Proteomic analysis of extracellular vesicles shed in vitro by MDA MB 231 breast carcinoma cells

Cross talk between tumor cells and connective tissue plays a key role in tumor progression. The communication is due to the release of signalling molecules from both tumor cells and surrounding stromal cells. Several secreted proteins lack the N-terminal signal peptides and, therefore, they are secreted by alternative unconventional processes such as secretion mechanism mediated by vesicle shedding in the extracellular matrix. Actually, a certain number of proteins, playing roles in some aspects of tumor progression, have been found in shed vesicles. For example, EMMPRIN, carried out in vesicles shed by tumor cells, stimulates matrix metalloproteinase (MMP) production in stromal fibroblasts…

PEP-19 and LPI camstatins are RNA-binding proteins

RNA-binding CSD-C2 protein and its interactors in nerve cell differentiation

Proteomic analysis of exosome-like vesicles derived from breast cancer cells.

Background/Aim: The phenomenon of membrane vesicle-release by neoplastic cells is a growing field of interest in cancer research, due to their potential role in carrying a large array of tumor antigens when secreted into the extracellular medium. In particular, experimental evidence show that at least some of the tumor markers detected in the blood circulation of mammary carcinoma patients are carried by membrane-bound vesicles. Thus, biomarker research in breast cancer can gain great benefits from vesicle characterization. Materials and Methods: Conditioned medium was collected from serum starved MDA-MB-231 sub-confluent cell cultures and exosome-like vesicles (ELVs) were isolated by ultra…

Extracellular membrane vesicle shedding and the blood-brain barrier

A phosphate-controlled regulator for the biosynthesis of the dalbavancin precursor A40926

Dbv4 is a DNA-binding protein acting as a positive regulator of the glycopeptide antibiotic A40926 biosynthesis

PROTEOMIC ANALYSIS OF VESICLES SHED BY BREAST CANCER CELLS IN VITRO

Combining in the melt physical and biological properties of poly(caprolactone) and chlorhexidine to obtain antimicrobial surgical monofilaments.

Bacterial infections on a sutured wound represent a critical problem, and the preparation of suture threads possessing antimicrobial properties is valuable. In this work, poly(caprolactone) (PCL) monofilaments were compounded at the concentration of 1, 2 and 4 % (w/w), respectively, to the antiseptic chlorhexidine diacetate (CHX). The incorporation was carried out in the melt by a single-step methodology, i.e. “online” approach. Mechanical tests revealed that the incorporation of CHX does not significantly change tensile properties of PCL fibres as the thermal profile adopted to prepare the compounded fibres does not compromise the antibacterial activity of CHX. In fact, CHX confers to comp…

Phosphate-controlled regulators for the biosynthesis of the dalbavancin precursor A40926

Histone RNA-binding proteins in the rat brain

Proteomic profiling of vesicles released by 8701-bc cells

8701-BC cells were shown to release “membrane vesicles” playing a role in tumor progression mechanisms. On the other hand, production of “exosomes”, smaller vesicles known to be involved in immune response activation, had not been revealed. The first goal of this study was to separate different vesicle populations from 8701-BC cell conditioned medium. To this aim, the medium was differentially centrifuged. Western analysis revealed that the 15,000xg pelletted fraction contains β1-integrin, which had been shown to be clustered in membrane vesicles shed by 8701-BC cells, but not Hsc70, a protein found in exosomes. On the contrary, Hsc70 is detectable while β1-integrin is not present in the fr…

Shedding of extracellular membrane vesicles from both normal and tumor cells in culture

Tumor cells of different origins shed extracellular membrane vesicles (MVs), that contain angiogenetic- and pro-apoptotic-factors as well as matrix metalloproteases (MMPs). In addition, also neurons and astrocytes in culture produce VEGF- and FGF2- containing MVs, while oligodendroglioma (G26/24) cells release FasL-containing MVs that inhibit neurite sprouting and cause neuronal apoptosis. Starting from these observations, we have been analyzing composition of MVs produced by both normal and tumor cells in culture. We found that MVs from G26/24 cells contain TRAIL, Hsp70, and VEGF. We also traced the route of shed MVs, by adding vesicles that contain 35S-labeled proteins to unlabeled neuron…