Expression of wtp53 and mtp53, as well as p53-MDM2 binding, in MM-derived cell lines, PCL patient cells, Saos-2 osteosarcoma cells, and normal BM MNCs. Total cell lysates of MM cell lines (U266, ARH-77, RPMI 8226, and OCI-My5), PCL patient cells (PCL1 and PCL2), Saos-2 p53-deficient osteosarcoma cells, and normal BM MNCs (without or 1 or 4 hours post-XRT) were immunoprecipitated with Ab-5 anti-wtp53 MoAb or Ab-3 anti-mtp53 MoAb and immunoblotted with DO-1 hrp anti-ptp53 MoAb. Normal BM MNCs served as a positive control for wtp53; U266 MM cells served as a positive control for mtp53; and p53-deficient Saos-2 cells served as a negative control for both wtp53 and mtp53 (A). Total cell lysates of RPMI 8226, Saos-2 osteosarcoma cells, and normal BM MNCs (without or 1 or 4 hours post-XRT) were immunoprecipitated with Ab-5 anti-wtp53 MoAb or Ab-3 anti-mtp53 MoAb, followed by immunoblotting with SMP14 anti-MDM2 MoAb (B).