Tumor necrosis factor alpha extended haplotypes and risk of gastric carcinoma

Lonicera japonica Thunb. Ethanol Extract Exerts a Protective Effect on Normal Human Gastric Epithelial Cells by Modulating the Activity of Tumor-Necrosis-Factor-α-Induced Inflammatory Cyclooxygenase 2/Prostaglandin E2 and Matrix Metalloproteinase 9

Gastric inflammation-related disorders are commonly observed digestive system illnesses characterized by the activation of proinflammatory cytokines, particularly tumor necrosis factor-α (TNF-α). This results in the induction of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PEG2) and matrix metallopeptidase-9 (MMP-9). These factors contribute to the pathogenesis of gastric inflammation disorders. We examined the preventive effects of Lonicera japonica Thunb. ethanol extract (Lj-EtOH) on gastric inflammation induced by TNF-α in normal human gastric mucosa epithelial cells (GES-1). The GES-1 cell line was used to establish a model that simulated the overexpression of COX-2/PGE2 and MMP-9 proteins induced by TNF-α to examine the anti-inflammatory properties of Lj extracts. The results indicated that Lj-EtOH exhibits significant inhibitory effects on COX-2/PEG2 and MMP-9 activity, attenuates cell migration, and provides protection against TNF-α-induced gastric inflammation. The protective effects of Lj-EtOH are associated with the modulation of COX-2/PEG2 and MMP-9 through the activation of TNFR-ERK 1/2 signaling pathways as well as the involvement of c-Fos and nuclear factor kappa B (NF-κB) signaling pathways. Based on our findings, Lj-EtOH exhibits a preventive effect on human gastric epithelial cells. Consequently, it may represent a novel treatment for the management of gastric inflammation.

Association between serum levels of 12 different cytokines and short-term efficacy of anti-PD-1 monoclonal antibody combined with chemotherapy in advanced gastric cancer

BACKGROUND

Gastric cancer (GC) is characterized by aggressive tumor growth and poor prognosis. The benefits of targeted anti-programmed death receptor 1 (PD-1) monoclonal antibody combined with chemotherapy have not yet been characterized. The tumor microenvironment and circulating factors have garnered interest as possible predictors of response and prognosis. The aim of this study was to evaluate whether cytokine levels in the serum of patients were related to tumor response to anti-PD-1 monoclonal antibody combined with chemotherapy and survival in advanced GC.

MATERIALS AND METHODS

Preoperative serum samples were collected from patients with GC (n = 52) and healthy individuals (n = 31). The levels of 12 different cytokines were measured using a multiple microsphere flow immunofluorescence assay. The association between cytokine levels and clinical response was analyzed using nonparametric Wilcoxon matched-pair ranked tests. Progression-free survival (PFS) time for all patients was recorded via evaluation of imaging results and follow-up via telephone. Kaplan-Meier and log-rank tests were used to plot survival curves.

RESULTS

The levels of interleukin (IL)-6, IL-1β, interferon (IFN)-γ, IL-17, and IL-12p70 in the control group were significantly lower than those in the GC group (p = 0.0002, p = 0.0065, p = 0.0003, p = 0.0303, and p = 0.0295, respectively). The level of IL-4 was significantly higher in healthy individuals than that in patients with GC (p = 0.0201). The cytokine levels in the good responder group were higher than those in the poor responder group before therapy. Patients treated with immunochemotherapy showed an overall reduction in all cytokine levels after treatment initiation. A high baseline level of IFN-γ was associated with a better prognosis. However, high IL-6 levels in patients after two cycles of immunochemotherapy indicated resistance. High IL-4 levels in patients treated with four cycles of immunochemotherapy were associated with better PFS.

CONCLUSIONS

Our study suggests that low levels of IFN-γ before immune checkpoint inhibitor treatment may be useful for the detection of a poor immunological status. Hence, a reduction in IL-6 levels is predictive of a longer PFS, and increased IL-4 levels are predictive of a good response. IL-4 and IL-6 may, therefore, serve as promising circulating predictive biomarkers for patients who can benefit from anti-PD-1 monoclonal antibodies administered in combination with chemotherapy.

Quercetin exerts anti-inflammatory effects via inhibiting tumor necrosis factor-α-induced matrix metalloproteinase-9 expression in normal human gastric epithelial cells

BACKGROUND

Gastric injury is the most common digestive system disease worldwide and involves inflammation, which can lead to gastric ulcer or gastric cancer (GC). Matrix metallopeptidase-9 [MMP-9 (gelatinase-B)] plays an important role in inflammation and GC progression. Quercetin and quercetin-rich diets represent potential food supplements and a source of medications for treating gastric injury given their anti-inflammatory activities. However, the effects and mechanisms of action of quercetin on human chronic gastritis and whether quercetin can relieve symptoms remain unclear.

AIM

To assess whether tumor necrosis factor-α (TNF-α)-induced MMP-9 expression mediates the anti-inflammatory effects of quercetin in normal human gastric mucosal epithelial cells.

METHODS

The normal human gastric mucosa epithelial cell line GES-1 was used to establish a normal human gastric epithelial cell model of TNF-α-induced MMP-9 protein overexpression to evaluate the anti-inflammatory effects of quercetin. The cell counting Kit-8 assay was used to evaluate the effects of varying quercetin doses on cell viability in the normal GES-1 cell line. Cell migration was measured using Transwell assay. The expression of proto-oncogene tyrosine-protein kinase Src (c-Src), phospho (p)-c-Src, extracellular-signal-regulated kinase 2 (ERK2), p-ERK1/2, c-Fos, p-c-Fos, nuclear factor kappa B (NF-κB/p65), and p-p65 and the effects of their inhibitors were examined using Western blot analysis and measurement of luciferase activity. p65 expression was detected by immunofluorescence. MMP-9 mRNA and protein levels were measured by quantitative reverse transcription polymerase chain reaction (qRT–PCR) and gelatin zymography, respectively.

RESULTS

qRT-PCR and gelatin zymography showed that TNF-α induced MMP-9 mRNA and protein expression in a dose- and time-dependent manner. These effects were reduced by the pretreatment of GES-1 cells with quercetin or a TNF-α antagonist (TNFR inhibitor) in a dose- and time-dependent manner. Quercetin and TNF-α antagonists decreased the TNF-α-induced phosphorylation of c-Src, ERK1/2, c-Fos, and p65 in a dose- and time-dependent manner. Quercetin, TNF-α antagonist, PP1, U0126, and tanshinone IIA (TSIIA) reduced TNF-α-induced c-Fos phosphorylation and AP-1–Luciferase (Luc) activity in a dose- and time-dependent manner. Pretreatment with quercetin, TNF-α antagonist, PP1, U0126, or Bay 11-7082 reduced TNF-α-induced p65 phosphorylation and translocation and p65–Luc activity in a dose- and time-dependent manner. TNF-α significantly increased GES-1 cell migration, and these results were reduced by pretreatment with quercetin or a TNF-α antagonist.

CONCLUSION

Quercetin significantly downregulates TNF-α-induced MMP-9 expression in GES-1 cells via the TNFR-c-Src–ERK1/2 and c-Fos or NF-κB pathways.

The Role of Tumor Necrosis Factor-α (TNF-α) Polymorphisms in Gastric Cancer: a Meta-Analysis

PURPOSE

Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine which may play a role in the development of gastric cancer (GC). This study aimed to investigate the association of five TNF-α polymorphisms including TNF-α-857, TNF-α-1031, TNF-α-863, TNF-α-308, and TNF-α-238 polymorphisms with GC risk.

METHODS

All eligible case-control studies were collected by searching PubMed, Scopus, and Web of Science. The association of the risk of GC with TNF-α polymorphisms was estimated using odds ratio (OR) and 95% confidence interval (CI). Heterogeneity was assessed via Cochrane's Q and I² analyses.

RESULTS

A total of 46 publications involving 16, 715 cases with GC and 27, 998 controls were recruited. The study revealed a significant association for TNF-α 308 (recessive model: OR = 0.646, P = 0.035), TNF-α-1031 (homozygote model: OR = 1.584, P = 0.027), and TNF-α-857 (homozygote model: OR = 1.760, P = 0.001) polymorphisms with the GC risk. The results of subgroup analysis based ethnicity found a significant association between GC risk and TNF-α-857 polymorphism in Caucasian subgroup (P = 0.005) and TNF-α-1031 polymorphism and GC risk in Asians (P = 0.018).

CONCLUSIONS

This study suggested that TNF-α-857 and TNF-α-1031 polymorphisms may be associated with the increased gastric cancer risk.

NF-κB in Gastric Cancer Development and Therapy

Gastric cancer is considered one of the most common causes of cancer-related death worldwide and, thus, a major health problem. A variety of environmental factors including physical and chemical noxae, as well as pathogen infections could contribute to the development of gastric cancer. The transcription factor nuclear factor kappa B (NF-κB) and its dysregulation has a major impact on gastric carcinogenesis due to the regulation of cytokines/chemokines, growth factors, anti-apoptotic factors, cell cycle regulators, and metalloproteinases. Changes in NF-κB signaling are directed by genetic alterations in the transcription factors themselves, but also in NF-κB signaling molecules. NF-κB actively participates in the crosstalk of the cells in the tumor micromilieu with divergent effects on the heterogeneous tumor cell and immune cell populations. Thus, the benefits/consequences of therapeutic targeting of NF-κB have to be carefully evaluated. In this review, we address recent knowledge about the mechanisms and consequences of NF-κB dysregulation in gastric cancer development and therapy.

The TNF-A-857*T Polymorphism is Associated with Gastric Adenocarcinoma Risk in a Costa Rican Population

BACKGROUND

Costa Rica is ranked as one of the countries with highest incidence of gastric cancer worldwide. Previous studies in Costa Rican populations have revealed associations between gastric cancer risk and several cytokine polymorphisms that seem to play a role in the regulation of the expression of these proteins. In this study, we assessed associations of the polymorphisms IL-6-174 G/C, IFNGR1-56 C/T, IL-8-251 T/A and TNF-A (-857 C/T, -308 A/G) with gastric pathologies in a high-risk population of Latin America.

METHODS

DNA samples of 47 patients with gastric adenocarcinoma, 53 with chronic gastritis, 56 with duodenal ulcer and 94 healthy controls, were genotyped for the five mentioned SNPs. All participants were ≥50-years-old. Genotyping was performed by PCR-RFLP and 5'-nuclease PCR assay. H. pylori infection, CagA status, pepsinogen (PG) I and II blood levels were determined by ELISA. Logistic regression analysis was used to determine possible associations of the polymorphisms with cancer, gastritis and duodenal ulcer, and linear regression analysis to determine associations with blood PG levels.

RESULTS

A total of 86.6% of the population was positive for H. pylori; of them, 51.6% was CagA+. Patients with the TNF-A-857*T allele had an increased risk for gastritis (OR: 3.67, p = 0.015) and gastric adenocarcinoma (OR:6.15, p = 0.001). Associations between other polymorphisms and gastric diseases, or PG levels, were not found.

CONCLUSIONS

Our results indicate that the TNF-A-857*T SNP is among the risk factors associated with the risk of gastric cancer in Costa Rica.

A meta-analysis of tumor necrosis factor-α-308 G>A polymorphism in gastric cancer

Background

Gastric cancer (GC) is the common cause of cancer-related deaths worldwide and inflammation represents the early phases in the GC.

Objective

To review the tumor necrosis factor (TNF)-α-308 G>A (GG, GA, and AA) in GC by meta-analysis studies for any differences in TNF-α-308 G>A gene polymorphisms.

Methods

Case–control studies published from 2003 to 2017 were identified by searching PubMed, EMASE, and the Internet with the English language. The analysis published on TNF-α-308 G>A polymorphism was analyzed and a limited number of articles were included in the present study. TNF-α-308 G>A from 4,157 patients and 5,185 healthy controls was evaluated. Studies were evaluated using Cochrane Q-test and publication bias was evaluated by constructing funnel plots.

Results

Overall, TNF-α-308 GA genotype showed significant association [P < 0.0001, odds ratio (OR), 95% confidence interval (CI) = 0.82 (0.74–0.91)]. However, meta-analysis of TNF-α-308 genotypes (GG, GA, AA, and GA + AA) between GC patients and controls showed nonsignificant association with GC [P > 0.05, recessive model: OR = 1.38, 95% CI: 1.15–1.66; dominant model: OR = 1.23, 95% CI: 1.09–1.39; (G/A) vs. (G/G): OR = 1.15, 95% CI: 1.02–1.28; (A/A) vs. (G/G): OR = 1.44, 95% CI: 1.19–1.73]. Analysis stratified by ethnicity showed same results in Asian and Caucasian populations.

Conclusions

Results revealed nonsignificant association of TNF-α-308 genotypes (GG, GA, AA, and GA + AA) and GC. TNF-α-308GA genotype showed significant association whereas homozygous genotype AA did not show association with GC risk.

LncRNA GASL1 inhibits tumor growth in gastric carcinoma by inactivating the Wnt/β-catenin signaling pathway

Growth arrest associated lncRNA 1 (GASL1) is a newly discovered tumor suppressor long non-coding RNA (lncRNA) in osteosarcoma; however its role in other malignancies remains unknown. The aim of the present study was to investigate the involvement of GASL1 in gastric cancer. In the current study, gastric cancer tissue and adjacent healthy tissue samples were collected from patients with gastric carcinoma, and blood samples were collected from patients with gastric carcinoma and healthy controls to detect the expression of serum GASL1. All patients were followed up for 5 years and the diagnostic and prognostic value of GASL1 for gastric carcinoma was evaluated by ROC and survival curve analyses, respectively. The chi-square test was used to analyze the correlation between serum levels of GASL1 and the clinicopathological features of patients with gastric carcinoma. A GASL1 expression vector and GASL1 small interfering RNA were transfected into gastric cancer cell lines and the effects on β-catenin expression and cell proliferation were examined by western blot and cell proliferation assays, respectively. The expression level of lncRNA GASL1 was significantly downregulated in gastric cancer tissues compared with adjacent normal tissues from patients with gastric carcinoma. In addition, serum levels of GASL1 were significantly decreased in patients with gastric carcinoma when compared with healthy controls. Serum GASL1 levels distinguished patients with gastric carcinoma from healthy controls, and low expression levels of GASL1 were associated with decreased postoperative survival time. GASL1 overexpression downregulated, while GASL1 knockdown upregulated β-catenin expression. GASL1 overexpression inhibited, and GASL1 knockdown promoted gastric cancer cell proliferation. In addition, treatment with a Wnt agonist demonstrated no significant effect on GASL1 expression, however the inhibitory effect of GASL1 overexpression on cell proliferation was reduced following treatment with the Wnt agonist. In conclusion, the GASL1 lncRNA may inhibit tumor growth in patients with gastric carcinoma by inactivating the Wnt/β-catenin signaling pathway.

Function of tumor necrosis factor alpha before and after mutation in gastric cancer

Purpose

To explore the cause of functional changes of tumor necrosis factor alpha (TNF-α) in development of gastric cancer through the structural changes of each site in TNF-α before and after mutation.

Methods

Three typical mutant sites (TNF-α-308G/A, 857C/T and 863C/A of TNF-α) were chosen and methods like ab initio modeling was adopted for 3D modeling of TNF-α before and after mutation, besides, the structural changes were also analyzed.

Results

Mutation of TNF-α-308G/A led to the production of multiple helical structures and that of 863C/A caused the production of one helical structure in its adjacent region. Mutation of 857C/T, however, did not cause the change in the basic structure of TNF-α.

Conclusions

Structural changes of TNF-α may have a significant effect on development of gastric cancer.

The relationship between tumor necrosis factor-α polymorphisms and gastric cancer risk: An updated meta-analysis

The aim of the present study was to evaluate the relationship between tumor necrosis factor-α (TNF-α) and the development of gastric cancer, and to investigate whether it can be used as a biological marker for gastric cancer. In the current study, a new meta-analysis was performed to assess the association between TNF-α gene polymorphisms and gastric cancer susceptibility. Subgroup analyses based on ethnicity, control population source and non-cardia cancers were also conducted. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. TNF-α 308 polymorphisms indicated a significant relationship with gastric cancer risk among a normal population [GA/AA vs. GG; 1.17 (1.10–1.23)]. In analysis stratified by ethnicity, TNF-α 238 displayed an association with gastric cancer risk in eastern populations [GA/AA vs. GG: 1.24 (1.02–1.50)], but not in western populations [GA/AA vs. GG: 0.96 (0.79–1.18)]. The overall ORs (95% CIs) for TNF-α 857, TNF-α 1031 and TNF-α 863 were 1.13 (1.04–1.24), 0.94 (0.85–1.05) and 0.89 (0.78–1.02), respectively, under dominant genetic model comparison. Among the above three SNPs, only TNF-α 857 was robustly associated with gastric cancer inclination, and this association remained consistently robust when limited to non-cardia gastric cancers [GA/AA vs. GG: 1.16 (1.03–1.31)]. TNF-α 308 and TNF-α 857 genotypes were potential risk factors of statistical significance in gastric cancer, and TNF-α 238 indicated to be significantly associated with gastric cancer risk only in eastern populations. TNF-α 1031 and TNF-α 863 were not significantly associated with gastric cancer risk.

Lack of association among TNF-α gene expression, -308 polymorphism (G > A) and virulence markers of Helicobacter pylori

Background

Tumor necrosis factor plays a critical role in the pathogenesis of gastric diseases such as gastric cancer, and an abnormal inflammatory response has frequently been observed in dyspeptic patients. Helicobacter pylori infection can induce a gastric mucosal inflammatory response that may be influenced by -308 (G > A) polymorphisms and gene expression of the TNF-α gene.

Methods

One hundred and thirty-four gastric biopsy samples were collected from patients of both genders (61♂ and 73♀, mean age 40.3 ± 24.2 years) with gastric symptoms. The -308 (G > A) polymorphism of TNF-α was characterized using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The expression level was measured using real-time PCR, and relative quantification (RQ) was calculated using the comparative CT method (2^-ΔΔCT).

Results

The analysis revealed an increase in TNF-α gene expression in patients with gastritis; on the other hand, no statistical differences were observed in patients with gastric cancer. In addition, no association was found among -308 polymorphism genotypes, virulence markers, or TNF-α gene expression.

Conclusions

Helicobacter pylori induces a large increase in TNF-α expression in patients with gastritis, regardless of tissue inflammation, but after the tissue becomes neoplastic, the presence of bacteria did not influence expression. These results suggest that the TNF-α pathway may play an important role in the progression from gastritis to gastric cancer

Association between hepatocellular carcinoma and tumor necrosis factor alpha polymorphisms in South Korea

AIM: To investigate associations between the tumor necrosis factor alpha (TNF-α) -1031 T>C, -863 C>A, -857 C>T, -308 G>A, and -238 G>A polymorphisms and HCC in Korea.

METHODS: Hepatocellular carcinoma (HCC) cases were diagnosed at CHA Bundang Medical Center from June 1996 to August 2008. The association between TNF-α polymorphisms and HCC was analyzed in 157 HCC patients and 201 controls using a polymerase chain reaction-restriction fragment length polymorphism assay. We investigated five TNF-α polymorphisms, which are TNF-α -1031 T>C, -863 C>A, -857 C>T, -308 G>A, and -238 G>A. The TNF-α genotype frequencies, genotype combinations and haplotypes were analyzed to disclose the association with HCC.

RESULTS: None of the TNF-α polymorphisms was significantly associated with HCC. However, nine genotype combinations had associations with increased likelihood of HCC. Among them, TNF-α -1031/-857/-238 TT/CC/GA (AOR = 18.849, 95%CI: 2.203-161.246, P = 0.007), TNF-α -1031/-308/-238 TT/GG/GA (AOR = 26.956, 95%CI: 3.071-236.584, P = 0.003), and TNF-α -1031/-238 TT/GA (AOR = 21.576, 95%CI: 2.581-180.394, P = 0.005) showed marked association with HCC. There were five haplotypes of TNF-α polymorphisms which were significantly associated with HCC. They are TNF-α -1031/-863/-857/-308/-238 T-C-C-G-A (OR = 25.824, 95%CI: 1.491-447.223, P = 0.0005), TNF-α -1031/-857/-308/-238 T-C-G-A (OR = 12.059, 95%CI: 2.747-52.950, P < 0.0001), TNF-α -1031/-857/-238 T-C-A (OR = 10.696, 95%CI: 2.428-47.110, P = 0.0001), TNF-α -1031/-308/-238 T-G-A (OR = 7.556, 95%CI: 2.173-26.280, P = 0.0002) and TNF-α -1031/-238 T-A (OR = 10.865, 95%CI: 2.473-47.740, P = 0.0001). Moreover, HCC Okuda stage III cases with the TNF-α -1031 CC genotype had better survival than those with the TT genotype (AOR = 5.795, 95%CI: 1.145-29.323).

CONCLUSION: Although no single TNF-α polymorphism is associated with HCC in this study, some TNF-α genotype combinations and haplotypes are associated with HCC. In addition, HCC Okuda stage III cases with the TNF-α -1031 TT genotype may have a better prognosis than those with the CC genotype.

Polymorphisms of Tumor Necrosis Factor Alpha in Moroccan Patients with Gastric Pathology: New Single-Nucleotide Polymorphisms in TNF-α(-193) (G/A)

Polymorphisms in tumor necrosis factor alpha (TNF-α) gene are emerging as key determinants of gastric diseases. The TNF-α⁻³⁰⁸ (G/A) and TNF-α⁻²³⁸ (G/A) single-nucleotide polymorphisms SNPs are the most extensively studied. However, all these studies are conducted in Caucasian and Asian populations. Thus, for the first time in Africa, we sought to investigate whether polymorphisms in TNF-α gene were associated with the development of gastric pathology in Morocco. Two SNPs located in the promoter region (positions −308 and −238) in TNF-α gene were genotyped in 244 individuals (170 patients and 74 healthy controls). Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using logistic regression analysis. The TNF-α⁻²³⁸ (G/A) genotype was significantly associated with a high risk of gastritis and gastric cancer (GC) (P = 0.001 and P = 0.002, resp.). Furthermore, a new polymorphism located in the promoter region at position −193 in TNF-α gene was identified. The distribution of this SNP was markedly different in patients suffering from ulcers. The association between TNF-α⁻¹⁹³ (G/A) genotype and high risk of ulcer was significant (P = 0.03). These results suggest that the TNF-α⁻¹⁹³ (G/A) allele has a protective function against gastric cancer by developing ulcer.

Investigation of -308G>A and -1031T>C polymorphisms in the TNFA promoter region in Polish peptic ulcer patients

BACKGROUND/AIMS

Tumor necrosis factor α (TNF-α) encoded by TNFA is a key mediator in inflammation, a precursor condition for peptic ulceration. Promoter polymorphisms of TNFA that influence its transcriptional activity and TNF-α production are known. TNFA-308G>A (rs1800629) and TNFA-1031T>C (rs1799964), which are responsible for increased TNFA transcription, could influence the risk of peptic ulceration. This study aimed to investigate these polymorphisms and to evaluate their association with peptic ulcer disease and Helicobacter pylori infection in the Polish population.

METHODS

Gastric mucosa specimens obtained from 177 Polish peptic ulcer patients were used to conduct rapid urease tests and to assess the investigated polymorphisms by polymerase chain reaction-restriction fragment length polymorphism. Genotyping data were compared with the results obtained from healthy individuals of Polish origin.

RESULTS

There were no significant differences in genotype and allele frequency of the investigated polymorphisms between peptic ulcer patients and healthy individuals. No associations between the frequencies of particular genotypes and alleles for both single-nucleotide polymorphisms (SNPs) and the presence of H. pylori infection in peptic ulcer patients and in subgroups of men and women with peptic ulcer disease were found.

CONCLUSIONS

The investigated SNPs are not risk factors for either peptic ulcer or H. pylori infection development in the Polish population. The results require verification in a larger cohort.

Screening of susceptibility genes and multi-gene risk analysis in gastric cancer

The aim of the study was to explore the relations between the genetic polymorphism and the susceptibility to the gastric cancer in Chinese Han population, and to analyze the multi-genes risk in the development of gastric carcinoma. A case-control study of 1:1 matching was performed on 564 individuals with primary gastric carcinoma in Nanjing, China. The genotypes of CYP2E1, GSTMl, GSTTl, NAT2, ALDH2, MTHFR, XRCCl, IL-1β, VDR, and TNF were detected by molecular biological techniques (PCR-RFLP and AS-PCR). Sole gene and gene-gene interactions were analyzed using Logistic regression model. The effect of multi-genes on gastric carcinoma was analyzed using multi-gene risk analysis model, which focused on the effect of multi-gene interaction on the development of gastric carcinoma. The genotypes involved in the susceptibility of gastric carcinoma were CYP2E1(c1/c1), NAT2M1(T/T), NAT2M2(A/A), XRCC1194(T/T), NAT2 phenotype (slow acetylator), MTHFR1298(A/C), and VDR TaqI(T/T), respectively. Multi-gene risk analysis model was introduced to analyze the effect of these genes on the gastric carcinoma. The results showed that there was a strong relation between odds ratio (OR) value of polygene combination and the gene frequency. With the increase of susceptibility gene frequency, the risk distribution curve of gastric carcinoma would shift to a more dangerous phase and exhibit a quantitative relation. Our results demonstrated that the OR of each gene can be utilized as an index to assess the effect of multiple susceptible genes on the occurrence of gastric carcinoma.

Association between TNF-α-308 G/A gene polymorphism and gastric cancer risk: a systematic review and meta-analysis

OBJECTIVE

Tumor necrosis factor-alpha (TNF-α) has been found to be associated with gastric carcinogenesis, but individually published results have been inconclusive. The aim of this study was to explore the relationship between the TNF-α-308 G/A polymorphism and gastric cancer risk.

METHODS

MEDLINE, EMBASE and the COCHRANE library databases were searched for relevant articles to identify all available data. The odds ratios (ORs) with 95% confidence intervals (95% CIs) from each study were used to assess the association between the TNF-α-308 G/A polymorphism and gastric cancer risk.

RESULTS

This meta-analysis included 30 studies (32 datasets) involving 7009 gastric cancer cases and 12,119 control subjects. Overall, a significant association was found between the TNF-α-308 G/A polymorphism and gastric cancer in AA+GA vs. GG (dominant contrast model) (OR=1.20, 95% CI=1.07-1.34, p=0.001). With stratification based on ethnicity, the TNF-α-308 G/A polymorphism was correlated with gastric cancer risk in Caucasians, using the dominant contrast model (OR=0.74, 95% CI=0.57-0.96, p=0.02), but not in East Asians and other ethnic groups. In the comprehensive subgroup analysis, a significant association was also found in recent articles (published after 2005), population-based high-quality studies, hospital-based high-quality studies, studies using the TaqMan method and non-cardia subgroups. However, the TNF-α-308 G/A polymorphism was not associated with specific histological types of gastric cancer risk.

CONCLUSIONS

The TNF-α-308 G/A polymorphism may contribute to susceptibility to gastric cancer in Caucasians, especially for non-cardia gastric cancer, as most strongly demonstrated in high-quality studies and in studies using the TaqMan genotyping method. Furthermore, we recommend the TaqMan method as the preferred genotyping method in DNA polymorphism studies.

TNF-α-308 polymorphism and risk of digestive system cancers: A meta-analysis

AIM: To evaluate the association between the tumour necrosis factor alpha-308 (TNF-α-308) gene polymorphism and the risk of digestive system cancers.

METHODS: All eligible case-control studies published up to December 2012 were identified by searching PubMed, Web of Science, Embase and China National Knowledge Internet without language restrictions. The risk of digestive system cancers associated with the TNF-α-308 polymorphism was estimated for each study using odds ratio (OR) together with its 95%CI, respectively. Cochrane Collaboration RevMan 5.1 was used to perform the analysis. A χ²-test-based Q statistic test and an I² test were performed to assess the between-study heterogeneity. When the Q test was significant (P < 0.05) or I² > 50%, the random effects model was used, otherwise the fixed effects model was used.

RESULTS: Fifty-eight studies from fifty-five publications with a total of 9986 cancer patients and 15511 healthy controls were included. Overall, a significant association was found between the TNF-α-308 polymorphism and the risk of digestive system cancers [dominant model: OR = 1.23, 95%CI: 1.09-1.39, (G/A) vs (G/G): OR = 1.15, 95%CI: 1.02-1.28, (A/A) vs (G/G): OR = 1.44, 95%CI: 1.19-1.73, recessive model: OR = 1.38, 95%CI: 1.15-1.66]. Furthermore, when the analysis was stratified by ethnicity, similar results were observed in both the Asian and Caucasian populations, except for the dominant model and heterozygote comparisons in the Asian population [dominant model: OR = 1.24, 95%CI: 0.99-1.56, (G/A) vs (G/G): OR = 1.09, 95%CI: 0.96-1.24]. When the cancer type subgroups were examined, similar results were detected in gastric and hepatocellular carcinomas; however, no significant association was observed among other digestive system cancers.

CONCLUSION: The TNF-α-308 gene polymorphism may be significantly associated with the risk of gastric and hepatocellular carcinomas, but not colorectal, pancreatic, or oesophageal cancer, in the Asian population.

Association between tumor necrosis factor-α rs1800629 polymorphism and risk of gastric cancer: a meta-analysis

Gastric cancer is mainly initiated by inflammation and chronic superficial gastritis, and tumor necrosis factor-α (TNF-α) is an inflammatory cytokine which plays an important role in the inflammation. TNF-α rs1800629 G/A polymorphism was proposed to be associated with gastric cancer risk, but previous studies on Caucasians reported conflicting results. We performed a meta-analysis to comprehensively assess the association between TNF-α rs1800629 polymorphism and gastric cancer risk in Caucasians. The pooled odds ratio (OR) with 95% confidence interval (95% CI) was calculated to assess the association. Eleven case-control studies with 7,427 subjects were finally included into the meta-analysis. Overall, TNF-α rs1800629 polymorphism was significantly associated with the increased risk of gastric cancer under four genetic comparison models (A versus G: OR = 1.32, 95% CI 1.12-1.56, P = 0.001; AA versus GG: OR = 1.76, 95% CI 1.37-2.26, P < 0.001; AA versus GG/GA: OR = 1.62, 95% CI 1.27-2.07, P < 0.001; AA/GA versus GG: OR = 1.35, 95% CI 1.14-1.60, P = 0.001). Meta-analysis of those studies with high quality showed that TNF-α rs1800629 polymorphism was still significantly associated with the increased risk of gastric cancer under four genetic comparison models. There was no risk of publication bias in the meta-analysis. The meta-analysis suggests that TNF-α rs1800629 polymorphism is associated with the increased risk of gastric cancer in Caucasians.

Interleukin-4 receptor -3223T&#8594;C polymorphism is associated with increased gastric adenocarcinoma risk

BACKGROUND

Gastric cancer remains one of the most common types of cancer worldwide, with a large geographical variation in incidence and mortality rates. Cytokine polymorphisms are the most studied host polymorphisms and are associated with an increased risk of stomach cancer in many regions, but have not been studied extensively in Eastern European populations.

OBJECTIVE

To investigate the potential association between five cytokine promoter polymorphisms (interleukin [IL] 1b -511C→T [rs16944], IL-4 receptor [IL-4R] -3223C→T [rs2057768], IL-8 -251T→A [rs4073], IL-10 -1082A→G [rs1800896] and tumour necrosis factor-alpha -308G→A [rs1800629]) and susceptibility to gastric adenocarcinoma in a Romanian population.

METHODS

A total of 347 subjects, consisting of 105 patients with gastric adenocarcinoma and 242 controls, were included. All cytokine polymorphisms were genotyped using allele-specific, commercially available probes. Hardy-Weinberg equilibrium in both groups was analyzed using the chi squared&nbsp;test, and the relationship between targeted polymorphisms and the risk of gastric cancer was estimated using OR and 95% CI.

RESULTS

A significant association between the IL-4R -3223C→T polymorphism and risk of gastric cancer was found. Carriers of the IL-4R -3223TT genotype were at a 2.5-fold increased risk for gastric cancer (OR 2.51 [95% CI 1.08 to 5.84]; P=0.041). Moreover, the presence of the IL-4R -3223TT genotype was associated with an increased risk of noncardia gastric adenocarcinoma (OR 3.08 [95% CI 1.25 to 7.58]; P=0.023). No associations were found among the other polymorphisms.

CONCLUSION

The results suggest that the IL-4R -3223C→T polymorphism may increase the risk of gastric adenocarcinoma, mainly for the noncardia type, in the Romanian population.

Effect of PSCA gene polymorphisms on gastric cancer risk and survival prediction: A meta-analysis

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.

Gastric cancer: basic aspects

Gastric cancer (GC) is a world health burden, ranging as the second cause of cancer death worldwide. Etiologically, GC arises not only from the combined effects of environmental factors and susceptible genetic variants but also from the accumulation of genetic and epigenetic alterations. In the last years, molecular oncobiology studies brought to light a number of genes that are implicated in gastric carcinogenesis. This review is intended to focus on the recently described basic aspects that play key roles in the process of gastric carcinogenesis. Genetic variants of the genes IL-10, IL-17, MUC1, MUC6, DNMT3B, SMAD4, and SERPINE1 have been reported to modify the risk of developing GC. Several genes have been newly associated with gastric carcinogenesis, both through oncogenic activation (GSK3β, CD133, DSC2, P-Cadherin, CDH17, CD168, CD44, metalloproteinases MMP7 and MMP11, and a subset of miRNAs) and through tumor suppressor gene inactivation mechanisms (TFF1, PDX1, BCL2L10, XRCC, psiTPTE-HERV, HAI-2, GRIK2, and RUNX3). It also addressed the role of the inflammatory mediator cyclooxygenase-2 (COX-2) in the process of gastric carcinogenesis and its importance as a potential molecular target for therapy.

Genetic and epigenetic alteration in gastric carcinogenesis

Gastric cancer (GC) is an important cause of morbidity and mortality worldwide. In addition to environmental factors, genetic factors also play an important role in GC etiology, as demonstrated by the fact that only a small proportion of individuals exposed to the known environmental risk factors develop GC. Molecular studies have provided evidence that GC arises not only from the combined effects of environmental factors and susceptible genetic variants but also from the accumulation of genetic and epigenetic alterations that play crucial roles in the process of cellular immortalization and tumorigenesis. This review is intended to focus on the recently described basic aspects that play key roles in the process of gastric carcinogenesis. Genetic variation in the genes DNMT3A, PSCA, VEGF, and XRCC1 has been reported to modify the risk of developing gastric carcinoma. Several genes have been newly associated with gastric carcinogenesis, both through oncogenic activation (MYC, SEMA5A, BCL2L12, RBP2 and BUBR1) and tumor suppressor gene inactivation mechanisms (KLF6, RELN, PTCH1A, CLDN11, and SFRP5). At the level of gastric carcinoma treatment, the HER-2 tyrosine kinase receptor has been demonstrated to be a molecular target of therapy.

Basic aspects of gastric cancer

Gastric cancer is a worldwide health burden, which is still the second most common cause of cancer related deaths with little improvement of long-term survival during the past decades. Understanding the molecular nature of this disease and its precursor lesions has been under intense investigation and our review attempts to highlight recent progress in this field of cancer research. First, host-related genetic susceptibility is dealt with genes involved in inflammation and carcinogen metabolism. Next, role of overexpression of a proinflammatory cytokine (interleukin-1beta) and deletion of a cell-cell adhesion molecule (E-cadherin) are described in experimental mouse models of gastric carcinogenesis. Finally, the role of stem cells in gastric cancer is covered.

Helicobacter pylori infection, host genetics and gastric cancer

Helicobacter pylori infects half the world's population and is responsible for a considerable global health burden, including peptic ulcer disease and gastric cancer. The infection causes a chronic gastritis, the severity and distribution of which determine the clinical outcome. Bacterial, environmental and host genetic factors combine to define the degree of gastric damage. Most patients have a limited mild pan-gastritis with no significant clinical consequences. Antral-predominant gastritis is associated with high gastric acid output and an increased risk of duodenal ulcers. Corpus-predominant gastritis is associated with a reduction in gastric acid, multifocal gastric atrophy and an increased risk of gastric cancer. Host genetic factors are particularly important in defining the severity and extent of Helicobacter-induced gastritis. The most relevant and consistent genetic factors uncovered thus far are in the interleukin-1 and tumor necrosis factor-A gene clusters. These cytokines appear to play a key role in the pathophysiology of gastric cancer and their roles have been confirmed in animal models that mimic human gastric neoplasia. More genetic factors have also been uncovered and, with advancing technology, there is every prospect of defining a full genetic risk profile in the next decade. This will aid in targeting the testing and treatment of Helicobacter pylori, which offers a true opportunity to prevent and defeat this global killer.

Analysis and estimates of the attributable risk for environmental and genetic risk factors in gastric cancer in a Chinese population

Development of gastric cancer is a multistage, multifactorial process. This study determined the population attributable risk for environmental and genetic risk factors in development of gastric cancer. A 1:1 cancer case-control study was undertaken in Nanjing, Jiangsu Province, China. A conditional-logistic regression model was used to determine environmental and genetic risk factors and calculate attributable risk (AR%) for each environmental and genetic risk factor in gastric cancer. In addition, the summary attributable risk (sAR) for all of the risk factors among 503 cases of gastric cancer patients and controls was determined. The environmental risk factors for gastric cancer in the Nanjing area were family history of tumor, consumption of pickled food, engorgement after hunger, irregular dietary habits, and lack of fruit intake. The genetic risk factors included the following genotypes: CYP2E1 wild, NAT2 M1 mutation, NAT2 slow-acetylators, XRCC1 194 mutation, MTHFR A1298C mutation, and IL-1B mutation. Combining environmental and genetic risk factors, sAR was 76.34%. Data suggest that genetic polymorphisms and environmental risk factors play concurrent roles in the development of gastric cancer. The results of this study indicate preventive strategies to avoid development of gastric cancer based on identified genetic polymorphisms and control of environmental risk factors.