TY - JOUR A1 - Ben Khaled, Najib A1 - Hammer, Katharina A1 - Ye, Liangtao A1 - Alnatsha, Ahmed A1 - Widholz, Sebastian A. A1 - Piseddu, Ignazio A1 - Sirtl, Simon A1 - Schneider, Julia A1 - Munker, Stefan A1 - Mahajan, Ujjwal Mukund A1 - Montero, Juan José A1 - Griger, Joscha A1 - Mayerle, Julia A1 - Reiter, Florian P. A1 - De Toni, Enrico N. T1 - TRAIL receptor targeting agents potentiate PARP inhibitor efficacy in pancreatic cancer independently of BRCA2 mutation status JF - Cancers N2 - Chemotherapy, the standard treatment for pancreatic ductal adenocarcinoma (PDAC), has only a modest effect on the outcome of patients with late-stage disease. Investigations of the genetic features of PDAC have demonstrated a frequent occurrence of mutations in genes involved in homologous recombination (HR), especially in the breast cancer susceptibility gene 2 (BRCA2). Olaparib, a poly(ADP-ribose) polymerase (PARP) inhibitor, is approved as a maintenance treatment for patients with advanced PDAC with germline BRCA1/2 mutations following a platinum-containing first-line regimen. Limitations to the use of PARP inhibitors are represented by the relatively small proportion of patients with mutations in BRCA1/2 genes and the modest capability of these substances of inducing objective response. We have previously shown that pancreatic cancer with BRCA2 mutations exhibits a remarkably enhanced sensitivity towards tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL) receptor-stimulating agents. We thus aimed to investigate the effect of combined treatment with PARP inhibitors and TRAIL receptor-stimulating agents in pancreatic cancer and its dependency on the BRCA2 gene status. The respective effects of TRAIL-targeting agents and the PARP inhibitor olaparib or of their combination were assessed in pancreatic cancer cell lines and patient-derived organoids. In addition, BRCA2-knockout and -complementation models were investigated. The effects of these agents on apoptosis, DNA damage, cell cycle, and receptor surface expression were assessed by immunofluorescence, Western blot, and flow cytometry. PARP inhibition and TRAIL synergized to cause cell death in pancreatic cancer cell lines and PDAC organoids. This effect proved independent of BRCA2 gene status in three independent models. Olaparib and TRAIL in combination caused a detectable increase in DNA damage and a concentration-dependent cell cycle arrest in the G2/M and S cell cycle phases. Olaparib also significantly increased the proportion of membrane-bound death receptor 5. Our results provide a preclinical rationale for the combination of PARP inhibitors and TRAIL receptor agonists for the treatment of pancreatic cancer and suggest that the use of PARP inhibitors could be extended to patients without BRCA2 mutations if used in combination with TRAIL agonists. KW - apoptosis KW - DNA damage KW - pancreatic neoplasms KW - poly(ADP-ribose) polymerase inhibitors KW - TNF-related apoptosis-inducing ligand Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290884 SN - 2072-6694 VL - 14 IS - 21 ER -