S-phase inhibitors induce vimentin expression in human promonocytic U-937 cells

Abstract

The administration of hydroxyurea (3 × 10 −4M) and cytosine arabinoside (10 −7 M) greatly induces the expression of the vimentin gene in human promonocytic leukemia U-937 cells. The induction takes place at both the mRNA and protein levels, as demonstrated by Northern blot, immunoblot and immunofluorescence assays. On the contrary, the drugs inhibit the expression of c- myc and omithine decarboxylase, and do not modify significantly the expression of β-actin. Since hydroxyurea and cytosine arabinoside trigger the phenotypic differentiation of U-937 cells, as demonstrated by the induction of the differentiation-specific CDllb and CDllc antigens, it is concluded that vimentin expression might be implicated in the maturation of these cells.