Dominant contribution of malignant endothelial cells to endotheliopoiesis in chronic myeloid leukemia.

OBJECTIVE: Although it has been well-established that hemangioblasts are present in chronic myeloid leukemia (CML) and contribute to both malignant hematopoiesis and endotheliopoiesis, the real contribution of CML-derived endothelial cells to endotheliopoiesis in CML patients has never been evaluated. The current study sought to determine CML-derived endotheliopoiesis in patients with CML.
MATERIALS AND METHODS: Endothelial cells were isolated from the bone marrow or peripheral blood of six newly diagnosed CML patients using an immunomagnetic approach. The resulting endothelial cells were immediately subjected to fluorescence in situ hybridization analysis to determine BCR-ABL-positive endothelial cells.
RESULTS: The purity of isolated endothelial cells was 94.47% +/- 2.37%. In bone marrow, the BCR-ABL-positive endothelial cells accounted for 70.8% +/- 10.7% of total freshly isolated endothelial cells. In peripheral blood, however, the BCR-ABL-positive endothelial cells accounted for only 20.8% +/- 9.8% of isolated endothelial cells.
CONCLUSION: The present data demonstrate a dominant contribution of CML-derived endothelial cells to endotheliopoiesis in newly diagnosed CML, and provide the rationale for targeting hemangioblasts and angiogenesis in management of CML.