Gene Summary

Gene:TLR4; toll like receptor 4
Aliases: TOLL, CD284, TLR-4, ARMD10
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. They recognize pathogen-associated molecular patterns that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity. The various TLRs exhibit different patterns of expression. This receptor has been implicated in signal transduction events induced by lipopolysaccharide (LPS) found in most gram-negative bacteria. Mutations in this gene have been associated with differences in LPS responsiveness. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jan 2012]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:toll-like receptor 4
Source:NCBIAccessed: 15 March, 2017


What does this gene/protein do?
Show (93)
Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 15 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Antigens, CD14
  • Prostate Cancer
  • Signal Transduction
  • Cancer Gene Expression Regulation
  • Disease Progression
  • Breast Cancer
  • Helicobacter pylori and cancer
  • Biomarkers, Tumor
  • Lipopolysaccharides
  • TNF
  • Toll-Like Receptors
  • Chromosome 9
  • Toll-Like Receptor 4
  • Staging
  • Toll-Like Receptor 2
  • Stomach Cancer
  • Helicobacter Infections
  • Immunity, Innate
  • Messenger RNA
  • Inflammation
  • Western Blotting
  • Colorectal Cancer
  • Case-Control Studies
  • Up-Regulation
  • Single Nucleotide Polymorphism
  • Genetic Predisposition
  • Cytokines
  • Immunohistochemistry
  • Cell Proliferation
  • Adenocarcinoma
  • NF-kappa B
  • Odds Ratio
  • Alleles
  • Asian Continental Ancestry Group
  • MYD88
  • Risk Factors
  • Apoptosis
  • Genotype
Tag cloud generated 15 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

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: TLR4 (cancer-related)

Park GB, Kim D
TLR4-mediated galectin-1 production triggers epithelial-mesenchymal transition in colon cancer cells through ADAM10- and ADAM17-associated lactate production.
Mol Cell Biochem. 2017; 425(1-2):191-202 [PubMed] Related Publications
Toll-like receptor 4 (TLR4) activation is a key contributor to the carcinogenesis of colon cancer. Overexpression of galectin-1 (Gal-1) also correlates with increased invasive activity of colorectal cancer. Lactate production is a critical predictive factor of risk of metastasis, but the functional relationship between intracellular lactate and Gal-1 expression in TLR4-activated colon cancer remains unknown. In this study, we investigated the underlying mechanism and role of Gal-1 in metastasis and invasion of colorectal cancer (CRC) cells after TLR4 stimulation. Exposure to the TLR4 ligand lipopolysaccharide (LPS) increased expression of Gal-1, induced EMT-related cytokines, triggered the activation of glycolysis-related enzymes, and promoted lactate production. Gene silencing of TLR4 and Gal-1 in CRC cells inhibited lactate-mediated epithelial-mesenchymal transition (EMT) after TLR4 stimulation. Gal-1-mediated activation of a disintegrin and metalloproteinase 10 (ADAM10) and ADAM 17 increased the invasion activity and expression of mesenchymal characteristics in LPS-activated CRC cells. Conversely, inhibition of ADAM10 or ADAM17 effectively blocked the generation of lactate and the migration capacity of LPS-treated CRC cells. Thus, the TLR4/Gal-1 signaling pathway regulates lactate-mediated EMT processes through the activation of ADAM10 and ADAM17 in CRC cells.

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.

Waki K, Yamada A
Blockade of high mobility group box 1 augments antitumor T-cell response induced by peptide vaccination as a co-adjuvant.
Cancer Sci. 2016; 107(12):1721-1729 [PubMed] Free Access to Full Article Related Publications
High mobility group box 1 (HMGB1) is a member of the family of damage-associated molecular patterns, which cause inflammation and trigger innate immunity through Toll-like receptors 2/4 and the receptor for advanced glycation end products. We examined the effect of glycyrrhizin, a selective inhibitor of HMGB1, on the induction of CTLs in mice. B6 mice, either OT-1 spleen cell-transferred or untransferred, were immunized with an s.c. injection of OVA257-264 peptide with topical imiquimod, and glycyrrhizin was mixed with the antigen peptide. Proliferation of OT-1 cells after immunization was enhanced by glycyrrhizin. The effect of glycyrrhizin was confirmed in other adjuvant systems, such as CpG oligonucleotide and monophosphoryl lipid A, but glycyrrhizin was not effective in Freund's incomplete adjuvant system. The augmenting effects of glycyrrhizin were also observed in other synthetic HMGB1 inhibitors, gabexate mesilate, nafamostat, and sivelestat. Thus, the effects are common to the HMGB1 inhibitors. Induction of CTLs detected by γ-interferon enzyme-linked immunospot assay was similarly augmented by glycyrrhizin. In a therapeutic vaccine model, glycyrrhizin inhibited the growth of s.c. transplanted EG.7 tumors. Expression of inflammatory cytokines in the skin inoculation site was downregulated by glycyrrhizin. These results suggest that HMGB1 inhibitors might be useful as a co-adjuvant for peptide vaccination with an innate immunity receptor-related adjuvant.

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.

An J, Li Z, Dong Y, et al.
Methicillin-Resistant Staphylococcus Aureus infection exacerbates NSCLC cell metastasis by up-regulating TLR4/MyD88 pathway.
Cell Mol Biol (Noisy-le-grand). 2016; 62(8):1-7 [PubMed] Related Publications
Methicillin-resistant Staphylococcus aureus (MRSA) infection is a major public health problem worldwide, which brings to a more great threat for cancer patients. It's necessary to give attentions to lung cancer combined with MRSA. This study mainly focuses on the influences of MRSA on lung cancer cells (A549). We first found that MRSA infection can enhance metastasis ability of A549 cell and increase matrix metalloproteinase (MMP2 and MMP9) expressions in MRSA-infected A549 cell. Toll-like receptors (TLRs) have been reported to play an important role in tumor cell initiation and migration, and regulate the expression of MMPs in tumors. Our further research indicates that Toll-like receptor 4 (TLR4)/molecules myeloid differentiation factor 88 (MyD88) signaling was up-regulated in MRSA-infected A549 cell. After silencing TLR4 or MyD88 gene, the enhanced metastasis ability of A549 cell by MRSA was decreased significantly; Also, MMP2 and MMP9 expression increase was reversed. In conclusion, MRSA infection can enhance NSCLC cell metastasis by up-regulating TLR4/MyD88 signaling.

Li Z, Block MS, Vierkant RA, et al.
The inflammatory microenvironment in epithelial ovarian cancer: a role for TLR4 and MyD88 and related proteins.
Tumour Biol. 2016; 37(10):13279-13286 [PubMed] Free Access to Full Article Related Publications
The tumor-associated inflammatory microenvironment may play a pivotal role in epithelial ovarian cancer (EOC) carcinogenesis and outcomes, but a detailed profile in patient-derived tumors is needed. Here, we investigated the expression of TLR4- and MyD88-associated markers in tumors from over 500 EOC patients using immunohistochemical staining. We demonstrate that high expression of TLR4 and MyD88 predicts poorer overall survival in patients with EOC; most likely, this is due to their association with serous histology and features of high tumor burden and aggressiveness, including stage, grade, and ascites at surgery. Combined TLR4 and MyD88 expression appears to serve as an independent risk factor for shortened survival time, even after covariate adjustment (both moderate HR 1.1 [95 % CI 0.7-1.8], both strong HR 2.1 [95 % CI 1.1-3.8], both weak as referent; p = 0.027). We reveal that in EOC tissues with elevated expression of both TLR4 and MyD88 and activated NF-κB signaling pathway, expression of hsp60, hsp70, beta 2 defensin, and HMGB1 are also enriched. In total, these results suggest that activation of TLR4/MyD88/NF-κB signaling by endogenous ligands may contribute to an inflammatory microenvironment that drives a more aggressive phenotype with poorer clinical outcome in EOC patients.

Meshkat M, Tanha HM, Naeini MM, et al.
Functional SNP in stem of mir-146a affects Her2 status and breast cancer survival.
Cancer Biomark. 2016; 17(2):213-22 [PubMed] Related Publications
In-silico investigation suggested a common variant within stem of miR-146a-5p precursor (rs2910164, n.60C>G) associated with breast cancer (BC) phenotypes. Our aim was computationally predicting possible targets of miR-146a-5p and probable rs2910164 mechanism of action in expression of phenotypes in BC. Additionally, a case-control study was designated to examine experimentally the correlation of mir-146a rs2910164 variant and BC phenotypes. In this study, 152 BC subjects and healthy controls were genotyped using RFLP-PCR. Allelic and genotypic association and Armitage's trend tests were run to investigate the correlation between the alleles and genotypes and expressed phenotypes of BC. Bioinformatics analyses introduce regulatory function of miR-146a-5p in numerous signaling pathways and impact of allele substitution upon mir-146a stem-loop stability. Logistic regression data represented the C allele of rs2910164 (OR = 4.00, p= 0.0037) as the risk allele and associated with Her2-positive phenotype. In a similar vein, data revealed the correlation of the C allele and cancer death less than two years in BC patients (OR = 2.65, p= 0.0217). Ultimately, unconditional logistical regression models suggested log-additive model for inheritance manner of rs2910164 in either Her2 status or BC survival (OR = 5.64, p= 0.0025 and OR = 3.13, p= 0.019, respectively). Using bioinformatics connected association of Her2 status to altered function of miR-146a-5p in regulation of focal adhesion and Ras pathway. Furthermore, computations inferred the association between death phenotype and studied SNP upon specific target genes of miR-146a-5p involved in focal adhesion, EGF receptor, Ras, ErbB, interleukin, Toll-like receptor, NGF, angiogenesis, and p53 feedback loops 2 signaling pathways. These verdicts may enhance our perceptions of how mir-146a rs2910164 affect expressed phenotypes in BC, and might have potential implications to develop BC treatment in future.

Sun W, Ma X, Shen J, et al.
Bioinformatics analysis of differentially expressed pathways related to the metastatic characteristics of osteosarcoma.
Int J Mol Med. 2016; 38(2):466-74 [PubMed] Free Access to Full Article Related Publications
In this study, gene expression data of osteosarcoma (OSA) were analyzed to identify metastasis-related biological pathways. Four gene expression data sets (GSE21257, GSE9508, GSE49003 and GSE66673) were downloaded from Gene Expression Omnibus (GEO). An analysis of differentially expressed genes (DEGs) was performed using the Significance Analysis of Microarray (SAM) method. Gene expression levels were converted into scores of pathways by the Functional Analysis of Individual Microarray Expression (FAIME) algorithm and the differentially expressed pathways (DEPs) were then disclosed by a t-test. The distinguishing and prediction ability of the DEPs for metastatic and non-metastatic OSA was further confirmed using the principal component analysis (PCA) method and 3 gene expression data sets (GSE9508, GSE49003 and GSE66673) based on the support vector machines (SVM) model. A total of 616 downregulated and 681 upregulated genes were identified in the data set, GSE21257. The DEGs could not be used to distinguish metastatic OSA from non-metastatic OSA, as shown by PCA. Thus, an analysis of DEPs was further performed, resulting in 14 DEPs, such as NRAS signaling, Toll-like receptor (TLR) signaling, matrix metalloproteinase (MMP) regulation of cytokines and tumor necrosis factor receptor-associated factor (TRAF)-mediated interferon regulatory factor 7 (IRF7) activation. Cluster analysis indicated that these pathways could be used to distinguish between metastatic OSA from non-metastatic OSA. The prediction accuracy was 91, 66.7 and 87.5% for the data sets, GSE9508, GSE49003 and GSE66673, respectively. The results of PCA further validated that the DEPs could be used to distinguish metastatic OSA from non-metastatic OSA. On the whole, several DEPs were identified in metastatic OSA compared with non-metastatic OSA. Further studies on these pathways and relevant genes may help to enhance our understanding of the molecular mechanisms underlying metastasis and may thus aid in the development of novel therapies.

Ge X, Cao Z, Gu Y, et al.
PFKFB3 potentially contributes to paclitaxel resistance in breast cancer cells through TLR4 activation by stimulating lactate production.
Cell Mol Biol (Noisy-le-grand). 2016; 62(6):119-25 [PubMed] Related Publications
Paclitaxel is a commonly used agent for breast cancer therapy, which comes across the obstacle "drug resistance", resulting in shortened overall survival of patients. Warburg effect has become one character of cancer cell and was reported to induce paclitaxel resistance, the mechanism of which is poorly understood. In this study, we sought to examine the role of 6-Phosphofructo-2-kinase (PFKFB3), a critical regulator of glycolysis, in paclitaxel resistance development. Two clones of paclitaxel resistant breast cancer cells, MCF-7RA and MCF-7RB, were established by a long term exposure of MCF-7 cells to paclitaxel. Consequently, PFKFB3 expression was found to be increased in MCF-7RA and MCF-7RB cells compared with MCF-7 cells. Silencing PFKFB3 expression markedly reduced the IC50 concentrations of MCF-7RA and MCF-7RB cells. Moreover, PFKFB3 modulated toll like receptor 4 (TLR4) and MyD88 expression as well as interleukin (IL)-6 and IL-8 release from breast cancer cells in response to paclitaxel exposure. In addition, PFKFB3 overexpression boosted up fructose-2,6-bisphosphate (F2,6BP) and lactate production. The enhanced lactate contributed to TLR4 signaling activation, IL-6 and IL-8 generation, and cell viability promotion in MCF-7 cells. In all, we characterized the novel role of PFKFB3 in induction of paclitaxel resistance by raising lactate production and activating TLR4 signaling.

Liu R, Luo F, Liu X, et al.
Biological Response Modifier in Cancer Immunotherapy.
Adv Exp Med Biol. 2016; 909:69-138 [PubMed] Related Publications
Biological response modifiers (BRMs) emerge as a lay of new compounds or approaches used in improving cancer immunotherapy. Evidences highlight that cytokines, Toll-like receptor (TLR) signaling, and noncoding RNAs are of crucial roles in modulating antitumor immune response and cancer-related chronic inflammation, and BRMs based on them have been explored. In particular, besides some cytokines like IFN-α and IL-2, several Toll-like receptor (TLR) agonists like BCG, MPL, and imiquimod are also licensed to be used in patients with several malignancies nowadays, and the first artificial small noncoding RNA (microRNA) mimic, MXR34, has entered phase I clinical study against liver cancer, implying their potential application in cancer therapy. According to amounts of original data, this chapter will review the regulatory roles of TLR signaling, some noncoding RNAs, and several key cytokines in cancer and cancer-related immune response, as well as the clinical cases in cancer therapy based on them.

Yang J, Qin N, Zhang H, et al.
Cellular uptake of exogenous calcineurin B is dependent on TLR4/MD2/CD14 complexes, and CnB is an endogenous ligand of TLR4.
Sci Rep. 2016; 6:24346 [PubMed] Free Access to Full Article Related Publications
Our previous research showed that recombinant calcineurin B (rhCnB) stimulates cytokine secretion by immune cells, probably through TLR4. Exogenous CnB can be incorporated into many different tumour cells in vitro, but the mode of uptake and receptors required remain unknown. Here, we report that exogenous CnB is taken up by cells in a time- and concentration-dependent manner via clathrin-dependent receptor-mediated internalization. Our findings further confirm that uptake is mediated by the TLR4/MD2 complex together with the co-receptor CD14. The MST results revealed a high affinity between CnB and the TLR4 receptor complex. No binding was detected between CnB and LPS. CnB inhibited the uptake of LPS, and LPS also inhibited the uptake of CnB. These results indicate that the uptake of exogenous CnB did not occur through LPS and that CnB was not a chaperone of LPS. Thus, we conclude that TLR4 receptor complexes were required for the recognition and internalization of exogenous CnB. CnB could be a potential endogenous ligand of TLR4 and function as an agonist of TLR4. These properties of CnB support its potential for development as an anti-cancer drug.

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.

Ansa-Addo EA, Thaxton J, Hong F, et al.
Clients and Oncogenic Roles of Molecular Chaperone gp96/grp94.
Curr Top Med Chem. 2016; 16(25):2765-78 [PubMed] Free Access to Full Article Related Publications
As an endoplasmic reticulum heat shock protein (HSP) 90 paralogue, glycoprotein (gp) 96 possesses immunological properties by chaperoning antigenic peptides for activation of T cells. Genetic studies in the last decade have unveiled that gp96 is also an essential master chaperone for multiple receptors and secreting proteins including Toll-like receptors (TLRs), integrins, the Wnt coreceptor, Low Density Lipoprotein Receptor-Related Protein 6 (LRP6), the latent TGFβ docking receptor, Glycoprotein A Repetitions Predominant (GARP), Glycoprotein (GP) Ib and insulin-like growth factors (IGF). Clinically, elevated expression of gp96 in a variety of cancers correlates with the advanced stage and poor survival of cancer patients. Recent preclinical studies have also uncovered that gp96 expression is closely linked to cancer progression in multiple myeloma, hepatocellular carcinoma, breast cancer and inflammation-associated colon cancer. Thus, gp96 is an attractive therapeutic target for cancer treatment. The chaperone function of gp96 depends on its ATPase domain, which is structurally distinct from other HSP90 members, and thus favors the design of highly selective gp96-targeted inhibitors against cancer. We herein discuss the strategically important oncogenic clients of gp96 and their underlying biology. The roles of cell-intrinsic gp96 in T cell biology are also discussed, in part because it offers another opportunity of cancer therapy by manipulating levels of gp96 in T cells to enhance host immune defense.

Seifert L, Werba G, Tiwari S, et al.
The necrosome promotes pancreatic oncogenesis via CXCL1 and Mincle-induced immune suppression.
Nature. 2016; 532(7598):245-9 [PubMed] Free Access to Full Article Related Publications
Neoplastic pancreatic epithelial cells are believed to die through caspase 8-dependent apoptotic cell death, and chemotherapy is thought to promote tumour apoptosis. Conversely, cancer cells often disrupt apoptosis to survive. Another type of programmed cell death is necroptosis (programmed necrosis), but its role in pancreatic ductal adenocarcinoma (PDA) is unclear. There are many potential inducers of necroptosis in PDA, including ligation of tumour necrosis factor receptor 1 (TNFR1), CD95, TNF-related apoptosis-inducing ligand (TRAIL) receptors, Toll-like receptors, reactive oxygen species, and chemotherapeutic drugs. Here we report that the principal components of the necrosome, receptor-interacting protein (RIP)1 and RIP3, are highly expressed in PDA and are further upregulated by the chemotherapy drug gemcitabine. Blockade of the necrosome in vitro promoted cancer cell proliferation and induced an aggressive oncogenic phenotype. By contrast, in vivo deletion of RIP3 or inhibition of RIP1 protected against oncogenic progression in mice and was associated with the development of a highly immunogenic myeloid and T cell infiltrate. The immune-suppressive tumour microenvironment associated with intact RIP1/RIP3 signalling depended in part on necroptosis-induced expression of the chemokine attractant CXCL1, and CXCL1 blockade protected against PDA. Moreover, cytoplasmic SAP130 (a subunit of the histone deacetylase complex) was expressed in PDA in a RIP1/RIP3-dependent manner, and Mincle--its cognate receptor--was upregulated in tumour-infiltrating myeloid cells. Ligation of Mincle by SAP130 promoted oncogenesis, whereas deletion of Mincle protected against oncogenesis and phenocopied the immunogenic reprogramming of the tumour microenvironment that was induced by RIP3 deletion. Cellular depletion suggested that whereas inhibitory macrophages promote tumorigenesis in PDA, they lose their immune-suppressive effects when RIP3 or Mincle is deleted. Accordingly, T cells, which are not protective against PDA progression in mice with intact RIP3 or Mincle signalling, are reprogrammed into indispensable mediators of anti-tumour immunity in the absence of RIP3 or Mincle. Our work describes parallel networks of necroptosis-induced CXCL1 and Mincle signalling that promote macrophage-induced adaptive immune suppression and thereby enable PDA progression.

Huang Z, Gan J, Long Z, et al.
Targeted delivery of let-7b to reprogramme tumor-associated macrophages and tumor infiltrating dendritic cells for tumor rejection.
Biomaterials. 2016; 90:72-84 [PubMed] Related Publications
Both tumor associated macrophages (TAMs) and tumor infiltrating dendritic cells (TIDCs) are important components in the tumor microenvironment that mediate tumor immunosuppression and promote cancer progression. Targeting these cells and altering their phenotypes may become a new strategy to recover their anti-tumor activities and thereby restore the local immune surveillance against tumor. In this study, we constructed a nucleic acid delivery system for the delivery of let-7b, a synthetic microRNA mimic. Our carrier has an affinity for the mannose receptors on TAMs/TIDCs and is responsive to the low-pH tumor microenvironment. The delivery of let-7b could reactivate TAMs/TIDCs by acting as a TLR-7 agonist and suppressing IL-10 production in vitro. In a breast cancer mouse model, let-7b delivered by this system efficiently reprogrammed the functions of TAMs/TIDCs, reversed the suppressive tumor microenvironment, and inhibited tumor growth. Taken together, this strategy, designed based upon TAMs/TIDCs-targeting delivery and the dual biological functions of let-7b (TLR-7 ligand and IL-10 inhibitor), may provide a new approach for cancer immunotherapy.

McCormick KD, Ghosh A, Trivedi S, et al.
Innate immune signaling through differential RIPK1 expression promote tumor progression in head and neck squamous cell carcinoma.
Carcinogenesis. 2016; 37(5):522-9 [PubMed] Related Publications
Head and neck squamous cell carcinoma (HNSCC) is a devastating disease for which new treatments, such as immunotherapy are needed. Synthetic double-stranded RNAs, which activate toll-like receptor 3 (TLR3), have been used as potent adjuvants in cancer immunotherapy by triggering a proapoptotic response in cancer cells. A better understanding of the mechanism of TLR3-mediated apoptosis and its potential involvement in controlling tumor metastasis could lead to improvements in current treatment. Using paired, autologous primary and metastatic HNSCC cells we previously showed that metastatic, but not primary tumor-derived cells, were unable to activate prosurvival NF-κB in response to p(I):p(C) resulting in an enhanced apoptotic response. Here, we show that transcriptional downregulation of receptor-interacting serine/threonine-protein kinase 1 (RIPK1) in metastatic HNSCC cells causes a loss of TLR3-mediated NF-κB signaling, resulting in enhanced apoptosis. Loss of RIPK1 strongly correlates with metastatic disease in a cohort of HNSCC patients. This downregulation of RIPK1 is possibly mediated by enhanced methylation of the RIPK1 promoter in tumor cells and enhances protumorigenic properties such as cell migration. The results described here establish a novel mechanism of TLR3-mediated apoptosis in metastatic cells and may create new opportunities for using double stranded RNA to target metastatic tumor cells.

Bolze PA, Patrier S, Cheynet V, et al.
Expression patterns of ERVWE1/Syncytin-1 and other placentally expressed human endogenous retroviruses along the malignant transformation process of hydatidiform moles.
Placenta. 2016; 39:116-24 [PubMed] Related Publications
INTRODUCTION: Up to 20% of hydatidiform moles are followed by malignant transformation in gestational trophoblastic neoplasia and require chemotherapy. Syncytin-1 is involved in human placental morphogenesis and is also expressed in various cancers. We assessed the predictive value of the expression of Syncytin-1 and its interactants in the malignant transformation process of hydatidiform moles.
METHODS: Syncytin-1 glycoprotein was localized by immunohistochemistry in hydatidiform moles, gestational trophoblastic neoplasia and control placentas. The transcription levels of its locus ERVWE1, its interaction partners (hASCT1, hASCT2, TLR4 and DC-SIGN) and two loci (ERVFRDE1 and ERV3) involved the expression of other placental envelopes were assessed by real-time PCR.
RESULTS: Syncytin-1 glycoprotein was expressed in syncytiotrophoblast of hydatidiform moles with an apical enhancement when compared with normal placentas. Moles with further malignant transformation had a higher staining intensity of Syncytin-1 surface unit C-terminus but the transcription level of its locus ERVWE1 was not different from that of moles with further remission and normal placentas. hASCT1 and TLR4, showed lower transcription levels in complete moles when compared to normal placentas. ERVWE1, ERVFRDE1 and ERV3 transcription was down-regulated in hydatidiform moles and gestational trophoblastic neoplasia.
CONCLUSIONS: Variations of Syncytin-1 protein localization and down-regulation of hASCT1 and TLR4 transcription are likely to reflect altered functions of Syncytin-1 in the premalignant context of complete moles. The reduced transcription in gestational trophoblastic diseases of ERVWE1, ERVFRDE1 and ERV3, which expression during normal pregnancy is differentially regulated by promoter region methylation, suggest a joint dysregulation mechanism in malignant context.

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.

Lv W, Chen N, Lin Y, et al.
Macrophage migration inhibitory factor promotes breast cancer metastasis via activation of HMGB1/TLR4/NF kappa B axis.
Cancer Lett. 2016; 375(2):245-55 [PubMed] Related Publications
Macrophage migration inhibitory factor (MIF) is up-regulated in diverse solid tumors and acts as the critical link between immune response and tumorigenesis. In this study, we demonstrated that MIF overexpression promoted migration of breast cancer cells by elevating TLR4 expression. Further investigation evidenced that MIF induced ROS generation. MIF-induced ROS led to ERK phosphorylation, which facilitated HMGB1 release from the nucleus to the cytoplasm. MIF overexpression also induced caveolin-1 phosphorylation. Caveolin-1 phosphorylation contributed to HMGB1 secretion from the cytoplasm to the extracellular matrix. The extracellular HMGB1 activated TLR4 signaling including NF-κB phosphorylation, which was responsible for the transcription of Snail and Twist as well as MMP2 activation. Furthermore, MIF-induced caveolin-1-dependent HMGB1 secretion might control the recruitment of CD11b+ immune cells. Our data suggested that MIF affected the intrinsic properties of tumors and the host immune response in tumor microenvironment by regulating the TLR4/HMGB1 axis, leading to metastasis of breast cancer.

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.

Taghavi Pourianazar N, Gunduz U
CpG oligodeoxynucleotide-loaded PAMAM dendrimer-coated magnetic nanoparticles promote apoptosis in breast cancer cells.
Biomed Pharmacother. 2016; 78:81-91 [PubMed] Related Publications
One major application of nanotechnology in cancer treatment involves designing nanoparticles to deliver drugs, oligonucleotides, and genes to cancer cells. Nanoparticles should be engineered so that they could target and destroy tumor cells with minimal damage to healthy tissues. This research aims to develop an appropriate and efficient nanocarrier, having the ability of interacting with and delivering CpG-oligodeoxynucleotides (CpG-ODNs) to tumor cells. CpG-ODNs activate Toll-like receptor 9 (TLR9), which can generate a signal cascade for cell death. In our study, we utilized three-layer magnetic nanoparticles composed of a Fe3O4 magnetic core, an aminosilane (APTS) interlayer and a cationic poly(amidoamine) (PAMAM) dendrimer. This will be a novel targeted delivery system to enhance the accumulation of CpG-ODN molecules in tumor cells. The validation of CpG-ODN binding to DcMNPs was performed using agarose gel electrophoresis, UV-spectrophotometer, XPS analyses. Cytotoxicity of conjugates was assessed in MDA-MB231 and SKBR3 cancer cells based on cell viability by XTT assay and flow cytometric analysis. Our results indicated that the synthesized DcMNPs having high positive charges on their surface could attach to CpG-ODN molecules via electrostatic means. These nanoparticles with the average sizes of 40±10nm bind to CpG-ODN molecules efficiently and induce cell death in MDA-MB231 and SKBR3 tumor cells and could be considered a suitable targeted delivery system for CpG-ODN in biomedical applications. The magnetic core of these nanoparticles represents a promising option for selective drug targeting as they can be concentrated and held in position by means of an external magnetic field.

Sewda K, Coppola D, Enkemann S, et al.
Cell-surface markers for colon adenoma and adenocarcinoma.
Oncotarget. 2016; 7(14):17773-89 [PubMed] Free Access to Full Article Related Publications
Early detection of colorectal cancer (CRC) is crucial for effective treatment. Among CRC screening techniques, optical colonoscopy is widely considered the gold standard. However, it is a costly and invasive procedure with a low rate of compliance. Our long-term goal is to develop molecular imaging agents for the non-invasive detection of CRC by molecular imaging-based colonoscopy using CT, MRI or fluorescence. To achieve this, cell surface targets must be identified and validated. Here, we report the discovery of cell-surface markers that distinguish CRC from surrounding tissues that could be used as molecular imaging targets. Profiling of mRNA expression microarray data from patient tissues including adenoma, adenocarcinoma, and normal gastrointestinal tissues was used to identify potential CRC specific cell-surface markers. Of the identified markers, six were selected for further validation (CLDN1, GPR56, GRM8, LY6G6D/F, SLCO1B3 and TLR4). Protein expression was confirmed by immunohistochemistry of patient tissues. Except for SLCO1B3, diffuse and low expression was observed for each marker in normal colon tissues. The three markers with the greatest protein overexpression were CLDN1, LY6G6D/F and TLR4, where at least one of these markers was overexpressed in 97% of the CRC samples. GPR56, LY6G6D/F and SLCO1B3 protein expression was significantly correlated with the proximal tumor location and with expression of mismatch repair genes. Marker expression was further validated in CRC cell lines. Hence, three cell-surface markers were discovered that distinguish CRC from surrounding normal tissues. These markers can be used to develop imaging or therapeutic agents targeted to the luminal surface of CRC.

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.

Pfirschke C, Engblom C, Rickelt S, et al.
Immunogenic Chemotherapy Sensitizes Tumors to Checkpoint Blockade Therapy.
Immunity. 2016; 44(2):343-54 [PubMed] Free Access to Full Article Related Publications
Checkpoint blockade immunotherapies can be extraordinarily effective, but might benefit only the minority of patients whose tumors are pre-infiltrated by T cells. Here, using lung adenocarcinoma mouse models, including genetic models, we show that autochthonous tumors that lacked T cell infiltration and resisted current treatment options could be successfully sensitized to host antitumor T cell immunity when appropriately selected immunogenic drugs (e.g., oxaliplatin combined with cyclophosphamide for treatment against tumors expressing oncogenic Kras and lacking Trp53) were used. The antitumor response was triggered by direct drug actions on tumor cells, relied on innate immune sensing through toll-like receptor 4 signaling, and ultimately depended on CD8(+) T cell antitumor immunity. Furthermore, instigating tumor infiltration by T cells sensitized tumors to checkpoint inhibition and controlled cancer durably. These findings indicate that the proportion of cancers responding to checkpoint therapy can be feasibly and substantially expanded by combining checkpoint blockade with immunogenic drugs.

Yun BH, Chon SJ, Choi YS, et al.
Pathophysiology of Endometriosis: Role of High Mobility Group Box-1 and Toll-Like Receptor 4 Developing Inflammation in Endometrium.
PLoS One. 2016; 11(2):e0148165 [PubMed] Free Access to Full Article Related Publications
Oxidative stress has been proposed as a potential factor associated with the establishment and progression of endometriosis. Although a few studies have shown possible mechanisms which may play roles in development, progression of endometriosis, few are known in regards of initiation of the disease, especially in the relationship with endometrium. The aim of our study was to investigate whether normal endometrium may be changed by Damage-associated molecular patterns (DAMPs), which may contribute developing pathologic endometrium to induce endometriosis. Endometrial tissues were obtained from 10 patients with fibroids undergoing hysterectomy at a university hospital. High mobility group box-1 (HMGB-1), which is a representative DAMP, has been chosen that may induce alteration in endometrium. In preceding immunohistochemistry experiments using paraffin-block sections from endometriosis (N = 33) and control (N = 27) group, retrospectively, HMGB-1 expression was shown in both epithelial and stromal cell. HMGB-1 expression was significantly increased in secretory phase of endometriosis group, comparing to the controls. To examine the alteration of endometrial stromal cell (HESC) by oxidative stress in terms of HMGB-1, cell proliferation and expression of its receptor, TLR4 was measured according to recombinant HMGB-1 use. Cell proliferation was assessed by CCK-8 assay; real-time PCR and western blotting were used to quantify Toll like receptor 4 (TLR4) mRNA and protein expression respectively. A TLR4 antagonist (LPS-RS) and an inhibitor of the NF-κB pathway (TPCA-1, an IKK-2 inhibitor) were used to confirm the relationships between HMGB-1, TLR4, and the NF-κB pathway. Passive release of HMGB-1 was significantly proportional to the increase in cell death (P<0.05). HESCs showed significant proliferation following treatment with rHMGB-1 (P<0.05), and increased TLR4 expression was observed following rHMGB-1 treatment (P<0.05) in a concentration-dependent manner. Treatment with a TLR4 antagonist and an NF-κB inhibitor resulted in suppression of rHMGB-1-induced HESC proliferation (P<0.05). Levels of IL-6 were significantly decreased following treatment with an NF-κB inhibitor (P<0.05). Our results support the development of altered, pathological endometrium resulted from oxidative stress in normal endometrium. These findings may provide important insights into the changes in endometrium linking the development and progression of endometriosis.

Lalaoui N, Hänggi K, Brumatti G, et al.
Targeting p38 or MK2 Enhances the Anti-Leukemic Activity of Smac-Mimetics.
Cancer Cell. 2016; 29(2):145-58 [PubMed] Related Publications
Birinapant is a smac-mimetic (SM) in clinical trials for treating cancer. SM antagonize inhibitor of apoptosis (IAP) proteins and simultaneously induce tumor necrosis factor (TNF) secretion to render cancers sensitive to TNF-induced killing. To enhance SM efficacy, we screened kinase inhibitors for their ability to increase TNF production of SM-treated cells. We showed that p38 inhibitors increased TNF induced by SM. Unexpectedly, even though p38 is required for Toll-like receptors to induce TNF, loss of p38 or its downstream kinase MK2 increased induction of TNF by SM. Hence, we show that the p38/MK2 axis can inhibit or promote TNF production, depending on the stimulus. Importantly, clinical p38 inhibitors overcame resistance of primary acute myeloid leukemia to birinapant.

Zaidi AH, Kelly LA, Kreft RE, et al.
Associations of microbiota and toll-like receptor signaling pathway in esophageal adenocarcinoma.
BMC Cancer. 2016; 16:52 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Toll-like receptors (TLRs) recognize known molecules from microbes and have an established role in tumorigenesis. Using a rat model of esophageal adenocarcinoma, and human clinical samples, we investigated genes central to TLR-mediated signal transduction and characterized the esophageal microbiome across the spectrum of esophageal adenocarcinoma carcinogenesis.
METHODS: We surgically induced bile/acid reflux in rats and their esophagi were harvested at 40 weeks post-surgery. Tissue samples from the model were selected for gene expression profiling. Additionally, for rat and human samples microbiome analysis was performed using PCR-ESI-MS-TOF technology with validation by fluorescence in situ hybridization.
RESULTS: Gene expression results in the rat model indicated a significant upregulation of TLRs 1-3, 6, 7 and 9 in EAC compared to normal epithelium. PCR-ESI-MS-TOF analysis revealed a prevalence of Escherichia coli in Barrett's esophagus (60%) and esophageal adenocarcinoma (100%), which was validated by fluorescence in situ hybridization. In the human clinical samples, Streptococcus pneumonia was detected in high abundance in gastroesophageal reflux disease and Barrett's esophagus (50-70%) in comparison to tumor adjacent normal epithelium, dysplasia, and esophageal adenocarcinoma (20-30%). E. coli was detected in the Barrett's esophagus and esophageal adenocarcinoma groups but was absent in the tumor adjacent normal epithelium, dysplasia, and the gastroesophageal reflux disease groups.
CONCLUSIONS: We demonstrated an association between the TLR signaling pathway and E. coli hinting towards possible early molecular changes being mediated by microbes in the rat model of esophageal adenocarcinoma carcinogenesis. Studies on human clinical samples also corroborate results to some extent; however, a study with larger sample size is needed to further explore this association.

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