Eukaryotic translation elongation factor 1A1 promotes proliferation of hepatocellular carcinoma cells by regulating cyclin D2 expression
10.3781/j.issn.1000-7431.2018.11.226
- Author:
Leifeng CHEN
1
Author Information
1. Department of General Surgery, Second Affiliated Hospital of Nanchang University
- Publication Type:Journal Article
- Keywords:
Carcinoma;
Cell cycle;
Cell proliferation;
Cyclin D2;
Eukaryotic translation elongation factor 1A1;
Gene expression regulation;
Hepatocellular;
Neoplastic
- From:
Tumor
2018;38(10):913-924
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To study the effects of eukaryotic translation elongation factor 1A1 (eEF1A1) on the cell cycle and proliferation of hepatocellular carcinoma (HCC) cells, and to explore the molecular mechanism. Methods: The expression of eEF1A1 protein in 101 HCC tissues and their adjacent tissues were detected by immunohistochemistry, and the correlations between the expression of eEF1A1 protein and the clinicopathologic parameters of HCC patients was further analyzed. The expressions of eEF1A1 mRNA and protein in HCC cells (including Huh7, SMMC7721, MHCC97H and Hep3B) and the normal liver cells HL-7702 were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. The specific shRNA-1/2 targeting eEF1A1 gene (eEF1A1-shRNA-1/2) and the overexpression plasmid pcDNA3.1- eEF1A1 were respectively transfected into Huh7 and SMMC7721 cells, and the alteration of eEF1A1 expression was verified by real-time fluorescent quantitative PCR and Western blotting, respectively. Then the proliferation and cell cycle of HCC cells were detected by EdU and FCM assays, respectively. In addition, the expressions of cyclin D2 and the signal transducer and activator of transcription 1 (STAT1)-related pathway proteins in Huh7 cells transfected with eEF1A1-shRNA-1/2 and in SMMC7721 cells transfected with pcDNA3.1- eEF1A1 were detected by Western blotting. Results: The expression level of eEF1A1 protein in HCC tissues was markedly higher than that in the adjacent tissues (P < 0.001). The expression levels of eEF1A1 mRNA and protein in four HCC cell lines were significantly higher than those in normal live cells (all P < 0.001). The high expression of eEF1A1 was closely related to tumor size and TNM stage in HCC patients (P < 0.01, P < 0.05). After transfection of eEF1A1-shRNA-1/2 into Huh7 cells, the expression levels of eEF1A1 mRNA and protein were significantly decreased (both P < 0.01), the proportion of G1 phase-cells increased significantly (P < 0.01), and the proliferation activity of Huh7 cells was significantly reduced (P < 0.01). After transfection of pcDNA3.1-eEF1A1 into SMMC7721 cells, the expression levels of eEF1A1 mRNA and protein were significantly increased (both P < 0.01), the proportion of G1 phase-cells was significantly reduced (P < 0.05), and the proliferation activity of SMMC7721 cells increased significantly (P < 0.05). In addition, the expression levels of cyclin D2, total and nuclear STAT1 proteins were decreased (all P < 0.05) in Huh7 cells with the downregulation of eEF1A1 expression. After eEF1A1 overexpression, the expression levels of cyclin D2, total and nuclear STAT1 proteins were increased (all P < 0.05) in SMMC7721 cells. However, the expression levels of cyclin D2, total and nuclear STAT1 proteins were unchanged (all P > 0.05) in SMMC7721 cells after eEF1A1 overexpression and treatment with STAT1 inhibitor fludarabine. Conclusion: eEF1A1 regulates the expression of cyclin D2 through STAT1 pathway, thereby promoting the cell cycle progression and proliferation of primary HCC cells.
