† These authors contributed equally.
Academic Editor: Graham Pawelec
Aims: Intrahepatic cholangiocarcinoma (ICC) is a highly malignant and heterogeneous cancer with a poor prognosis. At present, there is no optimal treatment except for surgical resection, and recurrence after resection will lead to death due to multidrug resistance. Changes in the redox signal have been found to be closely related to the growth and drug resistance of tumor cells. Therefore, the purpose of this study was to screen small molecule compounds from the redox library to find a drug for anti-ICC and to explore its downstream mechanism. Material and methods: Tumor clone and sphere formation of ICC cell lines, as well as mouse ICC organoid proliferation assays were utilized to screen the candidate drug in the Redox library. Western blotting, quantitative reverse-transcription polymerase chain reaction (qRT-PCR), as well as cell apoptosis and cell cycle flow cytometry assays were used to explore the mechanism. Results: We found that Hinokitiol was a candidate drug through inhibition of tumor clone and sphere formation, and the expression of cancer stem cell (CSC)-related genes. Furthermore, Hinokitiol significantly inhibited the proliferation of ICC cells by downregulating the ERK and P38 pathways. In addition, the combination of Hinokitiol and Palbociclib showed a significant inhibitory effect on human ICC cells and mouse ICC organoids. Conclusion: Hinokitiol may have the potential to be developed as a clinical therapeutic drug for ICC treatment.