Quantitative High-Performance Liquid Chromatography−Electrospray Ionization Tandem Mass Spectrometry Analysis of Bis-<i>N</i>7-Guanine DNA−DNA Cross-Links in White Blood Cells of Cancer Patients Receiving Cyclophosphamide Therapy
作者:Bhaskar Malayappan、L’Aurelle Johnson、Bei Nie、Dolly Panchal、Brock Matter、Pamala Jacobson、Natalia Tretyakova
DOI:10.1021/ac902923s
日期:2010.5.1
application of the new methodology is demonstrated for DNA extracted from blood of three cancer patients receiving 50−60 mg/kg of intravenous CPA. The highest numbers of G-NOR-G adduct (up to 18 adducts per 106 normal nucleotides) were observed 4−8 h following CPA administration, followed by a gradual decrease over time, probably due to adduct hydrolysis, DNA repair, and white blood cell death. This methodology
环磷酰胺 (CPA) 是一种广泛用于癌症化疗的 DNA 烷化剂。CPA 代谢活化为磷酰胺芥末和去甲氮芥 (NOR),它们将 DNA 中鸟嘌呤的 N-7 位烷基化以产生N- [2-( N 7-鸟嘌呤基) 乙基]- N -[2-羟乙基]-胺。 G-NOR-OH) 单加合物和N , N -双 [2-( N 7-鸟嘌呤基) 乙基] 胺交联 (G-NOR-G)。G-NOR-G 交联具有很强的细胞毒性,被认为是 CPA 生物活性的原因。在目前的工作中,同位素稀释高效液相色谱-电喷雾电离(正离子)串联质谱(HPLC-ESI +-MS/MS) 方法被开发用于准确量化人类血液中的 G-NOR-G 加合物。在我们的方法中,从白细胞 (5-20 μg) 提取的 DNA 中加入 [ 15 N 10 ]-G-NOR-G的内标,并进行热水解以从 DNA 中释放 G-NOR-G 加合物骨干。固相萃取后,G-NOR-G 偶联物通过毛细管