Poly(ethylene glycol) modification of beta-glucuronidase-antibody conjugates for solid-tumor therapy by targeted activation of glucuronide prodrugs
Poly(ethylene glycol) modification of beta-glucuronidase-antibody conjugates for solid-tumor therapy by targeted activation of glucuronide prodrugs
复制标题
DOI：
10.1007/s002620050387
复制
发表时间：
1997-08-01
影响因子：
5.8
通讯作者：
Roffler, SR
中科院分区：
文献类型：
--
作者：
Cheng, TL;Chen, BM;Roffler, SR
研究了大肠杆菌β-葡萄糖醛酸苷酶（β G）的甲氧基聚乙二醇（PEG）修饰，作为改善抗体-β G缀合物的稳定性和药代动力学的方法，用于靶向激活肿瘤细胞中的葡萄糖醛酸苷前药。引入3个PEG分子不影响β G活性，而更高程度的PEG修饰产生的酶活性的逐渐更大的损失，发现酶在血清中是稳定的，无论PEG修饰。PEG修饰的β G通过硫醚键与mAb RH 1偶联，mAb RH 1是一种与AS-30 D肝癌细胞表面结合的IgG（2a）抗体，（RH1-β G-3PEG），5.2（RH 1-β G-5 PEG）或9.8每个β G的（RH 1-β G-10 PEG）PEG分子，保留未修饰缀合物RH 1-β G的75%、45%和40%的组合抗原结合和酶活性。与在小鼠中观察到的RH 1-β G的快速血清清除相反，PEG修饰的缀合物显示出延长的血清半衰期。与RH 1-β G相比，RH 1-β G-3 PEG和RH 1-β G-5 PEG还表现出脾脏吸收减少和肿瘤积聚增加。对羟基苯胺芥子气（pHAM）的葡糖苷酸前药BHAMG在体内相对无毒。静脉注射6 mg/kg或12 mg/kg pHAM可使白色血细胞数量降低46%和71%，而80 mg/kg BHAMG可使这些水平降低22%。尽管RH 1-β G-5 PEG的肿瘤/血液比受到血清清除缓慢的不利影响，但用这种缀合物联合治疗小实体肝癌肿瘤，4天和5天后静脉注射BHAMG，治愈了所有7只患有严重联合免疫缺陷的小鼠。用对照抗体-β G缀合物和BHAMG的组合治疗延迟了肿瘤生长并治愈了六只小鼠中的两只，而单独用pHAM或BHAMG的治疗无效。
Methoxypoly(ethylene glycol) (PEG) modification of Escherichia coli beta-glucuronidase (beta G) was examined as a method to improve the stability and pharmacokinetics of antibody-beta G conjugates for the targeted activation of glucuronide prodrugs at tumor cells. Introduction of 3 PEG molecules did not affect beta G activity whereas higher degrees of PEG modification produced progressively greater loss of enzymatic activity The, enzyme was found to be stable in serum regardless of PEG modification. PEG-modified beta G was coupled via a thioether bond to mAb RH1, an IgG(2a) antibody that binds to the surface of AS-30D hepatoma cells, to produce conjugates with 3 (RH1-beta G-3PEG), 5.2 (RH1-beta G-5PEG) or 9.8 (RH1-beta G-10PEG) PEG molecules per beta G with retention of 75%, 45% and 40% of the combined antigen-binding and enzymatic activity of the unmodified conjugate RH1-beta G. In contrast to the rapid serum clearance of RH1-beta G observed in mice, the PEG-modified conjugates displayed extended serum half-lives. RH1-beta G-3PEG and RH1-beta G-5PEG also exhibited reduced spleen uptake and greater tumor accumulation than RH1-beta G. BHAMG, the glucuronide prodrug of p-hydroxyaniline mustard (pHAM), was relatively nontoxic in vivo. Injection of 6 mg/kg or 12 mg/kg pHAM i.v. depressed white blood cell numbers by 46% and 71% whereas 80 mg/kg BHAMG reduced these levels by 22%. Although the tumor/blood ratio of RH1-beta G-5PEG was adversely affected by slow clearance from serum, combined therapy of small solid hepatoma tumors with this conjugate, followed 4 and 5 days later with i.v. injections of BHAMG, cured all of seven mice with severe combined immunodeficiency. Combined treatment with a control antibody-beta G conjugate and BHAMG delayed tumor growth and cured two of six mice while treatment with pHAM or BHAMG alone was ineffective.