Overexpression of astrocyte-elevated gene-1 is associated with cervical carcinoma progression and angiogenesis

Abstract

Astrocyte-elevated gene-1 (AEG-1) is implicated in the oncogenesis and angiogenesis of various types of human cancers. However, the biological roles of AEG-1 in cervical carcinoma remain to be further elucidated. In the present study, we demonstrated that the expression of AEG-1 was markedly upregulated in the cervical carcinoma cell lines HeLa, CaSki and SiHa, as well as in 8 paired primary cervical carcinoma tissue (CCT) specimens at both the transcriptional and translational levels when compared with normal cervical epithelial cells (NCECs). Furthermore, immunohistochemical (IHC) analysis demonstrated that 180 of 200 (90%) archived CCT specimens exhibited positive staining for AEG-1, and statistical analysis revealed that the upregulation of AEG-1 was significantly correlated with the clinical staging of the patients (P=0.034), including T (P=0.019), N (P=0.038) and M classification (P=0.018) as well as tumor differentiation (P=0.043). Furthermore, loss- and gain-of-function results showed that knockdown of AEG-1 expression by specific shRNA not only inhibited SiHa cell proliferation and invasive ability, but also significantly decreased the expression of the angiogenesis-related genes HIF-1α, Tie2, VEGF and TEM1/CD248. Moreover, an increased vascular formation ability was observed in human umbilical vein endothelial cells (HUVECs) co-cultured with conditioned medium both from SiHa cells and NCECs transfected with ectopic AEG-1. In conclusion, these results suggest that elevated expression of AEG-1 plays an important role in the aggressiveness and angiogenesis of cervical carcinoma and that AEG-1 represents a novel and valuable predictive factor for the prognostic evaluation of cervical carcinoma patients.