Li Qian, Wei Shan-Shan, Li Jin-Gao, Chen Shao-Xian, Chen Jing, Huang Hui-Ting, Peng Qi, Xia Ping-Fang, She Miao-Rong
Department of Hematology, Guangdong People's Hospital (Guangdong Academy of Medical Sciences), Guangzhou 510080, Guangdong Province, China.
Department of Hematology, Jingmen Municipal First People's Hospital, Jingmen 448000, Hubei Province, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2017 Feb;25(1):85-89. doi: 10.7534/j.issn.1009-2137.2017.01.014.
To investigate the allo-NK cell-mediated killing effect enhanced by decitabine on leukemia stem cells(LSC) and the underlying mechanisms.
LSC were separated from KG1a cells by using immunomagnetic beads. Allo-NK cells were isolated and purified from PBMC of healthy donors. Cytotoxicity of allo-NK cells against LSC were measured by LDH releasing assay. The apoptosis induced by allo-NK cells in LSC and the expressions of NKG2D ligands including MICA/B and ULBP1-3 on LSC were detected by flow cytometry.
The killing rate of allo-NK cells to LSC treated with 10 µmol/L decitabine for 24 hours was significant higher than that to LSC without treatment(60.52%±3.52% vs 22.08%±2.07%, 73.93%±2.33% vs 28. 99%±3.13%, 83.08%±1.32% vs 36.44%±2.40%, respectively)at the effector-target ratios of 5:1, 10:1, 20:1 (P<0.05). At the effector-target ratio of 10:1, decitabine significantly enhanced the apoptosis of LSC induced by allo-NK cells (7.84%±0.34% vs 3.33%±0.64%)(P<0.05). The expressions of NKG2D ligands(MICA/B,ULBP1,ULBP2,ULBP3) on LSC treated with decitabine 10 µmol/L for 24 hours were significantly increased (P<0.05).
Decitabine may enhance the allo-NK cell-mediated killing effects on LSC by up-regulation of the expressions of NKG2D ligands on LSC.
探讨地西他滨增强同种异体自然杀伤（allo-NK）细胞对白血病干细胞（LSC）的杀伤作用及其潜在机制。
采用免疫磁珠法从KG1a细胞中分离LSC。从健康供者外周血单个核细胞（PBMC）中分离并纯化allo-NK细胞。采用乳酸脱氢酶（LDH）释放法检测allo-NK细胞对LSC的细胞毒性。通过流式细胞术检测allo-NK细胞诱导LSC凋亡的情况以及LSC上NKG2D配体包括MICA/B和ULBP1-3的表达。
在效应细胞与靶细胞比例为5:1、10:1、20:1时，用10 μmol/L地西他滨处理24小时的LSC，allo-NK细胞对其杀伤率显著高于未处理的LSC（分别为60.52%± 3.52%对22.08%±2.07%，73.93%±2.33%对28.99%±3.13%，83.08%±1.32%对36.44%±2.40%）（P<0.05）。在效应细胞与靶细胞比例为10:1时，地西他滨显著增强了allo-NK细胞诱导的LSC凋亡（7.84%±0.34%对3.33%±0.64%）（P<0.05）。用10 μmol/L地西他滨处理24小时的LSC上NKG2D配体（MICA/B、ULBP1、ULBP2、ULBP3）的表达显著增加（P<0.05）。
地西他滨可能通过上调LSC上NKG2D配体的表达来增强allo-NK细胞对LSC的杀伤作用。
