FIGURE 10.
B-RAF cooperates with C-RAF BxB in the activation of the MAPK cascade. A, total lung protein lysates from 2, 7, and 12 months old DOX-treated and control compound mice were gel separated and immunoblotted with the indicated antibodies; M, months, Genotype and induction status are as indicated. B, SpC-C-RAF BXB/SpC- rtTA/Tet-O-cre/B-RAFflox/flox compound mice were DOX-induced for 2 and 7 months and compared with aged-matched controls. Representative pictures and quantification of nuclear phospho-ERK staining (brown) of paraffin-embedded lung sections. Genotype and induction status are as indicated. Red arrows point to cells with nuclear staining. Hematoxylin was used as a counterstain. A total of 40 tumors from four mice for each group were analyzed. Mean values are + S.E.; t test, ***, p < 0.0005.