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) mRNA by Northern blot analysis. IL-8 specific transcripts were detected in uncultured blasts in 14/30 cases, 10/14 from patients with M4-M5 and 4/14 from cases with MO-M3 morphology. The transcript expression was associated with the detection of IL-8 molecule in blast cells by immunostaining performed on cytospin preparations. After 24-hour culture, a strong up-regulation or the appearance in cases negative before culture of IL-8 mRNA was observed in all cases tested, and culture supernatants contained high amounts of IL-8. Our data demonstrate that leukemic cells in AML are equipped with the functional apparatus for IL-8 production. Since IL-8 displays a wide range of biological activities, including the regulation of some membrane molecules relevant to adhesion and migration processes. its production by AML blasts might be of relevance for the pattern of leukemic growth.