Fig. 2

Features of PDOs derived from healthy and tumour mammary tissue. a Cellular debris could be detected both in intercellular lumens both outside of the organoid at small magnification. Neither basement membrane neither myoepithelial cells are present. b Tight junctions and desmosomes were visible between two cells that surrounded the lumen. c A large intercellular lumen with protein material inside was evidenced in this micrograph. In the basal layer of the cells, intercellular spaces (arrows) were dilated with interdigitation of the cytoplasmic membrane. Both basement membrane and myoepithelial cells were absent. d High magnification of the loosed intercellular spaces. The interdigitations between cells were evident, as pinocytosis vacuoles (arrows). e In this photomicrograph, the large number of Golgi complex was well represented. f Two intercellular lumens containing various material, lysosomes and protein granules were displayed in this micrograph. The nuclei appeared polylobed. g Representative image of numerous intracellular lumens with microvilli inside. h Representative micrograph of an internal lumen showing spherical and rod-shapes material (arrows). D1 = intercellular debris, D2 = outsider debris, **= intercellular lumens containing material. TJ = tight junction, D = desmosome, m = mitochondria, M = microvilli, N = nuclei, G = secretory granules, g = Golgi apparatus, Ly = lysosome. PDOs reported in this figure were derived from IDC Luminal A/B (a, b, f, g, i), IDC HER2+ (d), ILC luminal A (e, h) or from DCIS luminal A (c)