p53 reactivation with induction of massive apoptosis 1 (PRIMA 1) inhibits amyloid aggregation of mutant p53 in cancer cells
p53 mutants can form amyloid like structures that accumulate in cells. p53 reactivation with induction of massive apoptosis 1 (PRIMA 1) and its primary active metabolite, 2 methylene 3 quinuclidinone (MQ) can restore unfolded p53 mutants to a native conformation that induces apoptosis and activates several p53 target genes. However, whether PRIMA 1 can clear p53 aggregates is unclear. In this study, we investigated whether PRIMA 1 can restore aggregated mutant p53 to a native form. We observed that the p53 mutant protein is more sensitive to both PRIMA 1 and MQ aggregation inhibition than WT p53. The results of anti amyloid oligomer antibody assays revealed that PRIMA 1 reverses mutant p53 aggregate accumulation in cancer cells. Size exclusion chromatography of the lysates from mutant p53 containing breast cancer and ovarian cell lines confirmed that PRIMA 1 substantially decreases p53 aggregates. We also show that MDA MB 231 cell lysates can "seed" aggregation of the central core domain of recombinant WT p53, corroborating the prion like behavior of mutant p53. We also noted that this aggregation effect was inhibited by MQ and PRIMA 1. This study provides the first demonstration that PRIMA 1 can rescue amyloid state p53 mutants, a strategy that could be further explored as a cancer treatment.
The Journal of Biological Chemistry