HIF-1α inhibition affects BM and spleen colonization in mouse CLL and promotes ex vivo cell mobilization. (A) Spleen weight at the end of treatment with EZN-2208 (day 63) of mice transplanted with EµTCL1-derived leukemia and treated with EZN-2208 at day 54. Data are presented as mean values ± SEM (n = 3). (B) Percentage of leukemic cells (CD5⁺CD19⁺) in the BM of mice transplanted with EµTCL1-derived leukemia, treated with EZN-2208, and euthanized as in panel A (n = 3). (C) Percentage of annexin V⁺ leukemic cells (CD5⁺CD19⁺) in the BM and spleen of mice transplanted with EµTCL1-derived leukemia, treated with EZN-2208, and euthanized as in panel A (n = 3). (D) Number of microvessels per field (original magnification ×40) in spleen colonized by leukemic cells of mice treated and euthanized as in panel A. Data represent mean values ± SEM (n = 2). (E) Kaplan-Meier survival curve of mice transplanted with EµTCL1-derived leukemia, treated with EZN-2208, and euthanized when terminally sick (untreated, n = 7; EZN-2208-treated animals, n = 5). (F) Number of leukemic (CD5⁺CD19⁺) and nonleukemic (CD5⁻CD19⁻) cells released in the culture supernatant from spleen fragments of EµTCL1-derived leukemic mice after 48 hours ex vivo culture in bioreactor. Data are represented as mean values ± SEM of 3 independent experiments. (G) Percentage of annexin V⁺ leukemic (CD5⁺CD19⁺) and nonleukemic (CD5⁻CD19⁻) cells released from spleen fragment after ex vivo culture in bioreactor for 48 hours. Data are represented as mean values ± SEM of 3 independent experiments. (H) Percentage of annexin V⁺ leukemic (CD5⁺CD19⁺) cells within spleen fragments after ex vivo culture in bioreactor for 48 hours. Data represent mean values ± SEM of 3 independent experiments.