Figure 6.

Self-renewal and differentiation of VL30 retrotransposition-induced mammospheres. (A) Single cells deriving from trypsinized floating mammospheres, formed in non-adherent plates, were seeded into fresh plates and cultivated up to 5 days. Formation of secondary mammospheres is shown after 3 and 5 days of cultivation (magnification, ×20). (B) Mammospheres grown in normal cell-culture plates (a-e). The image in (a) shows a mammary acinus-like structure after 20 days of cultivation. White and black arrows in (b) indicate the respective inner and outer cell layer of an acinus. Images in (c-e) show acinus-like structures stained with hematoxylin/eosin: Black arrow in panels (c) and (d) indicates myofibroblast-like cells surrounding luminal epithelial-like cells shown in panel (e). Magnification, ×40 in (a and c). Panel (b) is an enlarged image of panel (a). Panels (d and e) are enlarged images of acinus-like structures similar to the image in (c). Data shown in (A and B) are representative of 3 independent experiments.