The perlecan-interacting growth factor progranulin regulates ubiquitination, sorting, and lysosomal degradation of sortilin.
Publication/Presentation Date
12-1-2017
Abstract
Despite extensive clinical and experimental studies over the past decades, the pathogenesis and progression to the castration-resistant stage of prostate cancer remains largely unknown. Progranulin, a secreted growth factor, strongly binds the heparin-sulfate proteoglycan perlecan, and counteracts its biological activity. We established that progranulin acts as an autocrine growth factor and promotes prostate cancer cell motility, invasion, and anchorage-independent growth. Progranulin was overexpressed in prostate cancer tissues vis-à-vis non-neoplastic tissues supporting the hypothesis that progranulin may play a key role in prostate cancer progression. However, progranulin's mode of action is not well understood and proteins regulating progranulin signaling have not been identified. Sortilin, a single-pass type I transmembrane protein of the Vps10 family, binds progranulin in neurons and targets progranulin for lysosomal degradation. Significantly, in DU145 and PC3 cells, we detected very low levels of sortilin associated with high levels of progranulin production and enhanced motility. Restoring sortilin expression decreased progranulin levels, inhibited motility and anchorage-independent growth and destabilized Akt. These results demonstrated a critical role for sortilin in regulating progranulin and suggest that sortilin loss may contribute to prostate cancer progression. Here, we provide the novel observation that progranulin downregulated sortilin protein levels independent of transcription. Progranulin induced sortilin ubiquitination, internalization via clathrin-dependent endocytosis and sorting into early endosomes for lysosomal degradation. Collectively, these results constitute a regulatory feed-back mechanism whereby sortilin downregulation ensures sustained progranulin-mediated oncogenesis.
Volume
64
First Page
27
Last Page
39
ISSN
1569-1802
Published In/Presented At
Tanimoto, R., Palladino, C., Xu, S. Q., Buraschi, S., Neill, T., Gomella, L. G., Peiper, S. C., Belfiore, A., Iozzo, R. V., & Morrione, A. (2017). The perlecan-interacting growth factor progranulin regulates ubiquitination, sorting, and lysosomal degradation of sortilin. Matrix biology : journal of the International Society for Matrix Biology, 64, 27–39. https://doi.org/10.1016/j.matbio.2017.04.001
Disciplines
Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods
PubMedID
28433812
Department(s)
Administration and Leadership
Document Type
Article