title: Suppression of cancer progression by MGAT1 shRNA knockdown.
abstract: Oncogenic signaling promotes tumor invasion and metastasis, in part, by increasing the expression of tri- and tetra- branched N-glycans. The branched N-glycans bind to galectins forming a multivalent lattice that enhances cell surface residency of growth factor receptors, and focal adhesion turnover. N-acetylglucosaminyltransferase I (MGAT1), the first branching enzyme in the pathway, is required for the addition of all subsequent branches. Here we have introduced MGAT1 shRNA into human HeLa cervical and PC-3-Yellow prostate tumor cells lines, generating cell lines with reduced transcript, enzyme activity and branched N-glycans at the cell surface. MGAT1 knockdown inhibited HeLa cell migration and invasion, but did not alter cell proliferation rates. Swainsonine, an inhibitor of α-mannosidase II immediately downstream of MGAT1, also inhibited cell invasion and was not additive with MGAT1 shRNA, consistent with a common mechanism of action. Focal adhesion and microfilament organization in MGAT1 knockdown cells also indicate a less motile phenotype. In vivo, MGAT1 knockdown in the PC-3-Yellow orthotopic prostate cancer xenograft model significantly decreased primary tumor growth and the incidence of lung metastases. Our results demonstrate that blocking MGAT1 is a potential target for anti-cancer therapy.
authors.affiliation: Ontario Cancer Institute, Princess Margaret Hospital, and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Reza
authors.initials: R
authors.lastname: Beheshti Zavareh
authors.forename: Mahadeo A
authors.initials: MA
authors.lastname: Sukhai
authors.forename: Rose
authors.initials: R
authors.lastname: Hurren
authors.forename: Marcela
authors.initials: M
authors.lastname: Gronda
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Wang
authors.forename: Craig D
authors.initials: CD
authors.lastname: Simpson
authors.forename: Neil
authors.initials: N
authors.lastname: Maclean
authors.forename: Francis
authors.initials: F
authors.lastname: Zih
authors.forename: Troy
authors.initials: T
authors.lastname: Ketela
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Swallow
authors.forename: Jason
authors.initials: J
authors.lastname: Moffat
authors.forename: David R
authors.initials: DR
authors.lastname: Rose
authors.forename: Harry
authors.initials: H
authors.lastname: Schachter
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Schimmer
authors.forename: James W
authors.initials: JW
authors.lastname: Dennis
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D018450:Disease Progression; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008297:Male; D051379:Mice; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics* / Q000378:metabolism; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000235:genetics* / Q000628:therapy*; D010641:Phenotype; D011134:Polysaccharides / Q000737:chemistry; D011471:Prostatic Neoplasms / Q000235:genetics / Q000628:therapy; D034741:RNA, Small Interfering / Q000378:metabolism*; D015398:Signal Transduction; D017026:Swainsonine / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D011134:Polysaccharides; D034741:RNA, Small Interfering; C561128:MGAT1 protein, human; D017351:N-Acetylglucosaminyltransferases; D017026:Swainsonine