Search Results (313)

The 90 kDa heat shock proteins (Hsp90) are molecular chaperones that regulate the stability and maturation of numerous client proteins implicated in the regulation of cancer hallmarks. Despite the potential of pan-Hsp90 inhibitors as anticancer therapeutics, their clinical development has been hindered by on-target toxicities, particularly ocular and cardiotoxic effects, as well as the induction of pro-survival, compensatory heat shock responses. Together, these and other complications have prompted the development of isoform-selective Hsp90 inhibitors. In this review, we discuss the molecular bases for Hsp90 function and inhibition and emphasize recent advances in isoform-selective targeting. Importantly, we highlight how Hsp90 inhibition can sensitize tumors to cancer immunotherapy by enhancing antigen presentation, reducing immune checkpoint expression, remodeling the tumor microenvironment, and promoting innate immune activation. Special focus is given to Hsp90β-selective inhibitors, which modulate immunoregulatory pathways without eliciting the deleterious effects observed with pan-inhibition. Preclinical and early clinical data support the integration of Hsp90 inhibitors with immune checkpoint blockade and other immunotherapeutic modalities to overcome resistance mechanisms in immunologically cold tumors. Therefore, the continued development of isoform-selective Hsp90 inhibitors offers a promising avenue to potentiate cancer immunotherapy with improved efficacy. Full article

The Eastern Carpathians are thrust to the east and north over their Eastern European foreland, tectonically covering it over an area several hundred kilometers across. Information about the nature of the underthrust part of the Carpathian foreland can be obtained from the rock fragments preserved in the sedimentary successions of the Carpathian fold and thrust belt, specifically in the Outer Dacides and the Moldavides. Fragments of felsic rocks occurring within the sedimentary units of the Upper Cretaceous successions of the Moldavides have long been attributed to the Cuman Cordillera—an intrabasinal ridge in the Eastern Outer Carpathians. This work is the first complex geochemical and geochronological study on the exotic igneous clasts of the Cuman Cordillera. Igneous clasts from the southern part of the Moldavides (Variegated clay nappe/formation) are investigated here. They include mainly granites and rhyolites. Phaneritic rocks are composed of cumulus plagioclase, albite, amphibole and biotite, and intercumulus quartz and potassium feldspar, with apatite, magnetite, sphene, and zircon as main accessories, while the porphyritic rocks have a mineral assemblage similar to that mentioned above, displayed in a porphyritic texture with a usually crystallized groundmass. SHRIMP U-Pb zircon dating indicated the 583–597 Ma age interval for magma crystallization. Based on calcareous nannofossils, the depositional age of the investigated igneous clasts is Cenomanian to Maastrichtian, implying that the Cuman Cordillera was an emerged piece of land, herein an active source of sediments in the flysch basin for at least 40 Ma, from the Early Cretaceous (Aptian) to the Late Cretaceous (Maastrichtian). The intrusive and subvolcanic rocks show similar trends for trace and major elements, evincing their comagmatic nature. The enrichment in LILE and LREE relative to HFSE and HREE, as well as the element anomalies (e.g., negative Nb, Ta, and Eu and positive Rb, Ba, K, and Pb) suggest a convergent continental plate margin tectonic setting. Mineral chemistry suggests magma crystallization in relatively oxic conditions (magnetite series), during ascent within a depth of 15 km to 5 km. The igneous rocks attributed to the Cuman ridge display compositional and geochronological features similar to Brno and Thaya batholiths in the Brunovistulian terrane, which could be a piece of the Carpathian foreland not covered by the Tertiary thrusts. Our data confirm the non-Carpathian origin of the igneous clasts, revealing a Neoproterozoic history of the Carpathian foreland units, which include a Cadomian/Pan-African continental arc, exposed mainly during the Late Cretaceous as an intrabasinal island of the Alpine Tethys, traditionally known as the Cuman Cordillera. Full article

Methylene blue is a type of azo pollutant that is used in the textile industry and endangers natural resources and human health by mixing wastewater into nature and drinking water. The aim of this study was to create active sites on the surface of PAN nanofibers for methylene blue (MB) adsorption. For this purpose, nanofibers obtained from polyacrylonitrile by the electrospinning method were modified with NiO nanoparticles (Ni) and treated with triethanolamine (TEA). The nanofiber obtained via treatment with tea was labeled as Am. The obtained nanofibers (Am/PAN/Ni-nl, PAN/Ni-nl, Am/PA-nl, and PAN-nl) were characterized comparatively by BET, FT-IR and SEM, and the adsorption performance was evaluated by time-dependent q_e, isotherm, kinetic and thermodynamic graphs. The shortest equilibrium time of 20 min and the highest equilibrium amount of 45.96 mg g⁻¹ were reached with 0.1 g of Am/PAN/Ni-nl. The Langmuir isotherm and pseudo-second-order kinetics were found to be appropriate, with an R² value of 0.9987. The enthalpy change was calculated as −92.947 kJ mol⁻¹. Using RSM, the adsorption for Am/PAN/Ni-nl obeyed the quadratic model and the adsorbent exhibited a maximum adsorption capacity of 52.3575 mg g⁻¹ for methylene blue at pH 6, 25 °C and 140 ppm. Full article

Background/Objectives: For viral entry into host cells, the spike (S) protein of coronavirus (CoV) uses its S1 domain to bind to the host receptor and S2 domain to mediate the fusion between virion and cellular membranes. The S1 domain acquired multiple mutations as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolved to give rise to Variant of Concerns (VOCs) but the S2 domain has limited changes. In particular, the stem helix in S2 did not change significantly and it is fairly well-conserved across multiple beta-CoVs. In this study, we generated a murine mAb 7B2 binding to the stem helix of SARS-CoV-2. Methods: MAb 7B2 was isolated from immunized mouse and its neutralization activity was evaluated using microneutralization, plaque reduction and cell–cell fusion assays. Bio-layer interferometry was used to measure binding affinity and AlphaFold3 was used to model the antibody–antigen interface. Results: MAb 7B2 has lower virus neutralizing and membrane block activities when compared to a previously reported stem helix-binding human mAb S2P6. Alanine scanning and AlphaFold3 modeling reveals that residues K1149 and D1153 in S form a network of polar interactions with the heavy chain of 7B2. Conversely, S2P6 binding to S is not affected by alanine substitution at K1149 and D1153 as indicated by the high ipTM scores in the predicted S2P6-stem helix structure. Conclusions: Our detailed characterization of the mechanism of inhibition of 7B2 reveals its distinctive binding model from S2P6 and yields insights on multiple neutralizing and highly conserved epitopes in the S2 domain which could be key components for pan-CoV vaccine development. Full article

Klebsiella pneumoniae can acquire resistance mechanisms to colistin and present a pan-resistant phenotype. Therefore, new alternative agents are imperative to control this pathogen, and the peptide Jelleine-I stands out as a promising prototype. Here, the antibacterial activity of Jelleine-I against clinical isolates of colistin-resistant K. pneumoniae (CRKP) was investigated. Antimicrobial activity was assessed by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time kill-curve assay. The release of 260 nm-absorbing materials (DNA/RNA) and the release of proteins were used in the lysis assay. Anti-biofilm activity was studied in microplates. In vivo activity was determined by the lethality assay using Tenebrio molitor larvae. The results show that the MIC of Jelleine-I ranged from 16 to 128 µM and the MBC was on average 128 µM. Jelleine-I at 200 µM killed all CRKP cells in suspension (10⁶ colony-forming units (CFU)/mL) after 150 min of incubation. Jelleine-I acts on the CRKP cell membrane inducing lysis. Biomass and viability of CRKP-induced biofilms are reduced after treatment with Jelleine-I, and the use of this peptide in T. molitor larvae infected with CRKP reduces lethality and improves overall larval health. In conclusion, Jelleine-I is a potential prototype for the development of new antimicrobial agents. Full article

Phase-separated membraneless biomolecular condensates in the cytoplasm and nucleus are now recognized to play a major role in modulating diverse functions in mammalian cells, and contribute to cancer pathogenesis through dysregulated function of condensates of transcription factors such as STAT3 and fusion oncoproteins. Oral cancer, the sixth most prevalent malignancy worldwide, in the absence of overt causes such as tobacco or alcohol, most frequently occurs in a U-shaped zone (floor of mouth, side of tongue, anterior fauces and retromolar region) reflecting the path of liquid transit through the mouth. The cellular basis for this “high-risk” zone and the biochemical mechanisms used by oral cells to combat repetitive tonicity and temperature stresses are incompletely understood. We had previously observed that at 37 °C, in OECM1 oral carcinoma cells, cytoplasmic condensates of antiviral human GFP-MxA GTPase disassembled within 1–2 min of exposure of cells to saliva-like one-third hypotonicity, and underwent “spontaneous” reassembly in the next 5–7 min. Moreover, hypotonic beverages (water, tea, coffee), investigated at 37 °C, triggered this condensate cycling. In the present studies we investigated whether this process was temperature sensitive, representative of cold vs. warm drinks. We observed a slowing of this cycle at 5 °C, and speeding up at 50 °C. The involvement in this disassembly/reassembly process of WNK-SPAK/OSR1 serine-threonine kinase pathway, best studied for regulation of water and Na, K and Cl influx and efflux in kidney tubule cells, was evaluated by us in oral cells using pathway inhibitors WNK463, WNK-IN-11 and closantel. The pan-WNK inhibitor WNK463 inhibited hypotonicity-driven condensate disassembly, while the SPAK/OSR1 inhibitor closantel markedly slowed reassembly. Unexpectedly, the WNK1-selective inhibitor (WNK-IN-11), triggered a dramatic and rapid (within 1 h) spheroid to fibril transition of GFP-MxA condensates in live cells, but without affecting MxA antiviral function. The new data suggest a novel hypothesis for the anatomic localization of oral cancer in the U-shaped “high-risk” zone in the mouth: dysfunction of biomolecular condensates in oral cells along the beverage transit pathway through the mouth due to repetitive tonicity and temperature stresses that might underlie a prooncogenic progression. Full article

With the rapid development of remote sensing technology, satellites can now capture multispectral (MS) and panchromatic (PAN) images simultaneously. MS images offer rich spectral details, while PAN images provide high spatial resolutions. Effectively leveraging their complementary strengths and addressing modality gaps are key challenges in improving the classification performance. From the perspective of deep learning, this paper proposes a novel dual-source remote sensing classification framework named the Diversity Extraction and Fusion Classifier (DEFC-Net). A central innovation of our method lies in introducing a modality-specific intra-class diversity modeling mechanism for the first time in dual-source classification. Specifically, the intra-class diversity identification and splitting (IDIS) module independently analyzes the intra-class variance within each modality to identify semantically broad classes, and it applies an optimized K-means method to split such classes into fine-grained sub-classes. In particular, due to the inherent representation differences between the MS and PAN modalities, the same class may be split differently in each modality, allowing modality-aware class refinement that better captures fine-grained discriminative features in dual perspectives. To handle the class imbalance introduced by both natural long-tailed distributions and class splitting, we design a long-tailed ensemble learning module (LELM) based on a multi-expert structure to reduce bias toward head classes. Furthermore, a dual-modal knowledge distillation (DKD) module is developed to align cross-modal feature spaces and reconcile the label inconsistency arising from modality-specific class splitting, thereby facilitating effective information fusion across modalities. Extensive experiments on datasets show that our method significantly improves the classification performance. The code was accessed on 11 April 2025. Full article

Background/Objectives: DNA methylation profiles have emerged as robust biomarkers of ageing, leading to the development of “epigenetic clocks” that estimate biological age. Most established clocks (e.g., Horvath’s 353-CpG pan-tissue clock and Hannum’s 71-CpG blood clock) require dozens to hundreds of CpG sites. This study presents a novel saliva-specific epigenetic clock built on 10 sites identified from Illumina MethylationEPIC (850 k) array data. Methods: Saliva DNA methylation was analysed from 3408 individuals (age range 15–89 years, 68% male, 32% female, no diagnosed disease) from the Muhdo Health Ltd. dataset (2022–2024), and 10 CpG sites were selected where methylation levels showed the strongest positive correlations with chronological age (Pearson r = 0.48–0.66, p < 1 × 10−20). These CpGs map to genes involved in developmental and metabolic pathways (including ELOVL2, CHGA, OTUD7A, PRLHR, ZYG11A, and GPR158). A linear combination of the 10 methylation sites was used to calculate a “DNA methylation age”. Results: The 10-CpG clock’s predictions were highly correlated with chronological age (r = 0.80, R2 = 0.64), with a mean absolute error of ~5.5 years. Its performance, while slightly less precise than Horvath’s or Hannum’s multi-CpG clocks, is notable given the minimal marker set. It was observed that all 10 clock CpGs undergo age-related hypermethylation. The biological significance of these loci is discussed, along with the potential health and forensic applications of a saliva-based epigenetic age predictor. Conclusions: This study demonstrates that a saliva-specific epigenetic clock using only 10 CpG sites can capture a substantial portion of age-related DNA methylation changes, providing a cost-effective tool for age estimation. Full article

Background: The efflux system is one of the resistance mechanisms that bacteria use to reduce the effectiveness of antibiotics, leading to the development of multidrug resistance. To evaluate other treatment choices, esomeprazole (ESO), omeprazole (OME), pantoprazole (PAN), vitamin D (VD), and vitamin K (VK) were tested for potential efflux pump (EP)-inhibiting activity. Methods: The minimum inhibitory concentrations (MICs) of the tested drugs were determined against K. pneumoniae ATCC 51503 and P. aeruginosa PAO1. Quantitative estimation of the EP-inhibiting activity of the tested medications was phenotypically investigated with a semi-automated fluorometric system and genotypically confirmed by real-time polymerase chain reaction (RT-PCR). Data were confirmed through docking study. Results: K. pneumoniae ATCC 51503 and P. aeruginosa PAO1 were positive efflux standard strains. VD and VK revealed an MIC_VD of 625–1250 µg/mL and MIC_VK of 2500–5000 µg/mL, lower than what was detected for PPIs (MIC_PPIs = 16,000–32,000 µg/mL). Vitamins showed powerful anti-efflux activity with remarkable ethidium bromide accumulation in K. pneumoniae ATCC 51503 and P. aeruginosa PAO1. Also, VD and VK significantly lowered the MIC of ciprofloxacin by 64-fold. On the molecular level, OME showed a notable decrease in the relative expression of the efflux-encoding genes acrB and mexA by 91.5% and 99.7% in ATCC 51503 and PAO1, respectively. Conclusion: This study highlights the anti-efflux activity of ESO, OME, PAN, VD, and VK against the tested Gram-negative strains. Hence, these PPIs and vitamins could be valuable adjuvant treatments to enhance the effectiveness of curing infections caused by MDR strains. Full article

Cytochrome P450 (CYP) enzymes are membrane-bound hemoproteins crucial for drug and xenobiotic metabolism. While more than 50 CYPs have been identified in humans, the isoforms from CYP1, 2, and 3 families contribute to the metabolism of about 80% of clinically approved drugs. To evaluate the effects of environmental chemicals on the activities of these important CYP enzyme families, we screened the Tox21 10K compound library to identify chemicals that inhibit CYP1A2, 2C9, 2C19, 2D6, and 3A4 enzymes. The data obtained from these five screenings were analyzed to reveal the structural classes responsible for inhibiting multiple and/or selective CYPs. Some known structural compound classes exhibiting pan-CYP inhibition, such as azole fungicides, along with established clinical inhibitors of CYPs, including erythromycin and verapamil inhibiting CYP3A4 and paroxetine and terbinafine inhibiting CYP2D6, were all confirmed in the current study. In addition, some selective CYP inhibitors, previously unknown but with potent activity (IC₅₀ values < 1 µM), were identified. Examples included yohimbine, an indole alkaloid, and loteprednol, a corticosteroid, which showed inhibitory activity in CYP2D6 and 3A4 assays, respectively. These findings suggest that assessment of a candidate compound’s impact on CYP function may allow pre-emptive mitigation of potential adverse reactions and toxicity during drug development or toxicological characterization of environmental chemicals. Full article

Phosphoinositide 3-kinases (PI3Ks) signaling represents an important pathway regulating cell proliferation, survival, invasion, migration, and metabolism. Notably, PI3K/AKT/mTOR signaling is frequently dysregulated in the majority of malignancies. Among the class IA PI3Ks (PI3Kα/β/δ), emerging evidence has implicated that PI3Kδ is not only overexpressed in leukocytes but also in solid tumors, including prostate cancer. The critical role of PI3Kδ in tumorigenesis and in the creation of a suppressive tumor microenvironment, along with the recent finding of PI3Kδ splice isoforms in promoting tumor aggressiveness and resistance, further demonstrates the potential of developing novel PI3Kδ-targeted cancer therapies. In this review, we comprehensively describe the functional mechanisms underlying the PI3Kδ-driven tumor progression and immune regulation in prostate cancer diseases. Furthermore, the recent preclinical and clinical studies on the development of PI3Kδ-/PI3K-targeted inhibitors as single agents and in combination therapies (with chemotherapy, radiation, hormone therapy, or immunotherapy) are summarized. Finally, we discuss the potential novel therapies for improving the treatment efficacies, as well as the current limitations and challenges of PI3Kδ-based therapies for prostate cancer. Full article

As a rarefied metallic element, strontium (Sr) is susceptible to significant environmental radioactive contamination risks during industrial mining and refining processes. In this study, NaA molecular sieves were prepared by alkali excitation using synthetic powders, which were homogeneously blended with the polyacrylonitrile (PAN) matrix, and nanoscale TiO₂ reinforcing phases were introduced. Finally, composite separation membranes (TiO₂-NaA@PANMs) with stable adsorption properties were constructed by electrostatic spinning technology. The micro-morphology and interfacial properties were characterized by SEM, XRD, and FT-IR systems. The adsorption experiments demonstrated that the equilibrium adsorption capacity of the system for Sr²⁺ reached 55.00 mg/g at the optimized pH = 6.0, and the theoretical saturated adsorption capacity at 298 K was 80.89 mg/g. The isothermal process conformed to the Langmuir’s model of monomolecular layer adsorption, and the kinetic behavior followed the quasi-secondary kinetic equation. Following three cycles of regeneration by elution with a 0.3 mol/L sodium citrate solution, the membrane material exhibited 81.60% Sr²⁺ removal efficacy. The composite membrane passages exhibited remarkable potential for utilization in engineering applications involving the treatment of complex nuclear wastewater. Full article

Background/Objectives: Metastatic prostate cancer (PCa) remains a major clinical challenge with limited therapeutic options. The long non-coding RNA H19 has been implicated in regulating cell adhesion molecules and collective migration, key features of metastatic dissemination. This study investigates the role of the Bromodomain and Extra-Terminal (BET) proteins BRD2, BRD3, and BRD4 in the H19-dependent transcriptional regulation of cell adhesion molecules. Currently, the major effects of BET inhibitors require androgen receptor (AR) expression. Methods: H19 was stably silenced in PC-3 (AR-null) and 22Rv1 (AR-positive) castration-resistant PCa cells. The cells were treated with the pan-BET inhibitors JQ1 and OTX015 or the BET degrader dBET6. In vivo, the effects of JQ1 were evaluated in xenograft mouse models. Chromatin immunoprecipitation (ChIP) and RNA-ChIP were used to assess BET protein recruitment and interaction with cell adhesion gene loci and H19. Organotypic slice cultures (OSCs) from fresh PCa surgical specimens were used as ex vivo models to validate transcriptional changes and BRD4 recruitment. Results: BET inhibition significantly reduced the expression of β4 integrin and E-cadherin and cell proliferation in both basal conditions, and following H19 knockdown in PC-3 and 22Rv1 cells. These effects were mirrored in JQ1-treated tumor xenografts, which showed marker downregulation and tumor regression. ChIP assays revealed that BRD4, more than BRD2/3, was enriched on β4 integrin and E-cadherin promoters, especially in regions marked by H3K27ac. H19 silencing markedly enhanced BRD4 promoter occupancy. RNA-ChIP confirmed a specific interaction between BRD4 and H19. These findings were validated in OSCs, reinforcing their clinical relevance. Conclusions: Our study demonstrates that BRD4 epigenetically regulates the H19-mediated transcriptional control of adhesion molecules involved in collective migration and metastatic dissemination. Importantly, these effects are independent of AR status, suggesting that targeting the H19/BRD4 axis may represent a promising therapeutic avenue for advanced PCa. Full article

FAM46C is a tumor suppressor initially identified in multiple myeloma (MM) but increasingly recognized for its role also in other cancers. Despite its significance, studies exploring the therapeutic potential of FAM46C in combination with targeted treatments remain limited. Sphingosine kinases (SphK1 and SphK2) are key regulators of sphingolipid signaling, a pathway essential for maintaining cell structure and function but frequently deregulated in tumors, making them promising targets for cancer therapy. Preliminary work from our laboratory showed that FAM46C expression synergizes with administration of SKI-I, a pan-inhibitor of sphingosine kinases. In this study, we focused specifically on SphK1, the sphingosine kinase predominantly implicated in cancer and investigated the combinatorial effect of forced FAM46C expression and treatment with PF-543, a selective SphK1 inhibitor. We found that FAM46C overexpression enhances, whereas its downregulation reduces, the cytotoxic efficacy of PF-543 in MM cell lines. Using an in vivo xenograft model, we further validated these findings, showing that FAM46C-expressing MM tumors are indeed sensitive to PF-543 while tumors harboring the D90G loss-of-function variant of FAM46C are not. Overall, our results uncover a novel synergistic interaction between FAM46C expression and SphK1 inhibition, highlighting a promising therapeutic strategy for MM treatment. Full article

Background: The mutation rate of p53 in breast cancer is around 20%. Specific p53 mutations exhibit prion-like abnormal misfolding and aggregation and gain oncogenic function, causing resistance to the chemotherapy drug doxorubicin. In this study, we identified key upstream regulatory molecules that inhibit the aggregation of p53 with the aim of increasing the anticancer effect of doxorubicin. Methods: Thioflavin T was employed as a fluorescent probe to detect prion-like protein aggregates within cells, the response to various inhibitors was evaluated using CCK8 assay, and the coefficient of drug interaction was calculated. The cell apoptosis ratio was evaluated using Caspase-3/7 based flow cytometry assay. Results: MDA-MB-231 cells (with p53 R280K mutation) and T47D cells (with p53 L194F mutation) had a strong Thioflavin T staining signal, but MDA-MB-468 cells (with p53 R273H mutation) had a weak Thioflavin T signal. Compared to MDA-MB-468 cells, which had a good response to doxorubicin, both MDA-MB-231 and T47D showed high doxorubicin drug resistance. Co-treatment with various misfolding p53 aggregation inhibitors and doxorubicin found that only the HSP70 inhibitor and doxorubicin had synergistic anticancer activity in both MDA-MB-231 and T47D cells. Furthermore, this co-treatment induced cell apoptosis in MDA-MB-231, which was reversed by a pan-caspase inhibitor. Conclusions: Doxorubicin resistance caused by specific p53 mutants can be resolved by co-treatment with a HSP70 inhibitor in breast cancer cells. Full article