Pharmacophore-Based Virtual Screening to Discover New Active Compounds for Human Choline Kinase a1

Choline kinase (CK) catalyses the transfer of the ATP gamma-phosphate to choline to generate phosphocholine and ADP in the presence of magnesium leading to the synthesis of phosphatidylcholine. Of the three isoforms of CK described in humans, only the a isoforms (HsCK alpha) are strongly associated with cancer and have been validated as drug targets to treat this disease. Over the years, a large number of Hemicholinium-3 (HC-3)-based HsCK alpha biscationic inhibitors have been developed though the relevant common features important for the biological function have not been defined. Here, selecting a large number of previous HC-3-based inhibitors, we discover through computational studies a pharmacophore model formed by five moieties that are included in the 1-benzyl-4-(N-methylaniline) pyridinium fragment. Using a pharmacophore-guided virtual screening, we then identified 6 molecules that showed binding affinities in the low mM range to HsCK alpha 1. Finally, protein crystallization studies suggested that one of these molecules is bound to the choline and ATP-binding sites. In conclusion, we have developed a pharmacophore model that not only allowed us to dissect the structural important features of the previous HC-3 derivatives, but also enabled the identification of novel chemical tools with good ligand efficiencies to investigate the biological functions of HsCK alpha 1

Novel insights into RNAi off-target effects using C. elegans paralogs

<p>Abstract</p> <p>Background</p> <p>In the few years since its discovery, RNAi has turned into a very powerful tool for the study of gene function by allowing post-transcriptional gene silencing. The RNAi mechanism, which is based on the introduction of a double-stranded RNA (dsRNA) trigger whose sequence is similar to that of the targeted messenger RNA (mRNA), is subject to off-target cross-reaction.</p> <p>Results</p> <p>We use a novel strategy based on phenotypic analysis of paralogs and predict that, in <it>Caenorhabditis elegans</it>, off-target effects occur when an mRNA sequence shares more than 95% identity over 40 nucleotides with the dsRNA. Interestingly, our results suggest that the minimum length necessary of a high-similarity stretch between a dsRNA and its target in order to observe an efficient RNAi effect varies from 30 to 50 nucleotides rather than 22 nucleotides, which is the length of siRNAs in <it>C. elegans</it>.</p> <p>Conclusion</p> <p>Our predictive methods would improve the design of dsRNA and ultimately the use of RNAi as a therapeutic tool upon experimental verification.</p

Enhanced antitumor activity of doxorubicin in breast cancer through the use of poly(butylcyanoacrylate) nanoparticles

The use of doxorubicin (DOX), one of the most effective antitumor molecules in the treatment of metastatic breast cancer, is limited by its low tumor selectivity and its severe side effects. Colloidal carriers based on biodegradable poly(butylcyanoacrylate) nanoparticles (PBCA NPs) may enhance DOX antitumor activity against breast cancer cells, thus allowing a reduction of the effective dose required for antitumor activity and consequently the level of associated toxicity. DOX loading onto PBCA NPs was investigated in this work via both drug entrapment and surface adsorption. Cytotoxicity assays with DOX-loaded NPs were performed in vitro using breast tumor cell lines (MCF-7 human and E0771 mouse cancer cells), and in vivo evaluating antitumor activity in immunocompetent C57BL/6 mice. The entrapment method yielded greater drug loading values and a controlled drug release profile. Neither in vitro nor in vivo cytotoxicity was observed for blank NPs. The 50% inhibitory concentration (IC50) of DOX-loaded PBCA NPs was significantly lower for MCF-7 and E0771 cancer cells (4 and 15 times, respectively) compared with free DOX. Furthermore, DOX-loaded PBCA NPs produced a tumor growth inhibition that was 40% greater than that observed with free DOX, thus reducing DOX toxicity during treatment. These results suggest that DOX-loaded PBCA NPs have great potential for improving the efficacy of DOX therapy against advanced breast cancers.This investigation was funded by FEDER, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I + D + I), Instituto de Salud Carlos III (FIS) through projects Nos PI11/01862 and PI11/02571, and by the Consejería de Salud de la Junta de Andalucía through project No PI-0338. The authors wish to express their gratitude to G Ortiz Ferron (CIC, University of Granada, Spain) for his skillful assistance with cytometry experiments

Synthesis, in Vitro Profiling, and in Vivo Evaluation of Benzohomoadamantane-Based Ureas for Visceral Pain: A New Indication for Soluble Epoxide Hydrolase Inhibitors

The soluble epoxide hydrolase (sEH) has been suggested as a pharmacological target for the treatment of several diseases, including pain-related disorders. Herein, we report further medicinal chemistry around new benzohomoadamantane-based sEH inhibitors (sEHI) in order to improve the drug metabolism and pharmacokinetics properties of a previous hit. After an extensive in vitro screening cascade, molecular modeling, and in vivo pharmacokinetics studies, two candidates were evaluated in vivo in a murine model of capsaicin-induced allodynia. The two compounds showed an anti-allodynic effect in a dose-dependent manner. Moreover, the most potent compound presented robust analgesic efficacy in the cyclophosphamide-induced murine model of cystitis, a well-established model of visceral pain. Overall, these results suggest painful bladder syndrome as a new possible indication for sEHI, opening a new range of applications for them in the visceral pain field

In vivo evaluation of soluble epoxide hydrolase inhibitors in murine models of allodynia, chemotherapy-induced neuropathic pain and visceral pain

Trabajo presentado en el IX EFMC International Symposium on Advances in Synthetic and Medicinal Chemistry, celebrado en Zagreb (Croacia), del 3 al 7 de septiembre de 2023Soluble epoxide hydrolase inhibitors (sEHI) are a new class of non-opioid analgesics, with a representative compound, EC5026, currently in clinical trials for the management of neuropathic pain [1]. Our group has recently designed, synthesized and pharmacologically evaluated novel series of potent benzohomoadamantane-based sEHI [2]. Herein, we report further medicinal chemistry around the abovementioned polycyclic scaffold to improve the potency and, particularly, the DMPK properties of previous hits. After an extensive in vitro screening cascade, molecular modeling, and in vivo pharmacokinetics studies, three candidates were selected for in vivo studies. Two compounds evaluated in a murine model of capsaicin-induced allodynia displayed potent anti-allodynic effect in a dose-dependent manner. Next, the most potent compound was evaluated in the cyclophosphamide-induced murine model of cystitis, a well-established model of visceral pain, presenting robust analgesic efficacy [3]. Finally, considering that chemotherapy-induced neuropathic pain (CINP), a severe side effect of several anticancer agents, is a largely unmet medical need [4], our third candidate was evaluated in a murine model of paclitaxel-induced neuropathic pain. CINP was performed by a daily injection of paclitaxel via i.p. (2 mg/kg), for 5 consecutive days. Mice developed neuropathic mechanical allodynia, which peaked on day 10 after the first paclitaxel administration ¿time when the acute effects of sEHI were tested. Subcutaneous administration of this candidate (2.5-5 mg/kg) completely reversed in a dose dependent manner the sensory hypersensitivity. Additionally, administration of the sEHI (5 mg/kg, s.c.) 30 min before each paclitaxel injection completely prevented the development of neuropathic allodynia. Collectively, these results suggest interstitial cystitis/pain bladder syndrome and CINP as possible new indications for sEHI. Acknowledgements: This work was funded by the Grant PID2020-118127RB-I00 funded by MCIN/AEI/10.13039/501100011033 and by ¿ERDF A way of making Europe¿ to S.V

Seroprevalence of Toxoplasma gondii in Gallus domesticus in Havana, Cuba

El estudio tuvo como objetivo determinar la seroprevalencia de T. gondii en Gallus domesticus en La Habana, Cuba. Se colectaron 300 muestras de sueros de pollitas White Leghorn L33 en fase de desarrollo en 2015, distribuidas a razón de 100 aves por cada lote incorporado a la unidad avícola desde procedencias diferentes. Las muestras fueron analizadas mediante un ELISA de inhibición y se utilizaron las pruebas Chi-cuadrado y Dócima de Duncan para comparar las proporciones de aves positivas entre los lotes estudiados. Se encontró una relativa baja seroprevalencia de T. gondii (9.6%), similar a otros hallazgos reportados a nivel internacional. Se evidenciaron diferencias significativas (p=0.0001) en la prevalencia de T. gondii entre los tres lotes de aves. Se concluye que la seroprevalencia de T. gondii en Gallus domesticus en La Habana es baja, aunque esta constituye un riesgo de infección para las poblaciones humanas y animales susceptibles.The aim of this study was to determine the seroprevalence of T. gondii in Gallus domesticus in Havana, Cuba. Three hundred serum samples were collected from White Leghorn pullets L33 in growing stage in 2015. Samples represented 100 birds per batch incorporated into the poultry unit from different origins. Samples were evaluated by an ELISA inhibition test and data was analyzed by the Chi-square and Duncan tests to compare proportions of positive birds among batches. A relatively low seroprevalence of T. gondii was found (9.6%), similar to other findings reported internationally. Significant differences (p=0.0001) in the prevalence of T. gondii among the three bird batches were found. It is concluded that the seroprevalence of T. gondii in Gallus domesticus in Havana is low, though this constitutes a risk of infection for susceptible human and animal populations

Final results from the PERUSE study of first-line pertuzumab plus trastuzumab plus a taxane for HER2-positive locally recurrent or metastatic breast cancer, with a multivariable approach to guide prognostication

Background: The phase III CLinical Evaluation Of Pertuzumab And TRAstuzumab (CLEOPATRA) trial established the combination of pertuzumab, trastuzumab and docetaxel as standard first-line therapy for human epidermal growth factor receptor 2 (HER2)-positive locally recurrent/metastatic breast cancer (LR/mBC). The multicentre single-arm PERtUzumab global SafEty (PERUSE) study assessed the safety and efficacy of pertuzumab and trastuzumab combined with investigator-selected taxane in this setting. Patients and methods: Eligible patients with inoperable HER2-positive LR/mBC and no prior systemic therapy for LR/mBC (except endocrine therapy) received docetaxel, paclitaxel or nab-paclitaxel with trastuzumab and pertuzumab until disease progression or unacceptable toxicity. The primary endpoint was safety. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Prespecified subgroup analyses included subgroups according to taxane, hormone receptor (HR) status and prior trastuzumab. Exploratory univariable analyses identified potential prognostic factors; those that remained significant in multivariable analysis were used to analyse PFS and OS in subgroups with all, some or none of these factors. Results: Of 1436 treated patients, 588 (41%) initially received paclitaxel and 918 (64%) had HR-positive disease. The most common grade 653 adverse events were neutropenia (10%, mainly with docetaxel) and diarrhoea (8%). At the final analysis (median follow-up: 5.7 years), median PFS was 20.7 [95% confidence interval (CI) 18.9-23.1] months overall and was similar irrespective of HR status or taxane. Median OS was 65.3 (95% CI 60.9-70.9) months overall. OS was similar regardless of taxane backbone but was more favourable in patients with HR-positive than HR-negative LR/mBC. In exploratory analyses, trastuzumab-pretreated patients with visceral disease had the shortest median PFS (13.1 months) and OS (46.3 months). Conclusions: Mature results from PERUSE show a safety and efficacy profile consistent with results from CLEOPATRA and median OS exceeding 5 years. Results suggest that paclitaxel is a valid alternative to docetaxel as backbone chemotherapy. Exploratory analyses suggest risk factors that could guide future trial design