Discovery of chemical probes that suppress Wnt/β‐catenin signaling through high‐throughput screening

Abstract

Aberrant activation of the Wnt/β‐catenin signaling pathway has been observed in a wide range of human tumors. Deregulation of the pathway is closely linked to various aspects of human carcinogenesis such as cell viability, regulation of cell cycle, epithelial‐mesenchymal transition, and maintenance of stemness. In addition, recent studies have disclosed the involvement of Wnt signaling in immune evasion of tumor cells. The accumulation of β‐catenin in the nucleus is a common feature of cancer cells carrying defects in the pathway, which leads to the continuous activation of T‐cell factor (TCF)/LEF transcription factors. Consequently, a genetic program is switched on, leading to the uncontrolled growth, prolonged survival, and acquisition of mesenchymal phenotype. As β‐catenin/TCF serves as a signaling hub for the pathway, β‐catenin/TCF‐dependent transcriptional activity is a relevant readout of the pathway. To date, a wide variety of synthetic TCF/LEF reporters has been developed, and high‐throughput screening (HTS) using these reporters has made significant contributions to the discovery of Wnt inhibitors. Indeed, HTS led to the identification of chemical probes targeting porcupine, a membrane bound O‐acyltransferase, and CREB‐binding protein, a transcriptional coactivator. This review focuses on various screening strategies for the discovery of Wnt inhibitors and their mode of action to help the creation of new concepts for assay/screening methods.

Involvement and Targeted Intervention of Mortalin-Regulated Proteome Phosphorylated-Modification in Hepatocellular Carcinoma

“…Here, we found that the phosphorylation of GSK3β at Ser9 was downregulated, whereas the phosphorylation of GSK3β at Tyr216 was upregulated in mortalin knockdown cells, which inhibited the phosphorylation of β-catenin at several main sites, such as Ser37, Thr41, and Tyr654. This downregulation of phosphorylation could inhibit β-catenin separation from the cell membrane, preventing it from entering the nucleus and performing its function and promoting the progression of cancer ( 44 , 45 ). In addition, the downstream apoptosis process-related genes, such as Bcl-XL, Bcl-2, and BAD, were also affected and induced the apoptosis process, consistent with their functions ( 46 ).…”

Morphological neurite changes induced by porcupine inhibition are rescued by Wnt ligands

“…A series of small molecule inhibitors speci cally target several of the proteins in the Wnt signaling pathway, such as Fzd, DVL, PORCN or Tankyrase, and could also be used as chemical probes to dissect the mechanism(s) of these signaling pathways (37,38). We therefore used Wnt-C59, a PORCN inhibitor, in embryonic hippocampal neurons, to research polarization, the development of dendritic trees, and maintenance and/or maturation of dendritic spines; these inhibitory molecules have the potential to be developed both as study reagents in cell biology as therapeutic agents (39,40).…”

Morphological Neurite Changes Induced by Porcupine Inhibition Are Rescued by Wnt Ligands

“…A series of small molecule inhibitors speci cally target several of the proteins in the Wnt signaling pathway, such as Fzd, DVL, PORCN or Tankyrase, and could also be used as chemical probes to dissect the mechanism(s) of these signaling pathways (37,38). We therefore used Wnt-C59, a PORCN inhibitor, in young hippocampal neurons, to research polarization, the development of dendritic trees, and maintenance and/or maturation of dendritic spines; these inhibitory molecules have the potential to be developed both as study reagents in cell biology as therapeutic agents (39,40).…”