Lyn, a src-like tyrosine-specific protein kinase, is expressed in HL60 cells induced to monocyte-like or...

During the in vitro differentiation of HL60 cells tyrosine-specific kinases are activated. The expression of lyn, a src-related tyrosine kinase, was studied by analysis of the steady-state levels of its transcript during the cell differentiation process induced by retinoic acid, phorbol 12-myristate 13-acetate and 1,25-dihydroxyvitamin D3. In contrast to an earlier report we observe only a small induction of the lyn-RNA levels compared to uninduced control cells. In unstimulated HL60 cells, the level for the lyn-transcript was comparatively high. A second, minor human lyn-transcript with an estimated size of 3.7 kb which has not been previously described, was identified.