van der Hout A H, Kok K, van der Veen A Y, Osinga J, de Leij L F, Buys C H
Department of Human Genetics, State University of Groningen, The Netherlands.
Cancer Genet Cytogenet. 1989 Mar;38(1):1-8. doi: 10.1016/0165-4608(89)90158-1.
In this study 12 small cell lung cancer cell lines were tested for amplification of myc oncogenes, the location of amplified sequences, and the possible correlation between number of dmin and degree of amplification in dmin-containing lines. C-myc appeared to be amplified in four cell lines, and N-myc amplification was detected in two cell lines. No amplification of L-myc was found. The degree of amplification in the different cell lines varied between 20X and 100X. The cell lines with myc amplification appeared to contain numerous dmin, although in one cell line they occurred in only 10% of the cells. The other cells in this line contained a homogeneously staining region (HSR). In situ hybridization was carried out to find the location of the amplification. In four cell llines the amplified myc genes were found to be located on the dmin. In the cell line with the HSR in most cells and dmin in a minority of its cells, amplification was found both at the HSR and on the dmin. In one cell line the myc sequences seemed to be dispersed through the genome. The ratio between the average number of dmin per cell and the degree of amplification did not vary considerably between the cell lines, with one exception. In that cell line the number of dmin exceeded the number of myc sequences by about one order of magnitude. Apparently, the population of dmin in this cell was heterogeneous and amplified myc genes were only present on a subpopulation.
在本研究中，对12个小细胞肺癌细胞系进行了检测，以确定myc癌基因的扩增情况、扩增序列的位置，以及含双微体（dmin）的细胞系中双微体数量与扩增程度之间的可能相关性。C-myc似乎在4个细胞系中发生了扩增，N-myc扩增在2个细胞系中被检测到。未发现L-myc扩增。不同细胞系中的扩增程度在20倍至100倍之间变化。有myc扩增的细胞系似乎含有大量双微体，尽管在一个细胞系中它们仅出现在10%的细胞中。该细胞系中的其他细胞含有均匀染色区（HSR）。进行原位杂交以确定扩增的位置。在4个细胞系中，发现扩增的myc基因位于双微体上。在大多数细胞有HSR且少数细胞有双微体的细胞系中，在HSR和双微体上均发现了扩增。在一个细胞系中，myc序列似乎分散在基因组中。各细胞系中每个细胞的双微体平均数量与扩增程度之间的比例除一个细胞系外变化不大。在该细胞系中，双微体数量比myc序列数量大约超出一个数量级。显然，该细胞中的双微体群体是异质的，扩增的myc基因仅存在于一个亚群体中。
