Fig. 4
KRAS/RAF1 Regulation of β-Catenin Requires the Activity of RAC1 (A and B) SW-480 cells transfected with vehicle or myc-tagged ([A], S191A or S605A) or flag-tagged ([B], S552A or S675A) β-catenin mutants were stained for DNA (magenta) and α-myc ([A], green) or α-flag ([B], green). (C) SW-480 cells were transfected with RAC1-directed siRNA, DN-RAC1, and DN-Cdc42 or treated with the RAC1-specific inhibitor NSC23766 and stained for DNA (magenta) and β-catenin (green). (D) SW-480 cells were subjected to an MTT assay (*p < 0.05 versus DMSO; error bars, SEM). (E) SW-480 cells were transfected with vehicle, KRASG12V-targeted siRNA, RAF1 siRNA, or DN-MEK1 and subjected to a RAC1 activity assay. The western blot was probed for RAC1 (top). Control lysates were probed for total RAC1 (bottom). (F) SW-480 cells treated as above were stained for phospho-cJun. (G) Human 293 cells transfected with constitutively active RAC1 and treated with PGE2 or DMSO were stained for DNA (magenta) and β-catenin (green). All images were captured using the same exposure and are representative of at least three independent experiments. Scale bar, 10 μm. |
Reprinted from Cell, 137(4), Phelps, R.A., Chidester, S., Dehghanizadeh, S., Phelps, J., Sandoval, I.T., Rai, K., Broadbent, T., Sarkar, S., Burt, R.W., and Jones, D.A., A two-step model for colon adenoma initiation and progression caused by APC loss, 623-634, Copyright (2009) with permission from Elsevier. Full text @ Cell