Nonresponsiveness of an SV40-transformed Balb/c-3T3 cell line to PDGF mitogenicity is correlated with an irreversible reduction in PDGF receptor number.
The effect of SV40 transformation on the mitogenic responsiveness of Balb/c-3T3 cells to platelet-derived growth factor was examined. The SV40 transformed cell line (SV40-3T3) did not require exogenous PDGF for growth in a serum-free medium containing insulin, transferrin and high density lipoprotein as macromolecular supplements. The SV40-3T3 cells were found to have undetectable PDGF-stimulated PDGF receptor autophosphorylation and markedly reduced PDGF binding. PDGF-induced PDGF receptor autophosphorylation and PDGF binding of the normal 3T3 cells were not reduced by incubation with conditioned medium from SV40 transformed cells; nor could PDGF binding to SV40-3T3 be increased by an 8-hour incubation with 0.5 mM suramin, a compound known to prevent the binding of PDGF to its receptor. These data suggest that SV40-3T3 cells do not produce PDGF in quantities that are sufficient to down regulate their PDGF receptor and suggest that the reduced PDGF responsiveness and PDGF receptor number in SV40-3T3 cells may be a reflection of a more permanent, perhaps genetic, alteration.
Dept. of Physiology, Chang Gung Medical College, Kweisan, Taoyuan, Taiwan, ROC.
J R
JR
Cook
D Y
DY
Wang
J K
JK
Chen
D016475:3T3 Cells / Q000166:cytology* / Q000648:ultrastructure; D000818:Animals; D002472:Cell Transformation, Viral / Q000502:physiology*; D016895:Culture Media, Serum-Free; D015536:Down-Regulation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology; D006128:Growth / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008934:Mitogens / Q000494:pharmacology*; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000378:metabolism / Q000494:pharmacology*; D017479:Receptors, Platelet-Derived Growth Factor / Q000187:drug effects / Q000378:metabolism*; D013539:Simian virus 40 / Q000502:physiology*; D013498:Suramin / Q000494:pharmacology
D016895:Culture Media, Serum-Free; D008934:Mitogens; D010982:Platelet-Derived Growth Factor; D013498:Suramin; D004815:Epidermal Growth Factor; D017479:Receptors, Platelet-Derived Growth Factor