人胶质瘤干细胞内在自我更新能力

目的 了解胶质瘤干细胞内在的自我更新和增殖能力。方法 观察原代胶质瘤细胞在单纯改良Eagle/F12培养液（DMEM/F12）中胶质瘤干细胞球的形成,并检测其CD133、胶质纤维酸性蛋白（GFAP）、微管相关蛋白（MAP2）、髓磷脂碱性蛋白（MBP）的表达。通过二代球体形成、细胞增殖测定、分化实验分析其自我更新、增殖、多能分化能力。通过裸鼠移植瘤实验观察所分离细胞球细胞与原代培养胶质瘤细胞成瘤能力的差异。结果 在单纯DMEM/F12培养液中形成的胶质瘤细胞球细胞表达神经干细胞标记CD133,不表达分化标志GFAP、MAP2,少数细胞表达MBP。分离出的胶质瘤细胞球细胞可在单纯DMEM/F12培养基中增殖,并能形成CD133阳性的二代细胞球,可分化为GFAP、MAP2、MBP阳性表达的肿瘤细胞。裸鼠成瘤实验显示其成瘤能力显著高于原代胶质瘤细胞。结论 胶质瘤干细胞能在无血清、无外源性细胞因子培养基中形成肿瘤干细胞球,胶质瘤干细胞的自我更新和增殖不依赖于外源性生长因子,它可能拥有自我更新的自身活化机制。

The endogenous regulation of self-renewal in human glioblastoma stem cells

Objective To observe the self-renewal and proliferation of glioblastoma stem cells cultured in serum-free medium without exogenous growth factor (SGFF-M).Methods Human primary glioblastoma cells were switched into SGFF-M. Glioblastoma spheres were formed, and the expression of differentiated antigen and undifferentiated antigen in glioblastoma spheres were examined. The capacity of self-renewal, proliferation and differentiation was analyzed by subspheres forming, proliferation in SGFF-M and differentiation assay in medium with 10% FBS (fetal bovine serum). Glioblastoma sphere cells and primarily cultured glioma cells were implanted into nude mice and made a comparison of the capability of tumor initiation.Results Glioblastoma spheres formed in SGFF-M expressed CD133, but not expressing GFAP (glial fibrillary acidic protein) and MAP2 (mitogen-activated protein 2). A few glioblastoma sphere cells expressed MBP (myelin basic protein). The glioblastoma sphere cells were able to proliferate in SGFF-M and generated free-floating subspheres expressing CD133. Most cells which produced from glioblastoma spheres and cultured in SGFF-M expressed GFAP, while a few expressed MAP2 and MBP. The glioblastoma sphere cells had stronger capability of tumor initiation in nude mice than primary cultured glioma cells. Conclusion The glioblastoma spheres formed in SGFF-M are glioblastoma stem cell spheres. The self-renewal and proliferation of glioblastoma stem cells are independent of exogenous growth factor. Genes or signal pathway in itself may regulate the self-renewal of glioblastoma stem cells.