Article

Overexpression of astrocyte elevated gene-1 (AEG-1) is associated with esophageal squamous cell carcinoma (ESCC) progression and pathogenesis.

State Key Laboratory of Oncology in Southern China, Department of Experimental Research, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong 510060, People's Republic of China.
Carcinogenesis (impact factor: 5.7). 04/2009; 30(5):894-901. DOI:10.1093/carcin/bgp064
Source: PubMed

ABSTRACT Astrocyte elevated gene-1 (AEG-1), upregulated in various types of human cancers, has been reported to be associated with the carcinogenesis of human cancer. However, the functional significance of AEG-1 in human esophageal squamous cell carcinoma (ESCC) remains unknown. In the present study, we showed the expression of AEG-1 was markedly upregulated in esophageal cancer cell lines and surgical ESCC specimens at both transcriptional and translational levels. Immunohistochemical analysis revealed that 80 of 168 (47.6%) paraffin-embedded archival ESCC specimens exhibited high levels of AEG-1 expression. Statistical analysis suggested the upregulation of AEG-1 was significantly correlated with the clinical staging of the ESCC patients (P = 0.001), T classification (P = 0.002), N classification (P = 0.034), M classification (P = 0.021) and histological differentiation (P = 0.035) and those patients with high AEG-1 levels exhibited shorter survival time (P < 0.001). Multivariate analysis indicated that AEG-1 expression might be an independent prognostic indicator of the survival of patients with ESCC. Furthermore, we found that ectopic expression of AEG-1 in ESCC cells could significantly enhance cell proliferation and anchorage-independent growth ability. Conversely, silencing AEG-1 by short hairpin RNAi caused an inhibition of cell growth and anchorage-independent growth ability on soft agar. Moreover, we demonstrated that the upregulation of AEG-1 could reduce the expression of p27(Kip1) and induce the expression of cyclin D1 through the AKT/FOXO3a pathway. Our findings suggest that the AEG-1 protein is a valuable marker of ESCC progression and that the upregulation of AEG-1 plays an important role in the development and pathogenesis of human ESCC.

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Keywords

AEG-1 protein
 
anchorage-independent growth ability
 
cell proliferation
 
ectopic expression
 
ESCC cells
 
ESCC patients
 
esophageal cancer cell lines
 
histological differentiation
 
human cancer
 
human cancers
 
human ESCC
 
human esophageal squamous cell carcinoma
 
Immunohistochemical analysis
 
independent prognostic indicator
 
M classification
 
short hairpin RNAi
 
Statistical analysis
 
surgical ESCC specimens
 
translational levels
 
various types
 

Chunping Yu