Abstract
All the BHK21 Clone 13 cells transformed by dimethylnitrosamine or nitrosomethylurea, and a single “spontaneously” transformed clone obtained in our laboratory, exhibit a conditional state of the transformed phenotype. Upon growth at 38.5°, they have a transformed phenotype (clonal morphology and the ability to plate in soft agar); when grown at 32°, their phenotype is normal. The conditional state of these cells, however, does not extend to their growth characteristics; their plating efficiency at the two temperatures in liquid medium is similar. Conversion from the normal to the transformed phenotype and the reverse is possible by temperature shifts. A working hypothesis is proposed suggesting that this phenomenon may be caused by a temperature-sensitive mutation of a cellular gene whose product is responsible for maintaining the normal phenotype. The high temperature would then affect either the synthesis or the function of the protein carrying the temperature-sensitive alteration and, as a consequence, the transformed phenotype would be expressed.
Keywords: in vitro chemical carcinogenesis, transformed phenotype conditioned by high temperature
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- Berwald Y., Sachs L. In vitro transformation of normal cells to tumor cells by carcinogenic hydrocarbons. J Natl Cancer Inst. 1965 Oct;35(4):641–661. [PubMed] [Google Scholar]
- Borenfreund E., Krim M., Sanders F. K., Sternberg S. S., Bendich A. Malignant conversion of cells in vitro by carcinogens and viruses. Proc Natl Acad Sci U S A. 1966 Aug;56(2):672–679. doi: 10.1073/pnas.56.2.672. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chen T. T., Heidelberger C. Cultivation in vitro of cells derived from adult C3H mouse ventral prostate. J Natl Cancer Inst. 1969 Jun;42(6):903–914. [PubMed] [Google Scholar]
- Chen T. T., Heidelberger C. Quantitative studies on the malignant transformation of mouse prostate cells by carcinogenic hydrocarbons in vitro. Int J Cancer. 1969 Mar 15;4(2):166–178. doi: 10.1002/ijc.2910040207. [DOI] [PubMed] [Google Scholar]
- DiPaolo J. A., Donovan P. J., Nelson R. L. In vitro transformation of hamster cells by polycyclic hydrocarbons: factors influencing the number of cells transformed. Nat New Biol. 1971 Apr 21;230(16):240–242. doi: 10.1038/newbio230240a0. [DOI] [PubMed] [Google Scholar]
- DiPaolo J. A., Donovan P., Nelson R. Quantitative studies of in vitro transformation by chemical carcinogens. J Natl Cancer Inst. 1969 May;42(5):867–874. [PubMed] [Google Scholar]
- DiPaolo J. A., Nelson R. L., Donovan P. J. Sarcoma-producing cell lines derived from clones transformed in vitro by benzo[a]pyrene. Science. 1969 Aug 29;165(3896):917–918. doi: 10.1126/science.165.3896.917. [DOI] [PubMed] [Google Scholar]
- Huberman E., Sachs L. Cell susceptibility to transformation and cytotoxicity by the carcinogenic hydrocarbon benzo[a]pyrene. Proc Natl Acad Sci U S A. 1966 Oct;56(4):1123–1129. doi: 10.1073/pnas.56.4.1123. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MACPHERSON I., MONTAGNIER L. AGAR SUSPENSION CULTURE FOR THE SELECTIVE ASSAY OF CELLS TRANSFORMED BY POLYOMA VIRUS. Virology. 1964 Jun;23:291–294. doi: 10.1016/0042-6822(64)90301-0. [DOI] [PubMed] [Google Scholar]
- Medina D., Sachs L. A cause of variation in clonal morphology of polyoma transformed hamster cells. Virology. 1965 Nov;27(3):398–408. doi: 10.1016/0042-6822(65)90120-0. [DOI] [PubMed] [Google Scholar]
- Mondal S., Heidelberger C. In vitro malignant transformation by methylcholanthrene of the progeny of single cells derived from C3H mouse prostate. Proc Natl Acad Sci U S A. 1970 Jan;65(1):219–225. doi: 10.1073/pnas.65.1.219. [DOI] [PMC free article] [PubMed] [Google Scholar]