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Updated: Sep 12, 2026

Proliferation and Differentiation of Murine Myeloid Precursor 32D/G-CSF-R Cells
Published on: February 21, 2018
Induced cell surface expression of functional alpha 2 beta 1 integrin during megakaryocytic differentiation of K562
S R Burger1, M M Zutter, S Sturgill-Koszycki
1Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110.
Abstract:
The pluripotential hematopoietic cell line K562 was studied as a model of inducible integrin expression accompanying differentiation. Differentiation along the megakaryocytic pathway was induced with phorbol 12,13-dibutyrate and differentiation along the erythroid pathway with hemin. Induction of megakaryocytic differentiation was associated with changes in cell morphology and with increased cell-cell and cell-substrate adhesion and spreading. Erythroid differentiation was not associated with changes in morphology or adhesion. Cell surface expression of the IIb-IIIa and alpha 2 beta 1 integrins increased markedly with phorbol treatment but decreased with hemin treatment. Phorbol-treated K562 cells, but not control cells or hemin-treated cells, adhered to collagen substrates in a Mg(2+)-dependent manner which was specifically inhibited by a monoclonal antibody directed against the alpha 2 beta 1 integrin. Northern blot analysis revealed that megakaryocytic differentiation of K562 cells was accompanied by de novo expression of the alpha 2 integrin mRNA with no change in the level of mRNA for the beta 1 subunit. K562 cells provide a model of differentiation-dependent, regulated integrin expression in which expression is up- or down-regulated depending upon the differentiation pathway selected.
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