Development of a functional assay for homologous recombination status in primary cultures of epithelial ovarian tumor and correlation with sensitivity to poly(ADP-ribose) polymerase inhibitors

PURPOSE: Poly(ADP-ribose) polymerase (PARP) inhibitors selectively target homologous recombination (HR)-defective cells and show good clinical activity in hereditary breast and ovarian cancer associated with BRCA1 or BRCA2 mutations. A high proportion (up to 50%) of sporadic epithelial ovarian cancers (EOC) could be deficient in HR due to genetic or epigenetic inactivation of BRCA1/BRCA2 or other HR genes. Therefore, there is a potential for extending the use of PARP inhibitors to these patients if HR status can be identified. We developed a functional assay of HR status in primary cultures of EOCs based on Rad51 focus formation that correlates well with sensitivity to the potent PARP inhibitor AG014699.

EXPERIMENTAL DESIGN: Primary cultures were derived from ascitic fluid from patients with EOCs. HR status was investigated by gammaH2AX and Rad51 focus formation by immunofluorescence. Cytotoxicity to PARP inhibitors was tested by sulforhodamine B and survival assay.

RESULTS: Twenty-five cultures were evaluated for HR status and cytotoxicity to PARP inhibitor. Following exposure to AG014699, there was an increase in Rad51 foci (HR competent) in 9 of 24 (36%) but no increase (HR deficient) in 16 of 24 (64%) cultures. Cytotoxicity was observed in 15 of 16 (93%) HR-deficient samples but not in 9 of 9 HR-competent samples following 24-hour exposure to 10 mumol/L AG014699.

CONCLUSION: HR status can be determined in primary cancer samples by Rad51 focus formation, and this correlates with in vitro response to PARP inhibition. Use of this assay as a biomarker now needs testing in the setting of a clinical trial.

Medienart:

E-Artikel

Erscheinungsjahr:

2010

Erschienen:

2010

Enthalten in:

Zur Gesamtaufnahme - volume:16

Enthalten in:

Clinical cancer research : an official journal of the American Association for Cancer Research - 16(2010), 8 vom: 15. Apr., Seite 2344-51

Sprache:

Englisch

Beteiligte Personen:

Mukhopadhyay, Asima [VerfasserIn]
Elattar, Ahmed [VerfasserIn]
Cerbinskaite, Aiste [VerfasserIn]
Wilkinson, Sarah J [VerfasserIn]
Drew, Yvette [VerfasserIn]
Kyle, Suzanne [VerfasserIn]
Los, Gerrit [VerfasserIn]
Hostomsky, Zdenek [VerfasserIn]
Edmondson, Richard J [VerfasserIn]
Curtin, Nicola J [VerfasserIn]

Links:

Volltext

Themen:

2609-88-3
8237F3U7EH
BRCA1 Protein
BRCA2 Protein
Biomarkers, Tumor
EC 2.4.2.30
EC 2.7.7.-
H2AX protein, human
Histones
Indoles
Journal Article
Lissamine rhodamine B
Poly(ADP-ribose) Polymerase Inhibitors
Poly(ADP-ribose) Polymerases
Rad51 Recombinase
Rhodamines
Rucaparib

Anmerkungen:

Date Completed 12.08.2010

Date Revised 11.03.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1158/1078-0432.CCR-09-2758

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM197156053