香菸致癌物

香菸致癌物 NNK 的代謝物和 CYP2A13 及 UGT2B7 基因多形性與泌

尿上皮癌之相關性

The Association among Metabolites of Tobacco Carcinogen NNK,

Genetic Polymorphisms of CYP2A13 and UGT2B7, and Urothelial

本研究為瞭解香菸致癌物 NNK 的代謝物（Free NNAL、Total NNAL、HA、

N7-MeG）、CYP2A13 codon 3375、UGT2B7 codon 802 基因多形性、抽菸與泌尿

上皮癌之相關性，進行病例對照研究。由臺大醫院泌尿科門診招收膀胱癌患者作 為本研究之病例組共 128 人，由臺北醫學大學附設醫院和萬芳醫院參與健康檢查 之民眾，排除罹患癌症者且與病例之年齡及性別配對共 128 位作為本研究之對照 組。受過標準化問卷訓練的訪員向研究對象說明本研究目的並簽署同意書後，接 受結構式問卷訪視，並收集血液和尿液檢體。問卷內容包括基本人口學、環境暴 露、疾病史及生活型態等資料。利用液相層析儀串聯質譜儀依序分離與定量尿液 中香菸致癌物 NNK 代謝物 Free NNAL、Total NNAL、HA 與 N7-MeG 的濃度。 萃取血液中 DNA，利用聚合酶連鎖反應增幅特定序列及使用限制片段長度多形 性分析 CYP2A13 codon 3375 和 UGT2B7 codon 802 之基因型。結果發現在調整 年齡、性別、教育程度、父母親氏族、抽菸、嚼食檳榔及農藥暴露等干擾因子後， 尿液中香菸致癌物 NNK 代謝物 Total NNAL、Conjugate NNAL、Free NNAL 與 HA 濃度越高，泌尿上皮癌的危險對比值顯著越高。若依對照組尿液中香菸致癌 物 NNK 代謝物分布的三分位分層後，Conjugate/Free NNAL 和 Conjugate/Total NNAL 比值之第二三分位者比第一三分位者顯著降低泌尿上皮癌的危險對比 值，而 Free/Total NNAL 和 HA/Total NNAL 比值越高則顯著增加泌尿上皮癌的危 險對比值。調整年齡、性別、教育程度、父母親氏族、抽菸、嚼食檳榔及農藥暴 露後，CYP2A13 codon 3375 基因多形性與泌尿上皮癌無關，而攜帶 UGT2B7 codon 802 His/Tyr 基因型者，泌尿上皮癌的危險對比值是攜帶 His/His 基因型者 的 1.68 倍（95%信賴區間 0.94 - 2.99）。抽菸且攜帶 UGT2B7 codon 802 His/Tyr 或 Tyr/Tyr 基因型者，泌尿上皮癌的危險對比值是未吸菸且攜帶 His/His 基因型者 的 2.06 倍（95%信賴區間 0.95 - 4.50），皆達統計邊緣顯著性。

英文摘要

Case-control study was conducted to explore the relationships among tobacco carcinogen NNK metabolites (Free NNAL、Total NNAL、HA、N7-MeG), genetic polymorphisms of CYP2A13 codon 3375 and UGT2B7 codon 802, cigarette smoking and urothelial carcinoma (UC). One hundred twenty eight pathologically proven UC patients were recruited at the Department of Urology, National Taiwan University

Hospital. Age-gender matched 128 control subjects without any sign or evidence of UC were collected from a hospital-based pool including those who received senior citizen health examination at Taipei Medical University Hospital and those who received adult health examination at Taipei Municipal WanFang Hospital. Well-trained personnel carried out standardized personal interviews based on a structured questionnaire, and peripheral blood and urine samples were collected simultaneously after study subjects provided their informed consent. Information obtained including sociodemographic characteristics, lifestyle, occupational and environmental exposure to possible carcinogens, and personal and familial disease history. Urine samples were examined by liquid chromatography-tandem mass spectrometry to separate and quantify free NNAL, total NNAL, HA and N7-MeG. DNA was extracted from buffy coat to analyze the polymorphism of CYP2A13 and UGT2B7 utilizing the polymerase chain reaction and restriction fragment length polymorphism assay. It was found that high total NNAL, conjugate NNAL, free NNAL and HA was significantly associated with the UC odds ratio (OR) aafter adjusted for age, gender, educational levels, paternal and maternal ethnicity, cigarette smoking, betel nut cheweing, and pesticide exposure status. After stratified by the tobacco carcinogen NNK metabolites ratio indices of control, the UC OR was significantly increased with the increment of free/total NNAL and HA/total NNAL ratio. UC OR was significantly decreased with the increment of Conjugate/Free NNAL and Conjugate/Total NNAL ratio. After adjusted for age, gender, educational levels, paternal and maternal ethnicity, cigarette smoking, betel nut cheweing, and pesticide exposure status, the UC OR was not associated with CYP2A13 codon 3375 polymorphisms. The OR of UGT2B7 codon 802 His/Tyr genotype versus His/His genotype was 1.68 (95% confidence interval, 0.94 - 2.99). Subjects carried UGT2B7 codon 802 His/Tyr and Tyr/Tyr genotype and with cigarette smoking, the UC OR was borderline significantly increased, the OR was 2.06, 95% confidence interval was 0.95 - 4.50 compared to those carried His/His genotype with non smoker.