Stromal TN-C alters normal 3-D mammary epithelial tissue architecture. A: Tissue sections from normal human mammary gland (top), DCIS (middle), and IDC (lower) stained with hematoxylin and eosin (H&E) (left) or TN-C (right). Scale bar, 50 μm. B: Morphology of MCF-10A acini generated in Matrigel in the absence (top) or presence (bottom) of TN-C for 8 days (phase contrast, left). Confocal immunofluorescence staining with laminin-V (green; middle and right), Ki-67 (red; middle), and cleaved caspase-3 (red; right) in 8 day cultures. Asterisk indicates loss of a continuous BM (middle) and position of cells residing outside of the BM zone (right) in the presence of TN-C. Scale bars, 50 μm. C: Quantification of Ki-67 immunoreactivity in MCF-10A acini revealed a 1.6-fold increase in proliferation (n = 66 acini, *P < 0.009), yet no differences in apoptosis (quantification of cleaved caspase-3 immunoreactivity; n = 40 acini, P = 0.68) in response to TN-C.