Pharmacological targeting of androgen receptor (AR) with bicalutamide (CDX) is additive in combination with of GDC0941 and GDC0980 in AR + triple-negative breast cancer (TNBC) cell lines. (A) Line graphs show viability of AR + cell lines treated with increasing concentrations of GDC-0941 (top) or GDC-0980 (bottom) alone (blue) or in combination (red) with 25 μM CDX. Dashed black line depicts the theoretical line of additivity of both drugs determined from the effect of CDX alone and either GDC-0941 or GDC-0980 alone. Error bars represent SD for three independent experiments. (B) Immunoblots from AR + TNBC cell lines treated with either CDX (25 μM), GDC-0941 (300 nM) or GDC0980 (100 nM) as single agents or CDX in combination with either GDC-0941 or GDC-0980 for 48 h analyzed for AR, p-AKT, AKT, p-S6, S6 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein.