Effects of down-regulation of AEG-1 expression on cell cycle and invasion of human cervical carcinoma cells

AIM: To investigate the effects of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell cycle and invasion of human cervical carcinoma SiHa cells.METHODS: The protein expression of AEG-1 was detected by Western blotting in normal cervical tissues, cervical squamous cell carcinoma tissues, HeLa cells, SiHa cells and CaSki cells. Control siRNA or AEG-1 siRNA was transfected into SiHa cells, and the protein expression of AEG-1 in SiHa cells was detected by Western blotting. The changes of cell cycle distribution and cell invasion were determined by flow cytometry and Boyden chamber, respectively. The protein levels of cyclin D1, cyclin-dependent kinase 2(CDK2) and matrix metalloproteinase-9 (MMP-9) were analyzed by Western blotting.RESULTS: The protein expression of AEG-1 in cervical squamous cell carcinoma tissues was significantly higher than that in normal cervical tissues (P<0.05). Meanwhile, the protein expression of AEG-1 in the 3 cervical carcinoma cell lines was obviously higher than that in normal cervical tissues, in which SiHa cells displayed the highest AEG-1 protein level (P<0.05). In addition, AEG-1 siRNA effectively down-regulated the protein expression of AEG-1 in SiHa cells, which led to increase the percentage at G0/G1 phase and reduced the invasion of SiHa cells. Furthermore, the protein levels of cyclin D1, CDK2 and MMP-9 in AEG-1 siRNA group were markedly lower than those in non-treatment group and control siRNA group (P<0.05).CONCLUSION: Over-expression of AEG-1 may be closely associated with the occurrence and development of cervical carcinoma, and the AEG-1 down-regulation-mediated cell cycle arrest and attenuation of invasion may be tightly related to the down-regulations of cyclin D1, CDK2 and MMP-9 at protein levels.