Oking or non-alcohol consumption subgroups (adjusted OR and 95 CI, see Table 3).Characteristics of Patients with/without H. pylori Infection, Smoking, and Alcohol Consumption in Relation to GSTP1 PolymorphismsA variant of GSTP1 has a lower efficiency for most of the environmental carcinogens (e.g. H. pylori infection, smoking, and alcohol consumption) that may cause some individuals’ susceptiGenetic Susceptibility to Gastric CarcinogenesisTable 1. Distribution of select patient characteristics.Variablesuperficial gastritis vs. Felypressin web atrophic gastritis superficial gastritis (n = 683) atrophic gastritis (n = 683) 55.0569.21 496superficial gastritis vs. gastric cancer superficial P valuea gastritis (n = 550) 0.824 0.904 56.6369.77 364 186 gastric cancer (n = 550) 57.22610.17 344P valuea0.328 0.Age (mean D), years #60 .60 Sex Male Female55.1669.26 4943933931.3733731.H. pyloriPositive Negative Smoking status Smoker Non-smoker Missing Alcohol use Yes No Missing 122 372 189 129 417 137 0.687 111 264 175 84 115 351 0.002* 185 320 178 181 368 134 0.212 171 213 166 141 106 303 0.002* 176 507 415 268 0.000* 134 416 271 279 0.000*a P value of the comparison with a two-sided x2 test. *Indicates statistical significance at P,0.05. doi:10.1371/journal.pone.0047178.tbility to gastric cancer and its precancerous conditions [26?8]. Therefore, we looked for interaction between GSTP1 genotype and H. pylori IgG, smoking, or alcohol consumption in gastric cancer and its precancerous conditions. Using Ile/Ile genotype and H. pylori IgG(? as a reference, the OR for (Ile/Val +Val/Val) genotype and H. pylori IgG(+) was 4.308 (95 CI = 3.062?.061) in atrophic gastritis subgroups, and the OR for (Ile/Val +Val/Val) genotype and H. pylori IgG(+) was 3.696 (95 CI = 2.475?.521) in gastric cancer subgroups. Using Ile/Ile genotype and nonsmoking as a reference, the OR for (Ile/Val +Val/Val) genotype and smoking was 0.782 (95 CI = 0.538?.136) in atrophic gastritis subgroups, and the OR for (Ile/Val +Val/Val) genotype and smoking was 1.638 (95 CI = 1.044?.571) in gastric cancer subgroups. Using Ile/Ile genotype and non-alcohol consumption as a reference, the OR for (Ile/Val +Val/Val) genotype and alcohol consumption was 0.862 (95 CI = 0.565?.313) inatrophic gastritis subgroups, and the OR for (Ile/Val +Val/Val) genotype and alcohol consumption was 1.641 (95 CI = 0.983?2.739) in gastric cancer subgroups. Association of the GSTP1 Val/ Val genotype with H. pylori IgG(+), smoking, or alcohol consumption could significantly increase atrophic gastritis and gastric cancer risk (Tables 4 and 5).DiscussionOver the past 20 years, 
there has been marked progress in our understanding of the role of genetic and environmental factors in the etiology of gastric cancer. GSTs are multifunctional and Potassium clavulanate supplier multigene products. They 
are versatile enzymes and participate in the nucleophilic attack of the sulfur 1326631 atom of glutathione on the electrophilic centers of various endogenous and xenobiotic compounds. Out of the major classes of GSTs, GSTP1 hasTable 2. Genotype distribution of GSTP1 among atrophic gastritis and gastric cancer cases and superficial gastritis controls and association with gastric cancer risk.superficial gastritis vs. atrophic gastritis superficial gastritis Ile/Ile Ile/Val Val/Val 421 247 15 atrophic gastritis 430 230 23 Adjusted OR (95 CI) 1.000 1.096(0.876?.372) 0.666(0.343?.294) 0.422 0.superficial gastritis vs gastric cancerPgastric superficial gastritis cancer 343 193 14 33.Oking or non-alcohol consumption subgroups (adjusted OR and 95 CI, see Table 3).Characteristics of Patients with/without H. pylori Infection, Smoking, and Alcohol Consumption in Relation to GSTP1 PolymorphismsA variant of GSTP1 has a lower efficiency for most of the environmental carcinogens (e.g. H. pylori infection, smoking, and alcohol consumption) that may cause some individuals’ susceptiGenetic Susceptibility to Gastric CarcinogenesisTable 1. Distribution of select patient characteristics.Variablesuperficial gastritis vs. atrophic gastritis superficial gastritis (n = 683) atrophic gastritis (n = 683) 55.0569.21 496superficial gastritis vs. gastric cancer superficial P valuea gastritis (n = 550) 0.824 0.904 56.6369.77 364 186 gastric cancer (n = 550) 57.22610.17 344P valuea0.328 0.Age (mean D), years #60 .60 Sex Male Female55.1669.26 4943933931.3733731.H. pyloriPositive Negative Smoking status Smoker Non-smoker Missing Alcohol use Yes No Missing 122 372 189 129 417 137 0.687 111 264 175 84 115 351 0.002* 185 320 178 181 368 134 0.212 171 213 166 141 106 303 0.002* 176 507 415 268 0.000* 134 416 271 279 0.000*a P value of the comparison with a two-sided x2 test. *Indicates statistical significance at P,0.05. doi:10.1371/journal.pone.0047178.tbility to gastric cancer and its precancerous conditions [26?8]. Therefore, we looked for interaction between GSTP1 genotype and H. pylori IgG, smoking, or alcohol consumption in gastric cancer and its precancerous conditions. Using Ile/Ile genotype and H. pylori IgG(? as a reference, the OR for (Ile/Val +Val/Val) genotype and H. pylori IgG(+) was 4.308 (95 CI = 3.062?.061) in atrophic gastritis subgroups, and the OR for (Ile/Val +Val/Val) genotype and H. pylori IgG(+) was 3.696 (95 CI = 2.475?.521) in gastric cancer subgroups. Using Ile/Ile genotype and nonsmoking as a reference, the OR for (Ile/Val +Val/Val) genotype and smoking was 0.782 (95 CI = 0.538?.136) in atrophic gastritis subgroups, and the OR for (Ile/Val +Val/Val) genotype and smoking was 1.638 (95 CI = 1.044?.571) in gastric cancer subgroups. Using Ile/Ile genotype and non-alcohol consumption as a reference, the OR for (Ile/Val +Val/Val) genotype and alcohol consumption was 0.862 (95 CI = 0.565?.313) inatrophic gastritis subgroups, and the OR for (Ile/Val +Val/Val) genotype and alcohol consumption was 1.641 (95 CI = 0.983?2.739) in gastric cancer subgroups. Association of the GSTP1 Val/ Val genotype with H. pylori IgG(+), smoking, or alcohol consumption could significantly increase atrophic gastritis and gastric cancer risk (Tables 4 and 5).DiscussionOver the past 20 years, there has been marked progress in our understanding of the role of genetic and environmental factors in the etiology of gastric cancer. GSTs are multifunctional and multigene products. They are versatile enzymes and participate in the nucleophilic attack of the sulfur 1326631 atom of glutathione on the electrophilic centers of various endogenous and xenobiotic compounds. Out of the major classes of GSTs, GSTP1 hasTable 2. Genotype distribution of GSTP1 among atrophic gastritis and gastric cancer cases and superficial gastritis controls and association with gastric cancer risk.superficial gastritis vs. atrophic gastritis superficial gastritis Ile/Ile Ile/Val Val/Val 421 247 15 atrophic gastritis 430 230 23 Adjusted OR (95 CI) 1.000 1.096(0.876?.372) 0.666(0.343?.294) 0.422 0.superficial gastritis vs gastric cancerPgastric superficial gastritis cancer 343 193 14 33.
