Toll-like receptor (TLR) and nucleosome-binding oligomerization domain (NOD) gene polymorphisms and endometrial cancer risk

Revealing of TLR-9 gene polymorphisms by qPCR HRM technique and their influence on TLR-9 serum level in acute myeloid leukemia patients: Case-control study

Acute myeloid leukemia (AML) is one of the most common and fatal malignancies that affect adults, which can quickly become aggressive if left untreated, and leukemia cells invade the bone marrow. TLR-9 is an innate immune cell receptor sensitive to various PAMPs and encoded by the TLR-9 gene. As is often known, genetic polymorphisms in any gene can help the development of the disease, and these three polymorphisms, rs187084, rs5743836, and rs352140 of TLR-9, have been studied in many different cancer disorders. Therefore, this study aimed to discover the multiple forms of a TLR-9 gene in a sample of Iraqi AML patients. A total of 120 participants in a case-control study were enrolled in the current study. Using CBC, some hematological parameters were evaluated, and the serum level of TLR-9 was assessed using the ELISA technique. DNA was extracted directly from blood, and a high-resolution melting (HRM) analysis was then carried out. The results revealed a significant difference in some blood parameters among patients and healthy control, while WBC and lymphocytes were without an evident difference between the two groups of the current investigation. The serum concentration of TLR-9 showed an elevated level in patients (P value < 0.01). Nonetheless, this increase was not affected by the genotype patterns of polymorphisms. According to the P-value, there was a significant difference in wild genotypes of the three polymorphisms (rs187084, rs5743836, and rs352140). At the same time, the odds ratio revealed the association with the disease as a protective factor. In contrast, there was a significant difference in the heterozygous and mutant genotypes of TLR-9 polymorphisms, though the odds ratio confirmed the association with the AML as a risk factor. The results of rs352140 were compatible with H.W.E since there were no significant differences between the observed and expected values for either patients or healthy controls. In contrast, the result of rs5743836 was not consistent with the HWE. Furthermore, although it corresponds with the healthy one, the finding of rs187084 conflicted with H.W.E. in the patient group. In conclusion, High serum levels of TLR-9 in patients could act as biomarkers for AML. The TLR-9 gene polymorphisms (rs187084, rs5743836, and rs352140) have been linked to an increased risk of AML and may impact the disease progression in the Iraqi population.

Pyroptosis-associated genes and tumor immune response in endometrial cancer

The occurrence and progression of tumors are linked to the process of pyroptosis. However, the precise involvement of pyroptosis-associated genes (PRGs) in endometrial cancer (EC) remains uncertain. 29 PRGs were identified as being either up-regulated or down-regulated in EC. PRGs subgroup analysis demonstrated distinct survival outcomes and diverse responses to chemotherapy and immune checkpoint blockade therapy. A higher expression of GPX4 and NOD2, coupled with lower levels of CASP6, PRKACA, and NLRP2, were found to be significantly associated with higher overall survival (OS) rates (p < 0.05). Conversely, lower expression of NOD2 was linked to lower progression-free survival (p = 0.021) and advanced tumor stage(p = 0.0024). NOD2, NLRP2, and TNM stages were identified as independent prognostic factors (p < 0.001). The LASSO prognostic model exhibited a notable decrease in OS among EC patients in the high-risk score group (ROC-AUC10-years: 0.799, p = 0.00644). Furthermore, NOD2 displayed a positive correlation with the infiltration of immune cells and the expression of immune checkpoints (p < 0.001). GPX4 and CASP6 are significantly associated with TMB and MSI (RTMB = 0.39; RMSI = 0.23). Additionally, a substantial upregulation of NOD2 was confirmed in both EC cells and tissue, indicating a positive relationship between advanced TNM stage (p < 0.0001) and infiltration of M1 phenotype macrophages. Nonetheless, its impact on patient OS did not reach statistical significance (p = 0.141). Our findings have contributed to the advancement of a prognostic model for EC patients. NOD2 receptor-mediated pyroptosis mechanism potentially regulates tumor immunity and promotes the transformation of macrophages from the M2 phenotype to the M1 phenotype, which significantly impacts the progression of EC.

Pathomorphological Manifestations and the Course of the Cervical Cancer Disease Determined by Variations in the TLR4 Gene

Cervical cancer (CC) is often associated with human papillomavirus (HPV). Chronic inflammation has been described as one of the triggers of cancer. The immune system fights diseases, including cancer. The genetic polymorphism of pathogen recognition receptors potentially influences the infectious process, development, and disease progression. Many candidate genes SNPs have been contradictory demonstrated to be associated with cervical cancer by association studies, GWAS. TLR4 gene activation can promote antitumor immunity. It can also result in immunosuppression and tumor growth. Our study aimed to investigate eight selected polymorphisms of the TLR4 gene (rs10759932, rs1927906, rs11536898, rs11536865, rs10983755, rs4986790, rs4986791, rs11536897) and to determine the impact of polymorphisms in genotypes and alleles on the pathomorphological characteristics and progression in a group of 172 cervical cancer subjects with stage I-IV. Genotyping was performed by RT-PCR assay. We detected that the CA genotype and A allele of rs11536898 were significantly more frequent in patients with metastases (p = 0.026; p = 0.008). The multivariate logistic regression analysis confirmed this link to be significant. The effect of rs10759932 and rs11536898 on progression-free survival (PFS) and overall survival (OS) has been identified as important. In univariate and multivariate Cox analyses, AA genotype of rs11536898 was a negative prognostic factor for PFS (p = 0.024; p = 0.057, respectively) and OS (p = 0.008; p = 0.042, respectively). Rs11536898 C allele predisposed for longer PFS (univariate and multivariate: p = 0.025; p = 0.048, respectively) and for better OS (univariate and multivariate: p = 0.010; p = 0.043). The worse prognostic factor of rs10759932 in a univariate and multivariate Cox analysis for survival was CC genotype: shorter PFS (p = 0.032) and increased risk of death (p = 0.048; p = 0.015, respectively). The T allele of rs10759932 increased longer PFS (univariate and multivariate: p = 0.048; p = 0.019, respectively) and longer OS (univariate and multivariate: p = 0.037; p = 0.009, respectively). Our study suggests that SNPs rs10759932 and rs11536898 may have the potential to be markers contributing to the assessment of the cervical cancer prognosis. Further studies, preferably with larger groups of different ethnic backgrounds, are needed to confirm the results of the current study.

The role of toll-like receptors (TLRs) and their therapeutic applications in endometrial cancer

Endometrial cancer (EC) is developed nations' most prevalent form of gynecologic cancer. Patients are frequently diagnosed with EC when the tumor is still limited to the uterus. Patients without tumor metastasis have a 5-year survival rate ranging from 80 to 90%; however, almost 16.8% of EC patients develop a metastatic form of the tumor. In the early stages of tumorigenesis, the immune system is able to identify aberrant cells as non-self, therefore providing the optimal pro-inflammatory microenvironment for the elimination of cancer cells. Although, chronic inflammation can be a crucial aspect of tumor development. Toll-like receptors (TLRs), as the main pattern recognition receptors (PRRs) in innate immunity, may stimulate an inflammatory response and provide cell survival in the tumor microenvironment (TME). TLRs are vital immunomodulators that may significantly impact the development of gynecologic malignancies. Therefore, TLR inhibitors are being researched for their possible benefits in treating gynecologic cancers. The aim of this study is to review the current knowledge in this field and provide some insight into the therapeutic potential of TLR inhibitors in EC.

Association of TLR4 gene 2026A/G (rs1927914), 896A/G (rs4986790), and 1196C/T (rs4986791) polymorphisms and cancer susceptibility: Meta-analysis and trial sequential analysis

BACKGROUND

This study was performed to assess the association of TLR4 gene 2026A/G (rs1927914), 896A/G (rs4986790), and 1196C/T (rs4986791) polymorphisms and cancer susceptibility based on published case-control studies.

METHODS

Web of Science, PubMed, Embase, CBM, WanFang Data, CNKI, and VIP database were used for article retrieving. Then, these articles were screened according to the study inclusion and exclusion criteria. The data was extracted, and the study quality was evaluated according to the principle of Newcastle-Ottawa Scale. Meta-analysis was performed by RevMan 5.4 and Stata MP-17 software. Trial sequential analysis was performed by TSA 0.9.5.10 Beta software.

RESULTS

Eighty-seven case-control studies including 25,969 cases and 32,119 controls were included in the meta-analysis. The diseases involved in case groups include prostate cancer, lung cancer, gastric cancer, hepatocellular carcinoma, colorectal cancer, etc. A versus G model of rs1927914, A versus G model of rs4986790 and C versus T model of rs4986791 showed that odds ratio (OR) = 1.08, OR = 0.85, and OR = 0.74 respectively. All the 3 comparisons were statistically significant. Sensitivity analysis showed that the results were stable. Publication bias analysis and trial sequential analysis showed that no significant publication bias was found in the results of the meta-analysis, and the probability of false positives was small.

CONCLUSION

People with A allele of rs1927914, G allele of rs4986790, or T allele of rs4986791 have higher risks of cancer. The results of meta-analysis are stable and have less probability of false positives.

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.

“Iron triangle” of regulating the uterine microecology: Endometrial microbiota, immunity and endometrium

The uterus is the core place for breeding new life. The balance and imbalance of uterine microecology can directly affect or even dominate the female reproductive health. Emerging data demonstrate that endometrial microbiota, endometrium and immunity play an irreplaceable role in regulating uterine microecology, forming a dynamic iron triangle relationship. Up to nowadays, it remains unclear how the three factors affect and interact with each other, which is also a frontier topic in the emerging field of reproductive tract microecology. From this new perspective, we aim to clarify the relationship and mechanism of the interaction of these three factors, especially their pairwise interactions. Finally, the limitations and future perspectives of the current studies are summarized. In general, these three factors have a dynamic relationship of mutual dependence, promotion and restriction under the physiological or pathological conditions of uterus, among which the regulatory mechanism of microbiota and immunity plays a role of bridge. These findings can provide new insights and measures for the regulation of uterine microecology, the prevention and treatment of endometrial diseases, and the further multi-disciplinary integration between microbiology, immunology and reproductive medicine.

Association of TLR4 Rs4986791 Polymorphism and TLR9 Haplotypes with Acute Myeloid Leukemia Susceptibility: A Case-Control Study of Adult Patients

Toll-like receptors (TLRs) have an important role in innate immunity, and single nucleotide polymorphisms (SNPs) of TLR genes influence the risk of developing hematological malignancies. We aimed to evaluate the effect of TLR2 (rs5743708), TLR4 (rs11536889, rs4986790, rs4986791), TLR9 (rs187084, rs352140, rs5743836) on AML risk, the relation between investigated SNPs and somatic mutations, clinical features, and the overall survival of adult AML patients. All mentioned SNPs were genotyped in 511 AML cases and 503 healthy controls. DNMT3A (R882), FLT3 (D835, ITD), and NPM1 mutations’ status were investigated in AML patients. TLR4 rs4986791 was associated with an increased risk of AML under the dominant model (OR = 1.61, 95% CI: 1.001–2.59). Variant genotypes of the TLR4 rs4986790 or rs4986791 were associated with the odds of developing AML in the codominant model (OR = 3.14; 95% CI: 1.12–8.84; p = 0.032). The TLR9 rs5743836 variant genotype was associated with the NPM1 mutation (p = 0.002). The investigated SNPs were not associated with the DNMT3A, FLT3 mutations and had no significant contribution to the hazard of death after adjusting for covariates. Our findings suggest that TLR4 rs4986791 is associated with AML susceptibility. The combined variant genotypes of TLR4 rs4986790 and rs4986791 increase AML risk, the TLR9 C-G-A haplotype may represent a promising approach to predict a person’s risk for developing AML.

Toll-like receptor gene polymorphisms in patients with myeloproliferative neoplasms

Toll-like receptors (TLRs) are a family of transmembrane receptors whose signaling control cellular processes of cell proliferation, survival, apoptosis, angiogenesis, remodeling, and repair of tissues. Polymorphisms in TLR genes can change the balance between pro and anti-inflammatory cytokines, modulating the risk of infection, chronic inflammation, and cancer. Although many studies have demonstrated the direct involvement of TLR signaling in the benefit of tumor cells in certain cancers, little is known about the influence of these gene polymorphisms on myeloproliferative neoplasms (MPNs). In this context, the objective of the study was to investigate a possible association between the TLR polymorphisms and the development of MPNs. 167 patients diagnosed with MPN and 222 healthy controls from the same region were evaluated. Genomic DNA was extracted and the TLR2 (rs5743708), TLR4 (rs4986790, rs4986791), TLR9 (rs5743836, rs187084) and JAK2V617F polymorphisms were genotyped by PCR-RFLP. The statistical analysis was performed by OpenEpi and SNPstat software. The JAK2V617F mutation was found in 68.32% of patients. TLR9-1486C/T CT genotype was less frequent in patients with polycythemia vera (PV) (OR 0.39, 95% CI 0.20-0.78, P = 0.025). When haplotype frequencies were analyzed, -1237T/-1486C (TLR9) was also less frequent in men (OR 0.58, 95% CI 0.36-0.94) and JAK negative men patients (OR 0.43, 95% CI 0.21-0.88). We can infer that the TLR9-1486 CT genotype could be associated with protection for PV and the TLR9-1237T/-1486C haplotype, protection for men, as well as for JAK negative men patients with MPN. There were no associations between TLR2 and TLR4 gene polymorphisms and MPN.

Prognostic Biomarker-Based Identification of Drugs for Managing the Treatment of Endometrial Cancer

INTRODUCTION

Uterine corpus endometrial carcinoma (UCEC) causes thousands of deaths per year. To improve the overall survival of patients with UCEC, there is a need to identify prognostic biomarkers and potential drugs.

OBJECTIVES

The aim of this study was twofold: the identification of prognostic gene signatures from expression profiles of pattern recognition receptor (PRR) genes and identification of the most effective existing drugs using the prognostic gene signature.

METHODS

This study was based on the expression profile of PRR genes of 541 patients with UCEC obtained from The Cancer Genome Atlas. Key prognostic signatures were identified using various approaches, including survival analysis, network, and clustering. Hub genes were identified by constructing a co-expression network. Representative genes were identified using k-means and k-medoids-based clustering. Univariate Cox proportional hazard (PH) analysis was used to identify survival-associated genes. 'cmap2' was used to identify potential drugs that can suppress/enhance the expression of prognostic genes.

RESULTS

Models were developed using hub genes and achieved a maximum hazard ratio (HR) of 1.37 (p = 0.294). Then, a clustering-based model was developed using seven genes (HR 9.14; p = 1.49 × 10^-12). Finally, a nine gene-based risk stratification model was developed (CLEC1B, CLEC3A, IRF7, CTSB, FCN1, RIPK2, NLRP10, NLRP9, and SARM1) and achieved HR 10.70; p = 1.1 × 10^-12. The performance of this model improved significantly in combination with the clinical stage and achieved HR 15.23; p = 2.21 × 10^-7. We also developed a model for predicting high-risk patients (survival ≤ 4.3 years) and achieved an area under the receiver operating characteristic curve (AUROC) of 0.86.

CONCLUSION

We identified potential immunotherapeutic agents based on prognostic gene signature: hexamethonium bromide and isoflupredone. Several novel candidate drugs were suggested, including human interferon-α-2b, paclitaxel, imiquimod, MESO-DAP1, and mifamurtide. These biomolecules and repurposed drugs may be utilised for prognosis and treatment for better survival.

Toll-Like Receptors Gene Polymorphisms in Autoimmune Disease

Toll-like receptors (TLRs) are important initiators of the immune response, both innate and acquired. Evidence suggests that gene polymorphisms within TLRs cause malfunctions of certain key TLR-related signaling pathways, which subsequently increases the risk of autoimmune diseases. We illustrate and discuss the current findings on the role of Toll-like receptor gene polymorphisms in numerous autoimmune diseases in this review, such as type 1 diabetes mellitus, Graves’ disease, rheumatoid arthritis, systemic lupus erythematosus and multiple sclerosis. The study of genetic variation in TLRs in different populations has shown a complex interaction between immunity and environmental factors. This interaction suggests that TLR polymorphisms affect the susceptibility to autoimmune diseases differently in various populations. The identification of Toll-like receptor gene polymorphisms can expand our understanding of the pathogenesis of autoimmune diseases, which will subsequently guide effective medical management and provide insight into prognosis and advanced treatments.

Endometrial cancer: a genetic point of view

BACKGROUND

Endometrial cancer is the fourth most frequent gynecological cancer and the most frequent type of uterine cancer. There is an increase in the incidence and mortality of uterine cancers in the past few decades, and there are no well-established screening programs for endometrial cancer currently. Most endometrial cancers arise through the interplay of familial, genetic, and lifestyle factors. Although a number of genetic factors modify endometrial cancer susceptibility, they are not of standard use in the clinical assessment of prognosis. We conducted a comprehensive systematic literature review to provide an overview of the relationship between genetic factors and risk for endometrial cancer.

METHODS

MEDLINE and EMBASE databases were searched for studies between January 2010 to March 2020 reporting the genes associated with endometrial cancer.

RESULTS

Through the selection process, we retrieved 186 studies comprising 329 genes identified using several molecular methodologies in all human chromosomes and in mitochondrial DNA. Endometrial cancer exhibits a molecular complexity and heterogeneity coherent with its clinical and histologic variability. Improved characterization of molecular alterations of each histological type provides relevant information about the prognosis and potential response to new therapies.

CONCLUSIONS

The current challenge is the integration of clinicopathologic and molecular factors to improve the diagnosis, prognosis, and treatment of endometrial cancer.

The role of Toll-like receptor 4 signaling pathway in ovarian, cervical, and endometrial cancers

Toll-like receptors (TLRs) are critical sensors related to inflammation and tumorigenesis. Among all subtypes, the TLR4 is a highly described transmembrane protein involved in the inflammatory process. The TLR4/myeloid differentiation factor 88 (MyD88) signaling pathway has been implicated in oncogenic events in several tissues and is associated with survival of patients. Through activation, TLR4 recruits adaptor proteins, i.e., MyD88 or TRIF, to triggers canonical and non-canonical signaling pathways that result in distinct immune responses. In most cancer cells, uncontrolled TLR4 signaling modifies the tumor microenvironment to proliferate and evade immune surveillance. By contrast, TLR4 activation can produce antitumor activities, thereby inhibiting tumor growth and enhancing the proper immune response. We review herein recent approaches on the role of the TLR4 signaling pathway and discuss potential candidates for gynecological cancer therapies; among these agents, natural and synthetic compounds have been tested both in vitro and in vivo. Since TLR4 ligands have been investigated as effective immune-adjuvants in the context of these aggressive malignancies, we described how TLR4 signaling controls part of the tumor-related inflammatory process and which are the new targeting molecules implicated in the regulation of tumorigenicity in ovarian, cervical, and endometrial cancers.

Functional Polymorphisms and Gene Expression of TLR9 Gene as Protective Factors for Nasopharyngeal Carcinoma Severity and Progression

Nasopharyngeal carcinoma (NPC) is a disease that is closely associated with EBV infection. Toll-like receptor 9 is an important factor mediating the interaction between EBV and the host immune response. Any genetic (single nucleotide polymorphisms, SNPs) or expression variation in TLR9 gene may modify the ability of the receptor to respond correctly to viral infection as in NPC. This study is aimed at evaluating the effect of TLR9 functional polymorphisms (TLR9-1486 T/C and TLR9-1237 T/C) and TLR9 mRNA expression in NPC severity and progression at diagnosis and after treatment. This study included 322 patients with NPC. RFLP-PCR and real-time PCR were used to assess, respectively, the genotypes and the mRNA expression of TLR9 gene. The genotyping analysis showed that the presence of mutated allele -1237C (TLR9-1237 TC+CC) was associated with large tumor size (p = 0.017; OR (CI 95%) = 1.888 (1.11-3.19)) at diagnosis. After treatment, the -1237C allele was associated with a better chance of complete remission (p = 0.031, OR (CI 95%) = 0.486 (0.25-0.95)), a lower risk of distant metastasis (p = 0.028, OR (CI 95%) = 0.435 (0.18-1.02)), and a lower risk of death by NPC (p = 0.003, OR (CI 95%) = 0.20 (0.06-0.67)). Kaplan-Meier analysis showed that patients with -1237CC and -1237TC genotypes had a better overall survival (OVS) (p < 0.01) and distant metastasis-free survival (DMFS) (p < 0.05). A multivariate analysis revealed that TLR9-1237 T/C polymorphism was an independent prognostic factor in OVS (p = 0.02; HR = 0.244) and DMFS (p = 0.048; HR = 0.388). The transcriptomic analysis showed that the mRNA expression was reduced in patients with larger tumor size (T4) (p = 0.013) and advanced clinical stage (SIII-SIV) (p = 0.037). The TLR9 mRNA expression was inversely correlated with tumor size (p = 0.014; r = −0.314) at diagnosis. Our results indicated for the first time that the functional -1237 T/C polymorphism and mRNA expression of TLR9 gene may be considered as protective factors for NPC severity and progression.

Toll-like receptor 9 polymorphisms and Helicobacter pylori influence gene expression and risk of gastric carcinogenesis in the Brazilian population

BACKGROUND

Toll-like receptors (TLRs) are the first line of host defense, and are involved in Helicobacter pylori (H. pylori) recognition and activation of both inflammatory and carcinogenic processes. The presence of single nucleotide polymorphisms (SNPs) in genes that activate the immune response may modulate the risk of precancerous lesions and gastric cancer (GC). Among them, Toll-like receptor 9 (TLR9) polymorphisms have emerged with a risk factor of infectious diseases and cancer, however the studies are still inconclusive.

AIM

To evaluate whether TLR9 rs5743836 and rs187084 SNPs contribute to the risk of gastric carcinogenesis, and its influence on mRNA expression.

METHODS

A case-control study was conducted to evaluate two TLR9 SNPs (TLR9-1237 TC-rs5743836 and TLR9-1486 CT-rs187084) in chronic gastritis (CG) and GC patients. A total of 609 DNA samples of peripheral blood [248 CG, 161 GC, and 200 samples from healthy individuals (C)] were genotyped by polymerase chain reaction-restriction fragment length polymorphism. All samples were tested for the H. pylori infection using Hpx1 and Hpx2 primers. Quantitative polymerase chain reaction by TaqMan^® assay was used to quantify TLR9 mRNA from fresh gastric tissues (48 GC, 26 CG, and 14 C).

RESULTS

For TLR9-1237, the TC + CC or CC genotypes were associated with a higher risk of GC than C [recessive model odds ratio (OR) = 5.01, 95% confidence interval (CI): 2.52-9.94, P < 0.0001], and the CG (recessive model OR =4.63; 95%CI: 2.44-8.79, P < 0.0001) groups. For TLR9-1486, an association between the CT + TT genotypes and increased risk of both GC (dominant model OR = 2.72, 95%CI: 1.57-4.72, P < 0.0001) and CG (dominant model OR = 1.79, 95%CI: 1.15-2.79, P = 0.0094) was observed when compared to the C group. Moreover, the presence of TLR9-1237 TC/CC + TLR9-1486 CC genotypes potentiate the risk for this neoplasm (OR = 18.57; 95%CI: 5.06-68.15, P < 0.0001). The TLR9 mRNA level was significantly higher in the GC group (RQ = 9.24, P < 0.0001) in relation to the CG group (RQ = 1.55, P = 0.0010) and normal mucosa (RQ = 1.0). When the samples were grouped according to the polymorphic genotypes and the presence of H. pylori infection, an influence of TLR9-1237 TC + CC polymorphic genotypes (P = 0.0083) and H. pylori infection (P < 0.0001) was observed on the upregulation of mRNA expression.

CONCLUSION

Our findings show that TLR9 rs5743836 and rs187084 polymorphisms are associated with a higher risk of carcinogenesis gastric, and that TLR9 mRNA levels can be modulated by TLR9-1237 TC + CC variant genotypes and H. pylori infection.

Toll-like receptor 6 expression, sequence variants, and their association with colorectal cancer risk

This is the first study to examine the potential correlation of the rs3796508 and rs5743810 SNPs of the TLR6 gene in patients with colorectal cancer (CRC) in a subset of the Saudi population. TLR6 gene expression was studied by real-time PCR assaysin 10 matching normal and cancer colon tissues. TLR6 expression at the protein level was determined by immunohistochemistry. A case-control search was conductedon 115 case patients and 102 controls. All samples were genotyped with the TaqMan assay for the TLR6 gene. Odds ratios and 95% confidence interval were computed from logistic regression models after adjusting for age, sex, and tumor localization. Our findings showed a decrease in TLR6 expression (p <0.001) in colon cancer tissues when compared to normal colon tissues. Global analysis revealed no significant association between the TLR6 rs3796508 and rs5743810 and CRC in this population. However, the Val/Met genotype of rs3796508 had a significantly higher frequency in the control group than in the cases for the male group (OR= 0.095, and p= 0.03385) or the volunteers aged more than 57 years OR= 0.152; and p= 0.04069, respectively). Two non-synonymous single nucleotide polymorphisms (SNP; S249P and V327M) were common in a few patients and were predicted as damaging by SIFT and Polyphen and were further analyzed for their protein stability and function using advanced bioinformatics tools. The results suggest that TLR6 rs3796508 has a crucial role as a protective factor against colorectal cancer in the older Saudi male population.

Correlation between IL28B/TLR4 genetic variants and HCC development with/without DAAs treatment in chronic HCV patients

In Egypt, Sofosbuvir (SOF) in combination with Dataclasvir (DCV) is the broadly used DAAs with excellent therapeutic profile. This study is designed to explore the relation between IL28B/TLR4 genetic variants and each of the followings; HCC development post SOF/DCV treatment, progression to HCC in naïve patients and SOF/DCV therapy outcome. A total of 493 blood samples were collected (controls (n = 70); HCV patients treated with SOF/DCV (n = 252) of whom 65 patients developed HCC, 187 patients didn't develop HCC (125 responders, 62 relapsers); naïve HCV patients (n = 171) had early (n = 48), late liver fibrosis (n = 21) and HCC (n = 102)). Both SNPs were genotyped using a TaqMan 5′ allelic discrimination assay. At IL28B rs12979860 SNP, the C allele was significantly correlating with the response rate more than T allele (OR 1.9, 95% CI 1.29–2.9, p = 0.004), while at TLR4 rs4986791 SNP, no association was found (OR 6.5, 95% 0.57–75.28, p = 0.09). Both SNPs couldn't detect the probability for HCC emergence after treatment. In naïve patients, the protective alleles were detected in their lowest frequency in HCC patients (p = 0.1, for rs12979860 and, p = 0.001 for rs4986791). SOF/DCV combination improved SVR rates in HCV genotype 4a infected patients regardless of IL28B genotype, with the best rates in those lacking the T allele.

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.

Identification of mRNAs related to endometrium function regulated by lncRNA CD36-005 in rat endometrial stromal cells

BACKGROUND

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder in women of reproductive age and is commonly complicated by adverse endometrial outcomes. Long non-coding RNAs (lncRNAs) are a class of non-protein-coding transcripts that are more than 200 nucleotides in length. Accumulating evidence indicates that lncRNAs are involved in the development of various human diseases. Among these lncRNAs, lncRNA CD36-005 (CD36-005) is indicated to be associated with the pathogenesis of PCOS. However, the mechanisms of action of CD36-005 have not yet been elucidated.

METHODS

This study determined the CD36-005 expression level in the uteri of PCOS rat model and its effect on the proliferation activity of rat primary endometrial stromal cells. RNA sequencing (RNA-seq) and bioinformatics analysis were performed to detect the mRNA expression profiles and the biological pathways in which these differentially expressed mRNAs involved, after CD36-005 overexpression in the primary endometrial stromal cells. The differential expression of Hmgn5, Nr5a2, Dll4, Entpd1, Fam50a, and Brms1 were further validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR).

RESULTS

CD36-005 is highly expressed in the uteri of PCOS rat model and promotes the proliferation of rat primary endometrial stromal cells. A total of fifty-five mRNAs differentially expressed were identified in CD36-005 overexpressed stromal cells. Further analyses identified that these differentially expressed mRNAs participate in many biological processes and are associated with various human diseases. The results of qRT-PCR validation were consistent with the RNA-seq data.

CONCLUSIONS

These data provide a list of potential target mRNA genes of CD36-005 in endometrial stromal cells and laid a foundation for further studies on the molecular function and mechanism of CD36-005 in the endometrium.

Evaluation of Toll-Like Receptor Expression with Clinicopathologic Variables in Endometrium Cancer

Objectives

Clinical evidence supports the association of toll-like receptor (TLR) with abnormal cell proliferation and cancer. In this study, we investigated the expression of TLRs 2, 4, 5, and 6 in healthy endometrium and endometrium cancer to study the relationship of these receptors' expression with carcinogenesis.

Methods

Patients who had undergone a hysterectomy owing to endometrium cancer (group 1, 66 patients), endometrial hyperplasia (group 2, 14 patients), and other reasons besides endometrium cancer (group 3, 20 patients as controls) were included. The cases in the first group were classified by histological type of the cancer, stage, grade, and size of the tumor. In all the cases, expressions of TLRs 2, 4, 5, and 6 were assessed, and the relationship of these receptors with clinicopathologic signs was analyzed. For immunohistochemical staining, nuclear and cytoplasmic stainings were considered positive. A Chi-squared test was used to assess the correlation of the groups. A p<0.05 was considered significant.

Results

The mean ages of patients in groups 1, 2, and 3 were 59.8 (range 33-83), 48.3 (range 40-59), and 53.4 (range 38-84) years, respectively. All types of TLRs were highly expressed in both types of endometrium cancer (groups 1 and 2). TLR expression was observed with a ratio of 87.9% in group 1, 100% in group 2, and 35% in group 3. There was a statistically significant association of TLR 2 among the three groups (p=0.000). TLR 6 expression in both group 1 and group 2 was significantly higher than that in the control group (p=0.000, p=0.000, respectively). In addition, TLR 6 was higher in cases with late-stage cancer (p=0.033). Regarding tumor grade and the size of the tumor, no association was found between TLR 2 and TLR 6.

Conclusion

TLR 2 and TLR 6 were significantly more expressed in cases with endometrium cancer and endometrial hyperplasia. In addition, the presence of TLR 6 may indicate the presence of late-stage endometrial cancer.

Comprehensive assessment of association between TLR4 gene polymorphisms and cancer risk: a systematic meta-analysis

Previous studies have explored the association between toll-like receptor 4 (TLR4) polymorphisms and risk of various cancers, but the results remained controversial. To obtain an assessment of the effect of TLR4 polymorphisms (rs4986790, rs4986791 and rs11536889) on cancer risk, fifty-five articles (containing 20107 cases and 28244 controls) were recruited for meta-analysis. Our result indicated that two Single Nucleotide Polymorphisms (SNP) in TLR4 were associated with decreased cancer risk for rs4986791: OR = 0.764, 95% CI: 0.652-0.894, P = 0.001 in allele model; OR = 0.769, 95%CI: 0.650-0.909, P = 0.002 in recessive model; OR = 0.505, 95% CI: 0.352-0.726, P = 0.000 in dominant model; for 11536889: OR = 0.927, 95% CI: 0.872–0.984, P = 0.013 in allele model; OR = 0.926, 95% CI: 0.862–0.944,P = 0.034 in recessive model. In terms of subgroup analyses sorted by ethnicity, only polymorphism of rs4986791 had a significant influence on decrease of cancer risk among both Caucasian and Asian populations. The findings suggested that TLR4 polymorphisms may serve as a genetic risk factor for cancers.

Association between TLR-9 polymorphisms and colon cancer susceptibility in Saudi Arabian female patients

Objective

The authors aimed to explore the relationship between the expression/polymorphisms of TLR-9 and susceptibility to colon cancer development in the Saudi Arabian population.

Methods

In total, blood samples from 115 patients with colon cancer and 102 participants without colon cancer were analyzed in this study. Three single-nucleotide polymorphisms (SNPs) were selected from the TLR-9 gene, including two sites within the TLR-9 gene’s promoter region (rs352144 and rs187084) and one site in a TLR-9 intron region (rs5743839). Odds ratios (ORs) and 95% confidence intervals (CIs) were computed from logistic regression models after adjusting for age, gender, and tumor localization. To investigate the differential expression of TLR-9 in colon cancer, TLR-9 expression was evaluated using quantitative real-time reverse transcription polymerase chain reaction on 40 matched normal and colon tissues.

Results

The authors found that TLR-9 expression was decreased in colon cancer tissues as compared with that in normal tissues. Moreover, significant associations between the TLR-9 rs187084 SNP and colon cancer risk were observed in female patients only. In rs187084, the T allele had a significantly lower frequency (2.8 times) in female cancer patients than in controls (0.27 vs 0.41). The TLR-9 rs352139 and rs352144 SNPs were significantly associated with colon cancer development when the tumor was located in the rectal area.

Conclusion

The findings support the hypothesis that TLR-9 has an anticancer role in colon cancer development. Furthermore, genetic variation may influence colon cancer development, and SNPs in TLR-9 could serve as biomarkers for decision making in the treatment of females with rectal cancer.

The role of Toll-like receptor 9 in gynecologic cancer

Toll-like receptor 9 (TLR9) plays a major role in the fight against DNA viruses infections. Despite its antitumor properties, inappropriate activation of TLR9 during chronic inflammation may cause the activation of transcription factors inducing pro-cancerous activities. Thus, the relationship between TLR9 and cancer remains highly confrontational especially in gynecological cancers and cervical cancer induced by viruses. In this review, we focus on the beneficial and detrimental role of TLR9 in gynecological carcinogenesis. TLR9 contributes to tumor regression by inducing cytotoxic T cell response (CTL), reducing the numbers of myeloid-derived suppressor cells (MDSCs), the tumor-associated macrophages (TAMs) and the regulatory T cells (T regs). It can however, also promote tumor progression and invasiveness of cervical tissue. Therefore, the dichotomous role of TLR9 needs to be carefully investigated in the setting of neoplastic disease.

Polymorphisms of glutathione S-transferase π 1 and toll-like receptors 2 and 9: Association with breast cancer susceptibility

Polymorphisms in antioxidant enzymes and innate immune receptors have been implicated in the development of various types of cancer. The present study aimed to investigate whether polymorphisms of glutathione S-transferase π 1 (GSTP1) and toll-like receptors (TLRs) 2 and 9 are associated with susceptibility to breast cancer among females. The study was conducted on 72 Egyptian female patients with breast cancer, along with 100 healthy volunteers. Polymorphisms of GSTP1 (codon 105 Ile/Val) and TLR9 rs187084 (1237T/C) genes were assessed by polymerase chain reaction (PCR)-restriction fragment length polymorphism, while the -196 to -174 deletion/insertion (del/ins) polymorphism of TLR2 was detected by PCR. The results indicated a decrease in GSTP1 Val allele frequency in breast cancer patients compared with healthy controls, at rates of 22.9 vs. 32.5%, respectively. In addition, the breast cancer group demonstrated a decreased TLR9 C allele frequency compared with the control group, at rates of 36.1 vs. 51.5%, respectively (P=0.0047). A non-significant difference was detected in the frequency of the TLR2 -196 to -174 del allele in breast cancer patients when compared to normal controls. In conclusion, these results suggested that the GSTP1 Val and TLR9 1237C alleles, but not TLR2 -196 to -174 del, are likely to be associated with breast cancer development among females.

TLR2 and TLR4 polymorphisms influence mRNA and protein expression in colorectal cancer

AIM: To evaluate the effect of promoter region polymorphisms of toll-like receptor (TLR)2-196 to -174del and TLR4-1607T/C (rs10759932) on mRNA and protein expression in tumor tissue and of TLR4+896A/G (rs4986790) on colorectal cancer (CRC) risk.

METHODS: The TLR2-196 to -174del polymorphism was investigated using allele-specific polymerase chain reaction (PCR) and the TLR4-1607T/C and TLR4+896A/G by PCR-restriction fragment length polymorphism (RFLP). We genotyped 434 DNA samples from 194 CRC patients and 240 healthy individuals. The mRNA relative quantification (RQ) was performed in 40 tumor tissue samples by quantitative PCR TaqMan assay, using specific probes for TLR2 and TLR4 genes, and ACTB and GAPDH reference genes were used as endogenous controls. Protein expression was analyzed by immunohistochemistry with specific primary antibodies.

RESULTS: No association was found for TLR4-1607T/C and TLR4+896A/G by three statistical models (log-additive, dominant and recessive). However, based on dominant and log-additive models, the polymorphic variant TLR2-196 to -174del was associated with increased CRC risk [dominant: odds ratio (OR) = 1.72, 95%CI: 1.03-2.89; P = 0.038 and log-additive: OR =1.59, 95%CI: 1.02-2.48; P = 0.039]. TLR2 mRNA expression was increased in tumor tissue (RQ = 2.36) when compared to adjacent normal tissue (RQ = 1; P < 0.0001), whereas the TLR4 mRNA showed a basal expression (RQ = 0.74 vs RQ = 1, P = 0.452). Immunohistochemistry analysis of TLR2 and TLR4 protein expression was concordant with the findings of mRNA expression. In addition, the TLR2-196 to -174del variant carriers showed mRNA relative expression 2.19 times higher than wild-genotype carriers. The TLR2 protein expression was also higher for the TLR2-196 to -174del variant carriers [117 ± 10 arbitrary unit (a.u.) vs 95 ± 4 a.u., P = 0.03]. However, for the TLR4 -1607T/C polymorphism no significant difference was found for both mRNA (P = 0.56) and protein expression (P = 0.26).

CONCLUSION: Our findings suggest that TLR2-196 to -174del polymorphism increases TLR2 mRNA expression and is associated with higher CRC risk, indicating an important role in CRC genetic susceptibility.

Associations between TLR9 polymorphisms and cancer risk: evidence from an updated meta-analysis of 25,685 subjects

A meta-analysis incorporating 34 case-control studies from 19 articles involving 12,197 cases and 13,488 controls was conducted to assess the effects of three genetic variants of Toll-like receptor 9 (TLR9): rs187084, rs352140, and rs5743836. Studies on associations between TLR9 polymorphisms and cancer risk were systematically searched in electronic databases. The reported odds ratios (OR) and 95% confidence intervals (CI) were pooled to assess the strength of any associations. The results showed that the rs187084 polymorphism was significantly associated with an increased risk of cancer (CC vs TC+TT: OR=1.14, 95% CI=1.02-1.28), specifically cervical cancer (C vs T: OR=1.19, 95% CI=1.05-1.34; TC vs TT: OR=1.32, 95% CI=1.10-1.58; CC vs TT: OR=1.31, 95% CI= 1.03-1.68; CC+TC vs TT: OR=1.32, 95% CI=1.11-1.56), and that this association was significantly positive in Caucasians (CC vs. TC+TT: OR=1.18, 95% CI=1.01-1.38). The rs352140 polymorphism had a protective effect on breast cancer (GA vs GG: OR=0.77, 95% CI=0.66-0.89), whereas the rs5743836 polymorphism was likely protective for digestive system cancers (CC+TC vs TT: OR=0.81, 95% CI=0.66-0.98). In conclusion, our results suggest that the rs187084 polymorphism may be associated with an elevated cancer risk, whereas polymorphisms of rs352140 and rs5743836 may play protective roles in the development of breast and digestive system cancers, respectively. From the results of this meta-analysis further large-scale case-control studies are warranted to verify associations between TLR9 polymorphisms and cancer.

Toll-like receptor 2 and 9 genetic polymorphisms and the susceptibility to B cell Non-Hodgkin Lymphoma in Egypt

Non-Hodgkin lymphomas (NHL) entail considerable heterogeneity regarding their morphology, clinical course, etiological factors, or response to therapy. Increased incidence of NHL in immunocompromised individuals and after autoimmune diseases suggests that infections and immune dysregulation could play a role in the susceptibility to NHL. Accordingly, genetic variation in Toll-like receptor (TLR) genes might be considered as molecular risk factors for NHL. The aim of the current study was to investigate the possible association between genetic polymorphism of the TLRs genes and B cell NHL (B-NHL) risk in Egypt. The present study included 100 B-NHL patients and 100 healthy controls. Genotyping of TLR2-1350 T/C and TLR9-1237 T/C were done by polymerase chain reaction restricted fragment length polymorphism (PCR-RFLP) technique. The frequency of TLR2-1350 T/C polymorphic genotypes in B-NHL patients was 18 % for the heteromutant genotype (TC) and 1 % for the homomutant (CC). There was no statistical difference in the distribution of TLR2-1350 T/C genotypes between B-NHL patients and controls. As for TLR9-1237 T/C, the frequency of the heteromutant genotype (TC) was 58 % and the homomutant genotype (CC) was 1 % in B-NHL patients. Calculated risk estimation revealed that TLR9-1237 (TC) heterotype conferred almost fourfold increased risk of B-NHL (odds ratio (OR) = 3.93, 95 % confidence interval (CI) = 2.16-7.14), and the risk was higher in patients with indolent subtypes (OR = 6.64, 95 %CI = 2.31-9.08). In conclusion, the study revealed that TLR9-1237 T/C polymorphism can be considered as molecular risk factor for B-NHL among Egyptians.

NOD2 polymorphisms associated with cancer risk: a meta-analysis

BACKGROUND

Emerging evidence indicated that common polymorphisms of NOD2 might impact individual susceptibility to cancer. However, the results from published studies were inconclusive. The aim of this meta-analysis was to elucidate whether NOD2 polymorphisms were associated with cancer risk.

METHODS

A systematically literature search was performed by using electronic databases including PubMed and Web of Science. ORs and their 95% CI were used to assess the strength of association between NOD2 gene polymorphisms and cancer risks.

RESULTS

Thirty case-control studies were included in this meta-analysis. The pooled analysis indicated that NOD2 rs2066842 C/T polymorphism was not significantly associated with cancer risk; for NOD2 rs2066844 C/T polymorphism, (TT+CT) genotype was associated with increased cancer risk compared with wild-type CC genotype (OR = 1.32, 95% CI = 1.01-1.72, P = 0.041); for NOD2 rs2066845 C/G polymorphism, individuals with (CC+CG) genotype were significantly associated with increased cancer risk compared with GG genotype (OR = 1.32, 95% CI = 1.01-1.72, P = 0.040); for NOD2 rs2066847 (3020insC) polymorphism, carriers of (insC/insC+insC/-) genotype were significantly associated with increased cancer risk compared with -/- carriers (OR = 1.23, 95% CI = 1.10-1.38, P<0.001). In the subgroup analysis of cancer type, (insC/insC+insC/-) genotype was significantly associated with increased risk of colorectal cancer, gastric cancer and MALT lymphoma, breast cancer, lung cancer, laryngeal cancer but not with urogenital cancer, pancreatic cancer, melanoma or non-Hodgkin lymphoma.

CONCLUSION

NOD2 rs2066844 C/T, rs2066845 C/G and rs2066847 (3020insC) polymorphisms might be associated with increased cancer risk. No significant association was observed between NOD2 rs2066842 C/T polymorphism and cancer risk. Further large-scale and well-designed studies are still needed to confirm the results of our meta-analysis.

Association of TLR2 and TLR4 polymorphisms with risk of cancer: a meta-analysis

BACKGROUNDS

The activation of Toll-like receptors (TLRs) may be an important event in the immune evasion of tumor cell. Recently, numerous studies have investigated the associations between TLR2 -196 to -174 del and two SNPs of TLR4 (rs4986790 and rs4986791) and the susceptibility to different types of cancer; however, the results remain conflicting. The aim of this study was to assess the association between TLR2 and TLR4 polymorphisms and cancer risk in a meta-analysis with eligible published studies.

METHODOLOGY/PRINCIPLE FINDINGS

A dataset composed of 14627 cases and 17438 controls from 34 publications were included in a meta-analysis to evaluate the association between overall cancer risk or cancer-specific risk and three SNPs of TLRs (TLR2 -196 to -174 del, TLR4 rs4986790 and rs4986791). The results showed that all of these three polymorphisms were significantly associated with the increased cancer risk (dominant model: OR = 1.64, 95% CI: 1.04-2.60 for TLR2 -196 to -174 del; OR = 1.19, 95% CI: 1.01-1.41 for TLR4 rs4986790; and OR = 1.47, 95% CI: 1.120-1.80 for TLR4 rs4986791; respectively). In stratified analysis, we found the effect of TLR2 -196 to -174 del on cancer risk remained significant in the subgroup of Caucasians and South Asians, but not in East Asians. However, the association between rs4986791 and cancer risk was significant in both South Asians and East Asians, but not in Caucasians. Furthermore, the association between rs4986790 and cancer risk was statistically significant in digestive cancers (dominant model: OR = 1.76, 95% CI: 1.13-2.73) and female-specific cancers (dominant model: OR = 1.50, 95% CI: 1.16-1.94). However, no significant association with risk of digestive system cancers was observed for TLR2 -196 to -174 del and TLR4 rs4986791.

CONCLUSIONS/SIGNIFICANCE

This meta-analysis presented additional evidence for the association between TLR2 and TLR4 polymorphisms and cancer risk. Further well-designed investigations with large sample sizes are required to confirm this conclusion.

Two novel susceptibility SNPs for ischemic stroke using exome sequencing in Chinese Han population

Genome-wide association studies (GWAS) of ischemic stroke (IS) have been performed on several cohorts of Caucasian or African population and Japanese, resulting in somewhat inconsistent conclusion. We aimed to identify susceptibility loci for IS by exome sequencing in a Chinese Han population. Exome sequencing was used to screen susceptibility loci among 100 cases and 100 matched controls. Significant SNPs from the first stage were verified in up to 3,554 participants from three hospital-based case-control studies. In the initial exome sequencing analysis, rs10489177 in c1orf156 gene located on chromosome 1q24 (p < 1 × 10(-8)) and rs17118 in XYLB gene located on chromosome 3p21 (p < 1 × 10(-6)) were found to be significantly associated with IS. In the following validation stage, significantly increased odds ratios were observed in individuals with rs10489177 GG (OR = 2.02, 95 % CI = 1.35-3.03) or rs17118 AA genotype (OR = 1.50, 95 % CI = 1.17-1.91). The rs10489177 GG genotype was associated with significantly increased risk for IS in individuals without hypertension (OR = 2.78, 95 % CI = 1.59-4.86) and in individuals without diabetes (OR = 1.93, 95 % CI = 1.27-2.94). In contrast, the rs17118 AA genotype may significantly increase the risk for IS, particularly for individuals with hypertension (OR = 1.73, 95 % CI = 1.08-2.78) and for individuals without diabetes (OR = 1.52, 95 % CI = 1.17-1.98) or non-smoker (OR = 1.59, 95 % CI = 1.16-2.19). Collectively, our study identified two novel loci (rs17118 and rs10489177) which were associated with an increased risk for IS in Chinese Han populations. Further studies are needed to confirm these associations in other populations and elucidate the biological mechanisms underlying the observed associations.

TLR-2 gene polymorphisms and susceptibility to cancer: evidence from meta-analysis

The ability to respond properly to Toll-like receptor (TLR) ligands may be impaired by polymorphisms within the TLR family of genes, which results in an altered susceptibility to cancers. However, the results of epidemiological studies remained inconsistent. To assess the effect of four selected polymorphisms (rs5743708, -196 to -174 del polymorphism, rs3804099, and rs3804100) in TLR-2 on cancer, we conducted a meta-analysis, up to November 2012; 20 case-control studies were available. Summary odds ratios (OR) and corresponding 95% confidence intervals (CIs) for polymorphisms in TLR-2 and cancer risk were estimated. Our meta-analysis identified that elevated cancer risk was statistically associated with -196 to -174 del allele in -196 to -174 del polymorphism (OR=1.63, 95% CI=1.10-2.41 for allele comparison; OR=1.64, 95% CI=1.05-2.57 for dominant model; OR=2.26, 95% CI=1.24-4.12 for recessive model; OR=2.57, 95% CI=1.30-5.08 for DD vs. II and OR=1.53, 95% CI=1.01-2.32 for ID vs. II in codominant model); whereas rs3804099 in TLR-2 was associated with decreased cancer risk. Moreover, in terms of stratified analyses by cancer type for -196 to -174 del polymorphism, significantly elevated risk was observed to be associated with -196 to -174 del allele in "other cancers." These findings indicate that polymorphisms in TLR-2 may play a role, although modest, in cancer development.

The TLR9 gene polymorphisms and the risk of cancer: evidence from a meta-analysis

Background

Growing studies have revealed the association between polymorphisms in the Toll-like receptor 9 (TLR9) and susceptibility to cancer, however, the results remained inconsistent.

Methodology/Principal Findings

To assess the effect of three selected SNPs (rs352140, rs5743836 and rs187084) in TLR9 on cancer, we performed a meta-analysis based on 11 case-control studies, including a total of 6,585 cancer cases and 7,506 controls. Summary odds ratios (OR) and corresponding 95% confidence intervals (CIs) for polymorphisms in TLR9 and cancer risk were estimated. Our meta-analysis indicated that rs352140 was associated with an increased cancer risk, especially in Caucasian. However, no significantly increased cancer risk was detected to be associated with rs187084 and rs5743836 either the overall or subgroup estimation.

Conclusions

These meta-analysis results indicate that polymorphisms in TLR9 may play a role in cancer development.

Regulators of global genome repair do not respond to DNA damaging therapy but correlate with survival in melanoma

Nucleotide excision repair (NER) orchestrates the repair of helix distorting DNA damage, induced by both ultraviolet radiation (UVR) and cisplatin. There is evidence that the global genome repair (GGR) arm of NER is dysfunctional in melanoma and it is known to have limited induction in melanoma cell lines after cisplatin treatment. The aims of this study were to examine mRNA transcript levels of regulators of GGR and to investigate the downstream effect on global transcript expression in melanoma cell lines after cisplatin treatment and in melanoma tumours. The GGR regulators, BRCA1 and PCNA, were induced in melanocytes after cisplatin, but not in melanoma cell lines. Transcripts associated with BRCA1, BRCA2, ATM and CHEK2 showed altered expression in melanoma cell lines after cisplatin treatment. In melanoma tumour tissue BRCA1 transcript expression correlated with poor survival and XPB expression correlated with solar elastosis levels. Taken together, these findings provide evidence of the mechanisms underlying NER deficiency in melanoma.

Toll-like receptor signalling and their therapeutic targeting in colorectal cancer

Intestinal homeostasis is dependent on the proper host/microbiota interaction via pattern recognition receptors. Toll-like receptors are a specialised group of membrane receptors which detect pathogen-associated conserved structures. They are present in the intestinal tract and are required for intestinal homeostasis. Dysregulation in the Toll-like receptor signalling can conceivably result in a dysregulated immune response which could contribute to major intestinal pathologies including colorectal cancer. Evidence for the role of microbiota and toll-like receptors in colorectal cancer is emerging. In this report the evidence for the contribution of toll-like receptors to the pathogenesis of colorectal cancer; potential mechanisms affecting toll-like receptor signalling; and their therapeutic targeting in colorectal cancer are reviewed.

NOD1 and NOD2 Signaling in Infection and Inflammation

Sensing intracellular pathogens is a process mediated by innate immune cells that is crucial for the induction of inflammatory processes and effective adaptive immune responses against pathogenic microbes. NOD-like receptors (NLRs) comprise a family of intracellular pattern recognition receptors that are important for the recognition of damage and microbial-associated molecular patterns. NOD1 and NOD2 are specialized NLRs that participate in the recognition of a subset of pathogenic microorganisms that are able to invade and multiply intracellularly. Once activated, these molecules trigger intracellular signaling pathways that lead to the activation of transcriptional responses culminating in the expression of a subset of inflammatory genes. In this review, we will focus on the role of NOD1 and NOD2 in the recognition and response to intracellular pathogens, including Gram-positive and Gram-negative bacteria, and on their ability to signal in response to non-peptidoglycan-containing pathogens, such as viruses and protozoan parasites.

The TLR4 gene polymorphisms and susceptibility to cancer: a systematic review and meta-analysis

Growing studies revealed the association between polymorphisms in Toll-like receptor 4 (TLR4) and susceptibility to cancer, however, the results remained inconsistent. To assess the effect of six selected SNPs (rs1927914, rs4986790, rs4986791, rs11536889, rs1927911 and rs2149356) in TLR4 on cancer, we conducted a meta-analysis, up to February 2012, 22 case-control studies were available. Summary odds ratios (OR) and corresponding 95% confidence intervals (CIs) for polymorphisms in TLR4 and cancer risk were estimated. Our meta-analysis identified that two SNPs (rs4986790 and rs4986791) in TLR4 were associated with increased cancer risk (for rs4986790: OR=1.24, 95% CI=1.01-1.52 in dominant model; OR=1.24, 95% CI=1.02-1.52 in overdominant model; for rs4986791: OR=1.81, 95% CI=1.18-2.77 in allele comparison; OR=1.79, 95% CI=1.15-2.80 in dominant model; OR=1.70, 95% CI=1.09-2.67 in overdominant model) and one SNP (rs1927911) in TLR4 was associated with decreased cancer risk (for rs1927911: OR=0.63, 95% CI=0.41-0.99 in allele comparison; OR=0.57, 95% CI=0.35-0.95 in dominant model; OR=0.67, 95% CI=0.46-0.97 in codominant model). Moreover, in terms of stratified analyses by cancer type for SNP rs4986790, significantly elevated risk was observed to be associated with G allele in gastric cancer and 'other cancers'. These findings indicate that polymorphisms in TLR4 may play a role, although modest, in cancer development.

Involvement of Toll-like Receptor 9 polymorphism in cervical cancer development

The role played by the polymorphism located in Toll-like Receptor 9 (TLR9) as a risk factor of cervical cancer remains elusive. Therefore, we studied the association of the TLR9 −1486 T/C (rs187084) and C2848T (rs352140) polymorphisms with cervical cancer. The TLR9 −1486 T/C and C2848T polymorphism was genotyped in 426 patients and 460 unrelated healthy females from the Polish population. Logistic regression analysis adjusting for age, pregnancy, oral contraceptive use, tobacco smoking, and menopausal status showed that both the TLR9 −1486 T/C and C2848T polymorphisms could be a genetic risk factor for cervical cancer. For the TLR9 −1486 T/C polymorphism, the adjusted OR for patients with the C/T genotype versus T/T genotype was 1.371 (95 % CI 1.021–1.842, p = 0.0361), the adjusted OR for the C/C genotype vs the T/T genotype was 1.300 (95 % CI 1.016–1.507, p = 0.0096), and the adjusted OR for the C/T or C/C genotype vs the T/T genotype was 1.448 (95 % CI 1.099–1.908, p = 0.0083). For the C2848T polymorphism, the adjusted OR for patients with the C/T genotype vs C/C genotype was 1.443 (95 % CI 1.019–2.043, p = 0.0380), the adjusted OR for the T/T genotype vs the C/C genotype was 1.237 (95 % CI 1.016–1.507, p = 0.0328), and the adjusted OR for the T/C or T/T genotype vs the C/C genotype was 1.345 (95 % CI 0.976–1.855, p = 0.0700). Our studies suggest that the TLR9 −1486 T/C and C2848T polymorphisms may be a genetic risk factor for cervical cancer.

Association of NOD1 and NOD2 genes polymorphisms with Helicobacter pylori related gastric cancer in a Chinese population

AIM: To investigate the association between the tag single nucleotide polymorphisms (TagSNPs) of NOD1 and NOD2 and the risk of developing gastric cancer.

METHODS: We conducted a hospital-based case-control study including 296 incident gastric cancer patients and 160 gastritis controls. Eight TagSNPs in the NOD1 and NOD2 genes were selected from the Hapmap database using the haploview software and genotyped by the Sequenom MassArray system. The serum levels of anti-Helicobacter pylori (H. pylori) IgG were measured by enzyme-linked immunosorbent assay to indicate H. pylori infection. The odds ratios (OR) and 95% confidence intervals (CI) were calculated by unconditional logistic regression, including sex and age as confounding factors.

RESULTS: The NOD1 rs2907749 GG genotype showed a decreased risk for gastric cancer (OR 0.50, 95% CI: 0.26-0.95, P = 0.04) while the rs7789045 TT genotype showed an increased risk (OR 2.14, 95% CI: 1.20-3.82, P = 0.01). An elevated susceptibility to gastric cancer was observed in the subjects with H. pylori infection and the NaOD1 rs7789045 TT genotype (OR 2.05, 95% CI: 1.07-3.94, P = 0.03) or the NOD2 rs7205423 GC genotype (OR 2.52, 95% CI: 1.05-6.04, P = 0.04). Haplotype analysis suggested that the distribution of AGT (rs2907749, rs2075820 and rs7789045) in NOD1 between the cases and control groups was significantly different (P corrected: 0.04), and the diplotype AGT/AGT was associated with an elevated gastric cancer risk (OR 1.98, 95% CI: 1.04-3.79, P = 0.04). The association of the NOD1 rs7789045 TT genotype and the diplotype AGT/AGT was significant with H. pylori-related diffuse-type gastric cancer (OR 3.00, 95% CI: 1.38-6.53, P = 0.01; OR 4.02, 95% CI: 1.61-10.05, P < 0.01, respectively).

CONCLUSION: Genetic polymorphisms in NOD1 and NOD2 may interact with H. pylori infection and may play important roles in promoting the development of gastric cancer in the Chinese population.

Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms in cancer: a meta-analysis

Toll-like receptor 4 (TLR4) is critical in the recognition of Gram-negative bacteria serving as a key immune system effector. Recently, a number of case-control studies were conducted to investigate the association between TLR4 gene polymorphism and cancer risk, especially Asp299Gly and Thr399Ile polymorphisms. However, published data were still conflicting. In this paper, we summarized 9463 cancer cases and 10,825 controls from 22 studies and attempted to assess the susceptibility of TLR4 gene polymorphism to cancers by a synthetical meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the relationship. Our results suggested that Asp299Gly represented a risk factor on cancers in digestive system (G allele versus A allele, OR=1.64, 95% CI: 1.02-2.64; GA+GG versus AA, OR=1.64, 95% CI: 1.00-2.71) but tend to have a protective effect on prostate cancer (GG versus AA, OR=0.37, 95% CI: 0.14-0.98; GG versus GA+AA, OR=0.37, 95% CI: 0.14-0.98). Thr399Ile polymorphism was significantly associated with an elevated cancer risk in overall analysis (T allele versus C allele, OR=1.72, 95% CI: 1.27-2.33; TC versus CC, OR=1.63, 95% CI: 1.18-2.26; TT+TC versus CC, OR=1.70, 95% CI: 1.24-2.34) and especially in gastrointestinal subgroup (T allele versus C allele, OR=2.01, 95% CI: 1.40-2.89; TC versus CC, OR=1.86, 95% CI: 1.26-2.74; TT+TC versus CC, OR=1.97, 95% CI: 1.35-2.88). Further prospective researches with larger numbers of worldwide participants are warranted to draw comprehensive and true conclusions.

Exogenous or endogenous Toll-like receptor ligands: which is the MVP in tumorigenesis?

Toll-like receptors (TLRs) are a class of pattern recognition receptors sensing microbial components and triggering an immune response against pathogens. In addition to their role in anti-infection immunity, increasing evidence indicates that engagement of TLRs can promote cancer cell survival and proliferation, induce tumor immune evasion, and enhance tumor metastasis and chemoresistance. Recent studies have demonstrated that endogenous molecules or damage-associated molecular patterns released from damaged/necrotic tissues are capable of activating TLRs and that the endogenous ligands-mediated TLR signaling is implicated in the tumor development and affects the therapeutic efficacy of tumors. Since both exogenous and endogenous TLR ligands can initiate TLR signaling, which is the most valuable player in tumor development becomes an interesting question. Here, we summarize the effect of TLR signaling on the development and progression of tumors, and discuss the role of exogenous and endogenous TLR ligands in the tumorigenesis.

Inherited variation in pattern recognition receptors and cancer: dangerous liaisons?

The group of pattern recognition receptors includes families of Toll-like receptors, NOD-like receptors, C-type lectin receptors, and RIG-I-like receptors. They are key sensors for a number of infectious agents, some of which are carcinogenic, and they launch an immune response against them. Inherited structural variation in genes encoding these receptors and proteins of their signaling pathways may affect their function, modulating cancer risk and features of cancer progression. Relevant malignancies, valuable gene polymorphisms, prime questions about future directions, and answers to these questions are analyzed in this review. It is possible to suggest that polymorphisms of genes encoding pattern recognition receptors and proteins of their signaling pathways may be associated with almost all cancer types, particularly with those in which carcinogenic infectious agents are responsible for the substantial share of cases (namely gastric cancer, colorectal cancer, liver cancer, cervical cancer, and nasopharyngeal carcinoma). The concept of selection of polymorphisms for further oncogenomic investigation, based on a combination of results from basic and epidemiological studies, is proposed.

The association between Toll-like receptor 2 single-nucleotide polymorphisms and hepatocellular carcinoma susceptibility

Background

Toll-like receptors (TLR) are key innate immunity receptors participating in an immune response. Growing evidence suggests that mutations of TLR2/TLR9 gene are associated with the progress of cancers. The present study aimed to investigate the temporal relationship of single nucleotide polymorphisms (SNP) of TLR2/TLR9 and the risk of hepatocellular carcinoma (HCC).

Methods

In this single center-based case-control study, SNaPshot method was used to genotype sequence variants of TLR2 and TLR9 in 211 patients with HCC and 232 subjects as controls.

Results

Two synonymous SNPs in the exon of TLR2 were closely associated with risk of HCC. Compared with those carrying wild-type homozygous genotypes (T/T), risk of HCC decreased significantly in individuals carrying the heterozygous genotypes (C/T) of the rs3804099 (adjusted odds ratio (OR), 0.493, 95% CI 0.331 - 0.736, P < 0.01) and rs3804100 (adjusted OR, 0.509, 95% CI 0.342 - 0.759, P < 0.01). There was no significant association found in two TLR9 SNPs concerning the risk of HCC. The haplotype TT for TLR2 was associated significantly with the decreased risk of HCC (OR 0.524, 95% CI 0.394 - 0.697, P = 0.000). Inversely, the risk of HCC increased significantly in patients with the haplotype CC (OR 2.743, 95% CI 1.915 - 3.930, P = 0.000).

Conclusions

These results suggested that TLR2 rs3804099 C/T and rs3804100 C/T polymorphisms were closely associated with HCC. In addition, the haplotypes composed of these two TLR2 synonymous SNPs have stronger effects on the susceptibility of HCC.

Association of polymorphisms in TLR genes and in genes of the Toll-like receptor signaling pathway with cancer risk

Toll-like receptors (TLRs) constitute a family of receptors directly recognizing a wide spectrum of exogenous and endogenous ligands playing the key role in realization of innate and adaptive immune response, and participating in the processes of cell proliferation, survival, apoptosis, angiogenesis, tissue remodeling and repair. Polymorphisms in TLR genes may shift balance between pro- and anti-inflammatory cytokines, modulating the risk of infection, chronic inflammation and cancer. The short list of TLR polymorphisms perspective for oncogenomic investigations can include rs10008492, rs4833103, rs5743815, rs11466657, rs7696175 (TLR1-TLR6-TLR10 gene cluster); rs3804100, rs4696480, -196 - -174 del (Delta22), GT-microsatellite polymorphism (TLR2); 829A/C (TLR3); rs5743836, rs352140 (TLR9). The extended list can additionally include rs4833095 rs5743551, rs5743618 (TLR1); rs5743704, rs62323857, rs1219178642 (TLR2); rs5743305, rs3775291, rs121434431, rs5743316 (TLR3); rs5744168 (TLR5); rs179008 (TLR7); rs3764880, rs2407992 (TLR8); rs352139, rs187084, rs41308230, rs5743844 (TLR9); rs4129009 (TLR10). General reasons for discrepancies between studies are insufficiency of sample size, age/gender/BMI/ethnic/racial differences, differences in prevalence of infectious agent in case and control groups, differences in immune response caused by specific ligand, differences in stratification, methods of diagnostics of cancer or chronic inflammatory conditions, genotyping methods, and chance. Future well-designed studies on large samples should shed light on the significance of TLR polymorphisms for cancer prevention.

Role of NOD1/CARD4 and NOD2/CARD15 gene polymorphisms in cancer etiology

NOD1/CARD4 and NOD2/CARD15 are members of Nod-like receptor family. They are located in cytosol, bind bacterial and viral ligands and play a key role in realization of innate and adaptive immune response, apoptosis, autophagy, and reactive oxygen species generation. Polymorphisms in NOD1/CARD4 and NOD2/CARD15 genes may shift balance between pro- and anti-inflammatory cytokines, modulating the risk of infection, chronic inflammation and cancer. NOD1/CARD4 and NOD2/CARD15 gene polymorphisms may be associated with altered risk of gastric, colorectal, breast, ovarian, prostate, testicular, lung, laryngeal, liver, gallbladder, biliary tract, pancreatic, small bowel, kidney, urinary bladder cancer, skin cancer, nonthyroid endocrine tumors, lymphoma and leukemia. The short list of such polymorphisms perspective for oncogenomic investigations may include rs2006847, rs2066845, rs2066844, rs2066842, ND(1)+32656, rs2075820 whereas rs104895493, rs104895476, rs104895475, rs104895474, rs104895473, rs104895472, rs104895462, rs104895461, rs104895460, rs104895438, rs5743291, rs5743260, rs2076756, rs2066843, Pro371Thr, Ala794Pro, Gln908His, rs72551113, rs72551107, rs6958571, rs2907749, rs2907748, rs2075822, rs2075819, rs2075818 may be added to the extended list. Reasons of discrepancies between different studies include confounding host genetic, bacterial, or environmental factors modulating penetrance of variant allele and affecting risk of condition increasing cancer risk, different bacterial impact in aetiology of such conditions, differences in sample size, clinicopathological characteristics, diagnostics, stratification, genotyping methods, and chance.

Impact of Toll-like receptor 4 polymorphisms on risk of cancer

Toll-like receptor 4 (TLR4) is one of the key immune system effectors playing the main role in recognition of viruses and bacteria. Dysregulation of the TLR4 signaling owing to single nucleotide polymorphisms (SNPs) may alter the ligand binding and balance between pro- and anti-inflammatory cytokines, thereby modulating the risk of chronic inflammation and cancer. TLR4 polymorphisms may be associated with at least nine types of cancer. The most intensively investigating TLR4 polymorphisms are Asp299Gly (rs4986790) and Thr399Ile (rs4986791). It seems to be that Asp299Gly and Thr399Ile are related to increased risk of precancerous gastric lesions, and, possibly, gastric cancer. Thr399Ile also may be connected with gallbladder cancer, and both of these polymorphisms apparently have no impact on risk of prostate cancer. However, the data about many SNPs and their associations with different types of cancer are conflicting, and further large, well-designed, comprehensive studies in various populations are necessary for solution of this problem. The short list of TLR4 SNPs for further investigation may include TLR4_896A/G (Asp299Gly, rs4986790), TLR4_1196C/T (Thr399Ile, rs4986791), Thr135Ala, TLR4_1859 G/A (rs11536858), TLR4_2032T/C (rs10116253), TLR4_2437A/G (rs1927914), TLR4_2856T/C (rs10759932), TLR4_3725 G/C (rs11536889), TLR4_7764 G/A (rs1927911), TLR4_11350G/C, TLR4_11912 G/T (rs2149356), TLR4_16649G/C (rs7873784), and TLR4_17050T/C (rs11536891).