scholarly journals Glycosylation Provides Both Stimulatory and Inhibitory Effects on Cell Surface and Soluble CD44 Binding to Hyaluronan

1998 ◽  
Vol 140 (2) ◽  
pp. 431-446 ◽  
Author(s):  
Timothy P. Skelton ◽  
Chunxun Zeng ◽  
Aaron Nocks ◽  
Ivan Stamenkovic
Keyword(s):  
Cell Surface ◽  
Cell Line ◽  
Glycosidase Inhibitors ◽  
Inhibitory Effects ◽  
Relative Contribution ◽  
Soluble Cd44 ◽  
Glycosylation Change ◽  
D Cells ◽  
Novel Strategy ◽  
Oligosaccharide Structures

Glycosylation has been implicated in the regulation of CD44-mediated cell binding of hyaluronan (HA). However, neither the relative contribution of N- and O-linked glycans nor the oligosaccharide structures that alter CD44 affinity for HA have been elucidated. To determine the effect of selective alteration of CD44 oligosaccharide composition on the affinity of CD44 for HA, we developed a novel strategy based on the use of affinity capillary electrophoresis (ACE). Soluble recombinant CD44–immunoglobulin fusion proteins were overproduced in the mutant CHO cell line ldl-D, which has reversible defects in both N- and O-linked oligosaccharide synthesis. Using this cell line, a panel of recombinant glycosidases, and metabolic glycosidase inhibitors, CD44 glycoforms with defined oligosaccharide structures were generated and tested for HA affinity by ACE. Because ldl-D cells express endogenous cell surface CD44, the effect of any given glycosylation change on the ability of cell surface and soluble CD44 to bind HA could be compared. Four distinct oligosaccharide structures were found to effect CD44-mediated HA binding: (a) the terminal α2,3-linked sialic acid on N-linked oligosaccharides inhibited binding; (b) the first N-linked N-acetylglucosamine residue enhanced binding; (c) O-linked glycans on N-deglycosylated CD44 enhanced binding; and (d) N-acetylgalactosamine incorporation into non–N-linked glycans augmented HA binding by cell surface CD44. The first three structures induced up to a 30-fold alteration in the intrinsic CD44 affinity for HA (Kd = 5 to >150 μM). The fourth augmented CD44-mediated cellular HA avidity without changing the intrinsic HA affinity of soluble CD44.

scholarly journals Cell surface oligosaccharides on Dictyostelium during development

1991 ◽  
Vol 99 (3) ◽  
pp. 485-495
Author(s):  
SUPAVADEE AMATAYAKUL-CHANTLER ◽  
MICHAEL A. J. FERGUSON ◽  
RAYMOND A. DWEK ◽  
THOMAS W. RADEMACHER ◽  
RAJ B. PAREKH ◽  
...  
Keyword(s):  
Cell Surface ◽  
Time Frame ◽  
Protein Glycosylation ◽  
Developmental Studies ◽  
Plant Glycoproteins ◽  
Chemical Technique ◽  
Cell Surface Glycoproteins ◽  
Oligosaccharide Structures ◽  
Surface Glycoproteins

Developmental studies of the changes in protein glycosylation are useful in elucidating the role of oligosaccharides in biological events. We have used the chemical technique, hydrazinolysis, to release oligosaccharides from cell surface glycoproteins of Dictyostelium discoideum. Oligomannose type, xylose- and fucose-containing oligosaccharides were found to be present. The charged oligosaccharides contained sulphate and mannose 6-phosphate residues; no sialic acid was detected. The charged oligosaccharides also contained significant amounts of xylose, arabinose, fucose and galactose, as well as mannose and N-acetylglucosamine, which were the main constituents of the neutral glycans. By monitoring the chemical characteristics of the liberated oligosaccharides, dramatic changes in both the charge and size distribution of cell surface oligosaccharides were observed throughout the 24 h period of cell development. A comparison, however, between the neutral glycan structures of prestalk and prespore cells, over the same time frame showed no dramatic differences Discoidin, a lectin present on the cell surface of 8 h cells, was found not to be glycosylated. Affinity chromatography using immobilised discoidin was used to probe a sugar library made from the cell surface glycoproteins of 8h cells. Discoidin was found to bind selectively an oligosaccharide with the structure Manα3(Manα6)(Xylβ2)Manβ4GlcNAc. This oligosaccharide lacks a conventional N,N'-diacetylchitobiose core and has only been previously observed in plant glycoproteins. Peptide-N-glycosidase F treatment of horseradish peroxidase released an identical structure, confirming that the oligosaccharide was not a degradation fragment of the hydrazine. The oligosaccharide was found to inhibit discoidinmediated haemagglutination with a Kt of 0.75 mM, a concentration approximately 100 times lower than that for galactose The correlation between changes in the amoebal plasma membrane oligosaccharide structures and the biological events occurring at different stages of development such as cell-cell adhesion and cellsubstratum attachment suggest an important role for sugars in these processes

scholarly journals Induction of Apoptosis of Metastatic Mammary Carcinoma Cells In Vivo by Disruption of Tumor Cell Surface CD44 Function

1997 ◽  
Vol 186 (12) ◽  
pp. 1985-1996 ◽  
Author(s):  
Qin Yu ◽  
Bryan P. Toole ◽  
Ivan Stamenkovic
Keyword(s):  
Cell Surface ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Lung Tissue ◽  
Mammary Carcinoma ◽  
Cell Types ◽  
Pulmonary Endothelium ◽  
Soluble Cd44

To understand how the hyaluronan receptor CD44 regulates tumor metastasis, the murine mammary carcinoma TA3/St, which constitutively expresses cell surface CD44, was transfected with cDNAs encoding soluble isoforms of CD44 and the transfectants (TA3sCD44) were compared with parental cells (transfected with expression vector only) for growth in vivo and in vitro. Local release of soluble CD44 by the transfectants inhibited the ability of endogenous cell surface CD44 to bind and internalize hyaluronan and to mediate TA3 cell invasion of hyaluronan-producing cell monolayers. Mice intravenously injected with parental TA3/St cells developed massive pulmonary metastases within 21–28 d, whereas animals injected with TA3sCD44 cells developed few or no tumors. Tracing of labeled parental and transfectant tumor cells revealed that both cell types initially adhered to pulmonary endothelium and penetrated the interstitial stroma. However, although parental cells were dividing and forming clusters within lung tissue 48 h following injection, >80% of TA3sCD44 cells underwent apoptosis. Although sCD44 transfectants displayed a marked reduction in their ability to internalize and degrade hyaluronan, they elicited abundant local hyaluronan production within invaded lung tissue, comparable to that induced by parental cells. These observations provide direct evidence that cell surface CD44 function promotes tumor cell survival in invaded tissue and that its suppression can induce apoptosis of the invading tumor cells, possibly as a result of impairing their ability to penetrate the host tissue hyaluronan barrier.

scholarly journals Insulin stimulates production of glyco-conjugate layers on the cell surface of gastric surface mucous cell line GSM06.

1996 ◽  
Vol 71 ◽  
pp. 108
Author(s):  
Yoshiaki Tabuchi ◽  
Norifumi Sugiyama ◽  
Tadashi Horiuchi ◽  
Kazuhisa Furuhama
Keyword(s):  
Cell Surface ◽  
Cell Line ◽  
Mucous Cell ◽  
Surface Mucous Cell

Inhibitory Effects of Indomethacin in Human MNNG/HOS Osteosarcoma Cell Line In Vitro

2019 ◽  
Vol 38 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Saied Mirshahidi ◽  
Rosalia de Necochea-Campion ◽  
Annie Moretta ◽  
Nadine L. Williams ◽  
Mark E. Reeves ◽  
...  
Keyword(s):  
Cell Line ◽  
Osteosarcoma Cell Line ◽  
Osteosarcoma Cell ◽  
Inhibitory Effects
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