Fig. 6

Melanoma cells impair expression of keratinocyte differentiation marker CK10. Tri-culture spheroids were generated by 3D cultivation of fibroblasts for three days, followed by simultaneous addition of keratinocytes and melanoma cells. HaCaT and SK-MEL-28 cells were labeled with CellTrackerRed CMPTX dye and CellTrackerGreen CMFDA, respectively. After another two days, tri-culture spheroids were treated with 0.01 ‰ of DMSO as control or 100 nM docetaxel for 15, 24, 48, and 72 h. Spheroids were cryosectioned into 10-μm thick slices and stained for CK10. (A and B) Representative confocal images of control (A) and docetaxel-treated cultures (B). In overlay images, CK10 immunostaining signals, SK-MEL-28, HaCaT, and nuclei are depicted in red, green, yellow, and blue, respectively. Scale bars: 100 μm. (C) Quantification of CK10-positive cells. Graph displays the amounts of CK10-positive cells as mean ± SEM (n ≥ 3 independent experiments; ** P < 0.01) in percent of the peripheral nuclei per slice. For each experiment and time point, ≥ 3 spheroids were analyzed