Role of TLR2-dependent inflammation in metastatic progression

Novel biomarkers identified by weighted gene co-expression network analysis for atherosclerosis

BACKGROUND

This study aimed to screen out the potential diagnostic biomarkers for atherosclerosis (AS).

METHODS

We downloaded the gene expression profiles GSE66360, GSE28829, GSE41571, GSE71226, and GSE100927 from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified using the "limma" package in R. Weighted gene co-expression network analysis (WGCNA) was applied to reveal the correlation between genes in different samples. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. The interaction pairs of proteins were retained by the STRING database, and the protein-protein interaction (PPI) network was visualized with the hub genes. Finally, the R packages "ggpubr" and "preprocessCore" were used to analyze immune cell infiltration.

RESULTS

In total, 40 overlapping genes both in GSE66360 and GSE28829 were found to be related to the occurrence of AS. Further, the top 10 network hub genes including TYROBP, CSF1R, TLR2, CD14, CCL4, FCER1G, CD163, TREM1, PLEK, and C5AR1 were identified as significant key genes. Moreover, four genes (TYROBP, CSF1R, FCGR1B, and CD14) were verified that could efficiently diagnose AS. Finally, the gene TYROBP was found to have a strong correlation with immune-infiltrating cells.

CONCLUSION

Our study identified four genes (TYROBP, CSF1R, FCGR1B, and CD14) that may be effective biomarkers for AS, with the potential to guide the clinical diagnosis of AS.

Exploring TLR signaling pathways as promising targets in cervical cancer: The road less traveled

Cervical cancer is the leading cause of cancer-related deaths for women globally. Despite notable advancements in prevention and treatment, the identification of novel therapeutic targets remains crucial for cervical cancer. Toll-like receptors (TLRs) play an essential role in innate immunity as pattern-recognition receptors. There are several types of pathogen-associated molecular patterns (PAMPs), including those present in cervical cancer cells, which have the ability to activate toll-like receptors (TLRs). Recent studies have revealed dysregulated toll-like receptor (TLR) signaling pathways in cervical cancer, leading to the production of inflammatory cytokines and chemokines that can facilitate tumor growth and metastasis. Consequently, TLRs hold significant promise as potential targets for innovative therapeutic agents against cervical cancer. This book chapter explores the role of TLR signaling pathways in cervical cancer, highlighting their potential for targeted therapy while addressing challenges such as tumor heterogeneity and off-target effects. Despite these obstacles, targeting TLR signaling pathways presents a promising approach for the development of novel and effective treatments for cervical cancer.

Emerging roles for tumor stroma in antigen presentation and anti-cancer immunity

Advances in immunotherapy in the last decade have revolutionized treatment paradigms across multiple cancer diagnoses. However, only a minority of patients derive durable benefit and progress with traditional approaches, such as cancer vaccines, remains unsatisfactory. A key to overcoming these barriers resides with a deeper understanding of tumor antigen presentation and the complex and dynamic heterogeneity of tumor-infiltrating antigen-presenting cells (APCs). Reminiscent of the 'second touch' hypothesis proposed by Klaus Ley for CD4+ T cell differentiation, the acquisition of full effector potential by lymph node- primed CD8+ T cells requires a second round of co-stimulation at the site where the antigen originated, i.e. the tumor bed. The tumor stroma holds a prime role in this process by hosting specialized APC niches, apparently distinct from tertiary lymphoid structures, that support second antigenic touch encounters and CD8+ T cell effector proliferation and differentiation. We propose that APC within second-touch niches become licensed for co-stimulation through stromal-derived instructive signals emulating embryonic or wound-healing provisional matrix remodeling. These immunostimulatory roles of stroma contrast with its widely accepted view as a physical and functional 'immune barrier'. Stromal control of antigen presentation makes evolutionary sense as the host stroma-tumor interface constitutes the prime line of homeostatic 'defense' against the emerging tumor. In this review, we outline how stroma-derived signals and cells regulate tumor antigen presentation and T-cell effector differentiation in the tumor bed. The re-definition of tumor stroma as immune rheostat rather than as inflexible immune barrier harbors significant untapped therapeutic opportunity.

METTL3 Regulates the Inflammatory Response in CPB2 Toxin-Exposed IPEC-J2 Cells through the TLR2/NF-κB Signaling Pathway

Clostridium perfringens beta2 (CPB2) toxin is one of the main pathogenic toxins produced by Clostridium perfringens, which causes intestinal diseases in animals and humans. The N6-methyladenosine (m6A) modification is the most common reversible modification in eukaryotic disease processes. Methyltransferase-like 3 (METTL3) regulates immunity and inflammatory responses induced by the bacterial infections in animals. However, METTL3's involvement in CPB2-treated intestinal porcine epithelial cell line-J2 (IPEC-J2) remains unclear. In the current study, we used methylated RNA immunoprecipitation-quantitative polymerase chain reaction, Western blotting and immunofluorescence assay to determine the role of METTL3 in CPB2-exposed IPEC-J2 cells. The findings revealed that m6A and METTL3 levels were increased in CPB2 treated IPEC-J2 cells. Functionally, METTL3 overexpression promoted the release of inflammatory factors, increased cytotoxicity, decreased cell viability and disrupted tight junctions between cells, while the knockdown of METTL3 reversed these results. Furthermore, METTL3 was involved in the inflammatory response of IPEC-J2 cells by activating the TLR2/NF-κB signaling pathway through regulating TLR2 m6A levels. In conclusion, METTL3 overexpression triggered the TLR2/NF-κB signaling pathway and promoted CPB2-induced inflammatory responses in IPEC-J2 cells. These findings may provide a new strategy for the prevention and treatment of diarrhea caused by Clostridium perfringens.

Upregulation of NOD1 and NOD2 contribute to cancer progression through the positive regulation of tumorigenicity and metastasis in human squamous cervical cancer

BACKGROUND

Metastatic cervical squamous cell carcinoma (CSCC) has poor prognosis and is recalcitrant to the current treatment strategies, which warrants the necessity to identify novel prognostic markers and therapeutic targets. Given that CSCC is a virus-induced malignancy, we hypothesized that the pattern recognition receptors (PRRs) involved in the innate immune response likely play a critical role in tumor development.

METHODS

A bioinformatics analysis, qPCR, IHC, immunofluorescence, and WB were performed to determine the expression of NOD1/NOD2. The biological characteristics of overexpression NOD1 or NOD2 CSCC cells were compared to parental cells: proliferation, migration/invasion and cytokines secretion were examined in vitro through CCK8/colony formation/cell cycle profiling/cell counting, wound healing/transwell, and ELISA assays, respectively. The proliferative and metastatic capacity of overexpression NOD1 or NOD2 CSCC cells were also evaluated in vivo. FCM, mRNA and protein arrays, ELISA, and WB were used to identify the mechanisms involved, while novel pharmacological treatment were evaluated in vitro and in vivo. Quantitative variables between two groups were compared by Student's t test (normal distribution) or Mann-Whitney U test (non-normal distribution), and one-way or two-way ANOVA was used for comparing multiple groups. Pearson χ² test or Fisher's exact test was used to compare qualitative variables. Survival curves were plotted by the Kaplan-Meier method and compared by the log-rank test. P values of < 0.05 were considered statistically significant.

RESULTS

NOD1 was highly expressed in CSCC with lymph-vascular space invasion (LVSI, P < 0.01) and lymph node metastasis (LM, P < 0.01) and related to worse overall survival (OS, P = 0.016). In vitro and in vivo functional assays revealed that the upregulation of NOD1 or NOD2 in CSCC cells promoted proliferation, invasion, and migration. Mechanistically, NOD1 and NOD2 exerted their oncogenic effects by activating NF-κb and ERK signaling pathways and enhancing IL-8 secretion. Inhibition of the IL-8 receptor partially abrogated the effects of NOD1/2 on CSCC cells.

CONCLUSIONS

NOD1/2-NF-κb/ERK and IL-8 axis may be involved in the progression of CSCC; the NOD1 significantly enhanced the progression of proliferation and metastasis, which leads to a poor prognosis. Anti-IL-8 was identified as a potential therapeutic target for patients with NOD1^high tumor.

Microbial Colonization and Inflammation as Potential Contributors to the Lack of Therapeutic Success in Oral Squamous Cell Carcinoma

This review discusses the microenvironment of evolving and established conventional oral squamous cell carcinoma, by far the most common oral cancer. The focus of this paper is mainly on the more recent data that describe the role of microorganisms, host-microbial interactions, and in particular, the contributions of cell-surface toll-like receptors on immune system cells and on normal and malignant epithelial cells to their functions that support carcinogenesis. Because carcinomas arising at various host surfaces share much in common, additional information available from studies of other carcinomas is included in the discussion. Accumulating evidence reveals the complex toll-like receptor-mediated tumor-supporting input into many aspects of carcinogenesis via malignant cells, stromal immune cells and non-immune cells, complicating the search for effective treatments.

Phytochemicals targeting NF-κB signaling: Potential anti-cancer interventions

Nuclear factor κB (NF-κB) is a ubiquitous regulator of the signalome and is indispensable for various biological cell functions. NF-κB consists of five transcription factors that execute both cytoplasmic and nuclear signaling processes in cells. NF-κB is the only signaling molecule that governs both pro- and anti-apoptotic, and pro- and anti-inflammatory responses. This is due to the canonical and non-canonical components of the NF-κB signaling pathway. Together, these pathways orchestrate cancer-related inflammation, hyperplasia, neoplasia, and metastasis. Non-canonical NF-κB pathways are particularly involved in the chemoresistance of cancer cells. In view of its pivotal role in cancer progression, NF-κB represents a potentially significant therapeutic target for modifying tumor cell behavior. Several phytochemicals are known to modulate NF-κB pathways through the stabilization of its inhibitor, IκB, by inhibiting phosphorylation and ubiquitination thereof. Several natural pharmacophores are known to inhibit the nuclear translocation of NF-κB and associated pro-inflammatory responses and cell survival pathways. In view of this and the high degree of specificity exhibited by various phytochemicals for the NF-κB component, we herein present an in-depth overview of these phytochemicals and discuss their mode of interaction with the NF-κB signaling pathways for controlling the fate of tumor cells for cancer-directed interventions.

•

NF-κB plays a pivotal role in the maintenance of homeostasis and various inflammation-mediated pathologies.

•

NF-κB is involved in cancer development and progression by modulating growth signaling and apoptosis pathways.

•

Phytochemicals modulating NF-κB activity should be exploited to design anticancer drugs with minimal side effects.

•

Use of these phytochemicals in adjunctive chemotherapy may enhance the chemosensitivity of existing chemotherapeutic drugs.

microRNAs and Corresponding Targets Involved in Metastasis of Colorectal Cancer in Preclinical In Vivo Models

The high death toll of colorectal cancer patients is due to metastatic disease which is difficult to treat. The liver is the preferred site of metastasis, followed by the lungs and peritoneum. In order to identify new targets and new modalities of intervention we surveyed the literature for microRNAs (miRs) which modulate metastasis of colorectal cancer in preclinical in vivo models. We identified 12 up-regulated and 19 down-regulated miRs corresponding to the latter criterium. The vast majority (n=16) of identified miRs are involved in modulation of epithelial-mesenchymal transition (EMT). Other categories of metastasis-related miRs exhibit tumor- and metastasis-suppressing functions, modulation of signaling pathways, transmembrane receptors and a class of miRs, which interfere with targets which do not fit into these categories. Finally, we discuss the principles of miR inhibition and reconstitution of function, prospective clinical evaluation of with miR-related agents in the context of clinical evaluation in metastasis relevant settings.

Identification of TLR2 Signalling Mechanisms Which Contribute to Barrett's and Oesophageal Adenocarcinoma Disease Progression

Simple Summary

Oesophageal adenocarcinoma (EAC) is a common type of oesophageal cancer with a rapidly rising incidence. Risk factors such as reflux, smoking, obesity and Barrett’s oesophagus cause chronic irritation and inflammation in the oesophagus. A receptor that causes inflammation, called Toll-like receptor 2 (TLR2), is expressed at higher levels in oesophageal cells from patients with Barrett’s and EAC, compared to disease-free patients. This study aimed to identify mechanisms involved in TLR2-mediated inflammation in oesophageal cells; and to assess whether TLR2 represents a therapeutic target to limit EAC development. Findings reveal that TLR2 activation in Barrett’s organoids and oesophageal cancer cells amplifies inflammation and promotes cancer development by causing the secretion of several inflammatory factors, most notably the nuclear protein, HMGB1. We demonstrate that TLR2 neutralisation efficiently blocks the inflammatory effects of TLR2 in these systems, revealing the therapeutic potential of TLR2 targeting to limit oesophageal disease and cancer progression.

Abstract

Chronic inflammation plays an important role in the pathogenesis of oesophageal adenocarcinoma (EAC) and its only known precursor, Barrett’s oesophagus (BE). Recent studies have shown that oesophageal TLR2 levels increase from normal epithelium towards EAC. TLR2 signalling is therefore likely to be important during EAC development and progression, which requires an inflammatory microenvironment. Here, we show that, in response to TLR2 stimulation, BE organoids and early-stage EAC cells secrete pro-inflammatory cytokines and chemokines which recruit macrophages to the tumour site. Factors secreted from TLR2-stimulated EAC cells are shown to subsequently activate TLR2 on naïve macrophages, priming them for inflammasome activation and inducing their differentiation to an M2/TAM-like phenotype. We identify the endogenous TLR2 ligand, HMGB1, as the factor secreted from EAC cells responsible for the observed TLR2-mediated effects on macrophages. Our results indicate that HMGB1 signalling between EAC cells and macrophages creates an inflammatory tumour microenvironment to facilitate EAC progression. In addition to identifying HMGB1 as a potential target for early-stage EAC treatment, our data suggest that blocking TLR2 signalling represents a mechanism to limit HMGB1 release, inflammatory cell infiltration and inflammation during EAC progression.

MYD88 Is a Potential Prognostic Gene and Immune Signature of Tumor Microenvironment for Gliomas

Purpose

To explore the profiles of immune and stromal components of the tumor microenvironment (TME) and their related key genes in gliomas.

Methods

We applied bioinformatic techniques to identify the core gene that participated in the regulation of the TME of the gliomas. And immunohistochemistry staining was used to calculate the gene expressions in clinical cases.

Results

The CIBERSORT and ESTIMATE were used to figure out the composition of TME in 698 glioma cases from The Cancer Genome Atlas (TCGA) database. Differential expression analysis identified 2103 genes between the high and the low-score group. Then the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, univariate Cox regression analysis, and protein–protein interaction (PPI) network construction were conducted based on these genes. MYD88 was identified as the key gene by the combination univariate Cox and PPI analysis. Furthermore, MYD88 expression was significantly associated with the overall survival and WHO grade of glioma patients. The genes in the high-expression MYD88 group were mainly in immune-related pathways in the Gene Set Enrichment Analysis (GSEA). We found that macrophage M2 accounted for the largest portion with an average of 27.6% in the glioma TIICs and was associated with high expression of MYD88. The results were verified in CGGA database and clinical cases in our hospital. Furthermore, we also found the MYD88 expression was higher in IDH1 wild types. The methylation rate was lower in high grade gliomas.

Conclusion

MYD88 had predictive prognostic value in glioma patients by influencing TIICs dysregulation especially the M2-type macrophages.

Functional variations of NFKB1 and NFKB1A in inflammatory disorders and their implication for therapeutic approaches

Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) is a sophisticated transcription factor that is particularly important in the inflammatory response, but it regulates more than 400 individual and dependent genes for parts of the apoptotic, angiogenic, and proliferative, differentiative, and cell adhesion pathways. NF-κB function is directly inhibited by the binding of inhibitor of κB (IκB), and the imbalance between NF-κB and IκB has been linked to the development and progression of cancer and a variety of inflammatory disorders. These observations might broaden the horizon of current knowledge, particularly on the pathogenesis of inflammatory diseases considering the roles of NF-κB and IκB. In this context, we focus this narrative review on a comparative discussion of our findings with other literature regarding variations of NFKB1 and NFKB1A and their association with susceptibility to widespread inflammatory disorders (such as atherosclerosis, morbid obesity, Behçet syndrome, Graves disease, Hashimoto disease) and common cancers (such as gliomas).

Zymosan promotes proliferation, Candida albicans adhesion and IL-1β production of oral squamous cell carcinoma in vitro

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck squamous cell carcinoma (HNSCC), and the effect of zymosan (ZYM), a component of the yeast cell wall, on oral cancer remains unclear. The CCK-8 proliferation assay was performed to evaluate the effect of ZYM on the proliferation of the OSCC cell lines WSU-HN4, WSU-HN6 and CAL27, and the potential mechanism was explored by quantitative real-time PCR, immunofluorescence assay and western blot. A cell adhesion assay was conducted to determine the adhesion of Candida albicans to OSCC cells, and the expression of related genes, including TLR2, MyD88, NLRP3, ASC, Caspase-1 and IL-1β, and proteins, including TLR2, MyD88, NF-κB p65, p-NF-κB p65 and E-cadherin was determined. Additionally, the pro-inflammatory cytokines including IL-6, IL-8, TNF-α and IL-1β produced by OSCC cells were detected using a chemiluminescence immunoassay (CLIA). In the current study, the CCK-8 assay showed that ZYM promoted the proliferation of WSU-HN4, WSU-HN6 and CAL27 cells via the TLR2/MyD88 pathway. The cell adhesion assay showed that the number of C. albicans cells per field significantly increased in ZYM-treated OSCC cells compared to controls. When treated with ZYM, OSCC cells secreted significantly more pro-inflammatory cytokine IL-1β, which could enhance inflammation in oral cancer microenvironment. In conclusion, ZYM from the fungal cell wall promotes the proliferation, C. albicans adhesion and IL-1β production in OSCC, as demonstrated by in vitro experiments.

The Activity of KIF14, Mieap, and EZR in a New Type of the Invasive Component, Torpedo-Like Structures, Predetermines the Metastatic Potential of Breast Cancer

Intratumor morphological heterogeneity reflects patterns of invasive growth and is an indicator of the metastatic potential of breast cancer. In this study, we used this heterogeneity to identify molecules associated with breast cancer invasion and metastasis. The gene expression microarray data were used to identify genes differentially expressed between solid, trabecular, and other morphological arrangements of tumor cells. Immunohistochemistry was applied to evaluate the association of the selected proteins with metastasis. RNA-sequencing was performed to analyze the molecular makeup of metastatic tumor cells. High frequency of metastases and decreased metastasis-free survival were detected in patients either with positive expression of KIF14 or Mieap or negative expression of EZR at the tips of the torpedo-like structures in breast cancers. KIF14- and Mieap-positive and EZR-negative cells were mainly detected in the torpedo-like structures of the same breast tumors; however, their transcriptomic features differed. KIF14-positive cells showed a significant upregulation of genes involved in ether lipid metabolism. Mieap-positive cells were enriched in genes involved in mitophagy. EZR-negative cells displayed upregulated genes associated with phagocytosis and the chemokine-mediated signaling pathway. In conclusion, the positive expression of KIF14 and Mieap and negative expression of EZR at the tips of the torpedo-like structures are associated with breast cancer metastasis.

Cancer-associated V-ATPase induces delayed apoptosis of protumorigenic neutrophils

Tumors and neutrophils undergo an unexpected interaction, in which products released by tumor cells interact to support neutrophils that in turn support cancer growth, angiogenesis, and metastasis. A key protein that is highly expressed by cancer cells in tumors is the a2 isoform V‐ATPase (a2V). A peptide from a2V (a2NTD) is secreted specifically by cancer cells, but not normal cells, into the tumor microenvironment. This peptide reprograms neutrophils to promote angiogenesis, cancer cell invasiveness, and neutrophil recruitment. Here, we provide evidence that cancer‐associated a2V regulates the life span of protumorigenic neutrophils by influencing the intrinsic pathway of apoptosis. Immunohistochemical analysis of human cancer tissue sections collected from four different organs shows that levels of a2NTD and neutrophil counts are increased in cancer compared with normal tissues. Significant increases in neutrophil counts were present in both poorly and moderately differentiated tumors. In addition, there is a positive correlation between the number of neutrophils and a2NTD expression. Human neutrophils treated with recombinant a2NTD show significantly delayed apoptosis, and such prolonged survival was dependent on NF‐κB activation and ROS generation. Induction of antiapoptotic protein expression (Bcl‐xL and Bcl‐2A1) and decreased expression of proapoptotic proteins (Bax, Apaf‐1, caspase‐3, caspase‐6, and caspase‐7) were a hallmark of these treated neutrophils. Autocrine secretion of prosurvival cytokines of TNF‐α and IL‐8 by treated neutrophils prolongs their survival. Our findings highlight the important role of cancer‐associated a2V in regulating protumorigenic innate immunity, identifying a2V as a potential important target for cancer therapy.

Activation of the pattern recognition receptor NOD1 augments colon cancer metastasis

While emerging data suggest nucleotide oligomerization domain receptor 1 (NOD1), a cytoplasmic pattern recognition receptor, may play an important and complementary role in the immune response to bacterial infection, its role in cancer metastasis is entirely unknown. Hence, we sought to determine the effects of NOD1 on metastasis. NOD1 expression in paired human primary colon cancer, human and murine colon cancer cells were determined using immunohistochemistry and immunoblotting (WB). Clinical significance of NOD1 was assessed using TCGA survival data. A series of in vitro and in vivo functional assays, including adhesion, migration, and metastasis, was conducted to assess the effect of NOD1. C12-iE-DAP, a highly selective NOD1 ligand derived from gram-negative bacteria, was used to activate NOD1. ML130, a specific NOD1 inhibitor, was used to block C12-iE-DAP stimulation. Stable knockdown (KD) of NOD1 in human colon cancer cells (HT29) was constructed with shRNA lentiviral transduction and the functional assays were thus repeated. Lastly, the predominant signaling pathway of NOD1-activation was identified using WB and functional assays in the presence of specific kinase inhibitors. Our data demonstrate that NOD1 is highly expressed in human colorectal cancer (CRC) and human and murine CRC cell lines. Clinically, we demonstrate that this increased NOD1 expression negatively impacts survival in patients with CRC. Subsequently, we identify NOD1 activation by C12-iE-DAP augments CRC cell adhesion, migration and metastasis. These effects are predominantly mediated via the p38 mitogen activated protein kinase (MAPK) pathway. This is the first study implicating NOD1 in cancer metastasis, and thus identifying this receptor as a putative therapeutic target.

Obesity Surgery and Cancer: What Are the Unanswered Questions?

Obesity has become a global epidemic with a soaring economic encumbrance due to its related morbidity and mortality. Amongst obesity-related conditions, cancer is indeed the most redoubtable. Bariatric surgery has been proven to be the most effective treatment for obesity and its associated metabolic and cardiovascular disorders. However, the understanding of whether and how bariatric surgery determines a reduction in cancer risk is limited. Obesity-related malignancies primarily include colorectal and hormone-sensitive (endometrium, breast, prostate) cancers. Additionally, esophago-gastric tumors are growing to be recognized as a new category mainly associated with post-bariatric surgery outcomes. In fact, certain types of surgical procedures have been described to induce the development and subsequent progression of pre-cancerous esophageal and gastric lesions. This emerging category is of great concern and further research is required to possibly prevent such risks. Published data has generated conflicting results. In fact, while overall cancer risk reduction was reported particularly in women, some authors showed no improvement or even increased cancer incidence. Although various studies have reported beneficial effects of surgery on risk of specific cancer development, fundamental insights into the pathogenesis of obesity-related cancer are indispensable to fully elucidate its mechanisms.

Research Progress of Mechanisms and Drug Therapy For Atherosclerosis on Toll-Like Receptor Pathway

Recent reports have established atherosclerosis (AS) as a major factor in the pathogenetic process of cardiovascular diseases such as ischemic stroke and coronary heart disease. Although the possible pathogenesis of AS remains to be elucidated, a large number of investigations strongly suggest that the inhibition of toll-like receptors (TLRs) alleviates the severity of AS to some extent by suppressing vascular inflammation and the formation of atherosclerotic plaques. As pattern recognition receptors, TLRs occupy a vital position in innate immunity, mediating various signaling pathways in infective and sterile inflammation. This review summarizes the available data on the research progress of AS and the latest antiatherosclerotic drugs associated with TLR pathway.

The ST2/Interleukin-33 Axis in Hematologic Malignancies: The IL-33 Paradox

Interleukin (IL)-33 is a chromatin-related nuclear interleukin that is a component of IL-1 family. IL-33 production augments the course of inflammation after cell damage or death. It is discharged into the extracellular space. IL-33 is regarded as an “alarmin” able to stimulate several effectors of the immune system, regulating numerous immune responses comprising cancer immune reactions. IL-33 has been demonstrated to influence tumorigenesis. However, as far as this cytokine is concerned, we are faced with what has sometimes been defined as the IL-33 paradox. Several studies have demonstrated a relevant role of IL-33 to numerous malignancies, where it may have pro- and—less frequently—antitumorigenic actions. In the field of hematological malignancies, the role of IL-33 seems even more complex. Although we can affirm the existence of a negative role of IL-33 in Chronic myelogenos leukemia (CML) and in lymphoproliferative diseases and a positive role in pathologies such as Acute myeloid leukemia (AML), the action of IL-33 seems to be multiple and sometimes contradictory within the same pathology. In the future, we will have to learn to govern the negative aspects of activating the IL-33/ST2 axis and exploit the positive ones.

Spz/Toll-6 signal guides organotropic metastasis in Drosophila

Targeted cell migration plays important roles in developmental biology and disease processes, including in metastasis. Drosophila tumors exhibit traits characteristic of human cancers, providing a powerful model to study developmental and cancer biology. We now find that cells derived from Drosophila eye-disc tumors also display organ-specific metastasis, invading receptive organs but not wing disc. Toll receptors are known to affect innate immunity and the tumor inflammatory microenvironment by modulating the NF-κB pathway. Our RNA interference (RNAi) screen and genetic analyses show that Toll-6 is required for migration and invasion of the tumor cells. Further, receptive organs express Toll ligands [Spätzle (Spz) family molecules], and ectopic Spz expression renders the wing disc receptive to metastasis. Finally, Toll-6 promotes metastasis by activating JNK signaling, a key regulator of cell migration. Hence, we report Toll-6 and Spz as a new pair of guidance molecules mediating organ-specific metastatic behavior and highlight a novel signaling mechanism for Toll-family receptors.

Ajulemic acid: potential treatment for chronic inflammation

Ajulemic acid (AJA, CT‐3, IP‐751, JBT‐101, anabasum) is a first‐in‐class, synthetic, orally active, cannabinoid‐derived drug that preferentially binds to the CB2 receptor and is nonpsychoactive. In preclinical studies, and in Phase 1 and 2 clinical trials, AJA showed a favorable safety, tolerability, and pharmacokinetic profile. It also demonstrated significant efficacy in preclinical models of inflammation and fibrosis. It suppresses tissue scarring and stimulates endogenous eicosanoids that resolve chronic inflammation and fibrosis without causing immunosuppression. AJA is currently being developed for use in 4 separate but related indications including systemic sclerosis (SSc), cystic fibrosis, dermatomyositis (DM), and systemic lupus erythematosus. Phase 2 clinical trials in the first 3 targets demonstrated that it is safe, is a potential treatment for these orphan diseases and appears to be a potent inflammation‐resolving drug with a unique mechanism of action, distinct from the nonsteroidal anti‐inflammatory drug (NSAID), and will be useful for treating a wide range of chronic inflammatory diseases. It may be considered to be a disease‐modifying drug unlike most NSAIDs that only provide symptomatic relief. AJA is currently being evaluated in 24‐month open‐label extension studies in SSc and in skin‐predominant DM. A Phase 3 multicenter trial to demonstrate safety and efficacy in SSc has recently been initiated.

Variations in Toll-like receptor and nuclear factor-kappa B genes and the risk of glioma

PURPOSE

Glioblastoma (GBM) is the most aggressive primary brain tumour in the adult nervous system and is associated with a poor prognosis. NF-KB activation is an important driver of the malignant phenotype that confers a negative prognosis in patients with GBM. NF-KB plays a role in Toll-like Receptors (TLR)-induced tumourigenesis. The aim of the present study was to investigate the association of a promoter region polymorphism of NFKB1 gene encoding the p50 subunit of NF-KB, namely -94ins/del ATTG, the most widely discussed the TLR2 Arg753Gln, TLR4Asp299Gly and TLR4Thr399Ile polymorphisms, their combined effects, and the glioma risk.

METHODS

A group of 120 Glioma patients and 225 control subjects were screened for these four polymorphisms using the PCR-RFLP method.

RESULTS

Statistical analysis indicates that the ins/ins genotype of NFKB -94ins/delATTG (p=0.003), and the AA genotype of TLR4Asp299Gly (p < 0.001) are risk factors for glioma and people carrying the ins allele have an approximately 1.47 times susceptibility risk of glioma whereas GG genotype of TLR2Arg753Gln seems to be protective against glioma (p = 0.002). Combined genotype analysis showed that del/ins-GG genotype of TLR2Arg753Gln-NFKB1, del/ins + GG genotype of TLR4Asp299Gly-NFKB1, del/ins-CC genotype of TLR4Thr399Ile-NFKB1 were risk factors for glioma development.

CONCLUSION

NFKB1 -94ins/delATTG and TLR4Asp299Gly polymorphisms are associated with increased glioma cancer risk in a Turkish population.

A role for proteoglycans in vascular disease

The content of proteoglycans (PGs) is low in the extracellular matrix (ECM) of vascular tissue, but increases dramatically in all phases of vascular disease. Early studies demonstrated that glycosaminoglycans (GAGs) including chondroitin sulfate (CS), dermatan sulfate (DS), keratan sulfate (KS) and heparan sulfate (HS) accumulate in vascular lesions in both humans and in animal models in areas of the vasculature that are susceptible to disease initiation (such as at branch points) and are frequently coincident with lipid deposits. Later studies showed the GAGs were covalently attached to specific types of core proteins that accumulate in vascular lesions. These molecules include versican (CSPG), biglycan and decorin (DS/CSPGs), lumican and fibromodulin (KSPGs) and perlecan (HSPG), although other types of PGs are present, but in lesser quantities. While the overall molecular design of these macromolecules is similar, there is tremendous structural diversity among the different PG families creating multiple forms that have selective roles in critical events that form the basis of vascular disease. PGs interact with a variety of different molecules involved in disease pathogenesis. For example, PGs bind and trap serum components that accumulate in vascular lesions such as lipoproteins, amyloid, calcium, and clotting factors. PGs interact with other ECM components and regulate, in part, ECM assembly and turnover. PGs interact with cells within the lesion and alter the phenotypes of both resident cells and cells that invade the lesion from the circulation. A number of therapeutic strategies have been developed to target specific PGs involved in key pathways that promote vascular disease. This review will provide a historical perspective of this field of research and then highlight some of the evidence that defines the involvement of PGs and their roles in the pathogenesis of vascular disease.

Tumor matrix remodeling and novel immunotherapies: the promise of matrix-derived immune biomarkers

Recent advances in our understanding of the dynamics of cellular cross-talk have highlighted the significance of host-versus-tumor effect that can be harnessed with immune therapies. Tumors exploit immune checkpoints to evade adaptive immune responses. Cancer immunotherapy has witnessed a revolution in the past decade with the development of immune checkpoint inhibitors (ICIs), monoclonal antibodies against cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or their ligands, such as PD1 ligand 1 (PD-L1). ICIs have been reported to have activity against a broad range of tumor types, in both solid organ and hematologic malignancy contexts. However, less than one-third of the patients achieve a durable and meaningful treatment response. Expression of immune checkpoint ligands (e.g., PD-L1), mutational burden and tumor-infiltrating lymphocytes are currently used as biomarkers for predicting response to ICIs. However, they do not reliably predict which patients will benefit from these therapies. There is dire need to discover novel biomarkers to predict treatment efficacy and to identify areas for development of combination strategies to improve response rates. Emerging evidence suggests key roles of tumor extracellular matrix (ECM) components and their proteolytic remodeling products in regulating each step of the cancer-immunity cycle. Here we review tumor matrix dynamics and matrix remodeling in context of anti-tumor immune responses and immunotherapy and propose the exploration of matrix-based biomarkers to identify candidates for immune therapy.

Oral cancer cells sustainedly infected with Porphyromonas gingivalis exhibit resistance to Taxol and have higher metastatic potential

Major obstacles to improving the prognosis of patients with oral squamous cell carcinoma (OSCC) are the acquisition of resistance to chemotherapeutic agents and development of metastases. Recently, inflammatory signals are suggested to be one of the most important factors in modulating chemoresistance and establishing metastatic lesions. In addition, epidemiological studies have demonstrated that periodontitis, the most common chronic inflammatory condition of the oral cavity, is closely associated with oral cancer. However, a correlation between chronic periodontitis and chemoresistance/metastasis has not been well established. Herein, we will present our study on whether sustained infection with Porphyromonas gingivalis, a major pathogen of chronic periodontitis, could modify the response of OSCC cells to chemotherapeutic agents and their metastatic capability in vivo. Tumor xenografts composed of P. gingivalis–infected OSCC cells demonstrated a higher resistance to Taxol through Notch1 activation, as compared with uninfected cells. Furthermore, P. gingivalis–infected OSCC cells formed more metastatic foci in the lung than uninfected cells.

Toll-like receptor 2 induces adenosine receptor A2a and promotes human squamous carcinoma cell growth via extracellular signal regulated kinases ½

Patient treatment for oral squamous cell carcinoma (OSCC) not associated with Human papillomavirus remains problematic. OSCC microenvironment is typically inflamed and colonized by microorganisms, providing ligands for toll-like receptors (TLR). In immune cells TLR2 and TLR4 activate NF-kB and extracellular signal regulated kinase (ERK)1/2 pathways, leading to upregulation of inhibitory adenosine receptors A2a and A2b, and reduction in stimulatory A1 and A3. How TLR and adenosine receptors function in SCC cells is not understood. To address this gap, we evaluated TLR and adenosine receptor expression and function in human OSCC cells and keratinocytes. TLR2 and A2a were co-expressed in pre-cancer and SCC cells of 17 oral specimens. In vitro, 5/6 OSCC lines expressed more TLR2 than TLR1, 4 or 6 mRNA. TLR2 ligands stimulated A2a expression in TLR2-high cell lines, but no A1 or A3 was detected with or without stimuli. In TLR2-high OSCC, TLR2/1, 2/6 and adenosine receptor agonists activated ERK1/2. TLR2-mediated ERK1/2 phosphorylation resulted in accumulation of c-FOS, ERK-dependent cell proliferation and reduced caspase-3 activity. Similar ERK1/2-dependent proliferation and decreased caspase-3 activity were caused by combined TLR2 and adenosine receptor stimuli. We conclude that TLR2 and adenosine receptor agonists, known to be present in the tumor microenvironment, may contribute to OSCC progression in part via direct effects on the ERK1/2 pathway in squamous carcinoma cells.

Obesity, Inflammation, and Cancer

Obesity, a worldwide epidemic, confers increased risk for multiple serious conditions, including cancer, and is increasingly recognized as a growing cause of preventable cancer risk. Chronic inflammation, a well-known mediator of cancer, is a central characteristic of obesity, leading to many of its complications, and obesity-induced inflammation confers additional cancer risk beyond obesity itself. Multiple mechanisms facilitate this strong association between cancer and obesity. Adipose tissue is an important endocrine organ, secreting several hormones, including leptin and adiponectin, and chemokines that can regulate tumor behavior, inflammation, and the tumor microenvironment. Excessive adipose expansion during obesity causes adipose dysfunction and inflammation to increase systemic levels of proinflammatory factors. Cells from adipose tissue, such as cancer-associated adipocytes and adipose-derived stem cells, enter the cancer microenvironment to enhance protumoral effects. Dysregulated metabolism that stems from obesity, including insulin resistance, hyperglycemia, and dyslipidemia, can further impact tumor growth and development. This review describes how adipose tissue becomes inflamed in obesity, summarizes ways these mechanisms impact cancer development, and discusses their role in four adipose-associated cancers that demonstrate elevated incidence or mortality in obesity.

Immune Regulation of Toll-Like Receptor 2 Engagement on CD4+ T Cells in Murine Models of Malignant Pleural Effusion

Toll-like receptor (TLR) 2 has a well-known role in sensing multiple ligands that include microbial products, endotoxin, and some extracellular matrix molecules; however, its role in the development of malignant pleural effusion (MPE) remains unknown. We performed the present study to explore the impact of TLR2 signaling on the development of MPE and to define the underlying mechanisms by which TLR2 works. Development of MPE was compared between TLR2^-/- and wild-type (WT) mice. The effect of TLR2 on differentiation of T helper type 17 (Th17), Th9, and Th2 cells in MPE was explored. The mechanisms of TLR2 on survival of mice bearing MPE were also investigated. MPE volume in TLR2^-/- mice was lower than that in WT mice, and the survival of TLR2^-/- mice bearing MPE was longer than that of WT mice. TLR2 deficiency increased, and TLR2 activation decreased, Th17 cells in MPE, whereas TLR2 signaling showed the contrary effects on Th2 cells. Th9 cells were increased in MPE of TLR2^-/- mice but were not influenced by TLR2 signaling. Intraperitoneal injection of anti-IL-17 monoclonal antibody (mAb), anti-IL-9 mAb, or recombinant mouse IL-4 accelerated the death of TLR2^-/- mice bearing MPE, and intraperitoneal injection anti-IL-17 mAb in TLR2^-/- mice was associated with a significantly shorter survival time than in WT mice. We have demonstrated, for the first time, that TLR2 signaling promotes the development of MPE and accelerates the death of mice bearing MPE by directly suppressing Th17 cell differentiation and directly promoting Th2 cell differentiation, and also by indirectly suppressing Th9 cell differentiation via an IL-17-dependent mechanism.

GFI1 downregulation promotes inflammation-linked metastasis of colorectal cancer

Inflammation is frequently associated with initiation, progression, and metastasis of colorectal cancer (CRC). Here, we unveil a CRC-specific metastatic programme that is triggered via the transcriptional repressor, GFI1. Using data from a large cohort of clinical samples including inflammatory bowel disease and CRC, and a cellular model of CRC progression mediated by cross-talk between the cancer cell and the inflammatory microenvironment, we identified GFI1 as a gating regulator responsible for a constitutively activated signalling circuit that renders CRC cells competent for metastatic spread. Further analysis of mouse models with metastatic CRC and human clinical specimens reinforced the influence of GFI1 downregulation in promoting CRC metastatic spread. The novel role of GFI1 is uncovered for the first time in a human solid tumour such as CRC. Our results imply that GFI1 is a potential therapeutic target for interfering with inflammation-induced CRC progression and spread.

Extracellular matrix and the myeloid-in-myeloma compartment: balancing tolerogenic and immunogenic inflammation in the myeloma niche

The last 10-15 years have witnessed a revolution in treating multiple myeloma, an incurable cancer of Ab-producing plasma cells. Advances in myeloma therapy were ushered in by novel agents that remodel the myeloma immune microenvironment. The first generation of novel agents included immunomodulatory drugs (thalidomide analogs) and proteasome inhibitors that target crucial pathways that regulate immunity and inflammation, such as NF-κB. This paradigm continued with the recent regulatory approval of mAbs (elotuzumab, daratumumab) that impact both tumor cells and associated immune cells. Moreover, recent clinical data support checkpoint inhibition immunotherapy in myeloma. With the success of these agents has come the growing realization that the myeloid infiltrate in myeloma lesions-what we collectively call the myeloid-in-myeloma compartment-variably sustains or deters tumor cells by shaping the inflammatory milieu of the myeloma niche and by promoting or antagonizing immune-modulating therapies. The myeloid-in-myeloma compartment includes myeloma-associated macrophages and granulocytes, dendritic cells, and myeloid-derived-suppressor cells. These cell types reflect variable states of differentiation and activation of tumor-infiltrating cells derived from resident myeloid progenitors in the bone marrow-the canonical myeloma niche-or myeloid cells that seed both canonical and extramedullary, noncanonical niches. Myeloma-infiltrating myeloid cells engage in crosstalk with extracellular matrix components, stromal cells, and tumor cells. This complex regulation determines the composition, activation state, and maturation of the myeloid-in-myeloma compartment as well as the balance between immunogenic and tolerogenic inflammation in the niche. Redressing this balance may be a crucial determinant for the success of antimyeloma immunotherapies.

The Role of IL-33-Dependent Inflammation in the Tumor Microenvironment

There is compelling evidence that inflammation contributes to tumorigenesis. Inflammatory mediators within the tumor microenvironment can either promote an antitumor immune response or support tumor pathogenesis. Therefore, it is critical to determine the relative contribution of tumor-associated inflammatory pathways to cancer development. Interleukin-33 (IL-33) is a member of the IL-1 family of cytokines that is released upon tissue stress or damage to operate as an alarmin. IL-33 has been primarily implicated in the induction of type-2 immune responses. However, recent findings have shown a role of IL-33 in several cancers where it may exert multiple functions. In this review, we will present the current knowledge on the role of IL-33 in the microenvironment of different tumors. We will highlight which cells produce and which cells are activated by IL-33 in cancer. Furthermore, we will explain how IL-33 modulates the tumor-associated inflammatory microenvironment to restrain or promote tumorigenesis. Finally, we will discuss the issues to be addressed first before potentially targeting the IL-33 pathway for cancer therapy.

Myeloid-derived suppressor cells and myeloid regulatory cells in cancer and autoimmune disorders

Myeloid-derived suppressor cells (MDSCs) were originally described as a heterogeneous population of immature cells derived from myeloid progenitors with immune-suppressive functions in tumor-bearing hosts. In recent years, increasing number of studies have described various populations of myeloid cells with MDSC-like properties in murine models of cancer and autoimmune diseases. These studies have observed that the populations of MDSCs are increased during inflammation and autoimmune conditions. In addition, MDSCs can effectively suppress T cell responses and modulate the activity of natural killer cells and other myeloid cells. MDSCs have also been implicated in the induction of regulatory T cell production. Furthermore, these cells have the potential to suppress the autoimmune response, thereby limiting tissue injury. Myeloid regulatory cells (Mregs) are recently attracting increasing attention, since they function in proinflammatory and immune suppression in autoimmune diseases, as well as in various types of cancer. Currently, research focus is directed from MDSCs to Mregs in cancer and autoimmune diseases. The present study reviewed the suppressive roles of MDSCs in various autoimmune murine models, the immune modulation of MDSCs to T helper 17 lymphocytes, as well as the proinflammatory and immunosuppressive roles of Mregs in various types of cancer and autoimmune diseases.

Monomeric annexin A2 is an oxygen-regulated toll-like receptor 2 ligand and adjuvant

BACKGROUND

Annexin A2 (ANXA2) is a pleiotropic, calcium-dependent, phospholipid-binding protein with a broad tissue distribution. It can be intracellular, membrane-bound, or secreted, and it exists as a monomer or heterotetramer. The secreted ANXA2 heterotetramer signals human and murine macrophages to produce IL-1, IL-6, and TNF-α through TLR4/MyD88- and TRIF-dependent pathways.

METHODS

GL261 glioma cells were cultured in 5 % or 20 % O2. Monomeric ANXA2 (ANXA2m) was identified as a TLR2-binding protein enriched in 5 % O2 by mass spectrometry. Purified ANXA2m and ANXA2-derived peptides were added to TLR2-expressing reporter cells and immature dendritic cells (DCs) cells in vitro. ANXA2m was then mixed with chicken ovalbumin (OVA) for vaccination of TLR2 (+/+) and TLR2 (-/-) mice for subsequent quantification of antigen-specific CD8(+) T cell responses. The TLR2-binding region of ANXA2m was determined using various peptides derived from the ANXA2 amino terminus on TLR2 reporter cells and in vaccinated mice.

RESULTS

ANXA2m is overexpressed by murine glioblastoma GL261 cells grown under 5 % O2, but not atmospheric 20 % O2, and acts as an adjuvant by inducing murine and human DC maturation through TLR2. ANXA2m upregulates CD80 and CD86 expression, enhances antigen cross-presentation, and induces the secretion of IL-12p70, TNF-α, and IFN-γ. The amino-terminal 15 amino acids of ANXA2m are necessary and sufficient for TLR2 binding and DC activation.

CONCLUSION

This novel finding adds to the known functions of ANXA2 and suggests ways to exploit it as a vaccine adjuvant. ANXA2-antigen fusion peptides could be developed for patients as "off-the-shelf" agents containing common tumor antigens. Alternatively, they could be "personalized" and synthesized after tumor sequencing to identify immunogenic tumor-specific neo-antigens. As the amino terminal 15 amino acids of ANXA2 are required to stimulate TLR2 activity, a fusion peptide could be as short as 30 amino acids if one or two CD8 T cell epitopes are fused to the ANXA2 amino terminal portion. Future work will address the efficacy of ANXA2 peptide fusions alone and in combination with established TLR agonists to induce synergy in preclinical models of glioma as observed in other vaccines.

Uygur medicine Xipayi Kui Jie'an affects gene expression profiles in intestinal tissue lesions in a rat model of ulcerative colitis

Background

The aim of this study was to investigate the mechanisms underlying the therapeutic effect of Uygur medicine KJA on UC in a rat model.

Methods

UC was induced in Wistar rats by application of 2, 4-dinitrochlorobenzene and acetic acid and were then treated with three different doses of KJA, and normal saline as control. After treatment for 20 days, the gene expression profile of colonic tissue was analyzed by microarray and verified by quantitative real-time RT-PCR.

Results

Animals treated with the three different doses of KJA were compared with normal saline controls, wherein microarray analysis identified 1991, 2163, and 1677 differentially expressed genes respectively, of which 444 genes were raised and 670 genes were decrease spliced together in the three doses tested. The KEGG pathway analyses found commonly raised genes related to several different biological functions. Interesting genes included TRL2, IL-1β, TGF-β1, and NF-κB were confirmed by quantitative PCR.

Conclusions

The therapeutic effect of KJA on UC is likely explained by specific effects on the expression of genes, which are the effector molecules known to be involved in the development of UC. Further studies on differentially expressed genes will help explain the mechanism of action of Uygur medicine KJA.

HIC1 Tumor Suppressor Loss Potentiates TLR2/NF-κB Signaling and Promotes Tissue Damage-Associated Tumorigenesis

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.

Integrative approach detected association between genetic variants of microRNA binding sites of TLRs pathway genes and OSCC susceptibility in Chinese Han population

Oral squamous cell carcinoma (OSCC) is a leading malignancy worldwide; the overall 5-year survival rate is approximately 50%. A variety of proteins in Toll-like receptors (TLRs) pathway have been related with the risk of OSCC. However, the influence of genetic variations in TLRs pathway genes on OSCC susceptibility is unclear. Previous studies mainly focused on the coding region of genes, while the UTR region remains unstudied. In the current study, a bioinformatics approach was performed to select candidate single nucleotide polymorphisms (SNPs) on microRNA binding sites of TLRs pathway genes related with OSCC. After screening 90 OSCC related TLRs pathway genes, 16 SNPs were selected for genotyping. We found that rs5030486, the polymorphisms on 3′ UTR of TRAF6, was significantly associated with OSCC risk. AG genotype of TRAF6 was strongly associated with a decreased risk of OSCC (OR = 0.252; 95% CI = 0.106, 0.598; p = 0.001). In addition, AG genotype was also related with a reduced risk of OSCC progression both in univariable analysis (HR = 0.303, 95% CI = 0.092, 0.995) and multivariable analysis (HR = 0.272, 95% CI = 0.082, 0.903). Furthermore, after detecting the mRNA expression level of TRAF6 in 24 OSCC patients, we found that TRAF6 expression level was significantly different between patients carrying different genotypes at locus rs5030486 (p = 0.013), indicating that rs5030486 of TRAF6 might contribute to OSCC risk by altering TRAF6 expression level. In general, these data indicated that SNP rs5030486 could be a potential bio-marker for OSCC risk and our results might provide new insights into the association of polymorphisms within the non-coding area of genes with cancers.

Alterations of gene expression and protein synthesis in co-cultured adipose tissue-derived stem cells and squamous cell-carcinoma cells: consequences for clinical applications

Introduction

This is the first study evaluating the interactions of human adipose tissue derived stem cells (ADSCs) and human squamous cell carcinoma cells (SCCs), with regard to a prospective cell-based skin regenerative therapy and a thereby unintended co-localization of ADSCs and SCCs.

Methods

ADSCs were co-cultured with A431-SCCs and primary SCCs (pSCCs) in a transwell system, and cell-cell interactions were analyzed by assessing doubling time, migration and invasion, angiogenesis, quantitative real time PCR of 229 tumor associated genes, and multiplex protein assays of 20 chemokines and growth factors and eight matrix metalloproteinases (MMPS). Results of co-culture were compared to those of the respective mono-culture.

Results

ADSCs’ proliferation on the plate was significantly increased when co-cultured with A431-SCCs (P = 0.038). PSCCs and ADSCs significantly decreased their proliferation in co-culture if cultured on the plate (P <0.001 and P = 0.03). The migration of pSCC was significantly increased in co-culture (P = 0.009), as well as that of ADSCs in A431-SCC-co-culture (P = 0.012). The invasive behavior of pSCCs and A431-SCCs was significantly increased in co-culture by a mean of 33% and 35%, respectively (P = 0.038 and P <0.001). Furthermore, conditioned media from co-cultured ADSC-A431-SCCs and co-cultured ADSCs-pSCCs induced tube formation in an angiogenesis assay in vitro.

In A431-SCC-co-culture 36 genes were up- and 6 were down-regulated in ADSCs, in A431-SCCs 14 genes were up- and 8 genes were down-regulated. In pSCCs-co-culture 36 genes were up-regulated in ADSCs, two were down-regulated, one gene was up-regulated in pSCC, and three genes were down-regulated. Protein expression analysis revealed that three proteins were exclusively produced in co-culture (CXCL9, IL-1b, and MMP-7). In A431-SCC-co-culture the concentration of 17 proteins was significantly increased compared to the ADSCs mono-culture (2.8- to 357-fold), and 15 proteins were expressed more highly (2.8- to 1,527-fold) compared to the A431-SCCs mono-culture. In pSCC-co-culture the concentration of 10 proteins was increased compared to ADSCs-mono-culture (2.5- to 77-fold) and that of 15 proteins was increased compared to pSCC mono-culture (2.6- to 480-fold).

Conclusions

This is the first study evaluating the possible interactions of primary human ADSCs with human SCCs, pointing towards a doubtlessly increased oncological risk, which should not be neglected when considering a clinical use of isolated human ADSCs in skin regenerative therapies.

Transformed epithelia trigger non-tissue-autonomous tumor suppressor response by adipocytes via activation of Toll and Eiger/TNF signaling

High tumor burden is associated with increased levels of circulating inflammatory cytokines that influence the pathophysiology of the tumor and its environment. The cellular and molecular events mediating the organismal response to a growing tumor are poorly understood. Here, we report a bidirectional crosstalk between epithelial tumors and the fat body-a peripheral immune tissue-in Drosophila. Tumors trigger a systemic immune response through activation of Eiger/TNF signaling, which leads to Toll pathway upregulation in adipocytes. Reciprocally, Toll elicits a non-tissue-autonomous program in adipocytes, which drives tumor cell death. Hemocytes play a critical role in this system by producing the ligands Spätzle and Eiger, which are required for Toll activation in the fat body and tumor cell death. Altogether, our results provide a paradigm for a long-range tumor suppression function of adipocytes in Drosophila, which may represent an evolutionarily conserved mechanism in the organismal response to solid tumors.

Animal models and the tumor microenvironment: studies of tumor-host symbiosis

The contributions of murine models to elucidation of processes central to tumor growth are reviewed. Localized acidosis, increased interstitial pressure, perturbations in structure and function of the extracellular matrix, hypoxia, angiogenesis, and co-optation of the immune response are all phenomena that promote tumor survival and metastasis. The use of animal models is critical to understanding the pathophysiology of these processes and the development of more effective cancer therapies.

Regulation of innate immune responses by transmembrane interactions: lessons from the TLR family

The mammalian innate immune response is responsible for the early stages of defense against invading pathogens. One of the major receptor families facilitating innate immune activation is the Toll-like receptor (TLR) family. These receptors are type 1 membrane proteins spanning the membrane with a single transmembrane domain (TMD). All TLRs form homo- and hetero-dimers within membranes and new data suggest that the single transmembrane domain of some of these receptors is involved in their dimerization and function. Newly identified TLR dimers are continuously reported but only little is known about the importance of the TMDs for their dimer assembly and signaling regulation. Uncontrolled or untimely activation of TLRs is related to a large number of pathologies ranging from cystic fibrosis to sepsis and cancer. In this review we will focus on the contribution of the TMDs of innate immune receptors - specifically TLR2-to their regulation and function. In addition, we will address the current issues remaining to be solved regarding the mechanistic insights of this regulation. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.

Primary tumours modulate innate immune signalling to create pre-metastatic vascular hyperpermeability foci

In mouse models of lung metastasis, before the appearance of significant metastases, localized changes in vascular permeability have been observed, which appear to set the stage for tumour growth. However, it is unclear whether this is also true in human patients. Here, we show that MD-2, a coreceptor for Toll-like receptor 4 that has a key role in the innate immune response, triggers the formation of regions of hyperpermeability in mice by upregulating C-C chemokine receptor type 2 (CCR2) expression. The CCR2–CCL2 system induces the abundant secretion of permeability factors such as serum amyloid A3 and S100A8. Disruption of MD-2 or CCR2 abrogates the formation of hyperpermeable regions, resulting in reduced tumour cell homing. Furthermore, fibrinogen, which is processed during permeability-mediated coagulation, is also localized in areas of elevated CCR2 expression in tumour-bearing human lungs. Our findings raise the possibility that CCR2 upregulation might represent a marker for regions of increased susceptibility to metastatic homing in lung cancer.

Tumours are thought to pave the way for metastases to distant organs by secreting factors create regions of increased vascular permeability. Hiratsuka et al. identify innate immune pathways that underlie this process in the pre-metastatic lungs of tumour-bearing mice and patients.

Toll-like receptor 2 mediates microglia/brain macrophage MT1-MMP expression and glioma expansion

BACKGROUND

Glioblastomas are the most aggressive primary brain tumors in humans. Microglia/brain macrophage accumulation in and around the tumor correlates with malignancy and poor clinical prognosis of these tumors. We have previously shown that microglia promote glioma expansion through upregulation of membrane type 1 matrix metalloprotease (MT1-MMP). This upregulation depends on signaling via the Toll-like receptor (TLR) adaptor molecule myeloid differentiation primary response gene 88 (MyD88).

METHODS

Using in vitro, ex vivo, and in vivo techniques, we identified TLR2 as the main TLR controlling microglial MT1-MMP expression and promoting microglia-assisted glioma expansion.

RESULTS

The implantation of mouse GL261 glioma cells into TLR2 knockout mice resulted in significantly smaller tumors, reduced MT1-MMP expression, and enhanced survival rates compared with wild-type control mice. Tumor expansion studied in organotypic brain slices depended on both parenchymal TLR2 expression and the presence of microglia. Glioma-derived soluble factors and synthetic TLR2 specific ligands induced MT1-MMP expression in microglia from wild-type mice, but no such change in MT1-MMP gene expression was observed in microglia from TLR2 knockout mice. We also found evidence that TLR1 and TLR6 cofunction with TLR2 as heterodimers in regulating MT1-MMP expression in vitro.

CONCLUSIONS

Our results thus show that activation of TLR2 along with TLRs 1 and/or 6 converts microglia into a glioma supportive phenotype.

The cardioprotective protein apolipoprotein A1 promotes potent anti-tumorigenic effects

Here, we show that apolipoprotein A1 (apoA1), the major protein component of high density lipoprotein (HDL), through both innate and adaptive immune processes, potently suppresses tumor growth and metastasis in multiple animal tumor models, including the aggressive B16F10L murine malignant melanoma model. Mice expressing the human apoA1 transgene (A1Tg) exhibited increased infiltration of CD11b(+) F4/80(+) macrophages with M1, anti-tumor phenotype, reduced tumor burden and metastasis, and enhanced survival. In contrast, apoA1-deficient (A1KO) mice showed markedly heightened tumor growth and reduced survival. Injection of human apoA1 into A1KO mice inoculated with tumor cells remarkably reduced both tumor growth and metastasis, enhanced survival, and promoted regression of both tumor and metastasis burden when administered following palpable tumor formation and metastasis development. Studies with apolipoprotein A2 revealed the anti-cancer therapeutic effect was specific to apoA1. In vitro studies ruled out substantial direct suppressive effects by apoA1 or HDL on tumor cells. Animal models defective in different aspects of immunity revealed both innate and adaptive arms of immunity contribute to complete apoA1 anti-tumor activity. This study reveals a potent immunomodulatory role for apoA1 in the tumor microenvironment, altering tumor-associated macrophages from a pro-tumor M2 to an anti-tumor M1 phenotype. Use of apoA1 to redirect in vivo elicited tumor-infiltrating macrophages toward tumor rejection may hold benefit as a potential cancer therapeutic.

TLR2 enhances ovarian cancer stem cell self-renewal and promotes tumor repair and recurrence

Primary ovarian cancer is responsive to treatment, but chemoresistant recurrent disease ensues in majority of patients. Recent compelling evidence demonstrates that a specific population of cancer cells, the cancer stem cells, initiates and sustains tumors. It is therefore possible that this cell population is also responsible for recurrence. We have shown previously that CD44+/MyD88+ epithelial ovarian cancer stem cells (CD44+/MyD88+ EOC stem cells) are responsible for tumor initiation. In this study, we demonstrate that this population drives tumor repair following surgery- and chemotherapy-induced tumor injury. Using in vivo and in vitro models, we also demonstrate that during the process of tumor repair, CD44+/MyD88+ EOC stem cells undergo self-renewal as evidenced by upregulation of stemness-associated genes. More importantly, we show that a pro-inflammatory microenvironment created by the TLR2-MyD88-NFκB pathway supports EOC stem cell-driven repair and self-renewal. Overall, our findings point to a specific cancer cell population, the CD44+/MyD88+ EOC stem cells and a specific pro-inflammatory pathway, the TLR2-MyD88-NFκB pathway, as two of the required players promoting tumor repair, which is associated with enhanced cancer stem cell load. Identification of these key players is the first step in elucidating the steps necessary to prevent recurrence in EOC patients.