Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 26587-26601 |
| Number of pages | 15 |
| Journal | Journal of Biological Chemistry |
| Volume | 281(36) |
| Issue number | 36 |
| DOIs | |
| Publication status | Published - 08 Sep 2006 |
Fingerprint
Cite this
}
BRCA1 Suppresses Osteopontin-mediated Breast Cancer. / El-Tanani, Mohamed; Campbell, Frederick; Crowe, Paul; Erwin, Pauline; Harkin, Paul; Pharoah, P.; Ponder, B.; Rudland, P.S.
In: Journal of Biological Chemistry, Vol. 281(36), No. 36, 08.09.2006, p. 26587-26601.Research output: Contribution to journal › Article
TY - JOUR
T1 - BRCA1 Suppresses Osteopontin-mediated Breast Cancer
AU - El-Tanani, Mohamed
AU - Campbell, Frederick
AU - Crowe, Paul
AU - Erwin, Pauline
AU - Harkin, Paul
AU - Pharoah, P.
AU - Ponder, B.
AU - Rudland, P.S.
PY - 2006/9/8
Y1 - 2006/9/8
N2 - BRCA1 is a well described breast cancer susceptibility gene thought to be involved primarily in DNA repair. However, mutation within the BRCA1 transcriptional domain is also implicated in neoplastic transformation of mammary epithelium, but responsible mechanisms are unclear. Here we show in a rat mammary model system that wild type (WT) BRCA1 specifically represses the expression of osteopontin (OPN), a multifunctional estrogen-responsive gene implicated in oncogenic transformation, particularly that of the breast. WT.BRCA1 selectively binds OPN-activating transcription factors estrogen receptor alpha, AP-1, and PEA3, inhibits OPN promoter transactivation, and suppresses OPN mRNA and protein both from an endogenous gene and a relevant model inducible gene. WT.BRCA1 also inhibits OPN-mediated neoplastic transformation characterized by morphology change, anchorage-independent growth, adhesion to fibronectin, and invasion through Matrigel. A mutant BRCA1 allele (Mut.BRCA1) associated with familial breast cancer lacks OPN suppressor effects, binds to WT.BRCA1, and impedes WT.BRCA1 suppression of OPN. Stable transfection of rat breast tumor cell lines with Mut.BRCA1 dramatically up-regulates OPN protein and induces anchorage independent growth. In human primary breast cancer, BRCA1 mutation is significantly associated with OPN overexpression. Taken together, these data suggest that BRCA1 mutation may confer increased tissue-specific cancer risk, in part by disruption of BRCA1 suppression of OPN gene transcription.
AB - BRCA1 is a well described breast cancer susceptibility gene thought to be involved primarily in DNA repair. However, mutation within the BRCA1 transcriptional domain is also implicated in neoplastic transformation of mammary epithelium, but responsible mechanisms are unclear. Here we show in a rat mammary model system that wild type (WT) BRCA1 specifically represses the expression of osteopontin (OPN), a multifunctional estrogen-responsive gene implicated in oncogenic transformation, particularly that of the breast. WT.BRCA1 selectively binds OPN-activating transcription factors estrogen receptor alpha, AP-1, and PEA3, inhibits OPN promoter transactivation, and suppresses OPN mRNA and protein both from an endogenous gene and a relevant model inducible gene. WT.BRCA1 also inhibits OPN-mediated neoplastic transformation characterized by morphology change, anchorage-independent growth, adhesion to fibronectin, and invasion through Matrigel. A mutant BRCA1 allele (Mut.BRCA1) associated with familial breast cancer lacks OPN suppressor effects, binds to WT.BRCA1, and impedes WT.BRCA1 suppression of OPN. Stable transfection of rat breast tumor cell lines with Mut.BRCA1 dramatically up-regulates OPN protein and induces anchorage independent growth. In human primary breast cancer, BRCA1 mutation is significantly associated with OPN overexpression. Taken together, these data suggest that BRCA1 mutation may confer increased tissue-specific cancer risk, in part by disruption of BRCA1 suppression of OPN gene transcription.
UR - http://www.scopus.com/inward/record.url?scp=33748749626&partnerID=8YFLogxK
U2 - 10.1074/jbc.M604403200
DO - 10.1074/jbc.M604403200
M3 - Article
C2 - 16807234
VL - 281(36)
SP - 26587
EP - 26601
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 36
ER -