... Accession Number : ADA246026. Title : Heat Induces Intracellular Acidification in Human A-431 Cells: Role of Na+ -H+ Exchange and Metabolism. ...

We have developed an online analytical method that combines A431 cell membrane chromatography (A431/CMC) with high performance liquid chromatography and mass spectrometry (LC/MS) for identifying active components from Radix Caulophylli acting on human EGFR. Retention fractions on A431/CMC model ...

... 1 2 acridine orange staining, and lactate dehydrogenase re- lease (13). ... bromide-acridine orange; lactate dehydrogenase (LDH) measurements ...

We report progress on performing a cell-based assay for the detection of EGFR on cell surfaces by using upconverting chelates. An upconversion microscope has been developed for performing assays and testing optical response. A431 cells are labeled with europium DOTA and imaged using this ...

To better assess the efficacy of erbB-targeted therapies, it would help to have optical reporting human tumor xenograft models that abundantly express erbB receptors. A-431 cells have frequently been used in erbB1-targeting studies, but a well-characterized optical reporting version of the cell line has not been ...

Essential oils are complex mixtures of odorous and volatile compounds derived from secondary plant metabolism. They can be isolated from many plants by mechanical pressing or hydro- and steam-distillation and are known to induce a wide range of biological effects through their antibacterial, antifungal, cytotoxic, antioxidant and antimutagenic activities. In order to explore their beneficial ...

This study was conducted to develop a quantitative assay system for use in the in vivo evaluation in mice of angiogenesis induced by human tumor cells. The human epidermoid carcinoma cells, A431 cells, were cultured on microcarriers. Microcarrier-attached ...

from embryonic lung were purchased from Coriell Institute (Camden NJ, USA). HCT116 cells, from colon in colon cancer (HCT116) and vulva carcinoma (A431) cancer cell lines as well as in primary IMR90 HeLa 0,1 1 10 100 1000 10000 1000 0,01 0,1 1 10 100 hsp genes HCT116 A431 ...

In this study, the differentiation-promoting effects of terbinafine (Lamisil), TB) were investigated in human epithelioid squamous carcinoma (A431) cells. The polyhydroxyethylmethacrylate (poly-HEMA)- and type-I collagen-coated culture plate models were adapted to harvest the TB-induced differentiated cells by ...

... Furthermore, shock, [Ca2+]J, and cAMP on inositol trisphosphate in human cell toxicity reactions related to PLC-mediated in- epidermoid A-431 ...

Lysophosphatidic acid (LPA) is a bioactive phospholipid that affects various biological functions, such as cell proliferation, migration, survival, wound healing, and tumor invasion through LPA receptors. Previously, we reported that LPA induces A431 colony dispersal, accompanied by disruption of cell-cell contacts ...

Cell interaction with extracellular matrix is a multi-step process characterized by cell attachment to substrata with subsequent cell spreading accompanied by actin cytoskeleton and cellular membrane receptor reorganization. It has been shown elsewhere that epidermoid carcinoma A431 ...

We describe here an analytical method of A431 cell membrane chromatography (A431/CMC) (CMC, cell membrane chromatography) combined with RPLC for recognition, separation, and identification of target components from traditional Chinese medicines (TCMs) Radix Caulophylli. The A431 ...

Condensed chromosomes from mitotic cells of A431 and lymphoblast GM131 cells were purified by a flow cytometric sorting and collected directly onto nitrocellulose discs. The blots containing purified chromosomes from A431 cells were then hybridized against iodinated protein ligands. Positive ...

One of the most fundamental biological processes in tumor metastasis is the process of epithelial-mesenchymal transition (EMT). During EMT, zinc-finger-family of transcription factors such as Snail, Slug and Twist, and matrix metalloproteinases (MMPs) are upregulated, and this correlates with increased tumor cell invasion and motility. We previously obtained a highly invasive ...

The basal levels of inositol monophosphate, inositol bisphosphate, and inositol trisphosphate (InsP3) in A-431 cells incubated in Na+ Hanks' solution were, respectively, 1.23 +/-0.18%, 0.17+/-0.03%, and 0.69+/-0.07% of the total radioactivity in the cell....

-4827/81/080281-10$02.00/0 Experimental Cell Research 134 (1981) 281-290 REORGANIZATION OF ARRAYS OF PREKERATIN FILAMENTS DURING MITOSIS during mitosis. In three out of four cell lines tested (Henle-407, A-431 and HeLa cells) the filamentous prekeratin networks disappeared at the initiation of ...

A431, a transformed cell line, is known to contain a high concentration of EGF receptors (EGFR). Exogenous CAM, when combined with purified membrane from A431 is strongly phosphorylated in the presence of EGF. The EGF-dependent phosphorylation of CAM did not alter the normal profile of the A431 ...

BackgroundCancer progression is closely linked to the epithelial-mesenchymal transition (EMT) process. Studies have shown that there is increased expression of tissue tranglutaminase (TG2) in advanced invasive cancer cells. TG2 catalyzes the covalent cross-linking of proteins, exhibits G protein activity, and has been implicated in the modulation of cell ...

We have recently reported that extracellular ATP induces a transient rise in cytosolic free Ca2+(Ca2+,) in individual human epidermoid carcinoma A431 cells (Gonzalez et al: Journal of Cellular Physiology 135:269-276, 1988). We have new studied nucleotide ...

Detection A. Near-Infrared B. ECL PlexTM ERK1/2 and phospho-ERK were detected in lysates of unstimulated and EGF-stimulated A431 cells. Two fold serial dilutions of lysate are shown. A. Odyssey Near-Infrared-Cell WesternTM assays � PearlTM Imager - Near-Infrared Animal Imaging System System Specifications Laser

nevertheless been recently shown that some similarity in amino acid compositionexistsbetween keratinsD cytokeratin and that the latter is uniformly distributed throughout the keratin network of all cells studied of the polyclonal rabbit antibody against epidermal keratins, respectively. vulva; E, A-431. Bar = 10pm

Ligand-binding assays are commonly applied to large numbers of cells in culture; the binding parameters derived from such assays reflect the ensemble average behavior of many cells. Equilibrium binding assays of epidermal growth factor (EGF) binding to the EGF receptor (EGFR) indicate that the EGFR exhibits two affinity states for EGF, one low affinity ...

Fluorescence resonance energy transfer between epidermal growth factor (EGF) molecules, labeled with fluorescent reporter groups, was used as a monitor for EGF receptor-receptor interactions in plasma membranes isolated from human epidermoid A431 cells. E...

Mystixin-7 and mystixin. II. small peptides structurally related to cortiootropin-releasing factor (CRF). have been shown to attenuate vascular leakage in injured skin. The goal of this study was to characterize changes in cytosolic Ca2+ concentration (Ca...

The function of the endogenous angiogenesis inhibitor thrombospondin-1 (TSP-1) in epithelial tumor development has remained controversial. We studied the in vitro growth characteristics and the in vivo tumor xenograft growth of the human squamous cell carcinoma cell lines A431 and SCC-13, stably transfected to ...

An assay using established cell lines, human A431 epidermal cells and mouse 3T3 fibroblasts, has been developed to predict the phototoxic potential of compounds. The test determines the viability of the two cell lines in response to UV light in both the presence and absence of the test ...

The cell surface receptor for epidermal growth factor (EGFR) is one of the most studied integral membrane proteins. The receptor is widely distributed in cells and tissues of mammalian and avian tissues and plays an important role in growth control. Binding of the epidermal growth factor (EGF) to EGFR initiates a complex biological response, which includes ...

Honokiol is a plant lignan isolated from bark and seed cones of Magnolia officinalis. Recent studies from our laboratory indicated that honokiol pretreatment decreased ultraviolet B-induced skin cancer development in SKH-1 mice. The aim of the present investigation was to study the effects of honokiol on human epidermoid squamous carcinoma A431 ...

Resveratrol (trans-3,4',5-trihydroxystilbene), a polyphenolic phytoalexin present mainly in grapes, red wine and berries, is known to possess strong chemopreventive and anticancer properties. Here, we demonstrated the anti-proliferative and apoptosis-inducing activities of resveratrol in human epidermoid carcinoma A431 cells. ...

A phase III clinical trial showed gemcitabine chemotherapy combined with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib significantly improved overall survival in patients with advanced pancreatic cancer. Therefore, we studied whether addition of gemcitabine to erlotinib in cancer cells having intrinsic or acquired erlotinib resistance could ...

Lewis Y (LeY) is a carbohydrate tumor-asssociated antigen. The majority of cancer cells derived from epithelial tissue express LeY type difucosylated oligosaccharide. Fucosyltransferase IV (FUT4) is an essential enzyme that catalyzes the synthesis of LeY oligosaccharide. Our previous studies have shown that FUT4 overexpression promotes ...

The authors have isolated and partially purified an intracellular vesicle fraction from A-431 cells that contains both epidermal growth factor (EGF) and enzymatically active EGF:receptor/kinase. Exposure of intact A-431 cells to EGF leads to an accumulation of both EGF and ...

Anti-EGFR monoclonal antibodies LA22 and Erbitux bind to different epitopes of EGFR. The chemimmunoconjugates of MMC with LA22 or Erbitux were prepared, and in vitro cytotoxicity assays with A549 cells showed that LA22-MMC was much more potent than Erbitux or Erbitux-MMC. Viabilities of A549 cells treated with LA22-MMC, Erbitux or Erbitux-MMC were 35%, ...

The objective of this study was to characterize the death mechanism of human epidermoid carcinoma cells (A431) triggered by photodynamic therapy (PDT) with pheophorbide a. First of all, significant inhibition on the survival of A431 cells (< 20 %) was observed when an irradiation dose of 5.1 J/cm2 combined with ...

Cytotoxic and antitumors factors have been documented in the venom of snakes, while little information is available on the identification of cytotoxic products in the snake serum. In this study, we purified and characterized a new cytotoxic factor from serum of the non venomous Phyton sebae, endowed with antitumor activity. The serum of the P. sebae, termed PSS, exerted a ...

A series of heterocycle-fused 1,2,3-triazoles were easily prepared by the 1,3-dipolar cycloaddition of heterocyclic ketene aminals or N,O-acetals with sodium azide and polyhalo isophthalonitriles in a one-pot reaction at room temperature without a catalyst and evaluated in vitro against a panel of human tumour cell lines. 1,3-Oxazoheterocycle fused 1,2,3-triazoles were more ...

BackgroundProtease activated receptors (PARs) consist of a family of four G protein-coupled receptors. Many types of cells express several PARs, whose physiological significance is mostly unknown.ResultsHere, we show that non-invasive resonant waveguide grating (RWG) biosensor differentiates signaling of endogenous protease activated receptor subtype 1 ...

We report a novel approach for the attachment of DNA fragments to the surface of live cells. By using fluorescence microscopy and flow cytometry we demonstrated that our synthetic conjugates of fatty acid with oligonucleotides can be incorporated in plasma membrane and then hybridized with complementary sequences at the cell surface. Method permits to ...

Previous reports have shown that EGF induces the phosphorylation of the EGF receptor. In the present study the authors report the EGF sensitive reduction of the phosphorylation of a 50KD protein in solubilized A431 membranes. Membranes were prepared from A431 cell using a technique previously ...

The crude ethanol extract from the leaves of Dendropanax cf. querceti (Araliaceae) from Monteverde, Costa Rica, exhibits cytotoxic activity against Hep-G2, A-431, and H-4IIE tumor cell lines. The active component has been isolated by activity-directed separation and identified by 1H- and 13C-NMR spectroscopy as the triterpene lupeol. ...

A series of new C₁₁ cyclopentenones 1�7 was isolated, together with four known metabolites 9/10, 12 and 13, from the extract of the didemnid ascidian Lissoclinum sp. The other didemnid ascidian Diplosoma sp. contained didemnenones 1, 2 and 5, and five known metabolites 8�12. The structures of 1�7 were elucidated by spectroscopic analyses. Cytotoxicity of the isolated ...

Lab-on-a-chip systems offer a versatile environment in which low numbers of cells and molecules can be manipulated, captured, detected and analysed. We describe here a microfluidic device that allows the isolation, electroporation and lysis of single cells. A431 human epithelial carcinoma ...

Clostridium perfringens iota-toxin is a binary toxin composed of an enzyme component (Ia) and a binding component (Ib). Each component alone lacks toxic activity, but together they act in binary combination to produce cytotoxic effects. We examined the cytotoxicity of Ib in 8 cell lines. A431 and A549 cells were ...

Insulin binding to its receptors was studied in cultured normal and transformed (A431 line) human epidermal keratinocytes. The specific binding was a temperature-dependent, saturable process. Normal keratinocytes possess a mean value of about 80,000 receptors per cell. Fifteen hours exposure of the cells to insulin ...

Simian virus 40 (SV40) virus-like particles (VLPs) are efficient nanocarriers for gene delivery. VLPs conjugated to human epidermal growth factor (hEGF) were prepared and the cell selectivity of the VLP was examined using human epithelial carcinoma A431 cells, which overexpress the EGF receptor. The endocytic ...

Highly invasive A431-III cells, which are derived from parental A431-P cells, were originally isolated by three successive passages through a Boyden chamber using a Matrigel-coated membrane support. The greater invasion potential shown by A431-III cells ...

Epidemiological, in vitro cell culture, and in vivo animal studies have shown that green tea or its constituent polyphenols, particularly its major polyphenol epigallocatechin-3-gallate (EGCG) may protect against many cancer types. In earlier studies, we showed that green tea polyphenol EGCG causes a G0/G1-phase cell cycle arrest and apoptosis of human ...

We present fluorescence lifetime imaging (FLIM) and fluorescence anisotropy imaging along with translational diffusion measurements of living cells labelled with green fluorescent protein (GFP) recorded in a single experiment. The experimental set-up allows for time and polarization-resolved fluorescence images to be measured in every frame of a fluorescence recovery after ...

Cyclic AMP phosphodiesterase (PDE) type 4 has been the subject of considerable interest as a potential molecular target for treating cutaneous inflammatory and allergic disorders; however, little is known regarding the expression of PDE 4 isogenes in human keratinocytes, the predominant cell type present in the epidermis. In this study, we investigated the expression of PDE 4 ...

A-kinase Anchoring Proteins (AKAPs) define an expanding group of scaffold proteins that display a signature binding site for the RI/RII subunit of protein kinase A. AKAP5 and AKAP12 are multivalent (with respect to protein kinases and phosphatases) and display the ability to associate with the prototypic member of G protein-coupled receptors, the beta(2)-adrenergic receptor. We probed the relative ...

In order to estimate the effects of the size and surface treatment (coating or non-coating) of titanium dioxide particles on their cytotoxicity and penetration into the cellular membrane, two types of non-treated titanium dioxide (TiO(2)) particles of 20 nm (LU175) and 250 nm (LU205) were exposed to CHO cells, RBL-2H3 cells, ...

Background and purpose:Andrographolide is the active component of Andrographis paniculata, a plant used in both Indian and Chinese traditional medicine, and it has been demonstrated to induce apoptosis in different cancer cell lines. However, not much is known about how it may affect the key receptors implicated in cancer. Knowledge of how andrographolide affects receptor ...

E-64-d /ethyl (2S, 3S)-3-((S)-3-methyl-1-(3-methylbutylcarbamoyl)butylcarbamoyl)oxirane-2-carboxylate/, a membrane-permeant derivative of the thiol protease-specific inhibitor E-64, was found to arrest human epidermoid carcinoma A431 cells at mitotic metaphase. This effect was dose-dependent with a threshold of 20..mu..g/ml in ...

Growth of the EGF receptor-expressing non-small-cell lung carcinoma cell line H125 seems to be at least partially driven by autocrine activation of the resident EGF receptors. Thus, the possibility of an EGF receptor-directed antiproliferative treatment was investigated in vitro using a monoclonal antibody (alpha EGFR ior egf/r3) against the human EGF ...

Background?-Santalol, an active component of sandalwood oil, has shown chemopreventive effects on skin cancer in different murine models. However, effects of ?-santalol on cell cycle have not been studied. Thus, the objective of this study was to investigate effects of ?-santalol on cell cycle progression in both p53 mutated human epidermoid carcinoma ...

Purpose: Systemic therapies when added to whole brain radiotherapy have failed to improve the survival of patients with multiple brain metastases. The epidermal growth factor receptor antibody cetuximab is an attractive option, if it is able to cross the blood-brain barrier. This might be proven with molecular imaging if the radiolabeled antibody is stable long enough to be effective. This study ...

Human tissue plasminogen activator (t-PA) was shown to bind specifically to human osteosarcoma cells (HOS), and human epidermoid carcinoma cells (A-431 cells). Crosslinking studies with DTSSP demonstrated high molecular weight complexes (130,000) between {sup 125}I-t-PA and ...

Mammalian cells store excess fatty acids as neutral lipids in specialised organelles called lipid droplets (LDs). Using a simple cell-based assay and open-source software we established a high throughput screen for LD formation in A431 cells in order to identify small bioactive molecules affecting lipid storage. Screening an n-butanol ...

The photosensitizer protoporphyrin IX, endogenously accumulated from the precursor aminolevulinic acid (ALA) as well as other less photodynamically effective intermediates, is a successful agent in photodynamic therapy. Despite encouraging clinical results, the basic mechanisms leading to cell death are not fully understood. To elucidate these fundamentals, the alteration of ...

Background:Laminin-5 (Ln5), a heterotrimer composed of three chains (?3, ?3, and ?2), is a major component of the basement membrane in most adult tissues. One of the chains, Ln5-?2, is a marker of invasive tumours because it is frequently expressed as a monomer in malignant tumours. Recent studies from our laboratories detected higher levels of Ln5-?2 expression in basal cell ...

BackgroundChemokines and their receptors are important players in tumorigenesis by facilitating tumor proliferation and metastasis. Little is known about the possible function of chemokine receptors in relation to the development and progression of malignant cutaneous tumors.ObjectiveThe aim of this study was to determine the chemokine receptor CCR3 expression pattern and the protein expression ...

MT477 is a novel thiopyrano[2,3-c]quinoline that has been identified using molecular topology screening as a potential anticancer drug with a high activity against protein kinase C (PKC) isoforms. The objective of the present study was to determine the mechanism of action of MT477 and its activity against human cancer cell lines. MT477 interfered with PKC activity as well as ...

Hepatocyte growth factor (HGF), a humoral mediator for regeneration of liver and kidney, possesses multiple biological activities. To investigate target cell specificity and to examine whether multiple actions of HGF are related to properties of the HGF receptor on target cells, we examined the effects of HGF on cell growth and ...

In this study substrates for protein-tyrosine kinases and protein kinase C are examined to gain a better understanding of the conditions of their phosphorylation, their functions, and their potential involvement in intracellular signaling pathways. The tissue, cell type, and intracellular distributions of two protein-tyrosine kinase substrates, termed p36 and p81, are ...

Under hypoxia, tumor cells produce a secretion that modulates their microenvironment to facilitate tumor angiogenesis and metastasis. Here, we observed that hypoxic or reoxygenated A431 carcinoma cells exhibited enhanced angiogenic and metastatic potential such as reduced cell-cell and ...

Epidermal growth factor (EGF) activates a well-characterized signal transduction cascade in a wide variety of cells. This activation leads to increased cell proliferation in most cell types. Among the early effects evoked by EGF are receptor clustering, cell rounding, and early gene expression. The influence of ...

Human ganglioside-specific sialidase, NEU3, localized at cell membranes is thought to regulate various biological processes at cell surfaces. We here explored functional subcellular localization of the sialidase by immunofluorescence and found accumulation at leading edges of cell membranes in the presence of serum in culture. In ...

Since skin cancer incidence and prevalence is constantly rising up the charts despite all efforts, search for newer, better agents for protection and treatment is required. Ginger (Zingiber officinale Roscoe), a monocotyledonous herb, is widely used as a herbal medicine, given the presence of homologous phenolic ketones, of which [6]-gingerol is the major one. The quantity of [6]-gingerol in the ...

Resveratrol (RES) is a potent anti-cancer agent. We have previously reported that RES arrests the growth of invasive human A431 squamous cell carcinoma (SCC) cells. In this study, we show that oral administration of RES to highly tumor-susceptible p53(+/-)/SKH-1 mice markedly delayed UV-induced skin tumorigenesis ...

A membrane-associated binding protein for 3,3',5-triiodo-L-thyronine (T3) was purified to apparent homogeneity from A431 human epidermoid carcinoma cells. A431 cells were specifically labeled with the N-bromoacetyl derivative of T3 labeled with SVI at the ...

Divalent lead cations (Pb�+) are toxic metal pollutants that may contribute to inflammatory diseases in people and animals. Human vascular smooth muscle cells in culture respond to low concentrations of Pb�+ ions by activating mediators of inflammation via the plasma membrane epidermal growth factor receptor (EGFR). These include cyclooxygenase-2 (COX-2) and cytosolic ...

Binding of fluorescein-conjugated epidermal growth factor (EGF) to individual A431 cells at 4 degrees C is measured by a quantitative fluorescence imaging technique. After background fluorescence and cell autofluorescence photobleaching corrections, the kinetic data are fit to simple models of one monovalent site ...

The release of alpha RNPs and their absorbtion by the cells from culture medium were studied. The rat fibroblasts of parental serum-dependent cell line LRec-1, and of selected serum-free cell line LRec-1sf rapidly released and absorbed alpha RNPs. In the latter case, both auto- and heterologous alpha RNPs were seen to penetrate, ...

Our current focus on the effects of Photodynamic Therapy (PDT) using silicon phthalocyanine Pc 4 photosensitizer on malignant T lymphocytes arose due to preclinical observations that Jurkat cells, common surrogate for human T cell lymphoma, were more sensitive to Pc 4-PDT-induced killing than epidermoid carcinoma ...

Our current focus on the effects of Photodynamic Therapy (PDT) using silicon phthalocyanine Pc 4 photosensitizer on malignant T lymphocytes arose due to preclinical observations that Jurkat cells, common surrogate for human T cell lymphoma, were more sensitive to Pc 4-PDT-induced killing than epidermoid carcinoma ...

Overexpression of epidermal growth factor receptor (EGFR) is associated with many types of cancers. It is of great interest to noninvasively image the EGFR expression in vivo. In this study, we labeled an EGFR-specific Affibody molecule (Eaff) with a near-infrared (NIR) dye IRDye800CW maleimide and tested the binding of this labeled molecule (Eaff800) in cell culture and ...