CCR7 regulates cell migration and invasion through MAPKs in metastatic squamous cell carcinoma of head and neck

CCR7 affects the tumor microenvironment by regulating the activation of naïve CD8+ T cells to promote the proliferation of oral squamous cell carcinoma

BACKGROUND

Head and neck cancer is the sixth most common malignancy worldwide, and oral squamous cell carcinoma (OSCC) is the most common head and neck cancer, being one of the leading causes of cancer morbidity and mortality worldwide. CC Chemokine receptor 7(CCR7) is a multifunctional G protein-coupled trans-membrane chemokine that affects immune cell chemotaxis, migration, and cancer progression through its interaction with its ligands C-C motif chemokine ligand 19(CCL19) and C-C motif chemokine ligand 21(CCL21). Numerous studies have demonstrated the involvement of CCR7 in the malignant progression of a variety of cancers, reflecting the pro-cancer properties of CCR7. The Cancer Genome Atlas data suggests CCR7 has elevated expression in oral cancer. Specifically, CCR7 expression in tumor microenvironment (TME) may regulate the ability of some immune cells to engage in anti-tumor immune responses. Since CD8+ T cells have become a key immunotherapeutic target, the role of CCR7 in antitumor immune response of naïve CD8+ T cells in TME has not been thoroughly investigated.

METHODS

A CCR7 knockout mouse model was constructed, and the mechanism of ccr7 on the regulation of tumor microenvironment by naïve CD8+ T cells was verified under the guidance of single-cell RNA sequencing combined with in vivo animal experiments and in vitro cell experiments.

RESULTS

CCR7 is knocked out with impaired tumor growth and altered CD8+ T cell profiles, revealing the importance of this protein in OSCC.

CONCLUSIONS

Inhibition of CCR7 enhances CD8+ T cell activation, proliferation, and anti-tumor function, suggesting its potential as a therapeutic target.

Analysis of the effect of CCR7 on the microenvironment of mouse oral squamous cell carcinoma by single-cell RNA sequencing technology

BACKGROUND

Studies have shown that CCR7, an important inflammatory factor, can promote the proliferation and metastasis of oral squamous cell carcinoma (OSCC), but its role in the tumor microenvironment (TME) remains unclear. This paper explores the role of CCR7 in the TME of OSCC.

METHODS

In this work, we constructed CCR7 gene knockout mice and OSCC mouse models. Single-cell RNA sequencing (scRNA-seq) and bioinformatics were used to analyze the differences in the OSCC microenvironment between three CCR7 gene knockout mice (KO) and three wild-type mice (WT). Immunohistochemistry, immunofluorescence staining, and flow cytometry were used to analyze the expression of key genes in significantly different cell types between the KO and WT groups. An in vitro experiment was used to verify the effect of CCR7 on M2 macrophage polarization.

RESULTS

In the mouse OSCC models, the tumor growth rate in the KO group was significantly lower than that in the WT group. Eight main cell types (including tumor cells, fibroblasts, macrophages, granulocytes, T cells, endothelial cells, monocytes, and B cells) were identified by Seurat analysis. The scRNA-seq results showed that the proportion of tumor cells was lower, but the proportion of inflammatory cells was significantly higher in the KO group than in the WT group. CellPhoneDB analysis results indicated a strong interaction relationship between tumor cells and macrophages, T cells, fibroblasts, and endothelial cells. Functional enrichment results indicated that the expression level of the Dusp1 gene in the KO group was generally higher than that in the WT group in various cell types. Macrophage subclustering results indicated that the proportion of M2 macrophages in the KO group was lower than that in the WT group. In vitro experimental results showed that CCR7 can promote M2 macrophage polarization, thus promoting the proliferation, invasion and migration of OSCC cells.

CONCLUSIONS

CCR7 gene knockout can significantly inhibit the growth of mouse oral squamous cell carcinoma by promoting the polarization of M2 macrophages.

CCL21-CCR7 signaling promotes microglia/macrophage recruitment and chemotherapy resistance in glioblastoma

Glioblastoma (GBM) is the most common and fatal primary tumor of the central nervous system (CNS) and current treatments have limited success. Chemokine signaling regulates both malignant cells and stromal cells of the tumor microenvironment (TME), constituting a potential therapeutic target against brain cancers. Here, we investigated the C-C chemokine receptor type 7 (CCR7) and the chemokine (C-C-motif) ligand 21 (CCL21) for their expression and function in human GBM and then assessed their therapeutic potential in preclinical mouse GBM models. In GBM patients, CCR7 expression positively associated with a poor survival. CCL21-CCR7 signaling was shown to regulate tumor cell migration and proliferation while also controlling tumor associated microglia/macrophage recruitment and VEGF-A production, thereby controlling vascular dysmorphia. Inhibition of CCL21-CCR7 signaling led to an increased sensitivity to temozolomide-induced tumor cell death. Collectively, our data indicate that drug targeting of CCL21-CCR7 signaling in tumor and TME cells is a therapeutic option against GBM.

Clinicopathological and prognostic value of chemokine receptor CCR7 expression in head and neck squamous cell carcinoma: a systematic review and meta-analysis

OBJECTIVES

This study aimed to identify the clinicopathological characteristics and prognostic value of CC chemokine receptor 7 (CCR7) expression in patients with head and neck squamous cell carcinoma (HNSSC).

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed in this meta-analysis. Up to the 2^nd of July 2022 a search was conducted using five databases: PubMed, Embase, Scopus, ProQuest, and Web of Science. The methodological standards for the epidemiological research scale were used to assess the quality of the included articles, and Stata software was used to synthesise the meta-analysis.

RESULTS

We considered 13 of the 615 studies which included 1005 HNSCC patients. High expression of CCR7 increased the pooled odds ratio (OR) of advanced stage, tumour size, metastasis and recurrence by 2.82 [95% confidence interval (CI) 1.84 to 4.33], 2.48 (95% CI 1.68, to 3.67), 3.57, 95% CI 2.25 to 5.05) and 3.93 (95% CI 2.03 to 7.64), respectively. High CCR7 reduced overall patient survival [hazard ratio 2.62 (95% CI 1.59 to 4.32)].

CONCLUSION

This study showed that high expression of CCR7 in HNSCC tumours was significantly associated with worse clinicopathological and survival outcomes, suggesting that CCR7 and its pathway could be potential therapeutic strategies for HNSCC.

LncRNA BCAR4 promotes migration, invasion, and chemo-resistance by inhibiting miR-644a in breast cancer

BACKGROUND

Metastasis and drug resistance of breast cancer have become a barrier to treating patients successfully. Long noncoding RNAs (lncRNAs) are known as vital players in cancer development and progression.  METHODS: The RT-qPCR were used to detect the gene expression. Colony formation assay, would healing assay, and transwell assay were performed to investigate oncogenic functions of cells. CCK8 assay was used to detect the cell viability. Western blot was applied to detect the protein level. Dual-luciferase reporter assay was used to determine the relationship between molecules. Mouse orthotopic xenograft tumor models were established to evaluate the effects of BCAR4 on tumor growth and metastasis in vivo.  RESULTS: LncRNA BCAR4 was significantly increased in breast cancer patients' tissues and plasma and upregulated in breast cancer cell lines. BCAR4 upregulation was correlated with the TNM stages and decreased after surgical removal of breast tumors. Silencing of BCAR4 suppressed breast cancer cell colony formation, migration, invasion, and xenograft tumor growth and promoted chemo-sensitivity. Mechanistically, BCAR4 facilitates breast cancer migration and invasion via the miR-644a-CCR7 axis of the MAPK pathway. BCAR4 promotes ABCB1 expression indirectly by binding to and down-regulating miR-644a to induce chemo-resistance in breast cancer.

CONCLUSIONS

Our findings provide insights into the oncogenic role of BCAR4 and implicate BCAR4 as a potential diagnostic biomarker and a promising therapeutic agent to suppress metastasis and inhibit chemo-resistance of breast cancer.

The CC ligand chemokine family members CCL17/CCL22 predict the survival and response to immune checkpoint blockade therapy of patients with head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is considered an immunosuppressive malignancy. Cross-talk between cancer cells and immune cells is modulated in part by CC ligand (CCL) chemokines, having a major effect on tumor progression. However, the predictive value and function of CCL family members in HNSCC have not been elucidated. Here, the predictive value of CCL members in cancer prognosis and Immune checkpoint blockade therapy response was investigated. CCL17 and CCL22 were screened as the key CCL chemokines in HNSCC through co-expression analysis. Further, the correlation between CCL17/CCL22 expression and cancer immune infiltration were evaluated based on TIMER and were validated by a set of scRNA-seq data. Moreover, the expression level of CCL17/CCL22 we evaluated to predict the response to Immune checkpoint blockade therapy in a panel of cancer types by using the TIDE database. Results indicated that CCL17/CCL22 had a high co-expression correlation and had a marginally statistical significance with the overall survival in HNSCC patients (P value = 0.057 and 0.055, respectively). Our findings showed high expression of CCL17/CCL22 was positively correlated with CD4⁺ T cell infiltration levels in HNSCCs and activate mTORC1 signaling pathway in CD4⁺ T cells. Further analysis from TIDE showed the high expression of CCL17/CCL22 might predict favorable responses to immune checkpoint blockade therapy in HNSCC patients. These findings provide an insight into the predictive roles of CCL17/CCL22 in HNSCC.

Role of chemokines in HPV-induced cancers

Human papillomaviruses (HPVs) cause cancers of the uterine cervix, oropharynx, anus, and vulvovaginal tract. Low-risk HPVs, such as HPV6 and 11, can also cause benign mucosal lesions including genital warts, and in patients with recurrent respiratory papillomatosis, lesions in the larynx, and on occasion, in the lungs. However, both high and less tumorigenic HPVs share a striking commonality in manipulating both innate and adaptive immune responses in HPV- infected keratinocytes, the natural host for HPV infection. In addition, immune/inflammatory cell infiltration into the tumor microenvironment influences cancer growth and prognosis, and this process is tightly regulated by different chemokines. Chemokines are small proteins and exert their biological effects by binding with G protein-coupled chemokine receptors (GPCRs) that are found on the surfaces of select target cells. Chemokines are not only involved in the establishment of a pro-tumorigenic microenvironment and organ-directed metastases but also involved in disease progression through enhancing tumor cell growth and proliferation. Therefore, having a solid grasp on chemokines and immune checkpoint modulators can help in the treatment of these cancers. In this review, we discuss the recent advances on the expression patterns and regulation of the main chemokines found in HPV-induced cancers, and their effects on both immune and non-immune cells in these lesions. Importantly, we also present the current knowledge of therapeutic interventions on the expression of specific chemokine and their receptors that have been shown to influence the development and progression of HPV-induced cancers.

CC chemokine receptor 7 promotes macrophage recruitment and induces M2-polarization through CC chemokine ligand 19&21 in oral squamous cell carcinoma

PURPOSE

This study aimed to investigate the impact of CC chemokine receptor 7 (CCR7) on the recruitment and polarization of tumor-associated macrophages (TAMs) in oral squamous cell carcinoma (OSCC).

METHODS

We analyzed CCR7 expression pattern, clinicopathological significance, and its association with M2 macrophage infiltration in OSCC by bioinformatic methods. Small interfering RNA (siRNA) was utilized to silence CCR7 in OSCC cells. Conditioned media (CM) was harvested from transfected OSCC cells to establish a co-culture model of THP-1 derived macrophages and OSCC cells. Transwell assay and cell adhesion assay were performed to examine the effect of CCR7 on macrophages recruitment and adhesion. Cytoskeleton was labelled by phalloidin to observe macrophage morphological changes. Moreover, phenotypic alteration of macrophages was measured using quantitative real-time PCR (qRT-PCR), flow cytometry, and immunofluorescence (IF) staining. Ultimately, recombinant human CCL19 and CCL21 were added into the medium of THP-1 derived macrophages to explore their effects on polarization in vitro.

RESULTS

In OSCC patients, the overexpression of CCR7 positively correlated with lymph node metastasis and M2 macrophage infiltration. Macrophage not only exhibited enhanced migration, invasion and adhesion abilities, but also appeared more spindle and branched in vitro when treated with CM from OSCC cells. However, these phenomena were abrogated with knockdown of CCR7. We also discovered that inhibition of CCR7 in OSCC cells suppressed TAMs polarization to an M2 phenotype. In addition, recombinant human CCL19 and CCL21 promoted macrophage M2-polarization in vitro.

CONCLUSION

CCR7 in OSCC cells promoted recruitment and M2-polarization of THP-1 derived macrophages in vitro by regulating production of CCL19 and CCL21.

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.

The Overexpression of Fibronectin 1 Promotes Cancer Progression and Associated with M2 Macrophages Polarization in Head and Neck Squamous Cell Carcinoma Patients

Purpose

This study aimed to investigate the biological roles of fibronectin 1 (FN1) in head and neck squamous cell carcinoma (HNSCC) and its effects on macrophage M2 polarization.

Methods

We analyzed FN1 expression pattern and examined its clinical relevance in HNSCC progression by bioinformatic analysis. Small interfering RNA (siRNA) was utilized to silence FN1 in HNSCC cells. Cell counting kit-8 (CCK-8) assay, colony formation assay, Transwell assay and wound healing assay were performed to reveal the effect of FN1 on malignant behaviors of HNSCC cells. Moreover, a co-culture model of macrophages and HNSCC cells was established to investigate whether FN1 induce macrophage M2 polarization. Finally, we used bioinformatic methods to explore the possible FN1-related pathways in HNSCC.

Results

FN1 is significantly overexpressed in HNSCC patients and has been obviously correlated with higher pathological stage and poor prognosis. Downregulation of FN1 suppressed the proliferation, migration and invasion of HNSCC cells, and inhibited macrophage M2 polarization in vitro. In addition, “PI3K-Akt” and “MAPK” signaling pathways may be involved in the malignant process of FN1 in HNSCC.

Conclusion

The overexpression of FN1 promotes HNSCC progression and induces macrophages M2 polarization. FN1 may serve as a promising prognostic biomarker and therapeutic target in HNSCC.

Chordin-Like 1 Regulates Epithelial-to-Mesenchymal Transition and Metastasis via the MAPK Signaling Pathway in Oral Squamous Cell Carcinoma

Background

Accumulating evidence suggests that dysregulation of Chordin-like 1 (CHRDL1) is associated with malignant biological behaviors in multiple cancers. However, the exact function and molecular mechanism of CHRDL1 in oral squamous cell carcinoma (OSCC) remain unclear.

Methods

The expression levels of CHRDL1 in OSCC tissues and CAL27 cells were determined by RT-qPCR. Immunohistochemical staining was applied to detect CHRDL1 protein expression in sample tissues from OSCC patients. Gain of function and knockdown by lentivirus were further used to examine the effects of CHRDL1 on cell proliferation, migration, invasion, and adhesion in OSCC. Tail vein injection of CAL27 cells with dysregulated CHRDL1 expression was further used to examine the effect of CHRDL1 on lung colonization. RNA sequencing was performed to explore the molecular mechanisms of CHRDL1 that underlie the progression of OSCC.

Results

CHRDL1 was significantly downregulated in OSCC tissues and CAL27 cells compared to controls. CHRDL1 knockdown enhanced migration, invasion, adhesion, and EMT, but not proliferation, in CAL27 cells. Overexpression of CHRDL1 had the opposite effects. Moreover, CHRDL1 was proven to inhibit tumor metastasis in vivo. Mechanistically, MAPK signaling pathway components, including ERK1/2, p38, and JNK, were found to regulate the malignant biological behaviors of CAL27 cells.

Conclusions

Our results suggest that CHRDL1 has an inhibitory effect on OSCC metastasis via the MAPK signaling pathway, which provides a new possible potential therapeutic target against OSCC.

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.

Hypoxia promotes the tolerogenic phenotype of plasmacytoid dendritic cells in head and neck squamous cell carcinoma

Objective

We aim to review the roles of plasmacytoid dendritic cells (pDCs) in head and neck squamous cell carcinoma (HNSCC) and explore the effects of hypoxia on the tolerogenic transformation of pDCs.

Background

pDCs, best known as professional type I interferon‐secreting cells, play key roles in immune surveillance and antitumor immunity. Recently, pDCs have been shown to be tolerogenic and correlate with poor prognosis in a variety of cancers, including HNSCC. However, it remains unclear what drives the tolerogenic transformation of pDCs in the HNSCC microenvironment. Hypoxia, a prominent hallmark of the tumor microenvironment (TME) of HNSCC, can interfere with multiple immune cells and establish an immunosuppressive TME.

Methods

In this review, we summarize the antitumor and protumor functions of pDCs, explore the effects of hypoxia on the migration and maturation of pDCs, and discuss related mechanisms in HNSCC.

Conclusions

pDCs mainly display protumor functions in HNSCC. The hypoxic TME in HNSCC can enhance the migration of pDCs and inhibit the differentiation and maturation of pDCs, promoting the tolerogenic phenotype of pDCs.

Chemokine-Cytokine Networks in the Head and Neck Tumor Microenvironment

Head and neck squamous cell carcinomas (HNSCCs) are aggressive diseases with a dismal patient prognosis. Despite significant advances in treatment modalities, the five-year survival rate in patients with HNSCC has improved marginally and therefore warrants a comprehensive understanding of the HNSCC biology. Alterations in the cellular and non-cellular components of the HNSCC tumor micro-environment (TME) play a critical role in regulating many hallmarks of cancer development including evasion of apoptosis, activation of invasion, metastasis, angiogenesis, response to therapy, immune escape mechanisms, deregulation of energetics, and therefore the development of an overall aggressive HNSCC phenotype. Cytokines and chemokines are small secretory proteins produced by neoplastic or stromal cells, controlling complex and dynamic cell-cell interactions in the TME to regulate many cancer hallmarks. This review summarizes the current understanding of the complex cytokine/chemokine networks in the HNSCC TME, their role in activating diverse signaling pathways and promoting tumor progression, metastasis, and therapeutic resistance development.

CCR7 as a therapeutic target in Cancer

The CCR7 chemokine axis is comprised of chemokine ligand 21 (CCL21) and chemokine ligand 19 (CCL19) acting on chemokine receptor 7 (CCR7). This axis plays two important but apparently opposing roles in cancer. On the one hand, this axis is significantly engaged in the trafficking of a number of effecter cells involved in mounting an immune response to a growing tumour. This suggests therapeutic strategies which involve potentiation of this axis can be used to combat the spread of cancer. On the other hand, the CCR7 axis plays a significant role in controlling the migration of tumour cells towards the lymphatic system and metastasis and can thus contribute to the expansion of cancer. This implies that therapeutic strategies which involve decreasing signaling through the CCR7 axis would have a beneficial effect in preventing dissemination of cancer. This dichotomy has partly been the reason why this axis has not yet been exploited, as other chemokine axes have, as a therapeutic target in cancer. Recent report of a crystal structure for CCR7 provides opportunities to exploit this axis in developing new cancer therapies. However, it remains unclear which of these two strategies, potentiation or antagonism of the CCR7 axis, is more appropriate for cancer therapy. This review brings together the evidence supporting both roles of the CCR7 axis in cancer and examines the future potential of each of the two different therapeutic approaches involving the CCR7 axis in cancer.

HPV infection related immune infiltration gene associated therapeutic strategy and clinical outcome in HNSCC

Background

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common tumor in human. Research has shown that HPV status HNSCC is a unique prognosis factor, which may due to its immune infiltration landscape. But the underlying mechanism is unclear.

Methods

In this study, we used a combination of several bioinformatics tools, including WCGNA, ssGSEA, CIBERSORT, TIDE,etc., to explore significant genes both related to HPV infection status and immune cell infiltration in HNSCC patients.

Results

Combined with several bioinformatics algorithms, eight hub genes were identified, including LTB, CD19, CD3D, SKAP1, KLRB1, CCL19, TBC1D10C and ARHGAP4. In HNSCC population, the hub genes had a stable co-expression, which was related to immune cell infiltration, especially CD8+ T cells, and the infiltrative immune cells were in a dysfunctional status. Samples with high hub genes expression presented with better response to immune check point block (ICB) therapy and sensitivity to bleomycin and methotrexate.

Conclusions

The eight hub genes we found presented with a stable co-expression in immune cell infiltration of HPV + ve HNSCC population. The co-expression of hub genes related to an immune microenvironment featuring an increase in immune cells but high degree of immune dysfunction status. Patients with high hub gene expression had a better response to ICB treatment, bleomycin and methotrexate. The co-expression of hub genes may be related to immune infiltration status in patients. The concrete molecular mechanism of hub genes function demands further exploration.

Ran promotes the proliferation and migration ability of head and neck squamous cell carcinoma cells

HNSCC is an aggressive tumor that often recurrence and metastasis. Although the treatment of HNSCC has improved over the past few decades, it is easy to recurrence even after comprehensive treatment. Ran is a small Ras-related GTPase belonging to the Ras superfamily. Recently, Ran has been proven to be an important oncogene involved in the metastatic progression of many human cancers. But there is seldom research on HNSCC about Ran. This study revealed the relationship between Ran expression and HNSCC characteristics, investigated the expression and role of Ran in HNSCC tissues and cells by means of immunohistochemistry, qRT-PCR, CCK-8, FCM and transwell migration assays. The results indicated that HNSCC tissues had significantly higher Ran expression than adjacent non-tumor tissues. The overall survival rate was significantly lower in patients with Ran-positive tumors than in those with Ran-negative tumors. Moreover, Ran was positively correlated with tumor grade, lymph node metastasis and recurrence. Ran was also high expressed in the HNSCC cell lines (PCI-37B and SCC9) and down regulated of Ran could evidently inhibit their proliferation, migration and down-regulate of Met protein. In conclusion, our findings suggested Ran could promote the proliferation and migration ability of HNSCC cells. Ran may play an important role in the development of HNSCC and may serve as a novel prognostic indicator of HNSCC.

The p38/MKP-1 signaling axis in oral cancer: Impact of tumor-associated macrophages

Oral squamous cell carcinomas (OSCC) constitute over 95% of all head and neck malignancies. As a key component of the tumor microenvironment (TME), chronic inflammation contributes towards the development, progression, and regional metastasis of OSCC. Tumor associated macrophages (TAMs) associated with OSSC promote tumorigenesis through the production of cytokines and pro-inflammatory factors that are critical role in the various steps of malignant transformation, including tumor growth, survival, invasion, angiogenesis, and metastasis. The mitogen-activated protein kinases (MAPKs) can regulate inflammation along with a wide range of cellular processes including cell metabolism, proliferation, motility, apoptosis, survival, differentiation and play a crucial role in cell growth and survival in physiological and pathological processes including innate and adaptive immune responses. Dual specificity MAPK phosphatases (MKPs) deactivates MAPKs. MKPs are considered as an important feedback control mechanism that limits MAPK signaling and subsequent target gene expression. This review outlines the role of MKP-1, the founding member of the MKP family, in OSCC and the TME. Herein, we summarize recent progress in understanding the regulation of p38 MAPK/MKP-1 signaling pathways via TAM-related immune responses in OSCC development, progression and treatment outcomes.

MiR-let-7a/f-CCR7 signaling is involved in the anti-metastatic effects of an herbal formula comprising Sophorae Flos and Lonicerae Japonicae Flos in melanoma

BACKGROUND

Metastasized melanoma is extremely difficult to treat. Activation of C-C chemokine receptor type 7 (CCR7) has been linked to melanoma metastasis. CCR7 can be directly regulated by miR-let-7. We have previously shown that an ethanolic extract of an herbal formula comprising Sophorae Flos and Lonicerae Japonicae Flos (SLE) inhibits melanoma cell migration and invasion.

PURPOSE

In this study, we determined whether SLE suppresses melanoma metastasis, and whether regulation of miR-let-7a/f-CCR7 signaling is involved in the effect.

STUDY DESIGN AND METHODS

Small RNA sequencing was conducted to compare miRNA expression profiles of B16F10 tumors dissected from SLE-treated or untreated mice. Western blot and RT-qPCR analyses were employed to examine protein and miRNA levels, respectively. A B16F10 melanoma lung metastasis mouse model was used to evaluate the effects of SLE on melanoma metastasis. MiR-let-7a/f-knockdown and CCR7-overexpression cell models were used to investigate the involvement of miR-let-7a/f-CCR7 signaling in the anti-metastatic effects of SLE.

RESULTS

It was found that SLE upregulated levels of miR-let-7a/f in B16F10 melanoma tissues. SLE significantly elevated levels of miR-let-7a/f, lowered the protein level of CCR7, inhibited the phosphorylation of CCR7 downstream molecules p38 and JNK in B16F10 and A375 melanoma cells. SLE inhibited B16F10 melanoma lung metastasis in mice. SLE upregulated levels of miR-let-7a/f, and lowered protein levels of CCR7, MMP-2, MMP-9, phospho-p38 (Thr180/Tyr182) and phospho-JNK (Thr183/Tyr185) in melanoma-invaded lung tissues. Knockdown of miR-let-7a/f diminished the effects of SLE on CCR7 signaling in, and invasion of, melanoma cells. Overexpression of CCR7 lessened the effects of SLE in inhibiting the phosphorylation of p38 and JNK in, and the invasive capability of, melanoma cells.

CONCLUSION

We for the first time demonstrated that SLE inhibits melanoma metastasis in mice, and that regulation of the miR-let-7a/f-CCR7 pathway contributes to the anti-metastatic mechanisms of SLE. These findings provide a pharmacological basis for developing SLE as a modern agent for treating metastatic melanoma. Additionally and importantly, this study suggests that regulating the miR-let-7a/f-CCR7 pathway is a novel strategy for controlling melanoma metastasis.

Prognostic value of immunoexpression of CCR4, CCR5, CCR7 and CXCR4 in squamous cell carcinoma of tongue and floor of the mouth

Background

Diverse studies have evidenced that chemokines can play a critical role in pathogenesis of oral squamous cell carcinoma (SCC). The main chemokines involved in oral carcinogenesis, tumor invasion and metastasis are CCR4, CCR5, CCR7 and CXCR4, and our aim was to evaluate the prognostic value of the immunoexpression of these chemokines in SCC of tongue and floor of the mouth.

Material and Methods

A retrospective descriptive study of the immunohistochemical expression of CCR4, CCR5, CCR7 and CXCR4 in paraffin-embedded samples of 124 patients with SCC of the tongue and floor of the mouth was performed, considering 98 cases from Brazil and 26 cases from Chile. Associations between variables were analyzed using chi-square test. Survival curves were performed using the Kaplan-Meier method and compared with long-rank test. For multivariate survival analysis, the Cox hazard model was established. The level of significance established was p≤0.05.

Results

The statistical analysis showed that samples with well or moderate WHO model differentiation (p=0.001) and a high expression of CCR5 (p=0.05) were significantly associated with a higher disease specific survival, which were also observed in Cox´s multivariate analysis (p=0.01). A higher expression of CCR7 (p=0.01) interfered significantly in disease-free survival in univariate analysis and in Cox´s multivariate analysis (p=0.05).

Conclusions

These results support additional evidence, showing that chemokine receptors CCR5 and CCR7 are helpful as biomarkers of poor prognosis in patients with SCC of the tongue and floor of the mouth.

Key words:Oral squamous cell carcinoma, prognosis, survival, chemokine receptor.

Hsa-let-7e-5p Inhibits the Proliferation and Metastasis of Head and Neck Squamous Cell Carcinoma Cells by Targeting Chemokine Receptor 7

This study aimed at determining the role of hsa-let-7e-5p in the progression of head and neck squamous cell carcinoma (HNSCC). The relative levels of hsa-let-7e-5p transcripts in 15 paired of HNSCC and adjacent non-tumor tissues and cells were examined by quantitative real-time PCR (qRT-PCR). The potential targets of hsa-let-7e-5p were predicted and validated by luciferase assay. The impact of altered hsa-let-7e-5p expression on HNSCC cell proliferation and metastasis was determined by CCK-8, wound healing, transwell migration and invasion assays. The effect of hsa-let-7e-5p over-expression on the growth of HNSCC was examined in vivo. Hsa-let-7e-5p expression was significantly down-regulated in HNSCC tissues and highly metastatic PCI-37B cells. Bioinformatic analysis predicted that hsa-let-7e-5p bound to the 3'untranslated region (3'UTR) of chemokine receptor 7(CCR7), which was validated by luciferase assay. While transfection with hsa-let-7e-5p mimic significantly decreased CCR7 protein expression, transfection with hsa-let-7e-5p inhibitor increased CCR7 protein expression in HNSCC cells. Similarly, hsa-let-7e-5p over-expression inhibited PCI-37B cell proliferation, wound healing, migration and invasion, while inhibition of endogenous hsa-let-7e-5p had opposite effects in PCI-37A cells. Hsa-let-7e-5p over-expression inhibited PCI-37B tumor growth in vivo. Therefore, hsa-let-7e-5p acts as a tumor suppressor to inhibit the progression of HNSCC by targeting CCR7 expression. Hsa-let-7e-5p and CCR7 may be therapeutic targets of HNSCC.

Autoencoder Based Feature Selection Method for Classification of Anticancer Drug Response

Anticancer drug responses can be varied for individual patients. This difference is mainly caused by genetic reasons, like mutations and RNA expression. Thus, these genetic features are often used to construct classification models to predict the drug response. This research focuses on the feature selection issue for the classification models. Because of the vast dimensions of the feature space for predicting drug response, the autoencoder network was first built, and a subset of inputs with the important contribution was selected. Then by using the Boruta algorithm, a further small set of features was determined for the random forest, which was used to predict drug response. Two datasets, GDSC and CCLE, were used to illustrate the efficiency of the proposed method.

Locally Trapping the C-C Chemokine Receptor Type 7 by Gene Delivery Nanoparticle Inhibits Lymphatic Metastasis Prior to Tumor Resection

Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype. Currently, no targeted treatment is available for TNBC, and the most common clinical therapy is tumor resection, which often promotes metastasis risks. Strong evidence suggests that the lymphatic metastasis is mediated by the C-C chemokine receptor type 7 (CCR7)/C-C motif chemokine ligand 21 crosstalk between tumor cells and the lymphatic system. It is hypothesized that CCR7 is a key immune modulator in the tumor microenvironment and the local blockade of CCR7 could effectively inhibit TNBC lymphatic metastasis. Accordingly, a plasmid encoding an antagonistic CCR7 affinity protein-CCR7 trap is delivered by tumor targeting nanoparticles in a highly metastatic 4T1 TNBC mouse model. Results show that CCR7 traps are transiently expressed, locally disrupt the signaling pathways in the tumor site, and efficiently inhibit TNBC lymphatic metastasis, without inducing immunosuppression as observed in systemic therapies using CCR7 monoclonal antibody. Significantly, upon applying CCR7 trap therapy prior to tumor resection, a 4T1 TNBC mouse model shows good prognosis without any further metastasis and relapse. In addition, CCR7 trap therapy efficiently inhibits the lymphatic metastasis in a B16F10 melanoma mouse model, indicating its great potential for various metastatic diseases treatment.

Meta-analysis of the prognostic value of C-C chemokine receptor type 7 in patients with solid tumors

Background

Expression of C-C chemokine receptor type 7 (CCR7) is associated with the prognosis of several cancers. The aim of this study was to conduct the meta-analysis to determine the prognostic value of CCR7 expression in solid tumors.

Materials and methods

We searched for relevant literature in the PubMed, Embase, and Cochrane Library databases (last updated on January 15, 2018). The associations of CCR7 expression with overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS), progress-free survival (PFS), and disease-specific survival (DSS) were estimated.

Results

In total, 30 qualified studies including 3,413 patients were enrolled. The results revealed that higher expression of CCR7 predicted poorer OS (pooled HR =1.79; 95% CI =1.49–2.16; P<0.001) and PFS (pooled HR =2.18; 95% CI =1.49–3.18; P<0.001), but was not associated with DFS (pooled HR =1.69; 95% CI =0.79–3.61; P=0.175), RFS (pooled HR =1.29; 95% CI =0.48–3.44; P=0.618), or DSS (pooled HR =3.06; 95% CI =0.38–24.83; P<0.294).

Conclusion

From this meta-analysis, we concluded that high expression of CCR7 in tumor tissue is associated with poor survival in patients with solid tumors, and may be a prognostic biomarker for tumor progression.

CXCR4 and CCR7 Expression in Primary Nodal Diffuse Large B-Cell Lymphoma-A Clinical and Immunohistochemical Study

BACKGROUND

A few studies have evaluated the expression of chemokine receptors CXCR4 and CCR7 in diffuse large B-cell lymphoma (DLBCL); however, the association between CXCR4 and CCR7 with bone marrow (BM) involvement and their synergistic effect on prognosis is still unclear. Our study investigated this aspect.

METHODS

Specimens were obtained from 61 primary nodal DLBCL patients and 100 reactive proliferative lymphadenitis patients. CXCR4 and CCR7 expression levels were examined by immunohistochemical staining; the relationship between these levels and clinical parameters and the differences in overall survival were analyzed.

RESULTS

CXCR4 and CCR7 overexpression was observed in the malignant lymph node tissues from most DLBCL patients. CCR7 expression was significantly higher in the non-GCB than the GCB subtype; CXCR4 positivity rates showed no significant difference between the 2 subtypes. In DLBCL patients with BM involvement, CXCR4 was overexpressed in almost all BM samples, but CCR7 expression was low in BM. CXCR4 overexpression was associated with advanced Ann Arbor stages, MYC overexpression, and increased extranodal infiltration; CCR7 was associated with advanced Ann Arbor stages and elevated LDH. Like the case for CCR7, the survival rate of CXCR4-positive DLBCL patients was significantly lower than that of the CXCR4-negative patients. CXCR4⁺CCR7⁺ patients had the lowest survival rate.

CONCLUSIONS

There is a positive correlation between CXCR4 overexpression and BM involvement. CXCR4 and CCR7 overexpression is associated with poorer overall survival, especially in CXCR4 and CCR7 copositive patients. CXCR4, CCR7, Ki-67 index, and MYC were independent prognostic factors for DLBCL. Blocking CXCR4 and/or CCR7 can be a novel therapeutic strategy for DLBCL.

Participation of hypoxia-inducible factor-1α and lymphangiogenesis in metastatic and non-metastatic lower lip squamous cell carcinoma

This study evaluated the lymphatic density and HIF-1α immunoexpression in lower lip squamous cell carcinoma (LLSCC) and their correlation with clinicopathological (nodal metastasis, clinical stage, histological grade, recurrence and disease outcome) and survival parameters in 20 metastatic and 20 non-metastatic LLSCCs. Lymphatic density was established by counting microvessels (D2-40⁺) at the tumor core (intratumoral lymphatic density, ILD) and at the invasive front (peritumoral lymphatic density, PLD) and percentages of immunopositive cells for HIF-1α were established. No statistically significant differences in lymphatic densities in relation to clinicopathological parameters were observed (P > 0.05). All cases exhibited nuclear and cytoplasmic HIF-1α immunoexpression, with relatively high percentages of positivity, but this expression was not statistically different in relation to clinicopathological variables (P > 0.05). Positive correlations were observed between ILD and PLD (P = 0.002), and between nuclear HIF-1α immunoexpression at the tumor core and ILD (P = 0.001). The results suggest ILD and PLD are not directly related to the development of lymph node metastasis in LLSCC. The striking expression of HIF-1α suggests the involvement of this protein in the etiopathogenesis of LLSCCs, possibly stimulating lymphangiogenesis at the tumor core. However, this protein does not seem to exert a determining influence on the biological aggressiveness of these tumors.

Vascular Stem/Progenitor Cell Migration and Differentiation in Atherosclerosis

SIGNIFICANCE

Atherosclerosis is a major cause for the death of human beings, and it takes place in large- and middle-sized arteries. The pathogenesis of the disease has been widely investigated, and new findings on vascular stem/progenitor cells could have an impact on vascular regeneration. Recent Advances: Recent studies have shown that abundant stem/progenitor cells present in the vessel wall are mainly responsible for cell accumulation in the intima during vascular remodeling. It has been demonstrated that the mobilization and recruitment of tissue-resident stem/progenitor cells give rise to endothelial and smooth muscle cells (SMCs) that participate in vascular repair and remodeling such as neointimal hyperplasia and arteriosclerosis. Interestingly, cell lineage tracing studies indicate that a large proportion of SMCs in neointimal lesions is derived from adventitial stem/progenitor cells.

CRITICAL ISSUES

The influence of stem/progenitor cell behavior on the development of atherosclerosis is crucial. An understanding of the regulatory mechanisms that control stem/progenitor cell migration and differentiation is essential for stem/progenitor cell therapy for vascular diseases and regenerative medicine.

FUTURE DIRECTIONS

Identification of the detailed process driving the migration and differentiation of vascular stem/progenitor cells during the development of atherosclerosis, discovery of the environmental cues, and signaling pathways that control cell fate within the vasculature will facilitate the development of new preventive and therapeutic strategies to combat atherosclerosis. Antioxid. Redox Signal. 00, 000-000.

CCR7 regulates ANO6 to promote migration of pancreatic ductal adenocarcinoma cells via the ERK signaling pathway

The increase in migratory ability of pancreatic ductal adenocarcinoma cells is a key event in the development of metastasis to the lymph nodes and distant organs. Although the C-C motif chemokine receptor 7 (CCR7) and its ligand, C-C motif chemokine ligand 21 (CCL21), have been revealed to serve an important role in tumor migration, their precise roles and potential underlying mechanisms remain largely unknown. The present study revealed that overexpression of CCR7 significantly promoted BxPC-3 cell migration, accompanied by the induction of anoctamin 6 (ANO6) expression, indicating that ANO6 is a downstream target of CCR7 signaling. Furthermore, the level of phosphorylated extracellular signal-regulated kinase (ERK) was significantly increased in CCR7-overexpressing BxPC-3 cells, indicating that ERK may be a potential mediator of CCR7-regulated ANO6 expression in BxPC-3 cells. To characterize the receptor-mediated pathway, a specific ERK inhibitor, U0126, was used, which reduced BxPC-3 cell migration and the expression of ANO6. In summary, the results of the present study demonstrate that CCR7 promoted BxPC-3 cell migration by regulating ANO6 expression perhaps via activation of the ERK signaling pathway.

Overexpression of hsa-miR-125a-5p enhances proliferation, migration and invasion of head and neck squamous cell carcinoma cell lines by upregulating C-C chemokine receptor type 7

Head and neck squamous cell carcinoma (HNSCC) is usually diagnosed accompanied by lymph node metastasis. C-C chemokine receptor type 7 (CCR7) is associated with the invasion and metastasis of tumors in HNSCC through various signaling pathways. The role of hsa-miR-125a-5p in HNSCC remains unclear. The present study was performed to investigate the association between hsa-miR-125a-5p and CCR7 in HNSCC. Reverse transcription-quantitative polymerase chain reaction was applied to analyze the expression of hsa-miR-125a-5p in clinical samples. Cell Counting Kit-8, Transwell and wound healing assays were used to detect cell proliferation, invasion, and metastasis, respectively, following overexpression of hsa-miR-125a-5p. Changes in protein expression of CCR7 were observed using western blotting. In the survival analysis, Student's t-tests and log rank tests were performed to analyze the association between the expression of hsa-miR-125a-5p, and HNSCC according to the Cancer Genome Atlas database. The expression of hsa-miR-125a-5p was identified to be significantly lower in cancer tissue compared with the corresponding adjacent normal tissues in clinical samples (P=0.038). The results of western blotting indicated that there was a positive regulatory association between hsa-miR-125a-5p and CCR7. Furthermore, overexpression of hsa-miR-125a-5p significantly enhanced the ability of cell proliferation, migration and invasion in HNSCC, with upregulation of CCR7. The results of survival analysis revealed that patients in the low expression group of hsa-miR-125a-5p tended to have longer survival times compared with the high expression group (P=0.045). Altogether, the data raised the possibility that hsa-miR-125a-5p has a significant role in promoting cancer in HNSCC, which may provide a basis for the treatment of HNSCC in molecular targeted therapy. Further studies are required to ascertain the role of hsa-miR-125a-5p in other HNSCC cell lines and in vivo.

Hypoxia modulates CCR7 expression in head and neck cancers

BACKGROUND

The chemokine receptor CCR7 is expressed on lymphocytes and dendritic cells and is responsible for trafficking of these cells in and out of secondary lymphoid organs. It has recently been shown that CCR7 expression is elevated in a number of cancers, including head and neck cancers, and that its expression correlates to lymph node (LN) metastasis. However, little is known about the factors that can induce CCR7 expression in head and neck cancers.

METHOD

We compared the protein expression and functional responses of CCR7 under normoxia and hypoxia in head and neck cancer cell lines OSC-19, FaDu, SCC-4, A-253 and Detroit-562 cultured as monolayers, spheroids, and grown in vivo as xenografts in balb/c mice. In addition, we analysed the correlation between hypoxia marker HIF-1α and CCR7 expression in a tissue microarray comprising 80 clinical samples with various stages and grades of malignant tumour and normal tissue.

RESULTS

Under hypoxia, the expression of CCR7 is elevated in both in vitro and in vivo models. Furthermore, in malignant tissue, a correlation is observed between hypoxia marker HIF-1α and CCR7 across all clinical stages. This correlation is also strong in early histological grade of tumours.

CONCLUSION

Hypoxia plays a role in the regulation of the expression of CCR7 and it may contribute to the development of a metastatic phenotype in head and neck cancers through this axis.

Complement C1q stimulates the progression of hepatocellular tumor through the activation of discoidin domain receptor 1

C1q is known to perform several functions in addition to the role it plays in complement activation. C1q contains a collagen-like portion and DDR1 (discoidin domain receptor 1) is a well-known collagen receptor. Accordingly, we hypothesized C1q might be a novel ligand of DDR1. This study shows for the first time C1q directly induces the activation and upregulation of DDR1, and that this leads to enhanced migration and invasion of HepG2 cells. In addition, C1q was found to induce the activations of mitogen-activated protein kinases (MAPKs) and phosphoinositide 3-kinase (PI3K)/Akt signaling, and to increase the expressions of matrix metalloproteinases (MMP2 and 9). Our results reveal a relationship between C1q and DDR1 and suggest C1q-induced DDR1 activation signaling may be involved in the progression of hepatocellular carcinoma.

Jak3 is involved in CCR7-dependent migration and invasion in metastatic squamous cell carcinoma of the head and neck

Patients with cervical lymph node metastasis in squamous cell carcinoma of the head and neck (SCCHN) exhibit a poor prognosis and low 5-year survival rate. It has been proven that chemokine receptor 7 (CCR7) promotes cellular migration and invasion in metastatic SCCHN. In the present study, the metastatic SCCHN PCI-37B cell line was utilized to explore the role of Janus activated kinase-3 (Jak3) in the CCR7-mediated signaling pathway in metastatic SCCHN cells. It was observed that phospho-Jak3 was expressed in SCCHN tissues. In addition, when the PCI-37B cells were analyzed in response to chemokine ligand 19 (CCL19), the ligand of CCR7, at the indicated time points, the results of the present study demonstrated that CCR7 induced Jak3 activation, and inhibition of Jak3 activity using a specific inhibitor, ZM39923, significantly attenuated CCR7-induced Jak3 phosphorylation. Migration and invasion assays and immunofluorescence staining experiments demonstrated that CCL19 promoted cell migration, invasion and F-actin rearrangment in CCR7-expressing SCCHN cells partially due to the activation of the Jak3 signaling pathway. These results demonstrate that the Jak3 signaling pathway is important for the CCR7-induced malignant biological behavior of SCCHN cells.

Galectin-7 promotes the invasiveness of human oral squamous cell carcinoma cells via activation of ERK and JNK signaling

Galectin-7 is a member of the β-galactoside-binding protein family, and is highly expressed in oral squamous cell carcinoma (OSCC). The aim of the present study was to investigate the effects of manipulating galectin-7 expression on the biological phenotype of human OSCC cells and the associated molecular mechanisms. Knockdown of endogenous galectin-7 via small interfering RNA (siRNA) was performed and cell proliferation, apoptosis, migration, and invasion were subsequently assessed. The data indicated that galectin-7 silencing had no impact on the proliferation or apoptosis of OSCC cells. However, compared with non-transfected cells, percentage wound closure was significantly lower in galectin-7-silenced cells following 24 h incubation, indicating decreased cell migration. Furthermore, Matrigel invasion assays demonstrated that galectin-7 knockdown significantly reduced the number of invaded cells, compared with the number in non-transfected cells. Western blot analysis indicated that galectin-7 overexpression resulted in a significant increase in the expression of the proteins matrix metalloproteinase (MMP)-2 and MMP-9. The invasive abilities of cells overexpressing galectin-7 significantly decreased following co-transfection with MMP-2- or MMP-9-specific siRNA. Increasing galectin-7 expression significantly enhanced the phosphorylation of extracellular signal-related kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) 1/2. Pharmacological inhibition of ERK or JNK activity significantly suppressed the invasiveness of galectin-7-overexpressing cells and abrogated the upregulation of MMP-2 and MMP-9. Taken together, the results of the current study provide novel evidence for the pro-invasive activity of galectin-7 in OSCC cells, which is associated with activation of ERK and JNK signaling and the induction of MMP-2 and MMP-9.

CXCR4 and CCR7: Two eligible targets in targeted cancer therapy

Cancer is one of the most common cause of death in the world with high negative emotional, economic, and social impacts. Conventional therapeutic methods, including chemotherapy and radiotherapy, have not proven satisfactory and relapse is common in most cases. Recent studies have focused on targeted therapy with more precise identification and targeted attacks to the cancer cells. For this purpose, chemokine receptors are proper targets and among them, CXCR4 and CCR7, with a crucial role in cancer metastasis, are being considered as desired candidates for investigation. In this review paper, the most important experimental results are highlighted on the potential targeted therapies based on CXCR4 and CCR7 chemokine receptors.

The role of Pyk2 in the CCR7-mediated regulation of metastasis and viability in squamous cell carcinoma of the head and neck cells in vivo and in vitro

In the present study, we aimed to demonstrate whether praline-rich tyrosine kinase-2 (Pyk2) participates in the chemokine receptor 7 (CCR7) downstream signaling network, and to determine the role of this molecule and the related mechanism in the CCR7-mediated regulation of viability and metastasis in vivo and in vitro of squamous cell carcinoma of the head and neck (SCCHN). We constructed the stable Pyk2 related non-kinase (PRNK)-expressing SCCHN cell line, and examined the viability, apoptosis, migration, invasion and adhesion ability in the transfected and untransfected SCCHN cells. An SCCHN tumor model in nude mice was designed and the tumor growth rate was assayed. E-cadherin and vimentin expression was assessed when Pyk2 was inactivated. We found that the stable PRNK-expressing SCCHN cells exhibited low viability, a high rate of apoptosis, low migratory ability, low invasive ability and low adhesion capacity. In the nude mouse body, the tumors formed by these cells grew slowly when compared to the tumor growth in the control group. When Pyk2 was inactivated, CCR7-induced E-cadherin and vimentin expression levels were altered. Thus, Pyk2 is a key downstream signaling molecules of CCR7 in SCCHN, which promotes SCCHN tumorigenesis and progression.

CXCR7 signaling induced epithelial-mesenchymal transition by AKT and ERK pathways in epithelial ovarian carcinomas

Epithelial-mesenchymal transition (EMT) plays an important role in oncogenesis, through which cancer cells acquire an invasion and metastasis capacity. Notably, the chemokine receptor CXCR7 and its ligands CCL19 can also facilitate lymph node metastasis in epithelial ovarian carcinomas. Here, we assumed that CXCR7 might be involved in the EMT process of epithelial ovarian carcinomas. In our study, CXCR7 activation and inhibition in SKOV3 were induced with exogenous CCL19 and CXCR7 small interfering RNA (CXCR7 siRNA), respectively. AKT and ERK protein of CXCR7 pathways as well as biomarkers (vimentin, snail, N-cadherin, and E-cadherin) of EMT were detected using the Western blot. Our results showed that CCL19 can induce AKT and ERK phosphorylation in a dose-dependent fashion; however, CXCR7 siRNA efficaciously suppressed CCL19-induced AKT and ERK phosphorylation in comparison with control siRNA. Importantly, CCL19 alone treatment can upregulate the expression of vimentin, snail, and N-cadherin of SKOV3 and downregulate the expression of E-cadherin. Conversely, knockdown of CXCR7 did not reveal any changes compared with CCL19 and the control. In conclusion, these findings demonstrate that EMT can be regulated by the CCL19/CXCR7 axis in epithelial ovarian carcinomas and then involved in the tumor cell invasion and metastasis process via activation of AKT and ERK pathways. Our study lays a new foundation for the treatment of epithelial ovarian carcinomas through antagonizing CXCR7.