TLR2

Gene Summary

Gene:TLR2; toll like receptor 2
Aliases: TIL4, CD282
Location:4q31.3
Summary:The protein encoded by this gene is a member of the Toll-like receptor (TLR) family which plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from Drosophila to humans and share structural and functional similarities. This protein is a cell-surface protein that can form heterodimers with other TLR family members to recognize conserved molecules derived from microorganisms known as pathogen-associated molecular patterns (PAMPs). Activation of TLRs by PAMPs leads to an up-regulation of signaling pathways to modulate the host's inflammatory response. This gene is also thought to promote apoptosis in response to bacterial lipoproteins. This gene has been implicated in the pathogenesis of several autoimmune diseases. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:toll-like receptor 2
Source:NCBIAccessed: 16 March, 2017

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 16 March 2017 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 16 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (5)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: TLR2 (cancer-related)

Lohani N, Rajeswari MR
Dichotomous Life of DNA Binding High Mobility Group Box1 Protein in Human Health and Disease.
Curr Protein Pept Sci. 2016; 17(8):762-775 [PubMed] Related Publications
The High mobility group box 1 (HMGB1) protein is an extremely versatile, highly conserved nuclear protein, with its unique intracellular and extracellular functions mediated by its relatively simple domain structure. Within the nucleus, HMGB1 binds to DNA minor groove in a nonspecific manner and causes bends in the double helix thus helps in recruiting a number of DNA binding protein and transcription factors, to facilitate transcription of various genes. HMGB1 also helps in DNA repair, chromatin remodeling, V (D) J recombination, and assembly of nucleosome on the chromatin. On contrary, under pathological conditions HMGB1 displays inflammatory response by interaction with specific cell surface receptors like RAGE, TLR-4, TLR9, and TLR2 and activates NF-kB downstream signaling pathways. The upregulation of HMGB1 is directly associated with the pathogenesis of cancer, sepsis, ischemia, hemorrhagic shock, anorexia, rheumatic disease, periodontal disease etc. Therefore, HMGB1 has been considered as a promising target in the treatment of various human diseases. The interest in HMGB1 is evident and reflected in the exponential increase in the recent publications, and therefore there is a need for an update on the understanding of the role of HMGB1 in pathogenesis and its potential application of HMGB1 as a therapeutic target in a number of human diseases.

Palaska I, Gagari E, Theoharides TC
The effects of P. gingivalis and E. coli LPS on the expression of proinflammatory mediators in human mast cells and their relevance to periodontal disease.
J Biol Regul Homeost Agents. 2016 Jul-Sep; 30(3):655-664 [PubMed] Related Publications
Mast cells (MCs) are tissue-resident immune cells that participate in a variety of allergic and inflammatory conditions, including periodontal disease, through the release of cytokines, chemokines and proteolytic enzymes. Porhyromonas gingivalis (P. g) is widely recognized as a major pathogen in the development and progression of periodontitis. Here we compared the differential effects of lipopolysaccharides (LPS) from P. g and E. coli on the expression and production of tumor necrosis factor (TNF), vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein (MCP-1) by human MCs. Human LAD2 MCs were stimulated with LPS from either P. g or E. coli (1-1000 ng/ml). MCs were also stimulated with SP (2μM) serving as the positive control or media alone as the negative control. After 24 h, the cells and supernatant fluids were collected and analyzed for β-Hexosaminidase (β-hex) spectrophotometrically, TNF, VEGF and MCP-1 release by ELISA and real-time polymerase chain reaction (PCR) for mediator gene expression, respectively. To assess the functional role of tolllike receptors (TRL) in mediator release, MCs were pre-incubated with either anti-TLR2 or anti- TLR4 (2 μg/ml) polyclonal antibody for 1 h before stimulation with LPS. When MCs were stimulated with SP (2 μM), there was a statistically significant β-hex release as well as release of TNF, VEGF and MCP-1. Stimulation of MCs with either type of LPS did not induce degranulation based on the lack of β-hex release. However, both types of LPS stimulated expression and release of TNF, VEGF and MCP-1. Although, P. g LPS induced significant release of TNF, VEGF and MCP-1, the effect was not concentration-dependent. There was no statistically significant difference between the effects of P. g and E. coli LPS. P. g LPS stimulated TNF through TLR-2 while E. coli utilized TRL-4 instead. In contrast, VEGF release by P. g LPS required both TRL-2 and TRL-4 while E. coli LPS required TLR-4. Release of MCP-1 was independent of TLR-2 or TLR-4. P. g LPS activates human MCs to generate and release TNF, VEGF and MCP-1 through different TLRs than E. coli LPS. MCs may, therefore, be involved in the inflammatory processes responsible for periodontal disease.

Shimabukuro M, Sato H, Izaki H, et al.
Depot- and gender-specific expression of NLRP3 inflammasome and toll-like receptors in adipose tissue of cancer patients.
Biofactors. 2016; 42(4):397-406 [PubMed] Related Publications
Gender difference in obesity-associated cardiovascular complication could be derived from divergent chronic inflammation. We evaluated depot- and gender-specific regulation of the innate immune system in human adipose tissues. Pair samples were obtained from subcutaneous (SAT) and visceral adipose tissue (VAT) during elective surgery (Male: 35; Female: 27). Expressions of pro- and anti-inflammatory adipocytokines were evaluated by semi-quantitative qPCR. Adipose cell-size distribution was obtained from tissue samples fixed in osmium tetroxide and analyzed by Beckman Coulter Multisizer. Levels of adiponectin were higher in SAT and VAT of female than those of male (P < 0.001 and P = 0.011, respectively). NLRP3, IL1β-IL18, TLR2 were comparable in SAT and VAT between genders. However, TLR4 and TLR9 were increased in female SAT and VAT and HMGB1 in female VAT. Levels of adiponectin were not correlated with mean diameter of adipocyte (φ, μm) in SAT and VAT of male, but negatively well correlated in those of female (r = -0.392 and r = -0.616). Such negative correlations were also observed between levels of TLR2, TLR4, and HMGB1 and φ in female. Levels of NLRP3 and IL1β were positively correlated with φ in male, but not in female. In conclusion, Innate signals were differentially expressed in male and female adipose tissues, suggesting that the depot- and gender-specific signals could be related to gender difference in chronic inflammation. © 2016 BioFactors, 42(4):397-406, 2016.

Echizen K, Hirose O, Maeda Y, Oshima M
Inflammation in gastric cancer: Interplay of the COX-2/prostaglandin E2 and Toll-like receptor/MyD88 pathways.
Cancer Sci. 2016; 107(4):391-7 [PubMed] Free Access to Full Article Related Publications
Cyclooxygenase-2 (COX-2) and its downstream product prostaglandin E2 (PGE2 ) play a key role in generation of the inflammatory microenvironment in tumor tissues. Gastric cancer is closely associated with Helicobacter pylori infection, which stimulates innate immune responses through Toll-like receptors (TLRs), inducing COX-2/PGE2 pathway through nuclear factor-κB activation. A pathway analysis of human gastric cancer shows that both the COX-2 pathway and Wnt/β-catenin signaling are significantly activated in tubular-type gastric cancer, and basal levels of these pathways are also increased in other types of gastric cancer. Expression of interleukin-11, chemokine (C-X-C motif) ligand 1 (CXCL1), CXCL2, and CXCL5, which play tumor-promoting roles through a variety of mechanisms, is induced in a COX-2/PGE2 pathway-dependent manner in both human and mouse gastric tumors. Moreover, the COX-2/PGE2 pathway plays an important role in the maintenance of stemness with expression of stem cell markers, including CD44, Prom1, and Sox9, which are induced in both gastritis and gastric tumors through a COX-2/PGE2 -dependent mechanism. In contrast, disruption of Myd88 results in suppression of the inflammatory microenvironment in gastric tumors even when the COX-2/PGE2 pathway is activated, indicating that the interplay of the COX-2/PGE2 and TLR/MyD88 pathways is needed for inflammatory response in tumor tissues. Furthermore, TLR2/MyD88 signaling plays a role in maintenance of stemness in normal stem cells as well as gastric tumor cells. Accordingly, these results suggest that targeting the COX-2/PGE2 pathway together with TLR/MyD88 signaling, which would suppress the inflammatory microenvironment and maintenance of stemness, could be an effective preventive or therapeutic strategy for gastric cancer.

Kim JH, Key EY, Song MJ, et al.
Toll-like receptor 2 gene polymorphisms in Korean women with human papillomavirus-related cervical neoplasia.
Acta Obstet Gynecol Scand. 2016; 95(7):829-35 [PubMed] Related Publications
INTRODUCTION: The aim of this study was to investigate the association between Toll-like receptor 2 (TLR2) gene polymorphisms and human papillomavirus (HPV)-related cervical neoplasia in Korean women.
MATERIAL AND METHODS: Peripheral blood samples collected from 127 patients with HPV-related cervical neoplasia and 175 healthy women were genotyped for the TLR2 -16934, +1350, intron1, and 3' untranslated region (UTR) polymorphisms using the polymerase chain reaction and restriction fragment length polymorphism method.
RESULTS: The TLR2 -16934 A/A, intron1 A/A, and +1350 T/C genotypes were more frequent in patients than in controls [odds ratio (OR) = 2.1, 95% CI = 1.302-3.475, p = 0.002; OR = 1.9, 95% CI = 1.168-3.169, p = 0.010; and OR = 1.9, 95% CI = 1.211-3.123, p = 0.006, respectively]. The frequencies of the TLR2 + 1350 C and 3'UTR G alleles were also higher in patients (OR = 2.0, 95% CI = 1.236-3.121, p = 0.004 and OR = 1.7, 95% CI = 1.005-3.076, p = 0.046, respectively). The genotype frequencies of TLR2 -16934 A/A and intron1 A/A increased with increasing oncogenic risk of the HPV genotype, as follows. low-risk type < high-risk type < HPV-16 and/or HPV-18 type (p = 0.008).
CONCLUSIONS: Our study provides the first evidence that TLR2 gene polymorphisms are associated with high-risk type HPV-related cervical neoplasia and may play an important role in susceptibility to HPV infection. Further large-scale and functional studies are needed to confirm the role of TLR2 gene polymorphisms in HPV-related cervical neoplasia.

Fischer M, Spies-Weisshart B, Schrenk K, et al.
Polymorphisms of Dectin-1 and TLR2 Predispose to Invasive Fungal Disease in Patients with Acute Myeloid Leukemia.
PLoS One. 2016; 11(3):e0150632 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Patients with acute myeloid leukemia (AML) who undergo induction chemotherapy are at high risk for invasive fungal disease (IFD). Dectin-1, a C-type lectin family member represents one of the most important pattern recognition receptors of the innate immune system and single nucleotide polymorphisms (SNPs) in the Dectin-1 gene have been associated with an increased risk of infectious complications. We sought to investigate the impact of three different Dectin-1 SNPs and one TLR2 SNP on developing IFD in 186 adult patients with newly diagnosed AML following anthracycline-based induction chemotherapy.
PATIENTS AND METHODS: Genotyping of Dectin-1 SNPs (rs16910526, rs3901533 and rs7309123) and TLR2 SNP (rs5743708) was performed by TaqMan method and pyrosequencing. IFD was defined according to the EORTC/MSG consensus guidelines. Multiple logistic regression analyses were applied to evaluate the association between the polymorphisms and the occurrence of pulmonary infections. Dectin-1 expression studies with SNP genotyped human monocytes were performed to elucidate susceptibility to IFD following chemotherapy.
RESULTS: We could demonstrate that patients carrying the Dectin-1 SNP rs7309123 G/G (n = 47) or G/G and C/G (n = 133) genotype revealed a significant higher risk for developing both pneumonia in general (adjusted odds ratio (OR): 2.5; p = 0.014 and OR: 3.0, p = 0.004) and pulmonary IFD (OR: 2.6; p = 0.012 and OR: 2.4, p = 0.041, respectively). Patients carrying the TLR2 SNP rs5743708 (R753Q, GA/AA genotype, n = 12) also revealed a significantly higher susceptibility to pneumonia including IFD. Furthermore, Dectin-1 mRNA expression in human monocytes was lower following chemotherapy.
CONCLUSION: To our best knowledge, this study represents the first analysis demonstrating that harbouring polymorphisms of Dectin-1 (rs7309123) or TLR2 (rs5743708) represents an independent risk factor of developing IFD in patients with AML undergoing induction chemotherapy.

Rybka J, Gębura K, Wróbel T, et al.
Variations in genes involved in regulation of the nuclear factor - κB pathway and the risk of acute myeloid leukaemia.
Int J Immunogenet. 2016; 43(2):101-6 [PubMed] Related Publications
Genes involved in regulation of the nuclear factor - kappa B (NF-κB) pathway are suggested to play a role in the pathogenesis of acute myeloid leukaemia (AML). The present study aimed to assess the association between the NF-κB1, TRAF3 and TLRs genes single nucleotide polymorphisms (SNPs) and disease susceptibility as well as progression in patients with AML. For this purpose 62 patients and 126 healthy individuals were genotyped for NF-κB1 (rs28362491), TRAF3 (rs11160707; rs12147254), TLR2 (rs201786064), TLR4 (rs4986790; rs4986791) and TLR9 (rs5743836; rs187084) alleles. Three SNPs were found to be associated with the risk for the AML development. The TRAF3 (rs12147254) AA homozygosity (RR = 2.770, P = 0.0392), TLR9 (rs5743836) C wild-type allele (RR = 2.542, P = 0.0096) as well as TLR9 (rs187084) T allele (RR = 13.396, P < 0.0001) and its homozygosity (RR = 11.805, P < 0.0001) were more frequent among patients with AML than healthy individuals. The associations of the rs187084 SNP were significant for both sexes. Moreover, patients who relapsed were more frequently characterized with the presence of the rs187084 TLR9 TT genotype (P = 0.045) or the rs12147254 TRAF3 A variant (P = 0.066). In conclusion, polymorphisms within the TLR9 and TRAF3 genes are associated with predisposition to AML and may affect the progression of the disease in the Polish population.

Maeda Y, Echizen K, Oshima H, et al.
Myeloid Differentiation Factor 88 Signaling in Bone Marrow-Derived Cells Promotes Gastric Tumorigenesis by Generation of Inflammatory Microenvironment.
Cancer Prev Res (Phila). 2016; 9(3):253-63 [PubMed] Related Publications
It has been established that COX-2 and downstream signaling by prostaglandin E2 (PGE2) play a key role in tumorigenesis through generation of inflammatory microenvironment. Toll-like receptor (TLR) signaling through myeloid differentiation factor 88 (MyD88) also regulates inflammatory responses in tumors. However, the relationship between these distinct pathways in tumorigenesis is not yet fully understood. We herein investigated the role of MyD88 in gastric tumorigenesis using Gan mice, which develop inflammation-associated gastric tumors due to the simultaneous activation of the COX-2/PGE2 pathway and Wnt signaling. Notably, the disruption of Myd88 in Gan mice resulted in the significant suppression of gastric tumorigenesis with the inhibition of inflammatory responses, even though COX-2/PGE2 pathway is constitutively activated. Moreover, Myd88 disruption in bone marrow-derived cells (BMDCs) in Gan mice also suppressed inflammation and tumorigenesis, indicating that MyD88 signaling in BMDCs regulates the inflammatory microenvironment. We also found that expression of Tlr2 and its coreceptor Cd14 was induced in tumor epithelial cells in Gan mice, which was suppressed by the disruption of Myd88. It has already been shown that TLR2/CD14 signaling is important for stemness of intestinal epithelial cells. These results indicate that MyD88 in BMDCs, together with COX-2/PGE2 pathway, plays an essential role in the generation of the inflammatory microenvironment, which may promote tumorigenesis through induction of TLR2/CD14 pathway in tumor epithelial cells. These results suggest that inhibition of TLR/MyD88 signaling together with COX-2/PGE2 pathway will be an effective preventive strategy for gastric cancer.

Mukherjee D, Devi KR, Deka M, et al.
Association of toll-like receptor 2 ∆22 and risk for gastric cancer considering main effects and interactions with smoking: a matched case-control study from Mizoram, India.
Tumour Biol. 2016; 37(8):10821-6 [PubMed] Related Publications
Toll-like receptors (TLRs) are evolutionary conserved cell surface receptors of the innate immune system. Smoking has significant immunological effects which are mediated via TLRs on various receptor-mediated innate response pathways. Polymorphisms of TLR genes are associated with susceptibility toward various malignancies. The present study was undertaken to examine the association between TLR2 ∆22 and gastric cancer. In this study, we also investigated the interaction between TLR2 ∆22 and smoking. A total of 133 histologically confirmed gastric cancer cases and 266 age-sex-matched controls were selected for this study. TLR2 ∆22 genotypes were determined by allele-specific polymerase chain reaction (PCR). Binary conditional logistic regression analysis was used to find the association of TLR2 ∆22 with risk of gastric cancer. Logistic regression using hierarchically well-formulated models was used for interaction analysis between smoking and TLR2 ∆22. Persons having TLR2 ∆22 heterozygous genotype had two times increased risk of gastric cancer in multivariate logistic regression model. The interaction analysis using hierarchical logistic regression models between smoking and TLR2 ∆22 by calculating separate X (2) for interaction model and only main effect model, the difference of X (2) 57.68-47.70 = 9.98 and degrees of freedom (df) 5-3 = 2, revealed significant (α = 0.05, df = 2) omnibus interaction. Our present study revealed TLR2 ∆22 to be significantly and independently associated with gastric cancer risk in Mizoram, and there is also evidence of significant interaction between smoking and TLR2 ∆22 with risk of gastric cancer.

Bock S, Murgueitio MS, Wolber G, Weindl G
Acute myeloid leukaemia-derived Langerhans-like cells enhance Th1 polarization upon TLR2 engagement.
Pharmacol Res. 2016; 105:44-53 [PubMed] Related Publications
Langerhans cells (LCs) represent a highly specialized subset of epidermal dendritic cells (DCs), yet not fully understood in their function of balancing skin immunity. Here, we investigated in vitro generated Langerhans-like cells obtained from the human acute myeloid leukaemia cell line MUTZ-3 (MUTZ-LCs) to study TLR- and cytokine-dependent activation of epidermal DCs. MUTZ-LCs revealed high TLR2 expression and responded robustly to TLR2 engagement, confirmed by increased CD83, CD86, PD-L1 and IDO expression, upregulated IL-6, IL-12p40 and IL-23p19 mRNA levels IL-8 release. TLR2 activation reduced CCR6 and elevated CCR7 mRNA expression and induced migration of MUTZ-LCs towards CCL21. Similar results were obtained by stimulation with pro-inflammatory cytokines TNF-α and IL-1β whereas ligands of TLR3 and TLR4 failed to induce a fully mature phenotype. Despite limited cytokine gene expression and production for TLR2-activated MUTZ-LCs, co-culture with naive CD4(+) T cells led to significantly increased IFN-γ and IL-22 levels indicating Th1 differentiation independent of IL-12. TLR2-mediated effects were blocked by the putative TLR2/1 antagonist CU-CPT22, however, no selectivity for either TLR2/1 or TLR2/6 was observed. Computer-aided docking studies confirmed non-selective binding of the TLR2 antagonist. Taken together, our results indicate a critical role for TLR2 signalling in MUTZ-LCs considering the leukemic origin of the generated Langerhans-like cells.

Maslinska D, Laure-Kamionowska M, Maslinski S, Szukiewicz D
Toll-like receptor 2 (TLR2) is a marker of angiogenesis in the necrotic area of human medulloblastoma.
Folia Neuropathol. 2015; 53(4):347-54 [PubMed] Related Publications
Angiogenesis plays a key role in the progression of malignant tumors. In recent years, anti-angiogenic drugs have been shown to be effective against tumors. However, some tumors are able to adopt escape mechanisms, suggesting that the vascular network in these tumors may be formed or may function in a different way. Medulloblastomas are tumors characterized by poor prognosis and low patient survival rates. These tumors rarely metastasize, but the reason why they almost always recur locally is not known. Central to mediating neoplastic changes is the interaction between cell surface receptors and their cognate ligands, which through intracellular signaling induce alternations in gene expression. In this context, the aim of our present study was to examine in medulloblastoma the distribution of Toll-like receptor 2 (TLR2) and receptor for advanced glycosylation end-product (RAGE), and mast cells associated with the tumor neovascularization process. Immunohistochemical study with a battery of specific antibodies was used. The results show that in the tumor necrotic area, TLR2 participates in all steps of vascular network formation, but in regions where the tumor was not affected by necrosis, the capillary network was TLR2 immunonegative. The TLR2 vascular network of the necrotic area was not associated with RAGE and mast cells. However, in the region of the medulloblastoma not affected by necrosis, the RAGE receptor was present in the endothelium of all capillaries, and mast cells were numerous only in the perivascular space of large brain and meningeal vessels at the border of the tumor. In conclusion, our results show that the receptor of innate immunity TLR2 plays an important role in recognition of ligands delivered by dying necrotic medulloblastoma cells and participates in tumor neovascularization. Moreover, the results show that the RAGE receptor and mast cells operate in different medulloblastoma regions and influence different parts of the tumor vascular network.

Ayari C, Besançon M, Bergeron A, et al.
Poly(I:C) potentiates Bacillus Calmette-Guérin immunotherapy for bladder cancer.
Cancer Immunol Immunother. 2016; 65(2):223-34 [PubMed] Related Publications
Non-specific immunotherapy consisting of intravesical instillation of Bacillus Calmette-Guérin (BCG) is currently the best available treatment to prevent non-muscle-invasive bladder tumor recurrence and progression. This treatment however is suboptimal, and more effective immunotherapeutic approaches are needed. Toll-like receptors (TLRs) play a major role in the activation of the immune system in response to pathogens and danger signals but also in anti-tumor responses. We previously showed that human urothelial cells express functional TLRs and respond to TLR2 and TLR3 agonists. In this study, we analyzed the potential of polyinosinic:polycytidylic acid [poly(I:C)], a TLR3 agonist, to replace or complement BCG in the treatment of non-muscle-invasive bladder cancer. We observed that poly(I:C) had an anti-proliferative, cytotoxic, and apoptotic effect in vitro on two low-grade human bladder cancer cell lines, MGH-U3 and RT4. In MGH-U3 cells, poly(I:C) induced growth arrest at the G1-S transition. Poly(I:C) also increased the immunogenicity of MGH-U3 and RT4 cells, inducing the secretion of MHC class I molecules and of pro-inflammatory cytokines. By comparison, poly(I:C) had less in vitro impact on two high-grade human bladder cancer cell lines, 5637 and T24, and on MBT-2 murine high-grade bladder cancer cells. The latter can be used as an immunocompetent model of bladder cancer. The combination poly(I:C)/BCG was much more effective in reducing MBT-2 tumor growth in mice than either treatment alone. It completely cured 29% of mice and also induced an immunological memory response. In conclusion, our study suggests that adding poly(I:C) to BCG may enhance the therapeutic effect of BCG.

Liu X, Gong J, Xu B
miR-143 down-regulates TLR2 expression in hepatoma cells and inhibits hepatoma cell proliferation and invasion.
Int J Clin Exp Pathol. 2015; 8(10):12738-47 [PubMed] Free Access to Full Article Related Publications
Hepatoma is a tumor with high degree of malignancy. A number of oncogenes and tumor suppressor genes play certain roles in tumorigenesis and progression. Among which, miRNA, as an important class of gene regulators, play important roles in regulating tumorigenesis and development of hepatoma. So know well the unique molecular pathway is very important. Here, we showed that there is a different miR-143 expression patterns in different hepatoma tissues, and that miR-143 expressions contribute disease progress. By contrast, we down-regulated the expression of miR-143 with miR-143 mimics in HepG2 cells resulting in decreased proliferation. And the decreased proliferations of HepG2 cells were due to a G0/G1 arrest of cell cycle. During this progress, the increased apoptosis may be another major cause for decreased proliferation of HepG2 cells. And then, we found miR-143 down-regulation induced decreased mRNA and protein expressions of TLR2 and NF-κB. These results show that HepG2 cells depend to a greater extent on miR-143 for proliferation, and miR-143 down-regulation may induce a cell cycle arrest though TLR and NF-κB pathway. miR-143 blockade may be beneficial in therapy of Hepatoma.

Biray Avci C, Kurt CC, Tepedelen BE, et al.
Zoledronic acid induces apoptosis via stimulating the expressions of ERN1, TLR2, and IRF5 genes in glioma cells.
Tumour Biol. 2016; 37(5):6673-9 [PubMed] Related Publications
Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor that affects older people. Although the current therapeutic approaches for GBM include surgical resection, radiotherapy, and chemotherapeutic agent temozolomide, the median survival of patients is 14.6 months because of its aggressiveness. Zoledronic acid (ZA) is a nitrogen-containing bisphosphonate that exhibited anticancer activity in different cancers. The purpose of this study was to assess the potential effect of ZA in distinct signal transduction pathways in U87-MG cells. In this study, experiments performed on U87-MG cell line (Human glioblastoma-astrocytoma, epithelial-like cell line) which is an in vitro model of human glioblastoma cells to examine the cytotoxic and apoptotic effects of ZA. IC50 dose of ZA, 25 μM, applied on U87-MG cells during 72 h. ApoDIRECT In Situ DNA Fragmentation Assay was used to investigate apoptosis of U87MG cells. The quantitative reverse transcription polymerase chain reaction (qRT-PCR) (LightCycler480 System) was carried out for 48 gene expression like NF-κB, Toll-like receptors, cytokines, and inteferons. Our results indicated that ZA (IC50 dose) increased apoptosis 1.27-fold in U87MG cells according to control cells. According to qRT-PCR data, expression levels of the endoplasmic reticulum-nuclei-1 (ERN1), Toll-like receptor 2 (TLR2), and human IFN regulatory factor 5 (IRF5) tumor suppressor genes elevated 2.05-, 2.08-, and 2.3-fold by ZA, respectively, in U87MG cells. Our recent results indicated that ZA have a key role in GBM progression and might be considered as a potential agent in glioma treatment.

Zidi S, Sghaier I, Gazouani E, et al.
Evaluation of Toll-Like Receptors 2/3/4/9 Gene Polymorphisms in Cervical Cancer Evolution.
Pathol Oncol Res. 2016; 22(2):323-30 [PubMed] Related Publications
Accumulative epidemiological evidence suggests that polymorphisms of Toll-like receptors signaling pathway elucidated the cellular and molecular mechanisms of human diseases whose gaining a primordial importance. The aim of our study is to identify the role of TLR 2 (-196 to -174 del), TLR 3 (1377 C>T), TLR 4 (Asp299Gly) and TLR 9 (G2848A) gene polymorphisms with the evolution of cervical cancer in Tunisian women. Blood samples were collected from histopathologically confirmed patients with cervical cancer and unrelated healthy female controls of similar ethnicity. Genotyping of the analyzed polymorphisms were done using Polymerase Chain Reaction and Restriction Fragment Length Polymorphism. For the TLR 2, Ins/Ins genotype is a protector factor [p = 0.006; OR: 0.35(0.16-0.73)] and the dominant genotype of TLR 3 increased the risk of CC in stage (III+IV); C/C versus C/T [p = 0.033; OR: 2.03(1.00-4.13)] and C/C versus C/T+T/T [p = 0.036; OR: 1.93(1.00-3.74)]. For TLR 4, the dominant genotype Asp/Asp is implicated in the occurrence of CC in stage (I+II) [p = 0.000; OR: 4.55(1.58-13.06)], [p = 0.001; OR: 3.49(1.44-8.45)] and in stage (III+IV) [p = 0.038; OR: 3.77(0.87-16.29)], [p = 0.007; OR: 5.21(1.65-16.46)] and the major allele Asp is a risk factor for the development of tumor in stage (I+II). The TLR2 Ins/Del genotype is associated with tumor evolution to stage (III+IV) [p = 0.003; OR: 3.00 (1.22-7.35)] and the genotypes Gly/Gly and Asp/Gly+Gly/Gly and Gly allele of TLR 4 are implicated in tumor evolution to the advanced stages. Further, TLR 2, TLR 3, TLR 4 and TLR 9 gene polymorphisms are implicated in the modulation of CC risk due to tobacco usage and statue of menopause among cases. Our study suggests a relationship between the incidence of the TLR2, TLR 3, TLR 4 and TLR9 mutations and the clinical progression of CC according to the FIGO classification. However, future studies with different demographic and clinical characteristics in ethnically diverse populations may provide a more comprehensive involvement of innate immunity in cervical cancer etiology in women worldwide.

Ojeda-Ojeda M, Martínez-García MÁ, Alpañés M, et al.
Association of TLR2 S450S and ICAM1 K469E polymorphisms with polycystic ovary syndrome (PCOS) and obesity.
J Reprod Immunol. 2016; 113:9-15 [PubMed] Related Publications
Toll-like receptors (TLRs) are activated by inflammatory stimuli and influence endothelial functions, contributing to the pathogenesis of atherosclerosis. We investigate the influence of polymorphisms in the genes encoding toll-like receptor 2 (TLR2) and 4 (TLR4) and endothelial adhesion molecules on polycystic ovary syndrome (PCOS) and its interaction with obesity. Ten single nucleotide polymorphisms were genotyped in 305 women with PCOS and 166 non-hyperandrogenic control women. In obese women, TLR2 S450S and ICAM1 K469E polymorphisms differently influenced metabolic variables and PCOS, respectively. Irrespective of PCOS, variant alleles of TLR2 S450S increased triglycerides, fasting insulin levels, and insulin resistance in obese women. TLR2 S450S interacted with obesity and PCOS on androstenedione levels, mutant alleles were associated with increased androstenedione concentrations in all women, with the exception of obese patients with PCOS (P=0.034). Regarding ICAM1 K469E, homozygosis for K469 alleles was more frequent in PCOS, but only in obese women (P=0.014). K469 alleles were also related to increased body mass index (P=0.017) and diastolic blood pressure (P=0.034). Moreover, ICAM1 K469E interacted with obesity and PCOS on serum triglyceride levels (P=0.019) and with PCOS on serum sex hormone-binding globulin concentrations (P=0.006). In conclusion, TLR2 S450S and ICAM1 K469E polymorphisms may be associated with PCOS and metabolic comorbidities in obese women.

Mehmeti M, Allaoui R, Bergenfelz C, et al.
Expression of functional toll like receptor 4 in estrogen receptor/progesterone receptor-negative breast cancer.
Breast Cancer Res. 2015; 17:130 [PubMed] Free Access to Full Article Related Publications
INTRODUCTION: Toll-like receptors (TLRs) are a family of pattern recognition receptors that are expressed on cells of the innate immune system. The ligands can be pathogen derived (pathogen associated molecular patterns; PAMPs) or endogenous (damage associated molecular patterns; DAMPs) that when bound induces activation of nuclear factor kappa B (NF-κB) and transcription of pro-inflammatory genes. TLRs have also been discovered in various malignant cell types, but with unknown function.
METHODS: In this study we performed a detailed analysis of TLR and co-receptor expression pattern and function in breast cancer. Expression patterns were examined using real-time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC) on three estrogen receptor-positive (ER(+)) and four estrogen receptor/progesterone receptor-negative (ER(-)/PR(-); ER/PR-negative) breast cancer cell lines, and a breast cancer cohort consisting of 144 primary breast cancer samples. The function was investigated using in vitro assays comprising PAMP/DAMP-stimulation, downstream signaling and TLR-silencing experiments.
RESULTS: We found that TLR4 was expressed in a biologically active form and responded to both PAMPs and DAMPs primarily in ER/PR-negative breast cancers. Stimulation of TLR2/4 in vitro induced expression of pro-inflammatory genes and a gene expression analysis of primary breast cancers showed a strong correlation between TLR4 expression and expression of pro-inflammatory mediators. In line with this, TLR4 protein expression correlated with a decreased survival.
CONCLUSIONS: These findings suggest that TLR4 is expressed in a functional form in ER/PR-negative breast cancers. Studies regarding TLR4-antagonist therapies should be focusing on ER/PR-negative breast cancer particularly.

Siewe B, Pham JT, Cohen M, et al.
Dysregulated B-cell TLR2 expression and elevated regulatory B-cell frequency precede the diagnosis of AIDS-related non-Hodgkin lymphoma.
AIDS. 2015; 29(13):1659-64 [PubMed] Free Access to Full Article Related Publications
OBJECTIVES: In antiretroviral therapy (ART)-treated patients, to determine if AIDS-related non-Hodgkin lymphoma (AIDS-NHL) is preceded by: elevated frequency of potentially malignant abnormal activated/germinal center-like B cells, elevated serum prevalence of B-cell stimulatory Toll-like receptor (TLR) ligands resulting from HIV infection-associated microbial translocation, dysregulated B-cell TLR expression/signaling, and perturbations in the frequency of immunoregulatory cells.
DESIGN: A case-control study nested with a cohort study of HIV-infected women.
METHODS: Prediagnostic AIDS-NHL cases (n = 12, collected 1-12 months before diagnosis) and controls (n = 42) from the Women's Interagency HIV Study cohort, were matched for HIV and ART status, age, race, and CD4 lymphocyte count. Serum levels of TLR ligands, the prevalence of malignancy-associated abnormal activated/germinal center-like (CD19CD10CD71CD86AID) B cells, TLR2 expression on B cells, expression of TLR2-modulating micro-RNA, and the frequency of regulatory T and B cells were assessed.
RESULTS: Diagnosis of AIDS-NHL was preceded by a significantly elevated frequency of activated/germinal center-like CD19CD10CD71CD86AID B cells (P = 0.0072), elevated serum prevalence of the TLR2 ligand, and significantly elevated B-cell TLR2 expression (P = 0.0015), positively correlating with the frequency of activated/germinal center-like B cells (rho = 0.7273, P = 0.0144). In cases, a purified subset of activated/germinal center-like B cells exhibited decreased expression of microRNAs that modulate TLR2 signaling, including miR-21, 146a, 146b, and 155. Finally, cases also exhibited significantly elevated frequencies of antitumor immunity inhibitory regulatory B cells (P = 0.0024), but not regulatory T cells.
CONCLUSIONS: Our findings suggest that increased microbial translocation and dysregulated TLR expression/signaling, coupled with an elevated frequency of regulatory B cells, precede the diagnosis of AIDS-NHL in HIV-infected ART-treated patients.

Barratt DT, Klepstad P, Dale O, et al.
Innate Immune Signalling Genetics of Pain, Cognitive Dysfunction and Sickness Symptoms in Cancer Pain Patients Treated with Transdermal Fentanyl.
PLoS One. 2015; 10(9):e0137179 [PubMed] Free Access to Full Article Related Publications
Common adverse symptoms of cancer and chemotherapy are a major health burden; chief among these is pain, with opioids including transdermal fentanyl the mainstay of treatment. Innate immune activation has been implicated generally in pain, opioid analgesia, cognitive dysfunction, and sickness type symptoms reported by cancer patients. We aimed to determine if genetic polymorphisms in neuroimmune activation pathways alter the serum fentanyl concentration-response relationships for pain control, cognitive dysfunction, and other adverse symptoms, in cancer pain patients. Cancer pain patients (468) receiving transdermal fentanyl were genotyped for 31 single nucleotide polymorphisms in 19 genes: CASP1, BDNF, CRP, LY96, IL6, IL1B, TGFB1, TNF, IL10, IL2, TLR2, TLR4, MYD88, IL6R, OPRM1, ARRB2, COMT, STAT6 and ABCB1. Lasso and backward stepwise generalised linear regression were used to identify non-genetic and genetic predictors, respectively, of pain control (average Brief Pain Inventory < 4), cognitive dysfunction (Mini-Mental State Examination ≤ 23), sickness response and opioid adverse event complaint. Serum fentanyl concentrations did not predict between-patient variability in these outcomes, nor did genetic factors predict pain control, sickness response or opioid adverse event complaint. Carriers of the MYD88 rs6853 variant were half as likely to have cognitive dysfunction (11/111) than wild-type patients (69/325), with a relative risk of 0.45 (95% CI: 0.27 to 0.76) when accounting for major non-genetic predictors (age, Karnofsky functional score). This supports the involvement of innate immune signalling in cognitive dysfunction, and identifies MyD88 signalling pathways as a potential focus for predicting and reducing the burden of cognitive dysfunction in cancer pain patients.

Fonte E, Agathangelidis A, Reverberi D, et al.
Toll-like receptor stimulation in splenic marginal zone lymphoma can modulate cell signaling, activation and proliferation.
Haematologica. 2015; 100(11):1460-8 [PubMed] Free Access to Full Article Related Publications
Recent studies on splenic marginal zone lymphoma identified distinct mutations in genes belonging to the B-cell receptor and Toll-like receptor signaling pathways, thus pointing to their potential implication in the biology of the disease. However, limited data is available regarding the exact role of TLRs. We aimed at characterizing the expression pattern of TLRs in splenic marginal zone lymphoma cells and their functional impact on the activation, proliferation and viability of malignant cells in vitro. Cells expressed significant levels of TLR1, TLR6, TLR7, TLR8, TLR9 and TLR10 mRNA; TLR2 and TLR4 showed a low, variable pattern of expression among patients whereas TLR3 and TLR5 mRNAs were undetectable; mRNA specific for TLR signaling molecules and adapters was also expressed. At the protein level, TLR1, TLR6, TLR7, TLR9 and TLR10 were detected. Stimulation of TLR1/2, TLR2/6 and TLR9 with their respective ligands triggered the activation of IRAK kinases, MAPK and NF-κB signaling pathways, and the induction of CD86 and CD25 activation molecules, although in a heterogeneous manner among different patient samples. TLR-induced activation and cell viability were also inhibited by a specific IRAK1/4 inhibitor, thus strongly supporting the specific role of TLR signaling in these processes. Furthermore, TLR2/6 and TLR9 stimulation also significantly increased cell proliferation. In conclusion, we demonstrate that splenic marginal zone lymphoma cells are equipped with functional TLR and signaling molecules and that the stimulation of TLR1/2, TLR2/6 and TLR9 may play a role in regulating disease pathobiology, likely promoting the expansion of the neoplastic clone.

Joyce BT, Gao T, Liu L, et al.
Longitudinal Study of DNA Methylation of Inflammatory Genes and Cancer Risk.
Cancer Epidemiol Biomarkers Prev. 2015; 24(10):1531-8 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Chronic inflammation plays a key role in cancer etiology. DNA methylation modification, one of the epigenetic mechanisms regulating gene expression, is considered a hallmark of cancer. Human and animal models have identified numerous links between DNA methylation and inflammatory biomarkers. Our objective was to prospectively and longitudinally examine associations between methylation of four inflammatory genes and cancer risk.
METHODS: We included 795 Normative Aging Study participants with blood drawn one to four times from 1999 to 2012 (median follow-up, 10.6 years). Promoter DNA methylation of IL6, ICAM-1, IFN, and TLR2 in blood leukocytes was measured using pyrosequencing at multiple CpG sites and averaged by gene for data analysis. We used Cox regression models to examine prospective associations of baseline and time-dependent methylation with cancer risk and compared mean methylation differences over time between cancer cases and cancer-free participants.
RESULTS: Baseline IFN hypermethylation was associated with all-cancer (HR, 1.49; P = 0.04) and prostate cancer incidence (HR, 1.69; P = 0.02). Baseline ICAM-1 and IL6 hypermethylation were associated with prostate cancer incidence (HR, 1.43; P = 0.02; HR, 0.70; P = 0.03, respectively). In our time-dependent analyses, IFN hypermethylation was associated with all-cancer (HR, 1.79; P = 0.007) and prostate cancer (HR, 1.57; P = 0.03) incidence; and ICAM-1 and IL6 hypermethylation were associated with prostate cancer incidence (HR, 1.39; P = 0.02; HR, 0.69; P = 0.03, respectively). We detected significant ICAM-1 hypermethylation in cancer cases (P = 0.0003) 10 to 13 years prediagnosis.
CONCLUSION: Hypermethylation of IFN and ICAM-1 may play important roles in early carcinogenesis, particularly that of prostate cancer.
IMPACT: These methylation changes could inform the development of early detection biomarkers and potential treatments of inflammation-related carcinogenesis.

Devi KR, Chenkual S, Majumdar G, et al.
TLR2∆22 (-196-174) significantly increases the risk of breast cancer in females carrying proline allele at codon 72 of TP53 gene: a case-control study from four ethnic groups of North Eastern region of India.
Tumour Biol. 2015; 36(12):9995-10002 [PubMed] Related Publications
Breast cancer (BC) is the second most common cancer in women. In the North Eastern Region (NER) of India, BC is emerging as an important concern as evidenced by the data available from population and hospital-based cancer registries. Studies on genetic susceptibility to BC are important to understand the increase in the incidence of BC in NER. The present case control study was conducted to investigate the association between tumour suppressor gene TP53 codon 72 polymorphism and innate immune pathway gene TLR2∆22 (-196-174) polymorphism with BC in females of NER of India for the identification of novel biomarker of BC. Four hundred sixty-two histopathologically confirmed BC cases from four states of NER of India, and 770 healthy controls were included by organizing community surveys from the neighbourhood of cases. In our study, no significant association between TP53 codon 72 polymorphisms and the risk of BC was found. However, our study has shown that TP53 codon 72 polymorphism is an important effect modifier. In the present study it was found that females carrying 22 base-pair deletion in the promoter region of their TLR2 gene had two times (AOR= 2.18, 95 % CI 1.13-4.21, p=0.019 in dominant model; AOR= 2.17, 95 % CI 1.09-4.34, p=0.027 in co-dominant model) increased risk of BC whwn they also carry proline allele at codon 72 of their TP53 gene.

Proença MA, de Oliveira JG, Cadamuro AC, et al.
TLR2 and TLR4 polymorphisms influence mRNA and protein expression in colorectal cancer.
World J Gastroenterol. 2015; 21(25):7730-41 [PubMed] Free Access to Full Article Related Publications
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.

Sharafeldin N, Slattery ML, Liu Q, et al.
A Candidate-Pathway Approach to Identify Gene-Environment Interactions: Analyses of Colon Cancer Risk and Survival.
J Natl Cancer Inst. 2015; 107(9) [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Genetic association studies have traditionally focused on associations between individual single nucleotide polymorphisms (SNPs) and disease. Standard analysis ignores interactions between multiple SNPs and environmental exposures explaining a small portion of disease heritability: the often-cited issue of "missing heritability."
METHODS: We present a novel three-step analytic framework for modeling gene-environment interactions (GEIs) between an angiogenesis candidate-gene pathway and three lifestyle exposures (dietary protein, smoking, and alcohol consumption) on colon cancer risk and survival. Logic regression was used to summarize the gene-pathway effects, and GEIs were modeled using logistic regression and Cox proportional hazards models. We analyzed data from 1541 colon cancer case patients and 1934 control subjects in the Diet, Activity and Lifestyle as a Risk Factor for Colon Cancer Study.
RESULTS: We identified five statistically significant GEIs for colon cancer risk. For risk interaction, odds ratios (ORINT) and 95% confidence intervals (CIs) were FLT1(rs678714) and BMP4(rs17563) and smoking (ORINT = 1.64, 95% CI = 1.11 to 2.41 and ORINT = 1.60, 95% CI = 1.10 to 2.32, respectively); FLT1(rs2387632 OR rs9513070) and protein intake (ORINT = 1.69, 95% CI = 1.03 to 2.77); KDR(rs6838752) and TLR2(rs3804099) and alcohol (ORINT = 1.53, 95% CI = 1.10 to 2.13 and ORINT = 1.59, 95% CI = 1.05 to 2.38, respectively). Three GEIs between TNF, BMP1, and BMPR2 genes and the three exposures were statistically significant at the 5% level in relation to colon cancer survival but not after multiple-testing adjustment.
CONCLUSIONS: Adopting a comprehensive biologically informed candidate-pathway approach identified GEI effects on colon cancer. Findings may have important implications for public health and personalized medicine targeting prevention and therapeutic strategies. Findings from this study need to be validated in other studies.

Janeckova L, Pospichalova V, Fafilek B, et al.
HIC1 Tumor Suppressor Loss Potentiates TLR2/NF-κB Signaling and Promotes Tissue Damage-Associated Tumorigenesis.
Mol Cancer Res. 2015; 13(7):1139-48 [PubMed] Related Publications
UNLABELLED: Hypermethylated in cancer 1 (HIC1) represents a prototypic tumor suppressor gene frequently inactivated by DNA methylation in many types of solid tumors. The gene encodes a sequence-specific transcriptional repressor controlling expression of several genes involved in cell cycle or stress control. In this study, a Hic1 allele was conditionally deleted, using a Cre/loxP system, to identify genes influenced by the loss of Hic1. One of the transcripts upregulated upon Hic1 ablation is the toll-like receptor 2 (TLR2). Tlr2 expression levels increased in Hic1-deficient mouse embryonic fibroblasts (MEF) and cultured intestinal organoids or in human cells upon HIC1 knockdown. In addition, HIC1 associated with the TLR2 gene regulatory elements, as detected by chromatin immunoprecipitation, indicating that Tlr2 indeed represents a direct Hic1 target. The Tlr2 receptor senses "danger" signals of microbial or endogenous origin to trigger multiple signaling pathways, including NF-κB signaling. Interestingly, Hic1 deficiency promoted NF-κB pathway activity not only in cells stimulated with Tlr2 ligand, but also in cells treated with NF-κB activators that stimulate different surface receptors. In the intestine, Hic1 is mainly expressed in differentiated epithelial cells and its ablation leads to increased Tlr2 production. Finally, in a chemical-induced mouse model of carcinogenesis, Hic1 absence resulted in larger Tlr2-positive colonic tumors that showed increased proportion of proliferating cells.
IMPLICATIONS: The tumor-suppressive function of Hic1 in colon is related to its inhibitory action on proproliferative signaling mediated by the Tlr2 receptor present on tumor cells.

Jouhi L, Koljonen V, Böhling T, et al.
The expression of Toll-like receptors 2, 4, 5, 7 and 9 in Merkel cell carcinoma.
Anticancer Res. 2015; 35(4):1843-9 [PubMed] Related Publications
AIM: We sought to clarify whether the expression of toll-like receptors (TLR) in Merkel cell carcinoma (MCC) is linked to tumor and patient characteristics, especially the presence of Merkel cell polyoma virus (MCV).
MATERIALS AND METHODS: The study comprised of 128 patients with data on Merkel cell polyomavirus (MCV) status and clinical features were included in the study. Immunohistochemistry for TLR expression was performed on tissue microarray (TMA) slides.
RESULTS: TLR 2, 4, 5, 7 and 9 expression was noted in most of the tumor specimens. Decreased expression of TLR 9 correlated strongly with MCV positivity. Cytoplasmic TLR 2 expression correlated with small tumor size, while nuclear TLR 2 and TLR 5 expressions with larger tumors. Increased nuclear TLR 4 expression and decreased TLR 7 expression were associated with older age.
CONCLUSION: TLR 2, 4, 5, 7 and 9 appear to reflect certain clinicopathological variables and prognostic markers of MCC tumors.

Liu S, Wang X, Shi Y, et al.
Toll-like receptor gene polymorphisms and susceptibility to Epstein-Barr virus-associated and -negative gastric carcinoma in Northern China.
Saudi J Gastroenterol. 2015 Mar-Apr; 21(2):95-103 [PubMed] Free Access to Full Article Related Publications
BACKGROUND/AIMS: Various polymorphisms in toll-like receptor (TLR) genes have been identified and associated with susceptibility to various malignancies, such as gastric carcinoma (GC), breast cancer, and prostate cancer. However, little is known about the polymorphisms of TLR genes and the susceptibility to GC in Northern China, especially to Epstein-Barr virus-associated GC (EBVaGC). We focused on the association with susceptibility to GC, especially to EBVaGC.
PATIENTS AND METHODS: Polymorphisms of the TLR2, 3, 4, and 9 genes were measured in 52 cases of EBVaGC and 157 cases of EBV-negative GC (EBVnGC). Ninety-four peripheral blood samples from healthy individuals were also examined.
RESULTS: For the TLR2 gene (196 to 174 del), there was no significant difference between the GC group and control group in genotype, but there was a significant difference in the del allele. As for the TLR3 gene (c. 1377C/T), there were significant differences between the GC group and the control group in both genotype and allelic frequency. No SNPs single nucleotide polymorphisms (SNPs) were found in the TLR4 gene at the sites Asp299Gly and Thr399Ile. As for TLR9 1486T/C (rs187084) and C2848T (rs352140), there was also no association between the GC group and control. In all of the indicators, there were no significant differences between EBVaGCs and EBVnGCs.
CONCLUSIONS: The TLR3 gene (c. 1377C/T) polymorphisms and the del allele of the TLR2 gene ( 196 to 174) were both associated with susceptibility to GC in Shangdong Province of Northern China. There was no interaction between EBV and TLR gene polymorphisms in EBVaGC.

Takakura K, Kajihara M, Ito Z, et al.
Dendritic-tumor fusion cells in cancer immunotherapy.
Discov Med. 2015; 19(104):169-74 [PubMed] Related Publications
A promising area of clinical investigation is the use of cancer immunotherapy to treat cancer patients. Dendritic cells (DCs) operate as professional antigen-presenting cells (APCs) and play a critical role in the induction of antitumor immune responses. Thus, DC-based cancer immunotherapy represents a powerful strategy. One DC-based cancer immunotherapy strategy that has been investigated is the administration of fusion cells generated with DCs and whole tumor cells (DC-tumor fusion cells). The DC-tumor fusion cells can process a broad array of tumor-associated antigens (TAAs), including unidentified molecules, and present them through major histocompatibility complex (MHC) class I and II pathways in the context of co-stimulatory signals. Improving the therapeutic efficacy of DC-tumor fusion cell-based cancer immunotherapy requires increased immunogenicity of DCs and whole tumor cells. We discuss the potential ability of DC-tumor fusion cells to activate antigen-specific T cells and strategies to improve the immunogenicity of DC-tumor fusion cells as anticancer vaccines.

Rybka J, Butrym A, Wróbel T, et al.
The expression of Toll-like receptors in patients with acute myeloid leukemia treated with induction chemotherapy.
Leuk Res. 2015; 39(3):318-22 [PubMed] Related Publications
Toll-like receptors play an important role in the host defense against microorganisms. TLRs are mainly expressed in human immune-related cells, such as monocytes, neutrophils, macrophages, dendritic cells, T cells, B cells and NK cells. The expression or up-regulation of TLRs has been demonstrated in some tumors and tumor cell lines but the role of TLRs in pathogenesis and development of acute leukemias remains unclear. The aim of this study was to evaluate the expression of TLR2, TLR4 and TLR9 and their significance as prognostic factors in patients with acute leukemias treated with induction chemotherapy. 103 patients with newly diagnosed acute myeloid leukemia (AML) were evaluated (47 females and 56 males). The median age of patients was 51 years. Using quantitative reverse transcriptase PCR, the mRNA expression of genes TLR2, TLR4 and TLR9 was measured. The mRNA expression of TLR2 and TLR4 was significantly higher in patients with NR than in patients with CR and CRi. We especially observed that mRNA expression of TLR2 and TLR4 was significantly higher in patients with myelomonocytic and monoblastic acute leukemia than in patients with other types of AML. The mRNA expression of TLR2 and TLR4 was higher in AML patients than in healthy individuals, although there was no statistically significant difference. Patients with higher mRNA expression of TLR2 and TLR4 had significantly shorter OS than patients with lower mRNA expression of TLR2 and TLR4. Multivariate analysis showed that mRNA expression of TLR2 and the age of patients were independent factors associated with treatment response. Our results suggest that TLRs could be an independent prognostic factor for response rate after induction therapy in patients with acute myeloid leukemias.

Lu CC, Kuo HC, Wang FS, et al.
Upregulation of TLRs and IL-6 as a marker in human colorectal cancer.
Int J Mol Sci. 2014; 16(1):159-77 [PubMed] Free Access to Full Article Related Publications
Toll-like receptors (TLRs) not only form an important part of the innate immune system but also serve to activate the adaptive immune system in response to cancer. Real-time PCR; immunohistochemical stain and Western blotting analyses were performed to clarify molecular alterations in colorectal cancer (CRC) patients. We identified Toll-like receptor 1 (TLR1), TLR2, TLR4 and TLR8 gene expression levels and downstream gene, i.e., interleukin-6 (IL-6), IL-8, interferon-α (IFN-α) and myeloid differentiation primary-response protein-88 (MyD88), expression levels in CRC patients and in cancer cell lines. CRC tissues have higher TLR1, TLR2, TLR4, TLR8, IL-6 and IL-8 gene expression levels than do the normal colon mucosa (p < 0.05). TLR2 expression varied in different cell types (mucosa and lymphocytes). There was no difference in the MyD88 and IFN-α gene expression levels between cancerous and normal colon mucosa. CRC patients had higher levels of IL-6 (p = 0.002) and IL-8 (p = 0.038) expression than healthy volunteers did; and higher IL-6 and IL-8 expression was also found to signify a higher risk of recurrence. CL075 (3M002) treatments can reduce the production of IL-8 in different cancer cell lines. The signaling pathway of TLRs in cancer tissue is different from that in normal cells; and is MyD88-independent. Higher expression levels of TLR1, TLR2, TLR 4 and TLR 8 mRNA were related to upregulation inflammatory cytokines IL-6 and IL-8 gene expression in tissue and to the upregulation of IL-6 in blood. The concentration of IL-6 in serum can be used as an indicator of the possibility of CRC recurrence. Treatment with 3M002 can reduce IL-6 production in vitro and may prevent CRC recurrence. Our findings provide evidence that TLR1, TLR2, TLR4 and TLR8 gene expression induce downstream IL-6 and IL-8 gene expression; detection of these expression levels can serve as a CRC marker.

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