Attenuation of CXCR4 responses by CCL18 in acute lymphocytic leukemia B cells

Analysis of prognostic value of lactate metabolism-related genes in ovarian cancer based on bioinformatics

BACKGROUND

Recent studies have provided evidence supporting the functional role and mechanism of lactate in suppressing anticancer immunity. However, there is no systematic analysis of lactate metabolism-related genes (LMRGs) and ovarian cancer (OV) prognosis.

RESULTS

Six genes (CCL18, CCND1, MXRA5, NRBP2, OLFML2B and THY1) were selected as prognostic genes and a prognostic model was utilized. Kaplan-Meier (K-M) and Receiver Operating Characteristic (ROC) analyses were further performed and indicated that the prognostic model was effective. Subsequently, the neoplasm_cancer_status and RiskScore were determined as independent prognostic factors, and a nomogram was established with relatively accurate forecasting ability. Additionally, 2 types of immune cells (Central memory CD8 T cell and Immature B cell), 4 types of immune functions (APC co inhibition, DCs, Tfh and Th1 cells), 9 immune checkpoints (BTLA, CTLA4, IDO1, LAG3, VTCN1, CXCL10, CXCL9, IFNG, CD27) and tumor immune dysfunction and exclusion (TIDE) scores were significantly different between risk groups. The expression of 6 genes were verified by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and the expression of 6 genes were higher in the high-grade serous carcinoma (HGSC) samples.

CONCLUSION

A prognostic model related to lactate metabolism was established for OV based on six genes (CCL18, CCND1, MXRA5, NRBP2, OLFML2B and THY1) that could provide new insights into therapy.

Histone modification-linked prognostic model for ovarian cancer reveals LBX2 as a novel growth promoter

Ovarian cancer (OC) is a deadly disease with limited treatment options and poor overall survival rates. This study aimed to investigate the role of histone modification-related genes in predicting the prognosis of OC patients. Transcriptome data from multiple cohorts, including bulk RNA-Seq data and single-cell scRNA-Seq data, were collected. Gene set enrichment analysis was used to identify enriched gene sets in the histone modification pathway. Differentially expressed genes (DEGs) between histone modification-high and histone modification-low groups were identified using Lasso regression. A prognostic model was constructed using five selected prognostic genes from the DEGs in the TCGA-OV cohort. The study found enrichment of gene sets in the histone modification pathway and identified five prognostic genes associated with OC prognosis. The constructed risk score model based on histone modification-related genes was correlated with immune infiltration of T cells and M1 macrophages. Mutations are more prevalent in the high-risk group compared to the low-risk group. Several drugs were screened against the model genes. Through in vitro experiments, we confirmed the expression patterns of the model genes. LBX2 facilitates the proliferation of OC. Histone modification-related genes have the potential to serve as biomarkers for predicting OC prognosis. Targeting these genes may lead to the development of more effective therapies for OC. Additionally, LBX2 represents a novel cell proliferation promoter in OC carcinogenesis.

Pro-Fibrotic Effects of CCL18 on Human Lung Fibroblasts Are Mediated via CCR6

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease of unknown origin, with a median patient survival time of ~3 years after diagnosis without anti-fibrotic therapy. It is characterized by progressive fibrosis indicated by increased collagen deposition and high numbers of fibroblasts in the lung. It has been demonstrated that CCL18 induces collagen and αSMA synthesis in fibroblasts. We aimed to identify the CCL18 receptor responsible for its pro-fibrotic activities.

METHODS

We used a random phage display library to screen for potential CCL18-binding peptides, demonstrated its expression in human lungs and fibroblast lines by PCR and immunostaining and verified its function in cell lines.

RESULTS

We identified CCR6 (CD196) as a CCL18 receptor and found its expression in fibrotic lung tissue and lung fibroblast lines derived from fibrotic lungs, but it was almost absent in control lines and tissue. CCL18 induced receptor internalization in a CCR6-overexpressing cell line. CCR6 blockade in primary human lung fibroblasts reduced CCL18-induced FGF2 release as well as collagen-1 and αSMA expression. Knockdown of CCR6 in a mouse fibroblast cell line abolished the induction of collagen and α-smooth muscle actin expression.

CONCLUSION

Our data indicate that CCL18 triggers pro-fibrotic processes via CCR6, highlighting its role in fibrogenesis.

Identification and validation of a CCL18-related signature for prediction of overall survival in patients with uveal melanoma

Uveal melanoma (UM), the most frequent primary intraocular tumor in adults, has poor prognosis. High C-C motif chemokine ligand 18 (CCL18) has been detected in various tumors and is closely correlated with patients' clinicopathological characteristics. However, the essential role of CCL18 in UM remains unclear. Therefore, this study aimed to explore the prognostic value of CCL18 in UM. Uveal melanoma cells (M17) were transfected with pcDNA3.1-CCL18 si-RNA using Lipofectamine™ 2000. Cell growth and invasion abilities were measured through Cell Counting Kit-8 assay and invasion assay. RNA expression data and clinical and histopathological details were downloaded from the UM in The Cancer Genome Atlas (TCGA-UM) and GSE22138 datasets, which were defined as the training and validation cohorts, respectively. Univariate and multivariate Cox regression analyses were performed to identify significant prognostic biomarkers. The coefficients of these significant biomarkers generated by multivariate Cox proportional hazard regression analysis were used to establish a risk score formula. Functional enrichment analyses were also carried out. We found that downregulated CCL18 inhibits M17 cell growth and invasion in vitro. CCL18 may affect UM progression by altering C-C motif receptor 8 related pathways. Higher CCL18 expression was associated with worse clinical outcomes and tumor-specific death in the TCGA-UM dataset. Based on the coefficients obtained from the Cox proportional hazard regression analysis, a CCL18-related prognostic signature formula was constructed as follows: risk score = 0.05590 × age +2.43437 × chromosome 3 status +0.39496 × Expression^CCL18. Notably, in this formula, the normal chromosome 3 was coded as 0, whereas the chromosome 3 loss was coded as 1. Each patient was assigned to either low-risk or high-risk groups using the median cut-off in the training cohort. High-risk patients survived for a shorter time than low-risk patients. The time-dependent and multivariate receiver operating characteristic curves showed promising diagnostic efficacy. Multivariate Cox regression analysis demonstrated the potential of this CCL18-related signature as an independent prognostic indicator. These results were validated using the GSE22138 dataset. In addition, in both TCGA-UM and GSE22138 datasets, stratification of clinical correlations and survival analyses based on this signature indicated the involvement of clinical progression and survival outcome in UM. In the high-risk group, Gene Ontology analyses mainly indicated the enrichment of immune response pathways, such as the T cell activation, response to interferon-gamma, antigen processing and presentation, interferon-gamma-mediated signaling pathway, MHC protein complex, MHC class II protein complex, antigen binding, and cytokine binding. Meanwhile, Kyoto Encyclopedia of Genes and Genomes analyses showed enrichments of pathways in cancer, cell adhesion, cytokine-cytokine receptor interaction, chemokine signaling pathway, Th1 and Th2 cell differentiation, and chemokine signaling pathway. Moreover, single-sample gene set enrichment analysis demonstrated the enrichment of almost all immune cells and immune functions in the high-risk group. In summary, a new prognostic CCL18-related signature was successfully established using the TCGA-UM dataset and validated using the GSE22138 dataset with meaningful predictive and diagnostic efficacies. This signature could serve as an independent and promising prognostic biomarker for patients with UM.

Specific lncRNA signatures discriminate childhood acute leukaemias: a pilot study

BACKGROUND

Long non-coding RNAs are RNAs longer than 200 bps that do not encode any proteins and are able to alter gene expression by acting on different steps of regulation, including DNA methylation and chromatin structure. They represent a class of biomarkers of crescent interest in the hematologic and oncologic fields. Recent studies showed that the expression levels of specific lncRNAs correlate with the prognosis of paediatric patients with Acute Lymphoblastic Leukaemia.

METHODS

We used NGS approaches to analyse the transcriptome of 9 childhood B-ALL patients and 6 childhood T-ALL patients, in comparison with B and T healthy lymphocytes from cord blood. We validate our findings both ex vivo, in a different cohort of 10 B-ALL and 10 T-ALL patients, and in silico using public datasets.

RESULTS

We characterised the lncRNA landscape for B-ALL, T-ALL, healthy B, and T cell progenitors. From the characterised signature, we selected candidate lncRNAs able to discriminate not only B-ALL and T-ALL from healthy subjects but also between the two types of leukaemia, and subsequently validated their potential as a diagnostic tool in an additional cohort of paediatric patients. We confirmed our finding with open access transcriptomic data, comparing ALL lncRNAs with AML lncRNA landscape as well. Finally, expression correlation analyses of T-ALL selected lncRNA biomarkers suggested a possible role in lymphocyte activation and the β-catenin signalling pathway for AC247036.1 and involvement in hedgehog signalling for HHIP-AS1.

CONCLUSIONS

Our work identified a lncRNA signature discriminating paediatric B-ALL and T-ALL from healthy subjects, between them and from AML. This study provides the keystone to future clinical studies determining the theragnostic value of the characterised long non coding transcriptome panorama in a clinical setting for childhood patient management.

The G-Protein–Coupled Estrogen Receptor Agonist G-1 Inhibits Proliferation and Causes Apoptosis in Leukemia Cell Lines of T Lineage

The G-protein–coupled estrogen receptor (GPER) mediates non-genomic action of estrogen. Due to its differential expression in some tumors as compared to the original healthy tissues, the GPER has been proposed as a therapeutic target. Accordingly, the non-steroidal GPER agonist G-1, which has often demonstrated marked cytotoxicity in experimental models, has been suggested as a novel anticancer agent for several sensitive tumors. We recently revealed that cell lines derived from acute T-cell (query) lymphoblastic leukemia (T-ALL) express the GPER. Here, we address the question whether G-1 is cytotoxic to T-ALL. We have shown that G-1 causes an early rise of intracellular Ca²⁺, arrests the cell cycle in G2/M, reduces viability, and provokes apoptosis in T-ALL cell lines. Importantly, G-1 caused destabilization and depolymerization of microtubules. We assume that it is a disturbance of the cytoskeleton that causes G-1 cytotoxic and cytostatic effects in our model. The observed cytotoxic effects, apparently, were not triggered by the interaction of G-1 with the GPER as pre-incubation with the highly selective GPER antagonist G-36 was ineffective in preventing the cytotoxicity of G-1. However, G-36 prevented the intracellular Ca²⁺ rise provoked by G-1. Finally, G-1 showed only a moderate negative effect on the activation of non-leukemic CD4⁺ lymphocytes. We suggest G-1 as a potential antileukemic drug.

A multi-cellular molecular signaling and functional network map of C-C motif chemokine ligand 18 (CCL18): a chemokine with immunosuppressive and pro-tumor functions

The C-C Motif Chemokine Ligand 18 (CCL18) is a beta-chemokine sub-family member with immunomodulatory functions in primates. CCL18-dependent migration and epithelial-to-mesenchymal transition of oral squamous cell carcinoma, squamous cell carcinoma of head and neck, breast cancer, hepatocellular carcinoma, non-small cell lung carcinoma, ovarian cancer, pancreatic ductal carcinoma and bladder cancer cells are well-established. In the tumor niche, tumor-associated macrophages produce CCL18 and its overexpression is correlated with reduced patient survival in multiple cancers. Although multiple receptors including C-C chemokine receptor type 3 (CCR3), type 6 (CCR6), type 8 (CCR8) and G-protein coupled estrogen receptor (GPER1) are reported for CCL18, the Phosphatidylinositol Transfer Protein, Membrane-Associated 3 (PITPNM3) receptor is currently considered as its predominant receptor. Characterization of the molecular events and check points associated with the immunosuppressive and cancer progression support functions induced by CCL18 for their potential towards therapeutic applications is an area of active research. Hence, in this study, we assembled 917 signaling events reported to be induced by CCL18 through their studied receptors in diverse cell types as an integrated knowledgebase for reference, data integration and gene-set enrichment analysis of global transcriptomic and/or proteomics datasets.

PARC/CCL18 is Associated with Inflammation, Emphysema Severity and Application of Inhaled Corticosteroids in Hospitalized COPD Patients

Background

Pulmonary and activation-regulated chemokine (PARC) also named CC-chemokine ligand 18 (CCL18) is a lung-predominant inflammatory protein that is found in serum. The relationship of PARC/CCL18 with the chronic obstructive pulmonary disease (COPD) is not fully understood. The aim of the present study is to analyze the expression of PARC/CCL18 in COPD.

Methods

Ninety-eight hospitalized COPD patients and 60 healthy volunteers from January 2019 to December 2019 were recruited in this retrospective study. Gender, age, height, weight, disease duration, smoking status, blood cell classification and count, length of hospital stay (LOS), symptom score, including COPD Assessment Test (CAT) score, modified British Medical Research Council (mMRC) score, lung function and therapy were recorded and serum PARC/CCL18 was analyzed by ELISA. The correlation between symptom score, blood cell classification and count, CRP, lung function parameters and serum levels of PARC/CCL18 and ROC curves of PARC/CCL18 levels and inhaled corticosteroids (ICS) were accessed.

Results

It was found that serum PARC/CCL18 level in hospitalized COPD population was significantly higher than that in healthy people (p=0.003). COPD patients with emphysema had significantly higher serum level of PARC/CCL18 than those without emphysema (p=0.049). Total lung capacity (TLC) and residual volume (RV)/TLC had positive correlation with serum level of PARC/CCL18 (p=0.001, 0.020, respectively). Furthermore, serum PARC/CCL18 level was predictive for the application ICS (p=0.003) and related to C-reactive protein (p <0.0001) in hospitalized COPD patients.

Conclusion

PARC/CCL18 is associated with the severity of inflammation and emphysema in COPD. Furthermore, PARC/CCL18 is a predictor of ICS application in the treatment of hospitalized COPD patients.

Natural Killer Cells from Allergic Donors Are Defective in Their Response to CCL18 Chemokine

Natural killer (NK) cells were originally described as cytolytic effector cells, but since then have been recognized to possess regulatory functions on immune responses. Chemokines locate NK cells throughout the body in homeostatic and pathological conditions. They may also directly stimulate immune cells. CCL18 is a constitutive and inducible chemokine involved in allergic diseases. The aim of this study was to evaluate CCL18’s effect on NK cells from allergic and nonallergic donors in terms of both chemotactic and immune effects. Results showed that CCL18 was able to induce migration of NK cells from nonallergic donors in a G-protein-dependent manner, suggesting the involvement of a classical chemokine receptor from the family of seven-transmembrane domain G-protein-coupled receptors. In contrast, NK cells from allergic patients were unresponsive. Similarly, CCL18 was able to induce NK cell cytotoxicity only in nonallergic subjects. Purified NK cells did not express CCR8, one of the receptors described to be involved in CCL18 functions. Finally, the defect in CCL18 response by NK cells from allergic patients was unrelated to a defect in CCL18 binding to NK cells. Overall, our results suggest that some NK cell functions may be defective in allergic diseases.

The immunosuppressive and pro-tumor functions of CCL18 at the tumor microenvironment

Chemokines are essential mediators of immune cell trafficking. In a tumor microenvironment context, chemotactic cytokines are known to regulate the migration, positioning and interaction of different cell subsets with both anti- and pro-tumor functions. Additionally, chemokines have critical roles regarding non-immune cells, highlighting their importance in tumor growth and progression. CCL18 is a primate-specific chemokine produced by macrophages and dendritic cells. This chemokine presents both constitutive and inducible expression. It is mainly associated with a tolerogenic response and involved in maintaining homeostasis of the immune system under physiological conditions. Recently, CCL18 has been noticed as an important component of the complex chemokine system involved in the biology of tumors. This chemokine induces T regulatory cell differentiation and recruitment to the tumor milieu, with subsequent induction of a pro-tumor (M2-like) macrophage phenotype. CCL18 is also directly involved in cancer cell-invasion, migration, epithelial-to-mesenchymal transition and angiogenesis stimulation, pinpointing an important role in the promotion of cancer progression. Interestingly, this chemokine is highly expressed in tumor tissues, particularly at the invasive front of more advanced stages (e.g. colorectal cancer), and high levels are detected in the serum of patients, correlating with poor prognosis. Despite the promising role of CCL18 as a biomarker and/or therapeutic target to hamper disease progression, its pleiotropic functions in a context of cancer are still poorly explored. The scarce knowledge concerning the receptors for this chemokine, together with the insufficient insight on the downstream signaling pathways, have impaired the selection of this molecule as an immediate target for translational research. In this Review, we will discuss recent findings concerning the role of CCL18 in cancer, integrate recently disclosed molecular mechanisms and compile data from current clinical studies.

Targeting chemokines for acute lymphoblastic leukemia therapy

Acute lymphoblastic leukemia (ALL) is a hematological malignancy characterized by the malignant clonal expansion of lymphoid hematopoietic precursors. It is regulated by various signaling molecules such as cytokines and adhesion molecules in its microenvironment. Chemokines are chemotactic cytokines that regulate migration, positioning and interactions of cells. Many chemokine axes such as CXCL12/CXCR4 and CCL25/CCR9 have been proved to play important roles in leukemia microenvironment and further affect ALL outcomes. In this review, we summarize the chemokines that are involved in ALL progression and elaborate on their roles and mechanisms in leukemia cell proliferation, infiltration, drug resistance and disease relapse. We also discuss the potential of targeting chemokine axes for ALL treatments, since many related inhibitors have shown promising efficacy in preclinical trials, and some of them have entered clinical trials.

CCL18 in the Progression of Cancer

A neoplastic tumor consists of cancer cells that interact with each other and non-cancerous cells that support the development of the cancer. One such cell are tumor-associated macrophages (TAMs). These cells secrete many chemokines into the tumor microenvironment, including especially a large amount of CCL18. This chemokine is a marker of the M2 macrophage subset; this is the reason why an increase in the production of CCL18 is associated with the immunosuppressive nature of the tumor microenvironment and an important element of cancer immune evasion. Consequently, elevated levels of CCL18 in the serum and the tumor are connected with a worse prognosis for the patient. This paper shows the importance of CCL18 in neoplastic processes. It includes a description of the signal transduction from PITPNM3 in CCL18-dependent migration, invasion, and epithelial-to-mesenchymal transition (EMT) cancer cells. The importance of CCL18 in angiogenesis has also been described. The paper also describes the effect of CCL18 on the recruitment to the cancer niche and the functioning of cells such as TAMs, regulatory T cells (T_reg), cancer-associated fibroblasts (CAFs) and tumor-associated dendritic cells (TADCs). The last part of the paper describes the possibility of using CCL18 as a therapeutic target during anti-cancer therapy.

CC Chemokines in a Tumor: A Review of Pro-Cancer and Anti-Cancer Properties of Receptors CCR5, CCR6, CCR7, CCR8, CCR9, and CCR10 Ligands

CC chemokines (or β-chemokines) are 28 chemotactic cytokines with an N-terminal CC domain that play an important role in immune system cells, such as CD4⁺ and CD8⁺ lymphocytes, dendritic cells, eosinophils, macrophages, monocytes, and NK cells, as well in neoplasia. In this review, we discuss human CC motif chemokine ligands: CCL1, CCL3, CCL4, CCL5, CCL18, CCL19, CCL20, CCL21, CCL25, CCL27, and CCL28 (CC motif chemokine receptor CCR5, CCR6, CCR7, CCR8, CCR9, and CCR10 ligands). We present their functioning in human physiology and in neoplasia, including their role in the proliferation, apoptosis resistance, drug resistance, migration, and invasion of cancer cells. We discuss the significance of chemokine receptors in organ-specific metastasis, as well as the influence of each chemokine on the recruitment of various cells to the tumor niche, such as cancer-associated fibroblasts (CAF), Kupffer cells, myeloid-derived suppressor cells (MDSC), osteoclasts, tumor-associated macrophages (TAM), tumor-infiltrating lymphocytes (TIL), and regulatory T cells (T_reg). Finally, we show how the effect of the chemokines on vascular endothelial cells and lymphatic endothelial cells leads to angiogenesis and lymphangiogenesis.

CCL18-induced HOTAIR upregulation promotes malignant progression in esophageal squamous cell carcinoma through the miR-130a-5p-ZEB1 axis

Accumulating evidence indicates that CCL18 and the long non-coding RNA, HOTAIR, have critical roles in cancer progression and metastasis, but the correlation between CCL18 and HOTAIR in esophageal squamous cell carcinoma (ESCC) and their downstream molecular mechanisms remain unclear. Overexpression of CCL18 in ESCC tissues was associated with a worse survival in patients with ESCC. CCL18 enhanced the invasiveness of ESCC cells in a dose-dependent manner, whereas CCL18 knockdown inhibited their invasiveness. In particular, CCL18 expression was positively associated with HOTAIR expression in ESCC tissues. Furthermore, CCL18 upregulated the expression of HOTAIR, and knockdown of HOTAIR alleviated the CCL18-induced invasiveness of ESCC cells. HOTAIR may act as a competing endogenous RNA and could effectively becoming a sponge for miR-130a-5p, thereby modulating the derepression of ZEB1 and promoting epithelial-mesenchymal transition in ESCC. Our study suggests that CCL18 contributes to the malignant progression of esophageal cancer by upregulating HOTAIR expression. HOTAIR overexpression may promote tumor invasiveness and progression in ESCC, given that HOTAIR functions as a miR-130a-5p sponge, positively regulating ZEB1. This provides new therapeutic targets for early diagnosis and treatment of ESCC.

Immune Tumor Microenvironment in Breast Cancer and the Participation of Estrogen and Its Receptors in Cancer Physiopathology

Breast cancer is characterized by cellular and molecular heterogeneity. Several molecular events are involved in controlling malignant cell process. In this sense, the importance of studying multiple cell alterations in this pathology is overriding. A well-identified fact on immune response is that it can vary depend on sex. Steroid hormones and their receptors may regulate different functions and the responses of several subpopulations of the immune system. Few reports are focused on the function of estrogen receptors (ERs) on immune cells and their roles in different breast cancer subtypes. Thus, the aim of this review is to investigate the immune infiltrating tumor microenvironment and prognosis conferred by it in different breast cancer subtypes, discuss the current knowledge and point out the roles of estrogens and its receptors on the infiltrating immune cells, as well as to identify how different immune subsets are modulated after anti-hormonal treatments in breast cancer patients.

GPER activation protects against epithelial barrier disruption by Staphylococcus aureus α-toxin

Sex bias in innate defense against Staphylococcus aureus skin and soft tissue infection (SSTI) is dependent on both estrogen production by the host and S. aureus secretion of the virulence factor, α-hemolysin (Hla). The impact of estrogen signaling on the immune system is most often studied in terms of the nuclear estrogen receptors ERα and ERβ. However, the potential contribution of the G protein-coupled estrogen receptor (GPER) to innate defense against infectious disease, particularly with respect to skin infection, has not been addressed. Using a murine model of SSTI, we found that GPER activation with the highly selective agonist G-1 limits S. aureus SSTI and Hla-mediated pathogenesis, effects that were absent in GPER knockout mice. Specifically, G-1 reduced Hla-mediated skin lesion formation and pro-inflammatory cytokine production, while increasing bacterial clearance. In vitro, G-1 reduced surface expression of the Hla receptor, ADAM10, in a human keratinocyte cell line and increased resistance to Hla-mediated permeability barrier disruption. This novel role for GPER activation in skin innate defense against infectious disease suggests that G-1 may have clinical utility in patients with epithelial permeability barrier dysfunction or who are otherwise at increased risk of S. aureus infection, including those with atopic dermatitis or cancer.

Tamoxifen induces toxicity, causes autophagy, and partially reverses dexamethasone resistance in Jurkat T cells

Estrogens demonstrate biological activity in numerous organ systems, including the immune system, and exert their effects through estrogen receptors (ER) of two types: intracellular ERα and ERβ that activate transcriptional factors and membrane G protein-coupled ER GPER. The latter is capable to mediate fast activation of cytosolic signaling pathways, influencing transcriptional events in response to estrogens. Tamoxifen (TAM), widely used in chemotherapy of ERα-positive breast cancer, is considered as an ERα antagonist and GPER agonist. TAM was shown to possess "off-target" cytotoxicity, not related to ER in various tumor types. The present work was designed to study biological effects of TAM on the glucocorticoid (GC)-resistant cell line Jurkat, derived from acute lymphoblastic leukemia of T lineage (T-ALL). We have shown that T-ALL cell lines, in contrast to healthy T cells, express only GPER, but not ERα or ERβ. TAM compromised mitochondrial function and reduced the viability and proliferation of Jurkat cells. Additionally, TAM induced autophagy in a GPER-dependent manner. Gene expression profiling revealed the up-regulation of autophagy-related gene ATG5. Interestingly, TAM sensitized Jurkat cells to dexamethasone (DEX) treatment, which may be related to its capacity to cause autophagy. We suggest that TAM-based adjuvant therapy may represent a novel strategy in T-ALL patients handling.

CCL18 enhances migration, invasion and EMT by binding CCR8 in bladder cancer cells

Increased expression of CCL18 has been observed in various malignancies and in the urine samples of patients with bladder cancer (BC). However, the roles of CCL18 in the development, progression and metastasis of BC remain unclear. The present study demonstrated that CCL18 expression was significantly associated with advanced clinical stages of BC. Furthermore, exogenous CCL18 promoted cell invasion and migration, and induced cell epithelial-mesenchymal transition (EMT) in BC cells. Western blotting demonstrated that E-cadherin, an epithelial marker, was decreased, whereas matrix metalloproteinase (MMP)-2 and vascular endothelial growth factor (VEGF)-C were increased in CCL18-treated cells. Blocking CCR8 via a small molecule inhibitor or short hairpin (sh)RNA mitigated the decrease in E-cadherin, and increase in MMP-2 and VEGF-C, caused by human recombinant (r)CCL18. CCR8 knockdown by shRNA reversed rCCL18-induced cancer cell invasion, migration and EMT. In conclusion, these data suggested that CCL18 may promote migration, invasion and EMT by binding CCR8 in BC cells. Inhibition of CCL18 activity by blocking CCR8 could be a potential therapeutic strategy for preventing the progression of BC.

CCL18 - Beyond chemotaxis

The chemokine CCL18 is constitutively expressed in human lung and serum, and is further elevated during pathologic conditions such as allergy, fibrosis and cancer, suggesting that it may participate in both homeostatic and inflammatory processes. Under steady state conditions, CCL18 has chemotactic activity, albeit modest, toward naïve T cells and as such, may be involved in the initiation of the adaptive response. Its chemotactic effect on inflammatory cells is ambiguous as it attracts both regulatory and inflammatory immune cells. CCL18 can also modulate tissue inflammation by inhibiting cell recruitment through binding to glycosaminoglycans with high affinity, thereby displacing other chemokines bound to the endothelial surface. CCL18 induces regulatory phenotype and function of immune cells through direct activation and plays a major role in fibrotic processes, particularly in the lung. Finally, CCL18 is involved in cancer cell activation and migration and also participates in immune tolerance toward cancer. Its high constitutive expression levels and its further up-regulation in many diseases, together with its moderate chemoattractant properties support the fact that this chemokine has activities beyond cell recruitment.

Elevated autocrine chemokine ligand 18 expression promotes oral cancer cell growth and invasion via Akt activation

Chemokine (C-C motif) ligand 18 (CCL18) has been implicated in the pathogenesis and progression of various cancers; however, in oral squamous cell carcinoma (OSCC), the role of CCL18 is unknown. In this study, we found that CCL18 was overexpressed in primary OSCC tissues and was associated with an advanced clinical stage. CCL18 was found in both the cytoplasm and cell membrane of OSCC cells and was predominantly produced by cancer epithelial cells, as opposed to tumor-infiltrating macrophages. In vitro studies indicated that the effects of endogenous CCL18 on OSCC cell growth, migration, and invasion could be blocked by treatment with a neutralizing anti-CCL18 antibody or CCL18 knockdown, while exogenous recombinant CCL18 (rCCL18) rescued those effects. Akt was activated in rCCL18-treated OSCC cells, while LY294002, a pan-PI3K inhibitor, abolished both endogenous and exogenous CCL18-induced OSCC cell invasion. In vivo, LY294002 treatment attenuated rCCL18-induced OSCC cell growth. Our results indicate that CCL18 acts in an autocrine manner via Akt activation to stimulate OSCC cell growth and invasion during OSCC progression. They also provide a potential therapeutic target for the treatment of oral cancer.

The role of G protein-coupled receptors in lymphoid malignancies

B cell lymphoma consists of multiple individual diseases arising throughout the lifespan of B cell development. From pro-B cells in the bone marrow, through circulating mature memory B cells, each stage of B cell development is prone to oncogenic mutation and transformation, which can lead to a corresponding lymphoma. Therapies designed against individual types of lymphoma often target features that differ between malignant cells and the corresponding normal cells from which they arise. These genetic changes between tumor and normal cells can include oncogene activation, tumor suppressor gene repression and modified cell surface receptor expression. G protein-coupled receptors (GPCRs) are an important class of cell surface receptors that represent an ideal target for lymphoma therapeutics. GPCRs bind a wide range of ligands to relay extracellular signals through G protein-mediated signaling cascades. Each lymphoma subgroup expresses a unique pattern of GPCRs and efforts are underway to fully characterize these patterns at the genetic level. Aberrations such as overexpression, deletion and mutation of GPCRs have been characterized as having causative roles in lymphoma and such studies describing GPCRs in B cell lymphomas are summarized here.

GPER-1/GPR30 a novel estrogen receptor sited in the cell membrane: therapeutic coupling to breast cancer

INTRODUCTION

Breast cancer is clinically classified as 'estrogen-positive' when at least 1% of cancer cells stain for the estrogen receptor alpha (ERα). However, recent research on both basic and clinical aspects of breast cancer suggests that GPER-1 (G protein-coupled estrogen receptor-1) may have an important role in breast cancer. Areas covered: This review provides a comprehensive and systematic literature search on GPER-1. We have focused on the role of GPER-1 in breast cancer and on resistance to endocrine therapy, an unsolved clinical issue still under discussion. Expert opinion: The discovery of GPER-1 as a novel estrogen receptor is unique and the signaling pathways activated by its stimulation, when compared to the classical nuclear ERα, indicate a potential role of GPER-1 in the genesis and mechanisms of drug resistance in breast cancer. Tumors expressing ERα represent the largest group of breast cancer patients indicating that more women eventually die from ERα-positive breast tumors than from other more malignant breast cancer subtypes such as HER2-positive and the triple negative groups. It is important to develop new strategies on endocrine therapy with regard to ERα and GPER-1 receptors to achieve innovative successful therapeutic tools.

CCL18 from tumor-cells promotes epithelial ovarian cancer metastasis via mTOR signaling pathway

CCL18 is a chemotactic cytokine involved in the pathogenesis and progression of various disorders, including cancer. Previously, our results showed high levels of CCL18 in the serum of epithelial ovarian carcinoma patients suggesting its potential as a circulating biomarker. In this study, we determined that CCL18 expression was up-regulated in ovarian carcinoma compared with adjacent tissue and was expressed in carcinoma cells in the tumor and not in normal ovarian epithelial cells by laser capture microdissection coupled with real-time RT-PCR. Moreover, correlation analysis showed that the CCL18 level was positively correlated with the metastasis of patients with ovarian cancer. Survival analysis also revealed that an increased level of CCL18 was associated with worse survival time in ovarian cancer patients. Over-expression of CCL18 led to enhanced migration and invasion of the Skov3 ovarian cancer cell line in vitro and in vivo. Finally, proteomics analysis demonstrated that CCL18-mediated ovarian cancer invasiveness was strongly correlated with the mTORC2 pathway. These findings suggest that the CCL18 chemokine has an important role in chemokine-mediated tumor metastasis, and may serve as a potential predictor for poor survival outcomes for ovarian cancer. © 2015 The Authors. Molecular Carcinogenesis published by Wiley Periodicals, Inc.

Adipose and Circulating CCL18 Levels Associate With Metabolic Risk Factors in Women

CONTEXT

Cardiometabolic complications in obesity may be linked to white adipose tissue (WAT) dysfunction. Transcriptomic studies of Sc WAT have reported that CCL18, encoding the CC chemokine ligand 18 (CCL18), is increased in obesity/insulin resistance but its functional role is unknown.

OBJECTIVE

Our objectives were to determine if CCL18 is secreted from Sc WAT and if secreted and/or serum levels associate with metabolic phenotypes. We also planned to define the primary cellular source and if CCL18 exerts effects on adipocytes.

DESIGN

This is a cohort study.

SETTING

The study took place in an outpatient academic clinic.

PARTICIPANTS

A total of 130 obese women scheduled for bariatric surgery and 35 nonobese controls were included.

METHODS

Insulin sensitivity was assessed by hyperinsulinemic euglycemic clamp or homeostasis model assessment. CCL18 was analyzed in serum/WAT incubates by ELISA. Effects of recombinant CCL18 was determined in cultures of primary human adipocytes and the monocyte cell line THP-1 differentiated into M0/M1/M2 macrophages.

MAIN OUTCOME MEASURE

Association with metabolic risk factors was measured.

RESULTS

CCL18 was secreted from WAT and the levels correlated positively with insulin resistance, Adult Treatment Panel III risk score and plasma triglycerides, independent of body mass index and better than other established adipocytokines. In 80 obese women, S-CCL18 levels were significantly higher in insulin resistant compared with insulin sensitive subjects. In WAT CCL18 mRNA was expressed in macrophages and correlated positively with immune-related genes, particularly those enriched in M2 macrophages. While CCL18 increased cyto-/chemokine expression in M0/M2-THP-1 cells, human adipocytes showed no responses in vitro.

CONCLUSIONS

Circulating and WAT-secreted CCL18 correlates with insulin resistance and metabolic risk score. Because CCL18 is macrophage-specific and associates with adipose immune gene expression, it may constitute a marker of WAT inflammation.

Not lost in translation: Emerging clinical importance of the G protein-coupled estrogen receptor GPER

It has been 20years that the G protein-coupled estrogen receptor (GPER) was cloned as the orphan receptor GPR30 from multiple cellular sources, including vascular endothelial cells. Here, I will provide an overview of estrogen biology and the historical background leading to the discovery of rapid vascular estrogen signaling. I will also review the recent advances in the understanding of the mechanisms underlying GPER function, its role in physiology and disease, some of the currently available GPER-targeting drugs approved for clinical use such as SERMs (selective estrogen receptor modulators) and SERDs (selective estrogen receptor downregulators). Many of currently used drugs such as tamoxifen, raloxifene, or faslodex™/fulvestrant were discovered targeting GPER many years after they had been introduced to the clinics for entirely different purposes. This has important implications for the clinical use of these drugs and their modes of action, which I have termed 'reverse translational medicine'. In addition, environmental pollutants known as 'endocrine disruptors' have been found to bind to GPER. This article also discusses recent evidence in these areas as well as opportunities in translational clinical medicine and GPER research, including medical genetics, personalized medicine, prevention, and its theranostic use.

Non-genomic oestrogen receptor signal in B lymphocytes: An approach towards therapeutic interventions for infection, autoimmunity and cancer

The non-genomic membrane bound oestrogen receptor (mER) regulates intracellular signals through receptor-ligand interactions. The mER, along with G-protein coupled oestrogen receptor GPR 30 (GPER), induces diverse cell signalling pathways in murine lymphocytes. The mER isoform ER-alpha46 has recently been demonstrated in human B and T lymphocytes as an analogue receptor for chemokine CCL18, the signalling events of which are not clearly understood. Ligand-induced mER and GPER signalling events are shared with BCR, CD19 mediated intracellular signalling through phospholipase C, PIP2/IP3/PI3 mediated activation of Akt, MAP kinase, and mTOR. Oestrogen has the ability to induce CD40-mediated activation of B cells. The complete signalling pathways of mER, GPR30 and their interaction with other signals are targeted areas for novel drug development in B cells during infection, autoimmunity and cancer. Therefore, an in depth investigation is critical for determining shared signal outputs during B cell activation. Here, we focus on the mode of action of membrane bound ER in B cells as therapeutic checkpoints.

CCL18/PITPNM3 enhances migration, invasion, and EMT through the NF-κB signaling pathway in hepatocellular carcinoma

Chemokine ligand 18 (CCL18) has been associated with hepatocellular carcinoma (HCC) metastasis. Here, we demonstrated a novel mechanism through which CCL18 enhances cell migration, invasion, and epithelial-mesenchymal transition (EMT) in HCC. (1) Using immunohistochemistry, we analyzed the expression of PITPNM3, a molecule that correlated with CCL18 signaling, in 149 HCC tissue specimens. The results showed that PITPNM3 expression is highly associated with tumor metastasis and differentiation; (2) in vitro experiments showed that CCL18 enhances cell migration, invasion, and EMT in PITPNM3((+)) HCC cells but not in PITPNM3((-)) cells. Silencing of PITPNM3 by short interfering RNA (siRNA) inhibited the induction of cell migration, invasion, and EMT by CCL18; (3) Cell migration, invasion, and EMT induced by CCL18 accompanied with the phosphorylation of IKK and IKBα as well as p65 nuclear translocation in PITPNM3((+)) HCC cells, but not in the cells that PITPNM3 is silenced with siRNA, implying that the activation of NF-κB signaling is involved in the action of CCL18/PITPNM3. These results suggest that CCL18 enhances HCC cell migration, invasion, and EMT through the expression of PITPNM3 and the activation of the NF-κB signaling pathway.

Increased μ-Calpain Activity in Blasts of Common B-Precursor Childhood Acute Lymphoblastic Leukemia Correlates with Their Lower Susceptibility to Apoptosis

Childhood acute lymphoblastic leukemia (ALL) blasts are characterized by inhibited apoptosis promoting fast disease progress. It is known that in chronic lymphocytic and acute myeloid leukemias the reduced apoptosis is strongly related with the activity of calpain-calpastatin system (CCS) composed of cytoplasmic proteases—calpains—performing the modulatory proteolysis of key proteins involved in cell proliferation and apoptosis, and of their endogenous inhibitor—calpastatin. Here, the CCS protein abundance and activity was for the first time studied in childhood ALL blasts and in control bone marrow CD19⁺ B cells by semi-quantitative flow cytometry and western blotting of calpastatin fragments resulting from endogenous calpain activity. Significantly higher μ-calpain (CAPN1) gene transcription, protein amounts and activity (but not those of m-calpain), with calpastatin amount and transcription of its gene (CAST) greatly varying were observed in CD19⁺ ALL blasts compared to control cells. Significant inverse relation between the amount/activity of calpain and spontaneous apoptosis was noted. Patients older than 10 years (considered at higher risk) displayed increased amounts and activities of blast calpain. Finally, treatment of blasts with the tripeptide calpain inhibitors II and IV significantly and in dose-dependent fashion increased the percentage of blasts entering apoptosis. Together, these findings make the CCS a potential new predictive tool and therapeutic target in childhood ALL.

CCL18 promotes epithelial-mesenchymal transition, invasion and migration of pancreatic cancer cells in pancreatic ductal adenocarcinoma

CCL18 is a chemokine that is primarily expressed in monocytes, macrophages and immature dendritic cells and plays a crucial role in immune and inflammation responses. Recently, CCL18 was found to play pivotal roles in the development of several kinds of cancers, but its expression status and role during the tumorigenesis of pancreatic cancer remain unknown. In this study, we performed immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) to evaluate the expression of CCL18 in human pancreatic ductal adenocarcinoma (PDAC) tissues and preoperative serum, respectively. The results showed that both cancer epithelial cells and mesenchymal macrophages in PDAC tissues positively expressed CCL18. Serum CCL18 levels were significantly higher in patients with PDAC in comparison to healthy controls. The expression of CCL18 in both cancer epithelial cells and mesenchymal cells was correlated with lymph node metastasis, histopathological grading and overall survival in 62 PDAC patients. In vitro assays showed that the gene and protein expression of CCL18 from U937 and THP-1 cell- derived macrophages were significantly higher than that from unstimulated U937 cells and THP-1 cells. In contrast, pancreatic cancer cell lines showed little to no CCL18 expression even after IL4 stimulation. Intriguingly, pancreatic cancer cell lines expressed the potential CCL18 receptors PITPNM3, CCR6 and GPR3. Furthermore, treatment with recombinant human CCL18 promoted the migration and invasion of pancreatic cancer cells, but had no effect on cell proliferation. Consistent with these results, CCL18 induced the expression of the epithelial-mesenchymal transition (EMT) related gene SNAIL1. Our findings suggest that the serum level of CCL18 is a potential biomarker for the diagnosis and prognosis of PDAC, and that the combined functions of CCL18 in mesenchymal and cancer cells might accelerate the progression of PDAC by promoting the epithelial-mesenchymal transition, invasion and migration of pancreatic cancer cells.

Expression dynamics of CXCL12 and CXCR4 during the progression of mycosis fungoides

BACKGROUND

Mycosis fungoides (MF) classically presents from patch stage to plaque stage over a number of years and finally progresses to tumour stage with nodal or visceral involvement. The mechanism of progression remains incompletely elucidated. Chemokines and their receptors are known to be involved in disease mechanisms, with CXCL12 and CXCR4 playing a critical role in carcinogenesis, invasion and cancer cell migration in various carcinomas.

OBJECTIVES

To investigate the expression of CXCL12 and CXCR4 in different cutaneous stages of MF.

METHODS

Formalin-fixed, paraffin-embedded skin samples from 40 patients with MF (21 patch stage, 10 plaque stage, nine tumour stage) and 30 non-neoplastic control skin samples were analysed. CXCL12 and CXCR4 were assessed by quantitative reverse-transcription polymerase chain reaction and immunohistochemical staining.

RESULTS

The expression level of mRNA for CXCL12 in plaque-stage MF was significantly higher than in control skin (P = 0.0035), or patch-stage (P = 0.0108) or tumour-stage disease (P = 0.0089). The CXCR4 mRNA expression level in plaque-stage disease was significantly higher than in control skin (P = 0.0090) or patch-stage disease (P = 0.0387). CXCL12- and CXCR4-positive cell rates in patch-stage and plaque-stage MF were significantly higher than those in control skin (P < 0.0001). CXCL12- and CXCR4-positive cell rates in tumour-stage MF were significantly lower than those in patch- and plaque-stage disease (P = 0.0274 and P = 0.0492, respectively).

CONCLUSIONS

Our data suggest that neoplastic T cells in MF are exposed to the microenvironment, given the abundance of CXCL12 during its progression, and also that neoplastic T cells express CXCR4, especially in the pretumour stage. We reveal that the CXCL12-CXCR4 axis plays a critical role in MF progression.

Sexual dimorphism and thyroid dysfunction: a matter of oxidative stress?

Thyroid diseases, such as autoimmune disease and benign and malignant nodules, are more prevalent in women than in men, but the mechanisms involved in this sex difference is still poorly defined. H₂O₂ is produced at high levels in the thyroid gland and regulates parameters such as cell proliferation, migration, survival, and death; an imbalance in the cellular oxidant-antioxidant system in the thyroid may contribute to the greater incidence of thyroid disease among women. Recently, we demonstrated the existence of a sexual dimorphism in the thyrocyte redox balance, characterized by higher H₂O₂ production, due to higher NOX4 and Poldip2 expression, and weakened enzymatic antioxidant defense in the thyroid of adult female rats compared with male rats. In addition, 17β-estradiol administration increased NOX4 mRNA expression and H₂O₂ production in thyroid PCCL3 cells. In this review, we discuss the possible involvement of oxidative stress in estrogen-related thyroid pathophysiology. Our current hypothesis suggests that a redox imbalance elicited by estrogen could be involved in the sex differences found in the prevalence of thyroid dysfunctions.

Expression and functional roles of G-protein-coupled estrogen receptor (GPER) in human eosinophils

Sexual dimorphism in asthma links the estrogen and allergic immune responses. The function of estrogen was classically believed to be mediated through its nuclear receptors, i.e., estrogen receptors (ERs). However, recent studies established the important roles of G-protein-coupled estrogen receptor (GPER/GPR30) as a novel membrane receptor for estrogen. To date, the role of GPER in allergic inflammation is poorly understood. The purpose of this study was to examine whether GPER might affect the functions of eosinophils, which play an important role in the pathogenesis of asthma. Here, we demonstrated that GPER was expressed in purified human peripheral blood eosinophils both at the mRNA and protein levels. Although GPER agonist G-1 did not induce eosinophil chemotaxis or chemokinesis, preincubation with G-1 enhanced eotaxin (CCL11)-directed eosinophil chemotaxis. G-1 inhibited eosinophil spontaneous apoptosis and caspase-3 activities. The anti-apoptotic effect was not affected by the cAMP-phospodiesterase inhibitor rolipram or phosphoinositide 3-kinase inhibitors. In contrast to resting eosinophils, G-1 induced apoptosis and increased caspase-3 activities when eosinophils were co-stimulated with IL-5. No effect of G-1 was observed on eosinophil degranulation in terms of release of eosinophil-derived neurotoxin (EDN). The current study indicates the functional capacities of GPER on human eosinophils and also provides the previously unrecognized mechanisms of interaction between estrogen and allergic inflammation.

CCL18 exhibits a regulatory role through inhibition of receptor and glycosaminoglycan binding

CCL18 has been reported to be present constitutively at high levels in the circulation, and is further elevated during inflammatory diseases. Since it is a rather poor chemoattractant, we wondered if it may have a regulatory role. CCL18 has been reported to inhibit cellular recruitment mediated by CCR3, and we have shown that whilst it is a competitive functional antagonist as assessed by Schild plot analysis, it only binds to a subset of CCR3 receptor populations. We have extended this inhibitory activity to other receptors and have shown that CCL18 is able to inhibit CCR1, CCR2, CCR4 and CCR5 mediated chemotaxis, but has no effect on CCR7 and CCR9, nor the CXC receptors that we have tested. Whilst CCL18 is able to bind to CCR3, it does not bind to the other receptors that it inhibits. We therefore tested the hypothesis that it may displace glycosaminoglycan (GAG) chemokines bound either in cis- on the leukocyte, or in trans-presentation on the endothelial surface, thereby inhibiting the recruitment of leukocytes into the site of inflammation. We show that CCL18 selectivity displaces heparin bound chemokines, and that chemokines from all four chemokine sub-classes displace cell bound CCL18. We propose that CCL18 has regulatory properties inhibiting chemokine function when GAG-mediated presentation plays a role in receptor activation.

Estrogen synthesis and signaling pathways during aging: from periphery to brain

Estrogens are the primary female sex hormones and play important roles in both reproductive and non-reproductive systems. Estrogens can be synthesized in non-reproductive tissues such as liver, heart, muscle, bone and brain, and tissue-specific estrogen synthesis is consistent with a diversity of estrogen actions. In this article we review tissue and cell-specific estrogen synthesis and estrogen receptor signaling in three parts: (i) synthesis and metabolism, (ii) the distribution of estrogen receptors and signaling, and (iii) estrogen functions and related disorders, including cardiovascular diseases, osteoporosis, Alzheimer's disease (AD), and Parkinson disease (PD). This comprehensive review provides new insights into estrogens by giving a better understanding of the tissue-specific estrogen effects and their roles in various diseases.

CC-chemokine ligand 18 induces epithelial to mesenchymal transition in lung cancer A549 cells and elevates the invasive potential

Lung cancer is one of the leading causes of cancer related death worldwide with more than a million deaths per year. The poor prognosis is due to its high aggressiveness and its early metastasis. Although the exact mechanisms are still unknown, the process of epithelial to mesenchymal transition (EMT) seems to be involved in these neoplastic processes. We already demonstrated that serum levels of CCL18, a primate specific chemokine, are highly elevated in patients with lung cancer and correlate with their survival time of patients with adenocarcinoma of the lung. Therefore, we hypothesized that CCL18 may be directly involved in pathological processes of lung cancer, e.g. EMT. We investigated the effect of CCL18 on A549, an adenocarcinoma cell line of the lung, on EMT and other cell functions like proliferation, chemotaxis, invasion, chemoresistance and proliferation. Exposure of A549 lung cancer cells to CCL18 in various concentrations decreases the epithelial marker E-cadherin, whereas FSP-1, a marker of the mesenchymal phenotype increases. Accordingly, CCL18 induced the transcriptional EMT regulator SNAIL1 in a dose dependent fashion. In contrast, an increasing CCL18 concentration was associated with a decline of cell proliferation rate. In addition, CCL18 induced chemotaxis of these cells and increased their chemoresistance. Therefore, CCL18 may be an interesting therapeutic target for NSCLC.

Position paper: The membrane estrogen receptor GPER--Clues and questions

Rapid signaling of estrogen involves membrane estrogen receptors (ERs), including membrane subpopulations of ERα and ERβ. In the mid-1990s, several laboratories independently reported the cloning of an orphan G protein-coupled receptor from vascular and cancer cells that was named GPR30. Research published between 2000 and 2005 provided evidence that GPR30 binds and signals via estrogen indicating that this intracellular receptor is involved in rapid, non-genomic estrogen signaling. The receptor has since been designated as the G protein-coupled estrogen receptor (GPER) by the International Union of Pharmacology. The availability of genetic tools such as different lines of GPER knock-out mice, as well as GPER-selective agonists and antagonists has advanced our understanding, but also added some confusion about the new function of this receptor. GPER not only binds estrogens but also other substances, including SERMs, SERDs, and environmental ER activators (endocrine disruptors; xenoestrogens) and also interacts with other proteins. This article represents a summary of a lecture given at the 7(th) International Meeting on Rapid Responses to Steroid Hormones in September 2011 in Axos, Crete, and reviews the current knowledge and questions about GPER-dependent signaling and function. Controversies that have complicated our understanding of GPER, including interactions with human ERα-36 and aldosterone as a potential ligand, will also be discussed.

Up-regulation of the chemokine CCL18 by macrophages is a potential immunomodulatory pathway in cutaneous T-cell lymphoma

Mycosis fungoides (MF) is the most frequent form of cutaneous T-cell lymphoma (CTCL), which can deteriorate from patch stage to dermal-based tumors and systemic involvement in years. The interaction of chemokines in the skin with CTCL cells might have implications for the pathogenesis of the disease. In this study, we show by PCR analysis and immunofluorescence staining that the chemokine CCL18 is present in skin biopsy specimens of patients with MF and its precursor form parapsoriasis en plaque but not in healthy tissue. In addition, the serum levels of CCL18 were increased threefold in MF patients compared with those in healthy controls. In skin, CCL18 was specifically expressed by CD163(+) CD209(+) macrophages at the invasive margin of the tumor and not expressed by mature CD208(+) dendritic cells in the center of the tumor. The chemokine CCL17 was, by contrast, ubiquitously expressed. Furthermore, CCL18 promoted the chemotaxis but not the proliferation of CTCL cells. CCL18 inhibited proliferation of tumor cells and abolished the CXCL12-induced growth of a CTCL cell line. These data link the increased expression of CCL18 with CTCL and suggest an immunomodulatory effect of the chemokine in the pathogenesis of CTCL.

Natural killer cells and malignant haemopathies: a model for the interaction of cancer with innate immunity

Despite recent progress in the therapeutic approach of malignant haemopathies, their prognoses remain frequently poor. Immunotherapy offers an alternative of great interest in this context but defect or abnormal expression of human leukocyte antigens (HLA), frequently observed in cancer cells, limits its efficiency. Natural killer (NK) cells, which are able to kill target cells in a HLA-independent way, represent a novel tool in the treatment of haematological malignancies. Abnormal NK cytolytic function is observed in all the haematological malignancies studied, such as acute leukaemia, myelodysplastic syndromes or chronic myeloid/lymphoid leukaemia. Several mechanisms are involved in the alterations of NK cytotoxicity: decreased expression of activating receptors, increased expression of inhibitory receptors or defective expression of NK ligands on target cells. Further studies are needed to identify how each type of haematological malignancy escapes from the innate immune response. Attempts to increase the expression of activating receptors, to counteract inhibitory receptors expression, or to increase NK cell cytotoxic capacities could overcome tumour escape from innate immunity. These therapies are based on monoclonal antibodies or culture of NK cells in presence of cytokines or dendritic cells. Moreover, many novel drugs used in haematological malignancies [tyrosine kinase inhibitors, IMIDs(®), proteasome inhibitors, demethylating agents, histone deacetylase inhibitors (HDACis), histamine dihydrochloride] display interesting immunomodulatory properties that affect NK cells. These data suggest that combined modalities associating cytotoxic drugs with innate immunity modulators may represent a major breakthrough in tumour eradication.