Vol. 4 No. 4 December 2005

Poster Session 

Dedon Interview

BME Elsewhere

Novartis Tour

Alumni Notes

Student Research

Printable Version

The BioTECH Quarterly

Student Research Spotlight
New Model for Investigating Role of Evi1 in Acute Myeloid Leukemia and Myelodysplastic Syndrome

Delbert Green, a sophomore from Opelousas, LA, plans on majoring in Biological Engineering with a minor in Brain and Cognitive Sciences. He has been working in Dr. Fernando Camargo’s lab at the Whitehead Institute since January 2005

By Delbert A. Green II ’08

    Aberrant expression of different transcription factors in hematopoietic (blood) cells has been implicated in several hematological disorders. In acute myeloid leukemia (AML), anomalous cells accumulate in the bone marrow, replace normal blood cells, and spread to other organs. Myelodysplastic syndrome (MDS) is characterized by the accumulation of genetic abnormalities in the hematopoietic stem cell (HSC).

   Anomalous activation of the transcription factor Evi1 leads to AML and MDS in mice and humans. In the hematopoietic lineage, Evi1 has been shown to be expressed exclusively in the pluripotent hematopoietic stem cell (HSC), indicating that Evi1 may play a role in sustaining the pluripotency of HSCs.

   In order to determine the role of Evi1 in adult hematopoiesis, thus defining the role of Evi1 in AML and MDS, we have created both in vitro and in vivo models of retroviral infection-induced over expression and ablation of Evi1 in HSCs.

    EMLs, a hematopoietic progenitor cell line, were infected with a retrovirus harboring an siRNA for silencing of Evi1. One to two days post-infection, Evi1-deficient HSCs show a slowed growth rate and morphology uncharacteristic of the HSC. After several days, most Evi1-deficient HSCs have died, though few show the morphology of red blood cells.

    Bone marrow-derived HSCs infected with the Evi1-siRNA were competitively transplanted into recipient mice. Evi1-deficient HSCs are unable to contribute to the blood lineage, indicating a competitive advantage of Evi1-positive HSCs in forming the hematopoietic system (Fig. 1).

Figure 1. Peripheral Blood Analysis (FACS). Lethally irradiated mice were rescued with donor Lin- BM cells. The peripheral blood was analyzed for host/donor blood reconstitution. (A-B) Control: Lin- BM cells infected with pMIG (MSCV-IRES-GFP) virus. (C-D) BM cells infected with Evi1-siRNA virus (which includes an IRES-GFP fusion). GFP+ is an indication of viral infection. In 1D, the absence of GFP+ cells indicates that Evi1-deficient donor cells did not contribute to the blood of rescued mice.

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