TY - JOUR
T1 - Induction of the BRCA2 promoter by nuclear factor-κB
AU - Wu, Kangjian
AU - Jiang, Shi Wen
AU - Thangaraju, Muthusamy
AU - Wu, Guojun
AU - Couch, Fergus J.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 2000/11/10
Y1 - 2000/11/10
N2 - BRCA2 is a tumor suppressor gene that has been implicated in response to DNA damage, cell cycle control, and transcription. BRCA2 has been found to be overexpressed in many breast tumors, suggesting that altered expression of the BRCA2 gene may contribute to breast tumorigenesis. To determine how BRCA2 is overexpressed in tumors, we investigated the transcriptional regulation of the BRCA2 promoter. Deletion mapping of the BRCA2 promoter identified three regions associated with 3-fold activation or repression and one upstream stimulatory factor binding site associated with 20-fold activation. Gel shift and cotransfection studies verified the role of USF in regulation of BRCA2 transcription. Analysis of the -144 to -59 region associated with 3-fold activation identified a putative NFκB binding site. Cotransfection of the p65 and p50 subunits of NFκB up-regulated the BRCA2 promoter 16-fold in a luciferase reporter assay, whereas mutations in the binding site ablated the effect. Gel shift and supershift assays with anti-p65 and -p50 antibodies demonstrated that NFκB hinds specifically to the NFκB site. In addition, ectopic expression of NFκB resulted in increased levels of endogeneous BRCA2 expression. Thus, NFκB and USF regulate BRCA2 expression through the BRCA2 promoter.
AB - BRCA2 is a tumor suppressor gene that has been implicated in response to DNA damage, cell cycle control, and transcription. BRCA2 has been found to be overexpressed in many breast tumors, suggesting that altered expression of the BRCA2 gene may contribute to breast tumorigenesis. To determine how BRCA2 is overexpressed in tumors, we investigated the transcriptional regulation of the BRCA2 promoter. Deletion mapping of the BRCA2 promoter identified three regions associated with 3-fold activation or repression and one upstream stimulatory factor binding site associated with 20-fold activation. Gel shift and cotransfection studies verified the role of USF in regulation of BRCA2 transcription. Analysis of the -144 to -59 region associated with 3-fold activation identified a putative NFκB binding site. Cotransfection of the p65 and p50 subunits of NFκB up-regulated the BRCA2 promoter 16-fold in a luciferase reporter assay, whereas mutations in the binding site ablated the effect. Gel shift and supershift assays with anti-p65 and -p50 antibodies demonstrated that NFκB hinds specifically to the NFκB site. In addition, ectopic expression of NFκB resulted in increased levels of endogeneous BRCA2 expression. Thus, NFκB and USF regulate BRCA2 expression through the BRCA2 promoter.
UR - http://www.scopus.com/inward/record.url?scp=0034634640&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034634640&partnerID=8YFLogxK
U2 - 10.1074/jbc.M004390200
DO - 10.1074/jbc.M004390200
M3 - Article
C2 - 10961992
AN - SCOPUS:0034634640
SN - 0021-9258
VL - 275
SP - 35548
EP - 35556
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 45
ER -