NEOPLASTIC TRANSFORMATION BY CRYSTALLINE SILICA AND OTHER MINERALS

从青年大鼠肺泡上皮细胞中建立了两种新的细胞系 II型上皮，以研究石英诱导的 转化机制原代培养物用 含有永生化基因的质粒（SV 40 T抗原或 腺病毒2 E1 A）和选择性标记。选定的转染菌落 对于上皮多边形细胞的形态特征， 在40代中保持了正常的形态和近二倍体的核型。 将新的细胞系在几个传代水平下冷冻保存。在 AE 6系（E1 A-永生化），用石英颗粒处理诱导 剂量依赖性毒性和伸长细胞的形态学变化 呈十字形生长模式，在4-5年后表现出来， 周文化转化的形态保持了几个小时。 段落。转化细胞显示有限的核型改变。 当注射到裸鼠体内时，几个转化株以间变性生长 癌两个独立的实验证实了这种石英诱导的 恶性转化当测试锚定独立生长时 在软琼脂中，未处理的AE 6细胞为阴性，而 转化的细胞系以高频率形成大球状体。 目前的工作旨在将该测定标准化，用于转化 肺泡细胞AE 5细胞系（SV 40-Tag-永生化）显示出许多 对石英诱导毒性的敏感性高于AE 6（E1 A- 转染）细胞系，并正在研究作为一个特别敏感的 二氧化硅转化模型。

Two new cell lines were established from young adult rat lung alveolar type II epithelium, in order to investigate quartz-induced transformation mechanisms. Primary cultures were transfected with plasmids containing immortalizing genes (either SV40 T antigen or adenovirus 2 E1A) and a selective marker. Transfected colonies, selected for morphological characteristics of epithelial polygonal cells, maintained normal morphology and near diploid karyotype for 40 passages. The new cell lines were cryopreserved at several passage levels. In the AE6 line (E1A- immortalized), treatment with quartz particles induced dose dependent toxicity and morphological changes with elongated cells showing a crisscross growth pattern, which became manifested after 4-5 weeks in culture. The transformed morphology was maintained over several passages. The transformed cells showed limited karyotypic alterations. When injected in nude mice, several transformed lines grew as anaplastic carcinomas. Two independent experiments confirmed this quartz-induced malignant transformation. When tested for anchorage independent growth in soft agar, the untreated AE6 cells were negative, whereas the transformed cell lines formed large spheroids with high frequency. Current work is aimed at standardizing this assay for transformation of alveolar cells. The AE5 cell line (SV40-Tag-immortalized) showed a much higher sensitivity to quartz-induced toxicity than the AE6 (E1A- transfected) cell line, and is being studied as a specially sensitive model for transformation by silica.