A preclinical study on the combination therapy of everolimus and transarterial chemoembolization in hepatocellular carcinoma

Transarterial chemoembolization (TACE) is commonly used for the treatment of locally advanced hepatocellular carcinoma (HCC) by its dual effects of chemotherapy and ischemic hypoxia. However, one of the side effects of TACE is the introduction of hypoxic condition, which in turn activates hypoxia-induced survival pathways and enhances VEGF-induced neovascularization by stabilizing HIF-1a expression. Herein, the preclinical therapeutic efficacy of the combined treatment of everolimus, a novel mTOR inhibitor and TACE for the treatment of HCC was investigated. The MHCC-97L cells were used for the study of the effect of combined treatment on cell proliferation and cellular apoptosis. HUVEC cells were used for the study on tube formation under different treatments. Inhibitions on the Akt/mTOR pathways were also studied. Finally, the effect on tumor growth was further study using an in vivo orthotopic model. The results demonstrated that everolimus enhanced the therapeutic efficacy of TACE in inhibiting cell proliferation, promoting apoptosis and inhibiting tube formation of endothelial cells by blocking the Akt/mTOR signaling pathway in vitro and inhibiting tumor growth and neoangiogenesis in vivo. Based on this preclinical study, the potential of combining everolimus with TACE was guaranteed which suggested the use of the combination therapy in the clinical treatment of advanced HCC patients.