CARCINOGENESIS OF XENOTRANSPLANTED HUMAN EPITHELIA

拟议研究的总体目的是证明 表型改变的细胞在体内的逐渐出现 人呼吸道异种移植体内致癌作用的研究 上皮组织。使用致癌物质或基因改变的人类细胞 使去上皮化的大鼠气管移植到S.C. 进入裸鼠，我们将监测它们在体内的行为和 对与环境有关的暴露或再暴露的敏感性 致癌物和促进剂。正常和改变的敏感性 细胞对化学试剂的作用将通过组织学的方法来证明 化生-异型增生病变的检测和组织化学 癌前生长的标志物。利用体内-体外 技术，这些相同的组织将被用来评估增加 选育株系的存活率和对末端分化的抗性 不允许正常人生长的培养介质 气管、支气管上皮细胞。永生细胞系或细胞 随着体外存活率的增加，将用于进一步的体内研究 异种移植于去上皮化组织的实验研究 评估其致瘤性和最终增加的气管 对化学试剂敏感。类似地，再次在 另一种模型假设先前的接触史 对化学或生物致癌物的敏感性增加 人类细胞到促进剂或化学致癌物，我们会 确定永生化的致癌细胞和非致瘤细胞 由病毒感染产生的气管-支气管源性(SV40- 腺病毒)转染(SV40，T抗原基因，B-myc，c-Ha-ras， C-ki-ras)或体外暴露于化学品(TPA、MNNG、 香烟烟雾冷凝物)在以下情况下呈现渐进性变化 在移植的气管内再生后暴露在体内。 这些变化将不仅在肿瘤发生方面进行评估 实验，但也有组织学序贯随访 使用组织化学标志物和通过监测 晚期肿瘤或侵袭性转移的表现 表型，即细胞表面的变化(如 与层粘连蛋白、纤维连接蛋白和凝集素结合)，演示 利用生物的入侵行为和定居潜力 化验。

The overall purpose of the proposed research is to demonstrate the gradual appearance of phenotypically altered cells during in vivo carcinogenesis of xeno-transplanted human respiratory tract epithelium. Using carcinogen- or genetically-altered human cells that repopulate de-epithelialized rat tracheas transplanted s.c. into nude mice, we will monitor their in vivo behavior and sensitivity to exposure or re-exposure to environmentally relevant carcinogens and promoters. The sensitivity of normal and altered cells to chemical agents will be demonstrated by histological detection of metaplastic-dysplastic lesions and histochemical markers of preneoplastic growth. Utilizing an in vivo - in vitro technique, these same tissues will be used to assess increased survival and resistance to terminal differentiation in selective culture media that do not permit growth of normal human tracheobronchial epithelial cells. Immortalized cell lines or cells with increased in vitro survival will be used for further in vivo experiments of xenotransplantation into de-epithelialized tracheas to assess their tumorigenicity and eventual increased sensitivity to chemical agents. Similarly and again to test in an alternative model the hypothesis that a prior history of exposure to chemical or biological carcinogens increases the sensitivity of human cells to promoters or chemical carcinogens, we will determine if immortalized tumorigenic and non-tumorigenic cells of tracheo-bronchial origin produced by viral infection (SV40- adenovirus) transfection (SV40, T antigen gene, B myc, c-Ha-ras, c-Ki-ras) or in vitro exposure to chemicals (TPA, MNNG, cigarette smoke condensate) exhibit progressive changes when exposed in vivo after repopulation in transplanted tracheas. These changes will be evaluated not only in tumorigenesis experiments, but also with histological sequential follow-up studies using histochemical markers and by monitoring the appearance of the late neoplastic or invasive-metastasizing phenotype, i.e., cell surface changes, (such as alterations in binding to laminin, fibronectin and lectins), demonstration of invasive behavior and colonization potential using biological assays.