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J G Delcros

Publications and source records attributed to J G Delcros.

At least 37 records · Page 2Linked to original sources
PubMed1996

High levels of spermine in IVF medium as a negative predictor of subsequent success of embryo transfer.

PURPOSE: Our purpose was to test the prediction that spermine levels in IVF culture supernatants measure by rapid ELISA assay correlate with subsequent success or failure to establish a pregnancy. RESULTS: Forty-nine patients undergoing gonadotropin-stimulated ovulation after LHRH analogue treatment in the current study succeeded and 57 failed. With the exception of the first 4 hr of culture, where polyamine levels were slightly (but not significantly) higher in supernatants associated with subsequent success, higher levels of polyamines were predictive of failure. CONCLUSIONS: The result in this study differs from previous data obtained with women ovulated using clomiphene where low spermine levels (assayed in an immunosuppression assay in vitro) correlated with failure to establish pregnancy, and detectable levels correlated with success. Supplementation of IVF culture medium with spermine and/or spermidine appears unlikely to improve IVF success rates, where the success rate is already very good, and may possibly do harm. The possibility that different methods of ovulation affect subsequent polyamine production in vitro by fertilized oocytes merits further study.

Culture Media, Conditioned↗
PubMed1996

Polyamine deprivation provokes an antalgic effect.

It is well established that inhibition of putrescine formation using D,L-2-(difluoromethyl)ornithine and feeding a polyamine-deficient diet together with non-absorbable antibiotics (neomycin and metronidazole), prevent almost completely the growth of tumors in rats. A similar regimen given to patients with prostate cancer not only reduced the titer of prostate specific antigen in serum, but surprisingly provoked at the same time an antalgic effect. This observation led us to study the potentiation effect of polyamine deprivation on pain threshold in healthy rats. Animals were fed for 2 weeks with an artificial diet of known polyamine content, in combination with antibiotics and 2-(difluoromethyl)ornithine, and were then submitted to pain stimuli using two models, the Randall-Selitto test and the Tail-Flick test. Polyamine deprivation produced in these models an increase in the latency of the response, even under conditions which did not produce significant changes of the polyamine concentrations in blood and brain. From these observations, we may conclude that the polyamines play a role in the perception of nociceptive stimuli under physiological conditions.

Analgesia↗
PubMed1996

Polyamine transport in mammalian cells. An update.

The uptake and release of the natural polyamines putrescine, spermidine and spermine by mammalian cells are integral parts of the systems that regulate the intracellular concentrations of these biogenic amines according to needs. Although a general feature of all tissues, polyamine uptake into intestinal mucosa cells is perhaps the most obvious polyamine transport pathway of physiological and pathophysiological importance. Mutant cell lines lacking the ability to take up polyamines from the environment are capable of releasing polyamines. This indicates that uptake and release are functions of two different transport systems. The isolation of a transporter gene from a mammalian cell line is still lacking. Overaccumulation of polyamines is controlled by release and by a feedback regulation system that involves de novo synthesis of antizyme, a well known protein that also regulates the activity of ornithine decarboxylase. Recent work has demonstrated that Ca(2+)-signalling pathways are also involved. Although there is consensus about the importance of polyamine uptake inhibitors in the treatment of neoplastic disorders, a practically useful uptake inhibitor is still missing. However, the attempts to target tumours, and to increase the selectivity of cytotoxic agents by combining them with the polyamine structure, are promising. New, less toxic and more selective anticancer drugs can be expected from this approach.

Animals↗
PubMed1996

Molecular requirements for polyamines binding to the antispermine monoclonal antibody Spm8-2.

The monoclonal antispermine antibody Spm8-2 was obtained by immunizing mice with a thyroglobulin-spermine conjugate. The molecular requirements for polyamines binding to this antibody were investigated by ELISA binding and inhibition tests, using a variety of natural polyamines and synthetic polyamine analogs. Four major structural determinants are important for the binding of polyamines by the antibody: (1) terminal amino groups: N-alkylation of both terminal amino groups of the polyamines leads to an important drop in the affinity for the antibody; (2) number of methylene groups spacing the amino groups: the four carbon chains appear to present the optimum length since the antibody binds polyamines with repeats of the aminobutyl moiety more actively than their homologues with shorter or longer carbon chains; (3) number of amino groups: the affinity of Spm8-2 for free homologous polyamines varied in the following order: pentamines > tetramines > triamines > diamines, showing the importance of the number of positive charges of the polyamines in the antibody-antigen reaction; the importance of charges is further emphasized by the dependence of antibody binding on the ionic strength of the medium; (4) N-acylation of one terminal amino group: the antibody binds more actively N1-acetylspermidine than spermidine or spermine. The binding properties of Spm8-2 suggest the presence of two recognition sequences, one selective for N-acylaminopropyl moieties, the second for the aminobutyl moiety.

Acetylation↗
PubMed1996

Observations with an S-adenosylmethionine decarboxylase inhibitor in rats with prostatic adenocarcinoma.

CGP 48664A (2-(4-aminoiminomethyl)-2,3-dihydro-1H-inden-1-ylidene dihydrochloride, CAS 149400-88-4) is a new potent inhibitor of S-adenosylmethionine decarboxylase with antitumor properties. In view of the eminent clinical problems in the treatment of non hormone dependent prostatic cancer, the antiproliferative potency of this compound was tested in Dunning MAT-LyLu rat prostatic adenocarcinoma. The compound proved inefficient in preventing the growth of this tumor, even at a near toxic dose. A reason for the lacking effect is presumably the inadequate accumulation of the drug in the tumor cells due to the excessive growth rate of the MAT-LyLu xenografts. Tumor growth seems not to be accompanied by a proportionally rapid vascularization of the tumor mass. CGP 48664A was found to be a potent inhibitor of polyamine oxidase. This property of the drug may have contributed to the activation of the phagocytic capacity of peritoneal macrophages from tumor-bearing rats.

Adenocarcinoma↗
PubMed1995

Spermine uptake is necessary to induce haemoglobin synthesis in murine erythroleukaemia cells.

To determine whether intracellular uptake of spermine is necessary to induce haemoglobin synthesis in murine erythroleukaemia (MEL) DS 19 cells, we used single-step selection for resistance to N1,N12-bis(ethyl)spermine (BESM), a cytotoxic spermine analogue, to isolate clones deficient in polyamine transport. The cells were approximately 500-fold more resistant to BESM than parental cells and were unable to accumulate BESM, putrescine, spermidine or spermine. Addition of spermine to the polyamine-transport-deficient cells failed to induce haemoglobin synthesis. Hexamethylene-1,6-bisacetamide, a well-known differentiating agent, induced haemoglobin synthesis in both parental and resistant cells. Polyamine-transport-deficient cells transfected with DNA purified from the parental cell line were further selected for their ability to grow in the presence of alpha-difluoromethylornithine and putrescine. The transfectants had an active transport system for polyamines, and spermine added to their culture medium accumulated inside the cells and induced haemoglobin production. These findings indicate that intracellular spermine uptake is required to induce haemoglobin production in MEL cells.

Animals↗
PubMed1995

Differential recognition of free and covalently bound polyamines by the monoclonal anti-spermine antibody SPM8-2.

The reactivity of an anti-spermine MAb (SPM8-2) toward polyamines either free or bound to a solid surface was investigated using equilibrium dialysis and ELISA methods. When polyamines were covalently linked to hydrophilized microtiter plates using carbodiimide, the MAb SPM8-2 reacted both with spermine and spermidine, with a higher affinity for the latter, but did not show any reactivity towards bound putrescine. In contrast, the MAb SPM8-2 reacted with all three polyamines bound to the microtiter plates with glutaraldehyde, with an affinity in the order: putrescine > spermidine > spermine. Equilibrium dialysis and competitive ELISA tests showed that the MAb SPM8-2 exhibited high affinity for free spermine and 50% and 5% cross-reactivity with free spermidine and putrescine respectively. The affinity of the MAb SPM8-2 for putrescine, spermidine and spermine appears to depend on whether the polyamine is free or bound. The antigenicity of the polyamines differs according to the nature of their link to the solid phase. These observations are discussed in the light of the structural modification produced by covalent binding of the polyamines. It is also concluded that when antibodies are used, due care has to be exercised in choosing the appropriate immunoassay for determining the specificity of antibodies directed against small haptens such as the polyamines.

Animals↗
PubMed1995

Spermine induces haemoglobin synthesis in murine erythroleukaemia cells.

The naturally occurring polyamine spermine induces haemoglobin synthesis in murine erythroleukaemia (MEL) cells. Haemoglobin production was accompanied by accumulation of cytoplasmic beta-globin mRNA and growth inhibition, but not by cell-cycle block or changes in cell volume. Hexamethylene-bisacetamide (HMBA), a well known differentiating agent, also induces haemoglobin production, but causes a G1 block and decreases cell volume. These findings indicate that HMBA and spermine affect MEL cells differently, even though both induce haemoglobin production.

Acetamides↗
PubMed1995

The structure of polyamine analogues determines haemoglobin production and cytotoxicity in murine erythroleukaemia cells.

The naturally occurring polyamine spermine induces haemoglobin synthesis in murine erythroleukaemia (MEL) cells. We have studied the ability of various polyamine analogues to inhibit cell growth and induce haemoglobin production. Polyamine analogues with free terminal amino groups were good inducers of haemoglobin production in MEL cells. Haemoglobin levels correlated with the number of positive charges: pentamines (five positive charges) were stronger inducers than tetramines (four positive charges). Compounds ethylated at their terminal amines were poor inducers of haemoglobin production but good inhibitors of MEL cell growth. These results provide evidence that polyamine analogues support specific biological functions of polyamines in MEL cells and suggest relationships between polyamine structure and function.

Animals↗
PubMed1993

Differential effects of spermine and its analogues on the structures of polynucleotides complexed with ethidium bromide.

The interactions of spermine and polyamine analogues with synthetic polynucleotides of various base sequences complexed with ethidium bromide (EB) were investigated using measurements of fluorescence intensity and steady-state fluorescence polarization. Spermine and polyamine analogues displaced some but not all of the EB bound to poly(dA-dT).poly(dA-dT) or poly(dG-dC).poly(dG-dC), suggesting that polyamines may stabilize these polynucleotides in a conformation with reduced affinity for EB. Modifications of the aliphatic backbone of spermine have pronounced effects on its ability to displace EB from poly(dA-dT).poly(dA-dT) but not from poly-(dG-dC).poly(dG-dC). Spermine and some but not all of the polyamine analogues caused fluorescence depolarization when they interacted with the complex of EB and poly(dA-dT).poly-(dA-dT). Neither spermine nor any of the analogues, however, induced fluorescence depolarization in the complex of EB with poly(dG-dC).poly(dG-dC) or poly(dA).poly(dT). This suggests that spermine and some spermine analogues induce structural changes specific to alternating A-T sequences.

Ethidium↗
PubMed1993

Immunization of rabbits with spermine induces antibodies to self antigens.

Rabbits were immunized under different schedules with spermine in the free form or with random noncovalent complexes of spermine or spermidine with ovalbumin. The specificity of the induced antibodies was determined by ELISA and by dot-immunobinding assay. Our results show that in vitro conjugation of spermine and spermidine to a carrier is not an obligatory prerequisite for obtaining corresponding antibodies. Anti-spermine antibodies were found in 9 of 19 animals injected with spermine. Furthermore, all 19 rabbits produced distinct populations of IgM and IgG antibodies which reacted with histones, various synthetic peptides of histones, as well with ubiquitin, a peptide of ubiquitin, dsDNA and two 29-base 5' synthetic oligodeoxynucleotides. Even in antisera with no detectable reactivity with spermine, antibodies to some of the unrelated antigens were found. The pattern of reactivity of the antisera with the various antigens was different for each immunized animal. These findings lend support to the view that polyamines may play a role in the appearance of autoantibodies.

Animals↗
PubMed1992

Effect of polyamine depletion on chromatin structure in U-87 MG human brain tumour cells.

The chromatin structure of polyamine-depleted U-87 MG human brain tumour cells was studied by following the kinetics of digestion of cell nuclei by micrococcal nuclease and bovine pancreatic DNAase I. Cells growing in monolayers were treated with either alpha-difluoromethylornithine (DFMO), to deplete putrescine and spermidine, or N1,N14-bis(ethyl)homospermine (BE-4-4-4), to deplete putrescine, spermidine and spermine. BE-4-4-4 increased the initial rates of digestion and the magnitudes of limit digest by both enzymes; DFMO increased the limit digests without affecting initial digestion rates. Addition of 1 mM-putrescine 1 day after addition of DFMO reversed the effect of DFMO on limit digests. (Because polyamine uptake is low in cells treated with BE-4-4-4, and because putrescine does not reverse the growth-inhibitory effects of BE-4-4-4, reversal of the effects of BE-4-4-4 with putrescine was not attempted.) The increases in initial rates and limit digests did not result from changes in the lengths of nucleosomal or linker DNA, from blocks in cell-cycle progression, or from growth inhibition caused by DFMO or BE-4-4-4. Thus, because the limit digest is highest in cells with the lowest polyamine levels, it seems clear that the enhanced enzymic digestion of nuclei is caused by polyamine depletion and its possible effect on chromatin structure.

Brain Neoplasms↗
PubMed1990

A novel covalent enzyme-linked immunoassay (CELIA) for simultaneously measuring free and immune complex bound antibodies of defined specificity. I. Application to naturally occurring antipolyamine antibodies in human sera.

A simple covalent enzyme-linked immunoassay procedure (CELIA) is described for the routine determination of free and immune complex-bound antibodies in sera. Assays for the latter could not have been performed by adsorption ELISA due to the high ionic strength of the reassociating buffer. For the measurement in human sera of free naturally occurring IgG and IgM antibody directed against the hapten spermine, polycarboxystyrene microtiter plates with covalently coupled spermine were used. For the determination of immune complex-bound antipolyamine IgG and IgM antibody titers, serum was first dissociated at pH 2.3 in tubes and then reassociated at pH 8.1 in the wells of a microtiter plate containing covalently bound spermine. The reactivity of anti-spermine antibodies was increased from 2- to 13-fold after dissociation and reassociation compared to that of non-dissociated area. The apparent reaction constant (Rapp.) of free IgG antibodies to spermine in the sera of 19 bronchopulmonary patients with cancer differed significantly from Rapp. values of IgG antibodies having this specificity in ten other patients with non-malignant disease.

Animals↗
PubMed1987

Protein-bound polyamines in the plasma of mice grafted with the Lewis lung carcinoma.

Protein-bound polyamines were isolated from the plasma of mice using antipolyamine antibodies covalently linked to magnetic latex spheres. Their subsequent separation by polyacrylamide gel electrophoresis (PAGE) showed that in plasma from normal mice, 3 proteins (27, 55 and 82 kDa) carrying polyamines could be visualized, whereas in mice bearing the Lewis lung carcinoma at least 8 other proteins of higher molecular mass (5 of 94, 110, 130, 145 and 160 kDa, and 3 of greater than 170 kDa) had bound polyamines. These protein-bound polyamines could be detected from the first week after tumour graft; they increased during the second and third week but decreased thereafter. These proteins were not bound by immunolatex spheres preincubated with spermine bound to a protein-carrier insulin. Moreover, the appearance of these protein-bound polyamines was not a consequence of the inflammatory process since in mice infected with heat-inactivated Brucella abortus, with the exception of a 65 kDa protein, polyamines were bound to the same proteins found in normal mice. In mice grafted with the Lewis lung carcinoma the concomitant decrease in transglutaminase-mediated polyamine (e.g. putrescine) binding capacity of plasma proteins provides additional evidence for the presence in vivo of polyamines already bound to plasma proteins.

Animals↗
PubMed1987

[Demonstration of polyamines bound to plasma proteins during tumor growth].

Using antipolyamine antibodies covalently bound to magnetic latex spheres, we have been able to isolate from the plasma of mice bearing the Lewis lung carcinoma, 8 proteins with bound polyamines. These proteins are not found in the plasma of healthy mice or in those suffering with chronic inflammatory infection.

Animals↗
PubMed1986

Transglutaminase activity and putrescine-binding capacity in cloned cell lines with different metastatic potential.

An inverse correlation was found between cellular transglutaminase activity and metastatic potential of four cloned cell lines derived from a primary nickel-induced rat rhabdomyosarcoma. Cellular transglutaminase activity as assessed with endogenous cellular protein or exogenous methylated casein was greatest in the clone F9-4/8 which is the least metastasizing. When the putrescine-binding capacity of one cellular derived protein - fibronectin - was examined with exogenous transglutaminase, it was found that the fibronectin derived from the clone F9-4/8 showed the lowest binding capacity compared with those from the other clones. However, when the overall binding capacity of cellular proteins from each cell line was examined no differences could be detected. The results are discussed in the light of the well-known role of fibronectin in cellular adhesion.

Animals↗
PubMed1984

A quantitative and qualitative study of the transglutaminase-mediated insertion of polyamines into plasma proteins from patients with bronchopulmonary cancer.

The transglutaminase-mediated incorporation of putrescine into proteins of plasma derived from 44 patients with histologically defined bronchopulmonary cancer was compared with that from an age-matched group of 18 patients hospitalized with non-malignant diseases. Two types of kinetic data were obtained over a range of putrescine concentrations 0.09 mM to 0.6 mM. Whereas the plasma from all the patients of the control group showed linear kinetics, that from only 24 patients of the cancer group showed linear kinetics. The remaining 20 showed kinetics typical of inhibition by excess substrate. PAGE analysis of [14C] putrescine-bound plasma proteins showed around 15 different bands. Among these putrescine-binding proteins, we identified, with the help of corresponding specific antisera, four protease inhibitors: alpha 2-macroglobulin, alpha 1-antitrypsin, alpha 1-antichymotrypsin and antithrombin III.

Acyltransferases↗