ACS Pharmacology and Translational Science最新文献

The orexin-2 receptor (OX₂R), a G protein-coupled receptor activated by the neuropeptides, orexin A and B, plays an integral role in orchestrating motivation, feeding behavior, and the sleep-wake cycle. Pharmacological modulation of OX₂R has shown therapeutic potential for a variety of central nervous system (CNS) diseases, most notably narcolepsy and insomnia. Noninvasive imaging of OX₂R could enable the visualization of its regional distribution, facilitate assessments of target engagement, and support the development of OX₂R-directed therapies. Nonetheless, there are currently no suitable radioligands available for imaging OX₂R with positron emission tomography (PET). Herein, we report the design and evaluation of two novel PET ligand candidates, [¹⁸F]1 ([¹⁸F]OX₂-2303) and [¹⁸F]2 ([¹⁸F]OX₂-2304), as potential imaging probes for OX₂R. Both candidates exhibit excellent OX₂R binding affinity (K_i = 0.1 and 1 nM, respectively) and remarkable selectivity over OX₁R (>600-fold). In vitro autoradiography confirmed robust and selective binding to OX₂R in rat brain sections. In vivo PET imaging revealed low brain uptake at baseline, attributed to active efflux by P-glycoprotein (P-gp) and/or breast cancer resistance protein (BCRP). Furthermore, pharmacological inhibition of these efflux transporters markedly enhanced brain penetration and OX₂R antagonists demonstrated notable blocking effects to OX₂R tracers during these conditions. Collectively, [¹⁸F]1 ([¹⁸F]OX₂-2303) and [¹⁸F]2 ([¹⁸F]OX₂-2304) constitute promising chemical starting points for the development of OX₂R PET radioligands, although further medicinal chemistry optimization will be required to overcome transporter-mediated efflux from the brain.

Monensin (MON) is a polyether ionophore antibiotic of natural origin and is an FDA-approved drug for veterinary use. Recent studies have highlighted its potential anticancer activity in various in vitro and in vivo models. In this study, we evaluated the anti-breast cancer activity of MON and 37 synthetic analog compounds using cell monolayer and organoid models. Through a mini-ring cell viability assay, several compounds were identified that were more potent and selective against breast cancer cells compared to non-cancerous cells, surpassing the activity of parent MON. MON and these compounds induced significant DNA fragmentation, reduced cell migration, and downregulated SOX2 expression. Furthermore, MON and the most potent analog, compound 12, reduced the percentage of CD44⁺/CD24^–/low stem-like cells and diminished colony formation properties. Proteomics analyses revealed that several pathways, including extracellular matrix organization, were significantly dysregulated by MON and compound 12 in breast cancer cells. Among these, TIMP2, a protein associated with the suppression of tumor growth and metastasis, was identified as one of the most prominently upregulated proteins by MON and compound 12 in MDA-MB-231 cells. This finding was also validated in other breast cancer and melanoma cell lines. To simulate breast cancer metastasis to the brain, a human hybrid organoid system: tumor in brain organoid (HOSTBO) model was developed. MON and compound 12 significantly reduced Ki-67 expression within the HOSTBOs, and compound 12 significantly downregulated SOX2 expression. Collectively, MON and compound 12 significantly reduced the proliferation of breast cancer stem-like cells in the organoid models, inhibited their migration, and dysregulated markers associated with stemness, demonstrating their potential as anti-metastatic agents and warranting further clinical development.

Parkinson’s disease (PD), the second most prevalent neurodegenerative disorder afflicting human health, is primarily characterized by the degeneration of dopaminergic neurons in the midbrain, leading to movement disorders as the main clinical manifestation. Extensive research has demonstrated that the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome and its accompanying neuroinflammation play a pivotal role in the progression of PD. ST-4, namely 15-oxosteviol, an analogue of the diterpene oridonin, exhibits potent and specific inhibition of NLRP3 in in vitro experiments. The anti-inflammatory effects of ST-4 were evaluated in mouse models of chronic and progressive disorders, in which it showed significant efficacy in ameliorating obesity, type 2 diabetes, and peritonitis. In this study, the potential interest of ST-4 for the treatment of neuroinflammatory diseases was further investigated in a PD mouse model. ST-4 effectively suppressed the activation of the NLRP3 inflammasome induced by lipopolysaccharide in neuronal cells. Additionally, treatment with ST-4 significantly improved various aspects of PD pathology, including behavioral impairments, loss of dopaminergic neurons, alterations in cerebral neurophysiology, and dysregulated gene expression associated with metabolic dysfunction, highlighting its therapeutic potential for the treatment of Parkinson’s disease.

Therapy-induced senescence (TIS) is a reversible growth arrest induced by anticancer treatments, which may contribute to the development of long-term therapy resistance in tumor cells. Senotherapeutics, agents targeting senescent cells, are being tested in clinical trials to improve patient outcomes. Due to the transient nature of TIS, we hypothesized that senolytics would be most effective when administered at the appropriate time. We created a reliable TIS cell line model in triple-negative breast cancer (TNBC) using experimental drug YM155. We observed that a single dose of YM155 triggers a brief senescence, leading to a persistent drug-tolerant state that cannot be reversed by redosing. This reversibility is not limited to cancer cells. It extends to noncancerous human cells and live zebrafish larvae, suggesting a rapid adaptation mechanism against xenobiotics. We identified transforming growth factor-β (TGF-β), a cytokine linked to TNBC chemoresistance, as being expressed alongside the emergence of drug tolerance. We inhibited TGF-β signaling to eliminate the tolerant phenotype and promote the clearance of cancer cells by immune cells. However, this was most effective within a specific time window after TIS induction. We suggest that the timely use of senotherapeutics could improve the effectiveness of anticancer drugs in clinical settings.

Xanthone, an oxygenated heterotricyclic phytochemical, has recently emerged as a promising scaffold in cancer research due to its multitargeted anticancer potential. Recent studies demonstrate its affinity for G-quadruplex (G4) DNA structures. In this context, herein, we describe the design and synthesis of a series of xanthone–benzimidazole conjugates to investigate their specific cytotoxic effects on cancer cells through the stabilization of telomeric G4 DNA structures. Comprehensive in vitro biophysical and cellular experiments were performed to screen the most effective compounds for targeting telomeric G4 DNA structures among them. The structure–activity relationship (SAR) of quadruplex-compound interactions was documented as well. The current study reveals that two compounds, XDBHEP and XDBAEP, exhibit maximum binding affinity and selectivity toward the antiparallel telomeric form of G4 DNA. These compounds stabilize this G4 DNA structure through binding within the DNA groove loci and exhibit a 1:1 molar binding stoichiometry. The specific cytotoxic effect of these compounds on different types of cancer cells, including A549, T-47D, and MCF-7, and their apoptotic-mediated cell death was further demonstrated by several in vitro cellular experiments. In addition, blood compatibility, ADME studies, pharmacokinetics, and biodistribution studies were also performed to assess the potential of these compounds for further in vivo and clinical investigations. Based on the current study, the selective antiparallel telomeric G4 DNA targeting properties and specific cancer cell cytotoxicity effects of xanthone–benzimidazole conjugates could provide valuable information to support the research community in the future development of new anticancer drugs through G4 DNA stabilization based on this pharmacophore.

Viral proteases are critical targets for antiviral drug development, but current screening methods for protease inhibitors often require high biosafety levels or lack cell-based relevance. Here, we developed a novel cell-based assay system utilizing recombinant green fluorescent protein (GFP) technology, designated as DIFF-recombinant GFP (DIFF-rGFP), for potentially high-throughput screening of viral protease inhibitors. By systematically investigating potential insertion sites within the green fluorescent protein (GFP), we constructed a series of recombinant green fluorescent proteins (rGFPs) that accommodate exogenous protease cleavage sequences. Using the 3-Chymotrypsin like protease (3CL^pro) of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) as a model, we demonstrated that the DIFF-rGFP assay relies on the coexpression of rGFP and the protease, with fluorescence intensity increasing upon inhibitor action. This assay eliminates the need for high biosafety laboratories and is performed at the cellular level. For proof of concept, we validated this method using two well-characterized SARS-CoV-2 3CL^pro inhibitors, GC376 and ensitrelvir, to demonstrate its applicability for inhibitor screening. Our results indicate that the DIFF-rGFP assay is a safe, efficient, and reliable platform for identifying viral protease inhibitors with potential applications in accelerating antiviral drug discovery.

This Viewpoint examines the emerging role of cannabidiol (CBD) in sports medicine, with a particular emphasis on its potential to support athlete health through indirect mechanisms. Rather than acting as a direct performance enhancer, CBD may contribute to improved readiness for training and competition by promoting better sleep, alleviating anxiety, and accelerating recovery. We also discuss challenges for antidoping compliance, including product contamination and regulatory gaps in Brazil, and highlight CBD’s promise as a safer alternative to opioids for pain management in athletes.

The circadian rhythms and cell cycle are closely interlinked, creating a fundamental regulatory axis vital for tissue homeostasis, which is frequently dysregulated in cancers. The circadian apparatus, which is regulated by the core clock components (BMAL1, CLOCK, PER, and CRY in mammals), establishes temporal order on cell proliferation by rhythmically regulating important cell cycle regulators such as WEE1, p21, and the oncogene MYC. This is frequently accomplished through overlapped signaling nodes that include particular kinases and ubiquitin ligases (e.g., FBXW7). Mounting evidence implicates disruption of this circadian clock-cell cycle synchrony, arising from genetic or environmental factors, as a significant contributor to tumorigenesis and progression via impacts on DNA repair fidelity, oncogene stability, and tumor suppressor pathways. This review critically evaluates the new concept of chrono-pharmacology for cancer, focusing on the substantial effects and side effects of different anticancer drugs that depend on the time-of-day efficacy. We discussed some interesting examples, like HSP90 inhibitors (ganetespib), HDAC inhibitors (quisinostat), topoisomerase inhibitors (doxorubicin), and BCL-2 family antagonists (Obatoclax, TW-37), whose therapeutic activities are tightly regulated by circadian control over their molecular targets, pharmacokinetic processes, and downstream physiological pathways. Furthermore, the circadian influence extends to the tumor microenvironment and antitumor immunity, suggesting novel chrono-immunotherapy approaches. By putting together the molecular bases of these temporal dynamics, this review underscores the significant potential of chronotherapy─the timed administration of drugs to improve cancer treatment by enhancing therapeutic indices and paving the way for personalized, temporally optimized oncology strategies.

Class A G protein-coupled receptors (GPCRs) are targets for ∼36% of commercial drugs. GPCRs in their apo-forms exhibit conformational heterogeneity, and more than a single active and inactive conformation exists in equilibrium. Distinct transient conformational states can be significantly populated and can be coupled with different agonists, transducers, and effectors, giving rise to divergent signaling pathways. The characterization of such transient conformational states, which may have eluded identification by X-ray crystallography and cryogenic electron microscopy, can be achieved through a combination of biophysical techniques, such as nuclear magnetic resonance, double electron–electron resonance spectroscopy, single-molecule fluorescence microscopy, molecular dynamics simulations, and mass spectrometry. We review findings about the functional, conformational states of four class A GPCRs, including detailed results for the adenosine A_2A and β₂ adrenergic receptors and important observations for the β₁ and μ opioid receptors. The identification of ligands that can bind to distinct conformations, e.g., agonists that activate favorable pathways while inhibiting deleterious ones, represents an important goal in drug development.

Leukemia Inhibitory Factor (LIF) is a pleiotropic cytokine secreted by tumor cells to evade immune detection, contributing to tumor progression and resistance to therapy. Targeting LIF has emerged as a promising strategy, with anti-LIF therapies in clinical trials across a variety of cancers. Glioblastoma, a highly aggressive LIF-secreting brain tumor, is a critical target for these emerging therapies. This study aimed to develop an anti-LIF immunoPET agent for monitoring LIF expression in vivo, improving detection and targeted treatment strategies for glioblastoma. An anti-LIF antibody was conjugated to p-SCN-Bz-DFO and radiolabeled with positron-emitting zirconium-89 (⁸⁹Zr). Target binding properties and stability of the radioimmunoconjugate were assessed by ELISA and size exclusion chromatography. The biodistribution of [⁸⁹Zr]Zr-DFO-anti-LIF was evaluated by PET/CT imaging in an orthotopic glioblastoma mouse model with LIF-positive (GL261N) and LIF-negative (GL261N-CRISPR/LIF) tumors at 24, 48, and 72 hours post-administration. Tumor LIF levels were measured ex vivo by immunohistochemistry. Mass spectrometry determined 2.4 ± 0.3 chelators per antibody molecule. Competitive ELISA demonstrated unaltered affinity post-conjugation. Radiolabeling at a 1 MBq of ⁸⁹Zr per 5 μg of anti-LIF ratio achieved >68% yield, >95% purity, and 0.17 ± 0.03 MBq/μg specific activity. The radioimmunoconjugate remained >90% intact after 72 h in both saline and mouse serum. PET imaging revealed specific accumulation in LIF-positive brain tumors in vivo (6 ± 1.26 % ID/mL at 72 h), which was 2-fold higher than that observed in the GL261N-CRISPR/LIF model. [⁸⁹Zr]Zr-DFO-anti-LIF was successfully synthesized, exhibiting specificity and stability in vitro and in vivo, thus supporting its potential for glioblastoma monitoring, as well as guiding anti-LIF therapies.