Association of CXCR4 and CCR7 chemokine receptor expression and lymph node metastasis in human cervical cancer

Targeting chemokine-receptor mediated molecular signaling by ethnopharmacological approaches

ETHNOPHARMACOLOGICAL RELEVANCE

Infection and inflammation are critical to global human health status and the goal of current pharmacological interventions intends formulating medications/preventives as a measure to deal with this situation. Chemokines and their cognate receptors are major regulatory molecules in many of these ailments. Natural products have been a keen source to the drug development industry, every year contributing significantly to the growing list of FDA approved drugs. A multiverse of natural resource is employed as a part of curative regimen in folk/traditional/ethnomedicine which can be employed to discover, repurpose, and design potent medications for the diseases of clinical concern.

AIM OF THE STUDY

This review aims to systematically document the ethnopharmacologically active agents targeting the infectious-inflammatory diseases through the chemokine-receptor nexus.

MATERIALS AND METHODS

Articles related to chemokine/receptor modulating ethnopharmacological anti-inflammatory, anti-infectious natural sources, bioactive compounds, and formulations have been examined with special emphasis on women related diseases. The available literature has been thoroughly scrutinized for the application of traditional medicines in chemokine associated experimental methods, their regulatory outcomes, and pertinence to women's health wherever applicable. Moreover, the potential traditional regimens under clinical trials have been critically assessed.

RESULTS

A systematic and comprehensive review on the chemokine-receptor targeting ethnopharmaceutics from the available literature has been provided. The article discusses the implication of traditional medicine in the chemokine system dynamics in diverse infectious-inflammatory disorders such as cardiovascular diseases, allergic diseases, inflammatory diseases, neuroinflammation, and cancer. On this note, critical evaluation of the available data surfaced multiple diseases prevalent in women such as osteoporosis, rheumatoid arthritis, breast cancer, cervical cancer and urinary tract infection. Currently there is no available literature highlighting chemokine-receptor targeting using traditional medicinal approach from women's health perspective. Moreover, despite being potent in vitro and in vivo setups there remains a gap in clinical translation of these formulations, which needs to be strategically and scientifically addressed to pave the way for their successful industrial translation.

CONCLUSIONS

The review provides an optimistic global perspective towards the applicability of ethnopharmacology in chemokine-receptor regulated infectious and inflammatory diseases with special emphasis on ailments prevalent in women, consecutively addressing their current status of clinical translation and future directions.

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.

EREG is a risk factor for the prognosis of patients with cervical cancer

Background

Cervical cancer continues to threaten women's health worldwide. Identifying critical oncogenic molecules is important to drug development and prognosis prediction for patients with cervical cancer. Recent studies have demonstrated that epiregulin (EREG) is upregulated in various cancer types, which contributes to cancer progression by triggering the EGFR signaling pathway. However, the role of EREG is still unclear.

Methods

In this study, we first conducted a comprehensive biological analysis to investigate the expression of EREG in cervical cancer. Then, we investigated the correlations between EREG expression level and clinicopathological features. In addition, we validated the effects of EREG expression on the proliferation and apoptosis of cervical cancer cells.

Results

Based on the public database, we found that the expression of EREG was higher in advanced cervical cancer samples. Survival analysis showed that EREG was a risk factor for the prognosis of cervical cancer. In vitro experiments demonstrated that EREG knockdown undermined proliferation and promoted apoptosis in cancer cells.

Conclusion

EREG plays a vital role in the progression of cervical cancer, which contributes to hyperactive cell proliferation and decreased cell apoptosis. It might be a valuable target for prognosis prediction and drug development for cervical cancer in the future.

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.

Small secretory proteins of immune cells can modulate gynecological cancers

Small secretory proteins of immune cells are mostly Cytokines, which include chemokines, interleukins, interferons, lymphokines and tumor necrosis factors but not hormones or growth factors. These secretory proteins are the molecular messengers and primarily involved in autocrine, paracrine and endocrine signaling as immunomodulating agents. Hence, these proteins actually regulate the cells of immune system to communicate with one another to produce a synchronized, robust, still self-regulated response to a specific antigen. Chemokines are smaller secreted proteins that control overall immune cell movement and location; these chemokines are divided into 4 subgroups, namely, CXC, CC, CX3C and C according to the position of 4 conserved cysteine residues. Complete characterization of cytokines and chemokines can exploit their vast signaling networks to develop cancer treatments. These secretory proteins like IL-6, IL-10, IL-12, TNFα, CCL2, CXCL4 & CXCL8 are predominantly expressed in most of the gynecological cancers, which directly stimulate immune effector cells and stromal cells at the tumor site and augment tumor cell recognition by cytotoxic T-cells. Hence; these secretory proteins are the major regulators, which can actually modulate all kinds of gynecological cancers. Furthermore, advancements in adoptive T-cell treatment have relied on the use of multiple cytokines/chemokines to establish a highly regulated environment for anti-tumor T cell growth. A number of in vitro studies as well as animal models and clinical subjects have also shown that cytokines/chemokines have broad antitumor activity, which has been translated into a number of cancer therapy approaches. This review will focus on the foremost cytokines & chemokines involved in the majority of the gynecological malignancies and discuss their basic biology as well as clinical applications.

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.

Down-regulated expression of miR-99a is associated with lymph node metastasis and predicts poor outcome in stage IB cervical squamous cell carcinoma: a case-control study

Background

Lymph node metastasis (LNM) accounts for the most important route of metastasis for cervical cancer. Yet, the status of LNM is different in patients with similar clinico-pathological variables. It has been revealed that microRNAs are widely involved in the occurrence and development of various malignancies, and the tumor-suppressive or promoting effects of microRNA-99 (miR-99) family have been previously reported. This study sought to investigate the predictive value of miR-99a for lymphogenous spread and its effect on the survival of patients with early-stage cervical squamous cell cancer (CSCC).

Methods

Patients with stage IB squamous cervical cancer who were treated surgically between October 2015 and November 2018 were enrolled. A total of 21 formalin-fixed paraffin-embedded tissues of pathologically confirmed positive lymph nodes were retrieved, and an additional 21 tissues of negative lymph nodes from patients well-matched on baseline characteristics were collected as the control group. TaqMan real-time quantitative polymerase chain reaction was used to examine the expression levels of miR-99a in the samples. Differential expression levels of miR-99a were compared between the 2 groups using independent sample t-test. Furthermore, the associations between miR-99a expression level and clinico-pathological parameters of these 42 patients was evaluated by Chi-square test or Fisher's exact-probability method, and their effects on survival were assessed using Kaplan-Meier product-limit method.

Results

There were no significant differences in baseline clinico-pathological parameters between the 2 groups (P>0.05). The expression levels of miR-99a in the node-positive group and control group were 1.61±3.09 and 16.77±30.40, respectively (P=0.029). Downregulated expression of miR-99a was closely related to depth of invasion (DOI) and lymph-vascular space invasion (P<0.05). Univariate analysis revealed that downregulated miR-99a and deeper DOI were associated with worse 5-year disease-free survival, while multivariate analysis showed that only the expression level of miR-99a was an independent factor for disease-free survival (HR =0.120; 95% CI: 0.015-0.979; P=0.048). Patients with downregulated miR-99a tended to have more unfavorable overall survival, but the difference did not reach statistical significance.

Conclusions

MiR-99a plays an inhibitory role in the pathogenesis of lymph node metastasis and may serve as a novel prognostic biomarker for patients with CSCC.

Novel insight into pancreatic adenocarcinoma pathogenesis using liquid association analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy associated with a poor prognosis. High-throughput disease-related-gene expression data provide valuable information on gene interaction, which consequently lead to deeper insight about pathogenesis. The co-expression analysis is a common approach that is used to investigate gene interaction. However, such an approach solely is inadequate to reveal the complexity of the gene interaction. The three-way interaction model is known as a novel approach applied to decode the complex relationship between genes.

METHODS

In the current study, the liquid association method was used to capture the statistically significant triplets involved in the PDAC pathogenesis. Subsequently, gene set enrichment and gene regulatory network analyses were performed to trace the biological relevance of the statistically significant triplets.

RESULTS

The results of the current study suggest that "response to estradiol" and "Regulation of T-cell proliferation" are two critical biological processes that may be associated with the PDAC pathogenesis. Additionally, we introduced six switch genes, namely Lamc2, Klk1, Nqo1, Aox1, Tspan1, and Cxcl12, which might be involved in PDAC triggering.

CONCLUSION

In the current study, for the first time, the critical genes and pathways involved in the PDAC pathogenesis were investigated using the three-way interaction approach. As a result, two critical biological processes, as well as six potential biomarkers, were suggested that might be involved in the PDAC triggering. Surprisingly, strong evidence for the biological relevance of our results can be found in the literature.

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.

The Role of Chemokines in Cervical Cancers

Both clinical-pathological and experimental studies have shown that chemokines play a key role in activating the immune checkpoint modulator in cervical cancer progression and are associated with prognosis in tumor cell proliferation, invasion, angiogenesis, chemoresistance, and immunosuppression. Therefore, a clear understanding of chemokines and immune checkpoint modulators is essential for the treatment of this disease. This review discusses the origins and categories of chemokines and the mechanisms that are responsible for activating immune checkpoints in cervical dysplasia and cancer, chemokines as biomarkers, and therapy development that targets immune checkpoints in cervical cancer research.

Mechanisms and Clinical Significance of Tumor Lymphatic Invasion

Tumor-associated lymphatic vessels play an important role in tumor progression, mediating lymphatic dissemination of malignant cells to tumor-draining lymph nodes and regulating tumor immunity. An early, necessary step in the lymphatic metastasis cascade is the invasion of lymphatic vessels by tumor cell clusters or single tumor cells. In this review, we discuss our current understanding of the underlying cellular and molecular mechanisms, which include tumor-specific as well as normal, developmental and immunological processes “hijacked” by tumor cells to gain access to the lymphatic system. Furthermore, we summarize the prognostic value of lymphatic invasion, discuss its relationship with local recurrence, lymph node and distant metastasis, and highlight potential therapeutic options and challenges.

MTSS1 inhibits colorectal cancer metastasis by regulating the CXCR4/CXCL12 signaling axis

The liver is the most common site of metastasis for colorectal cancer (CRC). Metastasis suppressor 1 (MTSS1), a potential tumor suppressor gene associated with tumor metastasis, has been reported to play an important role in cancer development. The present study aimed to investigate the effects and underlying mechanisms of MTSS1 on the biological behavior of CRC cells both in vitro and in vivo. A CRC mouse model with a high liver metastatic potential was established by injecting mice with SW1116 cells, and the association between MTSS1 expression levels and the metastatic potential of forming liver metastasis lesions was subsequently analyzed. MTSS1 gain‑ and loss‑of‑function experiments were performed by transfecting the CRC cell lines, SW1116 and DLD‑1, with Plvx‑IRES‑ZsGreen1‑MTSS1 plasmid and short hairpin RNA, respectively. Cell proliferation, migration, invasion and cell cycle distribution were analyzed by MTT, Transwell and flow cytometric assays, respectively. To further determine the underlying mechanisms of MTSS1 in CRC, the expression levels of cell surface chemokine C‑X‑C receptor 4 (CXCR4) and its downstream signaling factors, Rac and cell division cycle 42 (CDC42), were analyzed with or without C‑X‑C motif chemokine ligand 12 (CXCL12) stimulation. The results revealed that as the CRC metastatic potential increased, the expression levels of MTSS1 decreased. The overexpression of MTSS1 exerted an inhibitory effect on cell proliferation, migration and invasion, while the knockdown of MTSS1 exerted the opposite effects in vitro. Flow cytometric analysis and western blot analysis demonstrated that MTSS1 negatively regulated the expression levels of cell surface CXCR4 and its downstream signaling pathway activation. On the whole, the results of the present study indicate that MTSS1 may play an important negative role in CRC metastasis and the underlying mechanisms may involve the downregulation of the CXCR4/CXCL12 signaling axis.

CCR7 Has Potential to Be a Prognosis Marker for Cervical Squamous Cell Carcinoma and an Index for Tumor Microenvironment Change

The tumor microenvironment (TME) has an essential role in the development of cervical squamous cell carcinoma (CSCC); however, the dynamic role of the stromal and immune cells is still unclear in TME. We downloaded data from The Cancer Genome Atlas (TCGA) database and applied ESTIMATE and CIBERSORT algorithms to measure the quantity of stromal and immune cells and the composition of tumor-infiltrating immune cell (TIC) in 253 CSCC cases. The protein-protein interaction (PPI) network and Cox regression analysis presented the differentially expressed genes (DEGs). Then, C-C chemokine receptor type 7 (CCR7) was screened out as a prognostic marker by the univariate Cox and intersection analysis of PPI. Further analysis showed a positive correlation between the expression of CCR7 and the survival of CSCC patients. The result of the Gene Set Enrichment Analysis (GSEA) of genes in the high CCR7 expression group displayed a predominant enrichment in immune-related pathways. An enrichment in metabolic activities was observed in the low CCR7 expression group. CIBERSORT analysis showed a positive correlation between Plasma cells, CD8⁺ T cells, and regulatory T cells and the CCR7 expression, suggesting that CCR7 might play a crucial role in maintaining the immunological dominance status for TME. Therefore, the expression level of CCR7 might help predict the survival of CSCC cases and be an index that the status of TME transitioned from immunological dominance to metabolic activation, which presented a new insight into the treatment of CSCC.

Identification of prognosis-related genes in the cervical cancer immune microenvironment

BACKGROUND

Cervical cancer is the fourth most commonly diagnosed cancer in women worldwide. The metastasis and invasion of this type of cancer are closely related to the tumor microenvironment. Immune cells and stromal cells dominate the tumor microenvironment in cervical cancer. Therefore, we should further investigate the complex interplay between the tumor progression with immune cells or stromal cells.

METHODS

We downloaded the gene expression profiles and clinical data of 307 patients with cervical cancers based on the TCGA database. Subsequently, the Estimation of Stromal and Immune cells in Malignant Tumours using Expression data (ESTIMATE) algorithm was used to calculate the scores of stromal cells and immune cells in order to uncover differential expressed genes, and we analyzed the correlation between their scores and patient survival. Then the Cell type Identification By Estimating Relative Subsets Of known RNA Transcripts (CIBERSORT) deconvolution algorithm was applied to quantify the fraction and infiltration of 22 types of immune cells in cervical cancer. Moreover, we also used R language packs and network tools to analyze GO term, gene enrichment pathway, and protein-protein relationship to trace down genes related to inflammation and immune regulation.

RESULTS

The gene expression profiles and corresponding clinical data of 307 patients were obtained from TCGA database. The results showed that the scores were statistically significant between the high immunescore group and the low immunescore group. And the low immunescore group had shorter survival period than the high scores group (P = 0.035). Among the 22 types of immune cells, only T cells and mast cells were significantly related to the survival rate of cervical cancer patients. Moreover, PPI network analysis revealed that CCR5 and CXCL9, -10, -11/CXCR3 axis might be a new target for cervical cancer treatment. Finally, Kaplan-Meier survival curves found outnine representative genes significantly related to survival rate including BTNL8, CCR7, CD1E, CD6, CD27, CD79A, GRAP2, SP1B, LY9.

CONCLUSIONS

These genes can be used as markers for the prognosis and diagnosis of cervical cancer and also might be used as treatment targets.

Molecular landscape of recurrent cervical cancer

Cervical cancer (CC) is a major gynecological problem in developing and underdeveloped countries. Despite the significant advancement in early detection and treatment modalities, several patients recur. Moreover, the molecular mechanisms responsible for CC recurrence remains obscure. The patients with CC recurrence often show poor prognosis and significantly high mortality rates. The clinical management of recurrent CC depends on treatment history, site, and extent of the recurrence. Owing to poor prognosis and limited treatment options, recurrent CC often presents a challenge to the clinicians. Several in vitro, in vivo, and patient studies have led to the identification of the critical molecular changes responsible for CC recurrence. Both aberrant genetic and epigenetic modifications leading to altered cell signaling pathways have been reported to impact CC recurrence. Researchers are currently trying to dissect the molecular pathways in CC and translate these findings for better management of disease. This article attempts to review the existing knowledge of disease relapse, accompanying challenges, and associated molecular players in CC.

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.

A prognostic signature based on immune-related genes for cervical squamous cell carcinoma and endocervical adenocarcinoma

Cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) is the fourth commonest female malignancy worldwide. CESC progresses in immune-microenvironment mainly composed of infiltrating immune and stromal cells. Here, we performed an integrated analysis incorporating the expression profiles from the Cancer Genome Atlas (TCGA) database and scores of immune and stromal cells calculated by Estimation of Stromal and Immune cells in Malignant Tumours using Expression data (ESTIMATE) algorithm. A two-gene signature (CD1C and CD6 genes) was established to predict the prognosis of CESC. Based on this signature, patients were divided into the high- and low-risk groups, and this signature showed good prognostic performance according to the results of Kaplan-Meier analysis and receiver operating characteristic (ROC) analysis in train set and two validation sets. A nomogram was built for evaluating the clinical applicability of this signature. In addition, based on Tumor Immune Estimation Resource (TIMER) database, 2 hub genes showed negative correlations with tumor purity and positive correlations with infiltrating levels of immune filtrating cells. What's more, we propose new treatment strategies for the two prognostic subtypes. Low- risk patients were found presenting with a higher level of immune checkpoint molecules and showing higher immunogenicity in immunophenoscore (IPS) analysis, which indicated a better response for immunotherapy. Meanwhile, estimated by Genomics of Drug Sensitivity in Cancer (GDSC) database, the high-risk patients showed sensitive responses to five chemotherapy drugs. Finally, 10 candidate small-molecule drugs for CESC were defined. In summary, the CD1C-CD6 signature can accurately predict the prognosis of CESC.

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.

Regulatory T cells in breast cancer as a potent anti-cancer therapeutic target

Despite marked advances in treatment approaches, breast cancer is still going to be more prevalent, worldwide. High levels of regulatory T (Treg) cells have repeatedly been demonstrated in circulation, lymph nodes, and tumor samples from patients with various cancer types. The transcription factor Forkhead box protein 3 (Foxp3)-expressing Treg cells have the high suppressive potential of the immune system and are fundamental in preserving immune homeostasis and self-tolerance. However, they enhance tumor development by curbing efficient anti-tumor immune mechanisms in malignancies. Moreover, the accumulation of Treg cells in breast tumors is related to the short overall survival of patients. Treg cell frequency has been applied as an independent predicting factor to diagnose patients with a high risk of relapse. Pulling out all populations of Treg cells to promote the efficacy of anticancer treatment methods may potentially lead to hazardous autoimmune disorders. Thus, realizing the exact structure of tumor-infiltrating Treg cells is pivotal to efficiently target Treg cells in tumors. There are exclusive and non-exclusive approaches to lower down and degrade the number/function of Treg cells. These approaches can include inhibiting tumoral migration, depletion, interference with function, and utilizing T cell plasticity. This review article attempts to clarify the implications concerning the involvement of Treg cells in breast cancer progression and discuss the current approaches in the treatment of this cancer via modulation of Treg cells function.

Therapy-Induced Changes in CXCR4 Expression in Tumor Xenografts Can Be Monitored Noninvasively with N-[11C]Methyl-AMD3465 PET

Purpose

Chemokine CXCL12 and its receptor CXCR4 are constitutively overexpressed in human cancers. The CXCL12-CXCR4 signaling axis plays an important role in tumor progression and metastasis, but also in treatment-induced recruitment of CXCR4-expressing cytotoxic immune cells. Here, we aimed to demonstrate the feasibility of N-[¹¹C]methyl-AMD3465 positron emission tomography (PET) to monitor changes in CXCR4 density in tumors after single-fraction local radiotherapy or in combination with immunization.

Procedure

TC-1 cells expressing human papillomavirus antigens E6 and E7 were inoculated into the C57BL/6 mice subcutaneously. Two weeks after tumor cell inoculation, mice were irradiated with a single-fraction 14-Gy dose of X-ray. One group of irradiated mice was immunized with an alpha-viral vector vaccine, SFVeE6,7, and another group received daily injections of the CXCR4 antagonist AMD3100 (3 mg/kg -intraperitoneal (i.p.)). Seven days after irradiation, all animals underwent N-[¹¹C]methyl-AMD3465 PET.

Results

PET imaging showed N-[¹¹C]methyl-AMD3465 uptake in the tumor of single-fraction irradiated mice was nearly 2.5-fold higher than in sham-irradiated tumors (1.07 ± 0.31 %ID/g vs. 0.42 ± 0.05 % ID/g, p < 0.01). The tumor uptake was further increased by 4-fold (1.73 ± 0.17 % ID/g vs 0.42 ± 0.05 % ID/g, p < 0.01) in mice treated with single-fraction radiotherapy in combination with SFVeE6,7 immunization. Administration of AMD3100 caused a 4.5-fold reduction in the tracer uptake in the tumor of irradiated animals (0.24 ± 0.1 % ID/g, p < 0.001), suggesting that tracer uptake is indeed due to CXCR4-mediated chemotaxis.

Conclusion

This study demonstrates the feasibility of N-[¹¹C]methyl-AMD3465 PET imaging to monitor treatment-induced changes in the density of CXCR4 receptors in tumors and justifies further evaluation of CXCR4 as a potential imaging biomarker for evaluation of anti-tumor therapies.

Prognostic genes of melanoma identified by weighted gene co-expression network analysis and drug repositioning using a network-based method

Melanoma is one of the most malignant types of skin cancer. However, the efficacy and utility of available drug therapies for melanoma are limited. The objective of the present study was to identify potential genes associated with melanoma progression and to explore approved therapeutic drugs that target these genes. Weighted gene co-expression network analysis was used to construct a gene co-expression network, explore the associations between genes and clinical characteristics and identify potential biomarkers. Gene expression profiles of the GSE65904 dataset were obtained from the Gene Expression Omnibus database. RNA-sequencing data and clinical information associated with melanoma obtained from The Cancer Genome Atlas were used for biomarker validation. A total of 15 modules were identified through average linkage hierarchical clustering. In the two significant modules, three network hub genes associated with melanoma prognosis were identified: C-X-C motif chemokine receptor 4 (CXCR4), interleukin 7 receptor (IL7R) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit γ (PIK3CG). The receiver operating characteristic curve indicated that the mRNA levels of these genes exhibited excellent prognostic efficiency for primary and metastatic tumor tissues. In addition, the proximity between candidate genes associated with melanoma progression and drug targets obtained from DrugBank was calculated in the protein interaction network, and the top 15 drugs that may be suitable for treating melanoma were identified. In summary, co-expression network analysis led to the selection of CXCR4, IL7R and PIK3CG for further basic and clinical research on melanoma. Utilizing a network-based method, 15 drugs that exhibited potential for the treatment of melanoma were identified.

The role of CXCR4 in multiple myeloma: Cells' journey from bone marrow to beyond

CXCR4 is a pleiotropic chemokine receptor which acts through its ligand CXCL12 to regulate diverse physiological processes. CXCR4/CXCL12 axis plays a pivotal role in proliferation, invasion, dissemination and drug resistance in multiple myeloma (MM). Apart from its role in homing, CXCR4 also affects MM cell mobilization and egression out of the bone marrow (BM) which is correlated with distant organ metastasis. Aberrant CXCR4 expression pattern is associated with osteoclastogenesis and tumor growth in MM through its cross talk with various important cell signalling pathways. A deeper insight into understanding of CXCR4 mediated signalling pathways and its role in MM is essential to identify potential therapeutic interventions. The current therapeutic focus is on disrupting the interaction of MM cells with its protective tumor microenvironment where CXCR4 axis plays an essential role. There are still multiple challenges that need to be overcome to target CXCR4 axis more efficiently and to identify novel combination therapies with existing strategies. This review highlights the role of CXCR4 along with its significant interacting partners as a mediator of MM pathogenesis and summarizes the targeted therapies carried out so far.

Ectopic expression of CC chemokine receptor 7 promotes prostate cancer cells metastasis via Notch1 signaling

There currently exists no satisfactory treatment for patients with prostate cancer with local evolution and distant metastasis. Previous studies have confirmed the importance of CC chemokine receptor 7 (CCR7) in the invasion and metastasis of prostate cancer. And increasing evidence prove that Notch1 can play diametrically opposite roles in the development and progression of different tumors. To demonstrate the correlation between CCR7 and Notch1, PC-3 cells were transfected with pcDNA3.1-CCR7 or CCR7 si-RNA, respectively. Then Western blot analysis was used to detect the expressions of Notch1, ERK, P38, JNK, NF-κB, MMP-9, and epithelial-mesenchymal transition (EMT)-related proteins. Moreover, matrigel invasion assays were performed to assess the migratory and invasive activities of PC-3 cells. PcDNA3.1-CCR7 increased the expression of Notch1, phospho-MAPK, phospho-P65, MMP-9, N-cadherin, and Snail in PC-3 cells, but decreased the expression of E-cadherin. PcDNA3.1-CCR7 also promoted the migration and invasion of PC-3 cells. However, CCR7 si-RNA reversed the effect of pcDNA3.1-CCR7 in PC-3 cells. And MAPK and NF-κB pathway inhibitors were used to testify that activation of Notch1 induces EMT through MAPK and NF-κB pathway. All these results indicate that upregulation of Notch1 by CCR7 can accelerate the evolution of EMT and develop the invasion and metastasis in prostate cancer cells by activating MAPK and NF-κB signaling pathways in prostate cancer cells, which provides a new molecular evidence for targeted therapy in metastatic prostate cancer.

Expression of the RAC1, RHOA and CXCR4 proteins and their interaction as risk factors for infiltration to the nipple areola complex in operable breast carcinoma

BACKGROUND

Nipple areola complex (NAC) infiltration in operable breast carcinoma (OBC) is associated with local recurrence. NAC infiltration in OBC suggests that RAC1, RHOA and CXCR4 proteins are risk factors for migration and infiltration of OBC to NAC. This study aims to analyze the expression and interactions of these proteins as risk factors for NAC infiltration in OBC.

MATERIALS AND METHODS

This is an analytic observational cross-sectional study coupled with a categorical comparative study in each 40 subjects of OBC with and without NAC infiltration. The immunohistochemistry performed with a cut-off point based on the result of a receiver operating characteristics (ROC).

RESULTS

RAC1, p < 0.001 with POR 5.76, 95% CI: 2.06-16.08; RHOA, p < 0.001 with POR 7.00, 95% CI: 2.28-21.53; and CXCR4, p = 0.001 with POR 6.33, 95% CI 2.06-19.49. There was an interaction between RAC1 and RHOA (p < 0.001 with POR 17.14, 95% CI: 3.07-125.66); between RAC1 and CXCR4 (p < 0.001 with POR 30.93, 95% CI 3.62-686.89); between RHOA and CXCR4 (p < 0.001 with POR 10.21, 95% CI 2.19-54.17); and between the RAC1, RHOA and CXCR4 proteins (p < 0.001 with POR = 23.69, 95% CI 2.51-544.86).

CONCLUSION

We conclude that the expression of the RAC1, RHOA, and CXCR4 proteins and their interactions play a role as risk factors of NAC infiltration.

Cellular traffic through afferent lymphatic vessels

The lymphatic system has long been known to serve as a highway for migrating leukocytes from peripheral tissue to draining lymph nodes (dLNs) and back to circulation, thereby contributing to the induction of adaptive immunity and immunesurveillance. Lymphatic vessels (LVs) present in peripheral tissues upstream of a first dLN are generally referred to as afferent LVs. In contrast to migration through blood vessels (BVs), the detailed molecular and cellular requirements of cellular traffic through afferent LVs have only recently started to be unraveled. Progress in our ability to track the migration of lymph-borne cell populations, in combination with cutting-edge imaging technologies, nowadays allows the investigation and visualization of lymphatic migration of endogenous leukocytes, both at the population and at the single-cell level. These studies have revealed that leukocyte trafficking through afferent LVs generally follows a step-wise migration pattern, relying on the active interplay of numerous molecules. In this review, we will summarize and discuss current knowledge of cellular traffic through afferent LVs. We will first outline how the structure of the afferent LV network supports leukocyte migration and highlight important molecules involved in the migration of dendritic cells (DCs), T cells and neutrophils, i.e. the most prominent cell types trafficking through afferent LVs. Additionally, we will describe how tumor cells hijack the lymphatic system for their dissemination to draining LNs. Finally, we will summarize and discuss our current understanding of the functional significance as well as the therapeutic implications of cell traffic through afferent LVs.

CXCR4 overexpression is correlated with poor prognosis in colorectal cancer

AIMS

Colorectal cancer threatens human health due to its high mortality resulting from metastatic progression. The expression of C-X-C chemokine receptor type 4 (CXCR4) is absent or low in most healthy tissues but high in various types of tumours. In this study, we aim to determine the prognostic significance of CXCR4 in colorectal cancer.

MAIN METHODS

We retrospectively examined a total of 72 tissue samples, that qRT-PCR and immunohistochemistry were performed to detect the expression of CXCR4 as well as univariate and multivariate analyses were performed to explore the overall survival.

KEY FINDINGS

Our data demonstrated that CXCR4 expression was associated with lymph node metastasis (P = 0.049), histological differentiation (P = 0.01), distant metastasis (P = 0.02) and DNA mismatch repair (MMR) index (P = 0.0002). However, CXCR4 expression was not associated with age, sex, tumour diameter or depth of invasion. Furthermore, both univariate and multivariate analyses confirmed that CXCR4 was an independent factor in predicting unfavourable overall survival (hazard ratio, 0.188; 95% confidence interval, 0.038-0.757).

SIGNIFICANCE

In conclusion, our findings suggest that CXCR4 might contribute to clinical tumour progression and may be a valuable prognostic biomarker in colorectal cancer treatment.

AKIP1 promotes angiogenesis and tumor growth by upregulating CXC-chemokines in cervical cancer cells

Upregulation of A-kinase-interacting protein 1 (AKIP1) has been observed in breast and esophageal cancers, indicating that AKIP1 may be a potent oncogenic protein. However, the role of AKIP1 in cervical cancer still remains unknown. This study aimed to explore the role of AKIP1 in cervical cancer and to investigate the underlying mechanism of AKIP1 in tumor growth. Expression of AKIP1 in cervical cancer cells was determined by qRT-PCR and western blotting. Cell-Light EdU and colony formation assays were used to determine cell proliferation. CXCL1 and CXCL8 proteins were quantified by ELISA kits. Western blotting and qRT-PCR were used to examine the alterations in signaling-related proteins and mRNA, respectively. Endothelial cell tube formation assay was performed to evaluate the effect of AKIP1 on angiogenesis. A BALB/c nude mouse xenograft model was used to evaluate the role of AKIP1 in vivo. Cancer cell proliferation was inhibited and tumor growth and angiogenesis restrained in BALB/c nude mice by suppressing AKIP1 expression in cervical cancer cell lines. In addition, overexpression of AKIP1 in cervical cancer cells elevated the levels of CXCL1, CXCL2, and CXCL8. These three chemokines were not only involved in endothelial tube formation by binding to the endothelial receptor CXCR2, but also in cervical cancer cell proliferation and clone formation, which were induced by overexpression of AKIP1. Furthermore, we found that AKIP1-induced chemokine expression was decreased by an inhibitor of nuclear factor kappa-B kinase subunit β. These results show that AKIP1 is crucial in cervical cancer angiogenesis and growth by elevating the levels of the NF-κB-dependent chemokines CXCL1, CXCL2, and CXCL8.

Targeting the CXCL12/CXCR4 pathway and myeloid cells to improve radiation treatment of locally advanced cervical cancer

Cervical cancer is the fourth most commonly diagnosed cancer and the fourth leading cause of cancer death in women worldwide. Approximately half of cervical cancer patients present with locally advanced disease, for which surgery is not an option. These cases are nonetheless potentially curable with radiotherapy and cisplatin chemotherapy. Unfortunately, some tumours are resistant to treatment, and lymph node and distant recurrences are major problems in patients with advanced disease at diagnosis. New targeted treatments that can overcome treatment resistance and reduce metastases are urgently needed. The CXCL12/CXCR4 chemokine pathway is ubiquitously expressed in many normal tissues and cancers, including cervical cancer. Emerging evidence indicates that it plays a central role in cervical cancer pathogenesis, malignant progression, the development of metastases and radiation treatment response. Pre-clinical studies of standard-of-care fractionated radiotherapy and concurrent weekly cisplatin plus the CXCR4 inhibitor Plerixafor (AMD3100) in patient-derived orthotopic cervical cancer xenografts have shown improved primary tumour response and reduced lymph node metastases with no increase in early or late side effects. These studies have pointed the way forward to future clinical trials of radiotherapy/cisplatin plus Plerixafor or other newly emerging CXCL12 or CXCR4 inhibitors in women with cervical cancer.

Overexpression of CXCR4 promotes invasion and migration of non-small cell lung cancer via EGFR and MMP-9

The aim of the present study was to verify whether overexpression of CXC receptor 4 (CXCR4) promotes the invasion and migration of non-small cell lung cancer (NSCLC) via epidermal growth factor receptor (EGFR) and matrix metallopeptidase-9 (MMP-9), and to detect the association between CXCR4, EGFR and MMP-9. The effects of overexpression of CXCR4 on lung cancer cell functions were investigated by migration and invasion assays. Western blotting and zymograph assays were used to analyze the protein expression levels of EGFR and the production of MMP-9, respectively. Immunohistochemistry was applied to analyze the expression of EGFR, CXCR4 and MMP-9 in NSCLC. Statistical analyses were used to detect the associations among EGFR, CXCR4 and MMP-9 in NSCLC. Finally, survival analyses were performed. CXCR4 overexpression enhanced cell motility and invasion. CXCR4 also promoted expression of EGFR and elevated MMP-9 production. CXCR4, EGFR and MMP-9 were highly expressed in NSCLC, and were not identified as associated with age and sex (P>0.05). However, they were associated with tumor differentiation and lymph node metastasis (P<0.05). CXCR4, EGFR and CXCR4 expression were positively associated with one another in NSCLC (P<0.05). In addition, patients with positive expression of CXCR4, EGFR or MMP-9 in tumors exhibited significantly shorter overall survival compared with those with negative expression (P<0.05). In conclusion, CXCR4 overexpression enhanced cell motility and invasion via EGFR and MMP-9. CXCR4, EGFR and MMP-9 were identified as highly expressed in NSCLC, and there was positive correlation among them.

Biological/pathological functions of the CXCL12/CXCR4/CXCR7 axes in the pathogenesis of bladder cancer

CXC chemokine ligand 12 (CXCL12) is an important member of the CXC subfamily of chemokines, and has been extensively studied in various human body organs and systems, both in physiological and clinical states. Ligation of CXCL12 to CXCR4 and CXCR7 as its receptors on peripheral immune cells gives rise to pleiotropic activities. CXCL12 itself is a highly effective chemoattractant which conservatively attracts lymphocytes and monocytes, whereas there exists no evidence to show attraction for neutrophils. CXCL12 regulates inflammation, neo-vascularization, metastasis, and tumor growth, phenomena which are all pivotally involved in cancer development and further metastasis. Generation and secretion of CXCL12 by stromal cells facilitate attraction of cancer cells, acting through its cognate receptor, CXCR4, which is expressed by both hematopoietic and non-hematopoietic tumor cells. CXCR4 stimulates tumor progression by different mechanisms and is required for metastatic spread to organs where CXCL12 is expressed, thereby allowing tumor cells to access cellular niches, such as the marrow, which favor tumor cell survival and proliferation. It has also been demonstrated that CXCL12 binds to another seven-transmembrane G-protein receptor or G-protein-coupled receptor, namely CXCR7. These studies indicated critical roles for CXCR4 and CXCR7 mediation of tumor metastasis in several types of cancers, suggesting their contributions as biomarkers of tumor behavior as well as potential therapeutic targets. Furthermore, CXCL12 itself has the capability to stimulate survival and growth of neoplastic cells in a paracrine fashion. CXCL12 is a supportive chemokine for tumor neovascularization via attracting endothelial cells to the tumor microenvironment. It has been suggested that elevated protein and mRNA levels of CXCL12/CXCR4/CXCR7 are associated with human bladder cancer (BC). Taken together, mounting evidence suggests a role for CXCR4, CXCR7, and their ligand CXCL12 during the genesis of BC and its further development. However, a better understanding is still required before exploring CXCL12/CXCR4/CXCR7 targeting in the clinic.

Inhibitory effects of FKBP14 on human cervical cancer cells

The FK506-binding protein 14 (FKBP14), which belongs to a subfamily of immunophilins, has been implicated in various biochemical processes. However, its effects on human cervical cancer remain to be elucidated. The present study aimed to determine the exact role of FKBP14 in human cervical cancer cell proliferation, cell cycle progression, apoptosis, invasion and migration. Cell proliferation was measured by Cell Counting Kit‑8 assay. Flow cytometry was conducted to determine the effects of FKBP14 on cell cycle progression and apoptosis. Cell invasion and migration were determined by Transwell assay. The results of the present study demonstrated that silencing FKBP14 expression using short hairpin (sh)RNA suppressed proliferation, invasion and migration of HeLa and C‑33A cells, and also induced apoptosis and cell cycle arrest. Furthermore, silencing FKBP14 expression decreased the protein expression levels of B‑cell lymphoma 2 (Bcl‑2), matrix metalloproteinase (MMP)2 and MMP9, and increased the levels of caspase‑3 and Bcl‑2‑associated X protein in FKBP14 shRNA‑infected HeLa and C‑33A cells. In conclusion, FKBP14 may act as an oncogene through suppressing apoptosis and promoting motility in human cervical carcinogenesis; therefore, it may be considered a potential therapeutic target for the treatment of cervical cancer.

Emerging roles of the CXCL12/CXCR4 axis in pancreatic cancer progression and therapy

Chemokine networks regulate a variety of cellular, physiological, and immune processes. These normal functions can become appropriated by cancer cells to facilitate a more hospitable niche for aberrant cells by enhancing growth, proliferation, and metastasis. This is especially true in pancreatic cancer, where chemokine signaling is a vital component in the development of the supportive tumor microenvironment and the signaling between the cancer cells and surrounding stromal cells. Although expression patterns vary among cancer types, the chemokine receptor CXCR4 has been implicated in nearly every major malignancy and plays a prominent role in pancreatic cancer development and progression. This receptor, in conjunction with its primary chemokine ligand CXCL12, promotes pancreatic cancer development, invasion, and metastasis through the management of the tumor microenvironment via complex crosstalk with other pathways. Thus, CXCR4 likely contributes to the poor prognoses observed in patients afflicted with this malignancy. Recent exploration of combination therapies with CXCR4 antagonists have demonstrated improved outcomes, and abolishing the contribution of this pathway may prove crucial to effectively treat pancreatic cancer at both the primary tumor and metastases.

CCL21/CCR7 interaction promotes cellular migration and invasion via modulation of the MEK/ERK1/2 signaling pathway and correlates with lymphatic metastatic spread and poor prognosis in urinary bladder cancer

Lymph node metastasis in patients with urinary bladder cancer (UBC) is always associated with poor prognosis and is the determinant for tumor staging and the development of treatment regimens; however, its underlying mechanisms remain to be studied. Immunohistochemical staining of tumor sections from 62 UBC patients was performed using CCR7, D2-40 and CD34 antibodies. We showed that increased CCR7 expression was significantly associated with positive lymph node status (P=0.008), pT3-T4 tumor stage (P=0.015), tumor grade (P=0.010) and worse overall survival (OS, P<0.001) and that both CCR7 expression and lymph node metastasis were independent prognostic factors for OS (P=0.031 and P=0.001, respectively) based on multivariate analysis. We found that there was a significant association between MLVD and lymph node status (P=0.006), but this relation was not observed for MVD. Furthermore, we showed that increased CCR7 expression correlated significantly with higher MLVD (P=0.014) and MVD (P=0.002). Wound-healing and Matrigel Transwell assays indicated that activation of CCR7 with CCL21 significantly enhanced the invasion and migration abilities of UM-UC-3 cells, and this enhanced effect was significantly abrogated by CCR7 knockdown using siRNA. Western blot analysis revealed that the phospho-ERK1/2 level was markedly increased when UM-UC-3 cells were treated with CCL21 and significantly decreased when the CCR7 gene was silenced. MEK/ERK1/2 inhibition with PD98059 significantly suppressed the migration and invasion abilities of UM-UC-3 cells and also significantly abrogated the effects of CCL21/CCR7 on cell migration and invasion. Based on these results, we conclude that activation of the CCL21/CCR7 chemoaxis promotes lymph node metastasis of UBC in at least two ways. Firstly, although CCR7 is a promoting factor that induces both lymphangiogenesis and angiogenesis, it may promote lymph node metastasis through its lymphangiogenic effect rather than through its angiogenic effect. Secondly, the CCL21/CCR7 chemoaxis promotes the migration and invasion of UBC cells via the MEK/ERK1/2 signaling pathway rather than the PI3K/AKT pathway.

Association of CXCR4, CCR7, VEGF-C and VEGF-D expression with lymph node metastasis in patients with cervical cancer

OBJECTIVE

We attempted to investigate the expression of CXCR4, CCR7, VEGF-C and VEGF-D in cervical cancer specimens, and the association between CXCR4, CCR7, VEGF-C and VEGF-D expression with the clinicopathological parameters of patients with cervical cancer.

STUDY DESIGN

57 tissue microarrays including 9 normal cervical tissues and 48 cervical cancer tissues were purchased from Biomax. The association between CXCR4, CCR7, VEGF-C and VEGF-D expression with the clinicopathological parameters were evaluated. Then immunohistochemistry was used to assess the expression of CXCR4, CCR7, VEGF-C and VEGF-D in cervical cancer specimens. Finally, Spearman correlations were used for the correlation analyses between CXCR4, CCR7, VEGF-C and VEGF-D.

RESULTS

We revealed that CXCR4 expression was significantly higher in patients with squamous cell carcinomas (P=0.002) and lymph node metastasis (P=0.038), while CCR7 expression was significantly elevated in patients with lymph node metastasis (P=0.037). VEGF-C expression was markedly up-regulated in patients exhibiting FIGO stage II-III tumors (P=0.015) and lymph node metastasis (P=0.038), while VEGF-D expression was obviously increased in patients displaying FIGO stage II-III tumors (P=0.025), squamous carcinomas (P=0.017) and lymph node metastasis (P=0.037). The correlation analysis indicated that CXCR4, CCR7, VEGF-C and VEGF-D expression have a significant correlation to each other.

CONCLUSION

These results suggested that CXCR4, CCR7, VEGF-C and VEGF-D expression might have synergistic effects on the lymph node metastasis in patients with cervical cancer.

Agarose Spot as a Comparative Method for in situ Analysis of Simultaneous Chemotactic Responses to Multiple Chemokines

We describe a novel protocol to quantitatively and simultaneously compare the chemotactic responses of cells towards different chemokines. In this protocol, droplets of agarose gel containing different chemokines are applied onto the surface of a Petri dish, and then immersed under culture medium in which cells are suspended. As chemokine molecules diffuse away from the spot, a transient chemoattractant gradient is established across the spots. Cells expressing the corresponding cognate chemokine receptors migrate against this gradient by crawling under the agarose spots towards their centre. We show that this migration is chemokine-specific; meaning that only cells that express the cognate chemokine cell surface receptor, migrate under the spot containing its corresponding chemokine ligand. Furthermore, we show that migration under the agarose spot can be modulated by selective small molecule antagonists present in the cell culture medium.

Plerixafor Improves Primary Tumor Response and Reduces Metastases in Cervical Cancer Treated with Radio-Chemotherapy

Purpose: There is an important need to improve the effectiveness of radio-chemotherapy (RTCT) for cervical cancer. The CXCL12/CXCR4 pathway can influence RT response by recruiting normal myeloid cells to the tumor microenvironment that in turn can exert radioprotective effects, and may promote metastases. The objective of this study was to explore the efficacy and toxicity of combining RTCT with CXCL12/CXCR4 inhibition in cervical cancer.Experimental Design: CXCR4 expression was measured in 115 patients with cervical cancer. Two primary orthotopic cervical cancer xenografts (OCICx) with different levels of CXCR4 expression were treated with RT (30 Gy: 15 daily fractions) and weekly cisplatin (4 mg/kg), with or without the CXCR4 inhibitor Plerixafor (5 mg/kg/day). The endpoints were tumor growth delay and lymph node metastases. Acute intestinal toxicity was assessed using a crypt cell assay.Results: There was a fivefold variation in CXCR4 mRNA expression in the patient samples, and good correlation between the expression in patients and in the xenografts. The combination of RTCT and Plerixafor produced substantial tumor growth delay and reduced lymph node metastases compared with RTCT alone in both of the xenograft models. There was a trend toward reduced acute intestinal toxicity with the addition of Plerixafor to RTCT. There were no changes in normal organ morphology to suggest increased late toxicity.Conclusions: This study demonstrates that the addition of Plerixafor to standard RTCT improves primary tumor response and reduces metastases in cervical cancer with no increase in toxicity. This combination warrants further investigation in phase I/II clinical trials. Clin Cancer Res; 23(5); 1242-9. ©2016 AACR.

Use of NRP1, a novel biomarker, along with VEGF-C, VEGFR-3, CCR7 and SEMA3E, to predict lymph node metastasis in squamous cell carcinoma of the tongue

Lymph node (LN) metastasis has been suggested as a major prognostic factor for oral cancer. Knockdown of the growth factors and receptors involved in these metastatic mechanisms could significantly reduce LN metastasis and improve the survival of oral cancer patients after treatment. The present study, therefore, aimed to evaluate the expression levels of the following growth factors and receptors in squamous cell carcinoma (SCC) of the tongue: the vascular endothelial growth factor (VEGF)‑C and VEGF‑D, which bind to the cell surface tyrosine kinase receptor VEGF receptor‑3 (VEGFR‑3); C‑C motif chemokine receptor 7 (CCR7); neuropilin (NRP)1 and NRP2; and semaphorin 3E (SEMA3E). Furthermore, we assessed microvessel density (MVD) and lymphatic vessel density (LVD) to demonstrate the correlation between these factors and regional LN metastasis, with respect to the clinicopathological features. Finally, we analyzed the correlation between these proteins and overall or disease‑free survival, in order to demonstrate their prognostic value. Univariate analysis revealed a significant association between LN metastasis and the expression levels of VEGF‑C, VEGFR‑3, CCR7, NRP1, and SEMA3E, as well as LVD, in SCC cells. In contrast, multivariate analysis identified associations between LN metastasis and NRP1 expression, as well as between LN metastasis and LVD; however, no correlation was found between LN metastasis and the expression levels of the other proteins. The expression levels of VEGF‑C, VEGFR‑3, NRP1, and SEMA3E, as well as LVD, were correlated with disease‑free survival time. These results indicate that LN metastasis is associated with poor survival in SCC. This study suggests that NRP1 expression and LVD are independent factors that are likely to predict the risk of LN metastasis in SCC of the tongue, whereas the expression of VEGF‑C, VEGFR‑3, CCR7, and SEMA3E are non‑independent predictive factors.

CCL21/CCR7 Axis Contributed to CD133+ Pancreatic Cancer Stem-Like Cell Metastasis via EMT and Erk/NF-κB Pathway

Background

Tumor metastasis is driven by malignant cells and stromal cell components of the tumor microenvironment. Cancer stem cells (CSCs) are thought to be responsible for metastasis by altering the tumor microenvironment. Epithelial-mesenchymal transition (EMT) processes contribute to specific stages of the metastatic cascade, promoted by cytokines and chemokines secreted by stromal cell components in the tumor microenvironment. C-C chemokine receptor 7 (CCR7) interacts with its ligand, chemokine ligand 21(CCL21), to mediate metastasis in some cancer cells lines. This study investigated the role of CCL21/CCR7 in promoting EMT and metastasis of cluster of differentiation 133⁺ (CD133⁺) pancreatic cancer stem-like cells.

Methods

Panc-1, AsPC-1, and MIA PaCa-2 pancreatic cancer cells were selected because of their aggressive invasive potentials. CCR7 expression levels were examined in total, CD133⁺ and CD133⁻ cell fractions by Immunofluorescence analysis and real time-quantitative polymerase chain reaction (RT-qPCR). The role of CCL21/CCR7 in mediating metastasis and survival of CD133⁺ pancreatic cancer stem-like cells was detected by Transwell assays and flow cytometry, respectively. EMT and lymph node metastasis related markers (E-cadherin, N- cadherin, LYVE-1) were analyzed by western blot. CCR7 expression levels were analyzed by immunohistochemical staining and RT-qPCR in resected tumor tissues, metastatic lymph nodes, normal lymph nodes and adjacent normal tissues from patients with pancreatic carcinoma.

Results

CCR7 expression was significantly increased in CD133⁺ pancreatic cancer stem-like cells, resected pancreatic cancer tissues, and metastatic lymph nodes, compared with CD133⁻ cancer cells, adjacent normal tissues and normal lymph nodes, respectively. CCL21/CCR7 promoted metastasis and survival of CD133⁺ pancreatic cancer stem-like cells and regulated CD133⁺ pancreatic cancer stem-like cells metastasis by modulating EMT and Erk/NF-κB pathway.

Conclusions

These results indicate a specific role for CCL21/CCR7 in promoting EMT and metastasis in CD133⁺ pancreatic cancer stem-like cells. Furthermore the data also indicated the potential importance of developing therapeutic strategies targeting cancer stem-like cells and CCL21/CCR7 for reducing metastasis.

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 chemotactic interaction between CCL21 and its receptor, CCR7, facilitates the progression of pancreatic cancer via induction of angiogenesis and lymphangiogenesis

BACKGROUND

In this study, we report the influence of CCL21 and its receptor, CCR7, on the progression of pancreatic cancer and illuminates the correlation between the CCL21/CCR7 axis and the angiogenesis and lymphangiogenesis of pancreatic adenocarcinoma (PAC).

METHODS

A total of 30 patients with pancreatic cancer was involved in the current study. The expression of CCL21 and CCR7 in cancerous tissues, paracancerous tissues and normal pancreas were investigated using real-time PCR, Western blot and immunohistochemistry, respectively. In addition, we assessed microvessel density (MVD) and microlymphatic vessel density (MLVD) in tumor tissues using immunohistochemistry.

RESULTS

Compared to paracancerous tissues and normal pancreas, CCL21 expression in cancerous tissues was detected at a significantly low level. In contrast, the CCR7 expression was considerably higher in cancerous tissues than in normal pancreas and paracancerous tissues. Additionally, a significant correlation between the expression pattern of the CCL21/CCR7 axis and clinicopathological features, such as lymph node metastasis, was identified. Furthermore, we found that CCL21 expression was significantly associated with MVD but not significantly associated with MLVD, while CCR7 expression was significantly associated with MLVD but not significantly associated with MVD.

CONCLUSIONS

The chemotactic interaction between CCR7 and its ligand, CCL21, may be a critical event during progression in pancreatic cancer, and its underlying mechanism may be induction of angiogenesis and lymphangiogenesis regulated by this chemotactic interaction.

CCR7 mediates the TNF-α-induced lymphatic metastasis of gallbladder cancer through the "ERK1/2 - AP-1" and "JNK - AP-1" pathways

Background

CC-chemokine receptor 7 (CCR7), which plays an important role in cell directional movement, is highly expressed in various cancers and positively related to lymph node metastasis. The inflammatory cytokine tumour necrosis factor (TNF)-α promotes tumour progression and lymph node metastasis in gallbladder cancer (GBC). However, the expression of CCR7 in GBC is unclear, and its role in the TNF-α-induced lymphatic metastasis of GBC requires further research.

Methods

The expression of CCR7 in clinical samples was detected by immunohistochemistry, and the relationship between CCR7 and clinicopathological factors or the TNF-α level of the bile was analyzed. After treatment with various concentrations of TNF-α, CCR7 expression in GBC cell lines was measured by Western blotting. The relative luciferase reporter assay, site-directed mutagenesis and chromatin immunoprecipitation were used to analyze the promoter activity and transcriptional regulation of CCR7. MAPKs inhibitors were used to explore the upstream signalling molecules of AP-1. We established a NOZ cell line stably expressing lentiviral CCR7 shRNA that effectively silenced the expression of CCR7, and to determine the role of TNF-α - CCR7 axis in the migration of GBC cells to the lymphatic system by transwell assays and animal experiments.

Results

CCR7 was highly expressed in GBC samples. Higher expression of CCR7 was associated with American Joint Committee on Cancer (AJCC) staging and lymph node metastasis. Moreover, we found that CCR7 expression in GBC tissue was positively correlated with the levels of TNF-α in the bile, and that TNF-α enhanced the promoter activity and protein expression of CCR7 through the “ERK1/2-AP-1” and “JNK-AP-1” pathways. Finally, we revealed that TNF-α could promote GBC cell migration to lymphatic endothelial cells or lymph nodes through upregulation of CCR7 in vitro and in vivo.

Conclusions

Our study suggests that CCR7 is highly expressed in GBC, and mediates the TNF-α-induced lymphatic metastasis of GBC through the “TNF-α - ERK1/2 - AP-1 - CCR7” and “TNF-α - JNK - AP-1 - CCR7” pathways.

CXCR4 over-expression and survival in cancer: a system review and meta-analysis

C-X-C chemokine receptor 4 (CXCR4) is frequently over-expressed in various types of cancer; many agents against CXCR4 are in clinical development currently despite variable data for the prognostic impact of CXCR4 expression. Here eighty-five studies with a total of 11,032 subjects were included to explore the association between CXCR4 and progression-free survival (PFS) or overall survival (OS) in subjects with cancer. Pooled analysis shows that CXCR4 over-expression is significantly associated with poorer PFS (HR 2.04; 95% CI, 1.72-2.42) and OS (HR=1.94; 95% CI, 1.71-2.20) irrespective of cancer types. Subgroup analysis indicates significant association between CXCR4 and shorter PFS in hematological malignancy, breast cancer, colorectal cancer, esophageal cancer, renal cancer, gynecologic cancer, pancreatic cancer and liver cancer; the prognostic effects remained consistent across age, risk of bias, levels of adjustment, median follow-up period, geographical area, detection methods, publication year and size of studies. CXCR4 over-expression predicts unfavorable OS in hematological malignancy, breast cancer, colorectal cancer, esophageal cancer, head and neck cancer, renal cancer, lung cancer, gynecologic cancer, liver cancer, prostate cancer and gallbladder cancer; these effects were independence of age, levels of adjustment, publication year, detection methods and follow-up period. In conclusion, CXCR4 over-expression is associated with poor prognosis in cancer.

CXCR4 in breast cancer: oncogenic role and therapeutic targeting

Chemokines are 8–12 kDa peptides that function as chemoattractant cytokines and are involved in cell activation, differentiation, and trafficking. Chemokines bind to specific G-protein-coupled seven-span transmembrane receptors. Chemokines play a fundamental role in the regulation of a variety of cellular, physiological, and developmental processes. Their aberrant expression can lead to a variety of human diseases including cancer. C-X-C chemokine receptor type 4 (CXCR4), also known as fusin or CD184, is an alpha-chemokine receptor specific for stromal-derived-factor-1 (SDF-1 also called CXCL12). CXCR4 belongs to the superfamily of the seven transmembrane domain heterotrimeric G protein-coupled receptors and is functionally expressed on the cell surface of various types of cancer cells. CXCR4 also plays a role in the cell proliferation and migration of these cells. Recently, CXCR4 has been reported to play an important role in cell survival, proliferation, migration, as well as metastasis of several cancers including breast cancer. This review is mainly focused on the current knowledge of the oncogenic role and potential drugs that target CXCR4 in breast cancer. Additionally, CXCR4 proangiogenic molecular mechanisms will be reviewed. Strict biunivocal binding affinity and activation of CXCR4/CXCL12 complex make CXCR4 a unique molecular target for prevention and treatment of breast cancer.

A meta-analysis for CXCR4 as a prognostic marker and potential drug target in non-small cell lung cancer

Background

Recent reports have shown that C-X-C chemokine receptor type 4 (CXCR4) is a candidate oncogene in several types of human tumors, including non-small cell lung cancer (NSCLC). However, the correlation between CXCR4 expression and clinicopathological characteristics of NSCLC remains controversial and has not been emphasized. The aim of this study is to quantitatively evaluate the association of CXCR4 expression with the incidence of NSCLC and clinicopathological characteristics by performing a meta-analysis.

Methods

A detailed literature search was carried out for related research publications. Only articles in which CXCR4 expression was detected by immunohistochemical staining were included. Odds ratio (OR) and hazard ratio (HR) with 95% confidence intervals (CIs) were calculated and summarized.

Results

Final analysis of 1,872 NSCLC patients from 19 eligible studies was performed. We observed that CXCR4 expression was significantly higher in NSCLC than in normal lung tissue, based on the pooled OR from ten studies, including 678 NSCLCs and 189 normal lung tissues (OR =16.66, 95% CI =6.94–40.02, P<0.00001). CXCR4 expression was also significantly associated with clinical stages, metastatic status, and overall survival (OS) in NSCLC patients. In addition, CXCR4 mRNA high expression was found to correlate with worse OS of all NSCLC patients followed for 20 years, HR =1.24, P=0.0047.

Conclusion

The present meta-analysis indicated that CXCR4 protein expression is associated with an increased risk and worse survival in NSCLC patients. The aberrant CXCR4 protein and mRNA expression play an important role in the carcinogenesis and metastasis of NSCLC.

NFAT-1, Sp-1, Sp-3, and miR-21: New regulators of chemokine C receptor 7 expression in mature human dendritic cells

The chemokine C receptor 7 (CCR7) is a G-protein-coupled heptahelical receptor (GPCR) that is expressed on a wide variety of cells including memory T cells, B cells, mature dendritic cells, and cancer cells. Activated by its ligands CCL19 or CCL21, CCR7 plays a major role in metastasis of cancer cells. Recent studies demonstrated the role of NF-κB and AP-1 transcription factors in addition to let-7 microRNA in CCR7 expression. Our ChIP assays further show the binding of Sp-1, Sp-3 and NFAT-1 transcription factors to their potential binding sites in the 1Kb promoter region with the later found to inhibit whilst Sp-1, and Sp-3 were found to stimulate CCR7 expression as demonstrated by transfection assays. On the other hand, in addition to the known let-7 regulation of CCR7, we found miR-21 to have a highly conserved target region in CCR7 3'UTR and to be significantly down-regulated during the course of dendritic cell maturation, allowing for high expression of CCR7.

Construction of a CXCL12-KDEL fusion gene to inhibit head and neck squamous cell carcinoma metastasis by intracellular sequestration of CXCR4

The CXCL12-CXCR4 biological axis consisting of the chemotactic factor CXCL12 and its specific receptor CXCR4 plays an important role in oral cancer metastasis. High expression of CXCR4 may help oral squamous cancer cells invade local tissues and metastasize to lymph nodes. No obvious association was observed between CXCL12 expression and lymph node metastasis, suggesting that CXCL12 chemotaxis may only be related to CXCR4 expression on the tumor cell membrane. KDEL can be retained by receptors on the surface of the intracellular endoplasmic reticulum (ER) and also be called an ER retention signal sequence. So we adopted the KDEL sequence in this study to generate a CXCL12-KDEL fusion protein in combination with a traceable E-tag label. As such, CXCL12 was retained in the ER. Specific receptor CXCR4 binds to the CXCL12-KDEL, was also retained in the ER, and was thus prevented from reaching the oral squamous cancer cell surface. We reduced the cell surface level of CXCR4 and called the technique “intracellular sequestration.” By this way, we have finished blocking of CXCL12-CXCR4 biological axis and inhibiting lymph node metastasis of oral carcinoma.

Clinicopathological significance of CXCR4 in non-small cell lung cancer

Background

Emerging evidence indicates that C-X-C chemokine receptor type 4 (CXCR4) is a candidate oncogene in several types of human tumors including non-small cell lung cancer (NSCLC). However, the correlation between CXCR4 expression and clinicopathological characteristics of NSCLC remains unclear. Here, we conducted a meta-analysis to quantitatively evaluate the association of CXCR4 expression with the incidence of NSCLC and clinicopatho-logical characteristics.

Methods

A detailed literature search was made from Medline and Web of Science for related research publications written in English and Chinese. The methodological quality of the studies was also evaluated. Analyses of pooled data were performed. Odds ratio (OR) and hazard ratio (HR) were calculated and summarized.

Results

The final analysis of 1,446 NSCLC patients from 13 eligible studies was performed. We observed that CXCR4 expression was significantly higher in NSCLC than in normal lung tissue from the pooled OR from five studies including 380 NSCLC and 118 normal lung tissue (OR=12.86, 95% confidence interval =3.63–45.59, P<0.0001). CXCR4 expression was not associated with smoking status and type of pathology. However, CXCR4 expression was significantly associated with clinical stages, metastatic status, and overall survival in NSCLC patients.

Conclusion

The results of this meta-analysis suggest that CXCR4 expression is associated with an increased risk and worse survival in NSCLC patients. The aberrant CXCR4 expression plays an important role in the carcinogenesis and metastasis of NSCLC.

FOXP3 suppresses breast cancer metastasis through downregulation of CD44

Forkhead box protein 3 (FOXP3) plays an important role in breast cancer as an X-linked tumor suppressor gene. However, the biological functions and significance of FOXP3 in breast cancer metastasis remain unclear. Here, we find that, clinically, nuclear FOXP3 expression is inversely correlated with breast cancer metastasis. Moreover, we demonstrate that FOXP3 significantly inhibits adhesion, invasion and metastasis of breast cancer cells in vivo and in vitro. In addition, the adhesion molecule CD44 is found to be suppressed by FOXP3 through transcriptome sequence analysis (RNA-seq). A luciferase reporter assay, chromatin immunoprecipitation and electrophoretic mobility shift assay identify CD44 as a direct target of FOXP3. The expression of CD44 is downregulated by FOXP3 in breast cancer cells. Importantly, anti-CD44 antibody reverses the FOXP3 siRNA-induced effects on the breast cancer cells in vitro and FOXP3 expression level in the nucleus of breast cancer cells is inversely correlated with CD44 expression level in clinic breast cancer tissues. Taken together, the results from the present study suggest that FOXP3 is a suppressor of breast cancer metastasis. FOXP3 directly binds to the promoter of CD44 and inhibits its protein expression, thereby suppressing adhesion and invasion of human breast cancer cells. This finding highlights the therapeutic potential of FOXP3-CD44 signaling to inhibit breast cancer metastasis.

Does positive peritoneal cytology not affect the prognosis for stage I uterine endometrial cancer?: the remaining controversy and review of the literature

OBJECTIVE

The objective of this study was to elucidate factors that affect prognosis in patients with stage I endometrial cancer.

METHODS

The study group comprised 265 patients with stage I endometrial cancer treated surgically at either of our facilities between January 1998 and December 2010 (238 patients with negative peritoneal cytology and 27 patients with positive peritoneal cytology). Progression-free survivals were evaluated between the 2 groups, and multivariate analysis was conducted with correlation factors including positive peritoneal cytology, vessel permeation, lymph node dissection, histologic diagnosis, age at diagnosis, adjuvant chemotherapy, and the depth of myometrial invasion.

RESULTS

Disease-free survival was significantly poorer for patients with positive peritoneal cytology than those with negative peritoneal cytology on stage I disease (P = 0.000). The stratified log-rank test with vessel permeation shows the similar results. By univariate Cox model, positive peritoneal cytology, vessel permeation, and systemic lymph node dissection at surgery are significant factors on stage I endometrial cancer.

CONCLUSIONS

Although this is a small-scale preliminary study with adjustment of other factors, positive peritoneal cytology can contribute to the risk of progression-free survival in patients with stage I endometrial cancer.