Figure 6. Suppressing Ras-driven phenotypes involves decreased proliferation and preservation of MEC compartments.

Basal^RAS/GFP and luminal^RAS/GFP organoids were cultured under the indicated treatment conditions in 3D. Mitotic and cell death events were scored during the first 2 days of Dox treatment. (A) MEK inhibitor effects on MEC proliferation and survival. PD denotes MEK inhibitor PD0325901 at 100 nM. (B) PI3K/mTOR inhibitor effects on MEC proliferation and survival. Mean values reflect indices (events per organoid, normalized to a 24 hour acquisition period) derived from analyzing videos from 11 to 34 organoids of each genotype. Error bars indicate SEM. (C) PI3K/mTOR inhibitor effects on MEC compartmentalization. Organoids were recovered after 3D culture for 7 d, then fixed and stained with Hoechst and phalloidin. Panels depict equatorial confocal microscopy images (63X) of representative organoids of each indicated genotype and treatment condition. Bars, 50 μm. LY denotes PI3K inhibitor LY294002 at 10 μM. Rap denotes rapamycin at 5nM.