HNF4α Antagonists Discovered by a High-Throughput Screen for Modulators of the Human Insulin Promoter

Hepatocyte nuclear factor (HNF)4 alpha is a central regulator of gene expression in cell types that play a critical role in metabolic homeostasis, including hepatocytes, enterocytes, and pancreatic beta cells. Although fatty acids were found to occupy the HNF4 alpha ligand-binding pocket and were proposed to act as ligands, there is controversy about both the nature of HNF4 alpha ligands as well as the physiological role of the binding. Here, we report the discovery of potent synthetic HNF4 alpha antagonists through a high-throughput screen for effectors of the human insulin promoter. These molecules bound to HNF4 alpha with high affinity and modulated the expression of known HNF4 alpha target genes. Notably, they were found to be selectively cytotoxic to cancer cell lines in vitro and in vivo, although in vivo potency was limited by suboptimal pharmacokinetic properties. The discovery of bioactive modulators for HNF4 alpha raises the possibility that diseases involving HNF4 alpha, such as diabetes and cancer, might be amenable to pharmacologic intervention by modulation of HNF4 alpha activity.