Neurokinin‐1 receptor antagonist aprepitant regulates autophagy and apoptosis via ROS/JNK in intrahepatic cholangiocarcinoma

Abstract Background Intrahepatic cholangiocarcinoma (iCCA) has a poor prognosis and limited treatment options. Aprepitant, a selective NK‐1R antagonist, can inhibit the growth of various tumours in vitro and in vivo. However, it remains unclear whether aprepitant has cytotoxic effects on iCCA. Methods We measured the expression of SP/NK‐1R in clinical samples of iCCA by immunohistochemistry. Then, we detected the cytotoxic effects of aprepitant on iCCA cells via MTT, EdU and colony formation assay. We constructed a subcutaneous xenograft model of BALB/c nude mice by using HCCC‐9810 and RBE cell lines to explore the effects of aprepitant in vivo. To elucidate the potential mechanisms, we explored the pro‐apoptotic effect of aprepitant by flow cytometric, western blotting, ROS detection and JC‐1 staining. Furthermore, we detected the autophagic level of HCCC‐9810 and RBE by western blotting, mRFP‐eGFP‐LC3 adenovirus transfection and electron microscope. Results SP/NK‐1R is significantly expressed in iCCA. Aprepitant inhibited human iCCA xenograft growth and dose‐dependently decreased the viability of RBE and HCCC‐9810 cells. Aprepitant‐induced mitochondria‐dependent apoptosis through ROS/JNK pathway. Additionally, pretreatment with z‐VAD‐fmk partly reversed the effect of aprepitant on cell viability, while NAC completely attenuated the cytotoxic effects of aprepitant in vitro. Furthermore, we observed the dynamic changes of autophagosome in RBE and HCCC‐9810 cells treated with aprepitant. Conclusion SP/NK‐1R signalling is significantly activated in iCCA and promotes the proliferation of iCCA cells. By contrast, aprepitant can induce autophagy and apoptosis in iCCA cells via ROS accumulation and subsequent activation of JNK.