-
International Journal of Pharmaceutics Jun 2024Rhein, a natural anthraquinone compound derived from traditional Chinese medicine, exhibits potent anti-inflammatory properties via modulating the level of Reactive...
Rhein, a natural anthraquinone compound derived from traditional Chinese medicine, exhibits potent anti-inflammatory properties via modulating the level of Reactive oxygen or nitrogen species (RONS). Nevertheless, its limited solubility in water, brief duration of plasma presence, as well as its significant systemic toxicity, pose obstacles to its in vivo usage, necessitating the creation of a reliable drug delivery platform to circumvent these difficulties. In this study, an esterase-responsive and mitochondria-targeted nano-prodrug was synthesized by conjugating Rhein with the polyethylene glycol (PEG)-modified triphenyl phosphonium (TPP) molecule, forming TPP-PEG-RH, which could spontaneously self-assemble into RPT NPs when dispersed in aqueous media. The TPP outer layer of these nanoparticles enhances their pharmacokinetic profile, facilitates efficient delivery to mitochondria, and promotes cellular uptake, thereby enabling enhanced accumulation in mitochondria and improved therapeutic effects in vitro. The decline in RONS was observed in IL-1β-stimulated chondrocyte after RPT NPs treating. RPT NPs also exert excellent anti-inflammatory (IL-1β, TNF-α, IL-6 and MMP-13) and antioxidative effects (Cat and Sod) via the Nrf2 signalling pathway, upregulation of cartilage related genes (Col2a1 and Acan). Moreover, RPT NPs shows protection of mitochondrial membrane potential and inhibition of chondrocyte apoptosis. Moreover, These findings suggest that the mitochondria-targeted polymer-Rhein conjugate may offer a therapeutic solution for patients suffering from chronic joint disorders, by attenuating the progression of osteoarthritis (OA).
PubMed: 38945463
DOI: 10.1016/j.ijpharm.2024.124397 -
The Journal of Biological Chemistry Jun 2024The development of safe and effective broad-spectrum antivirals that target the replication machinery of respiratory viruses is of high priority in pandemic preparedness...
The development of safe and effective broad-spectrum antivirals that target the replication machinery of respiratory viruses is of high priority in pandemic preparedness programs. Here, we studied the mechanism of action of a newly discovered nucleotide analog against diverse RNA-dependent RNA polymerases (RdRp) of prototypic respiratory viruses. GS-646939 is the active 5'-triphosphate (TP) metabolite of a 4'-cyano modified C-adenosine analog phosphoramidate prodrug GS-7682. Enzyme kinetics show that the RdRps of human rhinovirus type 16 (HRV-16) and enterovirus 71 (EV-71) incorporate GS-646939 with unprecedented selectivity; GS-646939 is incorporated 20-50-fold more efficiently than its natural ATP counterpart. The RdRp complex of respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) incorporate GS-646939 and ATP with similar efficiency. In contrast, influenza B RdRp shows a clear preference for ATP and human mitochondrial RNA polymerase (h-mtRNAP) does not show significant incorporation of GS-646939. Once incorporated into the nascent RNA strand, GS-646939 acts as a chain-terminator although higher NTP concentrations can partially overcome inhibition for some polymerases. Modeling and biochemical data suggest that the 4'-modification inhibits RdRp translocation. Comparative studies with GS-443902, the active triphosphate form of the 1'-cyano modified prodrugs remdesivir and obeldesivir, reveal not only different mechanisms of inhibition, but also differences in the spectrum of inhibition of viral polymerases. In conclusion, 1'-cyano and 4'-cyano modifications of nucleotide analogs provide complementary strategies to target the polymerase of several families of respiratory RNA viruses.
PubMed: 38945449
DOI: 10.1016/j.jbc.2024.107514 -
Chembiochem : a European Journal of... Jun 2024Antibody-enzyme conjugates have shown potential as tissue-specific prodrug activators by antibody-directed enzyme prodrug therapy (ADEPT), but the approach met...
Antibody-enzyme conjugates have shown potential as tissue-specific prodrug activators by antibody-directed enzyme prodrug therapy (ADEPT), but the approach met challenges clinically due to systemic drug release. Here, we report a novel dual-targeting ADEPT system (DuADEPT) which is based on active cancer receptor targeting of both a trastuzumab-sialidase conjugate (Tz-Sia) and a highly potent sialidase-activated monomethyl auristatin E (MMAE) prodrug scaffold. The scaffold is based on a four-way junction of the artificial nucleic acid analog acyclic (L)-threoninol nucleic acid ((L)-aTNA) which at the ends of its four arms carries one nanobody targeting HER2 and three copies of the prodrug. Dual-targeting of the constructs to two proximal epitopes of HER2 was shown by flow cytometry, and a dual-targeted enzymatic drug release assay revealed cytotoxicity upon prodrug activation specifically for HER2-positive cancer cells. The specific delivery and activation of prodrugs in this way could potentially be used to decrease systemic side effects and increase drug efficacy, and utilization of Tz-Sia provides an opportunity to combine the local chemotherapeutic effect of the DuADEPT with an anticancer immune response.
PubMed: 38945824
DOI: 10.1002/cbic.202400437 -
Bioorganic & Medicinal Chemistry Letters Jun 2024Glioblastoma (GBM) is the most common form of malignant primary brain tumor and is one of the most lethal cancers. The difficulty in treating GBM stems from its highly...
Glioblastoma (GBM) is the most common form of malignant primary brain tumor and is one of the most lethal cancers. The difficulty in treating GBM stems from its highly developed mechanisms of drug resistance. Our research team has recently identified the fungal secondary metabolite ophiobolin A (OpA) as an agent with significant activity against drug-resistant GBM cells. However, the OpA's mode of action is likely based on covalent modification of its intracellular target(s) and thus possible off-target reactivity needs to be addressed. This work involves the investigation of an acid-sensitive OpA analogue approach that exploits the elevated acidity of the GBM microenvironment to enhance the selectivity for tumor targeting. This project identified analogues that showed selectivity at killing GBM cells grown in cultures at reduced pH compared to those maintained under normal neutral conditions. These studies are expected to facilitate the development of OpA as an anti-GBM agent by investigating its potential use in an acid-sensitive analogue form with enhanced selectivity for tumor targeting.
PubMed: 38942129
DOI: 10.1016/j.bmcl.2024.129863 -
Chemistry (Weinheim An Der Bergstrasse,... Jun 2024The multiplexity of cancer has rendered it the second leading cause of mortality worldwide and theragnostic prodrugs have gained popularity in recent years as a means of...
The multiplexity of cancer has rendered it the second leading cause of mortality worldwide and theragnostic prodrugs have gained popularity in recent years as a means of treatment. Theragnostic prodrugs enable the simultaneous diagnosis and therapy of tumors via high-precision real-time drug release monitoring. Herein, we report the development of the small theragnostic prodrug GF, based on the nucleoside anticancer agent gemcitabine and the fluorescent dye 5(6)-carboxyfluorescein. We have successfully demonstrated its efficient internalization in tumor cells, showing localization throughout both the early and late endocytic pathways. Its mechanism of cell internalization was evaluated, confirming its independence from nucleoside transporters. Its cellular localization via confocal microscopy revealed a clathrin-mediated endocytosis mechanism, distinguishing it from analogous compounds studied previously. Furthermore, GF exhibited stability across various pH values and in human blood plasma. Subsequently, its in vitro cytotoxicity was assessed in three human cancer cell lines (A549, U87 and T98). Additionally, its pharmacokinetic profile in mice was investigated and the consequent drug release was monitored. Finally, its in vivo visualization was accomplished in zebrafish xenotransplantation models and its in vivo efficacy was evaluated in A549 xenografts. The results unveiled an intriguing efficacy profile, positioning GF as a compelling candidate warranting further investigation.
PubMed: 38941241
DOI: 10.1002/chem.202401327 -
Clinical Pharmacology and Therapeutics Jun 2024There is an unmet need for safe and efficacious oral therapies for COVID-19 with low potential for drug-drug interactions. Obeldesivir is an orally administered...
There is an unmet need for safe and efficacious oral therapies for COVID-19 with low potential for drug-drug interactions. Obeldesivir is an orally administered nucleoside prodrug that has shown antiviral potency in nonclinical studies against SARS-CoV-2 and its circulating variants. Obeldesivir is metabolized to the active nucleoside triphosphate (GS-443902), which acts as an inhibitor of the SARS-CoV-2 RNA-dependent RNA polymerase, thereby inhibiting viral RNA synthesis. Here, we report the safety, tolerability, and pharmacokinetics from a first-in-human, randomized, placebo-controlled, phase I study following oral administration of obeldesivir and a phase I, open-label absorption, distribution, metabolism, and excretion study following oral administration of [C]-obeldesivir. Overall, obeldesivir was safe and well tolerated at single and multiple doses between 100 and 1,600 mg, with low potential for QT prolongation as assessed by QT-concentration analysis. The exposures to GS-441524 increased dose proportionally in the 100-900-mg dose range. GS-441524 accumulated by 35% after twice-daily and 12% after once-daily dosing for 5 days. Dose-proportional increases in the intracellular concentration of GS-443902 were also observed in peripheral blood mononuclar cells. Plasma exposure of GS-441524 was not significantly altered by food intake. Following oral administration of [C]-obeldesivir (500 mg; 100 μCi), the mean cumulative [C]-dose recovery was 90.7% with 58.5% in urine and 32.2% in feces. GS-441524 was the predominant plasma component (90% of C-area under the concentration-time curve) and was primarily eliminated via renal excretion. Collectively, data from these studies support selection of the obeldesivir 350 mg twice-daily dosing regimen for further evaluation in phase III studies for COVID-19.
PubMed: 38940465
DOI: 10.1002/cpt.3337 -
Chembiochem : a European Journal of... Jun 2024Cancer is one of the most serious threats to human health. Over the past few years, researchers have incrementally uncovered the pivotal role of tumor acidity in tumor...
Cancer is one of the most serious threats to human health. Over the past few years, researchers have incrementally uncovered the pivotal role of tumor acidity in tumor formation, development and treatment through in-depth scientific research. In addition, bioorthogonal reactions have been widely used in tumor diagnosis and therapy, owing to their advantageous characteristics, including small ligand size, biocompatibility, fast reaction kinetics, and high chemospecificity. Consequently, bioorthogonal reactions triggered by tumor acidity have become an emerging strategy in biomedical applications. On this basis, we introduce the concept and major strategies of tumor acidity-triggered bioorthogonal reactions, and review their progress in biomedical applications, with a particular focus on their importance in disease diagnosis and treatment. Finally, clinical challenges and future trends are also outlooked.
PubMed: 38940000
DOI: 10.1002/cbic.202400452 -
Chemical Science Jun 2024Cells are covered with a thick layer of sugar molecules known as glycans. Abnormal glycosylation is a hallmark of cancer, and hypersialylation increases tumor metastasis...
Cells are covered with a thick layer of sugar molecules known as glycans. Abnormal glycosylation is a hallmark of cancer, and hypersialylation increases tumor metastasis by promoting immune evasion and inducing tumor cell invasion and migration. Inhibiting sialylation is thus a potential anticancer treatment strategy. However, targeting sialic acids is difficult because of the lack of selective delivery tools. Here, we present a prodrug strategy for selectively releasing the global inhibitor of sialylation peracetylated 3F-Neu5Ac (PFN) in cancer cells using the reaction between phenyl azide and endogenous acrolein, which is overproduced in most cancer cells. The prodrug significantly suppressed tumor growth in mice as effectively as PFN without causing kidney dysfunction, which is associated with PFN. The use of sialylated glycans as immune checkpoints is gaining increasing attention, and the proposed method for precisely targeting aberrant sialylation provides a novel avenue for expanding current cancer treatments.
PubMed: 38939146
DOI: 10.1039/d4sc00969j -
Oral Diseases Jun 2024Oral lichen planus (OLP) is a chronic inflammatory disease characterized by a dense T-cell infiltration and the degeneration of basal keratinocytes. The potential...
OBJECTIVE
Oral lichen planus (OLP) is a chronic inflammatory disease characterized by a dense T-cell infiltration and the degeneration of basal keratinocytes. The potential functions of mucosal associated invariant T (MAIT) cells in OLP have been analyzed in our previous study. Keratinocytes under proinflammatory conditions have been demonstrated to activate T cells. This study was aimed to investigate how keratinocytes stimulate MAIT cells in OLP, and to explore the role of activated MAIT cells on keratinocytes.
METHODS AND RESULTS
Increased MAIT cells and higher activation marker CD69 were detected in OLP lesions by flow cytometry. The enhanced expression of MHC class I-like molecule (MR1) required for MAIT cell activation in the epithelial layer of OLP lesions was determined by immunohistochemistry. Keratinocytes treated by 5-A-RU prodrug and lipopolysaccharide, respectively, exhibited higher expression of MR1 and secretion of IL-18. In direct coculture systems consisting of keratinocytes and peripheral blood mononuclear cells, both 5-A-RU prodrug-pretreated keratinocytes and lipopolysaccharide-pretreated keratinocytes activated MAIT cells to secrete granzyme B, contributing to elevated keratinocyte apoptosis.
CONCLUSIONS
Keratinocytes were capable to activate MAIT cells via MR1 and cytokines in OLP, and granzyme B produced by activated MAIT cells intensified keratinocyte apoptosis, engaging in the pathogenesis of OLP.
PubMed: 38937944
DOI: 10.1111/odi.15057 -
Oral Oncology Jun 2024This retrospective study aimed to determine the optimal metronomic chemotherapy duration (MTCD) as adjuvant therapy for patients with locally advanced nasopharyngeal...
BACKGROUND
This retrospective study aimed to determine the optimal metronomic chemotherapy duration (MTCD) as adjuvant therapy for patients with locally advanced nasopharyngeal carcinoma (LANPC).
METHODS
This study involved LANPC patients treated with metronomic chemotherapy (MTC) using a 5-FU prodrug (S1, capecitabine, or tegafur) from May 2013 to September 2020. The optimal MTCD threshold was established using X-tile Bioinformatics software. The overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) were compared between short-term and long-term groups using propensity score matching (PSM).
RESULTS
A total of 546 patients were analyzed. MTCD was an independent prognostic factor for OS, PFS, and DMFS (all P < 0.05). Patients were categorized into long-term (>3 months) and short-term (≤3 months) MTCD groups. After a median follow-up of 48 months, significant differences were observed in 4-year OS (97.0 % vs. 87.1 %; P < 0.01), PFS (84.6 % vs. 70.9 %; P < 0.01), DMFS (87.3 % vs. 78.8 %; P < 0.01), and LRRFS (95.3 % vs. 87.4 %; P < 0.01) between the long-term and short-term groups. In the PSM-matched cohort of 196 patients per group, the long-term group demonstrated superior 4-year OS and LRRFS (97.3 % vs. 87.1 %, P < 0.01; 95.2 % vs. 90.0 %, P < 0.05). No significant differences in acute toxicities were observed between the groups (P > 0.05).
CONCLUSION
Extended MTC with a 5-FU prodrug (>3 months) may benefit NPC patients. Further prospective studies are needed to validate these findings.
PubMed: 38936007
DOI: 10.1016/j.oraloncology.2024.106908