis using univariate models showed elevated liver iron to be related to male sex (p<10⁻¹⁶, r² = 0.008), increasing age (p<10⁻¹⁶, r² = 0.013), and red meat intake (p<10⁻¹⁶, r² = 0.008). Elevated liver fat (>5.6% PDFF) was associated with a slight increase in prevalence of elevated liver iron (4.4% vs 6.3%, p = 0.0007). This study shows that population studies including measurement of liver iron concentration are feasible, which may in future be used to better inform patient stratification and treatment.

Serum levels of ferritin do not affect the prognosis of patients with hepatocellular carcinoma undergoing radiofrequency ablation

Background & aims

Hepatic iron accumulation can accelerate liver injury in patients with various chronic liver diseases and lead to hepatocarcinogenesis. We elucidated the impact of serum levels of ferritin on the prognosis of hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) in a large cohort.

Methods

We retrospectively analyzed 578 treatment-naïve HCC patients who underwent RFA. We divided our cohort into four groups by the quartile points of serum ferritin level: G1 (≤55 ng/mL, n = 148), G2 (56–130 ng/mL, n = 142), G3 (131–243 ng/mL, n = 144) and G4 (≥244 ng/mL, n = 144). We analyzed the recurrence and survival of patients using the Kaplan–Meier method. We also evaluated pathological iron deposition among patients with a solitary tumor smaller than 2 cm.

Results

The cumulative rates of overall recurrence and survival at 5 years were 81.6% and 66.3%, respectively. The serum levels of ferritin were correlated with pathological iron deposition. There were no significant differences in recurrence and survival rates according to serum levels of ferritin and pathological hepatic iron deposition.

Conclusions

Serum levels of ferritin do not affect the prognosis of HCC patients undergoing RFA.

Burden of non-alcoholic fatty liver disease in Australia

Non-alcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease in the Australian population, although precise estimates of prevalence are lacking. NAFLD may progress to liver fibrosis, cirrhosis, decompensated liver disease, and liver cancer and is becoming an increasingly common indication for liver transplantation in Australia and New Zealand. There is an extrahepatic burden of NAFLD extending beyond the liver, which is manifested by an increased risk of developing cardiovascular disease, diabetes, and chronic renal impairment, all of which are common causes of morbidity in the Australian population. Early recognition of those patients at high risk of developing advanced liver disease is essential in order to target those who will benefit from intensive lifestyle modification. In this review, we present data on the epidemiology of NAFLD within Australia, its associated health burden in terms of hepatic and extrahepatic complications, common clinical presentations, and indications for treatment. We also propose a research agenda that highlights knowledge needed to improve diagnosis and management specific to the Australian context.

Hepatic iron overload in the portal tract predicts poor survival in hepatocellular carcinoma after curative resection

BACKGROUND & AIMS

Hepatic iron overload is associated with liver injury and hepatocarcinogenesis; however, it has not been evaluated in patients with hepatocellular carcinoma (HCC) in Asia. The aim of this study was to clarify the degree and distribution of intrahepatic iron deposition, and their effects on the survival of HCC patients.

METHODS

Intrahepatic iron deposition was examined using non-tumorous liver tissues from 204 HCC patients after curative resection, and they were scored by 2 semi-quantitative methods: simplified Scheuer's and modified Deugnier's methods. For the Scheuer's method, iron deposition in hepatocytes and Kupffer cells was separately evaluated, while for the modified Deugnier's method, hepatocyte iron score (HIS), sinusoidal iron score (SIS) and portal iron score (PIS) were systematically evaluated, and the corrected total iron score (cTIS) was calculated by multiplying the sum (TIS) of the HIS, SIS, and PIS by the coefficient.

RESULTS

The overall prevalence of hepatic iron was 40.7% with the simplified Scheuer's method and 45.1% with the modified Deugnier's method with a mean cTIS score of 2.46. During a median follow-up of 67 months, the cTIS was not associated with overall survival. However, a positive PIS was significantly associated with a lower 5-year overall survival rate (50.0%) compared with a negative PIS (73.7%, P = .006). In the multivariate analysis, a positive PIS was an independent factor for overall mortality (hazard ratio, 2.310; 95% confidence interval, 1.181-4.517).

CONCLUSIONS

Intrahepatic iron deposition was common, and iron overload in the portal tract indicated poor survival in curatively resected HCC patients.

[The Development of Hepatocellular Carcinoma in Non-alcoholic Fatty Liver Disease]

Non-alcoholic fatty liver disease (NAFLD) may be one of the important causes of cryptogenic hepatocellular carcinoma (HCC). NAFLD-related HCCs (NAFLD-HCCs) have the following clinical features: high body mass index, deranged lipid profiles, diabetes mellitus, hypertension, and metabolic syndrome. Among them, obesity, diabetes mellitus, and high Fe contents in the liver are risk factors of developing HCC in patients with NAFLD. Inflammatory cytokines, adipokines, insulin like growth factor-I, and lipotoxicity are intermingled and may cross react with each other to develop HCC. Because there is no guideline for early detection of HCC in patients with NAFLD, NAFLD-HCCs tend to be greater in size and in advanced stages when detected compared with hepatitis virus-related HCCs. Therefore, there is an urgent need of a surveillance program for the early detection of HCC. Treatment of NAFLD-HCCs is not different from other causes-related HCCs. However, patients with NAFLD-HCCs have cardiovascular disease and other metabolic problems, which may complicate treatment.

Serum Iron Levels Decreased in Patients with HBV-Related Hepatocellular Carcinoma, as a Risk Factor for the Prognosis of HBV-Related HCC

Background: Hepatocellular carcinoma (HCC) is common and the second leading causes of cancer-related deaths. HCC usually occurs on the basis of chronic liver diseases. At present, the study of iron metabolism in chronic liver diseases was limited to chronic HCV infection, nonalcoholic fatty liver disease, and alcoholic liver disease. This study aimed to investigate the effect of serum iron levels on the progression of chronic HBV infection and the relationship with the prognosis of HBV-related HCC. Methods: A respective study involving 277 healthy individuals as controls (HC), 295 patients with chronic hepatitis B (CHB), 224 patients with HBV-related liver cirrhosis (HBV-related LC), and 586 patients with HBV- related HCC were enrolled in this study. Hematological parameters, HBVDNA and liver biochemistry were analyzed. Child-Pugh grade and BCLC stage of the HBV-related HCC patients were calculated. Results: The serum iron levels were lowest in the HBV- related HCC group as compared with HC, CHB, and HBV-related LC groups (35.07 ± 6.97, 27.37 ± 10.26, 24.53 ± 10.36 vs. 17.90 ± 0.14, P < 0.001). Strikingly, serum iron levels were lowest in HBV- related HCC patients with tumor size more than 10 cm as compared with HBV- related HCC patients with tumor size smaller than 3, 3-5, and 5-10 cm by subgroup analysis (22.12 ± 0.94, 21.44 ± 1.41, 15.65 ± 0.98 vs. 13.36 ± 1.15, P < 0.001). Serum iron levels significantly decreased with worsening Child-Pugh grades and BCLC stages in HBV-related HCC group. In addition, serum iron levels was positively correlated with Retinol-Binding Protein, total bile acid, hemoglobin, and lymphocyte and negatively correlated with white blood cell (WBC) and platelet in HBV- related HCC group. ROC curve analysis showed serum iron levels at 15.1 μmol/L as the optimal cut-off point for determining the survival of HBV-related HCC. By the Cox regression model analysis, serum iron levels <15.1 μmol/l together with higher AFP levels, worse BCLC stages, and larger tumor size showed higher mortality of HBV-related HCC patients (hazard ratio = 2.280, 95% confidence interval, 1.815-2.865; P < 0.001). Conclusions: Serum iron levels affected the progression of chronic HBV infection. The prognosis of HBV- related HCC patients with serum iron levels <15.1 μmol/l together with higher AFP levels, worse BCLC stages, and larger tumor lesion were poor.