AKT modulates PTEN expression in hepatocarcinoma HepG2 cells via C-MYC pathway
10.3781/j.issn.1000-7431.2020.11.667
- Author:
Chunhua GUO
1
Author Information
1. Department of Oncology, The Seventy Third Army Group Hospital
- Publication Type:Journal Article
- Keywords:
AKT signaling pathway;
Experimental;
Liver neoplasms;
Proto-oncogene proteins c-myc;
PTEN
- From:
Tumor
2020;40(2):102-112
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate whether C-myc is involved in the modulation of protein kinase B (PKB, also known as AKT) on the expression of phosphate and tension homology deleted on chromsome ten (PTEN) in hepatoma HepG2 cells. Methods: HepG2 cells were treated with different concentrations of AKT inhibitor Capivasertib (5, 10 and 20 nmol/L). The expression levels of AKT, phosphorylated (p)-AKT, Bad, p-Bad, C-myc and p-C-myc proteins were detected by Western blotting. The transcription levels of C-myc downstream genes eukaryotic initiation factor-4E (eIF-4E), branched‐chain amino acid aminotransferase 1 (BCAT1) and WW domain-containing E3 ubiquitin protein ligase 1 (WWP1) were detected by real-time fluorescent quantitative PCR. The expressions of eIF-4E, BCAT1 and WWP1 genes were silenced by siRNA, then the transcription and expression of PTEN were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. The effects of Capivasertib treatment or WWP1 gene silence on the expression and localization of PTEN protein in HepG2 cells were detected by cell immunofluorescence technique. Results: In HepG2 cells treated with different concentrations of Capivasertib for 8 h, the expression levels of p-AKT, p-C-myc and p-Bad were significantly downregulated as compared with the control group (all P < 0.01), and the expression levels of eIF-4E, BCAT1 and WWP1 mRNAs were also downregulated (all P < 0.01). Silencing eIF-4E, BCAT1 and WWP1 gene expressions had no significant effect on the transcription of PTEN (all P 0.01) but the silence of WWP1 gene could significantly enhance the expression of PTEN protein (P < 0.01). Both Capivasertib treatment and WWP1 gene silence could increase the expression level of PTEN and induce its aggregation on the cell membrane. Conclusion: AKT is able to affect the transcription of WWP 1 gene by C-myc pathwaty, and ultimately participates in the modulation of PTEN expression in HepG2 cells.
