[Experimental systems in CML biology]

It has been established that the BCR-ABL oncogene produced on the Philadelphia chromosome in human chronic myeloid leukemia(CML) directly causes leukemic transformation of multipotential progenitor cells. In order to study the molecular basis of this process, many convenient and useful biological assays have been found, including transformation of mouse bone marrow cells in primary culture and of Rat1 fibroblasts, cytokine-independent growth of dependent cell lines, retrovirus-mediated murine CML model, and transgenic mice model. New biological activities such as anti-apoptosis, anti-DNA repair, differentiation of ES cells may further give supportive explanations for clinical manifestation of CML. NOD/SCID transplantation model and conditional transgenic model may be the current best animal system by which to investigate cell dynamics in the most strict and natural circumstances.