Abstract: Background  PTEN is an anti-oncogene frequently inactivating in glioma. The previous study found that PTEN was closely related to cellular autophagy activity. The purpose of this paper is to study whether the inactivation of PTEN in glioma stem/progenitor cells (GSPCs) is correlative with the low autophagic activity in GSPCs. Methods  Wild-type PTEN genes were transferred into GSPCs mediated by adenovirus. The autophagic activity in GSPCs before or after the introduction of wild-type PTEN was detected by immunocytochemistry, electron microscopy, and Western blotting assay. Results After transfection of wild-type PTEN, a large number of microtuble-associated protein 1 light chain 3 (MAP1LC3)-positive granules could be found in the cytoplasm of GSPCs under a confocal microscopy, and these granules were demonstrated to be autophagosomes under an electron microscope. Moreover, the expression of autophagy-related gene Beclin-1 significantly increased after the transfection of wild-type PTEN gene. Conclusion The inactivation of PTEN in GSPCs is one reason of the low autophagic activity of GSPCs.

Key words: Glioma, Neoplastic stem cells, Genes, tumor suppressor, Transfection, Autophagy, Immunoblotting

摘要： 研究背景 PTEN 基因为影响中枢神经系统肿瘤细胞失活的抑癌基因，既往研究发现PTEN 基因与细胞自噬活性密切相关。本研究旨在探讨胶质瘤干/祖细胞PTEN 基因失活是否与其自噬活性降低有关。方法 通过腺病毒介导的野生型PTEN 基因转染胶质瘤干/祖细胞，免疫细胞化学染色和Western blotting 法检测并比较转染前后胶质瘤干/祖细胞自噬活性。结果 转染野生型PTEN 基因后，胶质瘤干/祖细胞胞质内可见大量微管相关蛋白1 轻链蛋白3 阳性颗粒，经电子显微镜鉴定为自噬小体，而且转染PTEN 基因的胶质瘤干/祖细胞自噬相关基因Beclin-1 表达水平显著升高。结论 胶质瘤干/祖细胞PTEN 基因失活可能是其自噬活性降低的原因之一。

关键词: 神经胶质瘤, 肿瘤干细胞, 基因, 肿瘤抑制, 转染, 自噬, 免疫印迹法