In vivo Invasion Assay and Enhancement of Differentiation of Low Passage Cultured Cells Derived from Human Non-Small Cell lung Carcinoma Using De-epithelialized Rat Tracheas Transplanted into Nude Mice.

利用裸鼠异种移植物研究人类肿瘤能够考虑宿主反应，而这在体外系统中是不可能的。裸鼠提供了一个类似于人类的入侵环境;然而，s.c.常规异种移植到裸鼠中的注射方法遇到了长潜伏期和低肿瘤摄取率的问题。本研究将低代次的人肺癌细胞株移植到裸鼠体内，观察其生长行为和侵袭能力。将6个细胞系接种到深上皮化的大鼠气管中（5 x 10^5个细胞/气管）。细胞接种后，将气管密封并移植到裸鼠皮下。在一个平行实验中，将这些细胞系（1 × 10^6个细胞）皮下注射到小鼠体内。皮下组织中，肿瘤发生率仅为13%，潜伏期长达18周，3株细胞未向周围浸润生长 ...更多信息 组织.在大鼠气管中，所有细胞系均在3周内增殖，其中4株细胞在1-2周内向气管壁浸润生长。生长在气管壁的细胞比生长在气管腔的细胞显示出更高的（^3H）胸苷标记指数和更大的聚集性，例如更大的核和突出的核仁。南卡罗来纳肿瘤发生率与气管壁浸润性生长的发生率相关。最初携带六种肿瘤的患者的存活率也与该系统的侵袭潜力密切相关。在气管移植中，所有细胞系均表现出与原发性病变相当或更高的分化程度。而大多数细胞系在小鼠皮下组织中的分化程度较低。用鳞状细胞癌衍生的细胞重新填充的气管移植物表面最初衬有2至3个细胞厚的扁平细胞层。而3例腺癌细胞复盖的上皮细胞最初分别由立方形、圆形和圆柱形细胞组成。此后，这些细胞系分别显示假复层模式、乳头状生长模式和筛状模式。超微结构显示，它们分别显示类似纤毛支气管上皮细胞、无纤毛支气管上皮细胞和支气管杯状细胞的结构，这些结果表明，使用低传代细胞系的系统可以在接种后不久评估相对少量细胞的侵袭潜力，并且可以用作临床上可靠的生物侵袭测定。而且，使用该系统对培养的细胞进行组织学检查被认为有利于评价分化，因为它提供了在原发性肿瘤或皮下直接细胞注射后形成的肿瘤中未观察到的独特增殖模式。少

The investigation of human tumors using nude mouse xenograft is capable of taking into account the host reactions, whereas this is impossible in in vitro system. Nude mice offer an invasion environment similar to that of humans; however, s.c. injection procedures for conventional xenotransplantation into nude mice have encountered problems with regard to long latency periods low tumor take rates. In this project, human lung tumor-derived cell lines with low passage generation were transplanted into nude mice to determine their growth behavior and invasive potential. Six cell lines were inoculated into deepithelialized rat tracheas (5 x 10^5 cells/trachea). After cell inoculation, the tracheas were sealed and transplanted into the subcutis of nude mice. In a parallel experiment, these cell lines (1 x 10^6 cells) were injected s.c. In the subcutis, the tumor take rate was only 13% with a long latency period of 18 weeks, and 3 cell lines did not show any invasive growth to the surrounding … More tissue. In rat tracheas, all cell lines proliferated within 3 weeks, and 4 of them showed invasive growth to the tracheal wall within 1-2 weeks. Cells growing in the tracheal wall showed higher (^3H) thymidine labeling indexes and greater atypia, such as larger nuclei and prominent nucleoli, than those in the tracheal lumen. The s.c. tumor take rate correlated with the incidence of invasive growth to the tracheal wall. The survival of the patients originally bearing the six tumors also correlated closely with the invasive potential of this system. In tracheal transplants, all cell lines showed comparable or higher degree of differentiation than in the primary lesion. While most cell lines showed lower degree of differentiation in the mouse subcutis. The surfaces of tracheal transplants repopulated with the cells derived form squamous cell carcinomas were initially lined by a layer of flattened cells 2 to 3 cells thick. While those repopulated with the cells from 3 cases of adenocarcinoma were initially lined by simple epithelia consisted of cuboidal-, round-, and columnar-shaped cells, respectively. Thereafter, those cell lines revealed pseudostratified pattern, papillary growth pattern, and cribriform pattern, respectively. Ultrastructurally, they showed structures resembling ciliated bronchial epithelial cells, non-ciliated bronchiolar epithelial cells, and bronchial goblet cells, respectively.These results indicate that the system using low passage cell lines can evaluate the invasive potential shortly after the inoculation; of a relatively small number of cells and can be used as a clinically reliable biological invasion assay. And, histological examination of cultured cells using this system was considered to be advantageous for evaluation of differentiation because it provided unique proliferation patterns unobserved in primary tumors or tumors formed after subcutaneous direct cell injections. Less