Carcinogenic and Related Non-Carcinogenic Hydrocarbons in Tissue Culture. II

Abstract

In a previous paper (1), a report was given of the action of 1:2:5:6-dibenzanthracene choleic acid, phenanthrene choleic acid, and desoxycholic acid on mouse fibroblasts in tissue cultures. The action of 20-methylcholanthrene choleic acid and acenaphthene choleic acid has been investigated in a similar manner. These studies have been concerned chiefly with the early effects of these substances on cells in vitro with special attention to the effects on growth and chromosome behaviour.

The author (1, 2) found an increase in cell proliferation and also a precocious splitting of the chromosomes in the prophase of mitosis, the latter frequently resulting in a “node and loop” formation, in cultures of mouse fibroblasts treated with 1:2:5:6-dibenzanthracene choleic acid. These effects were not observed in the presence of the non-carcinogenic phenanthrene choleic acid or desoxycholic acid or in untreated control cultures. The latter two test substances gave a decrease in growth rate when compared with the untreated controls.

Earle and Voegtlin (3) in a study of the influence of methylcholanthrene and dibenzanthracene on rat and mouse fibroblasts in tissue cultures reported growth retardation and degeneration of the cultures, even with a concentration of 0.0002 mg. of methylcholanthrene per c.c., the extent of the effect being directly proportional to the concentration of the carcinogenic hydrocarbon. Mauer (4) observed gross abnormalities of the chromosomes in cultures of chick fibroblasts treated with carcinogenic and non-carcinogenic hydrocarbons. The relatively high concentrations of the organic solvents used by him may, however, have been responsible for these effects (1, 5, 6). Owen, Weiss and Prince (7) extended their investigations to rootlet transplants of the pea and found a slight growth stimulation due to carcinogenic chemicals. Cook, Hart and Joly (8) found the effect of dibenzanthracene on proliferation and respiration of yeast to be either stimulative or inhibitory depending on the concentration.