Role of alcohol in the development and progression of hepatocellular carcinoma

Genomic instabilities in hepatocellular carcinoma: biomarkers and application in immunotherapies

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. For patients with advanced HCC, liver function decompensation often occurs, which leads to poor tolerance to chemotherapies and other aggressive treatments. Therefore, it remains critical to develop effective therapeutic strategies for HCC. Etiological factors for HCC are complex and multifaceted, including hepatitis virus infection, alcohol, drug abuse, chronic metabolic abnormalities, and others. Thus, HCC has been categorized as a "genomically unstable" cancer due to the typical manifestation of chromosome breakage and aneuploidy, and oxidative DNA damage. In recent years, immunotherapy has provided a new option for cancer treatments, and the degree of genomic instability positively correlates with immunotherapy efficacies. This article reviews the endogenous and exogenous causes that affect the genomic stability of liver cells; it also updates the current biomarkers and their detection methods for genomic instabilities and relevant applications in cancer immunotherapies. Including genomic instability biomarkers in consideration of cancer treatment options shall increase the patients' well-being.

The Impact of Probiotic Bifidobacterium on Liver Diseases and the Microbiota

Recent studies have shown the promising potential of probiotics, especially the bacterial genus Bifidobacterium, in the treatment of liver diseases. In this work, a systematic review was conducted, with a focus on studies that employed advanced Next Generation Sequencing (NGS) technologies to explore the potential of Bifidobacterium as a probiotic for treating liver pathologies such as Non-Alcoholic Fatty Liver Disease (NAFLD), Non-Alcoholic Steatohepatitis (NASH), Alcoholic Liver Disease (ALD), Cirrhosis, and Hepatocelullar Carcinoma (HCC) and its impact on the microbiota. Our results indicate that Bifidobacterium is a safe and effective probiotic for treating liver lesions. It successfully restored balance to the intestinal microbiota and improved biochemical and clinical parameters in NAFLD, ALD, and Cirrhosis. No significant adverse effects were identified. While more research is needed to establish its efficacy in treating NASH and HCC, the evidence suggests that Bifidobacterium is a promising probiotic for managing liver lesions.

The association between alcohol consumption and the risk of hepatocellular carcinoma according to glycemic status in Korea: A nationwide population-based study

BACKGROUND

Alcohol and diabetes are known risk factors for hepatocellular carcinoma (HCC); however, it is unclear whether the association between alcohol consumption and HCC risk differs by fasting serum glucose level and diabetes. We investigated the dose-response relationship between alcohol consumption and the risk of HCC according to glycemic status.

METHODS AND FINDINGS

This population-based observational cohort study included patients who underwent general health checkups in 2009 using the Korean National Health Insurance Service Database. The primary outcome was HCC incidence, and Cox proportional hazard regression analysis was performed to estimate the relationship between alcohol consumption and HCC risk according to glycemic status. A total of 34,321 patients newly diagnosed with HCC were observed in the median follow-up period of 8.3 years. In the multivariable model, we adjusted for age, sex, smoking, regular exercise, income, hypertension, dyslipidemia, and body mass index. Mild-to-moderate alcohol consumption increased the risk of HCC in all glycemic statuses (normoglycemia: hazard ratio [HR], 1.06; 95% confidence interval [CI], 1.02 to 1.10; prediabetes: HR, 1.19; 95% CI, 1.14 to 1.24; and diabetes: HR, 2.02; 95% CI, 1.93 to 2.11) compared to normoglycemic nondrinking. Heavy alcohol consumption also increased the risk of HCC in all glycemic statuses (normoglycemia: HR, 1.39; 95% CI, 1.32 to 1.46; prediabetes: HR, 1.67; 95% CI, 1.58 to 1.77; and diabetes: HR, 3.29; 95% CI, 3.11 to 3.49) compared to normoglycemic nondrinking. Since alcohol consumption information in this study was based on a self-administered questionnaire, there may be a possibility of underestimation. Although we excluded patients with a history of viral hepatitis using diagnosis codes, we could not obtain information on hepatitis B or hepatitis C serum markers.

CONCLUSIONS

Both mild-to-moderate and heavy alcohol consumption was associated with an increased risk of HCC in all glycemic statuses. The increased risk of HCC according to alcohol consumption was the highest in the diabetes group, suggesting that more intensive alcohol abstinence is required for patients with diabetes.

CYP2E1-dependent upregulation of SIRT7 is response to alcohol mediated metastasis in hepatocellular carcinoma

Long-term alcohol use is a confirmed risk factor of liver cancer tumorigenesis and metastasis. Multiple mechanisms responsible for alcohol related tumorigenesis have been proposed, including toxic reactive metabolite production, oxidative stress and fat accumulation. However, mechanisms underlying alcohol-mediated liver cancer metastasis remain largely unknown. We have previously demonstrated that SIRT7 regulates chemosensitivity by altering a p53-dependent pathway in human HCC. In the current study, we further revealed that SIRT7 is a critical factor in promoting liver cancer metastasis. SIRT7 expression is associated with disease stage and high SIRT7 predicts worse overall and disease-free survival. Overexpression of SIRT7 promotes HCC cell migration and EMT while knockdown of SIRT7 showed opposite effects. Mechanistically, we found that SIRT7 suppresses E-Cadherin expression through FOXO3-dependent promoter binding and H3K18 deacetylation. Knockdown of FOXO3 abolished the suppressive effect of SIRT7 on E-cadherin transcription. More importantly, we identified that alcohol treatment upregulates SIRT7 and suppresses E-cadherin expression via a CYP2E/ROS axis in hepatocytes both in vitro and in vivo. Antioxidant treatment in primary hepatocyte or CYP2E1-/- mice fed with alcohol impaired those effects. Reducing SIRT7 activity completely abolished alcohol-mediated promotion of liver cancer metastasis in vivo. Taken together, our data reveal that SIRT7 is a pivotal regulator of alcohol-mediated HCC metastasis.

Role of AMPK-SREBP Signaling in Regulating Fatty Acid Binding-4 (FABP4) Expression following Ethanol Metabolism

Fatty acid binding protein-4 (FABP4) is not normally expressed in the liver but is induced in alcohol-dependent liver disease (ALD)). This study sought to identify mechanisms whereby ethanol (EtOH) metabolism alters triglyceride accumulation and FABP4 production. Human hepatoma cells which were stably transfected to express alcohol dehydrogenase (ADH) or cytochrome P4502E1 (CYP2E1) were exposed to EtOH in the absence/presence of inhibitors of ADH (4-methylpyrazole) or CYP2E1 (chlormethiazole). Cells were analyzed for free fatty acid (FFA) content and FABP4 mRNA, then culture medium assayed for FABP4 levels. Cell lysates were analyzed for AMP-activated protein kinase-α (AMPKα), Acetyl-CoA carboxylase (ACC), sterol regulatory element binding protein-1c (SREBP-1c), and Lipin-1β activity and localization in the absence/presence of EtOH and pharmacological inhibitors. CYP2E1-EtOH metabolism led to increased FABP4 mRNA/protein expression and FFA accumulation. Analysis of signaling pathway activity revealed decreased AMPKα activation and increased nuclear-SREBP-1c localization following CYP2E1-EtOH metabolism. The role of AMPKα-SREBP-1c in regulating CYP2E1-EtOH-dependent FFA accumulation and increased FABP4 was confirmed using pharmacological inhibitors and over-expression of AMPKα. Inhibition of ACC or Lipin-1β failed to prevent FFA accumulation or changes in FABP4 mRNA expression or protein secretion. These data suggest that CYP2E1-EtOH metabolism inhibits AMPKα phosphorylation to stimulate FFA accumulation and FABP4 protein secretion via an SREBP-1c dependent mechanism.

Association Between Changes in Alcohol Consumption and Cancer Risk

IMPORTANCE

Although numerous studies have shown an association between alcohol consumption and cancer, how changes in drinking behavior increase or decrease the incidence of cancer is not well understood.

OBJECTIVE

To investigate the association between the reduction, cessation, or increase of alcohol consumption and the development of alcohol-related cancers and all cancers.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study analyzed adult beneficiaries in the Korean National Health Insurance Service. Participants (aged ≥40 years) included those who underwent a national health screening in both 2009 and 2011 and had available data on their drinking status. Data were analyzed from April 16 to July 6, 2020.

EXPOSURES

Alcohol consumption level, which was self-reported by participants in health screening questionnaires, was categorized into none (0 g/d), mild (<15 g/d), moderate (15-29.9 g/d), and heavy (≥30 g/d) drinking. Based on changes in alcohol consumption level from 2009 to 2011, participants were categorized into the following groups: nondrinker, sustainer, increaser, quitter, and reducer.

MAIN OUTCOMES AND MEASURES

The primary outcome was newly diagnosed alcohol-related cancers (including cancers of the head and neck, esophagus, colorectum, liver, larynx, and female breast), and the secondary outcome was all newly diagnosed cancers (except for thyroid cancer).

RESULTS

Among the 4 513 746 participants (mean [SD] age, 53.6 [9.6] years; 2 324 172 [51.5%] men), the incidence rate of cancer was 7.7 per 1000 person-years during a median (IQR) follow-up of 6.4 (6.1-6.6) years. Compared with the sustainer groups at each drinking level, the increaser groups had a higher risk of alcohol-related cancers and all cancers. The increased alcohol-related cancer incidence was associated with dose; those who changed from nondrinking to mild (adjusted hazard ratio [aHR], 1.03; 95% CI, 1.00-1.06), moderate (aHR, 1.10; 95% CI, 1.02-1.18), or heavy (aHR, 1.34; 95% CI, 1.23-1.45) drinking levels had an associated higher risk than those who did not drink. Those with mild drinking levels who quit drinking had a lower risk of alcohol-related cancer (aHR, 0.96; 95% CI, 0.92-0.99) than those who sustained their drinking levels. Those with moderate (aHR, 1.07; 95% CI, 1.03-1.12) or heavy (aHR, 1.07; 95% CI, 1.02-1.12) drinking levels who quit drinking had a higher all cancer incidence than those who sustained their levels, but when quitting was sustained, this increase in risk disappeared. Compared with sustained heavy drinking, reduced heavy drinking levels to moderate levels (alcohol-related cancer: aHR, 0.91 [95% CI, 0.86-0.97]; all cancers: aHR, 0.96 [95% CI, 0.92-0.99]) or mild levels (alcohol-related cancer: aHR, 0.92 [95% CI, 0.86-0.98]; all cancers: aHR, 0.92 [95% CI, 0.89-0.96]) were associated with decreased cancer risk.

CONCLUSIONS AND RELEVANCE

Results of this study showed that increased alcohol consumption was associated with higher risks for alcohol-related and all cancers, whereas sustained quitting and reduced drinking were associated with lower risks of alcohol-related and all cancers. Alcohol cessation and reduction should be reinforced for the prevention of cancer.

Oxidative Stress-A Key Player in the Course of Alcohol-Related Liver Disease

Oxidative stress is known to be an inseparable factor involved in the presentation of liver disorders. Free radicals interfere with DNA, proteins, and lipids, which are crucial in liver metabolism, changing their expression and biological functions. Additionally, oxidative stress modifies the function of micro-RNAs, impairing the metabolism of hepatocytes. Free radicals have also been proven to influence the function of certain transcriptional factors and to alter the cell cycle. The pathological appearance of alcohol-related liver disease (ALD) constitutes an ideal example of harmful effects due to the redox state. Finally, ethanol-induced toxicity and overproduction of free radicals provoke irreversible changes within liver parenchyma. Understanding the underlying mechanisms associated with the redox state in the course of ALD creates new possibilities of treatment for patients. The future of hepatology may become directly dependent on the effective action against reactive oxygen species. This review summarizes current data on the redox state in the natural history of ALD, highlighting the newest reports on this topic.

Protective Mechanism of Edible Food Plants against Alcoholic Liver Disease with Special Mention to Polyphenolic Compounds

Alcoholic liver disease (ALD) is one type of liver disease, causing a global healthcare problem and mortality. The liver undergoes tissue damage by chronic alcohol consumption because it is the main site for metabolism of ethanol. Chronic alcohol exposure progresses from alcoholic fatty liver (AFL) to alcoholic steatohepatitis (ASH), which further lead to fibrosis, cirrhosis, and even hepatocellular cancer. Therapeutic interventions to combat ALD are very limited such as use of corticosteroids. However, these therapeutic drugs are not effective for long-term usage. Therefore, additional effective and safe therapies to cope with ALD are urgently needed. Previous studies confirmed that edible food plants and their bioactive compounds exert a protective effect against ALD. In this review article, we summarized the hepatoprotective potential of edible food plants and their bioactive compounds. The underlying mechanism for the prevention of ALD by edible food plants was as follows: anti-oxidation, anti-inflammation, lipid regulation, inhibition of apoptosis, gut microbiota composition modulation, and anti-fibrosis.

Chronic Alcohol Exposure of Cells Using Controlled Alcohol-Releasing Capillaries

Alcohol is one of the main causes of liver diseases such as fatty liver, alcoholic hepatitis, and chronic hepatitis with liver fibrosis or cirrhosis. To reproduce the conditions of alcohol-induced liver diseases and to identify the disease-causing mechanisms at the cellular level, several methods have been used to expose the cells to ethanol. As ethanol evaporates easily, it is difficult to mimic chronic alcohol exposure conditions at the cellular level. In this study, we developed a glass capillary system containing ethanol, which could steadily release ethanol from the polyethylene tubing and hydrogel portion at both sides of the capillary. The ethanol-containing capillary could release ethanol in the cell culture medium for up to 144 h, and the concentration of ethanol in the cell culture medium could be adjusted by controlling the number of capillaries. A long-term exposure to ethanol by the capillary system led to an increased toxicity of cells and altered the cellular physiologies, such as increasing the lipid accumulation and hepatic transaminase release in cells, as compared to the traditional direct ethanol addition method. Ethanol capillaries showed different gene expression patterns of lipid accumulation- or chronic alcoholism-related genes. Our results suggest that our ethanol-containing capillary system can be used as a valuable tool for studying the mechanism of chronic alcohol-mediated hepatic diseases at the cellular level.

Endoplasmic Reticulum Stress Signaling and the Pathogenesis of Hepatocarcinoma

Hepatocellular carcinoma (HCC), also known as hepatoma, is a primary malignancy of the liver and the third leading cause of cancer mortality globally. Although much attention has focused on HCC, its pathogenesis remains largely obscure. The endoplasmic reticulum (ER) is a cellular organelle important for regulating protein synthesis, folding, modification and trafficking, and lipid metabolism. ER stress occurs when ER homeostasis is disturbed by numerous environmental, physiological, and pathological challenges. In response to ER stress due to misfolded/unfolded protein accumulation, unfolded protein response (UPR) is activated to maintain ER function for cell survival or, in cases of excessively severe ER stress, initiation of apoptosis. The liver is especially susceptible to ER stress given its protein synthesis and detoxification functions. Experimental data suggest that ER stress and unfolded protein response are involved in HCC development, aggressiveness and response to treatment. Herein, we highlight recent findings and provide an overview of the evidence linking ER stress to the pathogenesis of HCC.

2019 Update of Indian National Association for Study of the Liver Consensus on Prevention, Diagnosis, and Management of Hepatocellular Carcinoma in India: The Puri II Recommendations

Hepatocellular carcinoma (HCC) is one of the major causes of morbidity, mortality, and healthcare expenditure in patients with chronic liver disease in India. The Indian National Association for Study of the Liver (INASL) had published its first guidelines on diagnosis and management of HCC (The Puri Recommendations) in 2014, and these guidelines were very well received by the healthcare community involved in diagnosis and management of HCC in India and neighboring countries. However, since 2014, many new developments have taken place in the field of HCC diagnosis and management, hence INASL endeavored to update its 2014 consensus guidelines. A new Task Force on HCC was constituted that reviewed the previous guidelines as well as the recent developments in various aspects of HCC that needed to be incorporated in the new guidelines. A 2-day round table discussion was held on 5th and 6th May 2018 at Puri, Odisha, to discuss, debate, and finalize the revised consensus statements. Each statement of the guideline was graded according to the Grading of Recommendations Assessment Development and Evaluation system with minor modifications. We present here the 2019 Update of INASL Consensus on Prevention, Diagnosis, and Management of Hepatocellular Carcinoma in India: The Puri-2 Recommendations.

Use of a crossed high alcohol preferring (cHAP) mouse model with the NIAAA-model of chronic-binge ethanol intake to study liver injury

Aims

This study sought to compare mice bred to preferentially consume high amounts of alcohol (crossed-high alcohol preferring, cHAP) to c57BL/6 (C57) mice using a chronic-binge ethanol ingestion model to induce alcoholic liver disease (ALD).

Methods

Male C57 and cHAP mice were randomized to a Lieber-DeCarli control (LDC) diet, Lieber-DeCarli 5% (v/v) ethanol (LDE) diet or free-choice between 10% (v/v) ethanol in drinking water (EtOH-DW) and DW. After 4 weeks mice were gavaged with either 9 g/kg maltose-dextrin (LDC+MD) or 5 g/kg EtOH (LDE+Binge, EtOH-DW+Binge). Nine hours later tissue and serum were collected and analyzed.

Results

cHAP mice on EtOH-DW consumed significantly more ethanol than cHAP or C57 mice maintained on LDE. However, cHAP and C57 mice on the LDE+Binge regiment had greater hepatosteatosis and overall degree of liver injury compared to EtOH-DW+Binge. Changes in pro-inflammatory gene expression was more pronounced in cHAP mice than C57 mice. Analysis of liver enzymes revealed a robust induction of CYP2E1 in C57 and cHAP mice maintained on EtOH-DW+Binge or LDE+Binge. However, while C57 mice exhibited higher basal hepatic glutathione than cHAP mice, these mice appeared more susceptible to oxidative stress following LDE+Binge than cHAP counterparts.

Conclusions

Despite cHAP mice consuming more total ethanol prior to gavage when maintained on EtOH-DW, LDE followed by gavage created a more severe model of ALD in both C57 and cHAP mice. These data suggest factors other than total amount of alcohol consumed affect degree of ALD development in the chronic-binge model in cHAP mice.

Short Summary

cHAP mice voluntarily consume high amounts of ethanol and exhibited hepatic injury when subject to chronic-binge ethanol feeding with the Lieber-DeCarli diet. However, hepatic injury was reduced in cHAP mice in a chronic-binge model following voluntary high ethanol consumption in drinking water.

Altered fatty acid-binding protein 4 (FABP4) expression and function in human and animal models of hepatocellular carcinoma

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality. Risk factors for developing HCC include viral hepatitis, alcohol and obesity. Fatty acid-binding proteins (FABPs) bind long-chain free fatty acids (FFAs) and are expressed in a tissue-specific pattern; FABP1 being the predominant hepatic form, and FABP4 the predominant adipocyte form. The aims of this study were to investigate the expression and function of FABPs1-9 in human and animal models of obesity-related HCC.

METHODS

FABP1-9 expression was determined in a mouse model of obesity-promoted HCC. Based on these data, expression and function of FABP4 was determined in human HCC cells (HepG2 and HuH7) in vitro. Serum from patients with different underlying hepatic pathologies was analysed for circulating FABP4 levels.

RESULTS

Livers from obese mice, independent of tumour status, exhibited increased FABP4 mRNA and protein expression concomitant with elevated serum FABP4. In vitro, FABP4 expression was induced in human HCC cells by FFA treatment, and led to FABP4 release into culture medium. Treatment of HCC cells with exogenous FABP4 significantly increased proliferation and migration of human HCC cells. Patient serum analysis demonstrated significantly increased FABP4 in those with underlying liver disease, particularly non-alcoholic fatty liver disease (NAFLD) and HCC.

CONCLUSIONS

These data suggest FABP4, an FABP not normally expressed in the liver, can be synthesized and secreted by hepatocytes and HCC cells, and that FABP4 may play a role in regulating tumour progression in the underlying setting of obesity.