Induction of intracellular wild-type p53 amyloids leading to cellular transformation and tumor formation in mice

Abstract

Tumor suppressor p53 mutations, with subsequent loss-of-tumor suppressive function and gain-of oncogenic functions, are associated with more than 50% of human cancers. Aggregation and amyloid formation are also mechanisms by which wild type and mutant p53 might be involved in cancer, but the direct evidence of how aggregated p53 acts as an oncogene is lacking. In this study, we directly demonstrate that wild-type p53 amyloid formation imparts oncogenic properties to normal cells. Cells with p53 amyloids show enhanced survival, apoptotic resistance with increased proliferation and migration rates. The tumorigenic potential of p53 amyloid transformed cells is further confirmed in a mice xenograft model, wherein the tumor showed p53 amyloid aggregates. Gene-expression analysis and proteomic profiling suggest that p53 amyloid formation triggers aberrant expression of pro-oncogenes while downregulating the tumor-suppressive genes. Interestingly, disaggregating p53 rescues the cellular transformation and also inhibits tumor development in mice. We propose that wild-type p53 amyloid formation can potentially contribute to the initiation of tumor development.