RT Journal Article
SR Electronic
T1 Parallel signaling through IRE1α and PERK regulates pancreatic neuroendocrine tumor growth and survival
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 522102
DO 10.1101/522102
A1 Paul C. Moore
A1 Jenny Y. Qi
A1 Maike Thamsen
A1 Rajarshi Ghosh
A1 Justin Peng
A1 Micah J. Gliedt
A1 Rosa Meza-Acevedo
A1 Rachel E. Warren
A1 Annie Hiniker
A1 Grace E. Kim
A1 Dustin J. Maly
A1 Bradley J. Backes
A1 Feroz R. Papa
A1 Scott A. Oakes
YR 2019
UL http://biorxiv.org/content/early/2019/09/18/522102.abstract
AB Master regulators of the unfolded protein response (UPR)—IRE1α and PERK— promote adaptation or apoptosis depending on levels of endoplasmic reticulum (ER) stress. While the UPR is activated in many cancers, its effects on tumor growth remain unclear. Derived from endocrine cells, pancreatic neuroendocrine tumors (PanNETs) universally hypersecrete one or more peptide hormones, likely sensitizing these cells to high ER protein-folding stress. For the nearly 1,500 Americans diagnosed with PanNETs annually, surgery is the only potentially curative treatment; however the five-year survival is extremely low for those who develop metastatic disease. To assess whether targeting the UPR is a viable therapeutic strategy, we analyzed human PanNET samples and found evidence of elevated ER stress and UPR activation. We then used genetic and pharmacologic approaches to modulate IRE1α and PERK in cultured cells and xenograft and spontaneous genetic (RIP-Tag2) mouse models of PanNETs. We found that UPR signaling is optimized for adaptation and that inhibiting either IRE1α or PERK leads to hyperactivation and apoptotic signaling through the reciprocal arm, thereby halting tumor growth and survival. Our results provide a strong rationale for therapeutically targeting the UPR in PanNETs and other cancers experiencing elevated ER stress.Significance The unfolded protein response (UPR) is upregulated in human pancreatic neuroendocrine tumors and its genetic or pharmacological inhibition significantly reduces tumor growth in preclinical models, providing strong rationale for targeting the UPR in neoplasms with elevated ER stress.