Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiology has demonstrated that alcoholic beverages are causally related to oropharyngolaryngeal, esophageal, liver, colorectal, and female breast cancer. Among Japanese male alcoholics screened by endoscopy combined with esophageal iodine staining and immunofecal occult blood tests, 4.2% had esophageal squamous cell carcinoma (SCC); 1.2%, oropharyngolaryngeal SCC; 1.4%, stomach adenocarcinoma; 1.9%, colorectal adenocarcinoma. The inactive form of aldehyde dehydrogenase-2 (ALDH2), encoded by the gene ALDH2*1/2*2, which is prevalent in Asians, exposes them to higher levels of acetaldehyde after drinking and was a strong risk factor for these cancers among Japanese heavy drinkers. Inactive ALDH2 was also associated with synchronous and metachronous multiple esophageal cancers. These results suggest a general role of acetaldehyde, an established animal carcinogen, in carcinogenesis of the human alimentary tract. The oropharyngolarynx and esophagus lack ALDH2 activity, suggesting that after exposure to acetaldehyde derived from systemic, mucosal, salivary, or bacterial production or alcoholic beverages, these organs' inefficient degradation of acetaldehyde enhances the chances for local acetaldehyde-associated carcinogenesis. The normal alcohol dehydrogenase-2 (ADH2), encoded by ADH2*1/2*1, is another risk factor for oropharyngolaryngeal and esophageal cancer in Japanese alcoholics. For patients with both normal ADH2 and inactive ALDH2, the risks for oropharyngolaryngeal and esophageal cancer are enhanced in a multiplicative fashion. The responses to a simple questionnaire about both current and past facial flushing after drinking a glass of beer can indicate an individual's ALDH2 phenotype fairly well. Use of this questionnaire to obtain information on ALDH2-associated cancer susceptibility could contribute to the prevention of alcohol-related cancer in Asians.
 ...
PMID:[Alcohol and oropharyngolaryngeal and digestive tract cancer]. 1182 13

The aim of this study was to examine how aldehyde dehydrogenase-2 (ALDH2) genotypes and human leukocyte antigen (HLA) haplotypes contribute to the risk for esophageal cancer. We examined ALDH2 genotypes and HLA haplotypes in 29 Japanese patients with esophageal cancer. The ratio of patients who experienced current or former intense vasodilatation upon consuming alcohol (flushing type) was much higher in individuals with the inactive form of ALDH2 encoded by the ALDH2(2)/2(2) or ALDH2(1)/2(2) genotype than in those with the active form of ALDH2 encoded by the ALDH2(1)/2(1) genotype. The ratio of inactive ALDH2 was significantly higher in patients with esophageal cancer than in control normal subjects, suggesting that alcoholics with inactive ALDH2 were susceptible to esophageal cancer. HLA haplotypes A24, A26, B54, B61 and DR9 were prevalent in patients with esophageal cancer (82.8, 24.1, 34.5, 37.9 and 44.8%, respectively). HLA haplotype of A24 and inactive ALDH2 were simultaneously found in 58.6% of patients with esophageal cancer. Furthermore, we found other primary malignancies in 6 of 29 (20.7%) patients with esophageal cancer, and 4 of these 6 patients had both the inactive form of ALDH2 and the HLA A24 haplotype. The present study showed the high prevalence of the inactive form of ALDH2 and HLA haplotypes A24, A26, B54, B61 and DR9 in Japanese patients with esophageal cancer. Therefore, the examination of genotypes of ALDH2 loci and HLA haplotypes may allow the early detection of esophageal cancer in the Japanese population.
 ...
PMID:Aldehyde dehydrogenase-2 genotypes and HLA haplotypes in Japanese patients with esophageal cancer. 1216 74

The role of genetic polymorphisms in modulating xenobiotic metabolism and susceptibility to cancer and other health effects has been suggested in numerous studies. However, risk assessments have generally not used this information to characterize population variability or adjust risks for susceptible subgroups. This paper focuses upon the aldehyde dehydrogenase-2 (ALDH2) system because it exemplifies the pivotal role genetic polymorphisms can play in determining enzyme function and susceptibility. Allelic variants in ALDH2 cause decreased ability to clear acetaldehyde and other aldehyde substrates, with homozygous variants (ALDH2*2/2) having no activity and heterozygotes (ALDH2*1/2) having intermediate activity relative to the predominant wild type (ALDH2*1/1). These polymorphisms are associated with increased buildup of acetaldehyde following ethanol ingestion and increased immediate symptoms (flushing syndrome) and long-term cancer risks. We have used Monte Carlo simulation to characterize the population distribution of ALDH2 allelic variants and inter-individual variability in aldehyde internal dose. The nonfunctional allele is rare in most populations, but is common in Asians such that 40% are heterozygotes and 5% are homozygote variants. The ratio of the 95th or 99th percentiles of the Asian population compared to the median of the U.S. population is 14- to 26-fold, a variability factor that is larger than the default pharmacokinetic uncertainty factor (3.2-fold) commonly used in risk assessment. Approaches are described for using ALDH2 population distributions in physiologically based pharmacokinetic-Monte Carlo refinements of risk assessments for xenobiotics which are metabolized to aldehyde intermediates (e.g., ethanol, toluene, ethylene glycol monomethyl ether).
 ...
PMID:Population distribution of aldehyde dehydrogenase-2 genetic polymorphism: implications for risk assessment. 1247 14

Alcoholic beverages are causally related to cancer of the oral cavity, pharynx, larynx and esophagus. Ethanol is oxidized to acetaldehyde and then to acetate by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), both of which have genetic polymorphisms. A review of case-control studies of the effects of ALDH2, ADH2 and ADH3 genotypes shows consistently positive associations between inactive heterozygous ALDH2 and the less-active ADH2 genotypes and the risk for esophageal cancer in East Asian heavy drinkers and this enzyme-related vulnerability may extend to light-to-moderate drinkers. Some studies suggest similar associations with the risk for head and neck cancer in moderate-to-heavy-drinking Japanese. An established carcinogen in experimental animals, acetaldehyde can interact with human DNA. ALDH2-associated cancer susceptibility fits into a scenario in which acetaldehyde plays a critical role in the development of human cancer. Alcohol flushing and drinking behavior may partly explain this carcinogenic effect in carriers of less-active ADH2 genotypes. Whether the ADH3 genotype influences head and neck cancer risk in Western nations is controversial. Professional and public education about risky conditions connected to the ALDH2 and ADH2 genotypes and environmental factors is important in a new strategic approach to the prevention of alcohol-related cancers in East Asians. The use of simple tests to identify inactive ALDH2 on the basis of alcohol flushing responses could benefit many people, by helping them to identify their own cancer risks. Such testing could also help clinicians diagnose esophageal cancer earlier, through the use of endoscopic screening in the high-risk population.
 ...
PMID:Genetic polymorphisms of alcohol and aldehyde dehydrogenases and risk for esophageal and head and neck cancers. 1267 87

High alcohol sensitivity among Asians is mainly due to a genetic polymorphism in the low Km aldehyde dehydrogenase (ALDH2) gene. Strong correlations between the ALDH2 genotype and alcohol sensitivity or alcohol drinking habits have been reported. Another prevalent polymorphism in the alcohol dehydrogenase beta-subunit (ADH2 gene) among Asians appears to modify skin flushing reactions after exposure to ethanol but does not influence alcohol drinking behavior. Both the ADH2 and ALDH2 genotypes have been significantly correlated with the risk of alcoholism. In a Japanese occupational population, a gene-environment interaction of the ALDH2 genotype and daily hassles scores for development of problem drinking behavior was observed. Habitual drinkers with the ALDH2*1/*2 genotype had higher frequencies of sister-chromatid exchange in cultured lymphocytes and higher 8-OHdG levels in polymorphonuclear leukocytes than those with the ALDH2*1/*1 genotype. Alcoholics and heavy drinkers with the ALDH2*1/*2 genotype have been shown to have significantly elevated risks for esophageal and multiple cancers in upper digestive organs than those with the ALDH2*1/*1 genotype. In Japan, bronchial asthma patients with the ALDH2*1/*2 genotype have been shown to have a significantly elevated risk for experiencing alcohol-induced asthma compared with the ALDH2*1/*1 genotype. Providing services to determine these genotypes would be of great help for each individual to make a plan for tailor-made health promotion.
 ...
PMID:[Gene-environmental interactions in alcohol-related health problems--contributions of molecular biology to behavior modifications]. 1280 63

Enzymes encoded by two gene families, alcohol dehydrogenase ( ADH) and aldehyde dehydrogenase ( ALDH), mediate alcohol metabolism in humans. Allelic variants have been identified that alter metabolic rates and influence risk for alcoholism. Specifically, ADH1B*47His (previously ADH2-2) and ALDH2-2 have been shown to confer protection against alcoholism, presumably through accumulation of acetaldehyde in the blood and a resultant 'flushing response' to alcohol consumption. In the current study, variants at ADH1B (previously ADH2), ADH1C (previously ADH3), and ALDH2 were assayed in DNA extracts from participants belonging to a Southwest American Indian tribe ( n=490) with a high prevalence of alcoholism. Each subject underwent a clinical interview for diagnosis of alcohol dependence, as well as evaluation of intermediate phenotypes such as binge drinking and flushing response to alcohol consumption. Detailed haplotypes were constructed and tested against alcohol dependence and related intermediate phenotypes using both association and linkage analysis. ADH and ALDH variants were also assayed in three Asian and one African population (no clinical data) in order to provide an evolutionary context for the haplotype data. Both linkage and association analysis identified several ADH1C alleles and a neighboring microsatellite marker that affected risk of alcohol dependence and were also related to binge drinking. These data strengthen the support for ADH as a candidate locus for alcohol dependence and suggest further productive study.
 ...
PMID:Allelic variation at alcohol metabolism genes ( ADH1B, ADH1C, ALDH2) and alcohol dependence in an American Indian population. 1288

Early esophageal squamous cell carcinoma detected by esophageal iodine staining can be easily treated by endoscopic mucosectomy, and identifying its predictors is important in better selecting candidates to screen for this high-mortality cancer. The common etiologies of elevated mean corpuscular volume (MCV) and esophageal cancer, including folate deficiency, smoking, drinking and high acetaldehyde exposure, suggest testing MCV as such a predictor. Japanese alcoholic men with (n = 65) and without (n = 206) esophageal squamous cell carcinomas, excluding those with liver cirrhosis, were assessed for MCV within 7 days of their last drink, alone or in combination with findings from either the alcohol flushing questionnaire or genotyping to identify inactive aldehyde dehydrogenase-2 (ALDH2*1/2*2) and the less-active form of alcohol dehydrogenase-2 (ADH2*1/2*1), which pose risks for esophageal squamous cell carcinoma. MCV was higher in cancer patients than in the control group. MCV was higher in both groups in those who were heavier smokers, had lower body mass index (BMI), experienced alcohol flushing, and had ALDH2*1/2*2. After adjusting for age, drinking and smoking habits, BMI and ALDH2/ADH2 genotypes, macrocytosis of MCV > or =106 fl was associated with increased risk for esophageal cancer (OR = 2.75). Men with both MCV > or =106 fl and alcohol flushing had an even higher cancer risk (OR = 5.51). The combinations of MCV > or =106 fl with ALDH2*1/2*2 or ADH2*1/2*1 alone, and both ALDH2*1/2*2 and ADH2*1/2*1 (ORs = 11.44, 21.22 and 319.7, respectively) showed consistently higher risk than the corresponding group with MCV <106 fl (ORs = 7.24, 4.71 and 27.01, respectively). In conclusion, MCV measurement, alone or in combination with the markers of alcohol sensitivity, provides a new means of predicting risk for esophageal squamous cell carcinoma in Japanese alcoholic men.
 ...
PMID:Macrocytosis, a new predictor for esophageal squamous cell carcinoma in Japanese alcoholic men. 1294 54

Alcohol flushing after light drinking is triggered mainly by severe acetaldehydemia in individuals possessing inactive aldehyde dehydrogenase (ALDH)-2. Inactive ALDH2 encoded by ALDH2*1/2*2 and the low-activity form of alcohol dehydrogenase (ADH)-2 encoded by ADH2*1/2*1 enhance the risk for esophageal cancer in Japanese light to heavy drinkers, a significant association that emphasizes the importance of screening tests for inactive ALDH2 based on alcohol flushing. The objectives of the present report were (a). to evaluate the reliability of a simple questionnaire that asks about both current and past flushing for detecting inactive ALDH2 and (b). to predict cancer risk based on flushing in a case-control manner. The study subjects consisted of 233 Japanese men with esophageal squamous cell carcinoma and 610 cancer-free Japanese men. When current or former flushing individuals were considered to have inactive ALDH2, the sensitivity and specificity of the test were 84.8% and 82.3%, respectively, for the cases and 90.1% and 88.0%, respectively, for the controls. To clarify the characteristics of men who had genetically inactive ALDH2 but did not report alcohol flushing, we analyzed individuals possessing the ALDH2*1/2*2 genotype and found that those who also had ADH2*1/2*1 (both cases and controls) tended not to report current flushing, and those who did not report current flushing (controls only) tended to be heavier drinkers. As compared with overall never or rare drinking, the cancer risks for light (1-8.9 units/week; 1 unit = 22 g of ethanol), moderate (9-17.9 units/week), and heavy (18+ units/week) drinkers with current or former flushing (odds ratio = 6.69, 42.66, and 72.86, respectively) significantly exceeded the risks for those who had never flushed (odds ratio = 1.27, 10.12, and 15.61, respectively), even after adjustment for age, smoking, and diet. The flushing questionnaire may be used in large-scale epidemiological studies as a surrogate marker of ALDH2 genotype to predict individual cancer risk.
 ...
PMID:Alcohol flushing, alcohol and aldehyde dehydrogenase genotypes, and risk for esophageal squamous cell carcinoma in Japanese men. 1465 86

This article summarizes a symposium that was organized by Dr. Kim Fromme and presented at the 2003 annual meeting of the Research Society on Alcoholism in Ft. Lauderdale, Florida. The four presentations illustrate the emerging technologies and methods that are now being used to investigate the genetic basis of differential sensitivity to alcohol and their behavioral manifestations. Combining human genotyping with laboratory measures of behavior and subjective reports, these presentations represent state-of-the-art approaches to crossing the bridge from the Decade of the Brain to the Decade of Behavior. Dr. De Wit's paper describes her research on the neurobiological basis for individual differences in sensitivity to the stimulant and sedative effects of alcohol. Evidence suggests that activity of the dopaminergic and GABAergic neurotransmitters underlie these stimulant and sedative effects, respectively. Both Drs. Hutchison's and Corbin's papers describe their research on polymorphisms for the serotonin transporter (SLC6A4) as a determinant of the subjective effects of alcohol challenge. Dr. Hutchinson's and Ms. Ray's findings indicate that individuals with the short form of the SLC6A4 alleles (S) demonstrated a low level of response to alcohol, thus supporting previous research that the S allele may be associated with increased risk for alcohol dependence. In contrast, Dr. Corbin did not find a reliable association between the SLC6A4 genotype and subjective response to alcohol. Mr. Cook's and Dr. Wall's paper adds another dimension to this article by presenting research on both the aldehyde dehydrogenase (ALDH2) and alcohol dehydrogenase (ADH2) genetic variants and their association with the alcohol-related flushing response that is prevalent in Asian populations. Dr. David Goldman provides concluding remarks.
 ...
PMID:Biological and behavioral markers of alcohol sensitivity. 1511 32

In the history of diabetes, chlorpropamide alcohol flushing test (CPAF) was a big topic in the 1970s to 1980s. Alcohol tolerance after chlorpropamide has prognostic significance, with the intolerant group (CPAF-positive group) being less prone to develop vascular complication than the tolerant group (CPAF-negative group). A mechanism of CPAF has been regarded as the inhibition of aldehyde dehydrogenase 2 (ALDH2) by an N-alkyl-substituted derivative of chlorpropamide, and the expression of these mutations of ALDH2 and alcohol dehydrogenase 2 (ADH2) could determine the alcohol tolerance among the Japanese population. Therefore, we hypothesized that expression of different ALDH2 and ADH2 polymorphisms may induce differences in vascular complications in diabetes and conducted two studies. The first study (study 1) was to determine the association of ALDH2/AHD2 polymorphism with diabetic complications. To know the association of ALDH2/AHD2 polymorphism with diabetic vasculopathy and neuropathy, a total of 158 patients with type 2 diabetes were divided into four groups on the basis of ALDH2 "activity" and ADH2 "superactivity." The frequency of proteinuria and the percentage of proliferative retinopathy among the patients with retinopathy was higher in those with active ALDH2 and superactive ADH2. We speculated that protein kinase C isoforms up-regulated by 4-hydroxynonenal that was detoxified by ALDH2 and ADH2 may account for the long-term development of diabetic nephropathy and severe retinopathy. As for neuropathy, the frequency of symptomatic neuropathy was higher in patients with inactive ALDH2 and usual ADH2. We speculate that increased tissue levels of toxic aldehyde could result from inactive ALDH2 and usual ADH2 expression, which results in the increased level of reactive aldehyde in sensory neuron pathway, thereby causing symptomatic polyneuropathy.
 ...
PMID:ALDH2/ADH2 polymorphism associated with vasculopathy and neuropathy in type 2 diabetes. 1531 96


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>