Lenvatinib inhibits cholangiocarcinoma progression by targeting the FGF19/PI3K/AKT signaling pathway

Cholangiocarcinoma (CCA) is known for its high aggressiveness and dismal prognosis, whose effectiveness of systemic therapy remains limited. As a multi-target drug, lenvatinib has exhibited promising effects in many solid tumors. However, the therapeutic role of lenvatinib in CCA is rarely investigated. Here, the in vitro assays including EdU, colony formation, transwell, wound healing, and apoptosis analyses demonstrated that lenvatinib significantly inhibited the proliferation, migration, and invasion, while simultaneously inducing apoptosis of CCA cells. Mechanistically, lenvatinib downregulated the expression of FGF19 and inactivated the PI3K/AKT signaling pathway. Depletion of FGF19 enhanced the anti-tumor effects of lenvatinib, which was attributed to the inhibition of p-PI3K and p-AKT expression in CCA cells. In contrast, overexpression of FGF19 activated the PI3K/AKT signaling pathway, thereby impairing the inhibitory effects of lenvatinib against CCA. In addition, the AKT inhibitor, MK-2206, reinforced the lenvatinib-induced CCA inhibition. Notably, the in vivo experiment confirmed that the subcutaneous tumorigenicity of CCA cells in nude mice was weakened by lenvatinib. Lenvatinib markedly downregulated the expression of FGF19, p-AKT, Ki-67, vimentin, and VEGF in the xenograft tumor tissues. Collectively, these findings demonstrated that lenvatinib inhibits CCA progression by targeting the FGF19/PI3K/AKT signaling pathway. The present study provides novel experimental evidence for the potential clinical application of lenvatinib in CCA, which also highlights the promising role of targeting FGF19 in combined therapeutic approaches for CCA.