Fig. 1
Differential cytotoxicity and uptake of 3-bromopyruvate (3BP) in breast cancer cells. (A) Western blot and (B) the relative quantification of the optical density of each band showing the expression of MCT1 in triple negative breast cancer (TNBC) cell lines MDA-MB-231, MDA-MB-468, BT20, and BT549. Remaining metabolic activity (%) at (C) 1 or (D) 24 h as a measure of cell viability. Cells were treated with a concentration range of 3BP (0-300 μM) and cell viability measured using the MTT assay (n = 4). Trypan blue exclusion after 3BP treatment (20, 100, or 150 μM) for (E) 1 or (F) 24 h was used as a metabolism-independent metric of cell viability for the measurement of the sensitivity of MDA-MB-231 and BT20 cells to 3BP. (G) Transfection efficiency was assessed by Western blot analysis 1 and 2 days after addition of 3BP. (H) BT20 cells transfected with scramble (control) siRNA (sc-BT20) or siRNA targeting MCT1 (siMCT1-BT20) were exposed to 3BP for 24 h and their viability measured (n = 4). (I) Cell viability following 24 h exposure of BT20 and MDA-MB-231 cells to α-cyano-4-hydroxycinnamate (CHC), an MCT1 inhibitor, and 3BP (150 μM). Data were normalized to untreated controls. (J) Bromide level (78Br and 80Br) normalized to control measured by LC-MS/MS in MDA-MB-231 and BT20 cell lysates (n = 6). Error bars represent SD, ** and * represent P < 0.05 and 0.01 respectively as determined by multiple t tests