Humanized ADEPT comprised of an engineered human purine nucleoside phosphorylase and a tumor targeting peptide for treatment of cancer.
Humanized ADEPT comprised of an engineered human purine nucleoside phosphorylase and a tumor targeting peptide for treatment of cancer.
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DOI：
10.1158/1535-7163.mct-08-0652
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发表时间：
2009-01
影响因子：
5.7
通讯作者：
Morrison SL
中科院分区：
文献类型：
--
作者：
Afshar S;Asai T;Morrison SL
抗体导向酶前体药物治疗（ADEPT）中使用非人酶引起的免疫原性限制了其临床应用。为了克服这个问题，我们已经开发了一种突变的人嘌呤核苷磷酸化酶（PNP），与野生型酶不同，它接受（脱氧）腺苷为基础的前药作为底物。在测试的人PNP的不同突变体中，具有氨基酸取代E201 Q：N243 D（hDM）的双突变体在切割（脱氧）腺苷基前药中最有效。虽然hDM能够利用多种前药作为底物，但它在将2-氟-2 ′-脱氧腺苷裂解为细胞毒性药物方面最有效。为了使hDM靶向肿瘤部位，将酶融合至抗HER 2/neu肽模拟物（AHNP）。用hDM-AHNP处理表达HER 2/neu的肿瘤细胞导致酶活性的细胞定位。因此，无害的前药在肿瘤细胞附近转化为细胞毒性药物，导致肿瘤细胞凋亡。与非人酶不同，当用于ADEPT时，hDM应具有最小的免疫原性，从而为治疗肿瘤提供新的有希望的治疗剂。
Immunogenicity caused by the use of non-human enzymes in Antibody Directed Enzyme Prodrug Therapy (ADEPT) has limited its clinical application. To overcome this problem, we have developed a mutant human purine nucleoside phosphorylase (PNP), which unlike the wild-type enzyme, accepts (deoxy)adenosine-based prodrugs as substrates. Amongst the different mutants of human PNP tested, a double mutant with amino acid substitutions E201Q:N243D (hDM) is most efficient in cleaving (deoxy)adenosine-based prodrugs. While hDM is capable of utilizing multiple prodrugs as substrates, it is most effective at cleaving 2-fluoro-2′-deoxyadenosine to a cytotoxic drug. To target hDM to the tumor site, the enzyme was fused to an Anti-HER2/neu Peptide mimetic (AHNP). Treatment of HER2/neu expressing tumor cells with hDM-AHNP results in cellular localization of enzyme activity. As a consequence, harmless prodrug is converted to a cytotoxic drug in the vicinity of the tumor cells, resulting in tumor cell apoptosis. Unlike the non-human enzymes, the hDM should have minimal immunogenicity when used in ADEPT thus providing a novel promising therapeutic agent for the treatment of tumors.