Polymorphisms of the TLR4 gene and risk of gastric cancer

The association of TLR4 gene polymorphisms with the severity of peritonitis in acute inflammatory diseases of the abdominal cavity organs

OBJECTIVE

Aim: To determine the role of TLR4 gene polymorphisms as risk factors for peritonitis severity in patients undergoing surgery for acute inflammatory diseases of the abdominal cavity.

PATIENTS AND METHODS

Materials and Methods: The study included 139 patients who were operated on for acute abdominal diseases (acute appendicitis and cholecystitis, perforated gastric or duodenal ulcer, etc.). Depending on the number of points on the modified APACHE II scale, patients were divided into two groups: Group 1 - 1-3 points (63 patients, 45.3%) and Group 2 - 4 or more points (76 patients, 54.7%). Polymorphisms rs1927911, rs2149356 and rs4986790 were determined by polymerase chain reaction.

RESULTS

Results: The rs1927911 polymorphism of the TLR4 gene was protective for the development of peritonitis (according to the allelic model, OR 0.48; 95% CI 0.27-0.84; p=0.015). Regression analysis revealed a reduced (p=0.015) risk of severe peritonitis in rs1927911 A/A or G/A genotype carriers (OR 0.42; 95% CI 0.21-0.84) compared with G/G genotype carriers. There was no effect on the severity of peritonitis of TLR4 polymorphisms rs2149356 and rs4986790. There was a tendency to increase the frequency of the mutant G rs4986790 allele in patients with severe peritonitis (χ2=2.17; p<0.001). The analysis of the association of TLR4 gene polymorphisms with the phenotype of patients showed that carriers of mutant homozygotes and heterozygotes in the presence of severe peritonitis were older, had a tendency to coagulopathy, higher leukocytosis and leukocyte clotting rate.

CONCLUSION

Conclusions: Thus, the importance of TLR in the development of severe peritonitis was confirmed and the protective role of the rs1927911 promoter polymorphism was established.

Association between TLR2, TLR4, and TLR5 genetic variants and the risk of hepatocellular carcinoma in Moroccan population

Hepatocellular carcinoma (HCC) is the fifth most common human malignancy and the fourth most frequent cause of cancer-related deaths worldwide. Toll-like receptors (TLRs), are known to play a key role in hepatocarcinogenesis through induction of inflammation. We aimed to investigate the association between TLR2 rs3804099, TLR4 rs4986790, rs4986791, and rs11536889 and TLR5 rs5744174 and HCC risk in a total of 306 Moroccan subjects, including 152 HCC patient and 154 controls using a TaqMan allelic discrimination assay. Our result showed that the frequency of TLR4 rs11536889 C allele was higher in control group than in HCC patients (OR = 0.52, 95% CI = 0.30-0.88, p = 0.01). Moreover, under the dominant model, we observed that CG/CC genotypes were protective factors against HCC risk (OR = 0.51, 95% CI = 0.28-0.91, p = 0.02). However, no significant differences were found in the allele and genotype frequencies of TLR4 rs4986790 and rs4986791, between HCC patients and controls. Similarly, genotypic frequencies of TLR2 and TLR5 polymorphisms did not differ significantly between HCC patients and controls. However, TLR4 haplotype analysis revealed that ACC haplotype may be protective of HCC risk in patients with HCC (OR = 0.53, 95% CI = 0.31-0.92, p = 0.02). In conclusion, our result suggest that TLR4 rs11536889 polymorphism and ACC haplotype may decrease risk of hepatocellular carcinoma in Moroccan population.

An updated systematic review of the association between the TLR4 polymorphism rs4986790 and cancers risk

BACKGROUND

Toll-like receptor 4 (TLR4) is a lipopolysaccharide receptor that may influence tumor progression through inflammatory response and immune response. This complex process mainly occurs within cells. The correlation between TLR4 and neoplasms has been of great interest, but discrepancies remain.

METHODS

We analyze the literature retrieved from five databases (Web of Science, PubMed, Embase, CNKI, and Wan Fang) to assess the intensity of association using odds ratio (ORs) and 95% confidence intervals (95% CI). Meta-regression and subgroup analysis were utilized to find sources of heterogeneity. Publication bias is estimated using contour-enhanced funnel plots, Begg's test, and Egger's test, and we implemented sensitivity analysis to clarify the reliability of the outcomes. We also conducted an evaluation of the sample size using trial sequential analysis (TSA) method.

RESULTS

We found a significant association between rs4986790 and tumors (dominant model: OR [95% CI] = 1.25 [1.11-1.42]; heterozygous model OR [95% CI] = 1.25 [1.11-1.41]; and additive model: OR [95% CI] = 1.25 [1.10-1.41]. Specifically, the rs4986790 minor allele G may increase the risk of gastric cancer (dominant model: OR [95% CI] = 1.62 [1.3-2.03]; heterozygous model: OR [95% CI] = 1.57 [1.24-1.97]; additive model: OR [95% CI] = 1.64 [1.31-2.05] and other tumors (dominant model: OR [95% CI] = 1.36 [1.17-1.57]; heterozygous model: OR [95% CI] = 1.43 [1.25-1.63]; additive model: OR [95% CI] = 1.35 [1.18-1.55]. Further subgroup analysis showed that this association are both present in Caucasian and Asian.

CONCLUSION

The outcomes of our systemic review proved that the TLR4 polymorphism rs4986790 is associated with cancer, especially with gastric cancer, and this strong correlation are evident in Caucasians and Asian.

Toll-Like Receptor 4 Gene Polymorphisms and Susceptibility to Schizophrenia: A Case-Control Study

Schizophrenia is a common psychiatric disorder that exhibits a variety of symptoms. The exact etiology and pathogenesis are still doubtful. However, genetic and environmental factors seem to have a role. Years ago, the role of the immune system was focused on auto-antibodies, cytokines, different types of immune cells and immune genes. The Toll-like receptors (TLR) are a cornerstone of the innate immune system, particularly TLR4. TLR4 primarily recognises gram-negative lipopolysaccharides bacteria. This case-control study, for the first time to our knowledge, examined the role of TLR4 gene polymorphisms in 142 Egyptian schizophrenic patients and 175 healthy controls. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), four single nucleotide polymorphisms (SNPs) were investigated in the TLR4 gene rs11536889, rs10759931, rs1927911, and rs1927914. The Positive and Negative Syndrome Scale (PANSS) was used in diagnosis and assessment. A statistically significant association was observed between rs11536889, rs1927911 and rs1927914, but no association was found between rs10759931. There was no association between the different SNP genotypes and PANSS, except between rs1927914 and general psychopathologic symptoms. This study shows a strong association between TLR4 rs11356889 and rs1927911 minor alleles and schizophrenia. These findings could be additional evidence for the immune system's role in schizophrenia development. However, more studies with a more significant sample number, TLR4 protein assessment, and a larger number of SNPs are recommended.

Germline Genetic Variants of Viral Entry and Innate Immunity May Influence Susceptibility to SARS-CoV-2 Infection: Toward a Polygenic Risk Score for Risk Stratification

The ongoing COVID-19 pandemic caused by the novel coronavirus, SARS-CoV-2 has affected all aspects of human society with a special focus on healthcare. Although older patients with preexisting chronic illnesses are more prone to develop severe complications, younger, healthy individuals might also exhibit serious manifestations. Previous studies directed to detect genetic susceptibility factors for earlier epidemics have provided evidence of certain protective variations. Following SARS-CoV-2 exposure, viral entry into cells followed by recognition and response by the innate immunity are key determinants of COVID-19 development. In the present review our aim was to conduct a thorough review of the literature on the role of single nucleotide polymorphisms (SNPs) as key agents affecting the viral entry of SARS-CoV-2 and innate immunity. Several SNPs within the scope of our approach were found to alter susceptibility to various bacterial and viral infections. Additionally, a multitude of studies confirmed genetic associations between the analyzed genes and autoimmune diseases, underlining the versatile immune consequences of these variants. Based on confirmed associations it is highly plausible that the SNPs affecting viral entry and innate immunity might confer altered susceptibility to SARS-CoV-2 infection and its complex clinical consequences. Anticipating several COVID-19 genomic susceptibility loci based on the ongoing genome wide association studies, our review also proposes that a well-established polygenic risk score would be able to clinically leverage the acquired knowledge.

TLR4 promoter rs1927914 variant contributes to the susceptibility of esophageal squamous cell carcinoma in the Chinese population

Background

Toll-like receptor 4 (TLR4), as a key regulator of both innate and acquired immunity, has been linked with the development of various cancers, including esophageal cancer. This study aims to analyze the association of potential functional genetic polymorphisms in TLR4 with the risk of esophageal cancer.

Methods

This case-control study involved in 480 ESCC patients and 480 health controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype TLR4 rs1927914 polymorphism. Taqman probe method was used to determine the genotypes of TLR4 rs11536891 and rs7873784 variants. The relationship between TLR4 genetic variation and ESCC risk was analyzed by Logistic regression model by calculating the odds ratio (OR) and 95% confidence interval (95% CI).

Results

Compared with TLR4 rs1927914 AA genotype carriers, GG carriers had a lower ESCC risk (OR = 0.59, 95% CI [0.38–0.93], P = 0.023). Stratification analysis by age showed that TLR4 rs1927914 GG could affect the risk of ESCC in elderly people (OR = 0.59, 95% CI [0.36–0.97]). Smoking stratification analysis indicated that rs1927914 GG carriers were related to ESCC susceptibility among non-smokers (OR = 0.36, 95% CI [0.18–0.73]). Dual luciferase reporter assay suggested that rs1927914 G-containing TLR4 promoter displayed a 1.76-fold higher luciferase activity than rs1927914 A-containing counterpart in KYSE30 cells. Electrophoretic mobility shift assay (EMSA) showed the KYSE30 cell nuclear extract was able to bind the probe with rs1927914 G allele and this DNA-protein interaction could be eliminated by competition assays with unlabeled rs1927914 G probe, which indicating that the binding is sequence-specific. Our results also showed that TLR4 rs7873784 (G>C) and rs11536891 (T>C) conformed to complete genetic linkage. The genotype distributions of TLR4 rs11536891 variant among ESCC patients and normal controls have no statistical significance.

Conclusion

The TLR4 rs1927914 variant contributes to the ESCC risk by effecting the promoter activity.

microRNA-365 inhibits YAP through TLR4-mediated IRF3 phosphorylation and thereby alleviates gastric precancerous lesions

Background

Gastric carcinoma (GC) is currently one of the most common malignant tumors of the digestive system, and gastric precancerous lesions play a vital role in studying the mechanism of GC. Multiple microRNAs (miRNAs) have been documented to be potential biomarkers to indicate progression of gastric precancerous lesions. In this study, we explained the anti-cancer effect of miR-365 in gastric precancerous lesions via regulation of the TLR4/IRF3/YAP/CDX2 axis.

Methods

miR-365, TLR4, CDX2 and IPF3 expression was determined in GC and atrophic gastritis tissues and cells. After transfection of shRNA and overexpression plasmids, in vitro experiments detected the alteration of cell viability, apoptosis and inflammatory factors. Bioinformatics analysis, Co-IP and dual luciferase reporter gene assay were conducted to evaluate the binding between miR-365 and TLR4 as well as IRF3 and YAP. Rat models were established to explore the effect of the miR-365 and TLR4 on gastric precancerous lesions.

Results

miR-365 was poorly expressed in GC and atrophic gastritis tissues and GC cell lines, while TLR4, CDX2 and IRF3 were overexpressed. Of note, miR-365 was indicated to target TLR4 and thereby suppressed cancer progression and increased hemoglobin content. Interestingly, silencing of TLR4 was accompanied by decreased IRF3 phosphorylation and reduced expression with less binding between CDX2 and IRF3. Downregulation of YAP resulted in declined CDX2 expression in cancer cells. Moreover, the inhibitory role of miR-365 was further confirmed in animal models.

Conclusion

Taken together, miR-365-mediated TLR4 inhibition reduces IRF3 phosphorylation and YAP-mediated CDX2 transcription to impede progression of gastric precancerous lesions.

A Scoping Review of Interactions between Omega-3 Long-Chain Polyunsaturated Fatty Acids and Genetic Variation in Relation to Cancer Risk

This scoping review examines the interaction of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and genetic variants of various types of cancers. A comprehensive search was performed to identify controlled and observational studies conducted through August 2017. Eighteen unique studies were included: breast cancer (n = 2), gastric cancer (n = 1), exocrine pancreatic cancer (n = 1), chronic lymphocytic leukemia (n = 1), prostate cancer (n = 7) and colorectal cancer (n = 6). An additional 13 studies that focused on fish intake or at-risk populations were summarized to increase readers’ understanding of the topic based on this review, DHA and EPA interact with certain genetic variants to decrease breast, colorectal and prostate cancer risk, although data was limited and identified polymorphisms were heterogeneous. The evidence to date demonstrates that omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) may decrease cancer risk by affecting genetic variants of inflammatory pathways, oxidative stress and tumor apoptosis. Collectively, data supports the notion that once a genetic variant is identified, the benefits of a targeted, personalized therapeutic regimen that includes DHA and/or EPA should be considered.

TLR4 Polymorphisms and Expression in Solid Cancers

Toll-like receptors (TLRs) are a type of pattern-recognition receptor (PRR) that are part of the innate immune system known to recognize pathogen-associated molecular patterns and thereby play a crucial role in host immune response. Among the various known TLRs, TLR4 is one of the most extensively studied PRRs expressed by immune, certain nonimmune, and tumor cells. When TLR4 binds with the bacterial lipopolysaccharide, it induces production of proinflammatory cytokines, chemokines, and effector molecules as part of the immune response. Continuous exposure to pathogens and TLR4 signaling results in chronic inflammation that may further lead to malignant transformation. TLR4 is a highly polymorphic gene, and genetic variations are known to influence host immune response, leading to dysregulation of signaling pathway, which may affect an individual's susceptibility to various diseases, including cancer. Furthermore, TLR4 expression in different tumor types may also serve as a marker for tumor proliferation, differentiation, metastasis, prognosis, and patient survival. This review aims to summarize various reports related to TLR4 polymorphisms and expression patterns and their influences on different cancer types with a special focus on solid tumors.

Polymorphisms of TGFBR1, TLR4 are associated with prognosis of gastric cancer in a Chinese population

Background

Helicobacter pylori (H. pylori)-induced gastric cancer is an intricate progression of immune response against H. pylori infection. IL-16, TGF-β1 and TLR4 pathways were the mediators involved in the immune response. We hypothesized that genetic variations in genes of these pathways have potential susceptibility to gastric cancer risk, and predict clinical outcomes of patients.

Methods

To investigate the susceptibility and prognostic value of genetic variations of IL-16, TGFBR1 and TLR4 pathways to gastric cancer, we performed a case–control study combined a retrospective study in a Chinese population. Genotyping for all polymorphisms was based on the Sequenom’s MassARRAY platform, and H. pylori infection was determined by using an immunogold testing kit.

Results

We found rs10512263 CC genotype was found to be a decreased risk of gastric cancer (CC vs. TT: adjusted OR = 0.54, 95% CI 0.31–0.97); however, rs334348 GG genotype was associated with increased risk of gastric cancer (GG vs. AA: adjusted OR = 1.51, 95% CI 1.05–2.18). We found that carriers harboring rs1927911 A allele (GA/AA) or rs10512263 C allele (CT/CC) have unfavorable survival time than none carriers (rs1927911: GA/AA vs. GG: adjusted HR = 1.27, 95% CI 1.00–1.63; rs10512263: CT/CC vs. TT: adjusted HR = 1.29, 95% CI 1.02–1.63) and that individuals harboring both two minor alleles (rs1927911 GA/AA and rs10512263 CT/CC) suffered a significant unfavorable survival (adjusted HR = 1.64, 95% CI 1.17–2.31).

Conclusion

In short, we concluded that two polymorphisms (rs334348, rs10512263) in TGFBR1 were associated with risk of gastric cancer, and that TLR4 rs1927911 and TGFBR1 rs10512263 were associated with clinical outcomes of gastric cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0682-0) contains supplementary material, which is available to authorized users.

Exploring Spatial Trends and Influencing Factors for Gastric Cancer Based on Bayesian Statistics: A Case Study of Shanxi, China

Gastric cancer (GC) is the fourth most common type of cancer and the second leading cause of cancer-related deaths worldwide. To detect the spatial trends of GC risk based on hospital-diagnosed patients, this study presented a selection probability model and integrated it into the Bayesian spatial statistical model. Then, the spatial pattern of GC risk in Shanxi Province in north central China was estimated. In addition, factors influencing GC were investigated mainly using the Bayesian Lasso model. The spatial variability of GC risk in Shanxi has the conspicuous feature of being 'high in the south and low in the north'. The highest GC relative risk was 1.291 (95% highest posterior density: 0.789⁻4.002). The univariable analysis and Bayesian Lasso regression results showed that a diverse dietary structure and increased consumption of beef and cow milk were significantly (p ≤ 0.08) and in high probability (greater than 68%) negatively associated with GC risk. Pork production per capita has a positive correlation with GC risk. Moreover, four geographic factors, namely, temperature, terrain, vegetation cover, and precipitation, showed significant (p < 0.05) associations with GC risk based on univariable analysis, and associated with GC risks in high probability (greater than 60%) inferred from Bayesian Lasso regression model.

Genetic Variability as a Regulator of TLR4 and NOD Signaling in Response to Bacterial Driven DNA Damage Response (DDR) and Inflammation: Focus on the Gastrointestinal (GI) Tract

The fundamental role of human Toll-like receptors (TLRs) and NOD-like receptors (NLRs), the two most studied pathogen recognition receptors (PRRs), is the protection against pathogens and excessive tissue injury. Recent evidence supports the association between TLR/NLR gene mutations and susceptibility to inflammatory, autoimmune, and malignant diseases. PRRs also interfere with several cellular processes, such as cell growth, apoptosis, cell proliferation, differentiation, autophagy, angiogenesis, cell motility and migration, and DNA repair mechanisms. We briefly review the impact of TLR4 and NOD1/NOD2 and their genetic variability in the process of inflammation, tumorigenesis and DNA repair, focusing in the gastrointestinal tract. We also review the available data on new therapeutic strategies utilizing TLR/NLR agonists and antagonists for cancer, allergic diseases, viral infections and vaccine development against both infectious diseases and cancer.

Promoter Polymorphism of Toll-Like Receptor 4 is Associated with a Decreased Risk of Coronary Artery Disease: A Case-Control Study in the Chinese Han Population

Background

Coronary artery disease (CAD) is considered a chronic inflammatory disease of the blood vessels. Toll-like receptor 4 (TLR4) is a transmembrane receptor involved in inflammatory reactions. The aim of this study was to determine the association between polymorphisms in the promoter region and 3′-untranslated region (3′-UTR) of TLR4, and the associated CAD risk.

Material/Methods

This study enrolled 424 participants with CAD and 424 controls without CAD. The polymorphisms in the promoter region and 3′-UTR of TLR4 were identified from the HapMap database, including rs10116253, rs10983755, and rs11536889. Genomic DNA was extracted from peripheral blood. Polymerase chain reaction-restriction fragment length polymorphism was performed to identify genotype polymorphisms. Relative luciferase activity was measured using the dual-luciferase reporter assay system.

Results

TLR4 rs10116253 in the promoter region was associated with CAD risk. The variant (CC+TC) genotypes of rs10116253 were associated with a decreased CAD risk (OR 95% CI 0.73 (0.54–0.98), p=0.034). In the stratification analyses, the variant (CC+TC) genotypes of rs10116253 were observed to have a relationship with decreased CAD risk in the male subgroup (OR: 95% CI 0.68 (0.48–0.98), p=0.041). Moreover, the variant CC and (CC+TC) genotypes of rs10116253 were correlated with a decreased CAD risk in participants younger than 60-year-old (TC: OR (95% CI 0.62 (0.39–0.98), p=0.042; TC+CC: OR 95% CI 0.63 (0.41–0.98), p=0.039). Regarding rs10116253, the luciferase activity of the mutant C allele construct was lower than that of the wild T allele construct (5.215±0.009 vs. 5.304±0.041; p=0.087).

Conclusions

The results provided evidence of an association between the TLR4 rs10116253 in the promoter region and a reduced risk of CAD.

Association of the AURKA and AURKC gene polymorphisms with an increased risk of gastric cancer

Single nucleotide polymorphisms (SNPs) in mitotic checkpoint genes can contribute to susceptibility of human cancer, including gastric cancer (GC). We aimed to investigate the effects of Aurora kinase A (AURKA), Aurora kinase B (AURKB), and Aurora kinase C (AURKC) gene polymorphisms on GC risk in Slovenian population. We genotyped four SNPs in AURKA (rs2273535 and rs1047972), AURKB (rs2241909), and AURKC (rs758099) in a total of 128 GC patients and 372 healthy controls using TaqMan allelic discrimination assays to evaluate their effects on GC risk. Our results showed that genotype frequencies between cases and controls were significantly different for rs1047972 and rs758099 (P < 0.05). Our study demonstrated that AURKA rs1047972 TT and (CC + CT) genotypes were significantly associated with an increased risk of gastric cancer. Our results additionally revealed that AURKC rs758099 TT and (CC + CT) genotypes were also associated with increased GC risk. In stratified analysis, genotypes TT and (CC + CT) of AURKA rs1047972 SNP were associated with increased risk of both, intestinal and diffuse, types of GC. In addition, AURKC rs758099 TT and (CC + CT) genotypes were positively associated with increased intestinal type GC risk, but not with an increased diffuse type GC risk. Based on these results, we can conclude that AURKA rs1047972 and AURKC rs758099 polymorphisms could affect the risk of GC development. Further larger studies are needed to confirm these findings. © 2016 IUBMB Life, 68(8):634-644, 2016.

Association of FokⅠ polymorphism in vitamin D receptor gene with risk of gastric cancer in a Xinjiang Uygur population

AIM: To investigate whether the FokⅠ polymorphism in the vitamin D receptor gene is associated with risk of gastric cancer.

METHODS: A total of 147 Uygur patients with gastric cancer (group A) were randomly selected from March 2013 to May 2015 in the Tumor Hospital of Xinjiang Medical University, and 151 healthy Uygur people (group B) were used as controls. The FokⅠ polymorphism in the vitamin D receptor gene was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, followed by an intergroup comparison. By PCR-RFLP test, all the patients with gastric cancer were divided into an FF group (a) and an Ff + ff group (b) according to whether the patient carried the allele f. The D-dimer level of the two groups was then compared.

RESULTS: The frequency of the allele f in gastric cancer patients was higher than that in the control group (57.8% vs 47.4%, P < 0.05). Multivariate logistic regression analysis showed that the study subjects carrying the allele f (Ff + ff) had a higher gastric cancer risk than those without (FF) (OR = 2.85). The D-dimer level in the Ff + ff group was significantly elevated compared with the FF group (2.79 ± 1.21 vs 1.09 ± 0.65, P < 0.05). As the differentiation of gastric cancer worsened, the percentage of patients only carrying the allele F (FF) decreased gradually (P < 0.05).

CONCLUSION: The FokⅠ polymorphism in the vitamin D receptor gene is associated with susceptibility to gastric cancer. The allele f may be one of the risk factors for gastric cancer, whereas the allele F may be a protective factor. Moreover, the levels of D-dimer in patients with gastric cancer carrying the allele f (Ff, ff) are significantly higher than those only carrying the allele F (FF), suggesting that the allele f may be a regulator of D-dimer and thus influences the onset or prognosis of gastric cancer in Uygur people.

FokI Polymorphism of the Vitamin D Receptor Gene Is Associated with Susceptibility to Gastric Cancer: A Case-Control Study

Vitamin D is a potential protective agent against cancer, and its activity is mediated mainly by vitamin D receptor (VDR). The FokI polymorphism (rs10735810) represents a T-to-C transition (ATG to ACG) in exon 2 of the VDR gene, and this ATG represents the translation-initiation codon, encoded by the f allele. The FokI polymorphism results in the generation of a protein shortened by three amino acids, translated from the downstream ATG codon (the F allele). We investigated the relationship between the FokI polymorphism and gastric cancer in a Chinese Han population. A total of 187 patients and 212 healthy controls were enrolled. The FokI polymorphism was detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. The f allele frequency was higher in patients than that in controls (51.6% and 43.6%, P < 0.05). Multivariate logistics regression analysis revealed patients with the f allele (Ff + ff) showed a higher risk of gastric cancer [odds ratio (95% confidence interval) 2.73 (1.13~4.32)]. Patients with the f allele (Ff + ff) also presented a poorly differentiated type of gastric cancer (P < 0.05) and higher levels of C-reactive protein on admission than the FF group (5.5 ± 2.4 mg/L vs. 3.4 ± 1.3 mg/L, P < 0.05). Here, we show an association between the VDR FokI polymorphism and the susceptibility to gastric cancer, which may be helpful for early detection of high-risk individuals with the f allele for gastric cancer. Conversely, the F allele may be a protective factor against gastric cancer.

Host-microbe cross talk in cancer therapy

PURPOSE OF REVIEW

Microbiota secrete a multitude of factors that either confer virulence or promote colonization because they are continuously challenged by host immune responses. The dynamic interplay between the host's immune response and microbiota eventually determines the outcome for the host: health or disease. Toll-like receptors (TLRs) play a key role in this interplay as they can recognize both microbial and host-derived ligands on the basis of the context in which recognition occurs.

RECENT FINDINGS

Evidence is accumulating that conventional cancer therapies alter interactions and cross talks between the host and microbiota. This has been shown for intestinal mucositis, a common side-effect of various cancer therapies. Advances have been made in the development of new and less toxic cancer strategies. One promising field is immunotherapy on the basis of TLR activation through recognition of microbial-associated molecular patterns.

SUMMARY

Evidence is emerging, indicating that existing cancer therapies have implications on the composition and functionality of the host-microbiota environment. This may favor the colonization of pathogens and build up the overall toxicity of the drug. Exploitation of the host-microbiota cross talks mediated by TLRs is an emerging and promising field in the search for new, less toxic anticancer strategies.

Association of TLR4 gene polymorphisms with sporadic Parkinson's disease in a Han Chinese population

Parkinson's disease (PD) is considered as a multifactorial disorder involving complex interactions between genetic and environmental factors, while previous studies point to a pivotal role of neuroinflammation in the pathophysiology of PD. As a member of pattern recognition receptors, TLR4 plays an important role in the immune response and inflammatory responses. Growing evidences suggest that mutation of TLR4 gene may be connected with the development of PD. The objective of this study was to evaluate whether genetic polymorphisms of the TLR4 gene are associated with PD susceptibility. We genotyped three single-nucleotide polymorphisms of the TLR4 gene (rs1927911, rs1927914 and rs10116253) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) in unrelated 380 PD patients and 380 healthy-matched controls. Our study revealed that rs1927914 C allele carriers and C allele were probably related to a decreased risk of PD (p = 0.032 and p = 0.028, respectively) as well as male PD (p = 0.034) and early-onset PD (EOPD) (p = 0.023). In addition, there were significant differences in genotype and allele distribution in male PD patients and its healthy-matched control subgroup (p = 0.035 and p = 0.012, respectively). For rs1927911 and rs10116253 polymorphisms, genotype or allele frequencies did not differ between groups. Our data suggest that the TLR4 gene might contribute to the risk of developing PD in Han Chinese and rs1927914 polymorphism may be a protective factor for sporadic PD, male PD and EOPD.

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.

Toll-like receptor 4 gene polymorphism downregulates gene expression and involves in susceptibility to bladder cancer

Bladder cancer is the ninth most frequent malignancy in China. Toll-like receptor 4 (TLR4) is expressed on various cells and greatly involves in immune responses. Genetic polymorphism may affect the pathogenesis of diseases through various pathways. In the current study, we evaluated the association between genetic polymorphisms in TLR4 and risk of bladder cancer. We also examined the effect of the polymorphisms on gene expression. The TLR4 -729G/C and -260G/C polymorphisms were genotyped in 282 bladder cancer patients and 298 healthy controls in the Chinese population. Results showed that subjects with -729GC genotype are at significantly higher risk of bladder cancer than those with GG genotype [odds ratio (OR) = 2.50, 95% confidence interval (CI) = 1.39-4.48, P = 0.002]. Similarly, TLR4 -729C allele revealed a positive association with the disease (OR = 2.39, P = 0.002). The other polymorphism, TLR4 -260G/C, did not present clear correlations with bladder cancer. To understand the function of the polymorphisms, we evaluated TLR4 messenger RNA (mRNA) and protein levels in CD4+ T cells, CD8+ T cells, and monocytes from subjects carrying different TLR4 genotypes. Results revealed that subjects carrying -729GC genotype had significantly downregulated mRNA and protein levels of TLR4 in CD4+ T cells, CD8+ T cells, and monocytes compared to those carrying GG genotype. However, subjects with -260G/C polymorphism did not show any differences in gene expression from immune cells These data suggest that TLR4 polymorphism is associated with increased susceptibility to bladder cancer possibly by downregulating gene expression in various immune cells.

Genetics of gastric cancer

Gastric cancer remains highly prevalent and accounts for a notable proportion of global cancer mortality. This cancer is also associated with poor survival rates. Understanding the genetic basis of gastric cancer will offer insights into its pathogenesis, help identify new biomarkers and novel treatment targets, aid prognostication and could be central to developing individualized treatment strategies in the future. An inherited component contributes to <3% of gastric cancers; the majority of genetic changes associated with gastric cancer are acquired. Over the past few decades, advances in technology and high-throughput analysis have improved understanding of the molecular aspects of the pathogenesis of gastric cancer. These aspects are multifaceted and heterogeneous and represent a wide spectrum of several key genetic influences, such as chromosomal instability, microsatellite instability, changes in microRNA profile, somatic gene mutations or functional single nucleotide polymorphisms. These genetic aspects of the pathogenesis of gastric cancer will be addressed in this Review.

Effect of Mieyou decoction on TLRs/NF-κB65 signal pathway in mice with Helicobacter pylori associated gastritis with splenogastric hygropyrexia syndrome

AIM: To detect the gastric expression of Toll-like receptor 2 (TLR2), TLR4, nuclear factor-kappa B 65 (NF-κB65), and serum levels of interleukin-6 (IL-6) and IL-8 in mice with Helicobacter pylori (H. pylori) associated gastritis with splenogastric hygropyrexia syndrome (SGHS), and to investigate the mechanism underlying the therapeutic effect of Mieyou decoction in the treatment of chronic gastritis.

METHODS: BALB/c mouse were randomly divided into five groups: a control group, a model group, a high-concentration Mieyou decoction group, a low-concentrations Mieyou decoction group, and a triple therapy group (tinidazole, clarithromycin and bismuth potassium citrate granules), with 14 rats in each group. The BALB/c model of H. pylori-associated gastritis with SGHS using a composite method (fatness food + hygropyrexia environment + H. pylori). After the success of modeling, continuous administration 14 d. Immunohistochemistry was used to detect the expression TLR2, TLR4 and NF-κB65 proteins in gastric tissue; qPCR was used to detect the expression of TLR2, TLR4 and NF-κB65 mRNAs; ELISA was used to detect the levels of IL-6 and IL-8 in serum.

RESULTS: Compared with the control group, the expression of TLR2, TLR4, NF-κB65 proteins and mRNAs, and serum levels of IL-6 and IL-8 in the model group were significantly increased. After therapy, the expression of TLR2, TLR4, NF-κB65 proteins and mRNAs, and serum levels of IL-6 and IL-8 in the high-concentration Mieyou decoction group, low-concentration Mieyou decoction group, and triple therapy group were significantly decreased compared with the model group. The expression of TLR2, TLR4, NF-κB65 proteins and mRNAs, and serum levels of IL-6 and IL-8 in the high-concentration Mieyou decoction group were higher than those in the triple therapy group, but the differences were not statistically significant.

CONCLUSION: Mieyou decoction has a role in the treatment of H. pylori-associated gastritis with SGHS possibly by intervening the TLRs/NF-κB65 signal pathway.

Pattern-recognition receptors and gastric cancer

Chronic inflammation has been associated with an increased risk of several human malignancies, a classic example being gastric adenocarcinoma (GC). Development of GC is known to result from infection of the gastric mucosa by Helicobacter pylori, which initially induces acute inflammation and, in a subset of patients, progresses over time to chronic inflammation, gastric atrophy, intestinal metaplasia, dysplasia, and finally intestinal-type GC. Germ-line encoded receptors known as pattern-recognition receptors (PRRs) are critical for generating mature pro-inflammatory cytokines that are crucial for both Th1 and Th2 responses. Given that H. pylori is initially targeted by PRRs, it is conceivable that dysfunction within genes of this arm of the immune system could modulate the host response against H. pylori infection, and subsequently influence the emergence of GC. Current evidence suggests that Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR5, and TLR9), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) (NOD1, NOD2, and NLRP3), a C-type lectin receptor (DC-SIGN), and retinoic acid-inducible gene (RIG)-I-like receptors (RIG-I and MDA-5), are involved in both the recognition of H. pylori and gastric carcinogenesis. In addition, polymorphisms in genes involved in the TLR (TLR1, TLR2, TLR4, TLR5, TLR9, and CD14) and NLR (NOD1, NOD2, NLRP3, NLRP12, NLRX1, CASP1, ASC, and CARD8) signaling pathways have been shown to modulate the risk of H. pylori infection, gastric precancerous lesions, and/or GC. Further, the modulation of PRRs has been suggested to suppress H. pylori-induced inflammation and enhance GC cell apoptosis, highlighting their potential relevance in GC therapeutics. In this review, we present current advances in our understanding of the role of the TLR and NLR signaling pathways in the pathogenesis of GC, address the involvement of other recently identified PRRs in GC, and discuss the potential implications of PRRs in GC immunotherapy.

Genetic polymorphisms in the Toll-like receptor signalling pathway in Helicobacter pylori infection and related gastric cancer

BACKGROUND

Gastric cancer (GC) is a progressive process initiated by Helicobacter pylori-induced inflammation. Initial recognition of H. pylori involves Toll-like receptors (TLRs), central molecules in the host inflammatory response. Here, we investigated the association between novel polymorphisms in genes involved in the TLR signalling pathway, including TLR2, TLR4, LBP, MD-2, CD14 and TIRAP, and risk of H. pylori infection and related GC.

METHODS

A case-control study comprising 310 ethnic Chinese individuals (87 non-cardia GC cases and 223 controls with functional dyspepsia) was conducted. Twenty-five polymorphisms were detected by MALDI-TOF mass spectrometry, PCR, PCR-RFLP and real-time PCR.

RESULTS

Seven polymorphisms showed significant associations with GC (TLR4 rs11536889, TLR4 rs10759931, TLR4 rs1927911, TLR4 rs10116253, TLR4 rs10759932, TLR4 rs2149356 and CD14 -260 C/T). In multivariate analyses, TLR4 rs11536889 remained a risk factor for GC (OR: 3.58, 95% CI: 1.20-10.65). TLR4 rs10759932 decreased the risk of H. pylori infection (OR: 0.59, 95% CI: 0.41-0.86). Statistical analyses assessing the joint effect of H. pylori infection and the selected polymorphisms revealed strong associations with GC (TLR2, TLR4, MD-2, LBP and TIRAP polymorphisms).

CONCLUSIONS

Novel polymorphisms in TLR2, TLR4, MD-2, LBP, CD14 and TIRAP, genes encoding important molecules of the TLR signalling pathway, showed clear associations with H. pylori-related GC in Chinese.