Exosomes: Insights and therapeutic applications in cancer

Abstract

Cancer refers to the division of abnormal cells at an uncontrollable rate that possesses the ability to infiltrate and destroy normal tissues. It frequently spreads to normal tissues throughout the body, a condition known as metastasis, which is a significant concern. It is the second leading cause of mortality globally and treatment therapy can assist in improving survival rates. Exosomes are the extracellular vesicles secreted by several cells that act as messengers between cells. When engineered, exosomes act as promising drug delivery vehicles that help achieve targeted action at the tumour site and reduce the limitations of conventional treatments such as castration, chemotherapy, radiation, etc. The present review provides an overview of exosomes, the biogenesis, sources, isolation methods and characterization. The current status and applications of chemotherapeutic agents loaded, engineered exosomes in cancer treatment were convoluted.

Keywords: Cancer chemotherapy; Clinical trials; Drug delivery; Exosomes; Targeted drug delivery.

Graphical abstract

Fig. 1

Components and cargo activity of Exosomes; exosomes harbour surface proteins such as tetraspanins, MHC receptor, G-protein coupled receptor, Transferrin receptor and lipids. Also, internal components of the exosomes include DNA, RNA, mRNA, skeletal proteins, soluble proteins and chemical drugs.

Fig. 2

Biogenesis of exosomes: Exosome biogenesis First, endocytosis can be mediated by either a clathrin-dependant or clathrin-independent pathway, which is often active at the lipid raft, which contains a variety of tumour-specific receptors and signalling proteins (e.g., growth factor receptors, oncoproteins), as well as common membrane proteins like tetraspanins. Exosome biogenesis can be accomplished in either an ESCRT-dependant or ESCRT-independent manner via the endosomal network. Exosomes (intraluminal vesicles) reveal inward budding of the multivesicular structures as a result (MVB).

Fig. 3

Characterization techniques of Exosomes.