Molecular design, synthesis and anticancer activity of new thiopyrano[2,3-d]thiazoles based on 5-hydroxy-1,4-naphthoquinone (juglone).

A series of 11-substituted 9-hydroxy-3,5,10,11-tetrahydro-2H-benzo[6,7]thiochromeno[2,3-d][1,3]thiazole-2,5,10-triones 3.1-3.13 were synthesized via hetero-Diels-Alder reaction of 5-ene-4-thioxo-2-thiazolidinones and 5-hydroxy-1,4-naphthoquinone (juglone). The structure of newly synthesized compounds was established by means of spectral data and a single-crystal X-ray diffraction analysis. The synthesized compounds were tested on a panel of cell lines representing different types of cancer as well as normal and pseudonormal cells and peripheral human blood lymphocytes. Compound 3.10 was found to be the most active derivative, exhibiting a cytotoxic effect similar to doxorubicin's one (IC50 ranged from 0.6 to 5.98 µM), but less toxic to normal and pseudonormal cells. All synthesized compounds were able to interact with DNA, although their anticancer activity did not correlate with the potency of interaction with DNA. The status of p53 in colorectal cancer cells correlated with the activity of the synthesized derivatives 3.1, 3.7, and 3.10. Compound 3.10 did not have an acute toxic effect on the body of С57BL/6 mice, unlike the well-known anticancer drug doxorubicin, which was used as a positive control. The injection of 3.10 (20 mg/kg) to mice had no effect on the counts of leukocytes, erythrocytes, platelets and hemoglobin level in their blood, in contrast to doxorubicin, which caused anemia and leukopenia, indicating bio-tolerance of 3.10in vivo.

Elevation of truncated (48 kDa) form of unconventional myosin 1C in blood serum correlates with severe Covid-19.

In Covid-19 and autoimmune patients, there are several similarities revealed in the immune responses (Liu et al., 2021; Woodruff et al., 2020). Earlier, we firstly detected a truncated (48 kDa) form of the unconventional Myosin 1C (48/Myo1C) in a fraction of proteins soluble in 10% 2,2,2-trichloroacetic acid (TCA). These proteins were obtained from blood serum of patients with autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis (Kit et al., 2018). Here, we demonstrated that content of 48/Myo1C was also elevated in blood serum of the severe Covid-19 patients. Whereas in blood of 28 clinically healthy human individuals regularly tested for Covid-19 infection, the amount of this protein was undetectable or very low, in blood of 16 of 28 patients hospitalized with severe course of this disease, its amount was significantly increased. Dexamethasone, steroid hormone which is widely used for treatment of severe Covid-19 patients, induced time-dependent elevation of the 48/Myo1C in blood of such patients. The 48/Myo1C dose-dependently suppressed the viability of anti-CD3-activated lymphocytes of human peripheral blood. Recently, we used affinity chromatography on the magnetic poly(glycidyl-methacrylate) (mag-PGMA-NH2) microparticles functionalized with Myo1C and MALDI-TOF mass spectrometry with molecular modeling in silico in order to identify potential molecular partners of the 48/Myo1C. It was found that 48/Myo1C might bind to component 3 of the complement system and the anti-thrombin-III (Starykovych et al., 2021). Thus, the mechanisms of the pathogenic action of truncated form of Myo1C in severe COVID-19 patients may involve a suppression of the immune cells, as well as modulation of complement and coagulation cascades.

Covalent Conjugate of Ser-Pro-Cys Tripeptide with PEGylated Comb-Like Polymer as Novel Killer of Human Tumor Cells.

Recently, we detected a previously unknown Ser-Pro-Cys (SPC) tripeptide in the blood serum of multiple sclerosis patients. Its role as a biomarker of the autoimmune disease was suggested, although its origin and real biological activity remained unclear. Here, we created a biocompatible PEGylated comb-like polymer that was used as a platform for covalent immobilization of the SPC, which provided a possibility to explore the biological activity of this tripeptide. This macromolecular conjugate was synthesized via a reaction of the terminal epoxide group of the biocompatible copolymer of dimethyl maleate (DMM) and polyethylene glycol methyl ether methacrylate (PEGMA) with the amino group of the SPC tripeptide. Unexpectedly, the resulting conjugate containing SPC demonstrated anticancer activity in vitro. It possessed pro-apoptotic action toward human tumor cells, while there was no cytotoxic effect of that conjugate toward normal lymphocytes of human peripheral blood. The detected biological effects of the created conjugate inspired us to carry out a thorough study of structural and colloidal-chemical characteristics of this surface-active copolymer containing side PEG chains and a terminal nontoxic synthetic fragment. The copolymer composition, in particular, the content of the peptide fragment, was determined via elemental analysis and NMR spectroscopy. At CMC, it formed polymeric micelle-like structures with a hydrodynamic diameter of 180 ± 60 nm. The conjugation of the peptide fragment to the initial comb-like copolymer caused a change of zeta-potential of the formed micelle-like structures from -0.15 to 0.32 mV. Additional structural modification of the created polymeric nanoplatform was performed via attachment of fluorescein isothiocianate (FITC) dye that permitted monitoring of the behavior of the bioactive SPC-functionalized conjugate in the treated tumor cells. Its penetration into those cells and localization in their cytoplasm were revealed. The principal novelty of this study consists in finding that covalent conjugation of two nontoxic compounds-SPC tripeptide and comb-like PEGylated polymer-led to an unexpected synergy which appeared in the distinct cytotoxic action of the macromolecular complex toward human tumor cells. A potential role of peculiarities of the colloidal-chemical properties of the novel conjugate in its cytotoxic effect are discussed. Thus, synthesized comb-like PEGylated polymers can provide a prospective nanoplatform for drug delivery in anticancer chemotherapy.

Thiopyrano[2,3-d]thiazole structures as promising scaffold with anticancer potential.

Seven chromeno[4',3':4,5]thiopyrano[2,3-d]thiazole derivatives were synthesized and screened for their cytotoxic effects on different lines of mammalian leukemia, breast adenocarcinoma, glioblastoma, and pseudo-normal and normal cells. The derivative 3 demonstrated toxicity towards tumor cells of Jurkat, K562, U251, HL-60, MCF-7, and MDA-MB-231 lines. At the same time, this compound possessed low toxicity (IC50 > 100 µM) towards cells, used as control, representing non-tumor, somatic cells: HaCaT, HEK293 cells as well as murine Balb/c 3T3 and J774.2 cells, mink Mv1Lu cells, and normal mitogen-activated human blood lymphocytes. The derivative 3 induced apoptosis in human leukemia Jurkat T-cells and glioblastoma U251 cells via mitochondria-dependent pathway and inhibition of the DNA reparation enzyme PARP-1. This compound triggered pro-apoptotic morphological changes in Jurkat and U251 cells, namely chromatin condensation, nuclei fragmentation, and membrane blebbing. However, the DNA damaging effects of compound 3 were significantly lower in normal human lymphocytes, compared with such results in tumor Jurkat and U251 cells. The DNA damaging effects of compound 3 were unrelated to its DNA-binding and/or DNA-intercalating abilities. This compound induced the accumulation of endogenous reactive oxygen species (ROS), namely superoxide radicals, in human leukemia and glioblastoma cells. Our finding indicated that compound 3 inhibited the viability of human leukemia T-cells and glioblastoma cells via induction of DNA damage and apoptosis through ROS-mediated mitochondrial pathway.

Novel hybrid pyrrolidinedione-thiazolidinones as potential anticancer agents: Synthesis and biological evaluation.

A series of novel pyrrolidinedione-thiazolidinones was synthesized and subjected to physico-chemical characteristics. They were screened on a panel of cell lines representing different types of cancer, as well as normal human keratynocytes and lymphocytes of peripheral human blood. High antiproliferative activity of 1-(4-chlorophenyl)- and 1-(4-hydroxyphenyl)-3-{5-[(Z,2Z)-2-chloro-3-(4-nitrophenyl)-2-propenylidene]-4-oxo-2-thioxothiazolidin-3-yl}-1-(4-hydroxyphenyl)-pyrrolidine-2,5-diones 2a and 2b was revealed along with satisfactory cytotoxicity characteristics. Human T-leukemia cells of Jurkat line were the most sensitive to the action of 2a, 2b and 5-(2-allyloxybenzylidene) derivative 2f. At the same time, synthesized compounds demonstrated low toxicity towards normal human keratinocytes of HaCaT line and mitogen-activated lymphocytes of peripheral blood of healthy human donor. The compounds 2а and 2b demonstrated high selectivity (SI >9.2) towards studied leukemia, lung, breast, cervical, colon carcinoma and glioblastoma cells. Compounds 2a, 2b induced mitochondria-dependent apoptosis in treated Jurkat T-cells via increasing the level of proapoptotic Bax and EndoG proteins, and decreasing the level of antiapoptotic Bcl-2 protein. The cytotoxic action of compounds 2a, 2b towards Jurkat T-cells was associated with the single-strand brakes in DNA and its inter-nucleosomal fragmentation, without significant intercalation of these compounds into the DNA molecule. Compounds 2a, 2b did not induce significant DNA damage and changes in morphology of mitogen-activated lymphocytes of peripheral blood of healthy donor. Altogether, these data demonstrated anticancer potential of novel hybrid pyrrolidinedione-thiazolidinones which were relatively non-toxic for normal human cells.

The purification and identification of human blood serum proteins with affinity to the antitumor active RL2 lactaptin using magnetic microparticles.

The cytopoxic effect of RL2 lactaptin (the recombinant analog of proteolytic fragment of human kappa-casein) toward tumor cells in vitro and in vivo presents it as a novel promising antitumor drug. The binding of any drug with serum proteins can affect their activity, distribution, rate of excretion and toxicity in the human body. Here, we studied the ability of RL2 to bind to various blood serum proteins. Using magnetic microparticles bearing by RL2 as an affinity matrix, in combination with mass spectrometry and western blot analysis, we found a number of blood serum proteins possessing affinity for RL2. Among them IgA, IgM and IgG subclasses of immunoglobulins, apolipoprotein A1 and various cortactin isoforms were identified. This data suggests that in the bloodstream RL2 lactaptin takes part in complicate protein-protein interactions, which can affect its activity.

Fluorine-containing block/branched polyamphiphiles forming bioinspired complexes with biopolymers.

Colloidal-chemical characteristics of block/branched cationic and non-ionic polyamphiphiles containing poly(fluorine-alkyl methacrylate) (poly(FMA)) block and their intermolecular complexes with biopolymers were studied. The dependences of their surface activity and micelle size on the length of hydrophobic and hydrophilic blocks, as well as the length of side fluorine-alkyl branches were established. Poly(FMA)-block-poly(DMAEMA) was used for formation of interpolyelectrolyte complexes with plasmid DNA (pDNA) via their electrostatic interaction. Novel non-viral polyplexes were tested as gene delivery systems for mammalian cells. The results of DLS, TEM and MALDI-ToF studies demonstrated disaggregation of lysozyme (LYZ) aggregates in the presence of poly(FMA)-block-poly(NVP) and formation of the polyamphiphile…LYS complex possessing antibacterial action.