Fig. 7.

A tridimensional environment enhances the differential sensitivity between tumorigenic and normal-like cells. (a) Morphology of epithelial breast cells in different culture conditions. Upper panels: phase contrast micrographs of MDA-MB-231, MCF-7 and MCF-10A cells cultured in monolayer (2D); lower panels: confocal microscopy of MDA-MB-231, MCF-7 and MCF-10A cells cultured as spheroids (3D); nuclei were stained with Hoechst 33342 (blue); Scale bar: 20 μm. (b) Viability time curves after MB-PDT of 3D cultures with 20 μM of MB followed by of 4.5 J/cm² irradiation obtained at 1 h, 3 h and 24 h post-irradiation (n = 3 independent experiments).* p < 0.05 versus MCF-10A. (c) Comparison of the MB-PDT cytotoxic effect between 2D and 3D cell cultures at 24 h post-irradiation. *p < 0.05 versus MCF-10A 3D; #p < 0.05 MCF-10A 2D versus MCF-10A 3D. (n = 3 independent experiments). Results are shown as mean ± s.e.m