TY - JOUR
T1 - A germline mutation in the BRCA1 3'UTR predicts Stage IV breast cancer
AU - Dorairaj, Jemima J.
AU - Salzman, David W.
AU - Wall, Deirdre
AU - Rounds, Tiffany
AU - Preskill, Carina
AU - Sullivan, Catherine A.W.
AU - Lindner, Robert
AU - Curran, Catherine
AU - Lezon-Geyda, Kim
AU - McVeigh, Terri
AU - Harris, Lyndsay
AU - Newell, John
AU - Kerin, Michael J.
AU - Wood, Marie
AU - Miller, Nicola
AU - Weidhaas, Joanne B.
N1 - Funding Information:
JBW and the studies were supported by the following grants: R01 (01R01CA157749-01A1), as well as the Shannon Family Foundation. JJD was supported by the following grant: National Breast Cancer Research Institute (NBCRI) of Ireland.
PY - 2014/6/10
Y1 - 2014/6/10
N2 - Background: A germline, variant in the BRCA1 3'UTR (rs8176318) was previously shown to predict breast and ovarian cancer risk in women from high-risk families, as well as increased risk of triple negative breast cancer. Here, we tested the hypothesis that this variant predicts tumor biology, like other 3'UTR mutations in cancer.Methods: The impact of the BRCA1-3'UTR-variant on BRCA1 gene expression, and altered response to external stimuli was tested in vitro using a luciferase reporter assay. Gene expression was further tested in vivo by immunoflourescence staining on breast tumor tissue, comparing triple negative patient samples with the variant (TG or TT) or non-variant (GG) BRCA1 3'UTR. To determine the significance of the variant on clinically relevant endpoints, a comprehensive collection of West-Irish breast cancer patients were tested for the variant. Finally, an association of the variant with breast screening clinical phenotypes was evaluated using a cohort of women from the High Risk Breast Program at the University of Vermont.Results: Luciferase reporters with the BRCA1-3'UTR-variant (T allele) displayed significantly lower gene expression, as well as altered response to external hormonal stimuli, compared to the non-variant 3'UTR (G allele) in breast cancer cell lines. This was confirmed clinically by the finding of reduced BRCA1 gene expression in triple negative samples from patients carrying the homozygous TT variant, compared to non-variant patients. The BRCA1-3'UTR-variant (TG or TT) also associated with a modest increased risk for developing breast cancer in the West-Irish cohort (OR = 1.4, 95% CI 1.1-1.8, p = 0.033). More importantly, patients with the BRCA1-3'UTR-variant had a 4-fold increased risk of presenting with Stage IV disease (p = 0.018, OR = 3.37, 95% CI 1.3-11.0). Supporting that this finding is due to tumor biology, and not difficulty screening, obese women with the BRCA1-3'UTR-variant had significantly less dense breasts (p = 0.0398) in the Vermont cohort.Conclusion: A variant in the 3'UTR of BRCA1 is functional, leading to decreased BRCA1 expression, modest increased breast cancer risk, and most importantly, presentation with stage IV breast cancer, likely due to aggressive tumor biology.
AB - Background: A germline, variant in the BRCA1 3'UTR (rs8176318) was previously shown to predict breast and ovarian cancer risk in women from high-risk families, as well as increased risk of triple negative breast cancer. Here, we tested the hypothesis that this variant predicts tumor biology, like other 3'UTR mutations in cancer.Methods: The impact of the BRCA1-3'UTR-variant on BRCA1 gene expression, and altered response to external stimuli was tested in vitro using a luciferase reporter assay. Gene expression was further tested in vivo by immunoflourescence staining on breast tumor tissue, comparing triple negative patient samples with the variant (TG or TT) or non-variant (GG) BRCA1 3'UTR. To determine the significance of the variant on clinically relevant endpoints, a comprehensive collection of West-Irish breast cancer patients were tested for the variant. Finally, an association of the variant with breast screening clinical phenotypes was evaluated using a cohort of women from the High Risk Breast Program at the University of Vermont.Results: Luciferase reporters with the BRCA1-3'UTR-variant (T allele) displayed significantly lower gene expression, as well as altered response to external hormonal stimuli, compared to the non-variant 3'UTR (G allele) in breast cancer cell lines. This was confirmed clinically by the finding of reduced BRCA1 gene expression in triple negative samples from patients carrying the homozygous TT variant, compared to non-variant patients. The BRCA1-3'UTR-variant (TG or TT) also associated with a modest increased risk for developing breast cancer in the West-Irish cohort (OR = 1.4, 95% CI 1.1-1.8, p = 0.033). More importantly, patients with the BRCA1-3'UTR-variant had a 4-fold increased risk of presenting with Stage IV disease (p = 0.018, OR = 3.37, 95% CI 1.3-11.0). Supporting that this finding is due to tumor biology, and not difficulty screening, obese women with the BRCA1-3'UTR-variant had significantly less dense breasts (p = 0.0398) in the Vermont cohort.Conclusion: A variant in the 3'UTR of BRCA1 is functional, leading to decreased BRCA1 expression, modest increased breast cancer risk, and most importantly, presentation with stage IV breast cancer, likely due to aggressive tumor biology.
KW - BRCA1-3'UTR-variant
KW - Biomarker
KW - Breast cancer
KW - Diagnostic marker
KW - Metastatic breast cancer
KW - Mutation
KW - Stage IV breast cancer
UR - http://www.scopus.com/inward/record.url?scp=84902546055&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84902546055&partnerID=8YFLogxK
U2 - 10.1186/1471-2407-14-421
DO - 10.1186/1471-2407-14-421
M3 - Article
C2 - 24915755
AN - SCOPUS:84902546055
SN - 1471-2407
VL - 14
JO - BMC Cancer
JF - BMC Cancer
IS - 1
M1 - 421
ER -
