Organelle Specific O-Glycosylation Drives MMP14 Activation, Tumor Growth, and Metastasis

Publication date: 13 November 2017
Source:Cancer Cell, Volume 32, Issue 5
Author(s): Anh Tuan Nguyen, Joanne Chia, Manon Ros, Kam Man Hui, Frederic Saltel, Frederic Bard
Cancers grow within tissues through molecular mechanisms still unclear. Invasiveness correlates with perturbed O-glycosylation, a covalent modification of cell-surface proteins. Here, we show that, in human and mouse liver cancers, initiation of O-glycosylation by the GALNT glycosyl-transferases increases and shifts from the Golgi to the endoplasmic reticulum (ER). In a mouse liver cancer model, expressing an ER-targeted GALNT1 (ER-G1) massively increased tumor expansion, with median survival reduced from 23 to 10 weeks. In vitro cell growth was unaffected, but ER-G1 strongly enabled matrix degradation and tissue invasion. Unlike its Golgi-localized counterpart, ER-G1 glycosylates the matrix metalloproteinase MMP14, a process required for tumor expansion. Together, our results indicate that GALNTs strongly promote liver tumor growth after relocating to the ER.

Graphical abstract

Teaser

Nguyen et al. find that O-glycosylation increases during liver tumor progression, with increased expression of GALNT1 and glycosylation of ER-associated proteins. In mouse models, expression of GALNT1 in the ER, but not the Golgi, accelerates tumorigenesis and increases invasion through glycosylation of MMP14.


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