Search Results (259)

Intramedullary spinal cord glioblastoma (ISCG) is lethal due to lack of effective treatment. We previously established a rat C6-ISCG model and the antitumor effect of F3.CD-TK, an hNSC line expressing CD and TK, via producing cytocidal 5FU and GCV-TP. However, the neurotherapeutic potential of this hNSC approach has remained uninvestigated. Here for the first time, cultured F3.CD-TK cells were found to have a markedly higher oncolytic effect, which was GJIC-dependent, and BDNF expression but less VEGF secretion than F3.CD. In Rowett athymic rats, F3.CD-TK (1.5 × 10⁶ cells/10 µL × 2), injected near C6-ISCG (G55 seeding 7 days earlier: 10 K/each) and followed by q.d. (×5/each repeat; i.p.) of 5FC (500 mg/kg/5 mL/day) and GCV (25 mg/kg/1 mL/day), robustly mitigated cardiorespiratory, locomotor, and sensory deficits to improve neurofunction and overall survival compared to animals receiving either F3.CD or F3.CD-TK+F3.CD debris formula. The F3.CD-TK regimen exerted greater tumor penetration and neural inflammation/immune modulation, reshaped C6-ISCG topology to increase the tumor’s surface area/volume ratio to spare/repair host axons (e.g., vGlut1+ neurites), and had higher post-prodrug donor self-clearance. The multimodal data and mechanistic leads from this proof-of-principle study suggest that the overall stronger anti-ISCG benefit of our hNSC-based GDEPT is derived from its concurrent oncolytic and neurotherapeutic effects. Full article

Approximately 80% of breast cancer (BC) cases are estrogen receptor positive (ER+) and sensitive to hormone treatment; Tamoxifen is a prodrug, and its main plasmatic active metabolites are 4-hydroxytamoxifen (4-OH Tam) and endoxifen. Despite the effectiveness of tamoxifen therapy, resistance can be developed. An increment in eukaryotic initiation factor-4A complex (eIF4A) activity can result in tamoxifen-resistant tumor cells. For this work, we developed a cell variant resistant to 4-OH Tam and endoxifen, denominated MCF-7^{Var E}; then, the aim of this research was to reverse the acquired resistance of this variant to tamoxifen metabolites by incorporating the natural compound auraptene. Combination treatments of tamoxifen derivatives and auraptene successfully sensitized the chemoresistant MCF-7^{Var E}. Our data suggest a dual regulation of eIF4A and ER by auraptene. Joint treatments of 4-OH Tam and endoxifen with auraptene identified a novel focus for chemoresistance disruption. Synergy was observed using the auraptene molecule and tamoxifen-derived metabolites, which induced a sensitization in MCF-7^{Var E} cells and ERα parental cells that was not observed in triple-negative breast cancer cells (TNBC). Our results suggest a synergistic effect between auraptene and tamoxifen metabolites in a resistant ER+ breast cancer model, which could represent the first step to achieving a pharmacologic strategy. Full article

Using an endogenous carrier is the best method to address the biocompatibility of carriers in the drug delivery field. Herein, we prepared a glutathione-responsive paclitaxel prodrug micelle based on an endogenous molecule of L-glutathione oxidized (GSSG) for cancer therapy using one-pot synthesis. The carboxyl groups in L-glutathione oxidized were reacted with the hydroxyl group in paclitaxel (PTX) using the catalysts dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP). Then, the amino-polyethylene glycol monomethyl ether (mPEG-NH₂) was conjugated with GSSG to prepare PTX-GSSG-PEG. The structure of PTX-GSSG-PEG was characterized using infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and mass spectrometry (MS). The drug release kinetics of PTX within PTX-GSSG-PEG were quantified using ultraviolet spectroscopy (UV-Vis). The size of the PTX-GSSG-PEG micelles was 83 nm, as evaluated using dynamic light scattering (DLS), and their particle size remained stable in a pH 7.4 PBS for 7 days. Moreover, the micelles could responsively degrade and release PTX in a reduced glutathione environment. The drug loading of PTX in PTX-GSSG-PEG was 13%, as determined using NMR. Furthermore, the cumulative drug release rate of PTX from the micelles reached 72.1% in a reduced glutathione environment of 5 mg/mL at 120 h. Cell viability experiments demonstrated that the PTX-GSSG-PEG micelles could induce the apoptosis of MCF-7 cells. Additionally, cell uptake showed that the micelles could distribute to the cell nuclei within 7 h. To sum up, with this glutathione-responsive paclitaxel prodrug micelle based on the endogenous molecule GSSG, it may be possible to develop novel nanomedicines in the future. Full article

In this study, we report a novel platinum–doxorubicin conjugate that demonstrates superior therapeutic indices to cisplatin, doxorubicin, or their combination, which are commonly used in cancer treatment. This new molecular structure (1) was formed by conjugating an amphiphilic Pt(IV) prodrug of cisplatin with doxorubicin. Due to its amphiphilic nature, the Pt(IV)–doxorubicin conjugate effectively penetrates cell membranes, delivering both cisplatin and doxorubicin payloads intracellularly. The intracellular accumulation of these payloads was assessed using graphite furnace atomic absorption spectrometry and fluorescence imaging. Since the therapeutic effects of cisplatin and doxorubicin stem from their ability to target nuclear DNA, we hypothesized that the amphiphilic Pt(IV)–doxorubicin conjugate (1) would effectively induce nuclear DNA damage toward killing cancer cells. To test this hypothesis, we used flow the cytometric analysis of phosphorylated H2AX (γH2AX), a biomarker of nuclear DNA damage. The Pt(IV)–doxorubicin conjugate (1) markedly induced γH2AX in treated MDA-MB-231 breast cancer cells, showing higher levels than cells treated with either cisplatin or doxorubicin alone. Furthermore, MTT cell viability assays revealed that the enhanced DNA-damaging capability of complex 1 resulted in superior cytotoxicity and selectivity against human cancer cells compared to cisplatin, doxorubicin, or their combination. Overall, the development of this amphiphilic Pt(IV)–doxorubicin conjugate represents a new form of combination therapy with improved therapeutic efficacy. Full article

Ganciclovir (GCV) and its prodrug valganciclovir (VGCV) are antiviral medications primarily used to treat infections caused by cytomegalovirus (CMV), particularly in immunocompromised individuals such as solid organ transplant (SOT) recipients. Therapy with GCV is associated with significant side effects, including bone marrow suppression. Therefore, therapeutic drug monitoring (TDM) is mandatory for an appropriate balance between subtherapeutic and toxic drug levels. This study aimed to develop and validate three novel methods based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for GCV determination in serum (reference methodology), dried serum spots (DSS), and VAMS-Mitra™ devices. The methods were optimized and validated in the 0.1–25 mg/L calibration range. The obtained results fulfilled the EMA acceptance criteria for bioanalytical method validation. Assessment of DSS and VAMS techniques extended GCV stability to serum for up to a minimum of 49 days (at room temperature, with desiccant). Developed methods were effectively evaluated using 80 clinical serum samples from pediatric renal transplant recipients. Obtained samples were used for DSS, and dried serum VAMS samples were manually generated in the laboratory. The results of GCV determination using serum-, DSS- and VAMS-LC-MS/MS methods were compared using regression analysis and bias evaluation. The conducted statistical analysis confirmed the interchangeability between developed assays. The DSS and VAMS samples are more accessible and stable during storage, transport and shipment than classic serum samples. Full article

Cholangiocarcinoma (CCA) is a rare disease characterized by malignant cells derived from the epithelial cells of the biliary duct system. Despite extensive treatments, the prognosis for CCA remains poor, emphasizing the critical need for the development of novel treatments. Considerable attention has been directed towards innate immune effector cells, which can recognize tumor cells independently of the major histocompatibility complex, laying the foundation for the development of off-the-shelf drugs. In this study, we cultured innate immune cells obtained from the peripheral blood of healthy adults and conducted a comparative analysis of the effector functions against CCA cell lines by Vδ2 γδ T cells and NK cells. This analysis was performed using standard short- and long-term cytotoxicity assays, as well as ELISA for IFN-γ. Vδ2 γδ T cells demonstrated cytotoxicity and IFN-γ production in response to CCA cells in a TCR-dependent manner, particularly in the presence of tetrakis-pivaloyloxymethyl 2-(thiazole-2-ylamino)ethylidene-1,1-bisphosphonate, a bisphosphonate prodrug. In contrast, direct killing and antibody-dependent cellular cytotoxicity were relatively slow and weak. Conversely, NK cells displayed potent, direct cytotoxicity against CCA cells. In summary, both Vδ2 γδ T cells and NK cells show promise as innate immune effector cells for adoptive transfer therapy in the context of CCA. Full article

This review delves into recent advancements in the field of nitro(het)aromatic bioreductive agents tailored for hypoxic environments. These compounds are designed to exploit the low-oxygen conditions typically found in solid tumors, making them promising candidates for targeted cancer therapies. Initially, this review focused on their role as gene-directed enzyme prodrugs, which are inert until activated by specific enzymes within tumor cells. Upon activation, these prodrugs undergo chemical transformations that convert them into potent cytotoxic agents, selectively targeting cancerous tissue while sparing healthy cells. Additionally, this review discusses recent developments in prodrug conjugates containing nitro(het)aromatic moieties, designed to activate under low-oxygen conditions within tumors. This approach enhances their efficacy and specificity in cancer treatment. Furthermore, this review covers innovative research on using nitro(het)aromatic compounds as fluorescent probes for imaging hypoxic tumors. These probes enable non-invasive visualization of low-oxygen regions within tumors, providing valuable insights for the diagnosis, treatment planning, and monitoring of therapeutic responses. We hope this review will inspire researchers to design and synthesize improved compounds for selective cancer treatment and early diagnostics. Full article

Directed enzyme prodrug therapy (DEPT) strategies show promise in mitigating chemotherapy side effects during cancer treatment. Among these, the use of immobilized enzymes on solid matrices as prodrug activating agents (IDEPT) presents a compelling delivery strategy, offering enhanced tumor targeting and reduced toxicity. Herein, we report a novel IDEPT strategy by employing a His-tagged Leishmania mexicana type I 2′-deoxyribosyltransferase (His-LmPDT) covalently attached to glutaraldehyde-activated magnetic iron oxide nanoparticles (MIONPs). Among the resulting derivatives, PDT-MIONP3 displayed the most favorable catalyst load/retained activity ratio, prompting its selection for further investigation. Substrate specificity studies demonstrated that PDT-MIONP3 effectively hydrolyzed a diverse array of 6-oxo and/or 6-amino purine 2′-deoxynucleosides, including 2-fluoro-2′-deoxyadenosine (dFAdo) and 6-methylpurine-2′-deoxyribose (d6MetPRib), both well-known prodrugs commonly used in DEPT. The biophysical characterization of both MIONPs and PDT-MIONPs was conducted by TEM, DLS, and single particle ICPMS techniques, showing an ideal nanosized range and a zeta potential value of −47.9 mV and −78.2 mV for MIONPs and PDT-MIONPs, respectively. The intracellular uptake of MIONPs and PDT-MIONPs was also determined by TEM and single particle ICPMS on HeLa cancer cell lines and NIH3T3 normal cell lines, showing a higher intracellular uptake in tumor cells. Finally, the selectivity of the PDT-MIONP/dFAdo IDEPT system was tested on HeLa cells (24 h, 10 µM dFAdo), resulting in a significant reduction in tumoral cell survival (11% of viability). Based on the experimental results, PDT-MIONP/dFAdo presents a novel and alternative IDEPT strategy, providing a promising avenue for cancer treatment. Full article

The URH1p enzyme from the yeast Saccharomyces cerevisiae has gained significant interest due to its role in nitrogenous base metabolism, particularly involving uracil and nicotinamide salvage. Indeed, URH1p was initially classified as a nucleoside hydrolase (NH) with a pronounced preference for uridine substrate but was later shown to also participate in a Preiss-Handler-dependent pathway for recycling of both endogenous and exogenous nicotinamide riboside (NR) towards NAD+ synthesis. Here, we present the detailed enzymatic and structural characterisation of the yeast URH1p enzyme, a member of the group I NH family of enzymes. We show that the URH1p has similar catalytic efficiencies for hydrolysis of NR and uridine, advocating a dual role of the enzyme in both NAD⁺ synthesis and nucleobase salvage. We demonstrate that URH1p has a monomeric structure that is unprecedented for members of the NH homology group I, showing that oligomerisation is not strictly required for the N-ribosidic activity in this family of enzymes. The size, thermal stability and activity of URH1p towards the synthetic substrate 5-fluoruridine, a riboside precursor of the antitumoral drug 5-fluorouracil, make the enzyme an attractive tool to be employed in gene-directed enzyme-prodrug activation therapy against solid tumours. Full article

Bacterial nitroreductase enzymes capable of activating imaging probes and prodrugs are valuable tools for gene-directed enzyme prodrug therapies and targeted cell ablation models. We recently engineered a nitroreductase (E. coli NfsB F70A/F108Y) for the substantially enhanced reduction of the 5-nitroimidazole PET-capable probe, SN33623, which permits the theranostic imaging of vectors labeled with oxygen-insensitive bacterial nitroreductases. This mutant enzyme also shows improved activation of the DNA-alkylation prodrugs CB1954 and metronidazole. To elucidate the mechanism behind these enhancements, we resolved the crystal structure of the mutant enzyme to 1.98 Å and compared it to the wild-type enzyme. Structural analysis revealed an expanded substrate access channel and new hydrogen bonding interactions. Additionally, computational modeling of SN33623, CB1954, and metronidazole binding in the active sites of both the mutant and wild-type enzymes revealed key differences in substrate orientations and interactions, with improvements in activity being mirrored by reduced distances between the N5-H of isoalloxazine and the substrate nitro group oxygen in the mutant models. These findings deepen our understanding of nitroreductase substrate specificity and catalytic mechanisms and have potential implications for developing more effective theranostic imaging strategies in cancer treatment. Full article

Cancer cells show altered antioxidant defense systems, dysregulated redox signaling, and increased generation of reactive oxygen species (ROS). Targeting cancer cells through ROS-mediated mechanisms has emerged as a significant therapeutic strategy due to its implications in cancer progression, survival, and resistance. Extensive research has focused on selective generation of H₂O₂ in cancer cells for selective cancer cell killing by employing various strategies such as metal-based prodrugs, photodynamic therapy, enzyme-based systems, nano-particle mediated approaches, chemical modulators, and combination therapies. Many of these H₂O₂-amplifying approaches have demonstrated promising anticancer effects and selectivity in preclinical investigations. They selectively induce cytotoxicity in cancer cells while sparing normal cells, sensitize resistant cells, and modulate the tumor microenvironment. However, challenges remain in achieving selectivity, addressing tumor heterogeneity, ensuring efficient delivery, and managing safety and toxicity. To address those issues, H₂O₂-generating agents have been combined with other treatments leading to optimized combination therapies. This review focuses on various chemical agents/approaches that kill cancer cells via H₂O₂-mediated mechanisms. Different categories of compounds that selectively generate H₂O₂ in cancer cells are summarized, their underlying mechanisms and function are elucidated, preclinical and clinical studies as well as recent advancements are discussed, and their prospects as targeted therapeutic agents and their therapeutic utility in combination with other treatments are explored. By understanding the potential of these compounds, researchers can pave the way for the development of effective and personalized cancer treatments. Full article

With an estimated 10 million people infected, the deltaretrovirus human T-cell lymphotropic virus type 1 (HTLV-1) is the second most prevalent pathogenic retrovirus in humans after HIV-1. Like HIV-1, HTLV-1 overwhelmingly persists in a host via a reservoir of latently infected CD4⁺ T cells. Although most patients are asymptomatic, HTLV-1-associated pathologies are often debilitating and include adult T-cell leukaemia/lymphoma (ATLL), which presents in mature adulthood and is associated with poor prognosis with short overall survival despite treatment. Curiously, the strongest indicator for the development of ATLL is the acquisition of HTLV-1 through breastfeeding. There are no therapeutic or preventative regimens for HTLV-1. However, antiretrovirals (ARVs), which target the essential retrovirus enzymes, have been developed for and transformed HIV therapy. As the architectures of retroviral enzyme active sites are highly conserved, some HIV-specific compounds are active against HTLV-1. Here, we expand on our work, which showed that integrase strand transfer inhibitors (INSTIs) and some nucleoside reverse transcriptase inhibitors (NRTIs) block HTLV-1 transmission in cell culture. Specifically, we find that dolutegravir, the INSTI currently recommended as the basis of all new combination antiretroviral therapy prescriptions, and the latest prodrug formula of the NRTI tenofovir, tenofovir alafenamide, also potently inhibit HTLV-1 infection. Our results, if replicated in a clinical setting, could see transmission rates of HTLV-1 and future caseloads of HTLV-1-associated pathologies like ATLL dramatically cut via the simple repurposing of already widely available HIV pills in HTLV-1 endemic areas. Considering our findings with the old medical saying “it is better to prevent than cure”, we highly recommend the inclusion of INSTIs and tenofovir prodrugs in upcoming HTLV-1 clinical trials as potential prophylactics. Full article

The current standard oncotherapy for glioblastoma is limited by several adverse side effects, leading to a short-term patient survival rate paralleled by a worsening quality of life (QoL). Recently, Complementary and Integrative Medicine’s (CIM) innovative approaches have shown positive impacts in terms of better response to treatment, side effect reduction, and QoL improvement. In particular, promising potential in cancer therapy has been found in compounds coming from phyto- and mycotherapy. The objective of this study was to demonstrate the beneficial effects of a new phyto-mycotherapy supplement, named Ganostile, in the human glioblastoma cell line U251, in combination with chemotherapeutic agents, i.e., Cisplatin and a new platinum-based prodrug. Choosing a supplement dosage that mimicked oral supplementation in humans (about 1 g/day), through in vitro assays, microscopy, and cytometric analysis, it has emerged that the cells, after 48hr continuous exposure to Ganostile in combination with the chemical compounds, showed a higher mortality and a lower proliferation rate than the samples subjected to the different treatments administered individually. In conclusion, our data support the use of Ganostile in integrative oncology protocols as a promising adjuvant able to amplify conventional and new drug effects and also reducing resistance mechanisms often observed in brain tumors. Full article

Triple-negative breast cancer (TNBC) accounts for approximately 15–20% of all breast cancer types, indicating a poor survival prognosis with a more aggressive biology of metastasis to the lung and a short response duration to available therapies. Ibulocydine (IB) is a novel (cyclin-dependent kinase) CDK7/9 inhibitor prodrug displaying potent anti-cancer effects against various cancer cell types. We performed in vitro and in vivo experiments to determine whether IB inhibits metastasis and eventually overcomes the poor drug response in TNBC. The result showed that IB inhibited the growth of TNBC cells by inducing caspase-mediated apoptosis and blocking metastasis by reducing MMP-9 expression in vitro. Concurrently, in vivo experiments using the metastasis model showed that IB inhibited metastasis of MDA-MB-231-Luc cells to the lung. Collectively, these results demonstrate that IB inhibited the growth of TNBC cells and blocked metastasis by regulating MMP-9 expression, suggesting a novel therapeutic agent for metastatic TNBC. Full article

A promising de novo approach for the treatment of Castration-resistant prostate cancer (CRPC) exploits cell-mediated enzyme prodrug therapy comprising cytosine deaminase (CD) and fluorouracil (5-FC). The aim of this study was to determine the potential of bacterial CD-overexpressing hTERT-immortalized human adipose stem cells (hTERT-ADSC.CD) to suppress CRPC. A lentiviral vector encoding a bacterial CD gene was used to transfect and to generate the hTERT-ADSC.CD line. The ability of the cells to migrate selectively towards malignant cells was investigated in vitro. PC3 and hTERT-ADSC.CD cells were co-cultured. hTERT-ADSC.CD and 1 × 10⁶ PC3 cells were administered to nude mice via intracardiac and subcutaneous injections, respectively, and 5-FC was given for 14 days. hTERT-ADSC.CD were successfully engineered. Enhanced in vitro hTERT-ADSC.CD cytotoxicity and suicide effect were evident following administration of 5 μM 5-FC. hTERT-ADSC.CD, together with 5-FC, augmented the numbers of PC3 cells undergoing apoptosis. In comparison to controls administered hTERT-ADSC.CD monotherapy, hTERT-ADSC.CD in combination with 5-FC demonstrated a greater suppressive effect on tumor. In CPRC-bearing mice, tumor suppression was enhanced by the combination of CD-overexpressing ADSC and the prodrug 5-FC. Stem cells exhibiting CD gene expression are a potential novel approach to treatment for CRPC. Full article