The Antihistamine Astemizole Potentiates the Antitumor Efficacy of Sorafenib in Hepatocellular Carcinoma by Suppressing Proliferation, Metastasis, and Angiogenesis.

Hepatocellular carcinoma (HCC) is a highly aggressive malignancy with a poor prognosis. While sorafenib serves as the first-line therapy for advanced HCC, its efficacy is frequently hampered by side effects and the development of drug resistance, necessitating the development of novel agents to enhance HCC sensitivity to sorafenib. In this study, we demonstrate that the antihistamine astemizole significantly enhanced the antitumor efficacy of sorafenib in HCC cell lines. This combination treatment cooperatively inhibited HCC cells' proliferation and induced cell cycle arrest at the G1 phase, as evidenced by decreased cyclin D1 and p-Rb levels and increased p27 expression. Furthermore, the combination of astemizole and sorafenib synergistically inhibited HCC cells' migration, invasion, and adhesion. It also reduced F-actin polymerization and the expression of metastasis-regulating proteins, including p-Integrinβ1, FAK, and MMP1. Additionally, the combination treatment suppressed tube formation in HUVECs, accompanied by downregulation of HIF-1α and reduced VEGF secretion. Co-inhibition of Eag1 and the ERK/MAPK signaling pathway may underlie the enhanced anti-HCC effects of sorafenib by astemizole. Collectively, these findings indicate that astemizole significantly enhanced the antitumor activity of sorafenib by inhibiting proliferation, metastasis, and angiogenesis in HCC cells, suggesting its potential as a promising adjuvant to improve sorafenib-based therapy in HCC.