The chemokine system and cancer

Macrophage-conditioned medium enhances tunneling nanotube formation in breast cancer cells via PKC, Src, NF-κB, and p38 MAPK signaling

Tumor-associated macrophages (TAMs) secrete cytokines, chemokines, and growth factors in the tumor microenvironment (TME) to support cancer progression. Higher TAM infiltration in the breast TME is associated with a poor prognosis. Previous studies have demonstrated the role of macrophages in stimulating long-range intercellular bridges referred to as tunneling nanotubes (TNTs) in cancer cells. Intercellular communication between cancer cells via TNTs promotes cancer growth, invasion, metastasis, and therapy resistance. Given the important role of TNTs and macrophages in cancer, the role of macrophage-induced TNTs in chemotherapy drug doxorubicin resistance is not known. Furthermore, the mechanism of macrophage-mediated TNT formation is elusive. In this study, it is shown that the macrophage-conditioned medium (MΦCM) partially mimicked inflammatory TME, induced an EMT phenotype, and increased migration in MCF-7 breast cancer cells. Additionally, secreted proteins in MΦCM induced TNT formation in MCF-7 cells, which led to increased resistance to doxorubicin. Transcriptomic analysis of MΦCM-treated MCF-7 cells showed enrichment of the NF-κB and focal adhesion pathways, as well as upregulation of genes involved in EMT, extracellular remodeling, and actin cytoskeleton reorganization. Interestingly, inhibitors of PKC, Src, NF-κB, and p38 decreased macrophage-induced TNT formation in MCF-7 cells. These results reveal the novel role of PKC and Src in inducing TNT formation in cancer cells and suggest that inhibition of PKC and Src activity may likely contribute to reduced macrophage-breast cancer cell interaction and the potential therapeutic strategy of cancer.

The effects of tumor-derived supernatants (TDS) on cancer cell progression: A review and update on carcinogenesis and immunotherapy

Tumors can produce bioactive substances called tumor-derived supernatants (TDS) that modify the immune response in the host body. This can result in immunosuppressive effects that promote the growth and spread of cancer. During tumorigenesis, the exudation of these substances can disrupt the function of immune sentinels in the host and reinforce the support for cancer cell growth. Tumor cells produce cytokines, growth factors, and proteins, which contribute to the progression of the tumor and the formation of premetastatic niches. By understanding how cancer cells influence the host immune system through the secretion of these factors, we can gain new insights into cancer diagnosis and therapy.

Fu-Zheng-Yi-Liu Formula inhibits the stem cells and metastasis of prostate cancer via tumor-associated macrophages/C-C motif chemokine ligand 5 pathway in tumor microenvironment

Prostate cancer (PCa) is the second most common malignancy among men globally. The Fu-Zheng-Yi-Liu (FZYL) Formula has been widely utilized in the treatment of PCa. This study investigates whether the FZYL Formula can inhibit PCa by targeting the TAMs/CCL5 pathway. We conducted in vitro co-cultures and in vivo co-injections of PCa cells and TAMs to mimic their interaction. Results showed that the FZYL Formula significantly reduced the proliferation, colony formation, subpopulations of PCSCs, and sphere-formation efficacy of PCa cells, even in the presence of TAM co-culture. Additionally, the Formula markedly decreased the migration, invasion, and epithelial-mesenchymal transition (EMT) of PCa cells induced by TAMs. The FZYL Formula also reversed M2 phenotype polarization in TAMs and dose-dependently reduced their CCL5 expression and secretion, with minimal cytotoxicity observed. Mechanistic studies confirmed that the TAMs/CCL5 axis is a critical target of the FZYL Formula, as the addition of exogenous CCL5 partially reversed the formula's inhibitory effects on PCSCs self-renewal in the co-culture system. Importantly, the Formula also significantly inhibited the growth of PCa xenografts, bone metastasis, and PCSCs activity in vivo by targeting the TAMs/CCL5 pathway. Overall, this study not only elucidates the immunomodulatory mechanism of the FZYL Formula in PCa therapy but also highlights the TAMs/CCL5 axis as a promising therapeutic target.

Analyzing the Functional Roles and Immunological Features of Chemokines in COAD

Chemokines are key proteins that regulate cell migration and immune responses and are essential for modulating the tumor microenvironment. Despite their close association with colon cancer, the expression patterns, prognosis, immunity, and specific roles of chemokines in colon cancer are still not fully understood. In this study, we investigated the mutational features, differential expression, and immunological characteristics of chemokines in colon cancer (COAD) by analyzing the Tumor Genome Atlas (TCGA) database. We clarified the biological functions of these chemokines using Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. By univariate and multivariate COX regression analyses, we developed chemokine-based prognostic risk models. In addition, using Gene Set Enrichment Analysis (GSEA) and Gene Set Variant Analysis (GSVA), we analyzed the differences in immune responses and signaling pathways among different risk groups. The results showed that the mutation rate of chemokines was low in COAD, but 25 chemokines were significantly differentially expressed. These chemokines function in several immune-related biological processes and play key roles in signaling pathways including cytokine-cytokine receptor interactions, NF-kappa B, and IL-17. Prognostic risk models based on CCL22, CXCL1, CXCL8, CXCL9, and CXCL11 performed well. GSEA and GSVA analyses showed significant differences in immune responses and signaling pathways across risk groups. In conclusion, this study reveals the potential molecular mechanisms of chemokines in COAD and proposes a new prognostic risk model based on these insights.

Recent Advances in Nanomaterials for the Treatment of Acute Kidney Injury

Acute kidney injury (AKI) is a serious clinical syndrome with high morbidity, elevated mortality, and poor prognosis, commonly considered a "sword of Damocles" for hospitalized patients, especially those in intensive care units. Oxidative stress, inflammation, and apoptosis, caused by the excessive production of reactive oxygen species (ROS), play a key role in AKI progression. Hence, the investigation of effective and safe antioxidants and inflammatory regulators to scavenge overexpressed ROS and regulate excessive inflammation has become a promising therapeutic option. However, the unique physiological structure and complex pathological alterations in the kidneys render traditional therapies ineffective, impeding the residence and efficacy of most antioxidant and anti-inflammatory small molecule drugs within the renal milieu. Recently, nanotherapeutic interventions have emerged as a promising and prospective strategy for AKI, overcoming traditional treatment dilemmas through alterations in size, shape, charge, and surface modifications. This Review succinctly summarizes the latest advancements in nanotherapeutic approaches for AKI, encompassing nanozymes, ROS scavenger nanomaterials, MSC-EVs, and nanomaterials loaded with antioxidants and inflammatory regulator. Following this, strategies aimed at enhancing biocompatibility and kidney targeting are introduced. Furthermore, a brief discussion on the current challenges and future prospects in this research field is presented, providing a comprehensive overview of the evolving landscape of nanotherapeutic interventions for AKI.

STS ⅡA inhibited angiogenesis of lung adenocarcinoma by activating FOXO3 to inhibit CXCL1/STAT3/VEGF pathway

BACKGROUND

Lung adenocarcinoma (LUAD) is the most popular type of lung cancer. Sulfotanshinone IIA sodium (STS IIA) has been proven to have an anticancer effect. However, its role in LUAD and its underlying mechanism remain unclear.

OBJECTIVE

To investigate the role and mechanism of STS IIA in LUAD angiogenesis.

METHODS

The mRNA levels of genes, including forkhead box O3 (FOXO3) and chemokine C-X-C motif ligand 1 (CXCL1), were detected by qRT-PCR. The levels of proteins, including FOXO3, CXCL1, and vascular endothelial growth factor (VEGF), were measured by Western blot. The proliferation and angiogenesis of human umbilical vein endothelial cells (HUVECs) were detected by the EdU assay and the tubule formation assay, respectively. The binding relationship between FOXO3 and CXCL1 was detected by dual-luciferase reporter assay.

RESULTS

Our results illustrated that different concentrations of STS IIA inhibited the proliferation and angiogenesis of HUVECs. FOXO3 regulated the proliferation and angiogenesis of HUVECs inhibited by STS ⅡA via targeting CXCL1. Subsequently, we proved that exogenous CXCL1 alleviated the inhibition of proliferation and angiogenesis of HUVECs regulated by STS IIA via activating the STAT3/VEGF pathway. Finally, we found that STS IIA inhibited the angiogenesis of lung adenocarcinoma though FOXO3 to inhibit the CXCL1/STAT3/VEGF pathway.

CONCLUSION

Our study finally elucidated the underlying molecular mechanism by which STS ⅡA inhibits LUAD angiogenesis.

Biochemical aspects of the inflammatory process: A narrative review

Inflammation is a protective response of the body potentially caused by microbial, viral, or fungal infections, tissue damage, or even autoimmune reactions. The cardinal signs of inflammation are consequences of immunological, biochemical, and physiological changes that trigger the release of pro-inflammatory chemical mediators at the local of the injured site thus, increasing blood flow, vascular permeability, and leukocyte recruitment. The aim of this study is to give an overview of the inflammatory process, focusing on chemical mediators. The literature review was based on a search of journals published between the years 2009 and 2023, regarding the role of major chemical mediators in the inflammatory process and current studies in pathogenesis, diagnosis, and therapy. Some of the recent contributions in the study of inflammatory pathologies and their mediators, including cytokines and chemokines, the kinin system, free radicals, nitric oxide, histamine, cell adhesion molecules, leukotrienes, prostaglandins and the complement system and their role in human health and chronic diseases.

Clinical characterization of EFHD2 (swiprosin-1) in Glioma-associated macrophages and its role in regulation of immunosuppression

Glioblastoma has been extensively studied due to its high mortality and short survival. The evolution mechanism of tumor-associated macrophages (TAMs) to Glioma-associated microglia and macrophages (GAMs) in the tumor microenvironment (TME) remains to be elucidated. The tumor cell-to-cell interaction patterns have not been well defined yet. The EF-Hand Domain Family Member D2 (EFHD2) has been reported to be differentially expressed as an immunomodulatory molecule in a variety of cancers. But large-scale clinical data from multiple ethnic communities have not been used to investigate the role of EFHD2 in glioma. RNA-seq data from 313 or 657 glioma patients from the Chinese Glioma Genome Atlas (CGGA) database and 603 glioma patients from the Cancer Genome Atlas (TCGA) database were analyzed retrospectively. Cell localization was performed using single-cell sequencing data from the CGGA database and the GSE131928 dataset. Mouse glioma cell lines and primary macrophages isolated from Efhd2 knockout mice were co-cultured to validate the immunomodulatory effects of EFHD2 on macrophages and the remodeling of TME of glioblastoma. EFHD2 is enriched in high-grade gliomas, isocitrate dehydrogenase wild-type, and 1p/19q non-co-deficient gliomas. It is a potential biomarker of glioma-proneuronal subtypes and an independent prognostic factor for overall survival in patients with malignant glioblastoma. EFHD2 regulates the monocyte-macrophage system function and positively correlates with immunosuppressive checkpoints. Further experimental data demonstrates that Efhd2 influences the polarization state of GAMs and inhibits the secretion of TGF-β1. In vitro experiments have revealed that macrophages lacking Efhd2 suppress the vitality of two glioma cell lines and decelerate the growth of glioma xenografts. In conclusion, EFHD2 promises to be a key target for TME-related immunotherapy.

Neutrophil to lymphocyte ratio and principal component analysis offer prognostic advantage for dogs with mammary tumors

Introduction

In veterinary medicine, cancer is the leading cause of death in companion animals, and mammary gland tumors represent the most common neoplasm in female dogs. Several epidemiological risk factors, such as age, breed, hormones, diet, and obesity have been reported to be relevant for canine mammary tumors. Nowadays, the gold standard for diagnosis of canine mammary tumors is the pathological examination of the suspected tissue. However, tumor grade can only be assessed after surgical removal or biopsy of the altered tissue. Therefore, in cases of tumors that could be surgically removed, it would be very helpful to be able to predict the biological behavior of the tumor, before performing any surgery. Since, inflammation constitutes part of the tumor microenvironment and it influences each step of tumorigenesis, cellular and biochemical blood markers of systemic inflammation, such as the neutrophil to lymphocyte ratio (NLR) and the albumin to globulin ratio (AGR) have been proposed as prognostic factors for human cancer development. The NLR and the AGR have not been explored enough as prognostic factors for cancer development in veterinary medicine.

Methods

To determine the prognostic value of NLR in canine mammary tumors, clinical records including biochemistry and hematological studies of female dogs with mammary tumors and of control healthy dogs, were used to determine the pre-treatment NLR and AGR. Other clinical data included age, breed, tumor size, histological tumor grade, and survival time after surgery.

Results and discussion

It was found that a higher pre-treatment NLR value (NLR > 5) associates with less survival rate. In contrast, the AGR did not show any predictive value on the malignancy of the tumor. However, by combining the NLR with AGR, age of the dog, and tumor size in a principal component analysis (PCA), the grade of the tumor and survival after surgery could be appropriately predicted. These data strongly suggest that pre-treatment NLR values have a prognostic value for the survival rate after surgery of dogs with mammary tumors.

Tumour microenvironment and pituitary tumour behaviour

The pituitary tumour microenvironment encompasses a spectrum of non-tumoural cells, such as immune, stromal or endothelial cells, as well as enzymes and signalling peptides like cytokines, chemokines and growth factors, which surround the tumour cells and may influence pituitary tumour behaviour and tumourigenic mechanisms. Recently, there has been intensive research activity in this field describing various pituitary tumour-infiltrating immune and stromal cell subpopulations, and immune- and microenvironment-related pathways. Key changes in oncological therapeutic avenues resulted in the recognition of pituitary as a target of adverse events for patients treated with immune checkpoint regulators. However, these phenomena can be turned into therapeutic advantage in severe cases of pituitary tumours. Therefore, unravelling the pituitary tumour microenvironment will allow a better understanding of the biology and behaviour of pituitary tumours and may provide further developments in terms of diagnosis and management of patients with aggressively growing or recurrent pituitary tumours.

In vivo validation of 68Ga-labeled AMD3100 conjugates for PET imaging of CXCR4

INTRODUCTION

The chemokine receptor CXCR4 has been shown to be over-expressed in multiple types of cancer and is usually associated with aggressive phenotypes and poor prognosis. Successfully targeting and imaging the expression level of this receptor in tumours could inform treatment selection and facilitate patient stratification.

METHODS

Known conjugates of AMD3100 that are specific to CXCR4 have been radiolabelled with gallium-68 and evaluated in naïve and tumour-bearing mice. Tumour uptake of the radiotracers was compared to the known CXCR4-specific PET imaging agent, [⁶⁸Ga]Pentixafor.

RESULTS

Ex vivo biodistribution in naïve animals showed CXCR4-mediated uptake in the liver with both radiotracers, confirmed by blocking experiments with the high affinity CXCR4 antagonist Cu₂CB-Bicyclam (IC₅₀ = 3 nM). PET/CT imaging studies revealed one tracer to have a higher accumulation in the tumour (SUV_Mean of 0.89 ± 0.14 vs 0.32 ± 0.11). CXCR4-specificity of the best performing tracer was confirmed by administration of a blocking dose of Cu₂CB-Bicyclam, showing a 3- and 6-fold decrease in tumour and liver uptake, respectively.

CONCLUSION AND ADVANCES IN KNOWLEDGE

This initial study offers some interesting insights on the impact of some structural features on the pharmacokinetics and metabolic stability of the radiotracer. Additionally, as Pentixafor only binds to human CXCR4, the development of CXCR4-targeted imaging agents that bind to the receptor across different species could significantly help with preclinical evaluation of new CXCR4-specific therapeutics.

Allosteric Regulation of G-Protein-Coupled Receptors: From Diversity of Molecular Mechanisms to Multiple Allosteric Sites and Their Ligands

Allosteric regulation is critical for the functioning of G protein-coupled receptors (GPCRs) and their signaling pathways. Endogenous allosteric regulators of GPCRs are simple ions, various biomolecules, and protein components of GPCR signaling (G proteins and β-arrestins). The stability and functional activity of GPCR complexes is also due to multicenter allosteric interactions between protomers. The complexity of allosteric effects caused by numerous regulators differing in structure, availability, and mechanisms of action predetermines the multiplicity and different topology of allosteric sites in GPCRs. These sites can be localized in extracellular loops; inside the transmembrane tunnel and in its upper and lower vestibules; in cytoplasmic loops; and on the outer, membrane-contacting surface of the transmembrane domain. They are involved in the regulation of basal and orthosteric agonist-stimulated receptor activity, biased agonism, GPCR-complex formation, and endocytosis. They are targets for a large number of synthetic allosteric regulators and modulators, including those constructed using molecular docking. The review is devoted to the principles and mechanisms of GPCRs allosteric regulation, the multiplicity of allosteric sites and their topology, and the endogenous and synthetic allosteric regulators, including autoantibodies and pepducins. The allosteric regulation of chemokine receptors, proteinase-activated receptors, thyroid-stimulating and luteinizing hormone receptors, and beta-adrenergic receptors are described in more detail.

Logic Nanodevice-Mediated Receptor Assembly for Nongenetic Regulation of Cell Behavior in Tumor-like Microenvironment

The reprogramming of cell signaling and behavior through the artificial control of cell surface receptor oligomerization shows great promise in biomedical research and cell-based therapy. However, it remains challenging to achieve combinatorial recognition in a complicated environment and logical regulation of receptors for desirable cellular behavior. Herein, we develop a logic-gated DNA nanodevice with responsiveness to multiple environmental inputs for logically controlled assembly of heterogeneous receptors to modulate signaling. The "AND" gate nanodevice uses an i-motif and an ATP-binding aptamer as environmental cue-responsive units, which can successfully implement a logic operation to manipulate receptors on the cell surface. In the presence of both protons and ATP, the DNA nanodevice is activated to selectively assemble MET and CD71, which modulate the HGF/MET signaling, resulting in cytoskeletal reorganization to inhibit cancer cell motility in a tumor-like microenvironment. Our strategy would be highly promising for precision therapeutics, including controlled drug release and cancer treatment.

Optimization of triazolo[4,5-d]pyrimidines towards human CC chemokine receptor 7 (CCR7) antagonists

CCR7 signaling directs the migration of both immune cells and cancer cells to the lymph nodes, is involved in numerous chronic inflammatory disorders and lymph node metastases. Despite the therapeutic promise of CCR7 antagonists, no potent and selective small molecule CCR7 antagonists have been reported to date. Since most human chemokine G protein-coupled receptors (GPCRs) share a conserved intracellular allosteric binding site, new CCR7 antagonist chemotypes may be identified by screening small molecules that are known to target this site in other chemokine GPCRs. In this work, our previously prepared series of 14 scaffold-modified analogues of a known thiazolo[4,5-d]pyrimidine CXCR2 antagonist were screened as potential CCR7 antagonists. This resulted in the discovery of a triazolo[4,5-d]pyrimidine analogue with an IC₅₀ of 2.43 μM against CCR7 and 0.66 μM against CXCR2. Exploration of the structure-activity relationship (SAR) for the 3-, 5- and 7-position substituents of this triazolo[4,5-d]pyrimidine resulted in improved potency and selectivity, with an IC₅₀ of 0.43 μM and 11.02 μM against CCR7 and CXCR2, respectively, for the most selective derivative. Molecular docking showed that the binding mode of these triazolo[4,5-d]pyrimidines in CCR7 and CXCR2 corresponds with those of previously co-crystallized ligands.

ACKR3 promotes CXCL12/CXCR4-mediated cell-to-cell-induced lymphoma migration through LTB4 production

Chemotaxis is an essential physiological process, often harnessed by tumors for metastasis. CXCR4, its ligand CXCL12 and the atypical receptor ACKR3 are overexpressed in many human cancers. Interfering with this axis by ACKR3 deletion impairs lymphoma cell migration towards CXCL12. Here, we propose a model of how ACKR3 controls the migration of the diffused large B-cell lymphoma VAL cells in vitro and in vivo in response to CXCL12. VAL cells expressing full-length ACKR3, but not a truncated version missing the C-terminus, can support the migration of VAL cells lacking ACKR3 (VAL-ko) when allowed to migrate together. This migration of VAL-ko cells is pertussis toxin-sensitive suggesting the involvement of a Gi-protein coupled receptor. RNAseq analysis indicate the expression of chemotaxis-mediating LTB4 receptors in VAL cells. We found that LTB4 acts synergistically with CXCL12 in stimulating the migration of VAL cells. Pharmacologic or genetic inhibition of BLT1R markedly reduces chemotaxis towards CXCL12 suggesting that LTB4 enhances in a contact-independent manner the migration of lymphoma cells. The results unveil a novel mechanism of cell-to-cell-induced migration of lymphoma.

Transcriptome analysis preliminary reveals the immune response mechanism of golden cuttlefish (Sepia esculenta) larvae exposed to Cd

As a well-known marine metal element, Cd can significantly affect bivalve mollusk life processes such as growth and development. However, the effects of Cd on the molecular mechanisms of the economically important cephalopod species Sepia esculenta remain unclear. In this study, S. esculenta larval immunity exposed to Cd is explored based on RNA-Seq. The analyses of GO, KEGG, and protein-protein interaction (PPI) network of 1,471 differentially expressed genes (DEGs) reveal that multiple immune processes are affected by exposure such as inflammatory reaction and cell adhesion. Comprehensive analyses of KEGG signaling pathways and the PPI network are first used to explore Cd-exposed S. esculenta larval immunity, revealing the presence of 16 immune-related key and hub genes involved in exposure response. Results of gene and pathway functional analyses increase our understanding of Cd-exposed S. esculenta larval immunity and improve our overall understanding of mollusk immune functions.

The Role of Microglia in Inherited Retinal Diseases

Inherited retinal diseases (IRDs) are a leading cause of irreversible visual loss in the developed world. The primary driver of pathology in IRDs is pathogenic genetic variant. However, there is increasing evidence, from recent studies, for a role of the immune system in disease mechanism, particularly retinal microglia. Microglia are the primary immune cells in the retina and actively contribute to disease pathogenesis when activated locally by phagocytosing photoreceptors, inducing inflammation and signaling infiltration of circulating monocytes. In this article, we discuss the evidence for the contribution of retinal microglia to IRD pathogenesis reported so far using mice model.

Data mining and network analysis reveals C-X-C chemokine receptor type 5 is involved in the pathophysiology of age-related macular degeneration

Our previous studies found that the C-X-C motif chemokine receptor 5 (CXCR5) loss leads to retinal pigment epithelium (RPE) dysfunction and AMD pathogenesis. The current study aimed to characterize the G protein-coupled receptor (GPCR) structure of CXCR5 and analyze its interactions with AMD-related risk genes. The sequence alignments, homology model of CXCR5 and structural assessment analysis were performed. Data and text mining were then performed to identify AMD-related risk genes and their interaction with CXCR5 using statistical and mathematical algorithms. Sequence alignment and phylogenetic tree analysis revealed that human CXCR5 was highly similar (85.4839%) to the rabbit. The least similarity (33.871%) was found to be in zebrafish compared to the other species. The CXCR5 model structural assessment and secondary structure analysis exhibited an excellent model. Network analysis revealed that IL10, TNF, ICAM1, CXCL1, CXCL8, APP, TLR4, SELL, C3, IL17A and CCR2 were the most connected genes CXCR5. These findings suggest that CXCR5 signaling may regulate the biological function of RPE and modulate AMD pathophysiology via GPCR signaling and interacting with identified AMD risk genes. In summary, the data presented here provide novel and crucial insights into the molecular mechanisms of CXCR5 involvement in AMD.Communicated by Ramaswamy H. Sarma.

Comparison between Clinical Utility of CXCL-8 and Clinical Practice Tumor Markers for Colorectal Cancer Diagnosis

Owing to the high incidence and mortality rates of colorectal cancer (CRC), novel biomarkers for CRC diagnosis are critically needed. Therefore, this study is aimed at exploring the clinical utility of serum C-X-C motif chemokine 8 (CXCL-8) for CRC diagnosis and progression compared to the routinely used biomarkers, carcinoembryonic antigen (CEA), and carbohydrate antigen-19-9 (CA19-9). This study included 227 patients with CRC, 110 patients with colorectal adenoma (CA), and 123 healthy participants, who were recruited from the Fujian Medical University Union Hospital from July 1, 2019 to October 31, 2020. Serum concentrations of CXCL-8, CEA, and CA19-9 were detected using enzyme-linked immunosorbent assay and chemiluminescent microparticle immunoassay. Clinicopathological features of patients with CRC were collected and analyzed. The diagnostic efficacy of CXCL-8, CEA, and CA19-9 for CRC was evaluated using receiver operating characteristic (ROC) curves. We found that the serum concentrations of CXCL-8, CEA, and CA19-9 were significantly higher in patients with CRC than those in patients with CA and healthy controls. The diagnostic sensitivity of CXCL-8 alone was higher than those of CEA and CA19-9 both and when combined; thus, CXCL-8 may be better at discriminating patients with CRC from healthy controls and patients with CA. Moreover, combining CXCL-8 with CEA or CA19-9 improved their respective diagnostic performances in distinguishing patients with CRC from CA patients and healthy participants. Notably, we also found that serum concentrations of CXCL-8 were positively correlated with metastases and tumor size. Therefore, our study suggests that serum CXCL-8 may serve as an improved biomarker for CRC diagnosis compared to the traditional tumor markers CEA and CA19-9. Moreover, our findings indicate the potential efficacy of serum CXCL-8 levels as a CRC prognostic biomarker.

Role of senescent tumor cells in building a cytokine shield in the tumor microenvironment: mathematical modeling

Cellular senescence can induce dual effects (promotion or inhibition) on cancer progression. While immune cells naturally respond and migrate toward various chemotactic sources from the tumor mass, various factors including senescent tumor cells (STCs) in the tumor microenvironment may affect this chemotactic movement. In this work, we investigate the mutual interactions between the tumor cells and the immune cells that either inhibit or facilitate tumor growth by developing a mathematical model that consists of taxis-reaction-diffusion equations and receptor kinetics for the key players in the interaction network. We apply a mathematical model to a transwell Boyden chamber invasion assay used in the experiments to illustrate that STCs can play a pivotal role in negating immune attack through tight regulation of intra- and extra-cellular signaling molecules. In particular, we show that senescent tumor cells in cell cycle arrest can block intratumoral infiltration of CD8+ T cells by secreting a high level of CXCL12, which leads to significant reduction its receptors, CXCR4, on T cells, and thus impaired chemotaxis. The predictions of nonlinear responses to CXCL12 were in good agreement with experimental data. We tested several hypotheses on immune-tumor interactions under various biochemical conditions in the tumor microenvironment and developed new concepts for anti-tumor strategies targeting senescence induced immune impairment.

Activated PyK2 and Its Associated Molecules Transduce Cellular Signaling from the Cancerous Milieu for Cancer Metastasis

PyK2 is a member of the proline-rich tyrosine kinase and focal adhesion kinase families and is ubiquitously expressed. PyK2 is mainly activated by stimuli, such as activated Src kinases and intracellular acidic pH. The mechanism of PyK2 activation in cancer cells has been addressed extensively. The up-regulation of PyK2 through overexpression and enhanced phosphorylation is a key feature of tumorigenesis and cancer migration. In this review, we summarized the cancer milieu, including acidification and cancer-associated molecules, such as chemical reagents, interactive proteins, chemokine-related molecules, calcium channels/transporters, and oxidative molecules that affect the fate of PyK2. The inhibition of PyK2 leads to a beneficial strategy to attenuate cancer cell development, including metastasis. Thus, we highlighted the effect of PyK2 on various cancer cell types and the distribution of molecules that affect PyK2 activation. In particular, we underlined the relationship between PyK2 and cancer metastasis and its potential to treat cancer cells.

CC chemokine receptor 2 (CCR2) expression promotes diffuse large B-Cell lymphoma survival and invasion

In recent years, CC chemokine receptor 2 (CCR2) has been found to be involved in tumor growth, angiogenesis, epithelial mesenchymal transition, metastasis, and immune escape. CCR2 overexpression was first identified as a poor prognostic predictor in diffuse large B-cell lymphoma (DLBCL) in our published article, but the mechanisms involved remain unknown. In this work, we collected data from another 138 patients with DLBCL data and verified the CCR2 expression level and its relationship to clinicopathological characteristics. Furthermore, we explored the possible mechanisms via in vitro and in vivo experiments. We showed that CCR2 overexpression was an independent prognostic marker and predicted shorter overall survival (OS) and progression-free survival (PFS) in patients with DLBCL. Blockade of CCR2 expression with a CCR2 antagonist inhibited tumor cell proliferation, migration, and anti-apoptosis ability in vitro by affecting the PI3K/Akt signaling pathway and the p38 MAPK signaling pathway. Furthermore, administration of a CCR2 antagonist decreased tumor growth and dissemination of DLBCL cells and increased survival time in the xenograft model. Our study demonstrates that CCR2 expression plays an important role in the development of DLBCL by stimulating cell proliferation, migration, and anti-apoptosis. Therefore, the inhibition of CCR2 may be a potential target for anticancer therapy in DLBCL.

The DARC Side of Inflamm-Aging: Duffy Antigen Receptor for Chemokines (DARC/ACKR1) as a Potential Biomarker of Aging, Immunosenescence, and Breast Oncogenesis among High-Risk Subpopulations

The proclivity of certain pre-malignant and pre-invasive breast lesions to progress while others do not continues to perplex clinicians. Clinicians remain at a crossroads with effectively managing the high-risk patient subpopulation owing to the paucity of biomarkers that can adequately risk-stratify and inform clinical decisions that circumvent unnecessary administration of cytotoxic and invasive treatments. The immune system mounts the most important line of defense against tumorigenesis and progression. Unfortunately, this defense declines or "ages" over time-a phenomenon known as immunosenescence. This results in "inflamm-aging" or the excessive infiltration of pro-inflammatory chemokines, which alters the leukocyte composition of the tissue microenvironment, and concomitant immunoediting of these leukocytes to diminish their antitumor immune functions. Collectively, these effects can foster the sequelae of neoplastic transformation and progression. The erythrocyte cell antigen, Duffy antigen receptor for chemokines(DARC/ACKR1), binds and internalizes chemokines to maintain homeostatic levels and modulate leukocyte trafficking. A negative DARC status is highly prevalent among subpopulations of West African genetic ancestry, who are at higher risk of developing breast cancer and disease progression at a younger age. However, the role of DARC in accelerated inflamm-aging and malignant transformation remains underexplored. Herein, we review compelling evidence suggesting that DARC may be protective against inflamm-aging and, therefore, reduce the risk of a high-risk lesion progressing to malignancy. We also discuss evidence supporting that immunotherapeutic intervention-based on DARC status-among high-risk subpopulations may evade malignant transformation and progression. A closer look into this unique role of DARC could glean deeper insight into the immune response profile of individual high-risk patients and their predisposition to progress as well as guide the administration of more "cyto-friendly" immunotherapeutic intervention to potentially "turn back the clock" on inflamm-aging-mediated oncogenesis and progression.

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.

Site-Specific Polyplex on CCR7 Down-Regulation and T Cell Elevation for Lymphatic Metastasis Blocking on Breast Cancer

Tumor metastasis contributes to high cancer mortality. Tumor cells in lymph nodes (LNs) are difficult to eliminate but underlie uncontrollable systemic metastasis. The CC chemokine receptor 7 (CCR7) is overexpressed in tumor cells and interacts with CC chemokine ligand 21 (CCL21) secreted from LNs, potentiating their lymphatic migration. Here, a site-specific polyplex is developed to block the CCR7-CCL21 signal and kill tumor cells toward LNs, greatly limiting their lymphatic infiltration. A CCR7-targeting small interfering RNA (siCCR7) is condensed by mPEG-poly-(lysine) with chlorin e6 (Ce6) modification (PPLC) to form PPLC/siCCR7. The knockdown of CCR7 by siCCR7 in tumor cells significantly reduced their response on CCL21 and LN tropism. Additionally, photodynamic therapy-mediated immune activation precisely targets and kills tumor cells released from the primary foci before they reaches the LNs, reducing the number of tumor cells entering the LNs. Consequently, the PPLC/siCCR7 polyplexes inhibited up to 92% of lung metastasis in 4T1 tumor bearing mice and reduced tumor cell migration to LNs by up to 80%. This site-specific strategy optimized anti-metastasis efficacy and promotes the clinical translational development of anti-metastatic therapy.

Chemokine level predicts the therapeutic effect of anti-PD-1 antibody (nivolumab) therapy for malignant melanoma

Anti-programmed cell death protein 1 (PD-1) antibody drugs, nivolumab and pembrolizumab, are regarded as first-line therapies for advanced malignant melanoma. Anti-PD-1 therapy suppresses tumor immunity, and the therapeutic effect is frequently correlated with the number of tumor-infiltrating lymphocytes (TIL) and tumor mutation burden (TMB). However, sampling tumor tissues from the metastatic sites to examine the number of TILs and TMB level is often challenging. Herein, we focused on chemokines in blood to determine whether they can predict the therapeutic effect of anti-PD-1 (nivolumab) therapy. First, we measured 44 types of chemokines and cytokines in the blood of 8 advanced malignant melanomas before anti-PD-1 (nivolumab) treatment and examined the relationship between the levels of these proteins and therapeutic effect of the drug treatment, which suggested that C-C motif chemokine 5 (CCL5) and C-X-C motif chemokine ligand 12 (CXCL12) were candidates for biomarkers to predict the therapeutic effect of anti-PD-1 therapy. Next, we measured the blood levels of CCL5 and CXCL12 in 22 patients with advanced malignant melanomas before the administration of anti-PD-1 antibody. We evaluated tumor infiltration of CD8-positive T cells by immunostaining in nine patients in whom the metastatic site could be sampled at the beginning of the treatment. The patients with lower than average levels of CCL5 and CXCL12 had a large number of TILs (P = 0.04) and good disease-specific survival rate (P = 0.04). Therefore, CCL5 and CXCL12 could likely be used as biomarkers to predict the therapeutic effect of anti-PD-1 (nivolumab) therapy.

Cancer metastasis chemoprevention prevents circulating tumour cells from germination

The war against cancer traces back to the signature event half-a-century ago when the US National Cancer Act was signed into law. The cancer crusade costs trillions with disappointing returns, teasing the possibility of a new breakthrough. Cure for cancer post-metastases still seems tantalisingly out of reach. Once metastasized, cancer-related death is extremely difficult, if not impossible, to be reversed. Here we present cancer pre-metastasis chemoprevention strategy that can prevent circulating tumour cells (CTCs) from initiating metastases safely and effectively, and is disparate from the traditional cancer chemotherapy and cancer chemoprevention. Deep learning of the biology of CTCs and their disseminating organotropism, complexity of their adhesion to endothelial niche reveals that if the adhesion of CTCs to their metastasis niche (the first and the most important part in cancer metastatic cascade) can be pharmaceutically interrupted, the lethal metastatic cascade could be prevented from getting initiated. We analyse the key inflammatory and adhesive factors contributing to CTC adhesion/germination, provide pharmacological fundamentals for abortifacients to intervene CTC adhesion to the distant metastasis sites. The adhesion/inhibition ratio (AIR) is defined for selecting the best cancer metastasis chemopreventive candidates. The successful development of such new therapeutic modalities for cancer metastasis chemoprevention has great potential to revolutionise the current ineffective post-metastasis treatments.

Imaging CXCR4 receptors expression for staging multiple myeloma by using 68Ga-Pentixafor PET/CT: comparison with 18F-FDG PET/CT

OBJECTIVES

68Ga-Pentixafor positron emission tomography (PET) imaging targets CXCR4 expression which is overexpressed in multiple myeloma (MM). In this study, we evaluated the diagnostic utility of 68Ga-Pentixafor PET/CT for imaging CXCR4 expression in MM and compared results with 18F-fluorodeoxyglucose (18F-FDG) PET/CT.

METHODS

34 (21M; 13F; median age = 57.5 years) treatment naive multiple myeloma patients were recruited. All the patients underwent 18F-FDG PET/CT and 68Ga-Pentixafor PET/CT imaging. Freshly prepared 68Ga-Pentixafor (148-185 MBq) was injected intravenously and whole-body PET/CT (low-dose CT) was acquired at 1 h post-injection. The pattern of uptake (diffuse, focal or mixed) and the mean SUVmax value of all the lesions (when lesions were ≤5) or of the five most tracer avid lesions (when lesions was >5) were evaluated. Tumor to background ratio (TBRmax) was calculated for both the tracers. Durie Salmon plus staging (DSPS) was used for disease staging on PET and the results were compared with International staging system (ISS).

RESULTS

68Ga-Pentixafor PET/CT showed higher disease extent than seen on 18F-FDG PET/CT in 23/34 patients (68.0%), lesser disease extent in 2/34 (6%) and similar disease extent in 9/34 (26%) patients. Significantly (p < 0.001) higher TBRmax values (5.7; IQR 8.8) were observed on 68Ga-Pentixafor PET/CT as compared to 18F-FDG PET/CT values (2.9; IQR = 4.0). Both the techniques detected extramedullary lesions in six patients. On the other hand, 68Ga-Pentixafor detected medullary lesions in five, whereas, 18F-FDG PET in three patients. Further, only 68Ga-Pentixafor TBRmax correlated significantly (ρ = 0.421; 0.013) with bone marrow plasma cell percentage. 68Ga-Pentixafor PET upstaged more number (9/29) of patients as compared to (4/29) 18F-FDG PET imaging. On the other hand, 18F-FDG PET down-staged 9/29, whereas 68Ga-Pentixafor PET downstaged only 3/29 patients.

CONCLUSION

68Ga-Pentixafor PET/CT evaluated the whole-body disease burden of CXCR4 receptors non-invasively which is not possible by tissue sampling methods. This novel PET tracer has also implication for disease staging. Dual 68Ga-Pentixafor/18F-FDG PET/CT imaging may help in determining the tumor heterogeneity in MM.

ADVANCES IN KNOWLEDGE

This CXCR4 targeting PET tracer has a promising role in the development of CXCR4 targeting theranostics and also for response assessment to these therapies including the conventional treatment.

Identification of T cell-related biomarkers for breast cancer based on weighted gene co-expression network analysis

Breast cancer is the most frequent malignancy worldwide, with immunotherapy and targeted therapy being key strategies to improving the prognosis. We downloaded mRNA expression dataset of breast cancer from The Cancer Genome Atlas (TCGA) database, and divided preprocessed genes into 12 modules based on gene expression profile by weighted gene co-expression network analysis (WGCNA). The StromalScore, ImmuneScore and ESTIMATEScore of samples were assessed. The Kaplan-Meier curve showed that ImmuneScore was notably correlated with breast cancer patient's prognosis. By analyzing the connectivity between module eigengenes and clinical traits, the gene module closely related to ImmuneScore was obtained. Further, through intramodular gene connectivity and protein-protein interaction network topology analysis of module genes, hub genes (HLA-E, HLA-DPB1 and HLA-DRB1) in immune-related module were screened out. Finally, bioinformatics analysis displayed that HLA-DPB1 and HLA-DRB1 were notably overexpressed and HLA-E was underexpressed in breast cancer tissues. TIMER database analysis showed that three hub gene levels were significantly correlated with infiltration levels of CD8+ T cells and CD4+ T cells. Meanwhile, Pearson correlation analysis revealed positive correlation between three hub genes and those of immune checkpoint genes (LAG3, PD-1, PD-L1). Additionally, prognosis could be effectively evaluated by HLA-DPB1 and HLA-DRB1 levels, and differentially activated signalling pathways between high- and low-expression groups of HLA-E and HLA-DPB1 were obtained by gene set enrichment analysis. To conclude, this study identified three T cell-related biomarkers for breast cancer based on TCGA-BRCA dataset, and the screened genes could provide references for breast cancer immunotherapy.

CCR5 as a Prognostic Factor in Lower-Grade Glioma is Involved in the Remodeling of the Tumor Microenvironment

Background: Lower-grade gliomas (LGGs) carry a high risk of malignant transformation, leading to severe neurologic deterioration and ultimately, death. The tumor microenvironment (TME) plays an essential role in tumor maintenance, progression, and immunotherapy resistance. Therefore, the LGG TME deserves comprehensive exploration for a novel therapeutic target.

Methods: The ESTIMATE algorithm was used to estimate infiltrating stromal and immune cells of LGG patients obtained from the Cancer Genome Atlas (TCGA) database. Kaplan–Meier analysis was performed to classify survival differences. TME-related differentially expressed genes were identified between the low- and high-immune/stromal groups. Hub genes were screened by constructing protein–protein interaction networks and performing the Cox regression analysis. Differential analysis, survival analysis, gene set enrichment analysis, and clinical relevance analysis specific to hub genes were evaluated by using the TCGA and the Chinese Glioma Genome Atlas datasets, and the results were validated by qRT-PCR, Western blotting, and immunohistochemistry in tissues from LGG patients.

Results: The immune and stromal components in TME were negatively related to patient prognosis. Differentially expressed genes sharing immune score and stromal score were mainly involved in the immune response. C-C chemokine receptor type 5 (CCR5), as only a hub gene, was significantly higher in LGG patients than normal patients and negatively correlated with the prognosis of patients. High-expression CCR5 was positively related to immune-related and tumor progression pathways. CCR5 protein expression was higher in LGG with isocitrate dehydrogenase wildtype. Validated results showed that CCR5 was upregulated in LGG tissues at mRNA and protein levels and could affect immune cell infiltration. These results suggested that CCR5 was a potential indicator for the status of TME.

Conclusion: Glioma cells remodel the immune microenvironment through the high expression of CCR5 and lead to a poor prognosis in patients with LGG. The inhibition of CCR5 may contribute to the efficacy of LGG immunotherapy.

Recent advancements in the molecular biology of pituitary adenomas

INTRODUCTION

Pituitary adenomas are a common and diverse group of intracranial tumors arising from the anterior pituitary that are usually slow-growing and benign, but still pose a significant healthcare burden to patients. Additionally, they are increasing in both incidence and prevalence, leading to a need for better understanding of molecular changes in the development of these tumors.

AREAS COVERED

A PubMed literature search was conducted using the terms 'pituitary adenoma' in combination with keywords related to secretory subtype: lactotroph, somatotroph, corticotroph, gonadotroph and null cell, in addition to their transcription factor expression: PIT1, TPIT, and SF-1. Articles resulting from this search were analyzed, as well as relevant articles cited as their references. In this review, we highlight recent advances in the genetic and epigenetic characterization of individual pituitary adenoma subtypes and the effect it may have on guiding future clinical treatment of these tumors.

EXPERT OPINION

Understanding the molecular biology of pituitary adenomas is a fundamental step toward advancing the treatment of these tumors. Yet crucial knowledge gaps exist in our understanding of the underlying molecular biology of pituitary adenomas which can potentially be addressed by turning to differentially activated molecular pathways in tumor relative to normal gland.

MicroRNAs as the critical regulators of cell migration and invasion in thyroid cancer

Thyroid cancer (TC) is one of the most frequent endocrine malignancies that is more common among females. Tumor recurrence is one of the most important clinical manifestations in differentiated TC which is associated with different factors including age, tumor size, and histological features. Various molecular processes such as genetic or epigenetic modifications and non-coding RNAs are also involved in TC progression and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important biological process during tumor invasion and migration that affects the initiation and transformation of early-stage tumors into invasive malignancies. A combination of transcription factors, growth factors, signaling pathways, and epigenetic regulations affect the thyroid cell migration and EMT process. MicroRNAs (miRNAs) are important molecular factors involved in tumor metastasis by regulation of EMT-activating signaling pathways. Various miRNAs are involved in the signaling pathways associated with TC metastasis which can be used as diagnostic and therapeutic biomarkers. Since, the miRNAs are sensitive, specific, and non-invasive, they can be suggested as efficient and optimal biomarkers of tumor invasion and metastasis. In the present review, we have summarized all of the miRNAs which have been significantly involved in thyroid tumor cells migration and invasion. We also categorized all of the reported miRNAs based on their cellular processes to clarify the molecular role of miRNAs during thyroid tumor cell migration and invasion. This review paves the way of introducing a non-invasive diagnostic and prognostic panel of miRNAs in aggressive and metastatic TC patients.

The microenvironment of pituitary adenomas: biological, clinical and therapeutical implications

The microenvironment of pituitary adenomas (PAs) includes a range of non-tumoral cells, such as immune and stromal cells, as well as cell signaling molecules such as cytokines, chemokines and growth factors, which surround pituitary tumor cells and may modulate tumor initiation, progression, invasion, angiogenesis and other tumorigenic processes. The microenvironment of PAs has been actively investigated over the last years, with several immune and stromal cell populations, as well as different cytokines, chemokines and growth factors being recently characterized in PAs. Moreover, key microenvironment-related genes as well as immune-related molecules and pathways have been investigated, with immune check point regulators emerging as promising targets for immunotherapy. Understanding the microenvironment of PAs will contribute to a deeper knowledge of the complex biology of PAs, as well as will provide developments in terms of diagnosis, clinical management and ultimately treatment of patients with aggressive and/or refractory PAs.

Blood-Based Biomarkers for Alzheimer's Disease Diagnosis and Progression: An Overview

Alzheimer’s Disease (AD) is a progressive neurodegenerative disease characterized by amyloid-β (Aβ) plaque deposition and neurofibrillary tangle accumulation in the brain. Although several studies have been conducted to unravel the complex and interconnected pathophysiology of AD, clinical trial failure rates have been high, and no disease-modifying therapies are presently available. Fluid biomarker discovery for AD is a rapidly expanding field of research aimed at anticipating disease diagnosis and following disease progression over time. Currently, Aβ_1–42, phosphorylated tau, and total tau levels in the cerebrospinal fluid are the best-studied fluid biomarkers for AD, but the need for novel, cheap, less-invasive, easily detectable, and more-accessible markers has recently led to the search for new blood-based molecules. However, despite considerable research activity, a comprehensive and up-to-date overview of the main blood-based biomarker candidates is still lacking. In this narrative review, we discuss the role of proteins, lipids, metabolites, oxidative-stress-related molecules, and cytokines as possible disease biomarkers. Furthermore, we highlight the potential of the emerging miRNAs and long non-coding RNAs (lncRNAs) as diagnostic tools, and we briefly present the role of vitamins and gut-microbiome-related molecules as novel candidates for AD detection and monitoring, thus offering new insights into the diagnosis and progression of this devastating disease.

Roles and new Insights of Macrophages in the Tumor Microenvironment of Thyroid Cancer

Although most thyroid cancers have a good and predictable prognosis, the anaplastic, medullary, and refractory thyroid cancers still prone to recurrence and metastasis, resulting in poor prognosis. Although a number of newly developed targeted therapies have begun to be indicated for the above types of thyroid cancer in recent years, their ability to improve overall survival remain hindered by low efficacy. As the largest component of immune cells in tumor microenvironment, tumor-associated macrophages play a key role in the invasion and metastasis of thyroid cancer. There is much evidence that the immune system, tumor microenvironment and cancer stem cell interactions may revolutionize traditional therapeutic directions. Tumor-associated macrophages have been extensively studied in a variety of tumors, however, research on the relationship between thyroid cancer and macrophages is still insufficient. In this review, we summarize the functions of tumor-associated macrophages in different types of thyroid cancer, their cytokines or chemokines effect on thyroid cancer and the mechanisms that promote tumor proliferation and migration. In addition, we discuss the mechanisms by which tumor-associated macrophages maintain the stemness of thyroid cancer and potential strategies for targeting tumor-associated macrophages to treat thyroid cancer.

Colorectal Cancer: The Contribution of CXCL12 and Its Receptors CXCR4 and CXCR7

Simple Summary

Many signaling pathways are involved in cancer progression, and among these pathways, the CXCL12 axis and its two receptors CXCR4 and CXCR7 are well described for many cancers. This review presents the current knowledge on the role played by each of the actors of this axis in colorectal cancer and on its consideration in the development of new therapeutic strategies.

Abstract

Colorectal cancer is one of the most common cancers, and diagnosis at late metastatic stages is the main cause of death related to this cancer. This progression to metastasis is complex and involves different molecules such as the chemokine CXCL12 and its two receptors CXCR4 and CXCR7. The high expression of receptors in CRC is often associated with a poor prognosis and aggressiveness of the tumor. The interaction of CXCL12 and its receptors activates signaling pathways that induce chemotaxis, proliferation, migration, and cell invasion. To this end, receptor inhibitors were developed, and their use in preclinical and clinical studies is ongoing. This review provides an overview of studies involving CXCR4 and CXCR7 in CRC with an update on their targeting in anti-cancer therapies.

Colorectal liver metastasis: molecular mechanism and interventional therapy

Colorectal cancer (CRC) is one of the most frequently occurring malignancy tumors with a high morbidity additionally, CRC patients may develop liver metastasis, which is the major cause of death. Despite significant advances in diagnostic and therapeutic techniques, the survival rate of colorectal liver metastasis (CRLM) patients remains very low. CRLM, as a complex cascade reaction process involving multiple factors and procedures, has complex and diverse molecular mechanisms. In this review, we summarize the mechanisms/pathophysiology, diagnosis, treatment of CRLM. We also focus on an overview of the recent advances in understanding the molecular basis of CRLM with a special emphasis on tumor microenvironment and promise of newer targeted therapies for CRLM, further improving the prognosis of CRLM patients.

C-C Chemokine Receptor 7 in Cancer

C-C chemokine receptor 7 (CCR7) was one of the first two chemokine receptors that were found to be upregulated in breast cancers. Chemokine receptors promote chemotaxis of cells and tissue organization. Since under homeostatic conditions, CCR7 promotes migration of immune cells to lymph nodes, questions immediately arose regarding the ability of CCR7 to direct migration of cancer cells to lymph nodes. The literature since 2000 was examined to determine to what extent the expression of CCR7 in malignant tumors promoted migration to the lymph nodes. The data indicated that in different cancers, CCR7 plays distinct roles in directing cells to lymph nodes, the skin or to the central nervous system. In certain tumors, it may even serve a protective role. Future studies should focus on defining mechanisms that differentially regulate the unfavorable or beneficial role that CCR7 plays in cancer pathophysiology, to be able to improve outcomes in patients who harbor CCR7-positive cancers.

Inflammatory cytokines and distant recurrence in HER2-negative early breast cancer

Systemic inflammation is believed to contribute to the distant recurrence of breast cancer. We evaluated serum samples obtained at diagnosis from 249 case:control pairs with stage II-III Her2-negative breast cancer with or without subsequent distant recurrence. Conditional logistic regression analysis, with models fit via maximum likelihood, were used to estimate hazard ratios (HRs) and test for associations of cytokines with distant recurrence risk. The only biomarker associated with a significantly increased distant recurrence risk when adjusted for multiple testing was the proinflammatory cytokine IL-6 (HR 1.37, 95% confidence intervals [CI] 1.15, 1.65, p = 0.0006). This prospective-retrospective study provides evidence indicating that higher levels of the cytokine IL-6 at diagnosis are associated with a significantly higher distant recurrence risk.

RNF135 Promoter Methylation Is Associated With Immune Infiltration and Prognosis in Hepatocellular Carcinoma

RING finger protein 135 has an important role in the occurrence of many cancers; however its regulation and function of RNF135 in hepatocellular carcinoma remains unknown. The promoter methylation status and mRNA expression of RNF135 was evaluated by methylation-specific PCR, semi-quantitative RT-PCR, and real-time quantitative PCR in HCC tissues and cell lines, and further analyzed from The Cancer Genome Atlas database. Wound healing assay, transwell migration, cell viability, and colony formation assay were performed to investigate the function of RNF135. GSEA analysis, TIMER database, and ESTIMATE algorithm were used to decipher the associated pathway and immune infiltration. The survival analysis was applied to assess the prognostic value of RNF135. RNF135 expression was downregulated in HCC tissues and 5 of 8 HCC cell lines, and was negatively correlated with its promoter hypermethylation. Demethylating regent decitabine restored RNF135 expression on the cellular level. Knockdown of RNF135 expression enhanced the migration of HCC cells, while RNF135 overexpression and decitabine treatment repressed cell migration. Bioinformatics analysis and immunohistochemistry revealed a positive relationship between RNF135 expression and six immune cell infiltrates (B cells, CD4⁺ T cells, CD8⁺ T cells, neutrophils, macrophages, and dendritic cells). Survival analysis disclosed that RNF135 hypermethylation is independently associated with poor clinical outcomes in HCC. Decreased RNF135 expression driven by promoter hypermethylation frequently occurred in HCC and associated with prognosis of HCC. RNF135 functions as a tumor suppressor and is involved in tumor immune microenvironment in HCC.

Evolving polarisation of infiltrating and alveolar macrophages in the lung during metastatic progression of melanoma suggests CCR1 as a therapeutic target

Metastatic tumour progression is facilitated by tumour associated macrophages (TAMs) that enforce pro-tumour mechanisms and suppress immunity. In pulmonary metastases, it is unclear whether TAMs comprise tissue resident or infiltrating, recruited macrophages; and the different expression patterns of these TAMs are not well established. Using the mouse melanoma B16F10 model of experimental pulmonary metastasis, we show that infiltrating macrophages (IM) change their gene expression from an early pro-inflammatory to a later tumour promoting profile as the lesions grow. In contrast, resident alveolar macrophages (AM) maintain expression of crucial pro-inflammatory/anti-tumour genes with time. During metastatic growth, the pool of macrophages, which initially contains mainly alveolar macrophages, increasingly consists of infiltrating macrophages potentially facilitating metastasis progression. Blocking chemokine receptor mediated macrophage infiltration in the lung revealed a prominent role for CCR2 in Ly6C⁺ pro-inflammatory monocyte/macrophage recruitment during metastasis progression, while inhibition of CCR2 signalling led to increased metastatic colony burden. CCR1 blockade, in contrast, suppressed late phase pro-tumour MR⁺Ly6C^- monocyte/macrophage infiltration accompanied by expansion of the alveolar macrophage compartment and accumulation of NK cells, leading to reduced metastatic burden. These data indicate that IM has greater plasticity and higher phenotypic responsiveness to tumour challenge than AM. A considerable difference is also confirmed between CCR1 and CCR2 with regard to the recruited IM subsets, with CCR1 presenting a potential therapeutic target in pulmonary metastasis from melanoma.

Loss-of-function of the hippo transducer TAZ reduces mammary tumor growth through a myeloid-derived suppressor cell-dependent mechanism

TAZ, one of the key effectors in the Hippo pathway, is often dysregulated in breast cancer, leading to cancer stemness, survival, and metastasis. However, the mechanistic bases of these tumor outcomes are incompletely understood and even less is known about the potential role played by the non-malignant cellular constituents of the tumor microenvironment (TME). Here, we revealed an inverse correlation between TAZ expression and survival in triple-negative breast cancer (TNBC), but not other subtypes of breast cancer. We found that TAZ knockdown in two murine TNBC tumor cell line models significantly inhibited tumor growth and metastasis in immune competent but not immune deficient hosts. RNA-seq analyses identified substantial alterations in immune components in TAZ knockdown tumors. Using mass cytometry analysis, we found that TAZ-deficiency altered the immune landscape of the TME leading to significant reductions in immune suppressive populations, namely myeloid-derived suppressor cells (MDSCs) and macrophages accompanied by elevated CD8⁺ T cell/myeloid cell ratios. Mechanistic studies demonstrated that TAZ-mediated tumor growth was MDSC-dependent in that MDSC depletion led to reduced tumor growth in control, but not TAZ-knockdown tumor cells. Altogether, we identified a novel non-cancer cell-autonomous mechanism by which tumor-intrinsic TAZ expression aids tumor progression. Thus, our findings advance an understanding of the crosstalk between tumor-derived TAZ expression and the immune contexture within the TME, which may lead to new therapeutic interventions for TNBC or other TAZ-driven cancers.

Vitamin D Reduces Thyroid Cancer Cells Migration Independently From the Modulation of CCL2 and CXCL8 Chemokines Secretion

BACKGROUND

Vitamin D3 is largely involved in the regulation of calcium homeostasis. More recently, it was demonstrated that vitamin D exerts several beneficial effects against cancer progression through several mechanisms, including the reduction of cancer cells proliferation and migration. CXCL8 and CCL2 are two chemokines secreted by thyroid tumor cells. In the thyroid tumor microenvironment, these chemokines exert several pro-tumorigenic effects including the one to increase the metastatic potential. The aim of the present study was to investigate if vitamin D could modulate both thyroid cancer cell migration and their ability to secrete CCL2 and CXCL8.

METHODS

TPC-1 (RET/PTC rearranged) and 8505C (BRAFV600e mutated) thyroid cancer cell lines were treated with increasing concentrations of 1,25-OH-vitamin D3 (0-1,000 nM). Cell viability was assessed by WST-1 assay, cell migration was evaluated by transwell-migration chamber system, and CCL2 and CXCL8 levels were measured in the cell culture supernatants by ELISA.

RESULTS

Vitamin D did not affect cell viability but reduced, in a dose-dependent and significant manner, thyroid cancer cell migration (ANOVAs p < 0.05 for both TPC-1 and 8505C). Vitamin D differently modulated the secretion of CCL2 and CXCL8, by significantly inhibiting the secretion of CCL2 in both thyroid cancer cell lines and inhibiting the secretion of CXCL8 only in TPC-1 (ANOVAs p < 0.05).

CONCLUSIONS

Vitamin D treatment of thyroid cancer cell lines reduces cell migration independently from the inhibition of the secretion of pro-tumorigenic chemokines. Future studies specifically designed at clarifying the pathways involved in the different inhibitory effects of vitamin D on CCL2 and CXCL8 in thyroid cancer cells appear worthwhile.

A Combination of Glutaminase Inhibitor 968 and PD-L1 Blockade Boosts the Immune Response against Ovarian Cancer

Programmed cell death 1 ligand (PD-L1) blockade has been used therapeutically in the treatment of ovarian cancer, and potential combination treatment approaches are under investigation to improve the treatment response rate. The increased dependence on glutamine is widely observed in various type of tumors, including ovarian cancer. Kidney-type glutaminase (GLS), as one of the isotypes of glutaminase, is found to promote tumorigenesis. Here, we have demonstrated that the combined treatment with GLS inhibitor 968 and PD-L1 blockade enhances the immune response against ovarian cancer. Survival analysis using the Kaplan–Meier plotter dataset from ovarian cancer patients revealed that the expression level of GLS predicts poor survival and correlates with the immunosuppressive microenvironment of ovarian cancer. 968 inhibits the proliferation of ovarian cancer cells and enhances granzyme B secretion by CD8⁺ T cells as detected by XTT assay and flow cytometry, respectively. Furthermore, 968 enhances the apoptosis-inducing ability of CD8⁺ T cells toward cancer cells and improves the treatment effect of anti-PD-L1 in treating ovarian cancer as assessed by Annexin V apoptosis assay. In vivo studies demonstrated the prolonged overall survival upon combined treatment of 968 with anti-PD-L1 accompanied by increased granzyme B secretion by CD4⁺ and CD8⁺ T cells isolated from ovarian tumor xenografts. Additionally, 968 increases the infiltration of CD3⁺ T cells into tumors, possibly through enhancing the secretion of CXCL10 and CXCL11 by tumor cells. In conclusion, our findings provide a novel insight into ovarian cancer cells influence the immune system in the tumor microenvironment and highlight the potential clinical implication of combination of immune checkpoints with GLS inhibitor 968 in treating ovarian cancer.

A Comprehensive Computational Screening of Phytochemicals Derived from Saudi Medicinal Plants against Human CC Chemokine Receptor 7 to Identify Potential Anti-Cancer Therapeutics

Homeostatic trafficking of immune cells by CC chemokine receptor 7 (CCR7) keeps immune responses and tolerance in a balance. The involvement of this protein in lymph node metastasis in cancer marks CCR7 as a penitential drug target. Using the crystal structure of CCR7, herein, a comprehensive virtual screening study is presented to filter novel strong CCR7 binding phytochemicals from Saudi medicinal plants that have a higher binding affinity for the intracellular allosteric binding pocket. By doing so, three small natural molecules named as Hit-1 (1,8,10-trihydroxy-3-methoxy-6-methylanthracen-9(4H)-one), Hit-2 (4-(3,4-dimethoxybenzyl)-3-(4-hydroxy-3-methoxybenzyl)dihydrofuran-2(3H)-one), and Hit-3 (10-methyl-12,13-dihydro-[1,2]dioxolo[3,4,5-de]furo[3,2-g]isochromeno[4,3-b]chromen-8-ol) are predicted showing strong binding potential for the CC chemokine receptor 7 allosteric pocket. During molecular dynamics simulations, the compounds were observed in the formation of several chemical bonding of short bond distances. Additionally, the molecules remained in strong contact with the active pocket residues and experienced small conformation changes that seemed to be mediated by the CCR7 loops to properly engage the ligands. Two types of binding energy methods (MM/GBPBSA and WaterSwap) were additionally applied to further validate docking and simulation findings. Both analyses complement the good affinity of compounds for CCR7, the electrostatic and van der Waals energies being the most dominant in intermolecular interactions. The active pocket residue's role in compounds binding was further evaluated via alanine scanning, which highlighted their importance in natural compounds binding. Additionally, the compounds fulfilled all drug-like rules: Lipinski, Ghose, Veber, Egan, and Muegge passed many safety parameters, making them excellent anti-cancer candidates for experimental testing.

CXCR4-CCR7 Heterodimerization Is a Driver of Breast Cancer Progression

Metastatic breast cancer has one of the highest mortality rates among women in western society. Chemokine receptors CXCR4 and CCR7 have been shown to be linked to the metastatic spread of breast cancer, however, their precise function and underlying molecular pathways leading to the acquisition of the pro-metastatic properties remain poorly understood. We demonstrate here that the CXCR4 and CCR7 receptor ligands, CXCL12 and CCL19, cooperatively bind and selectively elicit synergistic signalling responses in invasive breast cancer cell lines as well as primary mammary human tumour cells. Furthermore, for the first time, we have documented the presence of CXCR4-CCR7 heterodimers in advanced primary mammary mouse and human tumours where number of CXCR4-CCR7 complexes directly correlate with the severity of the disease. The functional significance of the CXCR4-CCR7 association was also demonstrated when their forced heterodimerization led to the acquisition of invasive phenotype in non-metastatic breast cancer cells. Taken together, our data establish the CXCR4-CCR7 receptor complex as a new functional unit, which is responsible for the acquisition of breast cancer cell metastatic phenotype and which may serve as a novel biomarker for invasive mammary tumours.