Antitumor Effect of Esculetin on Sorafenib-Treated Human Hepatocellular Carcinoma Cell Lines Via Suppression of VEGF- EGFR/RAS/ERK/NF-B Pathway and Modulation of pI3K/ P38 Axis Crosstalk

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Sorafenib is a multi-tyrosine kinase inhibitor used to treat HCC. However, it has many side effects and induces resistance. Esculetin is a natural compound with reported anticancer activity. This study was designed to assess the chemotherapeutic effects of the sorafenib and esculetin combination on human HCC cells. Stock solutions from sorafenib and esculetin in Dimethyl sulfoxide (DMSO) were prepared and then diluted by Dulbecco's Modified Eagle Medium (DMEM) to obtain the required working concentrations. HepG2 and Huh-7 cells have been selected as in vitro model of HCC. Cytotoxicity was evaluated using an MTT assay. Flow cytometry analysis and scratch assay were performed to assess apoptosis and migration. Finally, vascular endothelial growth factor (VEGF), VEGFR-2, EGFR, NF-kappa B, and Ki-67, PI3K, p38MAPK levels were quantified through ELISA, while HRAS and ERK2 gene expression were detected through RT-PCR. The sorafenib and esculetin combination exerted a potent synergistic anti-tumor effect by modulating the EGFR and VEGF-RAS/ERK/PI3K/NF-kappa B axes associated with significant upregulation of the apoptotic p38MAPK/caspase-3 axis, modulation of pI3k/p38MAPK crosstalk and inhibition of the proliferation marker Ki67. This study paves the way for using esculetin as good adjuvant to sorafenib as a promising future treatment for hepatocellular carcinoma.