Polymorphisms of alcohol dehydrogenase-2 and aldehyde dehydrogenase-2 and esophageal cancer risk in Southeast Chinese males

AIM： To evaluate the impact of alcohol dehydrogenase-2 （ADH2） and aldehyde dehydrogenase-2 （ALDH2） polymorphisms on esophageal cancer susceptibility in Southeast Chinese males.METHODS： Two hundred and twenty-one esophageal cancer patients and 292 healthy controls from Taixing city in Jiangsu Province were enrolled in this study. ADH2 and ALDH2 genotypes were examined by polymerase chain reaction and denaturing high-performance liquid chromatography. Unconditional logistic regression was used to calculate the odds ratios （OR） and 95% confidence interval （CI）.RESULTS： The ADH G allele carriers were more susceptible to esophageal cancer, but no association was found between ADH2 genotypes and risk of esophageal cancer when disregarding alcohol drinking status. Regardless of ADH2 genotype, ALDH2G/A or A/A carriers had significantly increased risk of developing esophageal cancer, with homozygous individuals showing higher esophageal cancer risk than those who were heterozygous. A significant interaction between ALDH2 and drinking was detected regarding esophageal cancer risk; the OR was 3.05 （95% CI： 2.49-6.25）. Compared with non-drinkers carrying both ALDH2 G/G and ADH2 A/A, drinkers carrying both ALDH2 A allele and ADH2 G allele showed a significantly higher risk of developing esophageal cancer （OR = 8.36, 95% CI： 2.98-23.46）.CONCLUSION： Both ADH2 G allele and ALDH2 A allele significantly increase the risk of esophageal cancer development in Southeast Chinese males. ALDH2 A allele significantly increases the risk of esophageal cancer development especially in alcohol drinkers. Alcohol drinkers carrying both ADH2 G allele and ALDH2 A allele have a higher risk of developing esophageal cancer.

Correlations Between Polymorphisms of Extracellular Superoxide Dismutase, Aldehyde Dehydrogenase-2 Genes, as Well as Drinking Behavior and Pancreatic Cancer

Objective To investigate the correlation between drinking behavior combined with polymorphisms of extracellular superoxide dismutase （EC-SOD） and aldehyde dehydrogenase-2 （ALDH2） genes and pancreatic cancer. Methods The genetic polymorphisms of EC-SOD and ALDH2 were analyzed by polymerase chain reaction restriction fragment length polymorphism in the peripheral blood leukocytes obtained from 680 pancreatic cancer cases and 680 non-cancer controls. Subsequently the frequency of genotype was compared between the pancreatic cancer patients and the healthy controls.The relationship of drinking with pancreatic cancer was analyzed. Results The frequencies of EC-SOD （C/G） and ALDH2 variant genotypes were 37.35% and 68.82% respectively in the pancreatic cancer cases, and were significantly higher than those in the healthy controls （21.03% and 44.56%, all P〈0.01）. People who carried EC-SOD （C/G） （0R=2.24, 95% C1= 1.81-4.03, P〈0.01） or ALDH2 variant genotypes （OR=2.75, 95% CI=1.92-4.47, P〈0.01） had a high risk to develop pancreatic cancer. Those who carried EC-SOD （C/G） genotype combined with ALDH2 variant genotype had a high risk for pancreatic cancer （29.56% vs. 6.76%, 0R=7.69, 95% CI=3.58-10.51, P〈0.01）. The drinking rate of the pancreatic cancer group （64.12%） was significantly higher than that of the control group （40.15%; OR=2.66, 95% CI=1.30-4.42, P〈0.01）. An interaction between drinking and EC-SOD （C/G）/ALDH2 variant genotypes increased the risk of occurrence of pancreatic cancer （OR=25.00, 95% CI= 11.87-35.64, P〈0.01）. Conclusion EC-SOD （C/G）, ALDH2 variant genotypes and drinking might be the risk factors of pancreatic cancer.

Critical role of mitochondrial aldehyde dehydrogenase 2 in acrolein sequestering in rat spinal cord injury

Lipid peroxidation-derived aldehydes,such as acrolein,the most reactive aldehyde,have emerged as key culprits in sustaining post-spinal cord injury(SCI)secondary pathologies leading to functional loss.Strong evidence suggests that mitochondrial aldehyde dehydrogenase-2(ALDH2),a key oxidoreductase and powerful endogenous anti-aldehyde machinery,is likely important for protecting neurons from aldehydesmediated degeneration.Using a rat model of spinal cord contusion injury and recently discovered ALDH2 activator(Alda-1),we planned to validate the aldehyde-clearing and neuroprotective role of ALDH2.Over an acute 2 day period post injury,we found that ALDH2 expression was significantly lowered post-SCI,but not so in rats given Alda-1.This lower enzymatic expression may be linked to heightened acrolein-ALDH2 adduction,which was revealed in co-immunoprecipitation experiments.We have also found that administration of Alda-1 to SCI rats significantly lowered acrolein in the spinal cord,and reduced cyst pathology.In addition,Alda-1 treatment also resulted in significant improvement of motor function and attenuated post-SCI mechanical hypersensitivity up to 28 days post-SCI.Finally,ALDH2 was found to play a critical role in in vitro protection of PC12 cells from acrolein exposure.It is expected that the outcome of this study will broaden and enhance anti-aldehyde strategies in combating post-SCI neurodegeneration and potentially bring treatment to millions of SCI victims.All animal work was approved by Purdue Animal Care and Use Committee(approval No.1111000095)on January 1,2021.

Relationship between genetic polymorphisms of ALDH2 and ADH1B and esophageal cancer risk:A meta-analysis

AIM:To evaluate the contribution of alcohol dehydrogenase-1B(ADH1B)and aldehyde dehydrogenase-2 (ALDH2)polymorphisms to the risk of esophageal cancer.METHODS:Nineteen articles were included by searching MEDLINE,EMBASE and the Chinese Biomedical Database,13 on ADH1B and 18 on ALDH2.We performed a meta-analysis of case-control studies including 13 studies on ADH1B(cases/controls:2390/7100)and 18 studies on ALDH2(2631/6030).RESULTS:The crude odds ratio[OR(95%confidence interval)]was 2.91(2.04-4.14)for ADH1B*1/*1(vs ADH1B*2/*2)and 1.32(1.17-1.49)for ADH1B*1/*2.The crude OR for ALDH2*1/*2(vs ALDH2*1/*1)was 2.52(1.76-3.61).ADH1B*1/*1 increased the risk of esophageal cancer among never/rare[1.56(0.93-2.61)],moderate[2.71(1.37-5.35)],and heavy drinkers[3.22 (2.27-4.57)].ADH1B*1/*2 was associated with a modest risk among moderate drinkers[1.43(1.09-1.87)].ALDH2*1/*2 increased the risk among never/rare[1.28 (0.91-1.80)],moderate[3.12(1.95-5.01)],and heavy [7.12(4.67-10.86)]drinkers,and among ex-drinkers [5.64(1.57-20.25)].ALDH2*2/*2 increased the risk among drinkers[4.42(1.72-11.36)].ADH1B*1/*1 plus ALDH2*1/*2 was associated with the highest risk for heavy drinkers[12.45(2.9-53.46)].The results of the meta-regression analysis showed that the effects of ADH1B*1/*1 and ALDH2*1/*2 increased with the level of alcohol consumption.ALDH2*1/*2 was associated with a high risk among Taiwan Chinese and Japanese drinkers,as opposed to a moderate risk among drinkers in high-incidence regions of China's Mainland.ADH1B*1/*1 in heavy drinkers and ALDH2*1/*2 in moderate-toheavy drinkers was associated with similarly high risk among both men and women.CONCLUSION:ADH1B/ALDH2 genotypes affect the risk of esophageal cancer,and the risk is modified by alcohol consumption,ethnicity,and gender.

Genetic Polymorphisms in ADH1B and ALDH2 Are Associated with Colorectal Tumors in Japan: A Case-Control Study

Background: Unlike with esophageal cancer, acetaldehyde levels and genetic polymorphisms in alcohol dehydrogenase have not yet been shown to be contributing factors for colorectal cancer (CRC). This study aimed to clarify the mechanism of CRC development related to alcohol consumption and to the presence of genetic polymorphisms in the alcohol dehydrogenase, ADH1B and aldehyde dehydrogenase, ALDH2. Methods: This was a case-control study (221 cases and 179 controls) in patients with adenomas and intramucosal tumors who underwent endoscopic removal of all tumors. The amount of alcohol consumption was determined using a self-recorded questionnaire, and the tumor information was obtained from colonoscopy results. Blood samples were taken to analyze the following polymorphisms: ALDH2 Glu504Lys and ADH1B His48Arg. Results: The polymorphisms in ADH1B and ALDH2 had little influence on the development of colorectal adenoma or intramucosal cancer. Patients with ALDH2 (Glu/Glu) were more tolerant of alcohol than those with ALDH2 (Glu/Lys and Lys/Lys). Next, we examined certain combinations of the ADH1B genotypes. In the ALDH2 (Glu/Glu) group, an increased risk (OR = 3.4;95% CI 1.4 - 8.4;P = 0.009) was observed among moderate/heavy drinkers with ADH1B (His/His). In the ALDH2 (Glu/Lys and Lys/Lys) group, an increased risk (OR = 4.2;95% CI 1.1 - 16.7;P = 0.041) was found among moderate/heavy drinkers with ADH1B (Arg/His and Arg/Arg). Conclusions: ADH1B and ALDH2 activity may be involved in the development of CRC.

Evaluation in vinyl chloride monomer-exposed workers and the relationship between liver lesions and gene polymorphisms of metabolic enzymes

AIM： To analyze occupational health hazards exposure to doses lower than the Chinese occupational health standard in a selected VC polymerization plant in China, and also to elucidate the relationship between genetic polymorphisms and genetic susceptibility on liver lesions of workers exposed to vinyl chloride monomer （VCM）. METHODS： In order to explore the mechanism of VCM- related health effects, we used a case-control design to investigate the association between the genetic polymorphisms of metabolic enzymes and liver lesions in workers occupationally exposed to VCM. Genotypes of CYP2E1, GSTT1, GSTM1, ALDH2 and ADH2 were identified using PCR and PCR-RFLP. RESULTS： Even when the concentration of VCM was lower than the current Chinese occupational health standard, neurasthenia, pharyngeal irritation, liver ultrasonography abnormalities and hemoglobin disorders were significantly higher in exposure subjects compared to non-exposure subjects, and the relative risks （RRand 95% C1） were 1.74 （1.06-2.85）, 1.97 （1.56-2.48）, 10.69 （4.38-26.12）, and 2.07 （1.20-3.57）. CYP2E1 c1c2/c2c2 genotype was significantly associated with liver damages （OR 3.29, 95% CI 1.51-7.20, P〈0.01）. CONCLUSION： The incidences of neurasthenia and liver ultrasonography abnormalities significantly increase when the cumulative exposure dose increases. The genotypes of metabolic enzymes （CYP2E1 c1c2/c2c2, null GSTT1 and ADH2 1-1） play important roles in VCM metabolism. Polymorphisms of CYP 2E1, GSTT1 and ADH2 may be a major reason of genetic susceptibility in VCM-induced hepatic damage.

Relationships of early esophageal cancer with human papillomavirus and alcohol metabolism

BACKGROUND It is well known that an alcohol consumption habit together with inactive heterozygous aldehyde dehydrogenase-2(ALDH2)is an important risk factor for the development of esophageal squamous cell carcinoma(ESCC).It remains controversial whether human papillomavirus(HPV)infection contributes to the occurrence/development of ESCC.There has been no study in which the relationship between ESCC and HPV in addition to alcohol dehydrogenase-1B(ADH1B)and ALDH2 genotypes was evaluated.AIM To evaluate relationships between HPV infection and development of esophageal cancer,particularly early esophageal cancer,based on ADH1B/ALDH2 polymorphisms.METHODS We conducted an exploratory retrospective study using new specimens,and we enrolled 145 patients who underwent endoscopic resection for superficial ESCC and had been observed for more than two years by both physical examination and endoscopic examination in Hokkaido University Hospital.Saliva was collected to analyze genetic polymorphisms of ADH1B/ALDH2.We performed in situ hybridization for resected specimens to detect HPV by using an HPV type 16/18 probe.RESULTS HPV was detected in 15(10.3%)of the 145 patients with ESCC.HPV-positive rates in inactive ALDH2*1/*2 and ALDH2*1/*1+*2/*2 were 10.8%and 9.8%,respectively(P=1.00).HPV-positive rates in slow-metabolizing ADH1B*1/*1 and ADH1B*1/*2+*2/*2 were 12.0%and 10.0%,respectively(P=0.72).HPV-positive rates in the heavy or moderate alcohol consumption group and the light or rare consumption group were 11.1%and 8.7%,respectively(P=0.68).HPV-positive rates in the heavy smoking group and the light or no smoking group were 11.8%and 8.3%,respectively(P=0.59).The 3-year incidence rates of secondary ESCC or head and neck cancer after initial treatment in the HPV-positive and HPVnegative groups were 14.4%and 21.4%(P=0.22),respectively.CONCLUSION In the present situation,HPV status is considered to be less important than other risk factors,such as alcohol consumption,smoking habit,ADH1B/ALDH2 polymorphisms,and HPV status would therefore have no effect on ESCC risk management.

乙醛脱氢酶基因型对2-乙氧基乙醇代谢影响的研究

目的 探讨乙醛脱氢酶 (ALDH2 )不同基因型代谢 2 乙氧基乙醇 (EE)的能力是否存在差异。方法 采用个体采样 ,毛细柱气相色谱分析技术及PCR检测方法 ,比较不同基因型个体累计接触EE剂量与 2 乙氧基乙酸 (EAA)浓度对数值回归直线的回归系数。结果 ALDH2 不同基因型个体累计接触EE剂量与EAA浓度对数值存在线性关系 ,A基因型回归系数大于B基因型。结论 ALDH2