Inhibition of human HT-29 colon carcinoma cell adhesion by a 4-fluoro-glucosamine analogue
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B Woynarowska1, C J Dimitroff, M Sharma
1Department of Experimental Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
Abstract:
Cell surface glycoconjugates play an important role in cellular recognition and adhesion. Modification of these structures in tumour cells could affect tumour cell growth and behaviour, including metastasis. 2-Acetamido-1,3,6-tri-O-acetyl-4-deoxy-4-fluoro-alpha-D-glycopyranose (4-F-GlcNAc) was synthesized as a potential inhibitor and/or modifier of tumour cell glycoconjugates. The effect of this sugar analogue on the adhesive properties of human colon carcinoma HT-29 cells was evaluated. Treatment of HT-29 cells with 4-F-GlcNAc led to reduced cell surface expression of terminal lactosamine, sialy-Le(x) and sialyl-Le(a), as determined by Western blotting and flow cytometry. The aberrant expression of these oligosaccharide structures on the HT-29 cell surface resulted in: (1) decreased E-selectin mediated adhesion of human colon cells to human umbilical cord endothelial cells (HUVEC); (2) impaired adhesion of HT-29 cells to beta-galactoside binding lectin, galectin-1; and (3) reduced ability to form homotypic aggregates. After exposure to 4-F-GlcNAc, lysosomal associated membrane proteins (lamp) 1 and 2, and carcinoembryonic antigen (CEA) detected in HT-29 cells were of lower molecular weight, probably due to impaired glycosylation. These results strongly suggest that modification of tumour cell surface molecules can alter tumour cell adhesion and that tumour cell surface oligosaccharides may be suitable targets for therapeutic exploitation.
Insights
The sugar analogue 4-F-GlcNAc modifies tumor cell surface glycoconjugates, reducing cancer cell adhesion and metastasis. This suggests targeting tumor cell surface oligosaccharides could be a therapeutic strategy.
Area of Science:
- Biochemistry
- Cell Biology
- Glycobiology
Background:
- Cell surface glycoconjugates are crucial for cell recognition and adhesion.
- Altering these structures on tumor cells can impact growth, behavior, and metastasis.
Purpose of the Study:
- To synthesize and evaluate 2-Acetamido-1,3,6-tri-O-acetyl-4-deoxy-4-fluoro-alpha-D-glycopyranose (4-F-GlcNAc) as a potential inhibitor/modifier of tumor cell glycoconjugates.
- To assess the effect of 4-F-GlcNAc on the adhesive properties of human colon carcinoma HT-29 cells.
Main Methods:
- Synthesis of 4-F-GlcNAc.
- Treatment of HT-29 cells with 4-F-GlcNAc.
- Western blotting and flow cytometry to analyze cell surface expression of lactosamine, sialyl-Le(x), and sialyl-Le(a).
- Assays to evaluate E-selectin mediated adhesion to HUVECs, galectin-1 binding, and homotypic aggregation.
- Analysis of molecular weight of lysosomal associated membrane proteins (LAMP) 1 and 2, and carcinoembryonic antigen (CEA) via Western blotting.
Main Results:
- 4-F-GlcNAc treatment reduced cell surface expression of terminal lactosamine, sialyl-Le(x), and sialyl-Le(a) on HT-29 cells.
- Reduced expression of these oligosaccharides led to decreased E-selectin mediated adhesion to HUVECs, impaired galectin-1 binding, and reduced homotypic aggregation.
- 4-F-GlcNAc exposure resulted in lower molecular weight LAMP 1, 2, and CEA, indicating impaired glycosylation.
Conclusions:
- Modification of tumor cell surface molecules can significantly alter tumor cell adhesion.
- Tumor cell surface oligosaccharides represent promising targets for therapeutic intervention in cancer treatment.