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。为了研究它们是否会分泌干扰胶质瘤细胞增殖和运动的因子，我们用从小鼠胚胎脑中分离的神经干细胞(NSC/CM)的神经球培养获得的条件培养液中培养胶质瘤细胞。NSPC/CM含有抑制胶质瘤细胞增殖的因子(S)，抑制率为28-87%。Boyden小室实验发现NSPC/CM中含有另一种抑制胶质瘤细胞运动的因子(S)。NSPC/CM的过滤分级表明，50,000-100,000个标称分子量限制(NMWL)组分既包含细胞增殖抑制活性，也包含运动抑制活性。用柱层析法纯化该因子(S)失败。在倒置共聚焦激光扫描显微镜下的器官型脑片培养方法中，也检测到NSPC/CM对细胞运动的抑制作用。在这些观察的基础上，我们将203G胶质瘤细胞和/或NSPC移植到小鼠枕大池的鞘内。同时移植203G和NSPC的小鼠比只移植203G的小鼠存活时间长得多。我们得出结论：神经胶质瘤细胞分泌因子S可能控制胶质瘤细胞的增殖和侵袭。研究表明，NCSs在体内对胶质瘤细胞具有很强的趋向性。因此，我们用绿色荧光蛋白表达载体构建了分泌IL-12的神经干细胞，并检测了神经干细胞中IL-12的表达。神经干细胞的体外基因治疗可能成为恶性胶质瘤的一种新的治疗手段。

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.