1 Loss of Cdh1 and Pten Accelerates Cellular Invasiveness and Angiogenesis in the Mouse

E-cadherin (CDH1) is a cell adhesion molecule that coordinates key morphogenetic processes regulating cell growth, cell proliferation and apoptosis. Loss of CDH1 is a trademark of the cellular event epithelial to mesenchymal transition (EMT), which increases the metastatic potential of malignant cells. PTEN is a tumor suppressor gene commonly mutated in many human cancers, including endometrial cancer. In the mouse uterus, ablation of Pten induces epithelial hyperplasia, leading to endometrial carcinomas. However, loss of Pten alone does not affect longevity until around 5 mo. Similarly, conditional ablation of Cdh1 alone does not predispose mice to cancer. In this study, we characterized the impact of dual Cdh1 and Pten ablation (Cdh1d/d Ptend/d) in the mouse uterus. We observed that Cdh1d/d Ptend/d mice died at Postnatal Day 15-19 with massive blood loss. Their uteri were abnormally structured with curly horns, disorganized epithelial structure, and increased cell proliferation. Co-immunostaining of KRT8 and ACTA2 showed invasion of epithelial cells into the myometrium. Further, the uteri of Cdh1d/d Ptend/d mice had prevalent vascularization in both the endometrium and myometrium. We also observed reduced expression of estrogen and progesterone receptors, loss of cel