Transformation but not ras-transfection increases the expression of galectin-3 in human HOS cells.

In ras-transfected NIH3T3 cells, the transcription of the Mr 34,000 beta-galactoside specific lectin galectin-3 depends on transformation phenotypes. This observation suggests that this lectin is associated with the transformation process and/or that the ras oncogene may modulate its expression; nevertheless the involvement of ras-gene product in galectin-3 gene expression still remains unclear. In the present study, we investigated the galectin-3 expression in human HOS cells transiently or stably transfected with a ras-containing vector. We observed an increase in galectin-3 mRNA and protein content in stably ras-transfected cells which had lost their anchorage dependence for growth but no increase in cells which needed anchorage for growth or in transiently ras-transfected cells. These results suggest that the galectin-3 up-regulation in ras-transfected HOS cells is the consequence of the cell transformation rather than a direct effect of the ras gene product on galectin-3 gene expression.