彗星试验对4种化学物质诱导人淋巴细胞DNA损伤的检测

Detection for DNA Damage in Human Lymphocytes Induced by Four Chemicals Using Comet Assay

目的验证彗星试验可否用于检测不同类型化学诱变剂诱发的DNA损伤。方法人淋巴细胞经4-硝基喹啉氧化物(4-NQO,拟紫外线诱变剂)、甲基甲烷磺酸酯(MMS,烷化剂)、博来霉素(BLM,拟X射线诱变剂)和丝裂霉素C(MMC,DNA交联损伤剂)染毒3h,再培养0h或21h,然后用彗星试验检测这4种化合物所诱发的DNA单链断裂(SSB)。结果彗星试验能立即检出4-NQO、MMS和BLM诱发的SSB,并具有剂量-效应关系(P<0.01),在21hDNA损伤程度减轻(与0h比较,P<0.01)。MMC诱发的DNA损伤在染毒后21h才被检出,并有剂量-效应关系(P<0.01)。结论虽然这4种化学诱变剂的作用机制不同,但彗星试验仍能检测出他们诱发人淋巴细胞DNA损伤的效应。

Objective To validate feasibility of comet assay as a tool for detecting DNA damage induced by various types of chemical mutagens.Study of DNA damage induced by4chemicals on human lymphocytes was carried out in vitro.Methods Human lymphocytes were exposed to4-nitroquinoline-1-oxide(4NQO,a UV-mimetic agent ),methyl methanesulfonate(MMS,an alkylating agent ),Bleomycin(BLM,a radiamimetic agent )and Mitomycin(MMC,a DNA crosslink agent )for3h,the DNA single strand breaks(SSB)induced by4chemicals were measured immediately(0h-incubation)and21h-incubation after3h-exposure to the chemicals with comet assay.Results It was found that the SSB induced by4NQO,MMS and BLM,which revealed a dose-response relationship(P<0.01),could be detected immediately after the3h-exposure with comet assay,and the SSB diminished at the end of21h-incubation after the exposure(comparing with0h-incubation,P<0.01).The SSB induced by MMC could not be detected until21h after exposure with comet assay,and also showed a dose-response relationship(P<0.01).Con clusion Although the mutagenic mechanisms of4chemical mutagens were different,their DNA damage effects on human lymphocytes could be detected with comet assay.