Analysis of the kinetics of HSP70 induction and ERBB2 degradation following a singe dose of NVP-AUY922. BT-474 tumor-bearing animals were administered 50 mg/kg NVP-AUY922 at 0 hours. (a) The protein levels of HSP70 were determined by immunohistochemistry during the following week. (b) The quantification of the protein levels of HSP70. (c) ERBB2 protein levels were determined by immunohistochemistry and Western blot analysis. (d) The lowest single dose of NVP-AUY922 which mediates HSP90-p23 dissociation and reduced AKT phosphorylation was determined by immunoprecipitation and Western blot analysis. HSP70, heat shock protein 70; HSP90, heat shock protein 90.