Expression of the eukaryotic translation initiation factor 4E (eIF4E) and 4E-BP1 in esophageal cancer.
OBJECTIVE
The eukaryotic initiation factor 4E (eIF4E) has been shown to play a key role in cell growth, and several studies have documented an increased expression of eIF4E in a number of solid tumors, including breast, bladder, cervical and head and neck cancers. The aim of this study was to determine the level of expression of eIF4E and eIF4E-binding protein 1 (4E-BP1) in esophageal cancer.


METHODS
Tumor and normal adjacent tissue samples (as controls) were obtained from 99 patients with esophageal cancer. eIF4E and 4E-BP1 levels were determined by using Western blot analysis. eIF4E was purified by affinity chromatography using m(7)GTP-sepharose, and the levels of 4E-BP1 bound to eIF4E were determined.


RESULTS
: In cancerous esophageal tissues, eIF4E level was elevated by a mean of 12.59 +/- 1.66-fold, and 4E-BP1 was elevated by a mean of 15.76 +/- 2.45-fold when compared to normal adjacent tissues. Both eIF4E and 4E-BP1 expressions were higher in cancerous compared to noncancerous esophageal tissues.


CONCLUSIONS
A higher expression of eIF4E was correlated with advanced stages. The inverse relationship found between the increases in 4E-BP1 levels observed in esophagus tumors and lymph node involvement would support the hypothesis that the overexpression of eIF4E can be involved in tumorigenesis and a possible role of 4E-BP1 as a prognostic factor in esophageal cancer.
Salehi
Zivar
Z
Department of Biology, Faculty of Sciences, The University of Guilan, Rasht, Iran. geneticzs@yahoo.co.uk
Mashayekhi
Farhad
F
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D015153:Blotting, Western; D018797:Cell Cycle Proteins; D004938:Esophageal Neoplasms / Q000378:metabolism*; D039561:Eukaryotic Initiation Factor-4E / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation
D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; C087000:EIF4EBP1 protein, human; D039561:Eukaryotic Initiation Factor-4E; D010750:Phosphoproteins