Functional Ex Vivo Assay to Select Homologous Recombination-Deficient Breast Tumors for PARP Inhibitor Treatment

Autor: Roland Kanaar, Mark J. O'Connor, Carolien H.M. van Deurzen, Agnes Jager, Harry Vrieling, Dik C. van Gent, Matty Meijers, John W.M. Martens, Anieta M. Sieuwerts, Maaike P.G. Vreeswijk, Kishan A. T. Naipal, Jan H.J. Hoeijmakers, Johan P. de Winter, Nicole S. Verkaik, Petra ter Brugge, Najim Ameziane, Jos Jonkers
Přispěvatelé: Human genetics, CCA - Innovative therapy, Molecular Genetics, Pathology, Pulmonary Medicine, Medical Oncology
Rok vydání: 2014
Předmět:
Zdroj: Naipal, K A T, Verkaik, N S, Ameziane, N, van Deurzen, C H M, ter Brugge, P, Meijers, M, Sieuwerts, A M, Martens, J W, O'Connor, M J, Vrieling, H, Hoeijmakers, J H J, Jonkers, J, Kanaar, R, de Winter, J P, Vreeswijk, M P, Jager, A & van Gent, D C 2014, ' Functional Ex Vivo Assay to Select Homologous Recombination-Deficient Breast Tumors for PARP Inhibitor Treatment ', Clinical Cancer Research, vol. 20, no. 18, pp. 4816-4826 . https://doi.org/10.1158/1078-0432.CCR-14-0571
Clinical Cancer Research, 20(18), 4816-4826. American Association for Cancer Research Inc.
Clinical Cancer Research, 20(18), 4816-4826
ISSN: 1078-0432
DOI: 10.1158/1078-0432.ccr-14-0571
Popis: Purpose: Poly(ADP-ribose) polymerase (PARP) inhibitors are promising targeted treatment options for hereditary breast tumors with a homologous recombination (HR) deficiency caused by BRCA1 or BRCA2 mutations. However, the functional consequence of BRCA gene mutations is not always known and tumors can be HR deficient for other reasons than BRCA gene mutations. Therefore, we aimed to develop a functional test to determine HR activity in tumor samples to facilitate selection of patients eligible for PARP inhibitor treatment. Experimental design: We obtained 54 fresh primary breast tumor samples from patients undergoing surgery. We determined their HR capacity by studying the formation of ionizing radiation induced foci (IRIF) of the HR protein RAD51 after ex vivo irradiation of these organotypic breast tumor samples. Tumors showing impaired RAD51 IRIF formation were subjected to genetic and epigenetic analysis. Results: Five of 45 primary breast tumors with sufficient numbers of proliferating tumor cells were RAD51 IRIF formation deficient (11%, 95% CI, 5%–24%). This HR defect was significantly associated with triple-negative breast cancer (OR, 57; 95% CI, 3.9–825; P = 0.003). Two of five HR-deficient tumors were not caused by mutations in the BRCA genes, but by BRCA1 promoter hypermethylation. Conclusion: The functional RAD51 IRIF assay faithfully identifies HR-deficient tumors and has clear advantages over gene sequencing. It is a relatively easy assay that can be performed on biopsy material, making it a powerful tool to select patients with an HR-deficient cancer for PARP inhibitor treatment in the clinic. Clin Cancer Res; 20(18); 4816–26. ©2014 AACR.
Databáze: OpenAIRE