Figure 1

Spheres constitute a separate population. Ascitic cells were isolated from ovarian cancer patient ascites and separated into monolayer-forming single-cell suspensions (M-type samples; M) and spontaneous spheres (S-type samples; S), all as described in Materials and Methods. Lysates of each sample were analysed by western blot, with GAPDH as loading control. As interblot reference, a lysate (one and the same for all experiments) of the SKOV-3 cell line, derived from EOC malignant ascites, was used. Numbers refer to patients. A. Representative images of spheres, 40x magnification. Left: immediately after isolation. Right: Dispersed spheres do not form monolayers in culture, but continue to form spheres like this one and which then detach from the few adherent cells seen in the background. B. Top: Representative example of E-cadherin and vimentin expression in paired M- and S-type samples, each pair from one and the same patient. Below: The data on E-cadherin and vimentin expression levels throughout the whole cohort are summarized in box plots comparing the distribution of relative expression of these proteins in all M (n = 18) and S (n = 9) samples, respectively. Asterisks denote statistically significant differences (Mann–Whitney U test). C. Representative examples of E-cadherin and vimentin expression in paired M- and S-samples from two patients, and artificial spheroids (AS) created in vitro using the M-sample cells. D. Expression of integrin β3 in two paired M- and S-type samples, each pair from one and the same patient.