胶质瘤干-细胞超微结构分析

Ultrastructural analysis of glioma stem cells-progenitors

目的从超微结构方面探讨胶质瘤干-祖细胞（GSCP）体外培养无限扩增、基本不分化的解剖学基础。方法将GSCP常规进行包埋、切片，通过透射电镜进行观察和分析。结果GSCP的核质比高，线粒体、高尔基体、核糖体等结构较发达，但溶酶体少见，粗面内质网欠发达，未见典型的自噬小体。常染色质居多，异染色质少，有1～3个核仁。在GSCP的球体内，未见典型的凋亡细胞，相邻细胞间存在发育欠佳的桥粒或中间连接。结论GSCP是一类处于分化抑制状态的幼稚细胞，自噬活性丧失和其他细胞器的不发达是其分化抑制的重要原因。

Objective It is well known that glioma stem cells-progenitors （GSCP） proliferate indefinitely and hardly differentiate in vitro, however, the reasons remain unknown. The aim of this study was to explore the ultrastructural basis of GSCP. Methods GSCP, kept by our laboratory, were collected, embedded , and cut into ultrathin sections and observed under the transmission electron microscope. Results A single GSCP usually had relatively well developed mitochondria, Golgi apparatuses, ribosomes, and undeveloped rough endoplasmic reticulum, but seldom lysosomes and no typical autophagosomes were found, and the nuclear-cytoplasmic ratio was high. The nuclei frenquently contained huge amounts of euchromatin and a small quantity of heterochromatin, and in most nuclei there were only one nucleolus, however, two or more nucleoli were also common. Typical apoptotic cells could hardly be found in tumor-spheres, and between neighboring cells in tumor-spheres there were incompletely developed desmosomes or intermediate junction. Conclusion The ultrastructural features of glioma stem cells-progenitors showed that BTSCP were very primitive and the lack of autophagy and the underdevelopment of some other cellular organelles are probably the reasons for the differential inhibition of GSCPs.