We analyzed the relative expression of Hematopoietic cell phosphatase (HCP)
in mononuclear cells (MNC) of peripheral blood (PB), bone marrow (BIM) and
spleen of patients with juvenile myelomonocytic leukemia (JMML) and normal
donors. Two regions of HCP with alternative exon skipping of exon 6 or exo
n 12 are described. There was no difference in the expression of the amplif
ied 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 patien
ts or normal donors. In contrast, phytohemagglutinin (PHA) stimulated MNC o
f normal donors, Epstein-Barr Virus (EBV) transformed B-cells of JMML patie
nts, 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 skippi
ng. These results may indicate that alternative HCP exon skipping may be as
sociated with the proliferative state of the cell.