Huaier aqueous extract inhibits colorectal cancer stem cell growth partially via downregulation of the Wnt/β-catenin pathway

The existence of cancer stem cells (CSCs) is central to the pathogenesis and therapy resistance of colorectal cancer. The aim of this study was to evaluate whether Huaier aqueous extract, a Chinese medicine, has efficacy against CSCs and to investigate the mechanisms of its anticancer effects. It was observed that the Huaier extract significantly inhibited the spheroid formation potential (P<0.05) and decreased the aldehyde dehydrogenase (ALDH)-positive cell population in colorectal primary cancer cells (P<0.05). Western blotting analysis and Wnt/β-catenin reporter assays revealed that the Huaier extract downregulated the Wnt/β-catenin self-renewal pathway. This is the first study to demonstrate that Huaier aqueous extract acts as an effective agent for eradicating colorectal CSCs and identifies the Wnt/β-catenin pathway as its potential target, which may be a new approach for colorectal cancer therapy.