Astrocyte Elevated Gene-1 Interacts With β-Catenin and Increases Migration and Invasion of Colorectal Carcinoma

To investigate the astrocyte elevated gene-1 (AEG-1) expression and its relationship with the clinicopathological features of colorectal carcinoma (CRC) and -catenin signaling pathway. Real-time PCR, Western blot, immunohistochemistry, and immunofluorescence staining were performed to detect AEG-1 expression in CRC cell lines, 8 pairs of fresh CRC and adjacent nontumor tissues (ANT), 120 pairs of paraffin-embedded CRC specimens and ANT tissues, and 60 samples of lymph node metastatic CRC tissues. Scratch wound assay and transwell matrix penetration assay were performed to determine migration and invasion of SW480 cell lines with stable AEG-1 overexpression or SW620 cell lines with AEG-1 knockdown. AEG-1 expression was upregulated in CRC cell lines and tissues compared with ANT. Furthermore, AEG-1 expression level significantly correlated with UICC stage, and the N classification. AEG-1 overexpression significantly enhanced migration and invasion of SW480 cell lines. However, AEG-1 knockdown suppressed migration and invasion of SW620 cell lines. Meanwhile, there was a positive correlation between AEG-1 high expression and -catenin nuclear expression in CRC. AEG-1 overexpression increased nuclear -catenin accumulation in CRC cell lines. AEG-1 knockdown decreased nuclear -catenin accumulation in CRC cell lines. Moreover, we firstly found that AEG-1 interacted with -catenin in SW480 cell lines. Our results for the first time showed that AEG-1 interacted with -catenin in CRC cells and AEG-1 expression was closely associated with progression of CRC. AEG-1 might be a potential therapeutic target in CRC. (c) 2012 Wiley Periodicals, Inc.