IL-8 MESSENGER-RNA EXPRESSION AND IL-8 PRODUCTION BY ACUTE MYELOID-LEUKEMIA CELLS

Purified leukemic cells from 30 acute myeloid leukemia (AML) cases at diagnosis were investigated for the presence of interleukin 8 (IL-8) m RNA by Northern blot analysis. IL-8 specific transcripts were detected in uncultured blasts in 14/30 cases, 10/14 from patients with M4-M5 a nd 4/14 from cases with MO-M3 morphology. The transcript expression wa s associated with the detection of IL-8 molecule in blast cells by imm unostaining performed on cytospin preparations. After 24-hour culture, a strong up-regulation or the appearance in cases negative before cul ture of IL-8 mRNA was observed in all cases tested, and culture supern atants contained high amounts of IL-8. Our data demonstrate that leuke mic cells in AML are equipped with the functional apparatus for IL-8 p roduction. Since IL-8 displays a wide range of biological activities, including the regulation of some membrane molecules relevant to adhesi on and migration processes. its production by AML blasts might be of r elevance for the pattern of leukemic growth.