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Novel variously substituted thiohydantoin-based dispiro -indolinones were prepared using a regio- and diastereoselective synthetic route from 5-arylidene-2-thiohydantoins, isatines, and sarcosine. The obtained molecules were subsequently evaluated in vitro against the cancer cell lines LNCaP, PC3, HCT wt , and HCT (-/-) . Several compounds demonstrated a relatively high cytotoxic activity vs. LNCaP cells (IC 50 = 1.2-3.5 µM) and a reasonable selectivity index (SI = 3-10). Confocal microscopy revealed that the conjugate of propargyl-substituted dispiro -indolinone with the fluorescent dye Sulfo-Cy5-azide was mainly localized in the cytoplasm of HEK293 cells. P388-inoculated mice and HCT116-xenograft BALB/c nude mice were used to evaluate the anticancer activity of compound 29 in vivo. Particularly, the TGRI value for the P388 model was 93% at the final control timepoint. No mortality was registered among the population up to day 31 of the study. In the HCT116 xenograft model, the compound (170 mg/kg, i.p., o.d., 10 days) provided a T/C ratio close to 60% on day 8 after the treatment was completed. The therapeutic index-estimated as LD 50 /ED 50 -for compound 29 in mice was ≥2.5. Molecular docking studies were carried out to predict the possible binding modes of the examined molecules towards MDM2 as the feasible biological target. However, such a mechanism was not confirmed by Western blot data and, apparently, the synthesized compounds have a different mechanism of cytotoxic action.

We report herein a Pt(IV) prodrug with metronidazole in axial positions Pt - Mnz . The nitroaromatic axial ligand was conjugated with a cisplatin scaffold to irreversibly reduce under hypoxic conditions, thereby retaining the Pt(IV) prodrug in the area of hypoxia. X-ray near-edge adsorption spectroscopy (XANES) on dried drug-preincubated tumor cell samples revealed a gradual release of cisplatin from the Pt-Mnz prodrug instead of rapid intracellular degradation. The ability of the prodrug to penetrate into three-dimensional (3D) spheroid cellular cultures was evaluated by a novel electrochemical assay via a platinum-coated carbon nanoelectrode, capable of single-cell measurements. Using a unique technique of electrochemical measurements in single tumor spheroids, we were able to both detect the real-time response of the axial ligand to hypoxia and establish the depth of penetration of the drug into the tumor model.

Prostate cancer is one of the most commonly diagnosed men's cancers and remains one of the leading causes of cancer death. The development of approaches to the treatment of this oncological disease is an ongoing process. In this work, we have carried out the selection of ligands for the creation of conjugates based on the drug docetaxel and synthesized a series of three docetaxel conjugates. In vitro cytotoxicity of these molecules was evaluated using the MTT assay. Based on the assay results, we selected the conjugate which showed cytotoxic potential close to unmodified docetaxel. At the same time, the molar solubility of the resulting compound increased up to 20 times in comparison with the drug itself. In vivo evaluation on 22Rv1 (PSMA+) xenograft model demonstrated a good potency of the synthesized conjugate to inhibit tumor growth: the inhibition turned out to be more than 80% at a dose of 30 mg/kg. Pharmacokinetic parameters of conjugate distribution were analyzed. Also, it was found that PSMA-targeted docetaxel conjugate is less toxic than docetaxel itself, the decrease of molar acute toxicity in comparison with free docetaxel was up to 20%. Obtained conjugate PSMA-DOC is a good candidate for further expanded preclinical trials because of high antitumor activity, fewer side toxic effects and better solubility., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Prostate-specific membrane antigen (PSMA), also known as glutamate carboxypeptidase II (GCPII), is a suitable target for specific delivery of antitumor drugs and diagnostic agents due to its overexpression in prostate cancer cells. In the current work, we describe the design, synthesis, and biological evaluation of novel low-molecular PSMA ligands and conjugates with fluorescent dyes FAM-5, SulfoCy5, and SulfoCy7. In vitro evaluation of synthesized PSMA ligands on the activity of PSMA shows that the addition of aromatic amino acids into a linker structure leads to a significant increase in inhibition. The conjugates of the most potent ligand with FAM-5 as well as SulfoCy5 demonstrated high affinities to PSMA-expressing tumor cells in vitro . In vivo biodistribution in 22Rv1 xenografts in Balb/c nude mice of PSMA-SulfoCy5 and PSMA-SulfoCy7 conjugates with a novel PSMA ligand demonstrated good visualization of PSMA-expressing tumors. Also, the conjugate PSMA-SulfoCy7 demonstrated the absence of any explicit toxicity up to 87.9 mg/kg.

Herein, we describe the design, synthesis, and biological evaluation of novel betulin and N -acetyl-d-galactosamine (GalNAc) glycoconjugates and suggest them as targeted agents against hepatocellular carcinoma. We prepared six conjugates derived via the C-3 and C-28 positions of betulin with one or two saccharide ligands. These molecules demonstrate high affinity to the asialoglycoprotein receptor (ASGPR) of hepatocytes assessed by in silico modeling and surface plasmon resonance tests. Cytotoxicity studies in vitro revealed a bivalent conjugate with moderate activity, selectivity of action, and cytostatic properties against hepatocellular carcinoma cells HepG2. An additional investigation confirmed the specific engagement with HepG2 cells by the enhanced generation of reactive oxygen species. Stability tests demonstrated its lability to acidic media and to intracellular enzymes. Therefore, the selected bivalent conjugate represents a new potential agent targeted against hepatocellular carcinoma. Further extensive studies of the cellular uptake in vitro and the real-time microdistribution in the murine liver in vivo for fluorescent dye-labeled analogue showed its selective internalization into hepatocytes due to the presence of GalNAc ligand in comparison with reference compounds. The betulin and GalNAc glycoconjugates can therefore be considered as a new strategy for developing therapeutic agents based on natural triterpenoids.

Delocalized lipophilic cations (DLCs) are known as mitochondria-addressed molecules. Mitochondria targeting may provide opportunities for tumor detection. DLCs may have antioxidant or anticancer properties. In this study, we focused on the toxicity and localization of 2-[(E)-2-(5-fluoro-2-methyl-1H-indol-3-yl)ethenyl]-1,6-dimethylpyridin-1-ium iodide (62E2), which has recently been found as a novel cytotoxic fluorescent compound. The excitation maximum of 62E2 is 452 ± 10 nm and its emission maximum is 579 ± 10 nm. It is accumulated in the cells and stains mitochondria in nanomolar concentrations. 62E2 is cytotoxic and mitotoxic in low micromolar concentrations, and it demonstrates some selectivity of cytotoxicity against A549 cancer cells. The closest analog of 62E2 is F16, which is the fluorescent mitotoxic agent that has been described earlier as a potential anticancer agent. We hope that 62E2 described here is useful in expanding the diversity of cyanine fluorescent mitochondrial dyes and the analysis of their structure-activity relationships., (© 2020 Deutsche Pharmazeutische Gesellschaft.)

Three new and complementary approaches to S-arylation of 2-thiohydantoins have been developed: copper-catalyzed cross coupling with either arylboronic acids or aryl iodides under mild conditions, or direct nucleophilic substitution in activated aryl halides. For 38 diverse compounds, reaction yields for all three methods have been determined. Selected by molecular docking, they have been tested on androgen receptor activation, and p53-Mdm2 regulation, and A549, MCF7, VA13, HEK293T, PC3, LnCAP cell lines for cytotoxicity, Two of them turned out to be promising as androgen receptor activators (likely by allosteric regulation), and another one is shown to activate the p53 cascade. It is hoped that 2-thiohydantoin S-arylidenes are worth further studies as biologically active compounds., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The modification of Chan-Lam-Evans cross-coupling reaction for the selective Se-arylation of 2-selenohydantoins under base-free mild conditions via aryl boronic acids is described herein. This approach was used to synthesize novel 5-arylidene-3-substituted-2-(arylselanyl)-imidazoline-4-ones with high yields. The anticancer activity of the final compounds was evaluated in vitro against different cancer cells, and thus, the possibility of 5-arylidene-3-substituted-2-(arylselanyl)-imidazoline-4-ones successful application as cytotoxic agents was demonstrated.

Prostate-specific membrane antigen (PSMA), also known as glutamate carboxypeptidase II (GCPII), has recently emerged as a prominent biomarker of prostate cancer (PC) and as an attractive protein trap for drug targeting. At the present time, several drugs and molecular diagnostic tools conjugated with selective PSMA ligands are actively evaluated in different preclinical and clinical trials. In the current work, we discuss design, synthesis and a preliminary biological evaluation of PSMA-specific small-molecule carrier equipped by Doxorubicin (Dox). We have introduced an unstable azo-linker between Dox and the carrier hence the designed compound does release the active substance inside cancer cells thereby providing a relatively high Dox concentration in nuclei and a relevant cytotoxic effect. In contrast, we have also synthesized a similar conjugate with a stable amide linker and it did not release the drug at all. This compound was predominantly accumulated in cytoplasm and did not cause cell death. Preliminary in vivo evaluation has showed good efficiency for the degradable conjugate against PC3-PIP(PSMA + )-containing xenograft mine. Thus, we have demonstrated that the conjugate can be used as a template to design novel analogues with improved targeting, anticancer activity and lower rate of potential side effects. 3D molecular docking study has also been performed to elucidate the underlying mechanism of binding and to further optimization of the linker area for improving the target affinity., (Copyright © 2019. Published by Elsevier Ltd.)

Regioselective synthesis, biological evaluation and 3D-molecular modeling for a series of novel diastereomeric 2-thioxo-5H-dispiro[imidazolidine-4,3-pyrrolidine-2,3-indole]-2,5(1H)-diones are described. The studied compounds have been tentatively identified as potent small molecule MDM2/p53 PPI inhibitors and can therefore be reasonably regarded as promising anticancer therapeutics., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We have synthesized and characterized a panel of new binuclear mixed valence Cu(I,II) complexes containing substituted 2-alkylthio-5-arylmethylene-4H-imidazolin-4-ones with unusual structure. These complexes are shown to be cytotoxic for various cell lines. We have found that these compounds did not intercalate DNA, inhibited number of polymerases (telomerase predominantly), accumulated in the cell nucleus, and caused DNA degradation. Preliminary studies revealed that lead compound inhibited human breast adenocarcinoma growth in mice model.

Azacarbazoles have attracted significant interest due to their valuable properties, such as anti-pathogenic and antitumor activity. In this study, a series of structurally related tricyclic benzo[4,5]- and tertacyclic naphtho[2′,1′:4,5]imidazo[1,2-c]pyrimidinone derivatives with one or two positively charged tethers were synthesized and evaluated for anti-proliferative activity. Lead tetracyclic derivative 5b with two amino-bearing arms inhibited the metabolic activity of A549 lung adenocarcinoma cells with a CC50 value of 3.6 μM, with remarkable selectivity (SI = 17.3) over VA13 immortalized fibroblasts. Cell-cycle assays revealed that 5b triggers G2/M arrest without signs of apoptosis. A study of its interaction with various DNA G4s and duplexes followed by dual luciferase and intercalator displacement assays suggests that intercalation, rather than the modulation of G4-regulated oncogene expression, might contribute to the observed activity. Finally, a water-soluble salt of 5b was shown to cause no acute toxic effects, changes in mice behavior, or any decrease in body weight after a 72 h treatment at concentrations up to 20 mg/kg. Thus, 5b is a promising candidate for studies in vivo; however, further investigations are needed to elucidate its molecular target(s). [ABSTRACT FROM AUTHOR]

Purpose: High- and medium-throughput assays are now routine methods for drug screening and toxicology investigations on mammalian cells. However, a simple and cost-effective analysis of cytotoxicity that can be carried out with commonly used laboratory equipment is still required.Procedures: The developed cytotoxicity assays are based on human cell lines stably expressing eGFP, tdTomato, mCherry, or Katushka2S fluorescent proteins. Red fluorescent proteins exhibit a higher signal-to-noise ratio, due to less interference by medium autofluorescence, in comparison to green fluorescent protein. Measurements have been performed on a fluorescence scanner, a plate fluorimeter, and a camera photodocumentation system.Results: For a 96-well plate assay, the sensitivity per well and the measurement duration were 250 cells and 15 min for the scanner, 500 cells and 2 min for the plate fluorimeter, and 1000 cells and less than 1 min for the camera detection. These sensitivities are similar to commonly used MTT (tetrazolium dye) assays. The used scanner and the camera had not been previously applied for cytotoxicity evaluation. An image processing scheme for the high-resolution scanner is proposed that significantly diminishes the number of control wells, even for a library containing fluorescent substances. The suggested cytotoxicity assay has been verified by measurements of the cytotoxicity of several well-known cytotoxic drugs and further applied to test a set of novel bacteriotoxic compounds in a medium-throughput format.Conclusion: The fluorescent signal of living cells is detected without disturbing them and adding any reagents, thus allowing to investigate time-dependent cytotoxicity effects on the same sample of cells. A fast, simple and cost-effective assay is suggested for cytotoxicity evaluation based on mammalian cells expressing fluorescent proteins and commonly used laboratory equipment. [ABSTRACT FROM AUTHOR]

G4-stabilizing ligands are now being considered as anticancer, antiviral and antibacterial agents. Phenoxazine is a promising scaffold for the development of G4 ligands. Here, we profiled two known phenoxazine-based nucleoside analogs and five new nucleoside and non-nucleoside derivatives against G4 targets from telomere repeats and the KIT promoter region. Leading new derivatives exhibited remarkably high G4-stabilizing effects (comparable or superior to the effects of the commonly used selective G4 ligands PDS and NMM) and selectivity toward G4s over duplex (superior to BRACO-19). All phenoxazine-based ligands inhibited cellular metabolic activity. The phenoxazine derivatives were particularly toxic for lung adenocarcinoma cells A549' and human liver cancer cells HepG2 (CC 50 of the nucleoside analogues in the nanomolar range), but also affected breast cancer cells MCF7, as well as immortalized fibroblasts VA13 and embryonic kidney cells HEK293t (CC 50 in the micromolar range). Importantly, the CC 50 values varied mostly in accordance with G4-binding affinities and G4-stabilizing effects, and the phenoxazine derivatives localized in the cell nuclei, which corroborates G4-mediated mechanisms of action. • Phenoxazine-based derivatives were probed as G4 ligands. • Some derivatives exhibited remarkably high G4-stabilizing effects and selectivity. • All phenoxazine-based ligands inhibited cellular metabolic activity. • The ligands were particularly toxic for lung adenocarcinoma cells. • Localization in the cell nuclei corroborated G4-mediated mechanisms of action. [ABSTRACT FROM AUTHOR]

New copper(II) complexes of 2-alkylthio-5-arylmethylene-4H-imidazolin-4-ones: (5Z)-2-(methylsulfanyl)-3-(prop-2-en-1-yl)-5-(pyridin-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one) ( 1a ), (5Z,5′Z)-2,2′-(ethan-1,2-diyldisulfanyldiyl)bis(5-(2-pyridilmethylen)-3-allyl-3,5-dihydo-4Н-imidazole-4-one) ( 2a ) and (5Z,5′Z)-3,3′-hexan-1,6-diylbis[5-(2-pyridilmethylen)-2-methylthiotetrahydro-4Н-imidazole-4-one)] ( 3a ) were synthesized as possible anticancer drugs. Their structures were characterized by 1 H NMR spectroscopy, elemental analysis, and X-ray crystallography. The composition of the complexes were found for 1a (Cu:L = 1 : 1 ), 2a (Cu:L = 2 : 1 ), and 3a (Cu:L = 2 : 1 ). The chelation constants were found by competitive complexation with ethylenediamine tetraacetate: 1a (6.7 ± 0.6) × 10 15 M − 1 , 2a = (4.9 ± 0.4) × 10 19 M − 2 , and 3a (5.7 ± 0.5) × 10 19 M − 2 . Supramolecular binding with calf thymus DNA by competitive ethidium bromide quenching was made for complex 2a as the most promising anticancer model, the Stern–Volmer constants were found to be K SV = (8.0 ± 0.4) × 10 6 M − 1 , K q = (6.5 ± 0.4) × 10 5 M − 1 . The binding of the complex 2a to BSA was made by the Scatchard method, the value of the constant is K b = (1.9 ± 0.2) × 10 6 M − 1 . [ABSTRACT FROM AUTHOR]

A convenient and efficient catalytic procedure for the selective S -arylation of 2-thioxoimidazolidin-4-ones to give novel S -aryl substituted 2-thiohydantoins under mild reaction conditions using arylboronic acids is described. The anticancer activity of the compounds were evaluated in vitro . [ABSTRACT FROM AUTHOR]