|
|
Proc Natl Acad Sci U S A. 2001 May 22; 98(11): 6348–6353. doi: 10.1073/pnas.101132598. | PMCID: PMC33471 |
Copyright © 2001, The National Academy of Sciences Medical Sciences Frequent fusion of the JAZF1 and
JJAZ1 genes in endometrial stromal tumors Jason I. Koontz,*† A. Lee Soreng,*† Marisa Nucci,† Frank C. Kuo,*† Patrick Pauwels,‡ Herman van den
Berghe,‡ Paola Dal Cin,† Jonathan A. Fletcher,‡ and Jeffrey Sklar*†§ *Division of Molecular Oncology, †Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115; and ‡Center for Human Genetics, University of Leuven, B-3000 Leuven, Belgium Received December 19, 2000; Accepted March 16, 2001. Endometrial stromal tumors are divided into three types: benign
stromal nodules, endometrial stromal sarcomas, and undifferentiated
endometrial sarcomas. A variety of cytogenetic abnormalities involving
chromosome 7 have been reported in endometrial stromal sarcomas,
including a recurrent t(7;17)(p15;q21). We have identified two zinc
finger genes, which we have termed JAZF1 and
JJAZ1, at the sites of the 7p15 and 17q21 breakpoints.
Analyses of tumor RNA indicate that a
JAZF1/JJAZ1 fusion is present in all
types of endometrial stromal tumors; however, the fusion appears to be
rarer among endometrial stromal sarcomas that would be considered
high-grade according to certain classification schemes. These findings
suggest that the less malignant endometrial stromal tumors may evolve
toward more malignant types, but that some endometrial stromal sarcomas
with relatively abundant mitotic activity may compose a biologically
distinct group. Endometrial stromal tumors of
the uterus constitute a spectrum of neoplasms that exhibit varying
degrees of malignancy and can present a number of challenges with
respect to diagnosis and classification ( 1). Stromal nodules lie at the
benign end of this spectrum of neoplasms. These nodules consist of
well-circumscribed tumors composed of uniform cells resembling those of
normal endometrial stroma during the proliferative phase of the
menstrual cycle. Endometrial stromal sarcomas (ESSs) are malignant
neoplasms that occupy the middle of the spectrum and are histologically
similar to stromal nodules except for infiltration of the myometrium
and/or vascular invasion. Tumors that depart significantly in
histologic appearance from normal endometrial stroma are referred to as
undifferentiated endometrial sarcomas (or undifferentiated uterine
sarcomas) and represent the most malignant end of this tumor spectrum. In the older literature, all malignant endometrial stromal tumors were
categorized as ESSs and were subclassified into low-grade and
high-grade types ( 2, 3). High-grade ESSs were distinguished from
low-grade ESSs by an increased frequency of mitoses (>10 per high
power microscopic field) and were generally assumed to have a worse
prognosis. More recently, it has been argued that the number of mitoses
within ESSs is largely irrelevant to outcome, which is said to be
almost exclusively a function of stage at diagnosis ( 4– 6). Diagnosis and classification of endometrial stromal tumors has until
now been based primarily on histologic criteria. In recent years,
specific genetic alterations identified in different types of human
tumors have provided useful diagnostic markers, led to insights into
the basic biology of both neoplastic and normal tissues, and
increasingly contributed to the development of rational forms of cancer
therapy ( 7– 9). With these considerations in mind, we have
characterized the DNA and genes surrounding the breakpoints of a
recurrent chromosomal translocation, the t(7;17)(p15;q21), reported in
several cases of low-grade ESS ( 10– 13). We have found that
recombination at these breakpoints results in fusion of two previously
unknown genes, which we have termed JAZF1 and
JJAZ1. Fusion of these genes appears to be common in
low-grade ESSs but is not limited to these neoplasms and can be found
in other types of endometrial stromal tumors as well. However, the
incidence of this fusion appears to be reduced among ESSs that might be
classified as high-grade. Tissues and Cells. Initial molecular genetic studies were performed on four cases of
low-grade ESS found to have the t(7;17)(p15;q21)(see Table
1 for the full karyotypes). In case
BWH-42, the tissue was obtained from a metastatic retroperitoneal mass
in a 58-yr-old woman who had undergone a hysterectomy for a low-grade
ESS 16 years earlier; in case BWH-665, from a metastatic vaginal mass
in a 69-yr-old woman who had undergone a hysterectomy for a low-grade
ESS 18 years earlier; and in both case LU-550 and case LU-965, from
primary uterine tumors in 41-yr-old women. Cells cultured directly from
the tumors were grown in RPMI medium 1640 supplemented with 20% FCS,
Mito + Serum Extender (Becton Dickinson), and bovine pituitary extract
(Becton Dickinson) under standard conditions.
| Table 1Karyotypes of low-grade ESSs
initially studied |
Yeast Artificial Chromosomes (YACs), Bacterial Artificial
Chromosomes (BACs), and cDNAs. YACs and BACs were purchased from Research Genetics (Huntsville, AL).
Methods for growth of yeast and bacteria, as well as procedures for
isolation of YAC and BAC DNA, were as previously described ( 14, 15).
cDNAs were identified in lambda bacteriophage libraries prepared from
human fetal brain (Stratagene) and human umbilical vein endothelial
cells (HUVEC) ( 16) by hybridization of probes to plaque lifts on nylon
membranes. Phage DNA was isolated from clones in the HUVEC library
according to standard methods ( 17), and phagemid cDNA clones were
rescued from the brain library according to the supplier's
instructions. Plasmids containing expressed sequence tag cDNAs (ESTs)
were purchased from Genome Systems (St. Louis). Plasmid DNA was
purified from bacteria following standard protocols ( 18). Fluorescence in Situ, Southern Blot, and Northern Blot
Hybridization. DNA probes for fluorescence in situ hybridization
(FISH) were labeled by nick translation with biotin-tagged nucleoside
triphosphates by using the BioPrime labeling system (Life
Technologies). Hybridization was performed on slides of metaphase
chromosomes prepared according to methods of Fletcher and colleagues
( 15, 19). Procedures for Southern blot and Northern blot hybridization
have been described ( 15). Inverse PCR (I-PCR) and Reverse Transcription (RT)-PCR. I-PCR was performed following protocols previously described ( 15). For
RT-PCR, total RNA was transcribed into cDNA with Superscript II (Life
Technologies), using either 7AntisenseOuter or 17AntisenseOuter as a
primer (see below). The resulting cDNA was subjected to two rounds of
PCR using first the “Outer” and then the “Inner” set
of primers. The JAZF1 primers were 7SenseOuter
5′-CCACAGCAGTGGAAGCCTTA-3′, 7AntisenseOuter
5′-GCTTCTCTTCCCCTCCATTCAT-3′, 7SenseInner 5′-ATCACCCCCTCCTCTTCATT-3′,
and 7AntisenseInner 5′-GGACTCATCGCTGTCCGACT-3′. The JJAZ1
primers were 17SenseOuter 5′-GTTACTCGGCCTCCTCCTCCTC-3′,
17AntisenseOuter 5′-GGTTCAAATTCATTACTGGAAACTGC-3′, 17SenseInner
5′-GAGCTTTTCCTCCAGGCCTTTG-3′, and 17AntisenseInner
5′-CCGGGTTTTGTTTGATTGAGG-3′. Specific primers for glyceraldehyde
3-phosphate dehydrogenase (5′-CACATCGCTCAGACACCATG-3′ and
5′-GCCATGGAATTTGCCATGGG-3′) were used to assess the quality of the
input RNA. For RT-PCR of RNA from formalin-fixed, paraffin-embedded tissue, 10
serial 10-μm tissue sections were deparaffinized with three washes in
10 ml of xylene, washed twice with 100% EtOH, and then digested for
16 h at 60°C in 2 ml 1× digestion solution (20 mM
Tris ![[center dot]](/corehtml/pmc/pmcents/middot.gif) HCl, pH 8.0/20 mM Na 2EDTA/2%
SDS/2.5 mg/ml proteinase K). Eight milliliters of Trizol was added,
and the RNA was isolated according to the supplier's instructions.
First strand synthesis and nested PCR were performed with the following
primers: FusionOutF 5′-CACGCCACAGCAGTGGAAGC-3′, FusionOutR
5′-TTTGTTCTGGAGTTTCGATGAGACA-3′, FusionInnerF
5′-CCCACCCATCACCCCCTCCT-3′, and FusionInnerR
5′-GGTGCTATGAGATTCCGAGTTCGAAGA-3′. A 10-μm tissue section adjacent to
those used for extraction of RNA was examined histologically. Determination of Nucleotide Sequence and Computer-Assisted Analysis
of Derived Sequence. Sequence data were obtained by using the Amplicycle Sequencing Kit
(Perkin–Elmer) and analyzed by using the National Center for
Biotechnology Information (NCBI) blast server and the
gcg software package (Genetics Computer Group, Madison,
WI). Iterated sequence was suppressed in analyses for genes by use of
the repeatmasker2 software program
available at the MRC Mammalian Genetics Unit WWW server
( http://www.mgu.har.mrc.ac.uk/). Peptides were analyzed by using
software available at the Expert Protein Analysis System (ExPASy) WWW
server ( http://www.expasy.ch/). Identification of a YAC Spanning the Chromosome 7 Breakpoint. FISH was performed on metaphase preparations from the tumor of case
BWH-42, using as probes YACs from the Whitehead Centre d'Étude
du Polymorphisme Humain (CEPH) megaYAC contig 7.3 in the region of the
HOXA gene cluster (Fig.
a). FISH with YAC y830D2
produced hybridization signals limited to both derivative 7 (der7)
chromosomes in this tumor, whereas the analysis with YAC y816F12
demonstrated hybridization to the der13 and der17 chromosomes. FISH
with YACs y910G4 and y929H6 demonstrated hybridization signals on the
der17 and the der7 of the t(7;13). These results indicated that the
chromosome 7 breakpoints of both the t(7;17) and the t(7;13) of BWH-42
map within the 7.3 contig between YACs y830D2 and y816F12 but that the
breakpoints are separated by more than 1 megabase. Furthermore, the
chromosome 7 breakpoint in the t(7;17) lies between DNA contained
within y830D2 and y910G4.
YAC y908B12, which contains DNA between clones y830D2 and y910G4, was
then used as a probe and showed hybridization to both der7 chromosomes
and the der17 chromosome of BWH-42, thereby demonstrating that y908B12
spans the chromosome 7 breakpoint of the t(7;17) (Fig. b).
Additionally, analysis with YAC y908B12 of interphase nuclei from a
second case of low-grade ESS, BWH-665, produced three hybridization
signals (Fig. c). Construction of a BAC Contig Across the Chromosome 7 Breakpoint. An arrayed BAC library was screened by PCR using primers for the four
sequence-tagged sites (STSs) CHLC.GATA91C01, D7S516, CHLC.GGAA3F06, and
WI-5230, which lie at the centromeric end of the y908B12 YAC insert.
This screen identified BACs b60B19, b319D14, b390A17, and b332C6. To
determine overlaps and find additional BACs in the region, the
sequences at the ends of the inserts of the BACs were determined. A
search of the GenBank database indicated that DNA within a PAC clone,
p881H5, included the telomeric sequence within b390A17. DNA of this PAC
clone had been sequenced by the Genome Sequencing Center (GSC) at
Washington University
( http://genome.wustl.edu/est/esthmpg.html), and further
examination of chromosome 7 sequence data on the GSC web site using the
end sequences of the BAC inserts resulted in construction of the contig
shown in Fig. a. FISH
analyses on cases BWH-42 and BWH-665 using pooled probes from BACs
b60B19 through b459N13 in this contig demonstrated an identical
hybridization pattern to that seen with YAC y908B12 (data not shown).
These results indicated that the BAC contig spans the chromosome 7
breakpoint in the t(7;17) of case BWH-42.
Identification of a Gene in the Chromosome 7p15 BAC/PAC Contig
and Detection of the Breakpoint by Southern Blot Analysis. The EST database was queried for matches to the genomic sequence
available for this region. Probes for Southern blot analysis of tumor
DNA were then constructed by PCR amplification of repeat-free segments
of genomic DNA adjacent to or included in the expressed regions (Fig.
b). Such a probe derived from the region of overlap between
BAC b459N13 and PAC p881H5 (probe 459-10) detected non-germline bands
in both BamHI and HindIII digests of tumor DNA
from case BWH-42 but not in similar digests of DNA from normal
fibroblasts (Fig. c). The probe 459-10 also detected a
non-germline band in a BamHI digest of tumor DNA from case
BWH-665. The breakpoint region was further narrowed by hybridizing Southern
blots of tumor DNA with two probes, 459-BP8 and 459-BP9, amplified from
sequence lying 3-kb telomeric to 459-10 and separated from each other
by 798bp. Probe 459-BP9 detected bands identical to those seen with
probe 459-10 in the two cases. In both HindIII and
BamHI digests of DNA from BWH-42, probe 459-BP8 detected
non-germline bands distinct from those in case BWH-665 whereas, in case
BWH-665, probe 459-BP8 detected the non-germline band seen with probe
459-10, as well as a new non-germline band. Taken together, these
results indicated that the chromosome 7 breakpoint in case BWH-42 lies
in DNA between that contained in probes 459-BP8 and 459-BP9 and that
the breakpoint in case BWH-665 lies within DNA sequence contained in
probe 459-BP8. Detection of a Tumor-Specific Transcript with Hybridization Probes
for DNA Near the Chromosome 7 Breakpoint. The chromosome 7 breakpoint in cases BWH-42 and BWH-665 mapped to the
region of putative intronic sequence predicted by the alignment of the
EST AA431106 with the sequences of b459N13 and p881H5. A series of
overlapping ESTs presumably derived from a single gene were found in
the database, and a hybridization probe consisting of the three most 3′
exons of the gene was constructed. This probe was hybridized to
Northern blots containing polyadenylated RNA purified from normal human
fibroblasts, normal human endometrium, and four cases of low-grade ESSs
known to contain a t(7;17) (Fig. ). A
band corresponding to a transcript of ≈3.2 kb appeared in analyses of
RNA from both normal tissues and two tumors, and a second band
corresponding to a length of about 4.5 kb appeared in analyses of RNA
only from the four tumors.
To determine which part of the normal chromosome 7 gene hybridized to
the 4.5-kb transcript found in tumors, probes were designed to
represent the portions of the gene on the centromeric and telomeric
sides of the chromosome 7 breakpoint. Northern blot analysis with a
centromeric probe yielded a pattern of bands identical to that seen
with the original probe, and analysis with a telomeric probe yielded
only the 3.2-kb band (data not shown). These findings indicated that
the chromosome 7 gene is expressed in normal endometrium and that
disruption of the penultimate intron of the gene in at least some
tumors with the t(7;17) results in the production of an abnormal
transcript that contains only the centromeric portion of the gene. Identification of a BAC Clone Spanning the Breakpoint on Chromosome
17. Two sets of nested PCR primers were constructed to be oriented in a
tail-to-tail configuration and complementary to sequence 450 bp apart
on each side of the telomeric HindIII site in Fig.
b. Template for I-PCR with these primers was prepared by
HindIII digestion and subsequent self-ligation of genomic
DNA from tumor tissue in case BWH-42 and from normal fibroblasts of the
same patient. I-PCR amplification of these templates produced a
predicted, unrearranged 3.5-kb product from both tumor and normal DNA
and a predicted, rearranged 1.6-kb product only from the tumor DNA
(data not shown). The 1.6-kb I-PCR product was ligated into the pCR2.1Topo vector, and
the sequences at the ends of the insert of the resulting clone were
determined. One end sequence corresponded to chromosome 7 sequence up
to a HindIII site and then immediately diverged into
non-chromosome 7 sequence. When this new sequence was used to search
the GenBank database, it was found that a BAC, b307A16, from chromosome
17 contained matching sequence. These results indicated that the
breakpoint at chromosome 17q21 in case BWH-42 was contained in DNA of
b307A16. Identification of a Gene in the Chromosome 17 Breakpoint Region. Analysis of DNA within b307A16 revealed that about 3.8 kb of a 4.44-kb
EST, KIAA0160, map within genomic DNA beginning less than 20 kb away
from the chromosome 17 breakpoint; however, the first 647 bp of this
EST is not present anywhere in b307A16 or the overlapping BAC b542B22.
This observation suggested that a deletion had occurred in the genomic
DNA contained in b307A16 and that the predicted gene extends across the
chromosome 17 breakpoint. If this gene were disrupted by the chromosome
17 breakpoint, the orientation of the gene would be consistent with a
fusion of this gene with the gene disrupted by the breakpoint in
chromosome 7. To test this possibility, RNA derived from tumor BWH-42
and from control fibroblasts was analyzed by RT-PCR using primers
complementary to sense sequence at the 5′ end of both the 7 and 17
genes and anti-sense sequence located at the 3′ end of both genes, with
the primers paired in all four possible ways. In these experiments, the
primer pairs for the intact chromosome 17 gene amplified products from
the RNA of both the normal tissue and the tumor, but the recombinant 5′
chromosome 7–3′ chromosome 17 pair amplified a product of about 440 bp
only from the tumor RNA (Fig. ). The
reciprocal recombinant primer pair failed to amplify a product from
either of the RNA samples. The 5′ chromosome 7–3′ chromosome 17 primer
pair used in an RT-PCR assay of RNA derived from the three other tumors
analyzed previously in Northern blots yielded similar findings. These
results demonstrated that the chromosome 17 gene was disrupted by the
translocation and that a fusion transcript containing the 5′ end of the
chromosome 7 gene and the 3′ end of the chromosome 17 gene had been
created. Sequence analysis of the RT-PCR products confirmed that RNA
sequence transcribed from chromosome 7 had been joined to RNA sequence
transcribed from chromosome 17 at the sites indicated in Fig.
.
Structure of the Genes Identified at 7p15 and 17q21. Fig. a presents the sequence of the chromosome 7 gene, as
deduced from the GenBank and EST databases plus an additional 176 bp at
the 5′ end acquired through screening of two cDNA libraries derived
from human brain and human umbilical vein endothelial cells (HUVECs).
The entire sequence of the chromosome 17q21 gene is contained in the
EST KIAA0160 (Fig. b). The true 5′ ends of these
transcripts remain unknown because the ORFs continue to the 5′ ends of
the sequences assembled so far. Conceptual translation of the ORF of the chromosome 7 gene
revealed an N-proximal zinc finger domain as well as a nearly tandem
pair of zinc finger domains close to the C terminus. Similar analysis
of the chromosome 17 gene sequence revealed a zinc finger domain in the
C-terminal third of the coding sequence. All four of these zinc finger
domains are of the Cys2His2
class. Other than a possible bipartite nuclear localization sequence in
the chromosome 17 gene, these domains represented the only identifiable
motifs in the coding sequences and the only significant similarity
to other known genes. In light of these structural features, we refer
to the chromosome 7 gene by the acronym JAZF1, for
Juxtaposed with Another Zinc
Finger gene, and the chromosome 17 gene by JJAZ1,
for Joined to JAZF1. Analysis of Endometrial Stromal Tumors for the
JAZF1/JJAZ1 Fusion Transcript. RT-PCR was performed on RNA extracted from paraffin-embedded,
formalin-fixed tissues of five archival cases of low-grade ESS, for
which cytogenetic analysis had not been done, of three stromal nodules,
and of seven high-grade ESSs. RT-PCR performed with sense primers for
both JAZF1 and JJAZ1 and nested antisense
JJAZ1 primers demonstrated amplifiable template from each
case, as judged by the generation of JJAZ1 product. Each of
the three stromal nodules was also positive for the fusion transcript.
Among the ESSs, all low-grade cases were positive in this assay, but
only three of seven high-grade cases were positive (Table
2). Two of the high-grade tumors would be
considered undifferentiated endometrial sarcomas in the more recently
proposed classification system, and, of these, one was positive for the
fusion and the other not.
| Table 2Summary of RT-PCR results for JAZF1/JJAZ1
fusion RNA in archival tissuespecimens |
Chromosomal translocations generally affect the malignant
phenotype of cells that contain them through various kinds of
alterations in genes at or near the breakpoints in DNA of one or both
of the participating chromosomes ( 20). The t(7;17)(p15;q21) appears to
be an example of a chromosomal translocation resulting in a gene
fusion, in which the 5′ end of one gene, termed here JAZF1,
on chromosome 7 is joined to the 3′ end of a second gene, termed
JJAZ1, on chromosome 17. In this respect, the
t(7;17)(p15;q21) resembles the majority of chromosomal translocations
so far analyzed in soft tissue sarcomas, most of which contain fusions
of EWS or a related gene to a second gene encoding a
DNA-binding protein ( 21, 22). Whether detection of the
JAZF1/ JJAZ1 fusion always represents the
presence of the t(7;17)(p15;q21), or may be found in cells without a
translocation identifiable by cytogenetic analysis, remains to be
determined. The cDNAs for JAZF1 and JJAZ1 appear to specify
the synthesis of proteins composed of 243 and 739 aa, respectively.
Determination of the amino acid sequences encoded by the genes is
complicated by the fact that large ORFs are continuous with the 5′ ends
of the cDNA sequences assembled for the two genes; however, several
features of the cDNA sequences for both genes support the conclusion
that the first methionine codons represent the actual beginning of the
coding sequences. For instance, the total length of the cDNA sequences
for the two genes coincides with the estimated size of mRNA in bands
identified by Northern blot hybridization. Furthermore, in RNase
protection assays, probes generated from genomic DNA overlapping
sequence at the 5′ end of the JAZF1 cDNA protected a
fragment of RNA from liver and lung cells corresponding to a size
consistent with the cDNA representing the full length of the transcript
for this gene (comparable experiments for JJAZ1 were not
possible because genomic sequence at the 5′ end of this gene has not
yet been identified). Also, the nucleotides surrounding the putative
initiation codon in both genes (CACC ATGA in
JAZF1 and CGCG ATGG in JJAZ1) conform
well to the consensus rules proposed for vertebrate translational start
sites ( 23). Finally, the mouse ortholog of JAZF1 (contained
in the overlapping murine ESTs AI595264, AA061309, and AI428135) shows
striking homology to the human cDNA over the entire presumptive ORF but
diverges from the human cDNA 5′ of the position of the codon
provisionally assigned as the first methionine. Similarly, the
JJAZ1 Drosophila ortholog (encoding a conceptually
translated protein AAF49094) in genomic fly DNA contains termination
codons in all three reading frames shortly upstream of the position
corresponding to the putative first methionine in the human gene. The specific functions of JAZF1 and JJAZ1
and the reason for their involvement in a gene fusion associated with
neoplasia are not directly apparent from the sequences of the cDNAs.
The only recognizable regions within the two cDNAs resembling sequences
within known genes in humans and other species encode zinc finger
motifs, as often found in DNA binding proteins ( 24, 25). The two
C-proximal zinc finger domains encoded by JAZF1 are
particularly similar in structure and relative spacing to two zinc
fingers in the yeast protein Sfp1p, although the homology between these
two proteins is limited to these two paired zinc fingers. This
homology, albeit slight, might seem noteworthy in a cancer-related gene
because Sfplp negatively regulates the G 2/M
transition in the cell cycle of Saccharomyces cerevesiae by
serving as a transcriptional activator of the gene PDS1 ( 26,
27), the product of which inhibits Esp1p ( 28, 29), a protein that
dissociates the cohesin complexes responsible for holding together
sister chromatids during G 2 ( 30). However, in
transfected cultured cell lines, JAZF1 protein appears to have no
significant effect on transcription of reporter genes driven by the
promoter of PTTG1 ( 31, 32), the human ortholog of
PDS1 (data not shown). Another finding possibly relevant to the role of JAZF1 in
oncogenesis is the lack of JAZF1 RNA in tumors BWH-42 and
LU-954. The reason for the absence of this RNA is different in the two
cases: tumor LU-954 is monosomic for chromosome 7, whereas tumor BWH-42
contains unrearranged DNA for JAZF1 on the allele not broken
by the t(7;17), as demonstrated by Southern blot analysis. Failure to
detect RNA in the latter case may therefore be due to transcriptional
silencing of the normal copy of JAZF1, as has been noted in
the unrearranged alleles of MYC and BCL2 in some
tumors bearing chromosomal translocations with breakpoints in or near
these genes ( 33, 34). Loss of expression for normal versions of
JAZF1 in multiple tumors suggests a possible role of this
gene as a tumor suppressor, similar to the situation observed for
TEL, which is involved in chromosomal translocations and has
tumor suppressor activity in some acute lymphoblastic leukemias
( 35– 37). The distribution of the JAZF1/JJAZ1
fusion among uterine stromal tumors carries a number of implications
for the biology of these neoplasms. For example, the finding of the
fusion in stromal nodules raises the possibility that malignant
endometrial stromal tumors can develop from stromal proliferations that
are initially benign. Additionally, of the seven high-grade ESSs
studied, only three showed evidence of the fusion, suggesting that some
high-grade ESSs may arise by a different pathogenetic mechanism than
low-grade ESSs, despite the current tendency to consider all of these
tumors as clinically homogeneous. Alternatively, this discrepancy
between high and low grade tumors could be due to the relatively small
sample of cases studied or to the fact that we analyzed tumors for only
one form of the fusion and that functionally equivalent genetic
recombinations between JAZF1 and JJAZ1 at
intragenic sites that would not have been detected by us may be present
in some tumors. These explanations notwithstanding, if, after study of
more high-grade ESSs, the fusion is confirmed to be present only within
a subset of such tumors, it will be important to correlate possible
differences in clinical behavior with the presence or absence of this
genetic lesion. We thank Megan Smith for valuable technical assistance. This work
was supported by the National Foundation for Cancer Research and
National Institutes of Health-National Cancer Institute Grant CA-85995. | | ESS | endometrial stromal sarcoma | | | YAC | yeast
artificial chromosome | | | BAC | bacterial artificial chromosome | | | EST | expressed sequence tag | | | FISH | fluorescence in situ
hybridization | | | RT-PCR | reverse transcription–PCR | | | STS | sequence-tagged
site | | | I-PCR | inverse PCR |
1. Zaloudek C, Norris H J. In: Blaustein's Pathology of the Female Genital Tract. Kurman R J, editor. New York: Springer; 1994. pp. 487–528. 2. Norris H J, Taylor H B. Cancer. 1966;19:755–766. [PubMed] 3. Tavassoli F A, Norris H J. Histopathology. 1981;5:1–10. [PubMed] 4. Evans H L. Cancer. 1982;50:2170–2182. [PubMed] 5. Chang K L, Crabtree G S, Lim-Tan S K, Kempson R L, Hendrickson M R. Am J Surg Pathol. 1990;14:415–438. [PubMed] 6. Hendrickson M R, Longacre T A, Kempson R L. In: Diagnostic Surgical Pathology. Sternberg S S, editor. Philadelphia: Lippincott Williams & Wilkins; 1999. pp. 2203–2305. 7. Pegram M, Hsu S, Lewis G, Pietras R, Beryt M, Sliwkowski M, Coombs D, Baly D, Kabbinavar F, Slamon D. Oncogene. 1999;18:2241–2251. [PubMed] 8. Heise C, Sampson-Johannes A, Williams A, McCormick F, Von Hoff D D, Kirn D H. Nat Med. 1997;3:639–645. [PubMed] 9. le Coutre P, Mologni L, Cleris L, Marchesi E, Buchdunger E, Giardini R, Formelli F, Gambacorti-Passerini C. J Natl Cancer Inst. 1999;91:163–168. [PubMed] 10. Sreekantaiah C, Li F P, Weidner N, Sandberg A A. Cancer Genet Cytogenet. 1991;55:163–166. [PubMed] 11. Dal Cin P, Aly M S, De Wever I, Moerman P, van den Berghe H. Cancer Genet Cytogenet. 1992;63:43–46. [PubMed] 12. Pauwels P, Dal Cin P, Van de Moosdijk C N, Vrints L, Sciot R, van den Berghe H. Histopathology. 1996;29:84–87. [PubMed] 13. Hennig Y, Caselitz J, Bartnitzke S, Bullerdiek J. Cancer Genet Cytogenet. 1997;98:84–86. [PubMed] 14. Philippsen P, Stotz A, Scherf C. Methods Enzymol. 1991;194:169–182. [PubMed] 15. Morgan J A, Yin Y, Borowsky A D, Kuo F, Nourmand N, Koontz J I, Reynolds C, Soreng L, Griffin C A, Graeme-Cook F, et al. Cancer Res. 1999;59:6205–6213. [PubMed] 16. Ginsburg D, Handin R I, Bonthron D T, Donlon T A, Bruns G A, Latt S A, Orkin S H. Science. 1985;228:1401–1406. [PubMed] 17. Lech K, Reddy K J, Sherman L A. In: Current Protocols in Molecular Biology. Ausubel F M, Brent R, Kingston R E, Moore D D, Seidman J G, Smith J A, Struhl K, editors. Vol. 1. New York: Wiley; 1990. pp. 1.13.11–11.13.10. 18. Sambrook J, Fritsch E F, Maniatis T. Molecular Cloning: A Laboratory Manual. Plainview, NY: Cold Spring Harbor Lab. Press; 1989. 19. Fletcher J. In: Current Protocols in Human Genetics. Dracopoli N C, Haines J L, Korf B R, Moir D T, Morton C C, Seidman C E, Seidman J G, Smith D R, editors. Vol. 1. New York: John Wiley & Sons; 1994. pp. 10.13.11–10.13.10. 20. Rabbitts T H. Nature (London). 1994;372:143–149. [PubMed] 21. Ladanyi M. Diagn Mol Pathol. 1995;4:162–173. [PubMed] 22. Dei Tos A P, Dal Cin P. Virchows Arch. 1997;431:83–94. [PubMed] 23. Kozak M. Nucleic Acids Res. 1987;15:8125–8148. [PubMed] 24. Berg J M, Shi Y. Science. 1996;271:1081–1085. [PubMed] 25. Clarke N D, Berg J M. Science. 1998;282:2018–2022. [PubMed] 26. Xu Z, Norris D. Genetics. 1998;150:1419–1428. [PubMed] 27. Nasmyth K, Peters J-M, Uhlmann F. Science. 2000;288:1379–1384. [PubMed] 28. Yamamoto A, Guacci V, Koshland D. J Cell Biol. 1996;133:99–110. [PubMed] 29. Yamamoto A, Guacci V, Koshland D. J Cell Biol. 1996;133:85–97. [PubMed] 30. Ciosk R, Zachariae W, Michaelis C, Shevchenko A, Mann M, Nasmyth K. Cell. 1998;93:1067–1076. [PubMed] 31. Zou H, McGarry T J, Bernal T, Kirschner M W. Science. 1999;285:418–421. [PubMed] 32. Kakar S S. Gene. 1999;240:317–324. [PubMed] 33. Bentley D L, Groudine M. Mol Cell Biol. 1986;6:3481–3489. [PubMed] 34. Cleary M L, Smith S D, Sklar J. Cell. 1986;47:19–28. [PubMed] 35. Golub T R, Barker G F, Lovett M, Gilliland D G. Cell. 1994;77:307–316. [PubMed] 36. Golub T R, Barker G F, Stegmaier K, Gilliland D G. Curr Top Microbiol Immunol. 1996;211:279–288. [PubMed] 37. Takeuchi S, Seriu T, Bartram C R, Golub T R, Reiter A, Miyoshi I, Gilliland D G, Koeffler H P. Leukemia. 1997;11:1220–1223. [PubMed]
|
This article has been 
