Myeloid cell RelA/p65 promotes lung cancer proliferation through Wnt/β-catenin signaling in murine and human tumor cells

Genomic crosstalk between carbachol, a muscarinic receptor agonist, and the long-acting β2-adrenoceptor agonist, indacaterol, in human airway epithelial cells

Many patients with chronic obstructive pulmonary disease are susceptible to recurrent exacerbations. In this study, we hypothesized that endogenous acetylcholine (ACh) may act as a proinflammatory mediator because long-acting muscarinic receptor antagonists protect against exacerbations, which have an inflammatory basis. This possibility was explored by determining if carbachol (CCh), a stable ACh analog, was a genomic stimulus in BEAS-2B bronchial epithelial cells. The ability of CCh to interact with indacaterol (Ind), a long-acting β2-adrenoceptor agonist, was also assessed given that (1) sympathomimetic bronchodilators can promote adverse gene expression changes in airway structural cells, and (2) crosstalk between β2-adrenoceptor and Gq-coupled muscarinic receptor agonists is well described. Unlike Ind, which induced 624 unique genes, CCh was a relatively weak genomic stimulus, implying that ACh may not behave as a proinflammatory mediator as hypothesized. Nevertheless, checkerboard assays using BEAS-2B cells expressing a cAMP-response element luciferase reporter determined that CCh interacted with Ind in a supra-additive manner and that this interaction was replicated on 39 Ind-regulated genes. Functional annotation of the Ind-regulated transcriptomes identified "transcription" and "signalling" as the dominant themes, with gene ontology terms associated with "inflammation" and "immune processes" being highly represented. A comparable gene ontology signature was obtained when Ind and CCh were combined; however, the number, magnitude and duration of gene expression changes were significantly enhanced. If genomic interactions occur between a long-acting β2-adrenoceptor agonist and ACh in vivo, then they may enhance the expression of adverse-effect genes that could maintain, or even augment, features of lung pathology in chronic obstructive pulmonary disease. SIGNIFICANCE STATEMENT: Long-acting muscarinic receptor antagonists reduce exacerbation risk in chronic obstructive pulmonary disease, implying the etiology could have an inflammatory basis mediated by acetylcholine. However, in BEAS-2B cells, carbachol was a weak genomic stimulus, although it enhanced changes in indacaterol-regulated gene expression. Functional annotation of carbachol + indacaterol-regulated genes identified gene ontology terms associated with several themes, including inflammation. Interaction between a long-acting β2-adrenoceptor agonist and endogenous acetylcholine could, paradoxically, augment airway inflammation in patients with chronic obstructive pulmonary disease.

hERG activators exhibit antitumor effects in breast cancer through calcineurin and β-catenin-mediated signaling pathways

Background

Breast cancer remains a leading cause of mortality among women worldwide, with existing therapeutic options often accompanied by significant side effects and a persistent risk of disease recurrence. This highlights the need for novel drug candidates with new mechanisms of action by targeting alternative signaling pathways. While hERG channel is notoriously regarded as an off-target due to drug-induced cardiotoxicity, its therapeutic potential as a drug target remains largely unexplored.

Methods

This study investigated the role of hERG in breast cancer progression and its impact on patient survival. The anti-proliferative, anti-migratory, anti-invasive and pro-apoptotic effects of hERG activators were evaluated using the Cell Counting Kit-8, wound healing assay, transwell assay and cell apoptosis assay, respectively. Western blotting, Ca2+ imaging and immunofluorescence assays were employed to study their antitumor mechanisms of actions.

Results

We identified two novel hERG activators, SDUY429 and SDUY436, which effectively inhibited the proliferation and migration of MDA-MB-231 and MCF-7 cells. In addition, SDUY436 demonstrated significant anti-invasive and pro-apoptotic effects in MDA-MB-231 cells. Mechanistically, the anti-proliferative activity of hERG activators were mediated through calcineurin activation via enhanced calcium ion influx, which facilitated the nuclear translocation of nuclear factor of activated T cells (NFAT) and upregulated p21Waf/Cip expression. Furthermore, both SDUY429 and SDUY436 remarkably suppressed the migration and invasion of MDA-MB-231 cells by downregulating the protein kinase B (AKT)/glycogen synthase kinase-3 beta (GSK3β)/β-catenin signaling pathway. The observed reduction in phospho-AKT-Ser473 (pAKTS473) expression resulted in the decreased levels of phospho-GSK3β-Ser9 (pGSK3βS9), thereby limiting the nuclear localization of β-catenin, which led to the inhibition of cell migration and invasion. Notably, combining SDUY429 or SDUY436 with the AKT inhibitor MK-2206 produced synergistic anti-proliferative effects.

Conclusion

These findings suggest that hERG activators hold promise as new potential therapeutic agents for the treatment of breast cancer, paving the way for future investigations into their clinical applications.

p65 signaling dynamics drive the developmental progression of hematopoietic stem and progenitor cells through cell cycle regulation

Most gene functions have been discovered through phenotypic observations under loss of function experiments that lack temporal control. However, cell signaling relies on limited transcriptional effectors, having to be re-used temporally and spatially within the organism. Despite that, the dynamic nature of signaling pathways have been overlooked due to the difficulty on their assessment, resulting in important bottlenecks. Here, we have utilized the rapid and synchronized developmental transitions occurring within the zebrafish embryo, in conjunction with custom NF-kB reporter embryos driving destabilized fluorophores that report signaling dynamics in real time. We reveal that NF-kB signaling works as a clock that controls the developmental progression of hematopoietic stem and progenitor cells (HSPCs) by two p65 activity waves that inhibit cell cycle. Temporal disruption of each wave results in contrasting phenotypic outcomes: loss of HSPCs due to impaired specification versus proliferative expansion and failure to delaminate from their niche. We also show functional conservation during human hematopoietic development using iPSC models. Our work identifies p65 as a previously unrecognized contributor to cell cycle regulation, revealing why and when pro-inflammatory signaling is required during HSPC development. It highlights the importance of considering and leveraging cell signaling as a temporally dynamic entity.

Inference of gene regulatory networks based on directed graph convolutional networks

Inferring gene regulatory network (GRN) is one of the important challenges in systems biology, and many outstanding computational methods have been proposed; however there remains some challenges especially in real datasets. In this study, we propose Directed Graph Convolutional neural network-based method for GRN inference (DGCGRN). To better understand and process the directed graph structure data of GRN, a directed graph convolutional neural network is conducted which retains the structural information of the directed graph while also making full use of neighbor node features. The local augmentation strategy is adopted in graph neural network to solve the problem of poor prediction accuracy caused by a large number of low-degree nodes in GRN. In addition, for real data such as E.coli, sequence features are obtained by extracting hidden features using Bi-GRU and calculating the statistical physicochemical characteristics of gene sequence. At the training stage, a dynamic update strategy is used to convert the obtained edge prediction scores into edge weights to guide the subsequent training process of the model. The results on synthetic benchmark datasets and real datasets show that the prediction performance of DGCGRN is significantly better than existing models. Furthermore, the case studies on bladder uroepithelial carcinoma and lung cancer cells also illustrate the performance of the proposed model.

RELA promotes the progression of oral squamous cell carcinoma via TFAP2A-Wnt/β-catenin signaling

Oral squamous cell carcinoma (OSCC) has emerged as the most prevailing oral malignancy worldwide, characterized by cervical solid lymph node metastasis and strong local invasiveness. Overexpression of Transcription Factor AP-2 alpha (TFAP2A) is observed in a significant proportion of OSCC cases. In this study, we aimed to elucidate the function of TFAP2A in the progression of OSCC and the related molecular signaling pathways. The role of RELA was predicted using bioinformatics analysis. The mRNA abundances of RELA, TFAP2A, and β-catenin were assessed by Western blot and quantitative real-timePCR. The relationship between RELA, TFAP2A, and β-catenin and their correlation with clinicopathological characteristics of OSCC was evaluated. The target of RELA and TFAP2A was identified by the chromatin immunoprecipitation as well as luciferase reporter assay. The colony formation assay and MTS assay were performed to determine the proliferative level of OSCC cells. OSCC cell motility was determined by Transwell assay and wound-healing assay. The protein expressions of epithelial-mesenchymal transition-associated factors were evaluated by Western blot. The expressions of RELA and TFAP2A were elevated in OSCC, and their expressions displayed a positive correlation. The expression levels of RELA and TFAP2A were found to be associated with TNM staging and lymphatic metastasis of OSCC patients. RELA upregulation promoted OSCC progression, as manifested by increased levels of proliferation, invasion, and migration of OSCC cells. We also demonstrated that RELA was directly bound to the promoter of TFAP2A transcription, which activated multiple malignant and metastatic phenotypes. Furthermore, TFAP2A activated the Wnt/β-catenin signaling by targeting the promoter regions of β-catenin. The study found that RELA is critical for promoting the progression of OSCC via the RELA-TFAP2A-Wnt/β-catenin signaling pathway. The RELA-TFAP2A-Wnt/β-catenin signaling pathway is a potential target for reducing the aggressiveness of OSCC.

Explore the mechanism and substance basis of Mahuang FuziXixin Decoction for the treatment of lung cancer based on network pharmacology and molecular docking

BACKGROUND

Mahuang FuziXixin Decoction (MFXD) is a classic Chinese herbal formula for the treatment of lung cancer. However, its mechanisms of action are unclear. In present study, network pharmacology and molecular docking technology were employed to investigate the molecular mechanism and substance basis of MFXD for the treatment of lung cancer.

METHOD

The active compounds and corresponding targets of MFXD were collected through the TCMSP database. OMIM and GeneCards databases were applied to filter the targets of lung cancer. The protein-protein interaction (PPI) were acquired through the STRING platform. Metascape and the Bioinformatics server were used for the visualization of GO and KEGG analysis. The tissue and organ distribution of targets was evaluated based on the BioGPS database. The binding affinity between potential targets and active compounds was evaluated by molecular docking.

RESULT

A total of 51 active compounds and 118 targets of MFXD were collected. The target with a higher degree were identified through the PPI network, namely AR, RELA, NCOA1, EGFR, FOS, CCND1, ESR1 and HSP90AA1. GO and KEGG analysis suggested that MFXD treatment of lung cancer mainly involves hormone and response to inorganic substance, transcription regular complex, transcription factor binding and Pathways in cancer. Experimental validation showed that MFXD treatment inhibited the proliferation of NSCLC cells through downregulation the expression of EGFR, HIF1A, NCOA1 and RELA. Moreover, molecular docking revealed that hydrogen bond and hydrophobic interaction contribute to the binding of the compounds to targets.

CONCLUSION

Our findings comprehensively elucidated the actives, potential targets, and molecular mechanisms of MFXD against lung cancer, providing a promising strategy for the scientific basis and therapeutic mechanism of traditional Chinese medicine prescriptions for the treatment of the disease.

Transcriptome analysis of adipocytokines and their-related LncRNAs in lung adenocarcinoma revealing the association with prognosis, immune infiltration, and metabolic characteristics

Lung adenocarcinoma (LUAD) is amongst the major contributors to cancer-related deaths on a global scale. Adipocytokines and long non-coding RNAs (lncRNAs) are indispensable participants in cancer. We performed a pan-cancer analysis of the mRNA expression, single nucleotide variation, copy number variation, and prognostic value of adipocytokines. LUAD samples were obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Simultaneously, train, internal and external cohorts were grouped. After a stepwise screening of optimized genes through least absolute shrinkage and selection operator regression analysis, random forest algorithm,, and Cox regression analysis, an adipocytokine-related prognostic signature (ARPS) with superior performance compared with four additional well-established signatures for survival prediction was constructed. After determination of risk levels, the discrepancy of immune microenvironment, immune checkpoint gene expression, immune subtypes, and immune response in low- and high-risk cohorts were explored through multiple bioinformatics methods. Abnormal pathways underlying high- and low-risk subgroups were identified through gene set enrichment analysis (GSEA). Immune-and metabolism-related pathways that were correlated with risk score were selected through single sample GSEA. Finally, a nomogram with satisfied predictive survival probability was plotted. In summary, this study offers meaningful information for clinical treatment and scientific investigation.

Kruppel-like factor 13 inhibits cell proliferation of gastric cancer by inducing autophagic degradation of β-catenin

Zinc protein KLF13 is a tumor-suppressive member of Kruppel-like factors family, and yet the effect of KLF13 on gastric cancer has not been reported. Here, we aimed to investigate the role of KLF13 in gastric cancer and explored underlying molecular mechanisms. Firstly, it was found that KLF13 expression was significantly decreased in gastric cancer tissues and cancer cells compared with adjacent normal tissues and normal gastric epithelial cells, respectively. KEGG_Pathway and GO_BP analyses suggested that KLF13 was associated with CELL_CYCLE and CELL_PROLIFERATION. Then, our results further demonstrated that KLF13 could obviously inhibit gastric cancer proliferation and induce cell arrest at G2/M phase. Mechanistically, KLF13 decreased expressions of β-catenin and its target genes, CCND1 and MYC, via triggering autophagic degradation of β-catenin. KLF13 up-regulation facilitated co-localization and binding of β-catenin with autophagy protein p62, and exogenous overexpression of β-catenin or blocking autophagy process appeared to reverse KLF13-induced inhibition of gastric cancer proliferation. Furthermore, KLF13 overexpression promoted the expression of ubiquitin-conjugating enzyme E2, Ubc13 which is responsible for catalyzing the synthesis of 'Lys-63'-linked polyubiquitin chains and increased the binding of β-catenin with E3 ubiquitin ligase, TRAF6. In vivo, KLF13 overexpression also suppressed xenograft tumor growth of gastric cancer and down-regulated expressions of Ki67, β-catenin, Cyclin D1, and c-Myc in tumor tissues. Collectively, these data firstly demonstrated the involvement of KLF13 in inhibiting cell proliferation of gastric cancer through promoting autophagy-dependent degradation of β-catenin, which reinforced the evidence for suppressive roles of KLF13 in human tumors.

LiCl-induced immunomodulatory periodontal regeneration via the activation of the Wnt/β-catenin signaling pathway

Background

Growing evidence suggests that excessive inflammation hampers the regenerative capacity of periodontal ligament cells (PDLCs) and that activation of the Wnt/β‐catenin pathway is crucial in suppressing immune dysregulation.

Objective

This study aimed to establish the role of the Wnt/β‐catenin in regulating the immune microenvironment and its subsequent impact on periodontal regeneration.

Methods

Lithium chloride (LiCl, Wnt activator) was administered daily into the standard periodontal defects created in 12‐week‐old Lewis rats. Harvested at 1‐week and 2‐week post‐surgery, samples were then subjected to histological and immunohistochemical evaluation of macrophage distribution and phenotype (pro‐inflammatory M1 and anti‐inflammatory M2). A murine macrophage cell line, RAW 264.7, was stimulated with LiCl to activate Wnt/β‐catenin. Following treatment with the conditioned medium derived from the LiCl‐activated macrophages, the expression of bone‐ and cementum‐related markers of the PDLCs was determined. The involvement of Wnt/β‐catenin in the immunoregulation and autophagic activity was further investigated with the addition of cardamonin, a commercially available Wnt inhibitor.

Results

A significantly increased number of macrophages were detected around the defects during early healing upon receiving the Wnt/β‐catenin signaling cue. The defect sites in week 2 exhibited fewer M1 and more M2 macrophages along with an enhanced regeneration of alveolar bone and cementum in the Wnt/β‐catenin activation group. LiCl‐induced immunomodulatory effect was accompanied with the activation Wnt/β‐catenin signaling, which was suppressed in the presence of Wnt inhibitor. Exposure to LiCl could induce autophagy in a dose‐dependent manner, thus maintaining macrophages in a regulatory state. The expression level of bone‐ and cementum‐related markers was significantly elevated in PDLCs stimulated with LiCl‐activated macrophages.

Conclusion

The application of Wnt activator LiCl facilitates the recruitment of macrophages to defect sites and regulates their phenotypic switching in favor of periodontal regeneration. Suppression of Wnt/β‐catenin pathway could attenuate the LiCl‐induced immunomodulatory effect. Taken together, the Wnt/β‐catenin pathway may be targeted for therapeutic interventions in periodontal diseases.

TLR/WNT: A Novel Relationship in Immunomodulation of Lung Cancer

The most frequent cause of death by cancer worldwide is lung cancer, and the 5-year survival rate is still very poor for patients with advanced stage. Understanding the crosstalk between the signaling pathways that are involved in disease, especially in metastasis, is crucial to developing new targeted therapies. Toll-like receptors (TLRs) are master regulators of the immune responses, and their dysregulation in lung cancer is linked to immune escape and promotes tumor malignancy by facilitating angiogenesis and proliferation. On the other hand, over-activation of the WNT signaling pathway has been reported in lung cancer and is also associated with tumor metastasis via induction of Epithelial-to-mesenchymal-transition (EMT)-like processes. An interaction between both TLRs and the WNT pathway was discovered recently as it was found that the TLR pathway can be activated by WNT ligands in the tumor microenvironment; however, the implications of such interactions in the context of lung cancer have not been discussed yet. Here, we offer an overview of the interaction of TLR-WNT in the lung and its potential implications and role in the oncogenic process.

FERMT3 mediates cigarette smoke-induced epithelial-mesenchymal transition through Wnt/β-catenin signaling

Background

Cigarette smoking is a major risk factor for chronic obstructive pulmonary disease (COPD) and lung cancer. Epithelial–mesenchymal transition (EMT) is an essential pathophysiological process in COPD and plays an important role in airway remodeling, fibrosis, and malignant transformation of COPD. Previous studies have indicated FERMT3 is downregulated and plays a tumor-suppressive role in lung cancer. However, the role of FERMT3 in COPD, including EMT, has not yet been investigated.

Methods

The present study aimed to explore the potential role of FERMT3 in COPD and its underlying molecular mechanisms. Three GEO datasets were utilized to analyse FERMT3 gene expression profiles in COPD. We then established EMT animal models and cell models through cigarette smoke (CS) or cigarette smoke extract (CSE) exposure to detect the expression of FERMT3 and EMT markers. RT-PCR, western blot, immunohistochemical, cell migration, and cell cycle were employed to investigate the potential regulatory effect of FERMT3 in CSE-induced EMT.

Results

Based on Gene Expression Omnibus (GEO) data set analysis, FERMT3 expression in bronchoalveolar lavage fluid was lower in COPD smokers than in non-smokers or smokers. Moreover, FERMT3 expression was significantly down-regulated in lung tissues of COPD GOLD 4 patients compared with the control group. Cigarette smoke exposure reduced the FERMT3 expression and induces EMT both in vivo and in vitro. The results showed that overexpression of FERMT3 could inhibit EMT induced by CSE in A549 cells. Furthermore, the CSE-induced cell migration and cell cycle progression were reversed by FERMT3 overexpression. Mechanistically, our study showed that overexpression of FERMT3 inhibited CSE-induced EMT through the Wnt/β-catenin signaling.

Conclusions

In summary, these data suggest FERMT3 regulates cigarette smoke-induced epithelial–mesenchymal transition through Wnt/β-catenin signaling. These findings indicated that FERMT3 was correlated with the development of COPD and may serve as a potential target for both COPD and lung cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01881-y.

Methods to Detect NF-κB Activity in Tumor-Associated Macrophage (TAM) Populations

Macrophages are an abundant population in the tumor-infiltrating immune cells. The transcription factor NF-κB plays an important role in the response of tumor-associated macrophages (TAMs) to the tumor environmental cues. Detecting NF-κB activity in TAMs will help define the functional status of the TAMs. In this article, we describe several methods to detect NF-κB activity in TAM populations.

Vimentin loss promotes cancer proliferation through up-regulating Rictor/AKT/β-catenin signaling pathway

Vimentin protein is one of the main cytoskeleton and plays an important role in cell motility and metastasis. Nowadays, vimentin is widely studied as an epithelial-mesenchymal transition (EMT) marker of cancer cells while its involvement in cancer proliferation is poorly understood. In this study, we investigated the participation of vimentin in regulating cancer proliferation by silencing VIM gene in four cancer cell lines. Our results demonstrated that vimentin loss significantly induced cancer cell proliferation both in vitro and in vivo, which has not been reported so far. Mechanistically, knockdown of vimentin expression activated AKT phosphorylation and its downstream β-catenin signaling. Nuclear translocation and transcriptional activity of β-catenin was enhanced after silencing vimentin expression. Furthermore, vimentin loss could prevent Rictor from autophagy-dependent degradation via reducing AMPK-mediated autophagy signaling. AICAR, an AMPK activator, down-regulated Rictor and p-AKT levels while vimentin knockdown could rescue the effects. In vivo, it was also found that Ki67 expression and p-AKT/β-catenin signaling pathway were obviously up-regulated in the tumor tissues in which vimentin was silenced compared to control groups. Taken together, these data showed the novel function of vimentin in regulating cancer proliferation via Rictor/AKT/β-catenin signaling pathway, which suggested that it need more careful consideration before inhibiting metastatic cancers through targeting vimentin.

NF-κB in Cancer Immunity: Friend or Foe?

The emergence of immunotherapies has definitely proven the tight relationship between malignant and immune cells, its impact on cancer outcome and its therapeutic potential. In this context, it is undoubtedly critical to decipher the transcriptional regulation of these complex interactions. Following early observations demonstrating the roles of NF-κB in cancer initiation and progression, a series of studies converge to establish NF-κB as a master regulator of immune responses to cancer. Importantly, NF-κB is a family of transcriptional activators and repressors that can act at different stages of cancer immunity. In this review, we provide an overview of the selective cell-intrinsic contributions of NF-κB to the distinct cell types that compose the tumor immune environment. We also propose a new view of NF-κB targeting drugs as a new class of immunotherapies for cancer.

Bioinformatics Analyses Reveals a Comprehensive Landscape of CXC Chemokine Family Functions in Non-Small Cell Lung Cancer

Backgrounds. Lung cancer is a major source of tumor-related death each year with non-small cell lung cancer (NSCLC) being a prevalent subtype. The metastasis from NSCLC to the brain usually imposes many neuron disorders. Previous studies have suggested that communications among cancer cells and interstitial cells are essential in tumorigenesis and are influenced by chemokines. In the tumor microenvironment, CXC chemokines can participate in the shifting of immune cells and manage tumor cell condition, thus affecting the progression of cancer and patient destinies. However, the expression and values of CXC chemokine family in NSCLC have not been systematically illustrated using public databases. Methods. UALCAN, STRING, ONCOMINE, GeneMANIA, cBioPortal, GEPIA, TISIDB, TRRUST, TIMER, Kaplan-Meier Plotter, and R software were utilized in this study. Results. Based on the TIMER and UACLCAN databases, in LUAD patients, the expression levels of CXCL10, CXCL13, and CXCL14 were significantly elevated while the transcriptional levels of CXCL2/3/4/7/12/16 were significantly reduced; in LUSC patients, the expression levels of CXCL6/10/13/14 were significantly elevated while the expression levels of CXCL2/3/4/5/7/11/12/16/17 were significantly reduced. We found remarkable relevance between the pathological stages of LUAD patients and the expressions of CXCL8 (positive) and CXCL17 (negative). Similarly, there are significant correlations between the pathological stages of LUSC patients and the expressions of CXCL1/2/6/17. In LUAD, patients with low expression levels of CXCL1/4/7/8 and patients with high expression levels of CXCL12/14/16 were associated with a significantly better prognosis. But in LUSC, all correlations between chemokines and prognosis are statistically insignificant. Pairwise expression correlation analysis among CXC chemokines shows that there are 7 significant correlations (between CXCL1 and CXCL2, between CXCL1 and CXCL3, between CXCL1 and CXCL8, between CXCL2 and CXCL3, between CXCL4 and CXCL7, between CXCL9 and CXCL10, and between CXCL9 and CXCL11) in LUAD and 4 significant correlations (between CXCL1 and CXCL8, between CXCL2 and CXCL3, between CXCL4 and CXCL7, and between CXCL10 and CXCL11) in LUSC. Significant correlations between the expressions of CXC chemokines and the infiltration of six common types of immune cells were also discovered in both LUAD and LUSC. Conclusions. We provided a comprehensive landscape of the CXC chemokine family in LUAD and LUSC using the bioinformatics method and found differences between LUSC and LUAD in the field of CXC chemokines. Our study may help validate and identify known novel immunotherapeutic targets and prognostic biomarkers.

Tumor microenvironment pathways: Cross regulation in breast cancer metastasis

The tumor microenvironment (TME) is heterogeneous and contains a multiple cell population with surrounded immune cells, which plays a major role in regulating metastasis. The multifunctional pathways, Hedgehog (Hh), Wnt, Notch, and NF-kB, cross-regulates metastasis in breast cancer. This review presents substantial evidence for cross-regulation of TME components and signaling pathways, which makes breast TME more heterogeneous and complex, promoting breast cancer progression and metastasis as a highly aggressive form. We discoursed the importance of stromal and immune cells as well as their crosstalk in bridging the metastasis. We also discussed the role of Hh and Notch pathways in the intervention between breast cancer cells and macrophages to support TME; Notch signaling in the bidirectional communication between cancer cells and components of TME; Wnt signal pathway in controlling the factors responsible for EMT and NF-κB pathway in the regulation of genes controlling the inflammatory response. We also present the role of exosomes and their miRNAs in the cross-regulation of TME cells as well as pathways in the reprogramming of breast TME to support metastasis. Finally, we examined and discussed the targeted small molecule inhibitors and natural compounds targeting developmental pathways and proposed small molecule natural compounds as potential therapeutics of TME based on the multitargeting ability. In conclusion, the understanding of the molecular basis of the cross-regulation of TME pathways and their inhibitors helps identify molecular targets for rational drug discovery to treat breast cancers.

Anterior gradient 2 is a novel pro-tumor factor in pancreatic cancer under NF-κB subunit RelA trans-regulation that can be suppressed by eugenic acid

This study aimed to examine eugenic acid (EA) as an alternative therapeutic approach against pancreatic cancer. The pancreatic cancer xenograft mouse model was employed to determine the impacts of treatment with EA on the growth of tumors. Expressions of NF-κB subunit RelA as well as Anterior gradient 2 (AGR2) were quantified in pancreatic cells treated with EA. Chromatin immunoprecipitation and luciferase report assay were performed to examine the regulation of AGR2 by RelA. The function of AGR2 as a downstream effector EA treatment was further assessed through overexpression of AGR2 in pancreatic cells. EA suppressed the growth of xenograft pancreatic tumor, and promoted the overall survival of animals with xenograft tumors. Furthermore, EA downregulated the expression of AGR2 in pancreatic cancer cells via the RelA binding site. Ectopic AGR2 overexpression attenuated the EA-elicited inhibition on the growth of xenograft pancreatic tumor, and negated the EA-induced enhancement of mouse survival. EA ameliorates pancreatic cancer through suppression of AGR2 expression, and future studies in clinical settings are needed to further assess the anti-cancer efficacy of EA.

Circular RNA Hsa_circ_0004018 Inhibits Wnt/β-Catenin Signaling Pathway by Targeting microRNA-626/DKK3 in Hepatocellular Carcinoma

BACKGROUND AND AIM

Dysexpression of circular RNAs has been identified in multiple types of cancer. Hsa_circ_0004018 was reported to be significantly downregulated in hepatocellular carcinoma (HCC) and to display HCC-stage-specific expression features. However, the role of hsa_circ_0004018 in HCC progression remains unclear.

METHODS

The expression of hsa_circ_0004018 or microRNA-626 (miR-626) was detected in tumor tissues and paired non-tumor tissues from HCC patients, as well as in one normal human liver cell line and 5 HCC cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, dye exclusion assay, clonogenic assay, scratch migration assay and transwell assay were used to measure cell proliferation and migration capacity, respectively. Luciferase report assay and RNA pull down assay were performed to explore the regulatory effect of certain molecules on the expression of target genes.

RESULTS

We found that the expression of hsa_circ_0004018 was lower in tumor tissues than in their paired non-tumor tissues from 28 out of 41 HCC patients. The difference in the expression between tumor tissues and non-tumor tissues was statistically significant (p<0.001). Further analysis revealed that such lower expression in tumor tissues was much more common in bigger tumor size group (≥5cm) compared with the smaller tumor size group (<5cm) (85% vs 42%, p=0.0007). Similarly, hsa_circ_0004018 was downregulated in HCC cell lines. Additionally, a negative correlation between hsa_circ_0004018 and miR-626 expression was noticed in HCC tissues. Moreover, we observed that hsa_circ_0004018 interacted with miR-626/DKK3 and contributed to HCC cell proliferation and migration through inhibiting Wnt/β-catenin signaling pathway in vitro. Furthermore, hsa_circ_0004018 blocked xenograft tumor growth in vivo through inhibiting Wnt/β-catenin signaling pathway by targeting miR-626/DKK3.

CONCLUSION

We revealed that hsa_circ_0004018/miR-626/DKK3 regulatory axis may be a possible novel therapeutic target for HCC.

PLAC8 inhibits oral squamous cell carcinogenesis and epithelial-mesenchymal transition via the Wnt/β-catenin and PI3K/Akt/GSK3β signaling pathways

Placenta-specific 8 (PLAC8) is closely associated with the proliferation, apoptosis and autophagy of several tumor cells. However, the expression and function of PLAC8 in oral squamous cell carcinoma (OSCC) remain unknown. Therefore, the present study investigated the function and mechanism of PLAC8 in OSCC. Reverse transcription-quantitative PCR and western blot analyses were performed to quantify the expression of PLAC8 in OSCC cell lines. The function of PLAC8 in OSCC was investigated via transfection, the Transwell and Cell Counting Kit-8 assays, immunofluorescence staining and western blotting. The results demonstrated that PLAC8 exspression was downregulated in OSCC cell lines. PLAC8 inhibited the cell proliferation in OSCC. In addition, PLAC8 restrained invasion and epithelial-mesenchymal transition of OSCC cells. Furthermore, β-catenin helped to repress PLAC8 expression by regulating the Wnt/β-catenin and PI3K/Akt/GSK3β signaling pathways in OSCC cells. Collectively, the results of the present study suggest that PLAC8 acts as a tumor suppressor in OSCC by downregulating β-catenin.

Targeted inhibition of endothelial calpain delays wound healing by reducing inflammation and angiogenesis

Wound healing is a multistep phenomenon that relies on complex interactions between various cell types. Calpains are a well-known family of calcium-dependent cysteine proteases that regulate several processes, including cellular adhesion, proliferation, and migration, as well as inflammation and angiogenesis. CAPNS1, the common regulatory subunit of Calpain-1 and 2, is indispensable for catalytic subunit stabilization and activity. Calpain inhibition has been shown to reduce organ damage in various disease models. Here, we report that endothelial calpain-1/2 is crucially involved in skin wound healing. Using a mouse genetic model where Capns1 is deleted only in endothelial cells, we showed that calpain-1/2 disruption is associated with reduced injury-activated inflammation, reduced CD31⁺ blood vessel density, and delayed wound healing. Moreover, in cultured HUVECs, inhibition of calpain reduced TNF-α-induced proliferation, migration, and tube formation. Deletion of Capns1 was associated with elevated levels of IκB and downregulation of β-catenin expression in endothelial cells. These observations delineate a novel mechanistic role for calpain in the crosstalk between inflammation and angiogenesis during skin repair.

Gene Expression Profile Reveals Hematopoietic-Related Molecule Changes in Response to Hypoxic Exposure

The Qing-Tibet Plateau is characterized by low oxygen pressure, which is an important biomedical and ecological stressor. However, the variation in gene expression during periods of stay on the plateau has not been well studied. We recruited eight volunteers to stay on the plateau for 3, 7, and 30 days. Human Clariom D arrays were used to measure transcriptome changes in the mRNA expression profiles in these volunteers' blood. Analysis of variance (ANOVA) indicated that 699 genes were significantly differentially expressed in response to entering the plateau during hypoxic exposure. The genes with changes in transcript abundance were involved in the terms phosphoprotein, acetylation, protein binding, and protein transport. Furthermore, numerous genes involved in hematopoietic functions, including erythropoiesis and immunoregulation, were differentially expressed in response to hypoxia. This phenomenon may be one of reasons why the majority of people entering the plateau do not have excessive erythrocyte proliferation and are susceptible to infection.

Wnt1-inducible signaling protein 1 regulates laryngeal squamous cell carcinoma glycolysis and chemoresistance via the YAP1/TEAD1/GLUT1 pathway

Wnt1-inducible signaling protein 1 (WISP1) is a matricellular protein and downstream target of Wnt/β-catenin signaling. This study sought to determine the role of WISP1 in glucose metabolism and chemoresistance in laryngeal squamous cell carcinoma. WISP1 expression was silenced or upregulated in Hep-2 cells by the transfection of WISP1 siRNA or AdWISP1 vector. Ectopic WISP1 expression regulated glucose uptake and lactate production in Hep-2 cells. Subsequently, the expression of glucose transporter 1 (GLUT1) was significantly modulated by WISP1. Furthermore, WISP1 increased cell survival rates, diminished cell death rates, and suppressed ataxia-telangiectasia-mutated (ATM)-mediated DNA damage response pathway in cancer cells treated with cisplatin through GLUT1. WISP1 also promoted cancer cell tumorigenicity and growth in mice implanted with Hep-2 cells. Additionally, WISP1 activated the YAP1/TEAD1 pathway that consequently contributed to the regulation of GLUT1 expression. In summary, WISP1 regulated glucose metabolism and cisplatin resistance in laryngeal cancer by regulating GLUT1 expression. WISP1 may be used as a potential therapeutic target for laryngeal cancer.

IL-17C-mediated innate inflammation decreases the response to PD-1 blockade in a model of Kras-driven lung cancer

Chronic obstructive pulmonary disease (COPD) is associated with neutrophilic lung inflammation and CD8 T cell exhaustion and is an important risk factor for the development of non-small cell lung cancer (NSCLC). The clinical response to programmed cell death-1 (PD-1) blockade in NSCLC patients is variable and likely affected by a coexisting COPD. The pro-inflammatory cytokine interleukin-17C (IL-17C) promotes lung inflammation and is present in human lung tumors. Here, we used a Kras-driven lung cancer model to examine the function of IL-17C in inflammation-promoted tumor growth. Genetic ablation of Il-17c resulted in a decreased recruitment of inflammatory cells into the tumor microenvironment, a decreased expression of tumor-promoting cytokines (e.g. interleukin-6 (IL-6)), and a reduced tumor proliferation in the presence of Haemophilus influenzae- (NTHi) induced COPD-like lung inflammation. Chronic COPD-like inflammation was associated with the expression of PD-1 in CD8 lymphocytes and the membrane expression of the programmed death ligand (PD-L1) independent of IL-17C. Tumor growth was decreased in Il-17c deficient mice but not in wildtype mice after anti-PD-1 treatment. Our results suggest that strategies targeting innate immune mechanisms, such as blocking of IL-17C, may improve the response to anti-PD-1 treatment in lung cancer patients.

TRAF6 function as a novel co-regulator of Wnt3a target genes in prostate cancer

Background

Tumour necrosis factor receptor associated factor 6 (TRAF6) promotes inflammation in response to various cytokines. Aberrant Wnt3a signals promotes cancer progression through accumulation of β-Catenin. Here we investigated a potential role for TRAF6 in Wnt signaling.

Methods

TRAF6 expression was silenced by siRNA in human prostate cancer (PC3U) and human colorectal SW480 cells and by CRISPR/Cas9 in zebrafish. Several biochemical methods and analyses of mutant phenotype in zebrafish were used to analyse the function of TRAF6 in Wnt signaling.

Findings

Wnt3a-treatment promoted binding of TRAF6 to the Wnt co-receptors LRP5/LRP6 in PC3U and LNCaP cells in vitro. TRAF6 positively regulated mRNA expression of β-Catenin and subsequent activation of Wnt target genes in PC3U cells. Wnt3a-induced invasion of PC3U and SW480 cells were significantly reduced when TRAF6 was silenced by siRNA. Database analysis revealed a correlation between TRAF6 mRNA and Wnt target genes in patients with prostate cancer, and high expression of LRP5, TRAF6 and c-Myc correlated with poor prognosis. By using CRISPR/Cas9 to silence TRAF6 in zebrafish, we confirm TRAF6 as a key molecule in Wnt3a signaling for expression of Wnt target genes.

Interpretation

We identify TRAF6 as an important component in Wnt3a signaling to promote activation of Wnt target genes, a finding important for understanding mechanisms driving prostate cancer progression.

Fund

KAW 2012.0090, CAN 2017/544, Swedish Medical Research Council (2016-02513), Prostatacancerförbundet, Konung Gustaf V:s Frimurarestiftelse and Cancerforskningsfonden Norrland. The funders did not play a role in manuscript design, data collection, data analysis, interpretation nor writing of the manuscript.

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TRAF6 positively regulated mRNA expression of b-Catenin and subsequent activation of Wnt target genes in prostate cancer cells in vitro.

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High expression of LRP5, TRAF6 and c-Myc correlated with poor prognosis for patients with prostate cancer.

miRNA-302e attenuates inflammation in infantile pneumonia though the RelA/BRD4/NF-κB signaling pathway

In the present study, the main focus was investigating the role of microRNA (miRNA)-302e in infantile pneumonia (IP) and exploring the potential protective mechanisms. Briefly, the expression of miRNA-302e was reduced in a mouse model of IP. In addition, the administration of anti-miRNA-302e increased inflammation and induced the protein expression of RelA, bromodomain-containing protein 4 (BRD4) and nuclear factor (NF)-κB in the in vitro model of IP. In contrast, over-expression of miRNA-302e reduced inflammation and suppressed the protein expression of RelA, BRD4 and NF-κB in an in vitro model of IP. Small interfering (si)-RelA attenuated the effects of miRNA-302e on inflammation in an in vitro model of IP. Consistently, si-BRD4 or si-NF-κB attenuated the effects of miRNA-302e on inflammation in an in vitro model of IP. Taken together, the results of the present study demonstrated that miRNA-302e attenuated inflammation in IP through the RelA/ BRD4/ NF-κB signaling pathway.

Sox17 is required for endothelial regeneration following inflammation-induced vascular injury

Repair of the endothelial cell barrier after inflammatory injury is essential for tissue fluid homeostasis and normalizing leukocyte transmigration. However, the mechanisms of endothelial regeneration remain poorly understood. Here we show that the endothelial and hematopoietic developmental transcription factor Sox17 promotes endothelial regeneration in the endotoxemia model of endothelial injury. Genetic lineage tracing studies demonstrate that the native endothelium itself serves as the primary source of endothelial cells repopulating the vessel wall following injury. We identify Sox17 as a key regulator of endothelial cell regeneration using endothelial-specific deletion and overexpression of Sox17. Endotoxemia upregulates Hypoxia inducible factor 1α, which in turn transcriptionally activates Sox17 expression. We observe that Sox17 increases endothelial cell proliferation via upregulation of Cyclin E1. Furthermore, endothelial-specific upregulation of Sox17 in vivo enhances lung endothelial regeneration. We conclude that endotoxemia adaptively activates Sox17 expression to mediate Cyclin E1-dependent endothelial cell regeneration and restore vascular homeostasis.

Myeloid cell-derived LL-37 promotes lung cancer growth by activating Wnt/β-catenin signaling

Rationale: Antimicrobial peptides, such as cathelicidin LL-37/hCAP-18, are important effectors of the innate immune system with direct antibacterial activity. In addition, LL-37 is involved in the regulation of tumor cell growth. However, the molecular mechanisms underlying the functions of LL-37 in promoting lung cancer are not fully understood.

Methods: The expression of LL-37 in the tissues and sera of patients with non-small cell lung cancer was determined through immunohistological, immunofluorescence analysis, and enzyme-linked immunosorbent assay. The animal model of wild-type and Cramp knockout mice was employed to evaluate the tumorigenic effect of LL-37 in non-small cell lung cancer. The mechanism of LL-37 involving in the promotion of lung tumor growth was evaluated via microarray analyses, recombinant protein treatment approaches in vitro, tumor immunohistochemical assays, and intervention studies in vivo.

Results: LL-37 produced by myeloid cells was frequently upregulated in primary human lung cancer tissues. Moreover, its expression level correlated with poor clinical outcome. LL-37 activated Wnt/β-catenin signaling by inducing the phosphorylation of protein kinase B and subsequent phosphorylation of glycogen synthase kinase 3β mediated by the toll-like receptor-4 expressed in lung tumor cells. LL-37 treatment of tumor cells also decreased the levels of Axin2. In contrast, it elevated those of an RNA-binding protein (tristetraprolin), which may be involved in the mechanism through which LL-37 induces activation of Wnt/β-catenin.

Conclusion: LL-37 may be a critical molecular link between tumor-supportive immune cells and tumors, facilitating the progression of lung cancer.

Roles of DNA repair enzyme OGG1 in innate immunity and its significance for lung cancer

Cytokines are pivotal mediators of the immune response, and their coordinated expression protects host tissue from excessive damage and oxidant stress. Nevertheless, the development of lung pathology, including asthma, chronic obstructive pulmonary disease, and ozone-induced lung injury, is associated with oxidant stress; as evidence, there is a significant increase in levels of the modified guanine base 7,8-dihydro-8-oxoguanine (8-oxoG) in the genome. 8-OxoG is primarily recognized by 8-oxoguanine glycosylase 1 (OGG1), which catalyzes the first step in the DNA base excision repair pathway. However, oxidant stress in the cell transiently halts enzymatic activity of substrate-bound OGG1. The stalled OGG1 facilitates DNA binding of transactivators, including NF-κB, to their cognate sites to enable expression of cytokines and chemokines, with ensuing recruitments of inflammatory cells. Hence, defective OGG1 will modulate the coordination between innate and adaptive immunity through excessive oxidant stress and cytokine dysregulation. Both oxidant stress and cytokine dysregulation constitute key elements of oncogenesis by KRAS, which is mechanistically coupled to OGG1. Thus, analysis of the mechanism by which OGG1 modulates gene expression helps discern between beneficial and detrimental effects of oxidant stress, exposes a missing functional link as a marker, and yields a novel target for lung cancer.

Upregulated IQUB promotes cell proliferation and migration via activating Akt/GSK3β/β-catenin signaling pathway in breast cancer

Breast cancer was the highest incidence of tumor in women, which seriously threaten women's health. Our previous study found that the expression of IQUB (IQ motif and ubiquitin domain containing) was significantly increased in the development of breast cancer by transcriptome sequencing. However, there were no studies on the mechanism of IQUB in tumorigenesis. Further study showed that IQUB expression was significantly increased in breast cancer, which had a significantly positive correlation with pathological differentiation of breast cancer by tissue microarray analysis. Furthermore, we also discovered that IQUB overexpression could obviously promote the proliferation and migration of MCF‐7 cells and increase the proportion of MCF‐7 cells in S and G2/M phase in vitro study, while knockdown of IQUB caused inhibition of cell proliferation and migration in MDA‐MB‐231 cells and increased the proportion of MDA‐MB‐231 cells in G1 phase. Furthermore, IQUB overexpression or knockdown combined with treatment of Licl or MG‐132 showed that IQUB activated Akt to promote GSK3β phosphorylation, which in turn activated Wnt/β‐catenin signaling pathway in breast cancer cells. Taken together, these results indicated that upregulated IQUB promoted breast cancer cell proliferation and migration via activating Akt/GSK3β/β‐catenin signaling pathway, which played an important part in the tumorigenesis and development of breast cancer.

The nuclear transcription factor RelB functions as an oncogene in human lung adenocarcinoma SPC-A1 cells

Background

Lung cancer is a leading public health issue worldwide. Although therapeutic approaches have improved drastically in the last decades, the prognosis of lung cancer patients remains suboptimal. The canonical nuclear transcription factor kappa B (NF-κB) signalling pathway is critical in the carcinogenesis of lung cancer. The non-canonical NF-κB signalling pathway (represented by RelB) has attracted increasing attention in the pathogenesis of haematological and epithelial malignancies. However, the function of RelB in non-small cell lung cancer (NSCLC) is still unclear. Recently, high expression of RelB has been detected in NSCLC tissues. We have also demonstrated that RelB expression is an independent prognostic factor in NSCLC patients.

Methods

The mRNA and protein expression of RelB in NSCLC tissues were detected by qRT-PCR and IHC assay. The cell growth of SPC-A1 cells was detected in real-time using the x-Celligence system and xenograft tumour assays. The proliferation capability of cells was detected using a CFSE assay. Cell apoptosis was measured using Annexin V/PI staining, cell cycle was analyzed by the cytometry. Cell migration abilities were detected using the x-Celligence system and wound healing assays. The relative amounts of the active and inactive gelatinases MMP-2 and MMP-9 were examined using gelatin zymography experiments. Apoptosis of RelB depletion SPC-A1 cells after ionizing radiation at 8 Gy. The expression of cellular proliferation signal pathway related-proteins were examined by Western blot analysis.

Results

The expression of RelB increases in NSCLC tissues. High RelB expression was significantly correlated with advanced-metastatic stage in patients with NSCLC. RelB-silencing inhibits cell growth in vitro and in vivo. We found that RelB affected cell proliferation by regulating AKT phosphorylation. RelB silencing attenuates the migration and invasion abilities of SPC-A1 cells and is likely related to the down regulation of MMP-9 activity and Integrin β-1 expression. In addition, RelB modulated radiation-induced survival of NSCLC cells predominantly by regulating Bcl-xL expression.

Conclusions

Given the involvement of RelB in cell proliferation, migration, invasion, and radio-resistance, RelB functions as an oncogene in NSCLC cells. Our data here shed light on unexplored aspects of RelB in NSCLC.

Interactions Between the Canonical WNT/Beta-Catenin Pathway and PPAR Gamma on Neuroinflammation, Demyelination, and Remyelination in Multiple Sclerosis

Multiple sclerosis (MS) is marked by neuroinflammation and demyelination with loss of oligodendrocytes in the central nervous system. The immune response is regulated by WNT/beta-catenin pathway in MS. Activated NF-kappaB, a major effector of neuroinflammation, and upregulated canonical WNT/beta-catenin pathway positively regulate each other. Demyelinating events present an upregulation of WNT/beta-catenin pathway, whereas proper myelinating phases show a downregulation of WNT/beta-catenin pathway essential for the promotion of oligodendrocytes precursors cells proliferation and differentiation. The activation of WNT/beta-catenin pathway results in differentiation failure and impairment in remyelination. However, PI3K/Akt pathway and TCF7L2, two downstream targets of WNT/beta-catenin pathway, are upregulated and promote proper remyelination. The interactions of these signaling pathways remain unclear. PPAR gamma activation can inhibit NF-kappaB, and can also downregulate the WNT/beta-catenin pathway. PPAR gamma and canonical WNT/beta-catenin pathway act in an opposite manner. PPAR gamma agonists appear as a promising treatment for the inhibition of demyelination and the promotion of proper remyelination through the control of both NF-kappaB activity and canonical WNT/beta-catenin pathway.

Rig-G is a growth inhibitory factor of lung cancer cells that suppresses STAT3 and NF-κB

The expression of the retinoic acid-induced G (Rig-G) gene, an all trans retinoic acid (ATRA)-inducible gene, was observed in multiple cancer cells, including lung cancer cells. However, whether Rig-G is a tumor suppressor in lung cancer is unknown. Here, we found that ectopic expression of Rig-G can lead to a significant decrease in proliferation of lung cancer cells, resulting in an inhibition of tumor growth. Rig-G knockdown results in a modest increase in cell proliferation, as well as confers an increase in colony formation. Furthermore, transcriptome and pathway analyses of cancer cells revealed a fundamental impact of Rig-G on various growth signaling pathways, including the NF-κB pathway. Rig-G inhibits NF-κB activity by suppressing STAT3 in lung cancer cells. The downregulation of miR21 and miR181b-1 and subsequent activation of PTEN/Akt and CYLD/IκB signaling axis leading to decreased NF-κB activity required to maintain the tumor-inhibiting effect of Rig-G.. Our findings contribute to a better understanding of the antitumor effect mechanism of Rig-G, as well as offer a novel strategy for lung cancer therapy.

NF-κB RelA renders tumor-associated macrophages resistant to and capable of directly suppressing CD8+ T cells for tumor promotion

Activation of the inflammatory transcription factor NF-κB in tumor-associated macrophages (TAMs) is assumed to contribute to tumor promotion. However, whether and how NF-κB drives the antitumor macrophages to become pro-tumorigenic have not been determined in any cancer type yet. Similarly, how TAMs repress CD8⁺ cytotoxic T lymphocytes (CTLs) remains largely unknown, although their importance in regulatory T (Treg) cell regulation and tumor promotion has been well appreciated. Here, using an endogenous lung cancer model we uncover a direct crosstalk between TAMs and CTLs. TAMs suppress CTLs through the T-cell inhibitory molecule B7x (B7-H4/B7S1) in a cell-cell contact manner, whereas CTLs kill TAMs in a tumor antigen-specific manner. Remarkably, TAMs secrete the known T-cell suppressive cytokine interleukin-10 (IL-10) to activate, but not to repress, CTLs. Notably, one major role of cell-intrinsic NF-κB RelA is to drive TAMs to suppress CTLs for tumor promotion. It induces B7x expression in TAMs directly, and restricts IL-10 expression indirectly by repressing expression of the NF-κB cofactor Bcl3 and subsequent Bcl3/NF-κB1-mediated transcription of IL-10. It also renders TAMs resistant to CTLs by up-regulating anti-apoptotic genes. These studies help understand how immunity is shaped in lung tumorigenesis, and suggest a RelA-targeted immunotherapy for this deadliest cancer.

Feedback circuitry via let-7c between lncRNA CCAT1 and c-Myc is involved in cigarette smoke extract-induced malignant transformation of HBE cells

Cigarette smoking is a primary risk factor for the development of lung cancer, which is regarded as the leading cause of cancer-related deaths. The process of malignant transformation of cells, however, is complex and elusive. The present study investigated the roles of an lncRNA, CCAT1, and a transcriptional factor, c-Myc, in human bronchial epithelial (HBE) cell transformation induced by cigarette smoke extract. With acute and chronic treatment of HBE cells, cigarette smoke extract induced increases of CCAT1 and c-Myc levels and decreases of levels of let-7c, a microRNA. Down-regulation of c-Myc reduced the degree of malignancy and the invasion/migration capacity of HBE cells transformed by cigarette smoke extract. ChIP assays established that c-Myc, increased by cigarette smoke extract, binds to the promoter of CCAT1, activating its transcription. Further, let-7c suppressed the expression of c-Myc through binding to its 3'-UTR. In turn, CCAT1 promoted the accumulation of c-Myc through binding to let-7c and decreasing free let-7c, which influenced the neoplastic capacity of HBE cells transformed by cigarette smoke extract. These results indicate that a positive feedback loop ensures expression of cigarette smoke extract-induced CCAT1 and c-Myc via let-7c, which is involved in cigarette smoke extract-induced malignant transformation of HBE cells. Thus, the present research establishes a new mechanism for the reciprocal regulation between CCAT1 and c-Myc and provides an understanding of cigarette smoke extract-induced lung carcinogenesis.

Interactions between TGF-β1, canonical WNT/β-catenin pathway and PPAR γ in radiation-induced fibrosis

Radiation therapy induces DNA damage and inflammation leading to fibrosis. Fibrosis can occur 4 to 12 months after radiation therapy. This process worsens with time and years. Radiation-induced fibrosis is characterized by fibroblasts proliferation, myofibroblast differentiation, and synthesis of collagen, proteoglycans and extracellular matrix. Myofibroblasts are non-muscle cells that can contract and relax. Myofibroblasts evolve towards irreversible retraction during fibrosis process. In this review, we discussed the interplays between transforming growth factor-β1 (TGF-β1), canonical WNT/β-catenin pathway and peroxisome proliferator-activated receptor gamma (PPAR γ) in regulating the molecular mechanisms underlying the radiation-induced fibrosis, and the potential role of PPAR γ agonists. Overexpression of TGF-β and canonical WNT/β-catenin pathway stimulate fibroblasts accumulation and myofibroblast differentiation whereas PPAR γ expression decreases due to the opposite interplay of canonical WNT/β-catenin pathway. Both TGF-β1 and canonical WNT/β-catenin pathway stimulate each other through the Smad pathway and non-Smad pathways such as phosphatidylinositol 3-kinase/serine/threonine kinase (PI3K/Akt) signaling. WNT/β-catenin pathway and PPAR γ interact in an opposite manner. PPAR γ agonists decrease β-catenin levels through activation of inhibitors of the WNT pathway such as Smad7, glycogen synthase kinase-3 (GSK-3 β) and dickkopf-related protein 1 (DKK1). PPAR γ agonists also stimulate phosphatase and tensin homolog (PTEN) expression, which decreases both TGF-β1 and PI3K/Akt pathways. PPAR γ agonists by activating Smad7 decrease Smads pathway and then TGF-β signaling leading to decrease radiation-induced fibrosis. TGF-β1 and canonical WNT/β-catenin pathway promote radiation-induced fibrosis whereas PPAR γ agonists can prevent radiation-induced fibrosis.

Aerobic Glycolysis Hypothesis Through WNT/Beta-Catenin Pathway in Exudative Age-Related Macular Degeneration

Exudative age-related macular degeneration (AMD) is characterized by molecular mechanisms responsible for the initiation of choroidal neovascularization (CNV). Inflammatory processes are associated with upregulation of the canonical WNT/beta-catenin pathway in exudative AMD. We focus this review on the link between WNT/beta-catenin pathway activation and neovascular progression in exudative AMD through activation of aerobic glycolysis for production of angiogenic factors. Increased WNT/beta-catenin pathway involves hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). WNT/beta-catenin pathway stimulates PI3K/Akt pathway and then HIF-1alpha which activates glycolytic enzymes: glucose transporter (Glut), pyruvate dehydrogenase kinase 1 (PDK1), lactate dehydrogenase A (LDH-A), and monocarboxylate lactate transporter (MCT-1). This phenomenon is called aerobic glycolysis or the Warburg effect. Consequently, phosphorylation of PDK-1 inhibits the pyruvate dehydrogenase complex (PDH). Thus, a large part of pyruvate cannot be converted into acetyl-CoA in mitochondria and only a part of acetyl-CoA can enter the tricarboxylic acid cycle. Cytosolic pyruvate is converted into lactate through the action of LDH-A. In exudative AMD, high level of cytosolic lactate is correlated with increase of VEGF expression, the angiogenic factor of CNV. Photoreceptors in retina cells can metabolize glucose through aerobic glycolysis to protect them against oxidative damage, as cancer cells do.

Receptor for advanced glycation endproducts (RAGE) maintains pulmonary structure and regulates the response to cigarette smoke

The receptor for advanced glycation endproducts (RAGE) is highly expressed in the lung but its physiological functions in this organ is still not completely understood. To determine the contribution of RAGE to physiological functions of the lung, we analyzed pulmonary mechanics and structure of wildtype and RAGE deficient (RAGE^-/-) mice. RAGE deficiency spontaneously resulted in a loss of lung structure shown by an increased mean chord length, increased respiratory system compliance, decreased respiratory system elastance and increased concentrations of serum protein albumin in bronchoalveolar lavage fluids. Pulmonary expression of RAGE was mainly localized on alveolar epithelial cells and alveolar macrophages. Primary murine alveolar epithelial cells isolated from RAGE^-/- mice revealed an altered differentiation and defective barrier formation under in vitro conditions. Stimulation of interferone-y (IFNy)-activated alveolar macrophages deficient for RAGE with Toll-like receptor (TLR) ligands resulted in significantly decreased release of proinflammatory cytokines and chemokines. Exposure to chronic cigarette smoke did not affect emphysema-like changes in lung parenchyma in RAGE^-/- mice. Acute cigarette smoke exposure revealed a modified inflammatory response in RAGE^-/- mice that was characterized by an influx of macrophages and a decreased keratinocyte-derived chemokine (KC) release. Our data suggest that RAGE regulates the differentiation of alveolar epithelial cells and impacts on the development and maintenance of pulmonary structure. In cigarette smoke-induced lung pathology, RAGE mediates inflammation that contributes to lung damage.

IL-17C mediates the recruitment of tumor-associated neutrophils and lung tumor growth

Chronic obstructive pulmonary disease (COPD) is associated with an increased risk for lung cancer and an aberrant microbiota of the lung. Microbial colonization contributes to chronic neutrophilic inflammation in COPD. Nontypeable Haemophilus influenzae (NTHi) is frequently found in lungs of stable COPD patients and is the major pathogen triggering exacerbations. The epithelial cytokine interleukin-17C (IL-17C) promotes the recruitment of neutrophils into inflamed tissues. The purpose of this study was to investigate the function of IL-17C in the pulmonary tumor microenvironment. We subjected mice deficient for IL-17C (IL-17C^-/-) and mice double deficient for Toll-like receptor 2 and 4 (TLR-2/4^-/-) to a metastatic lung cancer model. Tumor proliferation and growth as well as the number of tumor-associated neutrophils was significantly decreased in IL-17C^-/- and TLR-2/4^-/- mice exposed to NTHi. The NTHi-induced pulmonary expression of IL-17C was dependent on TLR-2/4. In vitro, IL-17C increased the NTHi- and tumor necrosis factor-α-induced expression of the neutrophil chemokines keratinocyte-derived chemokine and macrophage inflammatory protein 2 in lung cancer cells but did not affect proliferation. Human lung cancer samples stained positive for IL-17C, and in non-small cell lung cancer patients with lymph node metastasis, IL-17C was identified as a negative prognostic factor. Our data indicate that epithelial IL-17C promotes neutrophilic inflammation in the tumor microenvironment and suggest that IL-17C links a pathologic microbiota, as present in COPD patients, with enhanced tumor growth.

Capn4 promotes epithelial-mesenchymal transition in human melanoma cells through activation of the Wnt/β-catenin pathway

Melanoma, as one of the most highly metastatic types of cancer, is resistant to current treatment methods, including popular targeted molecular therapy. Consequently, it is essential to develop a deeper understanding of the mechanisms involved in melanoma progression so that alternative treatments may be identified. To date, accumulating evidence supports the use of calpains, including calpain small subunit 1 (also known as Capn4 or CAPNS1), which affect cancer progression through many pathways, such as epithelial‑mesenchymal transition (EMT), the Wnt/β-catenin (β-catenin) and the nuclear factor κB (NF-κB) signaling pathways. The EMT pathway is well known as one of the most important events in tumor metastasis. The present study observed cross-talk among the EMT, β-catenin and NF-κB pathways. To identify the underlying mechanisms of Capn4 activity in melanoma cells, we determined Capn4 expression by gene chip and immunohistochemistral analyses in melanoma tissues and cells in vitro. The extent of apoptosis as determined by TUNEL assay, DAPI staining, and cleaved-caspase-3 assay was increased in human melanoma cells in which Capn4 expression had been knocked down when compared with untreated cells. Transwell assays and xenograft tumorigenicity studies were also performed to assess the effects of Capn4 on migration and invasion in vitro and tumor growth in vivo, respectively. The levels of β-catenin, vimentin, E-cadherin and N-cadherin were altered in human melanoma cells as determined by western blot analysis assay. Our study demonstrated that Capn4 is an underlying target for melanoma treatment.

Crosstalk between Wnt/β-Catenin and NF-κB Signaling Pathway during Inflammation

Besides its important role in embryonic development and homeostatic self-renewal in adult tissues, Wnt/β-catenin signaling exerts both anti-inflammatory and proinflammatory functions. This is, at least partially, due to either repressing or enhancing the NF-κB pathway. Similarly, the NF-κB pathway either positively or negatively regulates Wnt/β-catenin signaling. Different components of the two pathways are involved in this crosstalk, forming a complex regulatory network. This review summarizes our current understanding of the molecular mechanisms underlying the cross-regulation between the two pathways and discusses their involvement in inflammation and inflammation-associated diseases such as cancer.

Anthelmintic Niclosamide Disrupts the Interplay of p65 and FOXM1/β-catenin and Eradicates Leukemia Stem Cells in Chronic Myelogenous Leukemia

PURPOSE

Leukemia stem cells (LSC), which are insensitive to tyrosine kinase inhibitors (TKI), are an important source of TKI resistance and disease relapse in chronic myelogenous leukemia (CML). Obstacles to eradicating LSCs include limited understanding of the regulation network of LSCs. The current study aimed to examine the interplay between NF-κB and FOXM1/β-catenin, and the effect of its chemical intervention on CML LSCs.

EXPERIMENTAL DESIGN

The interplay between NF-κB and FOXM1/β-catenin was analyzed by reciprocal coimmunoprecipitation (co-IP) and chromatin immunoprecipitation (ChIP) assay in CML cells. The effect of disturbing NF-κB and FOXM1/β-catenin by niclosamide on the self-renewal capacity and survival of LSCs was evaluated in vitro in human primary CML CD34⁺ cells and in vivo in CML mice.

RESULTS

Reciprocal co-IP experiments showed physical interaction of p65 and FOXM1. p65 promoted transcription of FOXM1 gene. ChIP assay revealed recruitment of p65 on the promoter of FOXM1 gene. Conversely, FOXM1 and β-catenin positively regulated the nuclear translocation and transcriptional activity of NF-κB in CML cells. Niclosamide disrupted the positive feedback loop between NF-κB and FOXM1/β-catenin, thereby impairing the self-renewal capacity and survival of CML LSCs. Niclosamide decreased the long-term engraftment of human CML LSCs in NOD-SCID IL2Rγ chain-deficient (NOG) mice, and prolonged the survival of CML mice.

CONCLUSIONS

Interaction of p65 with FOXM1/β-catenin is critical in CML and its disruption by niclosamide eradicates LSCs. These findings may improve the understanding of a self-renewal regulatory mechanism of LSCs and offer a rationale-based approach to eliminate LSCs in CML. Clin Cancer Res; 23(3); 789-803. ©2016 AACR.

Increased expression of A Proliferation-inducing Ligand (APRIL) in lung leukocytes and alveolar epithelial cells in COPD patients with non small cell lung cancer: a possible link between COPD and lung cancer?

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by an excessive activation of the adaptive immune system and, in particular, uncontrolled expansion of the B-cell pool. One of the key promoters of B cell expansion is A PRoliferation-Inducing Ligand (APRIL). APRIL has been strongly linked to non small cell lung cancer (NSCLC) onset and progression previously. However, little is known about the expression of APRIL in the lungs of COPD patients.

Methods

Using immuno-fluorescence staining, the expression of APRIL was assessed in sections of lungs from 4 subjects with primary diagnosis of COPD (FEV₁ 33 ± 20 % predicted), 4 subjects with primary diagnosis of NSCLC, 4 subjects diagnosed with both COPD and NSCLC, smokers without COPD or NSCLC and 3 healthy never-smokers. The percentage of B cells, alveolar macrophages (AMs) and polymorphonuclear neutrophils (PMNs) in the lung and alveolar epithelial cells (AECs) that stained positively for APRIL was quantified using epi-fluorescence microscopy and image analysis software.

Results

The percentage of APRIL-expressing B cells, AMs, PMNs and alveolar epithelial cells (AECs) was higher in patients having both COPD and NSCLC than in patients with either COPD or NSCLC alone, SC or NSC (p < 0.03 for all comparisons). The percentage of APRIL-expressing AMs and AECs (but not in B cells) was higher in patients with NSCLC alone than in patients with COPD alone. The percentage of APRIL-expressing AECs (but not B cells or AMs) was higher in COPD patients than in SC and NSC (p < 0.05 for all comparisons). The percentage of APRIL-expressing B cells, AMs and AECs cells was similar in NSC and SC.

Conclusion

The percentage of APRIL-expressing B cells, AMs and AECs is higher in the lungs of patients with both COPD and NSCLC than in patients with COPD or NSCLC alone or control subjects. These findings suggest that APRIL may contribute to the pathogenesis of both COPD and NSCLC, and possibly to the development of NSCLC in patients with established COPD.

Overexpression of Suprabasin is Associated with Proliferation and Tumorigenicity of Esophageal Squamous Cell Carcinoma

Suprabasin is a recently identified oncoprotein that is upregulated in multiple cancers. However, the clinical significance and biological role of suprabasin in human esophageal squamous cell carcinoma (ESCC) remains unclear. In the current study, we reported that suprabasin was markedly overexpressed in ESCC cell lines and tissues at both mRNA and protein levels, and this was associated with advanced clinical stage, tumor-nodes-metastasis (TNM) classification, histological differentiation, tumor size and poorer survival. Furthermore, we found that both proliferation and tumorigenicity of ESCC cells were significantly induced by suprabasin overexpression, but inhibited by suprabasin knock-down. Moreover, we demonstrated that upregulation of suprabasin activated the Wnt/β-catenin signaling pathway and led to nuclear localization of β-catenin and upregulation of Cyclin D1 and c-Myc. Together, our results suggest that suprabasin plays an important oncogenic role in promoting proliferation and tumorigenesis of ESCC.

Cathelicidin, an antimicrobial peptide produced by macrophages, promotes colon cancer by activating the Wnt/β-catenin pathway

Here we found that levels of cathelicidin, an antimicrobial peptide, were increased in colon cancer tissues compared to noncancerous tissues. Importantly, cathelicidin was mainly expressed in immune cells. Contact with tumor cells caused macrophages to secrete cathelicidin. Neutralization of cathelicidin, in vivo, significantly reduced the engraftment of macrophages into colon tumors, as well as proliferation of tumor cells, resulting in an inhibition of tumor growth. Furthermore, treatment with cathelicidin neutralizing antibody de-activated the Wnt/β-catenin signaling pathway in tumor cells both in vivo and in vitro. Cathelicidin activated Wnt/β-catenin signaling by inducing phosphorylation of PTEN, leading to activation of PI3K/Akt signaling and subsequent phosphorylation of GSK3β, resulting in stabilization and nuclear translocation of β-catenin. These data indicate that cathelicidin, expressed by immune cells in the tumor microenvironment, promotes colon cancer growth through activation of the PTEN/PI3K/Akt and Wnt/β-catenin signaling pathways.

Cigarette smoke-induced disruption of pulmonary barrier and bacterial translocation drive tumor-associated inflammation and growth

Microorganisms have an important role in tumorgenesis by the induction of inflammation and by a direct impact on tumor cells. Chronic obstructive pulmonary disease (COPD) is associated with an increased risk for lung cancer and microbial colonization. We asked whether bacterial pathogens act as tumor promoters during CS-induced pulmonary inflammation. In a metastatic lung cancer (LC) model, Lewis lung carcinoma (LLC) cells were injected in mice to initiate the growth of tumors in the lung. Exposure to the combination of cigarette smoke (CS) and nontypeable Haemophilus influenzae (NTHi) synergistically increased metastatic growth. Lung levels of albumin and LDH, translocation of bacterial factors into tumor tissue, tumor inflammation, and tumor proliferation were significantly increased in mice exposed to CS in combination with NTHi. Bacterial pathogens increased the proliferation of cultured LLC cells and human cancer cell lines. Metastatic growth induced by the exposure to CS in combination with NTHi was reduced in mice deficient for IL-17. Our data provide evidence that CS-induced loss of pulmonary barrier integrity allows bacterial factors to translocate into tumor tissue and to regulate tumor-associated inflammation and tumor proliferation. Translocation of bacterial factors in tumor tissue links CS-induced inflammation with tumor proliferation.

High expression level of T-box transcription factor 5 predicts unfavorable survival in stage I and II gastric adenocarcinoma

The expression of T-box transcription factor 5 (TBX5) has previously been observed in human cancer. The aim of the present study was to investigate TBX5 expression and its potential clinical significance in gastric cancer (GC). Using reverse transcription-quantitative polymerase chain reaction, the TBX5 mRNA expression levels in 30 pairs of surgically resected healthy gastric tissues and early stage (stages I and II) GC tissues were evaluated. The TBX5 mRNA expression levels were increased in GC stage I and II tumor tissues (P=0.01, n=30) compared with the matched adjacent non-tumor tissue. However, no significant difference was observed in TBX5 mRNA expression levels in matched adjacent non-tumor tissue compared with the tumor tissue from stage III and IV GC samples (P=0.318, n=30). Immunohistochemical analysis for TBX5 expression was performed on 161 paraffin-embedded stage I and II GC tissue blocks. Statistical analysis was performed to evaluate the associations between TBX5 expression, clinicopathological factors and prognosis. Patients with stage I and II GC and tumors with high TBX5 expression levels presented poor overall survival (OS) rate (P=0.024). The Cox proportional hazards model analysis demonstrated that TBX5 expression was an independent risk factor (P=0.017). The present study indicates that high expression of TBX5 is associated with unfavorable OS rates in patients with stage I and II GC. In conclusion, the expression of TBX5 may be a valuable biomarker for the selection of cases of high-risk stage I and II GC.

Il-17A contributes to maintenance of pulmonary homeostasis in a murine model of cigarette smoke-induced emphysema

Smoking is the main risk factor for the development of the chronic obstructive pulmonary disease (COPD) in Western countries. Recent studies suggest that IL-17A and Th17 cells play a role in the pathogenesis of COPD. We used a murine model of chronic cigarette smoke (CS) exposure to explore the contribution of IL-17A to CS-induced lung damage and loss of pulmonary function. Histology and morphometry showed that IL-17A deficiency spontaneously resulted in a loss of lung structure under basal conditions. Even though inflammatory markers [IL-1β and granulocyte colony-stimulating factor (G-CSF)] were decreased in IL-17A-deficient mice (IL-17A(-/-)) exposed to CS compared with wild-type (WT) mice, IL-17A(-/-) mice were per se not protected from CS-induced emphysematous disease. Assessment of pulmonary function showed that IL-17A(-/-) mice were partially protected from CS-induced changes in total lung capacity. However, the respiratory elastance decreased and respiratory compliance increased in IL-17A(-/-) mice after exposure to CS. Morphometry revealed destruction of lung tissue in CS-exposed IL-17A(-/-) mice similar to WT mice. The expression of elastin was decreased in air-exposed IL-17A(-/-) mice and in CS-exposed WT and IL-17A(-/-) mice. Thus, in the present model of sterile CS-exposure, IL-17A contributes to normal lung homeostasis and does not mediate CS-induced loss of lung structure and pulmonary function.

Cigarette smoke-promoted acquisition of bacterial pathogens in the upper respiratory tract leads to enhanced inflammation in mice

BACKGROUND

Bacterial colonization and recurrent infections of the respiratory tract contribute to the progression of chronic obstructive pulmonary disease (COPD). There is evidence that exacerbations of COPD are provoked by new bacterial strains acquired from the environment. Using a murine model of colonization, we examined whether chronic exposure to cigarette smoke (CS) promotes nasopharyngeal colonization with typical lung pathogens and whether colonization is linked to inflammation in the respiratory tract.

METHODS

C57BL/6 N mice were chronically exposed to CS. The upper airways of mice were colonized with nontypeable Haemophilus influenzae (NTHi) or Streptococcus pneumoniae. Bacterial colonization was determined in the upper respiratory tract and lung tissue. Inflammatory cells and cytokines were determined in lavage fluids. RT-PCR was performed for inflammatory mediators.

RESULTS

Chronic CS exposure resulted in significantly increased numbers of viable NTHi in the upper airways, whereas NTHi only marginally colonized air-exposed mice. Colonization with S. pneumoniae was enhanced in the upper respiratory tract of CS-exposed mice and was accompanied by increased translocation of S. pneumoniae into the lung. Bacterial colonization levels were associated with increased concentrations of inflammatory mediators and the number of immune cells in lavage fluids of the upper respiratory tract and the lung. Phagocytosis activity was reduced in whole blood granulocytes and monocytes of CS-exposed mice.

CONCLUSIONS

These findings demonstrate that exposure to CS impacts the ability of the host to control bacterial colonization of the upper airways, resulting in enhanced inflammation and susceptibility of the host to pathogens migrating into the lung.

Overexpression of DHX32 contributes to the growth and metastasis of colorectal cancer

Our previous work demonstrates that DHX32 is upregulated in colorectal cancer (CRC) compared to its adjacent normal tissues. However, how overexpressed DHX32 contributes to CRC remains largely unknown. In this study, we reported that DHX32 was overexpressed in human colon cancer cells. Overexpressed DHX32 promoted SW480 cancer cells proliferation, migration, and invasion, as well as decreased the susceptibility to chemotherapy agent 5-Fluorouracil. Furthermore, PCR array analyses revealed that depleting DHX32 in SW480 colon cancer cells suppressed expression of WISP1, MMP7 and VEGFA in the Wnt pathway, and anti-apoptotic gene BCL2 and CA9, however, elevated expression of pro-apoptotic gene ACSL5. The findings suggested that overexpressed DHX32 played an important role in CRC progression and metastasis and that DHX32 has the potential to serve as a biomarker and a novel therapeutic target for CRC.