Epidemiologic data on alcoholic beverage consumption and risk of cancer

Combined Alcohol Exposure and KRAS Mutation in Human Pancreatic Ductal Epithelial Cells Induces Proliferation and Alters Subtype Signatures Determined by Multi-Omics Analysis

Simple Summary

Pancreatic ductal adenocarcinoma is a deadly disease wherein alcohol use increases the risk of developing this cancer. Mutations in the KRAS oncogene are required for alcohol to promote pancreatic cancer in mice, but little is known about the molecular events associated with the combined exposure of alcohol and mutant KRAS expression in pancreas cells. In this study, we use pancreas cell models with and without mutant KRAS to evaluate the impact of chronic alcohol exposure on transcription and protein expression. This study identifies numerous differentially expressed transcripts and proteins that could influence the emergence of oncogenic features, such as increased proliferation, in pancreas cells.

Abstract

Pancreatic Ductal adenocarcinoma (PDAC) is an aggressive cancer commonly exhibiting KRAS-activating mutations. Alcohol contributes to the risk of developing PDAC in humans, and murine models have shown alcohol consumption in the context of KRAS mutation in the pancreas promotes the development of PDAC. The molecular signatures in pancreas cells altered by alcohol exposure in the context of mutant KRAS could identify pathways related to the etiology of PDAC. In this study, we evaluated the combined effects of alcohol exposure and KRAS mutation status on the transcriptome and proteome of pancreatic HPNE cell models. These analyses identified alterations in transcription and translational processes in mutant KRAS cells exposed to alcohol. In addition, multi-omics analysis suggests an increase in the correlation between mRNA transcript and protein abundance in cells exposed to alcohol with an underlying KRAS mutation. Through differential co-expression, SERPINE1 was found to be influential for PDAC development in the context of mutant KRAS and ethanol. In terms of PDAC subtypes, alcohol conditioning of HPNE cells expressing mutant KRAS decreases the Inflammatory subtype signature and increases the Proliferative and Metabolic signatures, as we previously observed in patient samples. The alterations in molecular subtypes were associated with an increased sensitivity to chemotherapeutic agents gemcitabine, irinotecan, and oxaliplatin. These results provide a framework for distinguishing the molecular dysregulation associated with combined alcohol and mutant KRAS in a pancreatic cell line model.

Ethanol exposure of human pancreatic normal ductal epithelial cells induces EMT phenotype and enhances pancreatic cancer development in KC (Pdx1-Cre and LSL-KrasG12D ) mice

Alcohol is a risk factor for pancreatic cancer. However, the molecular mechanism by which chronic alcohol consumption influences pancreatic cancer development is not well understood. We have recently demonstrated that chronic ethanol exposure of pancreatic normal ductal epithelial cells (HPNE) induces cellular transformation by generating cancer stem cells (CSCs). Here, we examined whether chronic ethanol treatment induces epithelial–mesenchymal transition in HPNE cells and promotes pancreatic cancer development in KC (Pdx1‐Cre, and LSL‐Kras^G12D) mice. Our data demonstrate that chronic ethanol exposure of HPNE cells induces SATB2 gene and those cells became highly motile. Ethanol treatment of HPNE cells results in downregulation of E‐Cadherin and upregulation of N‐Cadherin, Snail, Slug, Zeb1, Nanog and BMI‐1. Suppression of SATB2 expression in ethanol‐transformed HPNE cells inhibits EMT phenotypes. KC mice fed with an ethanol‐containing diet show enhanced pancreatic cancer growth and development than those fed with a control diet. Pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of stem cell markers (CD133, CD44, CD24), pluripotency‐maintaining factors (cMyc, KLF4, SOX‐2, and Oct‐4), N‐Cadherin, EMT‐transcription factors (Snail, Slug, and Zeb1), and lower expression of E‐cadherin than those isolated from mice fed with a control diet. Furthermore, pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of inflammatory cytokines (TNF‐α, IL‐6, and IL‐8) and PTGS‐2 (COX‐2) gene than those isolated from mice fed with a control diet. These data suggest that chronic alcohol consumption may contribute to pancreatic cancer development by generating inflammatory signals and CSCs.

Alcohol-related head and neck cancer: Summary of the literature

Alcohol drinking is a risk factor for the development of head-and-neck malignancies, including oral, pharyngeal, and laryngeal cancers, and coupled with tobacco use, accounts for 75% of oral cancers. We summarized the literature on alcohol-related head and neck cancer (HNC) and identified gaps that represent areas for future investigation. Research indicates that alcohol consumption has not only been linked to the development of primary HNCs, but also to secondary cancers with continued alcohol intake, cancer recurrences, and other poor health outcomes. Given this evidence, several organizations have called for reduction or avoidance of alcohol, particularly in HNC survivors. Despite these strong recommendations, evidence suggests that HNC survivors continue to use alcohol. There is a need to forge collaborations among clinicians, researchers, and social workers, to address this problem of alcohol consumption in the growing population of HNC survivors.

Chronic ethanol exposure of human pancreatic normal ductal epithelial cells induces cancer stem cell phenotype through SATB2

The incidence of pancreatic cancer is on the rise. Risk factors for pancreatic cancer include alcohol toxicity and metabolic conditions such as obesity, hypertension, dyslipidaemia, insulin resistance and type 2 diabetes. However, the molecular mechanism by which chronic alcohol consumption contributes to pancreatic cancer is not well understood. The purpose of the study was to demonstrate the effects of long-term chronic ethanol exposure on the transformation of human pancreatic normal ductal epithelial (HPNE) cells. Our data showed that ethanol-transformed HPNE cells were more progressively transformed exhibiting spheroids and colonies, and anchorage-independent growth. These transformed cells contained high levels of reactive oxygen species and induced SATB2 expression. Furthermore, during ethanol-induced cellular transformation, cells gained the phenotypes of cancer stem cells (CSCs) by expressing pluripotency maintaining factors (Oct4, Sox2, cMyc and KLF4) and stem cell markers (CD24, CD44 and CD133). Ethanol-induced SATB2 can bind to the promoters of KLF4, Oct4, cMyc, Sox2, Bcl-2 and XIAP genes. Suppression of SATB2 expression in ethanol-transformed HPNE cells inhibited cell proliferation, colony formation and markers of CSCs and pluripotency. These data suggest that chronic alcohol consumption may contribute toward the development of pancreatic cancer by converting HPNE cells to cancer stem-like cells.

Adverse physical effects of alcohol misuse

This article outlines the majority of the adverse physical effects that have been described secondary to the consumption of alcohol at levels above recommended sensible limits. These conditions are cited according to the organ system they belong to. Only brief descriptions are provided because of the vastness of this topic. The underlying pathophysiology of tolerance and withdrawal is touched upon as this is of relevance to the psychiatrist. Definitions of the terms used describing alcohol misuse, and sensible upper limits of alcohol consumption are also mentioned.

Physical illness in psychiatric inpatients: comparison of patients with and without substance use disorders

BACKGROUND

Physical comorbidities and substance use are commonly reported in patients with mental disorders.

AIM

To examine somatic comorbidity in patients with substance use disorders (SUD) compared to patients with mental disorders but no SUD.

METHODS

Lifetime prevalence data on mental and physical health status were collected from inpatients in 12 mental health care facilities in five different countries. Differences in somatic comorbidity were examined by means of logistic regression analysis controlling for age and gender.

RESULTS

Of 2,338 patients, 447 (19%) had a primary or secondary SUD diagnosis. In comparison to patients with other mental disorders, patients with SUD had a higher prevalence of infectious and digestive diseases but a lower prevalence of endocrine, nutritional and metabolic disorders. Patterns of physical comorbidities differed according to type of substance used (alcohol use - cardiovascular; tobacco use - respiratory, neoplasms; cannabinoid use - injuries; opioid use - infectious, digestive; benzodiazepine use - endocrine, nutritional, metabolic; stimulants - urogenital).

CONCLUSIONS

SUD are related to specific somatic health risks while some of our findings point to potentially protective effects. The widespread prescription of benzodiazepines requires research on physical health effects. Early detection of SUD and their integration into programmes targeting physical comorbidity should be a priority in organizing mental health care.

Alcohol and smoking

The WHO ranks smoking and alcohol consumption as the first and third leading causes of the global burden of disease in industrialized countries, using disability-adjusted life years (DALYs) as a combined measure of premature death and disability. Smoking is responsible for 12.2% of all DALYs and alcohol consumption for 9.2%. For example in Germany, annually 110,000-140,000 humans die prematurely because of cigarette smoking and 40,000 because of alcohol drinking. In Europe and the USA, more than 20% of all hospitalized men and more than 9% of all hospitalized women suffer from alcohol-associated diseases. In Germany, about 2.0 million people in the age group 18-64 years (3.8% of all Germans) are alcohol abusers and 1.3 million people (2.4%) are alcohol-dependent. Alcohol can cause acute as well as chronic damage in nearly all body organs. Smoking damages also nearly every human body organ and is worldwide the most important single preventable health risk factor as well as the main cause for premature mortality in industrial countries. One third of the adult Germans as well as of the world population are active smokers; men smoke more frequently than women (34.0 vs. 25.1%). In this review a short overview will be given on the most important deleterious effects of alcohol and smoking. The most recent data about the pathophysiological relevance of non-alcoholic compounds of alcoholic beverages will also be discussed.

Wine, Resveratrol and Health: A Review

Several studies have cited the Mediterranean diet as an example of healthy eating. In fact, the Mediterranean diet has become the reference diet for the prevention of cardiovascular disease. Red wine seems to be an essential component of the diet, since moderate consumption of wine is associated with lower risk and mortality from cardiovascular disease. Evidence is also accumulating that wine helps prevent the development of certain cancers. Of all the many components of wine, resveratrol, which is a natural component specifically present in wine, has been identified as being mainly responsible for these health-promoting properties. Many valuable properties such as cardioprotective and anticarcinogenic activity have been attributed to resveratrol; however, its bioavailability is quite low. The bioactivity of metabolites derived from resveratrol, and the accumulation of resveratrol in vital organs are still under study, but there are high expectations of positive results. Other stilbene compounds are also considered in this review, despite being present in undetectable or very small quantities in wine. The present paper reviews all aspects of the health properties of wine, bioactive compounds found in wine, and their concentrations, bioavailability and possible synergistic effects.

Pancreatic intraepithelial neoplasia and ductal adenocarcinoma induced by DMBA in mice: effects of alcohol and caffeine

PURPOSE

To evaluate the effects of alcohol and caffeine in a pancreatic carcinogenesis mouse model induced by 7,12-dimethylbenzantracene (DMBA), according to the PanIN classification system.

METHODS

120 male, Mus musculus, CF-1 mice were divided into four groups. Animals received either water or caffeine or alcohol or alcohol + caffeine in their drinking water. In all animals, 1 mg of DMBA was implanted into the head of the pancreas. After 30 days, euthanasia was performed; excised pancreata were then fixed in formalin, stained with hematoxylin-eosin and categorized as follows: normal ducts, reactive hyperplasia, PanIN-1A, PanIN-1B, PanIN-2, PanIN-3 or adenocarcinoma.

RESULTS

PanIN lesions were verified in all groups. Adenocarcinoma was detected in 15% of animals in the caffeine group, 16.6% in the water group, 23.8% in the alcohol + caffeine group and 52.9% in the alcohol group (P<0.05).

CONCLUSIONS

The experimental pancreatic carcinogenesis mouse model using DMBA effectively induces PanIN lesions and pancreatic adenocarcinoma. This study verified the association between alcohol use and pancreatic adenocarcinoma; caffeine did not present the same effect.

The effect of ethanol and nitric oxide on the N-nitrosodimethylamine formation in HepG2 cells overexpressing CYP2E1

The influence of lipopolysaccharide (LPS) and the nitric oxide synthase (iNOS) inhibitor--N-nitro-L-arginine methyl ester (L-NAME)--on the formation of N-nitrosodimethylamine (NDMA) by HepG2 cells, engineered to overexpress CYP2E1, was assessed and compared with data from empty vector-transfected cells. HepG2 cells produced significant amounts of NDMA but its levels in the culture media of cells overexpressing CYP2E1 was significantly lower than in empty-vector transfected cells. LPS increased the formation of NDMA, the expression of the iNOS and the production of the nitric oxide (NO). On the other hand, L-NAME significantly decreased NDMA levels. The results above indicate that the synthesis of NDMA by HepG2 cells depends on NO production. Furthermore, ethanol did not affect iNOS expression but decreased NDMA levels in CYP2E1-transfected cells below the detection limit. It is probably caused by the increased N-nitrosodimethylamine metabolism. In conclusion, HepG2 cells' ability to synthesize NO with simultaneous CYP2E1 activation may lead to an increase of carcinogenic products of the NDMA metabolism.

Moderate alcohol consumption and the gastrointestinal tract

BACKGROUND

A high alcohol intake is significantly associated with diseases of the gastrointestinal tract, but less is known about the effects of moderate consumption, specifically moderate average volume of alcohol consumption.

METHODS

A systematic computer-assisted literature review was completed in order to review current scientific knowledge surrounding this topic.

RESULTS

Moderate alcohol consumption is associated with a number of gastrointestinal health risks, including liver diseases, oropharyngeal cancer, esophageal cancer and pancreatitis but may play a positive role in gastritis and cholelithiasis.

CONCLUSION

Moderate alcohol consumption may play a positive or negative role in disease etiology, but the overall conclusion is that moderate alcohol intake is not a high risk factor for many of the gastrointestinal diseases associated with high levels of consumption. The etiology of alcohol diseases is also linked to patterns of drinking, so this is an important area for future research in this area.

The role of antioxidants in the Mediterranean diets: focus on cancer

The incidence of certain cancers in the Mediterranean area is lower than in other areas of the world (e.g. in northern Europe and the USA). As nutrition and dietary factors comprise one of the three major factors for human carcinogenesis, the hypothesis was formulated that the dietary profile of the Mediterranean diet, rich in antioxidants, might exert preventive actions. Alas, the vast majority of experiments to prove this hypothesis have been obtained in vitro, and most of the necessary information on the absorption, distribution and metabolism of oligonutrients is currently lacking. Yet, even though the exact role of antioxidants in the Mediterranean diet is yet to be fully established, data from observational studies are strong enough to reinforce the notion that a diet low in saturated fat and alcohol and rich in plant food and whole grain, such as the traditional Mediterranean diet, is associated with lower risk of cancer and should be actively promoted.

A cross-national comparison of lifestyle between China and the United States, using a comprehensive cross-national measurement tool of the healthfulness of lifestyles: the Lifestyle Index

BACKGROUND

Extensive studies have revealed the importance of a healthy lifestyle and the role of each lifestyle factor in health. However, lifestyle factors have rarely been studied simultaneously. The authors propose an integrated approach to summarize total healthfulness of lifestyles and to enhance understanding of lifestyle patterns across countries.

METHODS

The authors created an overall measure of lifestyle called the Lifestyle Index (LI), integrating diet, physical activity, smoking, and alcohol use to provide a global tool of monitoring healthfulness and patterns of lifestyles. Using the LI, the authors conducted a cross-national comparison between China (n = 8352) and the United States (n = 9750).

RESULTS

The LI effectively reflected the healthfulness of lifestyle components in both countries. The mean of the LI scores was slightly higher in China than the US. Scores of diet quality, physical activity, and smoking were higher in China, but scores of alcohol behavior were higher in the US. Similar lifestyle patterns but different unhealthy behaviors were identified in these countries.

CONCLUSIONS

An assessment of total healthfulness of lifestyles and a better understanding of lifestyle patterns across countries using the LI can provide practical guidance to developing and targeting public health promotion activities to improve global public health.

Alcohol-related diseases of the oesophagus and stomach

This chapter deals with the most clinically relevant alcohol-related diseases of the oesophagus and stomach. Despite the early findings of W. Beaumont 170 years ago that excessive drinking is associated with gastric bleeding, systematic studies on the action of alcohol and alcoholic beverages on the function of the stomach have only been performed in the last 15 years. The aim of this review is to summarize the data on the effect of acute and chronic alcohol consumption/abuse on the oesophagus and stomach.

Neoplastic and antineoplastic effects of beta-carotene on colorectal adenoma recurrence: results of a randomized trial

BACKGROUND

In two large, randomized prevention trials, supplementation with beta-carotene increased the risk of lung cancer. Subjects in these studies were predominantly cigarette smokers, and the adverse effects were concentrated among those who also drank alcohol. Although beta-carotene supplementation appeared not to increase the risk of cancer generally, it is not clear if smoking and/or alcohol use alters the effect of beta-carotene on carcinogenesis at sites outside the lung.

METHODS

We studied the effect of beta-carotene supplementation on colorectal adenoma recurrence among subjects in a multicenter double-blind, placebo-controlled clinical trial of antioxidants for the prevention of colorectal adenomas. A total of 864 subjects who had had an adenoma removed and were polyp-free were randomly assigned (in a factorial design) to receive beta-carotene (25 mg or placebo) and/or vitamins C and E in combination (1000 mg and 400 mg, respectively, or placebo), and were followed with colonoscopy for adenoma recurrence 1 year and 4 years after the qualifying endoscopy. A total of 707 subjects had two follow-up examinations and provided smoking and alcohol use data. Adjusted multivariate risk ratios (RRs) and 95% confidence intervals (CIs) were used to assess the effects of beta-carotene on adenoma recurrence.

RESULTS

Among subjects who neither smoked cigarettes nor drank alcohol, beta-carotene was associated with a marked decrease in the risk of one or more recurrent adenomas (RR = 0.56, 95% CI = 0.35 to 0.89), but beta-carotene supplementation conferred a modest increase in the risk of recurrence among those who smoked (RR = 1.36, 95% CI = 0.70 to 2.62) or drank (RR = 1.13, 95% CI = 0.89 to 1.43). For participants who smoked cigarettes and also drank more than one alcoholic drink per day, beta-carotene doubled the risk of adenoma recurrence (RR = 2.07, 95% CI = 1.39 to 3.08; P for difference from nonsmoker/nondrinker RR <.001).

CONCLUSION

Alcohol intake and cigarette smoking appear to modify the effect of beta-carotene supplementation on the risk of colorectal adenoma recurrence.

Enhancing risk of ethanol on MeIQx-induced rat hepatocarcinogenesis is accompanied with increased levels of cellular proliferation and oxidative stress

We investigated promotion potential of ethanol after initiation of hepatocarcinogenesis in male, 21-day-old, F344 rats by exposure to 10 ppm 2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline pellet diet for 8 weeks. The rats in group 1 were then fed on liquid control diet for 16 weeks, group 2 receiving the same diet containing 5% ethanol for 8 weeks followed by 8 weeks on the control diet, while group 3 animals were given 5% ethanol containing liquid diet for the entire16 weeks. On sacrifice at the end of week 24, glutathione S-transferase placental form positive foci, putative preneoplastic lesions in the liver, cell proliferation as indicated by proliferating cell nuclear antigen immunohistochemical staining and levels of 8-hydroxydeoxyguanosine, a marker of oxidative DNA damage, were significantly increased in the liver of group 3 along with non significant alteration of 8-oxoguanine DNA glycosylase mRNA expression. Lack of persistent increase of above parameters was found in transient ethanol exposure group. These results suggest that chronic consumption of ethanol promotes hepatocarcinogenesis by increasing oxidative stress and cell proliferation. It is also evident that abstinence of ethanol during the second stage stops its persistent promotion effect.

Defining alcohol-related fatal medical conditions for social-cost studies in western societies: an update of the epidemiological evidence

OBJECTIVES

To elaborate a state-of-the-art list of alcohol-related fatal medical conditions for future social-cost studies in Western societies.

METHODS

Three major social-cost studies were compared with regard to their respective section on fatal health effects attributable to long-term as well as short-term use of alcohol. On discordant conditions, a systematic literature search was conducted in the Medline and ETOH databases.

RESULTS

There is no consensus between social-cost studies with respect to alcohol-related causes of mortality. Based on the recent epidemiological evidence on alcohol and health, this paper suggests an up-to-date list of fatal medical conditions for which the causal relationship has been established with sufficient scientific evidence. A further investigation is needed, however, to reestimate relative risks by meta-analysis.

CONCLUSIONS

Evaluating new epidemiological evidence regularly is necessary for the purpose of up-to-date social-cost studies.

A meta-analysis of alcohol drinking and cancer risk

To evaluate the strength of the evidence provided by the epidemiological literature on the association between alcohol consumption and the risk of 18 neoplasms, we performed a search of the epidemiological literature from 1966 to 2000 using several bibliographic databases. Meta-regression models were fitted considering linear and non-linear effects of alcohol intake. The effects of characteristics of the studies, of selected covariates (tobacco) and of the gender of individuals included in the studies, were also investigated as putative sources of heterogeneity of the estimates. A total of 235 studies including over 117 000 cases were considered. Strong trends in risk were observed for cancers of the oral cavity and pharynx, oesophagus and larynx. Less strong direct relations were observed for cancers of the stomach, colon and rectum, liver, breast and ovary. For all these diseases, significant increased risks were found also for ethanol intake of 25 g per day. No significant nor consistent relation was observed for cancers of the pancreas, lung, prostate or bladder. Allowance for tobacco appreciably modified the relations with laryngeal, lung and bladder cancers, but not those with oral, oesophageal or colorectal cancers. This meta-analysis showed no evidence of a threshold effect for most alcohol-related neoplasms. The inference is limited by absence of distinction between lifelong abstainers and former drinkers in several studies, and the possible selective inclusion of relevant sites only in cohort studies.

Promitogenic effects of ethanol, methanol, and ethanolamine in insulin-treated fibroblasts

The zinc-dependent potentiating effect of ethanol (EtOH) on insulin-stimulated DNA synthesis was studied with a focus on the possible site of EtOH action and the ability of other alcohols to elicit similar promitogenic effects. In serum-starved (27 hr) NIH 3T3 fibroblasts, 200-300 mM methanol (MeOH) and 0.1-1.5 mM ethanolamine (Etn), but not 3- to 9-carbon normal alcohols, enhanced the effect of insulin on DNA synthesis to varying extents. The promitogenic effects of EtOH and MeOH, but not that of Etn, required the presence of 15-25 microM zinc. The potentiating effects of Etn were enhanced by 5 mM choline (Cho) and inhibited by 1-3 mM hemicholinium-3 (HC-3), an inhibitor of Cho transporter and Cho kinase. In the presence of 15 microM zinc, 40 mM EtOH, which had no effect on its own, inhibited the potentiating effects of Cho and enhanced the inhibitory effects of HC-3 on synergistic stimulation of DNA synthesis by Etn and insulin. On the other hand, both Cho and HC-3 partially inhibited the promitogenic effect of 80 mM EtOH in the presence of 25 microM zinc. After a 10-min incubation, EtOH decreased the amount of cell-associated [(14)C]Cho in the absence but not in the presence of HC-3. After a 40-min incubation, Cho (5 mM) partially inhibited the cellular uptake as well as the metabolism of [(14)C]Etn. Whereas after the 40-min incubation 80 mM EtOH had no effects on Etn metabolism, in the absence of Cho it decreased the amount of cell-associated [(14)C]Etn. However, EtOH had no detectable effects on cell association of [(14)C]Etn after the 10-min incubation. The results suggest that in NIH 3T3 fibroblasts EtOH is a remarkably specific promitogen, and that it may act via a cell membrane site(s), also regulated by Cho (agonist) and HC-3 (antagonist), which can influence membrane binding and the promitogenic activity of Etn.

Ethanol enhances the stimulatory effects of lysophosphatidic acid on DNA synthesis but not cell proliferation in human and mouse fibroblasts

Lysophosphatidic acid (LPA), a constituent of serum, is a positive regulator of cell growth, while ethanol (EtOH) has been shown to exert both inhibitory and stimulatory effects on mitogenesis. In this work, we examined possible interactions between the effects of EtOH and LPA on DNA synthesis, cell proliferation, activating phosphorylation of p44/p42 mitogen-activated protein kinases (MAPK), and p70 S6 kinase (p70 S6K) activity. In fibroblasts derived from human or mouse embryo or the skin of healthy human subjects, LPA (1-20 microM) and EtOH (40-80 mM) synergistically stimulated DNA synthesis in a zinc-dependent manner. Nevertheless, EtOH did not modify the stimulatory effect of LPA on the proliferation of human embryonal fibroblasts. In the presence of zinc, EtOH did not affect LPA-induced activating phosphorylation of p42/p44 MAPKs, although an inhibitor of MAPK kinase inhibited the combined effects of LPA and EtOH on DNA synthesis. In contrast, in the presence of zinc, EtOH enhanced the stimulatory effect of LPA on p70 S6K activity. The results indicate that in human fibroblasts, in the presence of zinc, EtOH enhances the stimulatory effects of LPA on DNA synthesis, but not on cell proliferation, by a mechanism probably involving activation of p70 S6K.

Ethanol has multiple effects on DNA synthesis in fibroblasts depending on the presence of secreted growth regulators and zinc as well as the level of protein kinase C activation

Earlier we showed that in serum-starved (27 h), washed mouse fibroblasts and other cell lines 40-80 mM concentrations of ethanol (EtOH) potentiate, in a zinc (Zn2+)-dependent manner, the combined stimulatory effects of calcium (Ca2+) and insulin (Ins) on DNA synthesis. We now report that the promitogenic EtOH effects require removal of the used medium at least 6 h prior to treatments with EtOH, Zn2+, and Ins. If serum-starved (27 h) cells were continuously incubated for another 18-h period without replacing the medium, a secreted cellular factor moderately enhanced the mitogenic effect of Ins and simultaneously blocked the potentiating effect of EtOH on DNA synthesis measured during the last hour of treatments. However, the presence of Ca2+ (2.8 mM) plus Zn2+ (25 microM) or 25-300 nM phorbol 12-myristate 13-acetate (PMA) during the serum starvation period partially restored the promitogenic effect of EtOH. The PMA effect was blocked by the protein kinase C (PKC) inhibitor GF 109203X added for the second (18 h) period. Even at 300 nM, PMA failed to fully downregulate PKC-alpha, the major PKC isoform, over a 28-h period, suggesting that an activated PKC enzyme was involved in the restoration of EtOH effect. When EtOH (40-80 mM) was added for the entire serum starvation period and the incubations were continued for 18 h without removing the medium, EtOH inhibited both the combined actions of Ins and cellular factor as well as the promoting effect of newly added EtOH on Ins-dependent DNA synthesis. Coaddition of Zn2+ and PMA with EtOH prevented these inhibitory effects of EtOH. The results indicate that in mouse fibroblasts EtOH can both enhance and inhibit Ins-dependent DNA synthesis depending on the timing of EtOH treatment as well as the presence of Zn2+, cellular factors, and activators of the PKC system.

Moderate alcohol consumption: the gentle face of Janus

OBJECTIVES

The regular consumption of alcohol in moderate amounts (defined in North America as up to 2 drinks per day for men and 1 drink per day for females) has been recognized in the last decade as a negative risk factor for atherosclerosis and its clinical sequelae: coronary heart disease (CHD), ischemic stroke, and peripheral vascular disease. Mortality and morbidity attributable to CHD are 40-60% lower in moderate drinkers than among abstainers. Among the mechanisms accounting for these reductions, increased circulating concentrations of HDL-cholesterol and inhibition of blood coagulation appear to be paramount. Additional benefits are, in certain beverages, conferred by the presence of constituents other than alcohol (e.g., flavonoids and hydroxystilbenes), which prevent oxidative damage, free radical formation, and elements of the inflammatory response.

CONCLUSIONS

A number of other diseases appear to be beneficially modulated by moderate alcohol consumption based on epidemiologic surveys and, in some instances, experimental evidence. These include duodenal ulcer, gallstones, enteric infections, rheumatoid arthritis, osteoporosis, and diabetes mellitus (type II). Compared with abstainers, moderate drinkers exhibit improved mental status characterized by decreased stress and depression, lower absenteeism from work, and decreased incidence of dementia (including Alzheimer's disease). Although limits of safe drinking have been conservatively defined, it is regrettable that political considerations are hampering the clinical application of this knowledge and its dissemination to the lay public.

Ethanol potentiates the mitogenic effects of sphingosine 1-phosphate by a zinc- and calcium-dependent mechanism in fibroblasts

In mouse embryo NIH 3T3 fibroblasts, ethanol (60-80 mM) was found to enhance the stimulatory effects of sphingosine 1-phosphate (S1P) on both DNA synthesis and cell proliferation. Well-detectable potentiating effects of ethanol on S1P-induced mitogenesis required the presence of calcium (>1 mM) and zinc (20-40 microM) in the incubation medium. The amphibian tetrapeptide bombesin, which is known to mobilize intracellular calcium in fibroblasts, had no effect alone, but it approximately doubled the combined stimulatory effects of ethanol and S1P on DNA synthesis. The synergistic mitogenic effects of ethanol and S1P were also slightly enhanced, rather than inhibited, by the alcohol dehydrogenase inhibitor 4-methylpyrazole (5 mM). Of the various growth regulatory enzymes examined, ethanol detectably enhanced the stimulatory effects of S1P on the phosphosphorylation (activation) of p42/p44 mitogen-activated protein (MAP) kinases, but not of p38 MAP kinase. Cotreatment of fibroblasts with ethanol for 10 min also enhanced the stimulatory effects of S1P on the activities of c-Raf-1 kinase and p70 S6 kinase, but neither S1P nor ethanol had effects on phosphatidylinositol 3'-kinase and Akt/PKB kinase activities. Ethanol-plus-S1P-induced DNA synthesis was partially inhibited by both PD 98059 (50 microM) and rapamycin (10 nM), inhibitors of p42/p44 MAP kinase kinase and mTOR/p70 S6 kinases, respectively. The results indicate that in NIH 3T3 fibroblasts, ethanol can enhance the mitogenic effects of S1P by a zinc- and calcium-dependent mechanism involving both the rapamycin-sensitive p70 S6 kinase-dependent and the c-Raf-1/MAP kinase-dependent growth regulatory pathways.

Mortality and light to moderate alcohol consumption after myocardial infarction

BACKGROUND

Although heavy alcohol consumption increases total mortality, light to moderate consumption decreases cardiovascular and all-cause mortality in apparently healthy people. Since data are sparse on the relation of light to moderate alcohol intake to mortality in patients with previous myocardial infarction, we did a prospective study of mortality in men.

METHOD

Of 90,150 men in the Physicians' Health Study enrollment cohort who provided information on alcohol intake and who had no history of cancer, stroke, or liver disease, 5358 had a previous myocardial infarction. We estimated alcohol consumption by food-frequency questionnaire.

FINDINGS

During a mean follow-up of 5 years, 920 men died. After adjustment for several potential confounders, moderate alcohol intake was associated with a significant decrease in total mortality (p=0.016). Compared with men who rarely or never drank alcohol, those who drank one to four drinks per month had a relative risk for total mortality of 0.85 (95% CI 0.69-1.05); for two to four drinks per week, the relative risk was 0.72 (0.58-0.89); for one drink per day 0.79 (0.64-9.96); and for two or more drinks per day 0.84 (0.55-1.26).

INTERPRETATION

Men with previous myocardial infarction who consume small to moderate amounts of alcohol have a lower total mortality.

Effects of moderate alcohol consumption on the central nervous system

The concept of moderate consumption of ethanol (beverage alcohol) has evolved over time from considering this level of intake to be nonintoxicating and noninjurious, to encompassing levels defined as "statistically" normal in particular populations, and the public health-driven concepts that define moderate drinking as the level corresponding to the lowest overall rate of morbidity or mortality in a population. The various approaches to defining moderate consumption of ethanol provide for a range of intakes that can result in blood ethanol concentrations ranging from 5 to 6 mg/dl, to levels of over 90 mg/dl (i.e., approximately 20 mM). This review summarizes available information regarding the effects of moderate consumption of ethanol on the adult and the developing nervous systems. The metabolism of ethanol in the human is reviewed to allow for proper appreciation of the important variables that interact to influence the level of exposure of the brain to ethanol once ethanol is orally consumed. At the neurochemical level, the moderate consumption of ethanol selectively affects the function of GABA, glutamatergic, serotonergic, dopaminergic, cholinergic, and opioid neuronal systems. Ethanol can affect these systems directly, and/or the interactions between and among these systems become important in the expression of ethanol's actions. The behavioral consequences of ethanol's actions on brain neurochemistry, and the neurochemical effects themselves, are very much dose- and time-related, and the collage of ethanol's actions can change significantly even on the rising and falling phases of the blood ethanol curve. The behavioral effects of moderate ethanol intake can encompass events that the human or other animal can perceive as reinforcing through either positive (e.g., pleasurable, activating) or negative (e.g., anxiolysis, stress reduction) reinforcement mechanisms. Genetic factors and gender play an important role in the metabolism and behavioral actions of ethanol, and doses of ethanol producing pleasurable feelings, activation, and reduction of anxiety in some humans/animals can have aversive, sedative, or no effect in others. Research on the cognitive effects of acute and chronic moderate intake of ethanol is reviewed, and although a number of studies have noted a measurable diminution in neuropsychologic parameters in habitual consumers of moderate amounts of ethanol, others have not found such changes. Recent studies have also noted some positive effects of moderate ethanol consumption on cognitive performance in the aging human. The moderate consumption of ethanol by pregnant women can have significant consequences on the developing nervous system of the fetus. Consumption of ethanol during pregnancy at levels considered to be in the moderate range can generate fetal alcohol effects (behavioral, cognitive anomalies) in the offspring. A number of factors--including gestational period, the periodicity of the mother's drinking, genetic factors, etc.--play important roles in determining the effect of ethanol on the developing central nervous system. A series of recommendations for future research endeavors, at all levels, is included with this review as part of the assessment of the effects of moderate ethanol consumption on the central nervous system.