In Vitro Cell Transformation with Chemical Carcinogens

DIFFERENTIAL sensitivity of normal and neoplastic rodent fibroblasts growing in vitro to the toxic action of carcinogenic polycyclic hydrocarbons, suggested long ago by Haddow (1938), has been demonstrated by a number of investigators (Starikova and Vasiliev, 1962;Berwald and Sachs, 1963; Alfred and collaborators, 1964;Diamond, 1966). Neoplastic cells were found to be much more resistant to these compounds than their normal counterparts. Resistance to the toxic effects of carcinogenic hydrocarbons was shown to be characteristic for the cells of sarcomas induced by various types of agents: carcinogenic chemicals, plastic films, SV40 and polyoma viruses. Thus, decrease of the sensitivity to carcinogens regularly accompanied neoplastic transformation of these cells (see review and discussion in Vasiliev and Guelstein, 1963Guelstein, , 1966.The causes of the differential sensitivity of normal and neoplastic cells to carcinogenic hydrocarbons remain obscure. These compounds undergo various metabolic transformations in vivo (see review in Boyland and Weigert, 1947; Miller and Miller, 1965). In vitro they are rapidly accumulated by normal and neoplastic cells (Marimura, Kotin and Falk, 1964;Alfred et al., 1964;Diamond, 1966). It was not known, however, whether these substances might be metabolized by cells growing in vitro.The experiments described in this paper were performed in order to study the rate of metabolism of a carcinogenic hydrocarbon, 3,4-benzopyrene (BP), in cultures of normal and neoplastic fibroblasts of mice and hamsters.Similar experiments were made with cultures of fibroblasts from normal human embryos. As shown by Diamond (1966) and confirmed in this laboratory, normal human fibroblasts, in contrast to normal rodent cells, are resistant to the toxic effects of carcinogenic hydrocarbons. MATERIALS AND METHODS Cell culturesFirst subcultures of trypsinized cells of mouse, hamster and human embryos were used; the age of human embryos taken for trypsinization was about 2-3 months, that of rodent embryos about 17-19 days of pregnancy.Trypsinized embryonic cells were first grown in large vessels and then transferred into stoppered Carrel flasks 5 cm. in diameter. Continuous lines of neoplastic cells were also grown in Carrel flasks. Some information on the origin

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mentioning

confidence: 96%

Metabolic degradation of 3,4-benzopyrene in the cultures of normal and neoplastic fibroblasts.

Andrianov¹,

Belitsky²,

Ivanova³

et al. 1967

“…Success in inducing in vitro transformation in mammalian cells by chemical carcinogens (Berwald and Sachs, 1963;Heidelberger and Iype, 1967;Sanders and Burford, 1967) has opened the possibility of studying the mode of action of these carcinogens at the cellular and molecular level (Heidelberger, 1964(Heidelberger, , 1970 and is expected to shed light on the question of clonal selection in a population of apparently homogeneous cells. Environmentally induced selective pressure on cells, as in the case of temperature sensitive conditional lethal mutants, might offer the opportunity to test the theory of clonal selection in carcinogenic transformation of mammalian cells.…”

mentioning

confidence: 99%

On the Theory of Clonal Selection in Carcinogenic Transformation

Naha¹,

Ashworth²

1974

Summary.-A temperature sensitive variant (tsl3) of African green monkey kidney cell line, carrying a temperature sensitive lesion in thymidine metabolism, was transformed by 40 ug/ml of methylnitrosourea (MNU) at the restricted temperature of 39 5°C, whereas the same cell line was not transformed by MNU at the permissive temperature of 33°C. Results presented in this paper raise the possibility that clones of cells carrying a biochemical lesion might possibly contribute to carcinogenesis with respect to certain chemical carcinogens.

“…The carcinogen-containing medium was removed, the cultures were fed weekly for 4-5 weeks, and observed regularly for morphological changes. This is about the same post-treatment time as is required for C3H mouse cells to develop altered morphology (Chen and Heidelberger, 1969a, b;Reznikoff et al, 1973b) and is much longer than the 10-day post-treatment period after which colonies of transformed Syrian hamster cells are recognizable (Berwald and Sachs, 1963;DiPaolo and Donovan, 1967;DiPaolo et al, 1969aDiPaolo et al, , b, 1971.…”

Section: Mediamentioning

confidence: 95%

“…One system uses Syrian hamster embryo cells (Berwald and Sachs, 1963;DiPaolo and Donovan, 1967;DiPaolo et al, 1969aDiPaolo et al, , 1969bDiPaolo et al, , 1971 and the other uses C3H mouse prostate cells (Chen anid Heidelberger, 1969a, b) or a cloned line of C3H mouse embryo cells which has recently been established (Reznikoff et al, 1973a, b). As a means of quantifying the effects of the chemical, morphological changes have been scored.…”

mentioning

confidence: 99%

Chemical transformation of Chinese hamster cells. I. A comparison of some properties of transformed cells

Kirkland¹

1976

Summary.-Fifty-one subclones from carcinogen-treated cells of 3 tissues (kidney, liver and prostate) of the male Chinese hamster have been studied to determine the relationships of 3 criteria of in vitro transformation: morphological change, increased plating efficiency and growth in soft agar. There was no correlation between increased plating efficiency and the other 2 parameters. Morphological change was not always easily recognisable, particularly in cells derived from liver, and was not always a stable feature of any given subclone. This may be due to the technique of isolation used (ring cloning) or may be due to chemically-treated cells requiring long periods of culturing before attaining a stable phenotype. When a stable morphological appearance was achieved, there was good correlation between transformed morphology and colony formation in soft agar.The problems of scoring morphological change as an assessment of malignant transformation, and the importance of spontaneous morphological changes are discussed.