BRCA1 haploinsufficiency for replication stress suppression in primary cells.
BRCA1-a breast and ovarian cancer suppressor gene-promotes genome integrity. To study the functionality of BRCA1 in the heterozygous state, we established a collection of primary human BRCA1(+/+) and BRCA1(mut/+) mammary epithelial cells and fibroblasts. Here we report that all BRCA1(mut/+) cells exhibited multiple normal BRCA1 functions, including the support of homologous recombination- type double-strand break repair (HR-DSBR), checkpoint functions, centrosome number control, spindle pole formation, Slug expression and satellite RNA suppression. In contrast, the same cells were defective in stalled replication fork repair and/or suppression of fork collapse, that is, replication stress. These defects were rescued by reconstituting BRCA1(mut/+) cells with wt BRCA1. In addition, we observed 'conditional' haploinsufficiency for HR-DSBR in BRCA1(mut/+) cells in the face of replication stress. Given the importance of replication stress in epithelial cancer development and of an HR defect in breast cancer pathogenesis, both defects are candidate contributors to tumorigenesis in BRCA1-deficient mammary tissue.
1] Harvard Medical School, Boston, Massachusetts 02115, USA [2] Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
Shailja
S
Pathania
Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
Sangeeta
S
Bade
Stabilité Génétique et Oncogenèse, Université Paris-Sud, CNRS-UMR8200, Gustave-Roussy, Villejuif 94805, France.
Morwenna
M
Le Guillou
Harvard Medical School, Boston, Massachusetts 02115, USA.
Karly
K
Burke
Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
Rachel
R
Reed
1] Harvard Medical School, Boston, Massachusetts 02115, USA [2] Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
Christian
C
Bowman-Colin
Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
Ying
Y
Su
1] Harvard Medical School, Boston, Massachusetts 02115, USA [2] Department of Hematology/Oncology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.
David T
DT
Ting
1] Harvard Medical School, Boston, Massachusetts 02115, USA [2] Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
Kornelia
K
Polyak
1] Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA [2] Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, Massachusetts 02115, USA.
Andrea L
AL
Richardson
Stabilité Génétique et Oncogenèse, Université Paris-Sud, CNRS-UMR8200, Gustave-Roussy, Villejuif 94805, France.
Jean
J
Feunteun
1] Harvard Medical School, Boston, Massachusetts 02115, USA [2] Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
Judy E
JE
Garber
1] Harvard Medical School, Boston, Massachusetts 02115, USA [2] Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA.
David M
DM
Livingston
D000818:Animals; D001940:Breast / Q000166:cytology; D002478:Cells, Cultured; D018385:Centrosome / Q000502:physiology; D004261:DNA Replication / Q000235:genetics / Q000502:physiology*; D005260:Female; D019398:Genes, BRCA1 / Q000502:physiology*; D057895:Haploinsufficiency / Q000235:genetics / Q000502:physiology*; D006579:Heterozygote; D006801:Humans; D051379:Mice; D019244:RNA, Satellite / Q000235:genetics / Q000502:physiology; D051135:Rad51 Recombinase / Q000235:genetics / Q000502:physiology; D059767:Recombinational DNA Repair / Q000235:genetics / Q000502:physiology; D064047:Spindle Poles / Q000235:genetics / Q000502:physiology
D019244:RNA, Satellite; D051135:Rad51 Recombinase