Expression and release of adhesion molecules by human acute myelogenous leukemia blasts

The expression and release of adhesion molecules by acute myelogenous leuke mia (AML) blasts was investigated in vitro. For most patients AML blasts ex pressed relatively low levels of membrane-bound L-selectin and Intercellula r adhesion molecule 1 (ICAM-1), but their soluble forms were detected in th e supernatants for the majority of patients when AML blasts were cultured i n vitro. These in vitro levels of sL-selectin and sICAM-1 were considerably lower than the normal serum levels. Divergent and relatively small alterat ions in sL-selectin and sICAM-1 levels were usually observed when exogenous growth factors were present during AML blast culture, whereas increased sL -selectin levels were observed after coculture of AML blasts and normal leu cocytes. E- and P-selectin were neither expressed nor released by AML blast s. We conclude that AML blasts are a source of soluble adhesion molecules. (C) 1999 Elsevier Science Ltd. All rights reserved.