Endocytosis-dependent mitochondrial transfer is differentially stimulated by antineoplastic agents. (A) Percentage of GFP⁺mCherry⁺ live cells in the GFP⁺ gated population of the specified AML cell lines after 72 hours of coculture with MS-5 OMI/HTRA2-mCherry with the indicated dose of endocytosis inhibitors dansylcadaverine (DanzylCad) or chlorepromazine (ChlorPZ), normalized to control condition. (B) Data show mCherry fluorescence intensity of MS-5 OMI/HTRA2-mCherry cells treated with the indicated dose of DanzylCad or ChlorPZ for 72 hours normalized to control untreated condition. No significant differences were observed (NS). (C) Mean percentage ± SD of mCherry⁺ normalized to control condition of the AML#C3-1 cells after 72 hours of coculture with MS-5 OMI/HTRA2-mCherry with the indicated dose of endocytosis inhibitors DanzylCad or ChlorPZ. (D-G) HL-60, Kasumi-1, MOLM-14, NB-4, or U937 GFP⁺ AML cells were cocultured for 72 hours with (D,E,G) MitoTracker Red–loaded MS-5 or (F) MS-5 OMI/HTRA2-mCherry. Cocultures were treated with cytarabine (ARA) 3 µM or etoposide 3 µM (ETO), doxorubicin 0.3 µM (DOXO), or vincristine 1 nM (VINCRI). Grand mean (±standard error of the mean [SEM]) of mean response per cell line determined from 3 to 6 independent experiments. (D) Grand mean (±SEM) of viable AML cell counts normalized to control untreated condition (CT). (E) Data shown represents the grand mean (±SEM) of MitroTracker Red MFI for the leukemic GFP⁺ gated cells normalized to control condition. (F) Grand mean percentage of GFP⁺mCherry⁺ live cells in the GFP⁺ gated population normalized to control condition. ***P < .001 in a paired t test. (G) Cocultures were treated with cytarabine 3 µM (ARA) for 72 hours or prior to coculture MS-5 only (pre-ARA MS-5) or AML cells only (pre-ARA AML) were treated with ARA for 24 hours, and then treated cells were washed 2 times with PBS. Fresh medium was added, and cocultures were performed for 72 hours. Data shown represent the grand mean ± SEM MitroTracker Red MFI for the leukemic GFP⁺ gated cells normalized to control conditions. (A,B,D,E,G) ^NSP > .05, *P < .05, **P < .01, ***P < .001, determined by ANOVA.