The Comparison of Exosome and Exosomal Cytokines between Young and Old Individuals with or without Gastric Cancer

Abstract

Summary: Background: Exosomes are small extracellular vesicles secreted by various types of cells. Exosomes play an important role in intercellular communication by serving as vehicles for transferring proteins, lipids, mRNAs, microRNAs, and DNAs to recipient cells. This study investigated the role of exosomes in gastric cancer and the aging process by using a large number of human serum samples from young and aged individuals with or without gastric cancer. Methods: The age- and cancer-associated changes in exosome levels and exosomal cytokine content were measured. Exosomes in human serum were isolated by using a total exosome isolation reagent, followed by a quantification of isolated exosomes using a MicroBCA assay. Exosomal cytokines were measured by ELISA. Results: Serum exosome levels are increased by cancer and aging. Exosomal levels of TNF-α and TGF-β are increased, whereas IL-10 levels are reduced in gastric cancer. In addition, the cancer-associated changes in exosomal cytokines remain constant with age, even though aging affects every type of immune cells and immunomodulating factors. Conclusion: Gastric cancer and aging affect serum exosome and exosomal cytokines levels. Future studies would require the analysis of more diverse cytokines in exosomes derived from multiple types of cancer. Keywords: exosome, microvesicle, aging, cancer, cytokine