Differential expression of alpha-2,3-sialyltransferases and alpha-1,3/4-fucosyltransferases regulates the levels of sialyl Lewis a and sialyl Lewis x in gastrointestinal carcinoma cells

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Carvalho AS (Author) FMUP; Harduin-Lepers A (Author) Other; Magalhães AM (Author) Other; Machado E (Author) Other; Mendes N (Author) FMUP; Costa LT (Author) Other; Matthiesen R (Author) Other; Almeida R (Author) FMUP; Costa J (Author) Other; Celso Reis (Author) FMUP

Journal

Title: International Journal of Biochemistry and Cell Biology

Vol. 42 No. 11

Pages: 80-89

ISSN: 1357-2725

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 93 Citations

Scopus - 100 Citations

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-003-BBE

DOI: 10.1016/j.biocel.2009.09.010

Abstract (EN): Sialyl Lewis x and sialyl Lewis a expression depends on sialyltransferases and fucosyltransferases. In this study, we screened for major variations of sialyltransferases and fucosyltransferases involved in the synthesis and regulation of sialyl Lewis x and sialyl Lewis a epitopes in gastrointestinal carcinoma cells. Our results show that expression of ST3Gal IV in several gastrointestinal cell lines is correlated with the expression of sialyl Lewis x at the cell surface. ST3Gal IV overexpressed in the gastric MKN45 cell line, showed exclusive enzymatic activity towards glycoproteins containing terminal Gal beta 1-4GlcNAc structure. On the other hand, when ST3Gal III was overexpressed in MKN45, an increase in the expression levels of both sialyl Lewis epitopes was observed. ST3Gal III and ST3Gal IV lead to de novo synthesis of sialyl Lewis x determinant on different molecular weight glycoproteins of MKN45 cells suggesting that each enzyme used different substrates within the available glycoproteome. The final glycosylation step in sialyl Lewis x and sialyl Lewis a biosynthesis in MKN45 cell line was shown to be associated to FUT5, which efficiently fucosylated sialyl Lewis precursors on glycoproteins. Moreover we demonstrate that the expression of sialyl Lewis epitopes in the MKN45 was induced by cell confluence, which can be regarded as a model to study altered glycosylation during turnout progression. This increase was observed together with an increase in mRNA levels of ST-3GAL3, FUT5 and FUT6, and a decrease in FUT transcript levels in MKN45 confluent cells, suggesting a possible control at the transcriptional level.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10