Previous studies have shown that certain low molecular weight polar solvents downregulate c-myc gene expression and induce terminal differentiation of human HL-60 myeloid leukemia cells. We have examined the effects of ethanol on gene expression in this cell line. The results show that while ethanol induces a more differentiated phenotype, this agent has little effect on the self-renewal capacity of HL-60 cells. Ethanol treatment was also associated with a concentration-dependent and transient downregulation of c-myc transcripts. Similar effects were observed for c-myb mRNA levels. The results further show that ethanol exposure is associated with induction of tumor necrosis factor gene expression. These findings indicate that ethanol induces changes in specific gene expression during non-terminal differentiation of HL-60 cells. The clinical effects of this agent could thus be related to altered patterns of gene expression in hematopoietic or other cells.