The Secreted Midbody Remnants, MBsomes, as a New Class of mRNA Nanocarrier Applicable to Diverse Medical Fields

The midbodysome (MBsome), a secreted remnant of midbody during cell division, is now known to play a key role in cytokinesis. The MBsome is known to be either released into the extracellular space or autophagically degraded by daughter cells. However, recent studies have revealed that MBsomes can be maintained by cells even after cell division is complete, and that they accumulate in the cytoplasm and regulate cell proliferation and survival through integrin and epidermal growth factor receptor-dependent pathways. Here, we examined the ability of MBsomes to act as carriers of mRNAs, a novel function that has not been studied. We found that MBsomes isolated from human lung cancer cells and stem cells via sucrose cushion ultracentrifugation were 300–400 nm in size and stable for up to 4 days when stored at 4°C. In addition, we confirmed successful expression of the EGFP protein following incubation of the isolated MBsomes with the EGFP mRNA at room temperature. Moreover, MBsome-mediated Pdcd4 mRNA delivery into lung cancer cells could inhibit lung cancer cell migration and invasion. Taken together, our results suggest that MBsomes have the potential to serve as mRNA carriers and therapeutic agents capable of delivering a gene-of-interest.