In vitro crosstalk between fibroblasts and native human acute myelogenous leukemia (AML) blasts via local cytokine networks results in increased proliferation and decreased apoptosis of AML cells as well as increased levels of proangiogenic Interleukin 8.

Interactions between native human acute myelogenous leukemia (AML) blasts and nonleukemic cells in the bone marrow microenvironment seem important both for disease development chemosensitivity. Native human AML blasts from consecutive patients were cultured with normal human bone marrow stromal cells and two fibroblast lines (HFL1 and Hs27) separated by a semipermeable membrane. This bidirectional crosstalk via the cytokine network between AML blasts and fibroblasts caused (i) increased proliferation, (ii) mediated antiapoptotic signalling and (iii) increased local levels of proangiogenic IL8.