Gene Expression of the Hematopoietic Cell Phosphatase in Juvenile Myelomonocytic Leukemia

Abstract

We analyzed the relative expression of Hematopoietic cell phosphatase (HCP) in mononuclear cells (MNC) of peripheral blood (PB), bone marrow (BM) and spleen of patients with juvenile myelomonocytic leukemia (JMML) and normal donors. Two regions of HCP with alternative exon skipping of exon 6 or exon 12 are described. There was no difference in the expression of the amplified HCP cDNA regions in MNC of JMML patients compared to normal donors. The two forms of exon skipping were present in unstimulated MNC of JMML patients or normal donors. In contrast, phytohemagglutinin (PHA) stimulated MNC of normal donors, Epstein-Barr Virus (EBV) transformed B-cells of JMML patients, BFU-E and CFU-GM derived colonies of JMML patients, and the cell lines K562 and HEL did not or only barely express these two forms of exon skipping. These results may indicate that alternative HCP exon skipping may be associated with the proliferative state of the cell.