Characterization of exosomes derived from HR-MM cells. (A) Transmission electron micrographs of exosomes derived from parental cells (RPMI8226 cells cultured under 20% or 1% O2 conditions) and HR-MM cells (RPMI8226-HR cells cultured under 1% O2 condition). The scale bar represents 50 nm. (B) CD63 and CD81 (common exosomal markers) immunoblots of exosomes derived from RPMI8226 and RPMI8226-HR cells. These exosomes were isolated from 5 mL of culture media of RPMI8226 (5 × 105 cells/mL) or RPMI8226-HR cells (5 × 105 cells/mL) cultured under 20% O2 or 1% O2 conditions for 24 hours, respectively, and the same amounts of exosome lysate (30 µL) were loaded in each lane of the gels. The ratio of CD63 and CD81 expression is indicated below the panels. (C) The nanoparticle concentration and size distribution of the exosomes derived from RPMI8226 cells cultured under 20% or 1% O2 conditions for 24 hours (dotted lines) and RPMI8226-HR cells cultured under 1% O2 conditions for 24 hours (solid lines).
