Medical Genetics Commons^™

Constitutively Activated Pi3k Accelerates Tumor Initiation And Modifies Histopathology Of Breast Cancer, M. R. Sheen, J. D. Marotti, M. J. Allegrezza, M. Rutkowski, J. R. Conejo-Garcia, S. Fiering

Dartmouth Scholarship

The gene encoding phosphatidylinositol 3-kinase catalytic subunit α-isoform (PIK3CA, p110α) is frequently activated by mutation in human cancers. Based on detection in some breast cancer precursors, PIK3CA mutations have been proposed to have a role in tumor initiation. To investigate this hypothesis, we generated a novel mouse model with a Cre-recombinase regulated allele of p110α (myristoylated-p110α, myr-p110α) along with p53fl/fl deletion and KrasG12D also regulated by Cre-recombinase. After instillation of adenovirus-expressing Cre-recombinase into mammary ducts, we found that myr-p110α accelerated breast tumor initiation in a copy number-dependent manner. Breast tumors induced by p53fl/fl;KrasG12D with no or one copy of myr-p110α …