Celecoxib blocks AKT/mTOR in AKT/YapS127A-driven intrahepatic cholangiocarcinoma, activating p21/p27 for cycle arrest and suppressing Mcl-1 for apoptosis

Intrahepatic cholangiocarcinoma (iCCA) is a malignant liver tumor with insidious onset, limited treatments, and poor prognosis. Recent studies have shown that celecoxib exerts marked cytotoxic effects on cholangiocarcinoma cell lines, suggesting its potential as an iCCA therapy. However, the potential molecular and cellular mechanisms that link celecoxib treatment to its toxicological outcomes remain unclear. In this study, we induced iCCA in mice by overexpressing AKT and YapS127A (hereafter referred to as AKT/YapS127A) and administered celecoxib continuously to evaluate its antitumor effects in vivo. The results demonstrated that celecoxib effectively inhibited tumor growth in AKT/YapS127A-driven iCCA mice. Mechanistically, celecoxib boosted levels of cell cycle inhibitors p21^Waf1/Cip1 and p27^Kip1, leading to cell cycle arrest. It also promoted apoptosis by downregulating the expression of anti-apoptotic proteins Mcl-1 and Bcl-2. These effects were associated with the modulation of the AKT/mTORC1 signaling pathway. Consistently, celecoxib recapitulated AKT/mTORC1 inhibition and subsequent cell cycle/apoptotic regulator alterations in iCCA cell lines. Collectively, our study elucidated the molecular mechanisms through which celecoxib exerted its anti-tumor effects in iCCA, demonstrating its capacity to induce cytotoxic outcomes via the precise regulation of the AKT/mTORC1 pathway. These findings deepen understanding of the toxicological actions of celecoxib and provide critical insights for developing targeted iCCA therapies.