Abstract
Activating mutations in the Wnt pathway drive a variety of cancers, but the specific targets and pathways activated by Wnt ligands are not fully understood. To bridge this knowledge gap, we performed a comprehensive time-course analysis of Wnt-dependent signaling pathways in an orthotopic model of Wnt-addicted pancreatic cancer, using a porcupine (PORCN) inhibitor currently in clinical trials, and validated key results in additional Wnt-addicted models. The temporal analysis of the drug-perturbed transcriptome demonstrated direct and indirect regulation of more than 3,500 Wnt-activated genes (23% of the transcriptome). Regulation was both via Wnt/β-catenin and through the modulation of protein abundance of important transcription factors, including MYC, via Wnt-dependent stabilization of proteins (Wnt/STOP). Our study identifies a central role of Wnt/β-catenin and Wnt/STOP signaling in controlling ribosome biogenesis, a key driver of cancer proliferation.
Authors
Babita Madan, Nathan Harmston, Gahyathiri Nallan, Alex Montoya, Peter Faull, Enrico Petretto, David M. Virshup
Figure 8
PORCN inhibition leads to a reduction in expression of key ribosome biogenesis genes.
Copyright © 2019 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)