NEOPLASTIC TRANSFORMATION BY CRYSTALLINE SILICA AND OTHER MINERALS

从幼年大鼠肺泡中建立了两个新的细胞系 II型上皮，以研究石英诱导的 转变机制。将原代培养物转入 含有永生化基因的质粒(SV40T抗原或 腺病毒2E1a)和一个选择标记。已选择的转基因菌落 对于上皮性多边形细胞的形态特征， 连续传代40代，保持形态正常，核型接近二倍体。 新的细胞系在几个传代水平上进行了超低温保存。在 AE6系(E1a-永生化)，用石英颗粒处理诱导 细长细胞的剂量依赖性毒性和形态变化 呈现出交错生长的格局，在4-5年后表现出来 培养了几个星期。变形后的形态保持了几个以上 段落。转化的细胞表现出有限的核型改变。 当注射到裸鼠体内时，几条转化的线条生长为间变性。 癌症。两个独立的实验证实了这种由石英引起的 恶变。当进行锚定独立生长测试时 在软琼脂中，未经处理的AE6细胞呈阴性，而 转化后的细胞系形成大球体，频率较高。 目前的工作旨在标准化这一检测方法，用于转化 肺泡细胞。AE5细胞系(SV40-Tag-不朽)表现出 对石英引起的毒性比AE6更敏感(E1a- 细胞系，正在作为一种特殊敏感的细胞进行研究 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.