Systemic therapies for pancreatic ductal adenocarcinoma (PDAC) remain unsatisfactory. Clinical prognosis is particularly poor for tumor subtypes with activating aberrations in the MYC pathway, creating an urgent need for novel therapeutic targets. To unbiasedly find MYC-associated epigenetic dependencies, we conducted a drug screen in pancreatic cancer cell lines. Here, we found that protein arginine N-methyltransferase 5 (PRMT5) inhibitors triggered an MYC-associated dependency. In human and murine PDACs, a robust connection of MYC and PRMT5 was detected. By the use of gain- and loss-of-function models, we confirmed the increased efficacy of PRMT5 inhibitors in MYC-deregulated PDACs. Although inhibition of PRMT5 was inducing DNA damage and arresting PDAC cells in the G2/M phase of the cell cycle, apoptotic cell death was executed predominantly in cells with high MYC expression. Experiments in primary patient-derived PDAC models demonstrated the existence of a highly PRMT5 inhibitor–sensitive subtype. Our work suggests developing PRMT5 inhibitor–based therapies for PDAC.
Felix Orben, Katharina Lankes, Christian Schneeweis, Zonera Hassan, Hannah Jakubowsky, Lukas Krauß, Fabio Boniolo, Carolin Schneider, Arlett Schäfer, Janine Murr, Christoph Schlag, Bo Kong, Rupert Öllinger, Chengdong Wang, Georg Beyer, Ujjwal M. Mahajan, Yonggan Xue, Julia Mayerle, Roland M. Schmid, Bernhard Kuster, Roland Rad, Christian J. Braun, Matthias Wirth, Maximilian Reichert, Dieter Saur, Günter Schneider