ATTENUATION OF CHEMOTHERAPY INDUCED MYELOSUPPRESSION

描述：(申请人摘要)旨在改善的临床试验 逆转录病毒转导化疗的骨髓抑制副作用 已经建立了用于治疗实体瘤的化学保护基因 肿瘤。胸苷酸合酶(TS)是一种很好的候选药物 耐药基因治疗，因为1)它在DNA中起着关键作用 通过提供胸腺嘧啶酸的唯一从头来源进行生物合成，2)几个 最近开发出了新的TS抑制剂，并已投入临床 试验，以及3)许多TS导向的抑制剂的剂量限制毒性是 骨髓抑制。这些抑制剂中包括ZD1694、LY21514、 ZD9331、1843489和AG337。除了减轻药物的副作用外 化疗，导致耐药性的基因也可以被用作显性基因 可选标记。申请人最近已经证明了 二氢叶酸还原酶作为体内化学保护剂的研究 转基因造血细胞的筛选。这样做的目的是 应用是建立利用基因转移的可能性 胸苷合成酶减轻TS靶向毒副作用的研究 并确定TS是否可用作显性可选择标记。 这项申请的具体目的可以概括为：1)确定 导致与核苷酸亲和力降低的TS突变 抗叶酸抑制剂，2)构建编码变异体的逆转录病毒载体 TS和之前表征的DHFR的变种。3)测试是否有阻力 TS和DHFR抑制剂对化疗诱导的保护作用 骨髓抑制和如果体内选择的造血干细胞可以 在移植的小鼠身上实现。4)确定重组逆转录病毒 编码TS和DHFR变体的基因赋予转导的化学保护 人骨髓细胞、人脐血细胞和人 单个核外周血细胞。

DESCRIPTION: (Applicant's Abstract) Clinical trials aimed at ameliorating the myelosuppressive side effects of chemotherapy by retroviral transduction of chemoprotecting gene have been established for the treatment of solid tumors. Thymidylate synthase (TS) is an excellent candidate for drug resistance gene therapy because 1) it plays a critical role in DNA biosynthesis by providing the only de novo source of thymidylate, 2) several novel inhibitors of TS have recently been developed and are in clinical trials, and 3) the dose limiting toxicity of many TS-directed inhibitors is myelosuppression. Included among these inhibitors are ZD1694, LY21514, ZD9331, 1843489 and AG337. In addition to attenuating side effects of chemotherapy, genes that confer drug resistance can also be used as dominant selectable markers. The applicant has recently shown the feasibility of using dihydrofolate reductase as a chemoprotecting agent for in vivo selection of genetically modified hematopoietic cells. The goal of this application is to establish the possibility of using gene transfer of thymidylate synthase to attenuate the toxic side effects of TS targeted inhibitors and determine if TS can be used as a dominant selectable marker. The specific aims of this application can be summarized as: 1) Determine mutations of TS that result in decreased affinity for nucleotide and antifolate inhibitors, 2) Construct retroviral vectors that encode variants of TS and a previously characterized variant of DHFR. 3) Test if resistance to TS and DHFR inhibitors protect against chemotherapy induced myelosuppression and if in vivo selection of hematopoietic stem cells can be achieved in transplanted mice. 4) Determine if recombinant retroviruses that encode variants of TS and DHFR confer chemoprotection to transduced human bone marrow cells, human umbilical cord blood cells, and human mononuclear peripheral blood cells.