Identification of biologically active chemokine isoforms from ascitic fluid and elevated levels of CCL18/pulmonary and activation-regulated chemokine in ovarian carcinoma

The chemokine receptor CCR8 is not a high-affinity receptor for the human chemokine CCL18

The primate-specific chemokine CCL18 is a potent chemoattractant for T cells and is expressed at elevated levels in several inflammatory diseases. However, the cognate receptor for CCL18 remains unconfirmed. Here, we describe attempts to validate a previous report that the chemokine receptor CCR8 is the human CCL18 receptor (Islam et al. J Exp Med. 2013, 210:1889-98). Two mouse pre-B cell lines (4DE4 and L1.2) exogenously expressing CCR8 exhibited robust migration in response to the known CCR8 ligand CCL1 but not to CCL18. Similarly, CCL1 but not CCL18 induced internalization of CCR8 on 4DE4 cells. CCR8 expressed on Chinese hamster ovarian (CHO) cells mediated robust G protein activation, inhibition of cAMP synthesis and β-arrestin2 recruitment in response to CCL1 but not CCL18. Several N- and C-terminal variants of CCL18 also failed to stimulate CCR8 activation. On the other hand, and as previously reported, CCL18 inhibited CCL11-stimulated migration of 4DE4 cells expressing the receptor CCR3. These data suggest that CCR8, at least in the absence of unidentified cofactors, does not function as a high affinity receptor for CCL18.

Chemerin promotes invasion of oral squamous cell carcinoma by stimulating IL-6 and TNF-α production via STAT3 activation

AIMS

Elevated levels of adipokine chemerin have been identified in oral squamous cell carcinoma (OSCC) and found to be associated with metastasis to the cervical lymph nodes. The underlying mechanism through which chemerin affects OSCC progression is unclear. The aims of this study were firstly to determine chemerin levels and cytokine concentrations in serum from patients with OSCC and in OSCC cell cultures, and secondly to observe chemerin effects on OSCC cell cytokine secretion, migration, and invasion in vitro.

METHODS

Serum samples were collected from 20 patients diagnosed with OSCC, including groups with (LN+) and without (LN-) cervical lymph node metastasis. A Luminex liquid suspension assay was used to quantify serum concentrations of 27 types of cytokines. Correlations between chemerin and cytokines (i.e., IL-6, IL-15, GM-CSF, RANTES, TNF-α, and VEGF) were analyzed. ELISAs (enzyme-linked immunosorbent assays) were used to determine concentrations of chemerin and selected cytokines in serum and in supernatants of OSCC cell cultures (SCC9 and SCC25 cell lines). OSCC cells were stimulated with human recombinant chemerin, STAT3 inhibitor, or IL-6 together with TNF-α neutralizing antibodies. Phosphorylated STAT3 protein levels were measured with western blot analysis. OSCC cell migration and invasion were investigated with Transwell assays.

RESULTS

Compared to the LN- group, OSCC patients with cervical lymph node metastasis had higher levels of IL-6 (P = 0.006), IL-15 (P = 0.020), GM-CSF (P = 0.036), RANTES (P = 0.032), TNF-α (P = 0.005), VEGF (P = 0.006), and chemerin (P = 0.001). Patients' serum chemerin levels correlated directly with IL-6, GM-CSF, TNF-α, and VEGF levels in OSCC patients. Exogenous recombinant chemerin treatment promoted secretion of IL-6 and TNF-α via activation of STAT3 in OSCC cells. Chemerin induced OSCC-cell migration and invasion, and these effects were reduced by IL-6 and TNF-α neutralizing antibodies.

CONCLUSION

Our findings indicate that chemerin may play a role in advancing OSCC progression by increasing production of IL-6 and TNF-α, perhaps via a mechanism involving STAT3 signaling.

Immunotherapy Innovations in the Fight against Osteosarcoma: Emerging Strategies and Promising Progress

Immunosuppressive elements within the tumor microenvironment are the primary drivers of tumorigenesis and malignant advancement. The presence, as well as the crosstalk between myeloid-derived suppressor cells (MDSCs), osteosarcoma-associated macrophages (OS-Ms), regulatory T cells (Tregs), and endothelial cells (ECs) with osteosarcoma cells cause the poor prognosis of OS. In addition, the consequent immunosuppressive factors favor the loss of treatment potential. Nanoparticles offer a means to dynamically and locally manipulate immuno-nanoparticles, which present a promising strategy for transforming OS-TME. Additionally, chimeric antigen receptor (CAR) technology is effective in combating OS. This review summarizes the essential mechanisms of immunosuppressive cells in the OS-TME and the current immune-associated strategies. The last part highlights the limitations of existing therapies and offers insights into future research directions.

Chemokine N-terminal-derived peptides differentially regulate signaling by the receptors CCR1 and CCR5

Inflammatory chemokines are often elevated in disease settings, where the largest group of CC-chemokines are the macrophage inflammatory proteins (MIP), which are promiscuous for the receptors CCR1 and CCR5. MIP chemokines, such as CCL3 and CCL5 are processed at the N terminus, which influences signaling in a highly diverse manner. Here, we investigate the signaling capacity of peptides corresponding to truncated N termini. These 3-10-residue peptides displayed weak potency but, surprisingly, retained their signaling on CCR1. In contrast, none of the peptides generated a signal on CCR5, but a CCL3-derived tetrapeptide was a positive modulator boosting the signal of several chemokine variants on CCR5. In conclusion, chemokine N termini can be mimicked to produce small CCR1-selective agonists, as well as CCR5-selective modulators.

Prenatal exposure to benzo[a]pyrene depletes ovarian reserve and masculinizes embryonic ovarian germ cell transcriptome transgenerationally

People are widely exposed to polycyclic aromatic hydrocarbons, like benzo[a]pyrene (BaP). Prior studies showed that prenatal exposure to BaP depletes germ cells in ovaries, causing earlier onset of ovarian senescence post-natally; developing testes were affected at higher doses than ovaries. Our primary objective was to determine if prenatal BaP exposure results in transgenerational effects on ovaries and testes. We orally dosed pregnant germ cell-specific EGFP-expressing mice (F0) with 0.033, 0.2, or 2 mg/kg-day BaP or vehicle from embryonic day (E) 6.5-11.5 (F1 offspring) or E6.5-15.5 (F2 and F3). Ovarian germ cells at E13.5 and follicle numbers at postnatal day 21 were significantly decreased in F3 females at all doses of BaP; testicular germ cell numbers were not affected. E13.5 germ cell RNA-sequencing revealed significantly increased expression of male-specific genes in female germ cells across generations and BaP doses. Next, we compared the ovarian effects of 2 mg/kg-day BaP dosing to wild type C57BL/6J F0 dams from E6.5-11.5 or E12.5-17.5. We observed no effects on F3 ovarian follicle numbers with either of the shorter dosing windows. Our results demonstrate that F0 BaP exposure from E6.5-15.5 decreased the number of and partially disrupted transcriptomic sexual identity of female germ cells transgenerationally.

Neo-vascularization-based therapeutic perspectives in advanced ovarian cancer

The process of angiogenesis is well described for its potential role in the development of normal ovaries, and physiological functions as well as in the initiation, progression, and metastasis of ovarian cancer (OC). In advanced stages of OC, cancer cells spread outside the ovary to the pelvic, abdomen, lung, or multiple secondary sites. This seriously limits the efficacy of therapeutic options contributing to fatal clinical outcomes. Notably, a variety of angiogenic effectors are produced by the tumor cells to initiate angiogenic processes leading to the development of new blood vessels, which provide essential resources for tumor survival, dissemination, and dormant micro-metastasis of tumor cells. Multiple proangiogenic effectors and their signaling axis have been discovered and functionally characterized for potential clinical utility in OC. In this review, we have provided the current updates on classical and emerging proangiogenic effectors, their signaling axis, and the immune microenvironment contributing to the pathogenesis of OC. Moreover, we have comprehensively reviewed and discussed the significance of the preclinical strategies, drug repurposing, and clinical trials targeting the angiogenic processes that hold promising perspectives for the better management of patients with OC.

The immunosuppressive tumor microenvironment in hepatocellular carcinoma-current situation and outlook

Hepatocellular carcinoma (HCC) is one of the most severe malignant tumors that threaten human health, and its incidence is still on the rise recently. In spite of the current emerging treatment strategies, the overall prognosis of liver cancer remains worrying. Currently, immunotherapy has become a new research-active spot. The emergence of immune checkpoints and targeted immune cell therapy can significantly improve the prognosis of HCC. To a large extent, the effect of this immunotherapy depends on the tumor immune microenvironment (TME), an intricate system in which cancer cells and other non-cancer cells display various interactions. Understanding the immunosuppressive situation of these cells, along with the malignant behavior of cancer cells, can assist us to design new therapeutic approaches against tumors. Therefore, it is necessary to clarify the TME of HCC for further improvement of clinical treatment. This review discussed the functions of several immunosuppressive cells and exosomes in the latest research progress of HCC, including cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) and tumor-associated neutrophils (TANs) interacted actively to facilitate tumor progression. It further describes the treatment methods targeting them and the potential that needs to be explored in the future.

Anti-Tumoral Effect of Chemerin on Ovarian Cancer Cell Lines Mediated by Activation of Interferon Alpha Response

Simple Summary

Chemerin is a multifunctional protein with an important role in the immune system. Recent evidence showed that chemerin also regulates the development of cancer. Ovarian cancer is a common type of tumor in women. In this study, we observed that chemerin decreases the growth of ovarian cancer cell lines in vitro when cultivated in standard cell culture or in globular multicellular aggregates. When we examined the mechanisms involved in this process, we found that treatment of ovarian cancer cells with chemerin led to the activation of genes that are known to mediate the effects of interferon alpha (IFNα). The main effect of IFNα is to defend body cells against viral infections, but it is also able to defeat cancer cells. We observed that this activation of IFNα response by chemerin resulted from the increased production of IFNα protein in ovarian cancer cells, which then reduced cancer cells numbers. However, it remains to be investigated how exactly chemerin might be able to activate interferon alpha and its anti-tumoral actions.

Abstract

The pleiotropic adipokine chemerin affects tumor growth primarily as anti-tumoral chemoattractant inducing immunocyte recruitment. However, little is known about its effect on ovarian adenocarcinoma. In this study, we examined chemerin actions on ovarian cancer cell lines in vitro and intended to elucidate involved cell signaling mechanisms. Employing three ovarian cancer cell lines, we observed differentially pronounced effects of this adipokine. Treatment with chemerin (huChem-157) significantly reduced OVCAR-3 cell numbers (by 40.8% on day 6) and decreased the colony and spheroid growth of these cells by half. The spheroid size of SK-OV-3 ovarian cancer cells was also significantly reduced upon treatment. Transcriptome analyses of chemerin-treated cells revealed the most notably induced genes to be interferon alpha (IFNα)-response genes like IFI27, OAS1 and IFIT1 and their upstream regulator IRF9 in all cell lines tested. Finally, we found this adipokine to elevate IFNα levels about fourfold in culture medium of the employed cell lines. In conclusion, our data for the first time demonstrate IFNα as a mediator of chemerin action in vitro. The observed anti-tumoral effect of chemerin on ovarian cancer cells in vitro was mediated by the notable activation of IFNα response genes, resulting from the chemerin-triggered increase of secreted levels of this cytokine.

CCL18 Expression Is Higher in a Glioblastoma Multiforme Tumor than in the Peritumoral Area and Causes the Migration of Tumor Cells Sensitized by Hypoxia

Glioblastoma multiforme (GBM) is a brain tumor with a very poor prognosis. For this reason, researchers worldwide study the impact of the tumor microenvironment in GBM, such as the effect of chemokines. In the present study, we focus on the role of the chemokine CCL18 and its receptors in the GBM tumor. We measured the expression of CCL18, CCR8 and PITPNM3 in the GMB tumor from patients (16 men and 12 women) using quantitative real-time polymerase chain reaction. To investigate the effect of CCL18 on the proliferation and migration of GBM cells, experiments were performed using U-87 MG cells. The results showed that CCL18 expression was higher in the GBM tumor than in the peritumoral area. The women had a decreased expression of PITPNM3 receptor in the GBM tumor, while in the men a lower expression of CCR8 was observed. The hypoxia-mimetic agent, cobalt chloride (CoCl₂), increased the expression of CCL18 and PITPNM3 and thereby sensitized U-87 MG cells to CCL18, which did not affect the proliferation of U-87 MG cells but increased the migration of the test cells. The results indicate that GBM cells migrate from hypoxic areas, which may be important in understanding the mechanisms of tumorigenesis.

Transcriptomic characterization of Atlantic salmon (Salmo salar) head kidney following administration of Aeromonas salmonicida subsp. masoucida vaccine

Atlantic salmon is one of the most famous and economically important fish species globally. However, bacterial diseases constantly constrain salmon aquaculture. Thereinto, Aeromonas salmonicida subsp. masoucida (ASM), classified as atypical A. salmonicida, caused huge losses to salmonid industry in China. In this regard, we conducted transcriptome analysis in Atlantic salmon head kidney following the administration of ASM vaccination to reveal genes, their expression patterns, and pathways involved in immune responses. A total of 448.71 million clean reads were obtained, and 397.69 million reads were mapped onto the Atlantic salmon reference genome. In addition, 117, 1891, 741, 207, and 377 genes were significantly up-regulated, and 183, 1920, 695, 83, and 539 genes were significantly down-regulated post ASM vaccination at 12 h, 24 h, 1 m, 2 m, and 3 m, respectively. Furthermore, KEGG pathway analysis revealed that many differentially expressed genes (DEGs) following ASM vaccination were involved in cell adhesion molecules (H2-Aa-l and CD28-l),cytokine-cytokine receptor interaction (IL10, CXCL9, CXCL11, CXCR3, and CCL19), herpes simplex infection (IL1B, SOCS3-l, and C3-l), HTLV-I infection (Il1r2 and BCL2L1), influenza A (CXCL8 and Il12b), and PI3K-Akt signaling pathway (PIK3R3-l and Ddit4-l). Finally, the results of qRT-PCR showed a significant correlation with RNA-Seq results, suggesting the reliability of RNA-Seq for gene expression analysis. This study sets the foundation for further study on the vaccine protective mechanism in Atlantic salmon as well as other teleost species.

Spheroid Formation and Peritoneal Metastasis in Ovarian Cancer: The Role of Stromal and Immune Components

Ovarian cancer (OC) is one of the most common gynecological cancers, with the worst prognosis and the highest mortality rate. Peritoneal dissemination (or carcinomatosis) accompanied by ascites formation is the most unfavorable factor in the progression and recurrence of OC. Tumor cells in ascites are present as either separate cells or, more often, as cell aggregates, i.e., spheroids which promote implantation on the surface of nearby organs and, at later stages, metastases to distant organs. Malignant ascites comprises a unique tumor microenvironment; this fact may be of relevance in the search for new prognostic and predictive factors that would make it possible to personalize the treatment of patients with OC. However, the precise mechanisms of spheroid formation and carcinomatosis are still under investigation. Here, we summarize data on ascites composition as well as the activity of fibroblasts and macrophages, the key stromal and immune components, in OC ascites. We describe current knowledge about the role of fibroblasts and macrophages in tumor spheroid formation, and discuss the specific functions of fibroblasts, macrophages and T cells in tumor peritoneal dissemination and implantation.

Activation of NLRP3 Inflammasome by Virus-Like Particles of Human Polyomaviruses in Macrophages

Viral antigens can activate phagocytes, inducing inflammation, but the mechanisms are barely explored. The aim of this study is to investigate how viral oligomeric proteins of different structures induce inflammatory response in macrophages. Human THP-1 cell line was used to prepare macrophages that were treated with filamentous nucleocapsid-like particles (NLPs) of paramyxoviruses and spherical virus-like particles (VLPs) of human polyomaviruses. The effects of viral proteins on cell viability, pro-inflammatory cytokines’ production, and NLRP3 inflammasome activation were investigated. Filamentous NLPs did not induce inflammation while spherical VLPs mediated inflammatory response followed by NLRP3 inflammasome activation. Inhibitors of cathepsins and K⁺ efflux decreased IL-1β release and cell death, indicating a complex inflammasome activation process. A similar activation pattern was observed in primary human macrophages. Single-cell RNAseq analysis of THP-1 cells revealed several cell activation states different in inflammation-related genes. This study provides new insights into the interaction of viral proteins with immune cells and suggests that structural properties of oligomeric proteins may define cell activation pathways.

The non-ELR CXC chemokine encoded by human cytomegalovirus UL146 genotype 5 contains a C-terminal β-hairpin and induces neutrophil migration as a selective CXCR2 agonist

Human cytomegalovirus (HCMV) is a major pathogen in immunocompromised patients. The UL146 gene exists as 14 diverse genotypes among clinical isolates, which encode 14 different CXC chemokines. One genotype (vCXCL1_GT1) is a known agonist for CXCR1 and CXCR2, while two others (vCXCL1_GT5 and vCXCL1_GT6) lack the ELR motif considered crucial for CXCR1 and CXCR2 binding, thus suggesting another receptor targeting profile. To determine the receptor target for vCXCL1_GT5, the chemokine was probed in a G protein signaling assay on all 18 classical human chemokine receptors, where CXCR2 was the only receptor being activated. In addition, vCXCL1_GT5 recruited β-arrestin in a BRET-based assay and induced migration in a chemotaxis assay through CXCR2, but not CXCR1. In contrast, vCXCL1_GT1 stimulated G protein signaling, recruited β-arrestin and induced migration through both CXCR1 and CXCR2. Both vCXCL1_GT1 and vCXCL1_GT5 induced equally potent and efficacious migration of neutrophils, and ELR vCXCL1_GT4 and non-ELR vCXCL1_GT6 activated only CXCR2. In contrast to most human chemokines, the 14 UL146 genotypes have remarkably long C-termini. Comparative modeling using Rosetta showed that each genotype could adopt the classic chemokine core structure, and predicted that the extended C-terminal tail of several genotypes (including vCXCL1_GT1, vCXCL1_GT4, vCXCL1_GT5, and vCXCL1_GT6) forms a novel β-hairpin not found in human chemokines. Secondary NMR shift and TALOS+ analysis of vCXCL1_GT1 supported the existence of two stable β-strands. C-terminal deletion of vCXCL1_GT1 resulted in a non-functional protein and in a shift to solvent exposure for tryptophan residues likely due to destabilization of the chemokine fold. The results demonstrate that non-ELR chemokines can activate CXCR2 and suggest that the UL146 chemokines have unique C-terminal structures that stabilize the chemokine fold. Increased knowledge of the structure and interaction partners of the chemokine variants encoded by UL146 is key to understanding why circulating HCMV strains sustain 14 stable genotypes.

Human cytomegalovirus (HCMV) is a prevalent herpesvirus infecting an estimated 60% of the human population worldwide. It is commonly transmitted during early childhood and leads to life-long latency, where viral reactivation can cause severe complications in case of host immune suppression. Furthermore, HCMV is the leading cause of congenital infections. Circulating HCMV strains exhibit great genetic diversity unusual for DNA viruses. One of its most diverse genes is UL146, which encodes a chemokine that facilitates viral dissemination by exploiting the human immune system through mimicry of key immunity components. In this study, we investigate how the diversity of UL146 affects its signaling and structural properties to understand why its genetic diversity is maintained across human populations. We find that certain genotypes that lack key structural domains present in the human homologs nonetheless exert similar functions in the virus-host relationship. Furthermore, many of the UL146 genotypes contain novel structural elements critical for correct protein folding and with the potential to provide HCMV with additional immune modulatory and evasive features. Together, our data highlight a considerable degree of host-adaptation by HCMV and propose novel structural interactions with implications for the virus-host interplay.

The Impact of Obesity, Adipose Tissue, and Tumor Microenvironment on Macrophage Polarization and Metastasis

Tumor metastasis is a major cause of death in cancer patients. It involves not only the intrinsic alterations within tumor cells, but also crosstalk between these cells and components of the tumor microenvironment (TME). Tumorigenesis is a complex and dynamic process, involving the following three main stages: initiation, progression, and metastasis. The transition between these stages depends on the changes within the extracellular matrix (ECM), in which tumor and stromal cells reside. This matrix, under the effect of growth factors, cytokines, and adipokines, can be morphologically altered, degraded, or reorganized. Many cancers evolve to form an immunosuppressive TME locally and create a pre-metastatic niche in other tissue sites. TME and pre-metastatic niches include myofibroblasts, immuno-inflammatory cells (macrophages), adipocytes, blood, and lymphatic vascular networks. Several studies have highlighted the adipocyte-macrophage interaction as a key driver of cancer progression and dissemination. The following two main classes of macrophages are distinguished: M1 (pro-inflammatory/anti-tumor) and M2 (anti-inflammatory/pro-tumor). These cells exhibit distinct microenvironment-dependent phenotypes that can promote or inhibit metastasis. On the other hand, obesity in cancer patients has been linked to a poor prognosis. In this regard, tumor-associated adipocytes modulate TME through the secretion of inflammatory mediators, which modulate and recruit tumor-associated macrophages (TAM). Hereby, this review describes the cellular and molecular mechanisms that link inflammation, obesity, and cancer. It provides a comprehensive overview of adipocytes and macrophages in the ECM as they control cancer initiation, progression, and invasion. In addition, it addresses the mechanisms of tumor anchoring and recruitment for M1, M2, and TAM macrophages, specifically highlighting their origin, classification, polarization, and regulatory networks, as well as their roles in the regulation of angiogenesis, invasion, metastasis, and immunosuppression, specifically highlighting the role of adipocytes in this process.

Exosome-Transmitted miR-128 Targets CCL18 to Inhibit the Proliferation and Metastasis of Urothelial Carcinoma

Objective: To investigate the regulatory function of exosome-transmitted miR-128 and chemokine (C-C motif) ligand 18 (CCL18) on urothelial carcinomas (UCs).

Methods: Tumor tissues, paracancerous tissues, and serum were collected from 20 patients with UCs (diagnosed at Beijing Friendship Hospital, Capital Medical University). CCL18 was detected by immunohistochemistry and ELISA. PCR was used to measure the expression levels of CCL18 and mir-183, miR-128, mir-33a in UCs. We acquired exosomes from mesenchymal stem cells and synthesized exosomes overexpressing miR-128 (HMSC-128-EV). The effects of miR-128 on the migration and invasion abilities, apoptosis and epithelial-mesenchymal transition of BUC T24 cells were investigated by co-culturing HMSC-128-EV. The therapeutic potential of miR-128 on disease models was explored by injecting HMSC-128-EV into nude mice.

Results: The expression of CCL18 in UCs was significantly higher than that in normal tissues (p < 0.05), and the serum level of CCL18 in patients with UC was significantly increased compared with those in healthy controls (p < 0.05). CCL18 overexpression or downregulation enhanced or suppressed the proliferation, migration and invasion of BUC T24 cells, resectively (p < 0.05). The exosome-transmitted miR-128 can inhibit cell proliferation (p < 0.05), invasion (p < 0.05), and migration (p < 0.05) in UCs, and these effects can be reversed by CCL18. In terms of apoptosis, miR-128 was able to promote the occurrence of BUC T24 apoptosis (p < 0.05), which can also be reversed by CCL18. In addition, miR-128 can inhibit the proliferation (p < 0.05) and metastasis (p < 0.05) of UCs in nude mice.

Conclusion: The miR-128 inhibits the proliferation, invasion, migration of UCs, and promotes its apoptosis by regulating CCL18 secretion.

A combined biomarker panel shows improved sensitivity and specificity for detection of ovarian cancer

Background

Combined biomarkers can improve the sensitivity and specificity of ovarian cancer (OC) diagnosis and effectively predict patient prognosis. This study explored the diagnostic and prognostic values of serum CCL18 and CXCL1 antigens combined with C1D, FXR1, ZNF573, and TM4SF1 autoantibodies in OC.

Methods

CCL18 and CXCL1 monoclonal antibodies and C1D, FXR1, ZNF573, and TM4SF1 antigens were coated with microspheres. Logistic regression was used to construct a serum antigen‐antibody combined detection model; receiver‐operating characteristic curve (ROC) was used to evaluate the diagnostic efficacy of the model; and the Kaplan‐Meier method and Cox regression models were used for survival analysis to evaluate the prognosis of OC. Data from The Cancer Genome Atlas (TCGA) and Genotype‐Tissue Expression (GTEx) projects and online survival analysis tools were used to evaluate prognostic genes for OC. The CIBERSORT immune score was used to explore the factors influencing prognosis and their relationship with tumor‐infiltrating immune cells.

Results

The levels of each index in the blood samples of patients with OC were higher than those of the other groups. The combined detection model has higher specificity and sensitivity in the diagnosis of OC, and its diagnostic efficiency is better than that of CA125 alone and diagnosing other malignant tumors. CCL18 and TM4SF1 may be factors affecting the prognosis of OC, and CCL18 may be related to immune‐infiltrating cells.

Conclusions

The serum antigen‐antibody combined detection model established in this study has high sensitivity and specificity for the diagnosis of OC.

Role of macrophages in cancer progression and targeted immunotherapies

The vast complexity of the tumor microenvironment (TME) aggrandizes the underlying principles responsible for immune escape, therapy resistance, and treatment failure. The stromal and immune cell population circumjacent to the tumor cells affects the cancer cell cycle leading to tumor progression. Tumor-associated macrophages (TAMs) exhibiting a unique M2 polarization state constitute a significant portion of the TME. They serve as tumor suppressors at early stages and tumor promoters at advanced stages by governing various microenvironmental cues. TAMs secreted various pro-tumoral cytokines, chemokines, and matrix metalloproteases are known to regulate the different cell cycle molecules including checkpoint inhibitors in cancer cells leading to cell cycle progression with faulty cellular components. Moreover, TAMs are well-known immunosuppressors and thereby facilitating the tumor cells' evasion from immune recognition. This chapter will describe the interaction between TAMs and tumor cells, the involvement of TAMs in the regulation of cancer cell progression by controlling cell cycle checkpoints or molecular pathways, and current TAM-based therapies, including restriction of TAM recruitment, anti-survival strategies, or switching polarity. Moreover, this chapter will also emphasize recently developed drug targets and CAR-macrophage cell therapy that restricts tumor progression.

Sex Differences in Embryonic Gonad Transcriptomes and Benzo[a]pyrene Metabolite Levels After Transplacental Exposure

Polycyclic aromatic hydrocarbons like benzo[a]pyrene (BaP) are generated during incomplete combustion of organic materials. Prior research has demonstrated that BaP is a prenatal ovarian toxicant and carcinogen. However, the metabolic pathways active in the embryo and its developing gonads and the mechanisms by which prenatal exposure to BaP predisposes to ovarian tumors later in life remain to be fully elucidated. To address these data gaps, we orally dosed pregnant female mice with BaP from embryonic day (E) 6.5 to E11.5 (0, 0.2, or 2 mg/kg/day) for metabolite measurement or E9.5 to E11.5 (0 or 3.33 mg/kg/day) for embryonic gonad RNA sequencing. Embryos were harvested at E13.5 for both experiments. The sum of BaP metabolite concentrations increased significantly with dose in the embryos and placentas, and concentrations were significantly higher in female than male embryos and in embryos than placentas. RNA sequencing revealed that enzymes involved in metabolic activation of BaP are expressed at moderate to high levels in embryonic gonads and that greater transcriptomic changes occurred in the ovaries in response to BaP than in the testes. We identified 490 differentially expressed genes (DEGs) with false discovery rate P-values < 0.05 when comparing BaP-exposed to control ovaries but no statistically significant DEGs between BaP-exposed and control testes. Genes related to monocyte/macrophage recruitment and activity, prolactin family genes, and several keratin genes were among the most upregulated genes in the BaP-exposed ovaries. Results show that developing ovaries are more sensitive than testes to prenatal BaP exposure, which may be related to higher concentrations of BaP metabolites in female embryos.

Characteristics of Selected Adipokines in Ascites and Blood of Ovarian Cancer Patients

Simple Summary

Ovarian cancer is at the forefront of all cancers worldwide. A specific microenvironment for the secretion of various proteins, including adipokines, is formed around the neoplastic tissue. Five of these proteins, namely adiponectin, interleukin 6 (IL-6), interleukin 8 (IL-8), monocyte chemotactic protein-1 (MCP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1), were found to have a particular effect on metastasis. The review collects data available in the literature on the function and occurrence of these cytokines in ovarian cancer. The collected information will allow for the observation of these proteins in the area of diagnostics and the planning of further scientific research, and will enable the use of the cytokine level determination as biomarkers of neoplastic disease, its progression and prognosis.

Abstract

Ovarian cancer is one of the most common malignancies among women worldwide. The course of the disease is often latent and asymptomatic in the early stages, but as it develops, metastasis occurs, accompanied by accumulation of ascites in the peritoneal cavity. The ascites fluid constitutes a specific microenvironment influencing the processes of carcinogenesis. In ascites, signaling is mediated by various cytokines that control tumor cell proliferation, progression, metastasis, and chemoresistance. Adipokines, secreted into ascites and also appearing in blood, may be markers of ongoing processes related to the development of neoplastic disease. Moreover, a significant influence of adipocyte lipids on the growth of tumors, for which they are one of energy sources, is observed. Adiponectin, interleukin 6 (IL-6), interleukin 8 (IL-8), monocyte chemotactic protein-1 (MCP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1), discussed in the present review, were found to mediate the effects of omentum metastasis through homing, migration and invasion of ovarian cancer cells. Further research on those adipokines seem to be a natural consequence, allowing for a better understanding of the mechanisms of neoplastic disease and determination of the treatment procedure.

Investigation on the mechanisms of guiqi huoxue capsule for treating cervical spondylosis based on network pharmacology and molecular docking

BACKGROUND

Guiqi huoxue capsule (GQHXC) is a patented Chinese medicine used for treating a liver and kidney deficiency and blood stasis syndrome due to qi deficiency. It is caused by cervical spondylosis (cervical spondylotic radiculopathy (CSR), mixed cervical spondylosis mainly composed of nerve root type). Its underlying mechanisms need, however, to be further clarified.

METHODS

In this study, collecting compounds, predicting therapeutic targets, constructing networks, and analyzing biological functions and pathways were based on network pharmacology analysis. In addition, molecular docking verification was engaged to assess the binding potential of selected target-compound pairs.

RESULTS

We established 5 networks: compound-putative target network of GQHXC, protein-protein interaction (PPI) network related to CSR, compound-CSR target network, potential therapeutic targets PPI network, and herb-compound-target-pathway network. Network analysis indicated that 7 targets (tumor necrosis factor [TNF], interleukin 6 [IL6], nitric oxide synthase 3 [NOS3], Interleukin-8 [CXCL8], prostaglandin-endoperoxide synthase 2 [PTGS2], vascular endothelial growth factor A [VEGFA], and AP-1 transcription factor subunit [JUN]) might be the therapeutic targets of GQHXC in CSR. Moreover, molecular docking verification showed that TNF, IL6, NOS3, CXCL8, PTGS2, VEGFA, and JUN had a good is interaction with the corresponding compounds. Furthermore, enrichment analysis indicated that GQHXC might exert a curative role in CSR by regulating some important pathways, such as TNF signaling pathway, NF-kappa B signaling pathway, AGE-RAGE signaling pathway in diabetic complications, and so on.

CONCLUSION

Our study preliminarily explained the underlying mechanisms of GQHXC for treating CSR, and molecular docking verification was adopted as an additional verification. These findings laid a valuable foundation for experimental research and further application of GQHXC in the clinical treatment of CSR.

Chronological Gene Expression of Human Gingival Fibroblasts with Low Reactive Level Laser (LLL) Irradiation

Though previously studies have reported that Low reactive Level Laser Therapy (LLLT) promotes wound healing, molecular level evidence was uncleared. The purpose of this study is to examine the temporal molecular processes of human immortalized gingival fibroblasts (HGF) by LLLT by the comprehensive analysis of gene expression. HGF was seeded, cultured for 24 h, and then irradiated with a Nd: YAG laser at 0.5 W for 30 s. After that, gene differential expression analysis and functional analysis were performed with DNA microarray at 1, 3, 6 and 12 h after the irradiation. The number of genes with up- and downregulated differentially expression genes (DEGs) compared to the nonirradiated group was large at 6 and 12 h after the irradiation. From the functional analysis results of DEGs, Biological Process (BP) based Gene Ontology (GO), BP ‘the defense response’ is considered to be an important process with DAVID. Additionally, the results of PPI analysis of DEGs involved in the defense response with STRING, we found that the upregulated DEGs such as CXCL8 and NFKB1, and the downregulated DEGs such as NFKBIA and STAT1 were correlated with multiple genes. We estimate that these genes are key genes on the defense response after LLLT.

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.

Lymphocyte may be a reference index of the outcome of cancer patients with COVID-19

Background: The novel coronavirus infectious disease (COVID-19) is an international concern as it spreads through human populations and across national and international borders.

Methods: In this retrospective study, we consecutively included all cancer patients who had been identified as having a nucleic acid-confirmed COVID-19 from two designated hospitals in Wuhan, China. COVID-19 patients without cancer were also enrolled for comparison. The clinical data were gathered from the medical records from Jan 14 to March 12, 2020.

Results: Among the 117 cancer patients diagnosed with COVID-19, the median age was 63 years and 48.7% were male. Male sex, hematologic cancer, dyspnea on admission, and anti-cancer therapies were associated with an increased risk of mortality in cancer patients with COVID-19. We found that elevated levels of TNF-α, IL-2R, IL-6, and IL-8 were associated with a poorer prognosis in cancer patients with COVID-19, but no statistically significant association was found in patients without cancer. In addition, IL-2R and IL-6 markedly decreased in cancer patients who recovered from COVID-19. However, lymphocyte subsets were diminished in cancer patients who died from COVID-19, including total T cells, total B cells, helper T (Th) cells and suppressor T (Ts) cells.

Conclusions: Cancer patients with COVID-19 were associated with high mortality (23.9%). A decrease in lymphocyte subsets and higher levels of cytokines were associated with a higher risk of severe outcome and could be utilized as the reference index to predict the survival outcome of cancer patients with COVID-19.

Tumor Cell-Secreted ISG15 Promotes Tumor Cell Migration and Immune Suppression by Inducing the Macrophage M2-Like Phenotype

Interferon-stimulated gene 15 (ISG15) is known to be involved in tumor progression. We previously reported that ISG15 expressed on nasopharyngeal carcinoma (NPC) cells and related to poor prognosis of patients with NPC. We further observed that ISG15 can be secreted by NPC cell and expressed on the macrophages in situ. However, the role of ISG15 in tumor-associated macrophages (TAMs) remains poorly understood. In the present study, we found that ISG15 treatment induces macrophages with M2-like phenotype, and the enhancement of NPC cell migration and tumorigenicity. Mechanically, ISG15-induced M2-like phenotype is dependent on the interaction with its receptor, LFA-1, and engagement of SRC family kinase (SFK) signal, and the subsequent secretion of CCL18. Blocking LFA-1, or SRC signal with small molecular inhibitors, or neutralizing with anti-CCL18 antibody can impede the activation of LFA-1-SFK-CCL18 axis in ISG15-treated macrophages. Clinically, ISG15⁺ CD163⁺ TAMs related to impaired survival of patients and advanced tumor stage of NPC. Furthermore, we found ISG15⁺ CD163⁺ macrophages inhibited antitumor CD8⁺ cells responses in NPC. Together, our findings suggested tumor cell-secreted ISG15, which acted as a tumor microenvironmental factor, induces M2-like phenotype, promoting tumor progression and suppression of cytotoxic T lymphocyte response.

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.

Hypoxia Alters the Expression of CC Chemokines and CC Chemokine Receptors in a Tumor-A Literature Review

Hypoxia, i.e., oxygen deficiency condition, is one of the most important factors promoting the growth of tumors. Since its effect on the chemokine system is crucial in understanding the changes in the recruitment of cells to a tumor niche, in this review we have gathered all the available data about the impact of hypoxia on β chemokines. In the introduction, we present the chronic (continuous, non-interrupted) and cycling (intermittent, transient) hypoxia together with the mechanisms of activation of hypoxia inducible factors (HIF-1 and HIF-2) and NF-κB. Then we describe the effect of hypoxia on the expression of chemokines with the CC motif: CCL1, CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11, CCL13, CCL15, CCL16, CCL17, CCL18, CCL19, CCL20, CCL21, CCL22, CCL24, CCL25, CCL26, CCL27, CCL28 together with CC chemokine receptors: CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, and CCR10. To better understand the effect of hypoxia on neoplastic processes and changes in the expression of the described proteins, we summarize the available data in a table which shows the effect of individual chemokines on angiogenesis, lymphangiogenesis, and recruitment of eosinophils, myeloid-derived suppressor cells (MDSC), regulatory T cells (T_reg), and tumor-associated macrophages (TAM) to a tumor niche.

Metabolic reprograming of tumor-associated macrophages

A large body of scientific evidence corroborated by clinical and animal model experiments indicates that tumor-associated macrophages (TAMs) play a crucial role in tumor development and progression. TAMs are a key immune cell type present in tumor microenvironment (TME) and associated with poor prognosis, drug resistance, enhanced angiogenesis and metastasis in cancer. TAMs are a phenotypically diverse population of myeloid cells which display tremendous plasticity and dynamic metabolic nature. A complete interpretation of pro-tumoral and anti-tumoral metabolic switch in TAMs is essential to understand immune evasion mechanisms in cancer. Recent studies have also implicated epigenetic mechanisms as significantly regulators of TAM functions. In this review we provide an overview of metabolic circuitry in TAMs, its impact on immune effector cells and interventions aimed at rewiring the metabolic circuits in TAMs. Mechanisms responsible for TAM polarization in cancer are also discussed.

Preclinical and Clinical Immunotherapeutic Strategies in Epithelial Ovarian Cancer

In the past 20 years, the immune system has increasingly been recognized as a major player in tumor cell control, leading to considerable advances in cancer treatment. While promising with regards to melanoma, renal cancer and non-small cell lung cancer, immunotherapy provides, for the time being, limited success in other cancers, including ovarian cancer, potentially due to insufficient immunogenicity or to a particularly immunosuppressive microenvironment. In this review, we provide a global description of the immune context of ovarian cancer, in particular epithelial ovarian cancer (EOC). We describe the adaptive and innate components involved in the EOC immune response, including infiltrating tumor-specific T lymphocytes, B lymphocytes, and natural killer and myeloid cells. In addition, we highlight the rationale behind the use of EOC preclinical mouse models to assess resistance to immunotherapy, and we summarize the main preclinical studies that yielded anti-EOC immunotherapeutic strategies. Finally, we focus on major published or ongoing immunotherapy clinical trials concerning EOC.

Current insights into the metastasis of epithelial ovarian cancer - hopes and hurdles

BACKGROUND

Ovarian cancer is the most lethal gynecologic cancer and the fifth leading cause of cancer-related mortality in women worldwide. Despite various attempts to improve the diagnosis and therapy of ovarian cancer patients, the survival rate for these patients is still dismal, mainly because most of them are diagnosed at a late stage. Up to 90% of ovarian cancers arise from neoplastic transformation of ovarian surface epithelial cells, and are usually referred to as epithelial ovarian cancer (EOC). Unlike most human cancers, which are disseminated through blood-borne metastatic routes, EOC has traditionally been thought to be disseminated through direct migration of ovarian tumor cells to the peritoneal cavity and omentum via peritoneal fluid. It has recently been shown, however, that EOC can also be disseminated through blood-borne metastatic routes, challenging previous thoughts about ovarian cancer metastasis.

CONCLUSIONS

Here, we review our current understanding of the most updated cellular and molecular mechanisms underlying EOC metastasis and discuss in more detail two main metastatic routes of EOC, i.e., transcoelomic metastasis and hematogenous metastasis. The emerging concept of blood-borne EOC metastasis has led to exploration of the significance of circulating tumor cells (CTCs) as novel and non-invasive prognostic markers in this daunting cancer. We also evaluate the role of tumor stroma, including cancer associated fibroblasts (CAFs), tumor associated macrophages (TAMs), endothelial cells, adipocytes, dendritic cells and extracellular matrix (ECM) components in EOC growth and metastasis. Lastly, we discuss therapeutic approaches for targeting EOC. Unraveling the mechanisms underlying EOC metastasis will open up avenues to the design of new therapeutic options. For instance, understanding the molecular mechanisms involved in the hematogenous metastasis of EOC, the biology of CTCs, and the detailed mechanisms through which EOC cells take advantage of stromal cells may help to find new opportunities for targeting EOC metastasis.

Selective Allosteric Modulation of N-Terminally Cleaved, but Not Full Length CCL3 in CCR1

Chemokines undergo post-translational modification such as N-terminal truncations. Here, we describe how N-terminal truncation of full length CCL3^(1-70) affects its activity at CCR1. Truncated CCL3^(5-70) has 10-fold higher potency and enhanced efficacy in β-arrestin recruitment, but less than 2-fold increased potencies in G protein signaling determined by calcium release, cAMP and IP₃ formation. Small positive ago-allosteric ligands modulate the two CCL3 variants differently as the metal ion chelator bipyridine in complex with zinc (ZnBip) enhances the binding of truncated, but not full length CCL3, while a size-increase of the chelator to a chloro-substituted terpyridine (ZnClTerp), eliminates its allosteric, but not agonistic action. By employing a series of receptor mutants and in silico modeling we describe residues of importance for chemokine and small molecule binding. Notably, the chemokine receptor-conserved Glu287^7.39 interacts with the N-terminal amine of truncated CCL3^(5-70) and with Zn²⁺ of ZnBip, thereby bridging their binding sites and enabling the positive allosteric effect. Our study emphasizes that small allosteric molecules may act differently toward chemokine variants and thus selectively modulate interactions of specific chemokine subsets with their cognate receptors.

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.

Chemerin and Cancer

Chemerin is a multifunctional adipokine with established roles in inflammation, adipogenesis and glucose homeostasis. Increasing evidence suggest an important function of chemerin in cancer. Chemerin's main cellular receptors, chemokine-like receptor 1 (CMKLR1), G-protein coupled receptor 1 (GPR1) and C-C chemokine receptor-like 2 (CCRL2) are expressed in most normal and tumor tissues. Chemerin's role in cancer is considered controversial, since it is able to exert both anti-tumoral and tumor-promoting effects, which are mediated by different mechanisms like recruiting innate immune defenses or activation of endothelial angiogenesis. For this review article, original research articles on the role of chemerin and its receptors in cancer were considered, which are listed in the PubMed database. Additionally, we included meta-analyses of publicly accessible DNA microarray data to elucidate the association of expression of chemerin and its receptors in tumor tissues with patients' survival.

Discovery of CCL18 antagonist blocking breast cancer metastasis

Our previous studies have proved that CCL18 is the most secreted chemokine in breast cancer microenvironment by tumor associated macrophages (TAMs). CCL18 promotes breast cancer invasiveness by binding to its cognate receptor PITPNM3 and activating the downstream signaling pathways. The high level of CCL18 in serum or tumor stroma is associated with tumor metastasis and poor patients overall survival. In this study, we identify an effective small molecular compound (SMC) to antagonize the effect of CCL18. We screen more than 1000 SMCs from Sun Yat-sen University SMC library and select 15 top scored SMCs by using computer-aided virtual screening based on the structure of CCL18. Then in vitro cell migration assay narrows down the selected 15 SMCs to the most effective SMC-21598. We find 10 µM SMC-21598 significantly inhibits CCL18-induced breast cancer cells adherence, invasiveness, and migration. Our further surface plasmon resonance (SPR), fluorescence spectroscopy and isothermal titration calorimetry (ITC) assays reveal that SMC-21598 binds tightly to CCL18, which blocks the binding of CCL18 with its receptor PITPNM3. The in vivo animal experiments show that SMC-21598 doesn't significantly affect xenografts growth, but inhibits lung metastasis. Our study provides a potential lead compound to antagonize CCL18 function. It would be of great significance to develop SMC drugs to ameliorate breast cancer metastasis and prolong patients' survival.

Attributes of alternatively activated (M2) macrophages

Macrophages are cells of innate immunity and are derived from circulating monocytes and embryonic yolk sac. They exhibit high plasticity and polarize functionally in response to stimulus triggering it into classically activated M1 macrophages and alternatively activated M2 macrophages. This review summarizes markers of M2 macrophages like transmembrane surface receptors and signaling cascades initiated on their activation; cytokine and chemokine repertoires along with their receptors; and genetic markers and their involvement in immunomodulation. The detailed discussion emphasizes the role of these markers in imparting functional benefits to this subset of macrophages which define their venture in various physiological and pathological conditions.

Macrophage ERα promoted invasion of endometrial cancer cell by mTOR/KIF5B-mediated epithelial to mesenchymal transition

Tumor-associated macrophages (TAMs) exert tumor-promoting effects. There have been reports that estrogen receptors (ERs) are expressed on the infiltrating macrophages of endometriosis, ovarian cancer and lung cancer. However, the role of ERs in macrophages is not well characterized. In this study, we identified that ER alpha (ERα) expression on the macrophages of human endometrial cancer was positively correlated with cancer progression. Conditioned medium from selective ERα agonist-treated M2 macrophages induced the epithelial to mesenchymal transition (EMT) in endometrial cancer cells. However, this effect can be inhibited by ERα antagonist. Here, we showed that macrophages ERα-engaged abundantly produced chemokine (C-C motif) ligand 18 (CCL18), and its expression promoted the invasion of endometrial cancer cells by activating the extracellular signal-regulated kinase 1/2 pathway, whereas suppressing CCL18 abrogated these effects. Furthermore, we identified that CCL18 derived from TAMs upregulated KIF5B expression to promote EMT via activating the PI3K/AKT/mTOR signaling pathway in endometrial cancer. Overall, our findings show how ERα-engaged infiltrating macrophages initiate chronic inflammation and promote the aggressive progression of endometrial cancer cells. ERα-positive TAMs act as drivers of endometrial cancer, which may become a potential therapeutic target.

CCL18 promotes the metastasis of squamous cell carcinoma of the head and neck through MTDH-NF-κB signalling pathway

Metastasis is one of the primary causes for high mortality in patients with squamous cell carcinoma of the head and neck (SCCHN). Our previous study showed that chemokine (C‐C motif) ligand 18 (CCL18), derived from tumour‐associated macrophages (TAMs), regulates SCCHN metastasis by promoting epithelial‐mesenchymal transition (EMT) and preserving stemness. However, the underlying mechanism needs to be further investigation. Interestingly, metadherin (MTDH) expression was induced when SCCHN cells were stimulated with recombinant CCL18 protein in this study. Suppressing MTDH expression reversed CCL18‐induced migration, invasion and EMT in SCCHN cells. Furthermore, the NF‐κB signalling pathway was involved in the MTDH knock‐down cells with CCL18 stimulation. We performed ELISA to evaluate the CCL18 levels in the serums of 132 treatment‐naive SCCHN patients, 25 patients with precancerous lesion and 32 healthy donors. Our results demonstrated that serum CCL18 levels were significantly higher in SCCHN patients than patients with precancerous lesion and healthy individuals. CCL18 levels were found to be significantly correlated with tumour classification, clinical stage, lymph node metastasis and histological grade in SCCHN patients. Thus, our findings suggest that CCL18 may serve as a potential biomarker for diagnosis of SCCHN and promote SCCHN invasion, migration and EMT by MTDH‐NF‐κB signalling pathway.

Tumor-associated macrophages derived CCL18 promotes metastasis in squamous cell carcinoma of the head and neck

Background

Alternatively activated macrophages in tumor microenvironment is defined as M2 tumor-associated macrophages (M2 TAMs) that promote cancer progression. However, communicative mechanisms between M2 TAMs and cancer cells in squamous cell carcinoma of head and neck (SCCHN) remain largely unknown.

Methods

Quantitative real-time PCR, western blotting, enzyme-linked immunosorbent assay and flow cytometry were applied to quantify mRNA and protein expression of genes related to M2 TAMs, epithelial–mesenchymal transition (EMT) and stemness. Wounding-healing and Transwell invasion assays were performed to detect the invasion and migration. Sphere formation assay was used to detect the stemness of SCCHN cells. RNA-sequencing and following bioinformatics analysis were used to determine the alterations of transcriptome.

Results

THP-1 monocytes were successfully polarized into M2-like TAMs, which was manifested by increased mRNA and protein expression of CCL18, IL-10 and CD206. Conditioned medium from M2-like TAMs promoted the migration and invasion of SCCHN cells, which was accompanied by the occurrence of EMT and enhanced stemness. Importantly, CCL18 neutralizing antibody partially abrogated these effects that caused by conditional medium from M2-like TAMs. In addition, recombinant human CCL18 (rhCCL18) correspondingly promoted the malignant biological behaviors of SCCHN in vitro. Finally, RNA-sequencing analysis identified 331 up-regulated and 363 down-regulated genes stimulated by rhCCL18, which were statistically enriched in 10 cancer associated signaling pathways.

Conclusion

These findings indicate that CCL18 derived from M2-like TAMs promotes metastasis via inducing EMT and cancer stemness in SCCHN in vitro.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0620-1) contains supplementary material, which is available to authorized users.

Identification of six serum antigens and autoantibodies for the detection of early stage epithelial ovarian carcinoma by bioinformatics analysis and liquid chip analysis

The early detection of ovarian cancer is critical for improving the prognosis of patients, but there are currently insufficient tumor biomarkers for early detection owing to their low diagnostic sensitivity and specificity. The aim of the present study was to investigate the use of the serum antigens C-C motif chemokine ligand 18 and C-X-C motif chemokine ligand 1, and autoantibodies C1D, transmembrane 4 L six family member 1, zinc finger protein 675 and fragile X mental retardation 1 autosomal homolog 1, for the early screening of epithelial ovarian cancer (EOC). The expression of these sex genes/proteins in ovarian cancer and normal ovarian tissue was examined, and the potential functions of the six genes/proteins in ovarian cancer were analyzed by bioinformatics. Finally, these data were verified in clinical samples, and the multi-analyte suspension array method was compared with the ELISA method. Taken together, these data indicated that these six genes/proteins may serve as potential biomarkers for the early detection of EOC.

Tumor-Associated Macrophages and Dendritic Cells as Prototypic Type II Polarized Myeloid Populations

Environmental signals polarize mononuclear phagocytes which can express different functional programmes. Fully polarized type I and type II (or alternatively activated) macrophages are the extremes of a continuum of functional states. Tumor-derived and T cell-derived cytokines stimulate tumor associated macrophages (TAM) to acquire a polarized type II phenotype. These functionally polarized cells, and similarly oriented or immature dendritic cells present in tumors, play a key role in subversion of adaptive immunity and in inflammatory circuits which promote tumor growth and progression.

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 Promise of Immunotherapy in the Treatment of Hepatocellular Carcinoma

Advanced hepatocellular carcinoma (HCC) has presented a therapeutic challenge. Despite its heterogeneity, which is partially related to its various etiologies, it frequently arises in a background of chronic inflammation, which makes it a potentially excellent candidate for immunotherapeutic approaches. There is evidence of antitumor immunity in HCC as manifested by the cell infiltrate and its association with prognosis, the presence of tumor-associated antigens, and the reports of immune-mediated spontaneous regressions. However, both the liver itself and the tumor environment possess a diverse armamentarium of mechanisms that suppress antitumor immunity. Here, we describe the rationale for immunotherapy in HCC and discuss the emerging clinical data from various immunotherapeutic approaches including checkpoint inhibition, cell therapy, oncolytic viral therapy, and various combinatorial approaches. We also highlight the potential for various modalities to be adapted across different stages of the disease.

The Promise of Immunotherapy in the Treatment of Hepatocellular Carcinoma

Advanced hepatocellular carcinoma (HCC) has presented a therapeutic challenge. Despite its heterogeneity, which is partially related to its various etiologies, it frequently arises in a background of chronic inflammation, which makes it a potentially excellent candidate for immunotherapeutic approaches. There is evidence of antitumor immunity in HCC as manifested by the cell infiltrate and its association with prognosis, the presence of tumor-associated antigens, and the reports of immune-mediated spontaneous regressions. However, both the liver itself and the tumor environment possess a diverse armamentarium of mechanisms that suppress antitumor immunity. Here, we describe the rationale for immunotherapy in HCC and discuss the emerging clinical data from various immunotherapeutic approaches including checkpoint inhibition, cell therapy, oncolytic viral therapy, and various combinatorial approaches. We also highlight the potential for various modalities to be adapted across different stages of the disease.

Proteotranscriptomics Reveal Signaling Networks in the Ovarian Cancer Microenvironment

Ovarian cancer is characterized by early transcoelomic metastatic spread via the peritoneal fluid, where tumor cell spheroids (TU), tumor-associated T cells (TAT), and macrophages (TAM) create a unique microenvironment promoting cancer progression, chemoresistance, and immunosuppression. However, the underlying signaling mechanisms remain largely obscure. To chart these signaling networks, we performed comprehensive proteomic and transcriptomic analyses of TU, TAT, and TAM from ascites of ovarian cancer patients. We identify multiple intercellular signaling pathways driven by protein or lipid mediators that are associated with clinical outcome. Beyond cytokines, chemokines and growth factors, these include proteins of the extracellular matrix, immune checkpoint regulators, complement factors, and a prominent network of axon guidance molecules of the ephrin, semaphorin, and slit families. Intriguingly, both TU and TAM from patients with a predicted short survival selectively produce mediators supporting prometastatic events, including matrix remodeling, stemness, invasion, angiogenesis, and immunosuppression, whereas TAM associated with a longer survival express cytokines linked to effector T-cell chemoattraction and activation. In summary, our study uncovers previously unrecognized signaling networks in the ovarian cancer microenvironment that are of potential clinical relevance.

Targeting tumor-associated macrophages by anti-tumor Chinese materia medica

Tumor-associated macrophages (TAMs) play a key role in all stages of tumorigenesis and tumor progression. TAMs secrete different kinds of cytokines, chemokines, and enzymes to affect the progression, metastasis, and resistance to therapy depending on their state of reprogramming. Therapeutic benefit in targeting TAMs suggests that macrophages are attractive targets for cancer treatment. Chinese materia medica (CMM) is an important approach for treating cancer in China and in the Asian region. According to the theory of Chinese medicine (CM) and its practice, some prescriptions of CM regulate the body's internal environment possibly including the remodeling the tumor microenvironment (TME). Here we briefly summarize the pivotal effects of TAMs in shaping the TME and promoting tumorigenesis, invasion, metastasis and immunosuppression. Furthermore, we illustrate the effects and mechanisms of CMM targeting TAMs in antitumor therapy. Finally, we reveal the CMM's dual-regulatory and multi-targeting functions on regulating TAMs, and hopefully, provide the theoretical basis for CMM clinical practice related to cancer therapy.

Is serum level of CC chemokine ligand 18 a biomarker for the prediction of radiation induced lung toxicity (RILT)?

The CC chemokine ligand 18 (CCL18) is produced by alveolar macrophages in patients with fibrosing lung disease and its concentration is increased in various fibrotic lung diseases. Furthermore CCL18 is elevated in several malignancies as it is produced by tumor associated macrophages. In this study we aimed to analyze the role of CCL18 as a prognostic biomarker for the development of early radiation induced lung toxicity (RILT), i.e. radiation pneumonitis after thoracic irradiation and its significance in the course of the disease. Sixty seven patients were enrolled prospectively in the study. Patients were treated with irradiation for several thoracic malignancies (lung cancer, esophageal cancer, thymoma), either with conventionally fractionated or hypo-fractionated radiotherapy. The CCL18 serum levels were quantified with ELISA (enzyme-linked immunosorbent assay) at predefined time points: before, during and at the end of treatment as well as in the first and second follow-up. Treatment parameters and functional tests were also correlated with the development of RILT.Fifty three patients were evaluable for this study. Twenty one patients (39%) developed radiologic signs of RILT Grade >1 but only three of them (5.6%) developed clinical symptoms (Grade 2). We could not find any association between the different CCL18 concentrations and a higher incidence of RILT. Statistical significant factors were the planning target volume (odds ratio OR: 1.003, p = 0.010), the volume of the lung receiving > 20 Gy (OR: 1.132 p = 0.004) and age (OR: 0.917, p = 0.008). There was no association between serial CCL18 concentrations with tumor response and overall survival.In our study the dosimetric parameters remained the most potent predictors of RILT. Further studies are needed in order to estimate the role of CCL18 in the development of early RILT.

Aging and cancer: The role of macrophages and neutrophils

Impaired immune function has been implicated in the declining health and higher incidence of cancer in the elderly. However, age-related changes to immunity are not completely understood. Neutrophils and macrophages represent the first line of defence yet their ability to phagocytose pathogens decrease with aging. Cytotoxic T lymphocytes are critical in eliminating tumors, but T cell function is also compromised with aging. T cell responses can be regulated by macrophages and may depend on the functional phenotype macrophages adopt in response to microenvironmental signals. This can range from pro-inflammatory, anti-tumorigenic M1 to anti-inflammatory, pro-tumorigenic M2 macrophages. Macrophages in healthy elderly adipose and hepatic tissue exhibit a more pro-inflammatory M1 phenotype compared to young hosts whilst immunosuppressive M2 macrophages increase in elderly lymphoid tissues, lung and muscle. These M2-like macrophages demonstrate altered responses to stimuli. Recent studies suggest that neutrophils also regulate T cell function and, like macrophages, neutrophil function is modulated with aging. It is possible that age-modified tissue-specific macrophages and neutrophils contribute to chronic low-grade inflammation that is associated with dysregulated macrophage-mediated immunosuppression, which together are responsible for development of multiple pathologies, including cancer. This review discusses recent advances in macrophage and neutrophil biology in healthy aging and cancer.