Multi-omics analysis reveals distinct non-reversion mechanisms of PARPi resistance in BRCA1- versus BRCA2-deficient mammary tumors
BRCA1 and BRCA2 both function in DNA double-strand break repair by homologous recombination (HR). Due to their HR-defect, BRCA1/2-deficient cancers are sensitive to poly(ADP-ribose) polymerase inhibitors (PARPi) but they eventually acquire resistance. Preclinical studies yielded several PARPi resist...
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| Vydané v: | bioRxiv |
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| Hlavní autori: | , , , , , , , , , , , , , , , , , , , , |
| Médium: | Paper |
| Jazyk: | English |
| Vydavateľské údaje: |
Cold Spring Harbor Laboratory
07.09.2022
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| Vydanie: | 1.1 |
| Predmet: | |
| ISSN: | 2692-8205 |
| On-line prístup: | Získať plný text |
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| Shrnutí: | BRCA1 and BRCA2 both function in DNA double-strand break repair by homologous recombination (HR). Due to their HR-defect, BRCA1/2-deficient cancers are sensitive to poly(ADP-ribose) polymerase inhibitors (PARPi) but they eventually acquire resistance. Preclinical studies yielded several PARPi resistance mechanisms that do not involve BRCA1/2 reactivation, but their relevance in the clinic remains elusive. To investigate which BRCA1/2-independent mechanisms drive spontaneous resistance in vivo, we combined molecular profiling with functional analysis of the HR status of matched PARPi-naïve and PARPi-resistant mouse mammary tumors harboring large intragenic deletions that prevent functional restoration of BRCA1/2. We observed restoration of HR in 64% of PARPi-resistant BRCA1-deficient tumors but none in the PARPi-resistant BRCA2-deficient tumors. Moreover, we found that 53BP1 loss is the prevalent resistance mechanism in HR-proficient BRCA1-deficient tumors, whereas resistance in BRCA2-deficient tumors is mainly induced by the loss of PARG. Our combined multi-omics analysis catalogued additional genes and pathways potentially involved in modulating PARPi response. |
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| Bibliografia: | Competing Interest Statement: The authors have declared no competing interest. |
| ISSN: | 2692-8205 |
| DOI: | 10.1101/2022.09.07.506927 |