Identification of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase as a novel autophagy regulator by high content shRNA screening.

Oncogene
Authors
Keywords
Abstract

Deregulation of autophagy has been linked to multiple degenerative diseases and cancer, thus the identification of novel autophagy regulators for potential therapeutic intervention is important. To meet this need, we developed a high content image-based short hairpin RNA screen monitoring levels of the autophagy substrate p62/SQSTM1. We identified 186 genes whose loss caused p62 accumulation indicative of autophagy blockade, and 67 genes whose loss enhanced p62 elimination indicative of autophagy stimulation. One putative autophagy stimulator, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 (PFKFB4), drives flux through pentose phosphate pathway. Knockdown of PFKFB4 in prostate cancer cells increased p62 and reactive oxygen species (ROS), but surprisingly increased autophagic flux. Addition of the ROS scavenger N-acetyl cysteine prevented p62 accumulation in PFKFB4-depleted cells, suggesting that the upregulation of p62 and autophagy was a response to oxidative stress caused by PFKFB4 elimination. Thus, PFKFB4 suppresses oxidative stress and p62 accumulation, without which autophagy is stimulated likely as a ROS detoxification response.

Year of Publication
2015
Journal
Oncogene
Volume
34
Issue
45
Pages
5662-76
Date Published
2015 Nov 05
ISSN
1476-5594
URL
DOI
10.1038/onc.2015.23
PubMed ID
25772235
PubMed Central ID
PMC4573377
Links
Grant list
RC1 CA147961 / CA / NCI NIH HHS / United States
P30 CA072720 / CA / NCI NIH HHS / United States
R01CA130893 / CA / NCI NIH HHS / United States
R37 CA53370 / CA / NCI NIH HHS / United States
R01 CA163591 / CA / NCI NIH HHS / United States
R37 CA053370 / CA / NCI NIH HHS / United States
R01 CA130893 / CA / NCI NIH HHS / United States