Novel N-(Heterocyclylphenyl)benzensulfonamide Sharing an Unreported Binding Site with T-Cell Factor 4 at the ß-Catenin Armadillo Repeats Domain as an Anticancer Agent.

Despite intensive efforts, no inhibitors of the Wnt/ß-catenin signaling pathway have been approved so far for the clinical treatment of cancer. We synthesized novel N-(heterocyclylphenyl)benzenesulfonamides as ß-catenin inhibitors. Compounds 5-10 showed strong inhibition of the luciferase activity. Compounds 5 and 6 inhibited the MDA-MB-231, HCC1806, and HCC1937 TNBC cells. Compound 9 induced in vitro cell death in SW480 and HCT116 cells and in vivo tumorigenicity of a human colorectal cancer line HCT116. In a co-immunoprecipitation study in HCT116 cells transfected with Myc-tagged T-cell factor 4 (Tcf-4), compound 9 abrogated the association between ß-catenin and Tcf-4. The crystallographic analysis of the ß-catenin Armadillo repeats domain revealed that compound 9 and Tcf-4 share a common binding site within the hotspot binding region close to Lys508. To our knowledge, compound 9 is the first small molecule ligand of this region to be reported. These results highlight the potential of this novel class of ß-catenin inhibitors as anticancer agents.

Targeting the Grb2 cSH3 domain: Design, synthesis and biological evaluation of the first series of modulators.

Growth factor receptor bound protein 2 (Grb2) is an adaptor protein featured by a nSH3-SH2-cSH3 domains. Grb2 finely regulates important cellular pathways such as growth, proliferation and metabolism and a minor lapse of this tight control may totally change the entire pathway to the oncogenic. Indeed, Grb2 is found overexpressed in many tumours type. Consequently, Grb2 is an attractive therapeutic target for the development of new anticancer drug. Herein, we reported the synthesis and the biological evaluation of a series of Grb2 inhibitors, developed starting from a hit-compound already reported by this research unit. The newly synthesized compounds were evaluated by kinetic binding experiments, and the most promising derivatives were assayed in a short panel of cancer cells. Five of the newly synthesized derivatives proved to be able to bind the targeted protein with valuable inhibitory concentration in one-digit micromolar concentration. The most active compound of this series, derivative 12, showed an inhibitory concentration of about 6 µM for glioblastoma and ovarian cancer cells, and an IC50 of 1.67 for lung cancer cell. For derivative 12, the metabolic stability and the ROS production was also evaluated. The biological data together with the docking studies led to rationalize an early structure activity relationship.

Development of an inhalable antiviral powder formulation against respiratory syncytial virus.

Respiratory viruses including the respiratory syncytial virus (RSV) aggravate the global burden of virus-inflicted morbidity and mortality. Entry inhibitors are a promising class of antiviral drugs for combating these viruses, as they can prevent infection at the site of viral entry, i.e., the respiratory tract. Here we used a broad-spectrum entry inhibitor, composed of a ß-cyclodextrin backbone, functionalized with 11-mercapto-1-undecanesulfonate (CD-MUS) that is capable of neutralizing a variety of viruses that employ heparan sulfate proteoglycans (HSPG) to infect host cells. CD-MUS inactivates viral particles irreversibly by binding to viral attachment proteins through a multivalent binding mechanism. In the present study, we show that CD-MUS is well tolerated when administered to the respiratory tract of mice. Based on this, we developed an inhalable spray-dried powder formulation that fits the size requirements for lung deposition and disperses well upon use with the Cyclops dry powder inhaler (DPI). Using an in vitro dose-response assay, we show that the compound retained its activity against RSV after the spray drying process. Our study sets the stage for further in vivo studies, exploring the efficacy of pulmonary administered CD-MUS in animal models of RSV infection.

Mutual Effects of Single and Combined CFTR Modulators and Bacterial Infection in Cystic Fibrosis.

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators improve clinical outcomes with varied efficacies in patients with CF. However, the mutual effects of CFTR modulators and bacterial adaptation, together with antibiotic regimens, can influence clinical outcomes. We evaluated the effects of ivacaftor (IVA), lumacaftor (LUM), tezacaftor, elexacaftor, and a three-modulator combination of elexacaftor, tezacaftor, and ivacaftor (ETI), alone or combined with antibiotics, on sequential CF isolates. IVA and ETI showed direct antimicrobial activities against Staphylococcus aureus but not against Pseudomonas aeruginosa. Additive effects or synergies were observed between the CFTR modulators and antibiotics against both species, independently of adaptation to the CF lung. IVA and LUM were the most effective in potentiating antibiotic activity against S. aureus, while IVA and ETI enhanced mainly polymyxin activity against P. aeruginosa. Next, we evaluated the effect of P. aeruginosa pneumonia on the pharmacokinetics of IVA in mice. IVA and its metabolites in plasma, lung, and epithelial lining fluid were increased by P. aeruginosa infection. Thus, CFTR modulators can have direct antimicrobial properties and/or enhance antibiotic activity against initial and adapted S. aureus and P. aeruginosa isolates. Furthermore, bacterial infection impacts airway exposure to IVA, potentially affecting its efficacy. Our findings suggest optimizing host- and pathogen-directed therapies to improve efficacy for personalized treatment. IMPORTANCE CFTR modulators have been developed to correct and/or enhance CFTR activity in patients with specific cystic fibrosis (CF) genotypes. However, it is of great importance to identify potential off-targets of these novel therapies to understand how they affect lung physiology in CF. Since bacterial infections are one of the hallmarks of CF lung disease, the effects (if any) of CFTR modulators on bacteria could impact their efficacy. This work highlights a mutual interaction between CFTR modulators and opportunistic bacterial infections; in particular, it shows that (i) CFTR modulators have an antibacterial activity per se and influence antibiotic efficacy, and (ii) bacterial airway infections affect levels of CFTR modulators in the airways. These findings may help optimize host- and pathogen-directed drug regimens to improve the efficacy of personalized treatment.

RS6077 induces mitotic arrest and selectively activates cell death in human cancer cell lines and in a lymphoma tumor in vivo.

We synthesized a new inhibitor of tubulin polymerization, the pyrrole (1-(7H-pyrrolo[2,3- d]pyrimidin-4-yl)-1H-pyrrol-3-yl)(3,4,5-trimethoxy-phenyl)methanone 6 (RS6077). Compound 6 inhibited the growth of multiple cancer cell lines, with IC50 values in the nM range, without affecting the growth of non-transformed cells. The novel agent arrested cells in the G2/M phase of the cell cycle in both transformed and non-transformed cell lines, but single cell analysis by time-lapse video recording revealed a remarkable selectivity in cell death induction by compound 6: in RPE-1 non-transformed cells mitotic arrest induced was not necessarily followed by cell death; in contrast, in HeLa transformed and in lymphoid-derived transformed AHH1 cell lines, cell death was effectively induced during mitotic arrest in cells that fail to complete mitosis. Importantly, the agent also inhibited the growth of the lymphoma TMD8 xenograft model. Together these findings suggest that derivative 6 has a selective efficacy in transformed vs non-transformed cells and indicate that the same compound has potential as novel therapeutic agent to treat lymphomas. Compound 6 showed good metabolic stability upon incubation with human liver microsomes.

Induction of Ferroptosis in Glioblastoma and Ovarian Cancers by a New Pyrrole Tubulin Assembly Inhibitor.

We synthesized new aroyl diheterocyclic pyrrole (ARDHEP) 15 that exhibited the hallmarks of ferroptosis. Compound 15 strongly inhibited U-87 MG, OVCAR-3, and MCF-7 cancer cells, induced an increase of cleaved PARP, but was not toxic for normal human primary T lymphocytes at 0.1 µM. Analysis of the levels of lactoperoxidase, malondialdehyde, lactic acid, total glutathione, and ATP suggested that the in vivo inhibition of cancer cell proliferation by 15 went through stimulation of oxidative stress injury and Fe2+ accumulation. Quantitative polymerase chain reaction analysis of the mRNA expression in U-87 MG and SKOV-3 tumor tissues from 15-treated mice showed the presence of Ptgs2/Nfe2l2/Sat1/Akr1c1/Gpx4 genes correlated with ferroptosis in both groups. Immunofluorescence staining revealed significantly lower expressions of proteins Ki67, CD31, and ferroptosis negative regulation proteins glutathione peroxidase 4 (GPX4) and FTH1. Compound 15 was found to be metabolically stable when incubated with human liver microsomes.

Novel analgesic/anti-inflammatory agents: 1,5-Diarylpyrrole nitrooxyethyl sulfides and related compounds as Cyclooxygenase-2 inhibitors containing a nitric oxide donor moiety endowed with vasorelaxant properties.

The design of compounds able to combine the selective inhibition of cyclooxygenase-2 (COX-2) with the release of nitric oxide (NO) is a promising strategy to achieve potent anti-inflammatory agents endowed with an overall safer profile and reduced toxicity upon gastrointestinal and cardiovascular systems. With the aim of generating novel and selective COX-2 inhibiting NO-donors (CINOD) and encouraged by the promising results obtained with our nitrooxy- and hydroxyethyl ethers 11 and 12 reported in previous works, we shifted our attention on the synthesis of isosteric thioanalogs nitrooxy- and hydroxy ethyl sulfides 13a-c and 14a-c, respectively, along with their oxidation products nitrooxy- and hydroxyethyl sulfoxides 15a-c and 16a-c, respectively, also referred to as thio-CINOD. Preliminary data and metabolic analysis highlighted how the isosteric substitution of the ethereal oxygen atom of 11a-c with sulfur in compounds 13a-c, independently from the presence and the number of fluorine atoms in N1-phenyl ring, leads to new selective and highly potent COX-2 inhibitors, capable to induce vasorelaxant responses in vivo. The same behavior is observed with their oxidized counterparts nitrooxyethyl sulfoxides 15a-c, in which the oxidation state of the sulfur atom and the presence of the additional oxygen atom play a substantial role in enhancing compounds activity and vasorelaxation. In addition, the screened compounds proved significantly efficacious in mouse models of inflammation and nociception at the dose of 20 mg/kg.

Givinostat-Liposomes: Anti-Tumor Effect on 2D and 3D Glioblastoma Models and Pharmacokinetics.

Glioblastoma is the most common and aggressive brain tumor, associated with poor prognosis and survival, representing a challenging medical issue for neurooncologists. Dysregulation of histone-modifying enzymes (HDACs) is commonly identified in many tumors and has been linked to cancer proliferation, changes in metabolism, and drug resistance. These findings led to the development of HDAC inhibitors, which are limited by their narrow therapeutic index. In this work, we provide the proof of concept for a delivery system that can improve the in vivo half-life and increase the brain delivery of Givinostat, a pan-HDAC inhibitor. Here, 150-nm-sized liposomes composed of cholesterol and sphingomyelin with or without surface decoration with mApoE peptide, inhibited human glioblastoma cell growth in 2D and 3D models by inducing a time- and dose-dependent reduction in cell viability, reduction in the receptors involved in cholesterol metabolism (from -25% to -75% of protein levels), and reduction in HDAC activity (-25% within 30 min). In addition, liposome-Givinostat formulations showed a 2.5-fold increase in the drug half-life in the bloodstream and a 6-fold increase in the amount of drug entering the brain in healthy mice, without any signs of overt toxicity. These features make liposomes loaded with Givinostat valuable as potential candidates for glioblastoma therapy.

Neuroprotective effects of lignan 7-hydroxymatairesinol (HMR/lignan) in a rodent model of Parkinson's disease.

OBJECTIVES: Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of dopaminergic neurons in the Substantia Nigra pars compacta (SNc). The proinflammatory response can occur early in the disease, contributing to nigrostriatal degeneration. Identification of the new molecules, which are able to slow down the degenerative process associated with PD, represents one of the main interests. Recently, natural polyphenols, especially lignans, have raised attention for their anti-inflammatory, antioxidant, and estrogenic activity at a peripheral level. The aim of this study was to evaluate the central effects of chronic treatment with lignan 7-hydroxymatairesinol (HMR/lignan) on neurodegenerative, neuroinflammatory processes and motor deficits induced by a unilateral intrastriatal injection of 6-hydroxydopamine (6-OHDA) in rats to evaluate the potential neuroprotective properties of this compound. METHODS: Sprague-Dawley male rats underwent lignan (10 mg/kg) or vehicle treatment (oral) for 4 wk starting from the day of 6-OHDA injection. The degree of nigrostriatal damage was evaluated by immunohistochemistry. Moreover, we performed a quantitative and qualitative assessment of neuroinflammatory process, including phenotypic polarization of microglia and astrocytes. The motor performance was assessed by behavioral tests. RESULTS: We demonstrated that chronic treatment with HMR/lignan was able to slow down the progression of degeneration of striatal dopaminergic terminals in a rat model of PD, with a consequent improvement in motor performance. Nevertheless, the anti-inflammatory effect of HMR/lignan observed in SNc was not sufficient to protect dopaminergic cells bodies. CONCLUSION: These results suggest intriguing properties of HMR/lignan at neuroprotective and symptomatic levels in the context of PD.

Anti-tumor Efficacy Assessment of the Sigma Receptor Pan Modulator RC-106. A Promising Therapeutic Tool for Pancreatic Cancer.

Introduction: Pancreatic cancer (PC) is one of the most lethal tumor worldwide, with no prognosis improvement over the past 20-years. The silent progressive nature of this neoplasia hampers the early diagnosis, and the surgical resection of the tumor, thus chemotherapy remains the only available therapeutic option. Sigma receptors (SRs) are a class of receptors proposed as new cancer therapeutic targets due to their over-expression in tumor cells and their involvement in cancer biology. The main localization of these receptors strongly suggests their potential role in ER unfolded protein response (ER-UPR), a condition frequently occurring in several pathological settings, including cancer. Our group has recently identified RC-106, a novel pan-SR modulator with good in vitro antiproliferative activities toward a panel of different cancer cell lines. In the present study, we investigated the in vitro properties and pharmacological profile of RC-106 in PC cell lines with the aim to identify a potential lead candidate for the treatment of this tumor. Methods: Pancreatic cancer cell lines Panc-1, Capan-1, and Capan-2 have been used in all experiments. S1R and TMEM97/S2R expression in PC cell lines was quantified by Real-Time qRT-PCR and Western Blot experiments. MTS assay was used to assess the antiproliferative effect of RC-106. The apoptotic properties of RC-106 was evaluated by TUNEL and caspase activation assays. GRP78/BiP, ATF4, and CHOP was quantified to evaluate ER-UPR. Proteasome activity was investigated by a specific fluorescent-based assay. Scratch wound healing assay was used to asses RC-106 effect on cell migration. In addition, we delineated the in vivo pharmacokinetic profile and pancreas distribution of RC-106 in male CD-1 mice. Results: Panc-1, Capan-1, and Capan-2 express both SRs. RC-106 exerts an antiproliferative and pro-apoptotic effect in all examined cell lines. Cells exposure to RC-106 induces the increase of the expression of ER-UPR related proteins, and the inhibition of proteasome activity. Moreover, RC-106 is able to decrease PC cell lines motility. The in vivo results show that RC-106 is more concentrated in pancreas than plasma. Conclusion: Overall, our data evidenced that the pan-SR modulator RC-106 is an optimal candidate for in vivo studies in animal models of PC.

In Vivo and In Vitro Activities and ADME-Tox Profile of a Quinolizidine-Modified 4-Aminoquinoline: A Potent Anti-P. falciparum and Anti-P. vivax Blood-Stage Antimalarial.

Natural products are a prolific source for the identification of new biologically active compounds. In the present work, we studied the in vitro and in vivo antimalarial efficacy and ADME-Tox profile of a molecular hybrid (AM1) between 4-aminoquinoline and a quinolizidine moiety derived from lupinine (Lupinus luteus). The aim was to find a compound endowed with the target product profile-1 (TCP-1: molecules that clear asexual blood-stage parasitaemia), proposed by the Medicine for Malaria Venture to accomplish the goal of malaria elimination/eradication. AM1 displayed a very attractive profile in terms of both in vitro and in vivo activity. By using standard in vitro antimalarial assays, AM1 showed low nanomolar inhibitory activity against chloroquine-sensitive and resistant P. falciparum strains (range IC50 16-53 nM), matched with a high potency against P. vivax field isolates (Mean IC50 29 nM). Low toxicity and additivity with artemisinin derivatives were also demonstrated in vitro. High in vivo oral efficacy was observed in both P.berghei and P. yoelii mouse models with IC50 values comparable or better than those of chloroquine. The metabolic stability in different species and the pharmacokinetic profile in the mouse model makes AM1 a compound worth further investigation as a potential novel schizonticidal agent.

Toward the identification of neuroprotective agents: g-scale synthesis, pharmacokinetic evaluation and CNS distribution of (R)-RC-33, a promising SIGMA1 receptor agonist.

AIM: Nowadays, there is a great interest in the therapeutic potential of sigma1 receptor ligands for treating different CNS pathologies. Our previous investigations led to identify (R)-RC-33 as a potent and selective S1R agonist. RESULTS: Herein, we report the gram-scale synthesis, pharmacokinetic profile and CNS distribution of (R)-RC-33 in the mouse to determine the most suitable dosage schedule for in vivo administration. For comparative purposes, the same experiments were also performed with PRE-084, the most widely used S1R agonist commonly in pharmacological experiments. DISCUSSION: (R)-RC-33 shows a similar pharmacokinetic profile and a better CNS distribution when compared with PRE-084. CONCLUSION: (R)-RC-33 may be a promising candidate for in vivo studies in animal models of neurodegenerative diseases.

New Indole Tubulin Assembly Inhibitors Cause Stable Arrest of Mitotic Progression, Enhanced Stimulation of Natural Killer Cell Cytotoxic Activity, and Repression of Hedgehog-Dependent Cancer.

We designed 39 new 2-phenylindole derivatives as potential anticancer agents bearing the 3,4,5-trimethoxyphenyl moiety with a sulfur, ketone, or methylene bridging group at position 3 of the indole and with halogen or methoxy substituent(s) at positions 4-7. Compounds 33 and 44 strongly inhibited the growth of the P-glycoprotein-overexpressing multi-drug-resistant cell lines NCI/ADR-RES and Messa/Dx5. At 10 nM, 33 and 44 stimulated the cytotoxic activity of NK cells. At 20-50 nM, 33 and 44 arrested >80% of HeLa cells in the G2/M phase of the cell cycle, with stable arrest of mitotic progression. Cell cycle arrest was followed by cell death. Indoles 33, 44, and 81 showed strong inhibition of the SAG-induced Hedgehog signaling activation in NIH3T3 Shh-Light II cells with IC50 values of 19, 72, and 38 nM, respectively. Compounds of this class potently inhibited tubulin polymerization and cancer cell growth, including stimulation of natural killer cell cytotoxic activity and repression of Hedgehog-dependent cancer.

1,3,4-Oxadiazole-containing histone deacetylase inhibitors: anticancer activities in cancer cells.

We describe 1,3,4-oxadiazole-containing hydroxamates (2) and 2-aminoanilides (3) as histone deacetylase inhibitors. Among them, 2t, 2x, and 3i were the most potent and selective against HDAC1. In U937 leukemia cells, 2t was more potent than SAHA in inducing apoptosis, and 3i displayed cell differentiation with a potency similar to MS-275. In several acute myeloid leukemia (AML) cell lines, as well as in U937 cells in combination with doxorubicin, 3i showed higher antiproliferative effects than SAHA.

Chiral resolution and pharmacological characterization of the enantiomers of the Hsp90 inhibitor 2-amino-7-[4-fluoro-2-(3-pyridyl)phenyl]-4-methyl-7,8-dihydro-6H-quinazolin-5-one oxime.

Heat-shock protein 90 (Hsp90) is a molecular chaperone involved in the stabilization of key oncogenic signaling proteins, and therefore, inhibition of Hsp90 represents a new strategy in cancer therapy. 2-Amino-7-[4-fluoro-2-(3-pyridyl)phenyl]-4-methyl-7,8-dihydro-6H-quinazolin-5-one oxime is a racemic Hsp90 inhibitor that targets the N-terminal adenosine triphosphatase site. We developed a method to resolve the enantiomers and evaluated their inhibitory activity on Hsp90 and the consequent antitumor effects. The (S) stereoisomer emerged as a potent Hsp90 inhibitor in biochemical and cellular assays. In addition, this enantiomer exhibited high oral bioavailability in mice and excellent antitumor activity in two different human cancer xenograft models.

Synthesis and biological characterization of spiro[2H-(1,3)-benzoxazine-2,4'-piperidine] based histone deacetylase inhibitors.

Histone Deacetylases (HDACs) have become important targets for the treatment of cancer and other diseases. In previous studies we described the development of novel spirocyclic HDAC inhibitors based on the combination of privileged structures with hydroxamic acid moieties as zinc binding group. Herein, we report further explorations, which resulted in the discovery of a new class of spiro[2H-(1,3)-benzoxazine-2,4'-piperidine] derivatives. Several compounds showed good potency of around 100 nM and less in the HDAC inhibition assays, submicromolar IC50 values when tested against tumour cell lines and a remarkable stability in human and mouse microsomes. Two representative examples exhibited a good pharmacokinetic profile with an oral bioavailability equal or higher than 35% and one of them studied in an HCT116 murine xenograft model showing a robust tumour growth inhibition. In addition, the two benzoxazines were found to have a minor affinity for the hERG potassium channel compared to their corresponding ketone analogues.

Spiro[chromane-2,4'-piperidine]-based histone deacetylase inhibitors with improved in vivo activity.

A series of spiro[chromane-2,4'-piperidine] derivatives based on a previously published lead benzyl spirocycle 1 and bearing various N-aryl and N-alkylaryl substituents on the piperidine ring were prepared as novel histone deacetylase (HDAC) inhibitors. The compounds were evaluated for their abilities to inhibit nuclear HDACs, their in vitro antiproliferative activities, and in vitro ADME profiles. Based on these activities, 4-fluorobenzyl and 2-phenylethyl spirocycles were selected for further characterization. In vivo pharmacokinetic (PK) studies showed that both compounds exhibit an overall lower clearance rate, an increased half-life, and higher AUCs after intravenous and oral administration than spiropiperidine 1 under the conditions used. The improved PK behavior of these two compounds also correlated with superior in vivo antitumor activity in an HCT-116 xenograft model.

Discovery, synthesis, and pharmacological evaluation of spiropiperidine hydroxamic acid based derivatives as structurally novel histone deacetylase (HDAC) inhibitors.

New spiro[chromane-2,4'-piperidine] and spiro[benzofuran-2,4'-piperidine] hydroxamic acid derivatives as HDAC inhibitors have been identified by combining privileged structures with a hydroxamic acid moiety as zinc binding group. The compounds were evaluated for their ability to inhibit nuclear extract HDACs and for their in vitro antiproliferative activity on different tumor cell lines. This work resulted in the discovery of spirocycle 30d that shows good oral bioavailability and tumor growth inhibition in an HCT-116 murine xenograft model.