Cisplatin-based chemotherapy is frequently used to treat advanced gastric cancer (GC). However, the resistance often occurs with the mechanisms being not well understood. Recently, emerging evidence indicates that tumor-associated macrophages (TAMs) play an important role in chemoresistance of cancer. As the important mediators in intercellular communications, exosomes secreted by host cells mediate the exchange of genetic materials and proteins to be involved in tumor aggressiveness. The aim of the study was to investigate whether exosomes derived from TAMs mediate cisplatin resistance in gastric cancer. M2 polarized macrophages were obtained from mouse bone marrow or human PBMCs stimulated with IL-4 and IL-13. Exosomes isolated from M2 macrophages culture medium were characterized, and miRNA expression profiles of M2 derived exosomes (M2-exos) were analyzed using miRNA microarray. In vitro cell coculture was further conducted to investigate M2-exos mediated crosstalk between TAMs and tumor cells. Moreover, the in vivo experiments were performed using a subcutaneous transplantation tumor model in athymic nude mice. In this study, we showed that M2 polarized macrophages promoted cisplatin (DDP) resistance in gastric cancer cells and exosomes derived from M2 macrophages (M2-exos) are involved in mediating the resistance to DDP. Using miRNA profiles assay, we identify significantly higher levels of microRNA-21 (miR21) isomiRNAs in exosomes and cell lysate isolated from M2 polarized macrophage. Functional studies revealed that exosomal miR-21 can be directly transferred from macrophages to the gastric cancer cells, where it suppresses cell apoptosis and enhances activation of PI3K/AKT signaling pathway by down-regulation of PTEN. Our findings suggest that exosomal transfer of tumor-associated macrophages derived miR-21 confer DDP resistance in gastric cancer, and targeting exosome communication may be a promising new therapeutic strategy for gastric cancer patients.

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Exosomal transfer of tumor-associated macrophage-derived miR-21 confers cisplatin resistance in gastric cancer cells

The similarities between exosomes and liposomes, together with the high organotropism of several types of exosomes, have recently prompted the development of engineered-exosomes or exosome-mimetics, which may be artificial (liposomal) or cell-derived vesicles, as advanced platforms for targeted drug delivery. Here, we provide the current state-of-the-art of using exosome or exosome-inspired systems for drug delivery. We review the various approaches investigated and the shortcomings of each approach. Finally the challenges which have been identified to date in this field are summarized.

https://www.mdpi.com/1999-4923/10/4/218/pdf

Exosomes and Exosome-Inspired Vesicles for Targeted Drug Delivery

Extracellular vesicles (EVs) are under evaluation as therapeutics or as vehicles for drug delivery. Preclinical studies of EVs often use mice or other animal models to assess efficacy and disposition. However, as most EVs under evaluation are derived from human cells, they may elicit immune responses which may contribute to toxicities or enhanced EV clearance. Furthermore, EVs from different cell sources or EVs comprising various cargo may differ with respect to immunogenicity or toxicity. To assess EV-induced immune response and toxicity, we dosed C57BL/6 mice with EVs intravenously and intraperitoneally for 3 weeks. EVs were harvested from wild type or engineered HEK293T cells which were modified to produce EVs loaded with miR-199a-3p and chimeric proteins. Blood was collected to assess hematology, blood chemistry, and immune markers. Spleen cells were immunophenotyped, and tissues were harvested for gross necropsy and histopathological examination. No signs of toxicity were observed, and minima...

https://www.tandfonline.com/doi/pdf/10.1080/20013078.2017.1324730

Comprehensive toxicity and immunogenicity studies reveal minimal effects in mice following sustained dosing of extracellular vesicles derived from HEK293T cells

Sorafenib is a multikinase inhibitor capable of facilitating apoptosis, mitigating angiogenesis and suppressing tumor cell proliferation. In late-stage hepatocellular carcinoma (HCC), sorafenib is currently an effective first-line therapy. Unfortunately, the development of drug resistance to sorafenib is becoming increasingly common. This study aims to identify factors contributing to resistance and ways to mitigate resistance. Recent studies have shown that epigenetics, transport processes, regulated cell death, and the tumor microenvironment are involved in the development of sorafenib resistance in HCC and subsequent HCC progression. This study summarizes discoveries achieved recently in terms of the principles of sorafenib resistance and outlines approaches suitable for improving therapeutic outcomes for HCC patients.

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The mechanisms of sorafenib resistance in hepatocellular carcinoma: theoretical basis and therapeutic aspects

Metastasis is the main cause of lung cancer mortality. Bone marrow-derived mesenchymal stem cells (BMSCs) are a component of the cancer microenvironment and contribute to cancer progression. Intratumoral hypoxia affects both cancer and stromal cells. Exosomes are recognized as mediators of intercellular communication. Here, we aim to further elucidate the communication between BMSC-derived exosomes and cancer cells in the hypoxic niche. Exosomal miRNA profiling was performed using a microRNA array. Lung cancer cells and an in vivo mouse syngeneic tumor model were used to evaluate the effects of select exosomal microRNAs. Hypoxic BMSC-derived plasma exosomal miRNAs were assessed for their capacity to discriminate between cancer patients and non-cancerous controls and between cancer patients with or without metastasis. We demonstrate that exosomes derived from hypoxic BMSCs are taken by neighboring cancer cells and promote cancer cell invasion and EMT. Exosome-mediated transfer of select microRNAs, including miR-193a-3p, miR-210-3p and miR-5100, from BMSCs to epithelial cancer cells activates STAT3 signaling and increases the expression of mesenchymal related molecules. The diagnostic accuracy of individual microRNA showed that plasma exosomal miR-193a-3p can discriminate cancer patients from non-cancerous controls. A panel of these three plasma exosomal microRNAs showed a better diagnostic accuracy to discriminate lung cancer patients with or without metastasis than individual exosomal microRNA. Exosome-mediated transfer of miR-193a-3p, miR-210-3p and miR-5100, could promote invasion of lung cancer cells by activating STAT3 signalling-induced EMT. These exosomal miRNAs may be promising noninvasive biomarkers for cancer progression.

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Hypoxic BMSC-derived exosomal miRNAs promote metastasis of lung cancer cells via STAT3-induced EMT

Hypoxia is a common feature of many solid tumors, including hepatocellular carcinoma (HCC) Hypoxia can promote tumor progression and induce radiation and chemotherapy resistance As one of the major mediators of hypoxic response, hypoxia inducible factor-1 (HIF-1) has been shown to activate hypoxia-responsive genes, which are involved in multiple aspects of tumorigenesis and cancer progression, including proliferation, metabolism, angiogenesis, invasion, metastasis and therapy resistance It has been demonstrated that a high level of HIF-1 in the HCC microenvironment leads to enhanced proliferation and survival of HCC cells Accordingly, overexpression, of HIF-1 is associated with poor prognosis in HCC In this review, we described the mechanism by which HIF-1 is regulated and how HIF-1 mediates the biological effects of hypoxia in tissues We also summarized the latest findings concerning the role of HIF-1 in the development of HCC, which could shed light on new therapeutic approaches for the treatment of HCC

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The Role of Hypoxia Inducible Factor-1 in Hepatocellular Carcinoma

Exosomes are carriers of intercellular information and regulate the tumor microenvironment. They play an important role in drug resistance by transporting RNA molecules and proteins. However, their effects on sorafenib resistance in hepatocellular carcinoma (HCC) are not completely understood. Exosomes were isolated from two invasive hepatoma cell lines (MHCC-97 L and MHCC-97H), and their roles in regulating sorafenib resistance in liver cancer cells as well as the underlying molecular mechanisms were determined. The exosomes were analyzed by TEM (transmission electron microscopy), DLS (dynamic light scattering) and Western blotting. Cell viability, cell death and the effects of exosomes on the HGF/c-Met/Akt signaling pathway in cancer cells were analyzed by MTT assays, FACS analysis and Western blotting, respectively. Moreover, the effects of exosomes on sorafenib resistance in vivo were investigated using a subcutaneous transplantation tumor model in athymic nude mice. Exosomes derived from HCC cells were of the expected size and expressed the exosomal markers CD9 and CD63. They induced sorafenib resistance in vitro by activating the HGF/c-Met/Akt signaling pathway and inhibiting sorafenib-induced apoptosis. They also induced sorafenib resistance in vivo by inhibiting sorafenib-induced apoptosis. Moreover, exosomes derived from highly invasive tumor cells had greater efficacy than that of exosomes derived from less invasive cells. These data reveal the important role of HCC cell-derived exosomes in the drug resistance of liver cancer cells and demonstrate the intrinsic interaction between exosomes and their targeted tumor cells. This study suggests a new strategy for improving the effectiveness of sorafenib in treating HCC.

/pdf/exosomes-derived-from-hcc-cells-induce-sorafenib-resistance-pa0ni106c7.pdf

Exosomes derived from HCC cells induce sorafenib resistance in hepatocellular carcinoma both in vivo and in vitro

// Zhen Qu 1, 3, * , Junhua Wu 2, * , Junyi Wu 1, 2 , Anlai Ji 4, 5 , Guanghui Qiang 2, 5 , Yong Jiang 3 , Chunping Jiang 1 and Yitao Ding 1 1 Department of Hepatobiliary Surgery, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu Province, China 2 Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, Jiangsu Province, China 3 Department of Hepatobiliary Surgery, The First People's Hospital of Changzhou, The Third Hospital Affiliated to Soochow University, Changzhou, Jiangsu, China 4 Department of General Surgery, The Affiliated Hospital of Yangzhou University, Yangzhou, Jiangsu, China 5 Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, Jiangsu Province, China * These authors contributed equally to this work Correspondence to: Yong Jiang, email: yjiang8888@hotmail.com Chunping Jiang, email: chunpingjiang@163.com Yitao Ding, email: drdingyitao0@sina.com Keywords: HCC, exosomal miRNA-665, biomarker, ERK, tumor growth Received: April 13, 2017      Accepted: August 26, 2017      Published: September 14, 2017 ABSTRACT Recent studies have shown that circulating microRNAs are potential biomarkers for various types of malignancies. The aim of this study was to investigate the feasibility of using serum exosomal microRNAs (miRNAs) as novel serological biomarkers for hepatocellular carcinoma (HCC) diagnosis and prognosis. Exosomes are small membranous vesicles (30–100 nm). Exosomal miR-665 levels in HCC patients were significantly higher than those in healthy subjects ( P 5 cm), in tumours with local invasion and in those at an advanced clinical stage (stage III/IV) of HCC ( P = 0.0042, 0.0197, and 0.0276, respectively). The survival time of the exosomal miR-665 high-expression group ( n = 17) was significantly shorter than that of the low-expression group ( n = 13) ( P = 0.036). In addition, we found that HCC cell-derived exosomes promoted hepatoma cell proliferation and upregulated the expression level of proteins in the MAPK/ERK pathway in vitro and in vivo . This study suggests that serum exosomal miR-665 may be a novel minimally invasive biomarker for HCC diagnosis and prognosis.

/pdf/exosomal-mir-665-as-a-novel-minimally-invasive-biomarker-for-216y17fz1e.pdf

Exosomal miR-665 as a novel minimally invasive biomarker for hepatocellular carcinoma diagnosis and prognosis.

The liver has great regenerative capacity after functional mass loss caused by injury or disease. Many studies have shown that primary hepatocyte-derived exosomes, which can deliver biological information between cells, promote the regenerative process of the liver. However, the yield of exosomes is very limited. Recent studies have demonstrated that exosome-mimetic nanovesicles (NVs) can be prepared from cells with almost 100 times the production yield compared with exosomes. Thus, this study investigated the therapeutic capacity of exosome-mimetic NVs from primary hepatocytes in liver regeneration. Exosome-mimetic NVs were prepared by serial extrusions of cells through polycarbonate membranes, and the yield of these NVs was more than 100 times that of exosomes. The data indicated that the NVs could promote hepatocyte proliferation and liver regeneration by significantly enhancing the content of sphingosine kinase 2 in recipient cells. To the best of our knowledge, this is the first time that exosome-mimetic NVs from primary hepatocytes have been prepared, and these NVs have components similar to exosomes from primary hepatocytes and, in some respects, biofunctions similar to exosomes. Strategies inspired by this study may lead to substitution of exosomes with exosome-mimetic NVs for biofunctional purposes, including utilization in tissue repair and regeneration.

/pdf/exosome-mimetic-nanovesicles-from-hepatocytes-promote-4e950n8yfp.pdf

Exosome-Mimetic Nanovesicles from Hepatocytes promote hepatocyte proliferation in vitro and liver regeneration in vivo.

Exosomes are small, extracellular membrane- enclosed vesicles that contain a variety of molecules, including proteins, DNA, mRNA and non-coding RNA; these vesicles have been defined as new tools for intercellular communication between cells. Numerous types of cells, including stem cells, secrete exosomes into the extracellular environment, and are significant communicators in the tumor microenvironment. Stem cells are a unique cell population defined by their ability to indefinitely self-renew, differentiate into a variety of cell lines, and form clonal cell populations. Stem cells also secrete large amounts of exosomes, which have demonstrated great potential in a variety of diseases. Increasing evidence has revealed that the mechanism of interaction between stem cells and human tumor cells involves the exchange of biological material through exosomes. In this review, the latest developments in the role of stem cell-derived exosomes in cancer are highlighted.

/pdf/role-of-stem-cell-derived-exosomes-in-cancer-review-2opops2p8a.pdf

Junyi Wu

Papers

The Role of Hypoxia Inducible Factor-1 in Hepatocellular Carcinoma

Exosomes derived from HCC cells induce sorafenib resistance in hepatocellular carcinoma both in vivo and in vitro

Exosomal miR-665 as a novel minimally invasive biomarker for hepatocellular carcinoma diagnosis and prognosis.

Exosome-Mimetic Nanovesicles from Hepatocytes promote hepatocyte proliferation in vitro and liver regeneration in vivo.

Role of stem cell-derived exosomes in cancer (Review)