MDM2 and sarcoma: However, since many sarcomas overexpress Mdm2, and high levels of Mdm2 inactivate and cause degradation of p53 (Haupt et al, 1997a; Momand et al, 1992; Oliner et al, 1992, 1993; Nakayama et al, 1995; Momand et al, 1998; Vogelstein et al, 2000), wt p53 transfer into sarcoma cells that overexpress Mdm2 is unlikely to be efficacious (Chen et al, 1996; Meng et al, 1998).