Targeting chemokine pathways in esophageal adenocarcinoma

Chemokines and Their Receptors: Predictors of Therapeutic Potential in Tumor Microenvironment on Esophageal Cancer

Esophageal carcinoma (ESCA) is an aggressive solid tumor. The 5-year survival rate for patients with ESCA is estimated to be less than 20%, mainly due to tumor invasion and metastasis. Therefore, it is urgent to improve early diagnostic tools and effective treatments for ESCA patients. Tumor microenvironment (TME) enhances the ability of tumor cells to proliferate, migrate, and escape from the immune system, thus promoting the occurrence and development of tumor. TME contains chemokines. Chemokines consist of four major families, which are mainly composed of CC and CXC families. The main purpose of this review is to understand the CC and CXC chemokines and their receptors in ESCA, to improve the understanding of tumorigenesis of ESCA and determine new biomarkers for the diagnosis and prognosis of ESCA. We reviewed the literature on CC and CXC chemokines and their receptors in ESCA identified by PubMed database. This article introduces the general structures and functions of CC, CXC chemokines and their receptors in TME, as well as their roles in the progress of ESCA. Chemokines are involved in the development of ESCA, such as cancer cell invasion, metastasis, angiogenesis, and radioresistance, and are key determinants of disease progression, which have a great impact on patient prognosis and treatment response. In addition, a full understanding of their mechanism of action is essential to further verify that these chemokines and their receptors may serve as biomarkers or therapeutic targets of ESCA.

Exploring Potential Biomarkers in Oesophageal Cancer: A Comprehensive Analysis

Oesophageal cancer (OC) is the sixth leading cause of cancer-related death worldwide. OC is highly aggressive, primarily due to its late stage of diagnosis and poor prognosis for patients' survival. Therefore, the establishment of new biomarkers that will be measured with non-invasive techniques at low cost is a critical issue in improving the diagnosis of OC. In this review, we summarize several original studies concerning the potential significance of selected chemokines and their receptors, including inflammatory proteins such as interleukin-6 (IL-6) and C-reactive protein (CRP), hematopoietic growth factors (HGFs), claudins (CLDNs), matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), adamalysines (ADAMs), as well as DNA- and RNA-based biomarkers, in OC. The presented results indicate the significant correlation between the CXCL12, CXCR4, CXCL8/CXCR2, M-CSF, MMP-2, MMP-9 ADAM17, ADAMTS-6, and CLDN7 levels and tumor stage, as well as the clinicopathological parameters of OC, such as the presence of lymph node and/or distant metastases. CXCL12, CXCL8/CXCR2, IL-6, TIMP-2, ADAM9, and ADAMTS-6 were prognostic factors for the overall survival of OC patients. Furthermore, IL-6, CXCR4, CXCL8, and MMP-9 indicate higher diagnostic utility based on the area under the ROC curve (AUC) than well-established OC tumor markers, whereas CLDN18.2 can be used in novel targeted therapies for OC patients.

Chemoprevention of esophageal adenocarcinoma in a rat surgical model by a cysteinyl leukotriene receptor‑1 antagonist

Reflux of gastroduodenal contents into the esophagus leads to the development of esophagitis and inflammation-associated pathologies, such as Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). The role of the lipoxygenase (LOX) pathway in carcinogenesis has been recently reported; however, its involvement in esophageal carcinogenesis remains unclear. To address this, the present study investigated the potential of pranlukast, a cysteinyl leukotriene receptor-1 antagonist, to suppress the progression of BE and EAC in a rat duodenogastroesophageal reflux (DGER) model. Male Wistar rats that underwent DGER were divided into two groups. One group was fed commercial chow (control group), and the other was fed experimental chow containing pranlukast (pranlukast group). The rats were sacrificed at 10, 20, 30 and 40 weeks after surgery, and their esophagi were examined. Expression levels of 5-LOX, CD68, IL-8, VEGF and Ki-67 were investigated using immunohistochemistry, and apoptosis was analyzed using the TUNEL method. In the pranlukast group, esophagitis was milder, and the incidence of BE and EAC was significantly lower (P<0.05) compared with that in the control group at 40 weeks after surgery. The number of cells positive for IL-8 and VEGF were significantly lower in the pranlukast group compared with the control group. Proliferative activity was also lower in the pranlukast group compared with the control group (P<0.05). Pranlukast treatment increased apoptosis (P<0.05). Overall, Pranlukast suppressed esophageal carcinogenesis in a rat DGER model, decreasing inflammatory cytokines such as IL-8 and VEGF.

Elevated expression of CXCL3 in colon cancer promotes malignant behaviors of tumor cells in an ERK-dependent manner

BACKGROUND

CXC chemokine ligand 3 (CXCL3) is a member of CXC-type chemokine family that is identified as a major regulator in immune and inflammation responses. Recently, numerous evidence indicated that CXCL3 is broadly expressed in various human tumor types, and it is also known to play a critical role in mediating tumor development and progression. However, the expression profile of CXCL3 and the exact molecular mechanism behind the role of CXCL3 in colon adenocarcinoma (COAD) has not been fully elucidated.

METHODS

The expression and clinical significance of CXCL3 mRNA and protein in the tissues from COAD patients were estimated using bioinformatics and immunohistochemistry assays. The expression and roles of exogenous administration or overexpression of CXCL3 in HT-29 and SW480 COAD cells were determined using enzyme-linked immunosorbent assay(ELISA), Cell Counting Kit-8 (CCK-8) and Transwell assays. Mechanically, CXCL3-induced malignant behaviors were elucidated using western blotting assay and extracellular signal-regulated protein kinase 1/2 (ERk1/2) inhibitor PD98059.

RESULTS

The cancer genome atlas (TCGA)-COAD data analysis revealed that CXCL3 mRNA is highly expressed and has high clinical diagnostic accuracy in COAD. Increased expression of CXCL3 mRNA was associated with patient's clinical stage, race, gender, age, histological subtype, nodal mestastasis and tumor protein 53 (TP53) mutation status. Similarly, immunohistochemistry assay also exhibited that CXCL3 protein in COAD tissues was significantly up-regulated. Gene expression associated assay implied that CXC chemokine ligand 1 (CXCL1) and CXC chemokine ligand 2 (CXCL2) were markedly correlated with CXCL3 in COAD. Protein-protein interaction (PPI) analysis revealed that cyclin B1 (CCNB1), mitotic arrest deficient 2 like 1 (MAD2L1), H2A family member Z (H2AFZ) and CXCL2 may be the important protein molecules involved in CXCL3-related tumor biology. Gene set enrichment analysis (GSEA) analysis revealed that CXCL3 was mainly enriched in the cell cycle, DNA replication, NOD-like receptors, NOTCH and transforming growth factor-β (TGF-β) Signal pathways. In vitro, exogenous administration or overexpression of CXCL3 resulted in increased malignant behaviors of HT-29 and SW480 cells, and down-regulation of CXCL3 expression inhibited the malignant behaviors of these tumor cells. In addition, overexpression of CXCL3 affected the expression of genes related to extracellular signal regulated kinase (ERK) pathway, including ERK1/2, p-ERK, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax) and Cyclin D1. Finally, CXCL3-induced malignant behaviors in HT-29 and SW480 cells were obviously attenuated following treatment with ERK inhibitor PD98059.

CONCLUSION

CXCL3 is upregulated in COAD and plays a crucial role in the control of malignant behaviors of tumor cells, which indicated its involvement in the pathogenesis of COAD.

Characterizing isoform switching events in esophageal adenocarcinoma

Isoform switching events with predicted functional consequences are common in many cancers, but characterization of switching events in esophageal adenocarcinoma (EAC) is lacking. Next-generation sequencing was used to detect levels of RNA transcripts and identify specific isoforms in treatment-naïve esophageal tissues ranging from premalignant Barrett’s esophagus (BE), BE with low- or high-grade dysplasia (BE.LGD, BE.HGD), and EAC. Samples were stratified by histopathology and TP53 mutation status, identifying significant isoform switching events with predicted functional consequences. Comparing BE.LGD with BE.HGD, a histopathology linked to cancer progression, isoform switching events were identified in 75 genes including KRAS, RNF128, and WRAP53. Stratification based on TP53 status increased the number of significant isoform switches to 135, suggesting switching events affect cellular functions based on TP53 mutation and tissue histopathology. Analysis of isoforms agnostic, exclusive, and shared with mutant TP53 revealed unique signatures including demethylation, lipid and retinoic acid metabolism, and glucuronidation, respectively. Nearly half of isoform switching events were identified without significant gene-level expression changes. Importantly, two TP53-interacting isoforms, RNF128 and WRAP53, were significantly linked to patient survival. Thus, analysis of isoform switching events may provide new insight for the identification of prognostic markers and inform new potential therapeutic targets for EAC.

Expression of chemokine CXCL8/9/10/11/13 and its prognostic significance in head and neck cancer

BACKGROUND

Head and neck cancer (HNC) is a very popular cancer, with many primary sites and pathological types, at the top of the list of tumors. Chemokines are a class of small molecular basic proteins, whose N-terminal cysteine residues can be divided into four subunits by location and number, which significantly enhances the expression level in all kinds of cancers. However, in HNC, especially in head and neck squamous cell carcinoma, the chemokine CXCL8/9/10/11/13 has not been clearly explored for its diagnosis and prognosis.

METHODS

The ONCOMINE database was used to analyze the expression of chemokine family in various cancers. After CXCL8/9/10/11/13 was screened out, the expression of CXCL 8/9/11/13 in patients with HNC/normal people were analyzed by UALCAN database. The expression and pathological stages of CXCL 8/9/10/13 in HNC tissues were analyzed by the GEPIA database, and the relationship between its mRNA expression and the overall survival (OS) time of patients with HNC was analyzed by Kaplan-Meier plotter database. In addition, 171 co-expressed genes significantly related to CXCL8/9/10/11/13 mutation were screened by online tool cBioPortal, and the protein interaction network of these genes was constructed by STRING database. Finally, the potential functions of CXCL8/9/10/11/13 and its 171 co-expressed genes were explored by the enrichment and analysis function of David database.

RESULTS

Transcriptional expression of chemokine 8/9/10/11/13 was significantly increased in patients with HNC. Clinical stage of patients with HNC was significantly correlated with overexpression of CXCL9/10/11. In addition, the chemokine CXCL8/9/10/13 was significantly correlated with over-survival of patients with HNC, so it could be distinguished between short-term and long-term survival of patients with HNC. In conclusion, CXCL8/9/10/11/13 closely connected with the expression and prognosis of HNC.

CONCLUSION

In this study, our results suggest that chemokine CXCL8/9/10/11/13 may play a critical role in the development of HNC, and, according to relevant data, it may affect the survival and prognosis of patients with HNC.

Cytokine Interaction With Cancer-Associated Fibroblasts in Esophageal Cancer

Esophageal cancer (EC) is a highly aggressive cancer with poor outcomes under current treatment regimens. More recent findings suggest stroma elements, specifically cancer-associated fibroblasts (CAFs), play a role in disease occurrence and progression. Cancer-associated fibroblasts are largely the product of converted fibroblasts, but a variety of other local cell types including epithelial cells, endothelial cells, and mesenchymal cells have also been shown to transform to CAFs under the correct conditions. Cancer-associated fibroblasts primarily function in the communication between the tumor microenvironment and cancer cells via cytokine and chemokine secretions that accentuate immunosuppression and cancer growth. Cancer-associated fibroblasts also pose issues for EC treatment by contributing to resistance of current chemotherapeutics like cisplatin. Targeting this cell type directly proves difficult given the heterogeneity between CAFs subpopulations, but emerging research provides hope that treatment is on the horizon. This review aims to unravel some of the complexities surrounding CAFs’ impact on EC growth and therapy.

Chemokine-targeted therapies: An opportunity to remodel immune profiles in gastro-oesophageal tumours

Immunotherapies are transforming outcomes for many cancer patients and are quickly becoming the fourth pillar of cancer therapy. However, their efficacy of only ∼25% in gastro-oesophageal cancer has been disappointing. This is attributed to factors such as insufficient patient stratification and the pro-tumourigenic immune landscape of gastro-oesophageal tumours. The chemokine profiles of solid tumours and the availability of effector immune cells greatly influence the immune infiltrate, producing 'cold' or 'immune-excluded' tumours in which immunotherapies are unable to reinvigorate the immune response. Other biological functions for chemokines have emerged, such as promoting cell survival, polarising T cell responses, and supporting several hallmarks of cancer. Therefore, chemokine networks may be exploited with therapeutic intent to mobilise and polarise anti-tumour immune cells, with further utility as combination treatments to augment the efficacy of current cancer immunotherapies. Few studies have demonstrated the clinical benefit of chemokine-targeted therapies as monotherapies, and this review proposes their consideration as combination treatments. Herein, we explore the anti-tumour and pro-tumour implications of chemokine signalling in gastro-oesophageal cancer and discuss their value as prognostic and predictive biomarkers in response to treatment.

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.

Bioinformatics analysis of laryngeal squamous cell carcinoma: seeking key candidate genes and pathways

Background

Laryngeal squamous cell carcinoma (LSCC) is the second most aggressive head and neck squamous cell carcinoma. Although much work has been done to optimize its treatment, patients with LSCC still have poor prognosis. Therefore, figuring out differentially expressed genes (DEGs) contained in the progression of LSCC and employing them as potential therapeutic targets or biomarkers for LSCC is extremely meaningful.

Methods

Overlapping DEGs were screened from two standalone Gene Expression Omnibus datasets, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed. By applying STRING and Cytoscape, a protein–protein network was built, and module analysis was carried out. The hub genes were selected by maximal clique centrality with the CytoHubba plugin of Cytoscape. UALCAN and GEPIA data were examined to validate the gene expression findings. Moreover, the connection of the hub genes with LSCC patient overall survival was studied employing The Cancer Genome Atlas. Then, western blot, qRT-PCR, CCK-8, wound healing and transwell assays were bring to use for further verify the key genes.

Results

A total of 235 DEGs were recorded, including 83 upregulated and 152 downregulated genes. A total of nine hub genes that displayed a high degree of connectivity were selected. UALCAN and GEPIA databases verified that these genes were highly expressed in LSCC tissues. High expression of the SPP1, SERPINE1 and Matrix metalloproteinases 1 (MMP1) genes was connected to worse prognosis in patients with LSCC, according to the GEPIA online tool. Western blot and qRT-PCR testify SPP1, SERPINE1 and MMP1 were upregulated in LSCC cells. Inhibition of SPP1, SERPINE1 and MMP1 suppressed cell proliferation, invasion and migration.

Conclusion

The work here identified effective and reliable diagnostic and prognostic molecular biomarkers by unified bioinformatics analysis and experimental verification, indicating novel and necessary therapeutic targets for LSCC.

Cytokine-chemokine network driven metastasis in esophageal cancer; promising avenue for targeted therapy

Esophageal cancer (EC) is a disease often marked by aggressive growth and poor prognosis. Lack of targeted therapies, resistance to chemoradiation therapy, and distant metastases among patients with advanced disease account for the high mortality rate. The tumor microenvironment (TME) contains several cell types, including fibroblasts, immune cells, adipocytes, stromal proteins, and growth factors, which play a significant role in supporting the growth and aggressive behavior of cancer cells. The complex and dynamic interactions of the secreted cytokines, chemokines, growth factors, and their receptors mediate chronic inflammation and immunosuppressive TME favoring tumor progression, metastasis, and decreased response to therapy. The molecular changes in the TME are used as biological markers for diagnosis, prognosis, and response to treatment in patients. This review highlighted the novel insights into the understanding and functional impact of deregulated cytokines and chemokines in imparting aggressive EC, stressing the nature and therapeutic consequences of the cytokine-chemokine network. We also discuss cytokine-chemokine oncogenic potential by contributing to the Epithelial-Mesenchymal Transition (EMT), angiogenesis, immunosuppression, metastatic niche, and therapeutic resistance development. In addition, it discusses the wide range of changes and intracellular signaling pathways that occur in the TME. Overall, this is a relatively unexplored field that could provide crucial insights into tumor immunology and encourage the effective application of modulatory cytokine-chemokine therapy to EC.

Construction and Validation of a 7-Immune Gene Model for Prognostic Assessment of Esophageal Carcinoma

Background

We constructed a predictive risk model of esophageal carcinoma (EC) for prognostic prediction.

Material/Methods

Immune genes and the expression data were downloaded from the ImmPort database and The Cancer Genome Atlas database. Univariate analysis, Lasso regression, and multivariate analysis were applied to screen the ultimately included prognostic immune genes for the model based on the training cohort. Survival analysis and receiver operating characteristic (ROC) curve were applied to evaluate the model. The model was further validated in the testing and entire cohorts, and the clinical utility of the model and its ability to assess the subtypes of EC were evaluated in the entire cohort.

Results

We detected 297 differentially expressed immune genes, including 241 upregulated genes and 56 downregulated genes in EC patients. Based on these genes, we developed a 7-immune gene model of EC, including HSPA6, S100A12, NOS2, DKK1, OSM, AR, and OXTR. The area under the curve (AUC) of the model at 1 year was 0.825. Similarly, the AUC values for the validating cohorts were 0.813 and 0.816, respectively. Pathological stage and risk score of the model were independent prognostic factors. This model was effective for both subtypes of EC.

Conclusions

We constructed a 7-gene model consisting of HSPA6, S100A12, NOS2, DKK1, OSM, AR, and OXTR. This risk model could be used for prognostic prediction of EC.

Specific Receptors for the Chemokines CXCR2 and CXCR4 in Pancreatic Cancer

Background: The mortality rate of pancreatic cancer (PC) is equal to its incidence and the majority of PC patients die within a few months of diagnosis. Therefore, a search for new biomarkers useful in the diagnosis and prognosis of PC is ongoing. Objectives: The aim of our study was to compare the utility of CXCR2 and CXCR4 in the diagnosis and prediction of PC with classical tumor marker (carcinoembryonic antigen, CEA) and marker of inflammation–C-reactive protein (CRP). Patients and Methods: The study comprised 64 subjects — 32 PC patients and 32 healthy volunteers. Serum concentrations of tested proteins were analysed using immunological methods. Results: Serum CXCR2 and CXCR4 concentrations, similarly to those of CEA and CRP, were significantly elevated in PC patients compared to healthy controls. Moreover, concentrations of CXCR4 were significantly correlated with CXCR2 and CRP levels, while CRP concentrations were correlated with CXCR2 and CEA levels. The diagnostic sensitivity and the predictive value for negative (PV_−ve) results for CXCR4 were similar to those of CEA and higher than those of CXCR2 and CRP, while the area under the ROC curve (AUC) for CXCR4 was the highest among all tested proteins (CXCR2, CEA, CRP). Moreover, serum CXCR2 was found to be a significant predictor of PC risk. Conclusions: CXCR4 is a better candidate for a tumor marker than CXCR2 in the diagnosis of PC, while serum CXCR2 is a significant predictor of PC risk.

Characterizing caspase-1 involvement during esophageal disease progression

Barrett's esophagus (BE) is an inflammatory condition and a neoplastic precursor to esophageal adenocarcinoma (EAC). Inflammasome signaling, which contributes to acute and chronic inflammation, results in caspase-1 activation leading to the secretion of IL-1β and IL-18, and inflammatory cell death (pyroptosis). This study aimed to characterize caspase-1 expression, and its functional importance, during disease progression to BE and EAC. Three models of disease progression (Normal-BE-EAC) were employed to profile caspase-1 expression: (1) a human esophageal cell line model; (2) a murine model of BE; and (3) resected tissue from BE-associated EAC patients. BE patient biopsies and murine BE organoids were cultured ex vivo in the presence of a caspase-1 inhibitor, to determine the importance of caspase-1 for inflammatory cytokine and chemokine secretion.Epithelial caspase-1 expression levels were significantly enhanced in BE (p < 0.01). In contrast, stromal caspase-1 levels correlated with histological inflammation scores during disease progression (p < 0.05). Elevated secretion of IL-1β from BE explanted tissue, compared to adjacent normal tissue (p < 0.01), confirmed enhanced activity of caspase-1 in BE tissue. Caspase-1 inhibition in LPS-stimulated murine BE organoids caused a significant reduction in IL-1β (p < 0.01) and CXCL1 (p < 0.05) secretion, confirming the importance of caspase-1 in the production of cytokines and chemokines associated with disease progression from BE to EAC. Targeting caspase-1 activity in BE patients should therefore be tested as a novel strategy to prevent inflammatory complications associated with disease progression.

The significance of chemokine CXCL-8 in esophageal carcinoma

Chemokines are a group of small molecular weight proteins that are structurally related. These molecules play an important role in the growth, differentiation and activation of many types of cells [1, 2]. Chemokines are synthesized mostly by leukocytes and act through their cognate G-protein coupled receptors to cause a cellular response, such as migration, adhesion or chemotaxis [1, 3]. The chemokine family has been classified into four classes: CC, CXC, CX3C, and (X), based on the arrangement of N-terminal cysteine residues [4]. These small peptides may also be grouped into inflammatory, homeostatic or dual function chemokines. Inflammatory chemokines can be induced during an immune response, whereas homeostatic chemokines are involved in control of cell migration [5]. The chemokine receptors are seven-transmembrane receptors coupled to G-proteins, that consist of an N-terminus outside the cell surface, three extracellular and three intracellular loops as well as a C-terminus in the cytoplasm [6, 7].

CXC Chemokine Receptors in the Tumor Microenvironment and an Update of Antagonist Development

Chemokine receptors, a diverse group within the seven-transmembrane G protein-coupled receptor superfamily, are frequently overexpressed in malignant tumors. Ligand binding activates multiple downstream signal transduction cascades that drive tumor growth and metastasis, resulting in poor clinical outcome. These receptors are thus considered promising targets for anti-tumor therapy. This article reviews recent studies on the expression and function of CXC chemokine receptors in various tumor microenvironments and recent developments in cancer therapy using CXC chemokine receptor antagonists.

High-Fat Diet Accelerates Carcinogenesis in a Mouse Model of Barrett's Esophagus via Interleukin 8 and Alterations to the Gut Microbiome

BACKGROUND & AIMS

Barrett's esophagus (BE) is a precursor to esophageal adenocarcinoma (EAC). Progression from BE to cancer is associated with obesity, possibly due to increased abdominal pressure and gastroesophageal reflux disease, although this pathogenic mechanism has not been proven. We investigated whether environmental or dietary factors associated with obesity contribute to the progression of BE to EAC in mice.

METHODS

Tg(ED-L2-IL1RN/IL1B)#Tcw mice (a model of BE, called L2-IL1B mice) were fed a chow (control) or high-fat diet (HFD) or were crossbred with mice that express human interleukin (IL) 8 (L2-IL1B/IL8 mice). Esophageal tissues were collected and analyzed for gene expression profiles and by quantitative polymerase chain reaction, immunohistochemistry, and flow cytometry. Organoids were established from BE tissue of mice and cultured with serum from lean or obese individuals or with neutrophils from L2-IL1B mice. Feces from mice were analyzed by 16s ribosomal RNA sequencing and compared to 16s sequencing data from patients with dysplasia or BE. L2-IL1B were mice raised in germ-free conditions.

RESULTS

L2-IL1B mice fed an HFD developed esophageal dysplasia and tumors more rapidly than mice fed the control diet; the speed of tumor development was independent of body weight. The acceleration of dysplasia by the HFD in the L2-IL1B mice was associated with a shift in the gut microbiota and an increased ratio of neutrophils to natural killer cells in esophageal tissues compared with mice fed a control diet. We observed similar differences in the microbiomes from patients with BE that progressed to EAC vs patients with BE that did not develop into cancer. Tissues from dysplasias of L2-IL1B mice fed the HFD contained increased levels of cytokines that are produced in response to CXCL1 (the functional mouse homolog of IL8, also called KC). Serum from obese patients caused organoids from L2-IL1B/IL8 mice to produce IL8. BE tissues from L2-IL1B mice fed the HFD and from L2-IL1B/IL8 mice contained increased numbers of myeloid cells and cells expressing Cxcr2 and Lgr5 messenger RNAs (epithelial progenitors) compared with mice fed control diets. BE tissues from L2-IL1B mice raised in germ-free housing had fewer progenitor cells and developed less dysplasia than in L2-IL1 mice raised under standard conditions; exposure of fecal microbiota from L2-IL1B mice fed the HFD to L2-IL1B mice fed the control diet accelerated tumor development.

CONCLUSIONS

In a mouse model of BE, we found that an HFD promoted dysplasia by altering the esophageal microenvironment and gut microbiome, thereby inducing inflammation and stem cell expansion, independent of obesity.

Comparison between clinical significance of serum CXCL-8 and classical tumor markers in oesophageal cancer (OC) patients

C-X-C motif chemokine 8 (CXCL-8), known as interleukin-8, is a pro-inflammatory cytokine which acts as a chemotactic factor, mainly for leukocytes. CXCL-8 is produced by malignant cells, and therefore it can stimulate the growth and progression of various neoplasms, including oesophageal cancer (OC). The aim of the current study was to measure serum concentrations of chemokine CXCL-8 in OC patients and establish whether this protein might be considered a potential candidate for a tumor marker in the diagnosis and progression of OC. The study included 50 OC subjects (32 patients with squamous cell carcinoma of oesophagus-OSCC, 18 patients with adenocarcinoma-OAC) and 26 healthy volunteers. Serum CXCL-8 concentrations were measured using immunoenzymatic assay (ELISA). CRP levels were determined by immunoturbidimetric method, while classical tumor marker levels were measured using chemiluminescent immunoassay. CXCL-8 concentrations were significantly higher in OC patients compared to healthy controls. We demonstrated significant differences between CXCL-8 concentrations and depth of tumor invasion (T factor) in OC patients and OSCC subgroup. In addition, CXCL-8 levels were found to correlate positively with T factor and CRP concentrations. The diagnostic sensitivity, negative predictive value and the area under ROC curve (AUC) of CXCL-8 were higher than those of classical tumor markers. Our findings suggest the potential usefulness of CXCL-8 in the diagnosis and progression of OC. However, due to the non-specific nature of this chemokine, further research is needed to clarify the usefulness of CXCL-8 as a tumor marker of OC.

Novel drug candidates for treating esophageal carcinoma: A study on differentially expressed genes, using connectivity mapping and molecular docking

Patients with esophageal carcinoma (ESCA) have a poor prognosis and high mortality rate. Although standard therapies have had effect, there is an urgent requirement to develop novel options, as increasing drug tolerance has been identified in clinical practice. In the present study, differentially expressed genes (DEGs) of ESCA were identified in The Cancer Genome Atlas and Genotype-Tissue Expression databases. Functional and protein-protein interaction (PPI) analyses were performed. The Connectivity Map (CMAP) was selected to predict drugs for the treatment of ESCA, and their target genes were acquired from the Search Tool for Interactions of Chemicals (STITCH) by uploading the Simplified Molecular-Input Line-Entry System structure. Additionally, significant target genes and ESCA-associated hub genes were extracted using another PPI analysis, and the corresponding drugs were added to construct a network. Furthermore, the binding affinity between predicted drug candidates and ESCA-associated hub genes was calculated using molecular docking. Finally, 827 DEGs (|log₂ fold-change|≥2; q-value <0.05), which are principally involved in protein digestion and absorption (P<0.005), the plasminogen-activating cascade (P<0.01), as well as the ‘biological regulation’ of the Biological Process, ‘membrane’ of the Cellular Component and ‘protein binding’ of the Molecular Function categories, were obtained. Additionally, 11 hub genes were obtained from the PPI network (all degrees ≥30). Furthermore, the 15 first screen drugs were extracted from CMAP (score <−0.85) and the 9 second screen drugs with 70 target genes were extracted from STITCH. Furthermore, another PPI analysis extracted 51 genes, and apigenin, baclofen, Prestwick-685, menadione, butyl hydroxybenzoate, gliclazide and valproate were selected as drug candidates for ESCA. Those molecular docking results with a docking score of >5.52 indicated the significance of apigenin, Prestwick-685 and menadione. The results of the present study may lead to novel drug candidates for ESCA, among which Prestwick-685 and menadione were identified to be significant new drug candidates.

Distinct esophageal adenocarcinoma molecular subtype has subtype-specific gene expression and mutation patterns

Background

Esophageal carcinoma (EC), consists of two histological types, esophageal squamous carcinoma (ESCC) and esophageal adenocarcinoma (EAC). EAC accounted for 10% of EC for centuries; however, the prevalence of EAC has alarmingly risen 6 times and increased to about 50% of EC in recent 30 years in the western countries, while treatment options for EAC patients are still limited. Stratification of molecular subtypes by gene expression profiling methods had offered opportunities for targeted therapies. However, the molecular subtype in EAC has not been defined. Hence, Identification of EAC molecular subtypes is needed and will provide important insights for future new therapies.

Results

We performed meta-analysis of gene expression profiling data on three independent EAC cohorts and showed that there are two common molecular subtypes in EAC. Each of the two EAC molecular subtypes has subtype specific expression patterns and mutation signatures. Genes which were over-expressed in subtype I EACs rather than subtype II EAC cases, were enriched in biological processes including epithelial cell differentiation, keratinocyte differentiation, and KEGG pathways including basal cell carcinoma. TP53 and CDKN2A are significantly mutated in both EAC subtypes. 24 genes including SMAD4 were found to be only significantly mutated in subtype I EAC cases, while 30 genes including ARID1A are only significantly mutated in subtype II EACs.

Conclusion

Two EAC molecular subtypes were defined and validated. This finding may offer new opportunities for targeted therapies.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5165-0) contains supplementary material, which is available to authorized users.

The role of selected chemokines and their specific receptors in pancreatic cancer

Pancreatic carcinoma is a highly malignant disease associated with an extremely poor prognosis, which is caused by late presentation, aggressive invasion and metastases, as well as the detection of pancreatic carcinoma in its advanced stages. Thus, better understanding of the tumour biology of this malignancy is sorely needed to improve the clinical outcome. A great challenge for the medical practice is finding a new biomarker of pancreatic carcinoma that will be helpful in diagnosis, in prognosis and in making clinical decisions, including the assessment of patients' response to therapy. It is suggested that selected chemokines and their specific receptors play an important role in tumour progression, such as tumour growth, angiogenesis, proliferation and development of metastasis. In the present review, general characteristics of chemokines and their specific receptors as well as the significance of these molecules in tumour development are described. The crucial issue of this review is to summarise the importance of various chemokines and their specific receptors in pancreatic carcinoma. Understanding the role of chemokines in the pathogenesis of pancreatic carcinoma is extremely important since these proteins may be used as a potential tool in the diagnosis and prognosis of pancreatic carcinoma patients.

Identification of genes and pathways in esophageal adenocarcinoma using bioinformatics analysis

Esophageal adenocarcinoma (EAC) is one of the most common subtypes of esophageal cancer, and is associated with a low 5-year survival rate. The present study aimed to identify key genes and pathways associated with EAC using bioinformatics analysis. The gene expression profiles of GSE92396, which includes 12 EAC samples and 9 normal esophageal samples, were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between the EAC and normal samples were identified using the limma package in R language. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the identified DEGs were conducted using the online analysis tool, the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction (PPI) network of the DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape software. Finally, module analysis was conducted for the PPI network using the MCODE plug-in in Cytoscape. Of the 386 DEGs identified, the 150 upregulated genes were mainly enriched in the KEGG pathways of complement and coagulation cascades, maturity onset diabetes of the young and protein digestion and absorption; and the 236 downregulated genes were mainly enriched in amoebiasis, retinol metabolism and drug metabolism-cytochrome P450. Based on information from the STRING database, a PPI network comprising of 369 nodes and 534 edges was constructed in Cytoscape. The top 10 hub nodes with the highest degrees were determined as interleukin-8, involucrin, tissue inhibitor of metalloproteinase 1, fibronectin 1, serpin family E member 1, serpin family A member 1, cystic fibrosis transmembrane conductance regulator, secreted phosphoprotein 1, collagen type I alpha 1 chain and angiotensinogen. A total of 6 modules were detected from the PPI network that satisfied the criteria of MCODE score >4 and number of nodes >4. KEGG pathways enriched for the module DEGs were mainly within arachidonic acid metabolism, complement and coagulation cascades and rheumatoid arthritis. In conclusion, identification of these key genes and pathways may improve understanding of the mechanisms underlying the development of EAC, and may be used as diagnostic and therapeutic targets in EAC.

Matrix Metalloproteinases and Their Tissue Inhibitors in Comparison to Other Inflammatory Proteins in Gastric Cancer (GC)

Gastric cancer (GC) remains a major cause of cancer-related deaths worldwide. The lack of management strategies for the diagnosis of GC in patients gives rise to the challenging questions about the new tumor markers for GC. Developing malignant process may induce local and systemic inflammatory responses. Cancer-associated inflammation is characterized by the infiltration of immune cells. Thus, the inflammation-related proteins, such as cytokines, chemokines, and selected matrix metalloproteinases, may facilitate the growth, proliferation, and migration of tumor cells, including GC. Based on our previous findings, we assessed the significance of various inflammatory mediators as candidates for tumor markers of GC.

CXCL3 contributes to CD133(+) CSCs maintenance and forms a positive feedback regulation loop with CD133 in HCC via Erk1/2 phosphorylation

Although the chemotactic cytokine CXCL3 is thought to play an important role in tumor initiation and invasion, little is known about its function in hepatocellular carcinoma (HCC). In our previous study, we found that Ikaros inhibited CD133 expression via the MAPK pathway in HCC. Here, we showed that Ikaros may indirectly down-regulate CXCL3 expression in HCC cells, which leads to better outcomes in patients with CD133⁺ cancer stem cell (CSC) populations. CD133 overexpression induced CXCL3 expression, and silencing of CD133 down-regulated CXCL3 in HCC cells. Knockdown of CXCL3 inhibited CD133⁺ HCC CSCs’ self-renewal and tumorigenesis. The serum CXCL3 level was higher in HCC patients’ samples than that in healthy individual. HCC patients with higher CXCL3 expression displayed a poor prognosis, and a high level of CXCL3 was significantly associated with vascular invasion and tumor capsule formation. Exogenous CXCL3 induced Erk1/2 and ETS1 phosphorylation and promoted CD133 expression, indicating a positive feedback loop between CXCL3 and CD133 gene expression in HCC cells via Erk1/2 activation. Together, our findings indicated that CXCL3 might be a potent therapeutic target for HCC.

The Serum Concentrations of Chemokine CXCL12 and Its Specific Receptor CXCR4 in Patients with Esophageal Cancer

Objectives. Recent investigations have suggested that upregulated levels of inflammatory biomarkers, such as chemokines, may be associated with development of many malignancies, including esophageal cancer (EC). Based on our knowledge, this study is the first to assess the serum concentration of chemokine CXCL12 and its specific receptor CXCR4 in the diagnosis of EC patients. Material and Methods. The present study included 79 subjects: 49 patients with EC and 30 healthy volunteers. The serum concentrations of CXCL12 and CXCR4 and classical tumor markers such as carcinoembryonal antigen (CEA) and squamous cell cancer antigen (SCC-Ag) were measured using immunoenzyme assays, while C-reactive protein (CRP) levels were assessed by immunoturbidimetric method. Moreover, diagnostic criteria of all proteins tested and the survival of EC patients were assessed. Results. The serum concentrations of CXCL12 were significantly higher, while those of its receptor CXCR4 were significantly lower in EC patients compared to healthy controls. The diagnostic sensitivity, negative predictive value, and accuracy of CXCR4 were the highest among all analyzed proteins and increased for combined analysis with classical tumor markers and CRP levels. Conclusion. Our findings suggest that serum CXCR4 may improve the diagnosis of EC patients, especially in combination with classical tumor markers.

Chemokines and their receptors in esophageal cancer--the systematic review and future perspectives

Esophageal cancer (EC) is an aggressive malignant solid tumor with rapid progression and unfavorable prognosis. The 5-year survival rate for EC patients was estimated to be less than 10 %. Therefore, there is an urgent need to improve diagnostic tool and effective treatment therapies for EC patients. In our paper, the general structure and function of chemokines and their receptors as well as their role in cancer progression were shortly presented. Moreover, the aim of our paper was to summarize and refer the current findings concerning the role of selected chemokines and their receptors as candidates for tumor markers of EC. Some clinical investigations have proved the involvement of these proteins in proliferation, migration, invasiveness and metastasis of tumor cells. Increasing evidence from previous studies suggested that C-X-C motif chemokine 12 (CXCL12), also known as stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 may provide novel diagnostic and prognostic strategies to reduce the burden of EC. Moreover, therapy targeting the CXCL12/CXCR4 axis may open a new direction for treatment of EC patients. However, given their nonspecific nature, the diagnostic value of chemokines and their receptors may be limited. Therefore, future larger investigations, especially in the blood of EC patients, still need to be continued to further clarify the significance of these proteins as potential candidates for tumor markers in diagnosis and prognosis of EC patients.