Los degradadores moleculares que se unen a HuR suprimen el cáncer colorrectal con mutación en el gen BRAF.

AbstractBRAF gain-of-function mutations, particularly BRAF(V600E), affect roughly 10% of all patients with colorectal cancer (CRC), and portend poor prognosis with limited therapeutic interventions. BRAF inhibitors such as encorafenib are ineffective due to MAPK pathway reactivation driven by BRAF dimerization. Combined inhibition of BRAF and EGFR, although approved therapies, results in short survival benefits and frequent treatment resistance and relapse1,2,3. Here, through rational chemical library design coupled with parallel proteomic screening, we identified dHuR as a molecular glue degrader of human antigen R (HuR), an RNA-binding protein that drives tumour growth, invasion and therapy resistance. dHuR binds to the CRBN ubiquitin ligase to create a unique benzofuran-tethered composite surface to recruit HuR as a neosubstrate by engaging its β-hairpin G-loop degron, as revealed by the cryo-electron microscopy structure of the ternary complex. dHuR abrogated BRAF expression by inducing its exon 18 skipping, and demonstrated superior suppression of BRAF-mutant CRC tumours including those gaining resistance to BRAF inhibitors. Finally, we performed kinome library CRISPR screening and revealed that inactivation of EGFR or MEK enhanced dHuR cytotoxicity, thus establishing a combinatorial strategy to treat patients with refractory BRAF-mutant CRC.

Similar content being viewed by others









A reversible SRC-relayed COX2 inflammatory program drives resistance to BRAF and EGFR inhibition in BRAFV600E colorectal tumors



Article
Open access
09 February 2023












Fluoropyrimidine type, patient age, tumour sidedness and mutation status as determinants of benefit in patients with metastatic colorectal cancer treated with EGFR monoclonal antibodies: individual patient data pooled analysis of randomised trials from the ARCAD database



Article
Open access
24 February 2024












Co-targeting SRC overcomes resistance to BRAF inhibitors in colorectal cancer



Article
Open access
06 June 2025















MainCRC harbouring BRAF mutations (approximately 10% of cases) represents one of the most aggressive and therapeutically challenging CRC subtypes4, with a median survival of less than 12 months under current therapies3. Unlike BRAF-mutant melanoma, where BRAF inhibitors (for example, vemurafenib and encorafenib) show remarkable efficacy, BRAF-mutant CRC exhibits intrinsic resistance due to EGFR-dependent feedback reactivation of the MAPK pathway. Although the US Food and Drug Administration (FDA)-approved combination of encorafenib (a BRAF inhibitor (BRAFi)) + cetuximab (an anti-EGFR antibody) improves response rates (20–26% versus 5% with BRAFi alone)5,6, most patients derive no benefit, and responders typically relapse within 4–6 months6. Consequently, more than 75% of patients with BRAF-mutant CRC lack durable treatment options7, underscoring the urgent need for novel therapeutic modalities that overcome resistance or alternative targeting strategies for BRAF or its critical co-factors.The human RNA-binding protein HuR is encoded by the gene ELAV-like RNA-binding protein 1 (ELAVL1; also known as HUR) and binds to AU-rich elements within the introns or 3′ untranslated regions of target mRNAs, thereby regulating pre-mRNA processing, mRNA stability and translation8,9. HuR has a critical role in modulating mRNA stability and translational control, serving as a key post-transcriptional regulator of specific RNAs across both physiological and pathological contexts, particularly in cancer progression10,11. HuR is frequently overexpressed and/or abnormally enriched in the cytoplasm of cancer cells. Its aberrant expression is associated with high tumour grades and poor prognoses across a spectrum of malignancies, including CRC12. HuR enhances the expression of proteins that drive cancer progression, such as vascular endothelial growth factor (VEGF) and cell cycle regulators, particularly in response to stresses such as oncogenic mutations and chemotherapy or targeted therapies10,13,14. Through its pleotropic effects, HuR promotes tumour growth, invasion, angiogenesis and resistance to therapeutic agents, making it an important target for cancer therapeutics15. The discovery of small molecules and small interfering RNAs that inhibit the function of HuR have provided proof of concept for potential therapeutic benefit of targeting HuR in many cancer types, such as colorectal, pancreatic, renal, ovarian, breast, liver and lung cancers, as well as malignant peripheral nerve sheath tumour16,17,18,19,20,21,22,23,24,25. However, none of these drug candidates has been advanced to clinical development to date, owing to poor potency or lack of efficient delivery to the tumour26.Molecular glue degraders (MGDs), a novel class of chemical compounds, have recently emerged as a promising strategy for selectively targeting and degrading disease-causing proteins, including those considered ‘undruggable’. By chemically inducing ternary complex formation between a target protein and a ubiquitin E3 ligase, MGDs trigger proximity-driven ubiquitination and subsequent degradation of the target protein. Of note, recent breakthroughs have expanded the cereblon (CRBN)-based MGD target landscape. Beyond classical immunomodulatory drugs (IMiDs) such as thalidomide analogues—which target the transcription factors IKZF1, IKZF3, ZFP91, ZMYM2 and SALL4 (refs. 27,28,29,30)—MGDs have also been identified against additional zinc-finger proteins (for example, IKZF2 and WIZ)31,32, kinases (for example, CK1α)33 and scaffold proteins (for example, GSPT1)34. In addition, cryo-electron microscopy (cryo-EM) structural studies of CRBN–MGD–neosubstrate complexes have revealed critical molecular determinants for ternary complex formation35,36,37, including β-hairpin stabilization and hydrophobic ‘glue patches’. Despite these advances, fundamental challenges persist in rational MGD development. Serendipity still drives most discoveries owing to limited predictive tools. This bottleneck stems from the transient nature of MGD-induced protein–protein interactions and the lack of universal structural signatures for ‘glueable’ target interfaces. Recent computational efforts using deep learning platforms (for example, AlphaFold38) for interface prediction show promise but require experimental validation.Fortunately, emerging proteomic technologies are now enabling systematic discovery of MGD-responsive targets. Here we utilized large-scale proteomic profiling of cells treated with rationally designed CRBN modulators and identified MGDs targeting HuR. Mechanism-of-action studies showed that dHuRs function as molecular glues to induce a CRBN–MGD–HuR ternary complex, leading to the polyubiquitination and proteasomal degradation of HuR. Through a series of bioinformatics analyses, in vitro cell-based assays and in vivo models, we discovered that BRAF-mutated CRC cells are particularly sensitive to the treatment of dHuRs. The mechanism leading to this activity is at least in part due to the effects of HuR degradation on BRAF RNA splicing and decreased BRAF protein level. The anti-proliferative effect of HuR degradation is also demonstrated in BRAFi-resistant cancer cells and is associated with decreased oncogenic protein BRAF and EGFR and sustained decrease of MAPK pathway signalling as measured by p-ERK level. This combination of HuR degradation with EGFR–BRAF–MEK inhibition resulted in synergistic antitumour effects. These data support the development of dHuR in BRAF-mutated CRC.dHuRs identified by proteomicsTo systematically identify neosubstrates engaging CRBN, a CRBN-based molecular glue library with more than 10,000 compounds was designed. Approximately 200 representative compounds with diversified scaffolds were applied to a homogeneous time-resolved fluorescence (HTRF) assay for measuring the CRBN binary binding affinity, which was reflected in the displacement of thalidomide-red from the CRBN-binding pocket. Commercially available CRBN E3 ligase-modulatory drugs were included as benchmarks, and N-methylated pomalidomide (Poma-CH3) was specifically designed to abolish CRBN binding, serving as a negative control. At a fixed compound concentration of 1.6 µM, the HTRF scores revealed three binding classes: weak (HTRF score > 0.8), medium (0.8–0.4) and strong (less than 0.4). Of the tested compounds, 87.4% showed medium-to-strong CRBN-binding affinity (Fig. 1a), which indicates that the majority of the library compounds are CRBN binders. In this case, CRBN wild-type (WT, CRBN+/+) and knockout (KO, CRBN−/−) cells were treated with a set of compounds pooled randomly from the library and then subjected to global quantitative proteomics. As shown in Fig. 1b, HuR was identified as one of the top candidates, with protein abundance reduced specifically in CRBN WT cells but not in CRBN-KO cells upon pooled compound treatment.Fig. 1: Identification of dHuRs.The alternative text for this image may have been generated using AI.Full size imagea, HTRF-based primary screen of a compound library (1.6 µM) for CRBN binders. Cpds, compounds. b, Schematic of the proteomic screen in CRBN WT versus CRBN-KO cells treated with compound pools (left), and volcano plots showing protein abundance changes in JHH-7 CRBN WT (middle) or CRBN-KO (right) cells. LC–MS/MS, liquid chromatography–tandem mass spectrometry; TMT, tandem mass tag. c, Chemical structure and molecular weight (MW) of dHuR-1 (1). d, Immunoblot of HuR in JHH-7 cells treated with dimethyl sulfoxide (DMSO) or dHuR-1. e, Immunoblot of HuR in JHH-7 cells treated with dHuR-1 (10 µM) with or without MLN4924 (1 µM; a NEDD8 inhibitor) or MG132 (10 µM; a proteasome inhibitor). f, Quantified immunoblot of HuR in JHH-7 CRBN WT and CRBN-KO cells treated with cycloheximide (CHX; 100 µg ml−1) in the presence or absence of dHuR-1 (10 µM) over time (0–8 h). g, Schematic of the chemical structures of 2–7 generated by appending the dHuR-1 tail moiety to the core scaffold of Poma or lenalidomide (Lena; left). HTRF-measured binding affinity of the indicated compounds to CRBN (left y axis) and HiBiT-based quantification of HuR degradation (right y axis) are also shown (right). h, Chemical structure and MW of dHuR-2 (8), an optimized degrader. i, Volcano plots of protein abundance changes in KP4 cells treated with dHuR-1 or dHuR-2 (10 µM, 2 h). P values were determined by two-tailed, unpaired Student’s t-test (b,i). Grey dotted lines indicate cut-off of fold-change (FC) and P value (b,i). For gel source data, see Supplementary Fig. 2.We next examined endogenous protein expression in response to individual compounds and identified that dHuR-1 (1) strongly decreased the abundance of HuR in a dose-dependent and/or time-dependent manner (Fig. 1c,d). Treatment with the Nedd8 enzyme inhibitor MLN4924 or proteosome inhibitor MG132 prevented the dHuR-1-induced decrease of HuR (Fig. 1e). The shortened protein half-life as determined by the CHX chase assay was observed upon dHuR-1 treatment in CRBN WT but not in CRBN-KO cells (Fig. 1f and Extended Data Fig. 1a). Instead, the mRNA level was just slightly reduced (Extended Data Fig. 1b), which might be caused by the self-regulation of HuR on its own mRNA39. A dual-fluorescence reporter (HuR–GFP–IRES–mCherry) assay confirmed target degradation at the post-transcriptional level (Extended Data Fig. 1c). All these data supported dHuR-1-mediated CRBN-dependent degradation on HuR. In addition, nuclear–cytoplasmic fractionation demonstrated pan-compartmental HuR degradation (Extended Data Fig. 1d).To have a stronger degrader of HuR for further biophysical or biochemical and biological functional assays, a small scale of structure–activity relationship study was conducted by modifying the core (the ring system directly attached to glutarimide) and tail (the extension group attached to the core) substructures based on dHuR-1. We found that the unique benzofuran core of dHuR-1 was critical for HuR engagement versus IMiD scaffolds. Although 2–7 (for compound names, see Supplementary Information) showed binding affinity to CRBN, they lost activity on HuR degradation with the core replaced (Fig. 1g and Extended Data Fig. 1e). The optimized analogue dHuR-2 (8) achieved superior CRBN-binding affinity (HTRF half-maximal inhibitory concentration (IC50) = 0.16 µM) and HuR degradation potency (half-maximal degradation concentration (DC50) = 3.8 nM, maximum degradation (Dmax) = 96% and time to degrade half the protein (T1/2) = 2.45 h; Fig. 1h). Proteomic profiling and immunoblot analysis revealed selective degradation of HuR and the known CRBN neosubstrates ZFP91 and ZMYM2 with comparable potency, whereas GSPT1 and Hu protein paralogues (HuB, HuC and HuD) were spared; Fig. 1i and Extended Data Fig. 1f–h).Characterization of the CRBN–MGD–HuR complexInspired by the conserved β-hairpin G-loop topology in CRBN neosubstrates32,34,40, we mapped two analogous structural motifs in HuR (G58/G144 loops) by molecular docking. We found that mutagenesis on G58 but not G144 of the HuR reporter abolished dHuR-1-mediated degradation (Extended Data Fig. 2a). In addition, comprehensive mutagenesis revealed a strict glycine requirement at position 58, mirroring the conservation of the G-loop mechanism (Extended Data Fig. 2b). The G58N mutation disrupted the CRBN–HuR interaction as demonstrated by NanoBRET and co-immunoprecipitation assays (Fig. 2a and Extended Data Fig. 2c). Regarding which amino acids of CRBN were engaged in HuR degradation, we found that reintroduction of WT CRBN via transfection in 293T CRBN-KO cells restored the dHuR-1-dependent degradation of HuR reporter, whereas CRBN mutants (E377V or V388I)34,41 displayed diminished activity, with the double mutants exhibiting a stronger effect (Extended Data Fig. 2d). Consistently, endogenous mouse HuR could not be degraded in Crbn WT mouse embryonic fibroblasts but could be degraded in CrbnI391V/V380E double knock-in (KI) mouse embryonic fibroblasts (Extended Data Fig. 2e). The two sets of data indicated the critical role of both E377 and V388 in the CRBN–HuR complex.Fig. 2: Characterization of CRBN–MGD–HuR ternary complex formation.The alternative text for this image may have been generated using AI.Full size imagea, NanoBRET assay comparing ternary complex formation between CRBN and either WT HuR or the HuR(G58N) mutant induced by 10 μM dHuR-1. Data are presented as mean ± s.d.; n = 3 biologically independent samples. P values were determined by two-tailed, unpaired Student’s t-test. BRET, bioluminescence resonance energy transfer. b, TR-FRET assay showing ternary complex formation between His–DDB1–CRBN and GST–HuR induced by various concentrations (8 to 0.0005 μM, fourfold dilutions) of dHuR-1 or dHuR-2. c, Western blot detection of polyubiquitinated HuR after incubation with recombinant E1, E2 and E3 enzymes ± 100 μM dHuR-2 (2 h at 30 °C). For gel source data, see Supplementary Fig. 2. Ub, ubiquitin. d, Cryo-EM map of DDB1–CRBN bound to HuR and dHuR-2 (the DDB1 BPB domain was masked out). e, Binding pocket of dHuR-2 in the ternary complex. Key interacting residues are shown in stick representation, and Cα of G58 is shown in sphere representation. Hydrogen bonds are depicted as dashed lines. f, dHuR-2 (green) induced a tight protein–protein interaction between CRBN (grey) and HuR (pink). DDB1 was omitted for clarity. g, Binding of dHuR-2 created an additional buried surface area at the protein–protein interface between CRBN and HuR. The buried surface from the binding of dHuR-2 (light brown) was compared with the buried surface between CRBN and HuR (purple).With the degron of HuR mapped, human HuR protein containing RRM1 and RRM2 domains was purified, as well as the DDB1–CRBN–TBD proteins. Surface plasmon resonance (SPR) quantified CRBN–MGD interactions, showing tighter binding of dHuR-2 (affinity constant (KD) = 4.6 µM versus 15.5 µM; Extended Data Fig. 2f). The negative signal detected with CRBN(W386A) demonstrated a strict dependence on intact CRBN–MGD interfaces (Extended Data Fig. 2f), excluding off-target binding mechanisms. dHuR-2 also triggered stronger formation of the ternary complex as demonstrated by SPR experiments showing that HuR binds to CRBN–DDB1 with KD = 434 nM versus 299 nM in the presence of dHuR-1 versus dHuR-2 (Extended Data Fig. 2g). Consistently, time-resolved fluorescence resonance energy transfer (TR-FRET) ternary complex analysis revealed enhanced cooperativity for dHuR-2 over dHuR-1 (half-maximal effective concentration = 0.13 µM versus 0.71 µM; Fig. 2b). To establish a functional linkage between ternary complex formation and degradation machinery activation, the E3-substrate tagging by ubiquitin biotinylation (ESTUB) assay was conducted to check the ubiquitination of HuR. As expected, the polyubiquitin chain was added to endogenous HuR in the presence of dHuR-2 (Extended Data Fig. 2h). The in vitro reconstitution ubiquitination assay also confirmed that dHuR-2 drives CRL4–CRBN-mediated HuR polyubiquitination (Fig. 2c).To have a better understanding of ternary formation, we solved the cryo-EM structure of the DDB1–CRBN–MGD–HuR complex to 3.3 Å (Fig. 2d and Extended Data Fig. 3b) following the workflow as shown in Extended Data Fig. 3a. The structure revealed that HuR interacted with CRBN–dHuR-2 through its G-loop, with G58 having a critical role. The glutarimide ring of dHuR-2 engaged the Tri-W pocket of CRBN using W380, W386 and W400, while forming a hydrogen bond with the sidechains of H378. The benzofuran moiety packed against W386, H378 and P352 on CRBN, whereas the pyrazole moiety was positioned near the G58 loop of HuR. The phenyl ring of dHuR-2 orients towards the F150 loop of CRBN, probably stabilizing a ‘closed’ CRBN conformation42. In addition, a key residue, R53, on HuR interacted with E377 on CRBN (Fig. 2e). Furthermore, our degrader not only induced conformational changes in HuR (Extended Data Fig. 3c–f) but also promoted CRBN–HuR interactions, burying a total surface area of approximately 780 Å2 (Fig. 2f,g). These interactions created potential contacts between CRBN and HuR, specifically between CRBN residues Y355, H397 and R373 and HuR residues V56, A57 and N30, respectively (Extended Data Fig. 3g).HuR degradation inhibits BRAF-mutant CRCTo identify HuR-dependent cellular vulnerabilities, we analysed DepMap consortium data (https://depmap.org/portal), which revealed a strong positive correlation between HuR and BRAF, as well as MEK1 (encoded by MAP2K1; Extended Data Fig. 4a). BRAF mutation status emerged as the strongest predictor of HuR dependency across cancer cell lines (Fig. 3a). BRAF is more frequently mutated in skin cancers and CRCs, and the co-dependency was particularly pronounced in CRCs (Extended Data Fig. 4b,c). These analyses suggested that BRAF-mutant CRCs may be uniquely sensitive to HuR degradation.Fig. 3: HuR degradation exhibited selective efficacy in BRAF-mutant CRC and suppressed MAPK signalling.The alternative text for this image may have been generated using AI.Full size imagea, DepMap analysis revealed preferential sensitivity of BRAF-mutant tumour cells to HuR deletion. Data represent the difference in HUR CRISPR scores between mutant and WT cell lines with case numbers indicated. P values were calculated by two-tailed, unpaired Student’s t-test. Data were from DepMap (DepMapPublic23Q2+Score and Mutation22Q2Public; https://depmap.org/portal/). Dashed lines indicate cut-off for effect of gene aberration and P value. b, Growth inhibition of dHuR-2 in BRAF-mutant and WT cell lines over 8 days. Data were normalized to DMSO control. Data are presented as mean ± s.d.; n = 3 biologically independent samples. c, 3D spheroid growth assay of Colo205 cells stably expressing control single-guide RNA (sgRNA; sgCtrl) or HUR-targeting sgRNA (sgHuR) with or without doxycycline (Dox; 200 ng ml−1) induction (left). Data are presented as mean ± s.d.; n = 3 biologically independent samples. P values were determined by two-tailed, unpaired Student’s t-test. Immunoblot confirmed HuR depletion post-induction (right). d, Immunoblot analysis of HuR degradation in parental Colo205, CRBN−/− and HURG58A cells treated with dHuR-2 for 24 h. Vinculin served as a loading control. e, Corresponding 3D spheroid inhibition by dHuR-2 (0.001–1 μM) in Colo205 parental versus HURG58A cells over 8 days. f, Tumour growth curves in Colo205 xenografts (n = 6 per group) treated with vehicle or dHuR-2 (6.25–25 mg kg−1, b.i.d.) for 28 days. Data show mean tumour volume ± s.e.m. mpk, mg kg−1; p.o., oral administration. g, KEGG pathway enrichment analysis of downregulated genes in Colo205 cells treated with dHuR-2 (1 μM, 96 h) versus DMSO control. The top ten enriched pathways are shown (false discovery rate  30 µM) against the hERG ion channel. An exploratory tolerability study was conducted with dHuR-3 in both WT and humanized Crbn-KI mice, the latter of which enabled dHuR-3-induced HuR degradation in vivo. Treating these mice with dHuR-3 at an efficacious dose resulted in minimal body weight reduction despite efficient HuR degradation in multiple organs including the heart, liver, spleen, lung, kidney and brain (Supplementary Fig. 1). Standard toxicity and safety assessments were only conducted for DEG6498, the clinical candidate of HuR MGD from Degron Therapeutics. It has shown an acceptable toxicity and safety profile and has been approved by regulatory agencies for clinical development in advanced solid tumours, with BRAF-mutant tumours included as an expansion cohort (ClinicalTrials.gov NCT07244835).MethodsAny methods and additional references are included in the Supplementary Information.Reporting summaryFurther information on research design is available in the Nature Portfolio Reporting Summary linked to this article.

Data availability

All data supporting the findings of this study are available in the article and its Supplementary Information. Uncropped, full western blot images and gels have been provided in Supplementary Figs. 2–6. The eCLIP-seq datasets analysed in this study are publicly available (https://www.encodeproject.org/). Processed CRISPR screen and genetic mutation data of cell lines were downloaded from the DepMap (https://depmap.org/portal). RNA-seq data generated in this study have been deposited in the Genome Sequence Archive in the National Genomics Data Center, China National Center for Bioinformation/Beijing Institute of Genomics, Chinese Academy of Sciences (GSA-Human: HRA012545) and are publicly accessible (https://ngdc.cncb.ac.cn/gsa-human/browse). The proteomics data have been deposited to the ProteomeXchange Consortium (https://proteomecentral.proteomexchange.org) via the iProX partner repository with the dataset identifiers PXD077365 and PXD072281. The cryo-EM structure and map have been deposited in the Protein Data Bank (https://www.rcsb.org/) and the Electron Microscopy Data Bank (https://www.ebi.ac.uk/emdb/), under accession codes 9W2F and EMD-65569, respectively. Source data are provided with this paper.
ReferencesCorcoran, R. B. et al. EGFR-mediated re-activation of MAPK signaling contributes to insensitivity of BRAF mutant colorectal cancers to RAF inhibition with vemurafenib. Nature 2, 227–235 (2012).CAS 

Google Scholar 
Prahallad, A. et al. Unresponsiveness of colon cancer to BRAF(V600E) inhibition through feedback activation of EGFR. Nature 483, 100–103 (2012).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Kopetz, S. et al. Molecular profiling of BRAF-V600E-mutant metastatic colorectal cancer in the phase 3 BEACON CRC trial. Nat. Med. 30, 3261–3271 (2024).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Yi, Q. et al. Spectrum of BRAF aberrations and its potential clinical implications insights from integrative pan-cancer analysis. Front. Bioeng. Biotechnol. 14, 806851 (2022).Article 

Google Scholar 
Kopetz, S. et al. Phase II pilot study of vemurafenib in patients with metastatic BRAF-mutated colorectal cancer. J. Clin. Oncol. 33, 4032–4038 (2015).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Tabernero, J. et al. Encorafenib plus cetuximab as a new standard of care for previously treated BRAF V600E-mutant metastatic colorectal cancer: updated survival results and subgroup analyses from the BEACON study. J. Clin. Oncol. 39, 273–284 (2021).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Corcoran, R. B. et al. Combined BRAF, EGFR, and MEK inhibition in patients with BRAFV600E-mutant colorectal cancer. Cancer Discov. 8, 428–443 (2018).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Brennan, C. M. & Steitz, J. A. HuR and mRNA stability. Cell. Mol. Life Sci. 58, 266–277 (2001).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Mukherjee, N. et al. Integrative regulatory mapping indicates that the RNA-binding protein HuR (ELAVL1) couples pre-mRNA processing and mRNA stability. Mol. Cell 43, 327–339 (2011).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Wu, M., Tong, C. W. S., Yan, W., To, K. K. W. & Cho, W. C. S. The RNA binding protein HuR: a promising drug target for anticancer therapy. Curr. Cancer Drug Target. 19, 382–399 (2019).Article 
CAS 

Google Scholar 
Lachiondo-Ortega, S. et al. Hu antigen R (HuR) protein structure, function and regulation in hepatobiliary tumors. Cancers 14, 2666 (2022).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Kotta-Loizou, I., Giaginis, C. & Theocharis, S. Clinical significance of HuR expression in human malignancy. Med. Oncol. 31, 161 (2014).Article 
PubMed 

Google Scholar 
Levy, N. S., Chung, S., Furneaux, H. & Levy, A. P. Hypoxic stabilization of vascular endothelial growth factor mRNA by the RNA-binding protein HuR. J. Biol. Chem. 273, 6417–6423 (1998).Article 
CAS 
PubMed 

Google Scholar 
Kurosu, T. et al. HuR keeps an angiogenic switch on by stabilising mRNA of VEGF and COX-2 in tumour endothelium. Br. J. Cancer 104, 819–829 (2011).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Finan, J. M., Sutton, T. L., Dixon, D. A. & Brody, J. R. Targeting the RNA-binding protein HuR in cancer. Cancer Res. 83, 3507–3516 (2023).Article 
CAS 
PubMed 

Google Scholar 
Lang, M. et al. HuR small-molecule inhibitor elicits differential effects in adenomatosis polyposis and colorectal carcinogenesis. Cancer Res. 77, 2424–2438 (2017).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Jimbo, M. et al. Targeting the mRNA-binding protein HuR impairs malignant characteristics of pancreatic ductal adenocarcinoma cells. Oncotarget 6, 27312–27331 (2015).Article 
PubMed 
PubMed Central 

Google Scholar 
Chand, S. N. et al. Posttranscriptional regulation of PARG mRNA by HuR facilitates DNA repair and resistance to PARP inhibitors. Cancer Res. 77, 5011–5025 (2017).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Danilin, S. et al. Role of the RNA-binding protein HuR in human renal cell carcinoma. Carcinogenesis 31, 1018–1026 (2010).Article 
CAS 
PubMed 

Google Scholar 
Huang, Y.-H. et al. Delivery of therapeutics targeting the mRNA-binding protein HuR using 3DNA nanocarriers suppresses ovarian tumor growth. Cancer Res. 76, 1549–1559 (2016).Article 
CAS 
PubMed 

Google Scholar 
Yuan, Z., Sanders, A. J., Lin Ye, Y. W. & Jiang, W. G. Knockdown of human antigen R reduces the growth and invasion of breast cancer cells in vitro and affects expression of cyclin D1 and MMP-9. Oncol. Rep. 26, 237–245 (2011).CAS 
PubMed 

Google Scholar 
Zhang, Z., Huang, A., Zhang, A. & Zhou, C. HuR promotes breast cancer cell proliferation and survival via binding to CDK3 mRNA. Biomed. Pharmacother. 91, 788–795 (2017).Article 
CAS 
PubMed 

Google Scholar 
Papatheofani, V. et al. HuR protein in hepatocellular carcinoma: implications in development, prognosis and treatment. Biomedicines 9, 119 (2021).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Zhang, Y., Yang, L., Ling, C. & Heng, W. HuR facilitates cancer stemness of lung cancer cells via regulating miR-873/CDK3 and miR-125a-3p/CDK3 axis. Biotechnol. Lett. 40, 623–631 (2018).Article 
CAS 
PubMed 

Google Scholar 
Palomo-Irigoyen, M. et al. HuR/ELAVL1 drives malignant peripheral nerve sheath tumor growth and metastasis. J. Clin. Invest. 130, 3848–3864 (2020).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Schultz, C. W., Preet, R., Dhir, T., Dixon, D. A. & Brody, J. R. Understanding and targeting the disease-related RNA binding protein human antigen R (HuR). WIREs RNA 11, e1581 (2020).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Krönke, J. et al. Lenalidomide causes selective degradation of IKZF1 and IKZF3 in multiple myeloma cells. Science 343, 301–305 (2014).Article 
ADS 
PubMed 

Google Scholar 
Wu, W. et al. Overcoming IMiD resistance in T-cell lymphomas through potent degradation of ZFP91 and IKZF1. Blood 139, 2024–2037 (2022).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Renneville, A. et al. Avadomide induces degradation of ZMYM2 fusion oncoproteins in hematologic malignancies. Blood Cancer Discov. 2, 250–265 (2021).Article 
CAS 
PubMed 

Google Scholar 
Matyskiela, M. E. et al. SALL4 mediates teratogenicity as a thalidomide-dependent cereblon substrate. Nat. Chem. Biol. 14, 981–987 (2018).Article 
CAS 
PubMed 

Google Scholar 
Bonazzi, S. et al. Discovery and characterization of a selective IKZF2 glue degrader for cancer immunotherapy. Cell Chem. Biol. 30, 235–247.e12 (2023).Article 
CAS 
PubMed 

Google Scholar 
Ting, P. Y. et al. A molecular glue degrader of the WIZ transcription factor for fetal hemoglobin induction. Science 385, 91–99 (2024).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Krönke, J. et al. Lenalidomide induces ubiquitination and degradation of CK1α in del(5q) MDS. Nature 523, 183–188 (2015).Article 
ADS 
PubMed 
PubMed Central 

Google Scholar 
Matyskiela, M. E. et al. A novel cereblon modulator recruits GSPT1 to the CRL4(CRBN) ubiquitin ligase. Nature 535, 252–257 (2016).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Matyskiela, M. E. et al. Crystal structure of the SALL4–pomalidomide–cereblon–DDB1 complex. Nat. Struct. Mol. Biol. 27, 319–322 (2020).Article 
CAS 
PubMed 

Google Scholar 
Fischer, E. S. et al. Structure of the DDB1–CRBN E3 ubiquitin ligase in complex with thalidomide. Nature 512, 49–53 (2014).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Petzold, G., Fischer, E. S. & Thomä, N. H. Structural basis of lenalidomide-induced CK1α degradation by the CRL4CRBN ubiquitin ligase. Nature 532, 127–130 (2016).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Akdel, M. et al. A structural biology community assessment of AlphaFold2 applications. Nat. Struct. Mol. Biol. 29, 1056–1067 (2022).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Dai, W., Zhang, G. & Makeyev, E. V. RNA-binding protein HuR autoregulates its expression by promoting alternative polyadenylation site usage. Nucleic Acids Res. 40, 787–800 (2012).Article 
CAS 
PubMed 

Google Scholar 
Sievers, Q. L. et al. Defining the human C2H2 zinc finger degrome targeted by thalidomide analogs through CRBN. Science 362, eaat0572 (2018).Fink, E. C. et al. Crbn I391V is sufficient to confer in vivo sensitivity to thalidomide and its derivatives in mice. Blood 132, 1535–1544 (2018).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Watson, E. R. et al. Molecular glue CELMoD compounds are regulators of cereblon conformation. Science 378, 549–553 (2022).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Abascal, F. et al. Expanded encyclopaedias of DNA elements in the human and mouse genomes. Nature 583, 699–710 (2020).Article 

Google Scholar 
Marranci, A. et al. The landscape of BRAF transcript and protein variants in human cancer. Mol. Cancer 16, 85 (2017).Article 
PubMed 
PubMed Central 

Google Scholar 
Chang, S.-H. et al. Antagonistic function of the RNA-binding protein HuR and miR-200b in post-transcriptional regulation of vascular endothelial growth factor-A expression and angiogenesis. J. Biol. Chem. 288, 4908–4921 (2013).Article 
CAS 
PubMed 

Google Scholar 
Benson, A. B. et al. Colon Cancer, version 3.2024, NCCN Clinical Practice Guidelines in Oncology. J. Natl Comp. Cancer Netw. 22, e240029 (2024).Kopetz, S. et al. Encorafenib, cetuximab and chemotherapy in BRAF-mutant colorectal cancer: a randomized phase 3 trial. Nat. Med. 31, 901–908 (2025).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Wang, A. et al. Long noncoding RNA EGFR-AS1 promotes cell growth and metastasis via affecting HuR mediated mRNA stability of EGFR in renal cancer. Cell Death Dis. 10, 154 (2019).Article 
PubMed 
PubMed Central 

Google Scholar 
Kassabri, L. & Benhamou, R. I. Druglike molecular degraders of the oncogenic RNA-binding protein HuR. JACS Au 5, 3879–3891 (2025).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Fletcher, A. et al. A TRIM21-based bioPROTAC highlights the therapeutic benefit of HuR degradation. Nat. Commun. 14, 7093 (2023).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Benoit, R. M. et al. The X-ray crystal structure of the first RNA recognition motif and site-directed mutagenesis suggest a possible HuR redox sensing mechanism. J. Mol. Biol. 397, 1231–1244 (2010).Download referencesAcknowledgementsWe thank L. Zou for helpful discussions; N. Zheng for technical support; and the ENCODE Consortium and the ENCODE production laboratory for generating the datasets ENCSR296TSJ and ENCSR09OLNQ. Some data used in this publication were generated by Degron Therapeutics. Support from the Mass Spectrometry System, Flow System and the MCB Core Facility at the School of Life Science and Technology, ShanghaiTech University is also acknowledged.FundingThis research was supported by Shanghai Frontiers Science Center for Biomacromolecules and Precision Medicine at ShanghaiTech University. This work was supported by grants from the National Key R&D Program (no. 2025YFA1309004), the National Natural Science Foundation of China (nos. 31970671 and 92053118) and the Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of China (no. JYB2025XDXM502).Author informationAuthor notesThese authors contributed equally: Xiaocui Lu, Xiuyun Wang, Zheng Yang, Xusheng WangAuthors and AffiliationsSchool of Life Sciences and Technology, ShanghaiTech University, Shanghai, ChinaXiaocui Lu, Xiuyun Wang, Xusheng Wang, Lin Wang, Yisheng Pu, Keyu Zhang, Ziqiang Zhu, Lanxin Ye, Jiayuan Huang, Xiaofan Wei, Fang Bai & Yong CangDegron Therapeutics Co., Ltd, Shanghai, ChinaZheng Yang, Lin Wang, Chunhui Xu, I-Chung Lo, Chenlu Geng, Xiaobing Qian, Hao Dou, Hexiu Su & Yong CangInstitute for Advanced Study in Physics and ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, ChinaYanan ZhuAuthorsXiaocui LuView author publicationsSearch author on:PubMed Google ScholarXiuyun WangView author publicationsSearch author on:PubMed Google ScholarZheng YangView author publicationsSearch author on:PubMed Google ScholarXusheng WangView author publicationsSearch author on:PubMed Google ScholarLin WangView author publicationsSearch author on:PubMed Google ScholarChunhui XuView author publicationsSearch author on:PubMed Google ScholarI-Chung LoView author publicationsSearch author on:PubMed Google ScholarChenlu GengView author publicationsSearch author on:PubMed Google ScholarLin WangView author publicationsSearch author on:PubMed Google ScholarYisheng PuView author publicationsSearch author on:PubMed Google ScholarKeyu ZhangView author publicationsSearch author on:PubMed Google ScholarZiqiang ZhuView author publicationsSearch author on:PubMed Google ScholarLanxin YeView author publicationsSearch author on:PubMed Google ScholarJiayuan HuangView author publicationsSearch author on:PubMed Google ScholarXiaofan WeiView author publicationsSearch author on:PubMed Google ScholarFang BaiView author publicationsSearch author on:PubMed Google ScholarYanan ZhuView author publicationsSearch author on:PubMed Google ScholarXiaobing QianView author publicationsSearch author on:PubMed Google ScholarHao DouView author publicationsSearch author on:PubMed Google ScholarHexiu SuView author publicationsSearch author on:PubMed Google ScholarYong CangView author publicationsSearch author on:PubMed Google ScholarContributionsX.L., Xiuyun W., Z.Y. and Xusheng W. contributed equally. Z.Y. designed and synthesized the compounds. X.L. designed and performed the cellular assays for molecular glue mechanism-of-action validation. Xiuyun W. designed and performed the cell panel screen and exploration on overcoming BRAFi resistance and its synergist effect. Xusheng W. designed and performed the investigation on BRAF splicing regulation. H.D. and L.W. (Degron Therapeutics) designed and conducted the studies on binary and ternary complex evaluations. H.D. solved the cryo-EM structure. Y.Z. helped refine the cryo-EM map. C.X. and I-C.L. performed the bioinformatics analysis. C.G. conducted the degradation potency comparison supporting structure–activity relationship exploration. Y.P. was responsible for breeding the Crbn-KI mice and isolation of mouse embryonic fibroblasts. K.Z., Z.Z., L.Y., J.H. and X.W. assisted in performing the repeated experiments for verification and processing the western blot data. L.W. (ShanghaiTech University) and F.B. performed the degron prediction via computer-assisted drug design. X.Q. provided guidance to the project for the mechanistic, pharmacokinetics, pharmacodynamics and pharmacology studies. H.S. and Y.C. conceived the project and drafted the manuscript. All authors reviewed and edited the manuscript.Corresponding authorsCorrespondence to
Hao Dou, Hexiu Su or Yong Cang.Ethics declarations

Competing interests
Z.Y., L.W. (Degron Therapeutics), C.X., I-C.L., C.G., X.Q., H.D. and H.S. are current employees and shareholders of Degron Therapeutics. Y.C. is a shareholder and consultant of Degron Therapeutics, and receives research funding from Degron Therapeutics. Z.Y., H.S., C.G. and H.D. have a patent related to this work: WO2024114639A, titled ‘Compounds for modulating HuR (ELAVL1)’; these authors declare no other competing interests. The other authors declare no competing interests.

Peer review


Peer review information
Nature thanks Rene Bernards, Mikihiko Naito, Weiping Tang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

Additional informationPublisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Extended data figures and tablesExtended Data Fig. 1 Validation of HuR degradation.a, Immunoblot of HuR in JHH-7 CRBN WT and CRBN-KO cells treated with cycloheximide (CHX; 100 µg ml−1) in the presence or absence of dHuR-1 (10 µM) over time. Vinculin served as a loading control. b, RT-qPCR quantification of HUR mRNA in JHH-7 cells treated with 10 μM dHuR-1 for 24 h. GAPDH served as reference gene. c, Flow cytometry analysis of 293T cells co-transfected with HuR-eGFP-IRES-mCherry reporter and CRBN expression plasmid, then treated with DMSO or 10 μM dHuR-1 in the presence or absence of 1 μM MLN4924 for 24 h. The ratio of eGFP/mCherry fluorescence intensity was normalized to the DMSO-only group. d, Immunoblot analysis of HuR in cytoplasmic or nuclear fractions from KP4 cells treated with 10 μM dHuR-1 over time. Lamin B1 (nuclear) and Vinculin (cytoplasmic) served as fractionation controls. e, Chemical structure of 2-7. f, Immunoblot of HuR, ZMYM2, ZFP91, and GSPT1 in MOLT4 cells treated with DMSO or dHuR-1/dHuR-2 (0.1–10 µM, 24 h). g, Immunoblot of HuR, ZFP91, and ZMYM2 in Colo205 cells treated with DMSO or dHuR-2 (0.1–10000 nM, 24 h) and the relative protein abundance was quantified to determine the DC50 of dHuR-2. h, Immunoblot of HuR, HuB, HuC, and HuD in U-87 MG and U-118 MG cells treated with dHuR-1 or dHuR-2 (10 µM, 24 h). Data were presented as mean ± s.d.; n = 3 biologically independent samples (b, c). P values were determined by two-tailed unpaired Student’s t-test. For gel source data, see Supplementary Fig. 4.Extended Data Fig. 2 Validation of MGD-induced CRBN-HuR interactions.a,b, Flow cytometry analysis of 293T cells transfected with WT HuR-eGFP-IRES-mCherry reporter, G58N, or G144N (a) or the indicated G58X mutants (b) Upon treatment with 10 μM dHuR-1 for 24 h. The ratio of eGFP/mCherry fluorescence intensity was normalized to DMSO-only group for each reporter. c, Co-IP analysis in 293T cells transiently expressing FLAG-HuR and MYC-CRBN. Western blots showed immunoprecipitated FLAG-HuR or FLAG-HuR-G58N and associated MYC-CRBN in the presence of 100 μM dHuR-1. Vinculin served as negative control. d, Flow cytometry analysis of HuR-eGFP levels in 293T CRBNKO cells reconstituted with human WT CRBN or mutant CRBN (E377V, V388I, E377V/V388I) upon treatment of 10 μM dHuR-1 for 24 h. e, Immunoblot analysis of mouse HuR in embryonic fibroblasts from WT, CrbnV380E, CrbnI391V or CrbnV380E/I391V mice treated with dHuR-2 for 24 h. Vinculin served as a loading control. f, Sensorgrams showed direct interaction of dHuR-1 or dHuR-2 with CRBN. Steady-state response units (RU) were used to determine binding affinities. CRBN(W386A) was used as a negative control. g, Sensorgrams of HuR binding to CRBN-dHuR-1 or CRBN-dHuR-2, with CRBN titrated from 2.4 to 0.2 μM at a CRBN:MGD molar ratio of 1:70. Kinetic parameters were derived from 1:1 binding model fitting (Biacore 8k software). h, Immunoblot of HuR after pulled down by biotin-Ubi in ESTUB assay. Data were presented as mean ± s.d.; n = 3 biologically independent samples (a, b, d). P values were determined by two-tailed unpaired Student’s t-test. For gel source data, see Supplementary Fig. 4.Extended Data Fig. 3 Cryo-EM processing workflow and details of CRBN-MGD-HuR ternary complex formation.a, Cryo-EM processing schematic of CRBN-DDB1 with HuR and dHuR-2. b, Cryo-EM structure of DDB1:CRBN:HuR complex bound to dHuR-2 at 3.3 Å (DDB1 BPB domain was masked out). c, Structural superposition of HuR from the CRBN-dHuR-2-HuR ternary complex (pink) with the existing native HuR crystal structure (yellow, PDB 3hi9 (ref. 51)). d, Surface representation of the CRBN-dHuR-2-HuR ternary structure. e, Model of the HuR crystal structure (yellow) docked onto the CRBN-dHuR-2 in surface representation. f, Structural changes in HuR from its native state (yellow) to the ternary state with CRBN and dHuR-2 (pink). g, Detailed interactions observed in the CRBN-dHuR-2-HuR ternary complex. Key interacting residues were shown in stick representation and Cα of G58 was shown in sphere representation.Extended Data Fig. 4 HuR dependency in BRAF-mutant CRC.a, Top ten genes showing highest Pearson correlation with HuR dependency scores across 1,086 cancer cell lines (DepMap Public 24Q4). Gene symbols colored by positive (red) or negative (blue) correlation. b, Number of cell lines with or without BRAF mutations across tumor types in DepMap, ranked by the P values (determined by two-tailed unpaired Student’s t-test) for comparing HuR CRISPR scores between BRAF mutant and wildtype cells. c, Correlation of CRISPR score for HuR and BRAF depletion in BRAF-mutant (red) or WT (blue) CRC and melanoma cell lines. Data in panels a–c adapted from the public 25Q3 dataset from DepMap (www.depmap.org). d,e, Immunoblot analysis of HuR protein levels in BRAF-mutant (d) and WT (e) CRC cell lines treated with dHuR-2. f, Colony formation in 2 BRAF-mutant (WiDr and HT29) and 3 WT (HCT116, HCT15 and DLD1) CRC cell lines treated with dHuR-2 (0.01-1 μM, 8 days). g, Relative cell viability of doxycycline-inducible HUR-KO HT29 cells (sgCtrl vs sgHuR) over 8 days. Immunoblot confirmation of HuR depletion 96 h post-induction. h, Relative cell viability of HuR-knockout DLD1 and HCT116 cells (sgCtrl vs sgHUR) over 8 days. Immunoblot confirmation of HuR depletion 96 h post-induction. i, Colony formation of HT29 and DLD1 HUR-knockout cells after 12-day incubation. Data were presented as mean ± s.d.; n = 3 biologically independent samples (g, h). P values were determined by two-tailed unpaired Student’s t-test. For gel source data, see Supplementary Fig. 4.Extended Data Fig. 5 In vivo pharmacokinetics and pharmacodynamics of dHuR-2.a, Plasma concentration-time curves of dHuR-2 in C57BL/6 mice following single-dose administration via intravenous (i.v., 5 mg kg−1), intraperitoneal (i.p., 50 mg kg−1), and oral (p.o., 50 mg kg−1) routes. b, Body weight (BW) changes in Colo205 tumor-bearing mice (n = 6 per group) treated with vehicle or dHuR-2 (6.25-25 mg kg−1, b.i.d) over 28 days. Data were presented as mean ± s.e.m.. b.i.d., twice daily. c, Free plasma concentrations of dHuR-2 in mice bearing Colo205 xenografts at indicated time points after administration (6.25-25 mg kg−1) on Day 14. Dotted line indicated the DC80 of dHuR-2. d, In vivo target engagement validation. Immunoblot analysis of HuR protein levels in tumors from Fig. 3f at 12 h and 24 h post-final dose on Day 28. Tubulin served as a loading control. mpk: mg kg−1. e, Colo205 cells were treated with dHuR-2 (1 μM) for 24 h, followed by compound washout. HuR protein levels were analyzed by immunoblot at the indicated time points. For gel source data, see Supplementary Fig. 5.Extended Data Fig. 6 Effects of HuR depletion or degradation on MAPK signaling pathways and cell cycle regulation.a, Gene Set Enrichment Analysis (GSEA) showing significant downregulation of MAPK signaling (NES = −1.1866) and cell cycle (NES = −1.2203) pathways in Colo205 cells treated with 1 μM dHuR-2 vs DMSO control (96 h). b, KEGG pathway analysis of or downregulated proteins identified by whole cell proteomics in Colo205 treated with 1 μM dHuR-2 for 5 days. The top 10 enriched pathways were shown (FDR