用冷冻断裂技术和扫描电镜观察人类鼻咽癌细胞株侵袭到器官内的微细结构变化

STUDIES OF THE ULTRASTRUCTURAL CHANGES OF HUMAN NASO-PHARYNGEAL CANCER CELLS INVADED INTO ORGAN IN ORGAN CULTURE BY FREEZE CRACKING TECHNIQUE AND SCANNING ELECTRON MICROSCOPY

本实验利用冷冻断裂技术和扫描电镜观察了瘤细胞侵入器官后的微细结构的变化。实验结果发现培养1至2天后很多瘤细胞附在器官表面,瘤细胞沿器官表面爬行,同时伸出丝状伪足向器官内侵入。培养3天后有些瘤细胞已侵入器官内,当瘤细胞侵入器官后以各种方式与靶细胞相接触,但仍以丝状伪足作为联络的主要微器官,它利用分支的末端变粗部分抓住靶细胞表面,呈镶嵌状态或者与对方细胞沟通融合,象直接插入似的。有些丝状伪足比在器官外时短而粗,可能因细胞之间接触的距离变短之故。一旦瘤细胞在器官内积聚成团,便形成巢状结构,它们之间多从细胞两极伸出丝状伪足相互连接,而在细胞边侧之间多数留有一定的空隙,这种空隙是否由于瘤细胞带过多的电荷相互排斥的结果,尚没有足够证据肯定或否定这个问题。本实验完成了在光学显微镜下瘤细胞浸润过程中第4、5阶段的扫描电镜观察。

The present experiment applied the freeze cracking technique and scanning electron microscopy for further studies of ultrastructural changes of cancer cells after they invaded into the organ.It was found that,after two days of cultivation,there were a lot of cancer ceils which adhered on to the surface of organ fragments.The cancer cells migrated on the surface of the organ and at the same time penetrated into the organ by stretching out their pseudopodia.After 3 days of cultivation,some cancer cells had already invaded into the organ.After invasion they connected target cells of the organ by different ways,but their filopodium is the important organelle for the connection and communication with those target cells.The cancer cells caught the projecting portion of surface of target cells by branches of filopodia forming a mosaic pattern with them.Sometimes the filopodia of cancer cells fused with the opposed surface of target cells by inserting into it.Some filopodia became short and thick inside the organ due probably to the limited distance between cancer cells and target cells when they were in close contact to each other.Once the tumor cell nests were formed in the organ,the tumor cells connected each other by stretching out pseudopodia from both poles,but kept a definite space between cells.It is postulated that these inter-cellular spaces were formed probably by the repelling force of the identical electric charge of the tumor cell membranes.