Over-expression of eukaryotic translation initiation factor 4 gamma 1 correlates with tumor progression and poor prognosis in nasopharyngeal carcinoma.
BACKGROUND
The aim of the present study was to analyze the expression of eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathologic features, including patients' survival time.


METHODS
Using real-time PCR, we detected the expression of EIF4G1 in normal nasopharyngeal tissues, immortalized nasopharyngeal epithelial cell lines NP69, NPC tissues and cell lines. EIF4G1 protein expression in NPC tissues was examined using immunohistochemistry. Survival analysis was performed using Kaplan-Meier method. The effect of EIF4G1 on cell invasion and tumorigenesis were investigated.


RESULTS
The expression levels of EIF4G1 mRNA were significantly greater in NPC tissues and cell lines than those in the normal nasopharyngeal tissues and NP69 cells (P < 0.001). Immunohistochemical analysis revealed that the expression of EIF4G1 protein was higher in NPC tissues than that in the nasopharyngeal tissues (P < 0.001). In addition, the levels of EIF4G1 protein in tumors were positively correlated with tumor T classification (P = 0.039), lymph node involvement (N classification, P = 0.008), and the clinical stages (P = 0.003) of NPC patients. Patients with higher EIF4G1 expression had shorter overall survival time (P = 0.019). Multivariate analysis showed that EIF4G1 expression was an independent prognostic indicator for the overall survival of NPC patients. Using shRNA to knock down the expression of EIF4G1 not only markedly inhibited cell cycle progression, proliferation, migration, invasion, and colony formation, but also dramatically suppressed in vivo xenograft tumor growth.


CONCLUSIONS
Our data suggest that EIF4G1 can serve as a biomarker for the prognosis of NPC patients.
Tu
Luxia
L
Cancer Research Institute, Key Lab for Transcriptomics and Proteomics of Human Fatal Diseases, Ministry of Education and Guangdong Province, Southern Medical University, Guangdong Province, PR China.
Liu
Zhen
Z
He
Xiufang
X
He
Ying
Y
Yang
Huiling
H
Jiang
Qingping
Q
Xie
Siming
S
Xiao
Guanghui
G
Li
Xin
X
Yao
Kaitai
K
Fang
Weiyi
W
D000328:Adult; D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D049109:Cell Proliferation; D002469:Cell Separation; D018450:Disease Progression; D039603:Eukaryotic Initiation Factor-4G / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000235:genetics; D009367:Neoplasm Staging; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation; D023041:Xenograft Model Antitumor Assays
D014408:Biomarkers, Tumor; C113920:EIF4G1 protein, human; D039603:Eukaryotic Initiation Factor-4G
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