The beta-interferon-mediated antimitogenic state resembles the anti-viral state

Much controversy regarding the effect of interferons in control of the animal cell cycle can be reconciled by acknowledging that, until recently, few laboratories enjoyed access to both pure interferons and pure growth-factor preparations. Using such reagents, we show data that suggest that antimitogenic state in Balb/c-3T3 cells by beta-interferon resembles the antiviral state in two important regards: dosage and kinetics. Picomolar concentrations of homogeneous beta-interferon inhibit the mitogenic response to recombinant platelet-derived growth-factor B chain homodimer. The antimitogenic response is seen only when cells are exposed to pure beta-interferon for an extended time prior to platelet-derived growth-factor treatment. The interferon-mediated antimitogenic state is exerted at some point in the cell cycle subsequent to c-myc gene induction.