白血病骨髓基质细胞对白血病细胞屏蔽效应的体外实验研究

背景与目的:肿瘤微环境是影响肿瘤细胞转归的关键因素之一。骨髓微环境能保护白血病细胞,促进白血病细胞耐药、抗凋亡存活,但机制未完全阐明。本研究中我们主要观察骨髓基质细胞促白血病细胞抵抗柔红霉素(daunorubicin,DNR)杀伤的屏蔽效应,旨在探讨骨髓基质细胞增强Jurkat细胞抗凋亡、抗药特性的可能机制。方法:应用Percoll分离正常及白血病性骨髓单个核细胞,体外培养骨髓基质细胞模拟骨髓微环境功能,与白血病细胞Jurkat体外共培养。AnnexinV/PI双标法流式细胞仪检测0.5μmol/LDNR处理后Jurkat细胞凋亡率的变化。PI染色流式细胞仪检测细胞周期分布。结果:共培养后正常骨髓基质细胞抑制DNR诱导的Jurkat细胞凋亡,与单独悬浮培养组比较显著降低[(8.39±4.08)%和(16.02±1.00)%,P<0.05]。白血病骨髓基质细胞对Jurkat细胞的屏蔽效应强于正常骨髓基质细胞[Jurkat细胞凋亡率分别是(5.73±1.78)%和(8.39±4.08)%,P<0.05]。DNR处理正常或白血病骨髓基质细胞共培养组G0/G1期Jurkat细胞比例高于悬浮培养DNR处理组,而正常与白血病骨髓基质细胞屏蔽的Jurkat细胞G0/G1期阻滞现象无显著性差异[(47.96±5.88)%和(39.25±3.04)%,P>0.05]。结论:骨髓基质细胞可能部分通过阻滞白血病细胞于G0/G1期,抑制DNR诱导的白血病细胞

Leukemic bone marrow stromal cells in vitro protect leukemic cell line Jurkat cells from daunorubicin-induced apoptosis

BACKGROUND & OBJECTIVE: Tumor microenvironment affects tumor cells growth. Bone marrow microenvironment may protect leukemic cells from drug-induced damages, but the mechanism is unclear. This study was to explore the protection of bone marrow stromal cells (BMSCs) on leukemic cells against chemotherapy and its mechanism. METHODS: Normal and leukemic BMSCs were isolated using Percoll, and cocultured with human acute lymphocyte leukemic cell line Jurkat cells in vitro. After treatment of 0.5 micromol/L of daunorubicin (DNR), apoptosis and cell cycle distribution of Jurkat cells were analyzed by flow cytometry. RESULTS: When treated with DNR for 24 h, apoptosis rate of normal BMSCs-cocultured Jurkat cells was significantly lower than that of Jurkat cells without coculture [(8.39+/-4.08)% vs. (16.02+/-1.00)%, P < 0.05], and apoptosis rate of leukemic BMSCs-cocultured Jurkat cells was significantly lower than that of normal BMSCs-cocultured Jurkat cells [(5.73+/-1.78)% vs. (8.39+/-4.08)%, P < 0.05]; G(0)/G(1) phase percentage of BMSCs-cocultured Jurkat cells was significantly higher than that of Jurkat cells without coculture (P < 0.05), but the difference between Jurkat cells cocultured with normal and leukemic BMSCs was not significant (P > 0.05). CONCLUSION: Leukemic BMSCs may inhibit DNR-induced apoptosis in leukemic cells partly through G(0)/G(1) phase arrest.