Expression of the monocyte-specific esterase gene in leukemia-lymphoma cell lines

The expression of the monocyte esterase was examined in a panel of 77 continuous human leukemia-lymphoma cell lines representing all hematopoietic cell lineages and in 16 other cell lines. Accumulation of mRNA, determined by Northern blotting with the cDNA probe HMSE-1, and production of the protein, shown by isoelectric focusing on polyacrylamide gels, correlated with differentiation of the cells along the monocytic lineage. None of the lymphoid, erythroid, megakaryoblastic or Hodgkin's disease derived cell lines or the non-hematopoietic human tumor cell lines expressed the full-length mRNA of 2.0 kb. These results support the notion that this enzyme, a serine hydrolase with still unknown physiological functions, is specifically expressed in cells committed to the monocyte/macrophage cell lineage.