Search results for "Microvesicles"
showing 10 items of 173 documents
An active form of sphingosine kinase-1 is released in the extracellular medium as component of membrane vesicles shed by two human tumor cell line.
2010
Expression of sphingosine kinase-1 (SphK-1) correlates with a poor survival rate of tumor patients. This effect is probably due to the ability of SphK-1 to be released into the extracellular medium where it catalyzes the biosynthesis of sphingosine-1-phosphate (S1P), a signaling molecule endowed with profound proangiogenic effects. SphK-1 is a leaderless protein which is secreted by an unconventional mechanism. In this paper, we will show that in human hepatocarcinoma Sk-Hep1 cells, extracellular signaling is followed by targeting the enzyme to the cell surface and parallels targeting of FGF-2 to the budding vesicles. We will also show that SphK-1 is present in a catalitycally active form i…
Pathogens and extracellular vesicles: New paths and challenges to understanding and treating diseases
2021
Extracellular vesicles (EVs) have been described in all eukaryotic and prokaryotic cells as released membranous structures loaded with biomolecules including nucleic acids, glycoconjugates, lipids and proteins. Two main groups of vesicles with different biogenesis and size are considered to be the most predominant, Exosomes (30-100 nm) originating from multivesicular bodies, and microvesiculas (100-1000 nm) originating from plasma membrane. EVs participate in cellular communication between different organisms and can alter neighbour cells, participating in physiological and pathophysiological processes. In this issue, eleven reviews summarize the current knowledge in the characterization of…
Exosome-associated polysialic acid modulates membrane potentials, membrane thermotropic properties, and raft-dependent interactions between vesicles.
2020
In mammals, polysialic acid (polySia) attached to a small number of transmembrane protein carriers occurs on the surface of plasma membranes of neural, cancer, immune, and placental trophoblast cells. Here, our goal was to demonstrate the presence of polySia on exosomes and its effect on membrane properties. We isolated exosomes and found that polysialylated exosomes in fetal bovine serum originate mostly from placental trophoblasts, while in calf bovine serum, they originate from immune cells. Enzymatic removal of polySia chains from the exosomal surface makes the membrane surface potential more positive, transmembrane potential more negative, and reduces the activation energy for membrane…
Applying extracellular vesicles based therapeutics in clinical trials - an ISEV position paper.
2015
Extracellular vesicles (EVs), such as exosomes and microvesicles, are released by different cell types and participate in physiological and pathophysiological processes. EVs mediate intercellular communication as cell-derived extracellular signalling organelles that transmit specific information from their cell of origin to their target cells. As a result of these properties, EVs of defined cell types may serve as novel tools for various therapeutic approaches, including (a) anti-tumour therapy, (b) pathogen vaccination, (c) immune-modulatory and regenerative therapies and (d) drug delivery. The translation of EVs into clinical therapies requires the categorization of EV-based therapeutics …
CD90+ liver cancer cells modulate endothelial cell phenotype through the release of exosomes containing H19 lncRNA
2015
Background CD90+ liver cancer cells have been described as cancer stem-cell-like (CSC), displaying aggressive and metastatic phenotype. Using two different in vitro models, already described as CD90+ liver cancer stem cells, our aim was to study their interaction with endothelial cells mediated by the release of exosomes. Methods Exosomes were isolated and characterized from both liver CD90+ cells and hepatoma cell lines. Endothelial cells were treated with exosomes, as well as transfected with a plasmid containing the full length sequence of the long non-coding RNA (lncRNA) H19. Molecular and functional analyses were done to characterize the endothelial phenotype after treatments. Results …
Role of exosomes released by chronic myelogenous leukemia cells in angiogenesis
2012
The present study is designed to assess if exosomes released from Chronic Myelogenous Leukemia (CML) cells may modulate angiogenesis. We have isolated and characterized the exosomes generated from LAMA84 CML cells and demonstrated that addition of exosomes to human vascular endothelial cells (HUVEC) induces an increase of both ICAM-1 and VCAM-1 cell adhesion molecules and interleukin-8 expression. The stimulation of cell-cell adhesion molecules was paralleled by a dose-dependent increase of adhesion of CML cells to a HUVEC monolayer. We further showed that the treatment with exosomes from CML cells caused an increase in endothelial cell motility accompanied by a loss of VE-cadherin and β-ca…
Osteosarcoma cell-derived exosomes affect tumor microenvironment by specific packaging of microRNAs
2018
Abstract Bone microenvironment provides growth and survival signals essential for osteosarcoma (OS) initiation and progression. OS cells regulate communications inside tumor microenvironment through different ways and, among all, tumor-derived exosomes support cancer progression and metastasis. To define the contribution of OS-derived exosomes inside the microenvironment, we investigated the effects induced in bone remodeling mechanism and tumor angiogenesis. We demonstrated that exosomes promoted osteoclasts differentiation and bone resorption activity. Furthermore, exosomes potentiated tube formation of endothelial cells and increased angiogenic markers expression. We therefore investigat…
PO-146 Multiple myeloma-derived exosomes carry amphiregulin and are responsible for the uncoupled bone remodelling
2018
Introduction Multiple myeloma (MM) is a hematologic malignancy associated with osteolytic bone disease caused by the perturbation of the functional balance between bone resorption and bone formation. Exosomes, nanosize lipoproteic structures, have been recently recognised as a new mechanism of cell to cell communication during tumour growth and progression. We have previously shown that MM-exosomes are involved in osteolytic lesions but the underlying mechanism is still understood. We hypothesise that the epidermal growth factor receptor ligand Amphiregulin (AREG) can be delivered by multiple myeloma-derived exosomes and participate in modulating the response of the bone microenvironment to…
Cell-free DNA and exoDNA analysis in metastatic colorectal cancer patients (mCRC).
2020
e16093 Background: Liquid biopsy is a growing field in translational cancer research. Two of the most studied liquid biopsy biomarkers are cell-free DNA (cfDNA) and exosomes, nano-sized vesicles that transport protein and nucleic acids including DNA (exoDNA). Therefore, both cfDNA and exoDNA are potentially useful to investigate the molecular landscape of tumor with a minimally invasive approach. Here we investigate the prognostic and predictive role of both cfDNA and exoDNA in mCRC using Next Generation Sequencing (NGS) analysis. Methods: From July 2017 to September 2018, samples of 40 mCRC patients were collected at the Medical Oncology of the AOUP Paolo Giaccone of Palermo. Blood sample…
Exosomal shuttling of miR-126 in endothelial cells modulates adhesive and migratory abilities of chronic myelogenous leukemia cells.
2014
BACKGROUND: Recent findings indicate that exosomes released from cancer cells contain microRNAs (miRNAs) that may be delivered to cells of tumor microenvironment. RESULTS: To elucidate whether miRNAs secreted from chronic myelogenous leukemia cells (CML) are shuttled into endothelial cells thus affecting their phenotype, we first analysed miRNAs content in LAMA84 exosomes. Among the 124 miRNAs identified in LAMA84 exosomes, we focused our attention on miR-126 which was found to be over-overexpressed in exosomes compared with producing parental cells. Transfection of LAMA84 with Cy3-labelled miR-126 and co-culture of leukemia cells with endothelial cells (EC) confirmed that miR-126 is shuttl…