Objective: To assess the protein expression of astrocyte elevated gene-1 (AEG-1) in tissue specimens of laryngeal squamous cell carcinoma (LSCC), and to correlate its expression with clinicopathological parameters and prognosis in patients with LSCC.
Methods: RT-PCR was used to assay the expression of AEG-1 mRNA in 13 pairs of LSCC tissues and their corresponding noncarcinoma epithelia. Immunohistochemistry was performed on paraffin-embedded tissue specimens to investigate the protein expression of AEG-1 in 88 cases of LSCC specimens and 15 cases of adjacent epithelial samples.
Results: The expression of AEG-1 mRNA was significantly increased in LSCC tissues compared to adjacent noncarcinoma epithelial tissues (0.81 ± 0.17 vs. 0.23 ± 0.10;t = 10.337, P < 0.001). Meantime, the positive rate of AEG-1 protein in 88 cases of LSCC was 87.5% (77/88). However, 15 cases of adjacent noncarcinoma epithelial merely demonstrated negative or mild expression of AEG-1 protein. AEG-1 overexpression was closely correlated with T stage (χ(2) = 6.289, P = 0.018), clinical stage (χ(2) = 11.049, P < 0.01), metastasis (χ(2) = 20.859, P < 0.01) and recurrence(χ(2) = 13.459, P < 0.01). The overall survival rates of patients with AEG-1 overexpression and low expression were 35.9% and 86.4%, respectively (χ(2) = 23.409, P < 0.01). Multivariate Cox regression analysis revealed that AEG-1 expression was an independent prognostic factor (P = 0.016).
Conclusion: AEG-1 protein may play a critical role in the initiation and progression of LSCC, implicating its predictive value in prognosis.