PROTECTION OF LUNG FROM CYTOTOXIC DRUGS

肿瘤化疗药物，如博莱霉素和 氯乙基亚硝脲(CENU)与高发的 肺部毒性。这些药物所致的肺损伤和肺纤维化 是这些药物治疗效果的一个主要限制因素 治疗癌症的药物。博莱霉素和CENU都会引起DNA损伤 通过包括创建无嘌呤/脱嘧啶(AP)位点的机制， 导致细胞死亡的链断裂和异常DNA加合物。 细胞毒性药物的肺部毒性通常与 肺毛细血管内皮细胞损伤与I型、II型 肺泡上皮细胞。本项目将重点关注具体的作用 DNA修复蛋白在保护肺细胞免受DNA损伤中的作用 博莱霉素或CENU以及高氧血症，一种与 药物引起的肺部疾病的恶化。现建议，具体的 脱嘌呤/脱嘧啶核酸内切酶(APE)等DNA修复蛋白将 对博莱霉素所致的肺毒性具有保护作用 甲基鸟嘌呤DNA甲基转移酶(MGMT)对CENU的保护作用 诱导毒性。建议进行体外和体内研究。这个 假说是：肺细胞中特异性DNA修复蛋白的增强 将显著降低博莱霉素或CENU的毒性。具体目标 包括：1)使用病毒或非病毒载体来增加细胞内水平 DNA修复蛋白在肺细胞中的表达；2)确定 体外培养肺细胞DNA修复蛋白的表达水平 降低地毯(博莱霉素、CENU、高氧)对小鼠的肺细胞毒性 体外实验；3)确定转基因小鼠是否过表达DNA修复蛋白 肺部对药物(博莱霉素、CENU、 高氧)体内；4)确定DNA修复蛋白在体内是否增强 通过非病毒载体的呼吸道输送来减少肺毒性 来自体内的药物(博莱霉素、CENU、高氧血症)。如果成功，这将是 项目将为重点肺保护提供实验依据 祖细胞形成细胞毒性药物损伤，从而保护 肺泡毛细血管单位的完整性；如果发生损伤，允许 受保护的肺细胞在正常情况下的细胞重建 补偿性复制和分化。

Cancer chemotherapeutic agents such as bleomycin and the chloroethylnitrosureas (CENU) are associated with a high incidence of pulmonary toxicity. The lung injury and fibrosis induced by these drugs represents a major limiting factor in the therapeutic efficacy of these drugs in the treatment of cancer. Both bleomycin and CENU cause DNA damage by mechanisms including creation of apurinic/apyrimidinic (AP) sites, strand scissions and abnormal DNA adducts which lead to cell death. Pulmonary toxicity from cytotoxic drugs is typically associated with injury to the pulmonary capillary endothelium and the type I and type II alveolar epithelial cells. This project will focus on the role of specific DNA repair proteins in protecting lung cells from the DNA damaged caused by bleomycin or CENU and by hyperoxia, a condition associated with exacerbation of drug-induced lung disease. It is proposed that specific DNA repair proteins such as apurinic/apyrimidinic endonucleases (APE) will be protective from bleomycin-induce pulmonary toxicity and that methylguanine DNA methyltransferase (MGMT) will be protective from CENU induced toxicity. Both in vitro and in vivo studies are proposed. The hypothesis is: Augmentation of specific DNA repair proteins in lung cells will significantly reduce the toxicity of bleomycin or CENU. Specific aims include: 1) use viral or non-viral vectors to augment intracellular levels of DNA repair proteins in lung cell in vitro; 2) determine if augmentation of intracellular levels of DNA repair proteins in lung cells in vitro reduced lung cell toxicity from rugs (bleomycin, CENU, hyperoxia) in vitro; 3) determine if transgenic mice over-expressing DNA repair proteins in the lung are more resistant to toxicity from drugs (bleomycin, CENU, hyperoxia) in vivo; 4) determine if augmentation of DNA repair proteins in the lung by airway delivery of non-viral vectors reduces lung toxicity from drugs (bleomycin, CENU, hyperoxia) in vivo. If successful, this project will provide the experimental basis for protecting key lung progenitor cells form cytotoxic drug damage, thereby preserving the integrity of the alveolar capillary unit; and if injury occurs, permitting its cellular reconstitution by the protected lung cells undergoing normal compensatory replication and differentiation.