Cdc42 and RhoA activities and MAPK signaling are upregulated in Cdc42-overexpressing mammary glands. (A) Graph depicts RhoA activity as average light units (ALU) (± SEM) in lysates prepared from mammary organoids isolated from line 4 and control mice after 1 week and 3 weeks of dox treatment (*P = 0.02). Data represent four animals at 1 week and two animals at 3 weeks per group. (B) Graph shows Cdc42 activity as average OD 490 readings (± SEM) from lysates prepared from organoids isolated from line 4 and control mice after 1 week and 3 weeks of dox treatment (*P = 0.01). Data represent four animals per group at 1 week and three animals per group at 3 weeks. (C) Rac activity assay results are representative of three animals per group at 1 week and five animals per group at 3 weeks. (D) Western analysis of phosphorylated ERK, P38, and JNK in lysates prepared from whole mammary glands after 3 weeks of dox treatment (n = 5 pooled animals per group). Densitometry values are normalized to tubulin loading control and represented as fold change compared to control. Cdc42, cell division cycle 42; ERK, extracellular signal-related kinase; JNK, c-Jun N-terminal kinase; MAPK, mitogen-activated protein kinase; Rho, Ras homolog gene family, member A.