“The term ‘liquid biopsy’ describes the fact that a simple blood sample can contain many tumor-derived molecules and even tumor cells, enabling molecular analyses similar to those possible in tumor tissue samples,” says Ulrich Rodeck, M.D., Ph.D., Professor of Dermatology, Cutaneous Biology and Radiation Oncology at Jefferson and co-lead investigator of the study.
Jefferson is a leader in liquid biopsies for cancer. Massimo Cristofanilli, M.D., Director of the Jefferson Breast Care Center at the Sidney Kimmel Cancer Center discovered in 2004 that a blood test could help to predict the prognosis of women with breast cancer. This study established that the number of circulating tumor cells in a blood sample can give doctors a quick and minimally invasive snapshot of whether a patient is likely to respond to treatment or not. In addition to circulating tumor cells, the blood also contains free-floating cancer DNA, providing researchers with an option to access treatment-relevant gene alterations in blood samples.
The new partnership between Exosome Sciences Inc. and a Jefferson team led by Dr. Rodeck, and Adam Luginbuhl, M.D., Assistant Professor of Otolaryngology Head and Neck Surgery, will focus on exosomes as a novel liquid biopsy platform. Exosomes represent a rapidly evolving frontier in liquid biopsy research. They consist of tiny bubbles or sacs pinched off the surface of cells that contain cellular contents such as RNA and proteins enclosed by the cell membrane. Recently, researchers discovered that cancer cells release large amounts of exosomes. Evidence is building that shedding these exosomes may allow a tumor to become more aggressive, to resist treatment more efficiently and, to suppress the body’s attempt to fight the cancer by dampening the cancer-specific immune response.
The team aims to collect blood samples from patients with head and neck cancer, specifically tumors in the oral cavity. Exosome Sciences will separate and characterize tumor-derived exosomes. Further molecular characterization of exosomes derived from both, tumor and normal cells will be carried out at Jefferson. The investigators will initially focus on exosome-associated RNA because RNA is abundant in exosomes and can give researchers a sampling of the genes that are currently “in-use” by a cell. The inclusion of ‘normal’ exosome analysis will provide a look at the whole picture of treatment responses encompassing not just diseased but also normal tissues. The goal is to determine whether molecular signatures correlate with and predict patient responses. In future work, exosome protein content will be included in the analysis. It is expected that diverse liquid biopsy techniques will boost the ability to track cancer development and treatment responses in real time providing critical information to adjust treatment approaches.
“Head and neck cancer is an ideal disease entity to study. We’ll be able to look at how treatments affect not only tumor behavior, but also the normal tissue based on exosomes profiles, giving us a window into tolerability of treatment,” says Dr. Luginbuhl.
Exosome Sciences is a diagnostic subsidiary of Aethlon Medical, a developer of extracorporeal therapies that target the elimination of infectious viruses and tumor-secreted exosomes from the bloodstream.