ABSTRACT
Susceptibility to esophageal carcinoma (EC) is influenced by the interaction between genetic and environmental factors. To clarify the etiology of EC, several genome-wide association studies have identified single nucleotide polymorphisms (SNPs) in PCLE1 and RFT2 genes as esophageal squamous cell carcinoma (ESCC) susceptibility loci in Asian populations. This study aimed to determine whether these SNPs also modify the risk of esophageal adenocarcinoma (EAC) and ESCC in western populations of Caucasian ethnicity. A European case-control study including 349 EC patients and 580 controls matched for age, sex, geographical location, and race was carried out. The SNPs rs2274223 in the PCLE1 gene at chromosome 10q23 and rs13042395 in the RFT2 gene at chromosome 20p13 were determined using PCR. Genotype distributions were compared between patients and controls, and odds ratios with 95% confidence intervals were calculated. The total EC group included 86 patients with ESCC and 258 patients with EAC. The distribution of PLCE1 and RFT2 genotypes did not differ between patients with EAC or ESSC, and the controls. In contrast to the modulation of the risk of ESCC in Asians, it is unlikely that the PLCE1 rs2274223 and RFT2 13042395 SNPs play a role in EAC or ESCC susceptibility in Dutch Caucasians.
Subject(s)
Adenocarcinoma/genetics , Carcinoma, Squamous Cell/genetics , Esophageal Neoplasms/genetics , Membrane Transport Proteins/genetics , Phosphoinositide Phospholipase C/genetics , Polymorphism, Single Nucleotide , Adenocarcinoma/epidemiology , Carcinoma, Squamous Cell/epidemiology , Case-Control Studies , Esophageal Neoplasms/epidemiology , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Male , Netherlands/epidemiology , Polymorphism, Single Nucleotide/physiology , Risk Factors , White People/statistics & numerical dataABSTRACT
Esophageal cancer (EC) has a globally increasing incidence with poor curative treatment options and survival rates. Crucial risk factors are exposure to toxins or carcinogens. Microsomal epoxide hydrolase (mEH) is a biotransformation enzyme essential for the detoxification of xenobiotics. Polymorphisms in exon 3 and exon 4 of the microsomal epoxide hydrolase gene (EPHX1) modify catalytic activity of this enzyme and subsequently may play a role in EC etiology. This case-control study investigated whether these polymorphisms in the EPHX1 gene influence esophageal cancer susceptibility in a Dutch Caucasian population. A case-control study including 349 Caucasian EC patients and 581 Caucasian healthy controls was conducted and the polymorphisms Tyr113His (exon 3) and His139Arg (exon 4) in the EPHX1 gene were determined, using polymerase chain reaction. The distribution of exon 3 and exon 4 genotypes were compared between cases and controls. Analyses included a stratification according to tumor histology; esophageal adenocarcinoma (EAC) or squamous cell carcinoma (ESCC). Furthermore, on the basis of allelic in vitro enzyme activity assays, exon 3 and 4 genotypes were combined and categorized according to their predicted high, medium or low enzyme activity. Homozygosity and heterozygosity for both exon 3 and 4 polymorphisms were correlated with a decreased esophageal squamous cell carcinoma risk. Heterozygosity and homozygosity for both polymorphisms correlated with an increased and a decreased esophageal adenocarcinoma risk, respectively. Predicted intermediate and high activity genotypes were risk and protective factors for esophageal squamous cell carcinoma and esophageal adenocarcinoma, respectively. However, none of these associations were statistically significant. In conclusion, the polymorphisms in exon 3 and exon 4 of the EPHX1 gene do not seem to be modifiers of esophageal squamous cell carcinoma or esophageal adenocarcinoma risk in Dutch Caucasians.
