Association between tumor necrosis factor β 252 A/G polymorphism and risk of gastric cancer: a meta-analysis

Associations of lymphotoxin-a (LTA) rs909253 A/G gene polymorphism, plasma level and risk of ankylosing spondylitis in a Chinese Han population

Lymphotoxin-a (LTA) may be associated with the pathogenesis of inflammatory diseases. To assess the association of the LTA rs909253 A/G polymorphism with plasma level and risk of ankylosing spondylitis (AS) in a Chinese Han population. Genotyping and LTA plasma were tested by mass spectroscopy and enzyme-linked immunosorbent assay (ELISA), respectively. The results showed that the average plasma level of LTA in AS was significantly lower than in the controls (P = 0.000). Our results also indicated that LTA rs909253 A/G was associated with a decreased risk of AS (G vs. A: P = 0.014). Significant differences were also found between the rs909253 A/G genotype and down-regulated plasma level in AS patients, compared with controls. After stratification analysis, a decreased risk of AS was associated with the LTA rs909253 G allele (G vs. A) among female patients, younger patients (Yr. < 30), HLA-B27-positive patients. In addition, In conclusion, LTA rs909253 A/G genotype has a significant relationship with decreased susceptibility to AS.

HVEM network signaling in cancer

Somatic mutations in cancer cells may influence tumor growth, survival, or immune interactions in their microenvironment. The tumor necrosis factor receptor family member HVEM (TNFRSF14) is frequently mutated in cancers and has been attributed a tumor suppressive role in some cancer contexts. HVEM functions both as a ligand for the lymphocyte checkpoint proteins BTLA and CD160, and as a receptor that activates NF-κB signaling pathways in response to BTLA and CD160 and the TNF ligands LIGHT and LTα. BTLA functions to inhibit lymphocyte activation, but has also been ascribed a role in stimulating cell survival. CD160 functions to co-stimulate lymphocyte function, but has also been shown to activate inhibitory signaling in CD4⁺ T cells. Thus, the role of HVEM within diverse cancers and in regulating the immune responses to these tumors is likely context specific. Additionally, development of therapeutics that target proteins within this network of interacting proteins will require a deeper understanding of how these proteins function in a cancer-specific manner. However, the prominent role of the HVEM network in anti-cancer immune responses indicates a promising area for drug development.

Associations between inflammatory gene polymorphisms (TNF-α 308G/A, TNF-α 238G/A, TNF-β 252A/G, TGF-β1 29T/C, IL-6 174G/C and IL-10 1082A/G) and susceptibility to osteosarcoma: a meta-analysis and literature review

Associations between inflammatory gene polymorphisms (TNF-α 308G/A, TNF-α 238G/A, TNF-β 252A/G, TGF-β1 29T/C, IL-6 174G/C and IL-10 1082A/G) and osteosarcoma (OS) risk remain unclear. We conducted a systematic search to retrieve studies that investigated associations between inflammatory gene polymorphisms and OS risk. Nine studies that met the inclusion criteria were finally recruited in this meta-analysis. Overall, there was a significant association between TNF-α 308G/A, IL-10 1082A/G and OS risk, while there was no significant association between TNF-α 238G/A, TNF-β 252A/G and IL-6 174G/C and OS risk. Our subgroup analysis showed a significant association between IL-6 174G/C and IL-10 1082A/G and OS risk in Asians, while no such significant correlation was observed with TNF-α 308G/A, TNF-α 238G/A, TNF-β 252A/G and TGF-β1 29T/C polymorphisms. In Caucasians, there was a significant association between TNF-α 238G/A and the decreased incidence of OS. In conclusion, inflammatory gene polymorphisms play a key role in the occurrence and progression of OS. IL-6 174G/C polymorphism was obviously associated with OS risk in Asians, while TNF-α 238G/A polymorphism seemed to be associated with the decreased susceptibility to OS in Caucasians as Altman and Bland test indicated. Although controversial results were observed between IL-10 1082A/G and OS risk in Asians and Caucasians, it is difficult to make a definite conclusion about the role of IL-10 1082A/G polymorphism in the etiology of OS because our Altman and Bland test showed no good evidence to support a different effect in Asians and Caucasians.

Context-dependent roles for lymphotoxin-β receptor signaling in cancer development

The LTα1β2 and LIGHT TNF superfamily cytokines exert pleiotropic physiological functions through the activation of their cognate lymphotoxin-β receptor (LTβR). Interestingly, since the discovery of these proteins, accumulating evidence has pinpointed a role for LTβR signaling in carcinogenesis. Early studies have shown a potential anti-tumoral role in a subset of solid cancers either by triggering apoptosis in malignant cells or by eliciting an anti-tumor immune response. However, more recent studies provided robust evidence that LTβR signaling is also involved in diverse cell-intrinsic and microenvironment-dependent pro-oncogenic mechanisms, affecting several solid and hematological malignancies. Consequently, the usefulness of LTβR signaling axis blockade has been investigated as a potential therapeutic approach for cancer. Considering the seemingly opposite roles of LTβR signaling in diverse cancer types and their key implications for therapy, we here extensively review the different mechanisms by which LTβR activation affects carcinogenesis, focusing on the diverse contexts and different models assessed.

Helicobacter pylori infection and gastric carcinoma: Not all the strains and patients are alike

Gastric carcinoma (GC) develops in only 1%-3% of Helicobacter pylori (H. pylori) infected people. The role in GC formation of the bacterial genotypes, gene polymorphisms and host's factors may therefore be important. The risk of GC is enhanced when individuals are infected by strains expressing the oncoprotein CagA, in particular if CagA has a high number of repeats containing the EPIYA sequence in its C'-terminal variable region or particular amino acid sequences flank the EPIYA motifs. H. pylori infection triggers an inflammatory response characterised by an increased secretion of some chemokines by immunocytes and colonised gastric epithelial cells; these molecules are especially constituted by proteins composing the interleukin-1beta (IL-1β) group and tumour necrosis factor-alpha (TNF-α). Polymorphisms in the promoter regions of genes encoding these molecules, could account for high concentrations of IL-1β and TNF-α in the gastric mucosa, which may cause hypochlorhydria and eventually GC. Inconsistent results have been attained with other haplotypes of inflammatory and anti-inflammatory cytokines. Genomic mechanisms of GC development are mainly based on chromosomal or microsatellite instability (MSI) and deregulation of signalling transduction pathways. H. pylori infection may induce DNA instability and breaks of double-strand DNA in gastric mucocytes. Different H. pylori strains seem to differently increase the risk of cancer development run by the host. Certain H. pylori genotypes (such as the cagA positive) induce high degrees of chronic inflammation and determine an increase of mutagenesis rate, oxidative-stress, mismatch repair mechanisms, down-regulation of base excision and genetic instability, as well as generation of reactive oxygen species that modulate apoptosis; these phenomena may end to trigger or concur to GC development.

Polymorphisms of the LTA gene may contribute to the risk of myocardial infarction: a meta-analysis

Objective

The lymphotoxin-α (LTA), as one of the mediators of inflammation, may play an important role in the pathogenesis of myocardial infarction (MI). Genetic association studies (GAS) that have investigated the association between three common polymorphisms (A252G, G10A and C804A) of the LTA gene and susceptibility to MI have produced contradictory and inconclusive results. The aim of this meta-analysis is to provide a relatively comprehensive account of the association of these polymorphisms with susceptibility to MI.

Methods

A literature search for eligible GAS published before October 15, 2013 was conducted in the PubMed, Embase, Web of Science, Cochrane Library, and CNKI (China National Knowledge Infrastructure) databases. We performed a meta-analysis of fifteen case-control studies with a total of 22,549 MI patients and 16,105 healthy controls.

Results

For LTA A252G, a borderline significant overall association was found, indicating that GG genotype may confer an increased susceptibility to MI compared to AA and AG genotypes. Based on an ethnicity stratification analysis, a significant association was observed in Asians, but not in Caucasians. For LTA G10A, no significant overall association was found. However, subgroup analysis based on ethnicity suggested that the 10A allele may confer a significant increased susceptibility to MI only in Asian populations. For LTA C804A, the combined results revealed a significantly increased susceptibility to MI for carriers of the 804A allele in both overall analysis and stratified analyses.

Conclusion

This meta-analysis shows that LTA C804A may be associated with an increased susceptibility to MI, whereas LTA A252G and G10A may confer a significant increased susceptibility to MI only in Asians. Thus, these polymorphisms of the LTA gene can probably be used with other genetic markers together to identify individuals at high susceptibility to MI especially in Asians.

Quantitative assessment of the associations between DNA repair gene XRCC3 Thr241Met polymorphism and gastric cancer

Gastric cancer is one of the most prevalent types of cancer in the world today. Recently, there is a large sample volume of published case-control studies on XRCC3 Thr241Met polymorphism with gastric cancer. This will have an important impact on published article by meta-analysis regarding XRCC3 Thr241Met polymorphism with gastric cancer. Therefore, it is necessary to update by meta-analysis to comprehensively investigate the relationship between DNA repair gene XRCC3 Thr241Met polymorphism and gastric cancer. To preciously examine the association between the XRCC3 Thr241Met polymorphism and gastric cancer, we undertook a meta-analysis of 12 case-control studies. The association between the XRCC3 Thr241Met polymorphism and gastric cancer risk was assessed by odds ratios together with their 95 % confidence intervals using a fixed-effects model or random-effects model. We found that the XRCC3 Thr241Met polymorphism was not associated with an increased gastric cancer risk. However, the XRCC3 Thr241Met polymorphism was associated with decreased gastric cancer risk in Asians. In addition, there is no evidence of association on XRCC3 Thr241Met polymorphism with response to chemotherapy and prognosis in gastric cancer. The XRCC3 Thr241Met polymorphism might influence gastric cancer risk in Asians.