Fig. 2.

Curcumin induces ubiquitin-independent degradation of p53 and inhibits p53-induced apoptosis in leukemic cells. (A) M1-t-p53 myeloid leukemic cells were cultured for 5 h at 32°C without (–) or with the indicated concentrations of curcumin or dicoumarol and p53 level was determined. (B) M1-t-p53 cells were cultured for 5 h at 32°C in serum-free medium without (–) or with the indicated concentrations of curcumin, dicoumarol, or geldanamycin, and the p53 level was determined. (C) M1-t-p53 cells were cultured at 32°C without (–) or with the indicated concentrations of dicoumarol or curcumin, and the percentage of viable cells was determined after 23 h as described in ref. 20. (D) A31N-ts20 cells were cultured at 39°C for 24 h and then cultured for an additional 5 h at 39°C in the absence (–) or presence of the indicated concentrations of dicoumarol, geldanamycin, or curcumin, and p53 level was determined.