Journal of Molecular Biomarkers & Diagnosis

Enigmatic Exosomes: Role in health and disease with significance in cancer

Abstract

Nandini DB, Deepak BS, Nachiammai N and Madhushankari GS

Exosomes are small membrane derived vesicles secreted by a variety of mammalian cells during normal and pathologic conditions which are actively involved in conferring intercellular signals. They are enriched with mRNA, micro RNA, lipids and other cellular proteins which can be isolated from various body fluids. Recently their role as potential biomarkers is gained a lot of attention. Exosomes can reveal the cell of origin and the condition of the cell as well. Their role as biomarkers in diseases like Alzheimer’s, brain tumors, chronic kidney disease, salivary gland diseases, breast cancer has been already established. Role of tumor derived exosomes in cancer progression, metastasis and drug resistance is widely discussed at present times. In contrast, exosomes from healthy cells of the immune system appear to have anti-tumor characteristics. Anti-tumor therapies based on exosomes, for example, by blocking the formation of tumor-derived exosomes or having exosomes release therapeutic agents at specific sites is being explored. The use of exosomes from dendritic cells in tumor vaccination, the safety of which has been demonstrated in phase I studies. Salivary exosomes can be relevant diagnostic, prognostic and predictive biomarkers in oral diseases especially oral cancer. Exosomes isolated from cells infected with various intracellular pathogens, including Mycobacterium tuberculosis and Toxoplasma gondii, have been shown to contain microbial components and can promote antigen presentation and macrophage activation, suggesting that exosomes may function in immune surveillance. Their role in forensic analysis is also being explored. On the other hand, exosome mediated drug expulsion has led to drug resistance thus hindering the therapy.