In vitro and in vivo radiation sensitization of human tumor cells by a novel checkpoint kinase inhibitor, AZD7762.
In vitro and in vivo radiation sensitization of human tumor cells by a novel checkpoint kinase inhibitor, AZD7762.
复制标题
DOI：
10.1158/1078-0432.ccr-09-3277
复制
发表时间：
2010-04-01
期刊：
影响因子：
--
通讯作者：
Cook JA
中科院分区：
文献类型：
--
作者：
Mitchell JB;Choudhuri R;Fabre K;Sowers AL;Citrin D;Zabludoff SD;Cook JA
抑制检查点激酶1（Chk 1）已被证明可以通过细胞周期检查点消除和受损的DNA损伤修复来增强DNA损伤靶向化疗的细胞毒性。评价了一种新型Chk 1/2抑制剂AZD 7762在体外和体内异种移植物中对人肿瘤细胞放射敏感性的潜在增强作用。p53野生型和突变型人细胞系的存活率通过克隆形成测定进行评价。根据存活曲线（10%存活率时对照组与药物治疗组的放射剂量比）确定剂量调整因子（DMF）。进行流式细胞术、蛋白质印迹和辐射诱导的肿瘤再生长延迟测定。AZD 7762处理增强了p53突变肿瘤细胞系（DMF范围为1.6-1.7）的放射敏感性，其程度大于p53野生型肿瘤细胞系（DMF范围为1.1-1.2）。AZD 7762单独处理对任何细胞系的细胞毒性都很小，并且不会增强正常人成纤维细胞（SF 1522）的放射敏感性。AZD 7762治疗消除了辐射诱导的G2期延迟，抑制了辐射损伤修复（通过γ-H2 AX评估），并抑制了辐射诱导的细胞周期蛋白B表达。与单独辐射相比，暴露于5次每日辐射分次和2次每日AZD 7762剂量的HT 29异种移植物显示出显著的辐射增强。AZD 7762可有效增强突变型p53肿瘤细胞系和HT 29异种移植物的放射敏感性，单独给药或与放射联合给药时无不良毒性。本研究的结果支持在临床试验中将AZD 7762与放疗联合使用。
Inhibition of checkpoint kinase 1 (Chk1) has been shown to enhance the cytotoxicity of DNA damaging targeted chemotherapy through cell cycle checkpoint abrogation and impaired DNA damage repair. A novel Chk1/2 inhibitor, AZD7762 was evaluated for potential enhancement of radiosensitivity for human tumor cells in vitro and in vivo xenografts. Survival of both p53 wild type and mutant human cell lines was evaluated by clonogenic assay. Dose modification factors (DMF) were determined from survival curves (ratio of radiation doses for control versus drug-treated at 10% survival). Flow cytometry, western blot, and radiation-induced tumor regrowth delay assays were conducted. AZD7762 treatment enhanced radiosensitivity of p53 mutated tumor cell lines (DMFs ranging from 1.6–1.7) to a greater extent than for p53 wild type tumor lines (DMFs ranging from 1.1–1.2). AZD7762 treatment alone exhibited little cytotoxicity to any of the cell lines and did not enhance the radiosensitivity of normal human fibroblasts (SF1522). AZD7762 treatment abrogated radiation-induced G2 delay, inhibited radiation damage repair (assessed by γ-H2AX), and suppressed radiation-induced cyclin B expression. HT29 xenografts exposed to 5 daily radiation fractions and 2 daily AZD7762 doses exhibited significant radiation enhancement compared to radiation alone. AZD7762 effectively enhanced the radiosensitivity of mutated p53 tumor cell lines and HT29 xenografts and was without untoward toxicity when administered alone or in combination with radiation. The results of this study support combining AZD7762 with radiation in clinical trials.