title: Oncogenic ras-driven cancer cell vesiculation leads to emission of double-stranded DNA capable of interacting with target cells.
abstract: Cell free DNA is often regarded as a source of genetic cancer biomarkers, but the related mechanisms of DNA release, composition and biological activity remain unclear. Here we show that rat epithelial cell transformation by the human H-ras oncogene leads to an increase in production of small, exosomal-like extracellular vesicles by viable cancer cells. These EVs contain chromatin-associated double-stranded DNA fragments covering the entire host genome, including full-length H-ras. Oncogenic N-ras and SV40LT sequences were also found in EVs emitted from spontaneous mouse brain tumor cells. Disruption of acidic sphingomyelinase and the p53/Rb pathway did not block emission of EV-related oncogenic DNA. Exposure of non-transformed RAT-1 cells to EVs containing mutant H-ras DNA led to the uptake and retention of this material for an extended (30days) but transient period of time, and stimulated cell proliferation. Thus, our study suggests that H-ras-mediated transformation stimulates vesicular emission of this histone-bound oncogene, which may interact with non-transformed cells.
authors.affiliation: Montreal Children's Hospital, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Montreal Children's Hospital, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Chennakrishnaiah
authors.affiliation: McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Audemard
authors.affiliation: Montreal Children's Hospital, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Laura
authors.initials: L
authors.lastname: Montermini
authors.affiliation: Montreal Children's Hospital, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Meehan
authors.affiliation: Montreal Children's Hospital, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, Canada. Electronic address: janusz.rak@mcgill.ca.
authors.forename: Janusz
authors.initials: J
authors.lastname: Rak
mesh_terms: D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism*; D055354:Exosomes / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D011905:Genes, ras; D015894:Genome, Human; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D046529:Microscopy, Electron, Transmission; D009154:Mutation; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D051381:Rats; D013108:Sphingomyelin Phosphodiesterase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism
chemical_list: D000952:Antigens, Polyomavirus Transforming; D002843:Chromatin; D004273:DNA, Neoplasm; D004247:DNA; D013108:Sphingomyelin Phosphodiesterase; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)
keywords: Chromatin; DNA; Extracellular vesicle; Oncogene; Ras; Sphingomyelinase