Cytochrome P450 2E1 genetic polymorphism and gastric cancer in Changle,Fujian Province

AIM: Genetic polymorphism in enzymes of carcinogen metabolism has been found to have the influence on the susceptibility to cancer. Cytochrome P450 2E1 (CYP2E1) is considered to play an important role in the metabolic activation of procarcinogens such as N-nitrosoamines and low molecular weight organic compounds. The purpose of this study is to determine whether CYP450 2E1 polymorphisms are associated with risks of gastric cancer. METHODS: We conducted a population based case-control study in Changle county, Fujian Province, a high-risk region of gastric cancer in China. Ninety-one incident gastric cancer patients and ninety-four healthy controls were included in our study. Datas including demographic characteristics, diet intake, and alcohol and tobacco consumption of individuals in our study were completed by a standardized questionnaire.PCR-RFLP revealed three genotypes:heterozygote (C1/C2) and two homozygotes (C1/C1 and C2/C2) in CYP2E1. RESULTS: The frequency of variant genotypes (C1/C2 and C2/C2) in gastric cancer cases and controls was 36.3% and 24.5%, respectively. The rare homozygous C2/C2 genotype was found in 6 individuals in gastric cancer group(6.6%), whereas there was only one in the control group (1.1%). However, there was no statistically significant difference between the two groups (two-tailed Fisher's exact test P=0.066). Individuals in gastric cancer group were more likely to carry genotype C1/C2 (odds ratio, OR=1.50) and C2/C2 (OR=7.34) than individuals in control group (chi(2) =4.597, for trend P=0.032). The frequencies of genotypes with the C2 allele (C1/C2 and C2/C2 genotypes) were compared with those of genotypes without C2 allele (C1/C1 genotype) among individuals in gastric cancer group and control group according to the pattern of gastric cancer risk factors. The results show that individuals who exposed to these gastric cancer risk factors and carry the C2 allele seemed to have a higher risk of developing gastric cancer. CONCLUSION: Polymorphism of CYP2E1 gene may have some effect in the development of gastric cancer in Changle county, Fujian Province.

GSTM1,GSTT1,GSTP1 and CYP1A1 genetic polymorphisms and susceptibility to esophageal cancer in a French population:Different pattern of squamous cell carcinoma and adenocarcinoma

AIM:To evaluate the association between CYP1A1 and GSTs genetic polymorphisms and susceptibility to esophageal squamous cell carcinoma(SCC)and esophageal adenocarcinoma(ADC)in a high risk area of northwest of France. METHODS:A case-control study was conducted to investigate the genetic polymorphisms of these enzymes (CYPIAI*2C and GSTP1 exon 7 Val alleles,GSTMI*2/*2 and GSTTl *2/*2 null genotypes).A total of 79 esophageal cancer cases and 130 controls were recruited. RESULTS:GSTMI*2/*2 and CYPIAI*IA/*2C genotype frequencies were higher among squamous cell carcinomas at a level dose to statistical significance(OR =1.83,95% CI 0.88-3.83,P=0.11;OR=3.03,95% CI 0.93-9.90,P=0.07, respectively).For GSTP1 polymorphism,no difference was found between controls and cases,whatever their histological status.Lower frequency of GSTT1 deletion was observed in ADC group compared to controls with a statistically significant difference(OR=13.31,95% CI 1.66-106.92,P<0.01). CONCLUSION:In SCC,our results are consistent with the strong association of this kind of tumour with tobacco exposure.In ADC,our results suggest 3 distinct hypotheses: (1)activation of exogenous procarcinogens,such as small halogenated compounds by GSTT1;(2)contribution of GSTT1 to the inflammatory response of esophageal mucosa,which is known to be a strong risk factor for ADC, possibly through leukotriene synthesis;(3)higher sensitivity to the inflammatory process associated with intracellular depletion of glutathione.

New genes emerging for colorectal cancer predisposition

Colorectal cancer(CRC)is one of the most frequent neoplasms and an important cause of mortality in the developed world.This cancer is caused by both genetic and environmental factors although 35%of the variation in CRC susceptibility involves inherited genetic differences.Mendelian syndromes account for about5%of the total burden of CRC,with Lynch syndrome and familial adenomatous polyposis the most common forms.Excluding hereditary forms,there is an important fraction of CRC cases that present familial aggregation for the disease with an unknown germline genetic cause.CRC can be also considered as a complex disease taking into account the common diseasecommom variant hypothesis with a polygenic model of inheritance where the genetic components of common complex diseases correspond mostly to variants of low/moderate effect.So far,30 common,low-penetrance susceptibility variants have been identified for CRC.Recently,new sequencing technologies including exomeand whole-genome sequencing have permitted to add a new approach to facilitate the identification of new genes responsible for human disease predisposition.By using whole-genome sequencing,germline mutations in the POLE and POLD1 genes have been found to be responsible for a new form of CRC genetic predisposition called polymerase proofreading-associated polyposis.

Serum 25-hydroxyvitamin D,genetic susceptibility,and the risk of incident type 2 diabetes:A prospective cohort in East China

Background:The serum vitamin D level varies widely by population,and studies have linked vitamin D levels with the risk of type 2 diabetes mellitus(T2DM).However,the relationship is inconsistent and the impact of vitamin D on T2DM among East Chinese adults is unclear.The study aimed to investigate the association between serum 25-hydroxyvitamin D(25[OH]D)levels and the risk of T2DM and evaluated whether the association is modified by genetic predisposition.Methods:In the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors(SPECT-China)cohort,1862 participants free of T2DM at baseline were included.A weighted genetic risk score was calculated with 28 variants associated with T2DM.Hierarchical logistic models were used to examine the association of serum 25(OH)D and genetic risk with T2DM.Results:After a 5-year follow-up,132 cases of T2DM were documented.We observed no significant association between quartiles of serum 25(OH)D and T2DM risk after multivariable adjustment(χ^(2)=0.571,P_(for trend)=0.426).Compared to those in the lowest quartile of 25(OH)D,the odds ratios(ORs)(95%confidence interval[CI])for participants with increased quartiles were 1.29(0.74-2.25),1.35(0.77-2.36),and 1.27(0.72-2.24),respectively.We observed a positive association of glycated hemoglobin(HbA1c)with 25(OH)D at baseline(β=1.752,P=0.001)and after follow-up(β=1.385,P=0.003),and a negative association of ln conversion homeostasis model assessment(HOMA)-βwith 25(OH)D at baseline(β=-0.982,P=0.021).There was no significant interaction between 25(OH)D and diabetes genetic predisposition on the risk of T2DM(χ^(2)=2.710,P_(for interaction)=0.100).The lowest OR(95%CI)of T2DM was among participants with low genetic risk and the highest quartile of 25(OH)D(0.17[0.05-0.62]).Conclusion:Serum 25(OH)D may be irrelevant to the risk of incident T2DM among East Chinese adults regardless of genetic predisposition.

Pancreatic ductal adenocarcinoma: Risk factors, screening, and early detection

Pancreatic cancer is the fourth most common cause of cancer-related deaths in the United States, with over 38000 deaths in 2013. The opportunity to detect pancreatic cancer while it is still curable is dependent on our ability to identify and screen high-risk populations before their symptoms arise. Risk factors for developing pancreatic cancer include multiple genetic syndromes as well as modifiable risk factors. Genetic conditions include hereditary breast and ovarian cancer syndrome, Lynch Syndrome, familial adenomatous polyposis, Peutz-Jeghers Syndrome, familial atypical multiple mole melanoma syndrome, hereditary pancreatitis, cystic fibrosis, and ataxia-telangiectasia; having a genetic predisposition can raise the risk of developing pancreatic cancer up to 132-fold over the general population. Modifiable risk factors, which include tobacco exposure, alcohol use, chronic pancreatitis, diet, obesity, diabetes mellitus, as well as certain abdominal surgeries and infections, have also been shown to increase the risk of pancreatic cancer development. Several largevolume centers have initiated such screening protocols, and consensus-based guidelines for screening high-riskgroups have recently been published. The focus of this review will be both the genetic and modifiable risk factors implicated in pancreatic cancer, as well as a review of screening strategies and their diagnostic yields.

Glutathione S-transferases M1,T1 genotypes and the risk of gastric cancer:A case-control study

AIM: Glutathione S-transferases (GSTs) are involved in the detoxification of many potential carcinogens and appear to play a critical role in the protection from the effects of carcinogens. The contribution of glutathione S-transferases M1 and T1 genotypes to susceptibility to the risk of gastric cancer and their interaction with cigarette smoking are still unclear. The aim of this study was to determine whether there was any relationship between genetic polymorphisms of GSTT1 and GSTT1 and gastric cancer. METHODS: A population based case-control study was carried out in a high-risk area, Changle County, Fujian Province, China. The epidemiological data were collected by a standard questionnaire and blood samples were obtained from 95 incidence gastric cancer cases and 94 healthy controls. A polymerase chain reaction method was used to detect the presence or absence of the GSTT1 and GSTT1 genes in genomic DNA. Logistic regression model was employed in the data analysis. RESULTS: An increase in risk for gastric cancer was found among carriers of GSTT1 null genotype. The adjusted odds ratio (OR) was 2.63 95% Confidence Interval (95% CI) 1.17-5.88, after controlling for age, gender, cigarette smoking, alcohol drinking, and fish sauce intake. The frequency of GSTT1 null genotype in cancer cases (43.16%) was not significantly different from that in controls (50.00%). However, the risk for gastric cancer in those with GSTT1 null and GSTT1 non-null genotype was significantly higher than in those with both GSTT1 and GSTT1 non-null genotype (OR = 2.77, 95% CI 1.15-6.77). Compared with those subjects who never smoked and had normal GSTT1 genotype, ORs were 1.60 (95% CI:0.62-4.19) for never smokers with GSTT1 null type, 2.33 (95% CI 0.88-6.28) for smokers with normal GSTT1, and 8.06 (95% CI 2.83-23.67) for smokers with GSTT1 null type. CONCLUSIONS: GSTT1 gene polymorphisms may be associated with genetic susceptibility of stomach cancer and may modulate tobacco-related carcinogenesis of gastric cancer.

Relationship between ABO blood groups and carcinoma of esophagus and cardia in Chaoshan inhabitants of China

AIM:To study the relationship between ABO blood groups and carcinoma of esophagus and cardia in Chaoshan inhabitants of China, which is a unique Littoral high-risk area of esophageal carcinoma in China. The poor communication and transportation in the past has made Chaoshan a relatively closed area and kept its culture and custure of old China thousand years ago. METHODS: Data on age, sex, ABO blood type and X-ray or pathological diagnose of the patients with carcinoma of esophagus or cardia were collected from the Tumor Hospital. First Affiliated Hospital, Second Affiliated Hospital of Shantou University Medical College; and the Central Hospital of Shantou and the Central Hospital of Jieyang. A total of 6685 patients with esophageal carcinoma (EC) and 2955 patients with cardiac cancer (CC) in Chaoshan district were retrospectively assessed for their association with ABO blood groups. RESULTS: The distribution of ABO blood groups in patients with EC or CC was similar to the normal local population in Chaoshan. However, blood group B in male patients with CC and in the patients with carcinoma in the upper third esophagus was 2.3% and 4.7% higher than the corresponding controls. The relative risk B O was 1.1415 (P【0.05) and 1.2696 (P【0.05), respectively. No relationship was found between ABO blood groups and tumor differentiation. CONCLUSION: ABO blood group B is associated with the incidence of CC in male individuals and carcinoma in the upper third esophagus. The distribution of ABO blood groups varies in the different geographical and ethnic groups. As a result, proper controls are very important for such studies.

5-HTR2A Polymorphisms rs6311 and rs6313 and Major Depressive Disorder: A Meta-Analysis

rs6311 and rs6313 are two Single Nucleotide Polymorphisms (SNPs) on the Serotonin Receptor 2A gene (5-HTR2A) in complete linkage disequilibrium. Numerous gene association studies have examined the relationships between one or both of these two polymorphisms and Major Depressive Disorder (MDD), with conflicting results. The present meta-analysis examined 19 case-control gene association studies, 9 of which included rs6311 (n = 3382), and 15 of which included rs6313 (n = 5590). The strength of relationship with MDD was assessed by pooled odds ratios and 95% confidence intervals for both SNPs according to four genetic models. Heterogeneity was measured by Q and I2. Subgrouping was performed by minor allele and by ethnicity. Results were nonsignificant for all models and subgroups, suggesting that genotype alone does not play a major role in genetic susceptibility to depression. The potential for epistatic, epigenetic, and regulatory RNA interactions with these SNPs is discussed, and future areas of research are recommended.

Differences between hepatic and biliary lipid metabolism and secretion in genetically gallstone-susceptible and gallstone-resistant mice

OBJECTIVE: To investigate differences between hepatic and biliary lipid metabolism and secretion of genetically gallstone-susceptible (C57L) and resistant (AKR) mice and the mechanism of cholesterol gallstone formation. METHODS: The inbred C57L and AKR mice were fed a lithogenic diet containing 15% fat, 1.25% cholesterol and 0.5% cholic acid for four weeks. Hepatic cholesterol content and secretion rates of biliary lipids, as well as phenotypes of the liver and gallbladder were determined and examined before and after the feeding of the lithogenic diet. RESULTS: Both before and after ingestion of the lithogenic diet, hepatic secretion rates of all biliary lipids in C57L mice were markedly higher than that of AKR mice (P

Genetic susceptibility to traumatic brain injury and apolipoprotein E gene

Traumatic brain injury （TBI） is defined as an injury caused by a blow or jolt to the head or a penetrating head injury that disrupts the normal function of the brain. It is a common emergency and severe case in neurosurgery field. Nowadays, there are more and more evidences showing that TBI, which is apparently similar in pathology and severity in the acute stage, may have different outcomes. The known prognostic factors （such as age, severity of injury and treatments, etc.） explain only part of this variability and the concept of genetic susceptibility of traumatic brain injury has already been accepted by more and more people. It is now demonstrated that genetic polymorphism may play a key role in the susceptibility to TBI, even outcome follow-ing TBI. Although there are many genes that may involved in pathophysiological processes influencing TBI, apolipoprotein E gene has become one of the most extensive studied genes in neurotrauma and neurodegenerative disease and seems to take an important part in the neural responses to TBI. In this article, we will review the current understanding of the genetic susceptibility of TBI and the advancements regarding the impact of apolipoprotein E genotype on the severity and/or outcome following TBI.

Genetic variation of low-density lipoprotein-cholesterol and its clinical implications

Plasma lipids are controlled by genes and play an important role in the development of atherosclerosis. Dysplipidemia is an important risk factor for coronary artery disease (CAD). Coronary artery disease is the leading cause of mortality and morbidity in the developed world. More than 14 million Americans are afflicted with clinically significant CAD.~1 To illustrate the impact of CAD in developed countries, the medical and societal costs of CAD in the United States alone are in excess of $90 billion annually.~1 More than (600 000) Americans each year develop new cardiac events, more than 10% of which occur in Americans (<50) years of age.~1 Identifying genetic predisposition to early onset of CAD could help in understanding basic disease mechanism, guiding targeted preventive efforts, and planning appropriate therapeutic strategies.

Region 2 of 8q24 is associated with the risk of aggressive prostate cancer in Caribbean men of African descent from Guadeloupe （French West Indies）

Multiple regions of the genome have been associated with the risk of prostate cancer in Caucasians, particularly including several polymorphisms located at 8q24. Region 2 of 8q24 has been repeatedly found to be associated with the risk of prostate cancer among men of African descent, although one study performed in the Caribbean island of Jamaica did not report this finding. In this study, the single nucleotide polymorphism rs16901979, located in region 2 of 8q24, was genotyped in 498 cases of histologically confirmed prostate cancer and 541 controls from the French Caribbean islands of Guadeloupe, where the population is largely of African descent. The AA genotype and the A allele at rs16901979 were associated with elevated risks of prostate cancer （odds ratios [ORs] = 1.84, 95% confidence interval [95% CI] = 1.26-2.69, P= 0.002 and OR = 1.36, 95% CI = 1.13-1.64, P= 0.001, respectively）. Following stratification of the patients by disease aggressiveness, as defined by the Gleason score, the pooled genotypes AC ＋ AA were associated with a higher risk of a Gleasen score 〉7 at diagnosis （OR = 1.79, 95% CI = 1.17-2.73, P= 0.007）. In summary, the A allele at rs16901979 was associated with the risk of prostate cancer in the Caribbean population of Guadeloupe, confirming its involvement in populations of African descent. Moreover, our study provides the first evidence of an association between this variant and the risk of aggressive prostate cancer.

Influence of functional polymorphism in MIF promoter on sudden cardiac death in Chinese populations

Sudden cardiac death(SCD)is defined as an unexpected natural death without any obvious non-cardiac causes that occurs within 1 h with witnessed symptom onset or within 24 h without witnessed symptom onset.Genetic studies conducted during the past decade have markedly illuminated the genetic basis of the cardiac disorders associated with SCD.Macrophage migration inhibitory factor(MIF)is an upstream immunoregulatory cytokine associated with the pathogenesis of many inflammatory diseases including atherosclerosis and myocardial infarction.Previous studies have reported that the functional -794(CATT)_(5-8) polymorphism in MIF is unrelated to sudden infant deth syndrome susceptibility.However,there are no reports concerning the association between the polymorphism and adult SCD susceptibility.In the current study,we investigated the association between the-794(CATT)_(5-8) polymorphism and adult SCD susceptibility using 79 adult SCD cases and 313 healthy controls.All samples were analysed using a conventional polymerase chain reaction(PCR)technique.We found that CATT_(6) and 5-6 were the most common allele and genotype in both groups,respectively,while no significant association was found between the-794(CATT)_(5-8) polymorphism and SCD susceptibility.We also summarized the allele frequencies of 794(CATT)_(5-8) in cohorts of healthy people from different countries and found that the allele frequency distributions of the polymorphism in Chinese populations were quite different from that of American and European populations(P=0.005,P=0.0001,respectively),but similar to Japanese populations(P=0.827).In conclusion,this study indicates that the-794(CATT)_(5-8) polymorphism may not be associated with adult SCD susceptibility in Chinese populations.Different allele frequency distributions of the polymorphism in multiple populations may provide a useful reference for further genetic association studies.