Modulation of the expression of the rabbit galectin-3 gene by p53 and c-Ha-ras proteins and PMA

Galectin-3 is a galactose-binding lectin that has been foundin several mammalian tissues. Galectin-3 gene is expressed ina wide range of normal and tumoral cells. In the case of myeloidcells, its expression correlates with the differentiation ofmonocytes to macrophages. In the case of cancer cell lines,its expression correlates with tumorigenicity and metastaticpotential. The regulation of the expression of this gene isstill largely unknown. The rabbit galectin-3 gene has been isolatedand characterized. Its structure revealed an organization similarto that of the murine galectin-3 gene. The genomic sequenceslocated upstream from its 5' end, upon insertion upstream froma promoter-free reporter gene, exhibited a strong promoter activity.This activity was upregulated upon treatment of transfectedsmooth muscle cells with phorbol 12-myristate 13-acetate (PMA)as well as upon transfection with a EJ/ras encoding plasmid.Conversely, it was downmodulated upon transfection with wild-typep53 but not with mutated p53. The regulatory sequences involvedin the positive regulation of the gene were located upon serialdeletion experiments. gene cloning lectin promoter vascular smooth muscle cells