Expression of the granulocyte/macrophage colony-stimulating factor gene in leukemic blast cells from patients with acute non-lymphocytic leukemia.

Since granulocyte/macrophage colony-stimulating factor (GM-CSF) has been reported to stimulate the proliferation of clonogenic leukemia cells from patients with acute non-lymphocytic leukemia in vitro, the expression of the GM-CSF gene in primary human leukemic blast cells was studied. T-cell-depleted mononuclear cells in freshly drawn peripheral blood from patients with acute non-lymphocytic leukemia (ANLL) were subjected to the study. The expression of the GM-CSF gene was detected by Northern blotting analysis using [32P]GM-CSF as a probe. The GM-CSF gene was expressed in two out of five cases examined. In both of the patients who showed GM-CSF expression, remission could not be achieved.