Breast cancer (BC) is the most diagnosed malignancy in women and often progresses to distant metastasis. Unfortunately, current treatments inadequately address the clinical needs of metastatic BC (MBC) patients. This highlights the importance of developing effective therapies for MBC patients. One of the Hippo signaling transducers, transcriptional co-activator with PDZ-binding motif (TAZ), plays a major role in BC progression. Since TAZ mostly interacts with TEAD to facilitate its function, targeting TAZ-TEAD interaction may become a treatment approach for MBC patients. To identify inhibitors of TAZ-TEAD binding, we established a sensitive TR-FRET biosensor and performed an ultra-high throughput screen. Alexidine was identified as a TAZ-TEAD binding inhibitor capable of suppressing TAZ-induced migration and invasion in BC cells as well as metastasis in bone-on-a-chip and mouse models. In conclusion, we describe a robust method for screening inhibitors of TAZ-TEAD interaction, contributing to the development of effective cancer treatments.
© 2025 The Author(s).

The nucleocapsid protein (NP) of SARS-CoV-2, an RNA-binding protein, is capable of undergoing liquid-liquid phase separation (LLPS) during viral infection, which plays a crucial role in virus assembly, replication, and immune regulation. In this study, we developed a homogeneous time-resolved fluorescence (HTRF) method for identifying inhibitors of the SARS-CoV-2 NP-RNA interaction. Using this HTRF-based approach, we identified two natural products, sennoside A and sennoside B, as effective blockers of this interaction. Bio-layer interferometry assays confirmed that both sennosides directly bind to the NP, with binding sites located within the C-terminal domain. Additionally, fluorescence recovery after photobleaching (FRAP) experiments revealed that sennoside B significantly inhibited RNA-induced LLPS of the NP, while sennoside A displayed comparatively weaker activity. Thus, the developed HTRF-based assay is a valuable tool for identifying novel compounds that disrupt the RNA-binding activity and LLPS of the SARS-CoV-2 NP. Our findings may facilitate the development of antiviral drugs targeting SARS-CoV-2 NP.

The PINK1/Parkin pathway targets damaged mitochondria for degradation via mitophagy. Genetic evidence implicates impaired mitophagy in Parkinson's disease, making its pharmacological enhancement a promising therapeutic strategy. Here, we characterize two mitophagy activators: a novel Parkin activator, FB231, and the reported PINK1 activator MTK458. Both compounds lower the threshold for mitochondrial toxins to induce PINK1/Parkin-mediated mitophagy. However, global proteomics revealed that FB231 and MTK458 independently induce mild mitochondrial stress, resulting in impaired mitochondrial function and activation of the integrated stress response, effects that result from PINK1/Parkin-independent off-target activities. We find that these compounds impair mitochondria by distinct mechanisms and synergistically decrease mitochondrial function and cell viability in combination with classical mitochondrial toxins. Our findings support a model whereby weak or "silent" mitochondrial toxins potentiate other mitochondrial stressors, enhancing PINK1/Parkin-mediated mitophagy. These insights highlight important considerations for therapeutic strategies targeting mitophagy activation in Parkinson's disease.

Evidence suggests that ARV1 regulates sterol movement within the cell. Saccharomyces cerevisiae cells lacking ScArv1 have defects in sterol trafficking, distribution, and biosynthesis. HepG2 cells treated with hARV1 antisense oligonucleotides accumulate cholesterol in the endoplasmic reticulum. Mice lacking Arv1 have a lean phenotype when fed a high fat diet and show no signs of liver triglyceride or cholesterol accumulation, suggesting a role for Arv1 in lipid transport. Here, we explored the direct lipid-binding activity of recombinant human ARV1 using in vitro lipid-binding assays. ARV1 lipid-binding activity was observed within the first N-terminal 98 amino acids containing the conserved ARV1 homology domain (AHD). The zinc-binding domain and conserved cysteine clusters within the AHD were necessary for lipid binding. Both full-length ARV1 and the AHD bound cholesterol, several phospholipids, and phosphoinositides with high affinity. The AHD showed the highest binding affinity for monophosphorylated phosphoinositides. Several conserved amino acids within the AHD were necessary for phospholipid binding. Biochemical studies suggested that ARV1 exists as a dimer in cells, with oligomerization being critical for ARV1 function, as amino acid mutations predicted to have a negative effect on dimerization caused weakened or complete loss of lipid binding. Our results show for the first time that human ARV1 can directly bind cholesterol and phospholipids. How this activity may function to regulate lipid binding and maintain proper lipid trafficking and/or transport in cells requires further studies.
Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.

Bruton tyrosine kinase (BTK) is an important signaling hub that activates the B-cell receptor (BCR) signaling cascade. BCR activation can contribute to the growth and survival of B-cell lymphoma or leukemia. The inhibition of the BCR signaling pathway is critical for blocking downstream events and treating B-cell lymphomas. Herein, we report potent and orally available proteolysis-targeting chimeras (PROTACs) that target BTK to inactivate BCR signaling. Of the PROTACs tested, UBX-382 showed superior degradation activity for wild-type (WT) and mutant BTK proteins in a single-digit nanomolar range of half-maximal degradation concentration in diffuse large B-cell lymphoma cell line. UBX-382 was effective on 7 out of 8 known BTK mutants in in vitro experiments and was highly effective in inhibiting tumor growth in murine xenograft models harboring WT or C481S mutant BTK-expressing TMD-8 cells over ibrutinib, ARQ-531, and MT-802. Remarkably, oral dosing of UBX-382 for <2 weeks led to complete tumor regression in 3 and 10 mg/kg groups in murine xenograft models. UBX-382 also provoked the cell type-dependent and selective degradation of cereblon neosubstrates in various hematological cancer cells. These results suggest that UBX-382 treatment is a promising therapeutic strategy for B-cell-related blood cancers with improved efficacy and diverse applicability.
© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.