Development of an experimental model for human tracheobronchial carcinogenesis and a new method for early detection of tumor progression of malignant cell lines derived from human lung cancer using de-epithelialized rat tracheas xenotransplanted into nude

从9个供体获得的组织培养的正常人气管支气管上皮细胞用于重建去上皮化的大鼠气管。将重建的大鼠气管移植到裸鼠体内后，将含有100ug 7,12 -二甲基苯[a]蒽（DMBA）的蜂蜡颗粒插入气管腔内。经dmba处理的气管上皮细胞可传代培养。而大多数未经处理的气管上皮细胞不能传代培养。在体内用DMBA处理后，即使在含8%血清的培养基中，这些细胞也没有终末分化。这些细胞的核型显示出相当大的非整倍性。虽然这些细胞不能存活超过10次传代培养（42周），但这比对照细胞的存活时间要长得多。由于它们的生存时间更长，对血清诱导的终末分化和染色体改变有抵抗力，它们被认为是由化学致癌物在体内处理人类细胞产生的表型改变或部分转化的细胞。本项目建立的人肺肿瘤来源的三种腺癌细胞系也接种于去上皮大鼠气管，并异种移植到裸鼠体内。细胞增殖早期可见支气管表面上皮样、clara细胞样和杯状细胞样3种不同类型的细胞，瘤前病变分别为管状、乳头状和筛状。在这个“体内培养系统”中，我们将在进一步的研究中积极观察人类气管支气管癌的发生过程和气管支气管上皮的极早期癌症进展。这些检查也将使气管支气管癌的临床早期和更准确的发现成为可能。

Normal human tracheobronchial epithelial cells obtained by tissue culture from nine donors were used to repopulate de-epithelialized rat tracheas. After reconstruction of rat tracheas transplanted into nude mice, beeswax pellets contained 100ug 7, 12-dimethylbenz[a]anthracene (DMBA) were inserted into those lumina. Epithelial cells from DMBA-treated tracheas were subculturable., whereas epithelial cells from most untreated tracheas were not subculturable. After in vivo treatment with DMBA, those cells did not terminally differentiate even in medium containing 8% serum. Karyotypes from these cells showed considerable aneuploidy. Although these cells did not survive for more than 10 subcultures (42 weeks), this was considerably longer-than the survival of control cells. Because of their longer survival, resistance to serum-induced terminal differentlation and chromosome alterations, they were considered to be phenotypically altered or partially transformed cells produced by in vivo treatment of human cells with a chemical carcinogen.The human lung tumor-derived three adenocarcinoma cell lines which were established in this project were also inoculated into de-epithelialized rat tracheas, and xenotransplanted into nude mice. At early stage of cell proliferations, three different cell types which were bronchial surface epithelium-like, clara cell-like, and goblet cell-like were observed and three preneoplastic lesions which were tubular, papillar, and cribriform progressions were also observed respectively.In this "In Vivo Culture System", the process of human tracheobronchial carcinogenesis and very early stage of cancer progression in tracheobrochial epithelium will be possively observed in our further study. These investigations will also make it possible earlyer and more accurate detection of tracheobronchial carcinoma clinically.