CCR7 mediates human breast cancer cell invasion, migration by inducing epithelial-mesenchymal transition and suppressing apoptosis through AKT pathway

Modulation of esophageal squamous cell carcinoma progression: the impact of CCR7 on JAK2/STAT3 signaling pathway

BACKGROUND

Existing studies have already revealed the involvement of C-C chemokine receptor type 7 (CCR7) in diverse human cancers, including esophageal cell squamous carcinoma (ESCA). Our current study, aims to explore the relevant mechanisms implicated.

METHODS

ESCA cell lines were collected for CCR7 expression quantification using western blot. Following the transfection, the viability, migration and invasion of ESCA cells were evaluated via cell counting kit-8 and Transwell assays. The specific molecular mechanisms underlying the effects of CCR7 in ESCA cells were explored via calculating the expressions of proteins related to metastasis and Janus kinase 2/signal transduction and transcription activation 3 (JAK2/STAT3) signaling pathway via western blot. The correlation between CCR7 and metastasis-related proteins was explored via Pearson's correlation test.

RESULTS

CCR7 was high-expressed in ESCA cells and CCR7 knockdown repressed the viability, migration and invasion of ESCA cells, concurrent with the increased expression of E-cadherin (E-cad, which was also known as CDH1 and lowly expressed in ESCA cells) and the decreased expressions of vimentin (Vim, which was highly expressed in ESCA cells) and matrix metalloproteinase-9 (MMP-9, which was also highly expressed in ESCA cells). Meanwhile, CCR7 was positively correlated with Vim and MMP-9 yet negatively correlated with E-cad in ESCA cells, which indicated that CCR7 has a role in promoting tumor progression in ESCA cells. Besides, the phosphorylation of STAT3 and JAK2 in ESCA cells was elevated, which was diminished following CCR7 knockdown.

CONCLUSION

This study proves the modulation of CCR7 on ESCA in vitro, which was achieved via JAK2/STAT3 signaling pathway. Our discovery will provide new therapeutic basis and insights for ESCA.

Identifying epithelial-mesenchymal transition-related genes as prognostic biomarkers and therapeutic targets of hepatocellular carcinoma by integrated analysis of single-cell and bulk-RNA sequencing data

Background

Hepatocellular carcinoma (HCC) remains one of the most lethal cancers globally. Patients with advanced HCC tend to have poor prognoses and shortened survival. Recently, data from bulk RNA sequencing have been employed to discover prognostic markers for various cancers. However, they fall short in precisely identifying core molecular and cellular activities within tumor cells. In our present study, we combined bulk-RNA sequencing (bulk RNA-seq) data with single-cell RNA sequencing (scRNA-seq) to develop a prognostic model for HCC. The goal of our research is to uncover new biomarkers and enhance the accuracy of HCC prognosis prediction.

Methods

Integrating single-cell sequencing data with transcriptomics were used to identify epithelial-mesenchymal transition (EMT)-related genes (ERGs) implicated in HCC progression and their clinical significance was elucidated. Utilizing marker genes derived from core cells and ERGs, we constructed a prognostic model using univariate Cox analysis, exploring a multitude of algorithmic combinations, and further refining it through multivariate Cox analysis. Additionally, we conducted an in-depth investigation into the disparities in clinicopathological features, immune microenvironment composition, immune checkpoint expression, and chemotherapeutic drug sensitivity profiles between high- and low-risk patient cohorts.

Results

We developed a prognostic model predicated on the expression profiles of eight signature genes, namely HSP90AA1, CIRBP, CCR7, S100A9, ADAM17, ENG, PGF, and INPP4B, aiming at predicting overall survival (OS) outcomes. Notably, patients classified with high-risk scores exhibited a propensity towards diminished OS rates, heightened frequencies of stage III-IV disease, increased tumor mutational burden (TMB), augmented immune cell infiltration, and diminished responsiveness to immunotherapeutic interventions.

Conclusions

This study presented a novel prognostic model for predicting the survival of HCC patients by integrating scRNA-seq and bulk RNA-seq data. The risk score emerges as a promising independent prognostic factor, showing a correlation with the immune microenvironment and clinicopathological features. It provided new clinical tools for predicting prognosis and aided future research into the pathogenesis of HCC.

Immune Cell Migration to Cancer

Immune cell migration is required for the development of an effective and robust immune response. This elegant process is regulated by both cellular and environmental factors, with variables such as immune cell state, anatomical location, and disease state that govern differences in migration patterns. In all cases, a major factor is the expression of cell surface receptors and their cognate ligands. Rapid adaptation to environmental conditions partly depends on intrinsic cellular immune factors that affect a cell's ability to adjust to new environment. In this review, we discuss both myeloid and lymphoid cells and outline key determinants that govern immune cell migration, including molecules required for immune cell adhesion, modes of migration, chemotaxis, and specific chemokine signaling. Furthermore, we summarize tumor-specific elements that contribute to immune cell trafficking to cancer, while also exploring microenvironment factors that can alter these cellular dynamics within the tumor in both a pro and antitumor fashion. Specifically, we highlight the importance of the secretome in these later aspects. This review considers a myriad of factors that impact immune cell trajectory in cancer. We aim to highlight the immunotherapeutic targets that can be harnessed to achieve controlled immune trafficking to and within tumors.

Connecting the Dots: The Cerebral Lymphatic System as a Bridge Between the Central Nervous System and Peripheral System in Health and Disease

As a recently discovered waste removal system in the brain, cerebral lymphatic system is thought to play an important role in regulating the homeostasis of the central nervous system. Currently, more and more attention is being focused on the cerebral lymphatic system. Further understanding of the structural and functional characteristics of cerebral lymphatic system is essential to better understand the pathogenesis of diseases and to explore therapeutic approaches. In this review, we summarize the structural components and functional characteristics of cerebral lymphatic system. More importantly, it is closely associated with peripheral system diseases in the gastrointestinal tract, liver, and kidney. However, there is still a gap in the study of the cerebral lymphatic system. However, we believe that it is a critical mediator of the interactions between the central nervous system and the peripheral system.

CCL19: a novel prognostic chemokine modulates the tumor immune microenvironment and outcomes of cancers

BACKGROUND

CCL19 is a chemokine involved in cancer research due to its important role in the tumor microenvironment (TME) and clinical relevance in cancers. This study aimed to analyze transcription expression, genomic alteration, association with tumor immune microenvironment of CCL19 expression and its prediction value for prognosis and responses to immunotherapy for patients with cancers.

METHODS

RNA sequencing data and corresponding clinicopathological information of a total of large-scale cancer patients were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases. Multiplex immunofluorescence (mIF) was implemented to identify differential infiltration of Treg, CD8+ T cells, and tumor-associated macrophages, while CCL19 immunohistochemistry was conducted on 182 breast cancer samples from a real-world cohort.

RESULTS

Based on large-scale multi-center survival analysis of cancer patients, we found the prognosis of patients with high CCL19 expression was prominently better than those with low CCL19 expression. For patients from multiple independent cohorts, suppressed CCL19 expression exerts significant progressive phenotype and apoptosis activity of cancers, especially in breast and ovarian cancer. Interestingly, anti-tumor immune cells, specifically the CD8+ T cells and macrophages, were clustered from TME by elevated CCL19 expression. Additionally, higher CCL19 levels reflected heightened immune activity and substantial heterogeneity.

CONCLUSIONS

In conclusion, our findings support the notion that elevated CCL19 expression is linked to favorable outcomes and enhanced anti-tumor immunity, characterized by increased CD8+ T cells within the TME. This suggests the potential of CCL19 as a prognostic marker, predictive biomarker for immunotherapy, therapeutic target of cancers.

Construction of ceRNA prognostic model based on the CCR7/CCL19 chemokine axis as a biomarker in breast cancer

BACKGROUND

The study of CCR7/CCL19 chemokine axis and breast cancer (BC) prognosis and metastasis is a current hot topic. We constructed a ceRNA network and risk-prognosis model based on CCR7/CCL19.

METHODS

Based on the lncRNA, miRNA and mRNA expression data downloaded from the TCGA database, we used the starbase website to find the lncRNA and miRNA of CCR7/CCL19 and established the ceRNA network. The 1008 BC samples containing survival data were divided into Train group (504 cases) and Test group (504 cases) using R "caret" package. Then we constructed a prognostic risk model using RNA screened by univariate Cox analysis in the Train group and validated it in the Test and All groups. In addition, we explored the correlation between riskScores and clinical trials and immune-related factors (22 immune-infiltrating cells, tumor microenvironment, 13 immune-related pathways and 24 HLA genes). After transfection with knockdown CCR7, we observed the activity and migration ability of MDA-MB-231 and MCF-7 cells using CCK8, scratch assays and angiogenesis assays. Finally, qPCR was used to detect the expression levels of five RNAs in the prognostic risk model in MDA-MB-231 and MCF-7 cell.

RESULTS

Patients with high expression of CCR7 and CCL19 had significantly higher overall survival times than those with low expression. The ceRNA network is constructed by 3 pairs of mRNA-miRNA pairs and 8 pairs of miRNA-lncRNA. After multivariate Cox analysis, we obtained a risk prognostic model: riskScore= -1.544 *`TRG-AS1`+ 0.936 * AC010327.5 + 0.553 *CCR7 -0.208 *CCL19 -0.315 *`hsa-let-7b-5p. Age, stage and riskScore can all be used as independent risk factors for BC prognosis. By drug sensitivity analysis, we found 5 drugs targeting CCR7 (convolamine, amikacin, AH-23,848, ondansetron, flucloxacillin). After transfection with knockdown CCR7, we found a significant reduction in cell activity and migration capacity in MDA-MB-231 cells.

CONCLUSION

We constructed the first prognostic model based on the CCR7/CCL19 chemokine axis in BC and explored its role in immune infiltration, tumor microenvironment, and HLA genes.

Intracellular bacteria in cancer-prospects and debates

Recent evidence suggests that some human cancers may harbor low-biomass microbial ecosystems, spanning bacteria, viruses, and fungi. Bacteria, the most-studied kingdom in this context, are suggested by these studies to localize within cancer cells, immune cells and other tumor microenvironment cell types, where they are postulated to impact multiple cancer-related functions. Herein, we provide an overview of intratumoral bacteria, while focusing on intracellular bacteria, their suggested molecular activities, communication networks, host invasion and evasion strategies, and long-term colonization capacity. We highlight how the integration of sequencing-based and spatial techniques may enable the recognition of bacterial tumor niches. We discuss pitfalls, debates and challenges in decisively proving the existence and function of intratumoral microbes, while reaching a mechanistic elucidation of their impacts on tumor behavior and treatment responses. Together, a causative understanding of possible roles played by intracellular bacteria in cancer may enable their future utilization in diagnosis, patient stratification, and treatment.

CCL19+ dendritic cells potentiate clinical benefit of anti-PD-(L)1 immunotherapy in triple-negative breast cancer

BACKGROUND

The extensive involvement of dendritic cells (DCs) in immune contexture indicates their potent value in cancer immunotherapy. Understanding DC diversity in patient cohorts may strengthen the clinical benefit of immune checkpoint inhibitors (ICIs).

METHODS

Single-cell profiling of breast tumors from two clinical trials was performed to investigate DC heterogeneity. Multiomics, tissue characterization, and pre-clinical experiments were used to evaluate the role of the identified DCs in the tumor microenvironment. Four independent clinical trials were leveraged to explore biomarkers to predict ICI and chemotherapy outcomes.

FINDINGS

We identified a distinct CCL19-expressing functional state of DCs associated with favorable responses to anti-programmed death (ligand)-1 (PD-(L)1), which displayed migratory and immunomodulatory phenotypes. These cells were correlated with antitumor T cell immunity and the presence of tertiary lymphoid structures and lymphoid aggregates, defining immunogenic microenvironments in triple-negative breast cancer. In vivo, CCL19⁺ DC deletion by Ccl19 gene ablation dampened CCR7⁺CD8⁺ T cells and tumor elimination in response to anti-PD-1. Notably, high circulating and intratumoral CCL19 levels were associated with superior response and survival in patients receiving anti-PD-1 but not chemotherapy.

CONCLUSIONS

We uncovered a critical role of DC subsets in immunotherapy, which has implications for designing novel therapies and patient stratification strategies.

FUNDING

This study was funded by the National Key Research and Development Project of China, the National Natural Science Foundation of China, the Program of Shanghai Academic/Technology Research Leader, the Natural Science Foundation of Shanghai, the Shanghai Key Laboratory of Breast Cancer, the Shanghai Hospital Development Center (SHDC), and the Shanghai Health Commission.

CCR7 Mediates Cell Invasion and Migration in Extrahepatic Cholangiocarcinoma by Inducing Epithelial-Mesenchymal Transition

The epithelial-mesenchymal transition (EMT) contributes to the metastatic cascade in various tumors. C-C chemokine receptor 7 (CCR7) interacts with its ligand, chemokine (C-C motif) ligand 19 (CCL19), to promote EMT. However, the association between EMT and CCR7 in extrahepatic cholangiocarcinoma (EHCC) remains unknown. This study aimed to elucidate the prognostic impact of CCR7 expression and its association with clinicopathological features and EMT in EHCC. The association between CCR7 expression and clinicopathological features and EMT status was examined via the immunohistochemical staining of tumor sections from 181 patients with perihilar cholangiocarcinoma. This association was then investigated in TFK-1 and EGI-1 EHCC cell lines. High-grade CCR7 expression was significantly associated with a large number of tumor buds, low E-cadherin expression, and poor overall survival. TFK-1 showed CCR7 expression, and Western blotting revealed E-cadherin downregulation and vimentin upregulation in response to CCL19 treatment. The wound healing and Transwell invasion assays revealed that the activation of CCR7 by CCL19 enhanced the migration and invasion of TFK-1 cells, which were abrogated by a CCR7 antagonist. These results suggest that a high CCR7 expression is associated with an adverse postoperative prognosis via EMT induction and that CCR7 may be a potential target for adjuvant therapy in EHCC.

Establishment and validation of an aging-related risk signature associated with prognosis and tumor immune microenvironment in breast cancer

BACKGROUND

Breast cancer (BC) is a highly malignant and heterogeneous tumor which is currently the cancer with the highest incidence and seriously endangers the survival and prognosis of patients. Aging, as a research hotspot in recent years, is widely considered to be involved in the occurrence and development of a variety of tumors. However, the relationship between aging-related genes (ARGs) and BC has not yet been fully elucidated.

MATERIALS AND METHODS

The expression profiles and clinicopathological data were acquired in the Cancer Genome Atlas (TCGA) and the gene expression omnibus (GEO) database. Firstly, the differentially expressed ARGs in BC and normal breast tissues were investigated. Based on these differential genes, a risk model was constructed composed of 11 ARGs via univariate and multivariate Cox analysis. Subsequently, survival analysis, independent prognostic analysis, time-dependent receiver operating characteristic (ROC) analysis and nomogram were performed to assess its ability to sensitively and specifically predict the survival and prognosis of patients, which was also verified in the validation set. In addition, functional enrichment analysis and immune infiltration analysis were applied to reveal the relationship between the risk scores and tumor immune microenvironment, immune status and immunotherapy. Finally, multiple datasets and real-time polymerase chain reaction (RT-PCR) were utilized to verify the expression level of the key genes.

RESULTS

An 11-gene signature (including FABP7, IGHD, SPIB, CTSW, IGKC, SEZ6, S100B, CXCL1, IGLV6-57, CPLX2 and CCL19) was established to predict the survival of BC patients, which was validated by the GEO cohort. Based on the risk model, the BC patients were divided into high- and low-risk groups, and the high-risk patients showed worse survival. Stepwise ROC analysis and Cox analyses demonstrated the good performance and independence of the model. Moreover, a nomogram combined with the risk score and clinical parameters was built for prognostic prediction. Functional enrichment analysis revealed the robust relationship between the risk model with immune-related functions and pathways. Subsequent immune microenvironment analysis, immunotherapy, etc., indicated that the immune status of patients in the high-risk group decreased, and the anti-tumor immune function was impaired, which was significantly different with those in the low-risk group. Eventually, the expression level of FABP7, IGHD, SPIB, CTSW, IGKC, SEZ6, S100B, CXCL1, IGLV6-57 and CCL19 was identified as down-regulated in tumor cell line, while CPLX2 up-regulated, which was mostly similar with the results in TCGA and Human Protein Atlas (HPA) via RT-PCR.

CONCLUSIONS

In summary, our study constructed a risk model composed of ARGs, which could be used as a solid model for predicting the survival and prognosis of BC patients. Moreover, this model also played an important role in tumor immunity, providing a new direction for patient immune status assessment and immunotherapy selection.

Potential biomarkers and immune cell infiltration involved in aortic valve calcification identified through integrated bioinformatics analysis

Background: Calcific aortic valve disease (CAVD) is the most common valvular heart disease in the aging population, resulting in a significant health and economic burden worldwide, but its underlying diagnostic biomarkers and pathophysiological mechanisms are not fully understood. Methods: Three publicly available gene expression profiles (GSE12644, GSE51472, and GSE77287) from human Calcific aortic valve disease (CAVD) and normal aortic valve samples were downloaded from the Gene Expression Omnibus database for combined analysis. R software was used to identify differentially expressed genes (DEGs) and conduct functional investigations. Two machine learning algorithms, least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE), were applied to identify key feature genes as potential biomarkers for Calcific aortic valve disease (CAVD). Receiver operating characteristic (ROC) curves were used to evaluate the discriminatory ability of key genes. The CIBERSORT deconvolution algorithm was used to determine differential immune cell infiltration and the relationship between key genes and immune cell types. Finally, the Expression level and diagnostic ability of the identified biomarkers were further validated in an external dataset (GSE83453), a single-cell sequencing dataset (SRP222100), and immunohistochemical staining of human clinical tissue samples, respectively. Results: In total, 34 identified DEGs included 21 upregulated and 13 downregulated genes. DEGs were mainly involved in immune-related pathways such as leukocyte migration, granulocyte chemotaxis, cytokine activity, and IL-17 signaling. The machine learning algorithm identified SCG2 and CCL19 as key feature genes [area under the ROC curve (AUC) = 0.940 and 0.913, respectively; validation AUC = 0.917 and 0.903, respectively]. CIBERSORT analysis indicated that the proportion of immune cells in Calcific aortic valve disease (CAVD) was different from that in normal aortic valve tissues, specifically M2 and M0 macrophages. Key genes SCG2 and CCL19 were significantly positively correlated with M0 macrophages. Single-cell sequencing analysis and immunohistochemical staining of human aortic valve tissue samples showed that SCG2 and CCL19 were increased in Calcific aortic valve disease (CAVD) valves. Conclusion: SCG2 and CCL19 are potential novel biomarkers of Calcific aortic valve disease (CAVD) and may play important roles in the biological process of Calcific aortic valve disease (CAVD). Our findings advance understanding of the underlying mechanisms of Calcific aortic valve disease (CAVD) pathogenesis and provide valuable information for future research into novel diagnostic and immunotherapeutic targets for Calcific aortic valve disease (CAVD).

Site-Specific Polyplex on CCR7 Down-Regulation and T Cell Elevation for Lymphatic Metastasis Blocking on Breast Cancer

Tumor metastasis contributes to high cancer mortality. Tumor cells in lymph nodes (LNs) are difficult to eliminate but underlie uncontrollable systemic metastasis. The CC chemokine receptor 7 (CCR7) is overexpressed in tumor cells and interacts with CC chemokine ligand 21 (CCL21) secreted from LNs, potentiating their lymphatic migration. Here, a site-specific polyplex is developed to block the CCR7-CCL21 signal and kill tumor cells toward LNs, greatly limiting their lymphatic infiltration. A CCR7-targeting small interfering RNA (siCCR7) is condensed by mPEG-poly-(lysine) with chlorin e6 (Ce6) modification (PPLC) to form PPLC/siCCR7. The knockdown of CCR7 by siCCR7 in tumor cells significantly reduced their response on CCL21 and LN tropism. Additionally, photodynamic therapy-mediated immune activation precisely targets and kills tumor cells released from the primary foci before they reaches the LNs, reducing the number of tumor cells entering the LNs. Consequently, the PPLC/siCCR7 polyplexes inhibited up to 92% of lung metastasis in 4T1 tumor bearing mice and reduced tumor cell migration to LNs by up to 80%. This site-specific strategy optimized anti-metastasis efficacy and promotes the clinical translational development of anti-metastatic therapy.

Chemokine/GPCR Signaling-Mediated EMT in Cancer Metastasis

Metastasis, the chief cause of cancer-related deaths, is associated with epithelial-mesenchymal transition (EMT). In the tumor microenvironment, EMT can be triggered by chemokine/G-protein-coupled receptor (GPCR) signaling, which is closely associated with tumor progression. However, the functional links between chemokine/GPCR signaling-mediated EMT and metastasis remain unclear. Herein, we summarized the mechanisms of chemokine/GPCR signaling-mediated EMT with an insight into facilitating metastasis and clarified the role of chemokine in the local invasion, intravasation, circulation, extravasation, and colonization, respectively. Moreover, several potential pathways that might contribute to EMT based on the latest studies on GPCR signaling were proposed, including signaling mediated by G protein, β-arrestin, intracellular, dimerization activation, and transactivation. However, there is still limited evidence to support the EMT programme functional contribution to metastasis, which keeps a key question still open whether we should target EMT programme of cancer cells. Answers to that question might help develop an anticancer strategy or guide new directions for anticancer metastasis therapy.

The Multi-Functional Roles of CCR7 in Human Immunology and as a Promising Therapeutic Target for Cancer Therapeutics

An important hallmark of the human immune system is to provide adaptive immunity against pathogens but tolerance toward self-antigens. The CC-chemokine receptor 7 (CCR7) provides a significant contribution in guiding cells to and within lymphoid organs and is important for acquiring immunity and tolerance. The CCR7 holds great importance in establishing thymic architecture and function and naïve and regulatory T-cell homing in the lymph nodes. Similarly, the receptor is a key regulator in cancer cell migration and the movement of dendritic cells. This makes the CCR7 an important receptor as a drug and prognostic marker. In this review, we discussed several biological roles of the CCR7 and its importance as a drug and prognostic marker.

Development of a human antibody that exhibits antagonistic activity toward CC chemokine receptor 7

Background

CC chemokine receptor 7 (CCR7) is a member of G-protein-coupled receptor family and mediates chemotactic migration of immune cells and different cancer cells induced via chemokine (C-C motif) ligand 19 (CCL19) or chemokine (C-C motif) ligand 21 (CCL21). Hence, the identification of blockade antibodies against CCR7 could lead to the development of therapeutics targeting metastatic cancer.

Methods

CCR7 was purified and stabilized in its active conformation, and antibodies specific to purified CCR7 were screened from the synthetic M13 phage library displaying humanized scFvs. The in vitro characterization of selected scFvs identified two scFvs that exhibited CCL19-competitive binding to CCR7. IgG4’s harboring selected scFv sequences were characterized for binding activity in CCR7+ cells, inhibitory activity toward CCR7-dependent cAMP attenuation, and the CCL19 or CCL21-dependent migration of CCR7+ cells.

Results

Antibodies specifically binding to purified CCR7 and CCR7+ cells were isolated and characterized. Two antibodies, IgG4(6RG11) and IgG4(72C7), showed ligand-dependent competitive binding to CCR7 with KD values of 40 nM and 50 nM, respectively. Particularly, IgG4(6RG11) showed antagonistic activity against CCR7, whereas both antibodies significantly blocked the ligand-induced migration and invasion activity of CCR7+ cancer cells.

Conclusions

Two antibody clones were successfully identified from a synthetic scFv-displaying phage library using purified recombinant CCR7 as an antigen. Antibodies specifically bound to the surface of CCR7+ cells and blocked CCR7+ cell migration. Particularly, 6RG11 showed antagonist activity against CCR7-dependent cAMP attenuation.

Statement of Significance

Antibodies targeting CCR7 were identified and could serve as therapeutic reagents against cancer metastasis.

A comprehensive bioinformatics analysis to identify potential prognostic biomarkers among CC and CXC chemokines in breast cancer

Breast cancer (BC) is a major human health problem due to its increasing incidence and mortality rate. CC and CXC chemokines are associated with tumorigenesis and the progression of many cancers. Since the prognostic values of CC and CXC families' expression in various types of cancers are becoming increasingly evident, we aimed to conduct a comprehensive bioinformatics analysis elucidating the prognostic values of the CC and CXC families in BC. Therefore, TCGA, UALCAN, Kaplan–Meier plotter, bc-GenExMiner, cBioPortal, STRING, Enrichr, and TIMER were utilized for analysis. We found that high levels of CCL4/5/14/19/21/22 were associated with better OS and RFS, while elevated expression of CCL24 was correlated with shorter OS in BC patients. Also, high levels of CXCL9/13 indicated longer OS, and enhanced expression of CXCL12/14 was linked with better OS and RFS in BC patients. Meanwhile, increased transcription levels of CXCL8 were associated with worse OS and RFS in BC patients. In addition, our results showed that CCL5, CCL8, CCL14, CCL20, CCL27, CXCL4, and CXCL14 were notably correlated with the clinical outcomes of BC patients. Our findings provide a new point of view that may help the clinical application of CC and CXC chemokines as prognostic biomarkers in BC.

Advances in Research on the Effects and Mechanisms of Chemokines and Their Receptors in Cancer

Cancer is a common and intractable disease that seriously affects quality of life of patients and imposes heavy economic burden on families and the entire society. Current medications and intervention strategies for cancer have respective shortcomings. In recent years, it has been increasingly spotlighted that chemokines and their receptors play vital roles in the pathophysiology of cancer. Chemokines are a class of structurally similar short-chain secreted proteins that initiate intracellular signaling pathways through the activation of corresponding G protein-coupled receptors and participate in physiological and pathological processes such as cell migration and proliferation. Studies have shown that chemokines and their receptors have close relationships with cancer epigenetic regulation, growth, progression, invasion, metastasis, and angiogenesis. Chemokines and their receptors may also serve as potential targets for cancer treatment. We herein summarize recent research progresses on anti-tumor effects and mechanisms of chemokines and their receptors, suggesting avenues for future studies. Perspectives for upcoming explorations, such as development of multi-targeted chemokine-based anti-tumor drugs, are also discussed in the present review.

C-C Chemokine Receptor 7 in Cancer

C-C chemokine receptor 7 (CCR7) was one of the first two chemokine receptors that were found to be upregulated in breast cancers. Chemokine receptors promote chemotaxis of cells and tissue organization. Since under homeostatic conditions, CCR7 promotes migration of immune cells to lymph nodes, questions immediately arose regarding the ability of CCR7 to direct migration of cancer cells to lymph nodes. The literature since 2000 was examined to determine to what extent the expression of CCR7 in malignant tumors promoted migration to the lymph nodes. The data indicated that in different cancers, CCR7 plays distinct roles in directing cells to lymph nodes, the skin or to the central nervous system. In certain tumors, it may even serve a protective role. Future studies should focus on defining mechanisms that differentially regulate the unfavorable or beneficial role that CCR7 plays in cancer pathophysiology, to be able to improve outcomes in patients who harbor CCR7-positive cancers.

CXCL12 promotes CCR7 ligand-mediated breast cancer cell invasion and migration toward lymphatic vessels

Chemokines are a family of cytokines that mediate leukocyte trafficking and are involved in tumor cell migration, growth, and progression. Although there is emerging evidence that multiple chemokines are expressed in tumor tissues and that each chemokine induces receptor‐mediated signaling, their collaboration to regulate tumor invasion and lymph node metastasis has not been fully elucidated. In this study, we examined the effect of CXCL12 on the CCR7‐dependent signaling in MDA‐MB‐231 human breast cancer cells to determine the role of CXCL12 and CCR7 ligand chemokines in breast cancer metastasis to lymph nodes. CXCL12 enhanced the CCR7‐dependent in vitro chemotaxis and cell invasion into collagen gels at suboptimal concentrations of CCL21. CXCL12 promoted CCR7 homodimer formation, ligand binding, CCR7 accumulation into membrane ruffles, and cell response at lower concentrations of CCL19. Immunohistochemistry of MDA‐MB‐231–derived xenograft tumors revealed that CXCL12 is primarily located in the pericellular matrix surrounding tumor cells, whereas the CCR7 ligand, CCL21, mainly associates with LYVE‐1⁺ intratumoral and peritumoral lymphatic vessels. In the three‐dimensional tumor invasion model with lymph networks, CXCL12 stimulation facilitates breast cancer cell migration to CCL21‐reconstituted lymphatic networks. These results indicate that CXCL12/CXCR4 signaling promotes breast cancer cell migration and invasion toward CCR7 ligand–expressing intratumoral lymphatic vessels and supports CCR7 signaling associated with lymph node metastasis.

Does CCL19 act as a double-edged sword in cancer development?

Cancer is considered a life-threatening disease, and several factors are involved in its development. Chemokines are small proteins that physiologically exert pivotal roles in lymphoid and non-lymphoid tissues. The imbalance or dysregulation of chemokines has contributed to the development of several diseases, especially cancer. CCL19 is one of the homeostatic chemokines that is abundantly expressed in the thymus and lymph nodes. This chemokine, which primarily regulates immune cell trafficking, is involved in cancer development. Through the induction of anti-tumor immune responses and inhibition of angiogenesis, CCL19 exerts tumor-suppressive functions. In contrast, CCL19 also acts as a tumor-supportive factor by inducing inflammation, cell growth, and metastasis. Moreover, CCL19 dysregulation in several cancers, including colorectal, breast, pancreatic, and lung cancers, has been considered a tumor biomarker for diagnosis and prognosis. Using CCL19-based therapeutic approaches has also been proposed to overcome cancer development. This review will shed more light on the multifarious function of CCL19 in cancer and elucidate its application in diagnosis, prognosis, and even therapy. It is expected that the study of CCL19 in cancer might be promising to broaden our knowledge of cancer development and might introduce novel approaches in cancer management.

CCL19 associates with lymph node metastasis and inferior prognosis in patients with small cell lung cancer

OBJECTIVE

Small cell lung cancer (SCLC) is a systemic disease and most patients have metastases at diagnosis. Better understanding of the underlying mechanisms of SCLC metastasis may provide potential approach to improve clinical outcome.

METHODS

HTG Edge-seq was used to identify the differential gene expression between primary SCLC lesions and paired metastatic lymph nodes (LN). Overall survival (OS) analysis was performed in patients with different levels of plasma CCL19 concentration. Invasion, migration, proliferation, apoptosis and angiogenesis ability of SCLC cells and function of CD8 + T cells were evaluated in vitro to investigate the mechanism of CCL19 in promoting metastasis.

RESULTS

Four chemokines (CCL19, CCL21, CCL8, CCR1) were the most differentially expressed between primary lesions and metastatic LN. CCL19 was further investigated because its mRNA and protein level expression were also validated in four SCLC cell lines (H446, H69, H82, H196). Higher plasma CCL19 was associated with late lymph node (N3) metastasis (training cohort P = 0.044, validation cohort P = 0.020) and shorter OS (training cohort P = 0.040, validation cohort P = 0.047) in SCLC patients. Silencing CCL19 inhibited SCLC cell migration, invasion, proliferation and HUVECs tube formation. Furthermore, we found that CCL19 could decrease percentage of CD8 + Ki67 + and CD8 + GZMB + T cells and increase proportion of CD8 + PD1 + T cells.

CONCLUSION

CCL19 was associated with LN metastasis and poor prognosis in patients with SCLC. Its expression promoted tumor progression and metastasis and impaired the function of CD8 + T cells, suggesting CCL19 might be a potential target for SCLC.

The Epithelial-Stromal Microenvironment in Early Colonic Neoplasia

Stromal cells play a central role in promoting the progression of colorectal cancer. Here, we analyze molecular changes within the epithelial and stromal compartments of dysplastic aberrant crypt foci (ACF) formed in the ascending colon, where rapidly developing interval cancers occur. We found strong activation of numerous neutrophil/monocyte chemokines, consistent with localized inflammation. The data also indicated a decrease in interferon signaling and cell-based immunity. The immune checkpoint and T-cell exhaustion gene PDCD1 was one of the most significantly upregulated genes, which was accompanied by a decrease in cytotoxic T-cell effector gene expression. In addition, CDKN2A expression was strongly upregulated in the stroma and downregulated in the epithelium, consistent with diverse changes in senescence-associated signaling on the two tissue compartments. IMPLICATIONS: Decreased CD8 T-cell infiltration within proximal colon ACF occurs within the context of a robust inflammatory response and potential stromal cell senescence, thus providing new insight into potential promotional drivers for tumors in the proximal colon.

Evolution of the Tumor Microenvironment toward Immune-Suppressive Seclusion during Brain Metastasis of Breast Cancer: Implications for Targeted Therapy

Simple Summary

Brain metastases (BM) of breast cancer (BC) are new targets of immunotherapy, but their characteristics are unclear. Therefore, we analyzed the differential expression profile of the tumor microenvironment (TME) in primary breast cancer brain metastasis (BCBM). In the TME of BCBM, immune-related pathways were downregulated and tumor intrinsic factors were upregulated. Moreover, CD8+ T cells and M1 macrophages with cytotoxic effects were decreased, but M2 cells were increased, in BM. Most tumor-suppressive immune functions ceased after BM with a molecular subtype shift. These results suggest the need for targeted therapy and immunotherapy strategies for BCBM.

Abstract

Breast cancer (BC) is the second most common solid malignant tumor that metastasizes to the brain. Despite emerging therapies such as immunotherapy, whether the tumor microenvironment (TME) in breast cancer brain metastasis (BCBM) has potential as a target of new treatments is unclear. Expression profiling of 770 genes in 12 pairs of primary BC and matched brain metastasis (BM) samples was performed using the NanoString nCounter PanCancer IO360^TM Panel. Immune cell profiles were validated by immunohistochemistry (IHC) in samples from 50 patients with BCBM. Pathway analysis revealed that immune-related pathways were downregulated. Immune cell profiling showed that CD8+ T cells and M1 macrophages were significantly decreased, and M2 macrophages were significantly increased, in BM compared to primary BC samples (p = 0.001, p = 0.021 and p = 0.007, respectively). CCL19 and CCL21, the top differentially expressed genes, were decreased significantly in BM compared to primary BC (p < 0.001, both). IHC showed that the CD8+ count was significantly lower (p = 0.027), and the CD163+ and CD206+ counts were higher, in BM than primary BC (p < 0.001, both). A low CD8+ T cell count, low CD86+ M1 macrophage count, and high M2/M1 macrophage ratio were related to unfavorable clinical outcomes. BC exhibits an immunosuppressive characteristic after metastasis to the brain. These findings will facilitate establishment of a treatment strategy for BCBM based on the TME of metastatic cancer.

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.

The relation between ACKR4 and CCR7 genes expression and breast cancer metastasis

AIMS

Breast cancer is the most severe malignant tumor in women. Chemokines and their receptors appear to be implicated in tumorigenesis and metastatic pattern. Also the scavenger atypical chemokine receptors are emerging as crucial regulators for the availability of chemokines. Therefore the aim of the present study is to evaluate the expression of CCR7, ACKR4 and their ligand; CCL21 in human breast cancer.

MAIN METHODS

In this study, RT-PCR was done to detect the expression of CCR7 and ACKR4 in 50 non-metastatic and 30 metastatic breast cancer tissue. Also CCL21 level in the serum of study group was detected by ELISA. The expression of all markers is compared to 80 control healthy individual.

KEY FINDINGS

Our results revealed the increase in expression of CCR7 and CCL21 level in metastatic group compared to non-metastatic and control groups while ACKR4 expression is significantly increased in breast tissues of non-metastatic patients compared to both control and metastatic groups. Also there was significant positive correlation between CCR7 expression and CCL21 level in cancer patients and significant negative correlation between ACKR4 and both CCR-7 and CCL21 in both non-metastatic and metastatic cancer groups.

SIGNIFICANCE

Thus, it might be elucidating that ACKR4 and CCR7 could be a novel target for tumor therapy as targeting the chemokine-receptors axis might represent a powerful tool to prevent infiltration and metastasis and consequently improve cancer prognosis and treatment.

Comprehensive Analysis of Myeloid Signature Genes in Head and Neck Squamous Cell Carcinoma to Predict the Prognosis and Immune Infiltration

Myeloid cells are a major heterogeneous cell population in the tumor immune microenvironment (TIME). Imbalance of myeloid response remains a major obstacle to a favorable prognosis and successful immune therapy. Therefore, we aimed to construct a risk model to evaluate the myeloid contexture, which may facilitate the prediction of prognosis and immune infiltration in patients with head and neck squamous cell carcinoma (HNSCC). In our study, six myeloid signature genes (including CCL13, CCR7, CD276, IL1B, LYVE1 and VEGFC) analyzed from 52 differentially expressed myeloid signature genes were finally pooled to establish a prognostic risk model, termed as myeloid gene score (MGS) in a training cohort and validated in a test cohort and an independent external cohort. Furthermore, based on the MGS subgroups, we were able to effectively identify patients with a poor prognosis, aggressive clinical parameters, immune cell infiltration status and immunotherapy response. Thus, MGS may serve as an effective prognostic signature and predictive indicator for immunotherapy response in patients with HNSCC.

CCR7-CCL21 axis promotes the cervical lymph node metastasis of tongue squamous cell carcinoma by up-regulating MUC1

This study aims at investigating the potential role of MUC1 in CCR7-CCL21 axis-induced metastasis of tongue squamous cell carcinoma (TSCC). TSCC patients were selected for epidemiologic trends. The expression of CCR7 and MUC1 was detected via immunohistochemistry. SCC15 and CAL27 cells were induced by CCL21 and specific antibody to CCR7. Gene and protein expression was detected using qRT-PCR and western blotting. Migration and invasion capacities of TSCC cells were determined using wound healing and Transwell invasion assays. The male:female ratio of 78 patients was 1.6:1. Metastasis rate of cervical lymph nodes (CLNs) was 42.3%. CLN metastasis significantly correlated with T staging (P = 0.026), clinical staging (P = 0.024), and depth of invasion (DOI, P = 0.001). DOI significantly influenced CLN metastasis (P = 0.033, OR = 10.919) of TSCC, as did CCR7 (P = 0.041) and MUC1 (P = 0.026). The consistency of CCR7 and MUC1 expression was fairly good (Kappa = 0.683, P < 0.001). Reduced survival was significantly associated with higher expression of CCR7 (P = 0.039) and MUC1 (P = 0.030). CCL21 up-regulated MUC1 in SCC15 cells, which was inhibited when CCR7 was blocked. MUC1 positively correlated with TSCC cell migration and invasion. CCR7-CCL21 axis might promote CLN metastasis of TSCC by up-regulating MUC1. CCR7 and MUC1 show promise as potential biomarkers for TSCC treatment.

Increased expression of interleukin-21-inducible genes in minor salivary glands are associated with primary Sjögren’s syndrome disease characteristics

Objective

To determine the upregulation of IL-21-inducible genes in minor salivary glands (MSGs) in 28 primary SS (pSS) patients and 12 non-pSS subjects and correlate it with disease characteristics.

Methods

RNA sequencing was utilized to compare IL-21-inducible genes expression in the MSGs between pSS and non-pSS subjects. The subgroups were characterized according to the IL-21 score calculated by seven IL-21-inducible genes. Furthermore, the disease characteristics and transcripts implicated in hypoxia and interferon signalling were assessed in two pSS subgroups.

Results

We observed that the expression of the IL-21-inducible genes (IL-21, IL-21R, JAK3, STAT1, HLA-B, CCR7 and CXCL10), the so-called IL-21 signature genes, was significantly increased in pSS patients. The upregulation of JAK3 expression may be induced by hypomethylation of the JAK3 promoter in pSS patients and putatively associated with POU2F2. The patients with increased IL-21 signature gene expression showed an increased EULAR Sjögren’s Syndrome Disease Activity Index score and increased enrichment of B cells, memory B cells, CD4+ T cells and CD8+ T cells. Furthermore, the IL-21 scores in the anti-SSA+, SSB+, ANA+ and high IgG samples were higher than those in the respective antibody-negative samples and normal IgG. In addition, we found both hypoxia and IFN-relevant genes showed strong correlation with IL-21 signature gene expression, indicating their interaction in pSS.

Conclusion

IL-21 signature gene was associated with typical disease characteristics in pSS, which provides insight into the contribution of the IL-21 signalling pathway to the pathogenesis of the disease and might provide a novel treatment strategy for this subtype of pSS.

Comprehensive analysis of tumour mutation burden and the immune microenvironment in hepatocellular carcinoma

Tumour mutation burden (TMB) and the immune microenvironment (IME) are reportedly associated with immunotherapy responses, but this relationship remains unclear in hepatocellular carcinoma (HCC). We classified HCC patients in the liver hepatocellular carcinoma cohort from The Cancer Genome Atlas into low- and high-TMB groups and evaluated differences in immune infiltrates. Additionally, differentially expressed genes in the low- and high-TMB groups were identified, and functional analyses were conducted. A risk score model was constructed based on three differentially expressed immune genes (DEIGs). The Tumor Immune Estimation Resource database was utilized to analyse how the IME was affected by the three hub DEIGs. Finally, a prognostic nomogram combining risk scores and stages was established and externally validated with the International Cancer Genome Consortium and GSE14520 cohorts. High-TMB (top 20%) patients exhibited a worse prognosis (P = 0.017). Follicular helper cells (P = 0.001) and activated natural killer cells (P = 0.003) were enriched in high-TMB patients, while resting dendritic cells (P = 0.002) were enriched in low-TMB samples. A risk score model was generated with three hub DEIGs (CCR7, STC2 and S100A9) to predict overall survival in HCC cohorts. Moreover, copy number variations mainly reduced infiltration levels. The nomogram performed better than the risk score model in the training and validation datasets. Higher TMB was associated with IME diversification and worse prognosis in HCC. Mutations in three hub TMB-associated DEIGs correlated with lower immune cell infiltration.

Cytoplasmic CCR7 (CCR7c) immunoexpression is associated with local tumor recurrence in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a subtype of cancer, which tests negative for estrogen receptors, progesterone receptors, and lacks overexpression of the human epidermal growth factor 2 (C-erbB2, HER2/neu) gene. The expression of chemokines and their receptors, including CCR7, has been described in several types of cancer, contributing to tumor progression.

AIM OF THE STUDY

This study investigated the association between the membrane and cytoplasmic CCR7 expression and the prognosis of TNBC.

MATERIALS AND METHODS

Surgical paraffin histopathology blocks and clinico-pathological data were assessed from 133 patients. Samples were analyzed by immunohistochemistry and immunofluorescence using the Tissue Microarray technique for scoring the intensity of CCR7 expression.

RESULTS

TNBC patients in which the CCR7 labeling was predominantly in the cytoplasm of tumor cells presented increased local tumor recurrence (P = 0.033). Conversely, there was no statistical difference in five-year overall survival between the patients with low (77%) versus high (80%) cytoplasmic CCR7 expression (P = 0.7104). Additionally, the risk of death between these groups was 1.19 (95% CI = 0.48-2.91).

CONCLUSION

The cytoplasmic CCR7 expression associates with an increased incidence of tumor relapse in TNBC, not affecting patients survival. Consequently, the cell compartment in which the CCR7 localizes could serve as a prognostic marker in this cancer subtype.

A Translational Study of a Silicon Phthalocyanine Substituted with a Histone Deacetylase Inhibitor for Photodynamic Therapy

In this study, we synthesized and characterized a silicon phthalocyanine substituted with 3-hydroxypyridin-2-thione (SiPc-HDACi), designed to be a chemophotodynamic therapy agent acting as a histone deacetylase inhibitor, and we determined its photophysical, photochemical, and photobiological properties. Next, we evaluated its anticancer efficacy on MCF-7, double positive and MDA-MB-231, triple negative breast cancer cell lines, as well as on a healthy human endothelial cell line (HUVEC). Our results indicate that SiPc-HDACi can target nucleoli of cells, effectively inducing apoptosis while promoting cell cycle arrest thanks to its high singlet oxygen yield and its histone deacetylase downregulating properties, suggesting a powerful anticancer effect on breast cancer in vitro. Our further studies will be conducted with primary breast cancer cell culture to give a better insight into the anticancer mechanism of the compound.

A prognostic eight-gene expression signature for patients with breast cancer receiving adjuvant chemotherapy

Breast cancer is a popularly diagnosed malignant tumor. Genomic profiling studies suggest that breast cancer is a disease with heterogeneity. Chemotherapy is one of the chief means to treat breast cancer, while its responses and clinical outcomes vary largely due to the conventional clinicopathological factors and inherent chemosensitivity of breast cancer. Using the least absolute shrinkage and selection operator (LASSO) Cox regression model, our study established a multi-mRNA-based signature model and constructed a relative nomogram in predicting distant-recurrence-free survival for patients receiving surgery and following chemotherapy. We constructed a signature of eight mRNAs (IPCEF1, SYNDIG1, TIGIT, SPESP1, C2CD4A, CLCA2, RLN2, and CCL19) with the LASSO model, which was employed to separate subjects into groups with high- and low-risk scores. Obvious differences of distant-recurrence-free survival were found between these two groups. This eight-mRNA-based signature was independently associated with the prognosis and had better prognostic value than classical clinicopathologic factors according to multivariate Cox regression results. Receiver operating characteristic results demonstrated excellent performance in diagnosing 3-year distant-recurrence by the eight-mRNA signature. A nomogram that combined both the eight-mRNA-based signature and clinicopathological risk factors was constructed. Comparing with an ideal model, the nomograms worked well both in the training and validation sets. Through the results that the eight-mRNA signature effectively classified patients into low- and high-risk of distant recurrence, we concluded that this eight-mRNA-based signature played a promising predictive role in prognosis and could be clinically applied in breast cancer patients receiving adjuvant chemotherapy.

The Immune Checkpoint Kick Start: Optimization of Neoadjuvant Combination Therapy Using Game Theory

PURPOSE

In an upcoming clinical trial at the Moffitt Cancer Center for women with stage 2/3 estrogen receptor-positive breast cancer, treatment with an aromatase inhibitor and a PD-L1 checkpoint inhibitor combination will be investigated to lower a preoperative endocrine prognostic index (PEPI) that correlates with relapse-free survival. PEPI is fundamentally a static index, measured at the end of neoadjuvant therapy before surgery. We have developed a mathematical model of the essential components of the PEPI score to identify successful combination therapy regimens that minimize tumor burden and metastatic potential, on the basis of time-dependent trade-offs in the system.

METHODS

We considered two molecular traits, CCR7 and PD-L1, which correlate with treatment response and increased metastatic risk. We used a matrix game model with the four phenotypic strategies to examine the frequency-dependent interactions of cancer cells. This game was embedded in an ecological model of tumor population-growth dynamics. The resulting model predicts evolutionary and ecological dynamics that track with changes in the PEPI score.

RESULTS

We considered various treatment regimens on the basis of combinations of the two therapies with drug holidays. By considering the trade off between tumor burden and metastatic potential, the optimal therapy plan was a 1-month kick start of the immune checkpoint inhibitor followed by 5 months of continuous combination therapy. Relative to a protocol giving both therapeutics together from the start, this delayed regimen resulted in transient suboptimal tumor regression while maintaining a phenotypic constitution that is more amenable to fast tumor regression for the final 5 months of therapy.

CONCLUSION

The mathematical model provides a useful abstraction of clinical intuition, enabling hypothesis generation and testing of clinical assumptions.

CCL19 suppresses gastric cancer cell proliferation, migration, and invasion through the CCL19/CCR7/AIM2 pathway

Absent in melanoma 2 (AIM2) has been reported to be an important inflammasome component that exerts tumor suppression in several tumors. However, whether CCL19/CCR7/AIM2 is involved in the progression of GC still remains unclear. Quantitative real-time and ELISA assay were used to determine the expressions of AIM2, CCL19 and CCR7 in GC tissues and cell lines. CCK-8, Edu staining, flow cytometry, Transwell assay, and tumorigenesis in nude mice were used to explore the function of AIM2 and CCL19 in vitro and in vivo. Apoptosis and inflammation-related biomarkers were detected by Western blot and ELISA assay. H&E staining was used to assess the histological changes in the subcutaneous tumor model. Immunohistochemistry (IHC) was used to evaluate the expression of Ki-67. We found that expression levels of AIM2, CCL19 and CCR7 were obviously lower in early GC tissues than those in progressive GC tissues. In vitro assays revealed that CCL19 treatment could enhance the suppressive effects of AIM2 overexpression on cell proliferation, migration, and invasion through CCR7. An in vivo assay also demonstrated that silencing of AIM2 reversed the suppressive effects of CCL19 on tumor growth. Collectively, CCL19 overexpression significantly inhibited GC cell proliferation and tumor growth in vitro and in vivo by up-regulating the CCR7/AIM2 pathway. Thus, CCL19 activated CCR7/AIM2 signaling pathway and it may be a potential therapeutic approach for GC therapy.

The Roles of CCR7 for the Homing of Memory CD8+ T Cells into Their Survival Niches

Memory CD8+ T cells in the immune system are responsible for the removal of external Ags for a long period of time to protect against re-infection. Naïve to memory CD8+ T cell differentiation and memory CD8+ T cell maintenance require many different factors including local environmental factors. Thus, it has been suggested that the migration of memory CD8+ T cells into specific microenvironments alters their longevity and functions. In this review, we have summarized the subsets of memory CD8+ T cells based on their migratory capacities and described the niche hypothesis for their survival. In addition, the basic roles of CCR7 in conjunction with the migration of memory CD8+ T cells and recent understandings of their survival niches have been introduced. Finally, the applications of altering CCR7 signaling have been discussed.

The Role of CCL21/CCR7 Chemokine Axis in Breast Cancer Progression

Breast cancer is a leading cause of cancer-related deaths worldwide, predominantly caused by metastasis. It is generally accepted that the pattern of breast cancer metastasis is largely determined by the interaction between the chemokine receptors on cancer cells and the chemokines expressed at the sites of metastatic disease. Chemokine receptors belong to the G-protein-coupled receptors (GPCRs) family that appear to be implicated in inflammatory diseases, tumor growth and metastasis. One of its members, C-C Chemokine receptor 7 (CCR7), binds chemokines CCL19 and CCL21, which are important for tissue homeostasis, immune surveillance and tumorigenesis. These receptors have been shown to induce the pathobiology of breast cancer due to their ability to induce cellular proliferation and migration upon the binding of the cognate chemokine receptors. The underlying signaling pathways and exact cellular interactions within this biological system are not fully understood and need further insights. Thus, in this review, we summarize the essential roles of CCR7 and its receptors in breast cancer progression. Furthermore, we discuss the mechanisms of regulation that may lead to novel opportunities for therapeutic intervention. Despite the enormous advances in our knowledge of the nature of the chemokines in breast cancer metastasis, research about the involvement of CCR7 in cancer progression is still limited. Therefore, further studies are essential to illustrate the distinct roles of CCR7 in cancer progression and validate its potential as a preventive bio-factor for human breast cancer metastasis by targeting chemokine receptor genes.

CCL21/CCR7 interaction promotes EMT and enhances the stemness of OSCC via a JAK2/STAT3 signaling pathway

Chemokines and their receptors show a strong relationship with poor clinical outcomes in various cancers. However, their underlying mechanisms remain to be fully elucidated. In our research, we found C-C chemokine receptor 7 (CCR7) and its ligand chemokine ligand 21 (CCL21) were abnormally abundant in oral squamous cell carcinoma (OSCC) tissues, and CCR7 expression was correlated with poor prognosis of OSCC. After exogenous CCL21 stimulation, epithelial-mesenchymal transition (EMT) was promoted in OSCC cells, and cancer stem cell-related markers CD133, CD44, BMI1, ALDH1A1, and OCT4 increased. The migration, invasion, tumorsphere formation, and colony formation abilities of OSCC cells were enhanced, indicating that the stemness of OSCC cells was also improved. The knockdown and overexpression of CCR7 efficiently affected the CCL21-induced EMT and stemness of OSCC cells. When treated with CCL21, the phospho-JAK2 and phospho-STAT3 markedly increased. The inhibitor of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) significantly suppressed CCL21-induced EMT and stemness of OSCC cells. In conclusion, CCL21/CCR7 axis regulated EMT progress and promoted the stemness of OSCC by activating the JAK2/STAT3 signaling pathway. CCL21/CCR7 might be an effective target for OSCC prevention and treatment.

B cell and B cell-related pathways for novel cancer treatments

B cells are recognized as the main effector cells of humoral immunity which suppress tumor progression by secreting immunoglobulins, promoting T cell response, and killing cancer cells directly. Given these properties, their anti-tumor immune response in the tumor micro-environment (TME) is of great interest. Although T cell-related immune responses have become a therapeutic target with the introduction of immune checkpoint inhibitors, not all patients benefit from these treatments. B cell and B cell-related pathways (CCL19, -21/CCR7 axis and CXCL13/CXCR5 axis) play key roles in activating immune response through humoral immunity and local immune activation via tertiary lymphoid structure (TLS) formation. However they have some protumorigenic works in the TME. Thus, a better understanding of B cell and B cell-related pathways is necessary to develop effective cancer control. In this review, we summarize recent evidences regarding the roles of B cell and B cell-related pathways in the TME and immune response and discuss their potential roles for novel cancer treatment strategies.

CCL19 suppresses angiogenesis through promoting miR-206 and inhibiting Met/ERK/Elk-1/HIF-1α/VEGF-A pathway in colorectal cancer

The mechanisms underlying the role of chemokines in tumor angiogenesis is still not fully understood. In this study, we detected the influence of CCL19 on colorectal cancer (CRC) angiogenesis. The expression of CCL19 and CD31 in CRC tissues were detected by immunohistochemistry. Human CRC cell lines SW1116 and SW620 stably transfected with CCL19 lentivirus and CCL19 shRNA, and HUVEC stably transfected with CCR7 shRNA were used in our study. Our study showed that CCL19 was significantly low-expressed in CRC tissues and positively related to highly tumor microvessel density. In vitro, we observed that CCL19 high-expressed SW1116 supernatant was able to inhibit proliferation, migration, and sprouting responses of HUVEC, whereas CCL19 low-expressed SW620 supernatant can promote HUVEC angiogenesis. Additionally, we further demonstrated that these functions maybe achieved through promoting miR-206 thus inhibiting Met/ERK/Elk-1/HIF-1α/VEGF-A pathway in a CCR7-dependent manner. Mice angiogenesis model also confirmed that elevated expression of CCL19 inhibit the angiogenesis of CRC in vivo. In summary, our results supported that CCL19 can inhibit CRC angiogenesis through promoting miR-206 thus inhibiting Met/ERK/Elk-1/HIF-1α/VEGF-A pathway. This may be a novel therapeutic option for anti-vascular treatment in CRC.

CC chemokine receptor 7 promotes triple-negative breast cancer growth and metastasis

Metastasis is the leading cause of breast cancer-related death. Chemokine (C-C motif) receptor 7 (CCR7) plays important roles in breast cancer metastasis. However, the role of CCR7 in triple-negative breast cancer (TNBC) has not been fully elucidated. In this study, we found that CCR7 is highly expressed in both TNBC cell lines and breast cancer tissues. CCR7 was knocked down by shRNA in 4T1 and MDA-MB-231, two TNBC cell lines, and we found that the depletion of CCR7 significantly decreased TNBC cell proliferation, migration and invasion in vitro. Furthermore, we confirmed that the knockdown of CCR7 reduced the distant metastasis of 4T1 cells in an orthotopic mouse model. Proteomic analysis in 4T1 cells indicated that several signaling pathways such as epithelial cell adhesion molecule might contribute to CCR7's function in breast cancer metastasis. Our results suggest that CCR7 promotes TNBC metastasis and may serve as a target for breast cancer diagnosis and treatment.

CCR7 preservation via histone deacetylase inhibition promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells

The effects of Histone deacetylase (HDAC) inhibition on epithelial-mesenchymal transition (EMT) differs in various types of cancers. However, its function in hepatocellular carcinoma (HCC) is not well-explored. In this study, we investigated the effect of HDAC inhibition on EMT in HCC cells by using trichostatin A (TSA) and valproic acid (VPA). The results showed that TSA/VPA significantly induced EMT phenotype, as demonstrated by the decreased level of E-cadherin, increased level of N-cadherin, vimentin, Twist and snail, and enhanced capacity of cell migration and invasion. In addition, CCR7 was speculated and confirmed as a function target of HDAC inhibition. CCR7 promotes the progression of HCC and is associated with poor survival. Knockdown of CCR7 significantly attenuated the effect of TSA on EMT. Moreover, our results demonstrated that HDAC inhibition up-regulates CCR7 via reversing the promoter hypoacetylation and increasing CCR7 transcription. Taken together, our study has identified the function of HDAC in EMT of HCC and suggested a novel mechanism through which TSA/VPA exerts its carcinogenic roles in HCC. HDAC inhibitors require careful caution before their application as new anticancer drugs.

Impact of chemotactic factors and receptors on the cancer immune infiltrate: a bioinformatics study revealing homogeneity and heterogeneity among patient cohorts

Multiple soluble factors including proteins (in particular chemokines), non-proteinaceous factors released by dead cells, as well as receptors for such factors (in particular chemokine receptors, formyl peptide receptors and purinergic receptors), influence the recruitment of distinct cell subsets into the tumor microenvironment. We performed an extensive bioinformatic analysis on tumor specimens from 5953 cancer patients to correlate the mRNA expression levels of chemotactic factors/receptors with the density of immune cell types infiltrating the malignant lesions. This meta-analysis, which included specimens from breast, colorectal, lung, ovary and head and neck carcinomas as well as melanomas, revealed that a subset of chemotactic factors/receptors exhibited a positive and reproducible correlation with several infiltrating cell types across various solid cancers, revealing a universal pattern of association. Hence, this meta-analysis distinguishes between homogeneous associations that occur across different cancer types and heterogeneous correlations, that are specific of one organ. Importantly, in four out of five breast cancer cohorts for which clinical data were available, the levels of expression of chemotactic factors/receptors that exhibited universal (rather than organ-specific) positive correlations with the immune infiltrate had a positive impact on the response to neoadjuvant chemotherapy. These results support the notion that general (rather than organ-specific) rules governing the recruitment of immune cells into the tumor bed are particularly important in determining local immunosurveillance and response to therapy.

Gestational exposure to chlordecone promotes transgenerational changes in the murine reproductive system of males

Environmental factors can affect epigenetic events during germline reprogramming and impose distinctive transgenerational consequences onto the offspring. In this study, we examined the transgenerational effects of chlordecone (CD), an organochlorine insecticide with well-known estrogenic properties. We exposed pregnant mice to CD from embryonic day 6.5 to 15.5 and observed a reduction in spermatogonia (SG) numbers in F3, meiotic defects in spermatocytes and decrease in spermatozoa number in the first and third generation of male progeny. The RNA qRT-PCR expression analysis in F1 and transcriptomics analysis in F3 males using the whole testes revealed changes in the expression of genes associated with chromosome segregation, cell division and DNA repair. The expression of the master regulator of pluripotency, Pou5f1, decreased in foetal and increased in adult F1, but not in F3 adult testes. Analysis of histone H3K4me3 distribution revealed widespread changes in its occupancy in the genome of F1 and F3 generations. We established that 7.1% of altered epigenetic marks were conserved between F1 and F3 generations. The overlapping changes common to F1 and F3 include genes implicated in cell adhesion and transcription factor activities functions. Differential peaks observed in F1 males are significantly enriched in predicted ESR1 binding sites, some of which we confirmed to be functional. Our data demonstrate that CD-mediated impairment of reproductive functions could be transmitted to subsequent generations.

Increased frequency of CCR7+CD4+ T cells from patients with primary Sjögren's syndrome: An indicator of disease activity rather than of damage severity

Expression of CCR7 on T cells has been reported to be associated with the lymphocytic migration and infiltration, which is recognized as a vital part of the pathogenesis of Primary Sjögren's syndrome (pSS). Here, we compared the expression of CCR7 on CD4+T cells between pSS patients and control groups, including healthy donors (HD) and patients with systemic lupus erythematosus (SLE) and examined correlations with disease activity and damage severity, which were evaluated by EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) and Sjogren's Syndrome Disease Damage Index (SSDDI), respectively. Peripheral blood mononuclear Cells (PBMC) were obtained from patients and controls and expressions of CCR7 were evaluated by flow cytometry. CCR7 was selectively and frequently expressed on CD4⁺T cells, but less on CD8⁺ T cells of patients with pSS. In contrast, this phenomenon was neither seen in normal subjects nor in patients with SLE. The expression level of CCR7 in the peripheral blood CD4⁺ T cells is closely correlated with ESSDAI, but not SSDDI. Correspondently, the chemotactic index (CI) of CD4⁺T cells was higher than CD8⁺T cells in patients with pSS. Furthermore, the CI of CD4⁺T cells is also higher than that of other controls, which is correlated with ESSDAI. All the findings suggested that CCR7 might play an important role in the development of pSS by mediating the migration of CD4⁺cells. Thus, the expression of CCR7 in CD4⁺ T cells is probably a useful biomarker to evaluate and monitor disease activity. CCR7 can also potentially be a novel target for the therapy of pSS.

Expression of CCR6 in esophageal squamous cell carcinoma and its effects on epithelial-to-mesenchymal transition

Esophageal squamous cell carcinoma (ESCC) is the most common esophageal cancer associated with poor prognosis. We detected the expression of C-C motif chemokine receptor 6 (CCR6) and epithelial-to-mesenchymal transition (EMT) markers in esophageal tissues/cells, and evaluated the effects of CCR6 on ESCC cells proliferation, migration and invasion in response to C-C motif chemokine ligand 20 (CCL20) treatment. Our data showed CCR6 was highly expressed in ESCC cell lines (ECA-109 and TE-1), whereas kept in a low expression in normal cell lines HEEC (P < 0.001). CCL20 stimulus induced a significant decrease in the proliferation ability of ESCC (P < 0.05). The healing speed of CCL20 group was significantly higher than control in ECA-109 (P < 0.01), whereas significantly lower in αCCR6+CCL20 group than CCL20 group (P < 0.05).The number of cells permeabling through the polycarbonate membrane in CCL20 group was higher than control (P < 0.01). The cell number in αCCR6+CCL20 group was significantly reduced compared to CCL20 group in ECA-109 (P < 0.05). Moreover, after CCL20 stimulated in ECA-109, both mRNA and protein level of E-cadherin significantly decreased compared to control, while Vimentin was significantly higher. In αCCR6+CCL20 group, mRNA and protein level of E-cadherin significantly increased compared to CCL20 group, while Vimentin was much lower than CCL20 group. There was no significant difference in TE-1. In summary, high expression of CCR6 existed in the lymph node metastasis and TNM stage of ESCC. CCR6 play an important role in the regulation of tumor cell proliferation, invasion and migration. CCR6 may participate in regulating the occurrence of EMT in ESCC.

CCR7 mediates human breast cancer cell invasion, migration by inducing epithelial-mesenchymal transition and suppressing apoptosis through AKT pathway

Chemokine and the chemokine receptor have a key role in the tumor progress. Here, we supposed that CCR7 might induce the invasion, migration, and epithelial–mesenchymal transition (EMT) process of breast cancer. In this research, human breast cancer MCF‐7 and MDA‐MB‐231cells were treated with CCL19 and small‐interfering RNA (CCR7 siRNA) for activation and inhibition of CCR7, respectively. Cell invasion and transwell assays were used to detect the effect of CCR7 on invasion and migration. The results demonstrated that CCL19 mediated cell invasion and migration by inducing the EMT, with downregulation of E‐cadherin and up‐regulation of N‐cadherin and vimentin levels. On the other hand, knockdown of CCR7 revealed the changes compared with CCL19 group and the control group. Knockdown of CCR7 inhibits CCL19‐induced breast cancer cell proliferation, the cell cycle, migration, invasion and EMT. Moreover, we demonstrated that CCL19‐induced AKT phosphorylation; however, CCR7 siRNA suppressed CCL19‐induced AKT phosphorylation, a key regulator of tumor metastasis. In conclusion, all findings demonstrated that CCL19/CCR7 axis regulated EMT progress in breast cancer cells and mediated the tumor cell invasion and migration process via activation of AKT signal pathway. Our results suggested that CCR7 may regard as a therapeutic target for the breast cancer treatment.