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

环境化学物质或其 代谢物是一种手段，他们可能会影响年龄特异性 癌症的发病率。如果是这样，那么暴露于诱变剂和 在环境混合物中发现的致癌化学物质， 烟雾或城市空气中的颗粒物会有更多的突变， 与未暴露的组织相比，突变的模式或谱。 为了发现人类支气管上皮细胞是否暴露于这些混合物中 体内没有也没有更高数量的突变菌落，我们建议， 解剖了大约50个人的肺，测量了肺的数量和种类， 上支气管的解剖位置的功能突变 树肺捐赠者的年龄、吸烟状况和居住地不同。 地点（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多的 肺样本，并扫描至少1000个碱基对的核DNA序列， 测量10个与人类肺癌相关的特定点突变， 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）产生的影响 分裂和死亡率。如果正常组织的总体突变率 与细胞分裂率成比例，比整体营业额增加 假激素途径或慢性细胞强迫再增殖 毒性会增加在组织中发现的突变体的数量， 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和凋亡细胞的数量 来自同一肺供体的上支气管树的细胞， 如果有任何可归因于年龄、吸烟状况或 住宅位置。 影响细胞更新的一个特别关键的目标可能是 生长缓慢的中间肿瘤前集落，称为 肺发育不良和结肠腺瘤。我们的量化工作 模型（项目1）使我们预计，高分裂率和死亡率 是如此的接近匹配， 有利于新的增长。改变细胞分裂或死亡率的因素， 即使是很小的增量也会对年龄产生重大影响- 肺癌死亡率。因此，我们进一步建议， 确定细胞死亡和分裂的速度在“区域”， 在肺切片和病理学标本中均存在“发育不良 图书馆，以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.