Antineoplastic Agents/pharmacology; Breast Neoplasms/metabolism; Protein Serine-Threonine Kinases/antagonists & inhibitors; Pyrazoles/pharmacology; Pyrimidines/pharmacology; Animals; Antineoplastic Agents/toxicity; Apoptosis/drug effects; Aurora Kinases; Breast Neoplasms/genetics; Cell Line, Tumor; Cell Proliferation/drug effects; Cellular Senescence/drug effects; Cluster Analysis; Disease Models, Animal; Drug Resistance, Neoplasm/genetics; Female; G2 Phase Cell Cycle Checkpoints/drug effects; Gene Expression Profiling; Humans; Inhibitory Concentration 50; Mice; Mice, Nude; Mutation; Protein Serine-Threonine Kinases/metabolism; Pyrazoles/toxicity; Pyrimidines/toxicity; Receptor, ErbB-2/metabolism; Signal Transduction; Tumor Stem Cell Assay; Tumor Suppressor Protein p53/genetics; Tumor Suppressor Protein p53/metabolism; Xenograft Model Antitumor Assays