EVI1 Is Expressed in Megakaryocyte Cell Lineage and
Enforced Expression of EVI1 in UT-7/GM Cells
Induces Megakaryocyte Differentiation
Seiichi Shimizu,*
,
† Toshiro Nagasawa,† Osamu Katoh,‡ Norio Komatsu,§
Jun Yokota,* and Kazuhiro Morishita
¶,1
¶
Department of Biochemistry, Miyazaki Medical College, Miyazaki, Japan; *Biology Division, National Cancer Center
Research Institute, Tokyo, Japan; †Division of Hematology, Institute of Clinical Medicine, University of Tsukuba,
Ibaraki, Japan; ‡Department of Environment and Mutation, Research Institute for Radiation Biology and Medicine,
Hiroshima University, Hiroshima, Japan; and §Division of Hematology, Department of Medicine,
Jichi Medical School, Tochigi, Japan
Received March 2, 2002
3q21q26 syndrome, an acute myeloid leukemia (AML)
or myelodysplastic syndrome (MDS) with chromo-
somal translocations or inversions between the bands
3q21 and 3q26, is frequently associated with dys-
megakaryocytopoiesis and increased platelet counts
at the initial diagnosis. Since the EVI1 gene at 3q26 is
transcriptionally activated in 3q21q26 syndrome, we
assessed the role of EVI1 gene expression in the ab-
normal megakaryocytic differentiation in 3q21q26
syndrome. RT-PCR analysis of various types of hema-
topoietic cells revealed that the EVI1 gene is ex-
pressed specifically in CD34
؉
cells, megakaryocytes,
and platelets. UT-7 is a human immature megakaryo-
blastic leukemia cell line with dependence for the
growth on granulocyte–macrophage colony-stimulat-
ing factor (GM-CSF) (designated at UT-7/GM) and with
a differentiation capacity to erythroid (UT-7/EPO) and
megakaryocytic lineages (UT-7/TPO) by erythropoie-
tin (EPO) and thrombopoietin (TPO), respectively.
Among three UT-7 sublines, UT-7/GM, UT-7/EPO, and
UT-7/TPO, expression of the EVI1 gene was detected at
low levels in UT-7/GM and UT-7/EPO cells, but was
detected at a higher level in UT-7/TPO cells. When
UT-7/GM cells were cultured with TPO, the level of
EVI1 expression was increased, along with increased
numbers of polynuclear megakaryocytes and expres-
sion of the platelet factor 4 (PF-4) gene. Furthermore,
forced expression of the EVI1 gene in UT-7/GM cells
changed their morphology to polynuclear megakaryo-
cytes, stopped their growth, and induced cell death
within a month. These data indicate that expression of
the EVI1 gene is involved in progression of mega-
karyocytic differentiation and, thus, the dysmegakaryo-
cytopoiesis in 3q21q26 syndrome could be partly due
to an enhanced differentiation capacity of leukemia
cells and/or megakaryocytes by constitutive expres-
sion of the EVI1 gene.
© 2002 Elsevier Science (USA)
Key Words: EVI1; 3q21q26 syndrome; megakaryocyte;
thrombopoietin (TPO); acute myeloid leukemia; dys-
megakaryocytopoiesis; differentiation; myelodysplas-
tic syndrome; zinc finger protein; UT-7.
The ecotropic viral integration site-1 (EVI1) locus
was initially identified as a common site of retroviral
integration in myeloid tumors of the AKXD-23 recom-
binant inbred mouse strain (1). Over 30% of murine
viral-induced myeloid leukemias had viral integration
in the EVI1 locus and we previously isolated the EVI1
gene from this locus as a gene transcriptionally acti-
vated in murine leukemia cells (2). The EVI1 gene
encodes a protein with ten zinc finger motifs and an
acidic domain as a potential transcriptional factor (2).
The human EVI1 gene maps to chromosome 3q26, and
it is transcriptionally activated not only in murine
leukemias, but also in human acute myeloid leukemias
with chromosomal abnormalities at 3q26, such as
t(3;3)(q21;q26), ins(3)(q21q26), inv(3)(q21q26), and
dic(3)(q26;p21) (3–5). Furthermore, fusion mRNAs of
AML1/MDS1/EVI1 (6, 7) and TEL/MDS1/EVI1 (8)
were identified in t(3;21) and t(3;12), respectively.
Therefore, the EVI1 gene is thought to be one of the
important transcriptional factors for the pathogenesis
of murine and human myeloid leukemias.
Work was supported in part by Grants-in-Aid from the Ministry of
Health and Welfare.
1
To whom correspondence and reprint requests should be ad-
dressed at Department of Biochemistry, Miyazaki Medical College,
5200 Kihara, Miyazaki-Gun, Miyazaki-Ken 889-1692, Japan. Fax:
81-985-85-2401. E-mail: kmorishi@post.miyazaki-med.ac.jp.
Biochemical and Biophysical Research Communications 292, 609–616 (2002)
doi:10.1006/bbrc.2002.6693, available online at http://www.idealibrary.com on
609 0006-291X/02 $35.00
© 2002 Elsevier Science (USA)
All rights reserved.