Targeting proto-oncogene B-MYB G-quadruplex with a nucleic acid-based fluorescent probe

The B-MYB gene encodes a transcription factor (B-MYB) that regulates cell growth and survival. Abnormal expression of B-MYB is frequently observed in lung cancer and poses challenges for targeted drug therapy. Oncogenes often contain DNA structures called G-quadruplexes (G4s) in their promoter regions, and B-MYB is no exception. These G4s play roles in genetic regulation and are potential cancer treatment targets. In this study, a probe was designed to specifically identify a G4 within the promoter region of the B-MYB gene. This probe combines an acridine derivative ligand with a DNA segment complementary to the target sequence, enabling it to hybridize with the adjacent sequence of the G4 being investigated. Biophysical studies demonstrated that the acridine derivative ligands C5NH2 and C8NH2 not only effectively stabilized the G4 structure but also exhibited moderate affinity. They were capable of altering the G4 topology and exhibited enhanced fluorescence emission in the presence of this quadruplex. Additionally, these ligands increased the number of G4s observed in cellular studies. Through various biophysical studies, the target sequence was shown to form a G4 structure, even with an extra nucleotide tail added to its flanking region. Cellular studies confirmed the co-localization between the target sequence and the developed probe.

Targeting of G-quadruplex DNA with 99mTc(I)/Re(I) Tricarbonyl Complexes Carrying Pyridostatin Derivatives

The main goal of this work was to elucidate the potential relevance of (radio)metal chelates of 99mTc and Re targeting G-quadruplex structures for the design of new tools for cancer theranostics. 99mTc provides the complexes with the ability to perform single-photon-emission computed tomography imaging studies, while the Re complexes should act as anticancer agents upon interaction with specific G4 DNA or RNA structures present in tumor tissues. Towards this goal, we have developed isostructural 99mTc(I) and Re(I) tricarbonyl complexes anchored by a pyrazolyl-diamine (Pz) chelator carrying a pendant pyridostatin (PDS) fragment as the G4-binding motif. The interaction of the PDF-Pz-Re (8) complex with different G4-forming oligonucleotides was studied by circular dichroism, fluorescence spectroscopy and FRET-melting assays. The results showed that the Re complex retained the ability to bind and stabilize G4-structures from different DNA or RNA sequences, namely those present on the SRC proto-oncogene and telomeric RNA (TERRA sequence). PDF-Pz-Re (8) showed low to moderate cytotoxicity in PC3 and MCF-7 cancer cell lines, as typically observed for G4-binders. Biodistribution studies of the congener PDF-Pz-99mTc (12) in normal mice showed that the complex undergoes a fast blood clearance with a predominant hepatobiliary excretion, pointing also for a high in vitro stability.

Aptamers for the Delivery of Plant-Based Compounds: A Review

Natural compounds have a high potential for the treatment of various conditions, including infections, inflammatory diseases, and cancer. However, they usually present poor pharmacokinetics, low specificity, and even toxicity, which limits their use. Therefore, targeted drug delivery systems, typically composed of a carrier and a targeting ligand, can enhance natural product selectivity and effectiveness. Notably, aptamers-short RNA or single-stranded DNA molecules-have gained attention as promising ligands in targeted drug delivery since they are simple to synthesize and modify, and they present high tissue permeability, stability, and a wide array of available targets. The combination of natural products, namely plant-based compounds, with a drug delivery system utilizing aptamers as targeting agents represents an emerging strategy that has the potential to broaden its applications. This review discusses the potential of aptamers as targeting agents in the delivery of natural compounds, as well as new trends and developments in their utilization in the field of medicine.

Evaluation of miR-155 silencing using a molecular beacon in human lung adenocarcinoma cell line

Lung cancer (LC) is a leading cause of global cancer-related deaths, highlighting the development of innovative methods for biomarker detection improving the early diagnostics. microRNAs (miRs) alterations are known to be involved in the initiation and progression of human cancers and can act as biomarkers for diagnostics and treatment. Herein, we develop the application of molecular beacon (MB) technology to monitor miR-155-3p expression in human lung adenocarcinoma A549 cells without complementary DNA synthesis, amplification, or expensive reagents. Furthermore, we produced gold nanoparticles (AuNPs) for delivering antisense oligonucleotides into A549 cells to reduce miR-155-3p expression, which was subsequently detectable using the MB. The MB was designed and structural characterized by Förster Resonance Energy Transfer (FRET)-melting, Circular Dichroism (CD), Nuclear magnetic resonance (NMR), and fluorometric experiments, and then the hybridization conditions were optimized for an in vitro approach involving the detection of miR-155-3p in total RNA extracted from A549 cell line. The expression profile of miR-155-3p was obtained by RT-qPCR. The results demonstrated that MB was properly designed and showed efficacy in targeting miR-155-3p. Furthermore, a limit of detection down to nanomolar concentration was achieved and the specificity of the biosensor was proved. Moreover, the self-assembly of ASOs with AuNPs exhibited exceptional target specificity, effectively silencing miR-155-3p. Notably, compared to lipid-based transfection agent, AuNPs displayed superior silencing efficiency. We highlighted the ability of MB to detect changes in the target gene expression after gene silencing. Overall, this innovative approach represents a promising tool for detecting various biomarkers at the same time, with potential applications in clinical settings.

G-quadruplex ligands in cancer therapy: Progress, challenges, and clinical perspectives

Guanine-rich sequences can form G-quadruplexes (G4) in living cells, making these structures promising anti-cancer targets. Compounds able to recognize these structures have been investigated as potential anticancer drugs; however, no G4 binder has yet been approved in the clinic. Here, we describe G4 ligands structure-activity relationships, in vivo effects as well as clinical trials. Addressing G4 ligand characteristics, targeting challenges, and structure-activity relationships, this review provides insights into the development of potent and selective G4-targeting molecules for therapeutic applications.

RNA-based liposomes for oral cancer: From biophysical characterization to biological evaluation

Oral cancer incidence and mortality are increasing over time. The most common therapies for oral cancers are surgery and radiotherapy, either used alone or combined, and immunotherapy can be also an option. Although there are several therapeutic options, none of them are completely effective, and in addition, there are numerous associated side effects. To overcome these limitations, researchers have been trying to reduce these drawbacks by using drug delivery systems that carry drugs for specific delivery to cancer cells. For that purpose, RNA-coated liposomes to selectively deliver the ligands C8 (acridine orange derivative) and dexamethasone to oral cancer cells were produced, characterized, and biologically evaluated. Firstly, the RNA structure and binding interaction with ligands (C8 and dexamethasone) were evaluated by circular dichroism (CD), thermal difference spectroscopy (TDS), nuclear magnetic resonance (NMR) and fluorescence titrations. The biophysical assays evidenced the formation of an RNA hairpin and duplex structure. Moreover, steady-state and time-resolved fluorescence intensity and anisotropy experiments show that C8 forms a complex with RNA and adopts an open conformation upon RNA binding. Then, RNA-coated liposomes were characterized by dynamic light scattering, and diameters near 160 nm were observed. Time-resolved anisotropy measurements of C8 loaded in RNA-functionalized liposomes indicate the co-existence of free C8 in solution (inside the liposome) and C8 bound to RNA at the external liposome surface. The RNA-functionalized liposomes loaded with C8 or dexamethasone mediated a significant reduction in the cell viability of malignant UPCI-SCC-154 cells while maintaining viable non-malignant NHDF cells. Additionally, the liposomes were able to internalize the cells, with higher uptake by the malignant cell line. Overall, the results obtained in this work can contribute to the development of new drug delivery systems based on RNA-coated liposomes.

Pseudo-Bartter syndrome as the initial presentation of cystic fibrosis in children: an important diagnosis not to be missed

Pseudo-Bartter syndrome (PBS) is characterised by hyponatraemic, hypochloraemic metabolic alkalosis that mimics Bartter syndrome, without renal tubular disease. We present a case of an infant with a positive cystic fibrosis (CF) newborn screening, hospitalised during the summer with dehydration, oliguria and apathy. Blood analysis revealed hypochloraemic metabolic alkalosis, hypokalaemia and hyponatraemia. Urine analysis showed leucocyturia with reduced sodium and chloride excretion fraction, and urinary culture was positive for Citrobacter koseri After antibiotherapy and intravenous rehydration with additional supplementation of sodium and chloride, the patient recovered completely. PBS is one of CF complications that is especially prevalent in infants and young children with increased sweating and/or other causes of additional loss of sodium and chloride. Clinical awareness of this syndrome and its strong clinical suspicion are extremely important for an early diagnosis and treatment of CF, particularly in countries where the universal screening of CF is not routinely performed.

Palliative medicine in the emergency department: symptom control and aggressive care

OBJECTIVES

Identifying the prevalence of palliative care (PC) needs among patients who die at the emergency department (ED) and to assess symptom control and aggressiveness of care.

METHODS

We conducted a decedent cohort study of adults deceased at the ED of a Portuguese teaching hospital in 2016. PC needs were identified using the National Hospice Organization terminality criteria and comorbidities measurement by the Charlson's Index.

RESULTS

384 adults died at the ED (median age 82 (IQR 72-89) years) and 78.4% (95% CI 73.9% to 82.2%) presented PC needs. Only 3.0% (n=9) were referred to the hospital PC team. 64.5%, 38.9% and 57.5% experienced dyspnoea, pain and confusion, respectively. Dyspnoea was commonly medicated (92%), against 56% for pain and 8% for confusion. Only 6.3% of the patients were spared from aggressive interventions, namely blood collection (86.0%) or intravenous fluid therapy (63.5%). The burden of aggressive interventions was similar between those with or without withhold cardiopulmonary resuscitation order (median 3 (2-4) vs 3 (2-5)), p=0.082.

CONCLUSIONS

Nearly four out of five adults who died at the ED had PC needs at the time of admission. Most experienced poor symptom control and care aggressiveness in their last hours of life and were mostly unknown to the PC team. The findings urge improvements in the care provided to patients with PC needs at the ED, focusing on patient well-being and increased PC referral.

Harnessing G-quadruplex ligands for lung cancer treatment: A comprehensive overview

Lung cancer (LC) remains a leading cause of mortality worldwide, and new therapeutic strategies are urgently needed. One such approach revolves around the utilization of four-stranded nucleic acid secondary structures, known as G-quadruplexes (G4), which are formed by G-rich sequences. Ligands that bind selectively to G4 structures present a promising strategy for regulating crucial cellular processes involved in the progression of LC, rendering them potent agents for lung cancer treatment. In this review, we offer a summary of recent advancements in the development of G4 ligands capable of targeting specific genes associated with the development and progression of lung cancer.

Polythylene glycol severe allergy and SARS-CoV-2 vaccines: usefulness of testing with PEG 1500 extract

Summary

Background. Polyethylene glycol (PEG) is being used for first time as an excipient for mRNA anti-SARS-CoV-2 vaccines containing PEG 2000, highlighting it as a potential cause of anaphylaxis. Methods. We evaluated 126 patients with moderate-high risk of allergy to SARS-CoV-2 vaccines referred to our department from March-December 2021. Skin tests were performed with PEG 1500 extract (Roxall), using a stepwise approach, with readings at 30 minutes: prick tests with 0.1%, 1% and 10% concentrations; if negative, intradermal tests with 0.0001%, 0.001% and 0.01% concentrations. The same protocol was applied to 5 healthy controls Results. Six patients had positive immediate intradermal tests with PEG 1500, all with severe PEG allergy: one with a near-fatal anaphylaxis after glucocorticoid injection containing PEG 3350 and five with systemic allergic reactions after mRNA vaccines containing PEG 2000 (Pfizer-BioNTech or Moderna). One patient developed anaphylaxis during intradermal test. These six patients were negative to polysorbate 80. The remaining 120 patients had negative tests to PEG 1500; seven had positive tests to polysorbate 80. All controls had negative tests. Conclusions. To our knowledge this is the first study describing the allergy work-up testing with PEG 1500 commercial extract in the scope of SARS-CoV-2 vaccination. The algorithm designed for skin tests revealed to be a useful tool. Severe PEG allergy was diagnosed in 5% of patients, contraindicating PEG-containing vaccines. PEG allergy was excluded in one hundred patients that afterwards took SARS-CoV-2 vaccines containing PEG 2000. Investigation should be conducted in specialized drug allergy centers..

Assessment of Aptamer as a Potential Drug Targeted Delivery for Retinal Angiogenesis Inhibition

AT11-L0 is an aptamer derivative of AS1411 composed of G-rich sequences that can adopt a G-quadruplex (G4) structure and target nucleolin (NCL), a protein that acts as a co-receptor for several growth factors. Hence, this study aimed to characterize the AT11-L0 G4 structure and its interaction with several ligands for NCL targeting and to evaluate their capacity to inhibit angiogenesis using an in vitro model. The AT11-L0 aptamer was then used to functionalize drug-associated liposomes to increase the bioavailability of the aptamer-based drug in the formulation. Biophysical studies, such as nuclear magnetic resonance, circular dichroism, and fluorescence titrations, were performed to characterize the liposomes functionalized with the AT11-L0 aptamer. Finally, these liposome formulations with the encapsulated drugs were tested on the human umbilical vein endothelial cell (HUVEC) model to assess their antiangiogenic capacity. The results showed that the AT11-L0 aptamer-ligand complexes are highly stable, presenting melting temperatures from 45 °C to 60 °C, allowing for efficient targeting of NCL with a K_D in the order of nM. The aptamer-functionalized liposomes loaded with ligands C₈ and dexamethasone did not show cytotoxic effects in HUVEC cells compared with the free ligands and AT11-L0, as assessed by cell viability assays. AT11-L0 aptamer-functionalized liposomes encapsulating C₈ and dexamethasone did not present a significant reduction in the angiogenic process when compared with the free ligands. In addition, AT11-L0 did not show anti-angiogenic effects at the concentrations tested. However, C₈ shows potential as an angiogenesis inhibitor, which should be further developed and optimized in future experiments.

A Structural Perspective into the Interaction of an Oncogenesis-Relevant pre-miRNA G-Quadruplex Ligand Carrier with the Protein Nucleolin

The structural determinants of the interaction of the G-quadruplex (G4) motif found in precursor miRNA 149 (rG4) with the acridine orange derivative C8, a G4 ligand stabilizer possessing anticancer activity, and the protein nucleolin (overexpressed in cancer cells) were investigated by NMR spectroscopy. For the rG4/C8 complex, the results revealed a strong stabilizing interaction between the aromatic core and the iodinated ring of the C8 ligand with the rG4 structure. The NMR study revealed also different interaction patterns between nucleolin and rG4 and nucleolin and rG4/C8 complex. In the absence of the ligand, rG4 establishes interactions with polar residues of the protein while for the rG4/C8 complex, these contacts are mainly established with amino acids that have hydrophobic side chains. However, nucleolin chemical shift perturbation studies in the presence of rG4 or rG4/C8 reveal the same location between domains 1 and 2 of the protein, which suggests that the rG4 and rG4/C8 complex bind in this region. This puzzling structural study opens a new framework to study rG4/ligand/nucleolin complexes that might impact the biogenesis of miRNA 149.

Proteomics profiling of vitreous humor reveals complement and coagulation components, adhesion factors, and neurodegeneration markers as discriminatory biomarkers of vitreoretinal eye diseases

Introduction

Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are leading causes of visual impairment and blindness in people aged 50 years or older in middle-income and industrialized countries. Anti-VEGF therapies have improved the management of neovascular AMD (nAMD) and proliferative DR (PDR), no treatment options exist for the highly prevalent dry form of AMD.

Methods

To unravel the biological processes underlying these pathologies and to find new potential biomarkers, a label-free quantitative (LFQ) method was applied to analyze the vitreous proteome in PDR (n=4), AMD (n=4) compared to idiopathic epiretinal membranes (ERM) (n=4).

Results and discussion

Post-hoc tests revealed 96 proteins capable of differentiating among the different groups, whereas 118 proteins were found differentially regulated in PDR compared to ERM and 95 proteins in PDR compared to dry AMD. Pathway analysis indicates that mediators of complement, coagulation cascades and acute phase responses are enriched in PDR vitreous, whilst proteins highly correlated to the extracellular matrix (ECM) organization, platelet degranulation, lysosomal degradation, cell adhesion, and central nervous system development were found underexpressed. According to these results, 35 proteins were selected and monitored by MRM (multiple reaction monitoring) in a larger cohort of patients with ERM (n=21), DR/PDR (n=20), AMD (n=11), and retinal detachment (n=13). Of these, 26 proteins could differentiate between these vitreoretinal diseases. Based on Partial least squares discriminant and multivariate exploratory receiver operating characteristic (ROC) analyses, a panel of 15 discriminatory biomarkers was defined, which includes complement and coagulation components (complement C2 and prothrombin), acute-phase mediators (alpha-1-antichymotrypsin), adhesion molecules (e.g., myocilin, galectin-3-binding protein), ECM components (opticin), and neurodegeneration biomarkers (beta-amyloid, amyloid-like protein 2).

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Gallic Acid-Triethylene Glycol Aptadendrimers Synthesis, Biophysical Characterization and Cellular Evaluation

Herein, we describe the synthesis of an aptadendrimer by covalent bioconjugation of a gallic acid-triethylene glycol (GATG) dendrimer with the G-quadruplex (G4) AT11 aptamer (a modified version of AS1411) at the surface. We evaluated the loading and interaction of an acridine orange ligand, termed C_8, that acts as an anticancer drug and binder/stabilizer of the G4 structure of AT11. Dynamic light scattering experiments demonstrated that the aptadendrimer was approximately 3.1 nm in diameter. Both steady-state and time-resolved fluorescence anisotropy evidenced the interaction between the aptadendrimer and C₈. Additionally, we demonstrated that the iodine atom of the C₈ ligand acts as an effective intramolecular quencher in solution, while upon complexation with the aptadendrimer, it adopts a more extended conformation. Docking studies support this conclusion. Release experiments show a delivery of C₈ after 4 h. The aptadendrimers tend to localize in the cytoplasm of various cell lines studied as demonstrated by confocal microscopy. The internalization of the aptadendrimers is not nucleolin-mediated or by passive diffusion, but via endocytosis. MTT studies with prostate cancer cells and non-malignant cells evidenced high cytotoxicity mainly due to the C₈ ligand. The rapid internalization of the aptadendrimers and the fluorescence properties make them attractive for the development of potential nanocarriers.

Patient delay in acute myocardial infarction: a long journey still ahead

Background

It is overly known that time delays in acute myocardial infarction (AMI) strongly influence its outcomes. Patient delay (PD) is repeatedly pointed out as the longer one in this context, as well as it is the less modifiable one by organizational measures. Therefore, it is crucial to understand the reasons for longer PD in our population, to define proper strategies to improve PD and, ultimately, AMI-outcomes.

Methods

In this six-month prospective study of patients (pts) admitted in a tertiary hospital due to type-1 AMI, 194 pts were consecutively enrolled between May and October 2021. Data was based on a pts well-structured interview within 48h after admission and review of medical records.

Results

Our work spotted several aspects significantly influencing PD in AMI context (Figure 1). Concerning pts cardiovascular background, a trend towards a shorter PD was found in pts with at least one cardiovascular risk factor (CVRF) (p=0,08) and with a previous history of AMI (p=0,08). Regarding clinical presentation, a significantly shorter PD was found in pts presenting with associated symptoms (p=0,02), higher chest pain intensity (chest pain intensity ≥7 vs <7 in a 0–10 scale; p=0,03) and symptoms onset on weekdays rather than weekends (p=0,003). Regarding pts knowledge, significant differences were found when pts recognized their symptoms as AMI, presenting a shorter PD in this context (p=0,006). Curiously, pts ability to correctly identify AMI symptoms, when asked, or to acknowledge their CVRF (when present), did not influence PD. Considering sociodemographic factors, higher incomes (p=0,03) and non-rural residence (p=0,03) significantly translated into shorter PD. No differences were found in PD according to pts age, gender or educational level. After this initial univariate analysis, multiple linear regression was performed to identify possible predictors of PD. Four variables were identified: pts ability to recognize their symptoms as AMI (β −0.199; 95% CI: −277 to −34,87; p=0.012), living in a non-rural residence (β 0.154; 95% CI: 0.12–161.44; p=0.05), presenting associated symptoms (β −0.194; 95% CI: −257.43 to −28.84; p=0.014) and occurrence of symptoms on weekdays (β 0.170; 95% CI: 12.73–259.49; p=0.031) predicted shorter patient delays.

Conclusion

Our study clearly points to the need for increasing public awareness and educational measures, mainly in pts living in rural areas, in order to: 1) Improve pts knowledge about AMI symptoms, clarifying that atypical symptoms can happen; 2) Reinforce the importance of shortening AMI time delays, clearly explaining the concept “time is muscle”.

Funding Acknowledgement

Type of funding sources: None.

Nucleolin: a binding partner of G-quadruplex structures

Nucleolin protein is involved in a plethora of cellular pathways across the nucleolus, nucleus, and cytoplasm. The association of its RNA-binding domain (RBD) and its RGG (arginine-glycine-glycine-rich) domain allows it to interact with G-quadruplex structures in nucleic acids. We highlight evidence that the nucleolin/G-quadruplex partnership is of extensive relevance to neurodegenerative disease, cancer, and viral infections.

Targeting a G-quadruplex from let-7e pre-miRNA with small molecules and nucleolin

Let-7e precursor microRNA has the potential to adopt a G-quadruplex (rG4) structure and recently, its roles in oncology have been the focus of much attention, as it is now known that let-7e pre-miRNA is frequently dysregulated in cancers. Therefore, it is crucial to unveil and fully characterize its ability to adopt a rG4 structure, which could be stabilized or destabilized by small molecules and proteins such as nucleolin, a protein that is deeply associated with miRNA biogenesis. Herein, by combining a set of different methods such as circular dichroism (CD), nuclear magnetic resonance (NMR), UV spectroscopy (thermal difference spectra (TDS) and isothermal difference spectra (IDS)) and polyacrylamide gel electrophoresis (PAGE), we demonstrate the formation of the rG4 structure found in let-7e pre-miRNA sequence in the presence of K+ (5'-GGGCUGAGGUAGGAGG-3'). The ability of eight small molecules (or ligands) to bind to and stabilize this rG4 structure was also fully assessed. The dissociation constants for each RNA G-quadruplex/ligand complex, determined by surface plasmon resonance (SPR), ranged in the 10-6 to 10-9 M range. Lastly, the binding of the rG4 structure to nucleolin in the presence and absence of ligands was evaluated via CD, SPR, PAGE and confocal microscopy. The small molecules 360 A and PDS demonstrated attractive properties to targetthe rG4 structure of let-7e pre-miRNA and control its biology. Our findings also highlighted that the interaction of TMPyP4 with the G-quadruplex of let-7e precursor miRNA could block the formation of the complex between the rG4 and nucleolin. Overall, this study introduces an approach to target the rG4 found in let-7e pre-miRNA which opens up a new opportunity to control the microRNA biogenesis.

Stabilization of a DNA aptamer by ligand binding

G-rich aptamers such as AS1411 are small oligonucleotides that present several benefits comparatively to monoclonal antibodies, since they are easier to manufacture and store, have small size and do not stimulate an immune response. We analyzed AT11-B1, a modified sequence of AT11 (itself a modified version of AS1411), in which one thymine was removed from the bulge region. We studied G-quadruplex (G4) formation/stabilization using PhenDC3, PDS, BRACO-19, TMPyP4 and 360A ligands by different biophysical techniques, namely circular dichroism (CD), Förster resonance energy transfer (FRET-melting) and nuclear magnetic resonance (NMR). The CD spectra showed that AT11-B1 adopts a predominant G4 of parallel topology when the buffer contains KCl or when ligands are added. PhenDC3 induced a ΔT_m of 30 °C or more of the G4 structure as shown by CD- and FRET-melting experiments. The ligands demonstrate high affinity for AT11-B1 G4 and the NMR studies revealed that the AT11-B1 G4 involves four G-tetrad layers. The in silico studies suggest that all ligands bind AT11-B1 G4, namely, by stacking interactions, except PDS that may bind to the loop/groove interface. In addition, molecular dynamics simulations revealed that nucleolin (NCL) interacts with the AT11-B1 G4 structure through the RNA binding domain (RBD) 2 and the 12-residue linker between RBD1,2. Moreover, AT11-B1 G4 was internalized into a NCL-positive tongue squamous cell carcinoma cell line. In a nutshell, this study may help the identification of the ligands scaffolds to bind and stabilize AT11-B1, improving the targeting towards NCL that is overexpressed in cancer cells.

Molecular Beacon for Detection miRNA-21 as a Biomarker of Lung Cancer

Lung cancer (LC) is the leading cause of cancer-related death worldwide. Although the diagnosis and treatment of non-small cell lung cancer (NSCLC), which accounts for approximately 80% of LC cases, have greatly improved in the past decade, there is still an urgent need to find more sensitive and specific screening methods. Recently, new molecular biomarkers are emerging as potential non-invasive diagnostic agents to screen NSCLC, including multiple microRNAs (miRNAs) that show an unusual expression profile. Moreover, peripheral blood mononuclear cells’ (PBMCs) miRNA profile could be linked with NSCLC and used for diagnosis. We developed a molecular beacon (MB)-based miRNA detection strategy for NSCLC. Following PBMCs isolation and screening of the expression profile of a panel of miRNA by RT-qPCR, we designed a MB targeting of up-regulated miR-21-5p. This MB 21-5p was characterized by FRET-melting, CD, NMR and native PAGE, allowing the optimization of an in-situ approach involving miR-21-5p detection in PBMCs via MB. Data show the developed MB approach potential for miR-21-5p detection in PBMCs from clinical samples towards NSCLC.

Drug formulations for localized treatment of Human Papillomavirus-induced lesions

BACKGROUND

The human papillomavirus (HPV) is responsible for over 90% of all cervical cancer cases. The use of vaginal gels is often indicated for local vaginal drug delivery. Previous studies have shown that Thymus vulgaris essential oil (TEO) exhibits anticancer properties besides antifungal and antibacterial properties. Its activity derives from a specific increase in free radicals and oxidative stress caused in cancer cells. Furthermore, mitoxantrone (MTX), an anthracenedione and C₈, an acridine orange derivative, were shown to inhibit the growth of the cervical cancer cell line HeLa.

RESULTS

The results showed that TEO + C₈ is the most promising formulation in terms of viscosity and osmolality properties in vaginal fluid simulant (VFS). The combined action of TEO with the compound's MTX and C₈ resulted in HeLa cell viability reduction compared with the effect obtained with the individual formulations containing each one of the compounds.

CONCLUSIONS

The formulation TEO + C₈ holds promise in terms of cost-benefit and topical application of the active compound for the HeLa cells.

Pre-miRNA-149 G-quadruplex as a molecular agent to capture nucleolin

One of the most significant challenges in capturing and detecting biomarkers is the choice of an appropriate biomolecular receptor. Recently, RNA G-quadruplexes emerged as plausible receptors due to their ability to recognize with high-affinity proteins. Herein, we have unveiled and characterized the capability of the precursor microRNA 149 to form a G-quadruplex structure and determined the role that some ligands may have in its folding and binding capacity to nucleolin. The G-quadruplex formation was induced by K+ ions and stabilized by ligands, as demonstrated by nuclear magnetic resonance and circular dichroism experiments. Surface plasmon resonance measurements showed a binding affinity of precursor microRNA 149 towards ligands in the micromolar range (10-5-10-6 M) and a strong binding affinity to nucleolin RNA-binding domains 1 and 2 (8.38 × 10-10 M). Even in the presence of the ligand PhenDC3, the binding remains almost identical and in the same order of magnitude (4.46 × 10-10 M). The molecular interactions of the RNA G-quadruplex motif found in precursor miRNA 149 (5'-GGGAGGGAGGGACGGG- 3') and nucleolin RNA-binding domains 1 and 2 were explored by means of molecular docking and molecular dynamics studies. The results showed that RNA G-quadruplex binds to a cavity between domains 1 and 2 of the protein. Then, complex formation was also evaluated through polyacrylamide gel electrophoresis. The results suggest that precursor microRNA 149/ligands and precursor microRNA 149/nucleolin RNA-binding domains 1 and 2 form stable molecular complexes. The in vitro co-localization of precursor microRNA 149 and nucleolin in PC3 cells was demonstrated using confocal microscopy. Finally, a rapid and straightforward microfluidic strategy was employed to check the ability of precursor microRNA 149 to capture nucleolin RNA-binding domains 1 and 2. The results revealed that precursor microRNA 149 can capture nucleolin RNA-binding domains 1 and 2 labeled with Fluorescein 5-isothiocyanate in a concentration-dependent manner, but PhenDC3 complexation seems to decrease the ability of precursor microRNA 149 to capture the protein. Overall, our results proved the formation of the G-quadruplex structure in the precursor microRNA 149 and the ability to recognize and detect nucleolin. This proof-of-concept study could open up a new framework for developing new strategies to design improved molecular receptors for capture and detection of nucleolin in complex biological samples.

Radiolabeled Gold Nanoseeds Decorated with Substance P Peptides: Synthesis, Characterization and In Vitro Evaluation in Glioblastoma Cellular Models

Despite some progress, the overall survival of patients with glioblastoma (GBM) remains extremely poor. In this context, there is a pressing need to develop innovative therapy strategies for GBM, namely those based on nanomedicine approaches. Towards this goal, we have focused on nanoparticles (AuNP-SP and AuNP-SPTyr8) with a small gold core (ca. 4 nm), carrying DOTA chelators and substance P (SP) peptides. These new SP-containing AuNPs were characterized by a variety of analytical techniques, including TEM and DLS measurements and UV-vis and CD spectroscopy, which proved their high in vitro stability and poor tendency to interact with plasma proteins. Their labeling with diagnostic and therapeutic radionuclides was efficiently performed by DOTA complexation with the trivalent radiometals ⁶⁷Ga and ¹⁷⁷Lu or by electrophilic radioiodination with ¹²⁵I of the tyrosyl residue in AuNP-SPTyr8. Cellular studies of the resulting radiolabeled AuNPs in NKR1-positive GBM cells (U87, T98G and U373) have shown that the presence of the SP peptides has a crucial and positive impact on their internalization by the tumor cells. Consistently, ¹⁷⁷Lu-AuNP-SPTyr8 showed more pronounced radiobiological effects in U373 cells when compared with the non-targeted congener ¹⁷⁷Lu-AuNP-TDOTA, as assessed by cell viability and clonogenic assays and corroborated by Monte Carlo microdosimetry simulations.

Small-scale agricultural grassland management can affect soil fungal community structure as much as continental scale geographic patterns

A European transect was established, ranging from Sweden to the Azores, to determine the relative influence of geographic factors and agricultural small-scale management on the grassland soil microbiome. Within each of five countries (factor ‘Country’), which maximized a range of geographic factors, two differing growth condition regions (factor ‘GCR’) were selected: a favorable region with conditions allowing for high plant biomass production and a contrasting less favorable region with a markedly lower potential. Within each region, grasslands of contrasting management intensities (factor ‘MI’) were defined: intensive and extensive, from which soil samples were collected. Across the transect, ‘MI’ was a strong differentiator of fungal community structure, having a comparable effect to continental scale geographic factors (‘Country’). ‘MI’ was also a highly significant driver of bacterial community structure, but ‘Country’ was clearly the stronger driver. For both, ‘GCR’ was the weakest driver. Also at the regional level, strong effects of MI occurred on various measures of the soil microbiome (i.e. OTU richness, management-associated indicator OTUs), though the effects were largely regional-specific. Our results illustrate the decisive influence of grassland MI on soil microbial community structure, over both regional and continental scales, and, thus, highlight the importance of preserving rare extensive grasslands.

Molecular Beacon Assay Development for Severe Acute Respiratory Syndrome Coronavirus 2 Detection

The fast spread of SARS-CoV-2 has led to a global pandemic, calling for fast and accurate assays to allow infection diagnosis and prevention of transmission. We aimed to develop a molecular beacon (MB)-based detection assay for SARS-CoV-2, designed to detect the ORF1ab and S genes, proposing a two-stage COVID-19 testing strategy. The novelty of this work lies in the design and optimization of two MBs for detection of SARS-CoV-2, namely, concentration, fluorescence plateaus of hybridization, reaction temperature and real-time results. We also identify putative G-quadruplex (G4) regions in the genome of SARS-CoV-2. A total of 458 nasopharyngeal and throat swab samples (426 positive and 32 negative) were tested with the MB assay and the fluorescence levels compared with the cycle threshold (Ct) values obtained from a commercial RT-PCR test in terms of test duration, sensitivity, and specificity. Our results show that the samples with higher fluorescence levels correspond to those with low Ct values, suggesting a correlation between viral load and increased MB fluorescence. The proposed assay represents a fast (total duration of 2 h 20 min including amplification and fluorescence reading stages) and simple way of detecting SARS-CoV-2 in clinical samples from the upper respiratory tract.

The world upside down – after 20 years follow-up of dextro-transposition of the great arteries

Introduction

Congenital Heart Disease (CHD) affects under 1% of newborns and thanks to its prognosis improvement, most patients survive until adulthood. Dextro-transposition of the great arteries (dTGA) is a CHD classically palliated with atrial switch (ATS) procedure and nowadays corrected with an arterial switch (ARS), with better clinical outcomes. Nevertheless, several post-ATS patients remain alive and questions persist regarding their long-term prognosis.

Purpose

To observe a group of dTGA patients followed in an Adult CHD outpatients clinic, access their comorbidities, surgical interventions, complications and clinical outcomes.

Methods

We retrospectively analyzed a group of dTGA patients born between 1974 and 2001. Clinical features were collected and time-to-event statistics were analyzed. Adverse event was defined as at least one of the follows: death, stroke, myocardial infarction or coronary revascularization, arrhythmia and ventricular, valvular or conduct dysfunction.

Results

A total of 80 patients were enrolled with a mean follow-up of 26 years after surgery: 46% were female, median age 27 (19–57) year-old. Concerning other concomitant defects, 25% had ventricular septal defect, 12% pulmonary stenosis, 3% aortic coarctation and 1% single coronary ostium. ATS palliation was performed in 54% of patients (Senning procedure in 95%) and ARS (Jatene procedure) in 45% of patients; median age at procedure was 13 months and 10 days, respectively. During follow-up, almost all patients submitted to ARS remained in sinus rhythm (97%) versus 64% of ATS patients (p=0.037). The latter group had higher incidence of arrythmias (40% vs 3%, p=0.013), mostly atrial flutter or fibrillation (present in 28%), followed by bradyarrhythmia (10%); median time from surgery to first arrhythmic event in these patients was 23 years. Also, systemic ventricle systolic dysfunction (SVSD) and chronotropic incompetence were significantly higher in ATS (41% vs 3%, p<0.001 and 46% vs 9%, p=0.005, respectively); mean time to SVSD was 29 years. In respect to long-term outcomes in ARS, the most frequent complications were moderate to severe aortic regurgitation, pulmonary stenosis and regurgitation, occurring in 21%, 7% and 3%, respectively. Concerning both groups, mean time to first adverse-event was 21 years. Regarding gender and demographic features, there were no differences in time-to-adverse-event, comparing patients living in urban versus rural neighbourhoods and female versus male (Log Rank, p=0.368 and p=0.693). Only one patient died, submitted to ATS, at 46 years-old, from chronic heart failure.

Conclusion

After a long-term free of events, ATS patients experienced more arrhythmic complications and SVSD. ARS complications were anastomosis related. This report highlights the efforts that should be made to identify late complication is this particular population. Of note, no demographic or gender differences were observed.

Funding Acknowledgement

Type of funding sources: None. Gender analysis

Aptamer-Functionalized Gold Nanoparticles for Drug Delivery to Gynecological Carcinoma Cells

Cervical cancer is one of the most common cancers and is one of the major cause of deaths in women, especially in underdeveloped countries. The patients are usually treated with surgery, radiotherapy, and chemotherapy. However, these treatments can cause several side effects and may lead to infertility. Another concerning gynecologic cancer is endometrial cancer, in which a high number of patients present a poor prognosis with low survival rates. AS1411, a DNA aptamer, increases anticancer therapeutic selectivity, and through its conjugation with gold nanoparticles (AS1411-AuNPs) it is possible to improve the anticancer effects. Therefore, AS1411-AuNPs are potential drug carriers for selectively delivering therapeutic drugs to cervical cancer. In this work, we used AS1411-AuNPs as a carrier for an acridine orange derivative (C8) or Imiquimod (IQ). The AS1411 aptamer was covalently bound to AuNPs, and each drug was associated via supramolecular assembly. The final nanoparticles presented suitable properties for pharmaceutical applications, such as small size, negative charge, and favorable drug release properties. Cellular uptake was characterized by confocal microscopy and flow cytometry, and effects on cellular viability were determined by MTT assay. The nanoparticles were then incorporated into a gel formulation of polyethylene glycol, suitable for topical application in the female genital tract. This gel showed promising tissue retention properties in Franz cells studies in the porcine vaginal epithelia. These findings suggest that the tested nanoparticles are promising drug carriers for cervical cancer therapy.

G-Quadruplexes and Their Ligands: Biophysical Methods to Unravel G-Quadruplex/Ligand Interactions

Progress in the design of G-quadruplex (G4) binding ligands relies on the availability of approaches that assess the binding mode and nature of the interactions between G4 forming sequences and their putative ligands. The experimental approaches used to characterize G4/ligand interactions can be categorized into structure-based methods (circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography), affinity and apparent affinity-based methods (surface plasmon resonance (SPR), isothermal titration calorimetry (ITC) and mass spectrometry (MS)), and high-throughput methods (fluorescence resonance energy transfer (FRET)-melting, G4-fluorescent intercalator displacement assay (G4-FID), affinity chromatography and microarrays. Each method has unique advantages and drawbacks, which makes it essential to select the ideal strategies for the biological question being addressed. The structural- and affinity and apparent affinity-based methods are in several cases complex and/or time-consuming and can be combined with fast and cheap high-throughput approaches to improve the design and development of new potential G4 ligands. In recent years, the joint use of these techniques permitted the discovery of a huge number of G4 ligands investigated for diagnostic and therapeutic purposes. Overall, this review article highlights in detail the most commonly used approaches to characterize the G4/ligand interactions, as well as the applications and types of information that can be obtained from the use of each technique.

G-Quadruplex-Based Drug Delivery Systems for Cancer Therapy

G-quadruplexes (G4s) are a class of nucleic acids (DNA and RNA) with single-stranded G-rich sequences. Owing to the selectivity of some G4s, they are emerging as targeting agents to overtake side effects of several potential anticancer drugs, and delivery systems of small molecules to malignant cells, through their high affinity or complementarity to specific targets. Moreover, different systems are being used to improve their potential, such as gold nano-particles or liposomes. Thus, the present review provides relevant data about the different studies with G4s as drug delivery systems and the challenges that must be overcome in the future research.

New (Iso)quinolinyl-pyridine-2,6-dicarboxamide G-Quadruplex Stabilizers. A Structure-Activity Relationship Study

G-quadruplex (G4)-interactive small molecules have a wide range of potential applications, not only as drugs, but also as sensors of quadruplex structures. The purpose of this work is the synthesis of analogues of the bis-methylquinolinium-pyridine-2,6-dicarboxamide G4 ligand 360A, to identify relevant structure-activity relationships to apply to the design of other G4-interactive small molecules bearing bis-quinoline or bis-isoquinoline moieties. Thermal denaturation experiments revealed that non-methylated derivatives with a relative 1,4 position between the amide linker and the nitrogen of the quinoline ring are moderate G4 stabilizers, with a preference for the hybrid h-Telo G4, a 21-nt sequence present in human telomeres. Insertion of a positive charge upon methylation of quinoline/isoquinoline nitrogen increases compounds' ability to selectively stabilize G4s compared to duplex DNA, with a preference for parallel structures. Among these, compounds having a relative 1,3-position between the charged methylquinolinium/isoquinolinium nitrogen and the amide linker are the best G4 stabilizers. More interestingly, these ligands showed different capacities to selectively block DNA polymerization in a PCR-stop assay and to induce G4 conformation switches of hybrid h-Telo G4. Molecular dynamic simulations with the parallel G4 formed by a 21-nt sequence present in k-RAS gene promoter, showed that the relative spatial orientation of the two methylated quinoline/isoquinoline rings determines the ligands mode and strength of binding to G4s.

Targeting nucleolin by RNA G-quadruplex-forming motif

A high level of nucleolin (NCL) expression is often associated with a poor prognosis of patients with lung cancer (LC), suggesting that NCL can be used as a possible biomarker. NCL has been shown to display a marked preference for the binding to G-quadruplexes (G4). Here, we investigate the formation of an RNA quadruplex structure in a sequence found in the human precursor pre-MIR150 with the potential to recognize NCL. Circular dichroism (CD) spectra of pre-MIR150 G4-forming sequence (designated by rG4) indicate the formation of a parallel quadruplex structure in KCl or when complexed with the well-known G4 ligand PhenDC3. The thermal stability of rG4 is very high, and further increases in the presence of PhenDC3. The binding affinities of rG4 to PhenDC3 and NCL RBD1,2 are similar with KD values in the nanomolar range. PAGE results suggest the formation of a ternary quadruplex-ligand-protein complex (rG4-PhenDC3-NCL RBD1,2), indicative that PhenDC3 does not prevent the binding of rG4 to NCL RBD1,2. Finally, rG4 can recognize NCL-positive cells and, when fluorescently labeled, can be used as a probe for this protein. ELISA experiments indicate altered NCL expression patterns in liquid biopsies of LC patients in a non-invasive manner, potentially helping the diagnosis, prognosis, and patient response to treatment. Hence, labeled rG4 could be used as a detection probe of LC in liquid biopsies.

Recognition of nucleolin through interaction with RNA G-quadruplex

The development of novel biomarkers for early-stage diagnosis of prostate cancer (PCa) has attracted the attention of researchers in the last decade. Nucleolin (NCL) has emerged as a possible biomarker of PCa due to its high expression levels in the surface of PCa cells and affinity towards parallel G4s since it contains four RNA-binding domains (RBDs). Herein, we developed a novel strategy based on a microfluidic platform for the detection of NCL in biological samples, such as human plasma. The RNA G4 (rG4) sequence found in human precursor microRNA 92b (pre-miR-92b) was used as a molecular recognition probe since it forms a single dominant parallel rG4 conformation in the presence of 0.1 mM K+ as confirmed by NMR spectroscopy. The additional stability of the rG4 structure was provided by the acridine orange derivative ligand C8, which stabilizes the pre-miR-92b rG4 structure, as denoted by an increase in more than 30 °C of its melting temperature. FRET-melting assay revealed a remarkable synergistic effect of NCL RBD1,2 and C8 on the stabilization of the pre-miR-92b rG4. The binding of pre-miR-92b to NCL RBD1,2 was determined by in silico studies, which revealed a binding pocket formed by a 12-residue linker between RBD1 and RBD2. Both, pre-miR-92b rG4 and pre-miR-92b rG4/C8 complex demonstrated high affinity towards NCL RBD1,2, as proved by fluorimetric titrations (KD range between 10-12 and 10-9 M). The stability and nuclease resistance of pre-miR-92b rG4 and pre-miR-92b rG4/C8 complex were evaluated as molecular recognition probes to capture and detect NCL. Finally, the microfluidic platform detects NCL in complex biological samples, such as human plasma. Overall, this work demonstrates the usefulness of the microfluidic platform based on the pre-miR-92b to detect NCL and the possibility to be used as a valuable biomedical tool in PCa diagnosis.

Nanoaggregate-forming lipid-conjugated AS1411 aptamer as a promising tumor-targeted delivery system of anticancer agents in vitro

Nanoparticles offer targeted delivery of drugs with minimal toxicity to surrounding healthy tissue and have great potential in the management of human papillomavirus (HPV)-related diseases. We synthesized lipid-modified AS1411 aptamers capable of forming nanoaggregates in solution containing Mg²⁺. The nanoaggregates presented suitable properties for pharmaceutical applications such as small size (100 nm), negative charge, and drug release. The nanoaggregates were loaded with acridine orange derivative C₈ for its specific delivery into cervical cancer cell lines and HPV-positive tissue biopsies. This improved inhibition of HeLa proliferation and cell uptake without significantly affecting healthy cells. Finally, the nanoaggregates were incorporated in a gel formulation with promising tissue retention properties aiming at developing a local delivery strategy of the nanoaggregates in the female genital tract. Collectively, these findings suggest that the nanoformulation protocol has great potential for the delivery of both anticancer and antiviral agents, becoming a novel modality for cervical cancer management.

Metal-Based G-Quadruplex Binders for Cancer Theranostics

The ability of fluorescent small molecules, such as metal complexes, to selectively recognize G-quadruplex (G4) structures has opened a route to develop new probes for the visualization of these DNA structures in cells. The main goal of this review is to update the most recent research efforts towards the development of novel cancer theranostic agents using this type of metal-based probes that specifically recognize G4 structures. This encompassed a comprehensive overview of the most significant progress in the field, namely based on complexes with Cu, Pt, and Ru that are among the most studied metals to obtain this class of molecules. It is also discussed the potential interest of obtaining G4-binders with medical radiometals (e.g., 99mTc, 111In, 64Cu, 195mPt) suitable for diagnostic and/or therapeutic applications within nuclear medicine modalities, in order to enable their theranostic potential.

Aptamer-based approaches to detect nucleolin in prostate cancer

We have investigated the expression of nucleolin (NCL) in liquid biopsies of prostate cancer (PCa) patients and healthy controls to determine its correlation with tumor prognosis. To detect NCL we used a modified AS1411 aptamer designated by AS1411-N5. In presence of NCL, AS1411-N5 increases the fluorescence by assuming a G-quadruplex (G4) structure, while in the absence of NCL the fluorescence signal remains quenched. The structural characterization of AS1411-N5 was performed by biophysical studies, which demonstrated the formation of G4 parallel conformation in the presence of 100 mM K+ and the ability to recognize NCL with high affinity (KD = 138.1 ± 5.5 nM). Furthermore, the clinical relevance of NCL in PCa liquid biopsies was assessed by using an NCL-based ELISA assay. The protein was measured in the peripheral blood mononuclear cells (PBMCs) cell lysate of 158 individuals, including PCa patients and healthy individuals. The results depicted a remarkable increase of NCL levels in the PBMC's lysate of PCa patients (mean of 626.1 pg/mL whole blood) when compared to healthy individuals (mean of 198.5 pg/mL whole blood). The ELISA results also provided evidence for the usefulness of determining NCL levels in advanced PCa stages. Furthermore, a microfluidic assay showed the ability of AS1411-N5 in recognizing NCL in spiked human plasma samples.

Nucleolin as a potential biomarker for canine malignant neoplasia

Human nucleolin (NCL) is a multifunctional protein that is involved in diverse pathological processes. Recent evidences have shown that NCL is markedly overexpressed on the surface of most human cancer cells when compared to normal cells, being overexpressed in several malignant cells. Based on the exposed, the purpose of this pilot study is to investigate the expression pattern of NCL in canine malignant neoplasia and control groups. NCL expression at both messenger RNA and protein levels in the subcellular fractions were respectively detected by RT-PCR and western blotting, allowing to infer the NCL positivity rate in canine neoplasia. The identity of NCL amplicons obtained by RT-PCR was confirmed by Sanger sequencing and found to correspond to Canis lupus familiaris. Using flow cytometry, the blood cells expressing NCL from canine neoplasms were also identified using several cell surface markers and their levels quantified. These results showed that NCL expressed in lymphocytes, monocytes and neutrophils in dogs with malignant neoplasia is higher (> 50%) when compared with the control group. We found an increased expression of surface and cytoplasmic NCL in canine malignant neoplasia group, while nuclear NCL is predominantly found in the control group. Overall, this study discloses and identifies for the first time the presence of NCL in canine blood.

Optimal control of the COVID-19 pandemic: controlled sanitary deconfinement in Portugal

The COVID-19 pandemic has forced policy makers to decree urgent confinements to stop a rapid and massive contagion. However, after that stage, societies are being forced to find an equilibrium between the need to reduce contagion rates and the need to reopen their economies. The experience hitherto lived has provided data on the evolution of the pandemic, in particular the population dynamics as a result of the public health measures enacted. This allows the formulation of forecasting mathematical models to anticipate the consequences of political decisions. Here we propose a model to do so and apply it to the case of Portugal. With a mathematical deterministic model, described by a system of ordinary differential equations, we fit the real evolution of COVID-19 in this country. After identification of the population readiness to follow social restrictions, by analyzing the social media, we incorporate this effect in a version of the model that allow us to check different scenarios. This is realized by considering a Monte Carlo discrete version of the previous model coupled via a complex network. Then, we apply optimal control theory to maximize the number of people returning to "normal life" and minimizing the number of active infected individuals with minimal economical costs while warranting a low level of hospitalizations. This work allows testing various scenarios of pandemic management (closure of sectors of the economy, partial/total compliance with protection measures by citizens, number of beds in intensive care units, etc.), ensuring the responsiveness of the health system, thus being a public health decision support tool.

Does age at aortic coarctation repair have an impact on left ventricle size and function?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Adults with repaired aortic coarctation (CoA) require lifelong follow-up due to late complications, including left ventricular (LV) myocardial dysfunction. Age at the time of CoA repair is an important prognostic factor in these patients (pts).

Purpose

To evaluate LV size, ejection fraction (EF) and global longitudinal strain (GLS) values using 2D speckle tracking echocardiography (STE) in a population of adult pts with repaired CoA and to assess the relationship between these echocardiographic parameters and age at the time of CoA repair.

Methods

Retrospective analysis of adult pts with repaired CoA, followed in a Grown Up Congenital Heart Disease Centre. Pts with hemodynamically significant concomitant cardiac lesions were ruled out. Epidemiologic and clinical data were obtained from clinical records. Transthoracic echocardiograms were reviewed in order to assess GLS using 2DSTE (Echopac Software, GE).

Results

The study population consisted of 63 pts (61.9% male), with a mean age of 35.3 years at the time of the echocardiographic evaluation. The mean age at the time of the CoA repair was 117 months (95% CI 89.8-144.1 months).

Surgical repair was performed in 46 pts (73%): resection with subclavian artery flap aortoplasty (n = 21); patch aortoplasty (n = 15) and head-to-head anastomosis (n = 10). In 10 pts there was no data regarding the type of surgical repair. Seven pts (11.1%) were submitted to percutaneous intervention (6 with aortic stent implantation and 1 with balloon aortic angioplasty).

Mean LVEF was 63.4% (CI 95% 55.6 – 71.2%) and mean LV end-diastolic diameter (LVEDD) was 50mm (CI 95% 43-57mm). Mean GLS was - 17.3 (CI 95% 14.8- 19.8), which is inferior to the mean normal values reported for the software used.

Age at the time of CoA repair had a statistically significant positive linear relationship with LVEDD (r= 0.282; p= 0.026) and a linear negative relationship with both GLS (r= -0,29; p= 0.022) and LVEF (r= -0.33; p= 0.05).

Conclusion

Older age at the time of CoA repair was associated with increased LVEDD and decreased GLS and LVEF. Also, GLS may be an important tool for the identification of subclinical LV dysfunction in adult pts with repaired CoA.

A Phase I/II Clinical Trial to evaluate the efficacy of baricitinib to prevent respiratory insufficiency progression in onco-hematological patients affected with COVID19: A structured summary of a study protocol for a randomised controlled trial

OBJECTIVES

Baricitinib is supposed to have a double effect on SARS-CoV2 infection. Firstly, it reduces the inflammatory response through the inhibition of the Januse-Kinase signalling transducer and activator of transcription (JAK-STAT) pathway. Moreover, it reduces the receptor mediated viral endocytosis by AP2-associated protein kinase 1 (AAK1) inhibition. We propose the use of baricinitib to prevent the progression of the respiratory insufficiency in SARS-CoV2 pneumonia in onco-haematological patients. In this phase Ib/II study, the primary objective in the safety cohort is to describe the incidence of severe adverse events associated with baricitinib administration. The primary objective of the randomized phase (baricitinib cohort versus standard of care cohort) is to evaluate the number of patients who did not require mechanical oxygen support since start of therapy until day +14 or discharge (whichever it comes first). The secondary objectives of the study (only randomized phase of the study) are represented by the comparison between the two arms of the study in terms of mortality and toxicity at day+30. Moreover, a description of the immunological related changes between the two arms of the study will be reported.

TRIAL DESIGN

The trial is a phase I/II study with a safety run-in cohort (phase 1) followed by an open label phase II randomized controlled trial with an experimental arm compared to a standard of care arm.

PARTICIPANTS

The study will be performed at the Institut Català d'Oncologia, a tertiary level oncological referral center in the Catalonia region (Spain). The eligibility criteria are: patients > 18 years affected by oncological diseases; ECOG performance status < 2 (Karnofsky score > 60%); a laboratory confirmed infection with SARS-CoV-2 by means of real -time PCR; radiological signs of low respiratory tract disease; absence of organ dysfunction (a total bilirubin within normal institutional limits, AST/ALT≤2.5 X institutional upper limit of normal, alkaline phosphatase ≤2.5 X institutional upper limit of normal, coagulation within normal institutional limits, creatinine clearance >30 mL/min/1.73 m² for patients with creatinine levels above institutional normal); absence of HIV infection; no active or latent HBV or HCV infection. The exclusion criteria are: patients with oncological diseases who are not candidates to receive any active oncological treatment; hemodynamic instability at time of study enrollment; impossibility to receive oral medication; medical history of recent or active pulmonary embolism or deep venous thrombosis or patients at high-risk of suffering them (surgical intervention, immobilization); multi organ failure, rapid worsening of respiratory function with requirement of fraction of inspired oxygen (FiO₂) > 50% or high-flow nasal cannula before initiation of study treatment; uncontrolled intercurrent illness (ongoing or severe active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements); allergy to one or more of study treatments; pregnant or breastfeeding women; positive pregnancy test in a pre-dose examination. Patients should have the ability to understand, and the willingness to sign, a written informed consent document; the willingness to accept randomization to any assigned treatment arm; and must agree not to enroll in another study of an investigational agent prior to completion of Day +28 of study. An electronic Case Report Form in the Research Electronic Data Capture (REDCap) platform will be used to collect the data of the trial. Removal from the study will apply in case of unacceptable adverse event(s), development of an intercurrent illness, condition or procedural complication, which could interfere with the patient's continued participation and voluntary patient withdrawal from study treatment (all patients are free to withdraw from participation in this study at any time, for any reasons, specified or unspecified, and without prejudice).

INTERVENTION AND COMPARATOR

Treatment will be administered on an inpatient basis. We will compare the experimental treatment with baricitinib plus the institutional standard of care compared with the standard of care alone. During the phase I, we will define the dose-limiting toxicity of baricitinib and the dose to be used in the phase 2 part of the study. The starting baricitinib dose will be an oral tablet 4 mg-once daily which can be reduced to 2 mg depending on the observed toxicity. The minimum duration of therapy will be 5 days and it can be extended to 7 days. The standard of care will include the following therapies. Antibiotics will be individualized based on clinical suspicion, including the management of febrile neutropenia. Prophylaxis of thromboembolic disease will be administered to all participants. Remdesivir administration will be considered only in patients with severe pneumonia (SatO₂ <94%) with less than 7 days of onset of symptoms and with supplemental oxygen requirements but not using high-flow nasal cannula, non-invasive or invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO). In the randomized phase, tocilizumab or interferon will not be allowed in the experimental arm. Tocilizumab can be used in patients in the standard of care arm at the discretion of the investigator. If it is prescribed it will be used according to the following criteria: patients who, according to his baseline clinical condition, would be an ICU tributary, interstitial pneumonia with severe respiratory failure, patients who are not on mechanical ventilation or ECMO and who are still progressing with corticoid treatment or if they are not candidates for corticosteroids. Mild ARDS (PAFI <300 mmHg) with radiological or blood gases deterioration that meets at least one of the following criteria: CRP >100mg/L D-Dimer >1,000μg/L LDH >400U/L Ferritin >700ng/ml Interleukin 6 ≥40ng/L. The use of tocilizumab is not recommended if there are AST/ALT values greater than 10 times the upper limit of normal, neutrophils <500 cells/mm3, sepsis due to other pathogens other than SARS-CoV-2, presence of comorbidity that can lead to a poor prognosis, complicated diverticulitis or intestinal perforation, ongoing skin infection. The dose will be that recommended by the Spanish Medicine Agency in patients ≥75Kg: 600mg dose whereas in patients <75kg: 400mg dose. Exceptionally, a second infusion can be assessed 12 hours after the first in those patients who experience a worsening of laboratory parameters after a first favourable response. The use of corticosteroids will be recommended in patients who have had symptoms for more than 7 days and who meet all the following criteria: need for oxygen support, non-invasive or invasive mechanical ventilation, acute respiratory failure or rapid deterioration of gas exchange, appearance or worsening of bilateral alveolar-interstitial infiltrates at the radiological level. In case of indication, it is recommended: dexamethasone 6mg/d p.o. or iv for 10 days or methylprednisolone 32mg/d orally or 30mg iv for 10 days or prednisone 40mg day p.o. for 10 days.

MAIN OUTCOMES

Phase 1 part: to describe the toxicity profile of baricitinib in COVID19 oncological patients during the 5-7 day treatment period and until day +14 or discharge (whichever it comes first). Phase 2 part: to describe the number of patients in the experimental arm that will not require mechanical oxygen support compared to the standard of care arm until day +14 or discharge (whichever it comes first).

RANDOMISATION

For the phase 2 of the study, the allocation ratio will be 1:1. Randomization process will be carried out electronically through the REDcap platform ( https://www.project-redcap.org/ ) BLINDING (MASKING): This is an open label study. No blinding will be performed.

NUMBERS TO BE RANDOMISED (SAMPLE SIZE)

The first part of the study (safety run-in cohort) will consist in the enrollment of 6 to 12 patients. In this population, we will test the toxicity of the experimental treatment. An incidence of severe adverse events grade 3-4 (graded by Common Terminology Criteria for Adverse Events v.5.0) inferior than 33% will be considered sufficient to follow with the next part of the study. The second part of the study we will perform an interim analysis of efficacy at first 64 assessed patients and a definitive one will analyze 128 assessed patients. Interim and definitive tests will be performed considering in both cases an alpha error of 0.05. We consider for the control arm this rate is expected to be 0.60 and for the experimental arm of 0.80. Considering this data, a superiority test to prove a difference of 0.20 with an overall alpha error of 0.10 and a beta error of 0.2 will be performed. Considering a 5% of dropout rate, it is expected that a total of 136 patients, 68 for each study arm, will be required to complete study accrual.

TRIAL STATUS

Version 5.0. 14^th October 2020 Recruitment started on the 16^th of December 2020. Expected end of recruitment is June 2021.

TRIAL REGISTRATION

AEMPs: 20-0356 EudraCT: 2020-001789-12, https://www.clinicaltrialsregister.eu/ctr-search/search (Not publically available as Phase I trial) Clinical trials: BARCOVID19, https://www.clinicaltrials.gov/ (In progress) FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol."

Locking up the AS1411 Aptamer with a Flanking Duplex: Towards an Improved Nucleolin-Targeting

We have designed AS1411-N6, a derivative of the nucleolin (NCL)-binding aptamer AS1411, by adding six nucleotides to the 5′-end that are complementary to nucleotides at the 3′-end forcing it into a stem-loop structure. We evaluated by several biophysical techniques if AS1411-N6 can adopt one or more conformations, one of which allows NCL binding. We found a decrease of polymorphism of G-quadruplex (G4)-forming sequences comparing to AS1411 and the G4 formation in presence of K⁺ promotes the duplex folding. We also studied the binding properties of ligands TMPyP4, PhenDC3, PDS, 360A, and BRACO-19 in terms of stability, binding, topology maintenance of AS1411-N6, and NCL recognition. The melting experiments revealed promising stabilizer effects of PhenDC3, 360A, and TMPyP4, and the affinity calculations showed that 360A is the most prominent affinity ligand for AS1411-N6 and AS1411. The affinity determined between AS1411-N6 and NCL denoting a strong interaction and complex formation was assessed by PAGE in which the electrophoretic profile of AS1411-N6 showed bands of the dimeric form in the presence of the ligands and NCL.

Coronary artery fistulas: a single-center case series

Introduction

Coronary artery fistulas (CAFs) are rare anomalous connections between a coronary artery and a major vessel or cardiac chamber. Currently they are being increasingly encountered due to the more widespread use of various imaging modalities and coronary angiography. Although the vast majority of CAFs are incidentally diagnosed and have no clinical relevance, they can cause significant morbidity such as myocardial infarction, congestive heart failure and endocarditis.

Methods

A consecutive series of 55867 coronary arteriograms performed in our Cardiology Department from 2007 to 2019 was retrospectively investigated for the presence of coronary artery fistulas. Patients clinical, angiographic and therapeutic data up to november 2019 were analyzed. Data were obtained from medical records of hospital stay and subsequent consultations.

Results

We identified 50 patients who were diagnosed with one or more CAFs, with ages between 5 and 85 years (mean 59 years). 62% (n=31) were males.

The great majority of patients had a single fistula (n=34, 68%), 11 patients had two fistulas (22%), 1 patient had 3 fistulas (2%) and 4 patients had multiple fistulas (8%).

CAFs arose more frequently from the left anterior descending artery (n=27), followed by the right coronary (n=18), left circumflex (n=15), left main (n=5) and intermediate artery (n=2). The most frequent drainage site was the pulmonary artery (n=38).

The majority of CAFs were incidentally found (n=32; 64%) and thought to have no significance for the patients' clinical status. As for the rest of the patients, CAFs were diagnosed during evaluation of: a heart murmur (n=7); exertional chest pain with no associated significant atherosclerotic coronary artery disease (n=7); exertional dyspnea (n=2); positive exercise stress test (n=1); NSTEMI and cardiac arrest (n=1).

Regarding treatment, watchful waiting was the main approach (n=40; 80%). 3 patients had their CAFs closed during surgery for another heart condition (CABG/aortic valve replacement). In 1 patient, heart surgery was specifically conducted for fistula closure. 6 patients (12%) underwent fistula transcatheter closure.

Conclusion

CAFs are rare coronary anomalies and the majority has no clinical relevance, so watchful waiting is the commonest approach. When they are hemodynamically significant or symptoms/complications arise, surgical or transcatheter closure should be considered. This study describes the angiographic, clinical and therapeutic data of CAFs detected along the last 12 years in a single tertiary care center catheterization laboratory.

Funding Acknowledgement

Type of funding source: None

Human Papillomavirus G-Rich Regions as Potential Antiviral Drug Targets

Herein, we report, for the first time, the screening of several ligands in terms of their ability to bind and stabilize G-quadruplexes (G4) found in seven human Papillomavirus (HPV) genomes. Using a variety of biophysical assays, HPV G-quadruplexes were shown to possess a high degree of structural polymorphism upon ligand binding, which may have an impact on transcription, replication, and viral protein production. A sequence found in high-risk HPV16 genotype folds into multiple non-canonical DNA structures; it was converted into a major G4 conformation upon interaction with a well-characterized highly selective G4 ligand, PhenDC3, which may have an impact on the viral infection. Likewise, HPV57 and 58, which fold into multiple G4 structures, were found to form single stable complexes in the presence of two other G4 ligands, C₈ and pyridostatin, respectively. In addition, one of the selected compounds, the acridine derivative C₈, demonstrated a significant antiviral effect in HPV18-infected organotypic raft cultures. Altogether, these results indicate that targeting HPV G4s may be an alternative route for the development of novel antiviral therapies.

Nanotechnology activities: environmental protection regulatory issues data

Nanotechnology is a fascinating technology that is revolutionizing science and bringing countless benefits to the population. The economic side linked to nanotechnology has grown in recent years, as have the lines of research. However, nanoparticles can be toxic when released into the environment. In this work, a scientometric study was carried out in order to identify and describe scientific research on environmental protection involving nanotechnology with respect to regulatory studies. The research period was from 2003 to 2020, the database selected was Scopus and the software used for the study was Microsoft Excel and VOSviewer. According to specified keywords, the result presented by Scopus was a total of 106 publications. The clustering figures shown by VOSviewer showed that nanotoxicity studies were mostly aimed at protecting human health, to the detriment of environmental protection. Another interesting fact is that toxicity of nanomaterials has been studied from the perspective of risk assessment, including by the regulatory sector.