Role of chemokines in metastatic niche: new insights along with a diagnostic and prognostic approach

MicroRNA-532 as a probable diagnostic and therapeutic marker in cancer patients

The high mortality rate in cancer patients is always one of the main challenges of the health systems globally. Several factors are involved in the high rate of cancer related mortality, including late diagnosis and drug resistance. Cancer is mainly diagnosed in the advanced stages of tumor progression that causes the failure of therapeutic strategies and increases the death rate in these patients. Therefore, assessment of the molecular mechanisms associated with the occurrence of cancer can be effective to introduce early tumor diagnostic markers. MicroRNAs (miRNAs) as the stable non-coding RNAs in the biological body fluids are involved in regulation of cell proliferation, migration, and apoptosis. MiR-532 deregulation has been reported in different tumor types. Therefore, in the present review we discussed the role of miR-532 during tumor growth. It has been shown that miR-532 has mainly a tumor suppressor role through the regulation of transcription factors, chemokines, and signaling pathways such as NF-kB, MAPK, PI3K/AKT, and WNT. In addition to the independent role of miR-532 in regulation of cellular processes, it also functions as a mediator of lncRNAs and circRNAs. Therefore, miR-532 can be considered as a non-invasive diagnostic/prognostic marker as well as a therapeutic target in cancer patients.

Immunomodulatory properties of the lymphatic endothelium in the tumor microenvironment

The tumor microenvironment (TME) is an intricate complex and dynamic structure composed of various cell types, including tumor, stromal and immune cells. Within this complex network, lymphatic endothelial cells (LECs) play a crucial role in regulating immune responses and influencing tumor progression and metastatic dissemination to lymph node and distant organs. Interestingly, LECs possess unique immunomodulatory properties that can either promote or inhibit anti-tumor immune responses. In fact, tumor-associated lymphangiogenesis can facilitate tumor cell dissemination and metastasis supporting immunoevasion, but also, different molecular mechanisms involved in LEC-mediated anti-tumor immunity have been already described. In this context, the crosstalk between cancer cells, LECs and immune cells and how this communication can shape the immune landscape in the TME is gaining increased interest in recent years. In this review, we present a comprehensive and updated report about the immunomodulatory properties of the lymphatic endothelium within the TME, with special focus on primary tumors and tumor-draining lymph nodes. Furthermore, we outline emerging research investigating the potential therapeutic strategies targeting the lymphatic endothelium to enhance anti-tumor immune responses. Understanding the intricate mechanisms involved in LEC-mediated immune modulation in the TME opens up new possibilities for the development of innovative approaches to fight cancer.

Ezrin accelerates breast cancer liver metastasis through promoting furin-like convertase-mediated cleavage of Notch1

BACKGROUND

Ezrin, known as a crosslinker between the plasma membrane and actin cytoskeleton, is closely associated with breast cancer (BC) progression. Here, we explored a novel role of ezrin in breast cancer liver metastasis (BCLM).

METHODS

The clinical relevance of ezrin was evaluated using in silico tools and confirmed in BC specimens. The effect of ezrin on proliferation, migration and invasion was examined in vitro and in vivo using murine primary liver-metastatic breast cancer cells (mLM). The molecular mechanism involved in ezrin-mediated activation of the Notch1 signaling pathway was elucidated using in vitro models.

RESULTS

Data-mining demonstrated that ezrin mRNA and protein expression is up-regulated in breast cancer cohorts and has prognostic significance. Ezrin overexpression promotes cell proliferation, migration and invasion in vitro and in vivo. Hairy and enhancer of split-1 (Hes1) is one of the most significantly enriched candidates of differentially expressed genes in ezrin overexpression and control mLM cells. Ezrin can positively regulate Hes1 mRNA and protein expression, and their coexpression was associated with poor prognosis in BC patients. Ezrin promoted BC cell proliferation in a Hes1-dependent manner without directly interacting with Hes1. The functional link between ezrin and Hes1 is dependent on Notch1 activation through promotion of furin-like convertase cleavage.

CONCLUSION

Our results demonstrated that ezrin drives BCLM through activation of the Notch signaling pathway via furin-like convertase. These findings provide a better understanding of the mechanism of ezrin in breast cancer progression, with the goal of discovering a novel target for the treatment of BCLM in the future.

Role of chemokines in hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor worldwide, with an unsatisfactory prognosis, although treatments are improving. One of the main challenges for the treatment of HCC is the prevention or management of recurrence and metastasis of HCC. It has been found that chemokines and their receptors serve a pivotal role in HCC progression. In the present review, the literature on the multifactorial roles of exosomes in HCC from PubMed, Cochrane library and Embase were obtained, with a specific focus on the functions and mechanisms of chemokines in HCC. To date, >50 chemokines have been found, which can be divided into four families: CXC, CX3C, CC and XC, according to the different positions of the conserved N‑terminal cysteine residues. Chemokines are involved in the inflammatory response, tumor immune response, proliferation, invasion and metastasis via modulation of various signaling pathways. Thus, chemokines and their receptors directly or indirectly shape the tumor cell microenvironment, and regulate the biological behavior of the tumor. In addition, the potential application of chemokines in chemotaxis of exosomes as drug vehicles is discussed. Exosomes containing chemokines or expressing receptors for chemokines may improve chemotaxis to HCC and may thus be exploited for targeted drug delivery.

Thymus‑expressed chemokine secreted by breast cancer cells promotes metastasis and inhibits apoptosis

The aim of the present study was to investigate the underlying mechanisms of thymus-expressed chemokine (TECK) autocrine signaling, and its effect on carcinogenesis and the development of breast cancer. The present study also assessed epithelial-mensenchymal transition (EMT) and cell migration, invasion, proliferation and apoptosis. Breast cancer cell lines MCF-7 and MDA-MB-231 were used in the present study, and TECK basic expression in cancer cells was investigated using western blotting (WB). EMT markers, Akt pathway molecules and apoptosis indicators were detected by reverse transcription-quantitative PCR or WB. In order to assess migration and invasion, wound healing and Matrigel invasion assays were performed. Moreover, flow cytometry was used to assess the rate of proliferation and apoptosis. In vivo experiments were conducted in nude mice to assess cancer growth. It was revealed that breast cancer cells could secrete TECK in an autocrine manner. Furthermore, TECK could increase cell migration and invasion by promoting EMT and inhibit apoptosis via the Akt signaling pathway.

MiR-532-5p Suppresses Migration and Invasion of Lung Cancer Cells Through Inhibiting CCR4

Background: Studies showed that miR-532-5p suppresses proliferation and induces apoptosis of lung cancer (LC) cells; its role in LC is not fully understood. Therefore, this research aimed to reveal the effect and mechanism of miR-532-5p on migration and invasion of LC cells. Materials and Methods: The transfection efficiencies of miR-532-5p mimic, inhibitor, and overexpressed CCR4 were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The relationships between miR-532-5p and CCR4 in A549 and SBC-5 cells were predicted by targetScan and verified by dual-luciferase reporter assay, Western blot, and qRT-PCR. Migration and invasion of cells transfected with miR-532-5p mimic, inhibitor, and CCR4 were determined by scratch test and transwell assay, respectively. The levels of epithelial-to-mesenchymal transition (EMT)-related proteins (E-cadherin (E-Cad)), N-catenin (N-Cad), and vimentin) in cells were measured by Western blot. Results: MiR-532-5p mimic suppressed migration and invasion, while miR-532-5p inhibitor promoted migration and invasion of cells. CCR4 was a downstream target of miR-532-5p and both its protein and mRNA expressions were inhibited by miR-532-5p mimic, but promoted by miR-532-5p inhibitor. CCR4 promoted migration, invasion, and EMT process, and such effects of CCR4 were reversed by miR-532-5p mimic. Conclusion: MiR-532-5p functioned as a cancer suppressor by negatively regulating CCR4 in LC cells, pointing to a potential protective mechanism of miR-532-5p to LC patients.

Human omental adipose-derived mesenchymal stem cells enhance autophagy in ovarian carcinoma cells through the STAT3 signalling pathway

BACKGROUND

Our previous study showed that human omental adipose-derived stem cells (ADSCs) promote ovarian cancer growth and metastasis. In this study, the role of autophagy in the ovarian cancer-promoting effects of omental ADSCs was further determined.

METHODS

The growth and invasion of ovarian cancer cells were detected by CCK-8 and Transwell assays, respectively. The autophagy of ovarian cancer cells transfected with MRFP-GFP-LC3 adenoviral vectors was evaluated by confocal microscopy and western blot assay. Transfection of STAT3 siRNA was used to inhibit the expression of STAT3.

RESULTS

Our results show that autophagy plays a vital role in ovarian cancer and is promoted by ADSCs. Specifically, we show that proliferation and invasion are correlated with autophagy induction by ADSCs in two ovarian cancer cell lines under hypoxic conditions. Mechanistically, ADSCs activate the STAT3 signalling pathway, thereby promoting autophagy. Knockdown of STAT3 expression using siRNA decreased hypoxia-induced autophagy and decreased the proliferation and metastasis of ovarian cancer cells.

CONCLUSION

Taken together, our data indicate that STAT3-mediated autophagy induced by ADSCs promotes ovarian cancer growth and metastasis.

Chemokines and their Receptors: Multifaceted Roles in Cancer Progression and Potential Value as Cancer Prognostic Markers

Chemokines are chemotactic cytokines that mediate immune cell chemotaxis and lymphoid tissue development. Recent advances have indicated that chemokines and their cognate receptors play critical roles in cancer-related inflammation and cancer progression. On the basis of these findings, the chemokine system has become a new potential drug target for cancer immunotherapy. In this review, we summarize the essential roles of the complex network of chemokines and their receptors in cancer progression. Furthermore, we discuss the potential value of the chemokine system as a cancer prognostic marker. The chemokine system regulates the infiltration of immune cells into the tumor microenvironment, which induces both pro- and anti-immunity and promotes or suppresses tumor growth and proliferation, angiogenesis, and metastasis. Increasing evidence indicates the promising prognostic value of the chemokine system in cancer patients. While CCL2, CXCL10, and CX3CL1/CX3CR1 can serve as favorable or unfavorable prognostic factors depending on the cancer types, CCL14 and XCL1 possess good prognostic value. Other chemokines such as CXCL1, CXCL8, and CXCL12 are poor prognostic markers. Despite vast advances in our understanding of the complex nature of the chemokine system in tumor biology, knowledge about the multifaceted roles of the chemokine system in different types of cancers is still limited. Further studies are necessary to decipher distinct roles within the chemokine system in terms of cancer progression and to validate their potential value in cancer prognosis.

A Novel Tissue-Based Liver-Kidney-on-a-Chip Can Mimic Liver Tropism of Extracellular Vesicles Derived from Breast Cancer Cells

Extracellular vesicles (EVs) from cancer cells remodel distant organs to promote metastasis in vivo. A biomimetic microsystem may compensate costly and time-consuming animal models to accelerate the study of EV organotropism. A tissue-based liver-kidney-on-a-chip is developed with precision-cut tissue slices (PTSs) cultured to represent individual organs. The organotropism of breast cancer EVs is modeled using the biomimetic microsystem. A traditional animal model of EV organotropism is used to investigate the physiological similarity of the microfluidic model to animal models. It is demonstrated that breast cancer EVs show strong liver tropism rather than kidney tropism on both the microfluidic and animal models. It is found that the metastatic inhibitor AMD3100 inhibits liver tropism effectively in both the microfluidic and animal models. Overall, the tropism of EVs to different organs is reconstituted on the microfluidic model. The liver-kidney-on-a-chip may expand the capabilities of traditional cell culture models and provide a faster alternative to animal models for EV studies.

The role of liver microenvironment in hepatic metastasis

Metastasis is still poorly understood and thus further research must be conducted to provide insight into the driving factors. Novel research has revealed the significance of the microenvironment in the delegation of metastasis, expanding the field of cancer metastasis to cells and cell environments surrounding the migrated tumor cells. Research on hepatic metastasis is an ever-growing domain of this field, as several primary tumors can metastasize to the liver. The two features within the liver that promote metastasis—cellular and acellular—are found in the current interpretation of liver microenvironment. Novel findings of both are included in this review. Different hypotheses detailing the methods by which metastasis can occur must be included to understand the significance of the microenvironment, as well as a brief overview of the methods that can be used during research. This review aims to highlight the importance of liver microenvironment on the development or potential regression of hepatic metastasis through discussing both acellular and cellular components of liver microenvironment and their interaction with metastasis.

The Interplay Between Lymphatic Vessels and Chemokines

Chemokines are a family of small protein cytokines that act as chemoattractants to migrating cells, in particular those of the immune system. They are categorized functionally as either homeostatic, constitutively produced by tissues for basal levels of cell migration, or inflammatory, where they are generated in association with a pathological inflammatory response. While the extravasation of leukocytes via blood vessels is a key step in cells entering the tissues, the lymphatic vessels also serve as a conduit for cells that are recruited and localized through chemoattractant gradients. Furthermore, the growth and remodeling of lymphatic vessels in pathologies is influenced by chemokines and their receptors expressed by lymphatic endothelial cells (LECs) in and around the pathological tissue. In this review we summarize the diverse role played by specific chemokines and their receptors in shaping the interaction of lymphatic vessels, immune cells, and other pathological cell types in physiology and disease.

The extracellular matrix in tumor progression and metastasis

The extracellular matrix (ECM) constitutes the scaffold of tissues and organs. It is a complex network of extracellular proteins, proteoglycans and glycoproteins, which form supramolecular aggregates, such as fibrils and sheet-like networks. In addition to its biochemical composition, including the covalent intermolecular cross-linkages, the ECM is also characterized by its biophysical parameters, such as topography, molecular density, stiffness/rigidity and tension. Taking these biochemical and biophysical parameters into consideration, the ECM is very versatile and undergoes constant remodeling. This review focusses on this remodeling of the ECM under the influence of a primary solid tumor mass. Within this tumor stroma, not only the cancer cells but also the resident fibroblasts, which differentiate into cancer-associated fibroblasts (CAFs), modify the ECM. Growth factors and chemokines, which are tethered to and released from the ECM, as well as metabolic changes of the cells within the tumor bulk, add to the tumor-supporting tumor microenvironment. Metastasizing cancer cells from a primary tumor mass infiltrate into the ECM, which variably may facilitate cancer cell migration or act as barrier, which has to be proteolytically breached by the infiltrating tumor cell. The biochemical and biophysical properties therefore determine the rates and routes of metastatic dissemination. Moreover, primed by soluble factors of the primary tumor, the ECM of distant organs may be remodeled in a way to facilitate the engraftment of metastasizing cancer cells. Such premetastatic niches are responsible for the organotropic preference of certain cancer entities to colonize at certain sites in distant organs and to establish a metastasis. Translational application of our knowledge about the cancer-primed ECM is sparse with respect to therapeutic approaches, whereas tumor-induced ECM alterations such as increased tissue stiffness and desmoplasia, as well as breaching the basement membrane are hallmark of malignancy and diagnostically and histologically harnessed.

Flip-flops of natural killer cells in autoimmune diseases versus cancers: Immunologic axis

Natural killer (NK) cells play an essential role in the immune response to infections, inflammations, and malignancies. Recent studies suggest that NK cell surface receptors and cytokines are the key points of the disease development and protection. We hypothesized that the interactions between NK cell receptors and targeted cells construct an eventual niche, and this niche has an eventual profile in various autoimmune diseases and cancers. The NK cells preactivated with cytokines, such as interleukin-2 (IL-2), IL-12, IL-15, and IL-18 can have higher cytotoxicity; however, the toxic side effect of IL-2 should be considered. The vicissitudes of NK cell profile and its receptors obey the environmental communications and cell interactions. Our vision around the NK cells as an immune axis remained dual, and we still cannot judge the immune responses based on the NK cell flip-flop. A design of eventual niche to monitor the NK cell and targeted cell interaction is needed to strengthen our ability in diagnosis and treatment approaches based on the NK cells. Here, we have reviewed the shifts in the NK cells and their surface receptors in autoimmune diseases, solid tumors, and leukemia, and also discussed the effective chemokines that affect NK cell activation and proliferation. The main aim of this review is to present a broader vision of the NK cell changes in autoimmune disease and cancers.

The Diagnostic Value of Chemokine/Chemokine Receptor Pairs in Hepatocellular Carcinoma and Colorectal Liver Metastasis

Chemokines and their receptors have been proposed to play important roles in tumor progression and metastasis. To investigate their roles in the progression of primary and metastatic malignant liver tumors and their prognosis, we compared expression profiles of CXCL12/CXCR4, CCL20/CCR6, and CCL21/CCR7 in hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM). Immunohistochemistry was used to analyze the expression levels of the chemokine/chemokine receptor pairs in 29 HCC and 11 CRLM specimens and adjacent non-cancerous tissues, and correlations with clinicopathological variables and overall survival were determined. CCL20/CCR6 expression was higher in HCC than in adjacent non-cancerous tissues. High CCR6 expression in HCC was negatively associated with 5-year survival rate and was an independent prognostic factor for overall survival of HCC patients, whereas differences were not observed between CRLM and adjacent tissues. Furthermore, significantly higher expression of CCL21/CCR7 was found in CRLM than in HCC. In summary, the CCL20/CCR6 axis was elevated in HCC but not in CRLM, whereas the CCL21/CCR7 axis was elevated in CRLM but not in HCC.

The Dynamic Roles of Mesenchymal Stem Cells in Colon Cancer

Colon cancer is still one of the most common causes of cancer in human and is characterized by lymphocyte infiltrates and originates from the epithelial cells found in the lining of colon or rectum of the gastrointestinal tract. Mesenchymal stem cells (MSCs) are composed of the multipotent stem cell group of stroma and can be differentiated as various cell lineages, such as fibroblasts, osteoblasts, and adipocytes. MSCs provide mechanical and structural support and have potential functions during tumor growth and metastasis. The efficacy of MSC-based therapies is partly dependent on the migration and homing of MSCs to tumors and metastatic sites. However, their migratory and engraftment potential is poorly understood. In this review, the characteristics and mechanisms of MSC's dynamic interaction with colon cancer were summarized, particularly the potential functions of MSCs on colon cancer, including its role in improving tumor growth and as a potential candidate for tumor therapy. Understanding MSC homing provides new insights into the manipulation of MSC and the improvement of their efficacy for colon cancer therapy.

The chemokine system and its role in obesity

The chemokine system is a complex arrangement of molecules that attract leukocytes to the site of injury or inflammation. This chemotactic behavior gives the system the name "Chemokine." The intricate and redundant nature of the chemokine system has made it a subject of ongoing scientific investigation. Obesity is characterized as low-grade systemic or chronic inflammation that is responsible for the release of cytokines, adipokines, and chemokines. Excessive tissue fat expansion triggers the release of chemokines, which in turn attract various leukocytes and activate the resident immune surveillance system, eventually leading to worsening of obesity and other related comorbidities. To date, 50 chemokines and 20 chemokine receptors that belong to the G-protein-coupled receptor family have been discovered, and over the past two decades, the physiological and pathological roles of many of these chemokines and their receptors have been elucidated. The objective of this review is to present an update on the link between chemokines and obesity under the light of recent knowledge.

Reactive oxygen species in haematopoiesis: leukaemic cells take a walk on the wild side

Oxidative stress is related to ageing and degenerative diseases, including cancer. However, a moderate amount of reactive oxygen species (ROS) is required for the regulation of cellular signalling and gene expression. A low level of ROS is important for maintaining quiescence and the differentiation potential of haematopoietic stem cells (HSCs), whereas the level of ROS increases during haematopoietic differentiation; thus, suggesting the importance of redox signalling in haematopoiesis. Here, we will analyse the importance of ROS for haematopoiesis and include evidence showing that cells from leukaemia patients live under oxidative stress. The potential sources of ROS will be described. Finally, the level of oxidative stress in leukaemic cells can also be harnessed for therapeutic purposes. In this regard, the reliance of front-line anti-leukaemia chemotherapeutics on increased levels of ROS for their mechanism of action, as well as the active search for novel compounds that modulate the redox state of leukaemic cells, will be analysed.