人支气管上皮细胞恶变过程中生物学特性及超微结构的研究

Study on Biological Characteristic and Ultrastructure During the Malignant Transformation of Human Bronchial Epithelial Cell

目的：探讨烟草特异性亚硝胺（NNK）诱发人支气管上皮细胞（BEAS－2B）恶性转化过程中生物学特性及超微结构变化情况。方法：以500μg／ml的NNK处理BEAS－2B细胞24小时后，细胞在体外连续传代培养，在此过程中观测细胞生物学特性及超微结构的变化情况。结果：第5代细胞显示抗血清生长，细胞在裸鼠体内不成瘤。与对照细胞相比，细胞及细胞核形态、细胞器形态及数量无显著变化；第15代细胞在半固体琼脂中克隆形成率（0．032％）为对照细胞（0．0023％）的13．9倍，细胞在裸鼠体内不成瘤。细胞超微结构显示转化细胞特征；第25代细胞在裸鼠体内成瘤，组织学证实为鳞癌（Ⅰ～Ⅱ级）。细胞超微结构显示具有明显的肿瘤细胞特征。结论：浓度为500μg／ml的NNK可成功诱发BEAS－2B细胞恶性转化，在此过程中，细胞超微结构及生物学特性逐步改变，提示人支气管上皮细胞恶性转化过程是一个多步骤、多阶段的发展过程。

Objective： To study the biological characteristic and ultrastructure during the malignant transformation of human bronchial epithelial cell（BEAS-2B） induced by tobacco-specific nitrosamine（NNK）. Methods： BEAS-2B cells treated with NNK at the concentration of 500μg/ml for 24 hours were subcultured continuously in vitro and biological characteristic and ultrastructure of them were observed. Results： The serum resistance was significantly increased in the 5th passage BEAS-2BNNK cells and could not grow into tumor in nude mice. Compared with control ceils, there was no signicfiant difference in ultrastructrure; The plating efficiency of the 15th passage BEAS-2BNNK cells in soft agar（0. 032% ） increased 13.9-fold compared with that of control cells（0. 0023% ） The BEAS-2BNNK ceils bad the biological characteristic of transformation cells but could not grow into tumor in nude mice; The 25th passage ceils could grow into tumor in nude mice. The tumor was a squamous cell carcinoma in morphology confirmed by histopathological examination. The ultrastructrure showed that BEAS-2BNNK cells were Transformed into cancer cells. Condusion： The model of malignant transformation of BEAS-2B ceils induced by NNK（500μg/ml ） can be created successfully. During the period, the change of biological characteristic and ultrastructure indicated that the malignant transformation of human bronchial epithelial cell is a multiple-step course.