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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 -
ACS Chemical Biology Jun 2024TRIM7 is a ubiquitin E3 ligase with key regulatory functions, mediating viral infection, tumor biology, innate immunity, and cellular processes, such as autophagy and...
TRIM7 is a ubiquitin E3 ligase with key regulatory functions, mediating viral infection, tumor biology, innate immunity, and cellular processes, such as autophagy and ferroptosis. It contains a PRYSPRY domain that specifically recognizes degron sequences containing C-terminal glutamine. Ligands that bind to the TRIM7 PRYSPRY domain may have applications in the treatment of viral infections, as modulators of inflammation, and in the design of a new class of PROTACs (PROteolysis TArgeting Chimeras) that mediate the selective degradation of therapeutically relevant proteins (POIs). Here, we developed an assay toolbox for the comprehensive evaluation of TRIM7 ligands. Using TRIM7 degron sequences together with a structure-based design, we developed the first series of peptidomimetic ligands with low micromolar affinity. The terminal carboxylate moiety was required for ligand activity but prevented cell penetration. A prodrug strategy using an ethyl ester resulted in enhanced permeability, which was evaluated using confocal imaging.
PubMed: 38934237
DOI: 10.1021/acschembio.4c00301 -
Pharmaceutics Jun 2024The inhibition of the immune response in the tumor microenvironment by therapy regimens can impede the eradication of tumors, potentially resulting in tumor metastasis....
The inhibition of the immune response in the tumor microenvironment by therapy regimens can impede the eradication of tumors, potentially resulting in tumor metastasis. As a non-invasive therapeutic method, radiotherapy is utilized for tumor ablation. In this study, we aimed to improve the therapeutic impact of radiotherapy and trigger an immune response by formulating a benzothiazole sulfinate (BTS)-loaded fusion liposome (BFL) nanoplatform, which was then combined with radiotherapy for anti-cancer treatment. The platelet cell membrane, equipped with distinctive surface receptors, enables BFL to effectively target tumors while evading the immune system and adhering to tumor cells. This facilitates BFL's engulfment by cancer cells, subsequently releasing BTS within them. Following the release, the BTS produces sulfur dioxide (SO) for gas therapy, initiating the oxidation of intracellular glutathione (GSH). This process demonstrates efficacy in repairing damage post-radiotherapy, thereby achieving effective radiosensitization. It was revealed that an immune response was triggered following the enhanced radiosensitization facilitated by BFL. This approach facilitated the maturation of dendritic cell (DC) within lymph nodes, leading to an increase in the proportion of T cells in distant tumors. This resulted in significant eradication of primary tumors and inhibition of growth in distant tumors. In summary, the integration of personalized BFL with radiotherapy shows potential in enhancing both tumor immune response and the elimination of tumors, including metastasis.
PubMed: 38931953
DOI: 10.3390/pharmaceutics16060833 -
Pharmaceutics May 2024Fluoropyrimidine (FP) drugs are central components of combination chemotherapy regimens for the treatment of colorectal cancer (CRC). FP-based chemotherapy has improved... (Review)
Review
Fluoropyrimidine (FP) drugs are central components of combination chemotherapy regimens for the treatment of colorectal cancer (CRC). FP-based chemotherapy has improved survival outcomes over the last several decades with much of the therapeutic benefit derived from the optimization of dose and delivery. To provide further advances in therapeutic efficacy, next-generation prodrugs and nanodelivery systems for FPs are being developed. This review focuses on recent innovative nanodelivery approaches for FP drugs that display therapeutic promise. We summarize established, clinically useful FP prodrug strategies, including capecitabine, which exploit tumor-specific enzyme expression for optimal anticancer activity. We then describe the use of FP DNA-based polymers (e.g., CF10) for the delivery of activated FP nucleotides as a nanodelivery approach with proven activity in pre-clinical models and with clinical potential. Multiple nanodelivery systems for FP delivery show promise in CRC pre-clinical models and we review advances in albumin-mediated FP delivery, the development of mesoporous silica nanoparticles, emulsion-based nanoparticles, metal nanoparticles, hydrogel-based delivery, and liposomes and lipid nanoparticles that display particular promise for therapeutic development. Nanodelivery of FPs is anticipated to impact CRC treatment in the coming years and to improve survival for cancer patients.
PubMed: 38931855
DOI: 10.3390/pharmaceutics16060734