Synergistic interactions with PI3K inhibition that induce apoptosis

Activating mutations involving the PI3K pathway occur frequently in human cancers. However, PI3K inhibitors primarily induce cell cycle arrest, leaving a significant reservoir of tumor cells that may acquire or exhibit resistance. We searched for genes that are required for the survival of PI3K muta...

Full description

Bibliographic Details
Main Authors: Yaara Zwang, Oliver Jonas, Casandra Chen, Mikael L Rinne, John G Doench, Federica Piccioni, Li Tan, Hai-Tsang Huang, Jinhua Wang, Young Jin Ham, Joyce O'Connell, Patrick Bhola, Mihir Doshi, Matthew Whitman, Michael Cima, Anthony Letai, David E Root, Robert S Langer, Nathanael Gray, William C Hahn
Format: Article
Language:English
Published: eLife Sciences Publications Ltd 2017-05-01
Series:eLife
Subjects:
Online Access:https://elifesciences.org/articles/24523
Description
Summary:Activating mutations involving the PI3K pathway occur frequently in human cancers. However, PI3K inhibitors primarily induce cell cycle arrest, leaving a significant reservoir of tumor cells that may acquire or exhibit resistance. We searched for genes that are required for the survival of PI3K mutant cancer cells in the presence of PI3K inhibition by conducting a genome scale shRNA-based apoptosis screen in a PIK3CA mutant human breast cancer cell. We identified 5 genes (PIM2, ZAK, TACC1, ZFR, ZNF565) whose suppression induced cell death upon PI3K inhibition. We showed that small molecule inhibitors of the PIM2 and ZAK kinases synergize with PI3K inhibition. In addition, using a microscale implementable device to deliver either siRNAs or small molecule inhibitors in vivo, we showed that suppressing these 5 genes with PI3K inhibition induced tumor regression. These observations identify targets whose inhibition synergizes with PI3K inhibitors and nominate potential combination therapies involving PI3K inhibition.
ISSN:2050-084X