OBJECTIVETo investigate the biological behavior of stromal cell-derived factor-1 (SDF-1) on multiple myeloma (MM) cell migration and adhesion and it related signaling pathways.

METHODSExpression of adhesion molecules on MM cells of RPMI8226, XG-1 and XG-7 cells was analysed by flow cytometry, the influence of SDF-1 on CD29 and CD49e distribution by immunofluorescence, the effect of SDF-1 on chemotaxis of MM cells by transwell assay. Activation of phosphoinositide-3 kinase (PI3K) in MM cells treated with SDF-1 and by immunoblotting.

RESULTS3 strains of MM cell line expressed many adhesion molecule. RPMI8226, XG-7 cells were all high level of expression of CD29 (> 70%). XG-1, XG-7 cells were all high level of expression of CD44 (> 80%), and XG-7 cells was of CD49d (> 90%). In all of 3 strains, the levels of expression of CD49e were low (< 30%). SDF-1 could not upregulate their expression, but could trigger the establishment of polarized morphology of MM cells and the redistribution of CD29 and CD49e. SDF-1 promoted MM cells adhesion to endothelial cells, stimulated phosphorylation of P85 subunit of PI3K in MM cells and induced MM cells migration, which were inhibited by G protein inhibitor PTX and PI3K inhibitor wortmannin.

CONCLUSIONSDF-1 can promote MM cell adhesion to endothelial cells, trigger establishment of a polarized morphology of MM cells and redistribution of adhesion molecules and induce MM cells migration via PI3K signaling pathway.