ABSTRACT
The activation of C-C bonds by transition-metal complexes is of continuing interest and acetonitrile (MeCN) has attracted attention as a cyanide source with comparatively low toxicity for organic cyanation reactions. A diiron end-on µ-η1:η1-CN-bridged complex was obtained from a crystallization experiment of an open-chain iron-NHC complex, namely, µ-cyanido-κ2C:N-bis{[(acetonitrile-κN)[3,3'-bis(pyridin-2-yl)-1,1'-(methylidene)bis(benzimidazol-2-ylidene)]iron(II)} tris(hexafluorophosphate), [Fe2(CN)(C2H3N)2(C25H18N6)2](PF6)3. The cyanide appears to originate from the MeCN solvent by C-C bond cleavage or through carbon-hydrogen oxidation.
ABSTRACT
In this contribution, nanocatalysts with rather diverse architectures were designed to promote different intimacy degrees between Cu and SiO2 and consequently tune distinct Cu-SiO2 interactions. Previously synthesized copper nanoparticles were deposited onto SiO2 (NPCu/SiO2) in contrast to ordinarily prepared supported Cu/SiO2. NPCu@SiO2 and SiO2@Cu core-shell nanocatalysts were also synthesized, and they were all bulk and surface characterized by XRD, TGA, TEM/HRTEM, H2-TPR, XANES, and XPS. It was found that Cu0 is the main copper phase in NPCu/SiO2 while Cu2+ rules the ordinary Cu/SiO2 catalyst, and Cu0 and electron-deficient Cuδ+ species coexist in the core-shell nanocatalysts as a consequence of a deeper metal-support interaction. Catalytic performance could not be associated with the physical properties of the nanocatalysts derived from their architectures but was associated with the more refined chemical characteristics tuned by their design. Cu/SiO2 and NPCu/SiO2 catalysts led to the formation of furfuryl alcohol, evidencing that catalysts holding weak or no metal-support interaction have no significant impact on product distribution even in the aqueous phase. The establishment of such interactions through advanced catalyst architecture, allowing the formation of electron-deficient Cuδ+ moieties, particularly Cu2+ and Cu+ as unveiled by spectroscopic investigations, is critical to promoting the hydrogenation-ring rearrangement cascade mechanism leading to cycloketones.
ABSTRACT
BACKGROUND: N-(-9 acridinyl)-b-alanine hydrochloride (S-300) is the main byproduct of red blood cell (RBC) amustaline/glutathione(GSH) pathogen reduction, currently undergoing phase III US clinical trials following successful European studies(1-3). Phosphatidylinositol glycan, class A (Pig-a) X-linked gene mutagenesis is a validated mammalian in vivo mutation assay for genotoxicity, assessed as clonal loss of glycosylphosphatidylinositol-linked CD59 cell-surface molecules on reticulocytes (RETs) and RBCs. METHODS: Male Sprague-Dawley rats received continuous infusion of S-300 up to the maximum feasible dose (240 mg/kg/day-limited by solubility and volume) for 28 days. Positive controls received a known mutagen by oral gavage on Days 1-3. Plasma levels of S-300 were assessed by HPLC before, during and after infusion. CD59-negative RBCs and RETs were enumerated in pre-dose and Day 28 samples, using a flow cytometric method. Outcome was evaluated by predetermined criteria using concurrent and historical controls. Toxicity was assessed by laboratory measures and necropsy. RESULTS: S-300 reached maximum, dose-dependent levels (3-15 µmol/L) within 2-8 h that were sustained for 672 h and undetectable 2 h after infusion. Circulating RET levels indicated a lack of hematopoietic toxicity. Necropsy revealed minimal-mild observations related to poor S-300 solubility at high concentrations. Pig-a assessment met the preset acceptability criteria and revealed no increase in mutant RBCs or RETs. CONCLUSIONS: Maximum feasible S-300 exposure of rats by continuous infusion for 28 days was not genotoxic as assessed by an Organization for Economic Cooperation and Development-compliant, mammalian, in vivo Pig-a gene mutation assay that meets the requirements of International Conference on Harmonization (ICH) S2(R1) and FDA guidances on genotoxicity testing.
Subject(s)
Mutagenicity Tests , Rats, Sprague-Dawley , Animals , Male , Rats , Mutagenicity Tests/methods , CD59 Antigens/genetics , Reticulocytes/drug effects , Erythrocytes/drug effects , Erythrocytes/metabolism , Membrane Proteins/genetics , Mutagenesis/drug effects , Mutagens/toxicityABSTRACT
Toxocara canis can produce the "larva migrans" syndrome in humans, and in puppies, it can cause severe digestive disorders. The most used treatments are based on anthelmintics, although there are reports of anthelmintic (AH) resistance. The Yucatan Peninsula has a great variety of plant species whose AH properties are still unknown. The objective of this study was to evaluate the in vitro AH activity of ethanolic (EE), methanolic (ME) and aqueous (AE) extracts from the leaves of five native plant species of the Yucatan Peninsula on T. canis eggs of dogs from Merida, Yucatan. As part of a screening, the EE of the plants Alseis yucatanensis, Calea jamaicensis, Cameraria latifolia, Macrocepis diademata, and Parathesis cubana were evaluated at doses of 2400 and 3600 µg/ml. The EE and AE of A. yucatanensis and M. diademata presented high percentages (≥ 91.3%) of inhibition of the larval development of T. canis after six days of exposure. The lowest LC50 and LC99 was presented by the ME from A. yucatanensis (255.5 and 629.06 µg/ml, respectively) and the ME from M. diademata (222.4 and 636.5 µg/ml, respectively), and the AE from A. yucatanenesis (LC50 of 535.9 µg/ml). Chemical profiling of the most potent AH extract (Alseis yucatanensis) was carried out by LC-UV-HRMS. Data from the ME and AE from this plant indicated the presence of the known glucosylngoumiensine, kaempferol 3,7-diglucosyde, uvaol, linoleic acid and linolenic acid together with unknown alkaloids. The EE, ME and AE from leaves of M. diademata and A. yucatanensis could be developed as natural alternatives to control T. canis.
Subject(s)
Anthelmintics , Plant Extracts , Plant Leaves , Toxocara canis , Animals , Plant Extracts/pharmacology , Plant Extracts/chemistry , Anthelmintics/pharmacology , Anthelmintics/chemistry , Toxocara canis/drug effects , Dogs , Plant Leaves/chemistry , Mexico , Larva/drug effectsABSTRACT
Synthesis and characterization of the first two cyclic ethylene-bridged tetradentate NHC ligands, with an unsaturated (imidazole) and saturated backbone (2-imidazoline), are described. Complexes of both ligands containing palladium(ii) have been obtained. For platinum(ii) and gold(iii), only the unsaturated tetracarbene complexes could be isolated. The attempts to synthesize a methylene-bridged 2-imidazoline macrocycle are also described. Furthermore, a novel bisimidazolinium ligand precursor and its open-chain PdII and PtII tetracarbene complexes are obtained. Finally, it is shown that the unsaturated gold(iii) tetracarbene is able to induce apoptosis in malignant SK-N-AS neuroblastoma cells via the mitochondrial and ROS pathway and overcomes resistance to cisplatin in vitro.
ABSTRACT
Complement-mediated diseases can be treated using systemic inhibitors. However, complement components are abundant in circulation, affecting systemic inhibitors' exposure and efficacy. Furthermore, because of complement's essential role in immunity, systemic treatments raise infection risk in patients. To address these challenges, we developed antibody fusion proteins combining the alternative-pathway complement inhibitor factor H (fH1-5) with an anti-C3d monoclonal antibody (C3d-mAb-2fH). Because C3d is deposited at sites of complement activity, this molecule localizes to tissue complement while minimizing circulating complement engagement. These fusion proteins bind to deposited complement in diseased human skin sections and localize to activated complement in a primate skin injury model. We further explored the pharmacology of C3d-mAb-2fH proteins in rodent models with robust tissue complement activation. Doses of C3d-mAb-2fH >1 mg/kg achieved >75% tissue complement inhibition in mouse and rat injury models while avoiding circulating complement blockade. Glomerular-specific complement inhibition reduced proteinuria and preserved podocyte foot-process architecture in rat membranous nephropathy, indicating disease-modifying efficacy. These data indicate that targeting local tissue complement results in durable and efficacious complement blockade in skin and kidney while avoiding systemic inhibition, suggesting broad applicability of this approach in treating a range of complement-mediated diseases.
Subject(s)
Complement Factor H , Kidney Diseases , Humans , Mice , Rats , Animals , Complement Factor H/genetics , Complement C3d/metabolism , Kidney Diseases/etiology , Antibodies , Complement ActivationABSTRACT
BACKGROUND: Vesico-ureteral reflux (VUR) is a common associated urological anomaly in anorectal malformation (ARM)-patients. High-grade VUR requires antibiotic prophylaxis to prevent urinary tract infections (UTI's), renal scarring and -failure. The exact prevalence of high-grade VUR in ARM patients is unknown. Hence, the aim of this study was determining the incidence of high-grade VUR in ARM-patients, and its associated risk factors. METHODS: A multicenter retrospective cohort study was performed using the ARM-Net registry, including data from 34 centers. Patient characteristics, screening for and presence of renal anomalies and VUR, sacral and spinal anomalies, and sacral ratio were registered. Phenotypes of ARM were grouped according to their complexity in complex and less complex. Multivariable analyses were performed to detect independent risk factors for high-grade (grade III-V) VUR. RESULTS: This study included 2502 patients (50 % female). Renal screening was performed in 2250 patients (90 %), of whom 648 (29 %) had a renal anomaly documented. VUR-screening was performed in 789 patients (32 %), establishing high-grade VUR in 150 (19 %). In patients with a normal renal screening, high-grade VUR was still present in 10 % of patients. Independent risk factors for presence of high-grade VUR were a complex ARM (OR 2.6, 95 %CI 1.6-4.3), and any renal anomaly (OR 3.3, 95 %CI 2.1-5.3). CONCLUSIONS: Although renal screening is performed in the vast majority of patients, only 32 % underwent VUR-screening. Complex ARM and any renal anomaly were independent risk factors for high-grade VUR. Remarkably, 10 % had high-grade VUR despite normal renal screening. Therefore, VUR-screening seems indicated in all ARM patients regardless of renal screening results, to prevent sequelae such as UTI's, renal scarring and ultimately renal failure. TYPE OF STUDY: Observational Cohort-Study. LEVEL OF EVIDENCE: III.
Subject(s)
Anorectal Malformations , Registries , Vesico-Ureteral Reflux , Humans , Vesico-Ureteral Reflux/complications , Vesico-Ureteral Reflux/epidemiology , Vesico-Ureteral Reflux/diagnosis , Female , Male , Retrospective Studies , Anorectal Malformations/epidemiology , Anorectal Malformations/complications , Anorectal Malformations/diagnosis , Infant, Newborn , Risk Factors , Incidence , Infant , Abnormalities, Multiple/epidemiologyABSTRACT
Abstract This study aims to identify single nucleotide polymorphisms (SNPs) within KRTAP genes in alpacas (Vicugna pacos), which play a fundamental role in defining their physico-mechanical properties and potentially the quality of alpaca fiber, the primary product of their breeding. Thirty-four KRTAP genes, as annotated in the reference genome VicPac3.1, were investigated. Utilizing the reference genome, along with nine additional genomes and reads from 300 reduced representation DNA libraries of alpacas, SNPs were identified. Minor allele frequency (MAF) and genotyping rates were computed using PLINK software, while Illumina Scores were determined for each SNP using Illumina Design Studio software. Markers meeting the criteria of MAF ≥ 0.05, genotyping rate > 45%, and Illumina Score ≥ 0.6 per SNP were selected. A total of 67 SNPs were identified within intronic, exonic, and untranslated regions of KRTAP genes. Among these, 35 SNPs were incorporated into the 76K Alpaca SNP microarray, with 32 SNPs subsequently validated in a population of 936 alpacas. In conclusion, our findings delineate SNPs within KRTAPs that hold potential utility in genome-wide association studies, thereby facilitating the integration of modern breeding technologies into alpaca breeding programs.
Resumen Este estudio tiene como objetivo identificar polimorfismos de nucleótido simple (PNSs) dentro de los genes KRTAP en alpacas (Vicugna pacos), que juegan un papel fundamental en la definición de sus propiedades físico-mecánicas y la calidad de la fibra de alpaca, producto principal de su crianza. Se investigaron treinta y cuatro genes KRTAP, tal como están anotados en el genoma de referencia VicPac3.1. Utilizando el genoma de referencia, junto con nueve genomas adicionales y lecturas de 300 bibliotecas de representación reducida de ADN de alpacas, se identificaron los PNSs. La frecuencia de los alelos menores (MAF) y las tasas de genotipificación se calcularon utilizando el software PLINK, mientras que los Illumina Score se determinaron para cada PNS utilizando el software Illumina Design Studio. Se seleccionaron marcadores que cumplían con los criterios de MAF ≥ 0.05, tasa de genotipado > 45% e Illumina Score ≥ 0.6 por PNS. Se identificaron un total de 67 PNSs dentro de regiones intrónicas, exónicas y/o no traducidas de genes KRTAP. Entre estos, se incorporaron 35 PNSs al microarray 76K Alpaca SNP, y posteriormente se validaron 32 PNSs en una población de 936 alpacas. En conclusión, nuestros hallazgos identificaron los PNSs dentro de los KRTAP que tienen una utilidad potencial en estudios de asociación de todo el genoma, facilitando así la integración de tecnologías de reproducción modernas en los programas de reproducción de alpacas.
ABSTRACT
Ocular diseases are a growing global concern and have a significant impact on the quality of life. Cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy are the most prevalent ocular diseases. Their prevalence and the global market size are also increasing. However, the available pharmacotherapy is currently limited. These diseases share common pathophysiological features, including neovascularization, inflammation, and/or neurodegeneration. Histone deacetylases (HDACs) are a class of enzymes that catalyze the removal of acetyl groups from lysine residues of histone and nonhistone proteins. HDACs are crucial for regulating various cellular processes, such as gene expression, protein stability, localization, and function. They have also been studied in various research fields, including cancer, inflammatory diseases, neurological disorders, and vascular diseases. Our study aimed to investigate the relationship between HDACs and ocular diseases, to identify a new strategy for pharmacotherapy. This review article explores the role of HDACs in ocular diseases, specifically focusing on diabetic retinopathy, age-related macular degeneration, and retinopathy of prematurity, as well as optic nerve disorders, such as glaucoma and optic neuropathy. Additionally, we explore the interplay between HDACs and key regulators of fibrosis and angiogenesis, such as TGF-ß and VEGF, highlighting the potential of targeting HDAC as novel therapeutic strategies for ocular diseases.
Subject(s)
Diabetic Retinopathy , Glaucoma , Macular Degeneration , Infant, Newborn , Humans , Diabetic Retinopathy/drug therapy , Histone Deacetylases/metabolism , Quality of Life , Glaucoma/drug therapy , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylase Inhibitors/therapeutic use , Histone Deacetylase Inhibitors/chemistryABSTRACT
Mucormycosis is a lethal and difficult-to-treat fungal infection caused by fungi of the order Mucorales. Mucor lusitanicus, a member of Mucorales, is commonly used as a model to understand disease pathogenesis. However, transcriptional control of hyphal growth and virulence in Mucorales is poorly understood. This study aimed to investigate the role of Tec proteins, which belong to the TEA/ATTS transcription factor family, in the hyphal development and virulence of M. lusitanicus. Unlike in the genome of Ascomycetes and Basidiomycetes, which have a single Tec homologue, in the genome of Mucorales, two Tec homologues, Tec1 and Tec2, were found, except in that of Phycomyces blakesleeanus, with only one Tec homologue. tec1 and tec2 overexpression in M. lusitanicus increased mycelial growth, mitochondrial content and activity, expression of the rhizoferrin synthetase-encoding gene rfs, and virulence in nematodes and wax moth larvae but decreased cAMP levels and protein kinase A (PKA) activity. Furthermore, tec1- and tec2-overexpressing strains required adequate mitochondrial metabolism to promote the virulent phenotype. The heterotrimeric G beta subunit 1-encoding gene deletant strain (Δgpb1) increased cAMP-PKA activity, downregulation of both tec genes, decreased both virulence and hyphal development, but tec1 and tec2 overexpression restored these defects. Overexpression of allele-mutated variants of Tec1(S332A) and Tec2(S168A) in the putative phosphorylation sites for PKA increased both virulence and hyphal growth of Δgpb1. These findings suggest that Tec homologues promote mycelial development and virulence by enhancing mitochondrial metabolism and rhizoferrin accumulation, providing new information for the rational control of the virulent phenotype of M. lusitanicus.
Subject(s)
Mucor , Transcription Factors , Transcription Factors/genetics , Virulence/genetics , Oxidative Stress , Fungal Proteins/geneticsABSTRACT
The aim of this study was the identification of candidate genomic regions associated with fiber diameter in alpacas. DNA samples were collected from 1011 female Huacaya alpacas from two geographical Andean regions in Peru (Pasco and Puno), and three alpaca farms within each region. The samples were genotyped using an Affymetrix Custom Alpaca genotyping array containing 76,508 SNPs. After the quality controls, 960 samples and 51,742 SNPs were retained. Three association study methodologies were performed. The GWAS based on a linear model allowed us to identify 11 and 35 SNPs (-log10(p-values) > 4) using information on all alpacas and alpacas with extreme values of fiber diameter, respectively. The haplotype and marker analysis method allowed us to identify nine haplotypes with standardized haplotype heritability higher than six standard deviations. The selection signatures based on cross-population extended haplotype homozygosity (XP-EHH) allowed us to identify 180 SNPs with XP-EHH values greater than |3|. Four candidate regions with adjacent SNPs identified via two association methods of analysis are located on VPA6, VPA9, VPA29 and one chromosomally unassigned scaffold. This study represents the first analysis of alpaca whole genome association with fiber diameter, using a recently assembled alpaca SNP microarray.
ABSTRACT
The synthesis of a homoleptic azide-functionalised Au(I) bis-1,2,3-triazole-5-ylidene complex is reported, starting from a backbone-modified 1,2,3-triazolium salt ligand precursor. The incorporated azide handle allows for a straightforward modification of the complex according to click-chemistry protocols without impacting the steric shielding around the metal center, demonstrating the superiority of the presented triazole ligand framework over imidazole based systems. Employing the SPAAC and the CuAAC reactions, post-modification of the complex is facilitated with two model substrates, while retaining very high antiproliferative activity (nanomolar range IC50 values) in A2780 and MCF-7 human cancer cells.
ABSTRACT
Neuroblastoma is the most common extracranial solid tumor in childhood and arises from neural crest cells of the developing sympathetic nervous system. Prostaglandin E2 (PGE2) has been identified as a key pro-inflammatory mediator of the tumor microenvironment (TME) that promotes neuroblastoma progression. We report that the interaction between the microRNA miR-574-5p and CUG-binding protein 1 (CUGBP1) induces the expression of microsomal prostaglandin E2 synthase 1 (mPGES-1) in neuroblastoma cells, which contributes to PGE2 biosynthesis. PGE2 in turn specifically induces the sorting of miR-574-5p into small extracellular vesicles (sEV) in neuroblastoma cell lines. sEV are one of the major players in intercellular communication in the TME. We found that sEV-derived miR-574-5p has a paracrine function in neuroblastoma. It acts as a direct Toll-like receptor 7/8 (TLR7/8) ligand and induces α-smooth muscle actin (α-SMA) expression in fibroblasts, contributing to fibroblast differentiation. This is particularly noteworthy as it has an opposite function to that in the TME of lung carcinoma, another PGE2 dependent tumor type. Here, sEV-derived miR-574-5p has an autokrine function that inhibits PGE2 biosynthesis in lung cancer cells. We report that the tetraspanin composition on the surface of sEV is associated with the function of sEV-derived miR-574-5p. This suggests that the vesicles do not only transport miRs, but also appear to influence their mode of action.
ABSTRACT
Theoretically, a necrotic root canal fulfils all requirements as a niche for methanogens to inhabit. However, their presence in it and its implication in apical periodontitis (AP) is controversial. Therefore, to contribute to ending the controversy, this study aimed to detect and compare methanogens' presence in two distinct niches with supposedly different microenvironments; both were necrotic root canals associated with AP but one from patients with type 2 diabetes mellitus (T2DM) while the other from non-diabetic patients. A clinical examination was performed on 65 T2DM patients and 73 non-diabetic controls. Samples from necrotic root canals were obtained, and methanogens were identified. The presence of methanogens was three times higher (27.6%) in the T2DM group than in non-diabetic patients (8.2%). In addition, methanogens' presence was associated with a higher prevalence of periapical symptoms.
Subject(s)
Diabetes Mellitus, Type 2 , Euryarchaeota , Periapical Periodontitis , Humans , Diabetes Mellitus, Type 2/complications , Dental Pulp Cavity , Archaea , Root Canal Therapy , Periapical Periodontitis/diagnostic imaging , Periapical Periodontitis/therapy , NecrosisABSTRACT
Context: Anti-inflammatory drugs and biologics can effectively treat inflammatory conditions and diseases but can also cause burdensome side effects. Many patients prefer to use time-tested, traditional medicinal products and dietary supplements, but such products seldom receive the rigorous testing required for regulatory approvals of drugs and biologics. Thus, it is advantageous to demonstrate by experimentation the pharmacological and toxicological properties of unapproved natural products and compared to benchmark approved drugs or biologics. Objective: The studies intended to evaluate Samento®, a commercial hydro-alcoholic extract of the pentacyclic chemotype of Uncaria Tomentosa (Willd.) DC, for the prophylactic and treatment effects of irritant-induced inflammation and antigen-induced arthritic inflammation in two rat models. The studies were also intended to create a clinical bridge rationale for the use of Samento® in the treatment of inflammation in humans, with a suggested allometrically scaled starting dose. Design: The research team performed two in vivo animal model studies of induced inflammation in rats. Setting: The studies took place at the Universidad Peruana Cayetano Heredia in Lima, Peru. Prophylaxis Model of Irritant-Induced Inflammation: Holtzman rats in five groups (five each per group) were administered 14 daily doses of Samento® at 250, 500, and 1000 mg/kg of wet weight, or 40 mg/kg of naproxen sodium as a positive control, or nothing as a negative control. At 14 days the right legs of the rats were challenged by injection into the connective tissue by the chemical irritant carrageenan. Two hours thereafter the weight of the irritant-injected right leg was compared to the non-injected left leg of each rat, to determine the level of irritant-induced inflammation. Treatment Model of Antigen-Induced Arthritic Inflammation: Arthritic inflammation was induced in five groups of Lewis rats (five each per group) by intradermal injection of the tail with non-allogeneic, bovine type II collagen in incomplete Freund's adjuvant. A sixth group was not injected with collagen antigen as a non-induced control. Ten days after the induction of arthritic inflammation in the five injected groups, individual groups were treated with Samento® at 250, 500, and 1000 mg/kg of wet weight daily for 21 days, or 0.2 mg/kg of methotrexate twice per week as a positive control, or nothing as a negative control. At 21 days the animals were assessed for antigen-induced arthritic inflammation and assigned an analog score ranging from 0 to 4. Results: The research team confirmed the presence of pentacyclic oxindoles and the absence of tetracyclic oxindoles within Samento®. In the prophylactic model, 14 days of pretreatment with oral Samento® produced dose-dependent, statistically significant reductions in inflammation in the rats' leg weights between the carrageenan induction and postintervention, for the 250, 500, and 1000 mg/kg Samento® groups (P < .05 for all groups). The 1000 mg/kg group had a 74% anti-inflammatory effect versus 97% with the 40 mg/kg of naproxen sodium in the positive control group. In the treatment model, 21 days of oral administration of Samento® produced dose-dependent, statistically significant reductions in arthritic inflammation postintervention, for the 250, 500, and 1000 mg/kg Samento® groups (P < .05 for all groups). Treatment with the highest tested dose of the extract (1000 mg/kg) yielded an 85% anti-inflammatory effect versus 90% with 0.2 mg/kg of methotrexate in the positive control group. Conclusions: The two rat models revealed that the Uncaria phytotherapy Samento® was an effective prophylactic as well as a treatment for induced inflammation in rats. The highest dose of the pentacyclic chemotype of Uncaria approached the anti-inflammatory activities of the established benchmark pharmaceutical positive controls. The results in the two rat models suggest an allometrically scaled starting dose of Samento® of 4 g daily in humans.
ABSTRACT
Children with Group 3 medulloblastoma (G3 MB) have a very poor prognosis, and many do not survive beyond 5 years after diagnosis. A factor that may contribute to this is the lack of available targeted therapy. Expression of protein lin-28 homolog B (LIN28B), a regulator of developmental timing, is upregulated in several cancers, including G3 MB, and is associated with worse survival in this disease. Here, we investigate the role of the LIN28B pathway in G3 MB and demonstrate that the LIN28B-lethal-7 (let-7; a microRNA that is a tumor suppressor)-lymphokine-activated killer T-cell-originated protein kinase (PBK; also known as PDZ-binding kinase) axis promotes G3 MB proliferation. LIN28B knockdown in G3-MB-patient-derived cell lines leads to a significant reduction in cell viability and proliferation in vitro and in prolonged survival of mice with orthotopic tumors. The LIN28 inhibitor N-methyl-N-[3-(3-methyl-1,2,4-triazolo[4,3-b]pyridazin-6-yl)phenyl]acetamide (1632) significantly reduces G3 MB cell growth and demonstrates efficacy in reducing tumor growth in mouse xenograft models. Inhibiting PBK using HI-TOPK-032 also results in a significant reduction in G3 MB cell viability and proliferation. Together, these results highlight a critical role for the LIN28B-let-7-PBK pathway in G3 MB and provide preliminary preclinical results for drugs targeting this pathway.
Subject(s)
Cerebellar Neoplasms , Medulloblastoma , MicroRNAs , Humans , Mice , Animals , Medulloblastoma/genetics , Mitogen-Activated Protein Kinase Kinases/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Cell Proliferation/genetics , MicroRNAs/genetics , Cerebellar Neoplasms/genetics , Cell Line, Tumor , RNA-Binding Proteins/geneticsABSTRACT
Y-box binding protein 1 (YBX1 or YB1) is a therapeutically relevant oncoprotein capable of RNA and DNA binding and mediating protein-protein interactions that drive proliferation, stemness, and resistance to platinum-based therapies. Given our previously published findings, the potential for YB1-driven cisplatin resistance in medulloblastoma (MB), and the limited studies exploring YB1-DNA repair protein interactions, we chose to investigate the role of YB1 in mediating radiation resistance in MB. MB, the most common pediatric malignant brain tumor, is treated with surgical resection, cranio-spinal radiation, and platinum-based chemotherapy, and could potentially benefit from YB1 inhibition. The role of YB1 in the response of MB to ionizing radiation (IR) has not yet been studied but remains relevant for determining potential anti-tumor synergy of YB1 inhibition with standard radiation therapy. We have previously shown that YB1 drives proliferation of cerebellar granular neural precursor cells (CGNPs) and murine Sonic Hedgehog (SHH) group MB cells. While others have demonstrated a link between YB1 and homologous recombination protein binding, functional and therapeutic implications remain unclear, particularly following IR-induced damage. Here we show that depleting YB1 in both SHH and Group 3 MB results not only in reduced proliferation but also synergizes with radiation due to differential response dynamics. YB1 silencing through shRNA followed by IR drives a predominantly NHEJ-dependent repair mechanism, leading to faster γH2AX resolution, premature cell cycle re-entry, checkpoint bypass, reduced proliferation, and increased senescence. These findings show that depleting YB1 in combination with radiation sensitizes SHH and Group 3 MB cells to radiation.
Subject(s)
Brain Neoplasms , Cerebellar Neoplasms , Medulloblastoma , Neural Stem Cells , Y-Box-Binding Protein 1 , Animals , Humans , Mice , Brain Neoplasms/metabolism , Cell Proliferation , Cerebellar Neoplasms/pathology , DNA Damage , Hedgehog Proteins/metabolism , Medulloblastoma/pathology , Neural Stem Cells/metabolism , Y-Box-Binding Protein 1/metabolismABSTRACT
INTRODUCTION AND OBJECTIVE: Headache is a frequent reason for consultation between primary care physicians, emergency services physicians, and neurology specialists; however, it is not always well managed. The Andalusian Society of Neurology's Headache Study Group (SANCE) aimed to analyse headache management at different levels of care. MATERIAL AND METHODS: We conducted a descriptive cross-sectional study with data gathered through a retrospective survey in July 2019. Participants completed a series of structured questionnaires on different social and work-related variables from 4 different groups of healthcare professionals (primary care [PC], emergency departments, neurology departments, headache units). RESULTS: A total of 204 healthcare professionals completed the survey: 35 emergency department physicians, 113 PC physicians, 37 general neurologists, and 19 neurologists specialising in headache. Eighty-five percent of PC physicians reported prescribing preventive drugs, which were maintained for at least 6 months (59%), with flunarizine and amitriptyline being the most commonly used. Most patients attended at neurology consultations (65%) are referred by PC physicians, with changes in the headache pattern being the main reason for referral (74%). Healthcare professionals across all levels of care showed great interest in headache and in receiving training in headache management (97% of PC physicians, 100% of emergency services physicians, 100% of general neurologists). CONCLUSIONS: Migraine sparks great interest among healthcare professionals from different levels of care. Our results also reveal a lack of resources for headache management, which is reflected in the long waiting times. Other means of bilateral communication between different levels of care should be explored (eg, e-mail).