骨髓基质细胞及VLA-4抗体对儿童白血病细胞凋亡影响的研究

Effects of bone marrow stromal cells and VLA-4 antibody on apoptosis of childhood leukemia cells

摘要:

目的：研究骨髓基质细胞（BMSCs）对儿童白血病细胞的保护作用及细胞粘附分子缓慢抗原-4（VLA-4）抗体对原代白血病细胞凋亡的影响。方法：分离儿童白血病骨髓单个核细胞，培养BMSCs及白血病细胞。实验分4个组：①白血病细胞单独培养组（对照组）；②BMSCs＋白血病细胞组（BMSCs组）；③BMSCs上清+白血病细胞组（上清组）；④BMSCs＋白血病细胞＋VLA-4抗体组（抗体组）。流式细胞仪检测各组白血病细胞的凋亡率，RT-PCR方法检测各组白血病细胞survivin和bcl-2基因的表达。结果：BMSCs组和上清组的白血病细胞凋亡率均低于对照组，P<0.05。与BMSCs组和上清组比较，抗体组的凋亡率显著增高，P<0.05。抗体组12 h的凋亡率与24 h的凋亡率比较，差异有统计学意义，P<0.01。与BMSCs组和上清组比较，抗体组survivin、bcl-2基因的表达均有降低,P<0.05。结论：BMSCs对白血病细胞有保护作用，VLA-4抗体能够抑制白血病BMSCs与白血病细胞间的粘附，促进白血病细胞的凋亡。［中国当代儿科杂志，2010，12（11）：897-901］

Abstract:

OBJECTIVE: To study the protective effect of bone marrow stromal cells (BMSCs) upon childhood leukemia cells and the influence of VLA-4 antibody in vitro on leukemia cell apoptosis. METHODS: BMSCs from children with acute leukemia-were isolated by human lymphocyte separation medium. BMSCs (adherent) and leukemia cells (suspended) were cultured in vitro. This study included four groups: leukemia cells alone (control), leukemia cells+BMSCs, leukemia cells+BMSCs supernatant and leukemia cells+BMSCs+VLA-4 antibody. The apoptosis rate of leukemia cells in the four groups was determined by Annexin Ⅴ-FITC double-labeled flow cytometry. The expression of survivin and bcl-2 genes in leukemia cells was ascertained by RT-PCR. RESULTS: The apoptosis rate of leukemia cells in the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups was lower than that in the control group (P<0.05). Compared with the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups, the apoptosis rate of leukemia cells in the VLA-4 antibody group increased significantly (P<0.05). In the VLA-4 antibody group, the apoptosis rate of leukemia cells increased with prolonged culture time. There were significant differences in the apoptosis rate between 12 hrs and 24 hrs after VLA-4 antibody treatment (P<0.01). The expression of survivin and bcl-2 genes in leukemia cells from the VLA-4 antibody groups was reduced compared with that from the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups (P<0.05). CONCLUSIONS: BMSCs play protective roles on leukemia cells. VLA-4 antibody can block the adhesion between BMSCs and leukemia cells and promote leukemia cell apoptosis.［Chin J Contemp Pediatr, 2010, 12 (11):897-901］