KPT-330 decreased survival and clonogenic potential in CML-BC and Ph⁺ B-ALL cells. (A) Top panel: Representative (n = 3) western blot showing XPO1 protein levels in vehicle- or KPT-330–treated (1 µM, 72 hours) CD34⁺ CML-CP and CML-BC, and CD34⁺/CD19⁺ Ph⁺ ALL progenitor cells. Numbers above the blots indicate relative densitometric units. Bottom panel: Graph shows percentage of apoptosis (annexin V⁺) in vehicle- or KPT-330–treated (0-8 µM, 72 hours) NBM and CML-BC CD34⁺ cells. EC₅₀ was calculated as described in “Methods.” (B) Graph shows percentage of annexin V⁺ cells (mean ± SEM) in vehicle- and KPT-330 (0.5-1 µM, 72 hours)–treated NBM (n = 3), CML-CP (n = 3) and CML-BC (n = 3) CD34⁺ BM cells, and CD34⁺/CD19⁺ Ph⁺ B-ALL (n = 3) and Ph⁻ B-ALL (n = 3) BM cells. (C) Colony-forming ability of vehicle- or KPT-330–treated (0.5-1 µM, 72 hours) NBM (n = 3), CML-CP (n = 3), and CML-BC (n = 3) CD34⁺ BM cells. Clonogenic potential, shown as mean ± SEM, was normalized to the respective untreated sample. (D) Annexin V⁺ cells (mean ± SEM) in 32D-BCR/ABL cells treated with KPT-330 (1 µM, 24 hours) and imatinib (1 µM, 24 hours) used alone or in combination. Significance was determined using the Student t test of 3 identical experiments. Asterisks indicate P values vs NBM; *P < .05, **P < .01, ***P < .001.