Human stem cell model to study signal transduction and molecular regulation mechanisms in CML

Objective To develop a primary human hematopoietic stem/progenitor cell mod el for chronic myeloid leukemia (CIVIL) and study signal transduction and m olecular regulation mechanisms in CIVIL. Methods We developed a human model of p210(BCR/ABL) positive CIVIL by trans ducing normal human umbilical cord blood CD34(+) cells with a retroviral ve ctor containing the b3a2 bcr/abl cDNA. We also examined whether this model recreated the cellular phenotype of CIVIL by assessing cell adhesion, cell migration, cell proliferation and cell survival. Results We found that significantly more myeloid colony forming units grew from p210(BCR/ABL) expressing cells, adhesion of p210(BCR/ABL) expressing C D34(+) cells to fibronectin was decreased but migration over fibronectin wa s enhanced compared with mock transduced CD34+ cells. In this model, we sho wed that the presence of p210(BCR/ABL) leads to elevated levels of p27(kip) in p210(BCR/ABL) expressing CD34+ cells. We also showed that multidrug res istance-1 (MDR-1) Pgp was upregulated in the p210(BCR/ABL) expressing cells which correlates with the expression of p210(BCP/ABL). Conclusion This primary human CIVIL model recreates most of the features of CIVIL and provides a useful tool to study signal transduction and downstre am molecular regulation drived by the p210(BCR/ABL) oncogene in normal CD34 (+) cells.