Characterization of Metastatic Breast Cancer Cell Lines

The mouse metastatic mammary 4T1 tumor cell line (Cat# CRL-2539) and human MDA-MB-231 breast adenocarcinoma cell line (Cat# HTB-26) were purchased from the American Type Culture Collection (ATCC). The mouse mammary tumor MMTV-Myc cell line has been previously reported [62 (link), 63 (link)]. Cell lines were authenticated by short tandem repeat (STR) profiling in accordance with the standard ASN-0002-2011 in April 2015 (DDC Medical). 4T1 cells were maintained in RPMI supplemented with 10% fetal bovine serum (FBS) and 1% Antibiotic-Antimycotic solution (Invitrogen). The MDA-MB-231 cell line was maintained in DMEM supplemented with 10% FBS, 1% GlutaMAX (Invitrogen), 10mM HEPES, 1mM sodium pyruvate, non-essential amino acids and 1% Antibiotic-Antimycotic solution. MMTV-Myc cells were cultured in DMEM/F12 medium supplemented with 5% FBS, 1% GlutaMAX, 10mM HEPES, and 1% Antibiotic-Antimycotic solution. Stable knockdown of PF1 in MDA-MB-231 was performed with pLKO-PF1 shRNA (clone# TRCN0000015704), which was a kind gift from the laboratory of Gregory David (NYU School of Medicine, NY, USA) [44 (link)]. A second pLKO-PF1 shRNA construct (clone# TRCN0000084422, Sigma Aldrich) was used for stable knockdown in mouse 4T1 cells. Stable transfections were performed with 1 μg of DNA using TurboFect (ThermoScientific) according to the manufacturer's recommendations.