Work

The Fifth International Meeting of ISEV, ISEV2016, Rotterdam, The Netherlands, 4 – 7 May, 2016

Year: 2016

Type: article

Abstract: Introduction: Retrotransposons are remnants of ancient viral infections that infected the genome of our primate lineage through infection of germ cells.Scattered throughout the genome, these elements are capable of amplifying themselves as well as changing their position through RNA intermediates.Interestingly, retrotransposon elements are highly enriched in tumour extracellular vesicles (EVs) compared with their cells of origin and have been shown to be transferred in vitro from medulloblastoma cells to normal human umbilical vein endothelial cells (Balaj et al., 2011).Furthermore, the production of EVs seems to share resemblance with retroviral particle assembly, thus making retroviral-like particles a component of the EV contingent.Hence, we are now testing whether a high prevalence of the retrotransposon-like elements known as human endogenous retroviruses (HERVs) in tumour cell lines leads to selective packaging and transfer of exRNA through EVs.Methods: The assay is based on the BOGOTA construct (Contreras-Galindo et al., 2015), which includes parts of the HERV-K113 packaging signal, and is selected through a neomycin reporter gene.We have screened several cell lines for the presence of HERVs.Expression of neomycin is used to select for cell recipients and the initial confirmation of integration of the transferred retroviral element into the genome of the recipient.Results: Preliminary studies indicate that the transfer of retroviral elements is successful between different cell lines.The use of the BOGOTA construct results in a selective packaging of the reporter gene into EVs.The neomycin resistance encoding RNA is highly enriched in the resulting EVs compared with their cells of origin.Conclusion: The indication of retrotransposon transfer between different cell lines supports future studies to determine the role of retrotransposon transfer in tumorigenesis, and potentially as a means of generating therapeutic vehicles utilizing viral packaging signals.

Source: Journal of Extracellular Vesicles

DOI: 10.3402/jev.v5.31552