Life Science and Medical News from Around the Globe
“Zone in with Zon”—Exosomes: Tiny Packets of RNAs with Major Significance and Potential
Dr. Gerald Zon’s latest “Zone in with Zon” blog post, dated September 23, 2013, focuses on a discussion of “exosomes,” tiny ~30-100 nm extracellular vesicles discovered 30 years ago. These exosomes are released from cells and can fuse with the membrane of target cells and enable the transmission of exosome informational cargo, e.g., protein and RNA, into the target cell. According to Dr. Zon, “the ability to influence gene expression in distant cells through exosomes presents a remarkable model for cell-to-cell signaling that offers an entirely new perspective on intercellular communication. This also has potential therapeutic applications, such as in diagnosis, intervention, and artificial gene/mRNA delivery.” Dr. Zon cites an explosion of exosome-focused peer-reviewed articles in the last ten years, as evidence of increasing awareness of the importance of these information-loaded vesicles. He also highlighted a 2007 article by Valadi et al. that reported that exosomes from mast cells contained mRNA from ~1,300 genes, many of which were not present in the cytoplasm of the donor cell. He noted that in vitro translation showed that the exosome mRNA was functional and analysis of total RNA from the exosomes revealed the presence of small RNAs, including miRNAs. In addition, the RNA from mast cell exosomes was transferrable to other mast cells. Dr. Zon said this publication has been cited more that 1,300 times, particularly in the molecular biology of cancer. Dr. Zon goes on to discuss recent work documenting the release of exosomes by the human placenta into maternal circulation throughout pregnancy, as well as the role of tumor-released exosomes in promoting cancer developmement. Dr.