Metformin Counteracts HCC Progression and Metastasis Enhancing KLF6/p21 Expression and Downregulating the IGF Axis

Abstract

Background and Aims Hepatocellular carcinoma (HCC) is the common tumor of the liver. Unfortunately, most HCC seem to be resistant to conventional chemotherapy and radiotherapy. The poor efficacy of antitumor agents is also due, at least in part, to the inefficient drug delivery and metabolism exerted by the steatotic/cirrhotic liver that hosts the tumor. Thus, novel approaches in chemotherapy may be needed to improve the survival rate in patients with HCC. Metformin (METF) has been found to lower HCC risk; however, the mechanisms by which METF performs its anticancer activity are not completely elucidated. Previous studies have showed METF action on growth inhibition in the liver in a dose/time-dependent manner and its antitumor role by targeting multiple pathways. We investigated molecular effects of METF in an in vitro human hepatoma model (HepG2), studying cell cycle regulators, tumorigenesis markers, and insulin-like growth factor (IGF) axis regulation. Materials and Methods HepG2 cells were treated with METF (400 μM) for 24, 48, and 72 hours. METF action on cell cycle progression and cellular pathways involved in metabolism regulation was evaluated by gene expression analysis, immunofluorescence, and Western blot assay. Results By assessing HepG2 cell viability, METF significantly decreased growth cell capacity raising KLF6/p21 protein content. Moreover, METF ameliorated the cancer microenvironment reducing cellular lipid drop accumulation and promoting AMPK activity. The overexpression of IGF-II molecule and the IGF-I receptor that plays a main role in HCC progression was counteracted by METF. Furthermore, the protein content of HCC principal tumor markers, CK19 and OPN, linked to the metastasis process was significantly reduced by METF stimulus. Conclusion Our data show that METF could suppress HepG2 proliferation, through induction of cell cycle arrest at the G0/G1 phase. In addition, METF effect on the cancer microenvironment and on the IGF axis leads to the development of new METF therapeutic use in HCC treatment.

RETRACTED: Combination of aloin and metformin enhances the antitumor effect by inhibiting the growth and invasion and inducing apoptosis and autophagy in hepatocellular carcinoma through PI3K/AKT/mTOR pathway

“…HepG2 cells were treated with PBS (phosphate buffer saline) (control), aloin (50 μmol/L), MET (400 μmol/L), and aloin (50 μmol/L)+ MET (400 μmol/L). The cells in all groups were harvested after 48 hour of treatment to measure the expression of corresponding cellular markers.…”

Metformin and Everolimus: A Promising Combination for Neuroendocrine Tumors Treatment

“…These results confirm that combinatory treatment may actually display greater efficacy than the single monotherapies in both pancreatic and pulmonary NET models and support a potential clinical application of the metformin and everolimus combination. In particular, given the indolent behavior that characterizes most well-differentiated neuroendocrine tumors, chronic treatment with everolimus in combination with metformin at therapeutic doses is likely to provide benefits in terms of tumor growth, without significant additional toxic effects, as metformin is generally well-tolerated [28].…”

l-Carnitine counteracts in vitro fructose-induced hepatic steatosis through targeting oxidative stress markers

“…HepG2 cells were grown in 100 mm culture dishes with or without LC combined or not with F. Cellular extracts were obtained lysing the cells in RIPA buffer as previously described [24]. Thirty micrograms of proteins were separated by SDS-polyacrylamide gel electrophoreses (SDS-PAGE) and electrophoretically transferred to nitrocellulose membranes (Potran ® , Whatman ® Schleicher & Schuell).…”