Growth factor mRNA expression in AML blasts and normal bone marrow cells.

RT-PCR was performed with total cDNA synthesized from 10 000 AML blasts or NBM cells using a specific primer set for each growth factor as described in “Patients, materials, and methods.” Southern blots of PCR products were hybridized with the corresponding cytokine-specific probes. For each cytokine, the positive control was a cDNA from a murine cell line transfected with the corresponding human cytokine cDNA.