WS3 

WS3 is an allosteric inhibitor of 14-3-3 (14-3-3ζ: K_d = 2.29 μM). WS3 activates GSK3β by disrupting the binding of 14-3-3-pGSK3β, promotes the ubiquitination and degradation of NRF2, and inhibits the NRF2-ARE signaling pathway (IC₅₀ = 135 nM). It exerts antioxidant inhibition and chemotherapeutic/ferroptosis sensitizing effects in tumors with hyperactivated NRF2. WS3 binds to EBP1/IKKε and promotes the proliferation of β cells and retinal pigment epithelial (RPE) cells, which can be applied to islet regeneration and RPE expansion transplantation. WS3 is applicable to research related to age-related macular degeneration, retinal degeneration and non-small cell lung cancer^[1][2][3].

IC50: 0.28 μM (β cell proliferation)^[1]

WS3 (25 nM; 3 days) induces proliferation in senescent passage six primary human fetal RPE cells, with 25 nM WS3 causing a four-fold increase in EdU-positive cells relative to DMSO control, and elicits similar responses in primary adult rat and adult human RPE cells^[1].
WS3 (25 nM; serial passages through passage fifteen, split every three days) supports continuous proliferation of primary human fetal RPE cells through passage fifteen (maximal 1.95 doublings per passage at passage eleven), with proliferation ceasing immediately upon compound removal, and does not induce cell death during senescence^[1].
WS3 (25 nM; from passage six to passage ten) does not induce chromosomal abnormalities or tumorigenic events during long-term culture of primary human fetal RPE cells from passage six to passage ten^[1].
WS3 (25 nM) expanded primary human fetal RPE cells to passage ten differentiate into functional mature RPE monolayers (with cobblestone morphology, pigmentation, tight junctions, RPE marker expression, and POS phagocytosis) upon WS3 removal, and WS3-expanded primary adult human RPE cells similarly differentiate into mature RPE cells with appropriate gene expression^[1].
WS3 induces dose-dependent proliferation of mouse R7T1 β cells with an EC₅₀ of 0.074 μM^[2].
WS3 (50-200 nM; 48 h) potently inhibits NRF2-ARE signaling in A549 cells with an IC₅₀ of 135 nM, selectively reducing NRF2 and downstream target levels via proteasomal/ubiquitin-mediated degradation dependent on the SKP1-CUL1-β-TrCP complex, while sparing normal HUVEC and BEAS-2B cells^[3].
WS3 (50-200 nM; 4-48 h) disrupts the 14-3-3ζ-pGSK3β interaction in A549 cells, activating GSK3β to promote CUL1-β-TrCP-mediated NRF2 ubiquitination and degradation, with this effect reversible via GSK3β or PP2A inhibition^[3].
WS3 (20-400 nM; 24 h-2 week) induces oxidative stress, ferroptosis, and NRF2-dependent growth inhibition in A549 cells, with effects abrogated in NRF2-KO cells^[3].
WS3 (20-200 nM; 48 h-2 week) synergizes with carboplatin and ferroptosis inducers to enhance growth inhibition of A549 cells^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Transplantation of ex vivo WS3 (25 nM; seven passages)-expanded primary rat RPE cells preserves visual function and photoreceptor structure in dystrophic RCS rats, with visual acuity reaching 0.49 cycles/degree at postnatal day 90^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

569.58

C₂₈H₃₀F₃N₇O₃

1421227-52-2

Solid

Light yellow to yellow

CN1CCN(CC1)CC2=C(C=C(C=C2)NC(NC3=CC=C(C=C3)OC4=CC(NC(C5CC5)=O)=NC=N4)=O)C(F)(F)F

Room temperature in continental US; may vary elsewhere.

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

• [1]. Swoboda JG, et al. Small molecule mediated proliferation of primary retinal pigment epithelial cells. ACS Chem Biol. 2013 Jul 19;8(7):1407-11.
   [Content Brief]

  [2]. Swoboda JG, et al. Small molecule mediated proliferation of primary retinal pigment epithelial cells. ACS Chem Biol. 2013 Jul 19;8(7):1407-11.
   [Content Brief]

  [3]. Zhao J, et al. Discovery of an allosteric 14-3-3 inhibitor for suppressing NRF2-driven cancer via phenotypic screening and chemoproteomic-based target deconvolution. Chem Sci. 2025 Aug 20;16(37):17248-17260.