Fig. 2

CB-NK histones are actively transferred through MM cells. a: ARP1 and CB-NK cell proliferation during four days after over-expression of YWHAQ-GFP, YWHAZ-GFP and H2AZ-GFP vs control, measured by viable cell count. b-c: Transfer of YWHAZ and YWHAQ (b), and H2AZ (c) from CB-NK to ARP1 cells. CB-NK transduced with the corresponding protein fused to GFP are co-cultured with ARP1 cells for 30 min. ARP1 cells in blue (CMAC) and CB-NK show in green the corresponding GFP-fused protein. Arrows in c indicate H2AZ-vesicles and H2AZ adhered to the surface of MM cells. d: Transfer of H2AZ-GFP from CB-NK to MM (ARP1, RPMI and U266) and non-MM K562 cells after 24 h of co-culture. Target cells are shown in blue (CMAC) in plot 1, and plot 2 corresponds to the gate of CMAC+ cells. e. Transfer of H2AZ-GFP from CB-NK to MM and non-MM K562 cells after 24 h of co-culture performed in parallel at 37 °C and 4 °C. f to h: H2AZ can be transferred between tumor cells in a CB-NK independent manner. f: Transfer of H2AZ from tumor cells over-expressing H2AZ-GFP to neighboring tumor cells stained in blue (CMAC) after 30 min of co-culture. Arrows indicate H2AZ-vesicles and H2AZ-intercellular structure being transferred to neighboring tumor cells. g: H2AZ transfer from MM cells over-expressing H2AZ-GFP to neighboring MM cells in blue (CMAC) at different times (1 h, 5 h, 18 h) of co-culture. Statistical analysis shown is performed for each cell line vs 1 h time point. h: Transfer of GFP (plot on the left) and H2AZ-GFP (plot on the right) from MM and non-MM K562 cells over-expressing these proteins to neighboring MM and non-MM K562 cells after 24 h of co-culture. Representative images from at least three independent experiments