First Author | Ahn R | Year | 2013 |
Journal | Cancer Res | Volume | 73 |
Issue | 14 | Pages | 4521-32 |
PubMed ID | 23695548 | Mgi Jnum | J:199117 |
Mgi Id | MGI:5500863 | Doi | 10.1158/0008-5472.CAN-12-4178 |
Citation | Ahn R, et al. (2013) The ShcA PTB Domain Functions as a Biological Sensor of Phosphotyrosine Signaling during Breast Cancer Progression. Cancer Res 73(14):4521-32 |
abstractText | ShcA (SHC1) is an adapter protein that possesses an SH2 and a PTB phosphotyrosine-binding motif. ShcA generally uses its PTB domain to engage activated receptor tyrosine kinases (RTK), but there has not been a definitive determination of the role of this domain in tumorigenesis. To address this question, we employed a ShcA mutant (R175Q) that no longer binds phosphotyrosine residues via its PTB domain. Here, we report that transgenic expression of this mutant delays onset of mammary tumors in the MMTV-PyMT mouse model of breast cancer. Paradoxically, we observed a robust increase in the growth and angiogenesis of mammary tumors expressing ShcR175Q, which displayed increased secretion of fibronectin and expression of integrin alpha5/beta1, the principal fibronectin receptor. Sustained integrin engagement activated Src, which in turn phosphorylated proangiogenic RTKs, including platelet-derived growth factor receptor, fibroblast growth factor receptor, and Met, leading to increased VEGF secretion from ShcR175Q-expressing breast cancer cells. We defined a ShcR175Q-dependent gene signature that could stratify breast cancer patients with a high microvessel density. This study offers the first in vivo evidence of a critical role for intracellular signaling pathways downstream of the ShcA PTB domain, which both positively and negatively regulate tumorigenesis during various stages of breast cancer progression. Cancer Res; 73(14); 4521-32. (c)2013 AACR. |