Figure 2

CXCR2 is expressed on the surface of dHL-60 cells but not PANC-1 cells. (a) CXCR2 expressions by dHL-60 cells (i), 2D PANC-1 cells (ii), and dissociated 3D PANC-1 spheroids (iii) were measured by flow cytometry. Red histogram = stained sample; blue histogram = unstained control. The horizontal bars show percentages of CXCR2-positive cells. One representative experiment is shown. (iv) Bar plot showing the percentage of CXCR2-positive cells in dHL-60 cells, 2D PANC-1 cells, and 3D PANC-1 spheroids from at least three independent experiments. Bars show mean ± SD with mean values written above. ****: p < 0.0001, Brown-Forsythe and Welch ANOVA with Dunnett’s T3 multiple comparisons test. (b) CXCR2 expressions by dHL-60 cells (i), 2D PANC-1 cells (ii), and 3D PANC-1 spheroids (iii) were visualized by immunofluorescence. (i) Representative 40X confocal images of dHL-60 cells (blue, Hoechst) immunostained for CXCR2 (green). Scale bar, 20 µm. (ii) Representative 20X confocal images of 2D PANC-1 cells (blue, Hoechst) immunostained for CXCR2 (green). Scale bar, 50 µm. (iii) Representative 20X confocal images of gel-embedded 3D PANC-1 spheroids (blue, Hoechst) immunostained for CXCR2 (green). Images are maximum intensity projections of z-stacks with a 2 μm step size. Scale bar, 50 µm. Samples stained with the secondary antibody only were used as isotype control.