The discovery of an early detection biomarker for advancing disease like cancer is one of the major diagnostic challenges in medicine. Exosomes are microvesicles that are secreted by almost all cells and contain a cargo of DNA, RNA, and/or protein that is not only characteristic of their cell of origin but also capable of functionally impacting target cells and tissues. In this study, we utilized two sources of liquid biopsy to isolate and profile exosomes and perform molecular profiling potential relevant to cancer diagnostics. Using differential immuno-electron and atomic force microscopy, we have identified multiple structurally distinct subtypes of microvesicles and exosomes present in bronchial washings. We have also characterized the patterns of protein contained biomarkers associated with the unique class of exosomes identified in pulmonary washings. We have been able to identify at least three potential biomarkers potentially diagnostic of lung cancer from exosomes obtained with bronchial lavage. Lastly, we have used a bioinformatic approach to simulate potential functional networks of protein-protein interactions and determine how these protein cargoes of pulmonary exosomes impact adjacent pulmonary tissues and determine whether protein expression in specific subtypes of exosomes provides a predictive model of the current cancer state, remotely. Our results led us to conclude that the isolation of exosomes from liquid biopsy offers enormous potential to improve the diagnostic and prognostic capacity of liquid biopsy and their promise to revolutionize diagnostic medicine.

Citation Format: Ahmed Fadiel, Nirmal Sharma, Matthew L. Anderson. Standardized exosome isolation and profiling for biomarker discovery [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B52.