CARCINOGENESIS OF XENOTRANSPLANTED HUMAN EPITHELIA

本研究的总体目的是证明 细胞表型改变的逐渐出现， 异种移植人呼吸道的体内致癌作用 上皮 使用致癌物质或基因改变的人类细胞 使皮下移植的去上皮化的大鼠气管再生。 我们将监测它们的体内行为， 对接触或再次接触环境相关 致癌物和促进剂。 正常和改变的敏感性 将通过组织学检查证实细胞对化学试剂的反应。 化生-发育不良病变的检测和组织化学 肿瘤前生长的标志物。 利用体内-体外 技术，这些相同的组织将用于评估增加的 在选择性培养基中存活和对终末分化的抗性 不允许正常人生长的培养基 气管支气管上皮细胞 永生化细胞系或细胞 将用于进一步的体内研究， 异种移植到去上皮化的 气管，以评估其致瘤性，并最终增加 对化学试剂的敏感性。 同样地，再次测试在一个 替代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， 人类细胞的启动子或化学致癌物，我们将 确定永生化的致瘤细胞和非致瘤细胞 由病毒感染（SV 40- 腺病毒）转染（SV 40，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）表现出渐进的变化， 在移植的气管中再增殖后体内暴露。 这些变化将不仅在肿瘤发生中进行评估， 实验，但也与组织学连续随访 研究使用组织化学标记，并通过监测 出现晚期肿瘤或浸润转移 表型，即，细胞表面的变化（如 与层粘连蛋白、纤连蛋白和凝集素结合）， 入侵行为和定殖潜力 测定。

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.