两种人类淋巴母细胞TK、HPRT基因突变实验比较研究

Comparisons of Induced Mutations at TK and HPRT Loci Using Two Human Lymphoblastoid Cell Lines

背景与目的:比较2种人类淋巴细胞在4种受试物作用下TK、HPRT2个位点突变情况,为其在遗传毒性实验中的应用积累资料。材料与方法:甲磺酸乙酯(ethylmethanesulfonate,EMS),甲磺酸甲酯(methylmethanesulfonate,MMS),乙二醛(glyoxal,GLY),邻苯二胺(o-phenylenediamine,OPD)4种不同化学结构和致突变方式的致突变物作为受试物,采用微孔培养板法比较TK6和TK6-E6细胞在TK和HPRT2个位点的突变情况。结果:TK6-E6细胞比TK6细胞对4种受试物毒性更为耐受;4种受试物在2种细胞,2个位点突变实验结果均为阳性,以TK6-E6细胞的TK实验最为敏感;TK6的慢生长集落比例(RSC)较TK6-E6低,各受试物间无差别(P>0.05)。结论:TK6-E6和TK6细胞在TK、HPRT2个位点的基因突变实验中均能检出致突变物;TK6-E6相对于TK6对细胞毒性耐受,可以用于检测更高浓度的受试物,同时有较高的突变敏感性。

BACKGROUND ＆ AIM： Human somatic cells have species superiority over animal cells in genotoxicity assay. This study aimed to demonstrate the performance of specific gene mutation in two human lymphoblastoid cell lines with different p53 status for its further use in genotoxicity assay. MATERIALS AND METHODS： TK and HPRT mutation was induced by four chemical mutagens, including EMS （ethyl methanesulfonate）, MMS （methyl methanesulfonate）, GLY （glyoxal）, OPD （o-phenylenediamine）. Mutants were selected by microwell method. RESULTS： TK6-E6 was more tolerant to cytotoxic agents than TK6. All 4 agents induced positive mutation responses at two loci in two cell lines. The most sensitive mutation was at TK locus in TK6-E6. The RSC （rate of slow growth colonies） in TK6 was much lower than that in TK6-E6, and there was little variation in RSC to those mutagens. CONCLUSION： TK and HPRT mutation test in two cell lines could be used to assay genotoxicity. TK6-E6 was superior to TK6 in view of higher sensitivity and higher dosage treatment allowance.