Laerum O D, Mørk S, Rajewsky M F, Hansteen I L, Haugen A
Anticancer Res. 1983 May-Jun;3(3):187-94.
Analysis of chromosome numbers and flow cytometric measurements of relative DNA content have been performed on four neoplastic neurogenic rat cell lines obtained from fetal BD IX-rat brain cells exposed to N-ethyl-N-nitrosourea (EtNU) in vivo, which sequentially underwent neoplastic transformation in cell culture. In vitro, the cell lines showed varying degrees of ploidy (ranging from near-diploid to near-hexaploid values) and chromosome aberrations. When grown in vivo as solid tumours in BD IX-rats and in thymus deficient nude mice, or in intraperitoneal diffusion chambers in rats, the near diploid cell lines were stable. In the lines with higher ploidies the proportion of cells with near-diploid values increased. Upon retransfer to cell culture, the cell lines gradually changed to the original in vitro pattern. However, in some cases an elevated near-diploid fraction persisted during culture after retransfer. Despite the selection of malignant cells with different ploidy in vivo and in vitro, their ultrastructural morphology remained unchanged. Thus, in this system, near-diploid cells are favoured under conditions of in vivo growth.
对从在体内暴露于N-乙基-N-亚硝基脲（EtNU）的胎BD IX大鼠脑细胞中获得的四个肿瘤性神经源性大鼠细胞系进行了染色体数目分析和相对DNA含量的流式细胞术测量，这些细胞系在细胞培养中依次经历了肿瘤转化。在体外，这些细胞系显示出不同程度的倍性（范围从近二倍体到近六倍体值）和染色体畸变。当作为实体瘤在BD IX大鼠和胸腺缺陷裸鼠体内生长，或在大鼠的腹膜内扩散室中生长时，近二倍体细胞系是稳定的。在倍性较高的细胞系中，具有近二倍体值的细胞比例增加。重新转移到细胞培养后，细胞系逐渐恢复到原来的体外模式。然而，在某些情况下，重新转移后培养期间近二倍体部分持续升高。尽管在体内和体外选择了具有不同倍性的恶性细胞，但它们的超微结构形态保持不变。因此，在这个系统中，近二倍体细胞在体内生长条件下更受青睐。
