- 期刊
Arylamine N-Acetyltransferase Activity And 2 Aminofluorene-DNA Adducts Formation in Rat Glial Tumor Cells
大白鼠膠質細胞瘤細胞株中乙醯轉移酶的活性及2-AF-DNA的形成
摘要
芳香胺化合物經N基乙醯轉移酶之N基乙醯化後可誘發癌症，本研究是in vitro探討大白鼠膠質細胞瘤細胞株中乙醯黑心移酶的活性及2-AF-DNA的形成。取大白鼠大白鼠膠質細胞瘤細胞株利用乙醯化輔脢A作乙醯基，以2-aminofluorene(2-AF)和p-aminobencoiv acid(PABA)作受質再利用高壓層析儀分析乙醯轉移酶的活性。另取大白鼠大白氧膠質細胞瘤細胞株利用乙醯化輔脢A作乙醯基以2-aminofluorene(2-AF)作受質及以r-[32p]-dATP標識再利用高壓層析儀分析2-AF-DNA的形成。結果大白鼠膠質細胞瘤細胞株對AF及PABA受質皆有乙醯轉移酶的活性存在，其對AF及PABA的活性平均值各為1.08±0.18及0.96±0.16nmol/min/mg protein.2-AF-DNA adducts形成，依其對AF濃度30μM and 60μM為受質各為0.48±0.16 and 0.70±0.12pmol/mg DNA。 本實驗結果發現in vitro大白鼠膠質細胞瘤細胞株中有乙醯轉移酶的活性存在且可形成2-AF-DNA adducts。2-AF-DNA adducts形成是否是致膠質瘤因子，當然須再進一步in vivo的研究確認。
並列摘要
Arylamine N-acetvlation capacity by the N-acetyltransferase (NAT) may be an important causative factor in the initiation of cancer. Arylamine-DNA adducts formation have been correlated with the carcinogenic effect of heterocyclic aromatic amines. NAT activity in rat glial tumor cells was measured by high performance liquid chromatography (HPLC) using 2-aminofluorene (2-AF) and p-atninobenzoic acid (PABA) as substrares. 2-AF-DNA adducts formation in rat glial tumor cells was investigated by γ-[32p]-dATP and HPLC using 2-amninofluorene as substrates. The activities (Mean±SD) of NAT in rat glial cells was 1.08±0.18nmol/min/mg protein for the acetylation of 2-amninofluorene (n=12), and 0.96±0.16nmol/min/mg protein for the acetylation of p-aminobenzoic acid (n=12). 2-AF-DNA adducts formation in rat glial tumor cells with 30μ M and 60μ M AF were 0.48±0.16 and 0.70±0.12pmol/mg DNA, respectively. The results indicate that NAT was present in rat glial tumor cells, activating AF to become a mnetabolite able to bind covalently with DNA to form 2-AF-DNA.