Growth curve and Cell proliferation/activation pattern.

<p><b>A</b>: Microtissue volumes were calculated by the formula V = 4/3*Π*r3, where r = ½*√ d1*d2. Mean volumes are displayed in μm3 with their corresponding standard deviations. <b>B</b>: Mean and standard deviation of Ki67 positivity was calculated by counting Ki67 positive and negative cell nuclei on slices of three different spheroids representatively. Thereafter, the percentage of positive cell nuclei to whole cell cumber was calculated. Co-cultivation of both tumour cell lines with a fibroblast cell line led to a significant upregulation (p<0,05) of Ki67 expression in all microtissues.