Researchers propose 'RNAkine' nomenclature for naming extracellular ncRNAs

January 2, 2024: Authoritative review and analysis, including fact checking and peer review, have ensured the veracity of the information in this article. The Nanjing University School of Life Sciences have contributed to proofreading the text. The study of RNA witnessed a transformative moment in 2007 and 2008 when many individual teams reported findings of noncoding RNA (ncRNA) sequences within the extracellular space. This had led to a shift in focus from the intracellular roles to the cell-to-cell communication abilities of RNA. Extracellular ncRNAs have been observed to move within extracellular space either attached to extracellular vesicles (EVs) or proteins.

Zhang and his team were the first to observe the signaling capacity of extracellular miRNAs by showing how they are secreted by monocytes via EVs and absorbed by target endothelial cells to regulate angiogenesis. Increasing evidence indicates that extracellular miRNAs have significant roles in numerous physiological and pathological processes. Extracellular ncRNAs are seen as a new type of signaling molecules that report changes in the homeostatic balance between cells.

However, despite these important functional attributes, there is a lack of an accepted classification system that clearly identifies these molecules. Proposed terms such as EV RNAs and secreted RNAs, although valid, do not encompass their full significance and role in intercellular communication, leading to confusion.

In a recent paper in Trends in Endocrinology & Metabolism, a research team led by Prof. Chen Yu Zhang from Nanjing University, Prof. Antonio Vidal Puig from the University of Cambridge, and Dr. Jing Li from Nanjing University introduces the term "RNAkine" to describe extracellular ncRNAs. The new term merges conventional signaling molecules and ncRNAs into a specific category reflecting their active role in cell signaling.

RNAkines work hand in hand with conventional signaling molecules. For instance, leptin regulates food intake and energy based on the body's overall energy balance, while host-derived cytokines can manage the immune system during tumor development. RNAkines typically function in supporting local tissues, like the brown adipose tissue. The term RNAkine helps to point out their distinct dynamics in biological processes.

In brief, extracellular RNAs with active release and signaling roles in cell interaction are now referred to as RNAkines. This new term provides a concise definition, encourages consensus within the scientific and clinical communities. For more information, see the article "RNAkines are secreted messengers shaping health and disease" in Trends in Endocrinology & Metabolism (2023), DOI: 10.1016/j.tem.2023.12.004.