Fibroblast growth factor receptor 1 (FGFR1) is over-expressed in benign prostatic hyperplasia whereas FGFR2-IIIc and FGFR3 are not.

OBJECTIVE: Benign prostatic hyperplasia (BPH) is one of the major public health problems among men: 50% of men over 55 are concerned with this disease. Prostate growth is under the control of androgens which act by means of several growth factors such as fibroblast growth factors (FGFs), epidermal growth factor and transforming growth factor beta. Basic FGF (bFGF) has been shown to stimulate prostatic stromal growth. In BPH, bFGF concentration is two- to threefold higher than in normal prostate. In this work, the bFGF receptors (FGFR1, FGFR2-IIIc and FGFR3) genes expression was evaluated to study the correlation between the expression of bFGF receptors and induction of BPH. METHODS: The expression of FGFRs was analyzed by RT-PCR, FGFR1 was localized by immunohistochemistry and protein expression was evaluated by Western blot. RESULTS: A two- to eightfold over-expression of FGFR1 was observed in BPH compared with normal prostates. FGFR1 was localized in the stroma both in BPH and in normal prostates and 1.5- to 2.5-fold over-expression of the protein was observed. The expression of FGFR2-IIIc and FGFR3, more secondary receptors, was not significantly different between BPH and normal prostates. CONCLUSIONS: bFGF receptors and particularly FGFR1 seem to be involved in the induction and evolution of BPH and probably potentiate bFGF over-expression effects in BPH.

An evaluation of thiram toxicity on cultured human skin fibroblasts.

Thiram is widely used in agriculture as a fungicide and, to a lesser extent, as a vulcanizing agent in the rubber industry. In spite of the extensive use of thiram, knowledge on its toxicity and health risk remains limited, and few investigations have been performed to assess specific damage at the cellular and subcellular level. We report here the cytotoxic effects of thiram on cultured human skin fibroblasts. Our results demonstrated that thiram exposure induced a dose- and time-dependent decrease in the viable cell recovery with 100% cell death observed with a concentration of 5.0 mg/l. As judged by morphological changes and biochemical criteria, thiram-mediated cell death was not of the apoptotic but seemed to be of the necrotic type. This cell death was not associated with a modification of gene expression of different constituents of the extracellular matrix. A late increase of lactate production was evident after thiram treatment, suggesting a mitochondrial metabolic pathway dysfunction as reported by other authors using similar compounds. However, this phenomenon appeared as a secondary response to the toxic action of thiram. The cytotoxic effect of thiram is possibly due to an oxidant effect inherent to the structure of thiram and the interaction between thiram and vital cellular molecules.

Thiram-induced cytotoxicity is accompanied by a rapid and drastic oxidation of reduced glutathione with consecutive lipid peroxidation and cell death.

The toxic effect of thiram, a widely used dithiocarbamate fungicide, was investigated in cultured human skin fibroblasts. Cell survival assays demonstrated that thiram induced a dose-dependent decrease in the viable cell recovery. Thiram exposure resulted in a rapid depletion of intracellular reduced glutathione (GSH) content with a concomitant increase in oxidized glutathione (GSSG) concentration. Alteration of glutathione levels was accompanied by a dose-dependent decrease in the activity of glutathione reductase (GR), a key enzyme for the regeneration of GSH from GSSG. Thiram-exposed cells exhibited increased lipid peroxidation reflected by enhanced thiobarbituric acid reactive substances (TBARS) production, suggesting that GSH depletion and the lower GR activity gave rise to increased oxidative processes. To investigate the role of decreased GSH content in the toxicity of thiram, GSH levels were modulated prior to exposure. Pretreatment of fibroblasts with N-acetyl-L-cysteine (NAC), a GSH biosynthesis precursor, prevented both lipid peroxidation and cell death induced by thiram exposure. In contrast, thiram cytotoxicity was exacerbated by the previous depletion of cellular GSH by L-buthionine-(S,R)-sulfoximine (BSO). Taken together, these results strongly suggest that thiram induces GSH depletion, leading to oxidative stress and finally cell death.

Basic fibroblast growth factor and keratinocyte growth factor over-expression in benign prostatic hyperplasia.

The prostate growth is under the indirect control of androgens through the medium of many growth factors. The fibroblast growth factors (FGFs) seem to play an important part in stimulating the development of this organ. In this work, the expression of two FGFs: bFGF (or FGF2) and KGF (or FGF7), was studied in RT-PCR and semi-quantified in densitometry. Both genes expression was increased in BPH in comparison with normal prostates. A two to three times and a 1.5 to four times over-expressions were observed for bFGF and KGF, respectively. An over-expression of these growth factors could lead to a cell multiplication resulting in a pathological development of the prostate size. Moreover, bFGF and KGF act in parallel in the prostate, one stimulating the prostatic stroma and the other one stimulating the epithelium. These two growth factors could participate in the increase of the two tissues constituting the prostate.

Quantitation of reduced and total glutathione at the femtomole level by high-performance liquid chromatography with fluorescence detection: application to red blood cells and cultured fibroblasts.

A new rapid and highly sensitive HPLC method with ortho-phthalaldehyde (OPA) pre-column derivatization has been developed for determination of reduced glutathione (GSH) and total glutathione (GSHt) in human red blood cells and cultured fibroblasts. OPA derivatives are separated on a reversed-phase HPLC column with an acetonitrile-sodium acetate gradient system and detected fluorimetrically. An internal standard (glutathione ethyl ester) is added to facilitate quantitation. Total glutathione is determined after reduction of disulfide groups with dithiothreitol; the oxidized glutathione (GSSG) concentration is calculated by subtraction of the GSH level from the GSHt level. The assay shows high sensitivity (50 fmol per injection, the lowest reported), good precision (C.V. <5.0%), an analytical recovery of GSH and GSSG close to 100%, and linearity (r > 0.999). This HPLC technique is very simple and rapid. Its wide applicability and high sensitivity make it a convenient and reliable method for glutathione determination in various biological samples.