Figure 6.

Extracellular function of NM23‐H1 protein derived from tumor cells on primary cultured acute myelogenous leukemia (AML) cells. Overexpression of the NM23 gene found in many hematological malignancies predicts a poor treatment outcome, and the elevated serum level of NM23‐H1 protein is also a poor prognostic factor in patients with these diseases. Extracellular NM23‐H1 protein promotes the growth and survival of primary AML cells mediated by MAPK activation, signal transducers and activators of transcription (STAT) activation and cytokine release. Taken together, these observations suggest that extracellular NM23‐H1 may play an important role in the malignant progression of leukemia, and that inhibitors of these protein or inhibitors of the extracellular functions of these proteins should be evaluated for their treatment potential.