Chemical biology reveals CARF as a positive regulator of canonical Wnt signaling by promoting TCF/β-catenin transcriptional activity

Abstract

Wnt/β-catenin signaling regulates multiple biological processes and aberration of this pathway is frequently observed in human cancers. Previously, we uncovered NC043 as a small-molecule inhibitor of Wnt/β-catenin signaling. Here, we identified CARF as the cellular target of NC043. We found that NC043 binds directly to CARF through forming a covalent bond with the Cys-516 residue of CARF. Further study revealed that CARF interacts with Dvl, which potentiates the Dvl–c-Jun–β-catenin–TCF transcriptional complex and thus promotes Wnt signaling activation. NC043 could disrupt the interaction between CARF and Dvl, thereby impairing Wnt signal transduction. In line with this, knockdown of CARF in zebrafish leads to impairment of embryonic development, hematopoietic stem cell generation and caudal fin regeneration. Collectively, we identified CARF as the cellular target of NC043 and revealed CARF as a positive regulator of Wnt/β-catenin signal transduction.

Endothelial CDS2 deficiency causes VEGFA-mediated vascular regression and tumor inhibition

“…S6b). Furthermore, neither activation of Wnt/β-catenin signaling (endothelium-specific expression of constitutively activated form of β-catenin) 53 nor activation of Ca 2+ signaling (Inomycin treatment) 54,55 could rescue vessel regression phenotype in cds2 mutants with vegfa OE (Supplementary information, Fig. S6c-f).…”

Inhibition of nuclear Wnt signalling: challenges of an elusive target for cancer therapy

“…This molecule also inhibited tumour growth in a SW480 colon cancer xenograft mouse model in a dose‐dependent manner by up to ~70%. A detailed follow‐up study with the goal of determining the inhibitory mechanism of NC043 found that this molecule covalently binds to CARF (collaborator of ARF), a protein with context‐dependent effects on proliferation (He et al, ). Through a series of biochemical and proteomic studies, CARF was found to interact directly with DVL in the nucleus and to potentiate the formation of the TCF/LEF–β‐catenin complex and transcription of Wnt target genes (He et al, ).…”

“…A detailed follow‐up study with the goal of determining the inhibitory mechanism of NC043 found that this molecule covalently binds to CARF (collaborator of ARF), a protein with context‐dependent effects on proliferation (He et al, ). Through a series of biochemical and proteomic studies, CARF was found to interact directly with DVL in the nucleus and to potentiate the formation of the TCF/LEF–β‐catenin complex and transcription of Wnt target genes (He et al, ). The authors concluded that NC043 could covalently bind to CARF and disrupt its interaction with DVL, which then led to inhibition of β‐catenin‐dependent Wnt signalling in the nucleus.…”

“…CBP/p300 is also present in the OFF state, although the nature of its binding interaction in this state is less certain. CARF, a newly identified binding partner of DVL2, has been shown to be a positive regulator of Wnt signalling, although its precise binding to β‐catenin remains unknown (He et al, ). The chromatin remodelling complex BAF interacts through the ARID1 subunit via directly interacting with ChiLS.…”

The plant sesquiterpene lactone parthenolide inhibits Wnt/β-catenin signaling by blocking synthesis of the transcriptional regulators TCF4/LEF1

“…ICG-001 has been found to compete with CREB-binding protein for binding ␤-catenin, thereby inhibiting Wnt signaling (7). Our laboratory recently reported NC043 as a Wnt signaling inhibitor by targeting CARF (collaborator of ARF) to disturb TCF4 and ␤-catenin interaction (8,9). PTL, a sesquiterpene lactone, was first purified from the shoots of the medicinal plant feverfew (Tanacetum parthenium) (10,11), which is a Chinese folk medical plant and has been used to treat fever, headache, and arthritis for many years (12).…”