DEVELOPMENT OF CANCER DIAGNOSTICS AND MONITORING METHODS BASED ON ANALYSIS OF TUMOR-DERIVED EXOSOMES

Abstract

Exosomes are small (80 - 130 nm) membrane vesicles secreted by virtually all cell types. The main physiological function of exosomes is considered to transfer substance and information from cell to cell. The biochemical composition of exosomes retains similarities with the cell of origin and reflects their endosomal biogenesis; moreover exosomes contain various signaling and regulatory molecules, components of the extracellular matrix and enzymes. Malignant transformation is associated with the activation of the exosomes secretion by cells. Cancer cell - derived exosomes are shown to play essential role in disease progression. The most significant effects of exosomes include suppression of anti-tumor immunity, stimulation of invasive growth and metastasis, the development of chemo- resistance. Tumor-derived exosomes can be detected in biological fluids, including blood. Exosomes are biochemically stable, their complex composition determines the possibility of comprehensive analysis. Thus, circulating exosomes have emerged as a promising source of cancer diagnostics material as it was demonstrated by number of studies. Although many substantial and methodological questions still remain to be addressed. This review briefly summarizes the current concepts of exosomes biology and discusses the main methodological aspects of exosomes research. Results of recent investigations aimed to develop new methods for cancer diagnosis and monitoring based on the analysis of exosomes and exosomal components are presented in great details.