Chk2*1100delC Acts in synergy with the Ron receptor tyrosine kinase to accelerate mammary tumorigenesis in mice.

The CHEK2 (Chk2 in mice) polymorphic variant, CHEK2*1100delC, leads to genomic instability and is associated with an increased risk for breast cancer. The Ron receptor tyrosine kinase is overexpressed in a large fraction of human breast cancers. Here, we asked whether the low penetrance Chk2*1100delC allele alters the tumorigenic efficacy of Ron in the development of mammary tumors in a mouse model. Our data demonstrate that Ron overexpression on a Chk2*1100delC background accelerates the development of mammary tumors, and shows that pathways mediated by a tyrosine kinase receptor and a regulator of the cell cycle can act to hasten tumorigenesis in vivo.