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

环境化学物质或其可直接诱发突变 代谢物是它们可能影响年龄特异性的一种手段 癌症发病率。如果是这样的话，暴露在诱变剂和 香烟等环境混合物中发现的致癌化学物质 烟雾或城市空气颗粒物会有更多的突变 突变的模式或谱系比未暴露的组织。 为了发现人类支气管上皮细胞是否暴露在这些混合物中 在体内没有，也没有更多的突变菌落，我们建议 解剖约50个人的肺并测量其数量和种类 突变与上支气管解剖位置的关系 树。肺捐赠者在年龄、吸烟状况和居住地点上会有所不同 地理位置(农村/城市)。我们已经开发了两种使用 测量和识别基因点突变所需的灵敏度 人体组织。因为我们建议研究足够多的 并扫描至少1000个碱基对的核DNA序列和 我们测量了与人类肺癌相关的10个特定的点突变 希望能够发现突变谱是否 与这些相同序列的自发光谱显著不同 在人类细胞中。 然而，环境化学品可能会发挥其主要的致癌作用。 通过改变组织动力学或周转参数，即细胞 部门和死亡率。如果正常组织中的总突变率是 与细胞分裂率成正比，而不是整体营业额的增加 假性激素途径或慢性细胞强迫再繁殖的速率 毒性会增加组织中发现的突变体的数量，但不会 必然会改变它们的突变谱。因此，我们建议 计数上皮细胞中有丝分裂细胞和凋亡细胞的数量 来自同一肺捐赠者的上支气管树细胞并发现 如果有任何可归因于年龄、吸烟或 住宅区。 影响细胞周转的一个特别关键的目标可能是 减缓不断增长的中间肿瘤前殖民地，称为 肺不典型增生和结肠腺瘤。我们的量化工作 模型(项目1)使我们预计高分工和高死亡率 是如此紧密地匹配，以至于在 有利于新的增长。改变细胞分裂或死亡率的因素 即使是很小的增量预计也会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“区域”中细胞死亡和分裂的比率 肺解剖切片和病理标本均可见“异型增生” 图书馆发现这些参数是否随年龄、吸烟状况或 居住地。

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.