Dissociation between early loss of actin fibres and subsequent cell death in serum-deprived quiescent Balb/c-3T3 cells.
Serum withdrawal from either growing or quiescent Balb/c-3T3 murine fibroblasts causes a loss of F-actin fibres and focal adhesions within 30 min. Cells that are growing survive serum deprivation, whereas the great majority of density-arrested quiescent cells die during a period of up to 5 h from serum withdrawal. During this time an approximately constant fraction of the quiescent cell population dies per unit time. The population half-life is 60-70 min during this time. Addition of an appropriate cell growth factor or second messenger agonist at the time of serum withdrawal or within 2 h after serum withdrawal protects a similar fraction of viable cells. These findings suggest a model according to which withdrawal of serum (i.e. growth factors) initiates the death process in cells of the population with kinetics that approximate first-order kinetics. We postulate that appropriate growth factors or second messenger agonists block the initiating event that starts the cell death process.
D016475:3T3 Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion; D016923:Cell Death / Q000502:physiology*; D002470:Cell Survival / Q000187:drug effects; D003470:Culture Media; D019204:GTP-Binding Proteins / Q000378:metabolism; D006133:Growth Substances / Q000494:pharmacology; D007399:Interphase; D051379:Mice; D019000:Phosphotyrosine; D015398:Signal Transduction; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
D000199:Actins; D003470:Culture Media; D006133:Growth Substances; D019000:Phosphotyrosine; D014443:Tyrosine; D019204:GTP-Binding Proteins