Figure 5

CXCR2 inhibition attenuates dHL-60 cell-promoted proliferation of PANC-1 tumor spheroids only in the “contact” scenario but not in the “separated” scenario. (a) Representative confocal images of PANC-1 tumor spheroids (blue, Hoechst) immunostained for Ki-67 (green), a proliferation marker, at t = 24 h after dHL-60 cells or culture medium ± 1 μM AZD-5069 were loaded into the central channel (“separated”) or along with tumor spheroids into the tumor gel channel (“contact”) of the NTI-chip. Images are maximum intensity projections of z-stacks with a 2 μm step size. Scale bar, 50 µm. (b) Bar plot showing the percentage of Ki-67-positive cells per spheroid in specified conditions. Each data point represents a spheroid and n = 53–73 spheroids per condition. Bars show mean ± SD with mean values written above the points. At least three independent experiments were performed. ns: p ≥ 0.05, ****: p < 0.0001, Brown-Forsythe and Welch ANOVA with Dunnett's T3 multiple comparisons test.