Radiolytic activation of a cytarabine prodrug possessing a 2-oxoalkyl group: one-electron reduction and cytotoxicity characteristics
作者:Nao Hirata、Yusuke Fujisawa、Kazuhito Tanabe、Hiroshi Harada、Masahiro Hiraoka、Sei-ichi Nishimoto
DOI:10.1039/b816194a
日期:——
An anti-tumour agent of cytarabine (ara-C) was conjugated with a 2-oxopropyl group at the N(4) position to obtain a radiation-activated prodrug (oxo-ara-C) that targeted hypoxic tumour tissues with selective cytotoxicity. The parent anti-tumour agent, ara-C, was confirmed to be released from oxo-ara-Cvia one-electron reduction upon hypoxic X-ray treatment. The prodrug oxo-ara-C had dramatically reduced cytotoxicity against human lung adenocarcinoma A549 cells relative to ara-C because of the effect of 2-oxopropyl substituent. In contrast, X-ray treatment of hypoxic A549 cells containing oxo-ara-C enhanced the cytotoxic effect, indicating that toxic ara-C was preferentially released in hypoxic cellsvia radiolytic one-electron reduction by hydrated electrons (eaq−).
一种抗肿瘤药物阿糖胞苷(ara-C)与2-氧代丙基在N(4)位结合,形成一种辐射激活的前药(oxo-ara-C),该前药具有选择性的细胞毒性,可靶向缺氧肿瘤组织。经证实,在缺氧X射线治疗中,母体抗肿瘤药物ara-C可通过一电子还原从oxo-ara-C中释放出来。由于2-氧代丙基取代基的作用,前药oxo-ara-C对人类肺腺癌A549细胞的细胞毒性大大低于ara-C。相反,对缺氧A549细胞进行X射线治疗,含有oxo-ara-C的细胞会增强细胞毒性,这表明毒性ara-C优先在缺氧细胞中通过水合电子(eaq−)的辐射分解一电子还原释放出来。