Panobinostat induces expression and mitochondrial localization of Nur77, as well as induces loss of viability of primary CTCL cells. (A) Bone marrow– or peripheral blood–derived CD4⁺ primary CTCL cells from 5 patients with advanced CTCL were treated with the indicated concentrations of panobinostat or vorinostat for 48 hours. Then, the percentages of nonviable cells were determined by trypan blue dye uptake in a hemocytometer. Values represent the percentage of nonviable cell from each condition compared with untreated cells. * denotes values significantly different from that of untreated controls (P < .05). (B) Normal CD4⁺ cells from peripheral blood were treated with the indicated concentrations of panobinostat or vorinostat for 48 hours. Following this, the percentages of nonviable cells were determined by trypan blue dye uptake in a hemocytometer. Values represent the percentage of nonviable cells from each condition compared with untreated cells. (C) Total cell lysates from CD4⁺ cells harvested from the peripheral blood of a CTCL patient undergoing panobinostat treatment were prepared and immunoblot analysis was done for HDAC7 and Nur77. The levels of β-actin in the lysates served as the loading control. (D) Primary CTCL cells were harvested from a patient undergoing panobinostat treatment at the indicated times. Cells were incubated with MitoTracker for 30 minutes, cytospun, and stained with Nur77. Images were acquired with a Zeiss LSM510 meta confocal microscope equipped with a 63×/1.2 NA water immersion–objective lens.