RNAseq Analysis of Novel 1,3,4-Oxadiazole Chalcogen Analogues Reveals Anti-Tubulin Properties on Cancer Cell Lines

1,3,4-Oxadiazole derivatives are among the most studied anticancer drugs. Previous studies have analyzed the action of different 1,3,4-oxadiazole derivatives and their effects on cancer cells. This study investigated the characterization of two new compounds named 6 and 14 on HeLa and PC-3 cancer cell lines. Based on the previously obtained IC50, cell cycle effects were monitored by flow cytometry. RNA sequencing (RNAseq) was performed to identify differentially expressed genes, followed by functional annotation using gene ontology (GO), KEGG signaling pathway enrichment, and protein–protein interaction (PPI) network analyses. The tubulin polymerization assay was used to analyze the interaction of both compounds with tubulin. The results showed that 6 and 14 strongly inhibited the proliferation of cancer cells by arresting them in the G2/M phase of the cell cycle. Transcriptome analysis showed that exposure of HeLa and PC-3 cells to the compounds caused a marked reprograming of gene expression. Functional enrichment analysis indicated that differentially expressed genes were significantly enriched throughout the cell cycle and cancer-related biological processes. Furthermore, PPI network, hub gene, and CMap analyses revealed that compounds 14 and 6 shared target genes with established microtubule inhibitors, indicating points of similarity between the two molecules and microtubule inhibitors in terms of the mechanism of action. They were also able to influence the polymerization process of tubulin, suggesting the potential of these new compounds to be used as efficient chemotherapeutic agents

A liquid chromatography-mass spectrometry study on the spirocyclization of ninhydrin with the aminothiols

© 2018 Elsevier BV. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 24 month embargo from date of publication (May 2018) in accordance with the publisher’s archiving policy.Ninhydrin reacts with some aminothiols to form spiranes adducts whose optical and chromatographic properties have proved to be useful for chiral recognition. Liquid chromatography-mass spectrometry data along with spectroscopic analysis reveal that under certain conditions, in addition to the known single-spirane configuration, the spirothiazolidinic complexes can exist also as double- and mixed double-spiranes. The reaction was exploited to check the enantiomeric purity of two commercially available dosage form of D-penicillamine and to measure the aminothiol concentration in the urine sample from a subject under treatment with the drug. Separation of diastereoisomers was achieved on a C18 column in isocratic mode by using a mixture of an aqueous solution of formic acid (30 mmol/L)/acetonitrile (90:10, v/v) as a mobile phase. Diastereoisomers were detected by a fluorescence detector and mass spectrometer in short times and with a good resolution. Intra- and inter-assay reproducibility were under 4% with an average recovery of 98%. At a LOD of 0.01%, no evidence of the toxic distomer (L-enantiomer) was found in the biological sample and drugs

Chronic Citalopram Administration Causes a Sustained Suppression of Serotonin Synthesis in the Mouse Forebrain

BACKGROUND:Serotonin (5-HT) is a neurotransmitter with important roles in the regulation of neurobehavioral processes, particularly those regulating affect in humans. Drugs that potentiate serotonergic neurotransmission by selectively inhibiting the reuptake of serotonin (SSRIs) are widely used for the treatment of psychiatric disorders. Although the regulation of serotonin synthesis may be an factor in SSRI efficacy, the effect of chronic SSRI administration on 5-HT synthesis is not well understood. Here, we describe effects of chronic administration of the SSRI citalopram (CIT) on 5-HT synthesis and content in the mouse forebrain. METHODOLOGY/PRINCIPAL FINDINGS:Citalopram was administered continuously to adult male C57BL/6J mice via osmotic minipump for 2 days, 14 days or 28 days. Plasma citalopram levels were found to be within the clinical range. 5-HT synthesis was assessed using the decarboxylase inhibition method. Citalopram administration caused a suppression of 5-HT synthesis at all time points. CIT treatment also caused a reduction in forebrain 5-HIAA content. Following chronic CIT treatment, forebrain 5-HT stores were more sensitive to the depleting effects of acute decarboxylase inhibition. CONCLUSIONS/SIGNIFICANCE:Taken together, these results demonstrate that chronic citalopram administration causes a sustained suppression of serotonin synthesis in the mouse forebrain. Furthermore, our results indicate that chronic 5-HT reuptake inhibition renders 5-HT brain stores more sensitive to alterations in serotonin synthesis. These results suggest that the regulation of 5-HT synthesis warrants consideration in efforts to develop novel antidepressant strategies

Development of an LC–Tandem Mass Spectrometry Method for the Quantitative Analysis of Hercynine in Human Whole Blood

Given that the peculiar redox behavior of ergothioneine involves a rapid regeneration process, the measurement of its precursor and redox metabolite hercynine could be particularly useful in assessing its role in oxidative stress or other biological processes. Thus, a LC-MS/MS method for the determination of hercynine concentrations in whole blood was developed. After lysis of red blood cells by cold water, samples were filtered on micro concentrators at a controlled temperature of 4 °C. The clear filtered fluid was then treated with diethylpyrocarbonate to derivatize hercynine for the analysis by LC-MS/MS. The derivatized analyte was isocratically separated as a carbethoxy derivative on a C18 column with a mobile phase of an aqueous 0.1% v/v formic acid and acetonitrile (95:5). Effluents were monitored by MRM transitions at m/z 270.28→95 and 273.21→95 for hercynine and its deuterated counterpart, respectively. No cross-talk between MRM transitions was observed and a good linearity was found within a range of 35⁻1120 nmol/L. The LOD and LOQ were, respectively, 10.30 and 31.21 nmol/L with an intraday and intermediate precision below 7%. The average hercynine concentration in whole blood from 30 healthy male volunteers (aged 77 ± 12 years) was 178.5 ± 118.1 nmol/L. Overall, the method is easy to perform, allowing a rapid and accurate assessment of whole blood concentrations of hercynine

Synthesis and Antineoplastic Evaluation of Novel Unsymmetrical 1,3,4-Oxadiazoles

A series of novel 1,3,4-oxadiazoles was synthesized and evaluated for their cytotoxic activity in in vitro tumor models. Four of the new compounds (<b>2d</b>, <b>2j</b>, <b>2k</b>, and <b>2n</b>) showed growth inhibition in the XTT dye assay. The most active agent, <b>2j</b>, showed high potency against human cancer cells with IC₅₀s ranging from 0.05 to 1.7 μM. Preliminary SAR correlations suggested that the nature of chains on the oxadiazole is important for antitumor potency in vitro. Compound <b>2j</b> determined a G₂/M arrest of the cell cycle and also activated a strong apoptotic response. The β-tubulin immunofluorescence analysis indicated that compound <b>2j</b> effectively inhibited the microtubule organization in all cancer cell lines, causing the formation of abnormal spindle, which did not affect the normal human fibroblast cells NB1, Mrc-5 and IBR3. For all these reasons, compound <b>2j</b> could be a good candidate in chemopreventive or chemotherapeutic strategies

Tricyclic pyrazoles. Part 8. Synthesis, biological evaluation and modelling of tricyclic pyrazole carboxamides as potential CB2 receptor ligands with antagonist/inverse agonist properties

Previous studies have investigated the relevance and structure-activity relationships (SARs) of pyrazole derivatives in relation with cannabinoid receptors, and the series of tricyclic 1,4-dihydroindeno[1,2-c] pyrazoles emerged as potent CB2 receptor ligands. In the present study, novel 1,4-dihydroindeno[1,2-c] pyrazole and 1H-benzo[g]indazole carboxamides containing a cyclopropyl or a cyclohexyl substituent were designed and synthesized to evaluate the influence of these structural modifications towards CB1 and CB2 receptor affinities. Among these derivatives, compound 15 (6-cyclopropyl-1-(2,4- dichlorophenyl)-N-(adamantan-1-yl)-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamide) showed the highest CB2 receptor affinity (Ki ¼ 4 nM) and remarkable selectivity (KiCB1/KiCB2 ¼ 2232), whereas a similar affinity, within the nM range, was seen for the fenchyl derivative (compound 10: Ki ¼ 6 nM), for the bornyl analogue (compound 14: Ki ¼ 38 nM) and, to a lesser extent, for the aminopiperidine de rivative (compound 6: Ki ¼ 69 nM). Compounds 10 and 14 were also highly selective for the CB2 receptor (KiCB1/KiCB2 > 1000), whereas compound 6 was relatively selective (KiCB1/KiCB2 ¼ 27). The four com pounds were also subjected to GTPgS binding analysis showing antagonist/inverse agonist properties (IC50 for compound 14 ¼ 27 nM, for 15 ¼ 51 nM, for 10 ¼ 80 nM and for 6 ¼ 294 nM), and this activity was confirmed for the three more active compounds in a CB2 receptor-specific in vitro bioassay con sisting in the quantification of prostaglandin E2 release by LPS-stimulated BV2 cells, in the presence and absence of WIN55,212-2 and/or the investigated compounds. Modelling studies were also conducted with the four compounds, which conformed with the structural requirements stated for the binding of antagonist compounds to the human CB2 receptor.Depto. de Bioquímica y Biología MolecularFac. de MedicinaTRUEpu