Objective: To study the blocking effect of CXCR4 inhibitor AMD3100 on the adhesion of leukemia cells to osteoblast niche, and the reversal of multidrug resistance in leukemia cells.
Methods: Mesenchymal stem cells (MSCs) from leukemia patients were planted on the bio-derived bone scaffolds and then induced into osteoblasts to establish the bio-osteoblast niche. The levels of SDF-1were tested with ELISA. The leukemia cell line MV4-11 cells with FLT3-ITD mutation were inoculated into the bio-osteoblast niche to build a three-dimensional co- culture system. The expression level of CXCR4, adhesion and apoptosis rates of leukemia cells were observed by flow cytometry after incubation with AMD3100 and Ara-C for 24 h and 48 h.
Results: (1)The supernatant levels of SDF-1 in cultured osteoblast were (304 ± 18), (410 ± 28) and (396 ± 16) pg/ml on 7 th, 14 th and 21 th day, respectively. It reached the highest on 14 th day. The expression level of CXCR4 in cultured MV4-11 cells was (72 ± 16)%. (2)Adhesion rate of MV4-11 cells to osteoblast niche was (40.1 ± 8.1)% after AMD3100 treatment for 24 h, while that of control group was (65.6 ± 12.1)% (P<0.05). (3)The apoptosis rate of MV4-11 cells incubated with AMD3100 for 24 h was (5.6 ± 0.8)%, while that of control group was (2.5 ± 0.5)%. The apoptosis rates of AMD3100-induced MV4-11 cells were (10.0 ± 2.4)%, (17.8 ± 2.3)% and (25.1 ± 2.4)% after treatment with Ara-C at 0.02, 0.20, 2.00 mg/ml respectively and they were (6.7 ± 1.0)%, (10.3 ± 1.5)%, (16.2 ± 3.1)% respectively in AMD3100-noninduced control group, the difference was significant (P<0.05).
Conclusion: AMD3100 can block the interaction between osteoblasts niches and leukemia cells, and play an important role in the reversal of multidrug resistance in leukemia cells.
目的: 探讨CXCR4阻断剂AMD3100对白血病细胞与成骨龛黏附的影响及逆转白血病细胞耐药的作用。
方法: 在生物衍生骨上接种白血病患者骨髓来源的间充质细胞，并诱导其分化为成骨细胞，构建一种仿生性的成骨龛，并用ELISA法检测培养上清中SDF-1的表达水平；然后在成骨龛中接种FLT3-ITD突变阳性的白血病细胞株MV4-11细胞，构建三维共培养体系，流式细胞术检测CXCR4的表达水平；在此共培养体系中加入AMD3100后，应用BCECF荧光标记测定白血病细胞的黏附率，流式细胞术分析阿糖胞苷（Ara-C）作用前后白血病细胞凋亡的变化。
结果: ①白血病骨髓成骨细胞培养7、14、21 d上清中SDF-1含量分别为（304±18）、（410±28）和（396±16）pg/ml，第14天达高峰；MV4-11细胞CXCR4表达水平为（72±16）%。②AMD3100作用24 h，成骨龛对MV4-11细胞黏附率为（40.1± 8.1）%，而不加药物的对照组为（65.6±12.1）%，差异有统计学意义（P<0.05）。③加入Ara-C前，AMD3100作用组细胞的凋亡率为（5.6±0.8）%，对照组为（2.5±0.5）%。加入0.02、0.20、2.00 µg/ml Ara-C后，AMD3100作用组细胞凋亡率增加为（10.0±2.4）%、（17.8±2.3）％和（25.1±2.4）%，明显高于对照组[分别为（6.7±1.0）%、（10.3±1.5）%、（16.2±3.1）%]（P值均<0.05）。
结论: AMD3100能够阻断骨髓成骨细胞龛和白血病细胞的相互作用，在逆转白血病细胞耐药中起重要作用。