Development Of Gastric Cardia Adenocarcinoma Research Articles

MiR-1262 suppresses gastric cardia adenocarcinoma via targeting oncogene ULK1.

Gastric cardia adenocarcinoma (GCA) is one of two main gastric cancer subtypes and has its own epidemiological, pathogenic and clinical characteristics. Genetic polymorphisms locating in a microRNA (miRNA) gene enhancer could transcriptionally regulates miRNA expression via impacting binding of transcriptional factors. It is still unclear how miR-1262 and a potential regulatory rs12740674 polymorphism mapping to a strong enhancer region of miR-1262 contribute to GCA development. We genotyped miR-1262 rs12740674 in two independent case-control sets consisting of 1,024 GCA patients and 1,118 controls, and found that the rs12740674 CT or TT genotype carriers had a 0.69-fold decreased risk to develop GCA compared to the CC genotype carriers (95% confidence interval=0.57-0.84, P=2.1×10-4). In the genotype-phenotype correlation analyses of 21 pairs of GCA-normal tissues, the rs12740674 CT or TT genotype was associated with significantly increased levels of miR-1262. Cell proliferation, wound healing and transwell assays elucidated that miR-1262 is a novel GCA tumor suppressor. Consistently, a significantly down-regulated level of miR-1262 exists in GCA specimens compared to normal tissues. Furthermore, multiple lines of evidences indicated that oncogene ULK1 is the target gene of miR-1262 in GCA. Our findings demonstrate miR-1262 transcriptionally modulated by an enhancer genetic variant suppresses GCA via targeting oncogene ULK1. Our data highlight miR-1262 as a promising diagnostic marker and therapeutic target for GCA.

Helicobacter pylori Is Associated With Precancerous and Cancerous Lesions of the Gastric Cardia Mucosa: Results of a Large Population-Based Study in China.

Background: Helicobacter pylori (H. pylori) is widely accepted to be the most important cause of gastric non-cardia adenocarcinoma (GNCA), while its role in the development of gastric cardia adenocarcinoma (GCA) is not well-defined. We aimed to investigate current H. pylori infection in relation to the severity of both precancerous and cancerous lesions of the gastric cardia in an Asian population at high risk of GCA.Methods: A population-based cross-sectional study was conducted in Linzhou County, Henan Province, China. Two thousand three (2,003) randomly selected participants with data on current H. pylori infection, assayed by 13C-urea breath test (13C-UBT), and a sequence of histological diagnoses of the gastric cardia mucosa were analyzed.Results: Of 2,003 subjects, 828 (41.33%) were currently infected with H. pylori. The prevalence of current H. pylori infection increased with increasing severity of histological lesions, from 34.12% in subjects with normal gastric cardia mucosa to 52.17% in subjects with gastric cardia high-grade intraepithelial neoplasia (CHIN)/ gastric cardia adenocarcinoma (GCA) (P for trend <0.001). With H. pylori-negative subjects as the reference category, H. pylori-positive subjects had statistically significant elevated adjusted prevalence odds ratios (PORs) for each of the histological lesions. The PORs (95% CI) were 2.15 (1.74–2.64), 3.46 (2.08–5.75), 2.78 (1.90–4.07), and 3.05 (1.30–7.17) for subjects with carditis, cardia intestinal metaplasia (CIM), cardia low-grade intraepithelial neoplasia (CLIN), and CHIN/GCA), respectively. The associations remained when subjects with abnormal stomach non-cardia mucosa were excluded.Conclusions: This large epidemiologic study demonstrates a positive association between current H. pylori infection and the severity of both precancerous and cancerous lesions of the gastric cardia in an Asian population at high risk of GCA. These findings suggest that H. pylori infection may play a role throughout both early- and late-stage development of GCA.

Serologic Profile of Antiparietal Cell Antibodies, Pepsinogens, and H. pylori and Risk of Upper Gastrointestinal Cancer: A Nested Case-Control Study in China.

Autoimmune gastritis is understudied and possibly associated with gastric noncardia adenocarcinoma (GNCA) and esophageal squamous cell carcinoma (ESCC) in Western populations when it presents as pernicious anemia. A nested case-control study within a Chinese cohort included 100 ESCC, 200 gastric cardia adenocarcinoma (GCA), and 200 GNCA cases diagnosed between 1986 and 2001 and 400 controls. Serostatus of antiparietal cell antibodies (APCA), Helicobacter pylori antibodies, and pepsinogens were measured using commercial kits and serum collected at baseline. We used logistic regression to calculate odds ratios (OR) and 95% confidence interval (CI) for associations between serologic biomarkers and cancer risk adjusted for numerous potential confounders. There was an average interval of 8 years between baseline blood draw and cancer diagnosis. The baseline prevalence of APCA seropositivity was 10.0% and 14.5% in subjects who developed GCA and GNCA, respectively. APCA seropositivity was inversely associated with later development of GCA (OR = 0.42; 95% CI, 0.24-0.75), but not significantly associated with later development of GNCA (OR = 0.82; 95% CI, 0.50-1.36) or ESCC (OR = 1.05; 95% CI, 0.58-1.88). APCA seropositivity was significantly associated with low pepsinogen I/II ratios (OR = 3.69; 95% CI, 1.66-8.21), and individuals with low pepsinogen I/II ratios who were seronegative for APCA had the highest risk of both GCA and GNCA. APCA seropositivity measured years prior to diagnosis was associated with prevalent atrophic gastritis but inversely associated with incident GCA in this Chinese population. APCA may contribute to a growing list of serologic markers that can improve risk stratification for gastric cancer.

Clinical implication of telomere length-related polymorphisms in gastric cardia adenocarcinoma.

e15502 Background: Aberrant telomere lengthening is a critical feature of malignant cells. Short leukocyte telomere length (LTL) confers elevated risk of gastric cardia adenocarcinoma (GCA). Multiple genome-wide association studies (GWAS) identified various single nucleotide polymorphisms (SNPs) associated with LTL in different ethnic populations. However, it remains largely unexplored how these genetic variants are involved in GCA susceptibility. Methods: We systematically screened GWAS-identified candidate SNPs and tested the impact of thirty polymorphisms in genes associated with interindividual LTL variation on GCA using two-stage case-control comparisons consisting of 1,024 GCA patients and 1,118 controls. Results: We observed that CXCR4 rs6430612, TERT rs10069690 and rs2853676 as well as VPS34 rs2162440 are significantly associated with GCA development. A 0.64-fold decreased risk of GCA is associated with the CXCR4 rs6430612 CT genotype compared with the CC genotype ( P= 0.002). On the contrary, the TERT rs10069690 TT genotype carriers had a 1.83-fold increased risk to develop GCA compared to the CC genotype carriers ( P= 5.8×10-6). We also detected a 2.17-fold increased OR for GCA that was associated with the TERT rs2853676 TT genotype ( P= 2.6×10-6). In addition, the odds of having the VPS34 rs2162440 GA genotype in GCA patients was 1.35 compared with the GG genotype ( P= 0.002). In stratified analyses, the association between TERT rs10069690 polymorphism and GCA was more pronounced in nonsmokers ( Pinteraction=9.7×10-5) and nondrinkers ( Pinteraction= 4.6×10-5). Conclusions: Our results highlight the importance of both LTL and LTL-related genetic variants to GCA predisposition.

Genetic variations associated with telomere length confer risk of gastric cardia adenocarcinoma.

Aberrant telomere lengthening is a critical feature of malignant cells. Short leukocyte telomere length (LTL) confers elevated risk of gastric cardia adenocarcinoma (GCA). Multiple genome-wide association studies (GWAS) identified various single-nucleotide polymorphisms (SNPs) associated with LTL in different ethnic populations. However, it remains largely unexplored how these genetic variants are involved in GCA susceptibility. We systematically screened GWAS-identified candidate SNPs and tested the impact of 30 polymorphisms in genes associated with interindividual LTL variation on GCA using two-stage case-control comparisons consisting of 1024 GCA patients and 1118 controls. We observed that CXCR4 rs6430612, TERT rs10069690, and rs2853676 as well as VPS34 rs2162440 are significantly associated with GCA development. A 0.64-fold decreased risk of GCA is associated with the CXCR4 rs6430612 CT genotype compared with the CC genotype (P = 0.002). On the contrary, the TERT rs10069690 TT genotype carriers had a 1.83-fold increased risk to develop GCA compared to the CC genotype carriers (P = 5.8×10-6). We also detected a 2.17-fold increased OR for GCA that was associated with the TERT rs2853676 TT genotype (P = 2.6×10-6). In addition, the odds of having the VPS34 rs2162440 GA genotype in GCA patients were 1.35 compared with the GG genotype (P = 0.002). In stratified analyses, the association between TERT rs10069690 polymorphism and GCA was more pronounced in nonsmokers (Pinteraction=9.7 × 10-5) and nondrinkers (Pinteraction=4.6 × 10-5). Our results highlight the importance of both LTL and LTL-related genetic variants to GCA predisposition.

Aberrant methylation‐mediated downregulation of long noncoding RNA C5orf66‐AS1 promotes the development of gastric cardia adenocarcinoma

As a long non-coding RNA, C5orf66-AS1 is located at 5q31.1. Downregulation and aberrant hypermethylation of C5orf66-AS1 have been detected in a limited several tumors. However, the biological role and distribution of methylated CpG sites of C5orf66-AS1 in gastric cardia adenocarcinoma (GCA) development and prognosis are poorly clarified. The present study was to investigate the expression status and function of C5orf66-AS1 in GCA, and to detect the distribution of methylated CpG sites within the three CpG islands of the promoter and gene body of C5orf66-AS1, further to clarify its prognostic value in GCA patients. C5orf66-AS1 was significantly downregulated in GCA tissues and cell lines, and the expression level was associated with TNM stage, pathological differentiation, lymph node metastasis, and distant metastasis or recurrence. The expression level of C5orf66-AS1 was significantly increased in cancer cells after treated with 5-Aza-dC. Further methylation analysis demonstrated that the aberrant hypermethylation of the regions around the transcription start site of C5orf66-AS1 was more tumor specific and was associated with its expression. Moreover, Sp1 may upregulate C5orf66-AS1 expression and CpG sites hypermethylation within the binding sites may abrogate Sp1 binding. In addition, C5orf66-AS1 inhibited gastric cancer cell proliferation and invasion, and the dysregulation and hypermethylation of the regions around the transcription start site of C5orf66-AS1 were associated with poorer GCA patients' survival. These findings suggest that aberrant hypermethylation-mediated downregulation of C5orf66-AS1 may play important roles in GCA tumorigenesis and C5orf66-AS1 may serve as a potential prognostic marker in predicting GCA patients' survival.

Gastrectomy Increases Risk for Esophageal Adenocarcinoma and Gastric Cardia Adenocarcinoma: An Explorys Study

Introduction: Recent studies in patients who have undergone gastrectomy, primarily sleeve gastrectomy (SG),suggests the procedure exacerbates underlying gastroesophageal reflux disease (GERD) or may even lead to new GERD. Smaller studies have linked SG with the development of Barrett's Esophagus (BE). Current studies do not suggest that Roux-en-Y gastrectomy (RYG) exacerbates GERD, or leads to BE. However, there are no studies evaluating gastrectomy, mostly sleeve gastrectomy today, with the risk of developing either EA or gastric cardia adenocarcinoma (GCA). Aim: to determine if there was any association between gastrectomy or Roux-en-Y with either the development of EA or GCA, using the Explorys database. Methods: We performed a population-based analysis through the Explorys database. Explorys is an aggregate electronic medical record database representing over 54 million patients. It identifies diagnosis, procedures, and test results. Search terms such as neoplasm of lower third of esophagus (NLT) and neoplasm of cardia of stomach (NCS) were used to identify EA and GCA. We used GERD only as the disease control group and identified population cohorts with GERD that also had the diagnosis of BE, gastrectomy or Roux-en-Y. We used temporal attributes to delineate the order of diagnosis and procedure, where patients had to have GERD and the other diagnosis or intervention, prior the diagnosis of EA or GCA. Results: We found that populations of GERD who underwent gastrectomy, mostly sleeve, had an increased association with NCS with OR 13.73 (95% CI 12.07 - 15.62, P<0.0001) and RR 13.64 (95% CI 12.00 - 15.50, P<0.0001) and an increased association with NLT with OR 2.74 (95% CI 2.17 - 3.48, P<0.0001) and RR 2.75 (95% CI 2.17 - 3.48, P<0.0001). There was no association between Roux-en-Y and either NCS or NLT. In contrast, GERD with BE had an increased association with NCS with OR 4.70 (95% CI 4.16 - 5.30, P<0.0001) and RR4.69 (95% CI 4.15 - 5.29, P<0.0001) and an increased association with NLT with OR of 5.47 (95% CI 4.93 - 6.06, P<0.0001) and RR 5.45 (95% CI 4.92 - 6.04, P<0.0001). Conclusion: Patients with GERD who underwent gastrectomy, mostly sleeve, are at an increased risk for developing EA and GCA. In contrast, there was no association between GERD patients who underwent Roux-en-Y bypass gastrectomy with either EA or GCA. Further studies evaluating the risk of gastrectomy for GCA and EA are needed, especially in patients undergoing sleeve gastrectomy.

Promoter hypermethylation-mediated downregulation of miR-770 and its host gene MEG3, a long non-coding RNA, in the development of gastric cardia adenocarcinoma.

Maternally expressed gene 3 (MEG3) is an imprinted gene located at 14q32 which encodes an lncRNA and is downregulated in an expanding list of cancer cell lines and primary human cancers. The miR-770 is transcribed from the intronic sequence of MEG3 and MEG3 may be the host gene for miR-770. However, the biological role of MEG3 and miR-770 in gastric cardia adenocarcinoma (GCA) development and prognosis is poorly defined. The present study was to investigate the function and methylation status of MEG3 in GCA, and further to detect the functional association of miR-770 and its host gene MEG3 in GCA carcinogenesis and prognosis. MEG3 and miR-770 was significantly downregulated in GCA patients and cell lines, and their expression was associated with TNM stage and lymph node metastasis. Overexpression of MEG3 and miR-770 inhibited gastric cancer cell proliferation and invasion in vitro. Furthermore, the expression level of MEG3 and miR-770 was significantly increased in cancer cells after treated with 5-Aza-dC. The aberrant hypermethylation of proximal promoter and enhancer region of MEG3 was detected in GCA tissues. In addition, the proximal promoter and enhancer region hypermethylation and dysregulation of MEG3 and miR-770 were associated with poorer GCA patients' survival. These findings suggest that miR-770 and its host gene MEG3 may play tumor suppressor role and hypermethylation of proximal promoter and enhancer region may be one of the critical mechanisms in inactivation of MEG3 and miR-770 in GCA development. MEG3 and miR-770 may be used as potential biomarkers in predicting GCA patients' prognosis.

Association of genotypes of rs671 withinALDH2 with risk for gastric cardia adenocarcinoma in the Chinese Han population in high- and low-incidence areas.

Objective: This study aimed to determine if gastric cardia adenocarcinoma (GCA) risk was associated with the lys (A or *2) allele at the rs671 (glu504lys) polymorphism within the aldehyde dehydrogenase 2 (ALDH2) gene in a Chinese Han population. We also aimed to investigateALDH2 genotypic distributions between subjects from high- and low-incidence areas for both GCA and esophageal squamous cell carcinoma (ESCC). Methods: We designed a case-control study including 2,686 patients with GCA and 3,675 control subjects from high- and low-incidence areas for both GCA and ESCC in China. TaqMan allele discrimination assay was used to genotype the rs671 polymorphism.χ2 test and binary logistic regression analysis were used to estimate the odds ratios for the development of GCA, and multivariate ordinal logistic regression was used to analyzeALDH2 genotypic distributions among different groups. Results: Compared withALDH2*1/*1 homozygotes,ALDH2*1/*2 andALDH2*2/*2 carriers did not increase the risk for GCA in the Chinese Han population (P>0.05). Interestingly, the ratio of homozygous or heterozygousALDH2 *2 carriers in high-incidence areas for both GCA and ESCC was lower than that in low-incidence areas (P<0.001). Conclusions: Genotypes of rs671 atALDH2 may not increase GCA susceptibility in Chinese Han populations. In addition, theALDH2 genotypic distribution differs between Chinese Han populations from high- and low-incidence areas for both GCA and ESCC. Our findings may shed light on the possible genetic mechanism for the dramatic geographic differences of GCA occurrence in China.

Investigation of Cytotoxic T-lymphocyte antigen 4 Polymorphisms in Gastric Cardia Adenocarcinoma.

To assess the potential effects of Cytotoxic T-lymphocyte antigen 4 (CTLA4) gene polymorphisms on susceptibility to gastric cardia adenocarcinoma (GCA), we genotyped four polymorphisms (rs733618 A>G, rs16840252 C>T, rs231775 G>A and rs3087243 G>A) in CTLA4 and calculated odds ratios (ORs) with the corresponding 95% confidence intervals (95% CIs) for the genotype and allele distributions between GCA cases and controls. The CTLA4 genotypes were determined by the polymerase chain reaction-ligase detection reaction (PCR-LDR) analysis in 330 GCA patients and 608 unrelated cancer-free controls. In this case-control study, there was no significant difference in the genotype and allele distributions of four CTLA4 polymorphisms between GCA patients and controls. However, haplotype association analysis indicated that compared with CTLA4 Grs733618 Crs16840252 Grs231775 Crs3087243 , CTLA4 Grs733618 Crs16840252 Ars231775 Grs3087243 and Ars733618 Crs16840252 Grs231775 Ars3087243 haplotypes conferred increased risks of GCA (OR = 6.46, 95% CI = 1.33-31.28; P = 0.012; both); however, CTLA4 Ars733618 Crs16840252 Ars231775 Grs3087243 and Ars733618 Trs16840252 Grs231775 Grs3087243 haplotypes conferred decreased risks of GCA (P = 0.001 and P = 0.011, respectively). These results highlight that the rare CTLA4 haplotypes may affect the development of GCA in the Chinese population.

RANK rs1805034 T>C Polymorphism Is Associated with Susceptibility to Gastric Cardia Adenocarcinoma in a Chinese Population

Background: Gastric cardia adenocarcinoma (GCA) is a common malignant tumor of the digestive tract with a high incidence in China. Genetic factors such as single nucleotide polymorphisms (SNPs) may contribute to the carcinogenesis of GCA. Methods: We conducted a hospital-based case-control study to evaluate the genetic association of functional SNPs with susceptibility to GCA development. A total of 330 GCA cases and 608 controls were recruited for this study. The SNPs OPG rs3102735 T>C and rs2073618 G>C, RANK rs1805034 T>C, and RANKL rs9533156 T>C and rs2277438 A>G were determined using the ligation detection reaction method. Results: Our findings suggest that RANK rs1805034 T>C is associated with susceptibility to GCA, which is more evident among male patients, elderly patients (≥ 60 years), smokers, and patients who do not consume alcohol. Conclusion: Based on our findings, the functional SNP RANK rs1805034 T>C may be an indicator for individual susceptibility to GCA. However, further larger studies with other ethnic populations and tissue-specific biological characterization are required to confirm the current findings.

Interleukin 17A rs3819024 A>G polymorphism is associated with an increased risk of gastric cardia adenocarcinoma in a Chinese population

Gastric cardia adenocarcinoma (GCA) is one of the most common malignant tumors. In addition to environmental risk factors, genetic factors might play an important role in GCA carcinogenesis. To evaluate the association between polymorphisms in the interleukin 17A (IL17A) gene on the development of GCA, we conducted a hospital-based case–control study. A total of 243 GCA cases and 476 controls were recruited and their genotypes were determined using a custom-by-design 48-Plex SNPscan™ Kit. IL17A rs3819024 A > G polymorphism was found to be associated with the increased risk of GCA. When the IL17A rs3819024 AA homozygote genotype was used as the reference group, the AG genotype was associated with a significantly increased risk of GCA (AG versus AA: adjusted OR = 1.53, 95% CI = 1.05–2.23, p = 0.026). However, there was no significant association between five other SNPs and GCA. Stratified analyses indicated that a significantly increased risk of GCA associated with the IL17A rs3819024 A > G polymorphism was evident among male patients, patients who drank alcohol or those who never smoked. These findings indicated that functional polymorphism IL17A rs3819024 A > G might contribute to GCA susceptibility. Future larger studies with more rigorous study designs are required to confirm the current findings.

Genetic and epigenetic alterations of WWOX in the development of gastric cardia adenocarcinoma

WWOX is a tumor suppressor gene that maps to the common fragile site FRA16D and is involved in carcinogenesis and cancer progression in many different carcinomas. Reduced WWOX expression is associated with more aggressive phenotypes and poor patient outcomes in several cancers. The present study was conducted in order to elucidate more precisely the genetic and epigenetic alterations of WWOX that play a role in gastric cardia adenocarcinoma (GCA) carcinogenesis in a population from Northern China. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), PCR-simple sequence length polymorphism (PCR-SSLP), and methylation specific PCR (MSP) methods were used to characterize polymorphisms in the rs3764340, rs2548861, and rs1079635 loci, the level of loss of heterozygosity (LOH), and methylation status of WWOX, respectively. Protein and mRNA expression of WWOX in GCA tissues was quantified by immunohistochemistry and reverse transcription-PCR (RT-PCR). Family history of upper gastrointestinal cancer (UGIC) significantly increased the risk of developing GCA. The CG+GG genotype of rs3764340 and GT or TT genotype of rs2548861 significantly elevated the risk of developing GCA. LOH at the WWOX locus was observed in 45.6% tumors. The promoter and exon 1 methylation frequency of WWOX in GCA tissues was significantly higher than in corresponding normal tissues and was associated with UGIC family history. Protein and mRNA expression of WWOX was reduced in GCA tumor tissues and was associated with LOH and methylation of the gene. These results indicate that WWOX may play an important role in GCA especially in individuals with UGIC family history.

Smoking and COX-2 Functional Polymorphisms Interact to Increase the Risk of Gastric Cardia Adenocarcinoma in Chinese Population

BackgroundOver-expression and increased activity of cyclooxygenase (COX)-2 induced by smoking has been implicated in the development of cancer. This study aimed to explore the interaction between smoking and functional polymorphisms of COX-2 in modulation of gastric cardia adenocarcinoma (GCA) risk.Methods and FindingsThree COX-2 polymorphisms, including –1195G>A (rs689466), –765G>C (rs20417), and 587Gly>Arg (rs3218625), were genotyped in 357 GCA patients and 985 controls. In the multivariate logistic regression analysis, we found that the –1195AA, –765GC, and 587Arg/Arg genotypes were associated with increased risk of GCA (OR = 1.50, 95% CI = 1.05–2.13; OR = 2.06, 95% CI = 1.29–3.29 and OR = 1.67, 95% CI = 1.04–2.66, respectively). Haplotype association analysis showed that compared with G−1195-G−765- GGly587Arg, the A−1195-C−765-AGly587Arg conferred an increased risk of GCA (OR = 2.49, 95% CI = 1.54–4.01). Moreover, significant multiplicative interactions were observed between smoking and these three polymorphisms of –1195G>A, –765G>C, and 587Gly>Arg, even after correction by false discovery rate (FDR) method for multiple comparisons (FDR-P interaction = 0.006, 5.239×10−4 and 0.017, respectively). Similarly, haplotypes incorporating these three polymorphisms also showed significant interaction with smoking in the development of GCA (P for multiplicative interaction = 2.65×10−6).ConclusionThese findings indicated that the functional polymorphisms of COX-2, in interaction with smoking, may play a substantial role in the development of GCA.

Serum thyroglobulin, a biomarker for iodine deficiency, is not associated with increased risk of upper gastrointestinal cancers in a large Chinese cohort

Iodine concentrates in gastric tissue and may act as an antioxidant for the stomach. We previously showed that self-reported goiter was associated with significantly increased risk of gastric noncardia adenocarcinoma (GNCA) and nonsignificantly increased risks of gastric cardia adenocarcinoma (GCA) and esophageal squamous cell carcinoma (ESCC) in a prospective case-cohort study in a high-risk population in China. Negatively correlated with iodine levels, serum thyroglobulin (Tg) is a more sensitive biomarker of iodine deficiency than goiter. Our study aimed to determine whether baseline serum Tg was also associated with development of GNCA, GCA and ESCC in the same cohort, the Linxian General Population Nutrition Intervention Trial. Sera from ∼200 subjects of each case type and 400 noncases were tested for serum Tg concentration using appropriate assays. Tg was modeled as sex- and assay-specific quartiles in Cox regression models adjusted for age, smoking, alcohol, Helicobacter pylori status, pepsinogens I/II ratio, family history and commune of residence. In the final combined analysis, participants in the highest quartile of serum Tg, compared to those in the lowest quartile, had adjusted hazard ratios of 0.88 (95% confidence interval 0.50-1.52), 1.14 (0.63-2.05) and 0.78 (0.47-1.31) for GNCA, GCA and ESCC, respectively. Using serum Tg, a sensitive biomarker of iodine deficiency, we found no association between serum Tg concentrations and risk of these upper gastrointestinal (UGI) cancers in the study population. Our results do not support the hypothesis that iodine deficiency, as assessed by serum Tg, is associated with an increased risk of UGI cancers.

Aberrant methylation of the CpG island of HLTF gene in gastric cardia adenocarcinoma and dysplasia

Objectives To investigate the promoter methylation of HLTF in the tissues and plasma of patients with gastric cardia adenocarcinoma (GCA) and dysplasia. Design and methods Nested MSP approach was used to detect HLTF methylation status. Results The frequency of HLTF methylation in high grade dysplasia and GCA tumor tissues was significantly higher than that in chronic inflammation tissues and was significantly associated with upper gastrointestinal cancers (UGIC) family history and protein and mRNA expression of the gene. HLTF methylation was not found in the plasma of patients with chronic inflammation and low grade dysplasia, while 4.0% (1/25) of patients with high grade dysplasia and 20.8% of (20/96) GCA patients were detected with hypermethylation of HLTF in the plasma. Conclusions In all, HLTF methylation may exist in gastric cardia dysplasia stages and may play important role in the development of GCA especially in individuals with UGIC family history.

Association of candidate genetic variations with gastric cardia adenocarcinoma in Chinese population: a multiple interaction analysis

Single genetic variation may only have a modest effect on risk of gastric cardia adenocarcinoma (GCA) because this malignancy is believed to result from complex interactions among multiple genetic and environmental factors. However, it has been a challenge to characterize multiple interactions using parametric analytic approaches. This study utilized a multi-analytic strategy combining logistic regression (LR), multifactor dimensionality reduction (MDR) and classification and regression tree (CART) approaches to explore high-order interactions among smoking and 12 polymorphisms involved in different processes of carcinogenesis in 344 GCA patients and 324 controls. LR, MDR and CART analyses consistently suggested MMP-2 C-1306T polymorphism as the strongest individual factor for GCA risk. Intriguingly, a high-order interaction was consistently identified by MDR, LR and CART analyses. In MDR analysis, the three-factor model including MMP-2 C-1306T, FASL T-844C and FAS G-1377A yielded the highest testing accuracy of 0.632. When analysing combined effect of these three polymorphisms by LR, a significant gene dose effect was observed with the odds ratios (ORs) being increased with increasing numbers of risk genotypes (P(trend) = 4.736 × 10⁻¹²). In CART analysis, individuals carrying the combined genotypes of MMP-2 -1306CC, FASL-844TT or TC and FAS -1377AA had the highest risk for GCA (OR = 4.58; 95% confidence interval, 2.07-10.14) compared with the lowest risk carriers of the MMP-2 -1306CT or TT genotype. These results suggest that MMP-2 C-1306T polymorphism is an important risk factor for GCA and the multifactor interactions among polymorphisms in MMP-2, FASL and FAS play more important role in the development of GCA.

Human papillomavirus DNA and P16INK4Aexpression in concurrent esophageal and gastric cardia cancers

To investigate the relationship between human papillomavirus (HPV) infection and concurrent esophagus and gastric cardia cancer from the same patient (CC) and examine the significance of P16(INK4A) protein expression. Polymerase chain reaction was used to detect the presence of HPV type16 (HPV16). The expression of P16(INK4A) protein was detected using immunohistochemistry. Among the CC specimens, HPV16-DNA was found in eight cases of esophageal squamous cell carcinoma (ESCC) and five cases of gastric cardia adenocarcinoma (GCA), respectively (47% vs 29%), and two of both ESCC and GCA. P16(INK4A) was highly expressed in both ESCC and GCA. In the HPV-associated positive CC, higher P16(INK4A) expression was observed in the GCA than in the ESCC (75% vs 25%, P < 0.05). HPV16 as a correlated risk factor may play an important role in the development of ESCC and GCA. P16(INK4A) may be a screening index in the HPV-associated carcinoma of gastric cardia.

Correlation of hypermethylation of TSP1 gene with TGF-beta?1 level and T cell immunity in gastric cardia adenocarcinoma

Thrombospondin-1(TSP1) is an inhibitor of angiogenesis and its promoter hypermethylation has been found resulting in gene silencing in some primary human carcinomas. This study was to investigate the promoter methylation of TSP1 and its correlation with TGF-beta1 level and T cell immunity in gastric cardia adenocarcinoma (GCA). Methylation specific polymerase chain reaction (MSP) approach and immunohistochemistry method were used to examine the methylation status of the 5' CpG island and expression of TSP1 protein, respectively. The level of TGF-beta1 was measured by ELISA and T cell immunity of GCA by flow cytometry analysis. TSP1 methylation frequency was significantly higher in tumor specimens than in corresponding normal tissues (35.4% vs. 3.1%, P<0.001) and significantly higher in Stages III and IV tumor tissues than in Stages I and II tumor tissues (P<0.05). TSP1 protein expression was significantly lower in the tumor tissues than in corresponding normal tissues (P<0.05) and statistically correlated with its methylation status (P<0.01). The total level of TGF-beta1 was significantly higher in the GCA patients than in healthy controls(P<0.05) and significantly higher in Stages III and IV GCA patients than in Stages I and II GCA patients (P<0.05). The level of active TGF-beta1 was significantly higher in the GCA patients with hypermethylation of TSP1 than in the GCA patients without methylation of TSP1(P<0.05), but there was no statistical difference(P>0.05). The function of T cell immunity was significantly different between the GCA patients with hypermethylation of TSP1 and those without methylation of TSP1 (P<0.05). Promoter hypermethylation of TSP1 may play an important role in the development of GCA and reflect the biological behaviours of GCA.

An investigation on the polymorphisms of two DNA repair genes and susceptibility to ESCC and GCA of high-incidence region in northern China

To investigate the possible association of three SNPs, XRCC2 C41657T, XRCC2 G4234C and XRCC3 A17893G with susceptibility to esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA) in a population of northern China. XRCC2 C41657T, XRCC2 G4234C and XRCC3 A17893G SNP were genotyped by polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 583 cancer patients (329 ESCC and 254 GCA) and 614 healthy controls. The genotype distribution of the XRCC2 C41657T in ESCC and GCA patients were significantly different from that in healthy controls (P values = 0.04 and 0.04 respectively). And a significant difference was found in the allele distribution of GCA patients from that in controls (P = 0.01). The XRCC2 C41657T polymorphism was associated with a modest enhancement in ESCC risk and GCA risk: OR for C/T genotype was 1.38 (1.01-1.89) in GCA risk and for T/T genotype was 2.24 (1.10-4.57) in ESCC risk. When stratified for age, smoking status and family history of UGIC, the C/T genotype showed a modest significant trend on the risk of GCA patients in the groups of age < or =50 years and non-smokers, the adjusted OR were 2.84 (1.21-6.66) and 1.62 (1.06-2.49). The T/T genotype significantly increased the susceptibility of GCA patients in negative family history of UGIC (3.04, 1.02-8.32) and to ESCC patients in the group of age >50 years (3.03, 1.31-6.98), Negative family of UGIC (3.03, 1.12-7.07) and smokers (2.64, 1.02-6.83). The genotype and allele distribution of XRCC2 G4234C and XRCC3 A17893G in ESCC and GCA patients were not significantly different from that in healthy controls (all P values were above 0.05). In this study, we found that the C41657T polymorphism of XRCC2 genes might modify the risk of ESCC and GCA development.