Type

Journal Article

Authors

Martin Clynes
Simon J Morley
Brendan Power
Paula Meleady
Derek Walsh

Subjects

Biochemistry

Topics
keratins genetics lung neoplasms keratin 8 metabolism krt8 protein human epithelium eukaryotic initiation factor 4e biosynthesis cell differentiation bromodeoxyuridine humans physiology

Increased levels of the translation initiation factor eIF4E in differentiating epithelial lung tumor cell lines. (2003)

Abstract Rates of eukaryotic protein synthesis and proliferation are dependent upon the availability of eIF4F, the cap-binding translation initiation complex that guides the ribosome onto the mRNA. One possible rate-limiting factor in eIF4F complex formation is the availability of eIF4E, which interacts specifically with the mRNA cap structure. As such, it has a potential role in the selective translation of growth-related mRNAs, with overexpression of eIF4E resulting in aberrant cell growth and transformation. A number of studies suggest that eIF4E may play a role in cellular differentiation as well as proliferation. We have previously reported that post-transcriptional regulation is involved in the induction of keratins in epithelial lung tumor cell lines exposed to the differentiation-modulating agent, bromo-deoxyuridine (BrdU). Here, we demonstrate that these BrdU-treated lung cells express elevated levels of eIF4E protein and enhanced phosphorylation of eIF4E. Overexpression of eIF4E by cDNA transfection in the poorly differentiated, keratin-negative human lung cell line, DLKP, was found to promote a flattened, more epithelial appearance to these cells, coupled with the induction of simple keratins (keratins 8 and 18). In contrast, levels of eIF4E expression were found to decrease during BrdU-induced differentiation of the leukemic cell line, HL-60, suggesting that there are cell-type differences in the response to BrdU and in the requirement for eIF4E during differentiation.
Collections Ireland -> Dublin City University -> PubMed

Full list of authors on original publication

Martin Clynes, Simon J Morley, Brendan Power, Paula Meleady, Derek Walsh

Experts in our system

1
Martin Clynes
Dublin City University
Total Publications: 209
 
2
Paula Meleady
Dublin City University
Total Publications: 95