Antitumor activity of nitazoxanide against colon cancers: Molecular docking and experimental studies based on wnt/β‐catenin signaling inhibition

Abstract

In colon cancer, wingless (Wnt)/β‐catenin signaling is frequently upregulated; however, the creation of a molecular therapeutic agent targeting this pathway is still under investigation. This research aimed to study how nitazoxanide can affect Wnt/β‐catenin signaling in colon cancer cells (HCT‐116) and a mouse colon cancer model. Our study included 2 experiments; the first was to test the cytotoxic activity of nitazoxanide in an in vitro study on a colon cancer cell line (HCT‐116) versus normal colon cells (FHC) and to highlight the proapoptotic effect by MTT assay, flow cytometry and real‐time polymerase chain reaction (RT‐PCR). The second experiment tested the in vivo cytotoxic effect of nitazoxanide against 1,2‐dimethylhydrazine (DMH) prompted cancer in mice. Mice were grouped as saline, DMH control and DMH + nitazoxanide [100 or 200 mg per kg]. Colon levels of Wnt and β‐catenin proteins were assessed by Western blotting while proliferation was measured via immunostaining for proliferating cell nuclear antigen (PCNA). Treating HCT‐116 cells with nitazoxanide (inhibitory concentration 50 (IC50) = 11.07 μM) revealed that it has a more cytotoxic effect when compared to 5‐flurouracil (IC50 = 11.36 μM). Moreover, it showed relatively high IC50 value (non‐cytotoxic) against the normal colon cells. Nitazoxanide induced apoptosis by 15.86‐fold compared to control and arrested the cell cycle. Furthermore, nitazoxanide upregulated proapoptotic proteins (P53 and BAX) and caspases but downregulated BCL‐2. Nitazoxanide downregulated Wnt/β‐catenin/glycogen synthase kinase‐3β (GSK‐3β) signaling and PCNA staining in the current mouse model. Hence, our findings highlighted the cytotoxic effect of nitazoxanide and pointed out the effect on Wnt/β‐catenin/GSK‐3β signaling.