检测人外周血淋巴细胞抗6-TG突变的方法学问题

METHODOLOGICAL STUDIES OF THE ASSAYS FOR 6-THIOGUANINE-RESISTANT LYMPHOCYTES IN HUMAN PERIPHERAL BLOOD

本文就人外周血淋巴细胞抗6-TG突变体测定的方法学问题做了介绍。淋巴细胞抗6-TG突变体具有稳定的抗6-TG表型,胞内缺乏次黄嘌呤-鸟嘌吟转磷酸核糖基酶(HPRT),HPRT基因存在结构改变。血样经冷冻预处理或使用流式细胞光度术时,放射自显影法所测结果与克隆检测法相似,正常成人血淋巴细胞抗6-TG突变率为10^(-6)～10^(-5),肿瘤病人接受化疗或放疗后该值升高。抗6-TG细胞测定反映了人体内特殊基因位点的突变频率,是体内体细胞突变的良好指标。

The autoradiographic and the clonal assays for 6-thioguanine-resistant (TGr) lymphocytes in human blood are discussed. Studies show tha t the lymphocytes possess stable TGr phenotypes, which are deficient in hypoxanthine guanine phosphoribosyltransferase (HPRT) and have structural alterations in the HPRT gene. When lymphocytes are cryopreserved before study or flow cytometry are used to remove 'phenocopies' , TGr mutant frequencies (Mfs) determined by autoradiographic assay are generally similar to that of clonal assay. TGr lymphocyte Mfs are the order of 10-5-10-6 range for normal adults. Cancer patients exposed to potentially mutagenic treatments have elevated TGr lymphocyte Mfs. The TGr lymphocyte system is presented for human special-locus mutagenicity monitoring. Thus, the TGr lymphocytes of human blood are useful indicators of somatic mutations occurring in vivo.