HeLa-MLH1^-细胞的生物学特性检测

THE DETECTION OF BIOLOGICAL CHARACTERISTICS OF HELAMLH1 -CELL ①

对本实验室构建的错配修复功能缺陷细胞ＨｅＬａ－ＭＬＨ１－的次黄嘌呤鸟嘌呤磷酸核糖基转移酶（ｈｐｒｔ）基因自发突变率进行检测，发现相对于无ｈＭＬＨ１缺陷的对照细胞ＨｅＬａ－Ｒ９和ＨｅＬａ而言，其突变率分别提高了８７８倍和３５３倍（Ｐ＜００１），此表型改变与本实验室已构建的另一错配修复功能缺陷细胞ＨｅＬａ－ＭＳＨ２－相同。本实验室还证明ＨｅＬａ－ＭＬＨ１－细胞存在甲基硝基亚硝基胍（ｍｅｔｈｙｌｎｉｔｒｏｎｉｔｒｏｓｏｇｕａｎｉｄｉｎｅ，ＭＮＮＧ）耐受，这与我们在ＨｅＬａ－ＭＳＨ２－细胞实验中的发现不同，提示不同的错配修复基因功能缺陷对细胞表型影响不尽相同。

Spontaneous mutation rate at hypoxanthine phosphoribosyltransferase (hprt) locus increased markedly in HelaMLH1 - cell, mismatch repair (MMR) deficient cell line, it exhibited a 8.78 and 3.53fold increase in mutation frequency relative to MMRproficient HeLaR9 and HeLa cell line. This phenotype is similar to another mismatch repair defective cell line HeLaMSH2 -. MNNG tolerance also appeared in HeLaMLH1 -cell but no MNNG tolerance in HeLaMSH2 - cell. These data suggest that different MMR gene defect exerts different effects on mutator phenotypes.