A rapid in vitro assay for carcinogenicity of chemical substances in mammalian cells utilizing an attachment-independence endpoint

✍ Scribed by K. A. Traul; V. Kachevsky; J. S. Wolff; R. Hink; U. Nanna

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: French
• Weight: 406 KB
• Volume: 23
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910230209

✦ Synopsis

Abstract

Rauscher leukemia virus (RLV)‐infected rat embryo cells have been shown to be sensitive to neoplastic transformation by a variety of chemical carcinogens. The mass assay technique normally used requires 6 to 15 weeks before morphologically altered foci of cells are observed. While growth in soft agar is considered to be one of the best __in vitro__means for confirming neoplastic transformation, this assay requires 4 additional weeks beyond focus formation. We have devised a rapid new assay for determining carcinogenicity of chemicals. The method takes advantage of the range of chemical sensitivity of RLV‐infected rat embryo cells, but provides, in 10 days, for a readout based on the ability of transformed cells to survive under conditions which select for attachment independence. The target cells, 2FR~4~50, were treated for 72 h with chemical and then plated into Petri dishes containing a solid bottom layer of agar/medium. Viable cell counts were made 3 and 6 days later and compared to parallel data from solvent‐treated control cells. 2FR~4~50 cells treated with any of 10 chemical carcinogens, including such diverse compounds as benzo(a)pyrene, 3‐methylcholanthrene, 2‐acetylaminofluorene, NiSO~4~and urethane, showed an average increase of 225% in survival over controls. Phenanthrene, a non‐carcinogen, induced no increase in survival of 2FR~4~50 cells. This assay appears to permit detection of carcinogens of various chemical types with a simple test readout within 10 days.