Indication of Horizontal DNA Gene Transfer by Extracellular Vesicles

Abstract

The biological relevance of extracellular vesicles (EV) in intercellular communication has been well established. Thus far, proteins and RNA were described as main cargo. Here, we show that EV released from human bone marrow derived mesenchymal stromal cells (BM-hMSC) also carry high-molecular DNA in addition. Extensive EV characterization revealed this DNA mainly associated with the outer EV membrane and to a smaller degree also inside the EV. Our EV purification protocol secured that DNA is not derived from apoptotic or necrotic cells. To analyze the relevance of EV-associated DNA we lentivirally transduced Arabidopsis thaliana-DNA (A.t.-DNA) as indicator into BM-hMSC and generated EV. Using quantitative polymerase chain reaction (qPCR) techniques we detected high copy numbers of A.t.-DNA in EV. In recipient hMSC incubated with tagged EV for two weeks we identified A.t.-DNA transferred to recipient cells. Investigation of recipient cell DNA using quantitative PCR and verification of PCR-products by sequencing suggested stable integration of A.t.-DNA. In conclusion, for the first time our proof-of-principle experiments point to horizontal DNA transfer into recipient cells via EV. Based on our results we assume that eukaryotic cells are able to exchange genetic information in form of DNA extending the known cargo of EV by genomic DNA. This mechanism might be of relevance in cancer but also during cell evolution and development.

Biology and therapeutic potential of mesenchymal stem cell‐derived exosomes

“…The horizontal DNA gene transfer by exosomes released from BMSC was identified. It carries high‐molecular DNA, which was mainly associated with the outer exosome membrane for the exchange of genetic information mediating the intercellular communication during cell evolution and development 30 . In addition, exosomes were able to package and transfer their mitochondrial DNA to breast cancer cells, leading to restoration of metabolic activity and increased self‐renewal potential 27 …”

Extracellular vesicles as trans‐genomic agents: Emerging roles in disease and evolution

“…The mechanisms of DNA packaging in EV are poorly understood and whether DNA is packaged within the membrane‐bound space of EV remains unclear. Recent studies have revealed that DNA is not contained within the membrane‐enclosed space of EV, but is largely attached to the outer surface of EV . Indeed, treatment of EV with nucleases such as DNase I and Exonuclease III before DNA extraction significantly reduces the overall DNA detected from cancer cell‐derived EV (Yumi Kawamura and Takahiro Ochiya, 2017, personal observation), demonstrating that DNA is mainly associated with the outer EV membrane (Fig.…”

Tumor-derived extracellular vesicles: molecular parcels that enable regulation of the immune response in cancer

“…Since the discovery of extracellular DNA, it has been suggested that cancer cells may deliver oncogenic sequences via EVs, which might result in the transformation of surrounding normal cell types akin to an infection-like process (Bergsmedh et al, 2001;Fischer et al, 2016;García-Olmo et al, 2010;Kanada et al, 2015;Rak and Guha, 2012). Indeed, it has been demonstrated that EVs can impart transformed phenotypes into recipient cell types (characterized by cellular capacity for formation of foci in culture or anchorage-independent growth) (Antonyak et al, 2011;Hallal et al, 2019;Lee et al, 2014;Oushy et al, 2018).…”