Urolithin A targets the AKT/WNK1 axis to induce autophagy and exert anti-tumor effects in cholangiocarcinoma

Abstract

Urolithin A (UA; 3,8-dihydroxybenzo[c]chromen-6-one), a metabolite generated by intestinal bacteria during the biotransformation of ellagitannins, has gained considerable attention in treating several cancers. Cholangiocarcinoma (CCA) remains one of the most lethal cancers; it grows in a special environment constantly exposed to both blood and bile. Since UA is known to undergo enterohepatic recirculation, we hypothesized that UA might have significant antitumor effects in CCA. Here, we investigated the therapeutic potential of UA in CCA and aimed to elucidate its mechanisms, including autophagy. UA treatment inhibited cell proliferation and induced G2/M phase cell cycle arrest in CCA cells. UA also suppressed cell migration and invasion, but did not cause apoptosis. Furthermore, Western blotting and immunocytochemistry demonstrated increased LC3-II accumulation, while electron microscopy demonstrated induced autophagosomes after UA treatment, suggesting that UA upregulated autophagy in CCA cells. In xenograft mice treated with UA, tumor growth was inhibited with increased LC3-II levels. On the other hand, phospho-kinase array demonstrated downregulation of the AKT/WNK1 pathway. LC3-II expression was elevated in WNK1 knocked down cells, indicating that WNK1 is the key signal for regulating autophagy. Thus, UA exerted antitumor effects by suppressing the AKT/WNK1 signaling pathway and inducing autophagy. In conclusion, UA, a natural, well-tolerated compound, may be a promising therapeutic candidate for advanced CCA.

Trapa Bispinosa Roxb. Inhibits the Insulin-Dependent AKT/WNK1 Pathway to Induce Autophagy in Mice with Type 2 Diabetes

“…Regarding WNK1, Sahashi et al recently reported that urolithin A induces autophagy and exerts anti-tumor effects by regulating WNK1. 33 TBE contains high levels of ellagitannins, which are hydrolyzed to produce ellagic acid, 23 and the intestinal metabolite of ellagic acid is urolithin. 34 The fact that the main component of TBE is closely related to urolithin is important when considering the mechanism of action of TBE.…”

Urolithin A as a Potential Agent for Prevention of Age-Related Disease: A Scoping Review

“…A few studies focused on the antineoplastic impacts of UA supplementation [ 8 , 9 , 24 ]. Zhao et al investigated the impacts of UA in SW620 colorectal cancer cells [ 8 ].…”

“…The final study analyzed in this review was a human cell line study completed by Sahashi et al [ 24 ]. This study utilized HuCCT-1 and SSP-25 cells to model cholangiocarcinoma (CCA) in vitro and investigated UA treatment’s impacts in the neoplastic setting [ 24 ].…”

“…The final study analyzed in this review was a human cell line study completed by Sahashi et al [ 24 ]. This study utilized HuCCT-1 and SSP-25 cells to model cholangiocarcinoma (CCA) in vitro and investigated UA treatment’s impacts in the neoplastic setting [ 24 ]. Treatment with 40 μM of UA for 48 hours significantly reduced cell proliferation within tumor cell models and resulted in cell cycle arrest in the G2/M phase [ 24 ].…”

“…This study utilized HuCCT-1 and SSP-25 cells to model cholangiocarcinoma (CCA) in vitro and investigated UA treatment’s impacts in the neoplastic setting [ 24 ]. Treatment with 40 μM of UA for 48 hours significantly reduced cell proliferation within tumor cell models and resulted in cell cycle arrest in the G2/M phase [ 24 ]. This study further demonstrated a significant reduction of cell migration and invasion with similar doses [ 24 ].…”