Susceptibility to Helicobacter pylori infection: results of an epidemiological investigation among gastric cancer patients

Association Between Polymorphisms of Interleukin 1 Family Genes and Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies occurring worldwide and is most frequent type of liver cancer. The risk for developing HCC increases with the severity of inflammation and fibrosis. The members of the interleukin-1 (IL-1) family are primarily proinflammatory cytokines due to their ability to stimulate the expression of genes associated with inflammation and autoimmune diseases. Several studies have suggested that some proinflammatory cytokines, such as the IL-1 family (IL-1α, IL-1β, and IL-1 receptor antagonist) are involved in the pathogenesis of HCC.

Material/Methods

This study aimed to determine whether polymorphisms in the IL-1 family of genes are associated with HCC. We analyzed 178 HCC patients and 397 controls to investigate the association between polymorphisms in IL-1α, IL-1β, and IL-1 receptor antagonist (IL-1RA) genes and HCC in the Korean population. All subjects were genotyped for the selected SNPs in IL-1α, IL-1β, and IL-1RA genes by Golden-Gate SNP Genotyping Assay.

Results

Statistical analysis revealed a significant association at IL-1β between HCC and controls. Three individual polymorphisms (rs1143633, rs3917356, and rs1143627) were found to be associated with HCC. The SNPs of IL-1β gene (rs1143633A>G and rs1143627T>C) protected against HCC in the dominant model (p=0.027, OR=0.59, 95% CI=0.37–0.94; p=0.019, OR=0.56, 95% CI=0.34–0.91). The SNP of IL-1β gene (rs3917356G>A) increased the risk of HCC in the recessive model (p<0.001, OR=2.58, 95% CI=1.53–4.33), whereas other SNPs in IL-1α and IL-1RA showed no significant association between HCC patients and controls.

Conclusions

These results suggest that IL-1β in the IL-1 family contributes to HCC susceptibility.

Pharmacological regimens for eradication of Helicobacter pylori: an overview of systematic reviews and network meta-analysis

BACKGROUND

Approximately half of the world's population is infected with Helicobacter pylori (H.pylori), a bacterium shown to be linked with a series of gastrointestinal diseases. A growing number of systematic reviews (SRs) have been published comparing the effectiveness of different treatments for H.pylori infection but have not reached a consistent conclusion. The objective of this study is to provide an overview of SRs of pharmacological therapies for the eradication of H.pylori.

METHODS

Major electronic databases were searched to identify relevant SRs published between 2002 and February 2016. Studies were considered eligible if they included RCTs comparing different pharmacological regimens for treating patients diagnosed as H.pylori infected and pooled the eradication rates in a meta-analysis. A modified version of the 'A Measurement Tool to Assess Systematic Reviews' (AMSTAR) was used to assess the methodological quality. A Bayesian random effects network meta-analysis (NMA) was conducted to compare the different proton pump inhibitors (PPI) within triple therapy.

RESULTS

30 SRs with pairwise meta-analysis were included. In triple therapy, the NMA ranked the esomeprazole to be the most effective PPI, followed by rabeprazole, while no difference was observed among the three old generations of PPI for the eradication of H.pylori. When comparing triple and bismuth-based therapy, the relative effectiveness appeared to be dependent on the choice of antibiotics within the triple therapy; moxifloxacin or levofloxacin-based triple therapy were both associated with greater effectiveness than bismuth-based therapy as a second-line treatment, while bismuth-based therapy achieved similar or greater eradication rate compared to clarithromycin-based therapy. Inconsistent findings were reported regarding the use of levofloxacin/moxifloxacin in the first-line treatment; this could be due to the varied resistant rate to different antibiotics across regions and populations. Critical appraisal showed a low-moderate level of overall methodological quality of included studies.

CONCLUSIONS

Our analysis suggests that the new generation of PPIs and use of moxifloxacin or levofloxacin within triple therapy as second-line treatment were associated with greater effectiveness. Given the varied antibiotic resistant rate across regions, the appropriateness of pooling results together in meta-analysis should be carefully considered and the recommendation of the choice of antibiotics should be localized.

Evaluation of an Association of Blood Homocysteine Levels With Gastric Cancer Risk From 27 Case-Control Studies

High blood homocysteine levels may risk gastric cancer. However, observational studies have been plagued by chance, bias, confounding, or reverse causality. In this study, we assessed the relationship between blood homocysteine levels and gastric cancer by using a Mendelian randomization method, which is independent of nongenetic confounding.We took 2 steps to perform Mendelian randomization analysis. First, we evaluated the methylenetetrahydrofolate reductase (MTHFR) C677T association with gastric cancer by a meta-analysis of case-control studies including 7566 patients with gastric cancer and 10 640 control subjects from 27 Case-Control studies. Second, MTHFR C677T polymorphism, which affects the blood homocysteine levels, was used as an instrumental variable to calculate the risk and estimate the association of gastric cancer with this single nucleotide polymorphism (SNP). We obtained an estimate to the association of blood total homocysteine levels with this SNP from a meta-analysis of Genome-Wide Association Studies (GWAS), which comprises a total of 44 147 individuals.In our Mendelian randomization analysis, we demonstrated a significant effect of the blood homocysteine levels on gastric cancer risk, representing an OR of 2.56 (95% CI = 2.41-2.72; P = 5.0×10) for gastric cancer per 1-SD increase in the natural log-transformed blood total homocysteine levels.We proved that there is a causal relationship between blood total homocysteine and risk of gastric cancer, and this study will add insight into the treatment and pathology research of gastric cancer.

Associations of Il-1 Family-Related Polymorphisms With Gastric Cancer Risk and the Role of Mir-197 In Il-1f5 Expression

To explore whether the roles of IL-1 family single nucleotide polymorphisms (SNPs) of the microRNA binding sites (miR-SNPs) in the 3' untranslated region (3'-UTR) of their target genes in the progression of gastric cancer (GC) and verify the relationship between miR-197 with chronic inflammatory gene-IL1-F5 by microRNA target prediction, a case-control study which consisted of 500 cases and 500 frequency-matched healthy controls was conducted. Single nucleotide polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or allele-specific PCR (AS-PCR). Association between SNPs and GC risk was evaluated by adjusted odds ratios (ORs) and 95% confidence intervals (CIs) in unconditional logistic regression analyses. Quantitative real-time (qRT) PCR assay and Western Blot analyses were performed to analyze the miR-197 expression and the IL1-F5 expression. The variant homozygote and heterozygote genotype of rs9005 in IL-1RN were significantly associated with increased risks of GC (ORadjusted [95%CI]: 1.71[1.04-2.81] and ORadjusted[95%CI]: 1.36 [1.04-1.78]). Compared with the wild heterozygote genotype, the variant heterozygote genotype of rs2472188 and rs2515401 in IL-1F5 polymorphisms were significantly associated with increased GC risks (ORadjusted [95%CI]: 1.51[1.15-1.99] and ORadjusted[95%CI]: 1.36[1.04-1.76]), but no significant differences existed in other 7 IL-1 family SNPs (rs2856836 in IL-1A, rs3732131 in IL-1R1, rs1135354 and rs3771157 in IL-18RA, rs3180235, rs957201 and rs2515402 in IL-1F5) with GC. The recombinant plasmid-pGenesil-1-miR-197 could upregulate the expression of miR-197 and downregulate the expression of IL-1F5 in human gastric cancer cell lines SGC-7901 and BGC-823 cells after transfection, and the miR-197 inhibitor could facilitate the expression of IL1-F5 after transfecting the same cell lines. These results suggested that SNPs in the IL-1 family genes play important roles in the development of GC and the IL-1F5 might be the target gene of miR-197, and miR-197 might negatively regulate its expression.