Types Of Human Cell Lines Research Articles

1-Naphthaleneacetic Acid Improved the In Vitro Cell Culturing by Inhibiting Apoptosis.

In vitro cell culturing witnessed its applications in scientific research and industrial activities. Attempts to shorten the doubling time of cultured cells have never ceased. In plants, auxin is applied to promote plant growth, the synthetic derivative 1-Naphthaleneacetic acid (NAA) is a good example. Despite the auxin's naturally occurring receptors are not present in mammalian cells, studies suggested they may affect cell culturing. Yet the effects and mechanisms are still unclear. Here, an up to 2-fold increase in the yield of in vitro cultured human cells is observed. Different types of human cell lines and primary cells are tested and found that NAA is effective in all the cells tested. The PI staining followed by FACS suggested that NAA do not affect the cell cycling. Apoptosis-specific dye staining analysis implicated that NAA rescued cell death. Further bulk RNA sequencing is done and it is identified that the lipid metabolism-engaging and anti-apoptosis gene, ANGPTL4, is enhanced in expression upon NAA treatment. Studies on ANGPTL4 knockout cells indicated that ANGPTL4 is required for NAA-mediated response. Thus, the data identified a beneficial role of NAA in human cell culturing and highlighted its potency in in vitro cell culturing.

Cellular and bioenergetic effects of polystyrene microplastic in function of cell type, differentiation status and post-exposure time

The ubiquity of microplastics (MPs) in food sources and personal care products increasingly raises concerns on human health. However, little is known about the duration of the effects of MPs and whether effects depend on cellular differentiation status. Herein, cellular and bioenergetic effects of MPs in different exposure scenarios on four types of human cell lines derived from lung (A549 and BEAS-2B), colon (Caco-2) and liver (HepG2) were investigated. These cell lines are models for the major exposure routes in the body (inhalation, ingestion and physiological transport through the liver by the portal vein). To this aim, different scenarios were implemented by exposing undifferentiated and differentiated cells to single dosing of 2-μm polystyrene (PS) (102-105 particles/mL) for 48 h and 12 days. The undifferentiated Caco-2 cells with short exposure (48 h) showed the highest uptake rate of PS yet without significant cellular and mitochondrial responses. The biological effects, with the exception of ROS production, were not influenced by differentiation states of A549 and Caco-2 cells although differentiated cells showed much weaker ability to internalize PS. However, PS had significantly long-term impacts on cellular and mitochondrial functions even after the initial exposure period. In particular, Caco-2 cells that were post-exposed for 12 days after single PS dosing suffered higher oxidative stress and exhibited mitochondrial dysfunction than that for short exposure. Correspondingly, we observed that PS particles still remained in cell membrane and even in nuclei with high retention rate by 14-d post exposure during which metabolism and exchange of internalization and release occurred in cells. This indicates PS could induce chronic stress and even harmful effects on human cells after single intake that persists for a long time. This study paves the way for assessing the influence of PS on human health at low particle concentrations and with multiple exposure scenarios.

A Reverse Mutation E143K within the PrM Protein of Zika Virus Asian Lineage Natal RGN Strain Increases Infectivity and Cytopathicity.

Zika virus (ZIKV) is a positive-sense single-stranded RNA virus in the Flaviviridae, which is classified into two different lineages Asian and African. The outbreak of ZIKV Asian lineage isolates in 2015–2016 is associated with the increase in cases with prenatal microcephaly and Guillain–Barré syndrome, and has sparked attention throughout the world. Genome sequence alignment and the analysis of Asian and African lineage isolates indicate that amino acid changes, particular in positively charged amino acid substitutions in the pr region of prM protein might involve a phenotypic change that links with the global outbreak of ZIKV Asian-lineage. The study generated and characterized the virological properties of wild type and mutants of single-round infectious particles (SRIPs) and infectious clones (i.c.s) of ZIKV Asian-lineage Natal RGN strain, and then identified the function of amino acid substitutions at the positions 139 [Asn139→Ser139 (N139S)] and 143 [Glu143→Lys143 (E143K)] in ZIKV polyproteins (located within the pr region of prM protein) in the infectivity and cytopathogenicity. The E143K SRIP and i.c. of Natal RGN strain exhibited relatively higher levels of cytopathic effect, EGFP reporter, viral RNA and protein synthesis, and virus yield in three types of human cell lines, TE617, SF268 and HMC3, compared to wild type (WT), N139S SRIPs and i.c.s, which displayed more efficiency in replication kinetics. Additionally, E143K Natal RGN i.c. had greater activities of virus attachment and entry, yielded higher titers of intracellular and extracellular virions, and assembled the E proteins near to the plasma membrane in infected cells than the other i.c.s. The results indicate that the positively charged amino acid residue Lys143, a conserved residue in the pr region of prM of ZIKV African lineages, plays a crucial role in viral replication kinetics, including viral attachment, entry, assembly and egress. Thus, the negatively charged amino acid residue Glu143 within the pr region of prM leads to an alteration of the phenotypes, in particular, a lower replication efficiency of ZIKV Asian-lineage isolates with the attenuation of infectivity and cytopathicity.

Responsiveness assessment of cell cultures exposed to poly(tartaric acid) and its corresponding magnetic nanostructures

Cancer incidence is increasing progressively in recent years, and its wide distribution among younger generations raises even greater concerns. This caused an acceleration in the development of medicine by implementing modern methods for diagnosis, treatment, and therapy. In this context, polymer-functionalized magnetic nanomaterials evolved as helpful tools for both the medical and pharmacological fields. The present study reports the structural analysis and biocompatibility assessment of poly(tartaric acid) and its corresponding magnetic nanostructures. The current research aimed to elaborate a preliminary study on the responsiveness assessment of cell cultures exposed to these nanomaterials for future biomedical applications. Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) highlighted the successful attachment of the polyester on the magnetite surface and the preparation of the core-shell magnetic nanostructures. Biochemical experiments were performed in vitro on three types of human cell lines: normal keratinocytes, lung carcinoma, and skin melanoma. Viability, membrane integrity, and oxidative analyses performed on the obtained nanostructures proved a great inhibitory potential against cancer cell lines and little to no harmful effect against normal cell lines.

Spirulina maxima L-asparaginase: Immobilization, Antiviral and Antiproliferation Activities.

L-asparaginase (L-AsnA) enzyme has gained significant attention in the food, biocatalysts and pharmaceutics industry. It (L-AsnA) has been widely used in food processing industries as a promising acrylamide mitigating agent and as a therapeutic agent in the treatment of certain human cancers. Based on US Patent (4,433,054; 1984), L-asparaginase (L-AsnA) enzyme is immobilized by admixing the active enzyme on the polysaccharide to be in a gel form. The storage stability of immobilized L-AsnA enzyme and its anti-proliferation and antiviral activity were determined. In the present study, S. maxima was cultured at large scales (300 liter) for the production of enough extracellular L-asparaginase (L-AsnA) using modified (high N concentration) Zarrouk medium as we reported in a previous study. L-AsnA was immobilized on natural polymers, as agar cake beads, agarose pieces and gelatin blocks, in order to evaluate the efficiency of physical entrapment techniques. Anti-proliferation properties of L-AsnA against lung carcinoma A549, hepatocellular carcinoma Hep-G2 and prostate carcinoma PC3 human cancer cell lines were assessed by the MTT cell viability method. In addition, the antiviral activity against Coxsackie B3 (CSB3) Virus was assessed. The highest L-AsnA immobilized activity and immobilization yield were achieved with agar cakes bead. The purified S. maxima L-AsnA showed good antiviral activity against Coxsackie B3 (CSB3) Virus in a dose-dependent manner with an IC50 value 17.03 μg/ml. The antiviral mode of action is presumably due to their capability of inhibiting attachment, blocking the adsorption and penetration event of the viral replication cycle with 89.24%, 72.78% and 72.78%, respectively. Also, S. maxima L-AsnA showed anti-proliferation effect against lung carcinoma A549, hepatocellular carcinoma Hep-G2 and prostate carcinoma PC3 human cancer cell lines, with an IC50 of 22.54, 24.65 and 56.61 μg/ml, respectively. It is interesting to favor L-asparaginase of S. maxima which showed antiviral activity and anti-proliferation effect against different types of human cell lines. Thus, S. maxima microalgae might be a good source for L-AsnA enzymes and can be immobilized on natural polymers.

A high-throughput three-dimensional cell culture platform for drug screening

Traditional two-dimensional (2D) cell cultures lack the extracellular matrix (ECM)-like structure or dynamic fluidic microenvironment for cells to maintain in vivo functionality. Three-dimensional (3D) tissue scaffolds, on the other hand, could provide the ECM-like microenvironment for cells to reformulate into tissue or organoids that are highly useful for in vitro drug screening. In this study, a high-throughput two-chamber 3D microscale tissue model platform is developed. Porous scaffolds are selectively foamed on a commercially available compact disk using laser. Perfusion of cell culture medium is achieved with centrifugal force-driven diffusion by disk rotation. Experimental studies were conducted on the fabrication process under various gas saturation and laser power conditions. Cell cultures were performed with two types of human cell lines: M059K and C3A-sub28. It is shown that the structure of microscale porous scaffolds can be controlled with laser foaming parameters and that coating with polydopamine these scaffolds are inducive for cell attachment and aggregation, forming a 3D network. With many such two-chamber models fabricated on a single CD and perfusion driven by the centrifugal force from rotation, the proposed platform provides a simple solution to the high-cost and lengthy drug development process with a high-throughput and physiologically more relevant tissue model system.

One-Component Array Based on a Dansyl-Modified Polylysine: Generation of Differential Fluorescent Signatures for the Discrimination of Human Cells.

A one-component array-based sensor consisting of a dansyl-modified polylysine (PLL-Dnc) is capable of discriminating the types and compositional ratios of human cells using varying buffer conditions. The PLL-Dnc sensor array, which affords turn-on fluorescence responses against analyte cells that depend on the pH value and the ionic strength, generates differential fluorescence signatures of cells and successfully discriminates eight types of human cell lines (2.0 × 104 cells/mL) with 100% accuracy using multivariate analysis. The array also allows differentiation of the composition of the cell mixtures that contain cells with the same tissue origin but of different subtypes. The good discrimination ability and simple platform of our "one-component"-based array allows an easy and rapid sensing of cells without requiring any information on specific biomarkers.

GENETIC EFFECT OF MIGRATORY COMPOUNDS FROM BOTTLED NATURAL DRINKING WATER STORED UNDER DIRECT SUNLIGHT

The drinking water is one of the important routes for human exposure to contaminants through releasing of antimony (Sb) and polymers from polyethylene terephthalate (PET) plastic. The aim of this study was to investigate the effect of sunlight on chemical compounds migration into PET-bottled water and studying the cytotoxicity of di-butyl phthalate (DBP) and di-octyl phthalate (DOP) by SMART in Drosophila melanogaster. Four random water bottle samples produced by various companies as: A (PET, clear, 0.6L), B (PET, clear, 1.5L), C (PET, blue, 1.5L) and D (polycarbonate PC, blue, 19L) for studying the effect of direct sunlight exposure on migration of antimony and phthalates. Experiment was carried out in the presence of sunlight (7 h daily) for 210 day. The migrated compounds profile (µg/L) that detected sample (A) before storage were only two compounds formaldehyde (FA) and acetaldehyde (AA) out of nine compounds. During storage under sunlight, four compounds (Sb), bis-phenol A (BPA), dimethyl phthalate (DMP) and diethyl phthalate (DEP) were increased till 30th day then did not affect till the end of storage. Other detected compounds were continuously progressed till the end of storage with different rates. The highest rate was appeared in case of FA, it was 222 fold followed by DOP compound (173 fold) as well as DBP (75.3 fold) and finally the AA compound with 17.9 fold. Regarding to another sample B, only 3 compounds (BPA, DMP and DBP) were not detected at zero time. The AA compound was detected with the highest concentration (0.9µg/L) and the lowest one was DOP (0.007µg/L). Only four compounds were detected before storage named Sb, DOP, FA and AA, the lowest level (0.006µg/L) was noticed in DOP, while the moderate level was recorded in FA (0.03µg/L) and Sb (0.08µg/L). Other detected compounds; i.e. DBP, DOP, AA and FA were consequently increased with higher levels. This study investigated genotoxic effects of (DBP) and (DOP) at 30µg/ml concentration using the somatic mutation and recombination test (SMART). The cytotoxicity of the tested phthalate compounds was also assessed at five different concentrations 0.5, 1, 5, 10 and 20µg/ml in two types of human cell lines; liver cancer (HepG2), colon cancer (HCT-116) using neutral red cytotoxicity assay. All of tested compounds significantly showed high levels of tumor induction and frequency compared to the negative control in SMART assay. It was also reduced the viability of the HepG2 cell lines cells using different concentrations and the highest cytotoxic effect. While, on HCT-116 showed no cytotoxic effect.

CLC-Pred: A freely available web-service for in silico prediction of human cell line cytotoxicity for drug-like compounds.

In silico methods of phenotypic screening are necessary to reduce the time and cost of the experimental in vivo screening of anticancer agents through dozens of millions of natural and synthetic chemical compounds. We used the previously developed PASS (Prediction of Activity Spectra for Substances) algorithm to create and validate the classification SAR models for predicting the cytotoxicity of chemicals against different types of human cell lines using ChEMBL experimental data. A training set from 59,882 structures of compounds was created based on the experimental data (IG50, IC50, and % inhibition values) from ChEMBL. The average accuracy of prediction (AUC) calculated by leave-one-out and a 20-fold cross-validation procedure during the training was 0.930 and 0.927 for 278 cancer cell lines, respectively, and 0.948 and 0.947 for cytotoxicity prediction for 27 normal cell lines, respectively. Using the given SAR models, we developed a freely available web-service for cell-line cytotoxicity profile prediction (CLC-Pred: Cell-Line Cytotoxicity Predictor) based on the following structural formula: http://way2drug.com/Cell-line/.

Synthesis and biological evaluation of novel 5-chloro-N-(4-sulfamoylbenzyl) salicylamide derivatives as tubulin polymerization inhibitors.

A novel series of sulfonamide derivatives, coupled with a salicylamide scaffold, was designed and synthesized. The structures of the synthesized compounds were established using 1H NMR, 13C NMR and high-resolution mass spectroscopy. The synthesized compounds were tested in vitro against five types of human cell lines. Two were breast adenocarcinoma, including the hormone-dependent MCF-7 and the hormone-independent MDA-MB-231. The others were the colorectal adenocarcinoma Caco-2, the carcinoma HCT-116 and the immortalized retinal-pigmented epithelium, hTERT-RPE1. Nine sulfonamides were able to inhibit the growth of the four tested cancer cells. Compound 33 was the most active against the selected colon cancer (Caco-2 and HCT-116) subtypes, while compound 24 showed the best efficacy against the examined breast cancer (MCF-7 and MDA-MB-231) cells. The selectivity index introduced compounds 24 and 33 as having the best selectivity among the breast and colon subtypes, respectively. In vitro tubulin polymerization experiments and flow cytometric assays showed that compounds 24 and 33 led to cell cycle arrest at the G2/M phase in a dose-dependent manner by effectively inhibiting tubulin polymerization. Furthermore, the results of the molecular docking studies indicate that this class of compounds can bind to the colchicine-binding site of tubulin.

Photocatalytic degradation, toxicological assessment and degradation pathway of C.I. Reactive Blue 19 dye

Efficient degradation of dye-based environmental pollutants and industrially contaminated wastewater remains a formidable challenge. The photo-assisted catalytic degradation of anthraquinone Reactive Blue 19 (RB-19) dye was investigated by varying the operational parameters such as reaction time, catalyst (titanium dioxide, TiO2) loading, initial dye concentration, and hydrogen peroxide (H2O2) concentration. Pronounced dye degradation reaction was achieved at 1.0g/L of TiO2 after 180min of degradation period with 0.3×10−3mol/L of H2O2. UPLC/MS analysis scrutinized the intermediates and based on the electrospray ionization mass spectrometry (ESI-MS) analysis. A mechanistic degradation pathway has also been proposed. The complete degradation of RB-19 was confirmed by total organic carbon (TOC) and chemical oxygen demand (COD) analysis. Toxicity profile of untreated and photo catalytically-degraded dye was evaluated using three types of human cell lines, i.e., MCF 7, L 929 and HeLa cells. It was observed that transformed byproducts of RB-19 were less toxic than the original dye molecule. In conclusion, the UV/TiO2 mediated process can promisingly degrade RB-19 dye under optimized conditions. It is evident from the data obtained that the newly developed UV/TiO2-assisted mechanism could practically be used for the degradation of industrial dyes and/or dyes based waste effluents.

Oscillations of ultra-weak photon emission from cancer and non-cancer cells stressed by culture medium change and TNF-\u03b1

Cells spontaneously emit photons in the UV to visible/near-infrared range (ultra-weak photon emission, UPE). Perturbations of the cells’ state cause changes in UPE (evoked UPE). The aim of the present study was to analyze the evoked UPE dynamics of cells caused by two types of cell perturbations (stressors): (i) a cell culture medium change, and (ii) application of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α). Four types of human cell lines were used (squamous cell carcinoma cells, A431; adenocarcinomic alveolar basal epithelial cells, A549; p53-deficient keratinocytes, HaCaT, and cervical cancer cells, HeLa). In addition to the medium change, TNF-α was applied at different concentrations (5, 10, 20, and 40 ng/mL) and UPE measurements were performed after incubation times of 0, 30, 60, 90 min, 2, 5, 12, 24, 48 h. It was observed that (i) the change of cell culture medium (without added TNF-α) induces a cell type-specific transient increase in UPE with the largest UPE increase observed in A549 cells, (ii) the addition of TNF-α induces a cell type-specific and dose-dependent change in UPE, and (iii) stressed cell cultures in general exhibit oscillatory UPE changes.

LC/ESI-MS/MS profiling of Ulmus parvifolia extracts and evaluation of its anti-inflammatory, cytotoxic, and antioxidant activities.

In this study, a comparative liquid chromatography/mass spectroscopy (LC/ESI-MS/MS) profiling of different fractions of Ulmus parvifolia leaves and stems was performed. Identification of compounds was based on comparing the mass spectrometric information obtained including m/z values and individual compound fragmentation pattern to tandem mass spectral library search and literature data. Eleven compounds were tentatively identified in the different analyzed fractions. One of the major constituents of this plant was isolated and identified as Icariside E4 [dihydro-dehydro-diconiferyl alcohol-4-O-α-L-rhamnopyranoside] (5). The evaluation of anti-inflammatory activity of the total methanolic extract using nitric oxide inhibition on LPS-stimulated RAW 264.7 cells model strong anti-inflammatory activity with 17.5% inhibition of nitric oxide production versus 10% inhibition for dexamethasone. The cytotoxic activity of the methanolic extract and Icariside E4 was evaluated against four types of human cell lines using MTT assay. Icariside E4 showed cytotoxic effect against Hep-G2, MCF-7, and CACO-2 cell lines compared to a negligible activity for the total extract. The same extract showed a moderate antioxidant activity with SC50=362.5 μg/mL.

Discovery of characteristic molecular signatures for the simultaneous prediction and detection of environmental pollutants

Gene expression data may be very promising for the classification of toxicant types, but the development and application of transcriptomic-based gene classifiers for environmental toxicological applications are lacking compared to the biomedical sciences. Also, simultaneous classification across a set of toxicant types has not been investigated extensively. In the present study, we determined the transcriptomic response to three types of ubiquitous toxicants exposure in two types of human cell lines (HepG2 and HL-60), which are useful in vitro human model for evaluation of toxic substances that may affect human hepatotoxicity (e.g., polycyclic aromatic hydrocarbon [PAH] and persistent organic pollutant [POP]) and human leukemic myelopoietic proliferation (e.g., volatile organic compound [VOC]). The findings demonstrate characteristic molecular signatures that facilitated discrimination and prediction of the toxicant type. To evaluate changes in gene expression levels after exposure to environmental toxicants, we utilized 18 chemical substances; nine PAH toxicants, six VOC toxicants, and three POP toxicants. Unsupervised gene expression analysis resulted in a characteristic molecular signature for each toxicant group, and combination analysis of two separate multi-classifications indicated 265 genes as surrogate markers for predicting each group of toxicants with 100 % accuracy. Our results suggest that these expression signatures can be used as predictable and discernible surrogate markers for detection and prediction of environmental toxicant exposure. Furthermore, this approach could easily be extended to screening for other types of environmental toxicants.

Aldose reductase from Schistosoma japonicum: crystallization and structure-based inhibitor screening for discovering antischistosomal lead compounds

BackgroundSchistosomiasis is a neglected tropical disease with high morbidity and mortality in the world. Currently, the treatment of this disease depends almost exclusively on praziquantel (PZQ); however, the emergence of drug resistance to PZQ in schistosomes makes the development of novel drugs an urgent task. Aldose reductase (AR), an important component that may be involved in the schistosome antioxidant defense system, is predicted as a potential drug target.MethodsThe tertiary structure of Schistosoma japonicum AR (SjAR) was obtained through X-ray diffraction method and then its potential inhibitors were identified from the Maybridge HitFinder library by virtual screening based on this structural model. The effects of these identified compounds on cultured adult worms were evaluated by observing mobility, morphological changes and mortality. To verify that SjAR was indeed the target of these identified compounds, their effects on recombinant SjAR (rSjAR) enzymatic activity were assessed. The cytotoxicity analysis was performed with three types of human cell lines using a Cell Counting Kit-8.ResultsWe firstly resolved the SjAR structure and identified 10 potential inhibitors based on this structural model. Further in vitro experiments showed that one of the compounds, renamed as AR9, exhibited significant inhibition in the activity of cultured worms as well as inhibition of enzymatic activity of rSjAR protein. Cytotoxicity analysis revealed that AR9 had relatively low toxicity towards host cells.ConclusionsThe work presented here bridges the gap between virtual screening and experimental validation, providing an effective and economical strategy for the development of new anti-parasitic drugs. Additionally, this study also found that AR9 may become a new potential lead compound for developing novel antischistosomal drugs against parasite AR.

Antioxidant and Anticarcinogenic Effects of Methanolic Extract and Volatile Oil of Fennel Seeds (Foeniculum vulgare)

The present study evaluated the efficacy of fennel seed methanolic extract (FSME) for its antioxidant, cytotoxic, and antitumor activities and for its capacity to serve as a nontoxic radioprotector in Swiss albino mice. We also assessed the natural antioxidant compounds of FSME for use in industrial application. Cytotoxic activity of FSME was evaluated in a mouse model of Ehrlich ascites carcinoma (EAC) and on different types of human cell lines in vitro. The safety and optimum dose of FSME were determined. FSME, 100 mg/kg, was injected intraperitoneally into mice bearing EAC before the mice were exposed to three 2-Gy doses of gamma irradiation. After 30 days, mice were fasted for 18 hours and then sacrificed to observe the lifespan of EAC-bearing hosts. Malondialdehyde (MDA), catalase activity, glutathione content, and total protein in serum, liver tissue, and ascitic fluid were determined. Iron, total iron-binding capacity, transferrin, and ferritin were also evaluated in serum. The data showed the presence of different types of compounds in FSME, such as flavonoids, terpenoids, alkaloids, phenols, and sterols; estragole (71.099%) was the predominant alcohol, gallic acid was the phenolic compound (18.895%), and L-limonene was the most prevalent monoterpene hydrocarbon (11.967%). The mean±standard deviation 50% inhibitory concentrations were 50±0.03 μg/mL for the MCF7 breast cancer cell line and 48±022 μg/mL for the Hepg-2 liver cancer cell line. The significant increase in MDA levels and the significant decrease in catalase activity and glutathione content in liver and tumor tissue in mice bearing EAC were ameliorated after FSME administration. In contrast, total protein content was increased in ascitic fluid. Serum iron was inversely proportional to the levels of ferritin and transferrin and total iron-binding capacity. Administration of FSME before irradiation exerted a cytoprotective effect against gamma irradiation, as manifested by a restoration of the MDA level, catalase activity, and GSH content to near-normal levels. In conclusion, FSME may have remarkable anticancer potential against a breast cancer cell line (MCF7) and liver cancer cell line (Hepg-2). It also showed strong free radical-scavenging activity (100%). Thus, FSME may reduce oxidative stress and protect mouse cells from damage caused by reactive oxygen species. In addition, it could be used as a safe, effective, and easily accessible source of natural antioxidants to improve the oxidative stability of fatty foods during storage. FSME also exhibited an antitumor effect by modulating lipid peroxidation and augmenting the antioxidant defense system in EAC-bearing mice with or without exposure to radiation.

Protein Sensing and Cell Discrimination Using a Sensor Array Based on Nanomaterial-Assisted Chemiluminescence

Cross-reactive sensor arrays, known as "chemical noses", offer an alternative to time-consuming analytical methods. Here, we report a sensor array based on nanomaterial-assisted chemiluminescence (CL) for protein sensing and cell discrimination. We have found that the CL efficiencies are improved to varied degrees for a given protein or cell line on catalytic nanomaterials. Distinct CL response patterns as "fingerprints" can be obtained on the array and then identified through linear discriminant analysis (LDA). The sensing of 12 kinds of proteins at three concentrations, as well as 12 types of human cell lines among normal, cancerous, and metastatic, has been performed. Compared with most fluorescent or colorimetric approaches which rely on the strong interaction between analytes and sensing elements, our array offers the advantage of both sensitivity and reversibility.

Commentary on Resveratrol and Hormesis: Resveratrol—a hormetic marvel in waiting?

Hormesis is a phenomenon in which adaptive responses to low doses of otherwise-harmful factors (also called mild stressors) make cells and organisms more robust. In their review, Calabrese et al. provide evidence for resveratrol acting hormetically in different types of human cell lines. The effects of resveratrol represent a 'two-edged sword' in that it has contrasting effects at low and high doses in healthy and cancerogenous cells. What demarcates a low and a high dose needs to be clarified. Concentrations tested in cell cultures, moreover, may not be relevant to whole organisms. And data from animal models need not apply to humans. Co-morbidities should also be considered. More research is needed to understand the action of resveratrol on all cell types and conditions, and the optimum therapeutic concentration that applies to each of these. Future research needs to determine the dynamics of the effects of resveratrol in different subcellular compartments and the interactions of these. In addition, the interactions between resveratrol, environmental factors, other compounds and medications, diseases and the genetic background of the individual will need to be appreciated in order to gain a complete understanding of the hormetic response of resveratrol.

The BCL-2 5′ Untranslated Region Contains an RNA G-Quadruplex-Forming Motif That Modulates Protein Expression

The BCL-2 gene encodes a 25 kDa membrane protein that plays critical roles in the control of apoptosis. The regulation of BCL-2 gene expression is highly complex and occurs both transcriptionally and posttranscriptionally. In particular, the 5' upstream region of BCL-2 contains a number of elements that control its expression. We have identified a highly conserved 25-nucleotide G-rich sequence (BCL2Q), with potential to fold into a RNA G-quadruplex structure, located 42 nucleotides upstream of the translation start site of human BCL-2. In this study, we used a series of biophysical experiments to show that the BCL2Q sequence folds into a stable RNA G-quadruplex in vitro, and we conducted functional luciferase reporter-based assays, in a cell-free lysate and in three types of human cell lines, to demonstrate that the BCL2Q sequence modulates protein expression in the context of the 493-nucleotide native 5' untranslated region of BCL-2.

Hypoxia reduces the expression of heme oxygenase‐2 in various types of human cell lines

Heme oxygenase consists of two structurally related isozymes, heme oxygenase-1 and and heme oxygenase-2, each of which cleaves heme to form biliverdin, iron and carbon monoxide. Expression of heme oxygenase-1 is increased or decreased depending on cellular microenvironments, whereas little is known about the regulation of heme oxygenase-2 expression. Here we show that hypoxia (1% oxygen) reduces the expression levels of heme oxygenase-2 mRNA and protein after 48 h of incubation in human cell lines, including Jurkat T-lymphocytes, YN-1 and K562 erythroleukemia, HeLa cervical cancer, and HepG2 hepatoma, as judged by northern blot and western blot analyses. In contrast, the expression level of heme oxygenase-1 mRNA varies under hypoxia, depending on the cell line; it was increased in YN-1 cells, decreased in HeLa and HepG2 cells, and remained undetectable in Jurkat and K562 cells. Moreover, heme oxygenase-1 protein was decreased in YN-1 cells under the conditions used, despite the induction of heme oxygenase-1 mRNA under hypoxia. The heme oxygenase activity was significantly decreased in YN-1, K562 and HepG2 cells after 48 h of hypoxia. To explore the mechanism for the hypoxia-mediated reduction of heme oxygenase-2 expression, we showed that hypoxia shortened the half-life of heme oxygenase-2 mRNA (from 12 h to 6 h) in YN-1 cells, without affecting the half-life of heme oxygenase-1 mRNA (9.5 h). Importantly, the heme contents were increased in YN-1, HepG2 and HeLa cells after 48 h of incubation under hypoxia. Thus, the reduced expression of heme oxygenase-2 may represent an important adaptation to hypoxia in certain cell types, which may contribute to the maintenance of the intracellular heme level.