Chemical Carcinogenesis In Vitro: Limitations and Possibilities in the Use of Rat Liver Epithelial Cells for Screening Carcinogens
We have developed assays based on the in vitro properties of malignant liver epithelial cells in which the qualitative changes of the carcinogen-treated cell population, and the quantitative changes of individual cells within such a population, can be studied. Even with these improved methods, it is not possible to identify the transformed epithelial cells when the percentage of transformed cells is low. We have examined several conditions under which the untransformed cells are either killed or maintained, without cell division, while the viability or proliferation of the transformed cells is not affected. Using the selective methods and the improved techniques for the identification of transformed cells, it should be possible to investigate the mechanisms of chemical carcinogenesis and to use the liver epithelial cells for assessing the possible hepatocarcinogenic potency of environmental agents.
Concurrently, we are attempting to develop a cell system which can be used exclusively for carcinogen screening. In many existing fibroblastic cell systems, hepatocytes are added to metabolize chemical carcinogens to active metabolites which, in turn, induce the altered characteristic in the “target” cells. However, the metabolites excreted by the hepatocytes are mostly detoxified (conjugated) products. Experiments are going on to produce hybrid cells by fusing hepatocytes with fibroblasts. If the hybrids retain the capacity to metabolize carcinogens and the ability to form “piled-up” colonies after carcinogen-treatment, such cells should prove better than the co-cultivated mixture for carcinogen screening since the active metabolites formed de novo within the cell can induce transformation of the same cell.
KeywordsChinese Hamster Ovary Cell Sister Chromatid Exchange Chemical Carcinogenesis Nonmalignant Cell Transformed Epithelial Cell
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- Allen, T. D., P. T. Iype, and M. J. Murphy, 1978. The surface morphology of normal and malignant rat liver epithelial cells in culture. In Vitro, 12:837–844.Google Scholar
- Borenfreund, E., P. J. Higgins, M. Steinglass, and A. Bendich, 1975. Properties and malignant transformation of established rat liver parenchymal. J. Natl. Cancer Inst., 55: 375–384.Google Scholar
- Fusenig, N. E., S. M. Amer, P. Boukam, M. Lueder, and P. K. M. Worst, 1978. Methods for studying neoplastic transformation epidermal cells in culture by chemical carcinogens, pp. 53–70. In: “Methods for Carcinogenesis Tests at the Cellular Level and Their Evaluation for the Assessment of Occupational Cancer Hazards,” E. Vigliani (ed.). Carlo Erba Foundation, Italy.Google Scholar
- Hanks, J. H., and R. E. Wallace, 1949. Relation of oxygen and temperature in the preservation of tissues by refrigeration. Proc. Soc. Exp. Biol. Med., 71: 196–200.Google Scholar
- Hashimoto, Y., and H. S. Kitagawa, 1974.In vitro neoplastic transformation of epithelial cells of rat urinary bladder by nitrosamines. Nature, 252:497–499.Google Scholar
- Hay, R. J., 1975. The pancreatic epithelial cell in vitro: A possible model system for studies in carcinogenesis. Cancer Res., 35: 2289–2291.Google Scholar
- Heckman, C. A., and A. C. Olson, 1979. Morphological markers of oncogenic transformation in respiratory tract epithelial cells. Cancer Res., 39: 2390–2399.Google Scholar
- Iype, P. T., T. D. Allen, and D. J. Pillinger, 1975. Certain aspects of chemical carcinogenesis in vitro using adult rat liver cells, pp. 425–440. In: “Gene Expression and Carcinogenesis in Cultured Liver,” L. E. Gerschenson and E. B. Thompson (eds.). Academic Press, New York.Google Scholar
- Iype, P. T., J. E. Tomaszewski, and A. Dipple, 1979. Biochemical basis for cytotoxicity of DMBA in rat liver epithelial cells. Cancer Res., 39 (12): 4925–4929.Google Scholar
- Katsuta, H., and T. Takoaka, 1965. Carcinogenesis in tissue culture. III. Effects of the second treatments on DAB-induced proliferating liver cells of normal rats in culture. Jap. J. Exp. Med., 35: 231–248.Google Scholar
- Laishes, B. A., E. Roberts, and E. Farber, 1978. In vitro measurement of carcinogen-resistant liver cells during hepatocarcinogenesis. Int. J. Cancer,21 186–193.Google Scholar
- McMahon, J. B., and P. T. Iype, 1979. Specific inibition of proliferation of nonmalignant rat hepatic cells. Proc. Amer. Assoc. Cancer Res., 40: 1249–1254.Google Scholar
- Poiley, J. A., R. Raineri, and R. J. Pienta, 1979. Use of hamster hepatocytes to metabolize carcinogens in an in vitro bio-assay. J. Natl. Cancer Inst., 63: 519–524.Google Scholar
- Sattler, C. A., G. Michalopoulos, G. L. Battler, and H. C. Pitot, 1978. Ultrastructure of adult rat hepatocytes cultured on floating collagen membranes. Cancer Res., 38: 1539–1549.Google Scholar
- Solt, D. B., A. Medline, and E. Farber, 1977. Rapid emergence of carcinogen-induced hyperplastic lesions in a new model for the sequential analysis of the liver carcinogenesis. Am. J. Pathol., 88: 595–609.Google Scholar
- Stetka, D. G., and S. Wolff, 1976. Sister chromatid exchanges as an assay for genetic damage induced by mutagenic carcinogens II In vivo test for compounds requiring metabolic activation. Mutation Res., 41:343–350.Google Scholar
- Weinstein, I. B., J. M. Ornestein, R. Gebert, M. E. Kaighn, and U. C. Stadler, 1975a. Growth and structural properties of epithelial cell cultures established from normal rat liver and chemically induced hepatomas. Cancer Res., 35: 253–263.Google Scholar
- Weiss, M. C., 1975. Extinction, reexpression, and induction of liver-specific functions in hepatoma cell hybrids, pp. 346–357. In: “Gene Expression and Carcinogenesis in Cultured Liver,” L. E. Gerschenson and E. B. Thompson (eds.). Academic Press, New York.Google Scholar
- Williams, G. M., E. K. Weisburger, and J. H. Weisberger, 1973. Carcinoma after malignant conversion in vitro of epithelial-like cells from rat liver following exposure to chemical carcinogens. Cancer Res., 33: 606–612.Google Scholar