Liver cancer and alcohol

Alcohol and hepatocellular carcinoma: A review and a point of view

It is well recognized that one cause of chronic liver disease and hepatocellular carcinoma (HCC) is alcohol consumption. Research in Italy and the United States concludes that the most common cause of HCC (responsible for 32% to 45% of HCC) is alcohol. It has recently been shown that a significant relationship between alcohol intake, metabolic changes, and hepatitis virus infection does exist. Alcohol may be a factor in the development of HCC via direct (genotoxic) and indirect mechanisms (cirrhosis). There is only one way of diagnosing HCC, which is early identification through surveillance, when curative treatments become possible. After stopping alcohol intake the risk of liver cancer decreases by 6% to 7% a year, and an estimated time period of 23 years is also needed. Therefore, surveillance is also important in former drinkers and, in our opinion, independently from the presence of compensated cirrhosis. In cases of very early stage (VES) and early stage with portal hypertension, liver transplantation is the optimal option; and in cases of associated disease, percutaneous ethanol injections, radiofrequency and microwave ablation are the ideal treatments. Despite the possibility of detecting microvascular invasion with HR, several studies and some randomized controlled trials revealed that overall survival and DSF rates in patients with VES HCC are much the same after ablation and HR. Therefore, ablation can be regarded as a first-line choice for patients with VES HCC. It is important to emphasize that the choice of treatment should be weighed carefully in the context of a multidisciplinary cancer team.

Acute alcoholic hepatitis, end stage alcoholic liver disease and liver transplantation: An Italian position statement

Alcoholic liver disease encompasses a broad spectrum of diseases ranging from steatosis steatohepatitis, fibrosis, and cirrhosis to hepatocellular carcinoma. Forty-four per cent of all deaths from cirrhosis are attributed to alcohol. Alcoholic liver disease is the second most common diagnosis among patients undergoing liver transplantation (LT). The vast majority of transplant programmes (85%) require 6 mo of abstinence prior to transplantation; commonly referred to as the “6-mo rule”. Both in the case of progressive end-stage liver disease (ESLD) and in the case of severe acute alcoholic hepatitis (AAH), not responding to medical therapy, there is a lack of evidence to support a 6-mo sobriety period. It is necessary to identify other risk factors that could be associated with the resumption of alcohol drinking. The “Group of Italian Regions” suggests that: in a case of ESLD with model for end-stage liver disease < 19 a 6-mo abstinence period is required; in a case of ESLD, a 3-mo sober period before LT may be more ideal than a 6-mo period, in selected patients; and in a case of severe AAH, not responding to medical therapies (up to 70% of patients die within 6 mo), LT is mandatory, even without achieving abstinence. The multidisciplinary transplant team must include an addiction specialist/hepato-alcohologist. Patients have to participate in self-help groups.

Relative effects of heavy alcohol use and hepatitis C in decompensated chronic liver disease in a hospital inpatient population

BACKGROUND

Heavy alcohol use has been hypothesized to accelerate disease progression to end-stage liver disease in patients with hepatitis C virus (HCV) infection. In this study, we estimated the relative influences of heavy alcohol use and HCV in decompensated chronic liver disease (CLD).

METHODS

Retrospectively, 904 patients with cirrhotic disease admitted to our hospitals during January 2010-December 2012 were identified based on ICD9 codes. A thorough chart review captured information on demographics, viral hepatitis status, alcohol use and progression of liver disease (i.e. decompensation). Decompensation was defined as the presence of ascites due to portal hypertension, bleeding esophageal varices, hepatic encephalopathy or hepatorenal syndrome. Heavy alcohol use was defined as a chart entry of greater than six daily units of alcohol or its equivalent.

RESULTS

347 patients were included based on our selection criteria of documented heavy alcohol use (n = 215; 62.0%), hepatitis titers (HCV: n = 182; 52.5%) and radiological evidence of CLD with or without decompensation (decompensation: n = 225; 64.8%). Independent of HCV infection, heavy alcohol use significantly increased the risk of decompensation (OR = 1.75, 95% CI 1.11-2.75, p < 0.02) relative to no heavy alcohol use. No significance was seen with age, sex, race, HIV, viral hepatitis and moderate alcohol use for risk for decompensation. Additionally, dose-relationship regression analysis revealed that heavy, but not moderate alcohol use, resulted in a three-fold increase (p = 0.013) in the risk of decompensation relative to abstinence.

CONCLUSIONS

While both heavy alcohol use and HCV infection are associated with risk of developing CLD, our data suggest that heavy, but not moderate, alcohol consumption is associated with a greater risk for hepatic decompensation in patients with cirrhosis than does HCV infection.

Epidemiology of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common histologic type of primary liver cancer, accounting for between 85% and 90% of these malignancies. The overall prognosis of patients with liver cancer is poor, and an understanding of this disease and its risk factors is crucial for screening at-risk individuals, early recognition, and timely diagnosis. Most HCCs arise in the background of chronic liver disease caused by hepatitis B virus, hepatitis C virus, and chronic excessive alcohol intake. These underlying causes are characterized by marked variations in geography, gender, and other well-documented risk factors, some of which are potentially preventable.

Chronic inflammation and cancer: potential chemoprevention through nuclear factor kappa B and p53 mutual antagonism

Activation of nuclear factor-kappa B (NF- κB) as a mechanism of host defense against infection and stress is the central mediator of inflammatory responses. A normal (acute) inflammatory response is activated on urgent basis and is auto-regulated. Chronic inflammation that results due to failure in the regulatory mechanism, however, is largely considered as a critical determinant in the initiation and progression of various forms of cancer. Mechanistically, NF- κB favors this process by inducing various genes responsible for cell survival, proliferation, migration, invasion while at the same time antagonizing growth regulators including tumor suppressor p53. It has been shown by various independent investigations that a down regulation of NF- κB activity directly, or indirectly through the activation of the p53 pathway reduces tumor growth substantially. Therefore, there is a huge effort driven by many laboratories to understand the NF- κB signaling pathways to intervene the function of this crucial player in inflammation and tumorigenesis in order to find an effective inhibitor directly, or through the p53 tumor suppressor. We discuss here on the role of NF- κB in chronic inflammation and cancer, highlighting mutual antagonism between NF- κB and p53 pathways in the process. We also discuss prospective pharmacological modulators of these two pathways, including those that were already tested to affect this mutual antagonism.

Evaluation of mutagenic and genotoxic activities of lobeline and its modulation on genomic instability induced by ethanol

AIM

Lobeline is a natural alkaloid derived from Lobelia inflata that has been investigated as a clinical candidate for the treatment of alcoholism. In a pre-clinical trial, lobeline decreased the preference for and consumption of ethanol, due to the modulation of the nicotinic acetylcholine receptor. However, the interaction between lobeline and ethanol is poorly known and thus there are safety concerns. The present study was conducted to evaluate the mutagenic and genotoxic effects of lobeline and assess its modulation of ethanol-induced toxicological effects.

MAIN METHODS

CF-1 male mice were divided into five groups. Groups received an intraperitoneal injection of saline solution, lobeline (5 or 10mg/kg), ethanol (2.5 g/kg), or lobeline plus ethanol, once a day for three consecutive days. Genotoxicity was evaluated in peripheral blood using the alkaline comet assay. The mutagenicity was evaluated using both Salmonella/microsome assay in TA1535, TA97a, TA98, TA100, and TA102 Salmonella typhimurium strains and the micronucleus test in bone marrow. Possible liver and kidney injuries were evaluated using biochemical analysis.

KEY FINDINGS

Lobeline did not show genotoxic or mutagenic effects and did not increase the ethanol-induced genotoxic effects in blood. Lobeline also protected blood cells against oxidative damage induced by hydrogen peroxide. Biochemical parameters were not altered, indicating no liver or kidney injuries or alterations in lipid and carbohydrate metabolisms.

SIGNIFICANCE

These findings suggest that lobeline does not induce gene or chromosomal mutations, and that this lack of genetic toxicity is maintained in the presence of ethanol, providing further evidence of the safety of this drug to treat alcohol dependence.

Long noncoding RNA HOTTIP/HOXA13 expression is associated with disease progression and predicts outcome in hepatocellular carcinoma patients

Hepatocellular carcinoma (HCC) is among the leading causes of cancer-related death. Despite the advances in diagnosis and management of HCC, the biology of this tumor remains poorly understood. Recent evidence highlighted long noncoding RNAs (lncRNAs) as crucial determinants of HCC development. In this study we report the lncRNA HOXA transcript at the distal tip (HOTTIP) as significantly up-regulated in HCC specimens. The HOTTIP gene is located in physical contiguity with HOXA13 and directly controls the HOXA locus gene expression by way of interaction with the WDR5/MLL complex. HOX genes encode transcription factors regulating embryonic development and cell fate. We previously described HOX genes deregulation to be involved in hepatocarcinogenesis. Indeed, we observed the marked up-regulation of HOXA13 in HCC. Here, by correlating clinicopathological and expression data, we demonstrate that the levels of HOTTIP and HOXA13 are associated with HCC patients' clinical progression and predict disease outcome. In contrast to the majority of similar studies, our data were obtained from snap-frozen needle HCC biopsies (n=52) matched with their nonneoplastic counterparts collected from patients who had not yet received any HCC-tailored therapeutic treatments at the time of biopsy. In addition, taking advantage of gain and loss of function experiments in liver cancer-derived cell lines (HuH-6 and HuH-7), we uncover a novel bidirectional regulatory loop between HOTTIP/HOXA13.

CONCLUSION

Our study highlights the key role of HOTTIP and HOXA13 in HCC development by associating their expression with metastasis and survival in HCC patients, provides novel insights on the function of lncRNA-driven hepatocarcinogenesis, and paves the way for further investigation about the possible role of HOTTIP as a predictive biomarker of HCC.

The mammalian circadian clock in the suprachiasmatic nucleus exhibits rapid tolerance to ethanol in vivo and in vitro

BACKGROUND

Ethanol (EtOH) triggers cellular adaptations that induce tolerance in many brain areas, including the suprachiasmatic nucleus (SCN), the site of the master circadian clock. EtOH inhibits light-induced phase shifts in the SCN in vivo and glutamate-induced phase shifts in vitro. The in vitro phase shifts develop acute tolerance to EtOH, occurring within minutes of initial exposure, while the in vivo phase shifts exhibit no evidence of chronic tolerance. An intermediate form, rapid tolerance, is not well studied but may predict subsequent chronic tolerance. Here, we investigated rapid tolerance in the SCN clock.

METHODS

Adult C57BL/6 mice were provided 15% EtOH or water for one 12-hour lights-off period. For in vitro experiments, SCN-containing brain slices were prepared in the morning and treated for 10 minutes with glutamate +/- EtOH the following night. Single-cell neuronal firing rates were recorded extracellularly during the subsequent day to determine SCN clock phase. For in vivo experiments, mice receiving EtOH 24 hours previously were exposed to a 30-minute light pulse immediately preceded by intraperitoneal saline or 2 g/kg EtOH injection. Mice were then placed in constant darkness and their phase-shifting responses measured.

RESULTS

In vitro, the SCN clock from EtOH-exposed mice exhibited rapid tolerance, with a 10-fold increase in EtOH needed to inhibit glutamate-induced phase shifts. Co-application of brain-derived neurotrophic factor prevented EtOH inhibition, consistent with experiments using EtOH-naïve mice. Rapid tolerance lasts 48 to 96 hours, depending on whether assessing in vitro phase advances or phase delays. Similarly, in vivo, prior EtOH consumption prevented EtOH's acute blockade of photic phase delays. Finally, immunoblot experiments showed no changes in SCN glutamate receptor subunit (NR2B) expression or phosphorylation in response to rapid tolerance induction.

CONCLUSIONS

The SCN circadian clock develops rapid tolerance to EtOH as assessed both in vivo and in vitro, and the tolerance lasts for several days. These data demonstrate the utility of the circadian system as a model for investigating cellular mechanisms through which EtOH acts in the brain.

p53-Dependent and cell specific epigenetic regulation of the polo-like kinases under oxidative stress

The polo-like kinase (PLKs) family, consisting of five known members, are key regulators of important cell cycle processes, which include mitotic entry, centrosome duplication, spindle assembly, and cytokinesis. The PLKs have been implicated in a variety of cancers, such as hepatocellular carcinoma (HCC), with PLK1 typically overexpressed and PLKs 2-5 often downregulated. Altered expression of the PLKs in malignancy is often correlated with aberrant promoter methylation. Epigenetic marks are dynamic and can be modified in response to external environmental stimuli. The aim of our study was to determine if oxidative stress, a common feature of solid tumours, would induce changes to the promoter methylation of the PLKs resulting in changes in expression. We examined the promoter methylation status via MSP and subsequent expression levels of the PLK family members under exposure to hypoxic conditions or reactive oxygen species (ROS). Interestingly, murine embryonic fibroblasts exposed to hypoxia and ROS displayed significant hypermethylation of Plk1 and Plk4 promoter regions post treatment. Corresponding proteins were also depleted by 40% after treatment. We also examined the HCC-derived cell lines HepG2 and Hep3B and found that for PLK1 and PLK4, the increase in hypermethylation was correlated with the presence of functional p53. In p53 wild-type cells, HepG2, both PLK1 and PLK4 were repressed with treatment, while in the p53 null cell line, Hep3B, PLK4 protein was elevated in the presence of hypoxia and ROS. This was also the case for ROS-treated, p53 null, osteosarcoma cells, Saos-2, where the PLK4 promoter became hypomethylated and protein levels were elevated. Our data supports a model in which the PLKs are susceptible to epigenetic changes induced by microenvironmental cues and these modifications may be p53-dependent. This has important implications in HCC and other cancers, where epigenetic alterations of the PLKs could contribute to tumourigenesis and disease progression.

Human alcohol-related neuropathology

Alcohol-related diseases of the nervous system are caused by excessive exposures to alcohol, with or without co-existing nutritional or vitamin deficiencies. Toxic and metabolic effects of alcohol (ethanol) vary with brain region, age/developmental stage, dose, and duration of exposures. In the mature brain, heavy chronic or binge alcohol exposures can cause severe debilitating diseases of the central and peripheral nervous systems, and skeletal muscle. Most commonly, long-standing heavy alcohol abuse leads to disproportionate loss of cerebral white matter and impairments in executive function. The cerebellum (especially the vermis), cortical-limbic circuits, skeletal muscle, and peripheral nerves are also important targets of chronic alcohol-related metabolic injury and degeneration. Although all cell types within the nervous system are vulnerable to the toxic, metabolic, and degenerative effects of alcohol, astrocytes, oligodendrocytes, and synaptic terminals are major targets, accounting for the white matter atrophy, neural inflammation and toxicity, and impairments in synaptogenesis. Besides chronic degenerative neuropathology, alcoholics are predisposed to develop severe potentially life-threatening acute or subacute symmetrical hemorrhagic injury in the diencephalon and brainstem due to thiamine deficiency, which exerts toxic/metabolic effects on glia, myelin, and the microvasculature. Alcohol also has devastating neurotoxic and teratogenic effects on the developing brain in association with fetal alcohol spectrum disorder/fetal alcohol syndrome. Alcohol impairs function of neurons and glia, disrupting a broad array of functions including neuronal survival, cell migration, and glial cell (astrocytes and oligodendrocytes) differentiation. Further progress is needed to better understand the pathophysiology of this exposure-related constellation of nervous system diseases and better correlate the underlying pathology with in vivo imaging and biochemical lesions.

New Insights into the Pathogenesis of Alcohol-Induced ER Stress and Liver Diseases

Alcohol-induced liver disease increasingly contributes to human mortality worldwide. Alcohol-induced endoplasmic reticulum (ER) stress and disruption of cellular protein homeostasis have recently been established as a significant mechanism contributing to liver diseases. The alcohol-induced ER stress occurs not only in cultured hepatocytes but also  in vivo  in the livers of several species including mouse, rat, minipigs, zebrafish, and humans. Identified causes for the ER stress include acetaldehyde, oxidative stress, impaired one carbon metabolism, toxic lipid species, insulin resistance, disrupted calcium homeostasis, and aberrant epigenetic modifications. Importance of each of the causes in alcohol-induced liver injury depends on doses, duration and patterns of alcohol exposure, genetic disposition, environmental factors, cross-talks with other pathogenic pathways, and stages of liver disease. The ER stress may occur more or less all the time during alcohol consumption, which interferes with hepatic protein homeostasis, proliferation, and cell cycle progression promoting development of advanced liver diseases. Emerging evidence indicates that long-term alcohol consumption and ER stress may directly be involved in hepatocellular carcinogenesis (HCC). Dissecting ER stress signaling pathways leading to tumorigenesis will uncover potential therapeutic targets for intervention and treatment of human alcoholics with liver cancer.

Human alcohol-related neuropathology

Alcohol-related diseases of the nervous system are caused by excessive exposures to alcohol, with or without co-existing nutritional or vitamin deficiencies. Toxic and metabolic effects of alcohol (ethanol) vary with brain region, age/developmental stage, dose, and duration of exposures. In the mature brain, heavy chronic or binge alcohol exposures can cause severe debilitating diseases of the central and peripheral nervous systems, and skeletal muscle. Most commonly, long-standing heavy alcohol abuse leads to disproportionate loss of cerebral white matter and impairments in executive function. The cerebellum (especially the vermis), cortical-limbic circuits, skeletal muscle, and peripheral nerves are also important targets of chronic alcohol-related metabolic injury and degeneration. Although all cell types within the nervous system are vulnerable to the toxic, metabolic, and degenerative effects of alcohol, astrocytes, oligodendrocytes, and synaptic terminals are major targets, accounting for the white matter atrophy, neural inflammation and toxicity, and impairments in synaptogenesis. Besides chronic degenerative neuropathology, alcoholics are predisposed to develop severe potentially life-threatening acute or subacute symmetrical hemorrhagic injury in the diencephalon and brainstem due to thiamine deficiency, which exerts toxic/metabolic effects on glia, myelin, and the microvasculature. Alcohol also has devastating neurotoxic and teratogenic effects on the developing brain in association with fetal alcohol spectrum disorder/fetal alcohol syndrome. Alcohol impairs function of neurons and glia, disrupting a broad array of functions including neuronal survival, cell migration, and glial cell (astrocytes and oligodendrocytes) differentiation. Further progress is needed to better understand the pathophysiology of this exposure-related constellation of nervous system diseases and better correlate the underlying pathology with in vivo imaging and biochemical lesions.

Chemoprevention of hepatocellular carcinoma in patients with hepatitis C virus related cirrhosis

Interferon (IFN) therapy has been reported to decrease the risk of hepatocellular carcinoma (HCC) and improve survival by preventing liver-related deaths in patients with chronic hepatitis C virus (HCV) infection, while the role of IFN therapy on the natural history of hepatitis C related cirrhosis is still under debate. The ideal goal of therapy is to prevent the progression into end-stage disease. The use of IFN in patients with HCV compensated cirrhosis reduces the negative clinical evolution independently of the type of laboratoristic and virological response. In our experience, IFN therapy in HCV compensated cirrhosis is barely useful in prevention of HCC, as cirrhosis itself represents a risk of cancer. Some authors noted that IFN treatment reduces the risk of HCC independently of the virological response. It would probably be interesting to evaluate the efficacy of weekly low-dose pegylated (PEG)-IFN therapy in patients with HCV cirrhosis and to assess potential benefits of long-term PEG-IFN plus Ribavirin treatment.

The role of chronic inflammation in obesity-associated cancers

There is a strong relationship between metabolism and immunity, which can become deleterious under conditions of metabolic stress. Obesity, considered a chronic inflammatory disease, is one example of this link. Chronic inflammation is increasingly being recognized as an etiology in several cancers, particularly those of epithelial origin, and therefore a potential link between obesity and cancer. In this review, the connection between the different factors that can lead to the chronic inflammatory state in the obese individual, as well as their effect in tumorigenesis, is addressed. Furthermore, the association between obesity, inflammation, and esophageal, liver, colon, postmenopausal breast, and endometrial cancers is discussed.

Tetrahydroxystilbene glucoside protects against ethanol-induced liver injury in mice by inhibition of expression of inflammation-related factors

AIM: To investigate the protective effects of tetrahydroxystilbene glucoside (TSG) against acute ethanol-induced liver injury in mice and to explore the possible mechanisms involved.

METHODS: Kunming mice were randomly divided into five groups: normal control group, liver injury model group, low-(30 mg/kg) and high-dose (60 mg/kg) TSG groups, and Silibinin (50 mg/kg) group. Liver histopathology was measured by light microscopy. The contents of serum tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and IL-6 were assayed by ELSIA, and plasma endotoxin level was measured by LAL chromogenic endpoint assay. The mRNA expression of TNF-α and iNOS in liver tissue was detected by real-time PCR. The phospho-IκBα level and NF-κB nuclear translocation in hepatic tissue were measured by Western blot.

RESULTS: Compared to the control group, the model group showed significant hydropic degeneration and steatosis of hepatocytes, increased contents of serum TNF-α, IL-1β and IL-6 and plasma level of endotoxin (all P < 0.01), up-regulated mRNA expression of TNF-α and iNOS in liver tissue (TNF-α: 128.5 pg/mL ± 20.7 pg/mL vs 45.2 pg/mL ± 14.2 pg/mL; IL-1β: 71.8 pg/mL ± 9.1 pg/mL vs 33.1 pg/mL ± 9.5 pg/mL; IL-6: 59.8 pg/mL ± 13.1 pg/mL vs 23.7 pg/mL ± 5.9 pg/mL; endotoxin: 0.35 EU/mL ± 0.09 EU/mL vs 0.11 EU/mL ± 0.03 EU/mL. TNF-α mRNA: 1.33 ± 0.11 vs 0.63 ± 0.10; iNOS mRNA: 0.85 ± 0.09 vs 0.40 ± 0.07; phospho-IκB-α: 2.02 ± 0.14 vs 0.92 ± 0.19; NF-κB P65: 1.10 ± 0.14 vs 0.44 ± 0.13, P < 0.05, P < 0.01), and significantly increased phospho-IκBα level and NF-κB nuclear translocation in hepatic tissue (both P < 0.01). Compared to the model group, serum levels of TNF-α, IL-1β and IL-6 and plasma endotoxin level significantly decreased (all P < 0.05 or 0.01), the mRNA expression of TNF-α and iNOS was down-regulated, and phospho-IκBα level and NF-κB nuclear translocation in hepatic tissue were significantly inhibited in the TSG groups (TSG 60 mg/kg group: TNF-α: 65.9 pg/mL ± 13.9 pg/mL vs 128.5 pg/mL ± 20.7 pg/mL; IL-1β: 43.0 pg/mL ± 7.1 pg/mL vs 71.8 pg/mL ± 9.1 pg/mL; IL-6: 36.3 pg/mL ± 10.1 pg/mL vs 59.8 pg/mL ± 13.1 pg/mL; endotoxin: 0.20 EU/mL ± 0.05 EU/mL vs 0.35 EU/mL ± 0.09 EU/mL; TNF-α mRNA: 0.79 ± 0.09 vs 1.33 ± 0.11; iNOS mRNA: 0.53 ± 0.10 vs 0.85 ± 0.09; phospho-IκB-α: 1.35 ± 0.32 vs 2.02 ± 0.14; NF-κB P65: 0.62 ± 0.05 vs 1.10 ± 0.14, all P < 0.05 or 0.01).

CONCLUSION: TSG has a protective effect on acute alcoholic liver injury in mice possibly by decreasing endotoxin level and NF-κB nuclear translocation and attenuating the trigger of inflammation-related cascade amplification.