Salubrinal normalizes the deregulated acinar morphogenesis of MMTV-Neu mammary tumor cells. Single epithelial cells isolated from MMTV-Neu mouse mammary tumors were grown in 3D organotypic/Matrigel cell culture over a period of 10 days. (A) Size of vehicle control (CTRL) and salubrinal 5 ug/ml treated acini was calculated following the equation [(Length × width2)/2 = acini volume (mm3)] and plotted; Mann Whitney test p < 0.0001, n = 30. (B) Representative confocal images of equatorial sections through control and salubrinal treated MMTV-Neu acini stained with DAPI at day 10 in Matrigel. Salubrinal treatment reverted the tumorigenic phenotype of MMTV-Neu acini by promoting formation of normal lumens in growth arrested acini (lower panel) as compared to untreated acini showing luminal filling and increased size (upper panels).