Acquisition of aneuploidy drives mutant p53-associated gain-of-function phenotypes

Area of Science:

• Oncology
• Genetics
• Cell Biology

Background:

• Over half of human cancers harbor mutations in the p53 tumor suppressor gene.
• Mutant p53 proteins are hypothesized to gain novel oncogenic functions (gain-of-function, GOF).
• Understanding mutant p53 GOF is crucial for cancer therapy development.

Purpose of the Study:

• To investigate the mechanisms and phenotypes associated with mutant p53 GOF.
• To develop and characterize cell line models expressing endogenous mutant p53.
• To determine the role of aneuploidy in mutant p53-associated phenotypes.

Main Methods:

• Genetically engineered cell lines expressing endogenous missense mutant p53 (R175H, R273H) or p53-null.
• Characterized cell models for aneuploidy and GOF phenotypes in vitro and in vivo.
• Analyzed TP53 genotype and aneuploidy status in patient outcome data.

Main Results:

• Aneuploidy frequently occurred in cells expressing mutant p53.
• GOF phenotypes were clonal, independent of p53 alteration, and correlated with increased aneuploidy.
• High aneuploidy in tumors correlated with unfavorable patient prognosis, irrespective of TP53 genotype.

Conclusions:

• Genetic variation arising from aneuploidy accounts for diverse mutant p53 GOF phenotypes.
• Aneuploidy, not solely mutant p53, drives oncogenic phenotypes.
• Targeting aneuploidy may offer a therapeutic strategy for cancers with p53 mutations.