Association of polymorphisms in the TLR4 gene with the risk of developing neutropenia in children with leukemia

Toll-like Receptor 4, Osteoblasts and Leukemogenesis; the Lesson from Acute Myeloid Leukemia

Toll-like receptor 4 (TLR4) is a pattern-recognizing receptor that can bind exogenous and endogenous ligands. It is expressed by acute myeloid leukemia (AML) cells, several bone marrow stromal cells, and nonleukemic cells involved in inflammation. TLR4 can bind a wide range of endogenous ligands that are present in the bone marrow microenvironment. Furthermore, the TLR4-expressing nonleukemic bone marrow cells include various mesenchymal cells, endothelial cells, differentiated myeloid cells, and inflammatory/immunocompetent cells. Osteoblasts are important stem cell supporting cells localized to the stem cell niches, and they support the proliferation and survival of primary AML cells. These supporting effects are mediated by the bidirectional crosstalk between AML cells and supportive osteoblasts through the local cytokine network. Finally, TLR4 is also important for the defense against complicating infections in neutropenic patients, and it seems to be involved in the regulation of inflammatory and immunological reactions in patients treated with allogeneic stem cell transplantation. Thus, TLR4 has direct effects on primary AML cells, and it has indirect effects on the leukemic cells through modulation of their supporting neighboring bone marrow stromal cells (i.e., modulation of stem cell niches, regulation of angiogenesis). Furthermore, in allotransplant recipients TLR4 can modulate inflammatory and potentially antileukemic immune reactivity. The use of TLR4 targeting as an antileukemic treatment will therefore depend both on the biology of the AML cells, the biological context of the AML cells, aging effects reflected both in the AML and the stromal cells and the additional antileukemic treatment combined with HSP90 inhibition.

Genetic Sequence Variants in TLR4, MBL or IL-1 Receptor Antagonist is not Associated to Increased Risk for Febrile Neutropenia in Children with ALL

Sequence variants in genes involved in the immune system have previously been linked to neutropenia as well as infections in cancer patients. Sequence variants in genes coding for TLR4, MBL, and IL-1Ra were investigated in relation to clinical utility of identifying severe episodes of febrile neutropenia (FN) in a cohort of children undergoing treatment for acute lymphoblastic leukemia. The study included 122 children, where data on FN and microbiological findings were retrospectively collected from medical records. Sequence variants in genes coding for MBL, TLR4, and IL-1Ra were identified by pyrosequencing, TaqMan SNP genotyping assay, and gel electrophoresis. A total of 380 episodes of FN were identified and in 139 episodes, there was a microbiological defined infection. Age and treatment intensity were all associated with the risk of developing FN. No sequence variant was associated to increased numbers of FN episodes. Two sequence variants in the TLR4 gene increased the risk of viral infection, whilst sequence variants in the IL-1Ra gene were associated to a decreased risk of bacterial blood-stream infection (BSI). The investigated sequence variants did not associate with increased risk for FN or to severe infections, as to why the clinical utility as a risk-stratification tool is low. Most episodes of FN were classified as fever with unknown origin, emphasizing the need for improved microbial detection methods.

Apoptosis and genes involved in oral cancer - a comprehensive review

Oral cancers needs relentless research due to high mortality and morbidity associated with it. Despite of the comparable ease in accessibility to these sites, more than 2/3^rd cases are diagnosed in advanced stages. Molecular/genetic studies augment clinical assessment, classification and prediction of malignant potential of oral lesions, thereby reducing its incidence and increasing the scope for early diagnosis and treatment of oral cancers. Herein we aim to review the role of apoptosis and genes associated with it in oral cancer development in order to aid in early diagnosis, prediction of malignant potential and evaluation of possible treatment targets in oral cancer. An internet-based search was done with key words apoptosis, genes, mutations, targets and analysis to extract 72 articles after considering inclusion and exclusion criteria. The knowledge of genetics and genomics of oral cancer is of utmost need in order to stop the rising prevalence of oral cancer. Translational approach and interventions at the early stage of oral cancer, targeted destruction of cancerous cells by silencing or promoting involved genes should be the ideal intervention.

CD markers polymorphisms as prognostic biomarkers in hematological malignancies

The clusters of differentiation (CD) are surface molecules used for immunophenotyping of cells. The expression of CD markers is widely used to classify hematological malignancies, including leukemia and lymphoma. Single nucleotide polymorphisms (SNPs) are crucial genetic changes that can be associated with abnormal expression and function of CD markers. In this paper, we assess the prognostic effect of CD markers’ SNPs in hematological malignancies. Materials and methods and relevant literature was identified by a PubMed search (2001-2019) of English language papers using the following terms: ‘polymorphism’, ‘CD marker’, ‘leukemia’, ‘lymphoma’, ‘prognosis’, ‘CD marker’, and ‘polymorphism’. Many studies have demonstrated the effects of CD markers’ polymorphisms on risk of hematological malignancies. Also, SNPs of CD markers can be related with clinicopathological features, invasiveness, and response to therapy of these disorders. Considering the importance of SNPs in the expressions of CD markers, these genetic changes could be used as potential prognostic biomarkers in hematological malignancies. It is hoped that the evaluation of SNPs in CD markers will enable early diagnosis, prognosis, and detection of response to treatment. However, better understanding of SNPs in CD markers that are involved in hematological malignancies requires further studies on different populations of the worldwide.

Identification of novel lncRNAs involved in the pathogenesis of childhood acute lymphoblastic leukemia

This study aimed to explore novel long non-coding RNAs (lncRNAs) and the underlying mechanisms involved in childhood acute lymphoblastic leukemia (cALL). The GSE67684 dataset was downloaded from the Gene Expression Omnibus. Differentially expressed genes (DEGs) and lncRNAs (DELs) between Days 0, 8, 15 and 33 were isolated using random variance model corrective analysis of variance. Overlapping DEGs and DELs were clustered using Cluster 3.0. Bio-functional enrichment analysis was performed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Interactions between lncRNAs and mRNAs were calculated using dynamic simulations, and interactions among mRNAs were predicted using the STRING database. lncRNA-mRNA and protein-protein interaction (PPI) networks were visualized using Cytoscape. Subsequently, the expression levels of lncRNAs in biological samples from children with or without cALL were validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A total of 593 overlapping DEGs and 21 DELs were identified. After clustering, Profile 26 exhibited a continuously increasing temporal trend, whereas Profile 1 exhibited a continuous decreasing trend. Upregulated DEGs were significantly enriched in 1,825 GO terms and 166 KEGG pathways, whereas downregulated DEGs were significantly enriched in 196 GO terms and 90 KEGG pathways. The lncRNAs NONHSAT027612.2 and NONHSAT134556.2 were the top two regulators in the lncRNA-mRNA network. Toll-like receptor 4, cathepsin G, nucleotide-binding oligomerization domain containing 2 and cathepsin S may be considered the hub genes of the PPI network. RT-qPCR results indicated that the expression levels of the lncRNAs NONHSAT027612.2 and NONHSAT134556.2 were significantly elevated in the blood and bone marrow of patients with cALL compared with the controls. In conclusion, the lncRNAs NONHSAT027612.2 and NONHSAT134556.2 may serve important roles in the pathogenesis of cALL via regulating immune response-associated pathways.

Toll-like receptor genetic variations in bone marrow transplantation

The Toll-like receptor family mediates the innate immune system through recognizing the molecular patterns of microorganisms and self-components and leading the synthesis of the inflammatory mediators. We retrospectively examined whether or not genetic variations in toll-like receptor 1 (rs5743551, -7202GQ>A), toll-like receptor 2 (rs7656411, 22215G>T), and toll-like receptor 4 (rs11536889, +3725G>C) affected transplant outcomes in a cohort of 365 patients who underwent unrelated HLA-matched bone marrow transplantation (for hematologic malignancies through the Japan Marrow Donor Program. Only donor toll-like receptor 4 variation significantly improved the survival outcomes. A multivariate analysis showed that the donor toll-like receptor 4 +3725G/G genotype was significantly associated with a better 5-year progression-free survival and a lower 5-year transplant-related mortality than other variations. Furthermore, the donor toll-like receptor 4 +3725G/G genotype was associated with a significantly lower incidence of fatal infections than other variations. The validation study of 502 patients confirmed that the donor toll-like receptor 4 +3725G/G genotype was associated with better survival outcomes. Toll-like receptor4 genotyping in transplant donors may therefore be a useful tool for optimizing donor selection and evaluating pretransplantation risks.

Animal models of chemotherapy-induced mucositis: translational relevance and challenges

Chemotherapy for cancer patients induces damaging tissue reactions along the epithelium of the gastrointestinal tract (GIT). This chemotherapy-induced mucositis (CIM) is a serious side effect of cytotoxic drugs, and several animal models of CIM have been developed, mainly in rodents and piglets, to help understand the progression of CIM and how to prevent it. Animal models allow highly controlled experimental conditions, detailed organ (e.g., GIT) insights, standardized, clinically relevant treatment regimens, and discovery of new biomarkers. Still, surprisingly few results from animal models have been translated into clinical CIM management and treatments. The results obtained from specific animal models can be difficult to translate to the diverse range of CIM manifestations in patients, which vary according to the antineoplastic drugs, dose, underlying (cancer) disease, and patient characteristics (e.g., age, genetics, and body constitution). Another factor that hinders the direct use of results from animals is inadequate collaboration between basic science and clinical science in relation to CIM. Here, we briefly describe CIM pathophysiology, particularly the basic knowledge that has been obtained from CIM animal models. These model studies have indicated potential new preventive and ameliorating interventions, including supplementation with natural bioactive diets (e.g., milk fractions, colostrum, and plant extracts), nutrients (e.g., polyunsaturated fatty acids, short-chain fatty acids, and glutamine), and growth factor peptides (e.g., transforming growth factor and glucagon-like peptide-2), as well as manipulations of the gut microbiota (e.g., prebiotics, probiotics, and antibiotics). Rodent CIM models allow well-controlled, in-depth studies of animals with or without tumors while pig models more easily make clinically relevant treatment regimens possible. In synergy, animal models of CIM provide the basic physiological understanding and the new ideas for treatment that are required to make competent decisions in clinical practice.

SNP-SNP Interaction between TLR4 and MyD88 in Susceptibility to Coronary Artery Disease in the Chinese Han Population

The toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-dependent signaling pathway plays a role in the initiation and progression of coronary artery disease (CAD). We investigated SNP-SNP interactions between the TLR4 and MyD88 genes in CAD susceptibility and assessed whether the effects of such interactions were modified by confounding risk factors (hyperglycemia, hyperlipidemia and Helicobacter pylori (H. pylori) infection). Participants with CAD (n = 424) and controls (n = 424) without CAD were enrolled. Polymerase chain restriction-restriction fragment length polymorphism was performed on genomic DNA to detect polymorphisms in TLR4 (rs10116253, rs10983755, and rs11536889) and MyD88 (rs7744). H. pylori infections were evaluated by enzyme-linked immunosorbent assays, and the cardiovascular risk factors for each subject were evaluated clinically. The significant interaction between TLR4 rs11536889 and MyD88 rs7744 was associated with an increased CAD risk (p value for interaction = 0.024). In conditions of hyperglycemia, the interaction effect was strengthened between TLR4 rs11536889 and MyD88 rs7744 (p value for interaction = 0.004). In hyperlipidemic participants, the interaction strength was also enhanced for TLR4 rs11536889 and MyD88 rs7744 (p value for interaction = 0.006). Thus, the novel interaction between TLR4 rs11536889 and MyD88 rs7744 was related with an increased risk of CAD, that could be strengthened by the presence of hyperglycemia or hyperlipidemia.

The association between toll-like receptor 4 polymorphisms and diabetic retinopathy in Chinese patients with type 2 diabetes

PURPOSE

Diabetic retinopathy (DR) is one of the secondary microvascular complications of type 2 diabetes mellitus. Persistent inflammation and impaired neovascularisation may be important contributors to the development of DR. A recent study showed that toll-like receptor 4 (TLR4) polymorphisms were associated with DR. The present study was designed to determine whether single-nucleotide polymorphisms (SNPs) in the TLR4 gene were associated with DR in a Chinese Han population.

MATERIALS AND METHODS

Three SNPs (rs10759931, rs1927911 and rs1927914) in the TLR4 gene were chosen as candidate SNPs. Genomic DNA from type 2 diabetes patients and healthy controls were genotyped for the above-mentioned genetic variations through the use of PCR restriction fragment length polymorphism assay. Data were analysed by χ(2) analysis.

RESULTS

The results showed that the three analysed polymorphisms in the TLR4 gene were in Hardy-Weinberg equilibrium, both in the patients and in the controls. In the type 2 diabetes group, a significantly higher frequency of the C allele of rs1927914 was observed in patients with type 2 diabetes than that in controls. The result showed that the frequencies of the TT genotype and the T allele of rs1927914 were significantly decreased in patients with type 2 diabetes. Significantly increased frequencies of the CC genotype and the C allele of rs1927911 were observed in patients with type 2 diabetes. In the DR group, the C allele of rs1927914 was significantly increased in the DR group compared with that of the control. The frequencies of the CC genotype and the C allele of rs1927911 tended to be higher in patients with DR than in the healthy controls. However, no difference was found when the Bonferroni correction was applied. No difference was detected between patients and controls with regard to all haplotypes.

CONCLUSIONS

This study suggested that rs1927914 and rs1927911 were associated with type 2 diabetes mellitus and that rs1927914 was associated with susceptibility to DR in a Han Chinese population.

Associations of toll-like receptor (TLR)-4 single nucleotide polymorphisms and rheumatoid arthritis disease progression: an observational cohort study

OBJECTIVE

To examine the associations of toll-like receptor (TLR)-4 single nucleotide polymorphisms (SNPs) with disease progression in rheumatoid arthritis (RA).

METHODS

A total of 1188 RA patients were genotyped for TLR4 SNPs (rs1927911, rs11536878, and rs4986790). Measures of disease activity were examined, including Disease Activity Score-28 (DAS28), Multidimensional Health Assessment Questionnaire (MD-HAQ), Clinical Disease Activity Index (CDAI), and Simplified Disease Activity Index (SDAI). Genetic associations with these longitudinal measures were examined using generalized estimating equations in both univariate and multivariate analyses. Analyses were then stratified by antigen specific anti-citrullinated peptide antibody (ACPA) status including antibody to citrullinated fibrinogen and citrullinated histone H2B.

RESULTS

Disease activity measures progressed less over time in the homozygous minor allele group of rs1927911 including DAS28 (p<0.001), CDAI (p=0.008), and MD-HAQ (p=0.015) in univariate analysis and DAS28, CDAI and SDAI in multivariate analysis. Disease activity progression among those homozygous for the minor allele tended to be lower in the groups with positive ACPA though major differences by autoantibody status were not identified. There were no associations of TLR4 rs11536878 and rs4986790 SNPs with RA disease activity progression.

CONCLUSIONS

In this population, TLR4 rs1927911 genotypes are associated with disease activity independent of other covariates.

The association of polymorphisms of TLR4 and CD14 genes with susceptibility to sepsis in a Chinese population

Background

Sepsis is now the leading cause of death in the non-cardiovascular intensive care unit (ICU). Recent research suggests that sepsis is likely to be due to an interaction between genetic and environmental factors. Genetic mutations of toll-like receptor 4 (TLR4) and cluster of differentiation 14 (CD14) genes are involved in the immune and (or) inflammatory response. These may contribute to the susceptibility to sepsis in patients. This study was designed to evaluate whether the TLR4 and cluster CD14 gene polymorphisms are associated with susceptibility to sepsis.

Methods

The single nucleotide polymorphisms (SNPs) of TLR4 (rs10759932, rs11536889, rs7873784, rs12377632, rs1927907, rs1153879) and CD14 (rs2569190 and rs2563298) in patients with sepsis and control subjects in the Guangxi Province were analyzed by using the polymerase chain reaction-single base extension (PCR-SBE) and DNA sequencing methods.

Results

The rs11536889 polymorphism in TLR4 and rs2563298 polymorphism in CD14 were significantly associated with the risk of sepsis when compared to the control group. The frequencies of rs11536889 and rs2563298 polymorphisms in the group with sepsis were higher than that in the control group (OR = 1.430, 95% CI, 1.032-1.981, P<0.05; OR = 2.454, 95% CI, 1.458-4.130, P<0.05, respectively). Followed up haplotype analysis suggested that there were two haplotypes in which increased risk factors for sepsis were indicated.

Conclusions

The rs11536889 polymorphism in TLR4 and rs2563298 polymorphism in CD14, and two haplotypes were associated with increased susceptibility to sepsis.

Mucosal barrier injury, fever and infection in neutropenic patients with cancer: introducing the paradigm febrile mucositis

Infection remains one of the most prominent complications after cytotoxic treatment for cancer. The connection between neutropenia and both infections and fever has long been designated as 'febrile neutropenia', but treatment with antimicrobial agents and haematopoietic growth factors has failed to significantly reduce its incidence. Moreover, emerging antimicrobial resistance is becoming a concern that necessitates the judicious use of available antimicrobial agents. In addition to neutropenia, patients who receive cytotoxic therapy experience mucosal barrier injury (MBI) or 'mucositis'. MBI creates a port-de-entrée for resident micro-organisms to cause blood stream infections and contributes directly to the occurrence of fever by disrupting the highly regulated host-microbe interactions, which, even in the absence of an infection, can result in strong inflammatory reactions. Indeed, MBI has been shown to be a pivotal factor in the occurrence of inflammatory complications after cytotoxic therapy. Hence, the concept 'febrile neutropenia' alone may no longer suffice and a new concept 'febrile mucositis' should be recognized as the two are at least complementary. This review we summarizes the existing evidence for both paradigms and proposes new therapeutic approaches to tackle the perturbed host-microbe interactions arising from cytotoxic therapy-induced tissue damage in order to reduce fever in neutropenic patients with cancer.

Effect of the -2081G/A polymorphism of the TLR4 gene and its interaction with Helicobacter pylori infection on the risk of gastric cancer in Chinese individuals

AIMS

Toll-like receptor 4 (TLR4) plays an important role in gastric carcinoma. Using a case-control study, we analyzed the genotypic distribution of TLR4 rs10983755 (-2081G/A) and rs11536878 in a Chinese population and investigated the effect of their interactions with Helicobacter pylori infection on susceptibility to gastric cancer (GC) and atrophic gastritis (AG).

METHODS

In this study, 409 and 581 cases of GC and AG, respectively, were selected for analyses along with an equal number of matched controls. The TLR4 polymorphisms were genotyped using Sequenom MassARRAY. Serum levels of anti-H. pylori IgG were determined by enzyme-linked immunosorbent assay.

RESULTS

The TLR4-2081G/A polymorphism was negatively associated with GC (AG+AA vs. GG: odds ratio [OR]=0.70, 95% confidence interval [CI]=0.53-0.93, p=0.012). A decreased risk of GC was observed in H. pylori negative and TLR4-2081(AG+AA) genotype subjects [H. pylori(-)/AG+AA vs. H. pylori(+)/GG: OR=0.16, 95% CI=0.09-0.27, p<0.001]. The rs11536878 polymorphism was not associated with GC or AG.

CONCLUSIONS

The TLR4-2081G/A polymorphism seems to affect the risk of gastric carcinogenesis and may to some degree play a protective role against H. pylori infection.

The regulatory toll-like receptor 4 genetic polymorphism rs11536889 is associated with renal, coagulation and hepatic organ failure in sepsis patients

BACKGROUND

Toll-like receptor 4 (TLR4), a lipopolysaccharide (LPS) receptor complex signal-transducing molecule, plays a crucial role in sensing LPS from gram-negative bacteria. TLR4 signaling pathway activation by LPS plays a major role in sepsis pathogenesis. A single nucleotide polymorphism, rs11536889, in the 3'-untranslated region of the TLR4 gene is thought to affect TLR4 translation. This study aimed to investigate whether organ failure in sepsis patients is related to the TLR4 rs11536889 genotype.

METHODS

Adult Caucasian patients with sepsis from the intensive care unit of a university medical center were followed up for 90 days, and organ failure was recorded as the primary outcome variable. Blood samples were collected at enrollment for TLR4 rs11536889 genotyping. Sepsis-related organ failure assessment (SOFA) scores were quantified at sepsis onset and throughout the observational period to monitor organ failure.

RESULTS

A total of 210 critically ill patients with sepsis were enrolled into this study. Wild-type GG was compared to GC/CC. During their stay in the intensive care unit, GG patients presented significantly higher SOFA scores than did C allele carriers (7.9 ± 4.5 and 6.8 ± 4.2, respectively; p = 0.0005). Analysis of organ-specific SOFA sub-scores revealed significant differences in three organ systems: renal, coagulation and hepatic (p = 0.0005, p = 0.0245 and p < 0.0001, respectively). Additionally, the rs11536889 polymorphism was associated with a higher incidence of gram-negative infections.

CONCLUSIONS

These results offer the first evidence that TLR4 rs11536889 is a useful marker of organ failure in patients with sepsis.

Association of Toll-like receptor 4 polymorphisms with diabetic foot ulcers and application of artificial neural network in DFU risk assessment in type 2 diabetes patients

The Toll-Like receptor 4 (TLR4) plays an important role in immunity, tissue repair, and regeneration. The objective of the present work was to evaluate the association of TLR4 single nucleotide polymorphisms (SNPs) rs4986790, rs4986791, rs11536858 (merged into rs10759931), rs1927911, and rs1927914 with increased diabetic foot ulcer (DFU) risk in patients with type 2 diabetes mellitus (T2DM). PCR-RFLP was used for genotyping TLR4 SNPs in 125 T2DM patients with DFU and 130 controls. The haplotypes and linkage disequilibrium between the SNPs were determined using Haploview software. Multivariate linear regression (MLR) and artificial neural network (ANN) modeling was done to observe their predictability for the risk of DFU in T2DM patients. Risk genotypes of all SNPs except rs1927914 were significantly associated with DFU. Haplotype ACATC (P value = 9.3E − 5) showed strong association with DFU risk. Two haplotypes ATATC (P value = 0.0119) and ATGTT (P value = 0.0087) were found to be protective against DFU. In conclusion TLR4 SNPs and their haplotypes may increase the risk of impairment of wound healing in T2DM patients. ANN model (83%) is found to be better than the MLR model (76%) and can be used as a tool for the DFU risk assessment in T2DM patients.

A single nucleotide polymorphism in 3'-untranslated region contributes to the regulation of Toll-like receptor 4 translation

We have previously shown that a single nucleotide polymorphism rs11536889 in the 3'-untranslated region (UTR) of TLR4 was associated with periodontitis. In this study the effects of this single nucleotide polymorphism on Toll-like receptor (TLR) 4 expression were investigated. Monocytes from subjects with the C/C genotype expressed higher levels of TLR4 on their surfaces than those from subjects with the other genotypes. Peripheral blood mononuclear cells (PBMCs) from the C/C and G/C subjects secreted higher levels of IL-8 in response to lipopolysaccharide (LPS), a TLR4 ligand, than the cells from the G/G subjects. However, there was no significant difference in TLR4 mRNA levels in PBMCs from the subjects with each genotype. After stimulation with tripalmitoylated CSK(4) (Pam(3)CSK(4)), TLR4 mRNA levels increased in PBMCs from both the C/C and G/G subjects, whereas TLR4 protein levels increased in PBMCs from the C/C but not G/G subjects. Transient transfection of a series of chimeric luciferase constructs revealed that a fragment of 3'-UTR containing rs11536889 G allele, but not C allele, suppressed luciferase activity induced by LPS or IL-6. Two microRNAs, hsa-miR-1236 and hsa-miR-642a, were predicted to bind to rs11536889 G allele. Inhibition of these microRNAs reversed the suppressed luciferase activity. These microRNA inhibitors also up-regulated endogenous TLR4 protein on THP-1 cells (the G/G genotype) after LPS stimulation. Furthermore, mutant microRNAs that bind to the C allele inhibited the luciferase activity of the construct containing the C allele. These results indicate that genetic variation of rs11536889 contributes to translational regulation of TLR4, possibly by binding to microRNAs.

Lack of association between gene polymorphisms of Angiotensin converting enzyme, Nod-like receptor 1, Toll-like receptor 4, FAS/FASL and the presence of Helicobacter pylori-induced premalignant gastric lesions and gastric cancer in Caucasians

Background

Several polymorphisms of genes involved in the immunological recognition of Helicobacter pylori and regulating apoptosis and proliferation have been linked to gastric carcinogenesis, however reported data are partially conflicting. The aim of our study was to evaluate potential associations between the presence of gastric cancer (GC) and high risk atrophic gastritis (HRAG) and polymorphisms of genes encoding Angiotensin converting enzyme (ACE), Nod-like receptor 1 (NOD1), Toll-like receptor 4 (TLR4) and FAS/FASL.

Methods

Gene polymorphisms were analyzed in 574 subjects (GC: n = 114; HRAG: n = 222, controls: n = 238) of Caucasian origin. ACE I/D (rs4646994), NOD1 796G>A (rs5743336), TLR4 3725G>C (rs11536889), FAS 1377G>A (rs2234767), FAS 670A>G (rs1800682) and FASL 844T>C (rs763110) were genotyped by different PCR approaches and restriction fragment length polymorphism analysis.

Results

Frequencies of genotypes in our study are similar to the data reported on subjects of Caucasian ethnicity. There was a tendency for NOD1 796G/G genotype to be associated with increased risk of HRAG (62.4% vs. 54.5% in controls, p = 0.082). FAS 670G/G genotype was more frequent in HRAG when compared to controls, 23.9% and 17.2% respectively, however it failed to reach significance level (p = 0.077). We did not find any significant associations for all polymorphisms in relation to GC or HRAG. NOD1 796G>A and TLR4 3725G>C gene polymorphisms were also not associated with Helicobacter pylori infection.

Conclusions

ACE, NOD1, TRL4 and FAS/FASL gene polymorphisms are not linked with gastric carcinogenesis in Caucasians, and therefore they should not be considered as potential biomarkers for identifying individuals with higher risk for GC.