人视网膜母细胞瘤细胞系SO—Rb50克隆株染色体畸变的观察

目的:研究SO-Rb_(50)细胞系三个克隆株MC_2、MC_3、MC_4染色体畸变的差异。方法:对MC_2、MC_3、MC_4的第11代进行G-显带核型分析。结果:三个克隆株细胞的染色体数目和结构均有异常,出现不同类型的染色体畸变。细胞染色体核型分析见假二倍体核型,13号染色体畸变仅见于个别核型且在三个克隆株中畸变情况不同。发现5个标记染色体,其中标记染色体M_1出现频率最高,几乎见于每个细胞,是由1号染色体长臂部分重复构成(t(1;1)qter-p35::q24-ter);另外还有几个异常标记染色体M_2,M_3,M_4和M_5分别见于各个克隆株细胞。标记染色体M_4和M_5为2号染色体的变化,是在该细胞系染色体变化动态研究中首次发现。结论:SO-Rb(50)在体外培养连续传代后仍存在不同的克隆株,结合以往对该细胞系染色体畸变的动态研究,不同代数的瘤细胞染色体结构畸变有差异,进一步证明体外培养连续传代过程中染色体结构畸变呈动态变化。我们认为13号染色体的畸变不是Rb发生的唯一原因;1号染色体的变化与本细胞系的永生关系密切,其与Rb发生、发展的关系值得深入研究;其它染色体变化为继发改变。眼科学报1998;14:220～223。

An Investigation on Chromosome Aberration of SO-Rb_(50) Cloned Cell Strains

Purpose: To compare the differences of chromosome aberration among 3 cloning cells (MC2, ,MC3 and MC4)of SO-Rb50 cell line.Method: G-banding and karyotype analysis were performed on the 11th passage cells of MC2,MC3 and MC4 cell strains.Results: Both numerical abnormal and structural aberrations of chromosomes could be observed in these 3 coloned cell strains. Diploid cells had the preponderance over the aneuploid cells. However, some cells showed pseudiploid karyotypes. Several kinds of structural chromosome aberrations were observed. The chromosome aberrations in the same passage of different cell strains were different. Aberration of chromosome 13 was rare and the aberration feature were different in 3 coloned cell strains. Five marker chromosomes were identified.M1,t(1;1)qterp35: ;q24-ter could be found in all cell strains. Other markers were seen in different cell strains respectively. In our experiment , two marker chromosome in chromosome 2, MI and MS , were found in SO-Rb50 cell line for the first time.Conclusion : Chromosome aberrations were different with different cloned cell strains. Combined with formerly study in SO-Rb50 cell line, we found the chromosome aberration had dynamic changes during the long-term culture in vitro. We suggest that aberration of chromosome 13 is not the only cause of Rb;aberration of chromosome 1,a common event in some neoplasias as well as in SO-Rb50, plays a meaningful role in the immortalization of this cell line;other aberrations observed in our experiment could be considered as evidences of genomic instability of the cell strains and presumably enhance the growth potential of the cells in which they develop. Eye Science 1998; 14 ; 220 - 223.