[Role of AML1a in abnormal proliferation and differentiation of murine hematopoietic cells].

This study was aimed to explore the role and mechanism of AML1a in abnormal hematopoiesis in mice. Plasmids pMSCV-FLAG-AML1a-IRES-YFP and pMSCV-IRES-YFP together with envelope-encoding plasmid pECO and packaging plasmid pGP were respectively transfected into 293T cells by using a method of calcium phosphate precipitation to produce retrovirus. Bone marrow mononuclear cells (BMMNC) from male C57BL/6J mice were transfected with the retroviral vector MSCV expressing FLAG-AML1a fusion protein and yellow fluorescent protein (YFP). The cells were cultured in M3434 semi-solid medium for colony formation assay and in M5300 fluid medium containing murine IL-3 (mIL-3), IL-6 (mIL-6) and SCF (mSCF) for long-term culture. The results showed that transfection of AML1a into BMMNC enhanced colony formation, colony size of the AML1a group was significantly larger than that of the control group, and the colonies were mainly composed of CFU-E and CFU-GEMM. In the long-term culture, AML1a-transfected BMMNC showed differentiation block, while the control cells were in a more mature stage. It is concluded that AML1a may block the normal hematopoiesis at the stage of primitive progenitors. At the same time, AML1a also enhances the proliferation activity of primitive progenitor cells.