Impaired fibroblast growth factor receptor (FGFR) signaling is associated with many human conditions, including growth disorders, degenerative diseases, and cancer. Current FGFR therapeutics are based on chemical inhibitors of FGFR tyrosine kinase activity (TKIs). However, FGFR TKIs are limited in their target specificity as they generally inhibit all FGFRs and other receptor tyrosine kinases. In the search for specific inhibitors of human FGFR1, we identified VZ23, a DNA aptamer that binds to FGFR1b and FGFR1c with a KD of 55 nM and 162 nM, respectively, but not to the other FGFR variants (FGFR2b, FGFR2c, FGFR3b, FGFR3c, FGFR4). In cells, VZ23 inhibited the activation of downstream FGFR1 signaling and FGFR1-mediated regulation of cellular senescence, proliferation, and extracellular matrix homeostasis. Consistent with the specificity toward FGFR1 observed in vitro, VZ23 did not inhibit FGFR2-4 signaling in cells. We show that the VZ23 inhibits FGFR1 signaling in the presence of cognate fibroblast growth factor (FGF) ligands and its inhibitory activity is linked to its capacity to form unusual G-quadruplex structure. Our data suggest that targeting FGFR1 with DNA aptamers could be an effective alternative to TKIs for treating impaired FGFR1 signaling in human craniosynostoses.

• Publication type
• Journal Article MeSH

Heavy metals are naturally occurring components of the Earth's crust and persistent environmental pollutants. Human exposure to heavy metals occurs via various pathways, including inhalation of air/dust particles, ingesting contaminated water or soil, or through the food chain. Their bioaccumulation may lead to diverse toxic effects affecting different body tissues and organ systems. The toxicity of heavy metals depends on the properties of the given metal, dose, route, duration of exposure (acute or chronic), and extent of bioaccumulation. The detrimental impacts of heavy metals on human health are largely linked to their capacity to interfere with antioxidant defense mechanisms, primarily through their interaction with intracellular glutathione (GSH) or sulfhydryl groups (R-SH) of antioxidant enzymes such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR), and other enzyme systems. Although arsenic (As) is believed to bind directly to critical thiols, alternative hydrogen peroxide production processes have also been postulated. Heavy metals are known to interfere with signaling pathways and affect a variety of cellular processes, including cell growth, proliferation, survival, metabolism, and apoptosis. For example, cadmium can affect the BLC-2 family of proteins involved in mitochondrial death via the overexpression of antiapoptotic Bcl-2 and the suppression of proapoptotic (BAX, BAK) mechanisms, thus increasing the resistance of various cells to undergo malignant transformation. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of antioxidant enzymes, the level of oxidative stress, and cellular resistance to oxidants and has been shown to act as a double-edged sword in response to arsenic-induced oxidative stress. Another mechanism of significant health threats and heavy metal (e.g., Pb) toxicity involves the substitution of essential metals (e.g., calcium (Ca), copper (Cu), and iron (Fe)) with structurally similar heavy metals (e.g., cadmium (Cd) and lead (Pb)) in the metal-binding sites of proteins. Displaced essential redox metals (copper, iron, manganese) from their natural metal-binding sites can catalyze the decomposition of hydrogen peroxide via the Fenton reaction and generate damaging ROS such as hydroxyl radicals, causing damage to lipids, proteins, and DNA. Conversely, some heavy metals, such as cadmium, can suppress the synthesis of nitric oxide radical (NO·), manifested by altered vasorelaxation and, consequently, blood pressure regulation. Pb-induced oxidative stress has been shown to be indirectly responsible for the depletion of nitric oxide due to its interaction with superoxide radical (O2·-), resulting in the formation of a potent biological oxidant, peroxynitrite (ONOO-). This review comprehensively discusses the mechanisms of heavy metal toxicity and their health effects. Aluminum (Al), cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), and chromium (Cr) and their roles in the development of gastrointestinal, pulmonary, kidney, reproductive, neurodegenerative (Alzheimer's and Parkinson's diseases), cardiovascular, and cancer (e.g. renal, lung, skin, stomach) diseases are discussed. A short account is devoted to the detoxification of heavy metals by chelation via the use of ethylenediaminetetraacetic acid (EDTA), dimercaprol (BAL), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercapto-1-propane sulfonic acid (DMPS), and penicillamine chelators.

• MeSH
• Antioxidants metabolism   MeSH
• Bioaccumulation MeSH
• Environmental Pollutants toxicity   MeSH
• Humans MeSH
• Oxidative Stress * drug effects   MeSH
• Metals, Heavy * toxicity   MeSH
• Environmental Exposure adverse effects   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

AIMS: Embryonal tumours with PLAGL1 or PLAGL2 amplification (ET, PLAGL) show substantial heterogeneity regarding their clinical characteristics and have been treated inconsistently, resulting in diverse outcomes. In this study, we aimed to evaluate the clinical behaviour of ET, PLAGL and elucidate their response pattern across the different applied treatment regimens. METHODS: We conducted an in-depth retrospective analysis of clinical and serial imaging data of 18 patients with ET, PLAGL (nine each of PLAGL1 and PLAGL2 amplified). RESULTS: Patients with PLAGL1-amplified tumours (ET, PLAGL1) had fewer relapses (3/9), while PLAGL2-amplified tumours (ET, PLAGL2) were prone to early relapse or progression (8/9) and to distant, leptomeningeal and intraventricular relapses. Progression-free survival differed significantly between the subtypes (log-rank test, p = 0.0055). Postoperative treatment included chemotherapy (n = 17, various protocols), alone (n = 8) or combined with radiotherapy (n = 9). Responses to chemotherapy were observed in both subtypes, and incomplete resection was not associated with inferior survival. All three survivors with ET, PLAGL2 were treated with induction and high-dose chemotherapy with (n = 1-low-dose CSI and boost) or without (n = 2) radiotherapy, whereas five patients with less intensive chemotherapy relapsed. All six survivors with ET, PLAGL1 were treated with conventional chemotherapy regimens, with (n = 4-local radiotherapy n = 3; CSI and boost n = 1) or without (n = 2) radiotherapy. Two patients with ET, PLAGL1 relapsed after 8 years. CONCLUSIONS: Adjuvant therapy should be considered for all ET, PLAGL patients: Patients with ET, PLAGL2 might benefit from intensified chemotherapy regimens. In contrast, patients with ET, PLAGL1 showed superior outcomes without high-dose chemotherapy or craniospinal irradiation.

• MeSH
• Gene Amplification MeSH
• Child MeSH
• DNA-Binding Proteins * genetics   MeSH
• Adult MeSH
• Neoplasms, Germ Cell and Embryonal * genetics   therapy   pathology   diagnostic imaging   MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Central Nervous System Neoplasms * genetics   therapy   pathology   diagnostic imaging   MeSH
• Brain Neoplasms * genetics   therapy   MeSH
• Child, Preschool MeSH
• Retrospective Studies MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH

Topoisomerase II alpha and beta (TOP2A and TOP2B) isoenzymes perform essential and non-redundant cellular functions. Anthracyclines induce their potent anti-cancer effects primarily via TOP2A, but at the same time they induce a dose limiting cardiotoxicity through TOP2B. Here we describe the development of the obex class of TOP2 inhibitors that bind to a previously unidentified druggable pocket in the TOP2 ATPase domain to act as allosteric catalytic inhibitors by locking the ATPase domain conformation with the capability of isoform-selective inhibition. Through rational drug design we have developed topobexin, which interacts with residues that differ between TOP2A and TOP2B to provide inhibition that is both selective for TOP2B and superior to dexrazoxane. Topobexin is a potent protectant against chronic anthracycline cardiotoxicity in an animal model. This demonstration of TOP2 isoform-specific inhibition underscores the broader potential to improve drug specificity and minimize adverse effects in various medical treatments.

• MeSH
• Anthracyclines * adverse effects   pharmacology   MeSH
• DNA Topoisomerases, Type II * metabolism   chemistry   MeSH
• Topoisomerase II Inhibitors * pharmacology   chemistry   MeSH
• Cardiotonic Agents * pharmacology   chemistry   MeSH
• Cardiotoxicity * prevention & control   MeSH
• Humans MeSH
• Mice MeSH
• Poly-ADP-Ribose Binding Proteins antagonists & inhibitors   metabolism   chemistry   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Myoepithelial neoplasms of the skin and soft tissue still represent a confusing and somewhat controversial field in pathology as it appears that this category includes several different entities. However, recent studies have suggested that both apocrine mixed tumors (AMT) and cutaneous myoepitheliomas (CM) harbor identical chromosomal rearrangements involving the PLAG1 gene and hence may represent a morphological spectrum. The aim of the present study was to share our institutional experience with these tumors and specifically focus on studying their immunohistochemical and molecular features to further assess their relatedness. Eleven cases of AMT and 7 cases of CM were collected and analyzed using immunohistochemistry (IHC), PLAG1 FISH, and Archer FusionPlex assay. There were 14 male and 4 female patients with ages ranging from 26 to 85 years (median 55.8 years, mean 58.5 years). AMTs were mainly located in the head and neck (n = 10), while CMs were mainly located in the acral sites (n = 5). PLAG1 IHC was diffusely strongly positive in 14/17 (82%) cases, whereas a single case of AMT diffusely expressed HMGA2. Both tumor groups showed PLAG1 gene fusions which were detected in 6/13 analyzable samples (AMT, n = 4 and CM, n = 2), and included TRPS1::PLAG1 (n = 3), NDRG1::PLAG1 (n = 1), CTNNB1::PLAG1 (n = 1) and a novel PXDNL::PLAG1 fusion (n = 1). The remaining 5 cases were negative, 5 were not analyzable and the single case positive for HMGA2 by IHC revealed a potential HMGA2 gene rearrangement. The cases were further studied by FISH, with 12/17 cases showing PLAG1 gene rearrangement (AMT, n = 8 and CM, n = 4). Altogether, 14/18 cases showed PLAG1 gene rearrangement by at least one of the methods. PLAG1 immunohistochemistry had a 92% specificity and sensitivity. Our study provided additional data to suggest that AMT and CM share overlapping morphological and immunohistochemical features as well as molecular background characterized by PLAG1 gene fusions and thus represent a morphological spectrum. In addition, we identified a novel PXDNL::PLAG1 fusion and suggested that rare cases may harbor HMGA2 gene alterations which seem to be mutually exclusive with PLAG1 gene fusions. The relatedness of these tumors to salivary gland myoepithelial neoplasms and distinctness from eccrine mixed tumors and other skin and soft tissue myoepithelial neoplasms with EWSR1/FUS fusions is discussed.

• MeSH
• DNA-Binding Proteins * genetics   MeSH
• Adult MeSH
• Gene Rearrangement * MeSH
• In Situ Hybridization, Fluorescence MeSH
• Immunohistochemistry * MeSH
• Middle Aged MeSH
• Humans MeSH
• Myoepithelioma * genetics   pathology   MeSH
• Biomarkers, Tumor * genetics   analysis   MeSH
• Neoplasms, Complex and Mixed genetics   pathology   chemistry   MeSH
• Skin Neoplasms * genetics   pathology   MeSH
• Sweat Gland Neoplasms genetics   pathology   MeSH
• HMGA2 Protein * genetics   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH

The ABCB1 gene, encoding the ATP-dependent translocase ABCB1, plays a crucial role in the clearance of amyloid-beta (Aβ) peptides and the transport of cholesterol, implicating it in the pathogenesis of Alzheimer's disease. The study aims to investigate the association between polymorphisms in the ABCB1 gene and cognitive decline in individuals with mild cognitive impairment (MCI), particularly focusing on language function. A longitudinal cohort study involving 1 005 participants from the Czech Brain Aging Study was conducted. Participants included individuals with Alzheimer's disease, amnestic MCI, non-amnestic MCI, subjective cognitive decline, and healthy controls. Next-generation sequencing was utilized to analyze the entire ABCB1 gene. Cognitive performance was assessed using a comprehensive battery of neuropsychological tests, including the Boston Naming Test and the semantic verbal fluency test. Ten ABCB1 polymorphisms (rs55912869, rs56243536, rs10225473, rs10274587, rs2235040, rs12720067, rs12334183, rs10260862, rs201620488, and rs28718458) were significantly associated with cognitive performance, particularly in language decline among amnestic MCI patients. In silico analyses revealed that some of these polymorphisms may affect the binding sites for transcription factors (HNF-3alpha, C/EBPβ, GR-alpha) and the generation of novel exonic splicing enhancers. Additionally, polymorphism rs55912869 was identified as a potential binding site for the microRNA hsa-mir-3163. Our findings highlight the significant role of ABCB1 polymorphisms in cognitive decline, particularly in language function, among individuals with amnestic MCI. These polymorphisms may influence gene expression and function through interactions with miRNAs, transcription factors, and alternative splicing mechanisms.

• MeSH
• Alzheimer Disease genetics   MeSH
• Polymorphism, Single Nucleotide * MeSH
• Cognitive Dysfunction * genetics   MeSH
• Humans MeSH
• Longitudinal Studies MeSH
• Neuropsychological Tests MeSH
• ATP Binding Cassette Transporter, Subfamily B genetics   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• High-Throughput Nucleotide Sequencing MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH

Integral membrane proteins carry out essential functions in the cell, and their activities are often modulated by specific protein-lipid interactions in the membrane. Here, we elucidate the intricate role of cardiolipin (CDL), a regulatory lipid, as a stabilizer of membrane proteins and their complexes. Using the in silico-designed model protein TMHC4_R (ROCKET) as a scaffold, we employ a combination of molecular dynamics simulations and native mass spectrometry to explore the protein features that facilitate preferential lipid interactions and mediate stabilization. We find that the spatial arrangement of positively charged residues as well as local conformational flexibility are factors that distinguish stabilizing from non-stabilizing CDL interactions. However, we also find that even in this controlled, artificial system, a clear-cut distinction between binding and stabilization is difficult to attain, revealing that overlapping lipid contacts can partially compensate for the effects of binding site mutations. Extending our insights to naturally occurring proteins, we identify a stabilizing CDL site within the E. coli rhomboid intramembrane protease GlpG and uncover its regulatory influence on enzyme substrate preference. In this work, we establish a framework for engineering functional lipid interactions, paving the way for the design of proteins with membrane-specific properties or functions.

• MeSH
• DNA-Binding Proteins MeSH
• Endopeptidases metabolism   chemistry   genetics   MeSH
• Escherichia coli metabolism   genetics   MeSH
• Cardiolipins * metabolism   chemistry   MeSH
• Membrane Proteins * metabolism   chemistry   genetics   MeSH
• Protein Engineering * MeSH
• Escherichia coli Proteins * metabolism   chemistry   genetics   MeSH
• Molecular Dynamics Simulation MeSH
• Protein Binding MeSH
• Publication type
• Journal Article MeSH

Previous research indicated that the cytotoxic activity of the antitumor platinum(II) complex [Pt(1S,2S-diaminocyclohexane)(5,6-dimethyl-1,10-phenanthroline)]2+ (56MESS) was not primarily attributed to DNA binding, despite the complex being confirmed to localize also in the nucleus. In this study, we have demonstrated that the antiproliferative activity of 56MESS indeed involves DNA binding. Furthermore, in addition to binding duplex DNA, the complex also interacts with non-canonical secondary DNA structures, such as G-quadruplexes (G4s) and i-Motifs (iMs). This interaction leads to the suppression of G-regulated oncogene expression and disrupts key enzymatic processes associated with DNA, potentially contributing to DNA damage and the biological activity of 56MESS. These findings build upon previously published results, revealing that the anticancer activity of 56MESS is significantly more multifaceted than previously understood, involving multiple distinct mechanisms.

• MeSH
• DNA metabolism   chemistry   MeSH
• Down-Regulation * drug effects   MeSH
• G-Quadruplexes * drug effects   MeSH
• Humans MeSH
• Cell Line, Tumor MeSH
• Organoplatinum Compounds * pharmacology   chemistry   MeSH
• DNA Damage * drug effects   MeSH
• Cell Proliferation drug effects   MeSH
• Antineoplastic Agents * pharmacology   chemistry   MeSH
• Proto-Oncogene Proteins c-myc * genetics   metabolism   MeSH
• Proto-Oncogene Proteins p21(ras) * genetics   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

G-quadruplexes (G4s) are functional elements of the human genome, some of which inhibit DNA replication. We investigated replication of G4s within highly abundant microsatellite (GGGA, GGGT) and transposable element (L1 and SVA) sequences. We found that genome-wide, numerous motifs are located preferentially on the replication leading strand and the transcribed strand templates. We directly tested replicative polymerase ε and δ holoenzyme inhibition at these G4s, compared to low abundant motifs. For all G4s, DNA synthesis inhibition was higher on the G-rich than C-rich strand or control sequence. No single G4 was an absolute block for either holoenzyme; however, the inhibitory potential varied over an order of magnitude. Biophysical analyses showed the motifs form varying topologies, but replicative polymerase inhibition did not correlate with a specific G4 structure. Addition of the G4 stabilizer pyridostatin severely inhibited forward polymerase synthesis specifically on the G-rich strand, enhancing G/C strand asynchrony. Our results reveal that replicative polymerase inhibition at every G4 examined is distinct, causing complementary strand synthesis to become asynchronous, which could contribute to slowed fork elongation. Altogether, we provide critical information regarding how replicative eukaryotic holoenzymes navigate synthesis through G4s naturally occurring thousands of times in functional regions of the human genome.

• MeSH
• Aminoquinolines MeSH
• DNA Polymerase II * antagonists & inhibitors   metabolism   MeSH
• DNA Polymerase III * antagonists & inhibitors   metabolism   MeSH
• DNA chemistry   MeSH
• G-Quadruplexes * MeSH
• Genome, Human * MeSH
• Holoenzymes metabolism   MeSH
• Picolinic Acids pharmacology   MeSH
• Humans MeSH
• Microsatellite Repeats MeSH
• Poly-ADP-Ribose Binding Proteins MeSH
• DNA Replication * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

PI3K signaling pathway is crucial for a plethora of cellular processes and is extensively linked with tumorigenesis and chemo-/radioresistance. Although a number of small molecule inhibitors have been synthesized to control PI3K-mediated signaling, only a limited clinical success has been reached. Thus, the search for novel promising candidates is still ongoing. Herein, we present a novel series of N-(5-(2-morpholino-4-oxo-3,4-dihydroquinazolin-8-yl)pyridin-2-yl)acylamides designed to simultaneously inhibit PI3K and DNA-PK activity. Compared to a commercial DNA-PK/PI3K inhibitor AZD7648, synthesized compounds generally exhibited markedly lower baseline cytotoxicity in all tested cell lines (MC38, B16F10, 4T1, CT26 and HEK-239). Through an array of biological experiments, we selected two most promising compounds, 2 and 6. While in cell-free conditions, 6 acted as a very efficient pan-PI3K and DNA-PK inhibitor, in physiological conditions, 2 performed better and acted as a potent chemosensitizer able to increase the amount of DNA double strand breaks induced by doxorubicin. This was plausibly due to its improved ability to accumulate in nuclei as evidenced by confocal analyses. Importantly, using P-gp overexpressing CT26 cells, we found that 2 is an efficient inhibitor of multidrug resistance (MDR) able to down-regulate expression of mRNA encoding MDR-driving proteins ABCB1A, ABCB1B and ABCC1. We also demonstrate that 2 can be simply loaded into lipid nanoparticles that retain its chemosensitizing properties. Taken together, the presented study provides a solid basis for a subsequent rational structure optimization towards new generation of multitarget inhibitors able to control crucial signaling pathways involved in tumorigenesis and drug resistance.

• MeSH
• Drug Resistance, Neoplasm * drug effects   MeSH
• Phosphatidylinositol 3-Kinases metabolism   MeSH
• Phosphoinositide-3 Kinase Inhibitors * pharmacology   MeSH
• Protein Kinase Inhibitors * pharmacology   chemistry   chemical synthesis   MeSH
• Humans MeSH
• Drug Resistance, Multiple * drug effects   MeSH
• Molecular Structure MeSH
• Mice MeSH
• Cell Line, Tumor MeSH
• ATP Binding Cassette Transporter, Subfamily B, Member 1 * antagonists & inhibitors   metabolism   MeSH
• Cell Proliferation drug effects   MeSH
• DNA-Activated Protein Kinase * antagonists & inhibitors   metabolism   MeSH
• Antineoplastic Agents * pharmacology   chemistry   chemical synthesis   MeSH
• Drug Screening Assays, Antitumor MeSH
• Dose-Response Relationship, Drug MeSH
• Structure-Activity Relationship MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH