Mitochondrial-Localized Keratin 17 Promotes Chemoresistance in Basal-Like Pancreatic Cancer

A better understanding of the underlying molecular mechanisms driving this aggressive tumor subtype is necessary for the development of effective therapies. Notably, upregulation of keratin 17 (K17) in cancer is associated with poor patient outcome and the basal-like PDAC subtype.

Here, we identified a critical dependency of basal-like PDACs on de novo pyrimidine biosynthesis, driven by intra-mitochondrial K17. Mechanistically, K17 translocated into the mitochondrial intermembrane space via a mitochondrial localization sequence (MLS) recognized by the translocase of the outer mitochondrial membrane 20 (TOM20). In the mitochondria, K17 bound to and stabilized dihydroorotate dehydrogenase (DHODH), the rate-limiting enzyme of de novo pyrimidine biosynthesis, by preventing its ubiquitination-mediated degradation.