Lee Y Y, Kim E S, Seol J G, Kim B K, Binderup L, Elstner E, Park D J, Koeffler H P
Department of Internal Medicine, Han Yang University Hospital, Seoul, Korea.
Leukemia. 1996 Nov;10(11):1751-7.
The seco-steroid 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) induces differentiation and inhibits clonal proliferation of HL-60 cells. We analyzed the effect of a novel vitamin D3 analog, EB1089, on normal myeloid and leukemic cells as well as CD34+ cells. EB1089 showed an extraordinary inhibition of clonal growth of HL-60 cells (ED50 = 5 x 10(-11) M) and AML blast cells (ED50 = 9 x 10(-10) M) compared to 1,25(OH)2D3 without suppression of growth of normal human bone marrow CFU-GM. The CD34+ cells from acute myeloid leukemia (AML) blasts were inhibited in a dose-dependent fashion by 1,25(OH)2D3 with an ED50 of 1.2 x 10(-9) M; and even more strikingly, 10(-10) M of EB1089 inhibited all clonal growth of human CD34+ leukemic colony-forming cells. In contrast, both EB1089 and 1,25(OH)2D3 (10(-8) M) showed little or only mild inhibition of CD34+ clongenic hematopoietic cells from normal human peripheral blood (PB); and in liquid culture, EB1089 stimulated the proliferation of normal human CD34+ cells about 2.5 times as compared to control cultures. In order to evaluate the potential use of EB1089 for purging leukemic cells from normal CD34+ progenitor cells for PB stem cell transplantation (PBSCT), normal human PB mononuclear cells (PBMNC) were contaminated with HL-60 cells, and then CD34+ cells purified and treated with EB1089. We found that CD34+ purification and EB1089 purging was able to eliminate approximately 100% of HL-60 leukemic cells with no toxicity to normal CD34+ hematopoietic progenitor cells. These data suggested that purification of CD34+ cells and ex vivo treatment with EB1089 might provide an effective therapeutic approach for PBSCT.
甾体类维生素D3（1,25二羟基维生素D3，1,25(OH)2D3）可诱导HL-60细胞分化并抑制其克隆增殖。我们分析了一种新型维生素D3类似物EB1089对正常髓样细胞、白血病细胞以及CD34+细胞的作用。与1,25(OH)2D3相比，EB1089对HL-60细胞（半数有效剂量ED50 = 5×10(-11) M）和急性髓系白血病原始细胞（ED50 = 9×10(-10) M）的克隆生长具有显著抑制作用，且不抑制正常人骨髓CFU-GM的生长。急性髓系白血病（AML）原始细胞中的CD34+细胞被1,25(OH)2D3以剂量依赖性方式抑制，ED50为1.2×10(-9) M；更显著的是，10(-10) M的EB1089可抑制人CD34+白血病集落形成细胞的所有克隆生长。相比之下，EB1089和1,25(OH)2D3（10(-8) M）对来自正常人外周血（PB）的CD34+克隆造血细胞几乎没有抑制作用或仅有轻微抑制；在液体培养中，与对照培养相比，EB1089可使正常人CD34+细胞的增殖提高约2.5倍。为了评估EB1089在清除用于外周血干细胞移植（PBSCT）的正常CD34+祖细胞中的白血病细胞方面的潜在用途，将正常人PB单个核细胞（PBMNC）用HL-60细胞污染，然后纯化CD34+细胞并用EB1089处理。我们发现，CD34+细胞纯化和EB1089清除能够消除约100%的HL-60白血病细胞，且对正常CD34+造血祖细胞无毒性。这些数据表明，CD34+细胞纯化和EB1089体外处理可能为PBSCT提供一种有效的治疗方法。
