The H3.3 G34W oncohistone mutation increases K36 methylation by the protein lysine methyltransferase NSD1.

The H3.3 G34W mutation has been observed in 90% of the patients affected by giant cell tumor of bone (GCTB). It had been shown to reduce the activity of the SETD2 H3K36 protein lysine methyltransferase (PKMT) and lead to genome wide changes in epigenome modifications including a global reduction in DNA methylation.

Activation mechanism and steady state kinetics of Bruton's tyrosine kinase.

Bruton's tyrosine kinase (BTK) is a member of the Tec non-receptor tyrosine kinase family that is involved in regulating B cell proliferation. To better understand the enzymatic mechanism of the Tec family of kinases, the kinetics of BTK substrate phosphorylation were characterized using a radioactive enzyme assay. We first examined whether autophosphorylation regulates BTK activity.

Restoration of gap junctional intercellular communication by caffeic acid phenethyl ester (CAPE) in a ras-transformed rat liver epithelial cell line.

Caffeic acid phenethyl ester (CAPE), an active ingredient of honeybee propolis, has been identified as having anti-inflammatory, anti-viral and anti-cancer properties. Since the deficiency of gap junctional intercellular communication (GJIC) has been shown to be a characteristic of most cancer cells, this study was designed to test the hypothesis that the anti-carcinogenic activity of CAPE might be related to its ability to restore GJIC in tumorigenic GJIC-deficient cells (WB-ras2 cells). The results showed that CAPE restored GJIC, phosphorylation of connexin 43 (Cx43) and its normal localization on the plasma membrane in WB-ras2 cells after 3 days at 5 microg/ml concentration.

Plant phenolics decrease intestinal tumors in an animal model of familial adenomatous polyposis.

Epidemiological studies consistently indicate that consumption of fruits and vegetables lowers cancer risk in humans and suggest that certain dietary constituents may be effective in preventing colon cancer. Plant-derived phenolic compounds manifest many beneficial effects and can potentially inhibit several stages of carcinogenesis in vivo. In this study, we investigated the efficacy of several plant-derived phenolics, including caffeic acid phenethyl ester (CAPE), curcumin, quercetin and rutin, for the prevention of tumors in C57BL/6J-Min/+ (Min/+) mice.

Identification of surface residues of the monocyte chemotactic protein 1 that affect signaling through the receptor CCR2.

The CC chemokine, monocyte chemotactic protein, 1 (MCP-1) functions as a major chemoattractant for T-cells and monocytes by interacting with the seven-transmembrane G protein-coupled receptor CCR2. To identify which residues of MCP-1 contribute to signaling though CCR2, we mutated all the surface-exposed residues to alanine and other amino acids and made some selective large changes at the amino terminus. We then characterized the impact of these mutations on three postreceptor pathways involving inhibition of cAMP synthesis, stimulation of cytosolic calcium influx, and chemotaxis.

Identification of residues in the monocyte chemotactic protein-1 that contact the MCP-1 receptor, CCR2.

The CC chemokine, MCP-1, has been identified as a major chemoattractant for T cells and monocytes, and plays a significant role in the pathology of inflammatory diseases. To identify the regions of MCP-1 that contact its receptor, CCR2, we substituted all surface-exposed residues with alanine. Some residues were also mutated to other amino acids to identify the importance of charge, hydrophobicity, or aromaticity at specific positions.

Inhibitory effects of caffeic acid phenethyl ester on the activity and expression of cyclooxygenase-2 in human oral epithelial cells and in a rat model of inflammation.

We investigated the mechanisms by which caffeic acid phenethyl ester (CAPE), a phenolic antioxidant, inhibited the stimulation of prostaglandin (PG) synthesis in cultured human oral epithelial cells and in an animal model of acute inflammation. Treatment of cells with CAPE (2.5 microg/ml) suppressed phorbol ester (12-O-tetradecanoylphorbol-13-acetate; TPA) and calcium ionophore (A23187)-mediated induction of PGE2 synthesis.

Monomeric monocyte chemoattractant protein-1 (MCP-1) binds and activates the MCP-1 receptor CCR2B.

To address the role of dimerization in the function of the monocyte chemoattractant protein-1, MCP-1, we mutated residues that comprise the core of the dimerization interface and characterized the ability of these mutants to dimerize and to bind and activate the MCP-1 receptor, CCR2b. One mutant, P8A*, does not dimerize. However, it has wild type binding affinity, stimulates chemotaxis, inhibits adenylate cyclase, and stimulates calcium influx with wild type potency and efficacy.

Caffeic acid phenethyl ester profoundly modifies protein synthesis profile in type 5 adenovirus-transformed cloned rat embryo fibroblast cells.

Caffeic acid phenethyl ester (CAPE), an active component of propolis from bee hives, exerts a plethora of biological changes in diverse systems. These include antimitogenic, anticarcinogenic, anti-inflammatory and immunomodulatory responses. CAPE directly induces programmed cell death (apoptosis) in type 5 adenovirus (Ad5)-transformed cloned rat embryo fibroblast cells, wt3A.

Caffeic acid phenethyl ester stimulates human antioxidant response element-mediated expression of the NAD(P)H:quinone oxidoreductase (NQO1) gene.

Caffeic acid phenethyl ester (CAPE) is a phenolic antioxidant derived from the propolis of honeybee hives. CAPE was shown to inhibit the formation of intracellular hydrogen peroxide and oxidized bases in DNA of 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated HeLa cells and was also found to induce a redox change that correlated with differential growth effects in transformed cells but not the nontumorigenic parental ones. Mediated via the electrophile or human antioxidant response element (hARE), induction of the expression of NAD(P)H quinone oxidoreductase (NQO1) and glutathione S-transferase Ya subunit genes by certain phenolic antioxidants has been correlated with the chemopreventive properties of these agents.

Inhibitory effects of topical application of low doses of curcumin on 12-O-tetradecanoylphorbol-13-acetate-induced tumor promotion and oxidized DNA bases in mouse epidermis.

The effects of topical applications of very low doses of curcumin (the major yellow pigment in turmeric and the Indian food curry) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced oxidation of DNA bases in the epidermis and on tumor promotion in mouse skin were investigated. CD-1 mice were treated topically with 200 nmol of 7,12-dimethylbenz[a]anthracene followed one week later by 5 nmol of TPA alone or together with 1, 10, 100 or 3000 nmol of curcumin twice a week for 20 weeks. Curcumin-mediated effects on TPA-induced formation of the oxidized DNA base 5-hydroxymethyl-2'-deoxyuridine (HMdU) and tumor formation were determined.

Caffeic acid phenethyl ester is a potent and specific inhibitor of activation of nuclear transcription factor NF-kappa B.

Caffeic acid phenethyl ester (CAPE), an active component of propolis from honeybee hives, is known to have antimitogenic, anticarcinogenic, antiinflammatory, and immunomodulatory properties. The molecular basis for these diverse properties is not known. Since the role of the nuclear factor NF-kappa B in these responses has been documented, we examined the effect of CAPE on this transcription factor.

Inhibitory effects of caffeic acid phenethyl ester (CAPE) on 12-O-tetradecanoylphorbol-13-acetate-induced tumor promotion in mouse skin and the synthesis of DNA, RNA and protein in HeLa cells.

Topical application of caffeic acid phenethyl ester (CAPE), a constituent of the propolis of honeybee hives, to the backs of CD-1 mice previously initiated with 7,12-dimethylbenz[a]anthracene (DMBA) inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor promotion and the formation of 5-hydroxymethyl-2'-deoxyuridine (HMdU) in epidermal DNA. Topical application of 5 nmol TPA twice weekly for 20 weeks to mice previously initiated with 200 nmol of DMBA resulted in 18.8 skin papillomas per mouse.

Hydroxylated aromatic inhibitors of HIV-1 integrase.

Efficient replication of HIV-1 requires integration of a DNA copy of the viral genome into a chromosome of the host cell. Integration is catalyzed by the viral integrase, and we have previously reported that phenolic moieties in compounds such as flavones, caffeic acid phenethyl ester (CAPE, 2), and curcumin confer inhibitory activity against HIV-1 integrase. We now extend these findings by performing a comprehensive structure-activity relationship using CAPE analogues.

Apoptosis and altered redox state induced by caffeic acid phenethyl ester (CAPE) in transformed rat fibroblast cells.

Caffeic acid phenethyl ester (CAPE), which is derived from the propolis of bee hives, was shown previously to block tumor promoter- and carcinogen-generated oxidative processes in several assays and to engender differential toxicity to some transformed cells. To study the mechanisms of CAPE-induced differential cytotoxicity, nontumorigenic rat embryo fibroblasts (CREF) and adenovirus (type 5)-transformed CREF cells (Wt3A) were used. As shown by nucleosomal-length DNA degradation, morphological alterations by electron microscopy, in situ labeling of 3'-OH ends, and the appearance of a hypodiploid cell population by bivariant flow cytometry, cell death induced by CAPE in the transformed Wt3A cells was apoptosis.

Solution conformation of the N-(deoxyguanosin-8-yl)aminofluorene adduct opposite deoxyinosine and deoxyguanosine in DNA by NMR and computational characterization.

Two-dimensional proton NMR and energy minimization computations have been employed to characterize the conformations of the N-(deoxyguanosin-8-yl)aminofluorene adduct [(AF)G] positioned opposite deoxyguanosine in one, and opposite deoxyinosine in another DNA undecamer duplex in aqueous solution. The two oligomer duplexes used in this study are d[C1-C2-A3-T4-C5-(AF)G6-C7-T8-A9-C10-C11].[G12-G13-T14 -A15-G16-X17-G18- A19-T20-G21-G22], where X17 was deoxyinosine in one duplex and deoxyguanosine in another.

Caffeic acid phenethyl ester inhibits proliferation of human keratinocytes and interferes with the EGF regulation of ornithine decarboxylase.

Caffeic acid phenethyl ester (CAPE) was evaluated for its potential in regulating keratinocyte proliferation. CAPE inhibited the proliferation of SV40 transformed keratinocytes (Z114) in a concentration- and time-dependent manner. Inhibition by CAPE was seen with 0.

Expression of the transformed phenotype induced by diverse acting viral oncogenes mediates sensitivity to growth suppression induced by caffeic Acid phenethyl ester (cape).

Caffeic acid phenethyl ester (CAPE) displays enhanced growth suppressive and toxic effects toward cloned rat embryo fibroblast (CREF) cells transformed by adenovirus type 5 (Ad5) or the Ad5 E1A transforming gene versus untransformed CREF cells (Su et al, Mol Carcinogen 4: 231-242, 1991). The present study was conducted to determine if transformation of CREF cells with additional oncogenes rendered these cells sensitive to the antiproliferative effect of CAPE. Additionally, studies were conducted to determine if reversion of the transformed phenotype could modify CAPE sensitivity.

Growth suppression and toxicity induced by caffeic acid phenethyl ester (CAPE) in type 5 adenovirus-transformed rat embryo cells correlate directly with transformation progression.

The active component of the honeybee hive product propolis, caffeic acid phenethyl ester (CAPE), induces a selective growth suppressive and toxic effect toward cloned rat embryo fibroblast cells transformed by adenovirus type 5 (Ad5) or the Ad5 E1A transforming gene versus untransformed cloned rat embryo fibroblast cells (Z-z. Su et al., Mol.

Mutation and repair induced by the carcinogen 2-(hydroxyamino)-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP) in the dihydrofolate reductase gene of Chinese hamster ovary cells and conformational modeling of the dG-C8-PhIP adduct in DNA.

Three experiments using 20 microM 2-(hydroxyamino)-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP) were performed to induce mutations in the dihydrofolate reductase (DHFR) gene of a hemizygous Chinese hamster ovary (CHO) cell line (UA21). Metabolized forms of this chemical primarily bind at the C-8 position of guanine in DNA. In total, 21 independent induced mutants were isolated and 20 were characterized.

Novel Pseudomonas product stimulates interleukin-8 production in airway epithelial cells in vitro.

Because high concentrations of IL-8 are found in the sputum of cystic fibrosis patients, we hypothesized that Pseudomonas aeruginosa (PA) induces the production of IL-8 in airway epithelial cells and in monocytes. Therefore, we incubated the supernatant from PA culture with human transformed bronchial epithelial cells (16-HBE) or with monocytes. The culture medium of 16-HBE cells that had been incubated with PA supernatant for 6 h had chemotactic activity that was inhibited by an antibody to human IL-8.

A mutational hot spot induced by N-hydroxy-aminofluorene in dihydrofolate reductase mutants of Chinese hamster ovary cells.

Eighteen mutants deficient in dihydrofolate reductase (DHFR) activity were induced with 0.5 microM N-hydroxy-aminofluorene in four separate experiments. This carcinogen dose killed approximately 80% of the treated cells and resulted in a mutational frequency approximately 3 x 10(-6).

Inhibition of oxidative stress in HeLa cells by chemopreventive agents.

12-O-Tetradecanoylphorbol-13-acetate (TPA)-mediated oxidative stress in HeLa cells and its inhibition were studied by fluorometric measurement of H2O2 and by 3H-postlabeling of the oxidized bases 8-hydroxyl-2'-deoxyguanosine (8-OHdG) and 5-hydroxymethyl-2'-deoxyuridine (HMdU). TPA treatment (10 fmol/cell) caused approximately 7-fold increase in H2O2 levels (0.1 nmol TPA/ml), and 5-10-fold increase in 8-OHdG and HMdU (10 nmol TPA/ml).

Splicing mutants and their second-site suppressors at the dihydrofolate reductase locus in Chinese hamster ovary cells.

Point mutants induced with a variety of mutagens at the dihydrofolate reductase (dhfr) locus in Chinese hamster ovary (CHO) cells were screened for aberrantly spliced dhfr mRNA by RNase protection and/or reverse transcriptase coupled with cDNA amplification by the polymerase chain reaction (PCR). Of 115 mutants screened, 28 were found to be affected in splicing. All exhibited less than 1% correct splicing, probably because the selection procedure was stringent.

Overexpression, purification and characterization of human recombinant 15-lipoxygenase.

Human 15-lipoxygenase was expressed to high levels (approx. 20% of cellular protein) in a baculovirus/insect cell expression system. Catalytically active enzyme was readily purified (90-95% pure) from cytosolic fractions by anion-exchange chromatography on a Mono Q column with approx.