Steroid metabolism and binding in relation to prostatic cell growth and differentiation in vitro.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to S Chevalier.
Explore the source record for details and available documents.
We developed an assay to measure at acid pH the phosphotyrosine phosphatase activity in sera from patients with prostatic cancer. The method used quantifies the inorganic phosphate liberated from phosphotyrosine after incubation with serum, followed by the deproteinization of the reaction mixture. A high acid phosphatase (EC 3.1.3.2) activity towards phosphotyrosine was observed in all sera from patients with increased activity of prostatic acid phosphatase. This activity represented 96% of prostatic acid phosphatase and 77% of total acid phosphatase activities. Moreover, it was correlated (r = 0.91) with the amount of serum prostatic acid phosphatase determined by radioimmunoassay. When serum acid phosphatase activity was measured on several phosphorylated substrates, preferential hydrolysis was demonstrated for those in which the phosphate group was esterified on an aromatic ring rather than those presenting an aliphatic chain. Among phosphoamino acids, only phosphotyrosine was a good substrate, with little or no activity observed with phosphoserine and phosphothreonine. Human seminal plasma and partially purified prostatic acid phosphatase, tested for their activity on some of these substrates, gave similar results. On the other hand, sera from patients with above-normal alkaline phosphatase activity and no prostatic disease showed little or no activity on phosphotyrosine at both acid and alkaline pH values. Evidence is presented that the prostatic acid phosphatase in serum is a specific phosphotyrosine acid phosphatase.
The CEM-ON malignant T cell line and long-term cultured normal T cells can be induced to release CSF-1 in their culture supernatants. Chemical inducers (PMA + A23187) and, more interestingly, cytokines (tumor necrosis factor alpha (TNF alpha) and interleukin-1 alpha (IL-1 alpha)), as well as physiological (antigen + IL-2) or specific (anti-CD3 + IL-2 or PMA) stimuli, lead to rapid transient colony-stimulating factor-1 (CSF-1) gene expression and production of biologically active CSF-1. These data suggest that CSF-1 may play a role in the early phases of immune response.
Using the substrate poly[Glu80Na,Tyr20] [poly(GT)] and the autoradiographic detection of alkali-resistant phosphoproteins after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, tyrosine protein kinase (TPK) has been evidenced in human hyperplastic prostates (BPH) and the prostatic carcinoma cell lines PC3 and DU145. The enzyme was mainly found in the soluble fractions from hyperplastic tissues and in Triton extracts from the cell lines. However, its specific activity in tissues was 1.5- to 4.5-fold times higher in particulate than in soluble fractions and it was of the same order of magnitude as that of neoplastic cells. Under these conditions, no activity was detected in human seminal plasma and in sera from normal adult males or patients with BPH and/or prostatic carcinoma. On the other hand, some TPK activity was associated with human spermatozoa, with a specific activity 4- to 6-fold lower than in BPH tissue fractions and a total activity, per 10(6) cells, 5- to 20-fold lower than that in prostatic carcinoma cells. The activity of prostatic TPK was dependent upon the presence of the divalent cations Mn2+ or Mg2+ and it was completely abolished by heat denaturation. Angiotensin II, casein, and histone H2B were poor substrates compared to poly(GT). The TPK activities towards poly(GT) as well as endogenous proteins were not stimulated by epidermal growth factor and insulin or by dihydrotestosterone and estradiol. The autoradiography of alkali-resistant phosphoproteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed several bands in both BPH tissues and neoplastic cells (molecular weight ranging from 17,000 to 200,000). Preliminary characterization of TPK by gel filtration on Sephacryl S-300 showed that the soluble enzyme from BPH tissues had a molecular weight of 50,000, while the particulate-associated TPK, when assayed on poly(GT), eluted with proteins of Mr 210,000. When these peak fractions were used for endogenous phosphorylation, several major alkali-resistant phosphoproteins in the range of Mr 40,000-60,000 were evidenced, together with a Mr 110,000 band phosphorylated by the particulate TPK of Mr 210,000. In similar conditions, the TPK solubilized from rat liver membranes and partially purified by gel filtration was associated with a Mr 170,000 alkali-resistant phosphoprotein. Thus, TPKs are expressed in BPH tissues and carcinoma cell lines. In BPH tissues, two forms of TPK are expressed and the predominant enzyme is soluble and of low molecular weight (Mr 40,000-60,000).
To determine how functional changes such as growth and differentiation in the prostatic epithelium would alter protein phosphorylation on tyrosyl residues, differentiated (secretory) and basal (non-secretory) prostatic epithelial cells from normal and from metaplastic canine prostates were labeled with [32P]phosphate and their alkali-resistant phosphoproteins were analyzed by autoradiography after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The tyrosine protein kinase activity of the cells was also assayed by phosphorylation of a synthetic substrate, poly(Glu80-NaTyr20), in the presence of [gamma-32P]ATP. The prostates were characterized by tissue morphology and the cells by their density on Percoll gradients and [3H]thymidine incorporation into DNA. In prostates from intact dogs, tall columnar secretory epithelial cells were predominant and the non-secretory or basal epithelial cells were quiescent and did not incorporate [3H]thymidine. In metaplastic glands obtained from estrogen-treated castrated dogs, most of the isolated cells were non-secretory and synthesized DNA. Alkali-resistant phosphoproteins were present in all cell types. Except for two common phosphoproteins, p44 and p82, the relative phosphoprotein distribution within the gel differed when normal prostatic cells were compared to the metaplastic cells. However, the phosphoprotein patterns were the same in secretory and non-secretory cells from the same prostate tissue. On the other hand, the relative labeling intensity of phosphoproteins was always higher in non-secretory cells compared to corresponding secretory cells. Accordingly, tyrosine protein kinase (TPK) activity, expressed on a cell basis, was also higher in non-secretory cells; the ratios of TPK activities, non-secretory over corresponding secretory cells, was always higher than unity for all preparations but overlapped when cells from metaplastic glands were compared to those isolated from normal prostates. Thus, non-secretory epithelial cells isolated from either normal or metaplastic glands have a higher ability than corresponding secretory cells to phosphorylate endogenous alkali-resistant phosphoproteins and their TPK activity, measured with the synthetic substrate poly(Glu80-NaTyr20), is also higher.
To evaluate the possible role of intracellular phosphatases in the local regulation of prostatic functions, the effect of sodium orthovanadate (VO4), an inhibitor of phosphotyrosyl protein phosphatases, was studied on both protein phosphorylation and acid phosphatase activity. Secretory and non-secretory epithelial cells were isolated from normal and metaplastic prostates and incubated with [32P]phosphate in the presence and in the absence of VO4; the phosphoproteins were separated by electrophoresis and the gels were either directly submitted to autoradiography or after an alkali treatment to reveal those proteins enriched in phosphotyrosine. Prior to alkali treatment, several phosphoproteins were evidenced and in less than half of the cell preparations a slight increase in labeling intensity under vanadate (less than 75%) was observed in two phosphoproteins, p57 and p44. After alkali treatment: (1) the effect of VO4 on p57 remained in the order of 44-45% and it was restricted to less than half of non-secretory cell preparations; (2) its effect on p44 was intensified (134-207%) and observed in all cell types and in more than 80% of all preparations; and (3) in half of non-secretory cell preparations from metaplastic glands, an effect of VO4 on p35 (127%) became evident. In all instances, with normal and/or metaplastic prostates, protein phosphorylation activity, either total or alkali-resistant and in the presence or in the absence of VO4, was always higher in non-secretory epithelial cells as compared to secretory cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Antihuman lymphocyte rabbit (or horse) gamma globulins used in recipients of organ transplantation are prepared against thymocytes or immortalized cell lines, the only two sources so far allowing enough antigen preparation. These cells lack, however, the surface determinants characteristic of alloreactive blasts involved in the rejection process. We have derived long-term cultures of a panel of alloreactive (untransformed) clones from a rejected kidney. Among them, clone 1E7 has been chosen as a cytotoxic CD4+ (CD2+ CD3+ TCR alpha beta+) clone proliferating against HLA-DR8 targets. This clone (clonality assessed on T cell receptor genomic rearrangements) has been grown using weekly stimulations with the kidney donor-derived EBV cell line and recombinant IL-2. Clone cultures have been adapted to mass production after optimization of culture conditions satisfying pharmaceutical requirements. This procedure warranted a reproducible source of antigen since the functional and phenotypic characteristics of the immunizing 1E7 cells remained identical through the life span of the culture. In addition, the study of the total growth capacity of 1E7 cells showed consistent expansion until the 40th cell cycle, ensuring a progeny that will satisfy the large-scale requirement for a clinical trial. Rabbits were injected with 100 x 10(6) 1E7 cells (21, 14, and 7 days before bleeding). Sera were depleted of agglutinin by red blood cell absorption and globulin antiblast (GAB) prepared by SO4Na precipitation and ion exchange chromatography; 50% complement-mediated target cell lysis and 50% inhibition of E rosette formation and alloproliferation were obtained at GAB dilutions of about 1:250-1:500. Prescreened on cynomolgus monkeys, GAB could significantly prolong skin grafts when given prophylactically. Finally GAB have been used in human recipients of kidney grafts for prophylaxis of early rejection. Results of this pilot study are given in a separate report in this issue. In conclusion we have, for the first time, set up a large-scale preparation of polyclonal globulin against a normal human alloreactive clone, and this new reagent should present several advantages over classic antilymphocyte or antithymocyte sera because it contains specificities against activation antigens and has less crossreactivity variation among batches.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Repeated analysis of peripheral blood lymphocytes (PBLs) from a patient with large granular lymphocytosis, neutropenia, and rheumatoid arthritis revealed that approximately 45% of PBLs displayed the following phenotype: CD3+, CD4-, CD8-, CD16+, HNK-1-, WT31-. This population was purified for further analysis by depletion with anti-CD4 and anti-CD8 monoclonal antibodies (MoAbs). Southern blot analysis showed preferential rearrangements of the V gamma 9 genes. Northern blot demonstrated the presence of V gamma 9 mRNA transcripts. With MoAbs directed against either the V gamma 9 peptide (Ti gamma A) or the delta chain of the gamma delta T-cell receptor (TCR delta 1), we further demonstrated that those cell surfaces expressed both V gamma 9 and a delta gene product. In addition, analysis of the gamma gene rearrangements on six clones derived from this population demonstrated a unique rearrangement on a single chromosome, strongly suggesting the monoclonality of this T-cell population. Significant cytotoxic activity against K562, U937 was observed only after an in vitro culture period with interleukin-2 (IL-2), whereas no specific inhibitory effect on autologous bone marrow (BM) CFU-G was noted.
Human and canine prostatic specimens containing high levels of acid phosphatase (AP) activity were tested, at acid pH, for their ability to hydrolyze the major phosphoaminoacids present in phosphorylated proteins, phosphoserine (p-ser), phosphothreonine (p-thr), and phosphotyrosine (p-tyr). The cleavage of a synthetic substrate, para-nitrophenyl-phosphate (p-npp), was also measured as an indicator of AP activity; its inhibition by sodium-L-tartrate (T) was used as a criterion to identify prostatic acid phosphatase (PAP). It was found that: 1) the Km of p-tyr and p-npp were 2.0 mM and 0.41 mM, respectively, with similar Vmax values (0.078 and 0.087 mumoles of phosphate (Pi) liberated per minute per milligram of protein); 2) the ID50 were 0.25 mM and 0.50 mM with sodium orthovanadate (VO4) and T, respectively, using p-npp as substrate-with p-tyr as substrate, the values obtained were 0.016 mM and 0.11 mM, respectively; 3) activity toward p-ser and p-thr was minimal; 4) native PAP from dog seminal plasma, with a molecular weight of 90-100 kD, as determined by gel filtration on HPLC, hydrolyzed p-tyr preferentially, and this phosphatase (Pase) activity was also strongly inhibited by both T and VO4; and 5) the AP present in human and canine prostatic tissue and cells, as well as in their secretions, also preferentially hydrolyzed phosphotyrosine, and it was inhibited by T and VO4. It is proposed that these p-tyr Pases may be involved in the local regulation of prostatic growth.
The attachment and spreading of canine prostatic epithelial cells in primary monolayers and their subsequent proliferation were studied in Primaria and in polystyrene dishes either uncoated or coated with collagen type I, fibronectin, laminin, poly-D-lysine, or natural extracellular matrices (nECM) produced by canine prostatic epithelial or fibroblastic cells. Cells were inoculated in serum-free medium or in medium supplemented with either dialyzed fetal bovine serum (dFBS) or charcoal-treated dog serum at 10%. Dihydrotestosterone (DHT) and 5 alpha-androstane 3 alpha, 17 beta-diol (3 alpha, 17 beta-diol) at 10(-6) M or a mixture of steroids (androstenedione, testosterone, DHT, 3 alpha, 17 beta-diol, 5 alpha-androstane 3 beta, 17 beta-diol, estrone, and estradiol) were also added. Of all components and dishes tested, only dFBS and the nECM produced by prostatic epithelial cells increased cell attachment (850% and 450%, respectively). When the latter preparations were used in combination, an additive effect (1,500%) was observed, and the subsequent addition of dog serum after the attachment period yielded the highest number of growing prostatic epithelial cells. When prostatic epithelial cells were inoculated either in dishes coated with a nECM derived from prostatic fibroblasts or in presence of dog serum, a 50% inhibition in their plating efficiency was observed. The presence of collagen type I, fibronectin, laminin, or an nECM in the cultures, together with various steroids, had no effect on the cell unresponsiveness to steroids nor did it alter the mitogenic effect of dog serum. Thus, the attachment and spreading of canine prostatic epithelial cells in monolayers are mediated by nonsteroidal factors present in dFBS and in their nECM. Their presence, together with steroids, does not elicit a proliferative response to steroids nor did it increase the effect of growth-promoting factors in dog serum.
OX39, a murine IgG1 monoclonal antibody (MoAb) that recognizes the 55 kDa alpha chain of the rat interleukin 2 receptor (R-IL2), was studied in vitro for its ability to interfere with IL2 binding and IL2-induced proliferation on rat concanavalin A (ConA) blasts and in vivo in a model of rat heart allografts. In vitro studies indicated that OX39 MoAb interacts with a single class of sites on the alpha chain of the rat R-IL2 with a high affinity (KD = 0.8 nm) and competes with IL2 binding on this chain (KI = 0.53 nm). In contrast, OX39 MoAb was found to be 10-20 times less efficient in competing with IL2 binding to the high-affinity R-IL2 (KI approximately 10 nm). It is proposed that the epitope recognized by OX39 on the alpha chain (low-affinity R-IL2) is modified on (or buried in) the high-affinity R-IL2 configuration. Accordingly, OX39 was found to be a weak inhibitor in vitro on IL2-induced proliferation and in vivo on allograft rejection. Allograft survival was unaffected by doses of OX39 of 20 and 50 micrograms/rat for 9 days; only a borderline effect was noted when doses as high as 250 micrograms/rat were used. A significant, but restricted, effect of OX39 could be further detected when combined with low doses of cyclosporine A (1.5 mg/kg), which were ineffective by themselves. Together, our data suggest that in order to be efficient in vivo, anti-R-IL2 MoAbs must bind with high affinity to epitopes involved in the high-affinity IL2 binding site.
Following their separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, labeled proteins obtained from cultured canine prostatic epithelial cells incubated with [35S]-methionine and [32P]phosphate were subjected to alkali treatment, a method that is currently used to detect phosphotyrosine-containing proteins. Significant amounts of 35S-labeled material were lost during the alkali treatment. The crosslinking of proteins within the gels by glutaraldehyde treatment eliminated protein losses and did not alter the efficiency of phosphoester bond hydrolysis by alkali treatment. Consequently, the time required to detect alkali-resistant phosphoproteins by autoradiography was greatly reduced. Prostatic phosphoproteins were also shown to contain phosphotyrosine, indicating the presence of tyrosine protein kinase activity in these proliferating epithelial cells.
Using a whole cell assay system, the androgen binding capacity of canine prostatic epithelial cells was evaluated in relation to their function. Radiolabeled Methyltrienolone (R1881) was used as the ligand in the presence of an excess of Triamcinolone acetonide and the amount of [3H]R1881 bound to the cells at equilibrium was determined by either displacement or saturation studies. With immature cells in culture (3 days of attachment), displacement analysis revealed the presence of high affinity binding sites which were also present in cells cultured for 10 days. With freshly dispersed prostatic cells (mostly secretory epithelial cells) as well as with older cells in culture (17 and 24 days), only less specific binding sites were observed with both unlabeled R1881 and/or dihydrotesterone (DHT). In contrast, only the high affinity androgen receptor (AR) was present in cytosolic extracts prepared from normal glands. Displacement studies performed with cultured cells at different stages of growth also showed that the basal level as well as the degree of low affinity binding increased during the maturation of non-proliferating cells. The presence of multiple binding components was demonstrated by saturation studies performed with either cultured or freshly dispersed cells. The first component, that was saturated at 5 nM of [3H]R1881, was due to AR while the other two binding components, showing positive-cooperativity (Hill coefficients of 1.90 and 5.07, respectively), were saturated at concentrations of 15 and 30 nM of [3H]R1881. In contrast, the Hill coefficient for the AR was 0.88 indicating the presence of an independent component. It was calculated that only 11.4% of the total uptake of R1881 was attributed to AR binding, suggesting that the remainder may represent an intracellular pool of androgens. Thus, a whole cell binding assay represents a dynamic system for the detection, by saturation studies, of binding components that are not revealed using the conventional displacement studies or cell-free systems. It is proposed that these acceptor sites may play a role in differentiated prostatic function rather than in cell proliferation.
The androgen receptor content in the prostate has been usually evaluated using subcellular fractions without taking into account cellular and functional heterogeneity of the gland. Using enriched populations of immature canine prostatic epithelial cells cultured in primary monolayers, a whole cell assay system was developed to measure androgen receptors. Tritiated dihydrotestosterone (DHT) and/or methyltrienolone (R1881) in serum-free medium were used as ligands and Triamcinolone acetonide (0.5 microM) was added to prevent the binding of R1881 to other types of receptors. The amount of radiolabelled ligand specifically bound to the cells was determined at equilibrium. Specific binding was proportional to the number of cells seeded. Scatchard analysis revealed the presence of at least two types of binding sites. The Kd for the high affinity binding site was 2 x 10(-9) M. Competition studies indicated that this component was specific for androgens; Methyltrienolone, Mibolerone and the antiandrogen RU 23908 were the most efficient competitors. They were followed by DHT, 5 alpha-androstane-3 alpha, 17 beta-diol, testosterone, estradiol and estrone. Progesterone, 5 alpha-androstane-3 beta, 17 beta-diol and epitestosterone were not inhibitors. The level of specific binding was 11.0 +/- 7.6 fmol of bound R1881 per 10(6) cells (n = 34) or 2075 +/- 1434 fmol per mg of DNA; these values correspond to an average of 6624 +/- 4577 sites per cell. Thus, using this whole cell assay system, specific and androgen receptors were detected in immature prostatic epithelial cells in culture. This assay will therefore be useful to study the interrelationship between androgen binding activity and specific cell functions.
Explore the source record for details and available documents.
Using an antiserum raised against hamster oviductal zona pellucida, we observed specific immunogenic components of the reproductive tract on the zonae of oviductal eggs and in oviductal fluid. Results of immunohistochemical studies suggested that these oviductal components may originate from epithelial cells of the isthmus and, to a lesser extent, of the ampulla and fimbria. The oviductal immunogenic components have also been observed within the bursal cavity, which contains the ovary. These observations suggest that these oviductal components may play an important role in the first steps of the hamster reproductive process.