R-loop functions in Brca1-associated mammary tumorigenesis.
Proc Natl Acad Sci U S A
; 121(33): e2403600121, 2024 Aug 13.
Article
em En
| MEDLINE
| ID: mdl-39116124
ABSTRACT
Deleterious accumulation of R-loops, a DNA-RNA hybrid structure, contributes to genome instability. They are associated with BRCA1 mutation-related breast cancer, an estrogen receptor α negative (ERα-) tumor type originating from luminal progenitor cells. However, a presumed causality of R-loops in tumorigenesis has not been established in vivo. Here, we overexpress mouse Rnaseh1 (Rh1-OE) in vivo to remove accumulated R-loops in Brca1-deficient mouse mammary epithelium (BKO). R-loop removal exacerbates DNA replication stress in proliferating BKO mammary epithelial cells, with little effect on homology-directed repair of double-strand breaks following ionizing radiation. Compared to their BKO counterparts, BKO-Rh1-OE mammary glands contain fewer luminal progenitor cells but more mature luminal cells. Despite a similar incidence of spontaneous mammary tumors in BKO and BKO-Rh1-OE mice, a significant percentage of BKO-Rh1-OE tumors express ERα and progesterone receptor. Our results suggest that rather than directly elevating the overall tumor incidence, R-loops influence the mammary tumor subtype by shaping the cell of origin for Brca1 tumors.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteína BRCA1
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Carcinogênese
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Estruturas R-Loop
Limite:
Animals
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Female
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Humans
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2024
Tipo de documento:
Article
País de publicação:
Estados Unidos