Measurement of the critical DNA lesions produced by antibody-directed enzyme prodrug therapy (ADEPT) in vitro, in vivo and in clinical material
Measurement of the critical DNA lesions produced by antibody-directed enzyme prodrug therapy (ADEPT) in vitro, in vivo and in clinical material
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DOI：
10.1054/bjoc.2001.1843
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发表时间：
2001-06-15
影响因子：
8.8
通讯作者：
Hochhauser, D
中科院分区：
文献类型：
--
作者：
Webley, SD;Francis, RJ;Hochhauser, D
针对CEA阳性肿瘤的抗体导向酶前药治疗（ADEPT）系统目前正处于I期临床试验。它由前药4-[N，N-双（2-碘乙基）氨基]苯氧基羰基L-谷氨酸（ZD 2767 P）和F（ab '）（2）抗CEA抗体A5 B7与细菌酶羧肽酶G2（CPG 2）的偶联物组成。ZD 2767 P在肿瘤部位被抗体靶向CPG 2转化为活性双功能烷化剂（ZD 2767）。暴露1小时后，前药对人结肠直肠肿瘤LS 174 T细胞系的IC（50）值为55 +/-9 μ M。相比之下，ZD 2767 P与CPG 2共孵育导致活性增加229倍。使用改良彗星试验，在ZD 2767 P + CPG 2处理1 h内检测到DNA链间交联（ISC），并在24 h内修复。在ISC水平、生长抑制和ZD 2767浓度之间观察到明显的剂量反应。在F（ab '），A5 B7偶联物给药后72 h，对携带LS 147 T异种移植物的小鼠给予治疗剂量的ZD 2767 P，导致1 h后肿瘤中出现广泛的ISC;在24 h时观察到修复。在ADEPT I期临床试验的5例患者中研究了肿瘤活检和外周淋巴细胞。4例未检出ISC。这些患者还表现出偶联物定位不良，未观察到肿瘤反应。然而，在一个肿瘤活检中检测到显著水平的ISC，这也显示了缀合物定位和临床应答的证据。这些研究证明了彗星试验在体外和临床材料中ISC测量中的应用，并证实了ZD 2767 P的活化导致DNA交联的形成。(C)2001年癌症研究运动。
An antibody-directed enzyme prodrug therapy (ADEPT) system against CEA-positive tumours is currently in phase I clinical trials. It consists of a prodrug, 4-[N,N-bis(2-iodoethyl) amino] phenoxycarbonyl L-glutamic acid (ZD2767P) and a conjugate of the F(ab')(2) anti-CEA antibody A5B7 and the bacterial enzyme carboxypeptidase G2 (CPG2). ZD2767P is converted by antibody-targeted CPG2 into an active bifunctional alkylating drug (ZD2767) at the tumour site. The IC(50) value of the prodrug against the human colorectal tumour LS174T cell line was 55 +/- 9 muM following a 1 h exposure. In contrast, co-incubation of ZD2767P with CPG2 resulted in 229-fold increase in activity. Using a modified comet assay, DNA interstrand cross links (ISC) were detected within 1 h of ZD2767P + CPG2 treatment and were repaired by 24 h. A clear dose-response was seen between the level of ISC, growth inhibition and ZD2767 concentration. Administration of a therapeutic dose of ZD2767P 72 h after the F(ab'), A5B7 conjugate to mice bearing LS147T xenografts resulted in extensive ISC in the tumour after 1 h; repair was seen at 24 h. Tumour biopsies and peripheral lymphocytes were studied in 5 patients on the ADEPT phase I clinical trial. In 4 patients no ISC were detected. These patients also demonstrated poor localization of conjugate and no tumour response was seen. However a significant level of ISC was detected in one tumour biopsy, which also showed evidence of conjugate localization and clinical response. These studies demonstrate the application of the comet assay in the measurement of ISC in vitro and in clinical material and confirm that activation of ZD2767P results in the formation of DNA crosslinks. (C) 2001 Cancer Research Campaign.