Changes in the transcriptome of primary mouse mammary gland organoids in response to hyperactivation of the WNT/CTNNB1 pathway

Purpose: WNT/CTNNB1 signaling promotes mammary tumor formation in mice, but the direct and immediate effects of elevated levels of WNT/CTNNB1 signaling on the mouse mammary epithelium remain unknown. Using primary mouse mammary epithelial organoid cultures grown in minimal media we have studied the response of the mouse mammary epithelium to elevated levels of WNT/CTNNB1 signaling. Overall design: Primary mouse mammary epithelial organoid cultures were established from 8-11 week old female FVB/N virgin mice. Organoids were grown in the presence of either vehicle control (DMSO) or increasing concentrations of CHIR99021 (1 uM, 1.5 uM or 3 uM) for 7 days. RNA was harvested after 7 days of culture/treatment and used for bulk RNA sequncing. n=3 independent organoid cultures (rep1, rep2, rep3) from n=3 individual animals were used for n=4 different treatments per experiment (DMSO, 1uM CHIR99021, 1.5 uM CHIR99021, 3 uM CHIR99021), resulting in 3 x 4 = 12 samples total.