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

SPI1 Mediates N-Myristoyltransferase 1 to Advance Gastric Cancer Progression via PI3K/AKT/mTOR Pathway

Gastric cancer (GC) is a common digestive tract malignancy worldwide. N-myristoyltransferase 1 (NMT1) has been implicated in many cancers, but its association with gastric cancer remains to be clarified. Thus, this paper elucidated the role of NMT1 in GC. The NMT1 expression level in GC and normal tissue samples as well as the relationship between NMT1 high or low expression and overall survival in GC was analyzed via GEPIA. GC cells were transfected with NMT1 or SPI1 overexpression plasmid and short hairpin RNA against NMT1 (shNMT1) or shSPI1. NMT1, SPI1, p-PI3K, PI3K, p-AKT, AKT, p-mTOR, and mTOR levels were detected through qRT-PCR and western blot. MTT, wound healing, and transwell assays were applied to test cell viability, migration, and invasion. The binding relationship of SPI1 and NMT1 was determined through a dual-luciferase reporter assay and chromatin immunoprecipitation. NMT1 was upregulated in GC, the high level of which connected with a poor prognosis. Overexpressed NMT1 elevated viability, migration rate, and invasion rate of GC cells, whereas NMT1 knockdown leads to the opposite results. Besides, SPI1 could bind to NMT1. Overexpressed NMT1 reversed the effects of shSPI1 on decreasing viability, migration, invasion, p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR in GC cells, and NMT1 knockdown reversed the effects of SPI1 overexpression on increasing viability, migration, invasion, p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR. SPI1 upregulated NMT1 to facilitate the malignant behaviors of GC cells through the PI3K/AKT/mTOR pathway.

Evaluation of Tumor Necrosis Factor-Alpha Gene (−308 G/A, −238 G/A and −857 C/T) Polymorphisms and the Risk of Gastric Cancer in Eastern Indian Population

Introduction: Gastric cancer (GC) is one of the leading causes of cancer-related decimations worldwide. The gastric infection at both the stomach and duodenum with Helicobacter pylori causes inflammation by the tumor necrosis factor-alpha (TNF-α). The aim of the study was to associate and evaluate the three TNF-α gene polymorphisms at positions −308 G/A, −238 G/A, and −857 C/T with the risk of GC. Methods: A total of 156 individuals (consecutively diagnosed 95 GC patients and 61 controls) above the age of 18 years were enrolled in the study. Healthy individuals with normal upper gastrointestinal endoscopy (UGIE) irrespective of their family history of GC or peptic ulcer were included as controls. The cited three TNF-α gene polymorphisms were evaluated using polymerase chain reaction-restriction fragment length polymorphism (RFLP). Results: There was no significant difference in the distribution of gene polymorphisms as genetic factors, TNF-α−308 GA/AA (22.1% vs. 14.8%, p = 0.2), TNF-α−238 GA/AA (21% vs. 19.6%, p = 0.8), and TNF-α−857 CT/TT (8.4% vs. 11.5%, p = 0.5), between GC cases and healthy controls. A subgroup analysis of H. pylori-positive patients showed that there was no significant difference in the distribution of GA/AA polymorphisms in TNF-α−308 (15(45.5%) vs. 3(23%); p = 0.17) and −238 (12(36.3%) vs. 2(15.4%); p = 0.17), and the distribution of TT/CT −857 CT/TT (13(39.4%) vs. 2(15.4%); p = 0.13), among the GC cases and controls. Conclusion: The statistical comparisons of GA/AA vs. GG genotypes at −308 (with OR = 1.6, 95% CI: 0.6–3.8), −238 (OR = 1.09, 95% CI: 0.4–2.4) and TT/CT vs. CC genotypes at −857 (OR = 0.7, 95% CI: 0.2–2.1) did not suggest any association of TNF-α with GC in the population herein. Hence, the TNF-α (−308 G/A, −238 G/A and −857 C/T) may not be the associating factor for GC incidence determined by the PCR–RFLP method.

Peptic Ulcer and Gastric Cancer: Is It All in the Complex Host-Microbiome Interplay That Is Encoded in the Genomes of "Us" and "Them"?

It is increasingly being recognized that severe gastroduodenal diseases such as peptic ulcer and gastric cancer are not just the outcomes of Helicobacter pylori infection in the stomach. Rather, both diseases develop and progress due to the perfect storms created by a combination of multiple factors such as the expression of different H. pylori virulence proteins, consequent human immune responses, and dysbiosis in gastrointestinal microbiomes. In this mini review, we have discussed how the genomes of H. pylori and other gastrointestinal microbes as well as the genomes of different human populations encode complex and variable virulome–immunome interplay, which influences gastroduodenal health. The heterogeneities that are encrypted in the genomes of different human populations and in the genomes of their respective resident microbes partly explain the inconsistencies in clinical outcomes among the H. pylori-infected people.

Peripheral Cytokine Levels as a Prognostic Indicator in Gastric Cancer: A Review of Existing Literature

Although strong connections exist between the carcinogenesis of gastric cancer and chronic inflammation, gastric cancer is unique in that the chronic gastritis which frequently precedes carcinogenesis is strongly associated with H. pylori infection. The interplay between H. pylori virulence factors and host immune cells is complex but culminates in the activation of inflammatory pathways and transcription factors such as NF-κB, STAT3, and AP-1, all of which upregulate cytokine production. Due to the key role of cytokines in modulating the immune response against tumour cells as well as possibly stimulating tumour growth and proliferation, different patterns of cytokine secretion may be associated with varying patient outcomes. In relation to gastric cancer, interleukin-6, 8, 10, 17A, TNF, and IFN-γ may have pro-tumour properties, although interleukin-10, TNF, and IFN-γ may have anti-tumour effects. However, due to the lack of studies investigating patient outcomes, only a link between higher interleukin-6 levels and poorer prognosis has been demonstrated. Further investigations which link peripheral cytokine levels to patient prognosis may elucidate important pathological mechanisms in gastric cancer which adversely impact patient survival and allow treatments targeting these processes to be developed.

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.

Cytokine TGF-β1, TNF-α, IFN-γ and IL-6 Gene Polymorphisms and Localization of Premalignant Gastric Lesions in Immunohistochemically H. pylori-negative Patients

Background: Cytokines and their gene variants are proven to play a role in pathogenic gastritis and carcinogenesis. The study assesses associations of the cytokine gene polymorphisms with extension of atrophic gastritis/intestinal metaplasia (AGIM) in patients without Helicobacter pylori infection on immunohistochemistry study. Methods: 224 adult consecutive patients undergoing an upper digestive endoscopy were included and grouped according to localization of AGIM: 37 patients with antrum-limited AGIM, 21 corpus-limited AGIM, 15 extended-AGIM (antrum and corpus) and 151 patients had no AGIM. Medical records of the patients were checked and a structured direct interview was applied in order to collect clinical data, including digestive symptoms. In all cases, IFN-γ +874T>A, TGF-β1 +869T>C, TNF-α-308G>A and -238G>A, and IL-6 -174C>G polymorphisms were genotyped. Results: The mean age was significantly higher in the AGIM group, while the comorbidies were similar among patients with different localization of lesions or in patients without AGIM. There were no significant differences in digestive symptoms, nor in the consumption of non-steroidal anti-inflammatory drugs or proton pump inhibitor with the different extensions of AGIM. There was a significant association between oral anticoagulant consumption and localization of AGIM (P = 0.042), frequency being higher among patients with corpus-limited AGIM than those with no AGIM (P = 0.007, adjusted P = 0.041). TGF-β1 +869T>C was less frequent among patients with corpus-limited AGIM (n=7, 33.3%) and extended AGIM (n=5, 33.3%) than in antrum-limited AGIM (n=25, 67.6%). There were no other significant differences regarding variant and wild genotype frequencies of IFN-γ +874T>A (86.5%, 81.0%, 86.7%, p=0.814), TNF-α-308G>A (35.1%, 28.6%, 53.3%, p=0.48) and IL-6 -174C>G (70.3%. 61.9%, 73.3% p=0.656) among patients with antrum-limited, corpus-limited or extended AGIM. TGF-β1 +869T>C was associated with a decreased risk for corpus-affected AGIM (adjusted odds ratio: 0.42, 95% confidence interval: 0.19-0.93, P = 0.032). The dominant inheritance models no revealed significant association for IFN-γ +874T>A, TNF-α-308G>A and IL-6 -174C>G gene polymorphism and the risk of localization of AGIM. Conclusion: TGF-β1 +869T>C gene polymorphism is associated with a decreased risk for corporeal localization of premalignant lesions, while IFN-γ +874T>A, TNF-α-308G>A and IL-6 -174C>G are not associated with the risk for AGIM in immunohistochemically H. pylori negative patients.

The MK2 pathway is linked to G-CSF, cytokine production and metastasis in gastric cancer: a novel intercorrelation analysis approach

Background

Gastric cancer is associated with chronic inflammation, but there is still much to understand about the tumor microenvironment and the underlying tumor-promoting mechanisms. The Map kinase-activated protein kinase 2 (MK2) pathway is a regulator of inflammatory cytokine production that we have been studying in gastrointestinal cancers. Here, we set out to determine the significance of this gene in gastric cancer along with its downstream mediators and if there were differences in the primary tumors with and without metastasis.

Methods

Human gastric cancer tissues with and without metastasis were examined for MK2 expression and cytokine profile in organ culture supernatants. Advanced statistical methods including a lower triangular correlation matrix, novel rooted correlation network, linear and logistic regression modeling along with Kruskal–Wallis testing with Sidak correction for multiple testing were applied to gain understanding of cytokines/chemokines linked to metastasis.

Results

The MK2 pathway is strongly linked with metastasis and a panel of cytokines. Gene expression was able to classify gastric cancer metastasis 85.7% of the time. A significant association with a panel of cytokines was found, including G-CSF, GM-CSF, Mip-1β, IFN-α, MCP-1, IL-1β, IL-6, and TNF-α. Mip-1β was found to have the strongest association with MK2 and metastasis after Sidak correction for multiple testing.

Conclusions

MK2 gene expression and a novel associated cytokine panel are linked to gastric cancer metastasis. G-CSF is the strongest cytokine to differentiate between metastasis and non-metastasis patients and had the lowest P value, while Mip-1β showed the strongest association with MK2 and metastasis after Sidak correction. MK2 and associated cytokines are potential biomarkers for gastric cancer metastasis. The novel intercorrelation analysis approach is a promising method for understanding the complex nature of cytokine/chemokine regulation and links to disease outcome.

TNF-α G-308A genetic variants, serum CRP-hs concentration and DNA damage in obese women

Obesity is associated with inflammation, which can disturb genome stability. Tumor necrosis factor (TNF-α) polymorphism was found to affect TNF-α protein production and inflammation. Therefore, the present study illustrates the relationship between TNF-α polymorphism, the degree of inflammation assessed by serum high sensitivity C-reactive protein concentration (CRP-hs) and basal DNA damage in patients with obesity (BMI 30–34.9 kg/m²) and control subjects with proper body mass (BMI < 25 kg/m²). A total of 115 participants (75 obese premenopausal women; and 40 age-, and gender-matched controls) were included. Biochemical parameters (serum concentrations of total-cholesterol, HDL-cholesterol, LDL- cholesterol, triglycerides, glucose, apolipoprotein AI, CRP-hs) and endogenous DNA damage (determined by comet assay) were measured. TNF-α G-308A polymorphism (rs1800629) was analyzed by PCR-RFLP (PCR-restriction fragments length polymorphism). An effect of TNF-α genotype on serum CRP-hs concentration was noted (p = 0.031). In general, carriers of the rare A allele of the TNF-α G-308A polymorphism had significantly lower endogenous DNA damage and serum CRP-hs concentrations than GG homozygotes, however, the protective effect of the A allele was especially visible in non-obese women. Serum CRP-hs concentrations and levels of DNA damage (% DNA in tail) were significantly higher in obese than in controls (p = 0.001 and p < 0.0001, respectively). The adjusted multiple linear regression analyses revealed a significant, independent impact of obesity on DNA damage (p = 0.00000) and no effect of other covariates i.e. age, TNF-α genotype and serum CRP-hs concentration. Our study showed that obesity has a significant impact on the levels of endogenous DNA damage. Obesity abolished the protective effect of A allele of the TNF-α G-308A polymorphism on DNA damage and on inflammation development observed in non-obese A allele carriers.

Relationship between serum inflammatory cytokines and lifestyle factors in gastric cancer

Chronic inflammation is associated with increased risk of gastric cancer (GC), and GC risk is significantly associated with lifestyle. The aim of the present study was to explore the association between serum inflammatory cytokines and lifestyle factors in GC. A total of 20 serum inflammatory cytokines were measured in a hospital-based case-control population with 142 GC patients and 98 healthy controls. Controls without the selected healthy lifestyle factors were regarded as baseline, and correlation analysis was conducted to establish the association between serum inflammatory cytokines and lifestyle factors. The results demonstrated that several lifestyle factors (including eating fried and salty foods, eating quickly, smoking and drinking) could increase the risk of GC, while only eating fresh fruits could decrease the risk of GC. Correlation analysis revealed that increased serum interleukin (IL)-12/IL-23P40 levels was associated with GC risk as significant differences were observed in all lifestyle factors. Increased serum IL-8 was closely associated with smoking in GC patients, while increased IL-17α and IL-8 levels were associated with GC patients who ate salty foods. Increased IL-10 and decreased TGF-β levels were also associated with GC patients who ate fresh fruits. In conclusion, GC risk was strongly affected by lifestyle factors, which may regulate the expression of inflammatory cytokines and promote gastric carcinogenesis.

Genetic polymorphisms and gastric cancer risk: a comprehensive review synopsis from meta-analysis and genome-wide association studies

Objective

In the past few decades, more than 500 reports have been published on the relationship between single nucleotide polymorphisms (SNPs) on candidate genes and gastric cancer (GC) risk. Previous findings have been disputed and are controversial. Therefore, we performed this article to summarize and assess the credibility and strength of genetic polymorphisms on the risk of GC.

Methods

We used Web of Science, PubMed, and Medline to identify meta-analyses published before July 30th, 2018 that assessed associations between variants on candidate genes and the risk of GC. Cumulative epidemiological evidence of statistical associations was assessed combining Venice criteria and a false-positive report probability (FPRP) test.

Results

Sixty-one variants demonstrated a significant association with GC risk, whereas 29 demonstrated no association. Nine variants on nine genes were rated as presenting strong cumulative epidemiological evidence for a nominally significant association with GC risk, including APE1 (rs1760944), DNMT1 (rs16999593), ERCC5 (rs751402), GSTT1 (null/presence), MDM2 (rs2278744), PPARG (rs1801282), TLR4 (rs4986790), IL-17F (rs763780), and CASP8 (rs3834129). Eleven SNPs were rated as moderate, and 33 SNPs were rated as weak. We also used the FPRP test to identify 13 noteworthy SNPs in five genome-wide association studies.

Conclusions

Sixty-one variants are significantly associated with GC risk, and 29 variants are not associated with GC risk; however, five variants on five genes presented strong evidence for an association upgraded from moderate. Further study of these variants may be needed in the future. Our study also provides referenced information for the genetic predisposition to GC.

An updated association between TNF-α -238G/A polymorphism and gastric cancer susceptibility in East Asians

Polymorphisms in the tumor necrosis factor α (TNF-α) gene are emerging as key determinants of gastric diseases. The TNF-α-238G/A single-nucleotide polymorphism (SNP) is the most extensively studied. However, this association is inconsistent amongst different populations. We therefore conducted an updated meta-analysis to obtain a more precise estimate of the association of TNF-α-238G/A polymorphism with gastric cancer (GC) risk. A comprehensive search of PubMed, Embase, Chinese (CNKI and WanFang) databases was performed to identify relevant studies through 5 May 2018. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of the association. Fourteen studies were included in our meta-analysis involving 2999 cases and 4685 controls. There was no significant association between TNF-α-238G/A polymorphism and GC risk in the overall populations. In the subgroup analysis, we found that TNF-α-238G/A polymorphism was associated with the increased risk of GC amongst Asians, especially in Chinese, but not in Caucasians. Subgroup analysis by genotyping methods revealed increased risk for other methods. In conclusion, our present meta-analysis shows that TNF-α-238G/A polymorphism is associated with the risk of GC in East Asian individuals.

Role of polymorphisms in genes that encode cytokines and Helicobacter pylori virulence factors in gastric carcinogenesis

The Helicobacter pylori (H. pylori) infection is a determinant factor in gastric cancer (GC) development. However, the infection outcomes are variable and depend on both host and bacterial characteristics. Some host cytokines such as interleukin (IL)-1β, IL-1Ra, IL-8, IL-10 and tumor necrosis factor-α play important roles in the host immune system response to the pathogen, in the development of gastric mucosal lesions and in cell malignant transformation. Therefore, these host factors are crucial in neoplastic processes. Certain polymorphisms in genes that encode these cytokines have been associated with an increased risk of GC. On the other hand, various virulence factors found in distinct H. pylori bacterial strains, including cytotoxin-associated antigen A, vacuolating cytotoxin, duodenal ulcer promoting gene A protein, outer inflammatory protein and blood group antigen binding adhesin, have been associated with the pathogenesis of different gastric diseases. The virulent factors mentioned above allow the successful infection by the bacterium and play crucial roles in gastric mucosa lesions, including malignant transformation. Moreover, the role of host polymorphisms and bacterial virulence factors in gastric carcinogenesis seems to vary among different countries and populations. The identification of host and bacterium factors that are associated with an increased risk of GC development may be useful in determining the prognosis of infection in patients, what could help in clinical decision-making and in providing of an optimized clinical approach.

Association of tumor necrosis factor alpha gene polymorphisms with Helicobacter pylori infection in dyspeptic patients in Sri Lanka

Single nucleotide polymorphisms present on the promoter sequence of the TNF-α gene may affect production of TNF-α, a pro-inflammatory cytokine, during immune responses. The presence of TNF-α polymorphisms is also reportedly associated with more severe manifestations of Helicobacter pylori infection. However, the frequency of TNF-α polymorphisms and the associated disease severity vary between different patient groups. In this study, gastric biopsies and blood specimens were collected from 138 patients with dyspepsia undergoing routine upper gastrointestinal endoscopy. Our institution's Ethics Review Committee approved the study and written informed consent was obtained from all participants. The presence of H. pylori was confirmed histologically in all patients. The frequency of TNF-α polymorphisms in the study cohort was investigated using PCR-restriction fragment length polymorphism and expression of serum TNF-α quantitated using a commercial ELISA assay. The proportions of selected TNF-α polymorphisms (TNF-α -238, -308 and -863) were similar in H. pylori-positive and -negative patients. Homozygous mutations of TNF-α polymorphisms were rarely detected in the study group. There was a significant difference in TNF-α concentrations between patients with mild chronic gastritis and TNF-α -308 GG genotype and patients with moderate to severe chronic gastritis (P = 0.008). It was not possible to identify an association between these genotypes and disease severity because of the low frequency of heterozygous and homozygous mutated genes in Sri Lankan patients with dyspepsia.

PADI4 has genetic susceptibility to gastric carcinoma and upregulates CXCR2, KRT14 and TNF-α expression levels

PADI4 (peptidyl deiminase isoform 4) is overexpressed in many tumor tissues and converts arginine residues to citrulline residues. This study used an Illumina SNP microarray and a TaqMan assay to determine the possible association of the PADI4 gene with various tumor risks. Both genotyping methods demonstrated significant associations between the tag SNPs rs1635566 and rs882537 in the PADI4 locus with gastric carcinoma in two independent cohorts. Based on this genotyping result, we used the Cancer Pathway Finder, p53 Signaling, Signal Transduction and Tumor Metastasis PCR arrays to investigate the tumorigenic pathway of PADI4 in MNK-45 cells derived from gastric carcinoma. We detected significantly decreased expression levels of CXCR2, KRT14 and TNF-α in MNK-45 cells that were treated with anti-PADI4 siRNA. We also detected increased expression of these three genes in MNK-45 cells transfected with a pcDNA3.1 plasmid overexpressing PADI4. A highly similar result was also obtained for SGC 7901 cells, which also originate from gastric carcinoma. Our result indicates that the PADI4 gene has genetic susceptibility in gastric carcinoma. PADI4 contributes to gastric tumorigenesis by upregulating CXCR2, KRT14 and TNF-α expression, which are well known to activate angiogenesis, cell proliferation, cell migration and the immune microenvironment in tumors.

Genetic risk factors in thrombotic primary antiphospholipid syndrome: A systematic review with bioinformatic analyses

BACKGROUND

Antiphospholipid Syndrome (APS) is an autoimmune multifactorial disorder. Genetics is believed to play a contributory role in the pathogenesis of APS, especially in thrombosis development and pregnancy morbidity. In the last 20 years, extensive research on genetic contribution on APS indicates that APS is a polygenic disorder, where a number of genes are involved in the development of its clinical manifestations.

AIMS

The aim of this systematic review is to evaluate the genetic risk factors in thrombotic primary APS. Additionally, to assess the common molecular functions, biological processes, pathways, interrelations with the gene encoded proteins and RNA-Seq-derived expression patterns over different organs of the associated genes via bioinformatic analyses.

METHODS

Without restricting the year, a systematic search of English articles was conducted (up to 4th September 2017) using Web of Science, PubMed, Scopus, ScienceDirect and Google Scholar databases. Eligible studies were selected based on the inclusion criteria. Two researchers independently extracted the data from the included studies. Quality assessment of the included studies was carried out using a modified New-Castle Ottawa scale (NOS).

RESULTS

From an initial search result of 2673 articles, 22 studies were included (1268 primary APS patients and 1649 healthy controls). Twenty-two genes were identified in which 16 were significantly associated with thrombosis in primary APS whereas six genes showed no significant association with thrombosis. Based on the NOS, 14 studies were of high quality while 6 were low quality studies. From the bioinformatic analyses, thrombin-activated receptor activity (q = 6.77 × 10^-7), blood coagulation (q = 2.63 × 10^-15), formation of fibrin clot (q = 9.76 × 10^-10) were the top hit for molecular function, biological process and pathway categories, respectively. With the highest confidence interaction score of 0.900, all of the thrombosis-associated gene encoded proteins of APS were found to be interconnected except for two. Based on the pathway analysis, cumulatively all the genes affect haemostasis [false discovery rate (FDR) = 1.01 × 10^-8] and the immune system [FDR = 9.93 × 10^-2]. Gene expression analysis from RNA-Seq data revealed that almost all the genes were expressed in 32 different tissues in the human body.

CONCLUSION

According to our systematic review, 16 genes contribute significantly in patients with thrombotic primary APS when compared with controls. Bioinformatic analyses of these genes revealed their molecular interconnectivity in protein levels largely by affecting blood coagulation and immune system. These genes are expressed in 32 different organs and may pose higher risk of developing thrombosis anywhere in the body of primary APS patients.

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.

Tumor necrosis factor-alpha gene polymorphisms and susceptibility to ischemic heart disease: A systematic review and meta-analysis

BACKGROUND

A number of studies had reported the association between tumor necrosis factor-alpha (TNF-α) gene polymorphisms and ischemic heart disease (IHD) risk. However, the results remained controversial. Therefore, we performed a systematic review with multiple meta-analyses to provide the more precise estimations of the relationship.

METHODS

We systematically searched electronic databases (PubMed, the Web of Science, EMBASE, Medline, Chinese National Knowledge Infrastructure, WanFang and ChongQing VIP Database) for relevant studies published up to February 2017. The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for assessing the association. The present meta-analysis was performed using STATA 12.0 software.

RESULTS

In total, 45 articles with 17,375 cases and 15,375 controls involved were included. Pooled ORs revealed a significant association between TNF-α -308G/A gene polymorphism and IHD (A vs. G: OR = 1.22, 95% CI = 1.10-1.35; (AA + GA) vs. GG: OR = 1.18, 95% CI = 1.03-1.36; (AA vs. (GA+GG): OR = 1.37, 95% CI = 1.08-1.75)), indicating that the TNF-α -308A allele might be an important risk factor for IHD. No association between other TNF-α gene polymorphisms and susceptibility to IHD were observed. No publication bias were found. Sensitivity analyses indicated that our results were stable.

CONCLUSION

The present study indicated a possible association between the TNF-α -308G/A gene polymorphism and IHD risk. However, evidence was limited to confirm the role of TNF-α -238G/A, -857C/T, -863C/A, -1031T/C and other TNF-α gene polymorphisms in the risk of IHD.

TNF-α-308/-238 polymorphisms are associated with gastric cancer: A case-control family study in China

BACKGROUND

Associations of TNF-α-308 (rs1800629) and -238 (rs361525) with gastric cancer had the inconsistent indication among different populations.

METHODS

In this case-control family study, 47 families were determined with the probands diagnosed with gastric cancer (case family, n=296), accordingly 47 families without gastric cancer were matched with the case families by multivariate distribution of age, sex, social class, and pedigree size (control family, n=319). Polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR) was used to identify the TNF genotype. Chi-square test was used to compare the groups regarding genotype and the allele frequencies, HWE test for Hardy-Weinberg equilibrium.

RESULTS

The frequencies of TNF-α-308 GA and AA genotypes were significantly higher in case family than that in control family. The risk of gastric cancer was increased in GA and AA carriers in the first degree (OR=2.06, 95% CI=1.20-3.51 and OR=4.89, 95% CI=2.74-8.74), however the similar result was not found in the second degree. Helicobacter pylori infection status were significantly associated with risk of gastric cancer in first-degree relatives (OR=1.96, 95% CI=1.26-3.05) while no statistical significance was noted in the second-degree relatives. Haplotypes of TNF-α-308/-238 alleles, GA/GG, AA/GG and AA/GA indicated the susceptibilities to gastric cancer with OR and 95% confident intervals resulting 2.07 (1.34-3.21), 4.49 (2.74-7.33) and 4.98 (1.76-14.01) respectively.

CONCLUSIONS

TNF-α-G308A (rs1800629) polymorphisms are associated with gastric cancer in Chinese population. Haplotypes of TNF-α-308/-238 GA/GG, AA/GG and AA/GA increase the susceptibilities to gastric cancer. The first-degree relatives are more likely to develop into gastric cancer with TNF-α-G308 polymorphisms and H. pylori positive than the second-degree are.

Polymorphisms in HLA-DQ genes, together with age, sex, and Helicobacter pylori infection, as potential biomarkers for the early diagnosis of gastric cancer

BACKGROUND

Polymorphisms in inflammation-related genes are factors associated with the development of gastroduodenal diseases in Helicobacter pylori-infected individuals.

MATERIALS AND METHODS

We aimed to analyze polymorphisms in HLA-DQ, together with other host and H. pylori variables as risk factors for precancerous and cancerous gastric lesions. 1052 individuals were studied, including nonatrophic gastritis (NAG), intestinal metaplasia (IM), gastric cancer (GC) or duodenal ulcer (DU) patients, and healthy volunteers.

RESULTS

Patients with alleles DQA*01:01 (OR 0.78), *01:02 (OR 0.29), *01:03 (OR 0.31), and DQB*02:01/02 (OR 0.40) showed a reduced risk for GC. A multivariate logistic regression analyses showed that patients with homozygote genotypes DQA1*03:01 (OR 7.27) and DQA1*04:01 (OR 8.99) and DQB1*05:01:01 (OR 12.04) were at significantly increased risk for GC. Multivariate analyses also demonstrated that age (OR>10.0) and gender (OR>2.0) were variables that influenced significantly the risk for GC, while H. pylori infection (OR>2.5) increased the risk for IM.

CONCLUSIONS

We identified HLA-DQ alleles associated with IM and GC, and confirm that age, sex, and H. pylori infection are variables that also influence the risk for disease. The use of multiple markers, HLA-DQ alleles, age, sex, and H. pylori infection may be useful biomarkers for the early diagnosis of patients with IM and GC.

Interaction between Helicobacter pylori and host genetic variants in gastric carcinogenesis

Helicobacter pylori (H. pylori) is the definite carcinogen of gastric cancer. H. pylori infection induces chronic inflammation, causes DNA damage and aberrant methylation of genes and these pathways are involved in H. pylori-related gastric carcinogenesis. Polymorphisms of the genes involved in these pathways could alter susceptibility to gastric cancer. In this mini review, we focused on the role of polymorphisms in these genes on the susceptibility to gastric cancer, with a particular emphasis on their possible interactions with H. pylori infection. We found that many studies on this theme did not simultaneously report H. pylori infection and the interactions remained inconclusive.

The Association between C9orf72 Repeats and Risk of Alzheimer's Disease and Amyotrophic Lateral Sclerosis: A Meta-Analysis

C9orf72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) in Caucasian populations. However, the relationship between C9orf72 repeats and Alzheimer's disease (AD) was not clear. Additionally, there were few articles assessing C9orf72 in other ethnicities with ALS. In this meta-analysis, we aimed to investigate the relationship between C9orf72 repeat expansions (≥30 repeats) and intermediate repeat copies (20–29 repeats) and AD or ALS. The results suggested positive correlations between C9orf72 repeat expansions and the risk of Alzheimer's disease (OR = 6.36, 95% CI = 3.13–12.92, and p < 0.00001), while intermediate repeat copies of C9orf72 gene were not associated with the risk of the disease. C9orf72 repeat expansions were positively correlated with the risk of familial and sporadic ALS (OR = 293.25, 95% CI = 148.17–580.38, and p < 0.00001; OR = 35.57, 95% CI = 19.61–64.51, and p < 0.00001). There was a positive correlation between the gene variations and ALS risk among Caucasians and Asians (OR = 57.56, 95% CI = 36.73–90.22, and p < 0.00001; OR = 6.35, 95% CI = 1.39–29.02, and p = 0.02).

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.

Positive relationship between p42.3 gene and inflammation in chronic non-atrophic gastritis

OBJECTIVE

Gastric cancer (GC) is a typical type of inflammation-related tumor. The p42.3 gene is shown to be highly expressed in GC, but its association with gastritis remains unknown. We aimed to explore the relationship between gastric inflammation and p42.3 gene in vitro and in vivo.

METHODS

Normal gastric epithelial cells (GES-1) were treated with Helicobacter pylori (H. pylori) and tumor necrosis factor (TNF)-α. Total cell mRNA and protein were extracted and collected, and polymerase chain reaction and Western blot were performed to determine the relative expression of p42.3 gene. In total, 291 biopsy samples from patients with chronic non-atrophic gastritis were collected and immunohistochemistry was used to measure the p42.3 protein expression. The association between p42.3 protein expression and the clinicopathological characteristics of these patients were analyzed.

RESULTS

Both H. pylori and TNF-α significantly enhanced the p42.3 protein expression in GES-1 cells in a time and dose-dependent manner. In addition, p42.3 gene expression was positively associated with the severity of gastric mucosal inflammation and H. pylori infection (P = 0.000). Its expression was significantly more common in severe gastric inflammation and in H. pylori-infected cases.

CONCLUSION

p42.3 gene expression is associated with gastric mucosal inflammation that can be upregulated by TNF-α and H. pylori infection.