小剂量亚硒酸钠和全反式维甲酸联合使用诱导NB4细胞的凋亡及分化

目的 研究小剂量亚硒酸钠（2－5μmol/L）与全反式维甲酸（ATRA）联合使用对人急性早幼粒细胞白血病细胞株NB4凋亡及分化的影响。方法 采用膜联蛋白V（Annexin-V)荧光标记试剂盒检测细胞的磷脂酰丝氨酸（PS）外翻率和DNA片段化的琼脂糖凝胶电泳检测细胞凋亡，通过流式细胞术检测粒系分化细胞表面特异抗原CD11b表达，NBT还原实验检测细胞分化。结果 阴性对照组细胞术检测粒系分化细胞表达特异抗原CD11b表达，NBT还原实验检测细胞分化。结果 阴性对照组细胞PS外翻率为1．2％，5μmol/L亚硒酸钠处理NB4细胞48h后PS外翻率为0.8%,0.1μmol/L ATRA诱导48h后PS外翻率为2．0％，与对照组相比，差异均无显著性,而两者联合作用NB4细胞24，36，48h后的PS外翻率分别达到18.3%,25.9%,50.0%,DNA电泳呈典型的梯形带。小剂量（2μmol/L）亚硒酸钠没有诱导NB4细胞分化的能力，但其与0．1μmol/L的ATRA联合使用同单独使用0．1μmol/L的ATRA钠没有诱导NB4细胞分化的能力，但其与0．1μmol/L的ATRA联合使用单独使用0．1μmol/L的ARTA相比，CD11b表达阳性细胞率进一步增加，NBT还原能力也进一步增强。结论 小剂量的亚硒酸钠与ATRA联合使用可诱导NB4细胞发生凋亡及分化。

Apoptosis and differentiation induced by sodium selenite combined with all-trans retinoic acid (ATRA) in NB4 cells

OBJECTIVE: To study the effects of low dose sodium selenite combined with all-trans retinoic acid (ATRA) on apoptosis and differentiation of human acute promyelocytic leukemia (APL) NB4 cells. METHODS: Apo-ptosis was detected by translocation of phosphatidylserine (PS) with a Annexin-V kit and DNA fragmentation by agarose gel electrophoresis analysis, cell differentiation was studied by flow cytometry of CD(11b) expression and NBT reduction assay. RESULTS: Five micromol/L sodium selenite or 0.1 micromol/L ATRA alone could not induce apoptosis of NB4 cells within 48 hours. However, combination of the two drugs at the same doses as above could induce significant apoptosis in 48 hours characterized by increased PS translocation and DNA ladder. Sodium selenite at concentration of 2 micromol/L was not able to induce differentiation of NB4 cells, but when combined with 0.1 micromol/L ATRA, CD(11b) expression and NBT reduction were increased as compared with that of 0.1 micromol/L ATRA alone. CONCLUSION: Low dose sodium selenite could enhance the effects of low dose ATRA in inducing apoptosis and differentiation of NB4 cells.