Tumor-derived exosomes can specifically prevent cancer metastatic organotropism

Multi-targeted nanoarrays for early broad-spectrum detection of lung cancer based on blood biopsy of tumor exosomes

Liquid biopsies utilizing tumor exosomes offer a noninvasive approach for cancer diagnosis. However, validation studies consistently report that in the early stages of cancer, the secretion of exosomes by cancer cells is relatively low, while bodily fluids exhibit a high abundance of other interfering biomolecules. Additionally, target mutations or differences in biomarker expression among various lung cancer subtypes may contribute to detection failures. In this study, we propose a targeted nanoarray-based early cancer diagnostic approach for multiple subtypes of lung cancer. The targeted nanoarray was constructed by modifying five targeting aptamers onto mesoporous silica nanoparticles through the conjugation between amino and carboxyl groups. The flow cytometry experiments demonstrated the specific recognition ability of the targeted nanoarray to tumor exosomes in PBS, even at biomarker expression levels as low as 1.5 %. Moreover, the TEM results indicated that the targeted nanoarray could isolate tumor exosomes in the blood of tumor-bearing mice. Furthermore, the targeted nanoarray could detect tumor exosomes in the blood of various lung cancer bearing mice, including at the early stages of cancer, which has just been established for 7 days. Overall, the targeted nanoarray represents a promising tool for the early detection of various subtypes of lung cancer.

Harnessing exosomes as a platform for drug delivery in breast cancer: A systematic review for in vivo and in vitro studies

Breast cancer remains a significant global health concern, emphasizing the critical need for effective treatment strategies, especially targeted therapies. This systematic review summarizes the findings from in vitro and in vivo studies regarding the therapeutic potential of exosomes as drug delivery platforms in the field of breast cancer treatment. A comprehensive search was conducted across bibliographic datasets, including Web of Science, PubMed, and Scopus, using relevant queries from several related published articles and the Medical Subject Headings Database. Then, all morphological, biomechanical, histopathological, and cellular-molecular outcomes were systematically collected. A total of 30 studies were identified based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. These studies underwent assessment using the Systematic Review Centre for Laboratory Animal Experimentation risk of bias assessment tool. The results indicate that exosomes exhibit promise as effective drug delivery platforms, capable of hindering cancer cell viability, proliferation, migration, and angiogenesis. However, a comprehensive assessment is challenging due to some studies deviating from guidelines and having incomplete methodology. Addressing these, future studies should detail methodologies, optimize dosing, and enhance exosome production. Standardization in reporting, consistent protocols, and exploration of alternative sources are crucial.

Enhancing glioma-specific drug delivery through self-assembly of macrophage membrane and targeted polymer assisted by low-frequency ultrasound irradiation

The blood-brain Barrier (BBB), combined with immune clearance, contributes to the low efficacy of drug delivery and suboptimal treatment outcomes in glioma. Here, we propose a novel approach that combines the self-assembly of mouse bone marrow-derived macrophage membrane with a targeted positive charge polymer (An-PEI), along with low-frequency ultrasound (LFU) irradiation, to achieve efficient and safe therapy for glioma. Our findings demonstrate the efficacy of a charge-induced self-assembly strategy, resulting in a stable co-delivery nanosystem with a high drug loading efficiency of 44.2 %. Moreover, this structure triggers a significant release of temozolomide in the acidic environment of the tumor microenvironment. Additionally, the macrophage membrane coating expresses Spyproteins, which increase the amount of An-BMP-TMZ that can evade the immune system by 40 %, while LFU irradiation treatment facilitates the opening of the BBB, allowing for enormously increased entry of An-BMP-TMZ (approximately 400 %) into the brain. Furthermore, after crossing the BBB, the Angiopep-2 peptide-modified An-BMP-TMZ exhibits the ability to selectively target glioma cells. These advantages result in an obvious tumor inhibition effect in animal experiments and significantly improve the survival of glioma-bearing mice. These results suggest that combining the macrophage membrane-coated drug delivery system with LFU irradiation offers a feasible approach for the accurate, efficient and safe treatment of brain disease.

Recent advances in micro-physiological systems for investigating tumor metastasis and organotropism

Tumor metastasis involves complex processes that traditional 2D cultures and animal models struggle to fully replicate. Metastatic tumors undergo a multitude of transformations, including genetic diversification, adaptation to diverse microenvironments, and modified drug responses, contributing significantly to cancer-related mortality. Micro-physiological systems (MPS) technology emerges as a promising approach to emulate the metastatic process by integrating critical biochemical, biomechanical, and geometrical cues at a microscale. These systems are particularly advantageous simulating metastasis organotropism, the phenomenon where tumors exhibit a preference for metastasizing to particular organs. Organotropism is influenced by various factors, such as tumor cell characteristics, unique organ microenvironments, and organ-specific vascular conditions, all of which can be effectively examined using MPS. This review surveys the recent developments in MPS research from the past five years, with a specific focus on their applications in replicating tumor metastasis and organotropism. Furthermore, we discuss the current limitations in MPS-based studies of organotropism and propose strategies for more accurately replicating and analyzing the intricate aspects of organ-specific metastasis, which is pivotal in the development of targeted therapeutic approaches against metastatic cancers.

The role of extracellular vesicles in circulating tumor cell-mediated distant metastasis

Current research has demonstrated that extracellular vesicles (EVs) and circulating tumor cells (CTCs) are very closely related in the process of distant tumor metastasis. Primary tumors are shed and released into the bloodstream to form CTCs that are referred to as seeds to colonize and grow in soil-like distant target organs, while EVs of tumor and nontumor origin act as fertilizers in the process of tumor metastasis. There is no previous text that provides a comprehensive review of the role of EVs on CTCs during tumor metastasis. In this paper, we reviewed the mechanisms of EVs on CTCs during tumor metastasis, including the ability of EVs to enhance the shedding of CTCs, protect CTCs in circulation and determine the direction of CTC metastasis, thus affecting the distant metastasis of tumors.

Application of exosomes as nanocarriers in cancer therapy

Cancer remains the most common lethal disease in the world. Although the treatment choices for cancer are still limited, significant progress has been made over the past few years. By improving targeted drug therapy, drug delivery systems promoted the therapeutic effects of anti-cancer medications. Exosome is a kind of natural nanoscale delivery system with natural substance transport properties, good biocompatibility, and high tumor targeting, which shows great potential in drug carriers, thereby providing novel strategies for cancer therapy. In this review, we present the formation, distribution, and characteristics of exosomes. Besides, extraction and isolation techniques are discussed. We focus on the recent progress and application of exosomes in cancer therapy in four aspects: exosome-mediated gene therapy, chemotherapy, photothermal therapy, and combination therapy. The current challenges and future developments of exosome-mediated cancer therapy are also discussed. Finally, the latest advances in the application of exosomes as drug delivery carriers in cancer therapy are summarized, which provide practical value and guidance for the development of cancer therapy.

Engineering of dendritic cell bispecific extracellular vesicles for tumor-targeting immunotherapy

Advances in the development of therapeutic extracellular vesicles (EVs) for cancer immunotherapy have allowed them to emerge as an alternative to cell therapy. In this proof-of-concept work, we develop bispecific EVs (BsEVs) by genetically engineering EV-producing dendritic cells (DCs) with aCD19 scFv and PD1 for targeting tumor antigens and blocking immune checkpoint proteins simultaneously. We find that these bispecific EVs (EVs-PD1-aCD19) have an impressive ability to accumulate in huCD19-expressing solid tumors following intravenous injection. In addition, EVs-PD1-aCD19 can remarkably reverse the immune landscape of the solid tumor by blocking PD-L1. Furthermore, EVs-PD1-aCD19 can also target tumor-derived EVs in circulation, which prevents the formation of a premetastatic niche in other tissues. Our technology is a demonstration of bispecific EV-based cancer immunotherapy, which may inspire treatments against various types of tumors with different surface antigens and even a patient-tailored therapy.

Molecular imaging-guided extracellular vesicle-based drug delivery for precise cancer management: Current status and future perspectives

Extracellular vesicles (EVs), the mediators of intercellular communication, have attracted the attention of researchers for the important roles they play in cancer treatment. Compared with other inorganic nano-materials, EVs possess the advantages of higher biocompatibility, better physiochemical stability, easier surface modification, and excellent biosafety. They can be used as an advanced drug delivery system with an improved therapeutic index for various therapeutic agents. Engineered EV-based imaging and therapeutic agents (engineered EVs) have emerged as useful tools in targeted cancer diagnosis and therapy. Non-invasive tracing of engineered EVs contributes to a better evaluation of their functions in cancer progression, in vivo dynamic biodistribution, therapeutic response, and drug-loading efficiency. Recent advances in real-time molecular imaging (MI), and innovative EV labeling strategies have led to the development of novel tools that can evaluate the pharmacokinetics of engineered EVs in cancer management, which may accelerate further clinical translation of novel EV-based drug delivery platforms. Herein, we review the latest advances in EVs, their characteristics, and current examples of EV-based targeted drug delivery for cancer. Then, we discuss the prominent applications of MI for tracing both natural and engineered EVs. Finally, we discuss the current challenges and considerations of EVs in targeted cancer treatment and the limitations of different MI modalities. In the coming decades, EV-based therapeutic applications for cancer with improved drug loading and targeting abilities will be developed, and better anti-cancer effects of drug delivery nanoplatform will be achieved.

Neural stem cell-derived extracellular vesicles: The light of central nervous system diseases

Central nervous system (CNS) diseases are the leading cause of death worldwide. By performing compensatory functions and improving the inflammatory microenvironment, the transplantation of neural stem cells (NSCs) can promote functional recovery from brain injury, aging, brain tumours, and other diseases. However, the ability of NSCs to differentiate into neurons is limited, and they are associated with a risk of tumourigenicity. NSC-derived extracellular vesicles (NSC-EVs) can modulate the local microenvironment of the nervous system as well as distant neuronal functions. Thus, cell-free therapy may be a novel remedy for CNS disorders. This article reviews the characteristics, contents, and mechanisms of action of NSC-EVs as well as their roles and application prospects in various CNS diseases.

Tumor-derived extracellular vesicles in the colorectal cancer immune environment and immunotherapy

Despite significant advances in the screening, diagnosis, and treatment of colorectal cancer (CRC) immune checkpoint inhibitors (ICIs) continue to have limited utility outside of microsatellite-high disease. Given the durable response to immunotherapy seen across malignancies, increasing CRC response rates to ICI therapy is an active area of clinical research. An increasing body of work has demonstrated that tumor-derived extracellular vesicles (TEVs) are key modulators in tumor signaling and the determinants of the tumor microenvironment. Pre-clinical models have shown that TEVs are directly involved in antigen presentation and are involved in radiation-induced DNA damage signaling. Both direct and indirect modifications of these TEVs can alter CRC immunogenicity and ICI treatment response, making them attractive targets for potential therapeutic development. In addition, modified TEVs can be developed using several different mechanisms, with varied cargo including micro-RNAs and small peptide molecules. Recent work has shown strong pre-clinical evidence of injected modified TEV-induced ICI activity, with knockdown of the micro-RNA miR-424 in TEVs improving CRC immunogenicity and increasing anti-PD-1 activity in mouse models. Clinical trials are ongoing in the evaluation of modified TEVs in cancer therapy, but they appear to be a promising therapeutic target in CRC.

Cancer Therapy Empowered by Extracellular Vesicle-Mediated Targeted Delivery

Extracellular vesicles (EVs) are a class of nanoparticles that mediate signaling molecules delivery between donor and recipient cells. Heterogeneity in the content of EVs and their membrane surface proteins determines their unique targetability. Their low immunogenicity, capability to cross various biological barriers, and superior biocompatibility enable engineering-modified EVs to be ideal drug delivery carriers. In addition, the engineered EVs that emerge in recent years have become a powerful tool for cancer treatment through the selective delivery of bioactive molecules to therapeutic targets, such as tumor cells and stroma. Our review focuses on the various types of EV modifications and their promoting therapeutic capabilities, which provide an innovative means for cancer precision therapy.

Tumor-derived extracellular vesicles for the active targeting and effective treatment of colorectal tumors in vivo

Colorectal cancer remains one of the main causes of cancer-related deaths worldwide. Although numerous nanomedicine formulations have been developed to tackle the disease, their low selectivity still limits effective therapeutic outcomes. In this study, we isolated extracellular vesicles (EVs) from CT26 colorectal cancer cells and 4T1 murine mammary carcinoma cells, loaded them with the chemotherapeutic agent (doxorubicin, DOX). Then we evaluated the cellular uptake of the extracellular vesicles both in 2D monolayer and 3D tumor spheroid setups using confocal laser scanning microscope and flow cytometry. In vivo tumor homing of the extracellular vesicles was verified on CT26 tumor bearing BALB/c mice using in vivo imaging system. Finally, in vivo therapeutic effects were evaluated and compared using the same animal models treated with five doses of EV formulations. CT26-EV-DOX exhibited excellent biocompatibility, a high drug-loading capacity, controlled drug release behavior, and a high capability for targeting colorectal cancer cells. In particular, we verified that CT26-EV-DOX could preferentially be up taken by their parent cells and could effectively target and penetrate 3D tumor spheroids resembling colorectal tumors in vivo in comparison with their 4T1 derived EV partner. Additionally, treatment of colorectal tumor-bearing BALB/c mice with of CT26-EV-DOX significantly inhibited the growth of the tumors during the treatment course. The developed CT26-EV-DOX nanoparticles may present a novel and effective strategy for the treatment of colorectal cancer.

Self-assembly of DNA nanostructure containing cell-specific aptamer as a precise drug delivery system for cancer therapy in non-small cell lung cancer

Background

As the most common subtype in lung cancer, the precise and efficient treatment for non-small cell lung cancer (NSCLC) remains an outstanding challenge owing to early metastasis and poor prognosis. Chemotherapy, the most commonly used treatment modality, is a difficult choice for many cancer patients due to insufficient drug accumulation in tumor sites and severe systemic side-effects. In this study, we constructed a cell-specific aptamer-modified DNA nanostructure (Apt-NS) as a targeting drug delivery system achieving the precision therapy for lung cancer.

Methods

The synthesis of DNA nanostructure and its stability were evaluated using gel electrophoresis. The targeting properties and internalization mechanism were investigated via flow cytometry and confocal analyses. Drug loading, release, and targeted drug delivery were determined by fluorescence detection, Zeta potentials assay, and confocal imaging. CCK8 assays, colony formation, cell apoptosis, metastasis analyses and in vivo experiments were conducted to assess the biological functions of DNA nanostructure.

Results

Self-assembled DNA nanoparticles (Apt-NS) had excellent stability to serum and DNase I and the ability to specifically recognize A549 cells. Upon specific binding, the drug-loaded nanoparticles (Apt-NS-DOX) were internalized into target cells by clathrin-mediated endocytosis. Subsequently, DOX could be released from Apt-NS-DOX based on the degradation of the lysosome. Apt-NS-DOX exerted significant suppression of cell proliferation, invasion and migration, and also enhanced cell apoptosis due to the excellent performance of drug delivery and intracellular release, while maintaining a superior biosafety. In addition, the antitumor effects of Apt-NS-DOX were further confirmed using in vivo models.

Conclusions

Our study provided cell-specific aptamer-modified DNA nanostructures as a drug-delivery system targeting A549 cells, which could precisely and efficiently transport chemotherapeutic drug into tumor cells, exerting enhanced antineoplastic efficacy. These findings highlight that DNA nanostructure serving as an ideal drug delivery system in cancer treatment appears great promise in biomedical applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01701-5.

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.

Exosomes: A novel insight into traditional Chinese medicine

Exosomes are small extracellular vesicles and play an essential role in the mediation of intercellular communication both in health and disease. Traditional Chinese medicine (TCM) has historically been used to maintain human health and treat various diseases up till today. The interplay between exosomes and TCM has attracted researchers’ growing attention. By integrating the available evidence, TCM formulas and compounds isolated from TCM as exosome modulators have beneficial effects on multiple disorders, such as tumors, kidney diseases, and hepatic disease, which may associate with inhibiting cells proliferation, anti-inflammation, anti-oxidation, and attenuating fibrosis. Exosomes, a natural delivery system, are essential in delivering compounds isolated from TCM to target cells or tissues. Moreover, exosomes may be the potential biomarkers for TCM syndromes, providing strategies for TCM treatment. These findings may provide a novel insight into TCM from exosomes and serve as evidence for better understanding and development of TCM.

Novel active stealth micelles based on β2M achieved effective antitumor therapy

Micelles have been extensively investigated as drug delivery systems for loading of antitumor drugs with the advantages of good dispersibility, controllable size distribution, and high loading capacity. However, phagocytic clearance by the mononuclear phagocyte system remains a major impediment that inhibits blood circulation and thus tumor accumulation of micelles. Inspired by the antiphagocytic properties of β₂-microglobulin (β₂M), here we developed a β₂M-derived peptide for the surface functionalization of micelles. A β₂M-derived sequence was integrated with a matrix metalloproteinase-2 (MMP-2) cleavable sequence and then modified on the surface of poly(ethylene glycol)-b-poly(caprolactone) (PEG-PCL) micelles, endowing the micelles with both antiphagocytic and MMP-2-responsive properties. Compared to pristine PEG-PCL micelles, micelles modified with the dual-functional peptide exhibited higher inhibition of phagocytosis by macrophages in the absence of MMP-2, and enhanced internalization by tumor-associated macrophages in the presence of MMP-2, leading to enhanced tumor accumulation of the loaded photosensitizer, thus enabling antitumor therapy. These results demonstrated that antiphagocytic peptides derived from endogenous proteins are promising for functionalization of micelles in smart drug delivery.

Application of two-dimensional difference gel electrophoresis to identify protein changes between center, margin, and adjacent non-tumor tissues obtained from non-small-cell lung cancer with adenocarcinoma or squamous cell carcinoma subtype

Lung cancer is responsible for the most cancer-related mortality worldwide and the mechanism of its development is poorly understood. Proteomics has become a powerful tool offering vital knowledge related to cancer development. Using a two-dimensional difference gel electrophoresis (2D-DIGE) approach, we sought to compare tissue samples from non-small-cell lung cancer (NSCLC) patients taken from the tumor center and tumor margin. Two subtypes of NSCLC, adenocarcinoma (ADC) and squamous cell carcinoma (SCC) were compared. Data are available via ProteomeXchange with identifier PXD032736 and PXD032962 for ADC and SCC, respectively. For ADC proteins, 26 significant canonical pathways were identified, including Rho signaling pathways, a semaphorin neuronal repulsive signaling pathway, and epithelial adherens junction signaling. For SCC proteins, nine significant canonical pathways were identified, including hypoxia-inducible factor-1α signaling, thyroid hormone biosynthesis, and phagosome maturation. Proteins differentiating the tumor center and tumor margin were linked to cancer invasion and progression, including cell migration, adhesion and invasion, cytoskeletal structure, protein folding, anaerobic metabolism, tumor angiogenesis, EMC transition, epithelial adherens junctions, and inflammatory responses. In conclusion, we identified several proteins that are important for the better characterization of tumor development and molecular specificity of both lung cancer subtypes. We also identified proteins that may be important as biomarkers and/or targets for anticancer therapy.

Role of CD47-SIRPα Checkpoint in Nanomedicine-Based Anti-Cancer Treatment

Many cancers have evolved various mechanisms to evade immunological surveillance, such as the inhibitory immune checkpoint of the CD47-SIRPα signaling pathway. By targeting this signaling pathway, researchers have developed diverse nanovehicles with different loaded drugs and modifications in anticancer treatment. In this review, we present a brief overview of CD47-SIRPα interaction and nanomedicine. Then, we delve into recent applications of the CD47-SIRPα interaction as a target for nanomedicine-based antitumor treatment and its combination with other targeting pathway drugs and/or therapeutic approaches.

Extracellular Vesicle-Packaged CDH11 and ITGA5 Induce the Premetastatic Niche for Bone Colonization of Breast Cancer Cells

Although most breast cancer metastases in bone cause osteolytic lesions, the osteogenic niche has commonly been described as an initiator of early-stage bone colonization of disseminated cancer cells. Tumor cell-derived extracellular vesicles (EV) have been shown to determine the organotropism of cancer cells by transferring their cargo, such as nucleic acids and proteins, to resident cells at future metastatic sites and preparing a favorable premetastatic niche. Runt-related transcription factor 2 (RUNX2) and its regulated genes have been shown to facilitate the acquisition of osteomimetic features and to enhance the bone metastatic potential of breast cancer cells. In this study, we present in vivo and in vitro evidence to clarify the role of EVs released by breast cancer cells with high RUNX2 expression in the education of osteoblasts to form an osteogenic premetastatic niche. Furthermore, different extracellular vesicular proteins were identified that mediate events subsequent to the specific recognition of tumor-derived EVs by osteoblasts via cadherin 11 (CDH11) and the induction of the osteogenic premetastatic niche by integrin α5 (ITGA5). CDH11high/ITGA5high EVs were demonstrated to be responsible for the formation of a premetastatic niche that facilitates RUNX2 high-expressing breast cancer cell colonization in bone, revealing a potential EV-based premetastatic niche blockage strategy.

SIGNIFICANCE

This study provides mechanistic insights into the generation of an osteogenic premetastatic niche by breast cancer-derived EVs and identifies potential EV-derived diagnostic biomarkers and targets for breast cancer bone metastasis.

Advances of nanomedicines in breast cancer metastasis treatment targeting different metastatic stages

Breast cancer is the most common tumor in women, and the metastasis further increases the malignancy with extremely high mortality. However, there is almost no effective method in the clinic to completely inhibit breast cancer metastasis due to the dynamic multistep process with complex pathways and scattered occurring site. Nowadays, nanomedicines have been evidenced with great potential in treating cancer metastasis. In this review, we summarize the latest research advances of nanomedicines in anti-metastasis treatment. Strategies are categorized according to the metastasis dynamics, including primary tumor, circulating tumor cells, pre-metastatic niches and secondary tumor. In each different stage of metastasis process, nanomedicines are designed specifically with different functions. At the end of the review, we give our perspectives on current limitations and future directions in anti-metastasis therapy. We expect the review provides comprehensive understandings of anti-metastasis therapy for breast cancer, and boosts the clinical translation in the future to improve women's health.

The Key Role of Exosomes on the Pre-metastatic Niche Formation in Tumors

Exosomes or other extracellular vesicles released from cells play an important role in cell-to-cell communication by transferring bio-information (DNA, coding/non-coding RNA, and proteins), which indicates parental cell status to recipient cells in the extracellular environment. Increasingly, evidence shows that tumor-derived exosomes mediate tumor pre-metastatic niche (PMN) remodeling to establish a supportive and receptive niche to promote tumor cell colonization and metastasis. Uptake of genetic information by target cells in the extracellular environment triggers epigenetic changes that contribute to PMN formation. Here, we provide a comprehensive overview of the current understanding of exosomes-mediated reprogramming of cells in PMN formation.

Plasma Membrane Receptors Involved in the Binding and Response of Osteoclasts to Noncellular Components of the Bone

Osteoclasts differentiate from hematopoietic cells and resorb the bone in response to various signals, some of which are received directly from noncellular elements of the bone. In vitro, adherence to the bone triggers the reduction of cell–cell fusion events between osteoclasts and the activation of osteoclasts to form unusual dynamic cytoskeletal and membrane structures that are required for degrading the bone. Integrins on the surface of osteoclasts are known to receive regulatory signals from the bone matrix. Regulation of the availability of these signals is accomplished by enzymatic alterations of the bone matrix by protease activity and phosphorylation/dephosphorylation events. Other membrane receptors are present in osteoclasts and may interact with as yet unidentified signals in the bone. Bone mineral has been shown to have regulatory effects on osteoclasts, and osteoclast activity is also directly modulated by mechanical stress. As understanding of how osteoclasts and other bone cells interact with the bone has emerged, increasingly sophisticated efforts have been made to create bone biomimetics that reproduce both the structural properties of the bone and the bone’s ability to regulate osteoclasts and other bone cells. A more complete understanding of the interactions between osteoclasts and the bone may lead to new strategies for the treatment of bone diseases and the production of bone biomimetics to repair defects.

Identification of CD105+ Extracellular Vesicles as a Candidate Biomarker for Metastatic Breast Cancer

BACKGROUND

Extracellular vehicles (EVs) released by malignant tumor cells can mediate the immune response and promote metastasis through intercellular communication. EV analysis is an emerging cancer surveillance tool with advantages over traditional liquid biopsy methods. The aim of this pilot study is to identify actionable EV signatures in metastatic breast cancer.

MATERIALS AND METHODS

Under an IRB-approved protocol for the analysis of patient plasma, samples were collected from women with newly diagnosed or progressive metastatic breast cancer and from women without cancer. Enriched EVs were analyzed via a bead-based multiplex assay designed to detect 37 distinct tumor-relevant epitopes. The mean fluorescent intensity of EV epitopes meeting a minimum threshold of detectability was compared between groups via independent samples t-test. Subgroup analysis was conducted for metastatic breast cancer patients who were positive for estrogen and/or progesterone receptors and negative for HER2. Other variables potentially affecting CD105 levels were also analyzed.

RESULTS

CD105 was found to have a significantly higher mean fluorescent intensity in participants with metastatic breast cancer compared to control participants (P = 0.04). ER/PR+ subgroup analysis revealed a similar pattern compared to control participants (P = 0.01). Other analyzed variables were not found to have a significant correlation with CD105 levels.

CONCLUSIONS

CD105 EV levels were significantly higher in samples from participants with breast cancer compared to controls. Given that CD105 is known to mediate angiogenesis and promote metastasis, EV-associated CD105 in plasma represents a potential biomarker for diagnosis, surveillance and therapeutic targeting in patients with metastatic breast cancer.

Tumor Cell-Derived Exosomal miR-770 Inhibits M2 Macrophage Polarization via Targeting MAP3K1 to Inhibit the Invasion of Non-small Cell Lung Cancer Cells

Background

Non-small cell lung carcinoma (NSCLC) is a type lung cancer with high malignant behaviors. MicroRNAs (miRNAs) are known to be involved in progression of NSCLC. In order to explore potential targets for the treatment of NSCLC, bioinformatics tool was used to analyze differential expressed miRNAs between NSCLC and adjacent normal tissues.

Methods

Bioinformatics tool was used to find potential targets for NSCLC. Cell proliferation was investigated by Ki67 staining. Cell apoptosis was measured by flow cytometry. mRNA and protein expression in NSCLC cells were detected by RT-qPCR and Western-blot, respectively. Transwell assay was performed to test the cell migration and invasion. In order to investigate the function of exosomal miRNA in NSCLC, in vivo model of NSCLC was constructed.

Results

MiR-770 was identified to be downregulated in NSCLC, and miR-770 agomir could significantly inhibit NSCLC cell proliferation through inducing the apoptosis. Additionally, the metastasis of NSCLC cells was decreased by miR-770 agomir. MAP3K1 was identified to be the target mRNA of miR-770. Meanwhile, tumor cell-derived exosomal miR-770 inhibited M2 macrophage polarization via downregulation of MAP3K1, which in turn suppressed NSCLC cell invasion. Besides, tumor cell-derived exosomal miR-770 markedly decreased NSCLC tumor growth in vivo through suppressing M2 macrophage polarization.

Conclusion

Tumor cell-derived exosomal miR-770 inhibits M2 macrophage polarization to inhibit the invasion of NSCLC cells via targeting MAP3K1. Thus, this study provided a new strategy for the treatment of NSCLC.

Tumor-derived Exosome Promotes Metastasis via Altering its Phenotype and Inclusions

Although tumor-derived exosomes play an important role in the process of metastasis, differences in exosomes secreted by the same cells at different stages or conditions have not been noticed by most of the relevant researchers. Here we developed a lung cancer model in nude mice, and the phenotype and inclusions of exosomes secreted by early and advanced tumors were analysed. The size distribution and surface topography of these two exosomes were not significantly different, but the expression of CD63 in early tumor exosome (E-exosome) was significantly lower than that in advanced tumor exosome (A-exosome). α-SMA expression on HELF cells treated with A-exosome was significantly higher than that treated with E-exosome. The ability of A-exosome to promote the migration of A549 cells was better than E-exosome. Furthermore, small RNA sequence showed that only 3 of the 171 detected-small RNAs were expressed simultaneously in both exosomes. These findings proved that there are significant differences in inclusions and functions between the early and late exosomes of the same tumor. The study highlights the importance of exosomes in cancer metastasis, and might suggest exosomes can be used as biomarkers and therapeutic targets for cancer metastasis.