Vinca alkaloid drugs promote stress-induced translational repression and stress granule formation.

Oncotarget
Authors
Abstract

Resistance to chemotherapy drugs is a serious therapeutic problem and its underlying molecular mechanisms are complex. Stress granules (SGs), cytoplasmic ribonucleoprotein complexes assembled in cells exposed to stress, are implicated in various aspects of cancer cell metabolism and survival. SGs promote the survival of stressed cells by reprogramming gene expression and inhibiting pro-apoptotic signaling cascades. We show that the vinca alkaloid (VA) class of anti-neoplastic agents potently activates a SG-mediated stress response program. VAs inhibit translation initiation by simultaneous activation of eIF4E-BP1 and phosphorylation of eIF2α, causing polysome disassembly and SG assembly. VA-induced SGs contain canonical SG components but lack specific signaling molecules. Blocking VA-induced SG assembly by inactivating eIF4EBP1 or inhibiting eIF2α phosphorylation decreases cancer cell viability and promotes apoptosis. Our data describe previously unappreciated effects of VAs on cellular RNA metabolism and illuminate the roles of SGs in cancer cell survival.

Year of Publication
2016
Journal
Oncotarget
Volume
7
Issue
21
Pages
30307-22
Date Published
2016 May 24
ISSN
1949-2553
URL
DOI
10.18632/oncotarget.8728
PubMed ID
27083003
PubMed Central ID
PMC5058682
Links
Grant list
R01 CA168872 / CA / NCI NIH HHS / United States
R01 GM111700 / GM / NIGMS NIH HHS / United States
R21 NS094918 / NS / NINDS NIH HHS / United States