Effect of fatty acids on estradiol and testosterone binding to whole DU-145 prostate cells.

Cancer of the prostate is one of the leading causes of cancer related deaths in men. An important role in the development of prostate cancer is played by androgens and androgen ablation is therefore currently used in cancer treatment. In the past, estrogens were widely used in treatment of prostate cancer, but there are indications that estrogens could also be involved in carcinogenesis.

Cytotoxicity of combined essential fatty acids on a human prostate cancer cell line.

In this study the effect of single and concomitantly added n-6 or n-3 polyunsaturated fatty acids (PUFAs) was investigated on human prostate cells. Data obtained from the single fatty acids (FAs) experiments showed that except for oleic acid (OA), arachidonic (AA) and linoleic acid (LA), which had very little (less than 10% cells dead) effect on the cells, an increase in dead cells was observed at physiological concentrations of, eicosapentaenoic acid (EPA), gamma-linolenic acid (GLA) and alpha-linolenic acid (ALA). However, this was not the case when combining these acids at physiological concentrations.

Cytokine levels affected by gamma-linolenic acid.

This study was undertaken to assess whether gamma-linolenic acid (GLA) in the form of evening primrose oil (EPO) could affect rat serum cytokines, interferon-gamma (IFN-gamma), monocyte chemotactic protein-1 (MCP-1) and tumour necrosis factor-alpha (TNF-alpha). The following diets were administered: control, glucan, Freund's adjuvant and glucan plus Freund's adjuvant with and without GLA. In the presence of GLA, the IFN-gamma and MCP-1 levels were significantly decreased in contrast to the control group of TNF-alpha, which was significantly stimulated.

Does urokinase play a role in renal stone formation?

Renal stone formation is a complex multifactorial disease, and it is believed that the initial step in the pathogenesis of urolithiasis must be the precipitation of an organic matrix of mucoproteins followed by precipitation of minerals onto this matrix. An important factor in this process may be the activity and/or concentration of the urinary enzyme, urokinase, which would affect the level of urinary mucoproteins such as uromucoid. In support of this hypothesis, ELISA studies were conducted to investigate the urokinase concentrations in urine obtained from males (22-60 years) with and without renal stones.

A possible role for enzymes in tumour-cell invasion.

The complex molecular and cellular processes of metastatic invasion as well as the anti-invasion possibilities are summarized. Invasion by neoplastic cells is a major obstacle to successful cancer therapy. Enzymes such as hyaluronidase, sialyltransferase, urokinase-type plasminogen activator, plasmin, matrix metalloproteinases, and others, play central roles in the catabolism of extracellular matrix macromolecules.

The effect of essential fatty acids on growth and urokinase-type plasminogen activator production in human prostate DU-145 cells.

Urokinase-type plasminogen activator (uPA) is an important protease enzyme in carcinogenesis, and is involved in both invasion and metastasis of cancer. Increased uPA activity and decreased essential fatty acid (EFA) levels have been reported in cancer. This phenomenon may be explained by the fact that certain EFAs, such as gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA), inhibit uPA activity.

Influence of acetylsalicylic acid and metabolites on DU-145 prostatic cancer cell proliferation.

Conflicting reports have been published on the anti-tumour activities of acetylsalicylic acid in various cancers. Therefore, the effect of acetylsalicylic acid and its major metabolites has been studied on human prostatic carcinoma DU-145 cells. Investigations concentrated on the influence of acetylsalicylic acid, salicylic acid and salicyluric acid, on cell proliferation, DNA- and protein synthesis of DU-145 cells.

Binding of estradiol to whole prostatic DU-145 cells in the presence and absence of tamoxifen and acetylsalicylic acid.

Conflicting results have been obtained with regard to the estradiol receptor (ER) capacity of human prostatic tissue. Human prostatic DU-145 cells have been found to be ER-negative with immunohistochemical assays. The object of this investigation was to determine if whole DU-145 cells, which had been grown in monolayer culture, have ER and, if so, to confirm the finding with antiestrogens.

In vivo effects of urease-producing bacteria involved with the pathogenesis of infection-induced urolithiasis on renal urokinase and sialidase activity.

Many hypotheses have been proposed for renal stone formation. It has been argued that with infection-induced renal stones the hydrolysis of urea by bacterial urease increases urinary pH, with consequent stone formation. Unfortunately, this theory is not applicable to the micro-organisms that do not produce urease (e.

Can linoleic acid and gamma-linolenic acid be important in cancer treatment?

This hypothesis proposes that the essential fatty acids (EFAs), linoleic acid (LA) and gamma-linolenic acid (GLA), play important roles in cancer treatment. Oxidation of LA by lipoxidase especially increases tumour cell death, whilst GLA inhibits urokinase-type plasminogen activator (uPA) activity. Increased uPA activity is: firstly, responsible for cancer invasion and metastasis and secondly, responsible for proteolysis of lipoxidase which favours a decrease in cancer cell death.

Modulation of lipoxidase activity by urokinase-type plasminogen activator.

Malignant cells show increased urokinase (UK) activity and decreased peroxidation of essential fatty acids (EFA). In order to explore this phenomenon the effect of UK on the lipoxidase activity was spectrophotometrically investigated. Decreased lipoxidase activity was obtained with increased UK concentrations (r = -1.

The effect of gamma-linolenic acid and eicosapentaenoic acid on urokinase activity.

Urokinase (UK) is an important protease enzyme in carcinogenesis, and is involved in the invasion and metastasis of cancer. Thus, regulation of UK activity is likely to be important in healthy cell metabolism. As it has been reported that a decrease in delta 6-desaturated essential fatty acid (EFA) metabolites occurs in malignant cells and that gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA) exert antimutagenic effects, the effects of GLA and EPA on UK activity have been investigated in this study.

Sialic acid concentration and sperm motility.

Sialic acid (SA) forms an integral part of the sperm membrane, and the masking properties of SA are well documented. Masking of estrogen and melatonin receptors on the sperm midpiece by SA has been demonstrated. In this paper we report on the correlation of sperm bound SA concentration and motility.

Pyelonephritis: renal urokinase and sialidase (neuraminidase) activity in rats fed a standard laboratory diet.

Renal stone formation can be caused by many different and varied disturbances, some of which are poorly understood. The relationship between urinary infection and renal stone formation has not been completely clarified. It is argued that renal stones form primarily as a consequence of the hydrolysis of urea by the bacterial enzyme urease.

Pyelonephritis: renal urokinase activity in rats on essential fatty acid diets.

This study was undertaken to assess whether additions of different oils to the diets of male rats would affect the renal urokinase (UK) activity of healthy and pyelonephritic kidneys. Four groups of fatty acid diets were studied: fat-free, coconut oil, fish oil and evening primrose oil (EPO). Pyelonephritis was obtained by unilateral extrarenal urinary obstruction and subcutaneous injection of Escherichia coli.

The detachment cascade during metastasis.

The cause of detachment of tumour cells during metastasis is still one of the most intriguing questions of tumour propagation. A hypothesis is suggested herein for lysis of extracellular matrix that could ultimately lead to the detachment and spreading of malignant cells. According to this theory a certain optimal estrogen level initiates a series of enzymatic activations that culminate in detachment and spreading of tumour cells.

Putative melatonin receptor in human spermatozoa.

Melatonin is present in human semen, and may affect sperm motility. The presence of melatonin receptors on spermatozoa has not yet been reported. Detection of melatonin-binding sites may be limited because of the masking of such sites by sialic acid.

The effect of calcium and magnesium ions on urinary urokinase and sialidase activity.

The effect of a promoter (calcium) and an inhibitor (magnesium) of urolithiasis was spectrophotometrically studied on urokinase (0.45 IU) and sialidase (5 mM). Although these mineral did not affect the sialidase activity, total inhibition of urokinase activity was observed with either 0.

Effects of bacteria involved with the pathogenesis of infection-induced urolithiasis on the urokinase and sialidase (neuraminidase) activity.

It has been hypothesized that urinary urokinase and sialidase may play a role in urolithiasis. If these theories have substance it is to be expected that microorganisms may also affect these enzymes, since the association between urinary tract infection and renal stone formation is well known. It is generally assumed that Proteus mirabilis and Staphylococcus albus, which produce the urea-splitting enzyme urease, are responsible for stone formation.

A novel study on the effect of acetylsalicylic acid on the binding capacity of estrogen receptors from MCF-7 cells.

The effect of acetylsalicylic acid (ASA, aspirin) was investigated on [3H]-estradiol-17 beta ([3H]-E2) binding to estrogen receptors (ER) from MCF-7 mammary tumour cells. No effect was observed using the monoclonal estrogen receptor-enzyme immunoassay (ER-EIA). In contrast to the ER-EIA, the radioreceptor assay (RRA) showed decreases of [3H]-E2 specific binding in the presence of increasing amounts of ASA.

Pathogenesis of kidney stones.

Although many risk factors and theories exist in the literature for urinary stone formation, a hypothesis is suggested for the pathogenesis of renal stones. According to the matrix theory, a protein such as uromucoid activates the initial crystallisation process by promoting the formation of calcium oxalate and calcium phosphate crystals as well as clumping in whole urine. We put forward a theory whereby one of the most important factors in the matrix theory would be the composition and concentration of the protein.

Morphological effects of the catecholestrogens on cells of the seminiferous tubules of Sprague-Dawley rats.

Estradiol-17 beta (E2) and the two catecholestrogens 2-OHE2 and 4-OHE2, when daily administered at low doses of 10-40 ng/rat, were cytotoxic to the seminiferous epithelium. The structural changes seen after seven days exposure included abnormal meiotic type II cells with uneven chromosome distribution, the formation of binucleated and multinucleated giant cells, of which many were sloughed into the lumina of the seminiferous tubules. The effect of the 4-OHE2 metabolites were always more pronounced that that of 2-OHE2 or E2.