Metabolism of LY500307 in fibroblasts, HaCaT keratinocytes, and CTCL cell lines. CTCL cells accumulate significantly higher concentrations of LY500307 than normal skin cells. Fibroblasts and HaCaT keratinocytes catabolize intracellular LY-500307 faster than CTCL cell lines. SeAx cells, MyLa cells, HaCaT keratinocytes, and fibroblasts were treated with 10-μM LY-500307 for 0.5, 24, and 48 hours. The concentrations of LY-500307 were measured by LC-MS/MS in the cell pellet (A) and supernatant (B). Data are shown as means with SD (n = 3-4). ∗P < .05; ∗∗P < .01; # indicates significant difference compared with 24 hours.