Antitumor effects of rhamnazinon sorafenib-treated human hepatocellular carcinoma cell lines via modulation of VEGF signaling and PI3K/NF-κB p38/caspase-3 axes cross talk

Abstract

AimsHepatocellular carcinoma (HCC) is the most common liver malignancy,characterized by dysregulation of multiple oncogenic signaling pathways, including the VEGF/PI3K/NF-κB and p38 MAPK axes.Sorafenib is a multikinase inhibitor that targets Raf kinases and receptor tyrosine kinases,which mediate HCC angiogenesis.Rhamnazin is a VEGFR2 signaling inhibitor, which inhibits the phosphorylation of Vascular endothelial growth factor receptor 2(VEGFR2) and its downstream signaling regulators. This study was designed to assess the antitumor effects of rhamnazin on human HCC cell lines treated with sorafenib, and to investigate the molecular mechanisms mediating this effect. Main methodsHepG2 and HUH-7 HCC cell lines were used.Cell viability was assessed by MTT assay. NF-κB, p38MAPK, VEGF, VEGFR2, PI3K, and Ki67 levels were assessed using ELISA. Caspase-3 activity was measured colorimetrically. VEGFR2 expression was detected by RT-PCR. Key findingsMTT assay revealed that the sorafenib–rhamnazin combination showed significant cytotoxicity compared with sorafenib or rhamnazin alone. The sorafenib–rhamnazin combination also showed significant inhibition of the angiogenicVEGF/VEGFR2/PI3K/NF-κBsignaling axis associated with significant upregulation of the apoptotic p38MAPK/caspase-3 axis and inhibition of Ki67, a proliferation marker in HepG2 and HUH-7 cells. SignificanceRhamnazin potentiates the chemotherapeutic effect of sorafenib via modulation ofthe VEGF/PI3K/NF-κBsignaling axis, downregulation of VEGFR2 expression, and upregulation of the p38MAPK/caspase-3 axis in human HCC cell lines.