Troves From a Search For New Biomarkers: Blood-Borne RNA
Source: Rockefeller University
Summary: Researchers have devised an improved method for isolating and identifying tiny fragments of RNA in human blood products.
A timely and accurate diagnosis is the critical first step in treating everything from strokes to cancer. Today, doctors often rely on biomarkers, such as cardiac troponin, the protein that appears in the blood after a heart attack, to help them figure out what’s going on with patients. But the information the biomarkers provide can be limited. Now, in a breakthrough that could lead to powerful new ways to diagnose and track a wide range of medical conditions. Researchers from the Rockefeller University have devised an improved method for isolating and identifying tiny fragments of RNA in human blood products. On top of that, in the course of the project, they discovered that one of their study participants had a highly unusual concentration of RNA in his blood, a completely unexpected finding that prompted an ongoing follow-up study. The research findings were published in the journal Proceedings of the National Academy of Sciences.
The new approach overcomes daunting technical obstacles and establishes so-called extracellular RNA as a potentially reliable class of biomarkers. exRNA, as it’s also known, is released by many kinds of cells, including tumor cells, and circulates on its own in the blood. This method, which involves multiple refinements in the preparation and processing of the plasma and serum samples tested, solves that longstanding scarcity problem, and it has another advantage as well. In developing the new technique, the researchers processed and analyzed a total of 312 blood samples collected from 13 healthy subjects, including both men and women, over a two-month period. The discovery confirmed the efficacy and sensitivity of the team’s methods, and strengthened the case for exRNA as a reliable biomarker – P12’s exRNA profile remained stable for a full year. In addition, it opened up a whole new front in their research.
Thomas Tuschl, head of the laboratory, said “We can survey thousands of pieces of RNA, with origins across all cell types”, and further added, Identifying the specific tissue where the exRNA originates, along with its molecular structure and its abundance in the circulation, “has enormous potential for detecting disease processes and discovering new abnormalities.”
More information: Klaas E. A. Max et al, “Human plasma and serum extracellular small RNA reference profiles and their clinical utility”, Proceedings of the National Academy of Sciences (2018). DOI: 10.1073/pnas.1714397115