MEASURMENT OF MUTATIONS, MITOTIC AND APOPTOTIC CELLS IN DISSECTED HUMAN LUNGS

解剖人肺中突变、有丝分裂和凋亡细胞的测量

• 批准号: 6338778
• 负责人: HELMUT ZARBL
• 金额: $ 22.21万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-03 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6338778
• 关键词: DNA damage; age difference; air pollution; apoptosis; cell age; cell death; cell growth regulation; cell population study; cell proliferation; chemical carcinogenesis; clinical research; environment related neoplasm /cancer; environmental toxicology; histopathology; human population genetics; human tissue; lung neoplasms; nucleic acid sequence; polymerase chain reaction; postmortem; preneoplastic state; respiratory epithelium; tobacco abuse; urban area

Direct induction of mutation by environmental chemicals or their metabolites is one means by which they might effect the age-specific incidence of cancer. If this were so then tissues exposed to mutagenic and carcinogenic chemicals found in environmental mixtures such as cigarette smoke or urban air particulate would have more mutations with a different patter or spectrum of mutations than unexposed tissue. To discover if human bronchial epithelial cells exposed to these mixtures in vivo do nor do not have higher numbers of mutant colonies we propose to dissect some fifty human lungs and measure the number and kind of mutations as a function of anatomical position in the upper bronchial tree. Lung donors will differ in age, smoking status and residential location (rural/urban). We have already developed two methods with the sensitivity required to measure and identify point mutations in genes in human tissues. Because we propose to study a sufficiently large number of lung samples and scan at least 1000 base pairs of nuclear DNA sequence and measure 10 specific point mutations associated with human lung cancers, we expect to be able to discover if the mutational spectra or are not significantly different from spontaneous spectra for these same sequences in human cells. Environmental chemicals may, however, exert their major carcinogenic effect by changes tissue kinetic or turnover parameters, i.e. cell division and death rates. If overall mutation rates in normal tissues were proportioned to cell division rate, than an increase in overall turnover rate by a pseudo-hormonal pathway or forced repopulation by chronic cell toxicity would increase the number of mutants found in a tissue but not necessarily change their mutational spectrum. We therefore propose to enumerate the number of mitototic and apoptotic cells among the epithelial cells of the upper bronchial tree from the same lung donors and discover if there are any differences attributable to age, smoking status or residential location. An especially critical target for effects on cell turnover may be the slowing growing intermediate pre-neoplastic colonies called areas of dysplasia in the lung and adenomas in the colon. Our quantitative working model (Project 1) leads us to expect that high division and death rates are so closely matched that there would be less thana 1% difference in favor of new growth. Factors which change cell division or death rates by even a small increment would be expected to have major effects on the age- specific lung cancer mortality rates. We therefore further propose to determinate the rates of cell death and division in the "areas of dysplasia" in both dissected lung sections and pathology specimen libraries to discover if these parameters vary with age, smoking status or place of residence.

通过环境化学物质及其直接诱导突变 代谢物是一种可能影响年龄特定的方式 癌症的发病率。如果是这样，则会暴露于诱变和 在环境混合物（例如香烟）中发现的致癌化学物质 烟雾或城市空气颗粒物将具有更多的突变 突变的模式或频谱比未暴露的组织。 发现人支气管上皮细胞是否暴露于这些混合物 在体内做也没有更多的突变菌落我们建议 剖析约五十人肺，并测量 突变与上支气管中解剖位置的关系 树。肺捐献者的年龄，吸烟状况和住宅将有所不同 位置（农村/城市）。我们已经开发了两种方法 测量和识别基因中的点突变所需的灵敏度 人体组织。因为我们建议研究足够数量的 肺样本和扫描至少1000个核DNA序列和 测量与人类肺癌相关的10个特定点突变，我们 希望能够发现突变光谱还是不是 对于这些相同序列，与自发光谱显着不同 在人类细胞中。 但是，环境化学物质可能发挥其主要致癌性 通过改变组织动力学或周转参数的效果，即细胞 分裂和死亡率。如果正常组织中的总体突变率为 与细胞分裂率相称，而不是整体周转率的增加 伪激素途径的速率或慢性细胞强制重新填充 毒性会增加组织中发现的突变体的数量，但不会增加 一定会改变其突变频谱。因此，我们建议 列举上皮细胞的数量 来自同一肺供体的上支气管树的细胞并发现 如果有任何差异归因于年龄，吸烟状况或 住宅地点。 对细胞更新影响影响的一个特别关键的目标可能是 减慢了中间体塑料菌落的速度降低称为区域 结肠中肺和腺瘤的发育不良。我们的定量工作 模型（项目1）导致我们期望高分和死亡率 如此紧密地匹配，以至于差距差。 青睐新增长。通过改变细胞分裂或死亡率的因素 即使是一小撮增量也可以对年龄产生重大影响 - 特定的肺癌死亡率。因此，我们进一步建议 确定“ 发育不良“在解剖的肺部和病理标本中 图书馆发现这些参数是否因年龄，吸烟状态还是 居住地。