Stimulation of metastatic activity of breast cancer cells by plasma exosomes
Background. Malignant phenotype of cancer cells and metastatic potency of the tumor are determined by genetic factors. In addition, normal biological environment, including the nano-vesicles or exosomes, plays an important role in regulation of the structural and functional characteristics of malignant cells. Objective: presented study was aimed to evaluate mechanisms and to estimate effect of interaction of plasma exosomes and breast cancer cells in experimental conditions. Materials and methods. We used breast cancer cell culture MDA-MB-231 and exosomes isolated from plasma and cultural medium. Exosomes were analyzed by dynamic light scattering method and western blotting. Functional effects of exosomes were evaluated in in vitro and in vivo models. Results. In the present study we demonstrated that plasma exosomes stimulate the adhesion and the motility of breast cancer cells and induce the process of metastatic dissemination. Contact interaction of exosomes with cell surface is sufficient for stimulatory effect that is mediated by exosomal fibronectin and FAK-dependent signaling cascade. Conclusions. Further investigation of plasma exosomes structure and functions is required to better understand their input in regulation of malignant cell phenotype. This research has a potential to provide novel approaches for cancer therapy.