Chordin-Like 1 Suppresses Bone Morphogenetic Protein 4-Induced Breast Cancer Cell Migration and Invasion

Abstract

ShcA is an important mediator of ErbB2 and TGFβ-induced breast cancer cell migration, invasion and metastasis. We show that in the context of reduced ShcA levels, the BMP antagonist, Chordin-like 1 (Chrdl1), is upregulated in numerous breast cancer cells following TGFβ stimulation. BMPs have emerged as important modulators of breast cancer aggressiveness and we have investigated the ability of Chrdl1 to block BMP-induced increases in breast cancer cell migration and invasion. Breast cancer-derived conditioned media containing elevated concentrations of endogenous Chrdl1, as well as media containing recombinant Chrdl1, suppresses BMP4-induced signaling in multiple breast cancer cell lines. Live cell migration assays reveal that BMP4 induces breast cancer migration, which is effectively blocked by Chrdl1. We demonstrate that BMP4 also stimulated breast cancer cell invasion and matrix degradation, in part, through enhanced MMP2 and MMP9 activity that is antagonized by Chrdl1. Finally, high Chrdl1 expression was associated with better clinical outcomes in patients with breast cancer. Together, our data reveal that Chrdl1 acts as a negative regulator of malignant breast cancer phenotypes through inhibition of BMP signaling.