Möller L, Zeisig M
Unit for Analytical Toxicology, Karolinska Institute, NOVUM Research Park, Huddinge, Sweden.
Carcinogenesis. 1993 Jan;14(1):53-9. doi: 10.1093/carcin/14.1.53.
DNA adducts have been detected in laboratory animals after exposure to carcinogens as well as in human populations with known or suspected risk of developing cancer. Examples are smokers, coke and aluminium workers, urban citizens and roofers. The formation of DNA adducts is an early event in carcinogenesis which can be used for measuring target dose and as a biomarker for genotoxic risk. A method of analyzing 32P-postlabelled DNA adducts on reverse HPLC with on-line detection of 32P has been developed. The method permits direct injection of the 32P-postlabeling mixture into the analytical system without prior purification with background radioactivity on a low level. The method can be used in parallel with TLC analyses of 32P-postlabelled DNA adducts to improve the analytical capacity. The time for analysis of a typical single sample by HPLC and TLC is 30-60 min and 6-24 h respectively. A high (2 M) salt concentration in the HPLC eluent reduces the 32P background considerably. Also the peak tailing was substantially diminished, giving an ability to separate DNA adducts equal to or better than the TLC method. The method has been applied to 2-nitrofluorene (NF), a carcinogenic air pollutant, and N-acetyl-2-aminofluorene (AAF), a model carcinogen which is also a metabolite of NF. A number of DNA adducts are formed in the livers of rats. After oral administration of AAF and NF, DNA adducts in the liver have been characterized as dG-C8-AF and dG-C8-AAF. The major DNA adduct found in both NF- and AAF-administered animals was dG-C8-AF. The described HPLC method can, with minor adjustments, generally be used to analyze 32P-postlabelled DNA adducts.
在实验室动物接触致癌物后以及在已知或疑似有患癌风险的人群中都检测到了DNA加合物。例如吸烟者、焦炭和铝工人、城市居民以及屋顶工。DNA加合物的形成是致癌过程中的早期事件，可用于测量靶剂量并作为遗传毒性风险的生物标志物。已开发出一种在反相高效液相色谱（HPLC）上分析32P后标记DNA加合物并在线检测32P的方法。该方法允许将32P后标记混合物直接注入分析系统，无需事先纯化，背景放射性处于低水平。该方法可与32P后标记DNA加合物的薄层层析（TLC）分析并行使用，以提高分析能力。通过HPLC和TLC分析一个典型单一样品的时间分别为30 - 60分钟和6 - 24小时。HPLC洗脱液中高（2M）盐浓度可大幅降低32P背景。峰拖尾也显著减少，分离DNA加合物的能力与TLC方法相当或更好。该方法已应用于致癌空气污染物2 - 硝基芴（NF）以及作为NF代谢产物的模型致癌物N - 乙酰 - 2 - 氨基芴（AAF）。在大鼠肝脏中形成了多种DNA加合物。口服AAF和NF后，肝脏中的DNA加合物已被鉴定为dG - C8 - AF和dG - C8 - AAF。在给予NF和AAF的动物中发现的主要DNA加合物是dG - C8 - AF。所述的HPLC方法稍作调整后通常可用于分析32P后标记的DNA加合物。
