TRF2 inhibits a cell-extrinsic pathway through which natural killer cells eliminate cancer cells.

Dysfunctional telomeres suppress tumour progression by activating cell-intrinsic programs that lead to growth arrest. Increased levels of TRF2, a key factor in telomere protection, are observed in various human malignancies and contribute to oncogenesis. We demonstrate here that a high level of TRF2 in tumour cells decreased their ability to recruit and activate natural killer (NK) cells.

Down-regulation of DcR2 sensitizes androgen-dependent prostate cancer LNCaP cells to TRAIL-induced apoptosis.

Background: Dysregulation of many apoptotic related genes and androgens are critical in the development, progression, and treatment of prostate cancer. The differential sensitivity of tumour cells to TRAIL-induced apoptosis can be mediated by the modulation of surface TRAIL receptor expression related to androgen concentration. Our previous results led to the hypothesis that downregulation of TRAIL-decoy receptor DcR2 expression following androgen deprivation would leave hormone sensitive normal prostate cells vulnerable to the cell death signal generated by TRAIL via its pro-apoptotic receptors.

TNF-alpha-related apoptosis-inducing ligand decoy receptor DcR2 is targeted by androgen action in the rat ventral prostate.

The apoptotic cell death process in the prostate is known to be under the control of androgens. Tumor necrosis factor-alpha (TNF-alpha)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF-alpha family of cytokines, known to induce apoptosis upon binding to its death domain-containing receptors, DR4/TRAIL-R1 and DR5/TRAIL-R2. Two additional TRAIL receptors, DcR1/TRAIL-R3 and DcR2/TRAIL-R4, lack functional death domains and act as decoy receptors for TRAIL.

Characterization of tumour necrosis factor-alpha-related apoptosis-inducing ligand and its receptors in the adult human testis.

Tumour necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL) is a member of the tumour necrosis factor-alpha (TNF-alpha) family of cytokines which is known to induce apoptosis upon binding to its death domain-containing receptors, DR4/TRAIL-R1 and DR5/TRAIL-R2. Two additional TRAIL receptors, DcR1/TRAIL-R3 and DcR2/TRAIL-R4, lack functional death domains and act as decoy receptors for TRAIL. In this study, the presence of TRAIL and its receptors was investigated by immunohistochemistry in adult human testes.

Identification of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL) and its receptors in adult rat ventral prostate.

Tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor-alpha (TNF-alpha) family of cytokines that is known to induce apoptosis upon binding to its death domain-containing receptors, DR4/TRAIL-R1 and DR5/TRAIL-R2. Two additional TRAIL receptors, DcR1/TRAIL-R3 and DcR2/TRAIL-R4, lack functional death domains and act as decoy receptors for TRAIL. In this study, the presence of TRAIL and its receptors was investigated in adult rat hormonosensitive ventral prostate.

Expression of tumor necrosis factor-alpha-related apoptosis-inducing ligand and its receptors in rat testis during development.

Tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor-alpha family of cytokines that is known to induce apoptosis upon binding to its death domain-containing receptors, DR4/TRAIL-R1 and DR5/TRAIL-R2. Two additional TRAIL receptors, DcR1/TRAIL-R3 and DcR2/TRAIL-R4, lack functional death domains and act as decoy receptors for TRAIL. In this study, the presence of TRAIL and its receptors was investigated in the rat testis during development.

Role of sphingosine in the tumor necrosis factor alpha stimulatory effect on lactate dehydrogenase A expression and activity in porcine Sertoli cells.

In this study, the intracellular signaling mechanisms through which TNFalpha increases LDH(A4) activity/expression in primary cultures of porcine testicular Sertoli cells were investigated. Studies were focused on sphingomyelin hydrolysis pathway. Treatment of [(14)C]serine-labeled cells with TNFalpha (15 ng/ml, 0.

Tumor necrosis factor-alpha stimulates lactate dehydrogenase A expression in porcine cultured sertoli cells: mechanisms of action.

In the present study, we investigated the regulatory action of tumor necrosis factor-alpha (TNFalpha) on lactate dehydrogenase A (LDH A), a key enzyme involved in lactate production. To this end, use was made of a primary culture system of porcine testicular Sertoli cells. TNFalpha stimulated LDH A messenger RNA (mRNA) expression in a dose (ED50 = 2.

Annexin VI is secreted in human bile.

A calcium-binding protein of 68 kDa was isolated from human bile that precipitates upon addition of 5 mM CaCl2. This protein was recognized by an immunoaffinity purified anti-annexin VI antibody and it had a similar aminoacid composition as annexin VI. Phospholipase A2 activity was inhibited in vitro in a dose-dependent manner as reported for annexin VI.

Effect of various n-3/n-6 fatty acid ratio contents of high fat diets on rat liver and heart peroxisomal and mitochondrial beta-oxidation.

The present work extends tissue investigations previously performed in rat gastric mucosa on lipid metabolism alterations caused by n-3 and n-6 fatty acid-enriched diets. Liver and heart tissues are here studied and demonstrated to undergo, upon exposure to high fat diets with various n-3/n-6 fatty acid ratio contents, biochemical and morphological changes which may be enumerated as follows: (1) Rat liver peroxisomal prostaglandin E2, fatty acid but not bile acid beta-oxidation rates are enhanced, especially upon the diet with the higher n-3/n-6 fatty acid ratio. Mitochondrial beta-oxidation rates are little or not affected by the high fat diets.

Effect of anthracyclines on phospholipase A2 activity and prostaglandin E2 production in rat gastric mucosa.

The purpose of this study was to investigate in rats the effects of three anthracyclines, pirarubicin, doxorubicin and epirubicin on gastric prostaglandin E2 (PGE2) metabolism and phospholipase A2 (PLA2, EC 3.1.1.

Heart and liver membrane phospholipid homeostasis during acute administration of various antitumoral drugs to the rat.

The purpose of this study was to investigate in the rat heart and liver the effects of an acute administration of three anthracyclines, doxorubicin, epirubicin and pirarubicin, and an anthracenedione, mitoxantrone, on the membrane peroxidative status, which was estimated by the composition of polyunsaturated fatty acids (PUFA), and on the activities of the enzymes involved in membrane repair processes and lipid hydroperoxide detoxification. Rats were injected for four consecutive days with the drugs or saline (control) and killed 24 hr after the last injection. All the drugs induced an increase in plasma thiobarbituric reactive substances and alpha-tocopherol concentrations, both expressed per milligram of plasma lipids.

Effects of dietary n-6/n-3 ratios on lipid and prostaglandin E2 metabolism in rat gastric mucosa.

The effects of increased dietary n-3 polyunsaturated fatty acids on gastric mucosal lipid metabolism were studied in rats fed for 8 weeks with different combinations of fish and corn oils. Lipid composition, ex vivo prostaglandin E2 (PGE2) production and enzymatic activities involved in phospholipid metabolism and peroxisomal oxidative catabolism of fatty acids and PGE2 were examined. With dietary n-6/n-3 compositional ratios ranging between 75 and 3.

Subcellular localization of rat gastric phospholipase A2.

In the present study, we have performed experiments to gain some insight into the subcellular localization and biochemical properties of gastric mucosal phospholipase A2. After classical subcellular fractionation of whole glandular stomach mucosa, we found that gastric phospholipase A2 was essentially enriched in the 105,000 x g pellet that contains microsomes and plasma membranes. Except for the cytosol, all the subcellular fractions exhibited similar phospholipase A2 activity (i.

Isolation and properties of lipolysis inhibitory proteins from wheat germ and wheat bran.

Proteins inhibiting pancreatic lipase in vitro have been isolated from wheat germ and wheat bran, with relative molecular mass ranging from 24,400 to 27,500. Inhibition of pancreatic lipase by the wheat germ proteins is related to their ability to interact with the emulsified substrate and to hinder the adsorption of the enzyme on the interface. The extent of inhibition depends on the amount of substrate and is independent of the enzyme concentration.

Effects of dietary corn oil and salmon oil on the oxidation of fatty acids and prostaglandin E2 in rat gastric mucosa.

The investigations previously carried out by Grataroli and colleagues (1) to elucidate the relationships between dietary fatty acids, lipid composition, prostaglandin E2 production and phospholipase A2 activity in the rat gastric mucosa are, here, extended. In the present investigations, fatty acid and prostaglandin E2 catabolizing enzymes were assayed in gastric mucosa from rats fed either a low fat diet (corn oil: 4.4% w/w) (referred as control group), a corn oil-enriched diet (17%) or a salmon oil-enriched diet (12.

Subcellular distribution of lysophospholipase of rat intestinal mucosa.

We have studied the subcellular localization of rat intestinal lysophospholipase activity and some of the biochemical properties of this enzyme. After subcellular fractionation, an enriched activity was found in the high-speed pellet fraction containing the microsomes and the brush border membranes. Subsequently, these organelles were isolated.

Effects of dietary corn oil and salmon oil on lipids and prostaglandin E2 in rat gastric mucosa.

Three groups of male rats were fed either a corn oil-enriched diet (17%, w/w), a salmon oil-enriched diet (12.5%) supplemented with corn oil (4.5%) or a low-fat diet (4.

Phospholipase A2 activity of rat stomach.

Phospholipase A activity in rat stomach wall and in gastric content was studied using [1-14C]dioleoylphosphatidylcholine as substrate. The optimum activity of the stomach wall was found to take place at pH 7.0.

Hydrolysis of intralipid by pancreatic lipase and phospholipase A2-gel filtration studies.

Intralipid was incubated with pancreatic lipase (EC 3.1.1.

Detection of the cystic fibrosis protein by isoelectric focusing of serum and plasma.

We used the isoelectric focusing method developed by Wilson to analyze serum from individuals homozygous or heterozygous for cystic fibrosis. The presence of cystic fibrosis protein (CFP) was found in 37 out of 52 homozygous and 24 out of 34 heterozygous patients, which leads to a frequency of 71% for both families. Five out of 24 controls were found positive.

Adsorption of pancreatic (pro)phospholipase A2 to various physiological substrates.

The adsorption of pancreatic phospholipase was studied in vitro in the presence of egg yolk lipoprotein emulsion, Intralipid emulsion, and milk fat globules. When the emulsions are incubated with bile salts, the latter dissociate a considerable fraction of the phospholipids initially associated with the emulsions, leading to the coexistence of an emulsified phase and a phase of mixed micelles. After the addition of pancreatic phospholipase A2, gel filtration shows that the enzyme was more than 90% bound to mixed micelles, regardless of the type of emulsion used.

Non-competitive enzyme immunoassay of human trypsin 1.

A sandwich enzyme immunoassay was developed for human pancreatic trypsin 1 using polystyrene balls coated with specific IgG as the first antibody and peroxidase-labeled IgG as the second antibody. The entire assay takes 6 h and the detection limit is 0.5 microgram/l.

Studies on prophospholipase A2 and its enzyme from human pancreatic juice. Catalytic properties and sequence of the N-terminal region.

Upon tryptic activation of pure human prophospholipase A2, a heptapeptide is released from the N-terminal part of the protein yielding active phospholipase A2 (EC 3.1.1.

Isolation and properties of prophospholipase A2 from human pancreatic juice.

Human prophospholipase A2 was purified from pancreatic juice. The protein has a molecular weight of 14500 and a free N-terminal residue identified as aspartic acid (or asparagine). The amino acid composition was determined.