PLEURAL DOSIMETRY AND BIOMARKERS OF RESPONSE TO FIBERS

胸膜剂量测定和纤维反应的生物标志物

• 批准号: 2154543
• 负责人: Agnes B Kane
• 金额: $ 24.12万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1996-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2154543
• 关键词: asbestos; biomarker; cancer risk; chromosome aberrations; disease /disorder model; environment related neoplasm /cancer; genetic markers; histopathology; immunofluorescence technique; in situ hybridization; inhalation drug administration; injection /infusion; laboratory mouse; model design /development; molecular oncology; neoplasm /cancer genetics; nucleic acid probes; pleural cavity; transmission electron microscopy; tumor suppressor genes

Occupational exposure to asbestos fibers is associated with an increased risk of developing mesotheliomas, malignant tumors arising from the pleural or peritoneal linings. Widespread use of asbestos in the past raises public concern that environmental exposure may also produce mesotheliomas. Assessment of the risk of developing malignant mesothelioma after exposure to asbestos or other fibers is difficult because the minimum dose of fibers required to produce these tumors is unknown. Current rodent models of mesothelioma are unsatisfactory because they use extremely high doses of fibers delivered directly by intraperitoneal or intrapleural injection instead of inhalation. The objective of the proposed research is to develop a new animal model to determine the biologic effective dose of crocidolite asbestos fibers required to initiate the development of mesotheliomas. Fiber dosimetry will be expressed as the total number of fibers that deposit and persist in the pleural lining using tissue digestion, transmission electron microscopy, and video-enhanced differential interference contrast light microscopy to visualize fibers in potential target cell populations (Specific Aim #1). Two responses of potential target cells will be validated as specific and sensitive biologic markers of response to asbestos fibers deposited in the pleura. First, molecular markers for chromosomal damage induced by asbestos fibers will be developed using biotinylated DNA probes and in-situ hybridization. A mouse centromeric DNA probe will be used to detect chromosomal aneuploidy and structural aberrations. Loss of heterozygosity at the p53 tumor suppressor gene locus will be visualized by indirect immunofluorescence on metaphase spreads and interphase nuclei (Specific Aim #2). Second, quantitative markers of mesothelial cell injury and proliferation will be developed using morphometry (Specific Aim #3). Fiber dosimetry and biologic markers of response will be compared following intrapleural injection and inhalation of crocidolite asbestos fibers. These experiments will assess whether there is a correlation between the number of fibers deposited in the pleura, their persistence, and the number of population doubling times before the histologic appearance of malignant mesothelioma (Specific Aims #4 and 5). Ultimately, this new model could be used to extrapolate dose-response relationships to human exposure to asbestos and man-made mineral fibers in order to assess more accurately the risk of developing malignant mesotheliomas.

职业接触石棉纤维与增加有关 出现间皮瘤的风险，胸膜引起的恶性肿瘤 或腹膜衬里。 过去广泛使用石棉的使用 公众担心环境暴露也可能产生间皮瘤。 评估暴露后发生恶性间皮瘤的风险 由于纤维的最小剂量，要进行石棉或其他纤维非常困难 产生这些肿瘤所需的是未知的。 当前的啮齿动物模型 间皮瘤不令人满意，因为它们使用了极高的剂量 直接通过腹膜内或胸腔内注射传递的纤维 而不是吸入。 拟议研究的目的是 开发一种新的动物模型来确定生物学有效剂量的 需要开发的鳄鱼石棉纤维 间皮瘤。 纤维剂量法将表示为 使用组织沉积并持续在胸膜衬里的纤维 消化，传输电子显微镜和视频增强 差异干扰对比光显微镜可视化纤维 潜在的目标细胞种群（特定目标＃1）。 两个回应 潜在的靶细胞将被验证为特定和敏感的生物学 对石棉纤维的反应标志物沉积在胸膜中。 第一的， 石棉纤维诱导的染色体损伤的分子标记将是 使用生物素化的DNA探针和原位杂交开发。 鼠标 丝粒DNA探针将用于检测染色体非整倍性和 结构畸变。 p53肿瘤抑制剂的杂合性损失 基因基因座将通过中期间的间接免疫荧光可视化。 扩散和相间核（特定目标＃2）。 其次，定量 间皮细胞损伤和增殖的标志 使用形态计量学（特定目标＃3）。 纤维剂量法和生物标记 胸膜内注射和 吸入鳄鱼石棉纤维。 这些实验将评估 沉积在的纤维数之间是否存在相关性 胸膜，他们的持久性和人口倍增时间的数量 在恶性间皮瘤的组织学出现之前（具体目的 ＃4和5）。 最终，这种新模型可用于推断 与人类接触石棉和人造的剂量反应关系 矿物纤维以更准确地评估开发的风险 恶性间皮瘤。