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.
Radna
R L
RL
Department of Biological Science, Hunter College, City University of New York, New York 10021.
Caton
Y
Y
Jha
K K
KK
Kaplan
P
P
Li
G
G
Traganos
F
F
Ozer
H L
HL
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