LY500307 induces apoptosis and G2/M cell cycle arrest in CTCL cells. (A) CTCL cells were treated with 10-μM LY500307 or DMSO for 48 hours. Cells were then stained for 20 minutes with annexin V fluorescein isothiocyanate and 7AAD. Annexin V–positive cells were determined by flow cytometry. Representative data shown from 3 independent experiments (left) and mean value of 3 independent experiments with SD (right). Mean value of 3 independent experiments. (B) LY500307 activates caspase 3/7, which was determined using Caspase-Glo 3/7 assay. Cells were treated for 48 hours with 10 μM of LY500307. Activity was normalized to cells treated with DMSO (untreated Ctrl). Mean values of 3 independent experiments with SD are plotted. (C) Protein expression in CTCL cells, determined by performing western blots; 30 μg of protein was loaded for each sample, and GAPDH served as a loading Ctrl. The data shown are from 3 independent experiments. (D) LY500307 induces G2/M arrest of CTCL cells. Hut, MyLa, SeAx, and HH cells were either treated with vehicle or LY500307 for 24 hours. Cells were then fixed with 70% ethanol, and PI staining was performed for 30 minutes. Cell cycle distribution was analyzed using flow cytometry. Mean value of 3 independent experiments with SD is plotted. ∗P < .5. 7AAD, 7-aminoactinomycin; Ly, LY500307; PE-A, phycoerythrin-A.