Functional Properties of Circulating Exosomes Mediated by Surface-Attached Plasma Proteins.

Background: Exosomes and other types of extracellular vesicles present an important component of circulating plasma. Exosomes released by endothelial and blood cells account for majority of plasma exosomal population; exosomes secreted by other cells might cross tissue-plasma barrier and reach circulating plasma as well. Definitely, exosomes of different cellular origins are different by content and function.

Plasma exosomes stimulate breast cancer metastasis through surface interactions and activation of FAK signaling.

Purpose: The interaction between malignant cells and surrounding healthy tissues is a critical factor in the metastatic progression of breast cancer (BC). Extracellular vesicles, especially exosomes, are known to be involved in inter-cellular communication during cancer progression. In the study presented herein, we aimed to evaluate the role of circulating plasma exosomes in the metastatic dissemination of BC and to investigate the underlying molecular mechanisms of this phenomenon.

Variety and Dynamics of Proteoforms in the Human Proteome: Aspects of Markers for Hepatocellular Carcinoma.

We have previously developed an approach, where two-dimensional gel electrophoresis (2DE) was used, followed by sectional analysis of the whole gel using high-resolution nano-liquid chromatography-mass spectrometry (ESI LC-MS/MS). In this study, we applied this approach on the panoramic analysis of proteins and their proteoforms from normal (liver) and cancer (HepG2) cells. This allowed us to detect, in a single proteome, about 20,000 proteoforms coded by more than 4000 genes.

A semi-virtual two dimensional gel electrophoresis: IF-ESI LC-MS/MS.

A method for increasing the productivity of ESI LC-MS/MS (electrospray ionization-liquid chromatography-tandem mass spectrometry) was proposed and applied. After IF (isoelectric focusing) of the sample using IPG (immobilized pH gradient) strip, the strip was cut to sections, and every section was treated according to trypsinolysis protocol for MS/MS analysis. The peptides produced were further analyzed by ESI LC-MS/MS.