Endogenous stromal cell-derived factor-1 (CXCL12) supports autonomous growth of acute myeloid leukemia cells.

We investigated the role of endogenous stromal cell-derived factor-1 (SDF-1; CXCL12) in the survival and proliferation of acute myeloid leukemia (AML) cells in vitro. CD34(+) cells from the peripheral blood of five patients with AML, as well as five AML cell lines, produced and secreted SDF-1. Knock-down of endogenous SDF-1 expression using siRNA technology downregulated the constitutive phosphorylation of SDF-1-related signaling molecules and significantly inhibited spontaneous proliferation of the AML cell lines during a 3-day incubation in serum-free conditions. These results indicate that endogenous SDF-1 expression by AML cells plays a role in the autonomous growth of the cells.