Characterization of exosome release and extracellular vesicle-associated miRNAs for human bronchial epithelial cells irradiated with high charge and energy ions

Abstract

Exosomes are extracellular vesicles that mediate transport of nucleic acids, proteins, and other molecules. Prior work has implicated exosomes in the transmission of radiation nontargeted effects. Here we investigate the ability of energetic heavy ions, representative of species found in galactic cosmic rays, to stimulate exosome release from human bronchial epithelial cells in vitro. Immortalized human bronchial epithelial cells (HBEC3-KT F25F) were irradiated with 1.0 Gy of high linear energy transfer (LET) 48Ti, 28Si, or 16O ions, or with 10 Gy of low-LET reference γ-rays, and extracellular vesicles were collected from conditioned media. Preparations were characterized by single particle tracking analysis, transmission electron microscopy, and immunoblotting for the exosomal marker, TSG101. Irradiation with high-LET ions, but not γ-rays, stimulated exosome release by about 3-fold, relative to mock-irradiated controls. The exosome-enriched vesicle preparations contained pro-inflammatory damage-associated molecular patterns, including HSP70 and calreticulin. Additionally, miRNA profiling was performed for vesicular RNAs using NanoString technology. The miRNA profile was skewed toward a small number of species that have previously been shown to be involved in cancer initiation and progression, including miR-1246, miR-1290, miR-23a, and miR-205. Additionally, a set of 24 miRNAs was defined as modestly over-represented in preparations from HZE ion-irradiated versus other cells. Gene set enrichment analysis based on the over-represented miRNAs showed highly significant association with nonsmall cell lung and other cancers.

Carcinogenesis induced by space radiation: A systematic review

“…Exosome-derived miRNAs are confirmed to transmit non-targeted radiation effects in vitro , including genomic and telomeric instability [64] . As reported by Li et al , the presence of miRNAs which are relevant to the development of lung cancer were detected, including miR-1246, miR-1290, miR-23a, and miR-205 [63] . Wang et al found that heavy ions could enhance the transformation of epithelial cells to mesenchymal cells mediated by transforming growth factor beta (TGF-β).…”

“…Ding et al found that some growth-related pathways in human bronchial epithelial cells were significantly up-regulated after exposure to high-energy iron ions and silicon ions, including hypoxia inducible factor-1α (HIF-1α), mammalian target of rapamycin (mTOR), insulin-like growth factor-1 (IGF-1), ras homolog family member A (RhoA) and extracellular regulated protein kinases/mitogen-activated protein kinase (ERK/MAPK), indicating that heavy ions increased the potential risk of lung cancer [62] . Li et al found that 1 Gy of HZE ions have the ability to stimulate the exosome release by about 4-fold from human bronchial epithelial cells relative to 10 Gy reference γ-rays [63] . Exosome-derived miRNAs are confirmed to transmit non-targeted radiation effects in vitro , including genomic and telomeric instability [64] .…”

“… [78] carbon ions 290 MeV/u 50 keV/µm 0.25, 0.5, 0.75, 1 Gy 0.03 Gy/min Immortalized human bronchial epithelial cells titanium ions 230, 1000 MeV/u 200, 108 keV/µm 1 Gy - 1 Gy of HZE ions have the ability to stimulate the exosome release by about 4-fold from human bronchial epithelial cells relative to 10 Gy reference γ-rays. [63] silicon ions 65, 148 MeV/u 200, 100 keV/µm 1 Gy - oxygen ions 35 MeV/u 100 keV/µm 1 Gy - γ-rays 0.661 MeV - 3, 10 Gy 1.5 Gy/min Human lymphocytes X-rays 250 kVp - 1-6 Gy 1-2 Gy/min Complex chromosome exchanges are responsible for the increased effectiveness of carbon ions compared to X-rays at the first post-irradiation mitosis. [61] carbon ions 9.5 MeV/u 175 keV/µm 1, 2 Gy 1-2 Gy/min …”