Human Embryo Fibroblasts Research Articles

Sialidase activity in Glioblastoma cells treated with thyme oil

Background: Cancer is a genetic disease that causes aberrant cells to grow and spread uncontrollably throughout the body, where cerebral glioblastoma is one of the brain tumors. Thyme oil has many therapeutic properties such as antioxidants and anticancer.Aim of study: Estimate sialidase enzyme in human glioblastoma cancer cell line (AMGM5) and rat embryo fibroblasts cell line (REF) in supernatant and suspension cells treated with thyme oil extract and cells without it. Methods: Sialidase activity was measured by ELISA (Enzyme-linked immunosorbent assay) in supernatant and suspension cells of AMGM5 and REF cells treated and untreated with thyme oil extract. Results: Sialidase showed a high level in the Glioblastoma cell line ( AMGM5), while a low level in cells after exposure to diluted thyme oil (10μl/ml) after incubation for 24 hours, also showed a lower level in the Rat Embryo Fibroblast after being treated with thyme extract.Conclusions The sialidase enzyme showed increased in glioblastoma cells but decreased in its level in these cells after exposure to thyme oil extract, which means that thyme oil inhibited cancer cell growth.

A new benzoquinone and a new stilbenoid from Paphiopedilum exul (Ridl.) Rolfe

One new alkyl benzoquinone, paphionone (1), one new trans-stilbenoid, (E)-6,5′-dihydroxy-2,3′-dimethoxystilbene (2), and eight known stilbenoids and flavonoids (3-10) were isolated from the leaves and roots of Paphiopedilum exul (Orchidaceae). Their chemical structures were determined based on IR, ECD, MS and NMR analyses. Cytotoxicity of all isolated compounds towards human hepatocellular carcinoma (HepG2) cell line was examined in vitro by MTT assay. The para-hydroxybenzyl substituted stilbene 10 was potently cytotoxic to the cancer cells, with an IC50 value of 4.80 ± 1.10 μM (selectivity index = 20.83). All compounds were non-toxic to normal human embryo fibroblast (OUMS-36) cell line.

Antiproliferative Activity and Impact on Human Gut Microbiota of New O-Alkyl Derivatives of Naringenin and Their Oximes.

Naringenin is a 5,7,4'-trihydroxyflavanone naturally occurring mainly in citrus fruits, characterized by a wide spectrum of biological activity. Chemical modifications based on alkylation and oximation in most cases increase its bioactivity. The aim of our research was to evaluate the antiproliferative activity and influence on selected representatives of the human gut microbiota of new synthesized O-alkyl derivatives (A1-A10) and their oximes (B1-B10), which contain hexyl, heptyl, octyl, nonyl and undecyl chains attached to the C-7 or to both the C-7 and C-4' positions in naringenin. To the best of our knowledge, compounds A3, A4, A6, A8-A10 and B3-B10 have not been described in the scientific literature previously. The anticancer activity was tested on human colon cancer cell line HT-29 and mouse embryo fibroblasts 3T3-L1 using the sulforhodamine B (SRB) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays. We also determined the impacts of all compounds on the growth of Gram-positive and Gram-negative bacterial strains, such as Staphylococcus aureus, Enterococcus faecalis and Escherichia coli. The antimicrobial activity was expressed in terms of minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) values. For 7,4'-di-O-hexylnaringenin (A2), 7-O-undecylnaringenin (A9) and their oximes (B2, B9), which were safe for microbiota (MIC > 512 µg/mL) and almost all characterized by high cytotoxicity against the HT-29 cell line (A2: IC50 > 100 µg/mL; A9: IC50 = 17.85 ± 0.65 µg/mL; B2: IC50 = 49.76 ± 1.63 µg/mL; B9: IC50 = 11.42 ± 1.17 µg/mL), apoptosis assays were performed to elucidate their mechanisms of action. Based on our results, new compound B9 induced an apoptotic process via caspase 3/7 activation, which proved its potential as an anticancer agent.

Synthesis and cytotoxicity of novel cholesterol–cobalt bis(dicarbollide) conjugates

The novel conjugates of cholesterol with cobalt – bis(dicarbollide) were synthesized by the ring-opening reactions of the cyclic oxonium derivatives of [3,3′-Co(C2B9H11)2]– with the OH group of cholesterol 2-hydroxyethyl ether. The compounds obtained were tested for toxicity to glioblastoma U-87 MG cells and human embryo fibroblasts FECH-15 cells

Effect of exogenous microflora of the hepatobiliary system on the biochemical composition of bile and lipid peroxidation processes of somatic cell membranes in chronic opisthorchiasis

It has been epidemiologically established that the rate of primary cholangiocarcinomas increases greatly in the ObIrtysh basin which is hyperendemic for helminth Opisthorchis felineus in comparison with other regions where the population is not infested. In this connection chronic opisthorchiasis is considered as facultative liver precancer. The study of cholangiocarcinogenesis mechanisms will allow developing pathogenetic approaches to prevention of this tumor. Aim of the study was to investigate the significance of microbiota of the hepatobiliary tract of chronic opisthorchiasis patients in changing of biochemical composition of bile and investigation of its biological influence on somatic cells membrane. Material and methods. Objects of research: bacteria; inbred mice infected by opisthorchis; samples of bile, cultures of human embryo fibroblasts and splenocytes of inbred mice in vitro; blood plasma; standard primary and secondary bile acids. We studied: species of bacteria colonizing bile ducts; quantitative and qualitative composition of bile acids, and level of diene conjugates and malondialdehyde in duct bile samples; biological activity of bile on processes of lipid peroxidation of cell membranes in vitro; influence of bile and lipid peroxidation products on cytomembrane permeability; activity of antioxidant systems of the body. Results and discussion. It was found out, that bile of patients with chronic opisthorchiasis in majority of cases (77.0 %) was infected by different species of bacteria. In 30.0 % of cases certain types of intestinal bacteria (Proteus vulgaris, P. mirabilis, Citrobacter freundii, Bacteroides alcaligues faecalis, Clostridium, Streptococcus faecalis, Escherichia coli) change biochemical composition of duct bile – deconjugated primary and secondary bile acids and also high level of total bile acids are detected. Bile of the above biochemical composition, against the background of depletion of antioxidant system, induces activation of cell membrane lipid peroxidation processes and significantly increases their permeability to toxic components of bile. These processes are promotor in cholangiocarcinogenesis.

Effect of Cu-, Zn-containing complex based on a porous matrix on fibroblast proliferation, apoptosis, necrosis and nitric oxide production

A comparative study of the effect of a matrix based on porous aluminum oxide and a silicon organic polymer polydimethylsiloxane (PDMS) (А12O3@PDMS) and a matrix complex with copper and zinc sorbed on its surface (Cu@Zn- А12O3@PDMS) on the functional properties of fibroblasts has been carried out.Material and methods.The effect of the Cu@Zn- А12O3@PDMS complex and the matrix on the cell proliferative potential (MTT test), apoptosis, necrosis and the production of stable nitric oxide (NO) metabolites were studied in an in vitro experiment with a human embryo fibroblast cell line (HEF-15).Results.The compared samples of Cu@Zn-A12O3@PDMS and Al2O3@PDMS are similar in their physico-chemical properties. Study of HEF-15 functional potential indicates a higher level of cell proliferation and ability to produce NO after contact with the complex. There was no significant increase in apoptosis and necrosis of HEF-15 in the presence of samples of the complex and the carrier.Conclusion.The absence of a significant negative effect of the tested samples on the functional status of cells of the FEH-15 line (proliferation, apoptosis, necrosis, NO secretion) in vitro allows the use of the Cu@Zn-A12O3@PDMS complex for further analysis of its safety in experimental models of skin defects in animals.

Effects of Aspergillus fumigatus Conidia on Apoptosis and Proliferation in an In Vitro Model of the Lung Microenvironment.

Background/Aim: Aspergillus is often detected in respiratory samples from patients with chronic respiratory diseases, including pulmonary fibrosis, suggesting that it can easily colonize the airways. To determine the role of Aspergillus colonization in pulmonary fibrosis, we cultured human lung epithelial A549 cells or murine embryo fibroblast NIH/3T3 cells with Aspergillus conidia in 3D floating culture representing the microenvironment. Materials and Methods: Cells were cultured in two-dimensional (2D) and three-dimensional floating (3DF) culture with heat-inactivated Aspergillus fumigatus (AF) 293 conidia at an effector-to-target cell ratio of 1:10 (early-phase model) and 1:100 (colonization model), and RNA-sequencing and Western blots (WB) were performed. Results: AF293 conidia reduced A549 cell growth in 2D and 3DF cultures and induced apoptosis in A549 spheroids in 3DF culture. RNA-sequencing revealed the increased expression of genes associated with interferon-mediated antiviral responses including MX dymamin-like GTPase 1 (MX1). Interestingly, the decreased expression of genes associated with the cell cycle was observed with a high concentration of AF293 conidia. WB revealed that epithelial-mesenchymal transition was not involved. Notably, AF293 conidia increased NIH/3T3 growth only in 3DF culture without inducing an apoptotic reaction. RNA-sequencing revealed the increased expression of genes associated with interferon signalling, including MX2; however, the decreased expression of genes associated with the cell cycle was not observed. Conclusions: AF affects both apoptosis of epithelial cells and the growth of fibroblasts. A deeper understanding of the detailed mechanisms underlying Aspergillus-mediated signaling pathway in epithelial cells and fibroblasts will help us to understand the lung microenvironment.

Mutagenicity of N-hydroxy-4-aminobiphenyl in human TP53 knock-in (Hupki) mouse embryo fibroblasts.

TP53 harbors somatic mutations in more than half of human tumors with some showing characteristic mutation spectra that have been linked to environmental exposures. In bladder cancer, a unique distribution of mutations amongst several codons of TP53 has been hypothesized to be caused by environmental carcinogens including 4-aminobiphenyl (4-ABP). 4-ABP undergoes metabolic activation to N-hydroxy-4-aminobiphenyl (N-OH-4-ABP) and forms pre-mutagenic adducts in DNA, of which N-(deoxyguanosin-8-yl)-4-ABP (dG-C8-4-ABP) is the major one. Human TP53 knock-in mouse embryo fibroblasts (HUFs) are a useful model to study the influence of environmental carcinogens on TP53-mutagenesis. By performing the HUF immortalization assay (HIMA) TP53-mutant HUFs are generated and mutations can be identified by sequencing. Here we studied the induction of mutations in human TP53 after treatment of primary HUFs with N-OH-4-ABP. In addition, mutagenicity in the bacterial lacZ reporter gene and the formation of dG-C8-4-ABP, measured by 32 P-postlabelling analysis, were determined in N-OH-4-ABP-treated primary HUFs. A total of 6% TP53-mutants were identified after treatment with 40 μM N-OH-4-ABP for 24 hr (n = 150) with G>C/C>G transversion being the main mutation type. The mutation spectrum found in the TP53 gene of immortalized N-OH-4-ABP-treated HUFs was unlike the one found in human bladder cancer. DNA adduct formation (~40 adducts/108 nucleotides) was detected after 24 hr treatment with 40 μM N-OH-4-ABP, but lacZ mutagenicity was not observed. Adduct levels decreased substantially (sixfold) after a 24 hr recovery period indicating that primary HUFs can efficiently repair the dG-C8-4-ABP adduct possibly before mutations are fixed. In conclusion, the observed difference in the N-OH-4-ABP-induced TP53 mutation spectrum to that observed in human bladder tumors do not support a role of 4-ABP in human bladder cancer development.

Combined treatment with dissolved hydrogen molecule and platinum nanocolloid exerts carcinostatic/carcinocidal effects by increasing hydrogen peroxide generation and cell death in the human gastric cancer cell line NUGC-4

Many studies have shown that redox regulation is an effective therapeutic strategy for different types of cancer. We have previously demonstrated that combined treatment with dissolved hydrogen molecule (H2) and platinum nanocolloid (Pt-nc) has carcinostatic effects and that increased intracellular reactive oxygen species (ROS) levels were closely associated with carcinostatic effects in Ehrlich mouse ascites tumor cells. However, it is unknown whether combined treatment-induced ROS generation can occur in human cancer cells. Therefore, this study aimed to examine the carcinostatic effect of the combined treatment in human cells and investigate the relationship between treatment efficacy and ROS generation. H2 and Pt-nc treatment could exert cytostatic action by inhibiting the growth of human promyelocytic leukemia HL60 and human gastric adenocarcinoma-derived NUGC-4 cells; however, no effect was observed in normal human embryo fibroblast OUMS-36 cells by the temporary exposure. These findings indicate that combined treatment with H2 and Pt-nc may act selectively in tumor cells compared with normal cells. Additionally, combined treatment with H2 and Pt-nc resulted in an approximately 200-fold increase in intracellular ROS levels compared with the control, whereas the suppressive effect of tumor cell growth was abrogated entirely by catalase treatment in NUGC-4 cells. Furthermore, combined treatment with H2 and Pt-nc induced hydrogen peroxide generation, cellular morphological changes, cell death, and a decline in DNA synthesis-positive cells. In conclusion, combined treatment with H2 and Pt-nc can induce carcinostatic/carcinocidal effects through intracellular ROS increase, morphological changes, cell death, and DNA synthesis suppression in the human tumor cell line.

3,4,5-Trisubstituted-1,2,4-triazole Derivatives as Antiproliferative Agents: Synthesis, In vitro Evaluation and Molecular Modelling

Background: Cancer is the name given to various diseases that are mainly uncontrolled, related to cell growth and can affect various organs. Among them, lung cancer is the one, which, in its earliest stages, is difficult to diagnose, and it is asymptomatic until the disease progresses. Triazole ring is an important heterocyclic ring known with various pharmacological activities. Objective: It is aimed to synthesize and characterize novel 1,2,4-triazole derivatives and screen them for in vitro antiproliferative activity and binding analysis through docking studies. Method: In this study, we have synthesized new 2-[[5-[(4-aminophenoxy)methyl]-4-phenyl-4H- 1,2,4-triazol-3-yl]thio]-N-(substituted aryl)acetamide (5a-h) derivatives and investigated their anticancer activities against human lung cancer (A549) and mouse embryo fibroblast cell lines (NIH/3T3) by MTT, flow cytometric, caspase-3 and matrix metalloproteinase-9 (MMP-9) inhibition assays. Results: Compounds 5f, 5g and 5h showed the highest cytotoxicity and caused significant apoptosis. These compounds inhibited MMP-9, slightly whereas they did not effect caspase-3. Conclusion: 5f namely, N-(5-acetyl-4-methylthiazol-2-yl)-2-((5-((4-aminophenoxy)methyl)-4- phenyl-4H-1,2,4-triazol-3-yl)thio)acetamide exhibited as the most active compound with selective cytotoxicity and the highest MMP-9 inhibition. Besides, molecular modelling assessment was signified that antiproliferative activity of the compounds 5f, 5g and 5h was through a slight MMP-9 inhibition pathway.

Воздействие наноразмерных анионов кремний-молибденовой кислоты на плазматическую мембрану фибробластов эмбриона человека

Методом времяпролетной масс-спектрометрии вторичных ионов (ToF-SIMS) исследованы изменения состава плазматических мембран (ПМ) фибробластов эмбриона человека под воздействием наноразмерных анионов кремний-молибденовой кислоты (КМК). Измерены и интерпретированы зависимости масс-спектров основных липидов ПМ от концентрации КМК, коррелирующие с их послойными распределениями и со сродством холестерина к фосфолипидам. Обнаружен новый для биохимии клетки эффект – значительное снижение относительного содержания в ПМ холестерина и сфингомиелина под воздействием многозарядных анионов гетерополикислоты (ГПК). Для водных растворов КМК при концентрации С ~ 10мкМ/л и периода воздействия 48 ч обнаружено, что количество холестерина в ПМ снижается в 2–2.5 раза, при этом количество сфингомиелина уменьшается на 20–25%. Предложен новый механизм начального воздействия ГПК на плазматические мембраны, сводящийся к селективному травлению многозарядными анионами. Согласно предлагаемому механизму на первом этапе взаимодействия аниона полиоксометаллата с клеткой осуществляется экстракция из ПМ холестерина и сфингомиелина – основных регуляторов проницаемости и микровязкости ПМ. Как следствие возросшей проницаемости ПМ в клетках возможно ускорение жизненно важных трансмембранных и латеральных процессов.

Loss of p53 Sensitizes Cells to Palmitic Acid-Induced Apoptosis by Reactive Oxygen Species Accumulation.

Palmitic acid, the most common saturated free fatty acid, can lead to lipotoxicity and apoptosis when overloaded in non-fat cells. Palmitic acid accumulation can induce pancreatic β-cell dysfunction and cardiac myocyte apoptosis. Under various cellular stresses, the activation of p53 signaling can lead to cell cycle arrest, DNA repair, senescence, or apoptosis, depending on the severity/type of stress. Nonetheless, the precise role of p53 in lipotoxicity induced by palmitic acid is not clear. Here, our results show that palmitic acid induces p53 activation in a dose- and time-dependent manner. Furthermore, loss of p53 makes cells sensitive to palmitic acid-induced apoptosis. These results were demonstrated in human colon carcinoma cells (HCT116) and primary mouse embryo fibroblasts (MEF) through analysis of DNA fragmentation, flow cytometry, colony formation, and Western blots. In the HCT116 p53−/− cell line, palmitic acid induced greater reactive oxygen species formation compared to the p53+/+ cell line. The reactive oxygen species (ROS) scavengers N-acetyl cysteine (NAC) and reduced glutathione (GSH) partially attenuated apoptosis in the HCT116 p53−/− cell line but had no obvious effect on the p53+/+ cell line. Furthermore, p53 induced the expression of its downstream target genes, p21 and Sesn2, in response to ROS induced by palmitic acid. Loss of p21 also leads to more palmitic acid-induced cell apoptosis in the HCT116 cell line compared with HCT116 p53+/+ and HCT116 p53−/−. In a mouse model of obesity, glucose tolerance test assays showed higher glucose levels in p53−/− mice that received a high fat diet compared to wild type mice that received the same diet. There were no obvious differences between p53−/− and p53+/+ mice that received a regular diet. We conclude that p53 may provide some protection against palmitic acid- induced apoptosis in cells by targeting its downstream genes in response to this stress.

Cytokine-regulating activity of anti-virus preparation CelAgripus in Burkitt's lymphoma stable B-cell lines.

Cytokines activated in response to immunosuppressive viral infections can directly or indirectly affect the neoplastic transformation of B cells. In this study, we studied a new substance designed to produce the antiviral drug CelAgrip (CA, CelAgripus), which exhibits interferon (IFN) and cytokine-inducing activity and, apparently, can be used as an activator of antiviral immunity. Purpose - is to evaluate the cytokine-regulating effect of CA in Burkitt's lymphoma (LB) cell lines latently infected with the Epstein-Barr virus (EBV). to study the CA-induced expression of the cytokine genes IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17, IL-18, IFN-α, IFN -γ, IFN-β, IFN-λ1, IFN-λ2, IFN-λ3, TNF-α in normal and EBV transformed LB cells. Cell line: the human embryo fibroblasts (HEF), Namalva, Daudi, Raji, P3HR-1. Preparations: CA, gossypol-acetic acid (GAA), sodium carboxymethyl cellulose (Na-CMC). RT-PCR and methods for assessing cytotoxicity (MTT and Scepter 2.0 Merck cell counter). The effect of the CA preparation on the expression of IFN-λ, IL-1β, IL-6, IL-8 and IL-10 genes was revealed. We observed the activation of gene expression of IFN-λ, IL-1β, IL-6, IL-8 and suppression of IL-10 gene activity when treatment CA of LB cells. The substance CA has new effects on the activation of the expression of a number of key cytokine genes in stable Burkitt lymphoma cell lines.

Manipulation of Transgene Expression in Fibroblast Cells by a Multifunctional Linear-Branched Hybrid Poly(β-Amino Ester) Synthesized through an Oligomer Combination Approach.

Delivery of functional genetic materials into fibroblast cells to manipulate the transgene expression is of great significance in skin gene therapy. Despite numerous polymeric gene delivery systems having been developed, highly safe and efficient fibroblast gene transfection has not yet been achieved. Here, through a new linear oligomer combination strategy, linear poly(β-amino ester) oligomers are connected by the branching units, forming a new type of poly(β-amino ester). This new multifunctional linear-branched hybrid poly(β-amino ester) (LBPAE) shows high-performance fibroblast gene transfection. In human primary dermal fibroblasts (HPDFs) and mouse embryo fibroblasts (3T3s), ultrahigh transgene expression is achieved by LBPAE: up to 3292-fold enhancement in Gaussia luciferase (Gluc) expression and nearly 100% of green fluorescence protein expression are detected. Concurrently, LBPAE is of high in vitro biocompatibility. In depth mechanistic studies reveal that versatile LBPAE can navigate multiple extra- and intracellular barriers involved in the fibroblast gene transfection. More importantly, LBPAE can effectively deliver minicircle DNA encoding COL7A1 gene (a large and functional gene construct) to substantially upregulate the expression of type VII collagen (C7) in HPDFs, demonstrating its great potential in the treatment of C7-deficiency related genodermatoses such as recessive dystrophic epidermolysis bullosa.

Abstract 4293: Glycogen synthase kinase 3 b maintains mitotic arrest by regulating mitotic checkpoint complex levels

Abstract The cell cycle is regulated by checkpoints that ensure genomic integrity and proper cell division. We are investigating the role of a multifunctional ser/thr kinase, glycogen synthase kinase 3 (GSK3), in the regulation of the mitotic checkpoint. Our data show that spindle toxin-induced mitotic arrest is relieved in multiple cancer cell lines by the GSK3 inhibitors, SB 415286 (SB), RO-81220 (RO) and lithium chloride. Additionally, the mitotic index is reduced in CRISPR-generated GSK3β knockout human cells and GSK3β knockout mouse embryo fibroblasts compared to wild type cells in the presence of taxol. Mitotic arrest is dependent on the mitotic checkpoint complex (MCC), composed of Mad2, BubR1, Cdc20 and Bub1. GSK3 appears to target the MCC to regulate mitotic arrest. For example, Mad2, BubR1 and Bub1 localization at kinetochores and MCC assembly were both reduced by co-treatment of GSK3 inhibitors and spindle toxin compared to spindle toxin alone. These data imply that GSK3β plays a role in maintaining the mitotic checkpoint. The strength of the checkpoint was determined to act like a rheostat rather than a toggle-switch, as cells undergo mitotic slippage after prolonged arrest in spindle toxins. Our data indicates that GSK3 regulates the strength of the checkpoint, as illustrated by time lapse-imaging. GSK3-inhibition induced exit was observed to be dependent on how long the cells were arrested in mitosis prior to GSK3-inhibitor addition. GSK3 inhibition in taxol also decreases the amount of KnL1, part of the KMN network forming the kinetochore, at the centromeres. This indicates a regulatory role of GSK3 in kinetochore assembly and function. The Wnt-signaling pathway and the PI3K/Akt signaling pathway are known upstream regulators of GSK3β, negatively regulating GSK3β activity. Our data shows that inhibiting Wnt-signaling and PI3K/Akt-signaling in the presence of taxol, induces a longer mitotic arrest compared to taxol alone. This suggests that GSK3β is regulated upstream by the Wnt- and the PI3K/Akt signaling archs to control mitosis. Finally, our data implicated that de-acetylase sirtuin2 is a downstream target of GSK3 in its mitotic regulatory role. Our observations indicate a novel regulator of the checkpoint and novel insight in connecting growth-signaling pathways with mitosis. Citation Format: Maisha S. Rashid, William R. Taylor. Glycogen synthase kinase 3 b maintains mitotic arrest by regulating mitotic checkpoint complex levels [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4293.

Effect of Keggin Heteropoly Acids on Human Embryo Fibroblast Cells

The strong dependence of cytotoxicity of Keggin heteropoly acids [XM12O40]n–, X = Si or P, M = Mo and W, n = 3 or 4 on chemical composition is demonstrated using the example of human embryo fibroblast cells based on the results of diagnostics using impedance monitoring, scanning electron microscopy, and measurements of visible cell sizes. The explanation of this dependence based on the role of hydrolytic stability of multiply charged anions in the development of cytotoxicity of these compounds is suggested. The results make it possible to suggest a new mechanism for the development of selectivity of polyoxometalate cytotoxicity relative to the studied cells. The differentiated cytotoxic activity of polyoxometalates relative to oncogenic cells is predicted.

Tuberculostatic Activity of 2-Amino-6-Chloropurine Derivatives

Studies of the antimycobacterial activity of 2-amino-6-chloropurine and its N-acyl derivatives against laboratory (Mycobacterium tuberculosis H37Rv, M. avium, M. terrae) and clinical Mycobacterium tuberculosis strains (MDR-TB) identified compounds with high tuberculostatic activity (MIC from 0.35 – 1.5 μg/ml). The cytotoxic activities of the compounds with antimycobacterial activity against human embryo fibroblasts were studied in the MTT test, which showed that the study compounds were essentially nontoxic (IC50 > 50 μM). Further chemical modification may yield compounds with potential for creating drugs for the treatment of tuberculosis. With the aim of identifying the possible mechanism of the tuberculostatic activity, the ability of the study compounds to inhibit mycobacterial serine-threonine protein kinases (STPK) was assessed. The tuberculostatic activity of 2-amino-6-chloropurine derivatives was not linked with their inhibition of STPK.

Pentapeptide analogs of somatostatin containing a thiazolidine fragment: synthesis and cytotoxic activity

Pentapeptide analogs of somatostatin containing an (R)-1,3-thiazolidine fragment (Thz) of the general formula X—Thz—Phe—D-Trp—Lys(Y)—Thr—Z were synthesized for the first time. The synthesized compounds were tested for cytotoxic activity against three cancer cell lines (MCF-7, PC3, and HCT-116) and against human embryo fibroblasts.

Antiproliferative Activity of Niclosamide Against Melanoma and Colorectal Cancer Cells

Studies of the actions of niclosamide against tumor cells and normal human cells (human embryo kidney cells and pulmonary embryo fibroblast cells) showed higher levels of cytotoxic activity against tumor cells, including melanoma (the Mel-8, Mel-10, MS lines) and colorectal cancer (the Caco-2, COLO 320 HSR, and SW827 cells). Niclosamide was shown to have a high level of cytotoxic activity against cells with the multidrug resistance phenotype due to high levels of expression of MDR1 protein on the plasma membrane (the Mel-8 and MCF-7Adr lines). The proportion of tumor stem cells (TSC) was measured by flow cytometry as the proportion of cells forming side populations (SP). Niclosamide was found to act on TSC cells either more effectively (colorectal cancer line SW 837, (decreases in SP fraction size) or with the same effectiveness as the main population of tumor cells (SP fraction size unaltered).

Nitric Oxide Chemical Donor Affects the Early Phases of In Vitro Wound Healing Process

An artificial wound in a confluent monolayer of human keratinocyte HaCaT cells or mouse embryo fibroblast Swiss NIH 3T3 cells was used to analyze the effects of the nitric oxide (NO) chemical donor, S-nitroso-N-acetylpenicillamine (SNAP). SNAP exposure promoted an enhanced rate of wound closure and accelerated motility of both keratinocytes and fibroblasts compared to control cells. The wounded monolayer cultures of HaCaT and NIH 3T3 cells, treated with or without SNAP, were monitored under a phase contrast microscope. Structural and ultrastructural modifications were analyzed by scanning electron microscopy (SEM). The images were captured by a digital camera at different time points (0-28 h) and the wound area was analyzed through software included in Matlab®. As early as 15 min, SNAP induced significant cytoskeletal remodeling, as shown by immunostaining (phalloidin-labelling), which in turn was associated with increased filopodium number and length rise. NO donor treatment also induced overexpression of Ki-67 protein, a typical marker of cell proliferation, as shown by immunostaining. Both SNAP-induced migration and proliferation were antagonized by the NO-sensitive GC inhibitor 1H-[1,2,4]oxadiazolo[-4,3-a]quinoxalin-1-one (ODQ), which suggests activation of the NO/cGMP signalling cascade in the observed SNAP-induced effects in the early stages of the healing process. Moreover, we provide evidence that PPAR-β antagonist (GSK0660) may interfere with NO-mediated wound healing process. J. Cell. Physiol. 231: 2185-2195, 2016. © 2016 Wiley Periodicals, Inc.