The biosynthesis of the selectin-ligand sialyl Lewis x in colorectal cancer tissues is regulated by fucosyltransferase VI and can be inhibited by an RNA interference-based approach.

Abstract

Sialyl Lewis x (sLex) is a selectin ligand whose overexpression in epithelial cancers mediates metastasis formation. The molecular basis of sLex biosynthesis in colon cancer tissues is still unclear. The prerequisite for therapeutic approaches aimed at sLex down-regulation in cancer, is the identification of rate-limiting steps in its biosynthesis. We have studied the role of α1,3-fucosyltransferases (Fuc-Ts) potentially involved in sLex biosynthesis in specimens of normal and cancer colon as well as in experimental systems. We found that: (i) in colon cancer, but not in normal mucosa where the antigen was poorly expressed, sLex correlated with a Fuc-T which, like Fuc-TVI, was active on 3'sialyllactosamine at a low concentration (Fuc-T(SLN)); (ii) competitive RT-PCR analysis revealed that the level of Fuc-T mRNA expression in both normal and cancer colon was Fuc-TVI>Fuc-TIII>Fuc-TIV; Fuc-TV and Fuc-TVII expression was negligible; (iii) sLex was expressed only by the gastrointestinal cell lines displaying both Fuc-TVI mRNA and Fuc-T(SLN) activity, but not by those expressing only Fuc-TIII mRNA; (iv) transfection with Fuc-TVI cDNA, but not with Fuc-TIII cDNA, induced sLex expression in gastrointestinal cell lines; (v) Fuc-TVI knock-down with specific siRNA induced down-regulation of Fuc-TVI mRNA and Fuc-T(SLN) activity and a dramatic inhibition of sLex expression. These data indicate that in colon cancer tissues Fuc-TVI is a key regulator of sLex biosynthesis which can be the target of RNA-interference-based gene knock-down approaches.

• Authors: Marco Trinchera, Nadia Malagolini, Mariella Chiricolo, Donatella Santini, Francesco Minni, Anna Caretti, Fabio Dall'olio
• Journal: The international journal of biochemistry & cell biology (Int J Biochem Cell Biol) Vol. 43 Issue 1 Pg. 130-9 (Jan 2011) ISSN: 1878-5875 [Electronic] Netherlands
• PMID: 20965272 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2010 Elsevier Ltd. All rights reserved.

Chemical References

• DNA, Complementary
• Oligosaccharides
• Selectins
• Sialyl Lewis X Antigen
• Fucosyltransferases

Topics

• Base Sequence
• Colorectal Neoplasms (genetics, metabolism, secondary)
• DNA, Complementary (biosynthesis, genetics)
• Fucosyltransferases (genetics, metabolism)
• Gene Expression Regulation, Neoplastic
• Gene Knockdown Techniques
• Glycosylation
• Humans
• Molecular Sequence Data
• Neoplasm Metastasis
• Oligosaccharides (biosynthesis, genetics)
• RNA Interference
• Selectins (metabolism)
• Sialyl Lewis X Antigen
• Transfection
• Tumor Cells, Cultured