TDZ induces ROS production and mitochondrial depolarization in t(6;11) AML cell through calcium influx. (A) ROS levels detected 6, 16, and 24 hours after TDZ treatment compared with DMSO, in SHI-1 and HL60 cells (n = 2). (B) Mitochondrial depolarization evaluated by tetramethylrhodamine ethyl (TMRE) fluorescence measurement, 6 and 24 hours after TDZ treatment compared with DMSO, in SHI-1 and HL60 cells (n = 5). (C-D) Live intracellular Ca²⁺ in t(6;11) SHI-1 (C) and in non-t(6;11) HL60 (D) cell lines, loaded with Fluo-4 AM Ca²⁺ indicator, measured by flow cytometry, in Ca²⁺-containing or -free buffer (n = 5). Values are the mean ± SEM. *P < .05; **P < .01. (E-F) Live intracellular Ca²⁺ in t(6;11) (E) and non-t(6;11) primary (F) cells, loaded with Fluo-4 AM Ca²⁺ indicator, measured by flow cytometry. (G-H) Intracellular Ca²⁺ in SHI-1 (G) and t(6;11) primary cells (H) measured with a 2-photon microscope. Values are the mean fluorescence of 10 cells ± SEM. Images show baseline vs peak fluorescence of a representative cell. Bars represent 20 μm.