CXCL10 Expression Status is Prognostic in Patients with Advanced Thoracic Esophageal Squamous Cell Carcinoma

Lipopolysaccharide induces CCL2 through TLR4 signaling and promotes esophageal squamous cell carcinoma cell proliferation

Poor oral health is an independent risk factor for upper-aerodigestive tract cancers, including esophageal squamous cell carcinoma (ESCC). Our previous findings suggest that high expression of toll-like receptor (TLR) 4, which recognizes lipopolysaccharide (LPS) released from periodontal pathogens, correlates with a poor prognosis after esophagectomy for ESCC. We therefore hypothesized that LPS influences cancer cell proliferation and disease progression in ESCC. We used 8 ESCC cell lines to investigate how LPS affects ESCC cell proliferation and migration activity. We also assessed mRNA and protein expression to determine how LPS affects cytokine production and whether blocking TLR4 signaling attenuates that effect. We also used a mouse xenograft model to investigate whether LPS upregulates ESCC tumor progression in vivo. We then determined whether C-C motif chemokine ligand 2 (CCL2) expression in clinical samples correlates with 5-year overall survival (OS) and disease-specific survival (DSS) in ESCC patients after esophagectomy. LPS significantly upregulated cell proliferation and migration in all ESCC lines. It also upregulated CCL2 production. In vivo, subcutaneous LPS administration significantly increased ESCC tumor volume in mice. In clinical samples, high CCL2 expression significantly correlated with 5-year OS and DSS. There was also a significant correlation between CCL2 and TLR4 expression status, suggesting the involvement of an LPS-TLR4-CCL2 cascade in clinical settings. LPS significantly upregulates cell proliferation and tumor progression through an LPS-TLR4-CCL2 cascade and influences prognosis after esophagectomy for ESCC. This suggests improving the oral environment has the potential to improve the prognosis of ESCC patients after esophagectomy.

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.

Pretreatment periodontitis is predictive of a poorer prognosis after esophagectomy for esophageal cancer

BACKGROUND

Poor oral health is an independent risk factor for upper-aerodigestive tract cancers, including esophageal cancer. Several studies have investigated short-term outcomes after esophagectomy and the impact of periodontal disease, but few have examined the impact of periodontal disease on long-term outcomes. The purpose of this study was to investigate the rate of periodontitis among esophagectomy patients and the prognostic value of periodontitis and its effect on prognosis after esophagectomy.

METHODS

A total of 508 patients who underwent esophagectomy received oral health care from a dentist before cancer treatment at Akita University Hospital between January 2009 and December 2021. We assessed the presence and severity of the patients' periodontitis and divided them into no-periodontitis, mild periodontitis, severe periodontitis and edentulous jaw groups. We then assessed 10-year overall survival (OS) and disease-specific survival (DSS) and determined whether periodontitis was an independent prognostic factor affecting OS and DSS.

RESULTS

We found that 101 (19.9%) patients had no periodontitis, 207 (40.8%) had mild periodontitis, 176 (34.6%) had severe periodontitis requiring tooth extraction, and 24 (4.7%) had edentulous jaw. Both OS and DSS were significantly poorer in the periodontitis than no-periodontitis group (p < 0.001). In detail, the edentulous jaw group had the poorest prognosis (p < 0.001). Multivariate analysis showed that periodontitis was an independent risk factor affecting OS and DSS.

CONCLUSION

Esophageal cancer patients had a high prevalence of periodontitis. Moreover, the presence of periodontitis and severity of periodontitis are independent risk factors contributing to a poorer prognosis after esophagectomy.

Combined use of NK cells and radiotherapy in the treatment of solid tumors

Natural killer (NK) cells are innate lymphocytes possessing potent tumor surveillance and elimination activity. Increasing attention is being focused on the role of NK cells in integral antitumor strategies (especially immunotherapy). Of note, therapeutic efficacy is considerable dependent on two parameters: the infiltration and cytotoxicity of NK cells in tumor microenvironment (TME), both of which are impaired by several obstacles (e.g., chemokines, hypoxia). Strategies to overcome such barriers are needed. Radiotherapy is a conventional modality employed to cure solid tumors. Recent studies suggest that radiotherapy not only damages tumor cells directly, but also enhances tumor recognition by immune cells through altering molecular expression of tumor or immune cells via the in situ or abscopal effect. Thus, radiotherapy may rebuild a NK cells-favored TME, and thus provide a cost-effective approach to improve the infiltration of NK cells into solid tumors, as well as elevate immune-activity. Moreover, the radioresistance of tumor always hampers the response to radiotherapy. Noteworthy, the puissant cytotoxic activity of NK cells not only kills tumor cells directly, but also increases the response of tumors to radiation via activating several radiosensitization pathways. Herein, we review the mechanisms by which NK cells and radiotherapy mutually promote their killing function against solid malignancies. We also discuss potential strategies harnessing such features in combined anticancer care.

High TLR6 Expression Status Predicts a More Favorable Prognosis after Esophagectomy for Locally Advanced Thoracic Esophageal Squamous Cell Carcinoma

Most so-called "beneficial bacteria" in gut microbiota are Gram-positive, and TLR6 recognizes the peptidoglycan (PGN) present in their cell walls. We hypothesized that a high TLR6 expression status predicts a more favorable prognosis after esophagectomy. We used an ESCC tissue microarray (TMA) to examine TLR6 expression status in ESCC patients and to determine whether TLR6 expression status correlates with prognosis after curative esophagectomy. We also examined whether PGN influences the cell proliferation activity of ESCC lines. Clinical ESCC samples from 177 patients tested for the expression of TLR6 were categorized as 3+ (n = 17), 2+ (n = 48), 1+ (n = 68), or 0 (n = 44). High TLR6 expression (3+ and 2+) correlated with significantly more favorable 5-year overall survival (OS) and disease-specific survival (DSS) after esophagectomy than a lower TLR6 expression (1+ and 0). Univariate and multivariate analyses showed that TLR6 expression status is an independent prognostic factor that affects 5-year OS. PGN significantly inhibited the cell proliferation activity of ESCC lines. This is the first study to show that high TLR6 expression status predicts a more favorable prognosis in locally advanced thoracic ESCC patients after curative esophagectomy. PGN released from "beneficial bacteria" seems to have potential to inhibit the cell proliferation activity of ESCC.

Differential Anti-Tumor Effects of IFN-Inducible Chemokines CXCL9, CXCL10, and CXCL11 on a Mouse Squamous Cell Carcinoma Cell Line

Chemokines are a group of cytokines involved in the mobilization of leukocytes, which play a role in host defense and a variety of pathological conditions, including cancer. Interferon (IFN)-inducible chemokines C-X-C motif ligand 9 (CXCL), CXCL10, and CXCL11 are anti-tumor chemokines; however, the differential anti-tumor effects of IFN-inducible chemokines are not completely understood. In this study, we investigated the anti-tumor effects of IFN-inducible chemokines by transferring chemokine expression vectors into a mouse squamous cell carcinoma cell line, SCCVII, to generate a cell line stably expressing chemokines and transplanted it into nude mice. The results showed that CXCL9- and CXCL11-expressing cells markedly inhibited tumor growth, whereas CXCL10-expressing cells did not inhibit growth. The NH₂-terminal amino acid sequence of mouse CXCL10 contains a cleavage sequence by dipeptidyl peptidase 4 (DPP4), an enzyme that cleaves the peptide chain of chemokines. IHC staining indicated DPP4 expression in the stromal tissue, suggesting CXCL10 inactivation. These results suggest that the anti-tumor effects of IFN-inducible chemokines are affected by the expression of chemokine-cleaving enzymes in tumor tissues.

Identification of Potential Biomarkers Using Integrative Approach: A Case Study of ESCC

This paper presents a consensus-based approach that incorporates three microarray and three RNA-Seq methods for unbiased and integrative identification of differentially expressed genes (DEGs) as potential biomarkers for critical disease(s). The proposed method performs satisfactorily on two microarray datasets (GSE20347 and GSE23400) and one RNA-Seq dataset (GSE130078) for esophageal squamous cell carcinoma (ESCC). Based on the input dataset, our framework employs specific DE methods to detect DEGs independently. A consensus based function that first considers DEGs common to all three methods for further downstream analysis has been introduced. The consensus function employs other parameters to overcome information loss. Differential co-expression (DCE) and preservation analysis of DEGs facilitates the study of behavioral changes in interactions among DEGs under normal and diseased circumstances. Considering hub genes in biologically relevant modules and most GO and pathway enriched DEGs as candidates for potential biomarkers of ESCC, we perform further validation through biological analysis as well as literature evidence. We have identified 25 DEGs that have strong biological relevance to their respective datasets and have previous literature establishing them as potential biomarkers for ESCC. We have further identified 8 additional DEGs as probable potential biomarkers for ESCC, but recommend further in-depth analysis.

Role of IL4 and GMCSF in Predicting Survival in Esophageal Cancer

BACKGROUND

Esophageal cancer (EC) originates in the setting of chronic inflammation. Although previous studies have sought to understand the role of inflammatory signaling in EC, the effect of these immunologic changes on patient outcomes remains understudied. This study's objective was to identify relationships between cytokine levels and prognosis in a mixed cohort of esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC) patients.

STUDY DESIGN

A total of 37 serum cytokines were profiled at the time of resection using multiplex ELISA in 47 patients (42 esophageal adenocarcinoma, 5 esophageal squamous cell carcinoma). Cytokine levels were median-binarized and assessed using Cox regression models. Findings were validated at the RNA level using The Cancer Genome Atlas EC cohort (81 esophageal adenocarcinoma, 81 esophageal squamous cell carcinoma).

RESULTS

Univariable analysis revealed high serum interleukin 4 (IL4) and granulocyte-macrophage colony-stimulating factor (GMCSF) were negatively associated with overall survival (p = 0.046, p = 0.040). Multivariable analysis determined both high serum IL4 or high serum GMCSF were negatively associated with survival independent of important clinical factors (hazard ratio [HR] 7.55, p < 0.001; HR 5.24, p = 0.001). These findings were validated at the RNA level in The Cancer Genome Atlas EC cohort, where multivariable analysis identified high IL4 expression, high CSF2 expression (encodes GMCSF), and advanced pathologic stage as independent negative predictors of survival when controlled for clinical factors (HR 2.35, p = 0.012; HR 1.97, p = 0.040).

CONCLUSIONS

These results show that high IL4/GMCSF levels are negatively associated with survival in EC. These relationships are independent of pathologic stage and are identified across modalities, histologic subtypes, and the presence/absence of neoadjuvant therapy.

Tumor Immunogenic Cell Death as a Mediator of Intratumor CD8 T-Cell Recruitment

The success of anticancer treatments relies on a long-term response which can be mediated by the immune system. Thus, the concept of immunogenic cell death (ICD) describes the capacity of dying cancer cells, under chemotherapy or physical stress, to express or release danger-associated molecular patterns (DAMPs). These DAMPs are essential to activate dendritic cells (DCs) and to stimulate an antigen presentation to CD8 cytotoxic cells. Then, activated CD8 T cells exert their antitumor effects through cytotoxic molecules, an effect which is transitory due to the establishment of a feedback loop leading to T-cell exhaustion. This phenomenon can be reversed using immune checkpoint blockers (ICBs), such as anti-PD-1, PD-L1 or CTLA-4 Abs. However, the blockade of these checkpoints is efficient only if the CD8 T cells are recruited within the tumor. The CD8 T-cell chemoattraction is mediated by chemokines. Hence, an important question is whether the ICD can not only influence the DC activation and resulting CD8 T-cell activation but can also favor the chemokine production at the tumor site, thus triggering their recruitment. This is the aim of this review, in which we will decipher the role of some chemokines (and their specific receptors), shown to be released during ICD, on the CD8 T-cell recruitment and antitumor response. We will also analyze the clinical applications of these chemokines as predictive or prognostic markers or as new targets which should be used to improve patients' response.

Role of chemokine systems in cancer and inflammatory diseases

Chemokines are a large family of small secreted proteins that have fundamental roles in organ development, normal physiology, and immune responses upon binding to their corresponding receptors. The primary functions of chemokines are to coordinate and recruit immune cells to and from tissues and to participate in regulating interactions between immune cells. In addition to the generally recognized antimicrobial immunity, the chemokine/chemokine receptor axis also exerts a tumorigenic function in many different cancer models and is involved in the formation of immunosuppressive and protective tumor microenvironment (TME), making them potential prognostic markers for various hematologic and solid tumors. In fact, apart from its vital role in tumors, almost all inflammatory diseases involve chemokines and their receptors in one way or another. Modulating the expression of chemokines and/or their corresponding receptors on tumor cells or immune cells provides the basis for the exploitation of new drugs for clinical evaluation in the treatment of related diseases. Here, we summarize recent advances of chemokine systems in protumor and antitumor immune responses and discuss the prevailing understanding of how the chemokine system operates in inflammatory diseases. In this review, we also emphatically highlight the complexity of the chemokine system and explore its potential to guide the treatment of cancer and inflammatory diseases.

Cxcl10 chemokine induces migration of ING4-deficient breast cancer cells via a novel crosstalk mechanism between the Cxcr3 and Egfr receptors

The chemokine Cxcl10 has been associated with poor prognosis in breast cancer, but the mechanism is not well understood. Our previous study have shown that CXCL10 was repressed by the ING4 tumor suppressor, suggesting a potential inverse functional relationship. We thus investigated a role for Cxcl10 in the context of ING4 deficiencies in breast cancer. We first analyzed public gene expression datasets and found that patients with CXCL10-high/ING4-low expressing tumors had significantly reduced disease-free survival in breast cancer. In vitro, Cxcl10 induced migration of ING4-deleted breast cancer cells, but not of ING4-intact cells. Using inhibitors, we found that Cxcl10-induced migration of ING4-deleted cells required Cxcr3, Egfr, and the Gβγ subunits downstream of Cxcr3, but not Gαi. Immunofluorescent imaging showed that Cxcl10 induced early transient colocalization between Cxcr3 and Egfr in both ING4-intact and ING4-deleted cells, which recurred only in ING4-deleted cells. A peptide agent that binds to the internal juxtamembrane domain of Egfr inhibited Cxcr3/Egfr colocalization and cell migration. Taken together, these results presented a novel mechanism of Cxcl10 that elicits migration of ING4-deleted cells, in part by inducing a physical or proximal association between Cxcr3 and Egfr and signaling downstream via Gβγ. These results further indicated that ING4 plays a critical role in the regulation of Cxcl10 signaling that enables breast cancer progression.

Multifaceted Roles of Chemokines and Chemokine Receptors in Tumor Immunity

Simple Summary

Various immune cells are involved in host immune responses to cancer. T-helper (Th) 1 cells, cytotoxic CD8⁺ T cells, and natural killer cells are the major effector cells in anti-tumor immunity, whereas cells such as regulatory T cells and myeloid-derived suppressor cells are negatively involved in anti-tumor immunity. Th2 cells and Th17 cells have been shown to have both pro-tumor and anti-tumor activities. The migratory properties of various immune cells are essential for their function and critically regulated by the chemokine superfamily. In this review, we summarize the roles of various immune cells in tumor immunity and their migratory regulation by the chemokine superfamily. We also assess the therapeutic possibilities of targeting chemokines and chemokine receptors in cancer immunotherapy.

Abstract

Various immune cells are involved in host tumor immune responses. In particular, there are many T cell subsets with different roles in tumor immunity. T-helper (Th) 1 cells are involved in cellular immunity and thus play the major role in host anti-tumor immunity by inducing and activating cytotoxic T lymphocytes (CTLs). On the other hand, Th2 cells are involved in humoral immunity and suppressive to Th1 responses. Regulatory T (Treg) cells negatively regulate immune responses and contribute to immune evasion of tumor cells. Th17 cells are involved in inflammatory responses and may play a role in tumor progression. However, recent studies have also shown that Th17 cells are capable of directly inducting CTLs and thus may promote anti-tumor immunity. Besides these T cell subsets, there are many other innate immune cells such as dendritic cells (DCs), natural killer (NK) cells, and myeloid-derived suppressor cells (MDSCs) that are involved in host immune responses to cancer. The migratory properties of various immune cells are critical for their functions and largely regulated by the chemokine superfamily. Thus, chemokines and chemokine receptors play vital roles in the orchestration of host immune responses to cancer. In this review, we overview the various immune cells involved in host responses to cancer and their migratory properties regulated by the chemokine superfamily. Understanding the roles of chemokines and chemokine receptors in host immune responses to cancer may provide new therapeutic opportunities for cancer immunotherapy.

Wrinkle in the plan: miR-34a-5p impacts chemokine signaling by modulating CXCL10/CXCL11/CXCR3-axis in CD4+, CD8+ T cells, and M1 macrophages

BACKGROUND

In 2016 the first-in-human phase I study of a miRNA-based cancer therapy with a liposomal mimic of microRNA-34a-5p (miR-34a-5p) was closed due to five immune related serious adverse events (SAEs) resulting in four patient deaths. For future applications of miRNA mimics in cancer therapy it is mandatory to unravel the miRNA effects both on the tumor tissue and on immune cells. Here, we set out to analyze the impact of miR-34a-5p over-expression on the CXCL10/CXCL11/CXCR3 axis, which is central for the development of an effective cancer control.

METHODS

We performed a whole genome expression analysis of miR-34a-5p transfected M1 macrophages followed by an over-representation and a protein-protein network analysis. In-silico miRNA target prediction and dual luciferase assays were used for target identification and verification. Target genes involved in chemokine signaling were functionally analyzed in M1 macrophages, CD4⁺ and CD8⁺ T cells.

RESULTS

A whole genome expression analysis of M1 macrophages with induced miR-34a-5p over-expression revealed an interaction network of downregulated target mRNAs including CXCL10 and CXCL11. In-silico target prediction in combination with dual luciferase assays identified direct binding of miR-34a-5p to the 3'UTRs of CXCL10 and CXCL11. Decreased CXCL10 and CXCL11 secretion was shown on the endogenous protein level and in the supernatant of miR-34a-5p transfected and activated M1 macrophages. To complete the analysis of the CXCL10/CXCL11/CXCR3 axis, we activated miR-34a-5p transfected CD4⁺ and CD8⁺ T cells by PMA/Ionomycin and found reduced levels of endogenous CXCR3 and CXCR3 on the cell surface.

CONCLUSIONS

MiR-34a-5p mimic administered by intravenous administration will likely not only be up-taken by the tumor cells but also by the immune cells. Our results indicate that miR-34a-5p over-expression leads in M1 macrophages to a reduced secretion of CXCL10 and CXCL11 chemokines and in CD4⁺ and CD8⁺ T cells to a reduced expression of CXCR3. As a result, less immune cells will be attracted to the tumor site. Furthermore, high levels of miR-34a-5p in naive CD4⁺ T cells can in turn hinder Th1 cell polarization through the downregulation of CXCR3 leading to a less pronounced activation of cytotoxic T lymphocytes, natural killer, and natural killer T cells and possibly contributing to lymphocytopenia.

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.

CXCL10/CXCR3 signaling contributes to an inflammatory microenvironment and its blockade enhances progression of murine pancreatic precancerous lesions

The development of pancreatic cancer requires recruitment and activation of different macrophage populations. However, little is known about how macrophages are attracted to the pancreas after injury or an oncogenic event, and how they crosstalk with lesion cells or other cells of the lesion microenvironment. Here, we delineate the importance of CXCL10/CXCR3 signaling during the early phase of murine pancreatic cancer. We show that CXCL10 is produced by pancreatic precancerous lesion cells in response to IFNγ signaling and that inflammatory macrophages are recipients for this chemokine. CXCL10/CXCR3 signaling in macrophages mediates their chemoattraction to the pancreas, enhances their proliferation, and maintains their inflammatory identity. Blocking of CXCL10/CXCR3 signaling in vivo shifts macrophage populations to a tumor-promoting (Ym1⁺, Fizz⁺, Arg1⁺) phenotype, increases fibrosis, and mediates progression of lesions, highlighting the importance of this pathway in PDA development. This is reversed when CXCL10 is overexpressed in PanIN cells.

HDAC2 enhances esophageal squamous cell carcinoma development through down-regulating microRNA-503-5p and promoting CXCL10

Objective

Although esophageal squamous cell carcinoma (ESCC)-oriented mechanism has been widely explored, the integrated action of histone deacetylase 2 (HDAC2), microRNA (miR)-503-5p and C-X-C motif chemokine 10 (CXCL10) in ESCC has not been thoroughly explored. Thus, we performed the research to study the role of HDAC2/miR-503-5p/CXCL10 axis in ESCC.

Methods

ESCC tissues and mucosal tissues (5 cm from cancer tissues) were collected, in which HDAC2, miR-503-5p and CXCL10 expression levels were tested. The mechanism of HDAC2, miR-503-5p and CXCL10 was interpreted. The viability, colony formation ability, apoptosis, invasion and migration abilities of ESCC cells were tested after HDAC2, miR-503-5p or CXCL10 expression was altered. Tumorigenesis in mice was observed to further verify the in vitro effects of HDAC2 and miR-503-5p.

Results

HDAC2 and CXCL10 were up-regulated while miR-503-5p was down-regulated in ESCC. HDAC2 bound to miR-503-5p and miR-503-5p targeted CXCL10. Silencing HDAC2 or restoring miR-503-5p depressed viability, colony-forming, invasion and migration abilities and enhanced apoptosis of ESCC cells in vitro, as well as suppressed ESCC tumorigenesis in vivo. Inhibition of miR-503-5p or elevation of CXCL10 negated HDAC2 knockout-induced effects on ESCC cells.

Conclusion

This work elucidates that HDAC2 knockdown retards the process of ESCC by elevating miR-503-5p and inhibiting CXCL10 expression, which may provide a guidance for ESCC management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01068-8.

Prognostic Impact of CXCR7 and CXCL12 Expression in Patients with Esophageal Adenocarcinoma

BACKGROUND

Chemokines are major regulators of cell trafficking and adhesion. The chemokine CXCL12 and its receptors, CXCR4 and CXCR7, have been reported as biomarkers in various cancers, including esophageal cancer; however, there are few studies in esophageal adenocarcinoma (EAC). In this study, we investigated the relationship between expression of CXCL12, CXCR4, and CXCR7, and prognosis in patients with EAC.

METHODS

This study examined 55 patients with EAC who were treated in Toronto General Hospital from 2001 to 2010. Tissue microarray immunohistochemistry was used to evaluate the expression of CXCL12, CXCR4, and CXCR7. Evaluation of immunohistochemistry was performed by a pathologist without knowledge of patients' information and results were compared with the patients' clinicopathological features and survival.

RESULTS

High CXCR7 expression was significantly associated with lymphatic invasion (present vs absent, P = 0.005) and higher number of lymph node metastases (pN0-1 vs pN2-3, P = 0.0014). Patients with high CXCR7 expression (n = 23) were associated with worse overall (OS) and disease-free survival (DFS) (P = 0.0221, P = 0.0090, respectively), and patients with high CXCL12 (n = 24) tended to have worse OS and DFS (P = 0.1091, P = 0.1477, respectively). High expression of both CXCR7 and CXCL12 was an independent prognostic factor for OS and DFS on multivariate analysis (HR = 0.3, 95% CI: 0.1-0.9, P = 0.0246, HR = 0.3, 95% CI: 0.1-0.8, P = 0.0134, respectively).

CONCLUSIONS

High CXCR7 expression was associated with poor prognosis in patients with EAC, and high expression of CXCR7 with its ligand CXCL12 had a stronger association with prognosis. Further study of this potential biomarker using whole tissue samples and a larger sample size is warranted.

Chromobox 2 Expression Predicts Prognosis After Curative Resection of Oesophageal Squamous Cell Carcinoma

BACKGROUND/AIM

To investigate the function of chromobox 2 (CBX2) in oesophageal squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

We used real-time quantitative reverse transcription PCR (qRT-PCR) and immunohistochemistry to determine CBX2 expression levels in 13 human OSCC cell lines and clinical specimens of two independent cohorts of patients with OSCC.

RESULTS

PCR array analysis revealed that CBX2 was co-ordinately expressed with WNT5B in OSCC cell lines. RT-qPCR analysis of clinical samples revealed a high tumour-specific CBX2 expression compared with normal oesophageal tissues. High CBX2 expression was significantly associated with shorter disease-specific survival, hematogenous recurrence, and overall recurrence. Analysis of tissue microarrays of one cohort revealed that patients with higher CBX2 levels tended to have a shorter disease-specific survival.

CONCLUSION

CBX2 overexpression in OSCC tissues may serve as a novel biomarker for predicting survival and hematogenous recurrence.

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.

High TLR4 expression predicts a poor prognosis after esophagectomy for advanced thoracic esophageal squamous cell carcinoma

BACKGROUND

Poor oral health is an independent risk factor for upper aerodigestive tract cancers, including esophageal squamous cell carcinoma (ESCC). The pattern recognition receptor Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide in the cell walls of Gram-negative periodontal pathogens associated with the development and progression of ESCC. It is, therefore, plausible that TLR4 plays a crucial role in the pathogenesis of ESCC.

METHODS

We used an ESCC tissue microarray to confirm expression of TLR4 in patients with ESCC and to determine whether TLR4 expression status correlates with the clinicopathological features of these patients or their prognosis after esophagectomy. We also tested whether the combined expression statuses of TLR4 and TLR3 better correlate with prognosis in these patients than either parameter alone.

RESULTS

Clinical ESCC samples from all 177 patients tested showed expression of TLR4. Moreover, high TLR4 expression (3 + and 2 +) correlated with poorer 5-year overall survival after esophagectomy than lower TLR4 expression (1 +) (p = 0.0491). Patients showing high TLR4 expression tended to have a poorer prognosis whether treated with surgery alone or with surgery and adjuvant chemotherapy. Univariate and multivariate analyses showed TLR4 expression status to be an independent prognostic factor affecting 5-year overall survival. Patients exhibiting high TLR4 expression with low TLR3 expression had a much poorer prognosis than other patients (p = < 0.0001).

CONCLUSION

High TLR4 expression predicts a poor prognosis in advanced thoracic ESCC patients after esophagectomy.

Comparison of the incidences of anastomotic leakage when PDSII or LACLON are used in esophago-gastric conduit handsewn anastomosis after esophagectomy

The incidence of anastomotic leakage after esophagectomy remains around 10%. It was previously reported that PDSII rapidly loses tensile strength at pH 1.0 and pH 8.5. By contrast, LACLON degradation is reportedly insensitive to pH. We therefore compared LACLON with PDSII for esophago-gastric conduit, layer-to-layer, handsewn anastomosis. Between January 2016 and January 2020, 90 patients who received posterior mediastinal gastric conduit reconstruction with layer-to-layer handsewn anastomosis (51 using PDSII and 39 using LACLON) at Akita University Hospital were enrolled. The incidence of anastomotic leakage was significantly lower in the LACLON (2.6%, 1/39 patients) than PDSII group (15.7%, 8/51 patients) (p = 0.0268). Multivariable logistic analysis showed the risk of anastomotic leakage was significantly greater with PDSII than LACLON (odds ratio 11.01; 95% CI 1.326–277.64; p = 0.024). The percentages of time the pH was higher than 8 on the gastric conduit side of the anastomosis were 3.1%, 5.7%, 20.9% and 80.5%, respectively, in the four most recent patients. The present study showed that pH at the anastomosis soon after esophagectomy tends to be alkaline rather than acidic, which raises the possibility that this alkalinity facilitates the deterioration of surgical sutures including PDSII.

m6 A demethylase ALKBH5 promotes proliferation of esophageal squamous cell carcinoma associated with poor prognosis

Esophageal squamous cell carcinoma (ESCC) is one of the most fatal types of malignant tumors worldwide. Epitranscriptome, such as N⁶ -methyladenosine (m⁶ A) of mRNA, is an abundant post-transcriptional mRNA modification and has been recently implicated to play roles in several cancers, whereas the significance of m⁶ A modifications is virtually unknown in ESCC. Analysis of tissue microarray of the tumors in 177 ESCC patients showed that higher expression of m⁶ A demethylase ALKBH5 correlated with poor prognosis and that ALKBH5 was an independent prognostic factor of the survival of patients. There was no correlation between the other demethylase FTO and prognosis. siRNA knockdown of ALKBH5 but not FTO significantly suppressed proliferation and migration of human ESCC cells. ALKBH5 knockdown delayed progression of cell cycle and accumulated the cells to G0/G1 phase. Mechanistically, expression of CDKN1A (p21) was significantly up-regulated in ALKBH5-depleted cells, and m⁶ A modification and stability of CDKN1A mRNA were increased by ALKBH5 knockdown. Furthermore, depletion of ALKBH5 substantially suppressed tumor growth of ESCC cells subcutaneously transplanted in BALB/c nude mice. Collectively, we identify ALKBH5 as the first m⁶ A demethylase that accelerates cell cycle progression and promotes cell proliferation of ESCC cells, which is associated with poor prognosis of ESCC patients.

Expression and Malignant Potential of B4GALNT4 in Esophageal Squamous Cell Carcinoma

BACKGROUND

β-1,4-N-Acetyl-galactosaminyltransferase 4 (B4GALNT4), an enzyme involved in ganglioside synthesis, is upregulated in many cancers. We examine B4GALNT4 expression and its relationship to prognosis in esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Expression of B4GALNT4 mRNA and B4GALNT4 protein was analyzed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry, respectively, in 17 human ESCC cell lines and/or clinical specimens from two independent cohorts of 147 and 159 ESCC patients. The contributions of B4GALNT4 to proliferation, invasion, migration, and adhesion was evaluated in ESCC cells subjected to siRNA-mediated gene knockdown. Correlations between clinicopathological parameters and B4GALNT4 expression in clinical specimens were analyzed in both patient cohorts.

RESULTS

B4GALNT4 mRNA expression levels varied widely in ESCC cell lines, regardless of differentiation status or the originating tissue. Knockdown of B4GALNT4 significantly suppressed the proliferation, invasion, migration, and adhesion of ESCC cell lines compared with control cells. B4GALNT4 mRNA was overexpressed in ESCC tissues compared with adjacent normal esophageal tissues. High mRNA expression was significantly associated with poor disease-free survival and hematogenous recurrence, and high B4GALNT4 protein expression was also significantly related to poor disease-specific survival. On multivariable analysis, high B4GALNT4 expression was an independent predictor of poor prognosis. In both patient cohorts, high B4GALNT4 expression did not correlate with known prognostic factors, such as disease stage, lymphovascular invasion, or squamous cell-carcinoma-related antigen level.

CONCLUSIONS

B4GALNT4 influences the malignant behavior of ESCC cells. B4GALNT4 expression may serve as a novel prognostic marker, independent of established risk factors, for ESCC patients.

Chemokines and their receptors as biomarkers in esophageal cancer

Esophageal cancer (EC) is one of the most lethal malignancies of the digestive tract and remains to be improved poor prognosis. Two histological subtypes, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), are major characteristics of EC. Deep understanding about both subtypes is essential to overcome EC. Here, we focus on chemokines and their receptors as biomarkers and their current applications for the prognosis in EC. We reviewed relevant articles identified using PubMed database for the chemokines and their receptors in EC analyzed by immunohistochemistry. The primary objective is to summarize evidences for them as prognostic biomarkers in EC. A total of twenty-one articles were reviewed after exclusion. Most studies have been done in ESCC, and less in EAC. CXCL12 and its receptor CXCR4 have been shown in both subtypes as biomarkers. CXCR7, CXCL8 and its receptor CXCR2, and CCL21 and its receptor CCR7 have been examined in ESCC. Although it was a small number of reports, CXCL10, CCL4, and CCL5 have been indicated to have anti-tumor effects in ESCC. Chemokines and their receptors have the potential to be the biomarkers in EC. Comparative studies between ESCC and EAC will reveal the similarity and difference in these two subtypes of EC. These studies may indicate whether these molecules play important roles in both subtypes or are unique to one or another.

Proteolytic chemokine cleavage as a regulator of lymphocytic infiltration in solid tumors

In the past decade, immune-based therapies such as monoclonal antibodies against tumor epitopes or immune checkpoint inhibitors have become an integral part of contemporary cancer treatment in many entities. However, a fundamental prerequisite for the success of such therapies is a sufficient trafficking of tumor-infiltrating lymphocytes into the tumor microenvironment. This infiltration is facilitated by chemokines, a group of about 50 small proteins capable of chemotactically guiding leukocytes. Proteolytic inactivation of chemokines leading to an impaired infiltration of immune effector cells appears to be an efficient immune escape mechanism of solid cancers.

The CXCR3 and CX3CR1 chemokine receptor ligands CXCL9-11 and CX3CL1, respectively, are mainly responsible for the tumor-suppressive lymphocytic infiltration into the tumor micromilieu. Their structure explains the biochemical basis of their proteolytic cleavage, while in vivo data from mouse models and patient samples shed light on the corresponding processes in cancer. The emerging roles of proteases, e.g., matrix metalloproteinases, cathepsins, and dipeptidyl peptidase 4, in chemokine inactivation define new resistance mechanisms against immunotherapies and identify attractive new targets to enhance immune intervention in cancer.

Chemokines and their Receptors: Multifaceted Roles in Cancer Progression and Potential Value as Cancer Prognostic Markers

Chemokines are chemotactic cytokines that mediate immune cell chemotaxis and lymphoid tissue development. Recent advances have indicated that chemokines and their cognate receptors play critical roles in cancer-related inflammation and cancer progression. On the basis of these findings, the chemokine system has become a new potential drug target for cancer immunotherapy. In this review, we summarize the essential roles of the complex network of chemokines and their receptors in cancer progression. Furthermore, we discuss the potential value of the chemokine system as a cancer prognostic marker. The chemokine system regulates the infiltration of immune cells into the tumor microenvironment, which induces both pro- and anti-immunity and promotes or suppresses tumor growth and proliferation, angiogenesis, and metastasis. Increasing evidence indicates the promising prognostic value of the chemokine system in cancer patients. While CCL2, CXCL10, and CX3CL1/CX3CR1 can serve as favorable or unfavorable prognostic factors depending on the cancer types, CCL14 and XCL1 possess good prognostic value. Other chemokines such as CXCL1, CXCL8, and CXCL12 are poor prognostic markers. Despite vast advances in our understanding of the complex nature of the chemokine system in tumor biology, knowledge about the multifaceted roles of the chemokine system in different types of cancers is still limited. Further studies are necessary to decipher distinct roles within the chemokine system in terms of cancer progression and to validate their potential value in cancer prognosis.

The Distinct Roles of CXCR3 Variants and Their Ligands in the Tumor Microenvironment

First thought to orchestrate exclusively leukocyte trafficking, chemokines are now acknowledged for their multiple roles in the regulation of cell proliferation, differentiation, and survival. Dysregulation of their normal functions contributes to various pathologies, including inflammatory diseases and cancer. The two chemokine receptor 3 variants CXCR3-A and CXCR3-B, together with their cognate chemokines (CXCL11, CXCL10, CXCL9, CXCL4, and CXCL4L1), are involved in the control but also in the development of many tumors. CXCR3-A drives the infiltration of leukocytes to the tumor bed to modulate tumor progression (paracrine axis). Conversely, tumor-driven changes in the expression of the CXCR3 variants and their ligands promote cancer progression (autocrine axis). This review summarizes the anti- and pro-tumoral activities of the CXCR3 variants and their associated chemokines with a focus on the understanding of their distinct biological roles in the tumor microenvironment.

Plasma IFN-γ-inducible chemokines CXCL9 and CXCL10 correlate with survival and chemotherapeutic efficacy in advanced pancreatic ductal adenocarcinoma

OBJECTIVES

Recent studies have suggested that the CXCL9, 10, 11/CXCR3 axis is significant in immune regulation and therapeutic efficacy in human cancers; however, its role in pancreatic ductal adenocarcinoma (PDAC) remains unknown. This study serves to evaluate the prognostic prediction value of plasma IFN-γ-inducible chemokines, CXCL9 and CXCL10, in advanced PDAC.

METHODS

Two hundred patients with advanced PDAC receiving palliative chemotherapy were retrospectively recruited. The association between Plasma CXCL9/CXCL10 levels and survival time was first analyzed in a test group of 110 patients and then confirmed in a validation group of 90 patients.

RESULTS

High levels of CXCL9 and CXCL10 were significantly correlated with longer overall survival (OS) in advanced PDAC patients (314 vs. 136 days for CXCL9, P < 0.0001, and 374 vs. 163 days for CXCL10, P < 0.0001, respectively) in the test group, which was consistent with the results derived from the validation group. In addition, high levels of CXCL9 and CXCL10 were associated with longer time to progression (TTP) in patients receiving chemotherapy (100 vs. 60 days for CXCL9, P = 0.0021, and 104 vs. 67 days for CXCL10, P = 0.0057, respectively). Multivariate analyses confirmed that CXCL9 and CXCL10 were independent prognostic predictors for OS (hazard ratio [HR]: 0.452, P < 0.001 for CXCL9; and HR: 0.586, P = 0.007 for CXCL10, respectively) and TTP (HR: 0.656, P = 0.015 for CXCL9; and HR: 0.687, P = 0.040 for CXCL10, respectively).

CONCLUSIONS

Plasma CXCL9 and CXCL10 can be used to predict survival of advanced PDAC patients receiving chemotherapy, allowing clinicians to potentially improve treatment outcomes by identifying candidates for aggressive therapy.

The Role of CXC Chemokine Receptors 1-4 on Immune Cells in the Tumor Microenvironment

Chemokines govern leukocyte migration by attracting cells that express their cognate ligands. Many cancer types show altered chemokine secretion profiles, favoring the recruitment of pro-tumorigenic immune cells and preventing the accumulation of anti-tumorigenic effector cells. This can ultimately result in cancer immune evasion. The manipulation of chemokine and chemokine-receptor signaling can reshape the immunological phenotypes within the tumor microenvironment in order to increase the therapeutic efficacy of cancer immunotherapy. Here we discuss the three chemokine-chemokine receptor axes, CXCR1/2–CXCL1-3/5-8, CXCR3–CXCL9/10/11, and CXCR4-CXCL12 and their role on pro-tumorigenic immune cells and anti-tumorigenic effector cells in solid tumors. In particular, we summarize current strategies to target these axes and discuss their potential use in treatment approaches.

Epithelial-mesenchymal transition-converted tumor cells can induce T-cell apoptosis through upregulation of programmed death ligand 1 expression in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor, and it is urgently needed to develop novel therapeutic strategies including immunotherapy. In this study, we investigated the upregulation of the programmed death ligand 1 (PD‐L1) due to epithelial‐mesenchymal transition (EMT) in ESCC using an in vitro treatment system with the EMT inducer, glycogen synthase kinase (GSK)‐3 inhibitor, and we also analyzed the correlation of EMT and PD‐L1 expression in the clinical tumor samples of both tissue microarray (TMA) samples (n = 177) and whole tissue samples (n = 21). As a result, the inhibition of GSK‐3β induces EMT phenotype with upregulated vimentin and downregulated E‐cadherin as well as increased Snail and Zinc finger E box‐binding homeobox (ZEB)‐1 gene expression. Simultaneously, we showed that EMT‐converted ESCC indicated the upregulation of PD‐L1 at both protein (total and surface) and mRNA levels. Of importance, we showed that EMT‐converted tumor cells have a capability to induce T‐cell apoptosis to a greater extent in comparison to original epithelial type tumor cells. Furthermore, the immunohistochemical stains of ESCC showed that PD‐L1 expression on tumor cells was positively correlated with EMT status in TMA samples (P = .0004) and whole tissue samples (P = .0029). In conclusion, our in vitro and in vivo study clearly demonstrated that PD‐L1 expression was upregulated in mesenchymal type tumors of ESCC. These findings provide a strong rationale for the clinical use of anti‐PD‐1/anti‐PD‐L1 monoclonal antibodies for advanced ESCC patients.

TLR3 expression status predicts prognosis in patients with advanced thoracic esophageal squamous cell carcinoma after esophagectomy

BACKGROUND

The relationship between Toll-like receptors (TLRs) and esophageal squamous cell carcinoma (ESCC) is not completely understood.

METHODS

RT-qPCR was used to evaluate the mRNA expression of TLR1-10 in 13 ESCC lines. We then used ESCC tissue microarray (TMA) to confirm expression of TLR3 protein in patients with ESCC.

RESULTS

All ESCC lines showed 10-60 times higher TLR3 mRNA expression than PBLs. High expression of TLR3 correlated with favorable 5-year overall survival (OS) and disease specific survival (DSS) among patients with ESCC after esophagectomy (p < 0.01). Additionally, In the adjuvant chemotherapy group, TLR3 high patients had significantly better 5-year OS compared to TLR3 low patients (60.2%, 34.4%, respectively) but not in the surgery alone group.

CONCLUSION

High TLR3 expression is an independent prognostic factor and has the potential to serve as a clinically useful marker of the need for adjuvant chemotherapy after esophagectomy in patients with advanced thoracic ESCC.

CXCL9, CXCL10, CXCL11/CXCR3 axis for immune activation - A target for novel cancer therapy

Chemokines are proteins which induce chemotaxis, promote differentiation of immune cells, and cause tissue extravasation. Given these properties, their role in anti-tumor immune response in the cancer environment is of great interest. Although immunotherapy has shown clinical benefit for some cancer patients, other patients do not respond. One of the mechanisms of resistance to checkpoint inhibitors may be chemokine signaling. The CXCL9, -10, -11/CXCR3 axis regulates immune cell migration, differentiation, and activation, leading to tumor suppression (paracrine axis). However, there are some reports that show involvements of this axis in tumor growth and metastasis (autocrine axis). Thus, a better understanding of CXCL9, -10, -11/CXCR3 axis is necessary to develop effective cancer control. In this article, we summarize recent evidence regarding CXCL9, CXCL10, CXCL11/CXCR3 axis in the immune system and discuss their potential role in cancer treatment.

CXCL10 and CCL2 mRNA expression in monocytes is inversely correlated with the HLA-DR lower fraction of monocytes in patients with renal cell carcinoma

Circulating cluster of differentiation (CD)14+ human leukocyte antigen (HLA)-DRlow/- monocytes, those with a lower HLA-DR expression or are negative for HLA-DR, are considered to be involved in systemic immunosuppression in patients with several malignant tumors. However, few studies have investigated in detail the gene expression profile of CD14+HLA-DRlow/- monocytes. In the present study, the mRNA expression levels of immune-associated molecules in CD14+ monocytes isolated from healthy donors and patients with renal cell carcinoma (RCC) were analyzed. Consistent with previous studies, the percentage of HLA-DRlow/- cells in CD14+ monocytes was significantly increased in patients with RCC compared with healthy donors. In 3 of the 4 patients who underwent surgical resection of the primary tumor, the percentage of CD14+HLA-DRlow/- cells was significantly decreased following surgery. The mRNA expression levels of cyclooxygenase 2, transforming growth factor β, interleukin 6R, chemokine (C-C motif) ligand 2 (CCL2), chemokine (C-X-C motif) ligand 10 (CXCL10), oncostatin M, and vascular endothelial growth factor-A in CD14+ monocytes were quantified using reverse transcription-quantitative polymerase chain reaction. The results of the present study revealed that increased expression levels of CCL2 and CXCL10 were inversely correlated with the percentage of CD14+HLA-DRlow/- monocytes. This suggested that monocytes in RCC patients were immunologically suppressed, and that immunosuppression in RCC patients may be due, in part, to the dysfunction of circulating monocytes.