多聚赖氨酸修饰γ-Fe_2O_3纳米颗粒标记不影响神经母细胞瘤干细胞的活化和增殖

Polylysine-modified gamma-Fe_2O_3 nanoparticle labeling has no effect on neuroblastoma stem cell activation and proliferation

背景:维甲酸是最有潜力的神经母细胞瘤微小残留病灶的诱导剂,能诱导体内细胞分化,同时伴有肿瘤细胞增殖减低。目的:探讨纳米颗粒标记对神经母细胞瘤干细胞生物学特性的影响以及13-顺维甲酸对神经母细胞瘤干细胞的诱导分化作用。方法:采用无血清悬浮培养法体外分离培养神经母细胞瘤干细胞,多聚赖氨酸修饰γ-Fe_2O_3纳米颗粒标记神经母细胞瘤干细胞,在含有13-顺维甲酸的培养液中诱导分化培养,RT-PCR法检测标记前后和诱导前后Oct-4的表达变化,用细胞免疫荧光法观察标记前后和诱导前后nestin的表达变化。结果与结论:(1)20例患者的骨髓标本中有5例成功培养出神经母细胞瘤干细胞。(2)多聚赖氨酸修饰γ-Fe_2O_3纳米颗粒标记不影响神经母细胞瘤干细胞的活性和增殖能力,Oct-4 mRNA表达和nestin表达也没有明显变化。(3)加入13-顺维甲酸培养后,细胞形态发生变化,生长速度减慢,Oct-4 mRNA表达和nestin表达逐渐降低。(4)结果表明多聚赖氨酸修饰γ-Fe_2O_3纳米颗粒可以用于标记神经母细胞瘤干细胞,13-顺维甲酸可以诱导神经母细胞瘤干细胞分化。

BACKGROUND： Retinoic acid is the most promising inducer for neuroblastoma minimal residual lesion, and it can induce cell differentiation in vivo, accompanied by reducing tumor cell proliferation. OBJECTIVE： To study the effect of nanoparticle labeling on biological characteristics of neuroblastoma stem cells, and the role of 13-cis retinoic acid to induce differentiation of neuroblastoma stem cells. METHODS： Neuroblastoma stem cells were isolated and cultured in vitro using serum-free suspension culture method, labeled with polylysine-modified γ-Fe2O3 nanoparticles and induced in culture medium containing 13-cis retinoic acid. RT-PCR was used to detect the expression of Oct-4 before and after labeling as well as before and after induction. Immunofluorescence method was used to detect the expression of nestin before and after labeling as well as before and after induction. RESULTS AND CONCLUSION： Neuroblastoma stem cells were successfully cultured in the bone marrow samples from 5 of 20 cases. Polylysine-modified γ-Fe2O3 nanoparticle labeling did no influence the viability and proliferation ability of neuroblastoma stem cells, and also had no effect on Oct-4 mRNA and nestin expression. After cultured in the culture medium containing 13-cis retinoic acid, the cell shape changed and the growth rate slowed down. Moreover, the expression of Oct-4 mRNA and nestin was gradually reduced. These findings indicate that polylysine-modified gamma-Fe2O3 nanoparticles can be used to label neuroblastoma stem cells, and 13-cis retinoic acid can induce the differentiation of neuroblastoma stem cells.