Syndecan-1-dependent homotypic cell adhesion in HT58 lymphoma cells.
OBJECTIVE
Many cellular functions are controlled by cell-cell and cell-matrix interactions. It has recently been found that syndecans, transmembrane heparan sulphate (HS) proteoglycans, can act as receptors or co-receptors and modulate cell adhesion. Our aim was to study the role of syndecan-1 in the aggregation of human lymphoma cells, and to investigate its effect on cell survival.


METHODS
Immunocytochemistry, confocal laser scanning microscopy, flow cytometry and aggregation/reaggregation bio-assays were used on HT58, BL41/95 and Raji lymphoma cell lines.


RESULTS
Bio-assays showed that the aggregation of HT58 cells was inhibited by heparin, HS, removal of the HS chain and binding of the anti-syndecan-1 monoclonal antibody. In the search for a counter-receptor of syndecan-1, several adhesion molecules were tested, but none of them proved to be the adhesion partner. In the case of heparitinase/trypsin digestion with long-term inhibition of HS synthesis (sodium chlorate treatment), the inhibited aggregation was accompanied by cell cycle arrest and the induction of apoptosis.


CONCLUSIONS
The results obtained showed that surface syndecan-1 expression contributes to homotypic adhesion. In addition, HS chains, including those on syndecan-1, take part in the regulation of cell proliferation and active cell death in HT58 lymphoma cells.
Sebestyén
A
A
First Institute of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary.
Tótth
A
A
Mihalik
R
R
Szakács
O
O
Paku
S
S
Kopper
L
L
D017209:Apoptosis / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D002449:Cell Aggregation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D016222:Fibroblast Growth Factor 2 / Q000502:physiology; D005434:Flow Cytometry; D018922:HL-60 Cells; D019812:Heparan Sulfate Proteoglycans / Q000502:physiology; D006801:Humans; D016393:Lymphoma, B-Cell / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000502:physiology*; D011509:Proteoglycans / Q000502:physiology*; D017468:Receptors, Fibroblast Growth Factor / Q000502:physiology; D053668:Syndecan-1; D053667:Syndecans; D014407:Tumor Cells, Cultured
D019812:Heparan Sulfate Proteoglycans; D008562:Membrane Glycoproteins; D011509:Proteoglycans; D017468:Receptors, Fibroblast Growth Factor; C508241:SDC1 protein, human; D053668:Syndecan-1; D053667:Syndecans; D016222:Fibroblast Growth Factor 2