Journal: Journal of Extracellular Vesicles
Article Title: Large extracellular vesicles carry most of the tumour DNA circulating in prostate cancer patient plasma
Figure Lengend Snippet: Most extracellular DNA is packaged into L-EVs . (a) Tunable resistive pulse sensing (TRPS, qNano) using two different pore membranes (NP4000 and NP200) identified as L-EVs (left) and S-EVs (right) derived from PC3 cells. NP4000 membrane, which can detect particles with a diameter between 1.0 and 6.0 μm, was used for quantitation of L-EVs, while NP200 membrane, which can detect particles with a diameter between 60 and 400 nm, was used for quantitation of S-EVs. (b) Protein lysates from L-EVs and S-EVs purified by iodixanol density gradient (at 1.10 and 1.15 g/ml) were blotted with LO markers HSPA5 and CK18, and with Exo marker CD81. (c) Total DNA was quantified by Qubit Fluorometer in L-EVs and S-EVs isolated from PC3 and U87 cell lines. The plot shows the DNA ratio between L-EVs and S-EVs. (d) Double stranded (ds)DNA was quantified by High Sensitivity (HS) dsDNA Qubit Assay in L-EVs and S-EVs isolated from 1 ml of plasma from patients with mCRPC ( n = 40) and cancer-free individuals ( n = 6). (e) Quantification of both protein and DNA content in L-EVs and S-EVs isolated from conditioned media of 12.6 × 10 7 PC3 cells. (f) Single stranded (ss) and dsDNA in PC3-derived L-EVs and S-EVs, with or without treatment with DNase I and Exonuclease III, were quantified by Qubit. (g) Chip-based capillary electrophoresis (Bioanalyzer) showing the presence of dsDNA in PC3-derived L-EVs and S-EVs, with or without treatment with DNase I and Endonuclease III. L-EVs contain abundant DNA with a large peak around 10 kbp. Conversely, the amount of DNA in S-EVs is negligible. (h) ss- and dsDNA in PC3-derived L-EVs and S-EVs were quantified by Qubit after treatment with nucleases (DNase I and Exonuclease III) with or without addition of a detergent (Triton X-100) prior to nuclease treatment. (i) Chip-based capillary electrophoresis (Bioanalyzer) showing that only miniscule amounts of dsDNA could be detected after EV lysis using a detergent prior to treatment with nucleases.
Article Snippet: DNA extraction and characterization L- and S-EVs were treated with rDNase I (2 U/μl, DNA-Free Kit, Ambion) and Exonuclease III (200 U/μl, Thermofisher).
Techniques: Tunable Resistive Pulse Sensing, Derivative Assay, Quantitation Assay, Purification, Marker, Isolation, HS DSDNA Qubit Assay, Chromatin Immunoprecipitation, Electrophoresis, Lysis