Genetic variation in PSCA and risk of gastric advanced preneoplastic lesions and cancer in relation to Helicobacter pylori infection.
ABSTRACT: SNPs in the Prostate Stem Cell Antigen (PSCA) gene have been found associated with gastric cancer (GC) risk in a genome-wide association study. This association has been replicated in several populations. In this study we assessed the impact of PSCA genotype on the risk of advanced gastric precancerous lesions and GC. We used baseline gastric histopathology data and DNA from frozen gastric biopsies of 2045 subjects enrolled in a chemoprevention trial for gastric precancerous lesions in Venezuela, and 180 cases of GC from the same area. We analyzed 3 SNPs in the PSCA gene (rs2294008, rs9297976 and rs12155758) which were previously found to be associated with GC risk in Europeans. The T allele of rs2294008 was found to be associated with a higher prevalence of atrophic gastritis (OR = 1.44; 95% CI 1.03-2.01 for the dominant model) and intestinal metaplasia (OR = 1.50; 95% CI 1.13-1.98 for the dominant model). We also confirmed the association with higher risk of gastric cancer (OR = 2.34; 95% CI 1.36-4.01 for the allele carriers). SNP rs12155758 was not associated with risk of gastric preneoplastic lesions, but we confirmed its association with higher GC risk (OR 1.95; 95% CI 1.29-2.97 for dominant model). We tested the relevance of the presence of the Helicobacter pylori cagA gene, which is known to increase the risk of more severe gastric lesions, but we did not find any clearcut interaction with PSCA SNPs in defining risk of gastric precancerous lesions or cancer.
Project description:Previous studies have shown that two single-nucleotide polymorphisms (SNPs) in PSCA (rs2976392 and rs2294008) are associated with gastric cancer (GC), but the results are conflicting. Additionally, the prognostic value of PSCA gene polymorphisms for GC patients is unknown. We performed a meta-analysis using 9 eligible case-control studies to investigate the association between PSCA polymorphisms and GC risk, and additionally investigated the prognostic value of PSCA polymorphisms for GC patients with two eligible studies. The association was measured using random-effect or fixed-effect odds ratios (ORs) combined with 95% confidence intervals (CIs) according to the heterogeneity of the studies. We found that rs2294008 (dominant model: OR, 1.44; 95% CI, 1.16-1.79) and rs2976392 (dominant model: OR, 1.41; 95% CI, 0.98-2.04) polymorphisms were associated with increased risk of GC, although the association of rs2976392 was not statistically significant. For rs2294008, the associations were all consistently significant among the different subgroups stratified by ethnicity and tumor location, but not significant in intestinal or diffuse subtypes. For rs2976392, the associations were consistently significant for the intestinal, diffuse and non-cardia subtypes, but not significant for the cardia subtype. Furthermore, two eligible studies reported inverse results of PCSA in predicting the survival of GC patients (HR, 0.75; 95% CI, 0.59-0.96; and HR, 2.12; 95% CI, 1.22-3.69, respectively). In conclusion, PSCA gene polymorphisms are associated with increased risk of GC and are correlated with the prognosis of GC patients. Future studies are required to evaluate the molecular mechanisms of PSCA polymorphisms in GC and validate the prognostic value in a larger number of patients.
Project description:Gene-environment interactions may increase gastric cancer (GC) risk. Seven susceptibility loci identified by genome-wide association studies (GWASs) suggest that genetic factors play a role in gastric carcinogenesis. Meanwhile, Helicobacter pylori (H. pylori) infection, smoking, and alcohol drinking are also important environmental factors for gastric cancer. However, studies to explore the role of gene-environment interactions in gastric carcinogenesis, and particularly the relationship between the seven susceptibility loci and their potential interactions with H. pylori infection, smoking, and alcohol drinking in risk of GC, and severe intestinal metaplasia (IM)/dysplasia, have been inconclusive. A total of 1273 subjects in a Chinese population were recruited, and genotyping was carried out using the competitive allele-specific PCR (KASP) method. Unconditional logistic regression was applied to model the associations between genetic polymorphisms and the disease risk. Effect modifications by H. pylori infection, smoking and alcohol drinking were evaluated. PSCA rs2294008/rs2976392 showed a significant, multiplicative interaction with H. pylori infection in risk of GC. Meanwhile, PRKAA1 rs13361707 had an additive interaction with H. pylori infection. SLC52A3 rs13042395 showed an interaction with alcohol drinking in risk of GC. Moreover, three SNPs, MUC1 rs4072037, ZBTB20 rs9841504 and PRKAA1 rs13361707, were associated with precancerous gastric lesions (severe IM/dysplasia). Our data suggest that genetic predisposition factors identified by GWAS may interact with environmental risk factors, Particularly for H. pylori infection and alcohol consumption, to increase the risk of GC.
Project description:Eleven high-evidence single-nucleotide polymorphisms (SNPs) at nine loci for gastric cancer (GC) risk were reported, but their associations with survival remain unknown. In this study, we examined associations between SNP and GC survival by anatomic location and histology among 1147 incident cases from the Shanxi Upper Gastrointestinal Genetics Project. We further examined whether SNPs were expression quantitative trait loci in normal and tumor gastric tissues, and whether tumor versus normal somatic mRNA differences in 126 cases were associated with survival. No SNPs were associated with GC survival overall. However, subtype-specific associations were observed for gastric cardia adenocarcinomas at MUC1/TRIM46/1q22 rs2070803 [HRAA versus GA+GG = 2.16; 95% confidence interval (CI) = 1.24-3.78; P = 0.0068] and LTA/TNF/6p21.33 rs1799724 (HRTT+CT versus CC = 1.30; 95% CI = 1.07-1.57; P = 0.0077), and for diffuse-type GC at PSCA/8q24.3 rs2294008 (HRTT versus CT+CC = 1.99; 95% CI = 1.33-2.97; P = 7.8E-04). Rs2294008T was a cis-expression quantitative trait loci for PSCA, upregulating mRNA in normal gastric (? = 0.60; P = 5.7E-21) and GC (? = 0.30; P = 0.0089) tissues. Cases in the highest quartile (the smallest downregulation of tumor PSCA) had shortest survival than cases with the most downregulated PSCA (median survival of 0.47 years in the highest quartile versus 3.73 years in the lowest quartile; hazard ratio = 9.70; 95% CI = 2.46-38.4; P = 0.0012). Less striking effects for mRNA levels were observed for MTX1 at 1q22 in gastric cardia adenocarcinoma and for JRK at 8q24.3 in diffuse GC. Our results suggest three high-evidence GC risk loci have prognostic importance in GC subtypes. Future studies in well-characterized independent populations are warranted to validate our findings and further investigate the clinical utility of these variants in predicting GC prognosis.
Project description:Introduction:Genetic factors play an important role in the development of gastric cancer (GC), a prevalent malignancy in Central Asia. Recent studies have shown that single-nucleotide polymorphisms (SNPs) in several genes are associated with increased GC risk, indicating that genetic variation contributes to gastric carcinogenesis. Located on chromosome 8q24.2, the prostate stem cell antigen (PSCA) gene encodes a 123-amino acid glycoprotein related to the cell-proliferation inhibition and cell-death induction activity. SNPs in PSCA gene have been found to be associated with gastric cancer risk in a genome-wide association study, but results were not conclusive. This study aimed to investigate the association between two polymorphic variants of PSCA gene (rs2294008 and rs9297976) and the susceptibility to gastric cancer in Uzbekistan. Methods:Two hundred sixty eight patients with gastric cancer and a control group of 248 healthy individuals were included in this study. DNA samples isolated from these groups were genotyped using PCR-RFLP method. Comparative analysis of resulting genotypes showed a statistically significant association between CT genotype and gastric cancer (p=0.03, additive model of inheritance, Cochran-Armitage trend test). Results:Comparative analysis of the distribution of genotypes of rs2976392 polymorphism did not show a statistically significant difference; however, analysis of the distribution of the rs2976392 genotypes in a subgroup of young women revealed a statistically significant (p = 0.04, additive model of inheritance, Cochran-Armitage trend test) increase in the incidence of AA (38%) and AG (56%) genotypes in patients with GC, compared to the controls (20% and 40%). Conclusion:Our findings support that PSCA rs2294008 and rs9297976 polymorphism may contribute to the susceptibility to gastric cancer. Genotyping of these polymorphisms can potentially be recommended as one of the criteria for identification of high risk groups for gastric cancer development in Uzbekistan.
Project description:Genome-wide association studies have identified a SNP, rs2294008, on 8q24.3 within the prostate stem cell antigen (PSCA) gene, as a risk factor for bladder cancer. To fine-map this region, we imputed 642 SNPs within 100 Kb of rs2294008 in addition to 33 markers genotyped in one of the reported genome-wide association study in 8,652 subjects. A multivariable logistic regression model adjusted for rs2294008 revealed a unique signal, rs2978974 (r(2) = 0.02, D' = 0.19 with rs2294008). In the combined analysis of 5,393 cases and 7,324 controls, we detected a per-allele odds ratio (OR) = 1.11 [95% confidence interval (CI) = 1.06-1.17, P = 5.8 × 10(-5)] for rs2294008 and OR = 1.07 (95% CI = 1.02-1.13, P = 9.7 × 10(-3)) for rs2978974. The effect was stronger in carriers of both risk variants (OR = 1.24, 95% CI = 1.08-1.41, P = 1.8 × 10(-3)) and there was a significant multiplicative interaction (P = 0.035) between these two SNPs, which requires replication in future studies. The T risk allele of rs2294008 was associated with increased PSCA mRNA expression in two sets of bladder tumor samples (n = 36, P = 0.0007 and n = 34, P = 0.0054) and in normal bladder samples (n = 35, P = 0.0155), but rs2978974 was not associated with PSCA expression. SNP rs2978974 is located 10 Kb upstream of rs2294008, within an alternative untranslated first exon of PSCA. The non-risk allele G of rs2978974 showed strong interaction with nuclear proteins from five cell lines tested, implying a regulatory function. In conclusion, a joint effect of two PSCA SNPs, rs2294008 and rs2978974, suggests that both variants may be important for bladder cancer susceptibility, possibly through different mechanisms that influence the control of mRNA expression and interaction with regulatory factors.
Project description:The prostate stem cell antigen (PSCA) gene, which encodes a prostate-specific antigen (PSA), was identified as a gene involved in cell adhesion and proliferation. The associations between the PSCA rs2294008 and rs2976392 single nucleotide polymorphisms (SNPs) and gastric cancer (GCa) susceptibility were still controversial. To derive a more precise estimation of the associations, we conducted a case-control study of 1,124 cases and 1,192 controls in an eastern Chinese population. We found that the rs2294008T variant genotypes were associated with an increased GCa risk in this study population (CT vs CC, OR=1.59, 95% CI=1.33-1.89 and CT+TT vs CC, OR=1.38, 95% CI=1.17-1.62). For SNP rs2976392, the variant A genotypes were also associated with an increased GCa risk (AG vs GG, OR=1.61, 95% CI=1.35-1.91 and AG+AA vs GG, OR=1.47, 95% CI=1.25-1.74). The results were further validated by a meta-analysis. In conclusion, the results indicated that the PSCA rs2294008 T and rs2976392 A alleles were low-penetrate risk factors for GCa in this study population. However, large and well-designed studies are warranted to validate our findings.
Project description:Gastric cancer is a lethal disease with a high mortality rate. Studies have suggested that prostate stem cell antigen (PSCA) rs2294008 polymorphism is associated with gastric cancer (GC). In this case-control study, we investigated rs2294008 polymorphism in the Tibet, Hui and Han nationalities in the Qinghai area of China. Genomic DNA was extracted from the peripheral blood of 286, 315 and 350 healthy volunteers and from 219, 233 and 265 Helicobacter pylori-negative non-cardia GC patients from the Tibet, Hui and Han populations, respectively. The rs2294008 polymorphism was analyzed by denaturing high-performance liquid chromatography. rs2294008 CT and TT genotypes were associated with GC both in the Tibet and Han populations (adjusted OR=1.51, 1.47, 2.01, 1.85; 95% CI, 1.04-2.19, 1.05-2.06, 1.04-3.88, 1.03-3.34; P=0.030, 0.025, 0.039, 0.040, respectively). rs2294008 TT genotype was associated with GC in the Hui population (adjusted OR=2.14; 95% CI, 1.29-3.55; P=0.003). Furthermore, when stratified by histopathology, the rs2294008 CT and TT genotypes were associated with diffuse GC in the Tibet and Han nationalities (adjusted OR=1.93, 1.73, 2.69, 2.86; 95% CI, 1.09-3.44, 1.01-2.95, 1.06-6.84, 1.27-6.46; P=0.025, 0.045, 0.038, 0.011, respectively). However, the rs2294008 TT genotype was associated with both intestinal and diffuse types of GC (adjusted OR=2.10, 2.21; 95% CI, 1.17-3.75, 1.12-4.38; P=0.012, 0.023, respectively) and the rs2294008 CT genotype was only associated with intestinal-type GC in the Hui nationalitiy group (adjusted OR=1.60; 95% CI, 1.04-2.47; P=0.034). The results therefore showed that rs2294008 may differentially contribute to GC among different nationalities in one area and its role is independent from Helicobacter pylori-infection.
Project description:Recently, three genome-wide association studies have identified the PSCA (prostate stem cell antigen) rs2294008 polymorphism (C?>?T) associated with susceptibility to gastric cancer, bladder cancer, and duodenal ulcers, highlighting its critical role in disease pathogenesis. Given PSCA is reported to be overexpressed in cervical cancer and the rs2294008 can influence PSCA transcription, we aimed to determine the role of rs2294008 in susceptibility to cervical cancer. The genotyping was performed in the 1126 cases and 1237 controls. Our results showed the rs2294008 TT genotype significantly associated with a reduced risk of cervical cancer (adjusted OR?=?0.55, 95%?CI?=?0.38-0.79; recessive model). Stratified analyses revealed that the association was restricted to the subgroups of age?>?49 years, parity ? 1, abortion and early-stage cervical cancer. Immunohistochemistry assay showed the individuals carrying the TT genotype having lower PSCA expression than those with CC/CT genotypes. In summary, the PSCA rs2294008 polymorphism may serve as a biomarker of cervical cancer, particularly of early-stage cervical cancer.
Project description:An association between gastric cancer and the rs2294008 (C>T) polymorphism in the prostate stem cell antigen (PSCA) gene has been reported for several Asian populations. We set out to determine whether such an association exists in white individuals.We genotyped 166 relatives of gastric cancer patients, including 43 Helicobacter pylori-infected subjects with hypochlorhydria and gastric atrophy, 65 infected subjects without these abnormalities, 58 H pylori-negative relatives, and 100 population controls. Additionally, a population-based study of chronic atrophic gastritis provided 533 cases and 1054 controls. We then genotyped 2 population-based, case-control studies of upper gastrointestinal cancer: the first included 312 gastric cancer cases and 383 controls; the second included 309 gastric cancer cases, 159 esophageal cancer cases, and 211 controls. Odds ratios were computed from logistic models and adjusted for confounding variables.Carriage of the risk allele (T) of rs2294008 in PSCA was associated with chronic atrophic gastritis (adjusted odds ratio [OR], 1.5; 95% confidence interval [CI]: 1.1-1.9) and noncardia gastric cancer (OR, 1.9; 95% CI: 1.3-2.8). The association was strongest for the diffuse histologic type (OR, 3.2; 95% CI: 1.2-10.7). An inverse association was observed between carriage of the risk allele and gastric cardia cancer (OR, 0.5; 95% CI: 0.3-0.9), esophageal adenocarcinoma (OR, 0.5; 95% CI: 0.3-0.9), and esophageal squamous cell carcinoma (OR, 0.4; 95% CI: 0.2-0.9).The rs2294008 polymorphism in PSCA increases the risk of noncardia gastric cancer and its precursors in white individuals but protects against proximal cancers.
Project description:Gastric adenocarcinoma (GAC) imposes a considerable health burden around the world. Gene variation in prostate stem cell antigen gene (PSCA) has been identified to be associated with GAC risk, while the results showed regional variation. To explore the influence of PSCA gene variation on its expression and GAC risk in the Northwest Chinese population, four single nucleotide polymorphisms (SNPs) of PSCA were genotyped in 476 GAC cases and 481 controls using MassARRAY system. Two SNPs of rs2294008 (C>T) and rs2976392 (G>A) were identified to be associated with GAC risk. rs2294008, rs2976392 and rs10216533 made up two statistically significant haplotypes (Hap-CGG and Hap-TAG). Additionally, PSCA expression was analyzed by quantitative real time PCR, immunohistochemistry and tissue microarray. The results showed that PSCA expression was decreased in GAC tissues compared with adjacent normal tissues. For normal tissues, PSCA expression was higher with Hap-TA than that with Hap-CG. For GAC tissues, the differentiation degree of Hap-TA was higher than that of Hap-CG. The expression distribution of PSCA in multiple human organs showed disparity. These results suggest that PSCA gene variation has a potential effect on its expression and GAC risk in the Northwest Chinese population.