The Ink4a tumor suppressor gene product, p19(super Arf), interacts with MDM2 and neutralizes MDM2's inhibition of p53

Research was conducted to test whether the tumor suppressor gene product , p19(super Arf) hinders oncogenic transformation in primary cells and whether its role is abrogated when p53 is neutralized by viral oncoproteins and dominant-negative mutants. Cell cultures were monitored and maintained by calcium phosphate using the same amounts of DNA as in p53 degradation. Results showed high levels of genetic instability in p53 and that potent tumor suppressor activity resulted from the encoding of unrelated antioncogenic proteins with cooperating modes of action.