Antiproliferative Effect of Lenvatinib on Human Liver Cancer Cell Lines In Vitro and In Vivo

Background/Aim: Lenvatinib is a potent inhibitor of receptor tyrosine kinases, targeting vascular endothelial growth factor receptors (VEGFR1-3), fibroblast growth factor receptors (FGFR1-4), KIT, and RET. Here, we investigated the antiproliferative effects of lenvatinib in liver cancer cells in vitro and in vivo. Materials and Methods: Eleven hepatocellular carcinoma cell lines and two combined hepatocellular/cholangiocarcinoma cell lines were treated with 0-30 mu M lenvatinib. Cell growth, apoptosis and the expression of FGFR1-4, FGF19, fibroblast growth factor receptor substrate (FRS)2 alpha and RET were examined. Two HCC cell lines were subcutaneously implanted on nude mice and mice were treated with 3, 10, 30 mg/kg/day of lenvatinib or vehicle for 14 consecutive days. Tumor volume was measured every 3 days. Mice were sacrificed on day 15 and tumors were processed for histological examination. Blood vessels, microvessel density, necrosis, and apoptosis were also examined. Results: Lenvatinib dose- and time-dependently inhibited growth of all cell lines; however, sensitivity to lenvatinib varied. Apoptosis was not observed in any cell line, and expression of FGFR1, -2, -3 and -4, FGF19, FRS2 alpha, and RET were observed in these cell lines. Cell lines with high expression of these factors showed higher response to lenvatinib. In mice, lenvatinib dose-dependently suppressed tumor growth. Blood vessels and microvessel density were significantly reduced and the rate of necrosis was significantly increased by lenvatinib; apoptosis was not observed. Conclusion: Antiproliferative effects of lenvatinib on liver cancer cells were observed in vitro and in vivo. Lenvatinib may suppress tumor formation by inhibiting angiogenesis, and via an additional direct antiproliferative effect in some liver cancer cells.