Telleman P, Overkamp W J, van Wessel N, Studzian K, Wetselaar L, Natarajan A T, Zdzienicka M Z
Department of Radiation Genetics and Chemical Mutagenesis, Leiden University, The Netherlands.
Cancer Res. 1995 Aug 1;55(15):3412-6.
Three Mitomycin C (MMC)-hypersensitive mutants (CL-V1B, CL-V5B, and CL-V101B) were isolated from Chinese hamster V79B cells by the replica plating technique. In comparison to the parental cell line, CL-V1B, CL-V5B, and CL-V101B show about a 22-, 32-, and 13-fold increased sensitivity to MMC, respectively (judged by the D10). These mutants are also sensitive to other DNA cross-linking agents, such as 1,2,3,4-diepoxybutane (9-, 19-, and 12-fold, respectively) and cis-diamminedichloroplatinum(II) (17-, 12-, and 6-fold, respectively). CL-V5B and CL-V101B display an exclusive sensitivity to DNA cross-linking agents, whereas CL-V1B also shows an increased sensitivity to monofunctional alkylating agents, such as methyl methanesulfonate (3-fold) and ethyl methanesulfonate (2-fold), and UV254mm (2-fold). Approximately 2-3-fold higher levels of spontaneous chromosomal aberrations are found in these three mutants in comparison to wild-type V79B cells. At a MMC survival level of 80%, CL-V5B demonstrates a 16-fold higher level of MMC-induced chromosomal damage than V79B. Despite phenotypical heterogeneity within this group of mutants, hybrid clones derived after fusion remained MMC sensitive, indicating that these mutants belong to the same complementation group. To determine whether the mutants represent a new complementation group among other Chinese hamster cell mutants that also display hypersensitivity to MMC, CL-V1B cells were fused with mutants representing different complementation groups i.e., irs1, irs3, irs1SF, UV20, UV41, V-H4, and V-C8 cells. In all cases, the derived hybrids regained MMC sensitivity similar to wild-type cells, indicating that the CL-V1B mutant represents a new complementation group. The phenotype of CL-V1B, CL-V5B, and CL-V101B cells closely resembles the phenotype of Fanconi anemia cells, suggesting that these hamster mutants could be defective in a gene that is involved in this disorder.
通过影印平板技术从中国仓鼠V79B细胞中分离出三个对丝裂霉素C（MMC）敏感的突变体（CL-V1B、CL-V5B和CL-V101B）。与亲代细胞系相比，CL-V1B、CL-V5B和CL-V101B对MMC的敏感性分别增加了约22倍、32倍和13倍（通过D10判断）。这些突变体对其他DNA交联剂也敏感，如1,2,3,4-二环氧丁烷（分别为9倍、19倍和12倍）和顺二氯二氨铂（II）（分别为17倍、12倍和6倍）。CL-V5B和CL-V101B对DNA交联剂表现出独特的敏感性，而CL-V1B对单功能烷基化剂如甲磺酸甲酯（3倍）和乙磺酸乙酯（2倍）以及UV254nm（2倍）也表现出增加的敏感性。与野生型V79B细胞相比，在这三个突变体中发现自发染色体畸变水平大约高2-3倍。在MMC存活率为80%时，CL-V5B显示出比V79B高16倍的MMC诱导的染色体损伤水平。尽管这组突变体存在表型异质性，但融合后产生的杂交克隆对MMC仍然敏感，表明这些突变体属于同一互补群。为了确定这些突变体是否代表其他对MMC也表现出超敏反应的中国仓鼠细胞突变体中的一个新的互补群，将CL-V1B细胞与代表不同互补群的突变体即irs1、irs3、irs1SF、UV20、UV41、V-H4和V-C8细胞进行融合。在所有情况下，产生的杂种恢复了与野生型细胞相似的对MMC的敏感性，表明CL-V1B突变体代表一个新的互补群。CL-V1B、CL-V5B和CL-V101B细胞的表型与范可尼贫血细胞的表型非常相似，表明这些仓鼠突变体可能在与该疾病相关的基因中存在缺陷。
