Expression of the chemokine receptor CCR7 in prostate cancer presenting with generalized lymphadenopathy: report of a case, review of the literature, and analysis of chemokine receptor expression

Chemokines and cytokines: Axis and allies in prostate cancer pathogenesis

Chemokines are recognized as the major contributor to various tumorigenesis, tumor heterogeneity, and failures of current cancer therapies. The tumor microenvironment (TME) is enriched with chemokines and cytokines and plays a pivotal role in cancer progression. Chronic inflammation is also considered an instructive process of cancer progression, where chemokines are spatiotemporally secreted by malignant cells and leukocyte subtypes that initiate cell trafficking into the TME. In various cancers, prostate cancer (PCa) is reported as one of the leading cancers in the worldwide male population. The chemokines-mediated signaling pathways are intensively involved in PCa progression and metastasis. Emerging evidence suggests that chemokines and cytokines are responsible for the pleiotropic actions in cancer, including the growth, angiogenesis, endothelial mesenchymal transition, leukocyte infiltration, and hormone escape for advanced PCa and therapy resistance. Chemokine's system and immune cells represent a promising target to suppress tumorigenic environments and serve as potential therapy/immunotherapy for the PCa. In this review, an attempt has been made to shed light on the alteration of chemokine and cytokine profiles during PCa progression and metastasis. We also discussed the recent findings of the diverse molecular signaling of these circulating chemokines and their corresponding receptors that could become future targets for therapeutic management of PCa.

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.

Left axillary lymphadenopathy as initial presentation of metastatic prostate cancer: A rare case report

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Theoretically, prostate cancer can spread to any part of the body.

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Metastasis to axillary lymph node in a patient with normal urologic examination is rare.

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It may delay the diagnosis.

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A high suspicion index is essential in males presenting with symptoms suggestive of chest and abdominal-pelvic cancer.

Introduction and importance

Advanced prostate cancer often presents with lower urinary tract symptoms together with features of cancer on digital rectal examination. The commonest sites of metastasis include bone, liver and lungs. Metastasis to axillary lymph nodes is extremely unusual particularly as initial presentation of the disease.

Case presentation

We report an atypical case of a 40-year male patient presented with left axillary mass and normal initial urological evaluation. Histopathology and immunohistochemistry of the biopsies from the axillary mass and prostate confirmed the diagnosis of prostate adenocarcinoma. The patient declined anti-androgen monotherapy treatment and succumbed two months after establishment of the diagnosis.

Clinical discussion

Prostate cancer contributes significantly to the overall global cancer burden. Lymphatic metastasis to axillary lymph nodes is a very rare manifestation of prostate cancer and only a few cases have been reported in the literature. Therefore, clinical diagnosis of patients presenting with axillary lymphadenopathy may cause diagnostic delay. Careful physical and imaging examinations combined with pathological analysis are essential in the diagnosis of advanced prostate cancer with unusual presentation.

Conclusion

In theory, prostate cancer can cause metastatic spread to any part of the body. However, metastasis to axillary nodes has not been frequently noticed. Our report highlights the importance of considering prostate cancer among differential diagnoses in Afro-Caribbean males presenting with symptoms suggestive of chest and abdomino-pelvic cancer.

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.

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.

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.

Association between potentially functional polymorphisms of chemokine family members and the survival of esophageal cancer patients in a Chinese population

Background: The chemokine family plays an important role in the growth, invasion, and metastasis of tumors. However, most studies have only focused on a few genes or a few gene loci, and thus could not reveal the associations between functional polymorphisms of chemokine family members and tumor progression. This study aimed to determine the associations between single nucleotide polymorphisms (SNPs) of chemokine family members and the prognosis of esophageal cancer (EC).

Methods: The Cox risk proportional model and log-rank test were used to analyze the associations of 16 potentially functional SNPs in 13 genes from the chemokine family with the survival of 729 Chinese patients with EC.

Results: Prognostic analysis on the 16 SNPs showed that different genotypes of 5 SNPs were associated with patients’ survival and the risk of death. Multivariate Cox regression analysis showed that the risk of death was higher in CCL26rs2302009 genotype A/C carriers than in A/A carriers and it was also higher in CX3CL1rs2239352 genotype T/T carriers than in C/C carriers. Stepwise Cox regression analysis showed that CCL26rs2302009 genotype A/C was an independent prognostic factor of EC, and its association with increased risk of death was stronger in patients who were ≤60 years old, female, with tumors located in the middle part of esophagus, with undifferentiated or poorly differentiated tumors, with early-stage pathologic type disease, with the longest diameter of tumor ≤5cm than in their counterparts.

Conclusion: These findings suggest that CCL26rs2302009 may be a candidate biomarker for EC and its effect on death risk are associated with the histological grade, pathologic type, and the longest diameter of tumor.

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.

miR-199a-5p suppresses human bladder cancer cell metastasis by targeting CCR7

Background

C-C chemokine receptor type 7 (CCR7) overexpression correlated with lymphatic metastasis and poor prognosis is a major obstacle to bladder cancer treatment. Recent studies have revealed that miR-199a-5p was significantly abnormal expressed in several solid tumors and functioned as oncogene or tumor suppressor. This study was aimed to further investigate the effects of miR-199a-5p on the cell metastasis mediated by CCR7 in bladder cancer.

Methods

Quantitative Real Time PCR (qRT-PCR) was firstly performed to identified the expression of miR-199a-5p and CCR7 in human bladder cancer samples and cell lines. Following that, the effects of miR-199a-5p on cell migratory and invasive activities were assessed by wound healing and Matrigel invasion assays, respectively. Finally, luciferase reporter assay and western blot were employed to investigate whether CCR7 could directly interact with miR-199a-5p.

Results

miR-199a-5p downregulation and CCR7 upregulation were firstly observed in bladder cancer samples and cell lines. In addition, both miR-199a-5p downregulation and CCR7 upregulation were significantly involved in bladder cancer clinicopathological features. Moreover, overexpression of miR-199a-5p could inhibit baldder cancer cell migration and invasion. miR-199a-5p was confirmed to be able to target the 3′ untranslated region (UTR) of CCR7 and regulate the expression of CCR7, Matrix metalloproteinases 9 (MMP-9) and Epithelial-Mesenchymal Transition (EMT)-related proteins.

Conclusion

Our findings added newer insights into the multifaceted role played by miR-199a-5p/CCR7 in bladder cancer, prompting for the first time this miRNA/chemokine axis that regulates cell metastasis. The results strongly supported miR-199a-5p as a potential therapeutic agent and diagnostic marker of bladder cancer.

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

Background

CCR7 and MUC1 are correlated with lymph node metastasis in ESCC, but the role of MUC1 in the CCR7-induced lymphatic metastasis and the underlying molecular mechanism is still unclear.

Methods

The expression of CCR7 and MUC1 was detected in the ESCC samples by IHC, and the clinical significance of CCR7 and MUC1 in ESCC was analyzed. The expression of CCR7 and MUC1 in ESCC cell lines was detected by qRT-PCR and western blot. The effect of CCL21 on the migration and invasion of ESCC cells was determined by transwell assay. The activity of MUC1 promoter was determined by luciferase reporter assay. The activation of Erk, Akt and Sp1 was detected by western blot and the binding of Sp1 to the MUC1 promoter was determined by ChIP.

Results

The co-expression of CCR7 and MUC1 was detected in 153 ESCC samples by IHC, and both were correlated with lymph node metastasis, regional lymphatic recurrence and poor prognosis. Correspondingly, increasing levels of MUC1 mRNA and protein were detected in the ESCC cell lines KYSE410 and Eca9706 after treatment with CCL21 in a time- and dose-dependent manner. Furthermore, silencing MUC1 could remarkably suppress the invasion and migration of ESCC cells induced by CCL21. Moreover, heterologous CCR7 promoted the invasion and migration of KYSE150 and up-regulated MUC1 expression. Increasing levels of activated ERK1/2 and Akt were detected in KYSE410 after treating the cells with CCL21, and inhibiting the activation of ERK1/2 but not Akt caused the increased transcription of MUC1. Finally, the phosphorylation of Sp1 induced by ERK1/2 and subsequent increases in the binding of Sp1 to the muc1 promoter at −99/−90 were confirmed to cause the up-regulation of MUC1 induced by CCL21-CCR7.

Conclusions

Our findings suggested that MUC1 plays an important role in CCL21-CCR7-induced lymphatic metastasis and may serve as a therapeutic target in ESCC.

CCL21/CCR7 enhances the proliferation, migration, and invasion of human bladder cancer T24 cells

Objective

To investigate the effects of CCL21/CCR7 on the proliferation, migration, and invasion of T24 cells and the possible associated mechanisms: expression of MMP-2 and MMP-9, and regulation of BCL-2 and BAX proteins.

Methods

T24 cells received corresponding treatments including vehicle control, antibody (20ng/mL CCR7 antibody and 50 ng/ml CCL21), and 50, 100, and 200 ng/ml CCL21. Proliferation was evaluated by MTT assay; cell migration and invasion were assayed using a transwell chamber. Cell apoptosis was induced by Adriamycin (ADM). The rate of cell apoptosis was examined by flow cytometry using annexin V-FITC/PI staining. Western-blot was used to analyze MMP-2 and MMP-9 and BCL-2 and BAX proteins.

Results

CCL21 promoted T24 cell proliferation in concentration-dependent manner with that 200 ng/mL induced the largest amount of proliferation. Significant differences of cell migration were found between CCL21treatment groups and the control group in both the migration and invasion studies (P < 0.001 for all). The expressions of MMP-2 and MMP-9 proteins were significantly increased after CCL21 treatment (p < 0.05 for all). Protein expression of Bcl-21 follows an ascending trend while the expression of Bax follows a descending trend as the concentration of CCL21 increases. No difference was found between the control group and antibody group for all assessments.

Conclusion

CCL21/CCR7 promoted T24 cell proliferation and enhanced its migration and invasion via the increased expression of MMP-2 and MMP-9. CCL21/CCR7 had antiapoptotic activities on T24 cells via regulation of Bcl-2 and Bax proteins. CCL21/CCR7 may promote bladder cancer development and metastasis.

Rituximab for treating CD20+ prostate cancer with generalized lymphadenopathy: a case report and review of the literature

A role for CD20 antibodies in treating prostate cancer has not yet been established. We report a case of advanced prostate cancer presenting with generalized lymphadenopathy that expressed CCR7 and CD20. CCR7 expression in prostate cancer has been previously reported only once; the expression of CD20 has not been reported before. Rituximab therapy was initiated in this case and resulted in a significant biochemical response. This unique metastatic and biochemical pattern may signify a distinct subtype of prostate cancer that may be amenable to treatment with anti-CD20 antibodies.

Prostate cancer chemoprevention in men of African descent: current state of the art and opportunities for future research

Prostate cancer is the most frequently diagnosed malignancy in men. However, African American/Black men are 60 % more likely to be diagnosed with and 2.4 times more likely to die from prostate cancer, compared to Non-Hispanic White men. Despite the increased burden of this malignancy, no evidence-based recommendation regarding prostate cancer screening exists for the high-risk population. Moreover, in addition to screening and detection, African American men may constitute a prime population for chemoprevention. Early detection and chemoprevention may thus represent an integral part of prostate cancer control in this population. Importantly, recent research has elucidated biological differences in the prostate tumors of African American compared to European American men. The latter may enable a more favorable response in African American men to specific chemopreventive agents that target relevant signal transduction pathways. Based on this evolving evidence, the aims of this review are threefold. First, we aim to summarize the biological differences that were reported in the prostate tumors of African American and European American men. Second, we will review the single- and multi-target chemopreventive agents placing specific emphasis on the pathways implicated in prostate carcinogenesis. And lastly, we will discuss the most promising nutraceutical chemopreventive compounds. Our review underscores the promise of chemoprevention in prostate cancer control, as well as provides justification for further investment in this filed to ultimately reduce prostate cancer morbidity and mortality in this high-risk population of African American men.

Generalized lymphadenopathy: physical examination revisited

We report an unusual case of prostatic carcinoma in a 47-year-old male that presented with generalized lymphadenopathy. He initially presented with metastatic lymphadenopathy. He underwent a battery of investigations to find the primary site of origin but to no avail. Thereafter, a complete and diligent physical examination revealed a hard and irregular normal-sized prostrate which was later confirmed as the primary site of tumor. This case report reiterates the significance of a precise and complete physical examination that may prove vital in avoiding superfluous expensive investigations and a delay in diagnosis.

Effect of CCR7, CXCR4 and VEGF-C on the lymph node metastasis of human pancreatic ductal adenocarcinoma

The aim of the present study was to investigate the association between the expression of chemokine receptors CCR7 and CXCR4 and vascular endothelial growth factor (VEGF)-C and the lymph node metastasis of pancreatic ductal adenocarcinoma (PDAC). The mRNA transcription levels of CCR7, CXCR4 and VEGF-C were measured in 24 specimens by real-time reverse transcription (RT)-PCR, while the protein expression levels were measured in 65 specimens by immuohistochemistry. Professional software for pathological image manipulation (Image Pro Plus 6.0) was used to quantitate the results of the immunohistochemical staining. The mRNA and protein expression levels of CCR7, CXCR4 and VEGF-C were all significantly higher in the cancer samples compared with those in the adjacent normal tissue. The CCR7 and VEGF-C mRNA and protein expression levels were significantly higher in the patients with cancer types exhibiting lymph node metastasis and an advanced International Union Against Cancer (UICC) stage (P<0.05). The greater the number of metastatic lymph nodes, the higher the levels of CCR7 expression (P<0.05). There was a significant positive linear correlation between the mRNA and protein expression levels of CCR7 and VEGF-C (P<0.05). The mRNA and protein expression levels of CXCR4 were not correlated with the lymph node metastasis (P>0.05), however the strong positive expression of CCR7 and VEGF-C was significantly associated with the lymph node metastasis of PDAC.

Chemokines and chemokine receptors as promoters of prostate cancer growth and progression

Prostate cancer (CaP) is estimated to be first in incidence among cancers, with more than 240,000 new cases in 2012 in the United States. Chemokines and their receptors provide survival, proliferation, and invasion characteristics to CaP cells in both primary sites of cancer and metastatic locations. The emerging data demonstrate that many chemokines and their receptors are involved in the multistep process of CaP, leading to metastasis, and, further, that these factors act cooperatively to enhance other mechanisms of tumor cell survival, growth, and metastasis. Changes of chemokine receptor cohorts may be necessary to activate tumor-promoting signals. Chemokine receptors can activate downstream effectors, such as mitogen-activated protein kinases, by complex mechanisms of ligand-dependent activation of cryptic growth factors; guanosine triphosphate-binding, protein-coupled activation of survival kinases; or transactivation of other receptors such as ErbB family members. We describe vanguard research in which more than the classic view of chemokine receptor biology was clarified. Control of chemokines and inhibition of their receptor activation may add critical tools to reduce tumor growth, especially in chemo-hormonal refractory CaP that is both currently incurable and the most aggressive form of the disease, accounting for most of the more than 28,000 annual deaths.

Primary lymphomas of the prostate: two case reports and a review of the literature

Introduction

Non-Hodgkin lymphoma (NHL) is a common disease, but primary lymphoma of the prostate is rare.

Material and methods

Here we present two cases of primary NHL of the prostate and a review of the relevant literature.

Results

Both of them had no abnormal lymph node or hepatolienal enlargement. The first case underwent prostatic biopsy which indicated that it was NHL. The patient underwent combination chemotherapy three times, then a radical cystoprostatectomy. In the second case, the prostatic biopsy was not helpful for diagnosis. Therefore a radical prostatectomy was performed before the proper chemotherapy been given. He died half a year later because of a cerebrovascular accident.

Conclusions

We think it is difficult to get an accurate early diagnosis when the lymphoma occurs only in the prostate. Even the prostatic biopsy could not provide clear evidence. Early and appropriate treatment can extend the survival time and improve the quality of life.

Superior vena cava syndrome as a presentation of metastatic prostate cancer

Superior vena cava (SVC) syndrome is an uncommon complication of malignant disease caused by the obstruction of venous blood flow in the SVC. When present, a diagnosis of lung cancer or lymphoma will be made in approximately 95% of cases. Although other malignant diseases are occasionally associated with SVC, its occurrence in patients with prostate cancer is rare. We present a case of a patient presenting with SVC obstruction who was subsequently diagnosed with prostate adenocarcinoma. The patient has been successfully treated with GnRH agonist. This case reflects the importance of a full clinical assessment and pathological confirmation of suspected tumour prior to treatment.

Molecular networks that regulate cancer metastasis

Tumor metastases are responsible for approximately 90% of all cancer-related deaths. Although many patients can be cured, in the US and UK, cancer still causes 730,000 deaths every year, and it is second only to cardiovascular disease as a cause of death. The functional roles of many critical players involved in metastasis have been delineated in great detail in recent years, due to the draft of the human genome and to many associated discoveries. Here, we address several genetic events and critical factors that define the metastatic phenotype acquired during tumorigenesis. This involves molecular networks that promote local cancer-cell invasion, single-cell invasion, formation of the metastatic microenvironment of primary tumors, intravasation, lymphogenic metastasis, extravasation, and metastatic outgrowth. Altogether, these functional networks of molecules contribute to the development of a selective environment that promotes the seeding and malignant progression of tumorigenic cells in distant organs. We include here candidate target proteins and signaling pathways that are now under clinical investigation. Although many of these trials are still ongoing, they provide the basis for the development of new aspects in the treatment of metastatic cancers, which involves inhibition of these proteins and their molecular networks.

Clinical significance of CXCR4 and CCR7 expression in Barrett's esophagus, esophageal adenocarcinoma and esophageal squamous cell carcinoma

AIM: To detect the expression of CXC chemokine receptor 4 (CXCR4) and CC chemokine receptor 7 (CCR7) in normal esophageal mucosa, Barrett's esophagus (BE), esophageal adenocarcinoma (EADC), and esophageal squamous cell carcinoma (ESCC), and to investigate their clinical significance.

METHODS: The expression of CXCR4 and CCR7 in 56 normal esophageal mucosal specimens, 80 BE specimens (including 22 cases of BE with multifocal atypical hyperplasia), 25 EADC specimens, and 48 ESCC specimens was examined by immunohistochemistry. The expression levels of CXCR4 and CCR7 were then quantified and analyzed statistically.

RESULTS: The positive expression rates of CXCR4 and CCR7 in BE, EADC and ESCC were significantly higher than those in normal esophageal mucosa (CXCR4: 78.75%, 68.00%, 83.33% vs 39.29%; CCR7: 60.00%, 60.00%, 58.33% vs 30.36%; all P< 0.01). However, there were no significant differences in the positive expression rates of CXCR4 and CCR7 among BE, EADC and ESCC. The positive expression rates of CXCR4 were significantly higher than those of CCR7 in both BE and ESCC (P < 0.05 and 0.01). CXCR4 and CCR7 expression was not associated with gender, age, and lesion site in BE, EADC and ESCC, but correlated with tumor differentiation and lymph node metastasis in EADC (both P < 0.05) and TNM stage, lymph node metastasis, and differentiation in ESCC (all P < 0.05). A significant correlation was noted between CXCR4 and CCR7 expression in BE and EADC (r = 0.262, 0.490), but not in ESCC (r = 0.076).

CONCLUSION: Combined detection of CXCR4 and CCR7 expression may contribute to more accurate diagnosis of BE, EADC and ESCC. High expression levels of CXCR4 and CCR7 can be used as important parameters for evaluating tumor invasion and metastasis in both EADC and ESCC.

Chemotrap-1: an engineered soluble receptor that blocks chemokine-induced migration of metastatic cancer cells in vivo

Cancer and dendritic cells recognize and migrate toward chemokines secreted from lymphatics and use this mechanism to invade the lymphatic system, and cancer cells metastasize through it. The lymphatic-secreted chemokine ligand CCL21 has been identified as a key regulatory molecule in the switch to a metastatic phenotype in melanoma and breast cancer cells. However, it is not known whether CCL21 inhibition is a potential therapeutic strategy for inhibition of metastasis. Here, we describe an engineered CCL21-soluble inhibitor, Chemotrap-1, which inhibits migration of metastatic melanoma cells in vivo. Two-hybrid, pull-down, and coimmunoprecipitation assays allowed us to identify a naturally occurring human zinc finger protein with CCL21 chemokine-binding properties. Further analyses revealed a short peptide (∼70 amino acids), with a predicted coiled-coil structure, which is sufficient for association with CCL21. This CCL21 chemokine-binding peptide was then fused to the Fc region of human IgG1 to generate Chemotrap-1, a human chemokine-binding Fc fusion protein. Surface plasmon resonance and chemotaxis assays showed that Chemotrap-1 binds CCL21 and inhibits CCL21-induced migration of melanoma cells in vitro with subnanomolar affinity. In addition, Chemotrap-1 blocked migration of melanoma cells toward lymphatic endothelial cells in vitro and in vivo. Finally, Chemotrap-1 strongly reduced lymphatic invasion, tracking, and metastasis of CCR7-expressing melanoma cells in vivo. Together, these results show that CCL21 chemokine inhibition by Chemotrap-1 is a potential therapeutic strategy for metastasis and provide further support for the hypothesis that lymphatic-mediated metastasis is a chemokine-dependent process.

Clinical and biological significance of CXCR5 expressed by prostate cancer specimens and cell lines

Chemokines and chemokine receptors have been shown to be involved in metastatic process of prostate cancer (PCa). In this study, we show primary PCa tissues and cell lines (LNCaP and PC3) express CXCR5, a specific chemokine receptor for CXCL13. Expression of CXCR5 was significantly higher (p < 0.001) in PCa cases than compared to normal match (NM) tissues. CXCR5 intensity correlated (R(2) = 0.97) with Gleason score. While prostate tumor tissues with Gleason scores >or= 7, displayed predominantly nuclear CXCR5 expression patterns, PCa specimens with Gleason scores <or= 6 showed predominantly membrane and cytoplasmic expression patterns that were comparable to benign prostatic hyperplasia (BPH). Similar to tissue expression, PCa cell lines expressed significantly more CXCR5 than normal prostatic epithelial cells (PrECs), and CXCR5 expression was distributed among intracellular and extracellular compartments. Functional in vitro assays showed higher migratory and invasive potentials toward CXCL13, an effect that was mediated by CXCR5. In both PCa cell lines, CXCL13 treatment increased the expression of collagenase-1 or matrix metalloproteinase-1 (MMP-1), collagenase-3 (MMP-13), stromelysin-1 (MMP-3), stromelysin-2 (MMP-10) and stromelysin-3 (MMP-11). These data demonstrate the clinical and biological relevance of the CXCL13-CXCR5 pathway and its role in PCa cell invasion and migration.

Serum CXCL13 positively correlates with prostatic disease, prostate-specific antigen and mediates prostate cancer cell invasion, integrin clustering and cell adhesion

Chemokines and their corresponding receptor interactions have been shown to be involved in prostate cancer (PCa) progression and organ-specific metastasis. We have recently shown that PCa cell lines and primary prostate tumors express CXCR5, which correlates with PCa grade. In this study, we present the first evidence that CXCL13, the only ligand for CXCR5, and IL-6 were significantly elevated in PCa patient serum compared to serum from subjects with benign prostatic hyperplasia (BPH), or high-grade prostatic intraepithelial neoplasia (HGPIN) as well as normal healthy donors (NHD). Serum CXCL13 levels significantly (p<0.0001) correlated with serum prostate-specific antigen (PSA), whereas serum IL-6 levels significantly (p<0.0003) correlated with CXCL13 serum levels. CXCL13 was found to be a better predictor of PCa than PSA. CXCL13 was highly expressed by human bone marrow endothelial (HBME) cells and osteoblasts (OBs), but not osteoclasts (OCs), following treatment with physiologically relevant levels of interleukin-6 (IL-6). We further demonstrate that CXCL13, produced by IL-6-treated HBME cells, was able to induce PCa cell invasion in a CXCR5-dependent manner. CXCL13-mediated PCa cell adhesion to HBME cells and alpha(v)beta(3)-integrin clustering was abrogated by CXCR5 blockade. These results demonstrate that the CXCL13-CXCR5 axis is significantly associated with PCa progression.

Aberrant expression of chemokine receptor CXCR4 in gastrointestinal cancer tissues and cancer cell lines

AIM: To determine the expression status of chemokine receptor CXCR4 in gastrointestinal cancer and to explore its role in gastrointestinal carcinogenesis.

METHODS: Real-time PCR was used to detect mRNA expression of CXCR4 in gastrointestinal cancer samples. Reverse-transcription PCR (RT-PCR) and Western blot were used to determine the expression of CXCR4 in gastrointestinal cancer cell lines.

RESULTS: Level of CXCR4 mRNA was significantly higher in 24 colorectal cancer samples than in matched normal tissues (P < 0.001). Level of CXCR4 mRNA was also significantly higher in 30 gastric cancer samples than in matched normal tissues (P < 0.001). Both CXCR4 mRNA and CXCR4 protein were expressed strongly in colon cell lines HT-29 and SW-480, and gastric cell lines SGC-7901 and AGS. CXCR4 expression was correlated significantly with staging and lymph node metastasis in gastric cancers (P = 0.01 and P = 0.02, respectively).

CONCLUSION: CXCR4 is over-expressed in gastrointestinal cancers, and plays a role in gastrointestinal carcinogenesis.

Prostate Adenocarcinoma Presenting with Supraclavicular Node Enlargement: Report of a Case

This report describes a case of prostate adenocarcinoma presenting with supraclavicular adenopathy and deep venous thrombosis in the ipsilateral arm. Biopsy revealed the enlarged node to be an undifferentiated adenocarcinoma of unknown origin, while CT scan evidenced widespread adenopathies. Because of the increase in serum PSA, the immunohistochemical staining of the biopsy specimen was reviewed and strong positivity for PSA suggested a prostatic origin. We emphasize the importance of PSA immunohistochemistry and serum PSA level monitoring in men presenting with carcinoma of undetermined origin and generalized lymphadenopathies.

Aberrant expression of chemokine receptor 7 in colorectal cancer

AIM: To determine expression level of chemokine receptor 7 (CCR7) and explore its role in colorectal tumor pathogenesis.

METHODS: Immunohistochemistry was used to detect CCR7 protein in specimens. Expression of CCR7 mRNA was determined using reverse transcription PCR (RT-PCR). And Western blotting was used to detect CCR7 protein in colon cancer cells.

RESULTS: CCR7 mRNA expression was found in 45 colorectal cancer specimens and 12 cancer-adjacent normal tissues (χ² = 34.44, P < 0.01). CCR7 protein expression was found in 34 colorectal cancer specimens and 6 cancer-adjacent normal tissues (χ² = 28.51, P < 0.01). CCR7 mRNA and protein were expressed highly in colon cancer cell line SW-480, but lowly in HT-29.

CONCLUSION: CCR7 is involved in colorectal cancer pathogenesis and its expression in metastasis.

G-protein coupled chemoattractant receptors and cancer

Chemoattractant receptors are a group of seven transmembrane, G protein coupled receptors (GPCRs). They were initially identified mainly on leukocytes to mediate cell migration in response to pathogen or host-derived chemotactic factors. During the past decade, chemoattractant GPCRs have been discovered not only to mediate leukocyte chemotaxis thus promoting innate and adaptive host immune responses, but also to play essential roles in development, homeostasis, HIV infection, angiogenesis and wound healing. A growing body of evidence further indicates that chemoattractant GPCRs contribute to tumor growth, invasion, angiogenesis/angiostasis and metastasis. The diverse properties of GPCRs in the progression of malignant tumors have attracted intense interest in their potential as novel anti-tumor pharmacological targets.

Autologous chemotaxis as a mechanism of tumor cell homing to lymphatics via interstitial flow and autocrine CCR7 signaling

CCR7 is implicated in lymph node metastasis of cancer, but its role is obscure. We report a mechanism explaining how interstitial flow caused by lymphatic drainage directs tumor cell migration by autocrine CCR7 signaling. Under static conditions, lymphatic endothelium induced CCR7-dependent chemotaxis of tumor cells through 3D matrices. However, interstitial flow induced strong increases in tumor cell migration that were also CCR7 dependent, but lymphatic independent. This autologous chemotaxis correlated with metastatic potential in four cell lines and was verified by visualizing directional polarization of cells in the flow direction. Computational modeling revealed that transcellular gradients of CCR7 ligand were created under flow to drive this response. This illustrates how tumor cells may be guided to lymphatics during metastasis.

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

BACKGROUND

The chemokine receptors CXCR4 and CCR7 have been suggested to play an important role in cancer invasion and metastasis. The expression of these receptors in human cervical cancer, however, has seldom been characterized.

PATIENTS AND METHODS

We investigated the expression of CXCR4 and CCR7 in cervical cancer specimens and determined the association between their expression and the clinicopathological features observed, including patient outcome.

RESULTS

CXCR4 expression was significantly higher in elderly patients (P=0.025); it was also significantly increased in patients with cancers displaying large tumor size (P=0.010), deep stromal invasion (P=0.0004), lymph-vascular space involvement (P=0.0002), or lymph node metastasis (P<0.0001). CCR7 expression was significantly higher in cases of squamous cell carcinomas (P=0.010) and in patients with cancers showing large tumor size (P<0.0001), deep stromal invasion (P<0.0001), vaginal invasion (P=0.047), lymph-vascular space involvement (P=0.012), or lymph node metastasis (P<0.0001). Logistic regression analysis revealed that deep stromal invasion (P=0.017) and CXCR4 (P=0.016) and CCR7 (P=0.022) expression were independent factors that influenced pelvic lymph node metastasis. The disease-free survival and overall survival (OS) rates of patients exhibiting both CXCR4 and CCR7 expression were significantly reduced (P<0.0001). In addition, the expression of both CXCR4 and CCR7 was an independent prognostic factor for OS (95% confidence interval=1.03-17.86; P=0.046).

CONCLUSIONS

CXCR4 and CCR7 expression may be associated with lymph node metastasis; moreover, the expression of these receptors can serve as an indicator of poor prognosis in patients with cervical cancer.