British Journal of Cancer. 2014 May 27. [Epub ahead of print] [Link]
Curtin NJ, Edmondson RJ, Forrest I, Kaufmann A, Lane M, Patterson MJ, O’Donnel R, Sharrock R, Sutton RE, Wilson BT.
Background:Patients with malignant pleural effusions (MPEs) generally have advanced disease with poor survival and few therapeutic options. Cells within MPEs may be used to stratify patients for targeted therapy. Targeted therapy with poly(ADP ribose) polymerase inhibitors (PARPi) depends on identifying homologous recombination DNA repair (HRR)-defective cancer cells. We aimed to determine the feasibility of assaying HRR status in MPE cells.Methods:A total of 15 MPE samples were collected from consenting patients with non-small-cell lung cancer (NSCLC), mesothelioma and ovarian and breast cancer. Primary cultures were confirmed as epithelial by pancytokeratin, and HRR status was determined by the detection of Î³H2AX and RAD51 foci following a 24-h exposure to rucaparib, by immunofluorescence microscopy. Massively parallel next-generation sequencing of DNA repair genes was performed on cultured MPE cells.Results:From 15 MPE samples, 13 cultures were successfully established, with HRR function successfully determined in 12 cultures. Four samples – three NSCLC and one mesothelioma – were HRR defective and eight samples – one NSCLC, one mesothelioma, one sarcomatoid, one breast and four ovarian cancers – were HRR functional. No mutations in DNA repair genes were associated with HRR status, but there was probable loss of heterozygosity of FANCG, RPA1 and PARP1.Conclusions:HRR function can be successfully detected in MPE cells demonstrating the potential to stratify patients for targeted therapy with PARPi.British Journal of Cancer advance online publication, 27 May 2014; doi:10.1038/bjc.2014.261 www.bjcancer.com.