Blood, Vol. 95 No. 4 (February 15), 2000:
pp. 1509-1510
BRIEF REPORT
Mutations of the E2F4 gene in hematological
malignancies having microsatellite instability
Naoki Komatsu,
Seisho Takeuchi,
Takayuki Ikezoe,
Taizo Tasaka,
Yoshihiro Hatta,
Hisanori Machida,
Ian K. Williamson,
Claus R. Bartram,
H. Phillip Koeffler, and
Hirokuni Taguchi
Department of Internal Medicine, Kochi Medical School, Nankoku,
Japan; Department of Internal Medicine, Kagawa Prefectural Central
Hospital, Takamatsu, Japan; School of Medicine, Nihon University,
Tokyo, Japan; Division of Hematology/Oncology, Cedars-Sinai Research
Institute, UCLA School of Medicine, Los Angeles, CA; and the Institute
of Human Genetics, University of Heidelberg, Heidelberg, FRG.
 |
Abstract |
Mutations of coding repeats within the E2F4, TGF-
RII, BAX,
IGFIIR, and hMSH3 are critical targets of microsatellite
instability (MSI) in many kinds of cancers. We analyzed 9 childhood
acute lymphoblastic leukemia (ALL) samples, 5 acute myelocytic leukemia (AML) samples, and 10 adult T-cell leukemia (ATL) samples having MSI to
determine whether they had mutations of the E2F4, TGF-RII, BAX,
IGFIIR, and hMSH3 genes. Frameshift mutations were found at
trinucleotide repeats within a coding exon of the E2F4 gene in
2 of 10 (20%) ATL samples and 1 of 9 (11%) childhood ALL samples. No
mutations were found in the TGF-RII, BAX, IGFIIR, and
hMSH3 genes. E2F4 is a transcription factor that
influences the cell-cycle progression. These results suggest that
mutations of the E2F4 gene, presumably caused by an abnormality
of one of the DNA repair genes, may play an important role in
development of ATL and childhood ALL.
(Blood. 2000;95:1509-1510)
© 2000 by The American Society of Hematology.
| |
Introduction |
Microsatellite instability (MSI), representing either
an expansion or a reduction of (C-A)n repeats, has been
reported in many kinds of human malignancies.1-3 MSI
appears to reflect multiple replication errors because of a defective
mismatch repair gene, including hMSH2, hMLH1,
hPMS1, and hPMS2.4,5 Cancers with MSI show
exaggerated genomic instability at simple repeat sequences that
generate somatic frameshift mutations in genes containing these repeat
sequences. Somatic frameshift mutations of coding repeats within
the E2F4, TGF-RII, BAX, IGFIIR, and hMSH3 are recognized as critical targets of MSI in many kinds of
cancers.6-10 We previously found that MSI is present
in childhood acute lymphoblastic leukemia (ALL), acute myelocytic
leukemia (AML), and adult T-cell leukemia (ATL).11-13
However, the genes that are the target for mutation in hematological
malignancies with MSI are not known. In this study, we analyzed 24 hematological malignancies having MSI to determine whether mutations
occurred at coding repeats of 5 target genes: E2F4,
TGF-RII, BAX, IGFIIR, and hMSH3.
| |
Study design |
We previously analyzed for MSI using 48 childhood ALL, 17 AML, and
22 ATL samples.11-13 MSI was present in 9 (19%) childhood ALL specimens, 5 (29%) AML specimens, and 10 (45%) ATL specimens. These 24 samples with MSI were used in this study. Informed consent was
obtained from the patients, their parents, or both, as appropriate. Mutation analysis of the E2F4, TGF-RII, BAX, IGFIIR, and
hMSH3 genes were performed as reported
previously.6-10 A trinucleotide (AGC) repeat spanning
codons 306-321, which normally encodes 13 serine residues of the
E2F4 gene, was studied.6 For the TGF-RII gene, the poly (A) sequence (nucleotides 709-718) was
analyzed.7 For the BAX gene, the poly (G) sequence
in the third coding exon was analyzed.8 A fragment
containing the deoxyguanine repeat (nucleotides 4030-4140) was
investigated in the IGFIIR gene.9 For the hMSH3
gene, the track of 8 deoxyadenine in exon 7 was assessed.10
| |
Results and discussion |
Three (13%) samples contained mutations of the poly (AGC) tract
within E2F4 (Table 1). One sample
contained an E2F4 allele that was 6 codons (18 nucleotides)
shorter than the normal sequence. The 2 other samples contained
E2F4 alleles that were 3 codons (9 nucleotides) longer than the
normal sequence (Figure 1). By leukemia
subtype, 1 of 9 (11%) childhood ALL samples and 2 of 10 (20%) ATL
samples contained E2F4 mutations. The ALL patient with an
E2F4 mutation had a T-cell phenotype; 2 ATL patients with E2F4 mutations had acute-type ATL. All 3 samples with
E2F4 mutations had MSI at 1 or 2 loci. None of the 5 AML
samples had mutations within E2F4. No mutations were found
within the repeat sequence of TGF-RII, BAX, IGFIIR, and
hMSH3 genes (data not shown).
View larger version (45K):
[in this window]
[in a new window]
| Fig 1.
Sequencing of the mutated E2F4 gene.
Only the (AGC)13 tract and flanking regions of the E2F4 gene are
indicated. Sample 6 (acute ATL) shows a mutant nucleotide sequence.
|
|
The present study has found for the first time that mutations within
the important cell cycle gene E2F4 were present in
hematological malignancies with MSI. E2F is a family of transcription
factors, the activity of which influences the progression through the
G1-S transition of the cell cycle.14 E2F consensus binding
sites have been identified in the promoters of several
growth-regulatory genes, including c-myc, cyclin-dependent
kinases, and cyclin D1.15-17 E2F-mediated
transcriptional activation is repressed through a physical association
between E2F and proteins of the retinoblastoma family (pRB, p107,
p130). Five different E2Fs have been identified: E2F1, E2F2, and E2F3
interact preferentially with pRB18; E2F5 with
p13019; and E2F4 associates with all 3 of these proteins, especially p107 and p130 in a cell cycle-dependent
manner.14,18,20,21 The p107 and p130 proteins inhibit the
ability of E2F4 to transactivate genes whose promoter contains E2F
binding sites, whereas the capacity of E2F4 to bind DNA is
retained.22 This regulation of E2F4 is important in the
normal control of cell growth. For example, an E2F4 mutation
that prevented the protein from binding to p107 resulted in
transformation of NIH3T3 cells, allowing the cells to form
tumors.14 The poly (AGC) tract of E2F4 lies between the "marked box" region and the binding region of the
retinoblastoma family of proteins. This serine repeat domain may induce
transactivation of target genes.6 Even though a functional
effect of a mutation of this region has not been studied, changes in
this region might potentiate transcriptions of growth-stimulatory E2F4
target genes.
In this study, mutations were found only at the trinucleotide repeat
sequence within the E2F4 gene, and no mutations were found at
the single nucleotide repeat within the TGF-RII, BAX, IGFIIR,
and hMSH3 genes. This finding is congruent with the
previous findings that no mutations of the TGF-RII and
BAX genes were found in childhood ALL.23,24
Moreover, Kaneko et al25 reported that mutations of the
TGF-RII gene were not found in MDS patients with MSI. Taken together, these findings suggest that the mechanisms underlying the occurrence of such trinucleotide replication errors could differ from those of the single nucleotide frameshifts in hematological malignancies.
| |
Acknowledgment |
We thank Naoko Hayase for excellent secretarial help.
| |
Footnotes |
Submitted April 13, 1999; accepted October 15, 1999.
Supported in part by grant-in-aid from the Ministry of
Education, Science, Sports, and Culture of Japan; the Parker Hughes Trust; the C. and H. Koeffler FUND; and the Gladys Lichtenstein Grant.
Reprints: Seisho Takeuchi, 3rd Department of
Medicine, Kochi Medical School, Okohcho, Nankoku, Kochi 783-8505, Japan; e-mail: takeuti{at}kochi-ms.ac.jp.
The publication costs of this
article were defrayed in part by
page charge payment. Therefore,
and solely to indicate this fact,
this article is hereby marked
"advertisement"
in accordance with 18 U.S.C.
section 1734.
| |
References |
1.
Chong JM, Fukuyama M, et al.
Microsatellite instability in the progression of gastric carcinoma.
Cancer Res.
1994;54:4595[Abstract/Free Full Text].
2.
Egawa S, Uchida T, Suyama K, et al.
Genetic instability of microsatellite repeats in prostate cancer: relationship to clinicopathological variables.
Cancer Res.
1995;55:2418[Abstract/Free Full Text].
3.
Fleischhacker M, Lee S, Spira S, Takeuchi S, Koeffler HP.
DNA aneuploidy in morphologically normal colons from patients with colon cancer.
Mod Pathol.
1995;8:360[Medline]
[Order article via Infotrieve].
4.
Fishel R, Lescoe MK, Rao MRS, et al.
The human mutator gene homolog MSH2 and its association with hereditary nonpolyposis colon cancer.
Cell.
1993;75:1027[Medline]
[Order article via Infotrieve].
5.
Papadopoulos N, Nicolaides NC, Wei Y-F, et al.
Mutation of a mutL homolog in hereditary colon cancer.
Science.
1994;263:1625[Abstract/Free Full Text].
6.
Souza RF, Yin J, Smolinski KN, et al.
Frequent mutation of the E2F-4 cell cycle gene in primary human gastrointestinal tumors.
Cancer Res.
1997;57:2350[Abstract/Free Full Text].
7.
Togo G, Toda N, Kanai F, et al.
A transforming growth factor type II receptor gene mutation common in sporadic cecum cancer with microsatellite instability.
Cancer Res.
1996;56:5620[Abstract/Free Full Text].
8.
Rampino N, Yamamoto H, Ionov Y, et al.
Somatic frameshift mutations in the BAX gene in colon cancers of the microsatellite mutator phenotype.
Science.
1997;275:967[Abstract/Free Full Text].
9.
Souza RF, Appel R, Yin J, et al.
Microsatellite instability in the insulin-like growth factor 2 receptor gene in gastrointestinal tumours.
Nat Genetics.
1996;14:255[Medline]
[Order article via Infotrieve].
10.
Ikeda M, Orimo H, Moriyama H, et al.
Close correlation between mutations of E2F4 and hMSH3 genes in colorectal cancers with microsatellite instability.
Cancer Res.
1998;58:594[Abstract/Free Full Text].
11.
Takeuchi S, Seriu T, Tasaka T, et al.
Microsatellite instability and other molecular abnormalities in childhood acute lymphoblastic leukaemia.
Br J Haematol.
1997;98:134[Medline]
[Order article via Infotrieve].
12.
Tasaka T, Lee S, Spira S, et al.
Microsatellite instability during the progression of acute myelocytic leukemia.
Br J Haematol.
1997;98:219[Medline]
[Order article via Infotrieve].
13.
Hatta Y, Yamada Y, Tomonaga M, Miyosi I, Said JW, Koeffler HP.
Microsatellite instability in adult T-cell leukemia.
Br J Haematol.
1998;101:341[Medline]
[Order article via Infotrieve].
14.
Ginsberg D, Vairo G, Chittenden T, et al.
E2F-4, a new member of the E2F transcription factor family, interacts with p107.
Genes Dev.
1994;8:2665[Abstract/Free Full Text].
15.
Hiebert S, Lipp M, Nevins JR.
EIA-dependent trans-activation of the human MYC promoter is mediated by the E2F factor.
Proc Natl Acad Sci U S A.
1989;86:3594[Abstract/Free Full Text].
16.
Vairo G, Livingstone DM, Ginsberg D.
Functional interaction between E2F-4 and p130: evidence for distinct mechanisms underlying growth supression by different retinoblastoma protein family members.
Genes Dev.
1995;9:869[Abstract/Free Full Text].
17.
Herber B, Truss M, Beato M, Muller R.
Inducible regulatory elements in the human cyclin D1 promoter.
Oncogene.
1994;9:1295[Medline]
[Order article via Infotrieve].
18.
Ikeda MA, Jakoi L, Nevins JR.
A unique role for the Rb protein in controlling E2F accumulation during cell growth and differentiation.
Proc Natl Acad Sci U S A.
1996;93:3215[Abstract/Free Full Text].
19.
Hijmans EM, Voorhoeve PM, Beijersbergen RL, Van't Veer L, Bernards R.
E2F-5, a new family member that interacts with p130 in vivo.
Mol Cell Biol.
1995;15:3082[Abstract/Free Full Text].
20.
Beijersbergen RL, Kerkhoven RM, Zhu L, Carlée L, Voorhoeve PM, Bernards R.
E2F-4, a new member of the E2F gene family, has oncogenic activity and associates with p107 in vivo.
Genes Dev.
1994;8:1680.
21.
Moberg K, Starz MA, Lees JA.
E2F-4 switches from p130 to p107 and pRB in response to cell cycle reentry.
Mol Cell Biol.
1996;16:1436[Abstract/Free Full Text].
22.
Li JM, Hu PP-C, Shen X, Yu Y, Wang X-F.
E2F4-RB and E2F4-p107 complexes suppress gene expression by transforming growth factor through E2F binding sites.
Proc Natl Acad Sci U S A.
1997;94:4948[Abstract/Free Full Text].
23.
Salomons GS, Buitenhuis CKM, Muñoz CM, et al.
Mutational analysis of BAX and BCL-2 in childhood acute lymphoblastic leukemia.
Int J Cancer.
1998;79:273[Medline]
[Order article via Infotrieve].
24.
Molenaar JJ, Gérard B, Chambon-Pautas C, et al.
Microsatellite instability and frameshift mutations in BAX and transforming growth factor- RII gene are very uncommon in acute lymphoblastic leukemia in vivo but not in cell lines.
Blood.
1998;92:230[Abstract/Free Full Text].
25.
Kaneko H, Horiike S, Taniwaki M, Misawa SM.
Microsatellite instability is an early genetic event in myelodysplastic syndrome but is infrequent and not associated with TGF- receptor type II gene mutation.
Leukemia.
1996;10:1696[Medline]
[Order article via Infotrieve].
Top
Abstract
Introduction