Dox withdrawal restores acinar architecture of B-RafV600E transformed acini. (A) Micrographs of MCF-10A acini harboring a B-RafV600E transgene in the absence (left), presence (middle) and following removal of dox (right panel). Representative phase contrast (upper row) and fluorescence (lower row) micrographs were taken at day 59. Each micrograph was taken using a 10x objective. Note the enlarged diameter of the acini in which B-RafV600E is or has been expressed. Note also the absence of invasive cells and the reappearance of a regular acinar architecture in acini following dox wash-out (right panel). (B) Representative confocal microscopy sections of 53 days old acini stained with the proliferation marker KI-67 (pink). (C) Representative confocal microscopy sections of 53 days old acini stained with the apoptotic marker cleaved Caspase-3 (pink). In both B and C, the nuclei were stained with Topro-3 (blue). Acini grown in the presence of dox appear green due to the expression of the GFP reporter.