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Blood, Vol. 92 No. 9 (November 1), 1998:
pp. 3025-3034
RAPID COMMUNICATION
By
From the Department of Medicine, the Division of Hematology and
Oncology, Weill Medical College of Cornell University, New York, NY;
and the Genetics Department, Medicine Branch, National Cancer
Institute, Bethesda, MD.
Previously we reported that a karyotypically silent
t(4;14)(p16.3;q32.3) translocation is present in about 25% of multiple myeloma (MM) tumors, and causes overexpression of FGFR3, which is 50 to
100 kb telomeric to the 4p16 breakpoints. Frequent FGFR3 kinase
activating mutations in MM with t(4;14) translocations substantiate an
oncogenic role for FGFR3. We now report that the 4p16 breakpoints occur
telomeric to and within the 5 © 1998 by The American Society of Hematology.
DYSREGULATION of an oncogene by
translocation to an Ig locus is a seminal event in the pathogenesis of
most B-cell tumors.1 Recently, we have determined that
multiple myeloma (MM) is characterized by frequent translocations into
an Ig locus, including all members of our panel of 21 MM cell lines.
Moreover, at least three of these lines have two independent
translocations involving two IgH loci or an IgH locus plus and IgL
locus.2-5 Others have also reported a high incidence of Ig
translocations in MM, including occasional examples of coincidence of
two IgH translocations or an IgH translocation and an IgL translocation
in the same tumor.6-9 We have found that translocations to
the IgH locus at 14q32.3 primarily involve IgH switch regions, and
involve a large array of translocation partners.2 Three
loci are frequently involved (20% to 25% each): cyclin D1 on 11q13,
FGFR3 on 4p16, and c-maf on 16q23.3-5 In
each of these cases we have cloned the breakpoints and shown that they
are between 50 and 500 kb centromeric to the ectopically expressed
oncogene on the der(14) chromosome. The expression of these genes is
thought to be dysregulated by juxtaposition of endogenous promoters to
powerful regulatory regions of the IgH locus (eg, 3 Cell Culture
Cosmid Clones
Library The human testis 5 -Stretch Plus cDNA library was purchased from
Clontech (Palo Alto, CA). It contains both random-primed and oligo-dT
primed cDNA phage clones.
Primers and Probes The sequence of the primers used in a polymerase chain reaction (PCR) assay to amplify probes for the Northern blot analysis and to screen the cDNA library, in rapid amplification of cDNA ends (RACE) experiments, for sequencing analysis, and for amplification of hybrid transcripts, are listed in Table 1. All the following MMSET PCR reactions have been conducted on UTMC2 cDNA, unless specified. The exon 3 probe, used in the Northern blot analysis and to screen the cDNA library, was a 475-bp fragment PCR amplified using the primers pair 5541 and 5540. The exon 6-10 probe is a 900-bp fragment PCR amplified from the phage clone no. 714, using o58 primer and the T7 primer at the 3 end of the clone. The exon 19-23 probe is an 822-bp fragment
amplified with primers o76 and o77. The 3 exon 24 probe is a
402-bp fragment amplified with primers o83 and o82. Using o93 and o58
primer pair, a 1.7-kb fragment was amplified to cover the coding
sequence in exon 11. A 3340-bp fragment crossing the stop codon in exon
24 has been amplified using o80-o58 primer pairs. The Iµ probe has
been generated by PCR amplification using the primer pair 5518 and o52.
In addition to o99 and o48, the IgH primers used for PCR amplification
of hybrid transcripts are 5536 (Iµ), 5590 (JH1), 5592 (JH3), o64 (C ), o65 (C ), and o132 (Cµ).
RACE 5 RACE experiments were performed on 100 ng of
poly(A)+ cDNA from testis and KMM1, UTMC2, JIM3, and LP1 MM
cell lines using the 5 RACE System for Rapid Amplification of
cDNA Ends, Version 2.0 (GIBCO-BRL, Gaithersburg, MD). Specifically, the
first-strand cDNA was synthesized from 5761, the first PCR reaction was
performed using the 5540 primer, and the reaction product was nested
using 5760. The final product was fractionated on an agarose gel,
blotted, and hybridized with 5541-labeled oligonucleotide to confirm
the specificity of the PCR products. The DNA was then subcloned into the Original TA Cloning Kit (Invitrogen, San Diego, CA). To obviate the
extremely high GC content of the MMSET exon 1, the cDNA synthesis and
the PCR reactions have been performed in the additional presence of 5%
dimethyl sulfoxide (DMSO) and 1 mol/L Betaine (Sigma Chemical Co, St
Louis, MO).
Other Procedures Northern blot analysis, cDNA synthesis, PCR, and sequencing are described elsewhere.3 To sequence the GC-rich region upstream of exon 1, 1 mol/L Betaine was added to the sequencing reactions.GenBank accession numbers for MMSET.
The GenBank accession number for the 7,418-bp MMSET mRNA (type II),
encoding for a 1365 amino acid (aa) protein is AF071593; the accession
number for the 8389-bp mRNA (type I), encoding for a 647-aa protein is
AF071594; the accession number for exon 1, and 5
The MMSET Gene Is Identified by Sequence Analysis The translocation breakpoints on 4p16 are at the telomeric end of a 2-Mb cosmid contig that was fully sequenced during the search for the Huntington's disease gene4,10 (Fig 1). The sequence from cosmid 184d6 was analyzed for potential coding exons using the Gene Recognition and Analysis Internet Link (GRAIL),11 and the region corresponding to exon 3 identified. PCR primers (5540-5541) were used to generate a probe to screen a Northern blot, confirming that this region was expressed, and subsequently to screen a testis cDNA library. Ten independent phage clones were isolated. There was considerable heterogeneity in the 5 end, with one clone (no. 653) containing
25 bp in exon 1 and splicing to exon 3, one starting in exon 2a and
splicing to exon 3, and others starting at bp 39, 72 (no. 714), 83, 115, 254, and 435 of exon 3. All three of the clones extending beyond
exon 10 spliced to exon 12.
MMSET mRNA Transcripts Primarily Initiate in Exon 1 To analyze the 5 end, several 5 RACE experiments were
performed on poly-A enriched RNA from testis and the MM cell line KMM1
[that does not have a t(4;14) translocation]. The results were the
same for both samples, and confirmed the heterogeneous use of different
exons upstream of exon 3, that we have called 2a, 2b, 2c, and 2d, all
of which contain Alu repetitive elements. Additionally in the 5
RACE, exon 1 was identified spliced to various of the exon 2 and also
directly to exon 3. A primer from exon 1 (o99) was used in RT-PCR with
a primer from exon 3 to confirm the results of the 5 RACE, with
amplification of a heterogeneous PCR product, consistent with variable
exon usage between exons 1 and 3. Furthermore, amplification using o99
with primers in exon 11 (o93) or exon 24 (o80) generated products of
the expected size, with no evidence of downstream splicing (data not
shown). The sequence of the genomic segment that includes exon 1 and
the 5 flanking region has an extremely high GC nucleotide (85%)
content. This may explain the reason why exon 1 falls within an
approximately 1.1-kb gap in the published sequence of cosmid 75b9,
between the two sequences hsl75b9a and hsl75b9b. We sequenced this
region, and by computer analysis identified a potential promoter with TATA box 3037 bp upstream the first Sst I site (nt 2501) of
75b9b and by 5RACE identified transcripts that initiated 149 bp from this TATA box. We analyzed the published sequence of cosmid 75b9 with
the programs TSSG, TSSW, and ProScan12,13 and identified a
putative promoter approximately 8 kb telomeric to exon 1. We designed a
PCR primer (o134) in the exon 1a immediately downstream from this
promoter and demonstrated by hemi-nested reverse transcription (RT)-PCR that this exon was expressed at a very low level
in KMM1, and spliced appropriately to exon 3, and to no other exons.
Furthermore, no amplification was obtained using a pair of primers in
exon 1a and exon 1. Hence, we believe exon 1a represents the use of an
alternative promoter and first exon that is not very active in MM. This
suggests that there may be multiple promoters for this gene that may be
active in different cell types or at different stages of
differentiation. Based on our library screening and 5 RACE
experiments in testis and KMM1, it appears that the promoter upstream
of exon 1 is used most commonly.
MMSET mRNA Undergoes Complex Alternative Splicing and Differential Polyadenylation The sequence from the telomeric five cosmids (tel-75b9-184d6-190b4-19h1-96a2-cen) was stripped of repeats using RepeatMasker (Smit AFA, Green P: RepeatMasker at http://ftp.genome.washington.edu/RM/RepeatMasker.html), and used to probe the dbEST database.14 Expressed regions were identified and used to design oligonucleotide in the 3
untranslated exons 11 (o93) and 24 (o80) (Fig 1B). These primers were
used to amplify the intervening region from exon 6 (o58) by RT-PCR on
UTMC2 mRNA. Polyadenylation sites were identified by clustered initiation of 3 EST sequences downstream from consensus
polyadenylation signals (in exon 11 at bp 2990, 3095, 3286 and 8364; in
exon 24 at bp 4982 and 7395). By 3 RACE (no. 1112) we confirmed
that the additional polyadenylation signal in exon 11 at bp 2090 was also used in MM. A series of Northern blots identified transcripts of a
size consistent with the use of each of these polyadenylation signals
(see below). Sequence analysis identified another gene transcribed in
the opposite orientation with polyadenylation at 29270 of cosmid 96a2,
only 529 bp from the polyadenylation in exon 24 of MMSET, serving to
delimit the 3 end of the MMSET gene. The complete gene
organization is summarized in Table 2. The sequence of the phage clones and PCR products agreed with the published
genomic sequence, and the whole open reading frame (ORF) was sequenced in both orientations.
MMSET Encodes 647- and 1365-aa Proteins With Domains Homologous to Those Found in the Trithorax Group There is at least one AUG codon in exon 1, and in each of the alternatively spliced exons 2a, 2b, 2c, and 2d, but none in exon 1a. In exon 3 the first AUG is immediately downstream from an in-frame stop codon, and is followed by a long ORF that covers many exons. Following exon 10 there is an alternative splice either to exon 11 (type I transcripts) or exon 12 (type II transcripts). In exon 11 there is a termination codon 60 nucleotides (nt) after the splice site, and four polyadenylation signals. Following exon 12 the ORF continues to exon 24 where there is a stop codon, and two polyadenylation signals. These two alternatively spliced mRNAs are predicted to encode proteins of 647 aa and 1365 aa that share a common amino terminal (Fig 1C). This shared region contains a putative nuclear localization signal (NLS), an HMG (high mobility group) box that is characteristic of a large number proteins that bind DNA including SRY, the SOX family of transcription factors, the Hrx fusion partner AF17, and the RNA polymerase I transcription factor UBF,15 and a hath (homologous to the amino terminus of hepatoma derived growth factor [HDGF]) region that is also found in HRP-1 and HRP-2, identified by homology screening.16 HDGF has an NLS and an HMG box, and HRP-1 has an NLS, suggesting that these proteins may function in the nucleus. Not reported previously, the human and mouse G/T mismatch repair proteins MSH6 also contain the hath domain, although it is not conserved in yeast MSH6. The long MMSET protein also contains another copy of the hath motif, as well as another putative nuclear localization signal. In addition, it has four PHD (plant homeodomain) zinc fingers17 characterized by the C4-H-C3 motif, and an SET (Suvar3-9, Enhancer-of-zeste, Trithorax) domain,18,19 domains characteristic of the trithorax group proteins that during Drosophila development are required to maintain stable expression of the clustered homeotic genes.20 The entire carboxy terminal half is most homologous (81% over 666 aa) to the carboxy terminal of the recently described murine protein NSD1,21 a much larger protein of 2588 aa whose amino terminal portion interacts with several nuclear receptors (retinoic acid receptor, thyroid hormone receptor, and estrogen receptor).MMSET Is Highly Expressed in Testis and Thymus Using a probe from exon 3, a high level of expression of 5.2- and 7.7-kb mRNAs was detected in oligo-dT selected RNA from testis and thymus, and a much lower level in the other tissues examined (Fig 2A). Based on multiple probes on MM cell line RNA (see below), these appear to represent type II transcripts that use the two polyadenylation sites in exon 24. In addition, several fainter bands at 2.4, 3.1, and 4.0 kb are seen, consistent with type I transcripts that use the polyadenylation sites in exon 11 (see below).
MMSET Is Over-Expressed in the MM Cell Lines With t(4;14) We probed a Northern blot of total RNA from 14 MM cell lines using a probe from the 3 end of exon 24 (Fig 2B). A 7.7-kb mRNA was
detected in all 14 MM cell lines, with a higher level of expression in
5 of 6 cell lines with t(4;14) translocations: OPM2, JIM3, H929, UTMC2,
and LP-1, but not in KMS11. To study the effects of the translocation
on the expression of the different splice and polyadenylation forms of
MMSET, we used different regions of the gene to repeatedly probe a
Northern blot of oligo-dT selected RNA from MM cell lines with (JIM3
and UTMC2) and without (KMM1) the t(4;14) translocation. In Fig 2C a
much longer exposure of KMM1 is shown to demonstrate that there are
three bands (3.1, 5.2, and 7.7 kb) detected with an exon 6-10 probe,
consistent with 5.2- and 7.7-kb type II transcripts and, to a lesser
extent, a 3.1-kb type I transcript. In contrast, the expression in
UTMC-2 is not only more abundant, but the pattern is more complex.
Using the same exon 6-10 probe, in addition to the 5.2- and 7.7-kb type II transcripts, 3.1-, 4.0-, and 8.8-kb type I transcripts are more
prominent than in KMM1. These were confirmed to be type I transcripts
by using a probe from the 5 end of exon 11 (no. 1112) that
hybridized only to bands of approximately 3.1, 4.0, and 8.8 kb (data
not shown). With the exon 19-23 probe, in addition to the major 5.2- and 7.7-kb type II transcripts, there are fainter bands at 4.3, 6.1, and 8.6 kb. We have not determined what mRNAs these minor bands
represent, although the 4.3- and 8.6-, but not the 6.1-kb, bands are
also detected with a probe from 3 exon 24, suggesting that they
use the distal polyadenylation signal in exon 24. These mRNAs may be
formed by alternative splicing that we have been unable to detect, or
by the use of alternative promoters, or by specific mRNA degradation.
In JIM3, the translocation breakpoint is between exon 3 and 4 and, as
predicted, the mRNAs detected with an exon 6-10 probe are each about
600 bp smaller then the corresponding bands in UTMC2. This confirms
that it is the translocated MMSET allele that is
over-expressed. To determine if the translocation significantly altered
the ratio of the two transcripts, we performed a competitive RT-PCR
using a 5 primer in exon 10 and 3 primers in exon 11 and
exon 16 that indicated that the type II transcripts are relatively more
abundant in both the lines with and without the translocation (data not
shown).
The Dysregulated Expression of MMSET Initiates Both From Promoters on 4p16 and the IgH Locus Hypothesizing that the dysregulated MMSET expression may be the result of hybrid mRNA transcripts initiating in the IgH locus, we hybridized the same blot mentioned above with a probe from the Iµ exon (we did not probe with a JH probe because the JH exons are too short to hybridize efficiently). In UTMC2, the Iµ probe uniquely detected a 7.7-kb band that exactly cohybridized with the 7.7-kb type II MMSET transcript. Similarly, in JIM3 the same probe detected a band of 7.0 kb that exactly co-hybridized with the 7.0-kb band detected by the MMSET probes (data not shown). There was no expression detected in KMM1 that lacks a t(4;14) translocation. Although this result implied the existence of hybrid type II transcripts, it did not explain the over-expression of all of the different splice and polyadenylated forms of MMSET. To determine the transcription initiation of these forms, a 5 RACE was performed from exon 3 in UTMC2, and from exon 4 in
JIM3. In UTMC2 the results we obtained were similar to those in KMM1 and testis, with evidence of exon 2d upstream of exon 3, but primarily exon 1 spliced directly to exon 3. In JIM3 the 5 RACE indicated that transcription started in the intron upstream of exon 4 (at 2293 of
cosmid 184d6) and in switch gamma with splicing to exon 4. This
apparent use of cryptic promoters may explain the very broad appearance
of the MMSET bands detected on the JIM3 Northern blot, as though the
mRNAs initiate over an ill-defined area. Although in neither JIM3 or
UTMC2 did the 5 RACE identify the JH or Iµ hybrid transcripts,
a competitive RT-PCR in KMS11 and UTMC2 using 5 primers from
exon 1, JH, Iµ, and a 3 primer from exon 3 suggested equal or
greater amplification with Iµ and JH then exon 1 (data not shown).
This discrepancy suggests some artifactual skewing during the PCR so
that further analysis will be required to determine the relative
contribution of the different promoters.
The t(4;14) Translocation Results in Hybrid JH-MMSET and Iµ-MMSET mRNA Transcripts The t(4;14) translocation is predicted to result in IgH-MMSET and MMSET-IgH hybrid transcripts (Fig 3A). To confirm the existence of IgH-MMSET hybrid transcripts we performed RT-PCR using consensus JH primers (5590/2) with an exon 6 primer (o48), and an Iµ primer (5536) with the same exon 6 primer (Fig 3B). We detected PCR products of the predicted size only in the cell lines with the translocation, and not in other cell lines, peripheral blood, or tonsil. The cell lines with breakpoints telomeric to exon 3 (KMS11, UTMC2, and MM5.1) all had mRNAs that spliced appropriately from JH or Iµ to exon 3. The cell lines with breakpoints between exon 3 and 4 (JIM3 and H929) had hybrid mRNAs that spliced to exon 4, and OPM2, with a breakpoint between exon 4 and 5 had hybrid mRNAs that spliced to exon 5. By Northern blot we showed that Iµ-MMSET transcripts are primarily type II transcripts, with use of the distal polyadenylation signal in exon 24 (see above). RT-PCR results suggest that the JH-MMSET transcripts are also primarily type II: in UTMC2 mRNA, very strong amplification of a 2.7-kb PCR product was obtained with a JH-exon 17 primer pair, and only very weak amplification of a similar sized product with a JH-exon 11 primer pair (data not shown).
RT-PCR Amplification of JH-MMSET and Iµ-MMSET mRNA Transcripts Identifies MM Patient Samples With t(4;14) Translocation Previously we had identified three patients with MM in whom we could detect FGFR3 by RT-PCR of the BM RNA. In these three samples, but not in others, we detected hybrid mRNAs that spliced to exon 3, confirming the presence of the t(4;14) translocation. In LP1 we failed to detect a JH-, Iµ-, I-, or I-MMSET hybrid transcripts, although we have
demonstrated a t(4;14) translocation by fluorescence in situ
hybridization (FISH) analysis (data not shown). To analyze this
further, we performed a 5 RACE from exon 4 and identified
transcripts that appeared to initiate in switch gamma and spliced to
exon 4. This shows that although frequent, JH- and Iµ-MMSET
transcripts are not always seen with t(4;14) translocation. We expect
that the Iµ-MMSET hybrid transcripts initiate from the Iµ promoter.
The JH-MMSET hybrid transcripts may theoretically initiate from a V
region promoter if there is a VDJ rearrangement, or from a promoter
upstream of the D or J exons. Similar Iµ-Bcl-6 and JH-Bcl-6 hybrid
transcripts have been described that are associated with the t(3;14)
translocation.22 Using a consensus V region framework 3 (FR3) oligo we did not detect any FR3-MMSET hybrid transcripts,
suggesting that there is no sense V region transcribed upstream of
JH-MMSET mRNAs. A 5 RACE in UTMC2 from exon 3, nested to JH,
identified transcripts that appeared to initiate in the intron upstream
of J5. From our analysis it appears that the t(4;14) translocation is
frequently associated with JH and Iµ hybrid transcripts, and this
RT-PCR assay represents a convenient and sensitive method to identify this translocation in patients samples.
The Reciprocal Hybrid MMSET-C , and C (o132, o64, o65) in the
samples with t(4;14) translocation. We detected MMSET-C transcripts
in LP1, JIM3, MM5.1, MM.T1, MM.T2, but not in OPM2 that also has a
translocation to switch gamma (S); however, we did not detect
MMSET-IgH in UTMC2 or H929 in which the translocations are into Sµ
and S, respectively (Fig 3B). In comparison with the nearly
universal expression of IgH-MMSET hybrid transcripts, the reciprocal
MMSET-IgH hybrid transcripts are less frequently detected by our assay.
Most of the Hybrid Transcripts Would Not Be Predicted to Result in Fusion Proteins To determine whether the hybrid transcripts resulting from the t(4;14) translocation may potentially encode fusion proteins, we sequenced the PCR products and looked for ORFs. Because exon 3 has an in-frame stop codon upstream of the AUG, none of the transcripts that splice to exon 3 can result in a fusion protein, and they would be predicted to encode the full-length type II MMSET protein. Similarly, no fusion protein would be predicted for hybrid transcripts between JH-exon 4, exon 2b-C, exon 2e-C, or exon 3-C, because they are all out of
frame. Iµ transcripts are said to be sterile, but the Iµ exon has
several AUGs, and a translatable polypeptide chain has been
described.23 Iµ-exon 4 could result in a fusion protein
containing 17 aa from Iµ; however, the Iµ-exon 5 is out of frame.
In sterile transcripts that splice to exon 4 (or initiate upstream of
exon 4), the first AUG is in frame at nt 744, and in transcripts that
splice to exon 5, the first AUG at nt 908 is out of frame, but the
second one, at nt 999, is in frame. The nucleotide context of
AUG999 (it has a G 3 and G+4)
and AUG744 (only G+4) suggest that they may
potentially serve to initiate translation according to the Kozak
consensus sequence.24 Among the other hybrid transcripts
that might possibly result in a fusion protein is the JH-exon 5, if the
translocation occurred on the productive allele, and finally, the
reciprocal MMSET exon 4-C mRNA. In summary, with the exception of
the possible fusion proteins mentioned above, the translocation may be
predicted to result in the full-length MMSET protein if the breakpoint
is upstream of exon 3, or truncated proteins lacking either the amino
terminal 238, or 323 aa, if the breakpoints are upstream of exon 4 or
5, respectively.
We have shown previously that the t(4;14) translocation brings
FGFR3 within 50 to 100 kb of the strong 3
Following submission of this manuscript, the partial genomic structure and developmental expression of the same gene, named WHSC1, was reported by Stec et al.32
Submitted June 16, 1998;
accepted August 8, 1998.
1. Korsmeyer SJ: Chromosomal translocations in lymphoid malignancies reveal novel proto-oncogenes. Annu Rev Immunol 10:785, 1992[Medline] [Order article via Infotrieve]
2.
Bergsagel PL,
Chesi M,
Nardini E,
Brents LA,
Kirby SL,
Kuehl WM:
Promiscuous translocations into immunoglobulin heavy chain switch regions in multiple myeloma.
Proc Natl Acad Sci USA
93:13931,
1996
3.
Chesi M,
Bergsagel PL,
Brents LA,
Smith CM,
Gerhard DS,
Kuehl WM:
Dysregulation of cyclin D1 by translocation into an IgH gamma switch region in two multiple myeloma cell lines.
Blood
88:674,
1996 4. Chesi M, Nardini E, Brents LA, Schrock E, Ried T, Kuehl WM, Bergsagel PL: Frequent translocation t(4; 14)(p16.3; q32.3) in multiple myeloma is associated with increased expression and activating mutations of fibroblast growth factor receptor 3. Nat Genet 16:260, 1997[Medline] [Order article via Infotrieve]
5.
Chesi M,
Bergsagel PL,
Shonukan OO,
Martelli ML,
Brents LA,
Chen T,
Schröck E,
Ried T,
Kuehl WM:
Frequent dysregulation of the c-maf protooncogene at 16q23 by translocation to an immunoglobulin locus in multiple myeloma.
Blood
91:4457,
1998 6. Calasanz MJ, Cigudosa JC, Odero MD, Ferreira C, Ardanaz MT, Fraile A, Carrasco JL, Sole F, Cuesta B, Gullon A: Cytogenetic analysis of 280 patients with multiple myeloma and related disorders: Primary breakpoints and clinical correlations. Genes Chromosomes Cancer 18:84, 1997[Medline] [Order article via Infotrieve]
7.
Lai JL,
Zandecki M,
Mary JY,
Bernardi F,
Izydorczyk V,
Flactif M,
Morel P,
Jouet JP,
Bauters F,
Facon T:
Improved cytogenetics in multiple myeloma: A study of 151 patients including 117 patients at diagnosis.
Blood
85:2490,
1995 8. Sawyer JR, Waldron JA, Jagannath S, Barlogie B: Cytogenetic findings in 200 patients with multiple myeloma. Cancer Genet Cytogenet 82:41, 1995[Medline] [Order article via Infotrieve]
9.
Nishida K,
Tamura A,
Nakazawa N,
Ueda Y,
Abe T,
Matsuda F,
Kashima K,
Taniwaki M:
The Ig heavy chain gene is frequently involved in chromosomal translocations in multiple myeloma and plasma cell leukemia as detected by in situ hybridization.
Blood
90:526,
1997 10. Baxendale S, MacDonald ME, Mott R, Francis F, Lin C, Kirby S, James M, Zehetner G, Hummerich H, Valdes J, Collins FS, Deaven LJ, Gusella JF, Lehrach H, Bates GP: A cosmid contig and high resolution restriction map of the 2 megabase region containing the Huntington's disease gene. Nat Genet 4:181, 1993[Medline] [Order article via Infotrieve]
11.
Uberbacher EC,
Mural RJ:
Locating protein-coding regions in human DNA sequences by a multiple sensor-neural network approach.
Proc Natl Acad Sci USA
88:11261,
1991 12. Solovyev VV, Salamov AA, Lawrence CB: Identification of human gene structure using linear discriminant functions and dynamic programming. Intelligent Systems Mol Biol 3:367, 1995 13. Prestridge DS: Predicting Pol II promoter sequences using transcription factor binding sites. J Mol Biol 249:923, 1995[Medline] [Order article via Infotrieve]
14.
Altschul SF,
Madden TL,
Schaffer AA,
Zhang J,
Zhang Z,
Miller W,
Lipman DJ:
Gapped BLAST and PSI-BLAST: A new generation of protein database search programs.
Nucleic Acids Res
25:3389,
1997
15.
Baxevanis AD,
Landsman D:
The HMG-1 box protein family: Classification and functional relationships.
Nucleic Acids Res
23:1604,
1995 16. Izumoto Y, Kuroda T, Harada H, Kishimoto T, Nakamura H: Hepatoma-derived growth factor belongs to a gene family in mice showing significant homology in the amino terminus. Biochem Biophys Res Commun 238:26, 1997[Medline] [Order article via Infotrieve] 17. Aasland R, Gibson TJ, Stewart AF: The PHD finger: Implications for chromatin-mediated transcriptional regulation. Trends Biochem Sci 20:56, 1995[Medline] [Order article via Infotrieve] 18. Stassen MJ, Bailey D, Nelson S, Chinwalla V, Harte PJ: The Drosophila trithorax proteins contain a novel variant of the nuclear receptor type DNA binding domain and an ancient conserved motif found in other chromosomal proteins. Mech Dev 52:209, 1995[Medline] [Order article via Infotrieve] 19. Tschiersch B, Hofmann A, Krauss V, Dorn R, Korge G, Reuter G: The protein encoded by the Drosophila position-effect variegation suppressor gene Su(var)3-9 combines domains of antagonistic regulators of homeotic gene complexes. EMBO J 13:3822, 1994[Medline] [Order article via Infotrieve] 20. Gould A: Functions of mammalian Polycomb group and trithorax group related genes. Curr Opin Genet Dev 7:488, 1997[Medline] [Order article via Infotrieve] 21. Huang N, vom Baur E, Garnier JM, Lerouge T, Vonesch JL, Lutz Y, Chambon P, Losson R: Two distinct nuclear receptor interaction domains in NSD1, a novel SET protein that exhibits characteristics of both corepressors and coactivators. EMBO J 17:3398, 1998[Medline] [Order article via Infotrieve] 22. Ye BH, Chaganti S, Chang CC, Niu H, Corradini P, Chaganti RS, Dalla-Favera R: Chromosomal translocations cause deregulated BCL6 expression by promoter substitution in B cell lymphoma. |
Abstract
Introduction
Abstract
