Cell culture and cell lines

A variety of breast cancer cell lines were selected to intentionally recapitulate the variety of breast cancer subtypes. All lines were purchased from ATCC (Manassas, VA, USA) or DSMZ (Brunswick, Germany) between 2012 and 2015 as described previously.^{9, 25, 26} Cell lines were authenticated at the University of Michigan DNA Sequencing Core Facility with comparison to known sequences included from ATCC and DSMZ. All media, FBS and penicillin/streptomycin (50units/ml) were procured from Invitrogen, and all cell lines were maintained in a 5% CO2 cell culture incubator. The following breast cancer cell lines were grown in RPMI 1640 supplemented with 10% FBS: ZR75-30, MDA-MB-231, MDA-MB-453, BT474, BT20, AU565, HCC 1954, HCC 1806, HCC38, HCC70, ACC-231, and HCC 1937. ACC-302 cells were grown in 80% DMEM with 20% FBS. ACC-422 cells were grown in 85% MEM with 15% FBS. BT549 and T47D cells were grown in RPMI 1640 with 10% FBS and 0.023 IU/ml insulin. ACC-459, ACC-440, and CAMA-1 were grown in DMEM with 10% FBS. MCF-7 cells were grown in modified MEM with 0.023 IU/ml insulin in keeping with our previous studies.^{25, 26}