Suk W A, Poiley J A, Raineri R, Steuer A F, Tennant R W
Environ Mutagen. 1985;7(5):727-46. doi: 10.1002/em.2860070511.
This study provides a comparative evaluation among three independent laboratories of the responses to 16 chemicals in the retrovirus (Rauscher leukemia) infected Fischer rat embryo (RIFRE) cell-survival-in-aggregation assay. When suspended in liquid media above an agar base, control cells showed a rapid decline in cell survival, whereas cells that had previously been treated with chemical carcinogen survive in suspension longer than control cells. The endpoint, survival in aggregation, is measured by counting viable cells dissociated from aggregates in suspension for 4 days. By modifying previously reported procedures, we have improved the system so that a clear differential (positive or negative) response is achieved by cells treated with either a known carcinogen or known noncarcinogen. Using procedures designed to minimize assay variability, replicate assays were performed and the data analyzed for inter- and intralaboratory concordance. The RIFRE cell-survival-in-aggregation assay demonstrated a high degree of interlaboratory reproducibility in assessing the overall positive or negative responses of known carcinogens and noncarcinogens, and good qualitative reproducibility in assessing compounds tested under code. The assay could discriminate between known carcinogens and noncarcinogens. All chemicals were tested without the addition of a metabolic activation system. Cells exhibiting carcinogen-induced enhancement of survival in aggregation, when plated back onto a solid substrate and carried in culture, subsequently expressed transformation-associated changes in their cellular morphology, growth in semisolid media, and tumorigenicity in nude mice. These results indicate that retrovirus-infected Fischer rat embryo cells detect a carcinogen-mediated early event that progresses to neoplastic phenotypes. Survival in aggregation appears to require the presence of the exogenous retrovirus, since uninfected cells did not show a differential survival response when carcinogen-treated, noncarcinogen-treated, or control cells were compared. This system provides a reproducible method of detecting carcinogenic chemicals based on their ability to induce enhanced survival in aggregation of treated cells.
本研究对三个独立实验室在逆转录病毒（劳舍尔白血病病毒）感染的 Fischer 大鼠胚胎（RIFRE）细胞聚集存活试验中对 16 种化学物质的反应进行了比较评估。当悬浮于琼脂基底上方的液体培养基中时，对照细胞的存活率迅速下降，而先前用化学致癌物处理过的细胞在悬浮液中的存活时间比对照细胞长。聚集存活这一终点是通过对悬浮液中从聚集体解离的活细胞计数 4 天来测量的。通过改进先前报道的程序，我们对该系统进行了优化，使得用已知致癌物或已知非致癌物处理的细胞能够产生明显的差异（阳性或阴性）反应。采用旨在最小化试验变异性的程序，进行了重复试验，并对数据进行了实验室间和实验室内一致性分析。RIFRE 细胞聚集存活试验在评估已知致癌物和非致癌物的总体阳性或阴性反应方面表现出高度的实验室间可重复性，在评估编码测试的化合物方面具有良好的定性可重复性。该试验能够区分已知致癌物和非致癌物。所有化学物质均在不添加代谢活化系统的情况下进行测试。当将表现出致癌物诱导的聚集存活增强的细胞重新接种到固体基质上并进行培养时，它们随后在细胞形态、半固体培养基中的生长以及裸鼠致瘤性方面表现出与转化相关的变化。这些结果表明，逆转录病毒感染的 Fischer 大鼠胚胎细胞能够检测到致癌物介导的早期事件，该事件会发展为肿瘤表型。聚集存活似乎需要外源性逆转录病毒的存在，因为当比较致癌物处理、非致癌物处理或对照的未感染细胞时，未观察到差异存活反应。该系统基于化学物质诱导处理细胞聚集存活增强的能力，提供了一种检测致癌化学物质的可重复方法。
