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

CXCR1 Expression in MDA-PCa-2b Cell Upregulates ITM2A to Inhibit Tumor Growth

BACKGROUND

Chemokines, along with their receptors, exert critical roles in tumor development and progression. In prostate cancer (PCa), interleukin-8 (IL-8/CXCL8) was shown to enhance angiogenesis, proliferation, and metastasis. CXCL8 activates two receptors, CXCR1 and CXCR2. While CXCR2 expression was shown to promote PCa growth and metastasis, the role of CXCR1 remains unclear.

METHODS

In this study, we stably expressed CXCR1 and, as control, CXCR2 in the androgen-dependent PCa cell line MDA-PCa-2b to evaluate the effect of CXCR1 in tumor development.

RESULTS

MDA-PCa-2b-CXCR1 cells showed decreased cell migration, protein kinase-B (AKT) activation, prostate-specific antigen (PSA) expression, cell proliferation, and tumor development in nude mice, relative to MDA-PCa-2b-Vec and MDA-PCa-2b-CXCR2 cells. MDA-PCa-2b-CXCR1 cells also displayed a significant transition to mesenchymal phenotypes as characterized by decreased E-cadherin expression and a corresponding increased level of N-cadherin and vimentin expression. RNA-seq and Western blot analysis revealed a significant increase in the tumor suppressor integral membrane protein 2A (ITM2A) expression in MDA-PCa-2b-CXCR1 compared to control cells. In prostate adenocarcinoma tissue, ITM2A expression was also shown to be downregulated relative to a normal prostate. Interestingly, the overexpression of ITM2A in MDA-PCa-2b cells (MDA-PCa-2b-ITM2A-GFP) inhibited tumor growth similar to that of MDA-PCa-2b-CXCR1.

CONCLUSIONS

Taken together, the data suggest that CXCR1 expression in MDA-PCa-2b cells may upregulate ITM2A to abrogate tumor development.

E3 ubiquitin ligase HECW2: a promising target for tumour therapy

Ubiquitination is a prevalent post-translational modification that plays a crucial role in a wide range of pathophysiological processes, including cell proliferation, apoptosis, autophagy, immune response, and DNA damage repair. Among the enzymes involved in ubiquitination, E3 ubiquitin ligases are particularly significant, serving as key regulators of numerous diseases, including tumours. This review focuses on HECW2 (HECT, C2, and WW domain-containing E3 ubiquitin protein ligase 2, also known as NEDL2), providing a comprehensive overview of its interactors and its pathological roles in tumorous cancer and other diseases. The insights gained from this review may contribute to the development of novel treatment strategies for various diseases, particularly tumours.

The role of oxidative stress and inflammation biomarkers in pre- and postoperative monitoring of prostate cancer patients

INTRODUCTION

Prostate Cancer (PC) is a global health concern affecting men worldwide. Oxidative stress is believed to contribute to the initiation of early-stage PC lesions. Additionally, inflammation has long been acknowledged as a factor in the development of PC. We aimed to examine the biomarkers of oxidative stress and inflammation in PC patients before and after surgery.

PATIENTS AND METHODS

A cross-sectional study was conducted at the Urology Outpatient Clinic of Bezmialem Vakif University Hospital. A total of 150 individuals were included in the study, divided into five groups: 50 Healthy controls, 25 patients with Benign Prostatic Hyperplasia (BPH), 25 patients with Low-Risk Prostate Cancer (LRPC), 25 patients with Medium-Risk Prostate Cancer (MRPC), and 25 patients with High-Risk Prostate Cancer (HRPC). Measurements of Total Oxidant Status (TOS), Total Antioxidant Status (TAS), Total Thiol (TT), and Native Thiol (NT) were performed using photometric methods. Oxidative Stress Index (OSI) and Disulfide (DIS) levels were calculated mathematically. Levels of Interleukin-10 (IL-10), Interleukin-1beta (IL-1β), Tumor Necrosis Factor-alpha (TNF-α), Interleukin-6 (IL-6), and Presepsin were determined using commercially available enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

Compared to the healthy control group, the results indicated a statistically significant increase in both oxidative stress and inflammation levels. In the groups receiving both pharmaceutical therapy and surgical treatment (PC), a significant decrease in oxidative stress and inflammation levels was observed.

CONCLUSION

Consequently, it is suggested that the assessment of oxidative stress and inflammatory biomarkers should be incorporated in the pre- and postoperative monitoring of patients with PC.

Multiplex protein analysis and ensemble machine learning methods of fine needle aspirates from prostate cancer patients reveal potential diagnostic signatures associated with tumour grade

BACKGROUND

Improved molecular diagnosis is needed in prostate cancer (PC). Fine needle aspiration (FNA) is a minimally invasive biopsy technique, less traumatic compared to core needle biopsy, and could be useful for diagnosis of PC. Molecular biomarkers (BMs) in FNA-samples can be assessed for prediction, eg of immunotherapy efficacy before treatment as well as at treatment decision time points during disease progression.

METHODS

In the present pilot study, the expression levels of 151 BM proteins were analysed by proximity extension assay in FNA-samples from 16 patients, including benign prostate lesions (n = 3) and cancers (n = 13). An ensemble data analysis strategy was applied using several machine learning models.

RESULTS

Twelve potentially predictive BM proteins correlating with International Society of Urological Pathology grade groups were identified, among them vimentin, tissue factor pathway inhibitor 2, and integrin beta-5. The validity of the results was supported by network analysis that showed functional associations between most of the identified putative BMs. We also showed that multiple immune checkpoint targets can be assessed (eg PD-L1, CD137, and Galectin-9), which may support the selection of immunotherapy in advanced PC. Results are promising but need further validation in a larger cohort.

CONCLUSIONS

Our pilot study represents a "proof of concept" and shows that multiplex profiling of potential diagnostic and predictive BM proteins is feasible on tumour material obtained by FNA sampling of prostate cancer. Moreover, our results demonstrate that an ensemble data analysis strategy may facilitate the identification of BM signatures in pilot studies when the patient cohort is limited.

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.

The established chemokine-related prognostic gene signature in prostate cancer: Implications for anti-androgen and immunotherapies

Background

Prostate cancer (PCa) was one of the most common malignancies among men, while the prognosis for PCa patients was poor, especially for patients with recurrent and advanced diseases.

Materials and methods

Five PCa cohorts were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus databases, and the biochemical recurrence (BCR)-related chemokine genes were identified by LASSO-Cox regression. The chemokine-related prognostic gene signature (CRPGS) was established, and its association with PCa patients’ clinical, pathological and immune characteristics was analyzed. The association between CRPGS and PCa patients’ responses to androgen deprivation therapy (ADT) and immunotherapy was analyzed. The CRPGS was compared with other previously published molecular signatures, and the CRPGS was externally validated in our real-world AHMU-PC cohort.

Results

Four recurrence-free survival (RFS)-related chemokine genes (CXCL14, CCL20, CCL24, and CCL26) were identified, and the CRPGS was established based on the four identified chemokine genes, and TCGA-PRAD patients with high riskscores exhibited poorer RFS, which was validated in the GSE70768 cohort. The CRPGS was associated with the clinical, pathological, and immune characteristics of PCa patients. Low-risk PCa patients were predicted to respond better to ADT and immunotherapy. By comparing with other molecular signatures, the CRPGS could classify PCa patients into two risk groups well, and the CRPGS was associated with the m6A level, as well as TP53 and SPOP mutation status of PCa patients. In the AHMU-PC cohort, the CRPGS was associated with the advanced pathology stage and Gleason score.

Conclusions

The identified chemokine genes and CRPGS were associated with the prognosis of PCa, which could predict PCa patients’ responses to anti-androgen and immunotherapies.

Upregulation of PARG in prostate cancer cells suppresses their malignant behavior and downregulates tumor-promoting genes

Post-translational modification of nuclear proteins through the addition of poly(ADP-ribose) (pADPr) moieties is upregulated in many metastatic cancers, where the high levels of pADPr have often been associated with poor cancer prognosis. Although the inhibitors of poly(ADP-ribose) polymerases (PARPs) have been utilized as potent anti-cancer agents, their efficacy in clinical trials varied among patient groups and has often been unpredictable. Such outcome cannot be interpreted solely by the inability to keep PARP-driven DNA repair in check. The focus of studies on PARP-driven tumorigenesis have recently been shifted toward PARP-dependent regulation of transcription. Here we utilized the controlled overexpression of poly(ADP-ribose) glycohydrolase (PARG), a sole pADPr-degrading enzyme, to investigate pADPr-dependent gene regulation in prostate cancer PC-3 cells. We demonstrated that PARG upregulation reduces pADPr levels and inhibits the expression of genes in key tumor-promoted pathways, including TNFα/NF-kB, IL6/STAT3, MYC, and KRAS signaling, the genes involved in inflammation response, especially chemokines, and endothelial-mesenchymal transition. The observed effect of PARG on transcription was consistent across all tested prostate cancer cell lines and correlates with PARG-induced reduction of clonogenic potential of PC-3 cells in vitro and a significant growth inhibition of PC-3-derived tumors in nude mice in vivo.

Quizalofop-P-ethyl induced developmental toxicity and cardiotoxicity in early life stage of zebrafish (Danio rerio)

Quizalofop-P-ethyl (QpE), a highly efficient selective herbicide, has good control effect on annual and perennial weeds. However, its excessive use will pose a threat to the ecological environment. QpE has been proven harmful to aquatic organisms, but there is little evidence on the adverse effects of QpE in the early life of aquatic organisms. In this work, zebrafish (Danio rerio) embryos were treated with 0.10, 0.20, 0.30, 0.40, and 0.50 mg/L of QpE for 120 h. The findings revealed that the LC₅₀ value of QpE to zebrafish embryos was 0.23 mg/L at 96 hpf. QpE exposure significantly increased the mortality rate, decreased the hatching rate and caused morphological defects during zebrafish embryonic development, with a concentration dependent manner. QpE also caused severe morphological changes in the cardiovascular system, as well as resulted in a dysfunction in cardiovascular performance. Meanwhile, both histopathological examination and neutrophil observations showed inflammatory response occurred in the heart. Furthermore, several genes associated with heart development and inflammation were significantly altered following QpE exposure. A protein-protein interaction (PPI) network analysis proved that there was a connection between the changed heart development-relevant and inflammation-related genes. Taken together, our findings suggest that QpE causes cardiotoxicity in zebrafish embryos by altering the expression of genes in the regulatory network of cardiac development, which might be aggravated by inflammatory reactions, thereby affecting embryo development. These findings generated here are useful for in-depth assessment of the effects of QpE on early development of aquatic organisms and providing theoretical foundation for risk management measures.

Decursin inhibits tumor progression in head and neck squamous cell carcinoma by downregulating CXCR7 expression in vitro

CXC chemokine receptor 7 (CXCR7) is frequently overexpressed in cancer and plays a significant role in tumor growth and metastasis. Consequently, inhibition of CXCR7 is important for treatment strategies. However, little is known concerning the biological role of CXCR7 and its underlying mechanisms in head and neck squamous cell carcinoma (HNSCC). The present study investigated the role of CXCR7 in HNSCC, as well as the effects of decursin, a pyranocoumarin compound isolated from Angelica gigas Nakai, on CXCR7 and its downstream signaling. Expression levels of CXCR7 in HNSCC cells were examined using flow cytometry, reverse transcriptase PCR, western blot analysis, and immunofluorescence. The effects of CXCR7 on cell proliferation, migration, and invasion were studied using CCK-8, gap closure, and transwell assays. The results revealed that decursin significantly reduced CXCR7 expression and inhibited cell proliferation, migration, and invasion of human HNSCC cell lines. In addition, decursin induced G0/G1 cell cycle arrest in CXCR7-overexpressing cells and decreased the levels of cyclin A, cyclin E, and CDK2. Furthermore, CXCR7 promoted cancer progression via the STAT3/c-Myc pathway in HNSCC; suppression of CXCR7 with decursin prevented this effect. These results suggest that CXCR7 promotes cancer progression through the STAT3/c-Myc pathway and that the natural compound decursin targets CXCR7 and may be valuable in the treatment of HNSCC.

lncRNA MIAT/HMGB1 Axis Is Involved in Cisplatin Resistance via Regulating IL6-Mediated Activation of the JAK2/STAT3 Pathway in Nasopharyngeal Carcinoma

Cisplatin-based chemotherapy and radiotherapy are the main first-line treatment strategies for nasopharyngeal carcinoma (NPC) patients. Unfortunately, resistance is a major obstacle in the clinical management of NPC patients. We prove that the expression level of high-mobility group box 1 (HMGB1) is dramatically increased in resistant NPC cells than that in sensitive cells. HMGB1 induces the expression and secretion of IL6, which leads to constitutive autocrine activation of the JAK2/STAT3 pathway and eventually contributes to chemoresistance in NPC cells. Long non-coding RNAs (lncRNAs) have been identified as key regulators involved in drug resistance. In this study, using GO analysis of the biological process and differential expression analysis, we find 12 significantly altered IncRNAs in NPC cell lines, which may be involved in regulating gene expression. Furthermore, we determine that elevated lncRNA MIAT level upregulates HMGB1 expression, contributing to cisplatin resistance in NPC cells. We find that the deficiency of the lncRNA MIAT/HMGB1 axis, inhibition of JAK2/STAT3, or neutralization of IL6 by antibodies significantly re-sensitizes resistant NPC cells to cisplatin in resistant NPC cells. Moreover, we provide the in vivo evidence that the deficiency of HMGB1 reduces cisplatin-resistant tumor growth. Most importantly, we provide clinical evidence showing that the expression level of the lncRNA MIAT/HMGB1/IL6 axis is elevated in resistant NPC tumors, which is highly correlated with poor clinical outcome. Our findings identify a novel chemoresistance mechanism regulated by the lncRNA MIAT/HMGB1/IL6 axis, which indicates the possibilities for lncRNA MIAT, HMGB1, and IL6 as biomarkers for chemoresistance and targets for developing novel strategies to overcome resistance in NPC patients.

Up-regulation of CXCL8 expression is associated with a poor prognosis and enhances tumor cell malignant behaviors in liver cancer

CXCL8, a member of CXC chemokines, was constitutively expressed in many types of human cancers, and its overexpression has been shown to play a critical role in promoting tumorigenesis. The purpose of the present study was to determine CXCL8 expression in a commercial human liver tissue microarray, and elucidate the effects and underlying mechanisms by which CXCL8 is involved in the malignant progression of human liver cancer. Our data showed that high level expression of CXCL8 in tissues with liver cancer was identified as compared with non-cancer tissues, and its up-regulation was closely associated with clinical stage and tumor infiltration. In vitro, exogenous CXCL8 at concentrations of 10, 20 or 40 ng/ml obviously stimulated the proliferation abilities of HepG2 cells. Coupled with this, 10, 20 or 40 ng/ml of exogenous CXCL8 also triggered a significant elevation in HepG2 cells migration. Additionally, overexpression of CXCL8 in HepG2 cells also resulted in increased cell proliferation and migration capacities. Finally, Western blotting analysis showed that overexpression of CXCL8 increased the expression of ERK, p-ERK and survivin, decreased the expression of caspase-3 and BAX at protein level.

Research Trends and Regulation of CCL5 in Prostate Cancer

Prostate cancer (PCa) is considered as the most common cancer of urologic neoplasms, and its development and prognosis are associated with many factors. Chemokine receptor signaling combine with advances in advanced clinicopathological characteristics have provided new insights into the molecular landscape of prostate cancer. Chemokine (C-C motif) ligand 5 (CCL5) is an important member of the CC subfamily of chemokines. The expression of chemokine CCL5 is positively correlated with poor prognostic features in patients with PCa. Current study suggested that CCL5/CCR5 axis plays a significant role in the proliferation, metastasis, angiogenesis, drug resistance of prostate cancer cells and promotes self-renewal of prostate cancer stem cells (PCSCs). Due to the major domination in CCL5 by prostate cancer and the high cancer-specific mortality with prostate cancer, research on the CCL5/CCR5 axis effective antagonists is widespread application. However, challenges for precision oncology of CCL5/CCR5 axis and effective antagonists in CRPC remain. Herein, we summarized the crucial role of CCL5 in promoting the development of PCa and discussed the antitumor application of the antagonists of CCL5/CCR5 axis.

The Chemokine Receptor CCR3 Is Potentially Involved in the Homing of Prostate Cancer Cells to Bone: Implication of Bone-Marrow Adipocytes

Bone metastasis remains the most frequent and the deadliest complication of prostate cancer (PCa). Mechanisms leading to the homing of tumor cells to bone remain poorly characterized. Role of chemokines in providing navigational cues to migrating cancer cells bearing specific receptors is well established. Bone is an adipocyte-rich organ since 50 to 70% of the adult bone marrow (BM) volume comprise bone marrow adipocytes (BM-Ads), which are likely to produce chemokines within the bone microenvironment. Using in vitro migration assays, we demonstrated that soluble factors released by human primary BM-Ads are able to support the directed migration of PCa cells in a CCR3-dependent manner. In addition, we showed that CCL7, a chemokine previously involved in the CCR3-dependent migration of PCa cells outside of the prostate gland, is released by human BM-Ads. These effects are amplified by obesity and ageing, two clinical conditions known to promote aggressive and metastatic PCa. In human tumors, we found an enrichment of CCR3 in bone metastasis vs. primary tumors at mRNA levels using Oncomine microarray database. In addition, immunohistochemistry experiments demonstrated overexpression of CCR3 in bone versus visceral metastases. These results underline the potential importance of BM-Ads in the bone metastatic process and imply a CCR3/CCL7 axis whose pharmacological interest needs to be evaluated.

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.

CXC Chemokine/Receptor Axis Profile and Metastasis in Prostate Cancer

In this study, the effects of the CXC chemokine/receptor axis on lymph node and distant metastases of prostate cancer (PC) were analyzed. Further, mRNA expression data of metastatic PC were extracted from the Stand Up To Cancer–Prostate Cancer Foundation Dream Team database and differences between metastatic sites were comprehensively analyzed. CXC chemokine/receptor mRNA expression data of primary PC included in the Cancer Genome Atlas were used to analyze the relationships of CXC chemokine/receptor expression with lymph node metastasis and cancer progression. In metastatic PC, significantly higher expression of ELR⁺ CXC chemokines/receptors and significantly lower expression of ELR⁻ CXC chemokines/receptors were observed in bone metastases relative to lymph node metastases. In primary PC, significantly higher ELR⁻ CXC chemokine/receptor expression and significantly lower ELR⁺ CXC chemokine/receptor expression were observed in patients with lymph node metastasis relative to those without. Multivariate logistic regression analysis identified CXCL10 expression as an independent predictor of lymph node metastasis. Furthermore, the log-rank test results revealed that co-expression of CXCL10/CXCR3 was associated with postoperative recurrence. These findings demonstrate heterogeneous expression of CXC chemokine/receptor genes in primary PC as well as differences in expression patterns according to the metastatic site.

Gene expression profiling in dorsolateral prostates of prepubertal and adult Sprague-Dawley rats dosed with estradiol benzoate, estradiol, and testosterone

The imbalance of testosterone to estradiol ratio has been related to the development of prostate diseases. Although rat models of prostate diseases induced by endocrine-disrupting chemicals (EDCs) and/or hormone exposure are commonly used to analyze gene expression profiles in the prostate, most studies utilize a single endpoint. In this study, microarray analysis was used for gene expression profiling in rat prostate tissue after exposure to EDCs and sex hormones over multiple time points (prepubertal through adulthood). We used dorsolateral prostate tissues from Sprague-Dawley rats (male offspring) and postnatally administered estradiol benzoate (EB) on postnatal days (PNDs) 1, 3, and 5, followed by treatment with additional hormones [estradiol (E) and testosterone (T)] on PNDs 90-200, as described by Ho et al. Microarray analysis was performed for gene expression profiling in the dorsolateral prostate, and the results were validated via qRT-PCR. The genes in cytokine-cytokine receptor interaction, cell adhesion molecules, and chemokines were upregulated in the EB+T+E group on PNDs 145 and 200. Moreover, early-stage downregulation of anti-inflammatory gene: bone morphogenetic protein 7 gene was observed. These findings suggest that exposure to EB, T, and E activates multiple pathways and simultaneously downregulates anti-inflammatory genes. Interestingly, these genes are reportedly expressed in prostate cancer tissues/cell lines. Further studies are required to elucidate the mechanism, including analyses using human prostate tissues.

Biofluid quantification of TWEAK/Fn14 axis in combination with a selected biomarker panel improves assessment of prostate cancer aggressiveness

Background

Conventional clinical biomarkers cannot accurately differentiate indolent from aggressive prostate cancer (PCa). We investigated the usefulness of a biomarker panel measured exclusively in biofluids for assessment of PCa aggressiveness.

Methods

We collected biofluid samples (plasma/serum/semen/post-prostatic massage urine) from 98 patients that had undergone radical prostatectomy. Clinical biochemistry was performed and several cytokines/chemokines including soluble(s) TWEAK, sFn14, sCD163, sCXCL5 and sCCL7 were quantified by ELISA in selected biofluids. Also, the expression of KLK2, KLK3, Fn14, CD163, CXCR2 and CCR3 was quantified by real-time PCR in semen cell sediment. Univariate, logistic regression, and receiver operating characteristic (ROC) analyses were used to assess the predictive ability of the selected biomarker panel in conjunction with clinical and metabolic variables for the evaluation of PCa aggressiveness.

Results

Total serum levels of prostate-specific antigen (PSA), semen levels of sTWEAK, fasting glycemia and mRNA levels of Fn14, KLK2, CXCR2 and CCR3 in semen cell sediment constituted a panel of markers that was significantly different between patients with less aggressive tumors [International Society of Urological Pathology (ISUP) grade I and II] and those with more aggressive tumors (ISUP grade III, IV and V). ROC curve analysis showed that this panel could be used to correctly classify tumor aggressiveness in 90.9% of patients. Area under the curve (AUC) analysis revealed that this combination was more accurate [AUC = 0.913 95% confidence interval (CI) 0.782–1] than a classical non-invasive selected clinical panel comprising age, tumor clinical stage (T-classification) and total serum PSA (AUC = 0.721 95% CI 0.613–0.830).

Conclusions

TWEAK/Fn14 axis in combination with a selected non-invasive biomarker panel, including conventional clinical biochemistry, can improve the predictive power of serum PSA levels and could be used to classify PCa aggressiveness.

TroCCL4, a CC chemokine of Trachinotus ovatus, is involved in the antimicrobial immune response

CC chemokines are a large subfamily of chemokines that play an important role in the innate immune system. To date, several CC chemokines have been identified in fish species; however, the activities and functions of these putative chemokines remain ambiguous in teleosts, especially in the golden pompano, Trachinotus ovatus. Here, we characterized CC chemokine ligand 4 from T. ovatus (TroCCL4) and studied its functions. TroCCL4 contains a 294 bp open reading frame that encodes a putative peptide comprising 97 amino acids. TroCCL4 shares a high amino acid sequence similarity of 31.11%-78.35% with other CC chemokines sequences in humans and teleosts and has four cysteine residues that are conserved among other CC chemokines. TroCCL4 is also related to the macrophage inflammatory protein (MIP) group of CC chemokines. TroCCL4 expression was most abundant in immune organs and significantly upregulated in a time-dependent manner following Edwardsiella tarda infection. Recombinant TroCCL4 (rTroCCL4) induced the migration of peripheral blood leukocytes and the cellular proliferation of head kidney lymphocytes. In addition, rTroCCL4 inhibited the growth of Escherichia coli and E. tarda, indicating an antimicrobial function. Furthermore, the results of in vivo analysis showed that TroCCL4 overexpression in T. ovatus significantly enhanced macrophage activation; upregulated the gene expression of interleukin 1-β (IL-1β), interleukin 15 (IL15), interferon-induced Mx protein (Mx), tumor necrosis factor α (TNFα), complement C3, and major histocompatibility complex (MHC) class Iα and class IIα; and protected against bacterial infection in fish tissues. In contrast, knockdown of TroCCL4 expression resulted in increased bacterial dissemination and colonization in fish tissues. Taken together, our results provide evidence indicating that TroCCL4 has the ability to stimulate leukocytes and macrophages and enhance host immunity to defend against bacterial infection.

miR-761 inhibits human osteosarcoma progression by targeting CXCR1

microRNAs (miRs) are endogenous noncoding RNAs that participate in a variety of cellular processes by regulating multiple targets to promote or inhibit cell behaviors. Emerging evidence suggests that miR-761 plays important roles in human cancers to function as either a tumor suppressor gene or an oncogene. However, its biological role in osteosarcoma (OS) remains largely elusive. This study found the expression of miR-761 was significantly reduced in OS tissues and cell lines. CXC receptor-1 (CXCR1), an oncogene which was overexpressed in a variety of human cancers including OS, was identified as a novel target of miR-761 using bioinformatic, luciferase reporter, and western blot analyses. Cell function assays revealed that miR-761 could inhibit cell proliferation and invasion at least partially through targeting CXCR1. Collectively, our present study suggested that miR-761 may be a promising treatment biomarker for OS.

Maelstrom Directs Myeloid-Derived Suppressor Cells to Promote Esophageal Squamous Cell Carcinoma Progression via Activation of the Akt1/RelA/IL8 Signaling Pathway

Maelstrom (MAEL) is a novel cancer/testis-associated gene, which is not only expressed in the male testicular germ cells among human normal tissues, but is also aberrantly expressed in various cancer tissues. In our study, MAEL was characterized as a tumor-promoting gene and was significantly associated with esophageal squamous cell carcinoma (ESCC) recurrence and unfavorable prognosis. Kaplan-Meier analysis showed that patients with high MAEL expression had a shorter survival time. Functional experiments showed that MAEL promoted tumor cell growth and inhibited cell apoptosis. These results prompted us to investigate the factors affecting the tumorigenicity of MAEL Further experimentation demonstrated that MAEL enhanced the expression of phosphorylated Akt1, with subsequent phosphorylation of nuclear factor kappa B (NF-κB) subunit RelA in tumor cells, and chemoattracted myeloid-derived suppressor cells (MDSCs) by upregulating interleukin-8 (IL8) to accelerate tumor progression in the tumor microenvironment. We also found that TGFβ secreted by MDSCs could upregulate MAEL by inducing Smad2/Smad3 phosphorylation. In summary, this study revealed a mechanism by which MAEL could upregulate IL8 through Akt1/RelA to direct MDSCs homing into the tumor, suggesting that MAEL could be an attractive therapeutic target and a prognostic marker against ESCC. Cancer Immunol Res; 6(10); 1246-59. ©2018 AACR.

Novel role of Giα2 in cell migration: Downstream of PI3-kinase-AKT and Rac1 in prostate cancer cells

Tumor cell motility is the essential step in cancer metastasis. Previously, we showed that oxytocin and epidermal growth factor (EGF) effects on cell migration in prostate cancer cells require Giα2 protein. In the current study, we investigated the interactions among G-protein coupled receptor (GPCR), Giα2, PI3-kinase, and Rac1 activation in the induction of migratory and invasive behavior by diverse stimuli. Knockdown and knockout of endogenous Giα2 in PC3 cells resulted in attenuation of transforming growth factor β1 (TGFβ1), oxytocin, SDF-1α, and EGF effects on cell migration and invasion. In addition, knockdown of Giα2 in E006AA cells attenuated cell migration and overexpression of Giα2 in LNCaP cells caused significant increase in basal and EGF-stimulated cell migration. Pretreatment of PC3 cells with Pertussis toxin resulted in attenuation of TGFβ1- and oxytocin-induced migratory behavior and PI3-kinase activation without affecting EGF-induced PI3-kinase activation and cell migration. Basal- and EGF-induced activation of Rac1 in PC3 and DU145 cells were not affected in cells after Giα2 knockdown. On the other hand, Giα2 knockdown abolished the migratory capability of PC3 cells overexpressing constitutively active Rac1. The knockdown or knockout of Giα2 resulted in impaired formation of lamellipodia at the leading edge of the migrating cells. We conclude that Giα2 protein acts at two different levels which are both dependent and independent of GPCR signaling to induce cell migration and invasion in prostate cancer cells and its action is downstream of PI3-kinase-AKT-Rac1 axis.

CX3CL1/fractalkine enhances prostate cancer spinal metastasis by activating the Src/FAK pathway

Chemokines serve important roles in the development of cancer. C-X3-C motif chemokine ligand 1 (CX3CL1) has been demonstrated to promote metastases in different types of tumors. The authors' previous studies demonstrated that the CX3CL1 (also termed fractalkine)/steroid receptor coactivator (Src)/focal adhesion kinase (FAK) signaling pathway is associated with spinal metastasis. In the present study, it was observed that CX3CL1/C-X3-C motif chemokine receptor 1 (CX3CR1) was overexpressed in prostate cancer tissues with spinal metastasis compared with primary tumors. Overexpression of CX3CR1 induced cell proliferation, migration and invasion, and inhibited cellular apoptosis. However, repression of CX3CR1 reduced cell proliferation, migration and invasion, and increased cellular apoptosis. In addition, the Src/FAK pathway was activated by CX3CL1, which depends on the Tyr992 residue of epidermal growth factor receptor (EGFR) for phosphorylation. The inhibitors of these kinases repressed the cell migration induced by CX3CL1 or CX3CR1 overexpression. Furthermore, overexpression of CX3CR1 induced the spinal metastasis of prostate cancer in an in vivo mouse model. Therefore, CX3CL1 and its regulation of the EGFR, Src and FAK pathways may be potential targets for the early prevention of spinal metastasis in prostate cancer.

Dual PI3 K/mTOR inhibition reduces prostate cancer bone engraftment altering tumor-induced bone remodeling

Morbidity in advanced prostate cancer patients is largely associated with bone metastatic events. The development of novel therapeutic strategies is imperative in order to effectively treat this incurable stage of the malignancy. In this context, Akt signaling pathway represents a promising therapeutic target able to counteract biochemical recurrence and metastatic progression in prostate cancer. We explored the therapeutic potential of a novel dual PI3 K/mTOR inhibitor, X480, to inhibit tumor growth and bone colonization using different in vivo prostate cancer models including the subcutaneous injection of aggressive and bone metastatic (PC3) and non-bone metastatic (22rv1) cell lines and preclinical models known to generate bone lesions. We observed that X480 both inhibited the primary growth of subcutaneous tumors generated by PC3 and 22rv1 cells and reduced bone spreading of PCb2, a high osteotropic PC3 cell derivative. In metastatic bone, X480 inhibited significantly the growth and osteolytic activity of PC3 cells as observed by intratibial injection model. X480 also increased the bone disease-free survival compared to untreated animals. In vitro experiments demonstrated that X480 was effective in counteracting osteoclastogenesis whereas it stimulated osteoblast activity. Our report provides novel information on the potential activity of PI3 K/Akt inhibitors on the formation and progression of prostate cancer bone metastases and supports a biological rationale for the use of these inhibitors in castrate-resistant prostate cancer patients at high risk of developing clinically evident bone lesions.

Prostate cancer health disparities: An immuno-biological perspective

Prostate cancer (PCa) is the most commonly diagnosed malignancy in males, and, in the United States, is the second leading cause of cancer-related death for men older than 40 years. There is a higher incidence of PCa for African Americans (AAs) than for European-Americans (EAs). Investigations related to the incidence of PCa-related health disparities for AAs suggest that there are differences in the genetic makeup of these populations. Other differences are environmentally induced (e.g., diet and lifestyle), and the exposures are different. Men who immigrate from Eastern to Western countries have a higher risk of PCa than men in their native countries. However, the number of immigrants developing PCa is still lower than that of men in Western countries, suggesting that genetic factors are involved in the development of PCa. Altered genetic polymorphisms are associated with PCa progression. Androgens and the androgen receptor (AR) are involved in the development and progression of PCa. For populations with diverse racial/ethnic backgrounds, differences in lifestyle, diet, and biology, including genetic mutations/polymorphisms and levels of androgens and AR, are risk factors for PCa. Here, we provide an immuno-biological perspective on PCa in relation to racial/ethnic disparities and identify factors associated with the disproportionate incidence of PCa and its clinical outcomes.

The mysterious relation between inflammation and prostate cancer

Recent studies showed that inflammation is a critical cause for initiation and/or development of many cancers. In prostate cancer (PC), the inflammatory cells usually populate an immune-competent organ. This inflammatory organ can be involved in the initiation and progression of PC. Here, we mainly focus on the role of inflammation in the PC and progression of castration-resistant PC (CRPC). Moreover, we summarize the roles of inflammation factors (such as chemokines and cytokines) in PC and CRPC. Taken together, this review gives an insight into therapy for PC and CRPC through anti-inflammation.

A standardized herbal extract mitigates tumor inflammation and augments chemotherapy effect of docetaxel in prostate cancer

Activation of the NFκB pathway is often associated with advanced cancer and has thus been regarded as a rational therapeutic target. Wedelia chinensis is rich in luteolin, apigenin, and wedelolactone that act synergistically to suppress androgen receptor activity in prostate cancer. Interestingly, our evaluation of a standardized Wedelia chinensis herbal extract (WCE) concluded its efficacy on hormone-refractory prostate cancer through systemic mechanisms. Oral administration of WCE significantly attenuated tumor growth and metastasis in orthotopic PC-3 and DU145 xenografts. Genome-wide transcriptome analysis of these tumors revealed that WCE suppressed the expression of IKKα/β phosphorylation and downstream cytokines/chemokines, e.g., IL6, CXCL1, and CXCL8. Through restraining the cytokines expression, WCE reduced tumor-elicited infiltration of myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs) and endothelial cells into the tumors, therefore inhibiting angiogenesis, tumor growth, and metastasis. In MDSCs, WCE also reduced STAT3 activation, downregulated S100A8 expression and prevented their expansion. Use of WCE in combination with docetaxel significantly suppressed docetaxel-induced NFκB activation, boosted the therapeutic effect and reduced the systemic toxicity caused by docetaxel monotherapy. These data suggest that a standardized preparation of Wedelia chinensis extract improved prostate cancer therapy through immunomodulation and has potential application as an adjuvant agent for castration-resistant prostate cancer.

UNBS5162 inhibits the proliferation of esophageal cancer squamous cells via the PI3K/AKT signaling pathway

C‑X‑C motif chemokine ligand (CXCL) signaling has been demonstrated to be involved in cancer invasion and migration; therefore, CXCL antagonists may serve as anticancer drugs by preventing tumor proliferation. The present study aimed to investigate whether a pan antagonist of CXCLs, UNBS5162, may inhibit esophageal cancer proliferation and to identify the underlying mechanisms. Cell proliferation and cell colony formation results, which were determined by a Cell Counting Kit‑8 assay and crystal violet staining, respectively, demonstrated that UNBS5162 inhibited esophageal cancer cell proliferation. Following treatment with UNBS5162, Transwell migration and Matrigel invasion assays, and flow cytometry with Annexin V‑fluorescein isothiocyanate and propidium iodide staining, were performed to investigate cell migration, invasion and apoptosis in human esophageal cancer cells. The results indicated that invasion and migration was reduced in UNBS5162‑treated cells, while apoptosis was increased. Western blotting experiments confirmed that UNBS5162 downregulated the protein expression of proteins associated with the phosphatidylinositol 3‑kinase (PI3K)/AKT signaling pathway, including the levels of phosphorylated (p)‑AKT, p‑mechanistic target of rapamycin kinase, ribosomal protein S6 kinase β1 and cyclin D1. In addition, upregulated expression of programed cell death 4 was observed following UNBS5162 treatment. The present study demonstrated that UNBS5162 is a novel naphthalimide that may have potential therapeutic use for the prevention of esophageal cancer proliferation and metastasis via the PI3K/AKT signaling pathway.

Association of CCR2 (+190 G/A) Gene Variants and Ovarian Cancer Severity

AIM

Chemokines and their receptors play an important role in tumor progression. In the current study, we aimed to determine the association between the CCR2 gene (+190 G/A) polymorphism and ovarian cancer severity.

METHODS

CCR2 (+190 G/A) genotyping was performed using real-time polymerase chain reaction for DNA isolated from blood samples from a cohort of patients with ovarian cancer (n = 44) and a control group (n = 45).

RESULTS

The CCR2 (+190 G/A) GG genotype frequencies for patients were significantly higher in the stage III-IV cancer group (p = 0.036), and A allele carriers were significantly higher in the stage I-II ovarian cancer group.

CONCLUSION

The CCR2 (+190 G/A) GG genotype may be a potential risk factor for the severe forms of ovarian cancer and the A allele may be a risk-reducing factor for severe ovarian cancer.

Inhibition of androgen receptor promotes CXC-chemokine receptor 7-mediated prostate cancer cell survival

The atypical C-X-C chemokine receptor 7 (CXCR7) has been implicated in supporting aggressive cancer phenotypes in several cancers including prostate cancer. However, the mechanisms driving overexpression of this receptor in cancer are poorly understood. This study investigates the role of androgen receptor (AR) in regulating CXCR7. Androgen deprivation or AR inhibition significantly increased CXCR7 expression in androgen-responsive prostate cancer cell lines, which was accompanied by enhanced epidermal growth factor receptor (EGFR)-mediated mitogenic signaling, promoting tumor cell survival through an androgen-independent signaling program. Using multiple approaches we demonstrate that AR directly binds to the CXCR7 promoter, suppressing transcription. Clustered regularly interspaced short palindromic repeats (CRISPR) directed Cas9 nuclease-mediated gene editing of CXCR7 revealed that prostate cancer cells depend on CXCR7 for proliferation, survival and clonogenic potential. Loss of CXCR7 expression by CRISPR-Cas9 gene editing resulted in a halt of cell proliferation, severely impaired EGFR signaling and the onset of cellular senescence. Characterization of a mutated CXCR7-expressing LNCaP cell clone showed altered intracellular signaling and reduced spheroid formation potential. Our results demonstrate that CXCR7 is a potential target for adjuvant therapy in combination with androgen deprivation therapy (ADT) to prevent androgen-independent tumor cell survival.

Aggressive rat prostate tumors reprogram the benign parts of the prostate and regional lymph nodes prior to metastasis

In order to grow and spread tumors need to interact with adjacent tissues. We therefore hypothesized that small but aggressive prostate cancers influence the rest of the prostate and regional lymph nodes differently than tumors that are more indolent. Poorly metastatic (Dunning AT1) or highly metastatic (Dunning MLL) rat prostate tumor cells were injected into the ventral prostate lobe of immunocompetent rats. After 10 days—when the tumors occupied about 30% of the prostate lobe and lymph node metastases were undetectable—the global gene expression in tumors, benign parts of the prostate, and regional iliac lymph nodes were examined to define tumor-induced changes related to preparation for future metastasis. The tumors induced profound effects on the gene expression profiles in the benign parts of the prostate and these were strikingly different in the two tumor models. Gene ontology enrichment analysis suggested that tumors with high metastatic capacity were more successful than less metastatic tumors in inducing tumor-promoting changes and suppressing anti-tumor immune responses in the entire prostate. Some of these differences such as altered angiogenesis, nerve density, accumulation of T-cells and macrophages were verified by immunohistochemistry. Gene expression alterations in the regional lymph nodes suggested decreased quantity and activation of immune cells in MLL-lymph nodes that were also verified by immunostaining. In summary, even when small highly metastatic prostate tumors can affect the entire tumor-bearing organ and pre-metastatic lymph nodes differently than less metastatic tumors. When the kinetics of these extratumoral influences (by us named TINT = tumor instructed normal tissue) are more precisely defined they could potentially be used as markers of disease aggressiveness and become therapeutic targets.

Changes of plasma cytokines and chemokines expression level in nasopharyngeal carcinoma patients after treatment with definitive intensity-modulated radiotherapy (IMRT)

Background

Potential clinical application values of certain cytokines and chemokines that participate in the process of tumor growth, invasion, and metastasis have been reported. However, there still lack of biomarkers for a great many of malignancy. This study identified cytokines or chemokines involved in the occurrence and development of nasopharyngeal carcinoma (NPC), which might be a biomarker for noninvasive early diagnosis.

Methods

The plasma levels of 19 cytokines and chemokines were detected by the luminex liquid array-based multiplexed immunoassays in 39 NPC patients before and after treatment by definitive intensity-modulated radiotherapy (IMRT).

Results

Plasma levels of almost all of the 19 cytokines and chemokines in NPC patients were higher than healthy controls, while only IFN-γ, IL-1b IL-6, MCP-1, TNF-α, FKN, IL-12P70, IL-2, IL-5 and IP-10 showed significant differences. However, expression levels of most of the 19 cytokines and chemokines decreased after therapy, especially IFN-γ, IL-10, IL-1b, IL-6, IL-8, MCP-1, TNF-α, VEGF, IL-17A, IL-2, IL-5 and MIP-1b, have a dramatic decline. Taking together, plasma levels of IFN-γ, IL-1b, IL-6, MCP-1, TNF-α, IL-2 and IL-5 are significantly increased in NPC patients and dramatically decreased after treatment, suggesting these cytokines and chemokines might play important roles in the progress of NPC. More interestingly, the expression level of MPC-1 is significantly associated with clinical stage.

Conclusion

MCP-1 might involve in the genesis and development process of NPC, which might serve as a noninvasive biomarker for early diagnosis.

Prognostic value of inflammation in prostate cancer progression and response to therapeutic: a critical review

Prostate is an immune-competent organ normally populated by inflammatory cells. Prostatic inflammation origin can be multi-factorial and there are some emerging evidences on its possible role as a factor involved in prostate cancer (PC) pathogenesis and progression. This review critically analyzes the role of inflammation as a prognostic factor for progression and aggressiveness of PC. We verified the last 10 years literature data on the association between inflammation and PC aggressiveness, or PC response to therapies. Several studies tried to correlate different inflammatory factors with the aggressiveness and metastatization of PC; all data sustain the role of inflammation in PC progression but they also produce confusion to identify a reliable clinical prognostic marker. Data on patients submitted to radical prostatectomy (RP) showed that cases with marked intraprostatic tissue inflammation are associated with higher rate of biochemical progression; systemic inflammation markers appear to have a significant prognostic value. Analyzing data on patients submitted to radiotherapy (RT) emerges a significant association between high neuthrophil to lymphocyte ratio (NLR) and decreased progression free survival and overall survival; also plateled to lymphocyte ratio (PLR) and C-reactive protein (CRP) have been proposed as significant prognostic factors for progression and overall survival. In patients submitted to androgen deprivation therapy (ADT), inflammation may drive castration resistant PC (CRPC) development by activation of STAT3 in PC cells. NLR has been proposed as independent predictor of overall survival in CRPC submitted to chemotherapy. Most of data are focused on markers related to systemic inflammation such as NLR and CRP, more than specifically to chronic prostatic inflammation. The suggestion is that these inflammatory parameters, also if not specific for prostatic inflammation and possibly influenced by several factors other than PC, can integrate with established prognostic factors.

CXCL1 gene silencing inhibits HGC803 cell migration and invasion and acts as an independent prognostic factor for poor survival in gastric cancer

Chemokine (C-X-C motif) ligand 1 (CXCL1) is essential in oncogenesis and development of malignant tumors. The present study aimed to investigate CXCL1 expression in promoting lymph node metastasis in gastric cancer patients. Human gastric cancer cell lines were employed to detect CXCL1 expression. HGC803 cell migration and cell invasion were detected using a wound healing assay and Transwell invasion assay, respectively. A total of 100 patients who underwent radical gastric resection with lymph node dissection in the First Affiliated Hospital of Sun Yat-Sen University (Guangzhou, China) between 2007 and 2008 were included. Expression of CXCL1 and lymphatic vessel density (LMVD) was determined by using immunohistochemistry (IHC), and their association with clinicopathological features and prognosis was investigated. Cox survival regression analysis was used to analyze overall survival of patients. Results indicated that CXCL1 protein was expressed in all of investigated gastric cancer cell lines. Silencing of the CXCL1 gene reduced migratory and invasive ability of HGC803 cells. CXCL1 protein expression was detected by IHC in 41 patients (41%), these were associated with advanced tumor-node-metastasis (TNM) stage, LMVD, tumor differentiation and poor survival. LMVD was positively correlated with advanced TNM stage, size of tumor, tumor differentiation and poor survival rate. Furthermore, it was observed that TNM stage, tumor differentiation and CXCL1 were independent prognostic factors in the Cox survival regression analysis. Silencing of the CXCL1 gene inhibits HGC803 cell migration and invasion. The positive expression of CXCL1 is correlated with poor survival of gastric cancer patients and CXCL1 is an independent prognostic factor for gastric cancer.

CXCR3A contributes to the invasion and metastasis of gastric cancer cells

CXCR3, belonging to CXC chemokine receptors, has been identified to be overexpressed in various kinds of tumors. There are three mRNA variants of CXCR3 (CXCR3A, CXCR3B and CXCR3alt) in human cells. The functions of major CXCR3 isoforms (CXCR3A, CXCR3B) have been reported in some tumors including prostate and breast cancer. However, the effects of CXCR3A and CXCR3B on gastric cancer cell progression remain unknown. The present investigation found that CXCR3A mRNA level was upregulated but CXCR3B mRNA level was downregulated in gastric cancer cells and tissues. In vitro growth analysis showed that CXCR3A acted as a positive mediator in regulating cell growth, whereas CXCR3B exerted the opposite effect. In vitro invasion and migration assays showed that CXCL10 promoted gastric cancer cell invasion and migration via CXCR3A, but not CXCR3B. Moreover, knockdown of CXCR3A inhibited cell growth and metastasis in vivo. Additionally, CXCR3A knockdown attenuated matrix metalloproteinase (MMP)‑13 and IL‑6 expression, and reduced ERK1/2 activation. Together, these data suggest that CXCR3A contributes to the growth, invasion and metastasis of gastric cancer cells in vitro and in vivo, and thus may be a key mediator of gastric cancer progression.

From Inflammation to Prostate Cancer: The Role of Inflammasomes

Inflammation-associated studies entice specific attention due to inflammation's role in multiple stages of prostate cancer development. However, mechanistic regulation of inflammation inciting prostate cancer remains largely uncharacterized. A focused class of inflammatory regulators known as inflammasomes has recently gained attention in cancer development. Inflammasomes are a multiprotein complex that drives a cascade of proinflammatory cytokines regulating various cellular activities. Inflammasomes activation is linked with infection, stress, or danger signals, which are common events within the prostate gland. In this study, we review the potential of inflammasomes in understanding the role of inflammation in prostate cancer.

Therapeutic Efficacy of Cancer Stem Cell Vaccines in the Adjuvant Setting

Dendritic cell (DC)-based vaccine strategies aimed at targeting cancer stem-like cells (CSC) may be most efficacious if deployed in the adjuvant setting. In this study, we offer preclinical evidence that this is the case for a CSC-DC vaccine as tested in murine models of SCC7 squamous cell cancer and D5 melanoma. Vaccination of mice with an ALDH(high) SCC7 CSC-DC vaccine after surgical excision of established SCC7 tumors reduced local tumor relapse and prolonged host survival. This effect was augmented significantly by simultaneous administration of anti-PD-L1, an immune checkpoint inhibitor. In the minimal disease setting of D5 melanoma, treatment of mice with ALDH(high) CSC-DC vaccination inhibited primary tumor growth, reduced spontaneous lung metastases, and increased host survival. In this setting, CCR10 and its ligands were downregulated on ALDH(high) D5 CSCs and in lung tissues, respectively, after vaccination with ALDH(high) D5 CSC-DC. RNAi-mediated attenuation of CCR10 blocked tumor cell migration in vitro and metastasis in vivo T cells harvested from mice vaccinated with ALDH(high) D5 CSC-DC selectively killed ALDH(high) D5 CSCs, with additional evidence of humoral immunologic engagement and a reduction in ALDH(high) cells in residual tumors. Overall, our results offered a preclinical proof of concept for the use of ALDH(high) CSC-DC vaccines in the adjuvant setting to more effectively limit local tumor recurrence and spontaneous pulmonary metastasis, as compared with traditional DC vaccines, with increased host survival further accentuated by simultaneous PD-L1 blockade. Cancer Res; 76(16); 4661-72. ©2016 AACR.

CXCR6 expression in non-small cell lung carcinoma supports metastatic process via modulating metalloproteinases

Lung cancer (LuCa) is the leading cause of cancer-related deaths worldwide regardless of the gender. High mortality associated with LuCa is due to metastasis, molecular mechanisms of which are yet to be defined. Here, we present evidence that chemokine receptor CXCR6 and its only natural ligand, CXCL16, are significantly expressed by non-small cell lung cancer (NSCLC) and are involved in the pathobiology of LuCa. CXCR6 expression was significantly higher in two subtypes of NSCLC (adenocarcinomas-ACs and squamous cell carcinoma-SCCs) as compared to non-neoplastic tissue. Additionally, serum CXCL16 was significantly elevated in LuCa cases as compared to healthy controls. Similar to CXCR6 tissue expression, serum level of CXCL16 in AC patients was significantly higher than SCC patients. Biological significance of this axis was validated using SCC and AC cell lines. Expression of CXCR6 was higher in AC cells, which also showed higher migratory and invasive potential than SCC. Differences in migratory and invasive potential between AC and SCC were due to differential expression of metalloproteinases following CXCL16 stimulation. Hence, our findings suggest clinical and biological significance of CXCR6/CXCL16 axis in LuCa, which could be used as potential prognostic marker and therapeutic target.

β-Arrestin-2 Counters CXCR7-Mediated EGFR Transactivation and Proliferation

The atypical 7-transmembrane chemokine receptor, CXCR7, transactivates the EGFR leading to increased tumor growth in several tumor types. However, the molecular mechanism of CXCR7 ligand-independent EGFR transactivation is unknown. We used cDNA knock-in, RNAi and analysis of mitogenic signaling components in both normal prostate epithelial cells and prostate cancer cells to decipher the proliferation-inducing mechanism of the CXCR7-EGFR interaction. The data demonstrate that CXCR7-induced EGFR transactivation is independent of both the release of cryptic EGFR ligands (e.g., AREG/amphiregulin) and G-protein-coupled receptor signaling. An alternate signaling mechanism involving β-arrestin-2 (ARRB2/β-AR2) was examined by manipulating the levels of β-AR2 and analyzing changes in LNCaP cell growth and phosphorylation of EGFR, ERK1/2, Src, and Akt. Depletion of β-AR2 in LNCaP cells increased proliferation/colony formation and significantly increased activation of Src, phosphorylation of EGFR at Tyr-1110, and phosphorylation/activation of ERK1/2 compared with that with control shRNA. Moreover, β-AR2 depletion downregulated the proliferation suppressor p21. Stimulation of β-AR2-expressing cells with EGF resulted in rapid nuclear translocation of phosphorylated/activated EGFR. Downregulation of β-AR2 enhanced this nuclear translocation. These results demonstrate that β-AR2 is a negative regulator of CXCR7/Src/EGFR-mediated mitogenic signaling.

IMPLICATIONS

This study reveals that β-AR2 functions as a tumor suppressor, underscoring its clinical importance in regulating CXCR7/EGFR-mediated tumor cell proliferation. Mol Cancer Res; 14(5); 493-503. ©2016 AACR.

Periprostatic adipocytes act as a driving force for prostate cancer progression in obesity

Obesity favours the occurrence of locally disseminated prostate cancer in the periprostatic adipose tissue (PPAT) surrounding the prostate gland. Here we show that adipocytes from PPAT support the directed migration of prostate cancer cells and that this event is strongly promoted by obesity. This process is dependent on the secretion of the chemokine CCL7 by adipocytes, which diffuses from PPAT to the peripheral zone of the prostate, stimulating the migration of CCR3 expressing tumour cells. In obesity, higher secretion of CCL7 by adipocytes facilitates extraprostatic extension. The observed increase in migration associated with obesity is totally abrogated when the CCR3/CCL7 axis is inhibited. In human prostate cancer tumours, expression of the CCR3 receptor is associated with the occurrence of aggressive disease with extended local dissemination and a higher risk of biochemical recurrence, highlighting the potential benefit of CCR3 antagonists in the treatment of prostate cancer.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

The human chemokine receptor CCRL2 suppresses chemotaxis and invasion by blocking CCL2-induced phosphorylation of p38 MAPK in human breast cancer cells

The human chemokine receptor CCRL2 is a member of the atypical chemokine receptor family. CCRL2 is unable to couple with G-proteins and fails to induce classical chemokine signaling for the highly conserved DRYLAIV motif essential for signaling has been changed to QRYLVFL. We investigated whether CCRL2 is involved in the chemotaxis, invasion, and proliferation of human breast cancer cells. Firstly, expression of CCRL2 was determined in six breast cancer cell lines by real-time RT-PCR and Western blot. Then, we established stable cell lines overexpressing CCRL2 to explore the function of CCRL2 in chemotaxis and invasion by transwell assays, and the signaling downstream was further investigated. The effect of CCRL2 on proliferation was detected by colony formation assays and tumor xenograft study. We found that stable overexpression of CCRL2 in MDA-MB-231 and BT-549 cells attenuated the chemotaxis and invasion stimulated by its ligand CCL2. CCRL2 inhibits p38 MAPK (p38) phosphorylation and up-regulates the expression of E-cadherin. This effect was eliminated by the inhibitor of p38 MAPK. CCRL2 inhibited the growth of breast cancer cells in vitro and in vivo. Our results suggest that CCRL2 functions as a tumor suppressor in human breast cancer cells.

Chimeric antigen receptor-engineered T cells for the treatment of metastatic prostate cancer

Cancer immunotherapy was selected as the Breakthrough of the Year 2013 by the editors of Science, in part because of the successful treatment of refractory hematological malignancies with adoptive transfer of chimeric antigen receptor (CAR)-engineered T cells. Effective treatment of B cell leukemia may pave the road to future treatment of solid tumors, using similar approaches. The prostate expresses many unique proteins and, since the prostate gland is a dispensable organ, CAR T cells can potentially be used to target these tissue-specific antigens. However, the location and composition of prostate cancer metastases complicate the task of treating these tumors. It is therefore likely that more sophisticated CAR T cell approaches are going to be required for prostate metastasis than for B cell malignancies. Two main challenges that need to be resolved are how to increase the migration and infiltration of CAR T cells into prostate cancer bone metastases and how to counteract the immunosuppressive microenvironment found in bone lesions. Inclusion of homing (chemokine) receptors in CAR T cells may improve their recruitment to bone metastases, as may antibody-based combination therapies to normalize the tumor vasculature. Optimal activation of CAR T cells through the introduction of multiple costimulatory domains would help to overcome inhibitory signals from the tumor microenvironment. Likewise, combination therapy with checkpoint inhibitors that can reduce tumor immunosuppression may help improve efficacy. Other elegant approaches such as induced expression of immune stimulatory cytokines upon target recognition may also help to recruit other effector immune cells to metastatic sites. Although toxicities are difficult to predict in prostate cancer, severe on-target/off-tumor toxicities have been observed in clinical trials with use of CAR T cells against hematological malignancies; therefore, the choice of the target antigen is going to be crucial. This review focuses on different means of accomplishing maximal effectiveness of CAR T cell therapy for prostate cancer bone metastases while minimizing side effects and CAR T cell-associated toxicities. CAR T cell-based therapies for prostate cancer have the potential to be a therapy model for other solid tumors.

CsCCL17, a CC chemokine of Cynoglossus semilaevis, induces leukocyte trafficking and promotes immune defense against viral infection

CC chemokines are the largest subfamily of chemokines, which are important components of the innate immune system. To date, sequences of several CC chemokines have been identified in half-smooth tongue sole (Cynoglossus semilaevis); however, the activities and functions of these putative chemokines remain unknown. Herein, we characterized a CC chemokine, CsCCL17, from tongue sole, and examined its activity. CsCCL17 contains a 303 bp open reading frame, which encodes a polypeptide of 100 amino acids with a molecular mass of 12 kDa CsCCL17 is phylogenetically related to the CCL17/22 group of CC chemokines and possesses the typical arrangement of four cysteines and an SCCR motif found in known CC chemokines. Under normal physiological conditions, CsCCL17 expression was detected in spleen, liver, heart, gill, head kidney, muscle, brain, and intestine. When the fish were infected by bacterial and viral pathogens, CsCCL17 expression was significantly up-regulated in a time-dependent manner. Chemotactic analysis showed that recombinant CsCCL17 (rCsCCL17) induced migration of peripheral blood leukocytes. A mutagenesis study showed that when the two cysteine residues in the SCCR motif were replaced by serine, no apparent chemotactic activity was observed in the mutant protein rCsCCL17M. rCsCCL17 enhanced the resistance of tongue sole against viral infection, but rCsCCL17M lacked this antiviral effect. Taken together, these findings indicate that CsCCL17 is a functional CC chemokine with the ability to recruit leukocytes and enhance host immune defense in a manner that requires the conserved SCCR motif.

Monocyte-Induced Prostate Cancer Cell Invasion is Mediated by Chemokine ligand 2 and Nuclear Factor-κB Activity

STUDY BACKGROUND

The tumor microenvironment contains inflammatory cells which can influence cancer growth and progression; however the mediators of these effects vary with different cancer types. The mechanisms by which prostate cancer cells communicate with monocytes to promote cancer progression are incompletely understood. This study tested prostate cancer cell and monocyte interactions that lead to increased prostate cancer cell invasion.

METHODS

We analyzed the prostate cancer cell invasion and NF-κB activity and cytokine expression during interaction with monocyte-lineage cells in co-cultures. The roles of monocyte chemotactic factor (MCP-1/CCL2) and NF-κB activity for co-culture induced prostate cancer invasion were tested. Clinical prostate cancer NF-κB expression was analyzed by immunohistochemistry.

RESULTS

In co-cultures of prostate cancer cell lines with monocyte-lineage cells, (C-C motif) ligand 2 (CCL2) levels were significantly increased when compared with monocytes or cancer cells cultured alone. Prostate cancer cell invasion was induced by recombinant CCL2 in a dose dependent manner, similar to co-cultures with monocytes. The monocyte-induced prostate cancer cell invasion was inhibited by CCL2 neutralizing antibodies and by the CCR2 inhibitor, RS102895. Prostate cancer cell invasion and CCL2 expression induced in the co-cultures was inhibited by Lactacystin and Bay11-7082 NF-κB inhibitors. Prostate cancer cell NF-κB DNA binding activity depended on CCL2 dose and was inhibited by CCL2 neutralizing antibodies. Clinical prostate cancer NF-κB expression correlated with tumor grade.

CONCLUSIONS

Co-cultures with monocyte-lineage cell lines stimulated increased prostate cancer cell invasion through increased CCL2 expression and increased prostate cancer cell NF-κB activity. CCL2 and NF-κB may be useful therapeutic targets to interfere with inflammation-induced prostate cancer invasion.

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.

Inflammation and prostate cancer: friends or foe?

INTRODUCTION

Prostate cancer is the most common non-cutaneous malignancy diagnosed in men. Moving from histological observations since a long time, it has been recognized that innate and adaptive immunity actively participates in the pathogenesis, surveillance, and progression of prostate cancer.

MATERIALS AND METHODS

A PubMed and Web of Science databases search was performed for studies providing evidence on the roles of the innate and adaptive immunity during the development and progression of prostate cancer.

CONCLUSIONS

There are growing evidences that chronic inflammation is involved in the regulation of cellular events in prostate carcinogenesis, including disruption of the immune response and regulation of the tumor microenvironment. This review discusses the role played by the innate and adaptive immune system in the local progression of prostate cancer, and the prognostic information that we can currently understand and exploit.