One challenge to understanding cancer is identifying the meaningful genomic mutations that contribute to disease. Minichromosome maintenance (MCM) proteins are important regulators of the early steps in DNA replication. A mutation in the MCM4 protein, Chaos3, destabilizes the protein, inducing chromosome breaks and causing aggressive breast adenocarcinoma in female mice. A study by Li et al. shows that this mutation also causes genome instability and improved growth of the yeast, Saccharomyces cerevisiae. The yeast growth phenotype emerges simultaneously with aneuploidy, but aneuploidy does not contribute to the growth characteristics. Importantly, the growth phenotype induced by MCM4Chaos3 in yeast cells involves mutations in only a few genetic loci, suggesting that it may be possible to define the growth-enhancing mutations that contribute to cancer in this simple model.
Li XC, Schimenti JC, Tye BK (2009). Aneuploidy and improved growth are coincident but not causal in a yeast cancer model. PLoS Biol. 7, e1000161.
