AEG-1表达下调对人宫颈癌细胞细胞周期和侵袭能力的影响及其机制

 目的：研究星形细胞上调基因1（astrocyte elevated gene-1，AEG-1）在人宫颈鳞癌细胞和组织中的表达，探讨AEG-1表达下调对宫颈癌SiHa细胞细胞周期和侵袭能力的影响，并分析其可能的分子机制。方法：采用Western blotting检测正常宫颈组织、宫颈鳞癌组织、HeLa、SiHa和CaSki细胞中AEG-1蛋白的表达。将对照siRNA和AEG-1 siRNA分别转染SiHa细胞，利用Western blotting检测SiHa细胞中AEG-1蛋白的表达，采用流式细胞术检测细胞周期分布的变化，采用Boyden小室检测细胞侵袭能力的变化，最后采用Western blotting检测cyclin D1、细胞周期素依赖性激酶 2（CDK2）和基质金属蛋白酶9(MMP-9)蛋白表达的变化。结果：宫颈鳞癌组织中AEG-1蛋白表达显著高于正常宫颈组织（P<0.05），同时3株宫颈癌细胞中AEG-1蛋白表达均显著高于正常宫颈组织，其中SiHa细胞中AEG-1蛋白表达最高（P<0.05）。此外，AEG-1 siRNA能显著下调SiHa细胞中AEG-1蛋白的表达（P<0.05），其表达下调能明显促使SiHa细胞在G0/G1期的比例增加和降低其侵袭能力。Western blotting结果表明，AEG-1 siRNA组中cyclin D1、CDK2和MMP-9蛋白的表达均显著低于未处理组和对照siRNA组（P<0.05）。结论：AEG-1在宫颈癌中的高表达可能与宫颈癌的发生发展密切相关，其表达下调介导的细胞周期静止和侵袭能力降低可能与cyclin D1、CDK2和MMP-9蛋白表达下调密切相关。

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.