T3 or T4 induces MAPK activation in myeloma cells. T3 or T4 induces MAPK activation in myeloma cells. A, serum-starved CAG cells were treated for 10 minutes with T3 (1 nmol/L; *, P < 0.003) or T4 (100 nmol/L; *, P < 0.03), in the presence/absence of the MAPK inhibitor U0126 (30 μmol/L). pERK and ERK protein levels were measured by Western blot analysis. α-Tubulin was used to normalize the amount of loaded proteins. B, CAG cells were treated overnight with T3 or T4 (0.1–1,000 nmol/L) after which pERK and ERK were measured by Western blot analysis. Experiments were repeated twice, and results are presented as average ± SEM. For T3 and T4, *, P < 0.01 and P < 0.05, respectively. C, CAG cells were treated with DMSO (left), T3 (1 nmol/L, middle), and T4 (100 nmol/L, right), and immunofluorescence was done using pERK antibodies (labeled green) and nuclear stain (blue florescence). Cells were visualized by a florescent microscope equipped with a camera (model IX71; Olympus) with a 20×/0.50 objective lens and Cell∧A (version 3.1) Olympus software imaging. Keren Cohen et al. Mol Cancer Res 2011;9:1385-1394 ©2011 by American Association for Cancer Research