遺伝子に基づくN-アセチルトランスフェラーゼの代謝ポリモルフィズムと,低レベルの発癌物質への環境的暴露
P Vineis1, H Bartsch, N Caporaso
1Dipartimento di Scienze Biomediche e Oncologia Umana, University and Main Hospital, Torino, Italy.
Nature
|May 12, 1994
まとめ
遺伝的変異は,身体が発癌物質を処理する方法に影響します. 遺伝子のグループであるスローアセチレータは,環境への曝露が少ない場合,より高い発がん性アダクトを示し,リスク評価に影響を与えます.
科学分野:
- 環境衛生 環境衛生 環境衛生
- 毒理学 毒理学 毒理学
- 人間の遺伝学 人間の遺伝学
背景:
- 致癌物質の代謝は,遺伝的要因の影響を受け,個体によって大きく異なります.
- 発癌物質に対する個体間の感受性は,特に低レベルの環境曝露において極めて重要です.
- 環境におけるたばこ煙やディーゼルガスの排気は,低用量曝露が広範囲に及ぶ可能性のあるヒトの致癌物質の例である.
研究 の 目的:
- ヒトにおけるN-アセチル化フェノタイプ/ゲノタイプと発がん性アダクトレベルとの関係を調査する.
- 遺伝的要因が,低用量環境発癌物質の暴露に関連するリスクをどのように調節するかを評価する.
主な方法:
- 膀細胞におけるDNAアダクトと97人のボランティアにおける4-アミノビフェニル-ヘモグロビンアダクトの定量化.
- 決定されたN-アセチル化非誘導性フェノタイプ,対応するゲノタイプ,尿中のニコチン・コチニン濃度.
- アセチル化状態と曝露マーカーと相関するアダクトレベル.
主要な成果:
- 遅いアセチレータは,低いまたはゼロのニコチン-コチニンレベルでの急速なアセチレータよりも高い4-アミノビフェニルアダクトを示した.
- 遅いアセチレータと急速なアセチレータのアドクト濃度の違いは,ニコチン-コチニン濃度の上昇とともに減少した.
- N-アセチルトランスフェラーゼ遺伝子型は,アセチル化現象型を強く予測した.
結論:
- 遺伝的傾向,特に遅アセチレーターのフェノタイプは,低用量の発がん剤のクリアランスを損なう.
- 低用量の環境リスクの遺伝的調節は",リスク評価"手順の重要な考慮事項です.
- 個々の遺伝子の違いを理解することは,正確な環境リスク評価に不可欠です.
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