Skip to main content
. Author manuscript; available in PMC: 2011 May 1.
Published in final edited form as: Cancer Res. 2010 Oct 19;70(21):8526–8536. doi: 10.1158/0008-5472.CAN-10-1563

Figure 3. MEK-dependent BRAFV600E signaling elevates cellular ROS levels, which stimulate Thr223 phosphorylation of FOXO4 by JNK.

Figure 3

a) BRAFV600E expression increases cellular ROS. BRAFV600E-expressing HEK293T cells were treated 24 hours with 4mM NAC, 20μM U0126 or 45 minutes with 200μM H2O2 and analyzed for DCF fluorescence. b) Reduced MEK activity or cellular ROS inhibits BRAFV600E-induced FOXO4 phosphorylation by JNK. Experiment as in Fig. 2c, but upon pretreatment for 24hrs 20μM U0126 or 4mM NAC. c) Interference with cellular ROS levels inhibits FOXO4-induced senescence. Colo829 cells were transfected as in Fig. 1b and treated at days 1.5 and 5.5 post transfection with 1mM NAC and analyzed for colony formation and SA-β-GAL positivity.