Targeting AMPK, mTOR and β-Catenin by Combined Metformin and Aspirin Therapy in HCC: An Appraisal in Egyptian HCC Patients.

BACKGROUND: Hepatocellular carcinoma (HCC) is an expanding health problem with a great impact on morbidity and mortality, both in Egypt and worldwide. Recently, metformin and aspirin showed a potential anticancer effect on HCC, although the mechanism of this effect is not fully elucidated.

OBJECTIVE: The current work aimed to investigate the possibility of targeting AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and β-catenin proteins through combined metformin/aspirin treatment in the HepG2 cell line, and to explore such molecular targets in Egyptian HCC patients.

MATERIALS AND METHODS: HepG2 cells were exposed to increasing concentrations of metformin, aspirin and combined treatment, and an MTT assay was performed to determine half maximal inhibitory concentration (IC50 ). Caspase-3 activity, cell cycle analysis, and protein expression of AMPK, phosphorylated AMPK (pAMPK) and mTOR proteins were assessed. Furthermore, the expression and localization of β-catenin protein was assessed by immunocytochemistry, and protein expression of pAMPK, mTOR and β-catenin was assessed in Egyptian HCC and cirrhotic tissue specimens.

RESULTS: Metformin/aspirin combined treatment had a synergistic effect on cell cycle arrest at the G2/M phase and apoptosis induction in a caspase-dependent manner via downregulation of pAMPK and mTOR protein expression. Additionally, metformin/aspirin combined treatment enhanced cell-cell membrane localization of β-catenin expression in HepG2 cells, which might inhibit the metastatic potential of HepG2 cells. In Egyptian HCC specimens, pAMPK, mTOR and β-catenin proteins showed a significant increased expression compared with cirrhotic controls.

CONCLUSIONS: Targeting AMPK, mTOR and β-catenin by combined metformin/aspirin treatment could be a promising therapeutic strategy for Egyptian HCC patients, and possibly other HCC patients.