Publications

Abstract One of the major assets of anticancer nanomedicine is the ability to co-deliver drug combinations, as it enables targeting of different cellular populations and/or signaling pathways implicated in tumorigenesis and thus tackling tumor heterogeneity. Moreover, drug resistance can be circumvented, for example, upon co-encapsulation and delivery of doxorubicin and sphingolipids, as ceramides. Herein, the impact of short (C6) and long (C18) alkyl chain length ceramides on the nature of drug interaction, within the scope of combination with doxorubicin, was performed in bulk triple-negative breast cancer (TNBC) cells, as well as on the density of putative cancer stem cells and phenotype, including live single-cell tracking.& nbsp;C6-or C18-ceramide enabled a synergistic drug interaction in all conditions and (bulk) cell lines tested. However, differentiation among these two ceramides was reflected on the migratory potential of cancer cells, particularly significant against the highly motile MDA-MB-231 cells. This effect was supported by the down-regulation of the PI3K/Akt pathway enabled by C6-ceramide and in contrast with C18-ceramide. The decrease of the migratory potential enabled by the targeted liposomal combinations is of high relevance in the context of TNBC, due to the underlying metastatic potential.& nbsp;Surprisingly, the nature of the drug interaction assessed at the level of bulk cancer cells revealed to be insufficient to predict whether a drug combination enables a decrease in the percentage of the master regulators of tumor relapse as ALDH(+)/(high) putative TNBC cancer stem cells, suggesting, for the first time, that it should be extended further down to this level.

Abstract 4-Oxoquinoline derivatives have been often used in drug discovery programs due to their pharmacological properties. Inspired on chromone and 4-oxoquinoline chemical structure similarity, a small series of quinoline-based compounds was obtained and screened, for the first time, toward human monoamine oxidases isoforms. The data showed the N-(3,4-dichlorophenyl)-1-methyl-4-oxo-1,4-dihydroquinoline-3-carboxamide 10 was the most potent and selective MAO-B inhibitor (IC50 = 5.30 +/- 0.74 nM and SI: >= 1887). The data analysis showed that prototropic tautomerism markedly influences the biological activity. The unequivocal characterisation of the quinoline tautomers was performed to understand the attained data. To our knowledge, there have been no prior reports on the characterisation of quinolone tautomers by 2D NMR techniques, namely by H-1-N-15 HSQC and H-1-N-15 HMBC, which are proposed as expedite tools for medicinal chemistry campaigns. Computational studies on enzyme-ligand complexes, obtained after MM-GBSA calculations and molecular dynamics simulations, supported the experimental data.

Abstract Patients with breast or ovarian cancer have not benefited from improved efficacy with pegylated liposomal doxorubicin relative to free drug, likely due to the limited extent of the enhanced permeability and retention (EPR) effect, further compromising drug bioavailability in the tumor. Herein it is hypothesized that targeting nucleolin overexpressed in tumor endothelial cells (readily accessible from the vascular compartment), besides cancer cells, with PEGASEMP (doxorubicin hydrochloride in a lipid-based pegylated nanoparticle functionalized with a 31-aminoacid peptide targeting nucleolin), lessens the dependence on high systemic exposures and EPR effect for successful tumor targeting. This strategy has resulted in improved intracellular tumor bioavailability of doxorubicin, at low systemic exposure, associated with a safe toxicological profile. Levels of cell surface nucleolin dictated the antitumor activity of PEGASEMP against nucleolin-overexpressing solid tumors of diverse histological origin, evidencing a significant growth inhibition of malignant mesothelioma over the standard of care. Those observations were paralleled by an impairment of the nucleolin-positive vasculature and downregulation of typically overexpressed genes. Patient stratification based on nucleolin mRNA expression correlated with prognosis and enabled identification of breast and mesothelioma tumors that may potentially benefit from PEGASEMP. Overall, a novel principle of drug delivery is presented with potential therapeutic impact across nucleolin-overexpressing human cancers. Data Availability: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Abstract Chromone-3-phenylcarboxamides (Crom-1 and Crom-2) were identified as potent, selective, and reversible inhibitors of human monoamine oxidase B (hMAO-B). Since they exhibit some absorption, distribution, metabolism, and excretion (ADME)-toxicity liabilities, new derivatives were synthesized to map the chemical structural features that compose the pharmacophore, a process vital for lead optimization. Structure-activity relationship data, supported by molecular docking studies, provided a rationale for the contribution of the heterocycle's rigidity, the carbonyl group, and the benzopyran heteroatom for hMAO-B inhibitory activity. From the study, N-(3-chlorophenyl)-4H-thiochromone-3-carboxamide (31) (hMAO-B IC50 = 1.52 +/- 0.15 nM) emerged as a reversible tight binding inhibitor with an improved pharmacological profile. In in vitro ADME-toxicity studies, compound 31 showed a safe cytotoxicity profile in Caco-2, SH-SY5Y, HUVEC, HEK-293, and MCF-7 cells, did not present cardiotoxic effects, and did not affect P-gp transport activity. Compound 31 also protected SH-SY5Y cells from iron(III)-induced damage. Collectively, these studies highlighted compound 31 as the first-in-class and a suitable candidate for in vivo preclinical investigation.

Abstract The structure of the title quinoline carboxamide derivative, C26H25N3O, is described. The quinoline moiety is not planar as a result of a slight puckering of the pyridine ring. The secondary amine has a slightly pyramidal geometry, certainly not planar. Both intra- and intermolecular hydrogen bonds are present. Hirshfeld surface analysis and lattice energies were used to investigate the intermolecular interactions.

Abstract Cancer is a major cause of death worldwide and novel anticancer agents for its better management are much needed. Benzopyrone-based compounds, such as chromones, possess several distinctive chemical and biological properties, of which the cytotoxicity against cancer cells seems to be prominent. In this study, two series of compounds based on chromen-4-one (3-10) and chromane-2,4-dione (11-18) scaffolds were synthesized in moderate/high yields and evaluated for cytotoxicity against HL-60, MOLT-4, and MCF-7 cancer cells using MTT assay. In general, the compounds exhibited moderate cytotoxic effects against the cancer cell lines, among which, a superior potency could be observed against MOLT-4 cells. Chroman-2,4dione (11-18) derivatives had overall higher potencies compared to their chromen-4-one (3-10) counterparts. Compound 13 displayed the lowest IC50 values against HL-60 (IC50, 42.0 +/- 2.7 mu M) and MOLT-4 cell lines (IC50, 24.4 +/- 2.6 mu M), while derivative 11 showed the highest activity against MCF-7 cells (IC50, 68.4 +/- 3.9 04). In conclusion, this study provides important information on the cytotoxic effects of chromone derivatives. Benzochroman-2,4-dione has been identified as a promising scaffold, which its potency can be modulated by tailored synthesis with the aim of finding novel and dissimilar anticancer compounds.

Abstract The discovery and development of multitarget-directed ligands (MTDLs) is a promising strategy to find new therapeutic solutions for neurodegenerative diseases (NDs), in particular for Alzheimer's disease (AD). Currently approved drugs for the clinical management of AD are based on a single-target strategy and focus on restoring neurotransmitter homeostasis. Finding disease-modifying therapies AD and other NDs remains an urgent unmet clinical need. The growing consensus that AD is a multifactorial disease, with several interconnected and deregulated pathological pathways, boosted an intensive research in the design of MTDLs. Due to this scientific boom, the knowledge behind the development of MTDLs remains diffuse and lacks balanced guidelines. To rationalize the large amount of data obtained in this field, we herein revise the progress made over the last 5 years on the development of MTDLs inspired by drugs approved for AD. Due to their putative therapeutic benefit in AD, MTDLs based on MAO-B inhibitors will also be discussed in this review.

Abstract N-(3′-Chlorophenyl)-4-oxo-4H-chromene-3-carboxamide, compound 20 (IC 50 = 403 pM), acts as noncompetitive reversible inhibitor, and N-(3′,4′-dimethylphenyl)-4-oxo-4Hchromene- 3-carboxamide, compound 27 (IC 50 = 669 pM), acts as competitive reversible inhibitor. Therefore, the following corrections to the above article are as follows. Page 5879. In the abstract, line 9, "N-(3′-chlorophenyl)-4- oxo-4H-chromene-3-carboxamide (20)" should be "N-(3′- chlorophenyl)-4-oxo-4H-chromene-3-carboxamide (27)". Page 5884. In Figure 3 "mechanism of hMAO-B inhibition by chromones 20 (A) and 27 (B)" should be "mechanism of hMAO-B inhibition by chromones 27 (A) and 20 (B)". Page 5885. Line 4, "Concerning compound 20" should be "Concerning compound 27". Page 5885. Line 6, "different concentrations of 20" should be "different concentrations of 27". Page 5885. Line 8, "As for compound 27" should be "As for compound 20". Page 5885. Line 11, "for different concentrations of compound 27" should be "for different concentrations of compound 20". Page 5885. Line 19, should be "Chromones 27 (Figure 3A) and 20 (Figure 3B)" instead of "Chromones 20 (Figure 3A) and 27 (Figure 3B)". Page 5885. Lines 23-26, should be "27 (IC 50 = 0.67 nM) displayed IC 50 and Ki values within the picomolar range, and compound 20 (IC 50 = 0.40 nM), as a noncompetitive inhibitor, also showed a Ki extremely close to its IC 50 " instead of "20 (IC 50 = 0.40 nM) displayed IC 50 and Ki values slightly different but within the picomolar range, and compound 27 (IC 50 = 0.67 nM), as a noncompetitive inhibitor, showed a Ki equal to its IC 50 ." Page 5887. In the Conclusion, line 12, "competitive IMAOB" should be "noncompetitive IMAO-B". Page 5887. In the Conclusion, line 14, "a noncompetitive IMAO-B" should be "a competitive IMAO-B". © 2018 American Chemical Society.