The effect of differentiation inducers on the integrin expression of K562 erythroleukemia cells.

✍ Scribed by Maarit Järvinen; Jari Ylänne; Ismo Virtanen

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 465 KB
• Volume: 17
• Category: Article
• ISSN: 1065-6995
• DOI: 10.1006/cbir.1993.1078

✦ Synopsis

Abstract

We studied the effects of differentiation‐inducers on the integrin profile and adhesive properties of K562 leukemia cells. The fibronectin (Fn) receptor integrin, α~5~β~1~, was the only integrin expressed in suspension cultured K562 cells. When the cells were exposed to 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) immunoreactivity for the β~1~ integrin subunit was slightly enhanced. TPA exposure also induced the appearance of the α~2~, α~3~, α~v~ and β~3~ integrin subunits, but the platelet integrin subunit α~IIb~ was not detected. On the other hand, hemin chloride‐induced erythroid differentiation of K562 cells diminished the expression of the α~5~β~1~ integrin on the surface of the cells. Adhesion experiments with TPA‐exposed K562 cells indicated that although the adherence to the extracellular matrix (ECM) proteins as a rule was low a few cells spread on these proteins. The present results specify the effects of differentiation inducers on the integrin profile of K562 cells and excludes the comprehension that TPA would induce expression of the platelet integrin α~IIb~ on their surface. Our results also show, that an increased expression of a certain integrin does not necessarily lead to a comparable adhesion ability on its ligand in vitro.