Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.

Tumor suppressor function of laminin-binding alpha-dystroglycan requires a distinct beta3-N-acetylglucosaminyltransferase.

Bao X., Kobayashi M., Hatakeyama S., Angata K., Gullberg D., Nakayama J., Fukuda M.N., Fukuda M.

Alpha-dystroglycan (alpha-DG) represents a highly glycosylated cell surface molecule that is expressed in the epithelial cell-basement membrane (BM) interface and plays an essential role in epithelium development and tissue organization. The alpha-DG-mediated epithelial cell-BM interaction is often impaired in invasive carcinomas, yet roles and underlying mechanisms of such an impaired interaction in tumor progression remain unclear. We report here a suppressor function of laminin-binding glycans on alpha-DG in tumor progression. In aggressive prostate and breast carcinoma cell lines, laminin-binding glycans are dramatically decreased, although the amount of alpha-DG and beta-dystroglycan is maintained. The decrease of laminin-binding glycans and consequent increased cell migration were associated with the decreased expression of beta3-N-acetylglucosaminyltransferase-1 (beta3GnT1). Forced expression of beta3GnT1 in aggressive cancer cells restored the laminin-binding glycans and decreased tumor formation. beta3GnT1 was found to be required for laminin-binding glycan synthesis through formation of a complex with LARGE, thus regulating the function of LARGE. Interaction of the laminin-binding glycans with laminin and other adhesive molecules in BM attenuates tumor cell migratory potential by antagonizing ERK/AKT phosphorylation induced by the components in the ECM. These results identify a previously undescribed role of carbohydrate-dependent cell-BM interaction in tumor suppression and its control by beta3GnT1 and LARGE.

Proc. Natl. Acad. Sci. U.S.A. 106:12109-12114(2009) [PubMed] [Europe PMC]