Abstract
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths, characterized by highly hypoxic tumor microenvironment. Hypoxia-inducible factor-1α (HIF-1α) is a major regulator involved in cellular response to changes of oxygen levels, supporting the adaptation of tumor cells to hypoxia. Bruceine D (BD) is an isolated natural quassinoid with multiple anti-cancer effects. Here, we identified BD could significantly inhibit the HIF-1α expression and its subsequently mediated HCC cell metabolism. Using biophysical proteomics approaches, we identified inhibitor of β-catenin and T-cell factor (ICAT) as the functional target of BD. By targeting ICAT, BD disrupted the interaction of β-catenin and ICAT, and promoted β-catenin degradation, which in turn induced the decrease of HIF-1α expression. Furthermore, BD could inhibit HCC cells proliferation and tumor growth in vivo, and knockdown of ICAT substantially increased resistance to BD treatment in vitro. Our data highlight the potential of BD as a modulator of β-catenin/HIF-1α axis mediated HCC metabolism.
Keywords:
BD, bruceine D; Bruceine D; CETSA, cellular thermal shift assay; Cyt c, cytochrome c; DARTS, drug affinity responsive target stability; HCC, hepatocellular carcinoma; HIF-1α; HIF-1α, hypoxia-inducible factor-1α; HIF-1β, hypoxia-inducible factor-1β; Hepatocellular carcinoma; Hypoxia; ICAT; ICAT, inhibitor of β-catenin and T-cell factor; MST, microscale thermophoresis; Metabolism; ROS, reactive oxygen species; Tumor microenvironment; β-Catenin.