Expression of the chemokine receptor CCR6 in the Lewis lung carcinoma (LLC) cell line reduces its metastatic potential in vivo

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.

A Comprehensive Analysis of the Effects of Key Mitophagy Genes on the Progression and Prognosis of Lung Adenocarcinoma

The aim of our study was to perform a comprehensive analysis of the gene expression, copy number variation (CNV) and mutation of key mitophagy genes in the progression and prognosis of lung adenocarcinoma (LUAD). We obtained the data from The Cancer Genome Atlas (TCGA). Clustering analysis was performed to stratify the mitophagy related groups. The least absolute shrinkage and selection operator (LASSO) based cox model was used to select hub survival genes. An independent validation cohort was retrieved from Gene Expression Omnibus database. We found 24 out of 27 mitophagy genes were aberrantly expressed between tumor and normal samples. CNV gains were associated with higher expression of mitophagy genes in 23 of 27 mitophagy genes. The clustering analysis identified high and low risk mitophagy groups with distinct survival differences. The high risk mitophagy groups had higher tumor mutation burden, stemness phenotype, total CNVs and lower CD4+ T cells infiltration. Drugs targeted to high risk mitophagy groups were identified including the PI3K/AKT/mTOR inhibitor, HDAC inhibitor and chemotherapy agents such as cisplatin and gemcitabine. In addition, the differentially expressed genes (DEGs) were identified between mitophagy groups. Further univariate Cox analysis of each DEG and subsequent LASSO-based Cox model revealed a mitophagy-related prognostic signature. The risk score model of this signature showed a strong ability to predict the overall survival of LUAD patients in training and validation datasets. In conclusion, the mitophagy genes played an important role in the progression and prognosis of LUAD, which might provide useful information for the treatment of LUAD.

Comprehensive Exome Analysis of Immunocompetent Metastatic Head and Neck Cancer Models Reveals Patient Relevant Landscapes

Immunocompetent metastatic head and neck cancer (HNC) models, although scarce, can help understanding cancer progression and therapy responses in vivo. Their comprehensive genome characterizations are essential for translational research. We first exome-sequenced the two most widely used spontaneous metastatic immunocompetent models, namely AT-84 and SCC VII, followed by comprehensive genomic analyses with three prior-sequenced models (MOC2, MOC2-10, and 4MOSC2), together with patient tumors for utility assessment. AT-84 and SCC VII bear high HNC tumor resemblance regarding mutational signatures-Trp53, Fanconi anemia, and MAPK and PI3K pathway defects. Collectively, the five models harbor genetic aberrations across 10 cancer hallmarks and 14 signaling pathways and machineries (metabolic, epigenetic, immune evasion), to extents similar in patients. Immune defects in HLA-A (H2-Q10, H2-Q4, H2-Q7, and H2-K1), Pdcd1, Tgfb1, Il2ra, Il12a, Cd40, and Tnfrsf14 are identified. Invasion/metastatic genome analyses first highlight potential druggable ERBB4 and KRAS mutations, for advanced/metastatic oral cavity cancer, as well as known metastasis players (Muc5ac, Trem3, Trp53, and Ttn) frequently captured by all models. Notable immunotherapy and precision druggable targets (Pdcd1, Erbb4, Fgfr1, H/Kras, Jak1, and Map2k2) and three druggable hubs (RTK family, MAPK, and DNA repair pathways) are frequently represented by these models. Immunocompetent metastatic HNC models are worth developing to address therapy- and invasion/metastasis-related questions in host immunity contexts.

Analysis of prognostic genes in the tumor microenvironment of lung adenocarcinoma

Background

Prognostic genes in the tumor microenvironment play an important role in immune biological processes and the response of cancer to immunotherapy. Thus, we aimed to assess new biomarkers that are associated with immune/stromal cells in lung adenocarcinomas (LUAD) using the ESTIMATE algorithm, which also significantly affects the prognosis of cancer.

Methods

The RNA sequencing (RNA-Seq) and clinical data of LUAD were downloaded from the the Cancer Genome Atlas (TCGA ). The immune and stromal scores were calculated for each sample using the ESTIMATE algorithm. The LUAD gene chip expression profile data and the clinical data (GSE37745, GSE11969, and GSE50081) were downloaded from the Gene Expression Omnibus (GEO) for subsequent validation analysis. Differentially expressed genes were calculated between high and low score groups. Univariate Cox regression analysis was performed on differentially expressed genes (DEGs) between the two groups to obtain initial prognosis genes. These were verified by three independent LUAD cohorts from the GEO database. Multivariate Cox regression was used to identify overall survival-related DEGs. UALCAN and the Human Protein Atlas were used to analyze the mRNA /protein expression levels of the target genes. Immune cell infiltration was evaluated using the Tumor Immune Estimation Resource (TIMER) and CIBERSORT methods, and stromal cell infiltration was assessed using xCell.

Results

In this study, immune scores and stromal scores are significantly associated with the clinical characteristics of LUAD, including T stage, M stage, pathological stage, and overall survival time. 530 DEGs (18 upregulated and 512 downregulated) were found to coexist in the difference analysis with the immune scores and stromal scores subgroup. Univariate Cox regression analysis showed that 286 of the 530 DEGs were survival-related genes (p < 0.05). Of the 286 genes initially identified, nine prognosis-related genes (CSF2RB, ITK, FLT3, CD79A, CCR4, CCR6, DOK2, AMPD1, and IGJ) were validated from three separate LUAD cohorts. In addition, functional analysis of DEGs also showed that various immunoregulatory molecular pathways, including regulation of immune response and the chemokine signaling pathways, were involved. Five genes (CCR6, ITK, CCR4, DOK2, and AMPD1) were identified as independent prognostic indicators of LUAD in specific data sets. The relationship between the expression levels of these genes and immune genes was assessed. We found that CCR6 mRNA and protein expression levels of LUAD were greater than in normal tissues. We evaluated the infiltration of immune cells and stromal cells in groups with high and low levels of expression of CCR6 in the TCGA LUAD cohort. In summary, we found a series of prognosis-related genes that were associated with the LUAD tumor microenvironment.

Tumor-derived CCL20 affects B16 melanoma growth in mice

BACKGROUND

Chemokine ligand-20 (CCL20) expressed in the epidermis is a potent impetus for the recruitment of CC-chemokine receptor 6 (CCR6)-expressing subsets of DCs, B-cells and memory T-cells into the skin. CCL20 and CCR6+ immune cells have been detected in chronic inflammatory skin diseases and several malignancies, including melanoma. Yet, the functional contribution of the CCR6/CCL20 axis for melanoma progression remains controversial.

OBJECTIVE

The functional contribution of CCR6-expressing immune cell subsets and local CCL20 in the tumor microenvironment for the immune control of melanoma was studied.

METHODS

Homeostatic and inducible CCL20 secretion of murine (B16, Ret) and human (A375, C32) melanoma cells was analyzed by ELISA. To assess the functional relevance of CCR6/CCL20 interactions on local tumor progression, prestimulated or retrovirally transduced B16/F1 melanoma cells overexpressing CCL20 (B16-CCL20) were injected subcutaneously into C57BL/6 Wt mice and congenic CCR6-deficient (CCR6^-/-) mice. Infiltrating leucocytes were examined by flow cytometry in tumors and draining lymph nodes (DLNs).

RESULTS

Melanoma cell lines up-regulate CCL20 secretion upon stimulation with pro-inflammatory cytokines in vitro. While only moderate changes in phenotype and composition of leucocytes were detected in advanced tumors and DLNs, mice injected with CCR6+ B16-CCL20 cells developed smaller tumors compared to B16-Control injected littermates, with CCR6-/- mice displaying the most pronounced reduction in tumor growth and incidence.

CONCLUSION

Our results suggest that CCR6/CCL20 interactions and individual independent effects of CCL20 and CCR6 in the microenvironment may be essential for melanoma progression and suggest a decisive role of this chemokine axis for melanoma pathogenesis beyond chemoattraction.

Identification of a transcription factor-microRNA network in esophageal adenocarcinoma through bioinformatics analysis and validation through qRT-PCR

Purpose: The rapidly rising incidence of esophageal adenocarcinoma (EAC), which is usually diagnosed late with a poor prognosis, has become a growing problem. This study investigated the potential transcription factor (TF)-related molecular mechanisms of EAC by using bioinformatics analysis and qRT-PCR validation.

Methods: Expression profile datasets for mRNAs (GSE92396, GSE13898, GSE26886 and GSE1420) and miRNAs (GSE16456) were downloaded from the GEO database. Overlapping differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) were identified through integrative analysis. Then, a TF-miRNA-mRNA network was constructed based on bioinformatics data from the TRRUST, TRED and miRTarBase database. Furthermore, overall survival analysis for the mRNAs and miRNAs in the TF-miRNA-mRNA network was performed with data from TCGA, and qRT-PCR was used to validate the results.

Results: A total of 294 overlapping DEGs were identified in EAC tissues compared to normal tissues, including 181 downregulated and 113 upregulated genes. Then, 16 TFs that could target the DEGs and were related to cancer were predicted based on public databases, and 41 DEGs that could be targeted were identified as key genes. Additionally, 12 DEMs were predicted through miRTarBase to be associated with the key genes, and TP53-(miR-125b)-ID2 and JUN-(miR-30a)-IL1A from the TF-miRNA-mRNA network were identified to potentially play significant roles in EAC. Furthermore, CCL20, IL1A, ABCC3, hsa-miR-23b, and hsa-miR-191, which are involved in the TF-miRNA-mRNA network, were found to be significantly associated with patient survival in EAC. Finally, the expression of a miRNA-mRNA pair (hsa-miR-30a-5p and IL1A) was revealed to be correlated with prognosis.

Conclusion: In this study, a TF-miRNA-mRNA network was constructed to analyze the potential molecular mechanisms of EAC. Key genes and miRNAs associated with patient survival were identified, which may reveal promising approaches for EAC diagnosis and therapy.

CCL20 promotes migration and invasiveness of human cancerous breast epithelial cells in primary culture

The relation between the tumor and its microenvironment is one of the most interesting and less understood issues. Recently, we showed a role of CCL20 chemokine in proning the healthy tissue neighboring the tumor to carcinogenesis. Besides, tumor-secreted CCL20 induced proliferation, migration, and EMT of healthy cells. In this context, we have studied here if CCL20 had effects on the migration of cancer cells and the intracellular pathways used in breast epithelial cells in primary culture. Using molecular (siRNA) and pharmacological (inhibitors) techniques, we found multiple signaling kinases to be activated and involved in CCL20-induced tumor breast cell migration. CCL20 provoked a 2.5-fold increase of cell migration and invasion; CCL20 also enhanced MMP- 2 and MMP-9 mRNAs/protein expression and activities. Cell migration and invasiveness due to CCL20 significantly decreased when MMP-2 and MMP-9 were inhibited in CCL20-stimulated cells. CCL20 controlled MMP-2 expression through the JAK2/STAT3 pathway, while the expression of MMP-9 occurred by PKC-α that activated, consequently, c-Src, Akt, and finally NF-kB. These results reveal a role for CCL20 also in tumor breast cell and point to CCL20 as a novel therapeutic target in cancer.

Mutations in BALB mitochondrial DNA induce CCL20 up-regulation promoting tumorigenic phenotypes

mtDNA mutations are common in human cancers and are thought to contribute to the process of neoplasia. We examined the role of mtDNA mutations in skin cancer by generating fibroblast cybrids harboring a mutation in the gene encoding the mitochondrial tRNA for arginine. This somatic mutation (9821insA) was previously reported in UV-induced hyperkeratotic skin tumors in hairless mice and confers specific tumorigenic phenotypes to mutant cybrids. Microarray analysis revealed and RT-PCR along with Western blot analysis confirmed the up-regulation of CCL20 and its receptor CCR6 in mtBALB haplotype containing the mt-Tr 9821insA allele compared to wild type mtB6 haplotype. Based on reported role of CCL20 in cancer progression we examined whether the hyper-proliferation and enhanced motility of mtBALB haplotype would be associated with CCL20 levels. Treatment of both genotypes with recombinant CCL20 (rmCCL20) resulted in enhanced growth and motility of mtB6 cybrids. Furthermore, the acquired somatic alteration increased the in vivo tumor growth of mtBALB cybrids through the up-regulation of CCL20 since neutralizing antibody significantly decreased in vivo tumor growth of these cells; and tumors from anti-CCL20 treated mice injected with mtBALB cybrids showed significantly decreased CCL20 levels. When rmCCL20 or mtBALB cybrids were used as chemotactic stimuli, mtB6 cybrids showed increased motility while anti-CCL20 antibody decreased the migration and in vivo tumor growth of mtBALB cybrids. Moreover, the inhibitors of MAPK signaling and NF-κB activation inhibited CCL20 expression in mtBALB cybrids and decreased their migratory capabilities. Thus, acquired mtDNA mutations may promote tumorigenic phenotypes through up-regulation of chemokine CCL20.

Overexpression of CCL20 and its receptor CCR6 predicts poor clinical prognosis in human gliomas

Recent studies have demonstrated that the chemokine CCL20 and its receptor CCR6 may be involved in tumorigenesis, tumor progression and metastatic spread of various human malignancies. The aim of this study was to investigate the clinicopathological significance and prognostic value of CCL20 and CCR6 expression in human malignant glioma. CCL20 and CCR6 expression in human gliomas and nonneoplastic brain tissues was measured by immunohistochemistry. The association of CCL20 and CCR6 expression with clinicopathological factors or prognosis in glioma patients was statistically analyzed. The expression levels of CCL20 and CCR6 proteins were both up-regulated in glioma tissues. There was a significantly positive correlation between the expression of the two markers (r = 0.88; P < 0.001). In addition, the overexpressions of CCL20 and CCR6 were both detected in high-grade glioma tissues compared with those in low-grade tissues and increased with ascending tumor World Health Organization (WHO) grades (P = 0.006 and 0.008, respectively). The increased expressions of CCL20 and CCR6 proteins were also significantly correlated with low Karnofsky performance score (both P = 0.01). Moreover, univariate analysis found that CCL20 expression (P = 0.002), CCR6 expression (P = 0.002) and CCL20/CCR6 co-expression (P < 0.001) were all significantly associated with poor prognosis. In particular, glioma patients with CCL20/CCR6 co-expression have the shortest overall survival. Multivariate analysis further identified the expression levels of CCL20 and CCR6 to be independent prognostic factors. Our data suggest for the first time that CCL20 and CCR6 might play an important role in the regulation of aggressiveness in human gliomas. The up-regulation of CCL20 and CCR6 might be closely associated with poor clinical outcome of patients with gliomas.

MiR-21 is involved in cervical squamous cell tumorigenesis and regulates CCL20

MicroRNA 21 (miR-21) has been implicated in various aspects of carcinogenesis. However, its function and molecular mechanism in cervical squamous carcinoma have not been studied. Using TaqMan quantitative real-time PCR and Northern blot, we confirmed that miR-21 is significantly overexpressed in human cervical squamous cancer tissues and cell lines. Remarkably, we showed that the level of miR-21 correlates with the tumor differentiation and nodal status by ISH. Furthermore, we demonstrated that miR-21 regulates proliferation, apoptosis, and migration of HPV16-positive cervical squamous cells. In order to identify candidate target genes for miR-21, we used gene expression profiling. By luciferase reporter assays, we confirmed that CCL20 is one of its target genes, which is related to the HPV16 E6 and E7 oncogenes. Our results suggest that miR-21 may be involved in cervical squamous cell tumorigenesis.

CCR6 as a mediator of immunity in the lung and gut

Chemokines are key mediators of leukocyte recruitment during pathogenic insult and also play a prominent role in homeostasis. While most chemokine receptors bind to multiple chemokines, CCR6 is unique in that this receptor is one of only a few that can bind only a single chemokine ligand, CCL20. CCR6 is an important receptor that is involved in regulating several aspects of mucosal immunity, including the ability to mediate the recruitment of immature dendritic cells (DCs) and mature DCs, and professional antigen presenting cells (APCs) to the sites of epithelial inflammation. Further, CCR6 mediates the homing of both CD4(+) T (T-helper; Th) cells and DCs to the gut mucosal lymphoid tissue. DCs, which are known to be essential immune cells in innate immunity and in the initiation of adaptive immunity, play a central role in initiating a primary immune response. Herein, we summarize the role of CCR6 in immune responses at epithelial and mucosal sites in both the lung and gut based on a review of the current literature.

Expression of the chemokine receptor CCR6 correlates with a favorable prognosis in patients with adenocarcinoma of the lung

The relation between CCR6 expression and the clinicopathological characteristics of lung cancer and patient prognosis is not well understood and remains controversial. We, therefore, investigated the relationship between CCR6 expression and prognosis in patients with adenocarcinoma of the lung. We used semiquantitative real-time reverse transcription polymerase chain reaction to assess the expression of CCR6 mRNA in tumor samples from 84 patients with adenocarcinoma of the lung. We then correlated the levels of CCR6 mRNA with known clinicopathological features. The 5-year disease-free survival rate among patients expressing higher levels of CCR6 mRNA was significantly better than among those expressing lower levels (P = 0.009 by log-rank test). Multivariate Cox proportional hazard analyses revealed, being male [hazard ratio, 3.94; 95% confidence interval (CI), 1.58 to 10.36; P = 0.003], tumor size >30 mm (hazard ratio, 2.46; 95% CI, 1.08 to 5.73; P = 0.030), nodal metastasis (hazard ratio, 7.66; 95% CI, 2.62 to 23.3; P = 0.0002), and CCR6 (hazard ratio, 0.34; 95% CI, 0.11 to 0.93; P = 0.034) to be independent factors affecting the 5-year disease-free survival rate. Greater expression of CCR6 by tumor cells is an independent predictor of a better prognosis in patients with adenocarcinoma of the lung.