ß-Galactoside α2,6-sialyltranferase 1 promotes transforming growth factor-ß-mediated epithelial-mesenchymal transition.
J Biol Chem
; 289(50): 34627-41, 2014 Dec 12.
Article
en En
| MEDLINE
| ID: mdl-25344606
ABSTRACT
ß-Galactoside α2,6-sialyltranferase 1 (ST6GAL1) catalyzes the addition of terminal α2,6-sialylation to N-glycans. Increased expression of ST6GAL1 has been reported in diverse carcinomas and highly correlates with tumor progression. Here, we report that St6gal1 transcription and α2,6-sialylated N-glycans are up-regulated during TGF-ß-induced epithelial-mesenchymal transition (EMT) in GE11 cells, requiring the Sp1 element within the St6gal1 promoter. Knockdown of St6gal1 strongly suppressed TGF-ß-induced EMT with a concomitant increase in E-cadherin expression, a major determinant of epithelial cell adherens junctions. Conversely, overexpression of ST6GAL1 increased the turnover of cell surface E-cadherin and promoted TGF-ß-induced EMT. Overexpressing ß-galactoside α2,3-sialyltranferase 4 had little influence on EMT, indicating specificity for α2,6-sialylation. The basal mesenchymal phenotype of MDA-MB-231 human breast cancer cells was partially reversed by ST6GAL1 silencing. Moreover, ST6GAL1 knockdown inhibited the phosphorylation of Akt, but not Smad2, suggesting that ST6GAL1 contributes to EMT through a non-Smad signaling pathway. Taken together, our data indicate that ST6GAL1 promotes TGF-ß-dependent EMT as well as maintenance of the mesenchymal state by growth signaling, providing a plausible mechanism whereby up-regulated ST6GAL1 may promote malignant progression.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Sialiltransferasas
/
Antígenos CD
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Factor de Crecimiento Transformador beta
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Transición Epitelial-Mesenquimal
Límite:
Humans
Idioma:
En
Revista:
J Biol Chem
Año:
2014
Tipo del documento:
Article