The Role of CXC Chemokines in Cancer Progression

Prognostic impact of Interleukin-8 levels in lung cancer: A meta-analysis and a bioinformatic validation

BACKGROUND

High interleukin-8 (IL-8) levels have been linked to poor prognosis in lung cancer, but conclusive data are lacking.

MATERIALS AND METHODS

A comprehensive search was conducted on April 1st, 2023, from electronic databases, focusing on studies with IL-8 expression evaluations and the availability of hazard ratio (HR) and 95% confidence intervals (CI) for overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS) or adequate data for their estimation. Then, we examined IL-8 and CXCR1 RNA-seq data from The Cancer Genome Atlas (TCGA) dataset, and we correlated these data with OS.

RESULTS

Among 2655 produced records, 10 manuscripts involving both non-small cell lung cancer and small cell lung cancer, were included in the analysis. Two manuscripts and one study included two and three different cohorts, respectively, for a total of 14 cohorts of patients. Overall, 4 cohorts evaluated IL-8 levels in patients treated with chemotherapy, 3 cohorts immunotherapy, 2 cohorts surgical patients and 4 cohorts other treatments; 1 cohort was removed, as the type of treatments was lacking. The 12 cohorts included in the OS analysis revealed that patients with high IL-8 levels have a lower OS probability, as compared to patients with low IL-8 levels (HR=1.75, 95 % CI 1.36-2.26). No significant difference between patients with high and low IL-8 levels was observed in the 8 cohorts available for PFS analysis. Sensitivity analysis according to treatment revealed significant PFS and OS differences for patients treated with chemotherapy or immunotherapy. Analysis of RNA-seq data from TCGA, confirmed the correlation between high IL-8 and CXCR1 expression and worse OS in patients with resected lung cancer.

CONCLUSION

To the best of our knowledge, this study represents the first meta-analysis demonstrating a negative prognostic impact of high IL-8 level in lung cancer, particularly in patients treated with chemotherapy and/or immunotherapy.

Pluronic-Based Nanoparticles for Delivery of Doxorubicin to the Tumor Microenvironment by Binding to Macrophages

The active targeting drug delivery system based on special types of endogenous cells such as macrophages has emerged as a promising strategy for tumor therapy, owing to its tumor homing property and biocompatibility. In this work, the active tumor-targeting drug delivery system carrying doxorubicin-loaded nanoparticles (DOX@MPF127-MCP-1, DMPM) on macrophage (RAW264.7) surfaces via the mediation of interaction with the CCR2/MCP-1 axis was exploited. Initially, the amphiphilic block copolymer Pluronic F127 (PF127) was carboxylated to MPF127 at the hydroxyl terminus. Subsequently, MPF127 was modified with MCP-1 peptide to prepare MPF127-MCP-1 (MPM). The DOX was wrapped in MPM to form DMPM nanomicelles (approximately 100 nm) during the self-assembly process of MPM. The DMPM spontaneously bound to macrophages (RAW264.7), which resulted in the construction of an actively targeting delivery system (macrophage-DMPM, MA-DMPM) in vitro and in vivo. The DOX in MA-DMPM was released in the acidic tumor microenvironment (TME) in a pH-responsive manner to increase DOX accumulation and enhance the tumor treatment effect. The ratio of MA-DMPM homing reached 220% in vitro compared with the control group, indicating that the MA-DMPM was excellently capable of tumor-targeting delivery. In in vivo experiments, nonsmall cell lung cancer cell (NCI-H1299) tumor models were established. The results of the fluorescence imaging system (IVIS) showed that MA-DMPM demonstrated tremendous tumor-targeting ability in vivo. The antitumor effects of MA-DMPM in vivo indicated that the proportion of tumor cell apoptosis in the DMPM-treated group was 63.33%. The findings of the tumor-bearing mouse experiment proved that MA-DMPM significantly suppressed tumor cell growth, which confirmed its immense potential and promising applications in tumor therapy.

CXCR4/CXCL12 axis: "old" pathway as "novel" target for anti-inflammatory drug discovery

Inflammation is the body's defense response to exogenous or endogenous stimuli, involving complex regulatory mechanisms. Discovering anti-inflammatory drugs with both effectiveness and long-term use safety is still the direction of researchers' efforts. The inflammatory pathway was initially identified to be involved in tumor metastasis and HIV infection. However, research in recent years has proved that the CXC chemokine receptor type 4 (CXCR4)/CXC motif chemokine ligand 12 (CXCL12) axis plays a critical role in the upstream of the inflammatory pathway due to its chemotaxis to inflammatory cells. Blocking the chemotaxis of inflammatory cells by CXCL12 at the inflammatory site may block and alleviate the inflammatory response. Therefore, developing CXCR4 antagonists has become a novel strategy for anti-inflammatory therapy. This review aimed to systematically summarize and analyze the mechanisms of action of the CXCR4/CXCL12 axis in more than 20 inflammatory diseases, highlighting its crucial role in inflammation. Additionally, the anti-inflammatory activities of CXCR4 antagonists were discussed. The findings might help generate new perspectives for developing anti-inflammatory drugs targeting the CXCR4/CXCL12 axis.

CX3CL1 (Fractalkine)-CX3CR1 Axis in Inflammation-Induced Angiogenesis and Tumorigenesis

The chemotactic cytokine fractalkine (FKN, chemokine CX3CL1) has unique properties resulting from the combination of chemoattractants and adhesion molecules. The soluble form (sFKN) has chemotactic properties and strongly attracts T cells and monocytes. The membrane-bound form (mFKN) facilitates diapedesis and is responsible for cell-to-cell adhesion, especially by promoting the strong adhesion of leukocytes (monocytes) to activated endothelial cells with the subsequent formation of an extracellular matrix and angiogenesis. FKN signaling occurs via CX3CR1, which is the only known member of the CX3C chemokine receptor subfamily. Signaling within the FKN-CX3CR1 axis plays an important role in many processes related to inflammation and the immune response, which often occur simultaneously and overlap. FKN is strongly upregulated by hypoxia and/or inflammation-induced inflammatory cytokine release, and it may act locally as a key angiogenic factor in the highly hypoxic tumor microenvironment. The importance of the FKN/CX3CR1 signaling pathway in tumorigenesis and cancer metastasis results from its influence on cell adhesion, apoptosis, and cell migration. This review presents the role of the FKN signaling pathway in the context of angiogenesis in inflammation and cancer. The mechanisms determining the pro- or anti-tumor effects are presented, which are the cause of the seemingly contradictory results that create confusion regarding the therapeutic goals.

The multifaceted role of the CXC chemokines and receptors signaling axes in ALS pathophysiology

Amyotrophic lateral sclerosis (ALS) is a late-onset motor neuron disease with complex genetic basis and still no clear etiology. Multiple intertwined layers of immune system-related dysfunctions and neuroinflammatory mechanisms are emerging as substantial determinants in ALS onset and progression. In this review, we collect the increasingly arising evidence implicating four main CXC chemokines/cognate receptors signaling axes (CXCR1/2-CXCL1/2/8; CXCR3-CXCL9/10/11; CXCR4/7-CXCL12; CXCR5-CXCL13) in the pathophysiology of ALS. Findings in preclinical models implicate these signaling pathways in motor neuron toxicity and neuroprotection, while in ALS patients dysregulation of CXCLs/CXCRs has been shown at both central and peripheral levels. Immunological monitoring of CXC-ligands in ALS may allow tracking of disease progression, while pharmacological modulation of CXC-receptors provides a novel therapeutic strategy. A deeper understanding of the interplay between CXC-mediated neuroinflammation and ALS is crucial to advance research into treatments for this debilitating uncurable disorder.

BRCA1 mutation promotes sprouting angiogenesis in inflammatory cancer-associated fibroblast of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with inferior outcomes owing to its low treatment response and high invasiveness. Based on abundant cancer-associated fibroblasts (CAFs) and frequent mutation of breast cancer-associated 1 (BRCA1) in TNBC, the characteristics of CAFs in TNBC patients with BRCA1 mutation compared to wild-type were investigated using single-cell analysis. Intriguingly, we observed that characteristics of inflammatory CAFs (iCAFs) were enriched in patients with BRCA1 mutation compared to the wild-type. iCAFs in patients with BRCA1 mutation exhibited outgoing signals to endothelial cells (ECs) clusters, including chemokine (C-X-C motif) ligand (CXCL) and vascular endothelial growth factor (VEGF). During CXCL signaling, the atypical chemokine receptor 1 (ACKR1) mainly interacts with CXCL family members in tumor endothelial cells (TECs). ACKR1-high TECs also showed high expression levels of angiogenesis-related genes, such as ANGPT2, MMP1, and SELE, which might lead to EC migration. Furthermore, iCAFs showed VEGF signals for FLT1 and KDR in TECs, which showed high co-expression with tip cell marker genes, including ZEB1 and MAFF, involved in sprouting angiogenesis. Moreover, BRCA1 mutation patients with relatively abundant iCAFs and tip cell gene expression exhibited a limited response to neoadjuvant chemotherapy, including cisplatin and bevacizumab. Importantly, our study observed the intricate link between iCAFs-mediated angiogenesis and chemoresistance in TNBC with BRCA1 mutation.

The functional roles of chemokines and chemokine receptors in colorectal cancer progression

Colorectal cancer is a common malignancy with significant rates of morbidity and mortality. A number of factors, including the tumor microenvironment, chemokines, the inflammatory response, have an impact on the development of colorectal cancer. A critical component of the tumor microenvironment is chemokines. Various cell subsets are attracted to the tumor microenvironment through interactions with chemokine receptors. These cells have varying effects on the development of the tumor and the effectiveness of treatment. Additionally, chemokines can participate in inflammatory processes and have effects that are either pro- or anti-tumor. Chemokines can be exploited as targets for medication resistance and treatment in colorectal cancer. In this review, we discuss the expression of chemokines and chemokine receptors, and their relationship with immune cells in the tumor microenvironment. At the same time, we also collect and discuss the significance of chemokines and chemokine receptors in colorectal cancer progression, and their potential as molecular targets for CRC treatment.

CXC ligand 13 orchestrates an immunoactive microenvironment and enhances immunotherapy response in head and neck squamous cell carcinoma

Objectives: This study aims to systematically explore the role of chemokine CXC ligand 13 (CXCL13) in head and neck squamous cell carcinoma (HNSCC). Methods: The Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) databases provided the RNA-seq data for cancer and normal tissues, respectively. Gene set enrichment analysis was applied to search the cancer hallmarks associated with CXCL13 expression. TIMER2.0 was the main platform used to investigate the immune cell infiltration related to CXCL13. Immunohistochemistry was applied to explore the relationship between CXCL13 and patients' prognosis and the relationship between CXCL13 and tertiary lymphoid structures (TLSs). Results: The expression of CXCL13 was upregulated in most tumors, including HNSCC. The higher expression of CXCL13 was closely related to the positive prognosis of HNSCC. CXCL13 was mainly expressed in B cells and CD8 + T cells, revealing the relationship between its expression and immune activation in the tumor microenvironment. Furthermore, immunohistochemistry and multiple fluorescence staining analysis of HNSCC samples showed a powerful correlation between CXCL13 expression, TLSs formation, and positive prognosis. Finally, CXCL13 significantly increased the response to cancer immunotherapy. Conclusions: CXCL13 may function as a potential biomarker for predicting prognosis and immunotherapy response and associate with TLSs in HNSCC.

Global transcriptomic analysis of breast cancer and normal mammary epithelial cells infected with Borrelia burgdorferi

The bacterial spirochete Borrelia burgdorferi, the causative agent of Lyme Disease, can disseminate and colonize various tissues and organs, orchestrating severe clinical symptoms including arthritis, carditis, and neuroborreliosis. Previous research has demonstrated that breast cancer tissues could provide an ideal habitat for diverse populations of bacteria, including B. burgdorferi, which is associated with a poor prognosis. Recently, we demonstrated that infection with B. burgdorferi enhances the invasion and migration of triple-negative MDA-MB-231 cells which represent a type of breast tumor with more aggressive cancer traits. In this study, we hypothesized that infection by B. burgdorferi affects the expression of cancer-associated genes to effectuate breast cancer phenotypes. We applied the high-throughput technique of RNA-sequencing on B. burgdorferi-infected MDA-MB-231 breast cancer and normal-like MCF10A cells to determine the most differentially expressed genes (DEG) upon infection. Overall, 142 DEGs were identified between uninfected and infected samples in MDA-MB-231 while 95 DEGs were found in MCF10A cells. A major trend of the upregulation of C-X-C and C-C motif chemokine family members as well as genes and pathways was associated with infection, inflammation, and cancer. These genes could serve as potential biomarkers for pathogen-related tumorigenesis and cancer progression which could lead to new therapeutic opportunities.

Plasma Exosome Proteins ILK1 and CD14 Correlated with Organ-Specific Metastasis in Advanced Gastric Cancer Patients

The exosome plays important roles in driving tumor metastasis, while the role of exosome proteins during organ-specific metastasis in gastric cancer has not been fully understood. To address this question, peripheral blood samples from 12 AGC patients with organ-specific metastasis, including distant lymphatic, hepatic and peritoneal metastasis, were collected to purify exosomes and to detect exosome proteins by Nano-HPLC-MS/MS. Gastric cancer cell lines were used for in vitro experiments. Peripheral blood sample and ascites sample from one patient were further analyzed by single-cell RNA sequencing. GO and KEGG enrichment analysis showed different expression proteins of hepatic metastasis were correlated with lipid metabolism. For peritoneal metastasis, actin cytoskeleton regulation and glycolysis/gluconeogenesis could be enriched. ILK1 and CD14 were correlated with hepatic and peritoneal metastasis, respectively. Overexpression of CD14 and ILK1 impacted the colony formation ability of gastric cancer and increased expression of Vimentin. CD14 derived from immune cells in malignant ascites correlated with high activation of chemokine- and cytokine-mediated signaling pathways. In summary, biological functions of plasma exosome proteins among AGC patients with different metastatic modes were distinct, in which ILK1 and CD14 were correlated with organ-specific metastasis.

Type 2 Diabetes Mellitus and Efficacy Outcomes from Immune Checkpoint Blockade in Patients with Cancer

PURPOSE

No evidence exists as to whether type 2 diabetes mellitus (T2DM) impairs clinical outcome from immune checkpoint inhibitors (ICI) in patients with solid tumors.

EXPERIMENTAL DESIGN

In a large cohort of ICI recipients treated at 21 institutions from June 2014 to June 2020, we studied whether patients on glucose-lowering medications (GLM) for T2DM had shorter overall survival (OS) and progression-free survival (PFS). We used targeted transcriptomics in a subset of patients to explore differences in the tumor microenvironment (TME) of patients with or without diabetes.

RESULTS

A total of 1,395 patients were included. Primary tumors included non-small cell lung cancer (NSCLC; 54.7%), melanoma (24.7%), renal cell (15.0%), and other carcinomas (5.6%). After multivariable analysis, patients on GLM (n = 226, 16.2%) displayed an increased risk of death [HR, 1.29; 95% confidence interval (CI),1.07-1.56] and disease progression/death (HR, 1.21; 95% CI, 1.03-1.43) independent of number of GLM received. We matched 92 metformin-exposed patients with 363 controls and 78 patients on other oral GLM or insulin with 299 control patients. Exposure to metformin, but not other GLM, was associated with an increased risk of death (HR, 1.53; 95% CI, 1.16-2.03) and disease progression/death (HR, 1.34; 95% CI, 1.04-1.72). Patients with T2DM with higher pretreatment glycemia had higher neutrophil-to-lymphocyte ratio (P = 0.04), while exploratory tumoral transcriptomic profiling in a subset of patients (n = 22) revealed differential regulation of innate and adaptive immune pathways in patients with T2DM.

CONCLUSIONS

In this study, patients on GLM experienced worse outcomes from immunotherapy, independent of baseline features. Prospective studies are warranted to clarify the relative impact of metformin over a preexisting diagnosis of T2DM in influencing poorer outcomes in this population.

The role of CXCL family members in different diseases

Chemokines are a large family mediating a lot of biological behaviors including chemotaxis, tumor growth, angiogenesis and so on. As one member of this family, CXC subfamily possesses the same ability. CXC chemokines can recruit and migrate different categories of immune cells, regulate tumor's pathological behaviors like proliferation, invasion and metastasis, activate angiogenesis, etc. Due to these characteristics, CXCL subfamily is extensively and closely associated with tumors and inflammatory diseases. As studies are becoming more and more intensive, CXCLs' concrete roles are better described, and CXCLs' therapeutic applications including biomarkers and targets are also deeply explained. In this review, the role of CXCL family members in various diseases is summarized.

Establishment and Characterization of Free-Floating 3D Macrophage Programming Model in the Presence of Cancer Cell Spheroids

Reprogramming of tumor-associated macrophages (TAMs) is a promising strategy for cancer immunotherapy. Several studies have shown that cancer cells induce/support the formation of immunosuppressive TAMs phenotypes. However, the specific factors that orchestrate this immunosuppressive process are unknown or poorly studied. In vivo studies are expensive, complex, and ethically constrained. Therefore, 3D cell interaction models could become a unique framework for the identification of important TAMs programming factors. In this study, we have established and characterized a new in vitro 3D model for macrophage programming in the presence of cancer cell spheroids. First, it was demonstrated that the profile of cytokines, chemokines, and surface markers of 3D-cultured macrophages did not differ conceptually from monolayer-cultured M1 and M2-programmed macrophages. Second, the possibility of reprogramming macrophages in 3D conditions was investigated. In total, the dynamic changes in 6 surface markers, 11 cytokines, and 22 chemokines were analyzed upon macrophage programming (M1 and M2) and reprogramming (M1→M2 and M2→M1). According to the findings, the reprogramming resulted in a mixed macrophage phenotype that expressed both immunosuppressive and anti-cancer immunostimulatory features. Third, cancer cell spheroids were shown to stimulate the production of immunosuppressive M2 markers as well as pro-tumor cytokines and chemokines. In summary, the newly developed 3D model of cancer cell spheroid/macrophage co-culture under free-floating conditions can be used for studies on macrophage plasticity and for the development of targeted cancer immunotherapy.

The role of macrophages in the tumor microenvironment and tumor metabolism

The complexity and plasticity of the tumor microenvironment (TME) make it difficult to fully understand the intratumoral regulation of different cell types and their activities. Macrophages play a crucial role in the signaling dynamics of the TME. Among the different subtypes of macrophages, tumor-associated macrophages (TAMs) are often associated with poor prognosis, although some subtypes of TAMs can at the same time improve treatment responsiveness and lead to favorable clinical outcomes. TAMs are key regulators of cancer cell proliferation, metastasis, angiogenesis, extracellular matrix remodeling, tumor metabolism, and importantly immunosuppression in the TME by modulating various chemokines, cytokines, and growth factors. TAMs have been identified as a key contributor to resistance to chemotherapy and cancer immunotherapy. In this review article, we aim to discuss the mechanisms by which TAMs regulate innate and adaptive immune signaling in the TME and summarize recent preclinical research on the development of therapeutics targeting TAMs and tumor metabolism.