|
|||||||||
|
|
|
|
|
|
|
|
|
|
|
Blood, Vol. 91 No. 4 (February 15), 1998:
pp. 1382-1390
By
From the Molecular Biology Laboratory, Royal Bournemouth General
Hospital, Bournemouth, UK; Radiumhemmet, Karolinska Hospital, Stockholm
Sweden; the Department of Medicine, Huddinge Hospital, Huddinge,
Sweden; the Laboratory of Genome Analysis, Institute of General
Genetics, Russian Academy of Science, Moscow, Russia; and the
Microbiology and Tumorbiology Center, Karolinska Institute, Stockholm,
Sweden.
A region of chromosome 13q14.3, telomeric to the Retinoblastoma gene
RB-1 is frequently deleted in patients with B-cell chronic lymphocytic
leukemia (B-CLL). A cosmid and P1-derived artificial chromosome
(PAC) contig spanning over 600 kb has been constructed, which encompasses this locus. The contig clones have been used to order
a number of markers along the minimally deleted region and to localize
a series of CpG islands corresponding to possible candidate genes. A
novel polymorphic dinucleotide repeat, 6E3.2, present in one of the
ordered cosmid clones has been isolated for use in deletion mapping
studies of patient DNA. Leukemic samples from 229 CLL patients have
been screened for loss of heterozygosity using microsatellite markers
and analyzed for hemizygous and homozygous deletions by Southern blot
techniques using genomic probes selected from cosmids across the
region. Hemizygous deletions were found in 31% of cases with an
additional 10% showing homozygous loss. The use of these probes has
defined the commonly deleted area to less than 130 kb, centromeric to
the locus D13S272.
B-CELL CHRONIC LYMPHOCYTIC leukemia
(B-CLL) is the most frequently found leukemia among adults in Western
Europe and North America.1,2 However, little is known about
its etiology and pathogenesis. Cytogenetic analysis has shown recurring
abnormalities of which the most common are trisomy 12 and structural
abnormalities of chromosome 13q.3,4 Deletions or
translocations of chromosome 13q14 are found in approximately 20% of
cases5 and are often the sole abnormality in early stage
CLL, suggesting that the region contains one or more genes of
importance in the pathogenesis of B-CLL.6-8 The locus
D13S259 located 1.6 centimorgans telomeric to the
retinoblastoma gene has been found to be deleted homozygously in B-CLL
cases, indicating the likely presence of a tumor suppressor gene in its
vicinity.10-18 More recently we have shown a higher
incidence of homozygous loss at another locus, D13S319, located between
D13S25 and RB-1.19 With the availability of a series of YAC
contigs, cosmid clones, and microsatellite markers,20-23
subsequent studies have sought to further define the minimum critical
region of genetic loss.
We have produced a library of cosmids covering the region between
D13S273 and D13S31 including a contig covering over 600 kb that
contains the markers D13S319, D13S273, 206XF12, D13S25, and D13S262. A
series of nonrepetitive genomic probes were isolated from these cosmids
and used in the isolation of a series of P1-derived artificial
chromosome (PAC) clones that were integrated into the genomic map of the region. Previously identified microsatellite markers20,22 have been accurately ordered with respect to
each other and a novel polymorphic microsatellite has been isolated for
use in deletional mapping of B-CLL patient samples. A map of the region
has been created by integrating the cosmid and PAC data with
restriction maps of the yeast artificial chromosome (YAC) clones used
in the study. This has enabled the minimal region of loss in patient
samples to be defined within the contig borders and narrowed to less
than 130 kb.
Cosmid Subcloning
Contig Formation
PAC Library Screening A human genomic PAC library in the vector pCYPAC2N produced by Pieter de Jong's group at the Roswell Park Cancer Institute, Buffalo, NY, and obtained from the United Kingdom Human Genome Mapping Resource Centre, Cambridge, UK, was screened with a series of single copy probes isolated from four cosmids in separate locations within the deletion region. A series of nine PACs were isolated and mapped back to the chromosome 13q14.3 region by means of FISH and integrated into the cosmid and YAC map of the region.Identification of Potential Microsatellite Polymorphisms Cosmids from the contig were hybridized with a CA repeat probe (Pharmacia, Uppsala, Sweden) to indicate the presence of a number of potentially polymorphic repeat containing areas within the region. From one of these cosmids (cosmid C6a) the regions surrounding the dinucleotide repeat sequence (CA)n were sequenced by dideoxy chain termination sequencing and used in the design of primers to produce an informative polymorphic PCR probe for use in deletion studies.Pulse Field Gel Electrophoresis Total yeast high molecular weight DNA from the YACs C161, 9126, and 922A8 was prepared in 1% low melting temperature agarose. The YACs C161, 9126, and 922A8 were used in partial digestion mapping studies to identify distances between clusters of cutting sites for infrequently cutting enzymes using probes that recognize the right (URA3) or left (ARS 1 Trp 1) YAC vector arms.28Patient Samples Blood samples were obtained with informed consent from patients with B-CLL, whose diagnosis was based on lymphocyte morphology, CD19, CD23, CD5, and the weak expression of monotypic immunoglobulin. Peripheral blood samples were subjected to ficoll gradient centrifugation. In patients whose lymphocyte count was below 30 × 109 cells/L the mononuclear cells were either T-cell depleted using sheep red cell rosetting or positively selected for B cells using CD19-positive magnetic beads (Dynal, Oslo, Norway). The resulting mononuclear cells consisted of >95% leukemic cells as determined by immunophenotyping studies. Polymorphonuclear cells or T lymphocytes obtained with CD3-positive magnetic beads were used as control fractions. DNA was extracted from the separated leukemic and control cell fractions using a standard proteinase K phenol-chloroform extraction.29DNA Probes Probe p68RS2.0 recognizes a variable number tandem repeat (VNTR) polymorphism within the retinoblastoma gene30; ph2-42 recognizes the D13S25 locus; MGG15 recognizes a 5-kb EcoRI fragment from cosmid C9a, which contains the markers D13S319 and D13S272 within it; p9E4.3 is a 4.3-kb EcoRI fragment, which hybridizes to a CpG island <30 kb centromeric to D13S319; p6E4.5 recognizes a CpG island <200 kb centromeric to D13S319, p31a is located within 40 kb centromeric to p6E4.5; and p68c is located approximately 200 kb telomeric to D13S319. Other genomic probes used were p6E3.2, p9a, p9.19, p29a, p18a, p92c, and p25b, isolated from cosmids C9a, C29a, C18a, C92c, and C25b, respectively (Fig 1). Control probes used to help in the quantification of loss were a genomic clone from the renin gene located on chromosome 1, -interferon on chromosome 9, pb16 (bcl-2 cDNA clone corresponding to the 1.6-kb 3 part of the
first exon) on chromosome 18,31 p105-153A (5q11.2-5q13.3;
D5S39),32 and pc117.3, a genomic fragment from the bcl-1
gene on chromosome 11.
Southern Analysis Southern hybridization analysis was performed as described previously.15,19 Eight micrograms of leukemic DNA was digested with the restriction endonucleases EcoRI, Sac I, or HindIII, separated by 1% agarose gel electrophoresis and transferred to nylon filter (Hybond N, Amersham, Little Chalfont, UK). The samples were probed with a series of single copy probes from the region. The ratios between the signals obtained using 13q14.3 probes and signals obtained using the control probes was determined for each of the samples either by visual inspection or using a laser scanning densitometer (Pharmacia). Control cell DNA was included on all filters. Samples were determined to show hemizygous loss if the tumor signal was between 40% to 50% less intense compared with the control signal and to show homozygous loss if the tumor signal was below 10% of the control signal.Microsatellite Studies Tumor and normal DNA samples were PCR amplified to test for loss of heterozygosity at the following microsatellite loci: D13S273, D13S272, D13S319, and 6E3.2, in addition to PCR restriction fragment length polymorphisms (RFLP) present in the RB-1 gene33 and the polymorphic dinucleotide repeat and Ssp I site at the D13S25 locus.18 PCR amplification was performed using 100 ng of template DNA, 50 µmol/L of each of dCTP, dATP, dTTP, and dGTP and 2 µCi of 32P dCTP using 1 U Thermoprime polymerase (Applied Biotechnologies, Leatherhead, UK) in a total volume of 25 µL. The cycle conditions used for the primers were as follows: 94°C for 30 seconds, 58°C for 30 seconds, and 72°C for 30 seconds for the loci D13S319, D13S272, and 6E3.2; 94°C for 30 seconds, 57°C for 30 seconds, and 72°C for 30 seconds for D13S25; and 94°C for 30 seconds, 53°C for 30 seconds, and 72°C for 30 seconds for D13S273. The primer sequences used for the 6E3.2 polymorphism were 6E3.2FOR 5-GCAAGTGGATTGGTTTGGTTG-3 and 6E3.2REV
5-ACATAGCAAGACCCAGTCTC-3. All other microsatellite primer
sequences were obtained from previous studies.19,20 All
samples were amplified on two separate occasions for 24 cycles to
verify loss of heterozygosity (LOH) results.
Microsatellite products were separated on a 6% polyacrylamide gel for
between 2 and 5 hours depending on product size and exposed overnight to autoradiography film (Hyperfilm MP; Amersham). LOH results for each
tumor/normal pair were determined by visual inspection of the bands
resulting from the PCR. LOH was scored positive if one of the
polymorphic band's intensity was reduced by >75% between normal and
tumor samples. Homozygous loss was not determined by microsatellite
analysis.
FISH Analysis PAC clone DNA (1 µg) was labeled with digoxigenin 11-dUPT by nick translation and hybridized at a concentration of 10 ng/µL with an excess of blocking DNA (Cot1; GIBCO BRL) in a buffer containing 2 × SSC (1 × SSC = 0.15 mol/L NaCl/0.015 mol/L sodium citrate), 10% dextran sulphate and 1% sodium dodecyl sulfate (SDS) to metaphase spreads of control samples. A chromosome 13/21 centromeric probe (Alpha laboratories, Eastleigh, UK) labeled with biotin was used as a control for hybridization and chromosomal localization.
Cosmid and PAC Contig A total of 296 human specific cosmids were isolated from the subcloning of three nonchimeric YACs encompassing the minimally deleted region of 13q14.3 to create a highly enriched library of cosmids from this region. These cosmids were used to create several contigs including an overlapping group of 38 clones extending from approximately 200 kb centromeric of the marker D13S319 to over 100 kb telomeric to the marker D13S25. Nine PAC clones isolated from the Human Genome Mapping Project (HGMP) human PAC library were integrated into this detailed map (Fig 1). The cosmid clones, with an average insert size of 38 kb, have been used as a source of single copy markers from across the region and as the basis for the isolation of novel polymorphic microsatellites. The contig has been used in the ordering of a series of previously identified loci. The order centromeric to telomeric of these loci is D13S273, D13S319, D13S272, 206XF12, D13S25, and D13S262.
Pulse Field Gel Electrophoresis and CpG Island Screening
Deletion Mapping Southern blot analysis. A series of 229 leukemic DNA samples, in the majority of cases paired with control DNA from the same individuals, has been screened by hybridization with single copy probes including Rb1, Mgg15, and D13S25 and the novel markers p6E4.5a, p31a, p6E3.2, p9E4.3a, p9a, p25b, and p92c (Figs 3 and 4 ). The frequency of hemizygous loss varied between 20% (16 of 80) at RB-1, 30% (46 of 152) at D13S25, and 31% (71 of 229) at p9E4.3, which is within 30 kb centromeric of the D13S319 locus. The greatest incidence of homozygous loss was observed using this probe, with a total of 10% (22 of 229) of cases (Table 1).
Microsatellite studies. Fifty-eight patient samples were screened across the following microsatellite/RFLP polymorphism loci: RB1, D13S273, D13S319, D13S272, and D13S25. In most of the cases, large deletions encompassing several of these markers were observed. The results obtained from a select number of key patients are shown in Fig 5. The novel microsatellite 6E3.2 was found to be approximately 60% informative in the patient population screened. Hemizygous loss of the markers D13S272 and 6E3.2 is shown in Fig 5A and B in a patient (P4) who showed homozygous loss by hybridizational screening with an intervening marker.
Minimal region of deletion. Although the majority of cases showing loss had large deletions across the region, data from a few patients enabled us to delineate a minimal region of deletion within our contig. These cases are discussed next and represented diagrammatically in Fig 6.
Recessive genes involved in the prevention of oncogenesis are known as
tumor suppressor genes, and biallelic loss of function is required for
phenotypic expression of neoplasia.34 With the aim of
delineating the critical region of homozygous 13q14.3 loss in patients
with B-CLL we have constructed a detailed cosmid and PAC contig across
the region. High resolution mapping studies were focussed on the region
centromeric to the marker D13S25 and telomeric to the Rb1
locus.15,19 The contig produced has enabled not only the
ordering of closely spaced markers, but also the isolation of novel
polymorphic markers and the definition of the relevant area to a 130-kb
region. A number of CpG island probes have been identified and
isolated. These have proven useful for deletion studies performed on
patient samples, as landmark probes in the physical map of the region,
for pulse field gel studies, and as markers for the probable location
of genes in the region. In the majority of cases in which loss was
observed, the extent of the hemizygous or homozygous deletion detected
by the methods used in this study, ie, Southern hybridization and
microsatellite analysis, extended beyond the centromeric or telomeric
limits of the contig. However, in a select group of patients the
boundaries of deletion could be delineated within the contig borders.
Combining the results from 12 key patients defines the critical region
to between the markers 6E3.2 and D13S272, a distance of less than 130 kb, which is covered by a series of overlapping cosmid and PAC clones
in our map (Fig 1). The critical region defined in this study is
centromeric to a recently mapped minimal area of deletion by Bullrich
et al35 in a study of sixty cases. Stilgenbauer et
al,36 who screened 131 cases by FISH alone, determined a similar centromeric pattern of deletion to the present investigation, defining the critical area between D13S273 and D13S272, a distance of
210 kb to 600 kb according to our map.
Submitted May 1, 1997;
accepted October 3, 1997.
1.
Dameshek W:
Chronic lymphocytic leukemia: An accumulative disease of immunologically incompetent lymphocytes.
Blood
29:566,
1967
2. Foon KA, Gale RP: Chronic lymphocytic leukemias, in Handin RI,
Stossel TP, Lux SE (eds): Blood. Principles and Practice of Hematology.
Philadelphia, PA, Lippincott, 1995, p 783
3.
Hernandez JM,
Mecucci C,
Criel A,
Meeus P,
Michaux L,
Vanhoof A,
Verhoef G,
Louwagie A,
Schieff JM,
Michaux JL,
Boogaerts M,
Vandenberghe H:
Cytogenetic analysis of B-cell chronic lymphocytic leukemias classified according to morphologic and immunophenotypic (FAB) criteria.
Leukemia
9:2140,
1995[Medline]
[Order article via Infotrieve]
4.
Juliusson G,
Oscier DG,
Fitchett M,
Ross FM,
Stockdill G,
Mackie MJ,
Parker AC,
Castoldi DL,
Cuneo A,
Knuutila S,
Elonen E,
Gahrton G:
Prognostic subgroups in B-cell chronic lymphocytic leukemia defined by specific chromosomal abnormalities.
N Engl J Med
323:720,
1990[Abstract]
5. Oscier DG: Cytogenetic and molecular abnormalities in chronic
lymphocytic leukemia. Blood Rev 8:88 1994
6.
Matutes E,
Oscier D,
Garcia-Marco J,
Ellis T,
Coppelstone A,
Gillingham R,
Hamblin T,
Lens D,
Swansbury GJ,
Catovsky D:
Trisomy 12 defines a group of CLL with atypical morphology
7. Mould S, Gardiner A, Corcoran M, Oscier DG: Trisomy 12 and
structural abnormalities of 13q14 occurring in the same clone in
chronic lymphocytic leukaemia. Br J Haematol 92(2):389, 1996
8.
Neubauer A,
Richiero K,
Huhn D:
Alterations of the retinoblastoma susceptibility gene in chronic lymphocytic leukemia.
Leukemia Lymphoma
18:399,
1995
9.
Lalande M,
Dryja TP,
Schreck RR,
Shipley J,
Flint A,
Latt SA:
Isolation of human chromosome 13-specific DNA sequences cloned from flow sorted chromosomes potentially linked to the retinoblastoma locus.
Cancer Genet Cytogenet
13:283,
1984[Medline]
[Order article via Infotrieve]
10.
Sulimova GE,
Zakharev VM,
Udina IG,
Bliskovskii VV,
Kirillov AV,
Kapanadze BI,
Shchepinov MS,
Vorobeva NV,
Grafodatskii AS,
Yankovskii NK:
Probe pH2-42 of human locus D13S25: Sequence, localisation, and polymerase chain reaction markers.
Mol Biol
27:560,
1993
11.
Hawthorne LA,
Chapman RM,
Oscier DG,
Cowell JK:
The consistent translocation breakpoint seen in chronic B-cell leukeamia (B-CLL) involves deletion of the D13S25 locus which is distal to the retinoblastoma predisposition gene.
Oncogene
8:1415,
1993[Medline]
[Order article via Infotrieve]
12.
Brown AG,
Ross FM,
Dunne EM,
Steel CM,
Weir-Thompson EM:
Evidence for a new tumor suppressor locus (DBM) in human B-cell neoplasia telomeric to the retinoblastoma gene.
Nat Genet
3:67,
1993[Medline]
[Order article via Infotrieve]
13.
Liu Y,
Szekely L,
Grander D,
Soderhall S,
Juliusson G,
Gahrton G,
Linder S,
Einhorn S:
Chronic lymphocytic leukemia cells with allelic deletions at 13q14 commonly have one intact Rb1 gene: Evidence for the role of an adjacent locus.
Proc Natl Acad Sci USA
90:8697,
1993
14.
Chapman RM,
Corcoran MM,
Gardiner A,
Hawthorn LA,
Cowell JK,
Oscier DG:
Frequent homozygous deletions of the D13S25 locus in chromosome region 13q14 defines the location of a gene critical in leukaemogenesis in chronic B-cell lymphocytic leukaemia.
Oncogene
9:1289,
1994[Medline]
[Order article via Infotrieve]
15.
Devilder MC,
Francois S,
Bosic A,
Moreau A,
Mellerin MP,
Le Paslier D,
Bataille R,
Moisin JP:
Deletion cartography around the D13S25 locus in B-cell chronic lymphocytic leukemia and accurate mapping of the involved tumor suppressor gene.
Cancer Res
55:1355,
1995
16.
Stilgenbauer S,
Leupolt E,
Ohl S,
Weiss G,
Schroder M,
Fischer K,
Bentz M,
Lichter P,
Dohner H:
Heterogeneity of deletions involving Rb1 and the D13S25 locus in B-cell chronic lymphocytic leukemia revealed by fluorescent in-situ hybridization.
Cancer Res
55:3475,
1995
17.
Jabbar SAB,
Ganeshaguru K,
Wickremasinghe RG,
Hoffbrand AV,
Foroni L:
Deletion of chromosome 13 (band q14) but not trisomy 12 is a clonal event in B-chronic lymphocytic leukaemia (CLL).
Br J Haematol
90:476,
1995[Medline]
[Order article via Infotrieve]
18.
Ibbotson RE,
Chapman RM,
Corcoran MM,
Oscier DG:
PCR analysis of polymorphisms at the D13S25 locus.
Leukemia
10:1712,
1996[Medline]
[Order article via Infotrieve]
19.
Liu Y,
Hermanson M,
Grander D,
Merup M,
Wu X,
Heyman M,
Rasool O,
Juiliusson G,
Gahrton G,
Detlofsson R,
Nikiforova N,
Buys C,
Soderhall S,
Yankovsky N,
Zabarovsky E,
Einhorn S:
13q deletions in lymphoid malignancies.
Blood
86:1911,
1995
20.
Gyapay G,
Morrisette J,
Vignal A,
Dib C,
Fizames C,
Millasseau P,
Marc S,
Bernardi G,
Lathrop M,
Weissenbach J:
The 1993-1994 genethon human linkage map.
Nat Genet
7:246,
1994[Medline]
[Order article via Infotrieve]
21.
White A,
Tomfohrde J,
Stewart E,
Barnes R,
Le Paslier D,
Weissenbach J,
Cavalli-Sforza L,
Farrer L,
Bowcock A:
A 4.5-megabase yeast artificial chromosome contig from human chromosome 13q14.3 ordering 9 polymorphic microsatellites (22 sequence-tagged sites) tightly linked to the Wilson disease locus.
Proc Natl Acad Sci USA
90:10105,
1993
22.
Brodyanskii VM,
Sulimova GE,
Udina IG,
Aitova SS,
Shaikhaev GO,
Sharikova OA,
Zakharev VM,
Fedorova LI,
Zelen AV,
Einhorn S,
Baush C,
Laland M,
Ross M,
Yankovsky NK:
Screening of Yac clones and building a map of the chromosome 13 region often deleted during chronic B-cell lymphocytic leucosis.
Mol Biol
29:665,
1995
23.
Hawthorn L,
Roberts T,
Verlind E,
Kooy RF,
Cowell JK:
A yeast artificial chromosome contig that spans the RB1-D13S31 interval on human chromosome 13 and encompasses the frequently deleted region in B-cell chronic lymphocytic leukemia.
Genomics
30:425,
1995[Medline]
[Order article via Infotrieve]
24.
Bellanne-Chantelot C,
Barillot E,
Lacroix B,
Le Paslier D,
Cohen D:
A test case for physical mapping of human genome by repetitive sequence fingerprints: Construction of a physical map of a 420 kb YAC subcloned into cosmids.
Nucleic Acids Res
19:550,
1991
25.
Wapenaar MC,
Schiaffino MV,
Bassi MT,
Schaefer L,
Chinault AC,
Zoghbi HY,
Ballbio A:
A YAC-based binning strategy facilitating the rapid assembly of cosmid contigs
26.
Sinke RJ,
Suijkerbuijk RF,
Herbergs J,
Janssen H,
Cassiman JJ,
Geurts Van Kessel A:
Generation of a panel of somatic cell hybrids containing fragments of human chromosomes 12P by X-ray irradiation and cell fusion.
Genomics
12:206,
1992[Medline]
[Order article via Infotrieve]
27. Ledbetter SA, Nelson DL, Warren ST, Ledbetter DH: Rapid
isolation of DNA probes within specific chromosome regions by
interspersed repetitive sequence polymerase chain reaction. Genomics
6:475 1990
28.
Hamvas RMJ,
Francis F,
Cox R,
Nizetic D,
Goldsworthy E,
Brown SDM,
Lehrach H:
Rapid restriction analysis of YAC clones.
Nucleic Acids Res
22:1318,
1994
29. Maniatis T, Fritsch EF, Sambrook J: Molecular Cloning: A
Laboratory Manual. Cold Spring Harbor, NY, Cold Spring Harbor Laboratory, 1982
30.
Wiggs J,
Nordenskjold M,
Yandell D,
Rapaport BS,
Grondin V,
Janson M,
Werlius B,
Peterson R,
Craft A,
Riedel K,
Liberfarb R,
Walton D,
Wilson W,
Dryja T:
Prediction of the risk of hereditary retinoblastoma, using DNA polymorphisms within the retinoblastoma gene.
N Engl J Med
318:151,
1988[Abstract]
31.
Tsujimoto Y,
Croce CM:
Analysis of the structure, transcripts, and protein products of bcl-2, the gene involved in human follicular lymphoma.
Proc Natl Acad Sci USA
83:5214,
1986
32. Daniels RJ, Morrison KE, Suthers GK, Francis MJ, Thomas NH,
Ignatius J, Zerres K, Dubowitz V, Davies KE: Linkage studies in spinal
muscular atrophy, in Klinger HP (ed): Human Gene Mapping (vol 11).
Basel, Switzerland, Karger, 1991, p 1894
33.
Onadim Z,
Hungerford J,
Cowell JK:
Follow-up of retinoblastoma patients having prenatal and perinatal predictions for mutant gene carrier status using intragenic polymorphic probes from the RB-1 gene.
Br J Cancer
65:711,
1992[Medline]
[Order article via Infotrieve]
34.
Knudson AG:
Antioncogenes in human cancer.
Proc Natl Acad Sci USA
90:10914,
1993
35.
Bullrich F,
Veronese ML,
Kitada S,
Jurlander J,
Caligiuri MA,
Reed J,
Croce CM:
Minimal region of loss at 13q14 in B-cell chronic lymphocytic leukemia.
Blood
88:3109,
1996
36. (abstr)
Stilgenbauer S,
Nickolenko E,
Leupolt G,
Weib G,
Schroder M,
Fischer K,
Bentz M,
Lichter P,
Dohner H:
A novel tumor supressor gene may reside between D13S273 and D13S272 in B-CLL.
Ann Oncol
7:41,
1996
37. Kalachikov S, Migliazza A, Cayanis E, Fracchiolla NS, Bonaldo
MF, Lawton L, Jelenc P, Ye X, Qu X, Chien M, Hauptschein R, Gaidano G,
Vitolo U, Saglio G, Resegotti L, Brodjansky V, Yankovsky N, Zhang P,
Soares MB, Russo J, Edelman IS, Efstratiadis A, Dalla-Favera R, Fischer
S: Cloning and gene mapping of the chromosome 13q14 region deleted in
chronic lymphocytic leukemia. Genomics 42:369 1997
38.
Garcia-Marco JA,
Caldas C,
Price CM,
Wiedemann LM,
Ashworth A,
Catovsky D:
Frequent somatic deletion of the 13q12.3 locus encompassing BRCA2 in chronic lymphocytic leukemia.
Blood
88:1568,
1996
39.
Stilgenbauer S,
Liebisch P,
James MR,
Schroder M,
Schlegelberger B,
Fischer K,
Bentz M,
Lichter P,
Dohner H:
Molecular cytogenetic delineation of a novel critical genomic region in chromosome bands 11q22.3-923.1 in lymphoproliferative disorders.
Proc Natl Acad Sci USA
93:11837,
1996
40.
Hawthorne LA,
Cowell JK:
Regional assignment of EST sequences on human chromosome 13.
Cytogenet Cell Genet
72:72,
1996[Medline]
[Order article via Infotrieve]
41. (abstr)
Corcoran M,
Liu Y,
Mullenbach R,
Ibbotson R,
Rasool O,
Iyengar A,
Grander D,
Chapman R,
Yankovsky N,
Xu W,
Merup M,
Juliusson G,
Gahrton G,
Brodyansky V,
Buys C,
Zabarovsky E,
Oscier D,
Einhorn S:
Characterization of the minimal area of homozygous 13q14.3 deletion in B-CLL and isolation of candidate tumor supressor genes.
Blood
88:358a,
1996
42.
Craig JM,
Bickmore WA:
The distribution of CpG islands in mammalian chromosomes.
Nat Genet
7:376,
1994[Medline]
[Order article via Infotrieve]
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
 |
 |
|||||||
 |
 |
 |
 |
 |
 |
 |
 |
||
| Copyright © 1998 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
Abstract
Introduction
Abstract
Correlation between cytogenetic, clinical and laboratory features in 544 patients.
Br J Haematol
92:382,
1996
