Hecht Stephen S, Chen Menglan, Yagi Haruhiko, Jerina Donald M, Carmella Steven G
University of Minnesota Cancer Center, Minneapolis, Minnesota 55455, USA.
Cancer Epidemiol Biomarkers Prev. 2003 Dec;12(12):1501-8.
Individual differences in the metabolic activation and detoxification of carcinogenic polycyclic aromatic hydrocarbons (PAHs) may influence cancer risk. This has been investigated in many studies using genotyping approaches, but the results to date have been inconsistent. We propose that carcinogen metabolite phenotyping would be a more reliable way to determine the role of host metabolism in PAH-related cancer. Many PAHs are metabolically activated by formation of bay-region diol epoxides. Phenanthrene, generally considered to be noncarcinogenic, is the simplest PAH with a bay region and is metabolized to diol epoxides by the same enzymes and with the same stereochemistry as the prototypic carcinogenic PAH, benzo[a]pyrene. The major end product of this metabolic activation pathway is r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (trans, anti-PheT). We have developed a method for the analysis of trans, anti-PheT in human urine. r-1,t-2,4,c-3-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (trans, syn-PheT) was used as internal standard. After hydrolysis by beta-glucuronidase and sulfatase, solid phase extraction, and high-performance liquid chromatography collection, the sample was silylated and analyzed by gas chromatography-negative ion chemical ionization-mass spectrometry-selected ion monitoring at m/z 372. The resulting chromatograms were remarkably clean and trans, anti-PheT was readily detected in all human urine samples. Levels of trans, anti-PheT were 791 +/- 363 pmol/mg creatinine (n = 20) in psoriasis patients treated with a PAH-containing ointment, 25.7 +/- 16.8 pmol/mg creatinine (n = 32) in coke oven workers exposed to PAH, 4.58 +/- 2.95 pmol/mg creatinine (n = 31) in smokers, and 1.51 +/- 1.15 pmol/mg creatinine (n = 30) in nonsmokers. Levels of trans, anti-PheT correlated with levels of 1-hydroxypyrene in the urine of coke oven workers, smokers, and nonsmokers. Thus, trans, anti-PheT appears to be an excellent biomarker of PAH uptake. Levels of trans, anti-PheT were 8,000-19,000 times higher than those of the corresponding metabolite of benzo[a]pyrene. The results of this study demonstrate that trans, anti-PheT can be detected in human urine. We propose that measurement of this metabolite of phenanthrene may be important as part of a carcinogen metabolite-phenotyping approach to determine individual response to PAH exposure.
致癌多环芳烃（PAHs）代谢活化和解毒过程中的个体差异可能会影响癌症风险。许多研究已采用基因分型方法对此进行调查，但迄今为止结果并不一致。我们认为，致癌物代谢物表型分析将是确定宿主代谢在PAH相关癌症中作用的更可靠方法。许多PAHs通过湾区二醇环氧化物的形成而发生代谢活化。菲通常被认为是非致癌性的，它是具有湾区的最简单PAH，并且通过与原型致癌PAH苯并[a]芘相同的酶和相同的立体化学代谢为二醇环氧化物。这种代谢活化途径的主要终产物是r-1,t-2,3,c-4-四羟基-1,2,3,4-四氢菲（反式，反-PheT）。我们已经开发出一种分析人尿中反式，反-PheT的方法。r-1,t-2,4,c-3-四羟基-1,2,3,4-四氢菲（反式，顺-PheT）用作内标。经β-葡萄糖醛酸酶和硫酸酯酶水解、固相萃取和高效液相色谱收集后，样品进行硅烷化处理，然后通过气相色谱-负离子化学电离-质谱选择离子监测（m/z 372）进行分析。所得色谱图非常清晰，在所有人尿样品中都能很容易地检测到反式，反-PheT。在用含PAH软膏治疗的银屑病患者中，反式，反-PheT水平为791±363 pmol/mg肌酐（n = 20）；在接触PAH的焦炉工人中为25.7±16.8 pmol/mg肌酐（n = 32）；吸烟者中为4.58±2.95 pmol/mg肌酐（n = 31）；非吸烟者中为1.51±1.15 pmol/mg肌酐（n = 30）。焦炉工人、吸烟者和非吸烟者尿液中反式，反-PheT水平与1-羟基芘水平相关。因此，反式，反-PheT似乎是PAH摄入量的极佳生物标志物。反式，反-PheT水平比苯并[a]芘相应代谢物的水平高8000 - 19000倍。本研究结果表明，反式，反-PheT可在人尿中检测到。我们认为，作为致癌物代谢物表型分析方法的一部分，测量这种菲的代谢物对于确定个体对PAH暴露的反应可能很重要。
