Inhibition of NPM-ALK activity results in reduced Cyp40 and FKBP52 protein levels. (A) Western blot analysis examining NPM-ALK phosphorylation (anti-pALK blot) in Karpas 299 (upper) or SUP-M2 (lower) cells left untreated or treated with 25, 50 or 75 nM of the ALK inhibitor, Crizotinib, for 48 h. (B) NPM-ALK phosphorylation in Karpas 299 (upper) or SUP-M2 (lower) cells left untreated or treated with 75 nM Crizotinib for 24, 48 or 72 h. Note: all cells were split into fresh Crizotinib-containing media 24 and 48 h post-treatment to maintain the cells in logarithmic growth. (C & D) Western blot analysis of Cyp40, FKBP52 and FKBP51 protein levels in Karpas 299 (upper) or SUP-M2 (lower) cells treated as in (A) or (B). * indicates a non-specific band in the anti-FKBP51 blot. Quantification of blots are shown to the right and represent the mean and standard deviation of four (C) or three (D) independent experiments. p values comparing untreated cells to cells treated with each concentration of Crizotinib (C) or comparing treated cells at each time point to untreated cells at the 24 h time point (D) were obtained using paired, one-tailed t-tests. §p < 0.05, + p < 0.01, # p < 0.005.