The tumor suppressive role of eIF3f and its function in translation inhibition and rRNA degradation.

Bibliographic Details
Title: The tumor suppressive role of eIF3f and its function in translation inhibition and rRNA degradation.
Authors: Fushi Wen, Renyuan Zhou, Alex Shen, Andrew Choi, Diana Uribe, Jiaqi Shi
Source: PLoS ONE, Vol 7, Iss 3, p e34194 (2012)
Publisher Information: Public Library of Science (PLoS), 2012.
Publication Year: 2012
Collection: LCC:Medicine
LCC:Science
Subject Terms: Medicine, Science
More Details: Deregulated translation plays an important role in human cancer. We previously reported decreased eukaryotic initiation factor 3 subunit f (eIF3f) expression in pancreatic cancer. Whether decreased eIF3f expression can transform normal epithelial cells is not known. In our current study, we found evidence that stable knockdown of eIF3f in normal human pancreatic ductal epithelial cells increased cell size, nuclear pleomorphism, cytokinesis defects, cell proliferation, clonogenicity, apoptotic resistance, migration, and formation of 3-dimensional irregular masses. Our findings support the tumor suppressive role of eIF3f in pancreatic cancer. Mechanistically, we found that eIF3f inhibited both cap-dependent and cap-independent translation. An increase in the ribosomal RNA (rRNA) level was suggested to promote the generation of cancer. The regulatory mechanism of rRNA degradation in mammals is not well understood. We demonstrated here that eIF3f promotes rRNA degradation through direct interaction with heterogeneous nuclear ribonucleoprotein (hnRNP) K. We showed that hnRNP K is required for maintaining rRNA stability: under stress conditions, eIF3f dissociates hnRNP K from rRNA, thereby preventing it from protecting rRNA from degradation. We also demonstrated that rRNA degradation occurred in non-P body, non-stress granule cytoplasmic foci that contain eIF3f. Our findings established a new mechanism of rRNA decay regulation mediated by hnRNP K/eIF3f and suggest that the tumor suppressive function of eIF3f may link to impaired rRNA degradation and translation.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1932-6203
Relation: http://europepmc.org/articles/PMC3311619?pdf=render; https://doaj.org/toc/1932-6203
DOI: 10.1371/journal.pone.0034194
Access URL: https://doaj.org/article/17884a0f7e414dff9f1ac08d2054bf4e
Accession Number: edsdoj.17884a0f7e414dff9f1ac08d2054bf4e
Database: Directory of Open Access Journals
More Details
ISSN:19326203
DOI:10.1371/journal.pone.0034194
Published in:PLoS ONE
Language:English