2-[(4-Acetylphenyl)azo]-2-(3,4-dihydro-3,3-dimethyl-1(2H)-isoquinolinylidene)-acetamide (IQ-1)

• A cell-permeable tetrahydroisoquinolinylidene compound that modulates Wnt/b-catenin signaling by targeting the PR72/130 subunit of PP2A and thereby blocking PP2A/Nkd complex formation, resulting in diminished b-catenin/p300 interaction and a concomitant increase in b-catenin/CBP usage. Co-adminitration of IQ-1 (4 µg/ml) and Wnt3a (100 ng/ml), but neither reagent alone, has been shown to be sufficient in maintaining long-term (>48 days) murine ESCs (Embryonic Stem Cells) pluripotency in the absence of serum.

OTAVAchemicals Catalogue Number: 7070707017
CAS Registry Number: 331001-62-8
Purity: 96% (HPLC)

Ref.: Miyabayashi et al. Wnt/β-catenin/CBP signaling maintains long-term murine embryonic stem cell pluripotency. Proceedings of the National Academy of Sciences of the United States of America (2007), 104, 5668-5673

Abstract: Embryonic stem cells (ESCs) represent an important research tool and a potential resource for regenerative medicine. Generally, ESCs are cocultured with a supportive feeder cell layer of murine embryonic fibroblasts, which maintain the ESCs' capacity for self-renewal and block spontaneous differentiation. These cumbersome conditions, as well as the risk of xenobiotic contamination of human ESCs grown on murine embryonic fibroblasts, make it a priority to develop chemically defined methods that can be safely used for the expansion of ESCs. Using a high-throughput, cell-based assay, we identified the small molecule IQ-1 that allows for the Wnt/β-catenin-driven long-term expansion of mouse ESCs and prevents spontaneous differentiation. We demonstrate that IQ-1, by targeting the PR72/130 subunit of the serine/threonine phosphatase PP2A, prevents β-catenin from switching coactivator usage from CBP to p300. The increase in β-catenin/CBP-mediated transcription at the expense of β-catenin/p300-mediated transcription is critical for the maintenance of murine stem cell pluripotency.

DOI: 10.1073/pnas.0701331104