儿童白血病BMSCs及VLA-4抗体联合VP-16对白血病细胞凋亡的影响

目的研究儿童白血病(急性淋巴细胞白血病和急性髓系白血病)骨髓基质细胞(BMSCs)、缓慢抗原-4(VLA-4)抗体及VLA-4抗体联合化疗药物足叶乙甙(VP-16)对儿童白血病细胞凋亡的影响,探索儿童白血病新的治疗方法。方法分离培养儿童白血病骨髓单个核细胞,根据组别加入VLA-4抗体和VP-16,采用流式细胞仪检测不同组别白血病细胞的凋亡率。结果对照组与BMSCs组、骨髓基质上清组比较,其白血病细胞早期凋亡率均有显著增高,P<0.05,而BM-SCs组与骨髓基质上清组比较,白血病细胞早期凋亡率无显著差异。抗体组、BMSCs组和骨髓基质上清组白血病细胞凋亡率分别为12 h:(10.16±1.29)%,24 h:(13.72±1.72)%]、12 h:(4.99±1.66)%,24 h:(5.54±1.53)%]12 h:(6.06±1.77)%,24 h:(6.62±1.8)%],抗体组与BM-SCs组和骨髓基质上清组比较,其早期凋亡率均显著增加,P<0.05;抗体加药物组白血病细胞早期凋亡率最高,为12 h:(26.79±1.29)%,24 h:(20.81±1.39)%],与其他任何一组比较,差异显著,P<0.05;除BMSCs组和骨髓基质上清组,其他四个组12 h与24 h的白血病细胞早期凋亡率有显著差异,P<0.05。结论白血病患儿的BMSCs可以保护白血病细胞免于失巢凋亡和药物诱导的凋亡,VLA-4抗体可增强VP-16诱导的白血病细胞的凋亡敏感性。

Influence of bone marrow stromal cells and VLA-4 antibody combined with VP-16 on the apoptosis induction of leukemic cells

Objective To investigate the influence of BMSCs,VLA-4 antibody and VLA-4 antibody combined with VP-16 on the apoptosis induction of leukemic cells,to explore the possibility of developing a new modality of treatment for childhood leukemia. Methods Bone marrow stromal cells were isolated by human lymphocyte separation medium and in vitro culture BMSCs(adherent) and leukemic cells(suspended).Then add VLA-4 antibody and/or VP-16 to related groups to detect the apoptosis of leukemic cells in different groups through flow cytometry.Results The apoptosis rate of leukemic cells for BMSCs group,bone marrow stromal supernatant group were of 12 h:(4.99~1.66)%,24 h:(5.54±1.53) %] and 12 h:(6.06±1.77) %,24 h:(6.62±1.81) %].As compared with control group,the apoptosis rate of leukemic cells for BMSCs group and bone marrow stromal supematant group had significant difference,P<0.05.The comparison of leukemic cells' apoptosis rate between BMSCs group and bone marrow stromal supernatant group had no significant difference.The apoptosis rate of leukemic cells for the VLA-4 antibody group, VP-16 group,VLA-4 antibody plus VP-16 group were of 12 h:(10.16±1.29) %,24 h:(13.72±1.72) %],12 h:(17.05±1.14) %,24 h:(21.30±1.02) %] and 12 h:(20.81±1.39)%,24 h:(26.79±1.29)%,].Whether compared with the BMSCs group or with bone marrow stromal supernatant group,the apoptosis rate of leukemic cells for the VLA-4 antibody group, VP-16 group,VLA-4 antibody plus VP-16 group had significant difference,P<0.05.As for VLA-4 antibody group,VP-16 group and VLA-4 antibody plus VP-16 group,the comparison of apoptosis rate for any two groups had significant difference,P<0.05.VLA-4 antibodies plus VP-16 produce a stronger apoptosis induction effect.Additionally,the apoptosis rate of both BMSCs group and bone marrow stromal supernatant group had no significant difference between 12 h and 24 h.The apoptosis rate of leukemic cells of the other four groups had significant difference,P<0.05.To some degree,the apoptosis rate of leukemic cells induced by VLA-4 antibody,VP-16 was time-dependent,P<0.05.Conclusion BMSCs from childhood leukemia can protect leukemic cells from anoikis and VP-16 induced-apoptosis, and VLA-4 antibody may enhance VP-16 induced-apoptosis sensitivity.