Cate C C, Belloni D R, Marin-Padilla M
Department of Veterans Affairs Medical Center, White River Junction, VT 05009, USA.
Clin Exp Metastasis. 1995 May;13(3):203-17. doi: 10.1007/BF00132209.
Previous primary and secondary co-transfections of genomic DNA from a metastatic human small cell lung cancer cell line into NIH/3T3 cells resulted in a murine fibrosarcoma cell line (Tx93B) that produced frequent spontaneous lung metastases in subcutaneously injected tumor-bearing nude mice. In order to transfer the acquired metastatic behavior to additional cell lines that could then be tested in syngeneic immunocompetent animals, DNA from Tx93B cells was transfected without additional neo gene into Balb/c embryo fibroblasts, which led to the isolation of a tertiary transfectant cell line (D3) of low spontaneous metastatic potential in normal Balb/c mice. Subsequent cell lines established serially from lung metastases in mice injected with D3, and metastatic descendants of D3 (all selected for the original neo marker in G-418), resulted in three generations of metastatically variant cell lines capable of causing pulmonary metastases in 11.1%, 54.6%, and 89.5%, respectively, of subcutaneously injected animals, and in 100% of normal mice injected intraperitoneally. There was no apparent ras-family oncogene participation in the metastatic behavior of either of the two DNA donor cell lines or in the metastatically variant tertiary transfectants. Gelatin zymography indicated that the secretion of gelatinolytic enzymes in vitro by the variant cell lines was inversely proportional to their metastatic capability. Human Alu repeat gene sequences detected in the metastatic variants suggested that co-transfected metastasis-associated genes present in the original human DNA donor cell may have contributed to acquisition of the metastatic phenotype by the tertiary transfectant cell lines. The increase in metastatic potential observed in successive generations of the D3-derived tumor cell lines, further suggested that selection for cells having increased metastatic capability had occurred during passage in vivo accounting for the phenotypic change. Because of their common origin and progressively metastatic nature these cell lines may prove useful in the identification of metastasis-associated genes accessible through the use of differential expression cloning strategies.
先前将转移性人类小细胞肺癌细胞系的基因组DNA先后转染至NIH/3T3细胞中，产生了一种鼠纤维肉瘤细胞系（Tx93B），该细胞系在皮下注射荷瘤裸鼠中常发生自发性肺转移。为了将获得的转移行为转移至其他细胞系，以便随后在同基因免疫活性动物中进行测试，将Tx93B细胞的DNA在无额外新霉素基因的情况下转染至Balb/c胚胎成纤维细胞中，从而分离出在正常Balb/c小鼠中具有低自发转移潜能的第三代转染细胞系（D3）。随后，从注射D3的小鼠肺转移灶中连续建立细胞系，以及D3的转移后代（均在G-418中选择原始新霉素标记），产生了三代转移变异细胞系，分别在11.1%、54.6%和89.5%的皮下注射动物中以及100%的腹腔注射正常小鼠中能够引起肺转移。在两个DNA供体细胞系或转移变异的第三代转染细胞的转移行为中，均未发现明显的ras家族癌基因参与。明胶酶谱分析表明，变异细胞系在体外分泌的明胶酶与它们的转移能力成反比。在转移变异体中检测到的人类Alu重复基因序列表明，原始人类DNA供体细胞中共同转染的转移相关基因可能有助于第三代转染细胞系获得转移表型。在D3衍生的肿瘤细胞系连续几代中观察到的转移潜能增加，进一步表明在体内传代过程中发生了对具有增加转移能力细胞的选择，这解释了表型变化。由于它们的共同起源和逐渐转移的性质，这些细胞系可能有助于通过差异表达克隆策略鉴定可获得的转移相关基因。
