Resistance to therapy caused by intragenic deletion in BRCA2 Journal Article
| Authors: | Edwards, S. L.; Brough, R.; Lord, C. J.; Natrajan, R.; Vatcheva, R.; Levine, D. A.; Boyd, J.; Reis-Filho, J. S.; Ashworth, A. |
| Article Title: | Resistance to therapy caused by intragenic deletion in BRCA2 |
| Abstract: | Cells with loss of BRCA2 function are defective in homologous recombination (HR) and are highly sensitive to inhibitors of poly(ADP-ribose) polymerase (PARP), which provides the basis for a new therapeutic approach. Here we show that resistance to PARP inhibition can be acquired by deletion of a mutation in BRCA2. We derived PARP-inhibitor-resistant (PIR) clones from the human CAPAN1 pancreatic cancer cell line, which carries the protein-truncating c.6174delT frameshift mutation. PIR clones could form DNA-damage-induced RAD51 nuclear foci and were able to limit genotoxin-induced genomic instability, both hallmarks of a competent HR pathway. New BRCA2 isoforms were expressed in the resistant lines as a result of intragenic deletion of the c.6174delT mutation and restoration of the open reading frame (ORF). Reconstitution of BRCA2-deficient cells with these revertant BRCA2 alleles rescued PARP inhibitor sensitivity and HR deficiency. Most of the deletions in BRCA2 were associated with small tracts of homology, and possibly arose from error-prone repair caused by BRCA2 deficiency. Similar ORF-restoring mutations were present in carboplatin- resistant ovarian tumours from c.6174delT mutation carriers. These observations have implications for understanding drug resistance in BRCA mutation carriers as well as in defining functionally important domains within BRCA2. ©2008 Nature Publishing Group. |
| Keywords: | controlled study; aged; middle aged; gene sequence; human cell; frameshift mutation; gene deletion; mutation; sequence deletion; pancreatic neoplasms; protein domain; protein function; ovarian neoplasms; cytology; allele; dna damage; dna repair; carboplatin; gene expression; culture medium; alleles; cancer cell culture; drug resistance; drug resistance, neoplasm; enzyme activity; cell line, tumor; brca2 protein; tumor suppressor gene; gene expression regulation, neoplastic; dna; amino acid sequence; molecular sequence data; recombination, genetic; genomic instability; genes, brca2; nucleotide sequence; base sequence; cell nucleus; chromosome aberrations; sequence homology; tumor; mitomycin; nicotinamide adenine dinucleotide adenosine diphosphate ribosyltransferase; rad51 protein; genotoxicity; recombination; clone; inhibition; open reading frame; phthalazines; poly(adp-ribose) polymerases; open reading frames; poly(adenosine diphosphate ribose); fluorobenzenes |
| Journal Title: | Nature |
| Volume: | 451 |
| Issue: | 7182 |
| ISSN: | 0028-0836 |
| Publisher: | Nature Publishing Group |
| Date Published: | 2008-02-28 |
| Start Page: | 1111 |
| End Page: | 1115 |
| Language: | English |
| DOI: | 10.1038/nature06548 |
| PUBMED: | 18264088 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | --- - "Cited By (since 1996): 182" - "Export Date: 17 November 2011" - "CODEN: NATUA" - "Molecular Sequence Numbers: GENBANK: AY436640;" - "Source: Scopus" |
