Growth of immortal simian virus 40 tsA-transformed human fibroblasts is temperature dependent.
Simian virus 40 (SV40)-mediated transformation of human fibroblasts offers an experimental system for studying both carcinogenesis and cellular aging, since such transformants show the typical features of altered cellular growth but still have a limited life span in culture and undergo senescence. We have previously demonstrated (D. S. Neufeld, S. Ripley, A. Henderson, and H. L. Ozer, Mol. Cell. Biol. 7:2794-2802, 1987) that transformants generated with origin-defective mutants of SV40 show an increased frequency of overcoming senescence and becoming immortal. To clarify further the role of large T antigen, we have generated immortalized transformants by using origin-defective mutants of SV40 encoding a heat-labile large T antigen (tsA58 transformants). At a temperature permissive for large-T-antigen function (35 degrees C), the cell line AR5 had properties resembling those of cell lines transformed with wild-type SV40. However, the AR5 cells were unable to proliferate or form colonies at temperatures restrictive for large-T-antigen function (39 degrees C), demonstrating a continuous need for large T antigen even in immortalized human fibroblasts. Such immortal temperature-dependent transformants should be useful cell lines for the identification of other cellular or viral gene products that induce cell proliferation in human cells.
Department of Biological Science, Hunter College, City University of New York, New York 10021.
R L
RL
Radna
Y
Y
Caton
K K
KK
Jha
P
P
Kaplan
G
G
Li
F
F
Traganos
H L
HL
Ozer
D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D015153:Blotting, Western; D002455:Cell Division; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D009154:Mutation; D010641:Phenotype; D013696:Temperature
D000952:Antigens, Polyomavirus Transforming; D004279:DNA, Viral