Department of Medical Cell BioPhysics, University of Twente, Enschede, The Netherlands.
Laboratory of Experimental Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
PLoS One. 2020 Jun 4;15(6):e0233443. doi: 10.1371/journal.pone.0233443. eCollection 2020.
Large (> 1 μm) tumor-derived extracellular vesicles (tdEVs) enriched from the cell fraction of centrifuged whole blood are prognostic in metastatic castration-resistant prostate cancer (mCRPC) patients. However, the highest concentration of tdEVs is expected in the cell-free plasma fraction. In this pilot study, we determine whether mCRPC patients can be discriminated from healthy controls based on detection of tdEVs (< 1μm, EpCAM+) and/or other EVs, in cell-free plasma and/or urine. The presence of marker+ EVs in plasma and urine samples from mCRPC patients (n = 5) and healthy controls (n = 5) was determined by flow cytometry (FCM) and surface plasmon resonance imaging (SPRi) using an antibody panel and lactadherin. For FCM, the concentrations of marker positive (+) particles and EVs (refractive index <1.42) were determined. Only the lactadherin+ particle and EV concentration in plasma measured by FCM differed significantly between patients and controls (p = 0.017). All other markers did not result in signals exceeding the background on both FCM and SPRi, or did not differ significantly between patients and controls. In conclusion, no difference was found between patients and controls based on the detection of tdEVs. For FCM, the measured sample volumes are too small to detect tdEVs. For SPRi, the concentration of tdEVs is probably too low to be detected. Thus, to detect tdEVs in cell-free plasma and/or urine, EV enrichment and/or concentration is required. Furthermore, we recommend testing other markers and/or a combination of markers to discriminate mCRPC patients from healthy controls.
从离心全血细胞部分富集的大 (>1 μm) 肿瘤衍生细胞外囊泡 (tdEVs) 在转移性去势抵抗性前列腺癌 (mCRPC) 患者中具有预后价值。然而，tdEVs 的最高浓度预计存在于无细胞血浆部分。在这项初步研究中，我们确定是否可以基于检测无细胞血浆和/或尿液中的 tdEVs(<1μm，EpCAM+)和/或其他 EVs，来区分 mCRPC 患者和健康对照者。通过流式细胞术 (FCM) 和表面等离子体共振成像 (SPRi) 使用抗体面板和乳粘蛋白检测 mCRPC 患者 (n=5) 和健康对照者 (n=5) 的血浆和尿液样本中标记物+EV 的存在。对于 FCM，确定标记物阳性 (+) 颗粒和 EVs(折射率<1.42)的浓度。仅通过 FCM 测量的乳粘蛋白+颗粒和 EV 浓度在患者和对照组之间有显著差异 (p=0.017)。其他所有标记物在 FCM 和 SPRi 上均未产生超过背景的信号，或在患者和对照组之间无显著差异。总之，基于 tdEVs 的检测，未发现患者和对照组之间存在差异。对于 FCM，测量的样本量太小，无法检测到 tdEVs。对于 SPRi，tdEVs 的浓度可能太低而无法检测到。因此，要在无细胞血浆和/或尿液中检测 tdEVs，需要进行 EV 富集和/或浓缩。此外，我们建议测试其他标记物和/或标记物组合，以区分 mCRPC 患者和健康对照者。
