MCP-1/CCL2 Mediated by Autocrine Loop of PDGF-BB Promotes Invasion of Lung Cancer Cell by Recruitment of Macrophages Via CCL2–CCR2 Axis

Facts and Hopes on Neutralization of Protumor Inflammatory Mediators in Cancer Immunotherapy

In cancer pathogenesis, soluble mediators are responsible for a type of inflammation that favors the progression of tumors. The mechanisms chiefly involve changes in the cellular composition of the tumor tissue stroma and in the functional modulation of myeloid and lymphoid leukocytes. Active immunosuppression, proangiogenesis, changes in leukocyte traffic, extracellular matrix remodeling, and alterations in tumor-antigen presentation are the main mechanisms linked to the inflammation that fosters tumor growth and metastasis. Soluble inflammatory mediators and their receptors are amenable to various types of inhibitors that can be combined with other immunotherapy approaches. The main proinflammatory targets which can be interfered with at present and which are under preclinical and clinical development are IL1β, IL6, the CXCR1/2 chemokine axis, TNFα, VEGF, leukemia inhibitory factor, CCL2, IL35, and prostaglandins. In many instances, the corresponding neutralizing agents are already clinically available and can be repurposed as a result of their use in other areas of medicine such as autoimmune diseases and chronic inflammatory conditions.

Anti-CCL2 antibody combined with etoposide prolongs survival in a minimal residual disease mouse model of neuroblastoma

C-C motif chemokine ligand 2 (CCL2) is a monocyte chemoattractant that promotes metastatic disease and portends a poor prognosis in many cancers. To determine the potential of anti-CCL2 inhibition as a therapy for recurrent metastatic disease in neuroblastoma, a mouse model of minimal residual disease was utilized in which residual disease was treated with anti-CCL2 monoclonal antibody with etoposide. The effect of anti-CCL2 antibody on neuroblastoma cells was determined in vitro with cell proliferation, transwell migration, and 2-dimensional chemotaxis migration assays. The in vivo efficacy of anti-CCL2 antibody and etoposide against neuroblastoma was assessed following resection of primary tumors formed by two cell lines or a patient-derived xenograft (PDX) in immunodeficient NOD-scid gamma mice. In vitro, anti-CCL2 antibody did not affect cell proliferation but significantly inhibited neuroblastoma cell and monocyte migration towards an increasing CCL2 concentration gradient. Treatment of mice with anti-CCL2 antibody combined with etoposide significantly increased survival of mice after resection of primary tumors, compared to untreated mice.

Syk Inhibition Reprograms Tumor-Associated Macrophages and Overcomes Gemcitabine-Induced Immunosuppression in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an insidious disease with a low 5-year survival rate. PDAC is characterized by infiltration of abundant tumor-associated macrophages (TAM), which promote immune tolerance and immunotherapeutic resistance. Here we report that macrophage spleen tyrosine kinase (Syk) promotes PDAC growth and metastasis. In orthotopic PDAC mouse models, genetic deletion of myeloid Syk reprogrammed macrophages into immunostimulatory phenotype, increased the infiltration, proliferation, and cytotoxicity of CD8+ T cells, and repressed PDAC growth and metastasis. Furthermore, gemcitabine (Gem) treatment induced an immunosuppressive microenvironment in PDAC by promoting protumorigenic polarization of macrophages. In contrast, treatment with the FDA-approved Syk inhibitor R788 (fostamatinib) remodeled the tumor immune microenvironment, "re-educated" protumorigenic macrophages towards an immunostimulatory phenotype and boosted CD8+ T-cell responses in Gem-treated PDAC in orthotopic mouse models and an ex vivo human pancreatic slice culture model. These findings illustrate the potential of Syk inhibition for enhancing the antitumor immune responses in PDAC and support the clinical evaluation of R788 either alone or together with Gem as a potential treatment strategy for PDAC.

SIGNIFICANCE

Syk blockade induces macrophage polarization to an immunostimulatory phenotype, which enhances CD8+ T-cell responses and improves gemcitabine efficacy in pancreatic ductal adenocarcinoma, a clinically challenging malignancy.

Comparative effects of weight loss and incretin-based therapies on vascular endothelial function, fibrinolysis and inflammation in individuals with obesity and prediabetes: A randomized controlled trial

AIM

To test the hypothesis that glucagon-like peptide-1 receptor (GLP-1R) agonists have beneficial effects on vascular endothelial function, fibrinolysis and inflammation through weight loss-independent mechanisms.

MATERIALS AND METHODS

Individuals with obesity and prediabetes were randomized to 14 weeks of the GLP-1R agonist liraglutide, hypocaloric diet or the dipeptidyl peptidase-4 inhibitor sitagliptin in a 2:1:1 ratio. Treatment with drug was double blind and placebo-controlled. Measurements were made at baseline, after 2 weeks prior to significant weight loss and after 14 weeks. The primary outcomes were measures of endothelial function: flow-mediated vasodilation (FMD), plasminogen activator inhibitor-1 (PAI-1) and urine albumin-to-creatinine ratio (UACR).

RESULTS

Eighty-eight individuals were studied (liraglutide N = 44, diet N = 22, sitagliptin N = 22). Liraglutide and diet reduced weight, insulin resistance and PAI-1, while sitagliptin did not. There was no significant effect of any treatment on endothelial vasodilator function measured by FMD. Post hoc subgroup analyses in individuals with baseline FMD below the median, indicative of greater endothelial dysfunction, showed an improvement in FMD by all three treatments. GLP-1R antagonism with exendin (9-39) increased fasting blood glucose but did not change FMD or PAI-1. There was no effect of treatment on UACR. Finally, liraglutide, but not sitagliptin or diet, reduced the chemokine monocyte chemoattractant protein-1 (MCP-1).

CONCLUSION

Liraglutide and diet reduce weight, insulin resistance and PAI-1. Liraglutide, sitagliptin and diet do not change FMD in obese individuals with prediabetes with normal endothelial function. Liraglutide alone lowers the pro-inflammatory and pro-atherosclerotic chemokine MCP-1, indicating that this beneficial effect is independent of weight loss.

Role of CC-chemokine ligand 2 in gynecological cancer

Gynecological cancer is one of the most severe diseases that threaten the lives and health of women worldwide. Its incidence rate increases with each passing year and becomes more prevalent among young people. The prognosis of gynecological cancer remains poor despite significant advances in surgical removal and systemic chemotherapy. Several chemokines play a role in the progression of gynecologic cancers. CCL2 (CC-chemokine ligand 2), also termed MCP-1 (monocyte chemotactic protein 1), plays a significant physiological role in monocyte cell migration and the inflammatory response. Recent studies have demonstrated that CCL2 plays a pro-tumorigenic function in the tumor microenvironment. According to previous studies, CCL2 plays a significant role in the occurrence and development of gynecological cancers. Furthermore, recent studies noted that CCL2 could be a potential diagnostic biomarker and prognostic predictor. The purpose of this paper is to review the role of CCL2 in the occurrence and development of gynecological cancers and to discuss the potential therapeutic strategy of CCL2 for gynecological cancers, with a primary focus on breast cancer, ovarian cancer, cervical cancer, and endometrial cancer.

Engineered nanomaterials trigger abscopal effect in immunotherapy of metastatic cancers

Despite advances in cancer treatment, metastatic cancer is still the main cause of death in cancer patients. At present, the treatment of metastatic cancer is limited to palliative care. The abscopal effect is a rare phenomenon in which shrinkage of metastatic tumors occurs simultaneously with the shrinkage of a tumor receiving localized treatment, such as local radiotherapy or immunotherapy. Immunotherapy shows promise for cancer treatment, but it also leads to consequences such as low responsiveness and immune-related adverse events. As a promising target-based approach, intravenous or intratumoral injection of nanomaterials provides new opportunities for improving cancer immunotherapy. Chemically modified nanomaterials may be able to trigger the abscopal effect by regulating immune cells. This review discusses the use of nanomaterials in killing metastatic tumor cells through the regulation of immune cells and the prospects of such nanomaterials for clinical use.

NFAT as a Biomarker and Therapeutic Target in Non-Small Cell Lung Cancer-Related Brain Metastasis

Background

Brain metastases (BMs) are associated with poor prognosis and significant mortality, and approximately 25% of patients with non-small cell lung cancer (NSCLC) develop BMs. The present study was aimed to understand the relationships between BM and NSCLC and reveal potential biomarkers and therapeutic targets in NSCLC-related BM.

Methods

The differentially expressed genes (DEGs) expressed during NSCLC and BM development were predicted by bioinformatics analysis, and the expression of the upstream transcription factor nuclear factor of activated T cells (NFAT) was confirmed as a differential gene expressed in both NSCLC and BM. In addition, the expression of proteins encoded by these DEGs was verified by immunohistochemical experiments examining normal lung tissue, lung cancer tissue, and brain metastasis tissue from 30 patients with NSCLC related BM.

Results

The co-DEGs interleukin (IL)-11, cadherin 5 (CDH5) and C-C motif chemokine 2 (CCL2) link NSCLC and BM in the Gene Expression Omnibus (GEO) database, and NFAT may target the expression of these co-DEGs. In the GEO database, NFATc1 and NFATc3 were significantly downregulated in NSCLC tissues (P <.05), whereas NFATc1, NFATc2, NFATc3, and NFATc4 were significantly downregulated in BMs (P <.05). Consistent findings were observed in the immunohistochemical analysis.

Conclusion

NFATc1 and NFATc3 may play important roles in the occurrence of NSCLC and BM by regulating IL-11, CDH5, and CCL2.

Contrasting functions of the epithelial‑stromal interaction 1 gene, in human oral and lung squamous cell cancers

The epithelial‑stromal interaction 1 gene (EPSTI1) is known to play multiple roles in the malignant progression of breast cancer and also in some aspects of the immune responses to the tumor. However, the relevance of the gene in the onset/progression of oral squamous cell carcinoma (OSCC) and lung squamous cell carcinoma (LSCC) is not yet known. The present study was aimed at revealing the roles of EPSTI1 in conferring malignant characteristics to OSCC and LSCC, and the underlying mechanisms. Quantitative real‑time polymerase chain reaction (PCR) and western blot analyses demonstrated significant upregulation of EPSTI1 in all four OSCC cell lines (HSC2, HSC3, HSC3‑M3 and HSC4), and significant downregulation of EPST11 in all three LSCC cell lines (LK‑2, EBC‑1 and H226) used in the present study, as compared to the expression levels in the corresponding control cell lines. Both knockdown of EPST11 in OSCC and overexpression of the gene in LSCC suppressed cell proliferation, and induced cell‑cycle arrest in the G1 phase, with upregulation of p21 and downregulation of CDK2 and cyclin D1. Furthermore, these alterations of EPST11 gene expression in the OSCC and LSCC cell lines suppressed the cell migration ability and reversed the EMT phenotype of the tumor cells. Collectively, while EPSTI1 appears to have oncogenic roles in OSCC, it appears to exert tumor‑suppressive roles in LSCC. PCR array analyses revealed some genes whose expression levels were altered along with the modified EPSTI1 expression in both the OSCC and LSCC cell lines. These findings suggest that EPSTI1 may be a therapeutic target for both OSCC and LSCC.

Chemokine signaling in cancer-stroma communications

Cancer is a multi-faceted disease in which spontaneous mutation(s) in a cell leads to the growth and development of a malignant new organ that if left undisturbed will grow in size and lead to eventual death of the organism. During this process, multiple cell types are continuously releasing signaling molecules into the microenvironment, which results in a tangled web of communication that both attracts new cell types into and reshapes the tumor microenvironment as a whole. One prominent class of molecules, chemokines, bind to specific receptors and trigger directional, chemotactic movement in the receiving cell. Chemokines and their receptors have been demonstrated to be expressed by almost all cell types in the tumor microenvironment, including epithelial, immune, mesenchymal, endothelial, and other stromal cells. This results in chemokines playing multifaceted roles in facilitating context-dependent intercellular communications. Recent research has started to shed light on these ligands and receptors in a cancer-specific context, including cell-type specificity and drug targetability. In this review, we summarize the latest research with regards to chemokines in facilitating communication between different cell types in the tumor microenvironment.

Role of the CCL2-CCR2 signalling axis in cancer: Mechanisms and therapeutic targeting

The chemokine ligand CCL2 and its receptor CCR2 are implicated in the initiation and progression of various cancers. CCL2 can activate tumour cell growth and proliferation through a variety of mechanisms. By interacting with CCR2, CCL2 promotes cancer cell migration and recruits immunosuppressive cells to the tumour microenvironment, favouring cancer development. Over the last several decades, a series of studies have been conducted to explore the CCL2-CCR2 signalling axis function in malignancies. Therapeutic strategies targeting the CCL2- CCR2 axis have also shown promising effects, enriching our approaches for fighting against cancer. In this review, we summarize the role of the CCL2-CCR2 signalling axis in tumorigenesis and highlight recent studies on CCL2-CCR2 targeted therapy, focusing on preclinical studies and clinical trials.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

Research trends in pharmacological modulation of tumor-associated macrophages

As one of the most abundant immune cell populations in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play important roles in multiple solid malignancies, including breast cancer, prostate cancer, liver cancer, lung cancer, ovarian cancer, gastric cancer, pancreatic cancer, and colorectal cancer. TAMs could contribute to carcinogenesis, neoangiogenesis, immune-suppressive TME remodeling, cancer chemoresistance, recurrence, and metastasis. Therefore, reprogramming of the immune-suppressive TAMs by pharmacological approaches has attracted considerable research attention in recent years. In this review, the promising pharmaceutical targets, as well as the existing modulatory strategies of TAMs were summarized. The chemokine-chemokine receptor signaling, tyrosine kinase receptor signaling, metabolic signaling, and exosomal signaling have been highlighted in determining the biological functions of TAMs. Besides, both preclinical research and clinical trials have suggested the chemokine-chemokine receptor blockers, tyrosine kinase inhibitors, bisphosphonates, as well as the exosomal or nanoparticle-based targeting delivery systems as the promising pharmacological approaches for TAMs deletion or reprogramming. Lastly, the combined therapies of TAMs-targeting strategies with traditional treatments or immunotherapies as well as the exosome-like nanovesicles for cancer therapy are prospected.

Macrophage Polarization in Chronic Lymphocytic Leukemia: Nurse-Like Cells Are the Caretakers of Leukemic Cells

Macrophages are terminally differentiated innate immune cells. Through their activation, they can be polarized towards the pro-inflammatory M1 type or the wound healing-associated, anti-inflammatory M2 type macrophages. In the tumor microenvironment (TME), M2 is the dominant phenotype and these cells are referred to as tumor-associated macrophages (TAMs). TAMs secrete cytokines and chemokines, exerting an antiapoptotic, proliferative and pro-metastatic effect on the tumor cells. TAMs can be found in many cancers, including chronic lymphocytic leukemia (CLL), where they are called nurse-like cells (NLCs). Despite the generally indolent behavior of CLL, the proportion of treatment-refractory patients is significant. As with the majority of cancers, despite significant recent progress, CLL pathogenesis is poorly understood. The emerging role of the TME in nurturing the neoplastic process warrants the investigation of macrophages as a significant pathogenetic element of tumors. In this paper, we review the current knowledge on the role of stromal macrophages in CLL.

CC Chemokines in a Tumor: A Review of Pro-Cancer and Anti-Cancer Properties of the Ligands of Receptors CCR1, CCR2, CCR3, and CCR4

CC chemokines, a subfamily of 27 chemotactic cytokines, are a component of intercellular communication, which is crucial for the functioning of the tumor microenvironment. Although many individual chemokines have been well researched, there has been no comprehensive review presenting the role of all known human CC chemokines in the hallmarks of cancer, and this paper aims at filling this gap. The first part of this review discusses the importance of CCL1, CCL3, CCL4, CCL5, CCL18, CCL19, CCL20, CCL21, CCL25, CCL27, and CCL28 in cancer. Here, we discuss the significance of CCL2 (MCP-1), CCL7, CCL8, CCL11, CCL13, CCL14, CCL15, CCL16, CCL17, CCL22, CCL23, CCL24, and CCL26. The presentation of each chemokine includes its physiological function and then the role in tumor, including proliferation, drug resistance, migration, invasion, and organ-specific metastasis of tumor cells, as well as the effects on angiogenesis and lymphangiogenesis. We also discuss the effects of each CC chemokine on the recruitment of cancer-associated cells to the tumor niche (eosinophils, myeloid-derived suppressor cells (MDSC), tumor-associated macrophages (TAM), tumor-associated neutrophils (TAN), regulatory T cells (T_reg)). On the other hand, we also present the anti-cancer properties of CC chemokines, consisting in the recruitment of tumor-infiltrating lymphocytes (TIL).

HbF Levels in Sickle Cell Disease Are Associated with Proportion of Circulating Hematopoietic Stem and Progenitor Cells and CC-Chemokines

The concentration of circulating hematopoietic stem and progenitor cells has not been studied longitudinally. Here, we report that the proportions of Lin-CD34+38- hematopoietic multipotent cells (HMCs) and of Lin-CD34+CD38+ hematopoietic progenitors cells (HPCs) are highly variable between individuals but stable over long periods of time, in both healthy individuals and sickle cell disease (SCD) patients. This suggests that these proportions are regulated by genetic polymorphisms or by epigenetic mechanisms. We also report that in SCD patients treated with hydroxyurea, the proportions of circulating HMCs and HPCs show a strong positive and negative correlation with fetal hemoglobin (HbF) levels, respectively. Titration of 65 cytokines revealed that the plasma concentration of chemokines CCL2, CCL11, CCL17, CCL24, CCL27, and PDGF-BB were highly correlated with the proportion of HMCs and HPCs and that a subset of these cytokines were also correlated with HbF levels. A linear model based on four of these chemokines could explain 80% of the variability in the proportion of circulating HMCs between individuals. The proportion of circulating HMCs and HPCs and the concentration of these chemokines might therefore become useful biomarkers for HbF response to HU in SCD patients. Such markers might become increasingly clinically relevant, as alternative treatment modalities for SCD are becoming available.

Macrophage and Tumor Cell Cross-Talk Is Fundamental for Lung Tumor Progression: We Need to Talk

Regardless of the promising results of certain immune checkpoint blockers, current immunotherapeutics have met a bottleneck concerning response rate, toxicity, and resistance in lung cancer patients. Accumulating evidence forecasts that the crosstalk between tumor and immune cells takes center stage in cancer development by modulating tumor malignancy, immune cell infiltration, and immune evasion in the tumor microenvironment (TME). Cytokines and chemokines secreted by this crosstalk play a major role in cancer development, progression, and therapeutic management. An increased infiltration of Tumor-associated macrophages (TAMs) was observed in most of the human cancers, including lung cancer. In this review, we emphasize the role of cytokines and chemokines in TAM-tumor cell crosstalk in the lung TME. Given the role of cytokines and chemokines in immunomodulation, we propose that TAM-derived cytokines and chemokines govern the cancer-promoting immune responses in the TME and offer a new immunotherapeutic option for lung cancer treatment.

Effect of apigenin on whole transcriptome profile of TNFα-activated MDA-MB-468 triple negative breast cancer cells

The lack of hormone receptors in triple negative breast cancer (TNBC) is associated with the inefficacy of anti-estrogen chemotherapies, leaving fewer options for patient treatment and higher mortality rates. Additionally, as with numerous types of inflammatory breast cancer, infiltration of tumor associated macrophages and other leukocyte sub-populations within the tumor inevitably lead to aggressive, chemo-resistant, metastatic and invasive types of cancer which escape immune surveillance. These processes are orchestrated by the release of potent cytokines, including TNFα, IL-6 and CCL2 from the stroma, tumor and immune cells within the tumor microenvironment. The present study evaluated apigenin modulating effects on the pro-inflammatory activating action of TNFα in TNBC MDA-MB-468 cells, derived from an African American woman. Initially, cell viability was determined to establish an optimal sub-lethal dose of TNFα and apigenin in MDA-MB-468 cells. Subsequently, various treatments effects were evaluated using whole transcriptomic analysis of mRNA and long intergenic non-coding RNA with Affymetrix HuGene-2.1-st human microarrays. Gene level differential expression analysis was conducted on 48,226 genes where TNFα caused significant upregulation of 53 transcripts and downregulation of 11 transcripts. The largest upward differential shift was for CCL2 [+61.86 fold change (FC); false discovery rate (FDR), P<0.0001]; which was down regulated by apigenin (to +10.71 FC vs. Control; FDR P-value <0.001), equivalent to an 83% reduction. Several TNFα deferentially upregulated transcripts were reduced by apigenin, including CXCL10, C3, PGLYRP4, IL22RA2, KMO, IL7R, ROS1, CFB, IKBKe, SLITRK6 (a checkpoint target) and MMP13. Confirmation of CCL2 experimentally induced transcript alterations was corroborated at the protein level by ELISA assays. The high level of CCL2 transcript in the cell line was comparable to that in our previous studies in MDA-MB-231 cells. The differential effects of TNFα were corroborated by ELISA, where the data revealed a >10-fold higher releasing rate of CCL2 in MDA-MB-468 cells compared with in MDA-MB-231 cells, both of which were attenuated by apigenin. The data obtained in the present study demonstrated a high level of CCL2 in MDA-MB-468 cells and a possible therapeutic role for apigenin in downregulating TNFα-mediated processes in these TNBC cells.

CCL2 promotes cell migration by inducing epithelial-mesenchymal transition in oral squamous cell carcinoma

BACKGROUND

Although a few studies suggested that the chemokine CCL2 might be involved in the development of oral squamous cell carcinoma (OSCC), the exact mechanism remains unclear. In this study, we aimed to determine the resource of CCL2 in lesions and explored a potential mechanism that CCL2 promotes tumor progression. The study was an effort to provide new insights into the pathological role of CCL2 in OSCC.

METHODS

Specimens of OSCC and normal oral mucosa were stained using immunohistochemistry (IHC) to assess the CCL2 expression. Enzyme-linked immunosorbent assay (ELISA) was used to detect the difference of CCL2 between OSCC and normal oral mucosa cell lines. In addition, we treated OSCC cells with exogenous rCCL2 combined with or without CCL2 neutralizing antibody and then determined the changes of in epithelial-mesenchymal transition (EMT) markers and cell migration capacity using immunofluorescence, Western blotting, transwell migration, and wound healing assays.

RESULTS

We have found that CCL2 expression was upregulated significantly in both lesions and cell culture supernatant of OSCC compared with controls. IHC staining demonstrated that CCL2 expression was primarily located in the cytoplasm and cell membrane of cells. We have also found that rCCL2 could effectively induce EMT through upregulating Snail in OSCC cells, which was demonstrated by the decrease of E-cadherin and the increase of vimentin. In addition, we have found that CCL2 neutralizing antibody could block EMT induced by CCL2 in OSCC.

CONCLUSIONS

CCL2 secreted by cancer cells can promote cell migration by inducing EMT via paracrine or autocrine in OSCC.