Inhibition of glioma cell proliferation and invasion by neural stem cell factor and ex vivo gene therapy.

神经干细胞具有独特的分化、增殖和运动特性。为了研究它们是否分泌干扰胶质瘤细胞增殖和运动的因子，我们在条件培养基中培养胶质瘤细胞，条件培养基来自从胚胎小鼠脑分离的神经干细胞（NSC/CM）和神经球。NSPC/CM含有抑制胶质瘤细胞增殖28-87%的因子。通过Boyden室实验发现NSPC/CM含有另一种抑制胶质瘤细胞运动的因子。NSPC/CM的过滤分馏法发现，5万- 10万标称分子量（NMWL）的组分具有抑制细胞增殖和细胞运动的活性。用柱层析纯化因子失败。倒置共聚焦激光扫描显微镜还检测了NSPC/CM在器官型脑切片培养方法中对细胞运动的抑制作用。在此基础上，我们将203G胶质瘤细胞和/或NSPC移植到小鼠体内大池鞘内腔。同时移植了203G和NSPC的小鼠比只移植了203G的小鼠存活时间明显更长。我们认为NSPC分泌的因子可能控制胶质瘤细胞的增殖和侵袭。ncs已被证明具有在体内传播胶质瘤细胞的强向性。因此，我们利用GFP表达载体构建了能分泌白细胞介素12的NSCs，并检测了NSCs中白细胞介素12的表达。神经干细胞体外基因治疗可能是恶性胶质瘤的一种新的治疗方式。

Neural stem cells have unique differentiation-, proliferation-, and motility properties. To investigate whether they secrete factors that interfere with the proliferation and motility of glioma cells, we grew glioma cells in conditioned medium obtained from cultures of neurospheres including neural stem cells (NSC/CM) isolated from embryonic mouse brain. NSPC/CM contained factor(s) that inhibited the proliferation of glioma cells by 28-87%. NSPC/CM was found to contain another factor(s) that inhibited the motility of glioma cells by Boyden chamber assay. Filter-fractionation of NSPC/CM revealed that the 50,000 - 100,000 nominal molecular weight limit (NMWL) fraction contained the inhibitory activity of both cell-proliferation and -motility. Purification of the factor(s) by column chromatography was failed. Inhibition of cell-motility by NSPC/CM was also detected in the organotypic brain slice culture method using an inverted confocal laser scanning microscope. On the basis of these observations we transplanted 203G glioma cells and/or NSPC into the intrathecal space of the cisterna magna of mice in vivo. Mice transplanted with both 203G and NSPC survived significantly longer than did mice transplanted only with 203G. We concluded that NSPC secrete factor(s) that may control glioma cell proliferation and invasion. NCSs have been shown to exhibit potent tropism for disseminating glioma cells in vivo. Therefore we established NSCs which engineered to secrete interleukin 12 with GFP expressing vector, and the expression of interleukin 12 from NSCs was detected. Ex vivo gene therapy with NSCs may be a new treatment modality for the malignant glioma.