A Fragment-Based Approach for the Development of G-Quadruplex Ligands: Role of the Amidoxime Moiety

G-quadruplex (G4) nucleic acid structures have been reported to be involved in several human pathologies, including cancer, neurodegenerative disorders and infectious diseases; however, G4 targeting compounds still need implementation in terms of drug-like properties and selectivity in order to reach the clinical use. So far, G4 ligands have been mainly identified through high-throughput screening methods or design of molecules with pre-set features. Here, we describe the development of new heterocyclic ligands through a fragment-based drug discovery (FBDD) approach. The ligands were designed against the major G4 present in the long terminal repeat (LTR) promoter region of the human immunodeficiency virus-1 (HIV-1), the stabilization of which has been shown to suppress viral gene expression and replication. Our method is based on the generation of molecular fragment small libraries, screened against the target to further elaborate them into lead compounds. We screened 150 small molecules, composed by structurally and chemically different fragments, selected from commercially available and in-house compounds; synthetic elaboration yielded several G4 ligands and two final G4 binders, both embedding an amidoxime moiety; one of these two compounds showed preferential binding for the HIV-1 LTR G4. This work presents the discovery of a novel potential pharmacophore and highlights the possibility to apply a fragment-based approach to develop G4 ligands with unexpected chemical features

Atrophy, oxidative switching and ultrastructural defects in skeletal muscle of the ataxia telangiectasia mouse model

Ataxia telangiectasia is a rare, multi system disease caused by ATM kinase deficiency. Atm-knockout mice recapitulate premature aging, immunodeficiency, cancer predisposition, growth retardation and motor defects, but not cerebellar neurodegeneration and ataxia. We explored whether Atm loss is responsible for skeletal muscle defects by investigating myofiber morphology, oxidative/glycolytic activity, myocyte ultrastructural architecture and neuromuscular junctions. Atm-knockout mice showed reduced muscle and fiber size. Atrophy, protein synthesis impairment and a switch from glycolytic to oxidative fibers were detected, along with an increase of in expression of slow and fast myosin types (Myh7, and Myh2 and Myh4, respectively) in tibialis anterior and solei muscles isolated from Atm-knockout mice. Transmission electron microscopy of tibialis anterior revealed misalignments of Z-lines and sarcomeres and mitochondria abnormalities that were associated with an increase in reactive oxygen species. Moreover, neuromuscular junctions appeared larger and more complex than those in Atm wild-type mice, but with preserved presynaptic terminals. In conclusion, we report for the first time that Atm-knockout mice have clear morphological skeletal muscle defects that will be relevant for the investigation of the oxidative stress response, motor alteration and the interplay with peripheral nervous system in ataxia telangiectasia

Unveiling the morphogenetic code: A new path at the intersection of physical energies and chemical signaling

In this editorial, we discuss the remarkable role of physical energies in the control of cell signaling networks and in the specification of the architectural plan of both somatic and stem cells. In particular, we focus on the biological relevance of bioelectricity in the pattern control that orchestrates both developmental and regenerative pathways. To this end, the narrative starts from the dawn of the first studies on animal electricity, reconsidering the pioneer work of Harold Saxton Burr in the light of the current achievements. We finally discuss the most recent evidence showing that bioelectric signaling is an essential component of the informational processes that control pattern specification during embryogenesis, regeneration, or even malignant transformation. We conclude that there is now mounting evidence for the existence of a Morphogenetic Code, and that deciphering this code may lead to unprecedented opportunities for the development of novel paradigms of cure in regenerative and precision medicine

FGF9 – Nodal signaling negatively control meiotic entry of postnatal male germ cells

Fibroblast growth factor 9 (FGF9) produced by the somatic cells of the testis acts directly on germ cells to inhibit meiosis by upregulating levels of the RNA binding protein Nanos2, both in fetal and postnatal gonad [1]. Several studies have recently demonstrated that the anti-meiotic effect of FGF9 in the fetal testis is mediated by Nodal, a member of the TGF-Beta morphogen family. In fetal male germ cells FGF9 upregulates Cripto, which is a Nodal co-receptor, making these cells unable to enter meiosis [2]. However it is currently unknown how FGF9 acts postnatally to inhibit entry into meiosis of male mitotic germ cells. We first investigated which was the signal transduction pathway activated by FGF9 on postnatal mouse spermatogonia. We found that FGF9 signaling is dependent on ERK but not on AKT activation, which is instead triggered by Kit ligand (an inducer of meiotic entry that cooperates with retinoic acid). By qRT-PCR we found that Nodal and Cripto are expressed in postnatal spermatogonia and that FGF9 (but not Kit ligand) treatment promotes their upregulation. By western blot we found that phospho-Smad2, an indicator of active Nodal signaling, is increased in spermatogonia upon FGF9 treatment, suggesting that Nodal mediates FGF9 action also in postnatal male germ cells

Tumor growth rate to assess therapy response to immune-based combinations for metastatic renal cell carcinoma

Background: Radiological response assessment is becoming challenging with novel immune-based combinations for metastatic renal cell carcinoma (mRCC). RECIST criteria appear not exhaustively adequate to capture the kinetics of treatment response, which is better reflected by tumor growth rate (TGR). We explored TGR changes during first-line treatments and its association with clinical outcomes in mRCC. Research design and methods: We retrospectively evaluated TGR in untreated patients undergoing pembrolizumab/axitinib (P/A) or tyrosine-kinase inhibitors (TKI). TGR was calculated at the first (TGR1, after 3 months) and the second (TGR2, after 6 months) evaluation, thus assessing the TGR2-TGR1 difference. Results: Thirty-three patients were included (P/A n = 15, TKIs n = 18). Volumes firstly decreased more rapidly with TKIs, and then more slowly. Volumes initially remained stable with P/A, quickly decreasing until the second evaluation. TGR1 was related to progression-free survival (PFS; p = 0.023) and overall survival (p = 0.046) with P/A. TGR2 was correlated with PFS in all patients (p = 0.025). Patients with higher velocity volume reduction appeared to have improved survival benefits than patients with lower velocity considering both treatments, but especially with P/A. Conclusion: Combining immunotherapy with TKIs has an important role in enhancing the rapidity of tumor shrinkage. A rapid disease volume reduction correlates with better OS and PFS

Role of Pten deletion and BRafV600E mutation in the generation of testicular germ cell tumors

Testicular germ cell tumors (TGCT) represent the most common solid malignancy affecting males between the ages of 15 and 35, while ovarian germ cell tumours (OGCT) are a type of ovarian neoplasm principally affecting young women. Germ cell tumors (GCTs) account for about 95 % of testicular cancer cases and for only 2-3% of ovarian cancer cases (Siegel et al., 2011). Most TGCT are potentially curable, however approximately 5% of patients with TGCT develop chemoresistance and die from the disease. PTEN deletion and mutational activation of BRAF are frequent genetic alterations found in human TGCTs, suggesting that they might be directly involved in germ cell tumorigenesis. Furthermore, BRAF mutation positively correlates with the acquisition of resistence to cisplatin, the most commonly chemotherapic agent employed for the treatment of human TGCTs. We obtained heterozygous floxed Ptenloxp/+ BRafCA Spo11Cre mice showing ovarian teratomas and testicular tumors with an incidence of about 30% at 20 days post partum (dpp) . Since Spo- 11Cre is active at around 13.5 days post coitum (dpc) in female germ cells and at around 7 dpp in male germ cells (18), these results suggest that ovarian teratomas origin from early meiotic germ cells in the fetal period whereas GCT formation in males can be a postnatal event. By histological inspection, we found that cancer cells in testes showed features reminiscent of seminoma such as a diffuse, confluent multinodular pattern. However, by immunohistochemical staining, we observed that the cells within the tumor showed heterogeneous positivity for the pluripotency markers Oct4, Sox2, Nanog, Kit and Prdm14, suggesting that they can represent a mixed form of seminoma and embryonal carcinoma cells. Our results indicate that deregulated MAP and PI3 Kinase activation can lead to postnatal male germ cells transformation

Appropriateness of Mini-Invasive Approaches for Nausea and Vomiting Refractory to Medical Therapy in Palliative Care Setting: A Case Report

Introduction: Nausea and vomiting are frequent multifactorial symptoms in oncological patients. These manifestations, mainly affecting the advanced disease stages, may lead to existential, psychological, and physical suffering, with a negative impact on the quality of life (QoL) of the individual and his family. The medical approach makes use of a wide range of drugs, with different antiemetic potency and various mechanisms of action, taking into account the etiology and the patient’s response to the different therapeutic strategies. In recent years, in addition to pharmacological treatments, some endoscopic procedures have been integrated into clinical practice as promising palliative approaches. Case Presentation: Herein, we describe and discuss a case of a 64-year-old female affected by advanced stage pancreatic adenocarcinoma, in which different techniques – both medical and endoscopic – have been used to approach a refractory symptomatology with a negative impact on the patient’s QoL. In the context of a multidisciplinary approach in primary palliative care, a tailored intervention encompassing invasive methods for palliative purposes, may be considered adequate and appropriate when the prognostic expectation and the physical functionality indices allow it. Conclusion: Minimally invasive palliative interventions should be offered to patients with advanced cancer when symptoms become refractory to standard medical therapies, as part of the holistic approach in modern treatments. Therefore, the integration of an early palliative approach into the patient’s therapeutic path becomes essential for the management of all the individual’s needs

ADAR1 is a new target of METTL3 and plays a pro-oncogenic role in glioblastoma by an editing-independent mechanism

Background: N6-methyladenosine (m6A) and adenosine-to-inosine (A-to-I) RNA editing are two of the most abundant RNA modification events affecting adenosines in mammals. Both these RNA modifications determine mRNA fate and play a pivotal role in tumor development and progression. Results: Here, we show that METTL3, upregulated in glioblastoma, methylates ADAR1 mRNA and increases its protein level leading to a pro-tumorigenic mechanism connecting METTL3, YTHDF1, and ADAR1. We show that ADAR1 plays a cancer-promoting role independently of its deaminase activity by binding CDK2 mRNA, underlining the importance of ADARs as essential RNA-binding proteins for cell homeostasis as well as cancer progression. Additionally, we show that ADAR1 knockdown is sufficient to strongly inhibit glioblastoma growth in vivo. Conclusions: Hence, our findings underscore METTL3/ADAR1 axis as a novel crucial pathway in cancer progression that connects m6A and A-to-I editing post-transcriptional events

Cardiac Functional and Structural Abnormalities in a Mouse Model of CDKL5 Deficiency Disorder

CDKL5 (cyclin-dependent kinase-like 5) deficiency disorder (CDD) is a severe neurodevelopmental disease that mostly affects girls, who are heterozygous for mutations in the X-linked CDKL5 gene. Mutations in the CDKL5 gene lead to a lack of CDKL5 protein expression or function and cause numerous clinical features, including early-onset seizures, marked hypotonia, autistic features, gastrointestinal problems, and severe neurodevelopmental impairment. Mouse models of CDD recapitulate several aspects of CDD symptomology, including cognitive impairments, motor deficits, and autistic-like features, and have been useful to dissect the role of CDKL5 in brain development and function. However, our current knowledge of the function of CDKL5 in other organs/tissues besides the brain is still quite limited, reducing the possibility of broad-spectrum interventions. Here, for the first time, we report the presence of cardiac function/structure alterations in heterozygous Cdkl5 +/- female mice. We found a prolonged QT interval (corrected for the heart rate, QTc) and increased heart rate in Cdkl5 +/- mice. These changes correlate with a marked decrease in parasympathetic activity to the heart and in the expression of the Scn5a and Hcn4 voltage-gated channels. Interestingly, Cdkl5 +/- hearts showed increased fibrosis, altered gap junction organization and connexin-43 expression, mitochondrial dysfunction, and increased ROS production. Together, these findings not only contribute to our understanding of the role of CDKL5 in heart structure/function but also document a novel preclinical phenotype for future therapeutic investigation

Reduction of the microbial load in meat maturation rooms with and without alkaline electrolyzed water fumigation

Dry-aging is a process during which meat is stored within maturation chambers at low temperatures and low relative humidity, resulting in improved tenderness and flavor development. The cuts are exposed to the atmosphere by hanging them or setting them on racks in the maturation chamber without any protective packaging. Animals and humans are usually the major sources of bacterial food contamination in the meat industry, but other routes might be involved. Therefore, procedures to reduce or eliminate pathogens from surfaces are crucial for an effective hazard analysis critical control point program in the food industry and other environments. This study aimed to assess the survival of Listeria monocytogenes, Escherichia coli, Salmonella spp., and Staphylococcus aureus on the inner surface of dry aging chambers. Moreover, we tested the efficacy of alkaline electrolyzed water (REW) for its eventual application within a procedure aimed at reducing foodborne pathogens during meat storage. Environmental conditions inside the dry aging cabinet determine a reduction of circa 3 log CFU/cm2 of the considered microorganisms on the inner surface in 24 hours. Additionally, the nebulization of alkaline electrolyzed water with the smoking system increased the count reduction in 24 hours due to environmental conditions for L. monocytogenes (~1 log CFU/cm2) and for S. aureus (~2 log CFU/cm2). In this context, the use of REW can be justified for routine cleaning procedures of the surfaces, with the added value of being safe to handle, not containing environmental pollutants, and making it unnecessary to rinse surfaces due to its instability