Role of alpha v beta 5 and alpha v beta 6 integrin glycosylation in the adhesion of a colonic adenocarcinoma cell line (HT29-D4).
We have previously characterized the expression of the alpha nu beta 5 and alpha nu beta 6 integrins as major receptors for the human colonic adenocarcinoma cell line (HT29-D4), on vitronectin and fibronectin, respectively [Lehmann et al. (1994): Cancer Res 54:2102-2107]. In the present work we investigated the glycosylation role of these integrins in their adhesive functions. To this end, we used glycohydrolases to show that cell surface integrins were N-glycosylated and sialylated, and that only the alpha v subunit carried some immature oligosaccharide side chains. To alter the glycosylation state of the cell surface alpha v beta 5 and alpha v beta 6 integrins, we used two oligosaccharide-processing inhibitors: 1-deoxymannojirimycin (dMNJ) and tunicamycin (TM). Following treatment of HT29-D4 cells with dMNJ, cell surface alpha v beta 5 and alpha v beta 6 carried only high-mannose-type sugar chains, while TM-treated cells expressed de-N-glycosylated integrins. Neither alpha/beta heterodimers assembly nor cell surface expression were impaired in the presence of the drugs. Finally, we established that adhesion of dMNJ- or TM-treated cells was altered on both vitronectin and fibronectin substrata, whereas the adhesion of these cells on laminin or collagen type I was virtually unchanged.
Lehmann
M
M
Universite d'Aix-Marseille I, France.
El Battari
A
A
Abadie
B
B
Martin
J M
JM
Marvaldi
J
J
D017485:1-Deoxynojirimycin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000951:Antigens, Neoplasm; D002448:Cell Adhesion / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005353:Fibronectins / Q000502:physiology; D006031:Glycosylation; D019073:HT29 Cells; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D008361:Mannosidases / Q000037:antagonists & inhibitors; D019030:Receptors, Vitronectin / Q000378:metabolism*; D014415:Tunicamycin / Q000494:pharmacology; D043323:alpha-Mannosidase
D000900:Anti-Bacterial Agents; D000951:Antigens, Neoplasm; D004791:Enzyme Inhibitors; D005353:Fibronectins; D016023:Integrins; D019030:Receptors, Vitronectin; C064660:integrin alphaVbeta5; C073878:integrin alphavbeta6; D014415:Tunicamycin; D017485:1-Deoxynojirimycin; D008361:Mannosidases; D043323:alpha-Mannosidase