Aug 2026· Bioorganic chemistry (Print)· Vol 181, pp.
110388
· 0 citations· 23 references
Medicine
TL;DR
This work describes the design, synthesis, and biological evaluation of a series of JNK1-targeting PROTACs that recruit either CRBN or VHL E3 ligases that demonstrates excellent degradation potency and selectivity for JNK1, highlighting its potential as a valuable chemical probe for EMT-associated pathologies.
Abstract
Epithelial-mesenchymal transition (EMT) is essential for embryogenesis and tissue regeneration, yet its aberrant activation is closely associated with organ fibrosis and tumor metastasis. c-Jun N-terminal kinase 1 (JNK1) has been identified as a key mediator of transforming growth factor-β (TGF-β)-driven EMT, making it a promising therapeutic target. Herein, we describe the design, synthesis, and biological evaluation of a series of JNK1-targeting PROTACs that recruit either CRBN or VHL E3 ligases. Systematic structure-activity relationship optimization led to the discovery of compound YC2, which incorporates a newly developed VHL ligand modified with a 2,4-dimethyloxazole moiety, as a potent and selective degrader. YC2 induced efficient, concentration- and time-dependent degradation of JNK1 (DC₅₀ of 4.90 nM) via VHL-mediated ubiquitin-proteasome pathway engagement, while displaying strong selectivity over related kinases including JNK2, p38α, and ERK. Moreover, YC2 markedly attenuated TGF-β1-induced EMT, as evidenced by reduced fibronectin levels and restoration of E-cadherin expression, with efficacy comparable to nintedanib. Collectively, YC2 featuring a novel VHL ligand demonstrates excellent degradation potency and selectivity for JNK1, highlighting its potential as a valuable chemical probe for EMT-associated pathologies.
Cyclin-dependent kinase 8 (CDK8) has emerged as an important regulator of inflammatory signaling and immune homeostasis, representing a promising therapeutic target for psoriasis and other immune-mediated diseases. Herein, we report the structure-based optimization of the previously reported CDK8 inhibitor to develop a series of novel derivatives. Through systematic structure-activity relationship (SAR) analysis, compound LW-1 was identified as a lead candidate with potent CDK8 inhibitory activity (IC50 = 24.5 ± 1.4 nM) and significantly improved metabolic stability. Target engagment studies confirmed that LW-1 directly binds to CDK8 with high affinity. Mechanistically, LW-1 suppressed NF-κB-dependent transcription and reduced pro-inflammatory cytokine expression, while promoting regulatory T cell (Treg) differentiation through modulation of the STAT1 and TGF-β/Smad signaling pathways. Pharmacokinetic evaluation revealed that LW-1 possessed markedly improved metabolic stability (t₁/₂ = 37.11 min in mouse liver microsome) and prolonged elimination half-life in rats (t₁/₂ = 4.8 h, po), along with acceptable oral bioavailability (F = 27.1%). In the IMQ-induced psoriasis-like mouse model, LW-1 markedly alleviated skin inflammation by promoting Treg differentiation and suppressing pro-inflammatory cytokine production. Collectively, LW-1 represents a promising CDK8 inhibitor with improved drug-like properties and potent anti-psoriatic efficacy, providing a potential therapeutic candidate for the treatment of psoriasis and other inflammatory diseases.
C. Lei, Dawei Jin, Ajun Liu et al.· Bioorganic chemistry (Print)· 0 citations
The design and synthesis of SHP2 PROTACs that recruit the DCAF16 E3 ligase for targeted SHP2 degradation are reported that support the potential of SHP2-targeted protein degradation as an alternative strategy to enzymatic inhibition and provide a promising starting point for the further development of SHP2 degraders.
X. Pang, Yuxin Gan, Qingyuan Hu et al.· Bioorganic chemistry (Print)· 0 citations
Background: Hypoxia-inducible factor-1 alpha (HIF-1α) drives tumor adaptation to hypoxia by promoting angiogenesis, metabolic reprogramming, and survival signaling in clear cell renal cell carcinoma (ccRCC). Transcriptional activity of HIF-1α depends on its interaction with the p300/CBP (CREB-binding protein) coactivator via the C-terminal transactivation domain (C-TAD). Direct targeting of this protein–protein interface remains limited, highlighting the need for novel inhibitors.Methods: A structure-based virtual screening of ~250,000 compounds from the ZINC database was conducted to identify candidates targeting a predicted pocket within the HIF-1α C-TAD. Top hits were evaluated using molecular docking and 100 ns molecular dynamics simulations. The lead compound, HFS764, was further characterized using in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling, homogeneous time-resolved fluorescence (HTRF) assays, and differential scanning fluorimetry (DSF). Functional effects were assessed in Caki-1 cells under hypoxia using hypoxia response element (HRE)-luciferase assays, cell viability and vascular endothelial growth factor (VEGF) secretion.Results: HFS764 demonstrated stable binding within the HIF-1α pocket, with ligand root-mean-square deviation (RMSD) <0.20 nm and a predicted binding free energy of –22.38 kcal/mol. HTRF assays confirmed inhibition of the HIF-1α–p300 interaction (IC50 = 4.89 μM), while DSF showed ligand-induced stabilization (ΔTm = +2.0 °C). In Caki-1 cells, HFS764 suppressed HRE-driven transcription (IC50 = 4.27 μM), and reduced VEGF secretion under hypoxia. Selective cytotoxicity was observed (GI50: 14.70 μM in Caki-1 vs. 37.98 μM in HK-2; therapeutic index = 2.58).Conclusion: HFS764 disrupts the HIF-1α–p300 interface and suppresses hypoxia-driven signaling in ccRCC, supporting the use of transcriptional complex inhibition as a promising therapeutic strategy.
Mesfer Al Shahrani· Discover medicine· 0 citations
KLHL12 is identified as a potentially tumor-selective E3 ligase and the development of the first-in-class KLHL12-recruiting PROTACs are reported, which established KLHL12 as a promising tumor‑selective E3 ligase and provided a KLHL12-recruiting PROTAC platform for cancer therapy.
Shicheng Xu, Xian Zhang, Shun-Bo Hu et al.· Angewandte Chemie· 0 citations
SHP2 (Src homology 2 (SH2)-containing protein tyrosine phosphatase 2) is a tyrosine phosphatase that plays a critical role in numerous physiological and pathological cellular processes, including cell proliferation, survival, and migration through the regulation of multiple signaling pathways, such as RAS-RAF-mitogen-activated protein kinase, phosphatidylinositol 3-kinase (PI3K)-AKT, Janus tyrosine kinase (JAK), and signal transducer and activator of transcription pathways (STAT) in response to cytokines and growth factors. Through extensive structure-based optimization, we identified I-0436650, a preclinical candidate with an excellent pharmacological profile. I-0436650 is a low nanomolar allosteric inhibitor of human wild-type (wt) SHP2 and strongly inhibits ERK phosphorylation in cells. It exhibits antiproliferative activity in EGFR- and RAS-dependent cell lines, suppresses tumor growth as a single agent in xenograft models, and delays tumor relapse when combined with inhibitors of the same pathway, demonstrating the potential of vertical inhibition strategies.
Alina Ciammaichella, Francesca Puca, Danilo Fabbrini et al.· Journal of Medicinal Chemist...· 0 citations
The epigenetic regulator protein arginine methyltransferase 5 (PRMT5) is aberrantly overexpressed in triple-negative breast cancer (TNBC) and represents a promising therapeutic target. Currently reported PRMT5-targeting PROTAC degraders (MS4322 and MS115) are both derived from a tetrahydroisoquinoline scaffold. These compounds require treatment for more than five days to exert effective antiproliferative activities, and no in vivo antitumor efficacy has been reported. To address these limitations, we adopted the carbazole-based PRMT5 inhibitor PJ-68, which features a lower molecular weight and a more accessible linker attachment site. Herein, we reported a series of novel PRMT5 degraders with carbazole scaffold. The representative compound YZ-17 degraded PRMT5 (DC50 = 2.2 μM in HCC1806 and 3.3 μM in HCC1937 cells) and its adaptor protein MEP50 (DC50 = 2.0 μM and 2.9 μM, respectively) within 24 h. YZ-17 also suppressed PRMT5-mediated symmetric dimethylarginine (sDMA) modification and colony formation, induced G1 phase cell cycle arrest, and displayed favorable antiproliferative activities across several TNBC cell lines (IC50 = 2.6 - 3.7 μM). Importantly, YZ-17 showed in vivo efficacy in an HCC1806 xenograft model, achieving a tumor growth inhibition (TGI) of 44.12% at 30 mg/kg (i.p., every other day) without obvious toxicity. Collectively, YZ-17 represents a structurally novel PRMT5 degrader with rapid onset of action, effective in vitro and in vivo anti-TNBC activity, offering a distinct chemical tool for further functional studies of PRMT5.
Yu-Zhan Li, Yaxun Guo, Dazhao Mi et al.· European journal of medicina...· 0 citations
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