TY - JOUR
T1 - Identification of candidate tumor-suppressor genes in 6q27 by combined deletion mapping and electronic expression profiling in lymphoid neoplasms
AU - Steinemann, Doris
AU - Gesk, Stefan
AU - Zhang, Yanming
AU - Harder, Lana
AU - Pilarsky, Christian
AU - Hinzmann, Bernd
AU - Martin-Subero, Jose Ignacio
AU - Calasanz, Maria Jose
AU - Mungall, Andrew
AU - Rosenthal, André
AU - Siebert, Reiner
AU - Schlegelberger, Brigitte
PY - 2003/8/1
Y1 - 2003/8/1
N2 - Deletions in the long arm of chromosome 6 (6q) are among the most frequent chromosome aberrations in lymphoid neoplasms. Recently, the region of minimal deletion (RMDI) in 6q27 was narrowed down to 5-9 Mb. In the present study, we aimed to define the distal border of the commonly lost region in 6q27 more precisely and to identify and investigate tumor-suppressor genes (TSGs) from this region. Twenty-nine cases, in which our previous fluorescence in situ hybridization (FISH) screening that used a set of 36 YAC probes revealed loss in 6q25-27, were further investigated by means of FISH. In all cases, deletions of 6q27 extended from yeast artificial chromosome (YAC) 977e10 spanning the proximal border of RMDI to the most telomeric YAC 933f7 within the recently established YAC-contig of this region. An interstitial homozygous deletion, flanked by the telomeric probe TelVysion6q and YAC 97Ig12, was detected, which substantially narrows down the RMDI. To identify candidate TSGs down-regulated in malignant lymphomas from this region of homozygous loss, we performed electronic profiling of expressed sequences mapped to this region. This analysis suggested the gene PDCD2 originally thought to be involved in programmed cell death to be probably down-regulated in malignant B-cell lymphomas compared to normal B lymphocytes. Nevertheless, mutation analyses failed to identify mutations in the coding region of PDCD2 in nine lymphomas with FISH-proved 6q27 deletions. Furthermore, epigenetic studies in these nine and an additional 48 lymphomas did not show altered methylation of the PDCD2 locus in these tumors. Possibly haploinsufficiency is effectual in accelerating tumor progression.
AB - Deletions in the long arm of chromosome 6 (6q) are among the most frequent chromosome aberrations in lymphoid neoplasms. Recently, the region of minimal deletion (RMDI) in 6q27 was narrowed down to 5-9 Mb. In the present study, we aimed to define the distal border of the commonly lost region in 6q27 more precisely and to identify and investigate tumor-suppressor genes (TSGs) from this region. Twenty-nine cases, in which our previous fluorescence in situ hybridization (FISH) screening that used a set of 36 YAC probes revealed loss in 6q25-27, were further investigated by means of FISH. In all cases, deletions of 6q27 extended from yeast artificial chromosome (YAC) 977e10 spanning the proximal border of RMDI to the most telomeric YAC 933f7 within the recently established YAC-contig of this region. An interstitial homozygous deletion, flanked by the telomeric probe TelVysion6q and YAC 97Ig12, was detected, which substantially narrows down the RMDI. To identify candidate TSGs down-regulated in malignant lymphomas from this region of homozygous loss, we performed electronic profiling of expressed sequences mapped to this region. This analysis suggested the gene PDCD2 originally thought to be involved in programmed cell death to be probably down-regulated in malignant B-cell lymphomas compared to normal B lymphocytes. Nevertheless, mutation analyses failed to identify mutations in the coding region of PDCD2 in nine lymphomas with FISH-proved 6q27 deletions. Furthermore, epigenetic studies in these nine and an additional 48 lymphomas did not show altered methylation of the PDCD2 locus in these tumors. Possibly haploinsufficiency is effectual in accelerating tumor progression.
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U2 - 10.1002/gcc.10231
DO - 10.1002/gcc.10231
M3 - Article
C2 - 12800155
AN - SCOPUS:0038461936
SN - 1045-2257
VL - 37
SP - 421
EP - 426
JO - Genes Chromosomes and Cancer
JF - Genes Chromosomes and Cancer
IS - 4
ER -