Role of CCL20/CCR6 and the ERK signaling pathway in lung adenocarcinoma

Identification of macrophage-related genes correlated with prognosis and immunotherapy efficacy in non-small cell lung cancer

Background

Malignant tumours, particularly non-small cell lung cancer (NSCLC), pose a significant threat to human health due to their prevalence and lethality. Treatment methods for NSCLC vary greatly among individuals, making it crucial to identify predictive markers. Moreover, during tumour initiation and progression, tumour cells can release signaling molecules to induce polarization of macrophages towards a more tumour friendly M2 phenotype, which can promote tumour growth, metastasis, and drug resistance.

Methods

We employed a comprehensive approach, combining bulk RNA-seq and single-cell sequencing analysis.

Results

In our study, we used bulk RNA-seq and single-cell sequencing methods to analyze differential cells in NSCLC and adjacent tissues, searching for relevant marker genes that can predict prognosis and drug efficacy. We scrutinized biological phenomena such as macrophage-related gene methylation, copy number variation, and alternative splicing. Additionally, we utilized a co-culture technique of immune and tumour cells to explore the role of these genes in macrophage polarization. Our findings revealed distinct differences in macrophages between cancerous and adjacent tissues. We identified ANP32A, CCL20, ERAP2, MYD88, TMEM126B, TUBB6, and ZNF655 as macrophage-related genes that correlate with NSCLC patient prognosis and immunotherapy efficacy. Notably, ERAP2, TUBB6, CCL20, and TMEM126B can induce macrophage M0 to M2 polarization, promoting tumour proliferation.

Conclusion

These findings significantly contribute to our understanding of the NSCLC tumour immune microenvironment. They pave the way for further research into the potential of these genes as targets for regulating tumour occurrence and development.

Panel of miR-150 and linc00673, regulators of CCR6/CCL20 may serve as non-invasive diagnostic marker of non-small cell lung cancer

The C-C motif ligand 20 (CCL20) is a chemokine that specifically binds to the chemokine receptor 6 (CCR6) and the CCL20/CCR6 axis has been implicated in the non-small lung cancer (NSCLC) development and progression. Its expression is regulated by mutual interactions of non-coding RNAs (ncRNAs). This goals of presented study was to evaluate the expression level of CCR6/CCL20 mRNA in NSCLC tissue comparative to selected ncRNAs: miR-150, linc00673. The expression level of the studied ncRNAs was also assessed in serum extracellular vesicles (EVs). Thirty patients (n = 30) were enrolled as the study cohort. Total RNA was isolated from tumor tissue, adjacent macroscopically unchanged tissue and serum EVs. The expression level of studied genes and ncRNAs were estimated based on the qPCR method. Higher expression level of CCL20 mRNA but lower expression level of CCR6 mRNA were observed in tumor in comparison to control tissue. Relative to the smoking status, higher CCL20 (p < 0.05) and CCR6 mRNA (p > 0.05) expression levels were observed in current smokers than in never smokers. In serum EVs the expression level of miR-150 has a negative correlation with AJCC tumor staging, whereas the expression level of linc00673 positively correlated (p > 0.05). The lower expression level of miR-150 and higher expression level of linc00673 in serum EVs were observed in NSCLC patients with lymph nodes metastases (p > 0.05). Regarding the histopathological type, significantly lower expression level of miR-150 and higher expression level of linc00673 were observed in the serum EVs of patients with AC compared to patient with SCC. Our findings revealed that smoking significantly changed the expression level of CCL20 mRNA in NSCLC tissue. Changes in expression levels of miR-150 and linc00673 in the serum EVs of NSCLC patients in relation to presence of lymph node metastases and the stage of cancer development may serve as a non-invasive molecular biomarkers of tumor progression. Furthermore, expression levels of miR-150 and linc00673 may serve as non-intrusive diagnostic biomarkers differentiating adenocarcinoma from squamous cell carcinoma.

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.

Intrapleural Injection of Anti-PD1 Antibody: A Novel Management of Malignant Pleural Effusion

Background

Malignant tumors accompanied with malignant pleural effusion (MPE) often indicate poor prognosis. The therapeutic effect and mechanism of intrapleural injection of anti-programmed cell death protein 1 (PD1) on MPE need to be explored.

Methods

A preclinical MPE mouse model and a small clinical study were used to evaluate the effect of intrapleural injection of anti-PD1 antibody. The role of immune cells was observed via flow cytometry, RNA-sequencing, quantitative PCR, western blot, immunohistochemistry, and other experimental methods.

Results

Intrathoracic injection of anti-PD1 monoclonal antibody (mAb) has significantly prolonged the survival time of mice (P = 0.0098) and reduced the amount of effusion (P = 0.003) and the number of cancer nodules (P = 0.0043). Local CD8+ T cells participated in intrapleural administration of anti-PD1 mAb. The proportion of CD69+, IFN-γ+, and granzyme B+ CD8+ T cells in the pleural cavity was increased, and the expression of TNF-α and IL-1β in MPE also developed significantly after injection. Local injection promoted activation of the CCL20/CCR6 pathway in the tumor microenvironment and further elevated the expression of several molecules related to lymphocyte activation. Clinically, the control rate of intrathoracic injection of sintilimab (a human anti-PD1 mAb) for 10 weeks in NSCLC patients with MPE was 66.7%. Local injection improved the activity and function of patients' local cytotoxic T cells (CTLs).

Conclusions

Intrapleural injection of anti-PD1 mAb could control malignant pleural effusion and the growth of cancer, which may be achieved by enhancing local CTL activity and cytotoxicity.

CCL20 induces colorectal cancer neoplastic epithelial cell proliferation, migration, and further CCL20 production through autocrine HGF-c-Met and MSP-MSPR signaling pathways

CCL20-CCR6 interactions promote colorectal cancer through direct effects on neoplastic epithelial cells and through modulating the tumor microenvironment. The mechanism of these effects on neoplastic epithelial cells is poorly understood. This study demonstrates that CCL20 induces secretion of hepatocyte growth factor (HGF) and phosphorylation of HGF’s cognate receptor c-Met in HT29 and HCT116 colorectal cancer cell lines both in concentration- and time-dependent manners. Similar to CCL20, HGF induces migration, autofeedback CCL20 secretion, and ERK1/2 phosphorylation in the colon cancer cells. CCL20-dependent ERK1/2 phosphorylation is blocked by HGF inhibition, and CCL20-dependent migration and CCL20 secretion are blocked by inhibition of HGF or ERK. Interestingly, unlike CCL20, HGF does not induce proliferation of colon cancer cells, and CCL20-dependent cell proliferation is not blocked by direct HGF inhibition. CCL20-dependent proliferation, however, is blocked by the multi-tyrosine kinase inhibitor crizotinib. Exploring this effect, it was found that CCL20 also induces production of MSP and phosphorylation of MSP’s receptor MSPR by the colorectal cancer cells. CCL20-dependent cell proliferation is inhibited by directly blocking MSP-MSPR interactions. Thus, CCL20-mediated migration and CCL20 secretion are regulated through a pathway involving HGF, c-Met, and ERK, while CCL20-mediated proliferation is instead regulated through MSP and its receptor MSPR.

A Plausible Proposition of CCL20-Related Mechanism in Fusobacterium nucleatum-Associated Oral Carcinogenesis

Objective: The objective of this prospective observational case–control study is to evaluate the prevalence of Fusobacterium nucleatum in the tissues of oral squamous cell carcinoma (OSCC). Reconnoitering the CCL20-related mechanism of carcinogenesis in Fusobacterium nucleatum-positive OSCC is another objective. Methodology: Tissues from 50 OSCC patients and 30 healthy oral tissues were collected. The prevalence of Fusobacterium nucleatum was evaluated in both tumour and healthy tissue by polymerase chain reaction. The immunohistochemistry of OSCC tissues was conducted to evaluate the difference in the expression of CCL20 between Fusobacterium nucleatum-positive and -negative OSCC tissues. Results: Fusobacterium nucleatum was significantly (p < 0.001) prevalent in OSCC tissues (74%), compared to healthy tissues (26%). No association of Fusobacterium nucleatum or CCL20 immuno-expression with any clinical or histopathological features of OSCC was observed. While the intensity of CCL20 immuno-expression did not differ (p = 0.053), the CCL20-positive cell population was significantly different (p = 0.034) between Fusobacterium nucleatum-positive and -negative OSCC. Conclusion: Fusobacterium nucleatum is possibly prevalent in oral cancer tissues in the Indian population. By using immunohistochemistry, this is the first study to propose that the carcinogenesis in Fusobacterium nucleatum-positive OSCC may be CCL20-related. The findings enrich the knowledge of mechanisms involved in Fusobacterium nucleatum-mediated oral carcinogenesis.

Transcriptomic studies revealed pathophysiological impact of COVID-19 to predominant health conditions

Despite the association of prevalent health conditions with coronavirus disease 2019 (COVID-19) severity, the disease-modifying biomolecules and their pathogenetic mechanisms remain unclear. This study aimed to understand the influences of COVID-19 on different comorbidities and vice versa through network-based gene expression analyses. Using the shared dysregulated genes, we identified key genetic determinants and signaling pathways that may involve in their shared pathogenesis. The COVID-19 showed significant upregulation of 93 genes and downregulation of 15 genes. Interestingly, it shares 28, 17, 6 and 7 genes with diabetes mellitus (DM), lung cancer (LC), myocardial infarction and hypertension, respectively. Importantly, COVID-19 shared three upregulated genes (i.e. MX2, IRF7 and ADAM8) with DM and LC. Conversely, downregulation of two genes (i.e. PPARGC1A and METTL7A) was found in COVID-19 and LC. Besides, most of the shared pathways were related to inflammatory responses. Furthermore, we identified six potential biomarkers and several important regulatory factors, e.g. transcription factors and microRNAs, while notable drug candidates included captopril, rilonacept and canakinumab. Moreover, prognostic analysis suggests concomitant COVID-19 may result in poor outcome of LC patients. This study provides the molecular basis and routes of the COVID-19 progression due to comorbidities. We believe these findings might be useful to further understand the intricate association of these diseases as well as for the therapeutic development.

Systematic Analyses of a Chemokine Family-Based Risk Model Predicting Clinical Outcome and Immunotherapy Response in Lung Adenocarcinoma

Chemokines exhibited complicated functions in antitumor immunity, with their expression profile and clinical importance of lung adenocarcinoma (LUAD) patients remaining largely undetermined. This study aimed to explore the expression patterns of chemokine family in LUAD and construct a predictive chemokine family-based signature. A total of 497 samples were downloaded from the Cancer Genome Atlas (TCGA) data portal as the training set, and the combination of 4 representative Gene Expression Omnibus (GEO) datasets, including GSE30219, GSE50081, GSE37745, and GSE31210, were utilized as the validation set. A three gene-based signature was constructed using univariate and stepwise multivariate Cox regression analysis, classifying patients into high and low risk groups according to the overall survival. The independent GEO datasets were utilized to validate this signature. Another multivariate analysis revealed that this signature remained an independent prognostic factor in LUAD patients. Furthermore, patients in the low risk group featured immunoactive tumor microenvironment (TME), higher IPS scores and lower TIDE scores, and was regarded as the potential beneficiaries of immunotherapy. Finally, the role of risky CCL20 was validated by immunohistochemistry (IHC), and patients possessed higher CCL20 expression presented shorter overall survival (P = 0.011).

ERK5 modulates IL-6 secretion and contributes to tumor-induced immune suppression

Tumors exhibit a variety of strategies to dampen antitumor immune responses. With an aim to identify factors that are secreted from tumor cells, we performed an unbiased mass spectrometry-based secretome analysis in lung cancer cells. Interleukin-6 (IL-6) has been identified as a prominent factor secreted by tumor cells and cancer-associated fibroblasts isolated from cancer patients. Incubation of dendritic cell (DC) cultures with tumor cell supernatants inhibited the production of IL-12p70 in DCs but not the surface expression of other activation markers which is reversed by treatment with IL-6 antibody. Defects in IL-12p70 production in the DCs inhibited the differentiation of Th1 but not Th2 and Th17 cells from naïve CD4⁺ T cells. We also demonstrate that the classical mitogen-activated protein kinase, ERK5/MAPK7, is required for IL-6 production in tumor cells. Inhibition of ERK5 activity or depletion of ERK5 prevented IL-6 production in tumor cells, which could be exploited for enhancing antitumor immune responses.

Chemokine Receptor Antagonists: Role in Oncology

PURPOSE OF REVIEW

To evaluate the clinical potential of chemokine receptor antagonists for the treatment of patients with cancer.

RECENT FINDINGS

Chemokine receptors and their ligands can have a significant impact on the infiltration of cells into the tumor microenvironment. The receptors are increasingly being investigated as targets for the treatment of cancers. Recent studies are demonstrating the promise of chemokine receptor antagonists in this setting. There are many chemokine receptors, and each can have different functions depending on the cellular context. Targeting chemokine receptors is a promising strategy in both pre-clinical research and clinical trials. Inhibiting chemokine receptors that either recruit suppressive cells or improve cancer mobility and viability while sparing those necessary for proper immune trafficking may prove to dramatically improve treatment responses. Further research in this area is warranted and has the potential to dramatically improve patient outcomes.

Chemokine CCL20 promotes the paclitaxel resistance of CD44+CD117+ cells via the Notch1 signaling pathway in ovarian cancer

Studies have found that C-C motif chemokine ligand 20 (CCL20)/C-C motif chemokine receptor 6 (CCR6)/notch receptor 1 (Notch1) signaling serves an important role in various diseases, but its role and mechanism in ovarian cancer remains to be elucidated. The aim of the present study was to investigate the underlying mechanism of CCL20/CCR6/Notch1 signaling in paclitaxel (PTX) resistance of a CD44⁺CD117⁺ subgroup of cells in ovarian cancer. The CD44⁺CD117⁺ cells were isolated from SKOV3 cells, followed by determination of the PTX resistance and the CCR6/Notch1 axis. Notch1 was silenced in the CD44⁺CD117⁺ subgroup and these cells were treated with CCL20, followed by examination of PTX resistance and the CCR6/Notch1 axis. Furthermore, in nude mice, CD44⁺CD117⁺ and CD44⁻CD117⁻ cells were used to establish the xenograft model and cells were treated with PTX and/or CCL20, followed by proliferation, apoptosis, reactive oxygen species (ROS) and mechanism analyses. Higher expression levels of Oct4, CCR6, Notch1 and ATP binding cassette subfamily G member 1 (ABCG1), increased sphere formation ability, IC₅₀ and proliferative ability, as well as lower ROS levels and apoptosis were observed in CD44⁺CD117⁺ cells compared with the CD44⁻CD117⁻ cells. It was found that CCL20 could significantly increase the expression levels of Oct4, CCR6, Notch1 and ABCG1, enhance the IC₅₀, sphere formation ability and proliferation, as well as decrease the ROS and apoptosis levels in the CD44⁺CD117⁺ cells. However, Notch1 knockdown could markedly reverse these changes. Moreover, CCL20 could significantly increase the proliferation and expression levels of Oct4, CCR6, Notch1 and ABCG1 in the CD44⁺CD117⁺ groups compared with the CD44⁻CD117⁻ groups. After treatment with PTX, apoptosis and ROS levels were decreased in the CD44⁺CD117⁺ groups compared with the CD44⁻CD117⁻ groups. Collectively, the present results demonstrated that, via the Notch1 pathway, CCL20/CCR6 may promote the stemness and PTX resistance of CD44⁺CD117⁺ cells in ovarian cancer.

Tongue Cancer Cell-Derived CCL20 Induced by Interaction With Macrophages Promotes CD163 Expression on Macrophages

Background

CD163-positive macrophages contribute to the aggressiveness of oral squamous cell carcinoma. We showed in a previous report that CD163-positive macrophages infiltrated not only to the cancer nest but also to its surrounding epithelium, depending on the presence of stromal invasion in tongue carcinogenesis. However, the role of intraepithelial macrophages in tongue carcinogenesis remains unclear. In this study, we assessed the biological behavior of intraepithelial macrophages on their interaction with cancer cells.

Materials and Methods

We established the indirect coculture system (intraepithelial neoplasia model) and direct coculture system (invasive cancer model) of human monocytic leukemia cell line THP-1-derived CD163-positive macrophages with SCC25, a tongue squamous cell carcinoma (TSCC) cell line. Conditioned media (CM) harvested from these systems were analyzed using cytokine array and enzyme-linked immunosorbent assay and extracted a specific upregulated cytokine in CM from the direct coculture system (direct CM). The correlation of both this cytokine and its receptor with various clinicopathological factors were evaluated based on immunohistochemistry using clinical samples from 59 patients with TSCC. Moreover, the effect of this cytokine in direct CM on the phenotypic alterations of THP-1 was confirmed by real-time polymerase chain reaction, western blotting, immunofluorescence, and transwell migration assay.

Results

It was shown that CCL20 was induced in the direct CM specifically. Interestingly, CCL20 was produced primarily in SCC25. The expression level of CCR6, which is a sole receptor of CCL20, was higher than the expression level of SCC25. Our immunohistochemical investigation showed that CCL20 and CCR6 expression was associated with lymphatic vessel invasion and the number of CD163-positive macrophages. Recombinant human CCL20 induced the CD163 expression and promoted migration of THP-1. We also confirmed that a neutralizing anti-CCL20 antibody blocked the induction of CD163 expression by direct CM in THP-1. Moreover, ERK1/2 phosphorylation was associated with the CCL20-driven induction of CD163 expression in THP-1.

Conclusions

Tongue cancer cell-derived CCL20 that was induced by interaction with macrophages promotes CD163 expression on macrophages.

Anti-proliferative and anti-migratory properties of coffee diterpenes kahweol acetate and cafestol in human renal cancer cells

Despite improvements in systemic therapy options for renal cancer, it remains one of the most drug-resistant malignancies. Interestingly, reports have shown that kahweol and cafestol, natural diterpenes extracted from coffee beans, exhibit anti-cancer activity. However, the multiple potential pharmacological actions of both have yet to be fully understood. This study therefore investigated the effects of kahweol acetate and cafestol on human renal cancer ACHN and Caki-1 cells. Accordingly, the combination of kahweol acetate and cafestol administration synergistically inhibited cell proliferation and migration by inducing apoptosis and inhibiting epithelial-mesenchymal transition. Mechanistic dissection revealed that kahweol acetate and cafestol inhibited Akt and ERK phosphorylation. Moreover, kahweol acetate and cafestol downregulated the expression of not only C-C chemokine receptors 2, 5, and 6 but also programmed death-ligand 1, indicating their effects on the tumor microenvironment. Thus, kahweol acetate and cafestol may be novel therapeutic candidates for renal cancer considering that they exert multiple pharmacological effects.

The roles and mechanisms of the circular RNA circ_104640 in early-stage lung adenocarcinoma: a potential diagnostic and therapeutic target

Background

In recent years, there have been increasing reports that dysregulated circular RNAs (circRNAs) play a key role in the carcinogenesis of lung adenocarcinoma (LUAC). However, the role of circRNAs in early-stage LUAC is poorly understood.

Methods

The Gene Expression Omnibus (GEO) database and qRT-PCR were used to verify the abnormal expression of circRNAs, miRNAs and genes in early-stage LUAC tissues. shRNA and miRNA inhibitor are designed and synthesized to knock down circ_104640 and microRNA (miR)-145-5p expression. CCK-8 assay, colony formation assay and flow cytometry were used to study the effect of circ_104640 on cell proliferation and apoptosis. Bioinformatics analysis, dual luciferase reporter assays and argonaute 2 (Ago2) RNA immunoprecipitation (RIP) assays were chosen to find out the potential target of circ_104640.

Results

Based on the GEO database and tissue sample from our institution, we identified that the circRNA circ_104640, the miR-145-5p, and CCL20 (C-C motif chemokine ligand 20) were abnormally expressed in the tissues of early-stage LUAC. In vitro experiments showed that circ_104640 could exist stably in the cytoplasm, and a short pin RNA that targeted circ_104640 (sh-circ) inhibited cell growth and promoted apoptosis of LUAC cells. Dual luciferase reporter assays and Ago2 (RIP) assays confirmed the Ago2-dependent interaction of circ_104640 and miR-145-5p. In terms of mechanisms, we found that circ_104640 increased the expression of CCL20 by sponging miR-145-5p.

Conclusions

Our research demonstrated that circ_104640 could accelerate the proliferation of LUAC cells, while inhibiting LUAC cell apoptosis. circ_104640 may be a potential novel biomarker and therapeutic target for early-stage LUAC.

The Role of CCL20-CCR6 Axis in Ovarian Cancer Metastasis

Background

Chemokine networks play a key and complex role in tumor progression. CCL20 and its unique receptor CCR6 have been reported to mediate malignant biological activities in various cancers, but their role in ovarian cancer metastasis remains unclear.

Purpose

Our study aims to explore the effect of CCL20-CCR6 axis on ovarian cancer metastasis and its potential mechanism.

Methods

The transwell assay was used to detect the cell migration and invasion after CCL20 treatment. The CCK-8 assay was used to detect the cell viability after CCL20 treatment and CCR6 depletion. The mRNA and protein expression were assayed through qRT-PCR and Western blotting. The siRNAs and CRISPR-Cas9 system were adopted to suppress CCR6 expression. Intraperitoneal xenograft mouse model was constructed to test the pro-metastasis effect of CCL20-CCR6 axis in vivo. The differentially expressed genes induced by CCL20 were identified through RNA-sequencing, and immunohistochemistry staining was used to detect their protein expression in tumor tissues.

Results

Our results revealed that CCL20 treatment selectively promoted the migration and invasion of CCR6^high ovarian cancer cells, but had no effect on CCR6^low cells. Blockade of CCR6 expression effectively reversed the cell migration and invasion induced by CCL20 stimulation. Animal experiment proved that CCL20-CCR6 axis mediated ovarian cancer metastasis in vivo. The differentially expressed genes after CCL20 stimulation were associated with metastasis, and CCL20 induced an increased expression of CDH2 and VCAN and decreased CDH1 expression in cancer cells. Moreover, CCL20 stimulated the expression of N-cadherin and versican in tumor tissues and inhibited the expression of E-cadherin, while CCR6 knockout successfully blocked the expression changes.

Conclusion

Our findings revealed that CCL20-CCR6 axis promotes ovarian cancer metastasis both in vivo and in vitro, probably through increasing cancer cell adhesion and epithelial–mesenchymal transition. Blockade of CCL20-CCR6 axis might become a novel anti-tumor therapeutic target for ovarian cancer.

High serum CCL20 is associated with tumor progression in penile cancer

Serum cancer biomarker has been proven to be very valuable in cancer diagnosis, disease monitoring and prognosis assessment, despite there is still a lack of serum biomarker for penile cancer (PC). Our initial analysis on public GEO dataset identified CCL20 as a top C-C motif ligand (CCL) gene enriched in PC. The patients with PC exhibited markedly higher preoperative serum CCL20 level than healthy control. The area under the curve (AUC) was 0.855 with the sensitivity of 72.4%, and specificity of 93.5% to distinguish PC. Preoperative serum CCL20 level was significantly associated with clinicopathological characteristics including T stage (P=0.005), nodal status (P=0.008), and pelvic lymph node metastasis (P=0.007). PC Patients with high serum CCL20 level had shorter disease-free survival compared to those with low level (P<0.001). Cox regression analysis showed that serum CCL20 level could serve as an independent prognostic factor for disease-free survival with a HR of 3.980 (95% CI: 1.209-13.098, P=0.023). Furthermore, CCL20 expression was observed in PC tissues and cell lines. Knockdown of CCL20 expression markedly suppressed malignant phenotypes (cell proliferation, clonogenesis, apoptosis escape, migration and invasion), attenuated STAT3 and AKT signaling and reduced MMP2/9 secretion in PC cell lines. Consistently, CCL20 and its receptor CCR6 exhibited correlated expression pattern in PC tissues. In conclusion, serum CCL20 level might serve as a potential diagnostic and prognostic cancer biomarker for PC. CCL20 might activate multiple downstream oncogenic signaling pathways (STAT3, AKT, MMP2/9) to promote malignant progression of PC, which may warrant further investigation in the future.

The CCL20-CCR6 Axis in Cancer Progression

Chemokines, which are basic proteins that exert their effects via G protein-coupled receptors and a subset of the cytokine family, are mediators deeply involved in leukocyte migration during an inflammatory reaction. Chemokine (C-C motif) ligand 20 (CCL20), also known as macrophage inflammatory protein (MIP)-3α, liver activation regulated chemokine (LARC), and Exodus-1, is a small protein that is physiologically expressed in the liver, colon, and skin, is involved in tissue inflammation and homeostasis, and has a specific receptor C-C chemokine receptor 6 (CCR6). The CCL20-CCR6 axis has long been known to be involved in inflammatory and infectious diseases, such as rheumatoid arthritis and human immunodeficiency virus infections. Recently, however, reports have shown that the CCL20-CCR6 axis is associated with several cancers, including hepatocellular carcinoma, colorectal cancer, breast cancer, pancreatic cancer, cervical cancer, and kidney cancer. The CCL20-CCR6 axis promotes cancer progression directly by enhancing migration and proliferation of cancer cells and indirectly by remodeling the tumor microenvironment through immune cell control. The present article reviewed the role of the CCL20-CCR6 axis in cancer progression and its potential as a therapeutic target.

Tumor-Associated Macrophages Induce Migration of Renal Cell Carcinoma Cells via Activation of the CCL20-CCR6 Axis

This study investigated tumor-associated macrophages activity in the microenvironment of renal cell carcinoma. Via a co-culture with macrophage-like cells differentiated from human monocyte cell line THP-1 and U937 cells, the migration ability of ACHN and Caki-1 cells, which are human renal cell carcinoma cell line cells, was significantly increased, as was the epithelial–mesenchymal transition change. A chemokine array identified the CCL20-CCR6 axis as a concentration-dependent signal in ACHN and Caki-1 cell migration. Akt in the ACHN and Caki-1 cells was activated by macrophage-like cells, and the CCL20 neutralizing antibody suppressed migration ability, epithelial–mesenchymal transition, and Akt phosphorylation in the ACHN and Caki-1 cells. Akt inhibitor AZD5363 also decreased the epithelial–mesenchymal transition change and migration ability in the ACHN and Caki-1 cells. In 42 renal cell carcinoma tissues, patients with CCR6 and macrophage infiltration indicated poor prognoses. In the tumor microenvironment of renal cell carcinoma, cancer cells are activated by CCL20 secreted by tumor-associated macrophages through Akt activation, followed by epithelial–mesenchymal transition and an acquired migration ability. Thus, inhibition of the CCL20-CCR6 axis may be a potential therapeutic strategy for renal cell carcinoma.

lncRNA‑u50535 promotes the progression of lung cancer by activating CCL20/ERK signaling

The ligand/receptor pair C‑C motif chemokine ligand 20 (CCL20)/C‑C motif chemokine receptor 6 (CCR6) is considered to be highly activated in lung cancer and significantly accelerates lung cancer progression through activation of ERK signaling. In addition, it has been shown that long non‑coding RNA‑u50535 (lncRNA‑u50535) upregulates CCL20 expression and facilitates cancer progression in colorectal cancer (CRC). However, the effects of lncRNA‑u50535 in lung cancer progression and whether lncRNA‑u50535 regulates CCL20/CCR6/ERK signaling in lung cancer remain ill‑defined. Therefore, the aim of the present study was to investigate the effects of lncRNA‑u50535 on CCL20/CCR6/ERK signaling in lung cancer progression. The results demonstrated that lncRNA‑u50535 expression was upregulated in lung cancer tissues and cell lines compared with normal tissues and cells. Knockdown of lncRNA‑u50535 decreased lung cancer cell proliferation and migration, induced G0/G1 phase arrest and promoted cell apoptosis. Western blot and luciferase reporter gene assays demonstrated that lncRNA‑u50535 overexpression increased the translation and transcription of CCL20. In addition, knockdown of lncRNA‑u50535 decreased CCL20, CCR6 and p‑ERK levels. The effects of lncRNA‑u50535 on cell proliferation and cell apoptosis were weakened when CCL20 was silenced. Overall, the present study demonstrated that lncRNA‑u50535 may function as an oncogene in lung cancer progression by regulating CCL20/ERK signaling.

DEPDC1 drives hepatocellular carcinoma cell proliferation, invasion and angiogenesis by regulating the CCL20/CCR6 signaling pathway

DEP domain containing 1 (DEPDC1) functions as an oncogene in hepatocellular carcinoma (HCC). However, the underlying mechanism of DEPDC1 remains largely unknown. The present study revealed that DEPDC1 knockdown inhibited HCC cell proliferation, colony formation and invasion in vitro and suppressed the growth of HCC xenografts in vivo. Furthermore, DEPDC1 overexpression promoted HCC cell proliferation, colony formation and invasion. DNA microarray, reverse transcription-quantitative-PCR and western blotting results demonstrated that DEPDC1 knockdown in Huh-7 significantly inhibited the expression of chemokine (C-C motif) ligand 20 (CCL20) and chemokine (C-C motif) receptor 6 (CCR6). In addition, the expression of CCL20 and CCR6 were upregulated in HCC tissues and cell lines, and were positively correlated with DEPDC1 expression. CCL20 or CCR6 knockdown via small interfering RNA reversed the effects of DEPDC1 overexpression in HCC cells. Furthermore, it was revealed that conditioned medium from DEPDC1 upregulated Li-7 and Hep3B cells led to angiogenesis in vitro, whereas CCL20 knockdown in Li-7 and Hep3B cells or CCR6 knockdown in human umbilical vein endothelial cells reversed the angiogenic effect of DEPDC1 overexpression. In conclusion, DEPDC1 facilitated cell proliferation, invasion and angiogenesis via the CCL20/CCR6 pathway in HCC.

Modulation of the CCR6-CCL20 Axis: A Potential Therapeutic Target in Inflammation and Cancer

Prototypical functions of the chemokine receptor CCR6 include immune regulation by maneuvering cell chemotaxis and selective delimiting of the pro-inflammatory T_H17 and regulatory T_reg subsets during chronic or acute systemic inflammation. Inhibition of CCR6 is proposed to attenuate disease symptoms and promote recuperation of multiple inflammatory and autoimmune disorders. Prescription medicines with pharmacodynamics involving the inhibition of the chemokine axis CCR6–CCL20 are very limited. The development of such therapeutics is still at an early experimental stage and has mostly involved the utilization of pre-clinical models and neutralizing mono or polyclonal antibodies against either partner (CCR6 or CCL20). Other methods include the constitutive use of small molecules as peptide inhibitors or small interfering ribonucleic acid (siRNA) to interfere with transcription at the nuclear level. In our review, we aim to introduce the wide array of potential CCR6–CCL20 inhibitors with an emphasis on attendant immune-modulator capacity that have been tested in the research field to date and are immensely promising compounds as forerunners of future curatives. Sixteen different tractable inhibitors of the CCR6–CCL20 duo have been identified as possessing high medicinal potential by drug developers worldwide to treat autoimmune and inflammatory diseases as shown in Figure 1. A multitude of antibody preparations are already available in the current pharmaceutical market as patented treatments for diseases in which the CCR6–CCL20 axis is operative, yet they must be used only as supplements with existing routinely prescribed medication as they collectively produce adverse side effects. Novel inhibitors are needed to evaluate this invaluable therapeutic target which holds much promise in the research and development of complaisant remedies for inflammatory diseases.

Sputum Detection of Predisposing Genetic Mutations in Women with Pulmonary Nontuberculous Mycobacterial Disease

Nontuberculous mycobacterial lung disease (NTM), including Mycobacterium avium complex (MAC), is a growing health problem in North America and worldwide. Little is known about the molecular alterations occurring in the tissue microenvironment during NTM pathogenesis. Utilizing next generation sequencing, we sequenced sputum and matched lymphocyte DNA in 15 MAC patients for a panel of 19 genes known to harbor cancer susceptibility associated mutations. Thirteen of 15 NTM subjects had a diagnosis of breast cancer (BCa) before or after NTM infection. Thirty three percent (4/12) of these NTM-BCa cases exhibited at least 3 somatic mutations in sputa compared to matched lymphocytes. Twenty four somatic mutations were detected with at least one mutation in ATM, ERBB2, BARD1, BRCA1, BRCA2, AR, TP53, PALB2, CASP8, BRIP1, NBN and TGFB1 genes. All four NTM-BCa patients harboring somatic mutations also exhibited 15 germ line BRCA1 and BRCA2 mutations. The two NTM subjects without BCa exhibited twenty somatic mutations spanning BRCA1, BRCA1, BARD1, BRIP1, CHEK2, ERBB2, TP53, ATM, PALB2, TGFB1 and 3 germ line mutations in BRCA1 and BRCA2 genes. A single copy loss of STK11 and AR gene was noted in NTM-BCa subjects. Periodic screening of sputa may aid to develop risk assessment biomarkers for neoplastic diseases in NTM patients.

In vitro chemokine (C-C motif) receptor 6-dependent non-inflammatory chemotaxis during spermatogenesis

Background

Chemokine (C-C motif) receptor 6 (CCR6) is present in sperm and plays a significant role in sperm motility and chemotaxis acting in the reproductive tracts. However, the expression and functional significance of CCR6 in testis are still poorly understood, especially in the process of spermatogenesis.

Methods and results

CCR6 was expressed in spermatogenic cell lines and its expression was shown in an age-dependent upregulation manner from puberty to adulthood in mouse testis. Immunostaining results confirmed the localization of CCR 6 in testis. Further chemotaxis assays demonstrated that spermatogenic cells GC-1 and -2 exhibited a directional movement toward CCR6-specific ligand such as CCL20 or Sertoli cells in vitro.

Conclusions

The present findings indicate that CCR6 is involved in the chemotaxis of spermatogenic cells in vitro and promotes chemotaxis under non-inflammatory conditions during normal spermatogenesis.

Electronic supplementary material

The online version of this article (10.1186/s40659-018-0161-z) contains supplementary material, which is available to authorized users.