Real-time Cell Electronic Sensing Research Articles

Different Effects of Cigarette Smoke, Heated Tobacco Product and E-Cigarette Vapour on Orbital Fibroblasts in Graves' Orbitopathy; a Study by Real Time Cell Electronic Sensing.

Thyroid autoimmunity in Graves’ disease (GD) is accompanied by Graves’ orbitopathy (GO) in 40% of the cases. Orbital fibroblasts (OF) play a key role in the pathogenesis and cigarette smoking is a known deteriorating factor. Alongside conventional cigarettes (CC) new alternatives became available for smokers, including heated tobacco products (HTP) and E-cigarettes (ECIG). We aimed to study the cellular effects of smoke extracts (SE) in orbital fibroblasts. Primary OF cultures from GO and NON-GO orbits were exposed to different concentrations of SE (1%, 50%) and the changes were followed using Real Time Cell Electronic Sensing (RT-CES). Untreated GO and NON-GO cells had different maximum cell index (CI) values of 3.3 and 2.79 respectively (p < 0.0001). CC, HTP and ECIG treated NON-GO fibroblasts exhibited peak CIs of 2.62, 3.32 and 3.41 while treated GO cells’ CIs were higher, 5.38, 6.25 and 6.33, respectively (p < 0.0001). The metabolic activity (MTT) decreased (p < 0.001) and hyaluronan production doubled (p < 0.02) after 50% of CC SE treatment in all cell cultures. GO fibroblasts were more sensitive to low concentration SE then NON-GO fibroblasts (p < 0.0001). The studied SEs exerted different effects. RT-CES is a sensitive technique to detect the effects of very low concentration of SE on fibroblasts.

Targeting radiation-induced upstream stimulatory factor-1 by histone deacetylase inhibitors to reverse radioresistance in prostate cancer.

Ionizing radiation (IR) is a standard modality for the management of solid tumors. Apart from its killing effects, IR can induce pro-survival factors leading to radioresistance of cancer. Mechanistic understanding of radiation resistance is warranted to overcome the pro-survival effects of IR. The aim of this study was to investigate the role of upstream stimulatory factor-1 (USF-1) in the induction of radioresistance in prostate cancer and its targeting by histone deacetylase (HDAC) inhibitors to reverse resistance. This study reports here that USF-1 is a marker for radioresistance in PC-3 cells. Using protein-DNA array analysis, it was documented that DNA binding activity of USF-1 was elevated following IR in PC-3 cells. Novel HDAC inhibitors downregulated USF-1 binding either alone or in combination with IR. A 5Gy dose of IR induced the expression of target genes of USF-1 (human telomerase reverse transcriptase [hTERT], IGF2R, CyclinB1, and Cdk1), however, HDAC inhibitors alone or in combination with IR reduced their expression as measured by real time RT PCR analysis. Furthermore, immunofluorescence analysis revealed that while USF-1 localized primarily in the nucleus following IR, it localized in the cytoplasm when treated with HDAC inhibitors/combination. Maximum effects of modulation of USF-1 expression (overexpression or suppression) were observed on hTERT activity as determined by dual-luciferase reporter assay. To further confirm the role of USF-1 in radioresistance, cell growth was analyzed using the real-time cell electronic sensing (RT-CES) system. This study found that USF-1-transfected cells proliferated faster than the vector-transfected cells with or without treatments with HDAC inhibitors/IR/combination. Colony forming assay also confirmed that USF-1 overexpression led to increased survival following IR. Importantly, colony-forming assay demonstrated that HDAC inhibitors reversed the radioresistance in both PC-3 and DU-145 cells. These studies demonstrate that HDAC inhibitors reverse the radioresistance in prostate cancer through down-modulation of USF-1-mediated transactivation of target genes involved in cell proliferation and cell cycle.

Cytotoxicity, cellular uptake and apoptotic responses in human coronary artery endothelial cells exposed to ultrasmall superparamagnetic iron oxide nanoparticles.

Ultrasmall superparamagnetic iron oxide nanoparticles (USPION) possess reactive surfaces, are metabolized and exhibit unique magnetic properties. These properties are desirable for designing novel theranostic biomedical products; however, toxicity mechanisms of USPION are not completely elucidated. The goal of this study was to investigate cell interactions (uptake and cytotoxicity) of USPION using human coronary artery endothelial cells as a vascular cell model. Polyvinylpirrolidone-coated USPION were characterized: average diameter 17 nm (transmission electron microscopy [TEM]), average hydrodynamic diameter 44 nm (dynamic light scattering) and zeta potential -38.75 mV. Cells were exposed to 0 (control), 25, 50, 100 or 200 μg/mL USPION. Concentration- and time-dependent cytotoxicity were observed after 3-6 hours through 24 hours of exposure using Alamar Blue and Real-Time Cell Electronic Sensing assays. Cell uptake was evaluated by imaging using live-dead confocal microscopy, actin and nuclear fluorescent staining, and TEM. Phase-contrast, confocal microscopy, and TEM imaging showed significant USPION internalization as early as 3 hours after exposure to 25 μg/mL. TEM imaging demonstrated particle internalization in secondary lysosomes with perinuclear localization. Three orthogonal assays were conducted to assess apoptosis. TUNEL staining demonstrated a marked increase in fragmented DNA, a response pathognomonic of apoptosis, after a 4-hour exposure. Cells subjected to agarose gel electrophoresis exhibited degraded DNA 3 hours after exposure. Caspase-3/7 activity increased after a 3-hour exposure. USPION uptake resulted in cytotoxicity involving apoptosis and these results contribute to further mechanistic understanding of the USPION toxicity in vitro in cardiovascular endothelial cells.

Application of electric cell-substrate impedance sensing toward personalized anti-cancer therapeutic selection

BackgroundCell-based analysis may have the potential for using patient-derived tissues/cells as a basis for a more direct prediction of therapeutic outcomes.MethodsThis study focused on the application of the Real Time Cell Electronic Sensing (RT-CES) system for screening effective anticancer drugs to different types of prostate cancers. The goal was to demonstrate the potential application of such technology toward the suitability in selection of personalized medicine. Three prostate cancer cell lines, DU145, LNCaP, and PC-3, and a normal prostate cell line were used. Docetaxel, Carboplatin, Abiraterone Acetate, Mitoxantrone, Sunitinib Malate were used as testing drugs.ResultsCellular adhesion, proliferation and drug induced cellular responses were monitored by the RTCES system, and the results were correlated to the well-established cell viability tests. Identification of an effective drug from a panel of available anticancer drugs to a specific cancer cell line, or testing the effectiveness of a certain drug to a panel of prostate cancer cell lines was demonstrated. Cellular resistance to a drug at single dose and multiple dose challenges was monitored by RT-CES measurement, while such resistance was not detectable by endpoint cell viability assays.ConclusionsThe results of this study highlighted the advantages of such real-time impedance-based sensing system for applications in chemotherapy reagent selection.

Potential role of nucleoside diphosphate kinase in myricetin-induced selective apoptosis in colon cancer HCT-15 cells

The flavonoid myricetin (MYR) is derived from vegetables and fruits. It has been shown to exert anti-cancer effects in various cell lines; however, the exact mechanism underlying these effects is yet to be elucidated. In this study, we evaluated the anti-cancer effects induced by MYR treatment in colon cancer HCT-15 cells. To detect cell proliferation, we conducted MTT assay and real time-cell electronic sensing (RT-CES). We next performed comet assay and Annexin V and PI staining to detect cellular apoptotic features. After that, we conducted two-dimensional electrophoresis (2-DE) analysis to identify apoptotic proteins. The results of this analysis revealed that eight spots were differentially expressed. Among the spots, we selected nucleoside diphosphate kinase (NDPK) for further investigation, as it has been shown to regulate cancer cell apoptosis and metastasis. After that, we conducted realtime-PCR and western blot to detect the expression of NDPK mRNA and protein and wound-healing assay to detect cell migration and invasion. Finally, we performed NDPK siRNA transfection study and the results showed that NDPK knockdown inhibited apoptosis. Based on these collective results, we suggest that MYR induces apoptosis in human colon cancer HCT-15 cells selectively by increasing the expression of NDPK and other caspase-regulated apoptosis proteins.

Anti-HIV Activity of Ocimum labiatum Extract and Isolated Pheophytin-a.

Ocimum plants are traditionally used to manage HIV/AIDS in various African countries. The effects of Ocimum labiatum extract on HIV-1 protease (PR) and reverse transcriptase (RT) is presented here along with characterization of an identified bioactive compound, achieved through 1H- and 13C-NMR. The extract’s effect on HIV-1 replication was assessed by HIV-1 p24 antigen capture. Cytotoxicity of samples was evaluated using tetrazolium dyes and real-time cell electronic sensing (RT-CES). Ocimum labiatum inhibited HIV-1 PR with an IC50 value of 49.8 ± 0.4 μg/mL and presented weak inhibition (21%) against HIV-1 RT. The extract also reduced HIV-1 replication in U1 cells at a non-cytotoxic concentration (25 μg/mL). The CC50 value of the extract in U1 cells was 42.0 ± 0.13 μg/mL. The HIV-1 PR inhibiting fraction was purified using prep-HPLC and yielded a chlorophyll derivative, pheophytin-a (phy-a). Phy-a inhibited HIV-1 PR with an IC50 value of 44.4 ± 1.5 μg/mL (51 ± 1.7 μM). The low cytotoxicity of phy-a in TZM-bl cells was detected by RT-CES and the CC50 value in U1 cells was 51.3 ± 1.0 μg/mL (58.9 ± 1.2 μM). This study provides the first in vitro evidence of anti-HIV activity of O. labiatum and isolated phy-a, supporting further investigation of O. labiatum for lead compounds against HIV-1.

Quercetin loading CdSe/ZnS nanoparticles as efficient antibacterial and anticancer materials

Quercetin (Qe) plays an important role in inflammation, antibacterial, anticancer, and aging. However, Qe has extremely low water solubility, which is a major challenge in drug absorption. In this study, we described a simple method for synthesis of Qe/CdSe/ZnS nanoparticles (QCZ NPs). The QCZ NPs had an average diameter of 10nm and prominent yellow emission under UV irradiation. We investigated the antibacterial activity of QCZ NPs against drug-resistant Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) in vitro. Results showed that QCZ NPs had considerably more effective antibacterial activities than Qe or CdSe nanoparticles (CdSe NPs). Antibacterial experiment results showed that QCZ NPs acted against E. coli and B. subtilis by disrupting the bacterial cell wall and membrane. In vivo study, the QCZ NPs could cure inflammation and lesion which caused by E. coli. In anticancer assays, the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] cell proliferation assays exhibited the cytotoxicity of QCZ NPs increased approximately 2–6 fold compared to raw Qe and CdSe NPs. Moreover, by using RT-CES (real-time cell electronic sensing) studies, we had demonstrated QCZ NPs have also an effect on migration and proliferation of BGC-823 cells. CdSe NPs loaded with Qe, these QCZ NPs exhibited excellent antibacterial (E. coli and B. subtilis) and anticancer (BGC-823) activities.

Evaluation of the Cytotoxicity of α-Cyclodextrin Derivatives on the Caco-2 Cell Line and Human Erythrocytes.

Cyclodextrins, even the 6-membered α-cyclodextrin, are approved in the various pharmacopoeias as pharmaceutical excipients for solubilizing and stabilizing drugs as well as for controlling drug release. Recently α-cyclodextrin has also been marketed as health food with beneficial effects on blood lipid profiles. However, the concentration of α-cyclodextrin used may be very high in these cases, and its toxic attributes have to be seriously considered. The objective of this study was to investigate the cytotoxicity of various, differently substituted α-cyclodextrin derivatives and determine relationship between the structures and cytotoxicity. Three different methods were used, viability tests (MTT assay and Real Time Cell Electronic Sensing on Caco-2 cells) as well as hemolysis test on human red blood cells. The effect of α-cyclodextrin derivatives resulted in concentration-dependent cytotoxicity, so the IC50 values have been determined. Based on our evaluation, the Real Time Cell Electronic Sensing method is the most accurate for describing the time and concentration dependency of the observed toxic effects. Regarding the cytotoxicity on Caco-2 cells, phosphatidylcholine extraction may play a main role in the mechanism. Our results should provide help in selecting those α-cyclodextrin derivatives which have the potential of being used safely in medical formulations.

Cellular injury evidenced by impedance technology and infrared microspectroscopy

Fourier Transform Infrared (FTIR) spectroscopy is finding increasing biological application, for example in the analysis of diseased tissues and cells, cell cycle studies and investigating the mechanisms of action of anticancer drugs. Cancer treatment studies routinely define the types of cell-drug responses as either total cell destruction by the drug (all cells die), moderate damage (cell deterioration where some cells survive) or reversible cell cycle arrest (cytostasis). In this study the loss of viability and related chemical stress experienced by cells treated with the medicinal plant, Plectranthus ciliatus, was investigated using real time cell electronic sensing (RT-CES) technology and FTIR microspectroscopy. The use of plants as medicines is well established and ethnobotany has proven that crude extracts can serve as treatments against various ailments. The aim of this study was to determine whether FTIR microspectroscopy would successfully distinguish between different types of cellular injury induced by a potentially anticancerous plant extract. Cervical adenocarcinoma (HeLa) cells were treated with a crude extract of Pciliatus and cells monitored using RT-CES to characterize the type of cellular responses induced. Cell populations were then investigated using FTIR microspectroscopy and statistically analysed using One-way Analysis of Variance (ANOVA) and Principal Component Analysis (PCA). The plant extract and a cancer drug control (actinomycin D) induced concentration dependent cellular responses ranging from nontoxic, cytostatic or cytotoxic. Thirteen spectral peaks (915cm−1, 933cm−1, 989cm−1, 1192cm−1, 1369cm−1, 1437cm−1, 1450cm−1, 1546cm−1, 1634cm−1, 1679cm−1 1772cm−1, 2874cm−1 and 2962cm−1) associated with cytotoxicity were significantly (p value<0.05, one way ANOVA, Tukey test, Bonferroni) altered, while two of the bands were also indicative of early stress related responses. In PCA, poor separation between nontoxic and cytostatic responses was evident while clear separation was linked to cytotoxicity. RT-CES detected morphological changes as indicators of cell injury and could distinguish between viable, cytostatic and cytotoxic responses. FTIR microspectroscopy confirmed that cytostatic cells were viable and could still recover while also describing early cellular stress related responses on a molecular level.

PH‐responsive near‐infrared emitting conjugated polymer nanoparticles for cellular imaging and controlled‐drug delivery

ABSTRACTIn this article, pH‐responsive near‐infrared emitting conjugated polymer nanoparticles (CPNs) are prepared, characterized, and their stabilities are investigated under various conditions. These nanoparticles have capacity to be loaded with water insoluble, anticancer drug, camptothecin (CPT), with around 10% drug loading efficiency. The in vitro release studies demonstrate that the release of CPTs from CPNs is pH‐dependent such that significantly faster drug release at mildly acidic pH of 5.0 compared with physiological pH 7.4 is observed. Time and dose‐dependent in vitro cytotoxicity tests of blank and CPT‐loaded nanoparticles are performed by real‐time cell electronic sensing (RT‐CES) assay with hepatocellular carcinoma cells (Huh7). The results indicate that CPNs can be effectively utilized as vehicles for pH‐triggered release of anticancer drugs. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 114–122

MicroRNA library-based functional screening identified miR-137 as a suppresser of gastric cancer cell proliferation.

Uncontrolled proliferation is a key characteristic of gastric carcinogenesis and the precise mechanisms underlying the altered proliferation behaviors of GC cells have not been clearly elucidated. miRNAs has been suggested to play a crucial role in the pathogenesis and development of various cancers. In the present study, we employed an impedance-based real-time cell electronic sensing (RT-CES) system to detect the effects of ectopically expressed miRNAs on GC cell proliferation. miRNA mimics were transfected into gastric cancer cell line SGC7901 and the effect of individual miRNA on the proliferation rate of the cells was measured by the RT-CES system. The screening results were validated with qRT-PCR and miR-137 was selected for further research. The effects of ectopically expressed miR-137 on GC cell growth and cell cycle progress were measured using MTT assay and flow cytometry. The target gene of miR-137 was predicted using different bioinformatics tools and the direct interaction between miR-137 and the 3'-UTR was confirmed with a luciferase reporter assay. The in vivo effect of miR-137 on GC cell proliferation was examined with a tumor-bearing nude mouse model. The correlation between miR-137 expression and patients' prognosis was explored in a cohort of 38 patients. Prognosis was explored in a cohort of 38 patients. Ectopic expression of miR-137 was sufficient to inhibit GC cell proliferation both in vitro and in vivo. Bioinformatics prediction and luciferase reporter assay revealed CDK6 as a target gene through which miR-137 exerted an inhibitory function. Moreover, miR-137 expression positively correlated with better prognosis. Our data indicated an important regulatory role of miR-137 in GC cell proliferation and that it may be explored as a prognostic marker for GC.

A multifunctional ribonuclease A-conjugated carbon dot cluster nanosystem for synchronous cancer imaging and therapy.

Carbon dots exhibit great potential in applications such as molecular imaging and in vivo molecular tracking. However, how to enhance fluorescence intensity of carbon dots has become a great challenge. Herein, we report for the first time a new strategy to synthesize fluorescent carbon dots (C-dots) with high quantum yields by using ribonuclease A (RNase A) as a biomolecular templating agent under microwave irradiation. The synthesized RNase A-conjugated carbon dots (RNase A@C-dots) exhibited quantum yields of 24.20%. The fluorescent color of the RNase A@C-dots can easily be adjusted by varying the microwave reaction time and microwave power. Moreover, the emission wavelength and intensity of RNase A@C-dots displayed a marked excitation wavelength-dependent character. As the excitation wavelength alters from 300 to 500 nm, the photoluminescence (PL) peak exhibits gradually redshifts from 450 to 550 nm, and the intensity reaches its maximum at an excitation wavelength of 380 nm. Its Stokes shift is about 80 nm. Notably, the PL intensity is gradually decreasing as the pH increases, almost linearly dependent, and it reaches the maximum at a pH = 2 condition; the emission peaks also show clearly a redshift, which may be caused by the high activity and perfective dispersion of RNase A in a lower pH solution. In high pH solution, RNase A tends to form RNase A warped carbon dot nanoclusters. Cell imaging confirmed that the RNase A@C-dots could enter into the cytoplasm through cell endocytosis. 3D confocal imaging and transmission electron microscopy observation confirmed partial RNase A@C-dots located inside the nucleus. MTT and real-time cell electronic sensing (RT-CES) analysis showed that the RNase A@C-dots could effectively inhibit the growth of MGC-803 cells. Intra-tumor injection test of RNase A@C-dots showed that RNase A@C-dots could be used for imaging in vivo gastric cancer cells. In conclusion, the as-prepared RNase A@C-dots are suitable for simultaneous therapy and in vivo fluorescence imaging of nude mice loaded with gastric cancer or other tumors.

Effect of paclitaxel on proliferation of human Tenon fibroblast and its probably mechanism

Background The excessive growth of human Tenon fibroblasts (HTFs) is a primary cause of failure of anti-glaucomatous filtering surgery.To seek a drug of anti-fibrosis is of an important significance for improving the successful rate of anti-glaucomatous filtration surgery.Objective The goal of this study was to investigate the effect of paclitaxel on proliferation of HTFs in vitro.Methods Human Tenon tissue was obtained during the anti-glaucomatous filtering surgery.HTFs were cultivated using explant method and 3-6 generations of cells were used in the experiment.The cells were identified by immunochemistry using keratin,vimentin,fibronectin and S-100.Different concentrations (0,1 ×10-s,1 × 10-7,1 × 10-6 mol/L) of paclitaxel were added into the medium,and then the cell indexes (CI) in the various groups were detected by real-time cell electronic sensing (RT-CES) 24 hours after affection of paclitaxel.Apoptosis of the cells was examined using DAPI staining,and the proportion of the cells in different cycles were assayed by flow cytorneter 12 hours after addition of paclitaxel.The expressions of matrix metalloproteinase-1 (MMP-1) protein and mRNA were detected by ELISA and real-time PCR,respectively.Results The cells migrated from the cultivated tissue within 7 days with the fibrocyte-like shape.The cells showed the positive response for vimentin and absent response for keratin,fibronectin and S-100.The CI values were 1.093 ±0.191,0.665 ± 0.093 and 0.473 ± 0.117 in the 1 × 10-8,1 × 10-7 and 1 × 10-6 mol/L paclitaxel groups,showing significant rise in comparison with the 1.514 ±0.283 of the 0 mol/L paclitaxel group (all at P =0.000).The cell nuclei were normal in the 0 mol/L paclitaxel group,however,blue-fluorescent particles and apoptotic bodied were found in the cell nuclei after affection of paclitaxel.The proportion of G2/M phase of cells were (9.20±0.80) ％,(12.37±0.45)％ and (13.80±0.35)％ in the 1×10-8 mol/L,1×10-7 mol/L and 1×10-6 mol/L paclitaxel groups,which were higher than the (7.17±0.50) ％ in the 0 mol/L paclitaxel group (P=0.005,0.000,0.000).In addition,the relative expressing level of M MP-1 mRNA (MMP-1 mRNA/GAPDH mRNA) and the expression level of MMP-1 protein in the HTFs were significantly lower in the 1 ×10-8 mol/L,1 × 10-7 mol/L and 1 × 10-6 mol/L paclitaxel groups than those in the 0 mol/L group (all at P＜0.05).Conclusions Paclitaxel at the concentrations of 1 × 10-8 mol/L-1 × 10-6 mol/L inhibits the proliferation of HTFs in vitro by arresting the cellular mitosis and inducing cell apoptosis.These effects probably associated with down-regulation of MMP-1 expression in the HTFs. Key words: Paclitaxe/pharmacology ; Glaucoma/surgery; Tenon capsule/ cytology; Fibroblast/cytology; Matrix metalloproteinase-1

Dual functionality of conjugated polymer nanoparticles as an anticancer drug carrier and a fluorescent probe for cell imaging

Multifunctional nanoparticles based on a green emitting, hydrophobic conjugated polymer, poly[(9,9-bis{propeny}fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1,3}-thiodiazole)] (PPFBT), that acts both as a fluorescent reporter and a matrix to accommodate an anti-cancer compound, camptothecin (CPT), were prepared, characterized and their potential as a fluorescent probe for cell imaging and as a drug delivery vehicle were evaluated via in vitro cell assays. The cell viability of human hepatocellular carcinoma cell line (Huh7) was investigated in the absence and presence of CPT with sulforhodamine B (SRB) and real-time cell electronic sensing (RT-CES) cytotoxicity assays.

Cytotoxic, Cytostatic and HIV-1 PR Inhibitory Activities of the Soft Coral Litophyton arboreum

Bioassay-guided fractionation using different chromatographic and spectroscopic techniques in the analysis of the Red Sea soft coral Litophyton arboreum led to the isolation of nine compounds; sarcophytol M (1), alismol (2), 24-methylcholesta-5,24(28)-diene-3β-ol (3), 10-O-methyl alismoxide (4), alismoxide (5), (S)-chimyl alcohol (6), 7β-acetoxy-24-methylcholesta-5-24(28)-diene-3,19-diol (7), erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8), and 24-methylcholesta-5,24(28)-diene-3β,7β,19-triol (9). Some of the isolated compounds demonstrated potent cytotoxic- and/or cytostatic activity against HeLa and U937 cancer cell lines and inhibitory activity against HIV-1 protease (PR). Compound 7 was strongly cytotoxic against HeLa cells (CC50 4.3 ± 0.75 µM), with selectivity index of SI 8.1, which was confirmed by real time cell electronic sensing (RT-CES). Compounds 2, 7, and 8 showed strong inhibitory activity against HIV-1 PR at IC50s of 7.20 ± 0.7, 4.85 ± 0.18, and 4.80 ± 0.92 µM respectively. In silico docking of most compounds presented comparable scores to that of acetyl pepstatin, a known HIV-1 PR inhibitor. Interestingly, compound 8 showed potent HIV-1 PR inhibitory activity in the absence of cytotoxicity against the cell lines used. In addition, compounds 2 and 5 demonstrated cytostatic action in HeLa cells, revealing potential use in virostatic cocktails. Taken together, data presented here suggest Litophyton arboreum to contain promising compounds for further investigation against the diseases mentioned.

The Kinetic Signature of Toxicity of Four Heavy Metals and Their Mixtures on MCF7 Breast Cancer Cell Line

This study evaluated the kinetic signature of toxicity of four heavy metals known to cause severe health and environmental issues—cadmium (Cd), mercury (Hg) lead (Pb) arsenic (As)—and the mixture of all four metals (Mix) on MCF7 cancer cells, in the presence and absence of the antioxidant glutathione (GSH). The study was carried out using real time cell electronic sensing (RT-CES). RT-CES monitors in real time the electrical impedance changes at the electrode/culture medium interface due to the number of adhered cells, which is used as an index of cell viability. Cells were seeded for 24 h before exposure to the metals and their mixtures. The results showed that in the presence and absence of cellular glutathione, arsenic was the most cytotoxic of all five treatments, inducing cell death after 5 h of exposure. Lead was the least cytotoxic in both scenarios. In the presence of cellular GSH, the cytotoxic trend was As > Cd > MIX > Hg > Pb, while in the absence of GSH, the cytotoxic trend was As > Hg > MIX > Cd > Pb. The findings from this study indicate the significance of glutathione-mediated toxicity of the metals examined—particularly for mercury—and may be clinically relevant for disorders such as autism spectrum disorder where decreased glutathione-based detoxification capacity is associated with increased mercury intoxication.

Inhibition of HIV-1 enzymes, antioxidant and anti-inflammatory activities of Plectranthus barbatus

Ethnopharmacological relevancePlectranthus barbatus is widely used in African countries as an herbal remedy to manage HIV/AIDS and related conditions. Aim of the studyTo investigate the HIV-1 inhibitory, anti-inflammatory and antioxidant properties of P. barbatus and thereby provide empirical evidence for the apparent anecdotal success of the extracts. Materials and methodsEthanolic extract of P. barbatus's leaves was screened against two HIV-1 enzymes: protease (PR) and reverse transcriptase (RT). Cytotoxicity of the extract was determined through measuring tetrazolium dye uptake of peripheral blood mononuclear cells (PBMCs) and the TZM-bl cell line. Confirmatory assays for cytotoxicity were performed using flow cytometry and real-time cell electronic sensing (RT-CES). The free radical scavenging activity of the extract was investigated with 2,2-diphenyl-1-picrylhydrazyl while the anti-inflammatory properties of the plant extract were investigated using a Th1/Th2/Th17 cytometric bead array technique. ResultsP. barbatus extract inhibited HIV-1PR and the 50% inhibitory concentration (IC50) was 62.0µg/ml. The extract demonstrated poor inhibition of HIV-1 RT. Cytotoxicity testing presented CC50 values of 83.7 and 50.4µg/ml in PBMCs and TZM-bl respectively. In addition, the extract stimulated proliferation in HIV negative and positive PBMCs treated. RT-CES also registered substantial TZM-bl proliferation after extract treatment. The extract exhibited strong antioxidant activity with an IC50 of 16µg/ml and reduced the production of pro-inflammatory cytokines indicating anti-inflammatory potential. ConclusionThis is the first demonstration of the in vitro anti HIV-1 potential of P. barbatus including direct activity as well as through the stimulation of protective immune and inflammation responses. The low cytotoxicity of the extract is also in agreement with the vast anecdotal use of this plant in treating various ailments with no reported side-effects.

Abstract 3816: DNA variation at BARD1 predicts response to aurora kinase inhibition in neuroblastoma.

Abstract Background: Neuroblastoma remains responsible for a disproportionately high number of pediatric cancer deaths, necessitating novel treatment approaches. Our lab has previously reported DNA variations in the BRCA1-associated RING domain 1 (BARD1) gene to be significantly associated with high-risk neuroblastoma in an ongoing genome-wide association study (Capasso Nat Gen 2009). The expression of an oncogenic isoform, BARD1β, correlated with this disease associated common variation, and isoform specific depletion showed differential growth inhibition in a risk haplotype dependent manner (Bosse Can Res 2012). Furthermore, this isoform was shown to bind to and stabilized aurora kinase A and B in neuroblastoma cells, suggesting a mechanism for its oncogenicity and a potential therapeutic strategy. Methods: Short interfering RNAs (siRNAs) targeting AURKA, AURKB and BARD1β were tested individually in a panel of neuroblastoma cell lines (n=8) stratified by risk haplotype. Cell growth was measured by real time cell electronic sensing (RT-CES), and mRNA knockdown was confirmed by quantitative PCR. The pharmacologic inhibitors MLN8237, a selective aurora kinase A inhibitor; AZD1152, a selective aurora kinase B inhibitor; and CCT137690, a pan-aurora kinase A and B inhibitor were tested in vitro in an expanded neuroblastoma cell line panel (n=10), and cell viability was measured with a CellTiter-Glo(R) Luminescent Cell Viability Assay. Results: AURKB knockdown resulted in a trend of greater growth inhibition in neuroblastoma cell lines harboring a BARD1 risk haplotype, directly correlating with growth inhibition following BARD1β knockdown (R2=0.57, p=0.03). AURKA depletion showed significant growth inhibition (mean inhibition=45%, p&amp;lt;0.0001), but no correlation with BARD1 genotype was observed. Aurora A kinase inhibition with MLN8237 resulted in significant cytotoxicity (IC50 30 -750nM), and further analysis of published studies using MLN8237 in vivo on murine xenograft models of neuroblastoma showed that the cell lines with the BARD1 risk haplotype had significantly greater tumor reduction with this single agent therapy. AZD1152 and CCT137690 were less potent inhibitors of growth (IC50 30nM-10mM and 250nM-3mM, respectively). Conclusion: Taken together, these data support a model of BARD1 acting in a pathway involving the aurora kinase proteins in neuroblastoma cells, suggesting that BARD1 genotypes have the potential to be a biomarker of aurora kinase inhibitor activity, but the associations are complex and unlikely to be binary predictors of sensitivity or insensitivity. These data support the continued investigation of MLN8237 in clinical trials for high-risk neuroblastoma and further exploration of the mechanisms by which DNA variation at BARD1 influences neuroblastoma oncogenicity and therapeutic vulnerabilities. Citation Format: Vanessa M. Pineros, Kris R. Bosse, Lori S. Hart, Sharon J. Diskin, JulieAnn Rader, John M. Maris. DNA variation at BARD1 predicts response to aurora kinase inhibition in neuroblastoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3816. doi:10.1158/1538-7445.AM2013-3816

Evaluation of NK cell function by flowcytometric measurement and impedance based assay using real-time cell electronic sensing system.

Although real-time cell electronic sensing (RT-CES) system-based natural killer (NK) cytotoxicity has been introduced, it has not been evaluated using human blood samples. In present study, we measured flowcytometry based assay (FCA) and RT-CES based NK cytotoxicity and analyzed degranulation activity (CD107a) and cytokine production. In 98 healthy individuals, FCA with peripheral blood mononuclear cells (PBMCs) at effector to target (E/T) ratio of 32 revealed 46.5 ± 2.6% cytolysis of K562 cells, and 23.5 ± 1.1% of NK cells showed increased degranulation. In RT-CES system, adherent NIH3T3 target cells were resistant to basal killing by PBMC or NK cells. NK cell activation by adding IL-2 demonstrated real-time dynamic killing activity, and lymphokine-activated PBMC (E/T ratio of 32) from 15 individuals showed 59.1 ± 6.2% cytotoxicity results after 4 hours incubation in RT-CES system. However, there was no significant correlation between FCA and RT-CES cytotoxicity. After K562 target cell stimulation, PBMC produced profound proinflammatory and immunoregulatory cytokines/chemokines including IL-2, IL-8, IL-10, MIP-1α β, IFN-γ, and TNF-α, and cytokine/chemokine secretion was related to flowcytometry-based NK cytotoxicity. These data suggest that RT-CES and FCA differ in sensitivity, applicability and providing information, and further investigations are necessary in variable clinical conditions.

Involvement of P38MAPK in human corneal endothelial cell migration induced by TGF-β2

Because human corneal endothelial cells do not proliferate once the endothelial monolayer is formed, corneal wound healing is thought to be mediated by cell enlargement or migration rather than proliferation. However, the cellular mechanisms involved in corneal wound healing have not been fully determined. Because transforming growth factor-β2 (TGF-β2) isoform is present in high concentrations in normal human aqueous humor, it may play a role in human corneal endothelial cell wound healing. The purpose of this study was to determine the effect of TGF-β2 on the proliferation and migration of cultured human corneal endothelial cells (HCECs). To achieve this, we first examined the effect of TGF-β2 on the wound closure rate in an in vitro HCEC wound healing model. However, unexpectedly TGF-β2 had no effect on the wound closure rate in this model. Therefore, a real-time cell electronic sensing (RT-CES) system and the BrdU incorporation assay were used to determine the effect of TGF-β2 (0.1–10 ng/ml) on cultured HCEC proliferation during in vitro wound healing. The specificity of this effect was confirmed by adding the TGF-β receptor I kinase inhibitor. TGF-β2 inhibited the proliferation of HCECs in a dose dependent way and was blocked by TGF-β receptor I kinase inhibitor. Next, the Boyden chamber assay was used to determine how TGF-β2 (10 ng/ml) affect HCEC migration. Exposure to TGF-β2 increased cell migration, and a synergistic effect was observed when FGF-2 was added. To determine whether the mitogen-activated protein kinase (MAPK) signaling pathway is involved in the migration of HCECs, western blot analysis and Bio-Plex™ suspension array were used to detect phosphorylation of Erk1/2, p38, and JNK in HCECs stimulated by TGF-β2 and/or FGF-2. The effect of the p38 MAPK inhibitor, SB239063 (10 μM), on TGF-β2 and/or FGF-2-induced cellular migration was determined by the Boyden chamber assay. Both TGF-β2 and FGF-2-induced p38 phosphorylation, and a synergistic effect was observed with exposure to both growth factors. SB 239063 inhibited TGF-β2 and FGF-2-induced migration of HCECs. These results indicate that TGF-β2 reduces proliferation but stimulates migration of cultured HCECs. In addition, TGF-β2 and FGF-2 may have synergistic effects on the migration of HCECs mediated by p38 MAPK phosphorylation.