Cholesterol metabolism and resistance to tamoxifen

► MUC1 upregulated the expression of the cholesterol metabolic pathway. ► Tam inhibits ACAT, cholesterol biosynthesis and ChEH activity and stimulates ROS production in tumor cells. ► Tumor initiating cells expressed MUC1 and are dysregulated for cholesterol metabolism. ► MUC1, ACAT, and ChEH are druggable targets for breast cancer treatment.