The receptor protein tyrosine phosphatase PTPRB negatively regulates FGF2-dependent branching morphogenesis

Soady, K. J., Tornillo, G., Kendrick, H., Meniel, V., Olijnyk-Dallis, D., Morris, J. S. , Stein, T. , Gusterson, B. A., Isacke, C. M. and Smalley, M. J. (2017) The receptor protein tyrosine phosphatase PTPRB negatively regulates FGF2-dependent branching morphogenesis. Development, 144(20), pp. 3777-3788. (doi: 10.1242/dev.149120) (PMID:28870991)

Abstract

PTPRB is a transmembrane protein tyrosine phosphatase known to regulate blood vessel remodelling and angiogenesis. Here we demonstrate that PTPRB negatively regulates branching morphogenesis in the mammary epithelium. We show that Ptprb is highly expressed in adult mammary stem cells and also, although at lower levels, in estrogen receptor positive luminal cells. During mammary development Ptprb expression is down-regulated during puberty, a period of extensive of ductal outgrowth and branching. In vivo shRNA knockdown of Ptprb in the cleared mammary fat pad transplant assay resulted in smaller epithelial outgrowths with an increased branching density and also increased branching in an in vitro organoid assay. Organoid branching was dependent on stimulation by FGF2, and Ptprb knockdown in mammary epithelial cells resulted in a higher level of FGFR activation and ERK1/2 phosphorylation, both at baseline and following FGF2 stimulation. Therefore, PTPRB regulates branching morphogenesis in the mammary epithelium by modulating the response of the FGFR signalling pathway to FGF stimulation. Considering the importance of branching morphogenesis in multiple taxa, our findings have general importance outside mammary developmental biology.

• Item Type: Articles
• Keywords: Branching morphogenesis, FGFR2, Mammary stem cells, PTPRB, Terminal end bud gene expression.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Stein, Dr Torsten and Morris, Professor Joanna and Gusterson, Professor Barry
• Authors: Soady, K. J., Tornillo, G., Kendrick, H., Meniel, V., Olijnyk-Dallis, D., Morris, J. S., Stein, T., Gusterson, B. A., Isacke, C. M., and Smalley, M. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences; College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Development
• Publisher: The Company of Biologists Ltd
• ISSN: 1477-9129
• ISSN (Online): 1477-9129
• Published Online: 04 September 2017
• Copyright Holders: Copyright © 2017 The Company of Biologists Ltd
• First Published: First published in Development 144(20): 3777-3788
• Publisher Policy: Reproduced in accordance with the publisher copyright policy