Unveiling Anticancer Potential of COX-2 and 5-LOX Inhibitors: Cytotoxicity, Radiosensitization Potential and Antimigratory Activity against Colorectal and Pancreatic Carcinoma.

Apart from cytotoxicity, inhibitors of the COX-2 enzyme have demonstrated additional effects important for cancer treatment (such as radiosensitization of tumor cells and cell antimigratory effects); however, the relationship between the inhibition of other inflammation-related enzyme 5-LOX inhibitors and anticancer activity is still not well understood. In our study, the cytotoxicity of thirteen COX-2 and 5-LOX inhibitors previously presented by our group (1-13) was tested on three cancer cell lines (HCT 116, HT-29 and BxPC-3) and one healthy cell line (MRC-5). Compounds 3, 5, 6 and 7 showed moderate cytotoxicity, but good selectivity towards cancer cell lines. IC50 values were in the range of 22.99-51.66 µM (HCT 116 cell line), 8.63-41.20 µM (BxPC-3 cell line) and 24.78-81.60 µM (HT-29 cell line; compound 7 > 100 µM). In comparison to tested, commercially available COX-2 and 5-LOX inhibitors, both cytotoxicity and selectivity were increased. The addition of compounds 6 and 7 to irradiation treatment showed the most significant decrease in cell proliferation of the HT-29 cell line (p < 0.001). The antimigratory potential of the best dual COX-2 and 5-LOX inhibitors (compounds 1, 2, 3 and 5) was tested by a wound-healing assay using the SW620 cell line. Compounds 1 and 3 were singled out as compounds with the most potent effect (relative wound closure was 3.20% (24 h), 5,08% (48 h) for compound 1 and 3.86% (24 h), 7.68% (48 h) for compound 3). Considering all these results, compound 3 stood out as the compound with the most optimal biological activity, with the best dual COX-2 and 5-LOX inhibitory activity, good selectivity towards tested cancer cell lines, significant cell antimigratory potential and a lack of toxic effects at therapeutic doses.

Dynamic and Assembly Characteristics of Deep-Cavity Basket Acting as a Host for Inclusion Complexation of Mitoxantrone in Biotic and Abiotic Systems.

We describe the preparation, dynamic, assembly characteristics of vase-shaped basket 13- along with its ability to form an inclusion complex with anticancer drug mitoxantrone in abiotic and biotic systems. This novel cavitand has a deep nonpolar pocket consisting of three naphthalimide sides fused to a bicyclic platform at the bottom while carrying polar glycines at the top. The results of 1 H Nuclear Magnetic Resonance (NMR), 1 H NMR Chemical Exchange Saturation Transfer (CEST), Calorimetry, Hybrid Replica Exchange Molecular Dynamics (REMD), and Microcrystal Electron Diffraction (MicroED) measurements are in line with 1 forming dimer [12 ]6- , to be in equilibrium with monomers 1(R) 3- (relaxed) and 1(S) 3- (squeezed). Through simultaneous line-shape analysis of 1 H NMR data, kinetic and thermodynamic parameters characterizing these equilibria were quantified. Basket 1(R) 3- includes anticancer drug mitoxantrone (MTO2+ ) in its pocket to give stable binary complex [MTO⊂1]- (Kd =2.1 µM) that can be precipitated in vitro with UV light or pH as stimuli. Both in vitro and in vivo studies showed that the basket is nontoxic, while at a higher proportion with respect to MTO it reduced its cytotoxicity in vitro. With well-characterized internal dynamics and dimerization, the ability to include mitoxantrone, and biocompatibility, the stage is set to develop sequestering agents from deep-cavity baskets.

Synthesis, characterization, and in vivo evaluation of the anticancer activity of a series of 5- and 6-(halomethyl)-2,2'-bipyridine rhenium tricarbonyl complexes.

We report the synthesis, characterization, and in vivo evaluation of the anticancer activity of a series of 5- and 6-(halomethyl)-2,2'-bipyridine rhenium tricarbonyl complexes. The study was promoted in order to understand if the presence and position of a reactive halomethyl substituent on the diimine ligand system of fac-[Re(CO)3]+ species may be a key molecular feature for the design of active and non-toxic anticancer agents. Only compounds potentially able to undergo ligand-based alkylating reactions show significant antiproliferative activity against colorectal and pancreatic cell lines. Of the new species presented in this study, one compound (5-(chloromethyl)-2,2'-bipyridine derivative) shows significant inhibition of pancreatic tumour growth in vivo in zebrafish-Panc-1 xenografts. The complex is noticeably effective at 8 µM concentration, lower than its in vitro IC50 values, being also capable of inhibiting in vivo cancer cells dissemination.

Discovery of 1-Benzhydryl-Piperazine-Based HDAC Inhibitors with Anti-Breast Cancer Activity: Synthesis, Molecular Modeling, In Vitro and In Vivo Biological Evaluation.

Isoform-selective histone deacetylase (HDAC) inhibition is promoted as a rational strategy to develop safer anti-cancer drugs compared to non-selective HDAC inhibitors. Despite this presumed benefit, considerably more non-selective HDAC inhibitors have undergone clinical trials. In this report, we detail the design and discovery of potent HDAC inhibitors, with 1-benzhydryl piperazine as a surface recognition group, that differ in hydrocarbon linker. In vitro HDAC screening identified two selective HDAC6 inhibitors with nanomolar IC50 values, as well as two non-selective nanomolar HDAC inhibitors. Structure-based molecular modeling was employed to study the influence of linker chemistry of synthesized inhibitors on HDAC6 potency. The breast cancer cell lines (MDA-MB-231 and MCF-7) were used to evaluate compound-mediated in vitro anti-cancer, anti-migratory, and anti-invasive activities. Experiments on the zebrafish MDA-MB-231 xenograft model revealed that a novel non-selective HDAC inhibitor with a seven-carbon-atom linker exhibits potent anti-tumor, anti-metastatic, and anti-angiogenic effects when tested at low micromolar concentrations.

Biocompatibility and antibiofilm activity of graphene-oxide functionalized titanium discs and collagen membranes.

The aims of the study were: 1) to evaluate the effect on biofilm formation of barrier membranes and titanium surfaces coated with graphene-oxide (GO); 2) to analyze the connection between the superficial topography of the tested materials and the amount of bacterial accumulation on them and 3) to analyze the biocompatibility of GO functionalized discs using the zebrafish model. METHODS: Single species bacterial biofilms (Streptococcus oralis, Veilonella parvula, Fusobacterium nucleatum, Porphyomonas gingivalis) were grown on GO-free membranes, membranes coated with 2 and 10 µg/ml of GO, GO-free and GO-coated titanium discs. The biofilms were analyzed by determining the CFU count and by Scanning Electron Microscopy (SEM) and the materials' topography by Atomic Force Microscopy (AFM). Zebrafish model was used to determine the materials' toxicity and inflammatory effects. RESULTS: AFM showed similar roughness of control and GO-coated materials. CFU counts on GO-coated discs were significantly lower than on control discs for all species. CFU counts of S. oralis, V. parvula and P. gingivalis were lower on biofilms grown on both types of GO-coated membranes than on GO-free membrane. SEM analysis showed different formation of single species biofilm of S. oralis on control and GO-coated materials. GO-functionalized titanium discs do not induce toxic or inflammatory effects. SIGNIFICANCE: Titanium implant surfaces functionalized with GO have shown to be biocompatible and less susceptible to biofilm formation. These results encourage further in vivo investigation of the tested materials on infection prevention, specifically in prevention and reduction of peri-implant mucositis and periimplantitis incidence.

Coumarin-Palladium(II) Complex Acts as a Potent and Non-Toxic Anticancer Agent against Pancreatic Carcinoma Cells.

Pancreatic carcinoma still represents one of the most lethal malignant diseases in the world although some progress has been made in treating the disease in the past decades. Current multi-agent treatment options have improved the overall survival of patients, however, more effective treatment strategies are still needed. In this paper we have characterized the anticancer potential of coumarin-palladium(II) complex against pancreatic carcinoma cells. Cells viability, colony formation and migratory potential of pancreatic carcinoma cells were assessed in vitro, followed by evaluation of apoptosis induction and in vivo testing on zebrafish. Presented results showed remarkable reduction in pancreatic carcinoma cells growth both in vitro and in vivo, being effective at micromolar concentrations (0.5 µM). Treatments induced apoptosis, increased BAX/BCL-2 ratio and suppressed the expression of SOX9 and SOX18, genes shown to be significantly up-regulated in pancreatic ductal adenocarcinoma. Importantly, treatments of the zebrafish-pancreatic adenocarcinoma xenografts resulted in significant reduction in tumor mass, without provoking any adverse toxic effects including hepatotoxicity. Presented results indicate the great potential of the tested compound and the perspective of its further development towards pancreatic cancer therapy.

Design, synthesis, and biological evaluation of thiazole bioisosteres of goniofufurone through in vitro antiproliferative activity and in vivo toxicity.

The synthesis of several new goniofufurone bioisosteres was achieved in which the phenyl residue was replaced by a thiazole ring. The key steps of the synthesis included the initial condensation of cyanohydrin benzoates with cysteine ethyl ester hydrochloride, followed by the subsequent reaction of resulting C-4' epimeric thiazolines with DBU, to introduce 5-deoxy functionality and to elaborate the thiazole ring in one step. Synthesized compounds showed potent growth inhibitory effects against selected human tumour cell lines, especially bioisostere 4, which in the culture of MCF-7 cells displayed the highest activity (IC50 = 0.19 nM) of all compounds under evaluation. This molecule exhibited 64474-fold higher antiproliferative activity than lead 2 and was1053-fold more active than the commercial antitumour agent doxorubicin in the culture of MCF-7 cells. The structural features of the tested compounds responsible for their antiproliferative activity have been identified by preliminary SAR analysis. The toxicity of the most active compound 4 was assessed by an in vivo experiment in a zebrafish model (Danio rerio), whereupon it was found non-toxic at any of the tested concentrations up to 125 µM.

Identification of novel potent and non-toxic anticancer, anti-angiogenic and antimetastatic rhenium complexes against colorectal carcinoma.

Combination therapy targeting both tumor growth and vascularization is considered to be a cornerstone for colorectal carcinomas (CRC) treatment. However, the major obstacles of most clinical anticancer drugs are their weak selective activity towards cancer cells and inherent inner organs toxicity, accompanied with fast drug resistance development. In our effort to discover novel selective and non-toxic agents effective against CRC, we designed, synthesized and characterized a series of rhenium(I) tricarbonyl-based complexes with increased lipophilicity. Two of these novel compounds were discovered to possess remarkable anticancer, anti-angiogenic and antimetastatic activity in vivo (zebrafish-human HCT-116 xenograft model), being effective at very low doses (1-3 µM). At doses as high as 250 µM the complexes did not provoke toxicity issues encountered in clinical anticancer drugs (cardio-, hepato-, and myelotoxicity). In vivo assays showed that the two compounds exceed the anti-tumor and anti-angiogenic activity of clinical drugs cisplatin and sunitinib malate, and display a large therapeutic window.

New minor groove covering DNA binding mode of dinuclear Pt(II) complexes with various pyridine-linked bridging ligands and dual anticancer-antiangiogenic activities.

New anticancer platinum(II) compounds simultaneously targeting tumor cells and tumor-derived neoangiogenesis, with new DNA interacting mode and large therapeutic window are appealing alternative to improve efficacy of clinical platinum chemotherapeutics. Herein, we describe three novel dinuclear [{Pt(en)Cl}2(µ-L)]2+ complexes with different pyridine-like bridging ligands (L), 4,4'-bipyridine (Pt1), 1,2-bis(4-pyridyl)ethane (Pt2) and 1,2-bis(4-pyridyl)ethene (Pt3), which highly, positively charged aqua derivatives, [{Pt(en)(H2O)}2(µ-L)]4+, interact with the phosphate backbone forming DNA-Pt adducts with an unique and previously undescribed binding mode, called a minor groove covering. The results of this study suggested that the new binding mode of the aqua-Pt(II) complexes with DNA could be attributed to the higher anticancer activities of their chloride analogues. All three compounds, particularly complex [{Pt(en)Cl}2(µ-4,4'-bipy)]Cl2·2H2O (4,4'-bipy is 4,4'-bipyridine) (Pt1), overcame cisplatin resistance in vivo in the zebrafish-mouse melanoma xenograft model, showed much higher therapeutic potential than antiangiogenic drug sunitinib malate, while effectively blocking tumor neovascularization and melanoma cell metastasis. Overall therapeutic profile showed new dinuclear Pt(II) complexes could be novel, effective and safe anticancer agents. Finally, the correlation with the structural characteristics of these complexes can serve as a useful tool for developing new and more effective anticancer drugs.

Lectin from Laetiporus sulphureus effectively inhibits angiogenesis and tumor development in the zebrafish xenograft models of colorectal carcinoma and melanoma.

In spite of extensive usage of Laetiporus sulphureus (sulphur polypore) in traditional European and Asian ethno-medicine for centuries, its anticancer therapeutic potential and toxicity profile remained explored in animal models. Herein, using zebrafish (Danio rerio), as a preclinical animal model, we demonstrated that L. sulphureus lectin (LSL) and ethanol extract (LSE) are non-toxic at high doses up to 400-500 µg/mL, while they effectively inhibited angiogenesis and cancer development at much lower doses. Lectin showed 74-fold higher anti-angiogenic potency than the extract, and even 378-fold higher therapeutic potential than sunitinib-malate, cardiotoxic and myelosupressive anti-angiogenic drug of clinical relevance. Using wound healing and MTT assays, we proved LSL's strong antimigratory effect and selective endothelial cytotoxicity in relation to lung fibroblasts. In addition, employing the zebrafish xenograft models, we demonstrated that LSL almost completely reduced growth, neovascularization and metastasis of human colorectal carcinoma and mouse melanoma. Even more, LSL exerted 8-fold higher potency towards colorectal carcinoma than melanoma, showing markedly higher activity than cisplatin, while LSE failed to express any anticancer activity. Accompanied with non-toxic response, including neutropenia and inflammation, the results of this study strongly imply that LSL could be used as safe adjuvant in chemotherapy against colorectal carcinoma and melanoma.

Streptomyces sp. BV410 isolate from chamomile rhizosphere soil efficiently produces staurosporine with antifungal and antiangiogenic properties.

Applying a bioactivity-guided isolation approach, staurosporine was separated and identified as the active principle in the culture extract of the new isolate Streptomyces sp. BV410 collected from the chamomile rhizosphere. The biotechnological production of staurosporine by strain BV410 was optimized to yield 56 mg/L after 14 days of incubation in soy flour-glucose-starch-mannitol-based fermentation medium (JS). The addition of FeSO4 significantly improved the staurosporine yield by 30%, while the addition of ZnSO4 significantly reduced staurosporine yield by 62% in comparison with the starting conditions. Although staurosporine was first isolated in 1977 from Lentzea albida (now Streptomyces staurosporeus) and its potent kinase inhibitory effect has been established, here, the biological activity of this natural product was assessed in depth in vivo using a selection of transgenic zebrafish (Danio rerio) models, including Tg(fli1:EGFP) with green fluorescent protein-labeled endothelial cells allowing visualization and monitoring of blood vessels. This confirmed a remarkable antiangiogenic activity of the compound at doses of 1 ng/ml (2.14 nmol/L) which is below doses inducing toxic effects (45 ng/ml; 75 nmol/L). A new, efficient producing strain of commercially significant staurosporine has been described along with optimized fermentation conditions, which may lead to optimization of the staurosporine scaffold and its wider applicability.

Mononuclear gold(III) complexes with phenanthroline ligands as efficient inhibitors of angiogenesis: A comparative study with auranofin and sunitinib.

Gold(III) complexes with 1,7- and 4,7-phenanthroline ligands, [AuCl3(1,7-phen-κN7)] (1) and [AuCl3(4,7-phen-κN4)] (2) were synthesized and structurally characterized by spectroscopic (NMR, IR and UV-vis) and single-crystal X-ray diffraction techniques. In these complexes, 1,7- and 4,7-phenanthrolines are monodentatedly coordinated to the Au(III) ion through the N7 and N4 nitrogen atoms, respectively. In comparison to the clinically relevant anti-angiogenic compounds auranofin and sunitinib, gold(III)-phenanthroline complexes showed from 1.5- to 20-fold higher anti-angiogenic potential, and 13- and 118-fold lower toxicity. Among the tested compounds, complex 1 was the most potent and may be an excellent anti-angiogenic drug candidate, since it showed strong anti-angiogenic activity in zebrafish embryos achieving IC50 value (concentration resulting in an anti-angiogenic phenotype at 50% of embryos) of 2.89µM, while had low toxicity with LC50 value (the concentration inducing the lethal effect of 50% embryos) of 128µM. Molecular docking study revealed that both complexes and ligands could suppress angiogenesis targeting the multiple major regulators of angiogenesis, such as the vascular endothelial growth factor receptor (VEGFR-2), the matrix metalloproteases (MMP-2 and MMP-9), and thioredoxin reductase (TrxR1), where the complexes showed higher binding affinity in comparison to ligands, and particularly to auranofin, but comparable to sunitinib, an anti-angiogenic drug of clinical relevance.

Redox behavior and biological properties of ferrocene bearing porphyrins.

In order to improve antimicrobial effects of previously studied meso-tetrakis(4-ferrocenylphenyl)porphyrin 1, we have modified its structure by replacing two trans-positioned ferrocenylphenyl moieties with methoxy methylene substituted tert-butylphenyl moieties. Newly synthesized 54,154-bis-(ferrocenyl)-104,204-bis-(tert-butyl)-102,106,202,206-tetrakis-(methoxy-methylene)-5,10,15,20-tetraphenylporphyrin 4 was chemically characterized in detail (by NMR, UV/Vis, IR, MALDI-TOF and ESI MS spectrometry, cyclic voltammetry, prediction of the relative lipophilicity as well as computational methods) and its biological effects were studied in terms of its antibacterial and antifungal activity (both with and without photoactivation), cytotoxicity, hemolysis and DNA cleavage. New ferrocene bearing porphyrin 4 has demonstrated a broader antimicrobial spectrum and modified effects on eukaryotic cells compared to 1. This was discussed in terms of its i) increased lipophilicity, while exhibiting lower toxicity, and ii) the redox potential of a two-electron process that is shifted to lower values, in comparison to ferrocene, thus, entering the physiologically available range and being activated towards redox interactions with biomolecules.

Mononuclear gold(iii) complexes with l-histidine-containing dipeptides: tuning the structural and biological properties by variation of the N-terminal amino acid and counter anion.

Gold(iii) complexes with different l-histidine-containing dipeptides, [Au(Gly-l-His-NA,NP,N3)Cl]Cl·3H2O (1a), [Au(Gly-l-His-NA,NP,N3)Cl]NO3·1.25H2O (1b), [Au(l-Ala-l-His-NA,NP,N3)Cl][AuCl4]·H2O (2a), [Au(l-Ala-l-His-NA,NP,N3)Cl]NO3·2.5H2O (2b), [Au(l-Val-l-His-NA,NP,N3)Cl]Cl·2H2O (3), [Au(l-Leu-l-His-NA,NP,N3)Cl]Cl (4a) and [Au(l-Leu-l-His-NA,NP,N3)Cl][AuCl4]·H2O (4b), have been synthesized and structurally characterized by spectroscopic (1H NMR, IR and UV-vis) and single-crystal X-ray diffraction techniques. The antimicrobial efficiency of these gold(iii) complexes, along with K[AuCl4] and the corresponding dipeptides, was evaluated against the broad panel of Gram-positive and Gram-negative bacteria and fungi, displaying their moderate inhibiting activity. Moreover, the cytotoxic properties of the investigated complexes were assessed against the normal human lung fibroblast cell line (MRC5) and two human cancer, cervix (HeLa) and lung (A549) cell lines. None of the complexes exerted significant cytotoxic activity; nevertheless complexes that did show selectivity in terms of cancer vs. normal cell lines (2a/b and 4a/b) have been evaluated using zebrafish (Danio rerio) embryos for toxicity and antiangiogenic potential. Although the gold(iii) complexes achieved an antiangiogenic effect comparable to the known angiogenic inhibitors auranofin and sunitinib malate at 30-fold higher concentrations, they had no cardiovascular side effects, which commonly accompany auranofin and sunitinib malate treatment. Finally, binding of the gold(iii) complexes to the active sites of both human and bacterial (Escherichia coli) thioredoxin reductases (TrxRs) was demonstrated by conducting a molecular docking study, suggesting that the mechanism of biological action of these complexes can be associated with their interaction with the TrxR active site.

Selected 4-phenyl hydroxycoumarins: in vitro cytotoxicity, teratogenic effect on zebrafish (Danio rerio) embryos and molecular docking study.

A study of structure cytotoxic-activity relationship of three hydroxy 4-phenyl-coumarins and basic coumarin molecule against two human cell lines (MRC5 fibroblasts and A375 melanoma cells) is presented. Of all investigated compounds the highest cytotoxic activity in both cell lines was determined for 7,8-dihydroxy-4-phenyl coumarin. SAR studies revealed the influence of phenyl group and hydroxyl group's number and position on cytotoxic activity. In addition, to get an insight about their binding preferences at the active site of the receptor (catalytic subunit of cAMP-dependent protein kinase) molecular docking studies were performed. Docking studies suggest that 4-phenyl hydroxycoumarins are potent cAMP-dependent protein kinase inhibitors, better than their analogs without phenyl group. The teratogenic potential was assessed in zebrafish embryo toxicity test and results showed that 4-phenyl dihydroxycoumarins were more while 7-hydroxy-4-phenyl coumarin was less embryo toxic in comparison to coumarin. In order to examine selected 4-phenyl hydroxycoumarins as a new lead compounds the druglikeness of selected 4-phenyl hydroxycoumarins was estimated by using Lipinski's "rule of five". All selected 4-phenyl hydroxycoumarins proved to have satisfying pharmacokinetic profile.

Synthesis and evaluation of series of diazine-bridged dinuclear platinum(II) complexes through in vitro toxicity and molecular modeling: correlation between structure and activity of Pt(II) complexes.

Polynuclear Pt(II) complexes are a novel class of promising anticancer agents with potential clinical significance. A series of pyrazine (pz) bridged dinuclear Pt(II) complexes with general formulas {[Pt(L)Cl]2(µ-pz)}(2+) (L, ethylenediamine, en; (±)-1,2-propylenediamine, 1,2-pn; isobutylenediamine, ibn; trans-(±)-1,2-diaminocyclohexane, dach; 1,3-propylenediamine, 1,3-pd; 2,2-dimethyl-1,3-propylenediamine, 2,2-diMe-1,3-pd) and one pyridazine (pydz) bridged {[Pt(en)Cl]2(µ-pydz)}(2+) complex were prepared. The anticancer potential of these complexes were determined through in vitro cytotoxicity assay in human fibroblasts (MRC5) and two carcinoma cell lines (A375 and HCT116), interaction with double stranded DNA through in vitro assay, and molecular docking study. All complexes inhibited cell proliferation with inhibitory concentrations in the 0.5-120 µM range. While {[Pt(1,3-pd)Cl]2(µ-pz)}(2+) showed improved activity and {[Pt(en)Cl]2(µ-pydz)}(2+) showed comparable activity to that of clinically relevant cisplatin, {[Pt(en)Cl]2(µ-pydz)}(2+) was less toxic in an assay with zebrafish (Danio rerio) embryos, causing no adverse developmental effects. The in vitro cytotoxicity of all diazine-bridged dinuclear Pt(II) complexes is discussed in correlation to their structural characteristics.