Fig. 8

CA and Tz cooperatively inhibit in vitro survival of Tz-resistant SKBR-3 cells. a Cells were cultured for 7d with control medium (Ctr), CA, Tz or CA + Tz supplemented medium, which was changed every 48 h. Cell survival is expressed as arbitrary units (A.U.) after exposure of cultures to MTT for 4 h. Mean values and standard deviation (indicated as vertical bars) from three independent replicates (n = 3) are shown. P < 0.05 (*), P < 0.01 (**), P < 0.001 (***). b Cells were cultured for 7d with control medium (Ctr), CA, Tz or CA + Tz supplemented medium, which was changed every 48 h. A representative immunoblot analysis is shown, which was performed with anti-ERBB2, anti phospho-Ser⁴⁷³ AKT, anti AKT, anti p62, anti-Tubulin and anti-Vinculin antibodies on whole cell lysates. Tubulin is shown as loading controls for ERBB2. Vinculin is shown as loading controls for pAKT, AKT and p62. Numbers on each lane represent ERBB2 levels, pAKT/AKT ratios, and p62 levels determined as described in Methods. c Working model of CA and Tz effects in ERBB2+ breast cancer cells and proposed mechanisms of action