Chemokine biology on immune checkpoint–targeted therapies

CCL20 in the tumor microenvironment: implications for cancer progression and therapeutic approaches

Increasing knowledge of the immunosuppressive tumor microenvironment in cancer-related processes has led to the developing of novel immune-based therapies that have changed the cancer treatment paradigm. In the tumor microenvironment, the plethora of soluble factors secreted by tumor cells interacts with immune cells and non-immune components to deliver signals necessary for tumor progression. Accordingly, targeting tumor-derived factors inducing this immunosuppressive tumor microenvironment has become an appealing therapeutic potential in advancing cancer treatment. CCL20, a chemokine best known to induce leucocyte migration in response to pathological and inflammatory conditions, has been implicated in tumor proliferation, angiogenesis, metastasis, immunosuppression, and therapeutic resistance. Notably, CCL20 and its receptor CCR6 are important in tumor microenvironment interactions. This review discusses the interaction between the CCL20-CCR6 axis and the tumor microenvironment and how these interactions promote tumor progression. Also, an outline of studies utilizing CCL20 in combination with other standard cancer treatments has been shed.

Diversity of the immune microenvironment and response to checkpoint inhibitor immunotherapy in mucosal melanoma

Mucosal melanoma (MucM) is a rare cancer with a poor prognosis and low response rate to immune checkpoint inhibition (ICI) compared with cutaneous melanoma (CM). To explore the immune microenvironment and potential drivers of MucM's relative resistance to ICI drugs, we characterized 101 MucM tumors (43 head and neck [H&N], 31 female urogenital, 13 male urogenital, 11 anorectal, and 3 other gastrointestinal) using bulk RNA-Seq and immunofluorescence. RNA-Seq data show that MucM has a significantly lower IFN-γ signature levels than CM. MucM tumors of the H&N region show a significantly greater abundance of CD8+ T cells, cytotoxic cells, and higher IFN-γ signature levels than MucM from lower body sites. In the subcohort of 35 patients with MucM treated with ICI, hierarchical clustering reveals clusters with a high and low degree of immune infiltration, with a differential ICI response rate. Immune-associated gene sets were enriched in responders. Signatures associated with cancer-associated fibroblasts, macrophages, and TGF-β signaling may be higher in immune-infiltrated, but ICI-unresponsive tumors, suggesting a role for these resistance mechanisms in MucM. Our data show organ region-specific differences in immune infiltration and IFN-γ signature levels in MucM, with H&N MucM displaying the most favorable immune profile. Our study might offer a starting point for developing more personalized treatment strategies for this disease.

ANGPTL2 promotes immune checkpoint inhibitor-related murine autoimmune myocarditis

Use of immune checkpoint inhibitors (ICIs) as cancer immunotherapy advances rapidly in the clinic. Despite their therapeutic benefits, ICIs can cause clinically significant immune-related adverse events (irAEs), including myocarditis. However, the cellular and molecular mechanisms regulating irAE remain unclear. Here, we investigate the function of Angiopoietin-like protein 2 (ANGPTL2), a potential inflammatory mediator, in a mouse model of ICI-related autoimmune myocarditis. ANGPTL2 deficiency attenuates autoimmune inflammation in these mice, an outcome associated with decreased numbers of T cells and macrophages. We also show that cardiac fibroblasts express abundant ANGPTL2. Importantly, cardiac myofibroblast-derived ANGPTL2 enhances expression of chemoattractants via the NF-κB pathway, accelerating T cell recruitment into heart tissues. Our findings suggest an immunostimulatory function for ANGPTL2 in the context of ICI-related autoimmune inflammation and highlight the pathophysiological significance of ANGPTL2-mediated cardiac myofibroblast/immune cell crosstalk in enhancing autoimmune responses. These findings overall provide insight into mechanisms regulating irAEs.

Fat Loss in Patients with Metastatic Clear Cell Renal Cell Carcinoma Treated with Immune Checkpoint Inhibitors

The purpose of this study was to determine the prognostic impact of fat loss after immune checkpoint inhibitor (ICI) treatment in patients with metastatic clear cell renal cell carcinoma (ccRCC). Data from 60 patients treated with ICI therapy for metastatic ccRCC were retrospectively analyzed. Changes in cross-sectional areas of subcutaneous fat (SF) between the pre-treatment and post-treatment abdominal computed tomography (CT) images were expressed as percentages and were divided by the interval between the CT scans to calculate ΔSF (%/month). SF loss was defined as ΔSF < -5%/month. Survival analyses for overall survival (OS) and progression-free survival (PFS) were performed. Patients with SF loss had shorter OS (median, 9.5 months vs. not reached; p < 0.001) and PFS (median, 2.6 months vs. 33.5 months; p < 0.001) than patients without SF loss. ΔSF was independently associated with OS (adjusted hazard ratio (HR), 1.49; 95% confidence interval (CI), 1.07-2.07; p = 0.020) and PFS (adjusted HR, 1.57; 95% CI, 1.17-2.12; p = 0.003), with a 5%/month decrease in SF increasing the risk of death and progression by 49% and 57%, respectively. In conclusion, Loss of SF after treatment initiation is a significant and independent poor prognostic factor for OS and PFS in patients with metastatic ccRCC who receive ICI therapy.

Immunomodulatory effects of regorafenib: Enhancing the efficacy of anti-PD-1/PD-L1 therapy

Anti-PD-1/PD-L1 therapy has shown significant benefits in the treatment of a variety of malignancies. However, not all cancer patients can benefit from this strategy due to drug resistance. Therefore, there is an urgent need for methods that can effectively improve the efficacy of anti-PD-1/PD-L1 therapy. Combining anti-PD-1/PD-L1 therapy with regorafenib has been demonstrated as an effective method to enhance its therapeutic effect in several clinical studies. In this review, we describe common mechanisms of resistance to anti-PD-1/PD-L1 therapy, including lack of tumor immunogenicity, T cell dysfunction, and abnormal expression of PD-L1. Then, we illustrate the role of regorafenib in modifying the tumor microenvironment (TME) from multiple aspects, which is different from other tyrosine kinase inhibitors. Regorafenib not only has immunomodulatory effects on various immune cells, but can also regulate PD-L1 and MHC-I on tumor cells and promote normalization of abnormal blood vessels. Therefore, studies on the synergetic mechanism of the combination therapy may usher in a new era for cancer treatment and help us identify the most appropriate individuals for more precise treatment.

Systematic Analysis of Chemokines Reveals CCL18 is a Prognostic Biomarker in Glioblastoma

Background

Glioblastoma (GBM) is the most common and aggressive brain tumor in adults, in which chemokines are often upregulated and may play pivotal roles in their development and progression. Chemokines are a large subfamily of cytokines with leukocyte chemotactic activities involved in various tumor progression. However, gene expression patterns of the chemokines on a global scale were not known in GBM.

Methods

Differentially expressed chemokine genes in glioma and normal samples were screened by using The Cancer Genome Atlas (TCGA) database. Cox regression identified the prognosis-related genes in each glioma subtype. The protein expression levels of chemokines in 72 glioma tissues were detected by ELISA.

Results

We found that the transcripts of seven chemokines, including CCL2, CCL8, CCL18, CCL28, CXCL1, CXCL5, and CXCL13, were highly expressed in GBM that evidenced by involving immune cell infiltration regulation and accompanied with worse outcomes of GBM patients. The prognostic nomogram construction demonstrated that CCL18 held the highest risk score in patients with GBM. Furthermore, experiments on 72 glioma tissue samples confirmed that CCL18 protein expression was positively associated with tumor grade and IDH1 status but inversely with glioma patients’ overall survival (OS).

Conclusion

Our study reveals comprehensive and comparable roles of chemokine members in glioblastoma, and identified CCL18 as a critical driver of GBM malignant behaviors, therefore providing a potential target for developing prognosis and therapy in human glioblastoma.

Expression of CX3CL1 and CCL28 in Spinal Metastases of Lung Adenocarcinoma and Their Correlation with Clinical Features and Prognosis

Lung adenocarcinoma is the most common non-small-cell lung cancer. In this paper, we aim to investigate the expression of chemokine ligand 1 (cx3cl1) and chemokine ligand 28 (CCL28) in spinal metastases of lung adenocarcinoma and their correlation with clinical features and prognosis. We analyzed the clinical data of 40 patients with lung adenocarcinoma and spinal metastases who underwent surgery in our hospital from January 2018 to January 2021 retrospectively. The expression levels of cx3cl1 and CCL28 in bone metastases were detected by immunohistochemistry, and the staining results were sorted and classified. Combined with the follow-up results and clinicopathological data, we statistically analyzed the expression of cx3cl1 and CCL28 in spinal bone metastases and their correlation with prognosis. Among the 40 patients with spinal metastasis of lung adenocarcinoma, 7 cases were strongly positive for cx3cl1, 25 cases were moderately positive, and 8 cases were weakly positive and negative. CCL28 was strongly positive in 9 cases, moderately positive in 26 cases, weakly positive and negative in 5 cases. The expression of cx3cl1 was correlated with ECOG score (P = 0.005) and visceral organ metastasis (P = 0.004), but not with age, sex, and the number of bone metastases (P > 0.05). The expression of CCL28 was correlated with ECOG score (P = 0.022) and visceral organ metastasis (P = 0.003), but not with age, sex, and the number of bone metastases (P > 0.05). The OS of patients with strong cx3cl1 positive was significantly shorter than that of patients with medium positive and weak positive (P < 0.001). The survival time was 10, 7, and 4 months, respectively. The OS of patients with strong positive CCL28 was significantly shorter than that of patients with medium positive and weak positive CCL28 (P = 0.004). The survival time was 12, 8, and 4 months, respectively. Univariate analysis showed that ECOG score (P < 0.001), chemotherapy (P = 0.032), visceral organ metastasis (P = 0.002), cx3cl1 expression (P < 0.001), and CCL28 expression (P = 0.004) were the risk factors of OS. Cox regression analysis showed that the expression of cx3cl1 was an independent risk factor for OS in patients with spinal metastasis of lung adenocarcinoma (P = 0.044). Cx3cl1 and CCL28 were highly/strongly positive in spinal metastases of lung adenocarcinoma. The level of cx3cl1 can be used as an index to judge the clinical prognosis of patients with spinal metastasis of lung adenocarcinoma, which can better reflect the prognosis of patients than CCL28.

Cutting-Edge Platforms for Analysis of Immune Cells in the Hepatic Microenvironment-Focus on Tumor-Associated Macrophages in Hepatocellular Carcinoma

The role of tumor-associated macrophages (TAMs) in the pathogenesis of hepatocellular carcinoma (HCC) is poorly understood. Most studies rely on platforms that remove intrahepatic macrophages from the microenvironment prior to evaluation. Cell isolation causes activation and phenotypic changes that may not represent their actual biology and function in situ. State-of-the-art methods provides new strategies to study TAMs without losing the context of tissue architecture and spatial relationship with neighboring cells. These technologies, such as multispectral imaging (e.g., Vectra Polaris), mass cytometry by time-of-flight (e.g., Fluidigm CyTOF), cycling of fluorochromes (e.g., Akoya Biosciences CODEX/PhenoCycler-Fusion, Bruker Canopy, Lunaphore Comet, and CyCIF) and digital spatial profiling or transcriptomics (e.g., GeoMx or Visium, Vizgen Merscope) are being utilized to accurately assess the complex cellular network within the tissue microenvironment. In cancer research, these platforms enable characterization of immune cell phenotypes and expression of potential therapeutic targets, such as PDL-1 and CTLA-4. Newer spatial profiling platforms allow for detection of numerous protein targets, in combination with whole transcriptome analysis, in a single liver biopsy tissue section. Macrophages can also be specifically targeted and analyzed, enabling quantification of both protein and gene expression within specific cell phenotypes, including TAMs. This review describes the workflow of each platform, summarizes recent research using these approaches, and explains the advantages and limitations of each.

Mutations Status of Chemokine Signaling Pathway Predict Prognosis of Immune Checkpoint Inhibitors in Colon Adenocarcinoma

In recent years, tumor immunotherapy has become an important treatment program and popular research focus. However, the use of immune checkpoint inhibitors (ICI) in the treatment of colorectal cancer still has limitations due to the current markers only being able to predict the prognosis of a small number of patients. As the chemokine signaling pathway can promote the anti-tumor response of the immune system by recruiting immune cells, we explored the relationship between mutations in the chemokine signaling pathway and the prognosis of colon adenocarcinoma (COAD) patients receiving ICI treatment. To analyze the relationship between chemokine mutation status and the prognosis of patients receiving ICI treatment, clinical and mutation data, with immunotherapy, for a COAD cohort was obtained from "cbioportal." Then, combining this with COAD cohort data from The Cancer Genome Atlas (TCGA) database, the panorama of gene mutation, immunogenicity, and difference in tumor microenvironment (TME) of chemokine pathways with different mutation statuses were analyzed. High-mut status has been proved to be a prognostic indicator of COAD patients receiving ICI treatment by Univariate and Multivariate Cox regression analysis. CIBERSORT analysis showed that the infiltration degree of M1 macrophages, neutrophils, and activated natural killer (NK) cells was higher in those with high-mut status. Immunogenicity of the high-mut group was also significantly increased, with the mutation number of tumor mutation burden (TMB), neoantigen load (NAL), DNA damage repair (DDR) pathway and microsatellite instability biomarker (MSI-H) being significantly higher. In this study, we found that the mutation state of chemokine pathways is closely associated with the prognosis of COAD patients undergoing ICI treatment. The higher number of TMB, NAL, and DDR mutations and inflammatory TME, may be the mechanism of behind a better prognosis. This discovery provides a possible idea for ICI therapy of COAD.

Correlation of Tim-3 expression with chemokine levels for predicting the prognosis of patients with glioblastoma

Glioblastoma (GBM) immunotherapy, which blocks the checkpoint inhibitor molecule T cell immunoglobulin domain and mucin domain-3 (Tim-3), has potential therapeutic applications. However, not all patients do benefit from the targeted therapy. This study aimed to explore Tim-3 expression correlated chemokine profiles and immune cell infiltration and investigate their potential as prognostic markers of glioblastoma (GBM) immunotherapy. We analyzed transcriptional data of GBM from TCGA database, to measure Tim-3 expression by R package DESeq2 analysis and observed differentially expressed genes in GBM samples with high Tim-3 expression levels. We also probed the relative gene enrichment pathways. Tim-3 expression was evident in biological processes including the recruitment of immune cells. We also identified some chemokines related to Tim-3 expression. The expression levels of CCL18, CXCL13 and CCL7 were significantly higher in GBM tissues with high Tim-3 expression than in GBM tissues with low Tim-3 expression. In addition, exploring the relationship between immune cell infiltration and Tim-3 expression suggested that Tim-3 expression was positively related to significant immune cell infiltration.

Overcoming Resistance to Tumor-Targeted and Immune-Targeted Therapies

Resistance to anticancer therapies includes primary resistance, usually related to lack of target dependency or presence of additional targets, and secondary resistance, mostly driven by adaptation of the cancer cell to the selection pressure of treatment. Resistance to targeted therapy is frequently acquired, driven by on-target, bypass alterations, or cellular plasticity. Resistance to immunotherapy is often primary, orchestrated by sophisticated tumor-host-microenvironment interactions, but could also occur after initial efficacy, mostly when only partial responses are obtained. Here, we provide an overview of resistance to tumor and immune-targeted therapies and discuss challenges of overcoming resistance, and current and future directions of development. SIGNIFICANCE: A better and earlier identification of cancer-resistance mechanisms could avoid the use of ineffective drugs in patients not responding to therapy and provide the rationale for the administration of personalized drug associations. A clear description of the molecular interplayers is a prerequisite to the development of novel and dedicated anticancer drugs. Finally, the implementation of such cancer molecular and immunologic explorations in prospective clinical trials could de-risk the demonstration of more effective anticancer strategies in randomized registration trials, and bring us closer to the promise of cure.

Systematic Analyses of a Chemokine Family-Based Risk Model Predicting Clinical Outcome and Immunotherapy Response in Lung Adenocarcinoma

Chemokines exhibited complicated functions in antitumor immunity, with their expression profile and clinical importance of lung adenocarcinoma (LUAD) patients remaining largely undetermined. This study aimed to explore the expression patterns of chemokine family in LUAD and construct a predictive chemokine family-based signature. A total of 497 samples were downloaded from the Cancer Genome Atlas (TCGA) data portal as the training set, and the combination of 4 representative Gene Expression Omnibus (GEO) datasets, including GSE30219, GSE50081, GSE37745, and GSE31210, were utilized as the validation set. A three gene-based signature was constructed using univariate and stepwise multivariate Cox regression analysis, classifying patients into high and low risk groups according to the overall survival. The independent GEO datasets were utilized to validate this signature. Another multivariate analysis revealed that this signature remained an independent prognostic factor in LUAD patients. Furthermore, patients in the low risk group featured immunoactive tumor microenvironment (TME), higher IPS scores and lower TIDE scores, and was regarded as the potential beneficiaries of immunotherapy. Finally, the role of risky CCL20 was validated by immunohistochemistry (IHC), and patients possessed higher CCL20 expression presented shorter overall survival (P = 0.011).

NT5DC2 knockdown inhibits colorectal carcinoma progression by repressing metastasis, angiogenesis and tumor-associated macrophage recruitment: A mechanism involving VEGF signaling

Colorectal cancer (CRC) is one of the most commonly diagnosed tumors among human worldwide. Angiogenesis and tumor-associated macrophage (TAM) recruitment are closely associated with CRC development. Nevertheless, the mechanisms revealing CRC progression are still not fully understood. 5'-Nucleotidase domain containing 2 (NT5DC2), a member of the NT5DC family, modulates various cellular events to mediate tumor growth, and thus serves as a disgnostic biomarker. Here, we explored the potential of NT5DC2 on tumor progression in CRC. We first found that NT5DC2 expression was significantly up-regulated in CRC tissues and cell lines. CRC patients with higher NT5DC2 expression showed poor overall survival. Furthermore, CRC cell lines stably transfected with shNT5DC2 lentivirus plasmids exhibited markedly reduced cell proliferation, migration and invasion compared with the negative control group. Hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor A (VEGF-A) expression levels were remarkably reduced in CRC cells with NT5DC2 deletion, along with evidently reduced tube formation in the HUVECs cultured in the collected conditional medium. The expression levels of CC chemokine ligand 2 (CCL2) and its receptor CCR2 were found to be greatly down-regulated in CRC cells transfected with shNT5DC2. Moreover, NT5DC2 knockdown markedly suppressed the activation of protein kinase-B/nuclear transcription factor κB (AKT/NF-κB) signaling in CRC cells. Furthermore, we found that NT5DC2 deletion obviously reduced the TAM recruitments through suppressing CCL2/CCR2 and AKT/NF-κB signaling pathways. Intriguingly, our in vitro experiments demonstrated that VEGF reduction was necessary for shNT5DC2-inhibited cell proliferation, migration, invasion, angiogenesis and TAM recruitment. In vivo studies also confirmed that NT5DC2 knockdown effectively reduced the tumor growth and VEGF expression in a xonegraft mouse model with CRC. Lung metastasis of CRC cells was also hindered by NT5DC2 deletion in vivo. Collectively, our results indicated a previously unrecognized NT5DC2/VEGF/CCL2 axis involved in CRC development and metastasis.