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- Bjartell, Anders, et al.
(författare)
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Production of alpha-1-antichymotrypsin by PSA-containing cells of human prostate epithelium
- 1993
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Ingår i: Urology. - 1527-9995. ; 42:5, s. 502-510
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Tidskriftsartikel (refereegranskat)abstract
- Prostate-specific antigen (PSA) is a chymotrypsin-like serine protease exclusively produced by the prostate epithelium, and abundant in seminal fluid. In serum, PSA is predominantly complexed to a liver-derived serine protease inhibitor, alpha-1-antichymotrypsin (ACT). A higher proportion of serum PSA is complexed to ACT in prostate cancer than in benign prostate hyperplasia. Since the molecular basis for this is unclear, we have investigated whether or not ACT may be produced in the prostate gland. Immunocytochemistry, using either monoclonal or polyclonal IgGs, demonstrated specific immunostaining for ACT in normal PSA-containing prostate epithelium. Production of ACT in the normal PSA-producing prostate epithelium was demonstrated by means of nonradioactive in situ hybridization using 30-mer anti-sense DNA probes for ACT and for PSA. The ACT and PSA coding transcripts, as detected by in situ hybridization, were distributed perinuclearly, in contrast to the specific immunostaining for ACT and PSA which was most intense in the apical portion of the secretory cells. The results strongly suggest local production and release of ACT by the normal prostate epithelium that may be important for interaction between PSA and ACT in extracellular compartments.
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- Björk, Thomas, et al.
(författare)
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Alpha 1-antichymotrypsin production in PSA-producing cells is common in prostate cancer but rare in benign prostatic hyperplasia
- 1994
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Ingår i: Urology. - : Elsevier BV. - 1527-9995 .- 0090-4295. ; 43:4, s. 427-434
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE. To investigate the distribution and production of alpha 1-antichymotrypsin (ACT) and prostate-specific antigen (PSA) in benign hyperplastic and malignant prostatic tissue, respectively. METHODS. Using monoclonal anti-ACT and anti-PSA IgGs for immunocytochemistry and alkaline phosphatase conjugated 30-mer oligodeoxynucleotide probes for nonradioactive in situ hybridization, tissue specimens were studied from 15 patients with benign prostatic hyperplasia after transurethral resection of the prostate (TURP) and from 9 patients with bladder cancer who underwent cystoprostatectomy. Cancer specimens were from 23 TURP patients and from ultrasound guided core biopsies in 14 patients. Prostate tumors were graded according to the Gleason system. RESULTS. We found no or only occasional small foci of immunostaining for ACT, and no ACT transcripts in the PSA-producing epithelium in areas with benign nodular hyperplasia. By contrast, a high proportion of cells expressed both ACT and PSA in prostate cancers with low Gleason score, as detected by immunocytochemistry and in situ hybridization. Poorly differentiated tumor cells manifested greater variation in immunostaining for both ACT and PSA. As compared to tumors of low Gleason score, high-score tumors less frequently manifested immunostaining for ACT than for PSA, and less frequently generated hybridization signals for both PSA and ACT transcripts. CONCLUSIONS. A significantly higher proportion of serum PSA has been reported to be complexed to ACT in patients with prostate cancer than in patients with benign prostatic hyperplasia. The presently reported lack of ACT production in PSA-containing BPH nodules may contribute to this by making conditions less optimal for complex formation between PSA and ACT. As opposed to this, production of both ACT and PSA in prostate cancers may enhance the complex formation between PSA and ACT.
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- CHRISTENSSON, Anders, et al.
(författare)
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Complex formation between protein C inhibitor and prostate‐specific antigen in vitro and in human semen
- 1994
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 220:1, s. 45-53
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Tidskriftsartikel (refereegranskat)abstract
- Protein C inhibitor (PCI), a serine‐proteinase inhibitor first purified from human blood plasma, occurs at high concentrations (3–4 μM) in seminal fluid in both a high‐molecular‐mass and low‐molecular‐mass form. Immunochemical data have previously suggested that PCI in seminal plasma forms complexes with the most abundant serine proteinase in semen, prostate‐specific antigen (PSA). To provide a structural characterization of the PCI target, immunodetected as PSA, a procedure was developed to isolate low‐molecular‐mass and high‐molecular‐mass‐forms of PCI from seminal fluid. The high‐molecular‐mass form of PCI, recognized by monoclonal antibodies against PSA, was dissociated by alkaline treatment into the low‐molecular‐mass form of PCI and a 33‐kDa protein identified as PSA by 25 conclusive steps of N‐terminal sequence analysis. We developed a sensitive immunofluorometric assay (IFMA) to measure PCI‐PSA complexes in body fluids and investigated the rate at which purified PSA may form complexes with purified PCI. Formation of complexes detected by this IFMA and the appearance of SDS‐stable approximately 90‐kDa complexes paralleled loss of PSA activity recorded with chromogenic substrates. The rate of complex formation was slow compared to that reported for PCI and activated protein C, but was enhanced up to sixfold in the presence of heparin. Less than 10% of the initial PSA activity remained after 3 h incubation with a sevenfold molar excess of PCI and in the presence of heparin. In freshly collected ejaculates, the rate of PCI‐PSA complex formation measured by IFMA was similar to that observed between the purified proteins, and paralleled the appearance of SDS‐stable complexes by immunoblotting. During gel dissolution in freshly collected ejaculates, approximately 40% of immunodetected PCI becomes complexed to PSA. Although PCI is a slow inhibitor of PSA, complexes between PCI and PSA are detected at levels that correspond to an inactivation of up to 5% of the PSA activity in the ejaculate.
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- Christensson, A, et al.
(författare)
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Serum prostate specific antigen complexed to alpha 1-antichymotrypsin as an indicator of prostate cancer
- 1993
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Ingår i: Journal of Urology. - 1527-3792. ; 150:1, s. 100-105
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Tidskriftsartikel (refereegranskat)abstract
- Prostate specific antigen (PSA) in serum has recently been shown to occur in complex with alpha 1-antichymotrypsin and as an approximately 30 kDa. noncomplexed molecular form. We characterized PSA by 3 different assays in samples from 144 patients with benign prostatic hyperplasia (BPH) and 121 with carcinoma of the prostate. One of these noncompetitive assays measured total PSA by detecting PSA complexed to serine proteinase inhibitors and the noncomplexed molecular form, a second measured only PSA in complex with alpha 1-antichymotrypsin, whereas a third detected the noncomplexed form. PSA in complex with alpha 1-antichymotrypsin was the predominant form in all patient sera. Noncomplexed PSA constituted a minor fraction that was significantly smaller in patients with untreated prostate cancer than in those with BPH (p < 0.0001). The proportion of noncomplexed PSA does not correlate to the serum concentration of PSA or that of alpha 1-antichymotrypsin. In men with a serum PSA concentration of less than 10 micrograms./l. the combination of assays measuring total PSA immunoreactivity, the noncomplexed molecular form and PSA in complex with alpha 1-antichymotrypsin may facilitate discrimination between prostate cancer and BPH.
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- Eerola, Riitta, et al.
(författare)
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Expression of Prostate Specific Antigen on the Surface of a Filamentous Phage
- 1994
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X. ; 200:3, s. 1346-1352
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Tidskriftsartikel (refereegranskat)abstract
- We have constructed two phagemid vectors containing the gene coding for human Prostate Specific Antigen (PSA) translationally fused to a pelB signal sequence and minor coat protein III of phage fd leading to phage particles that carry PSA on their tips. Phages were characterized by Western blotting and by panning, using biotinylated monoclonal anti-PSA antibodies immobilized onto streptavidin-coated microtitration wells. Binding of PSA-phages was 102- to 5×103-fold more effective than that of wildtype phages. Trypsin treatment of the phage abolished the specific binding. Competitive panning with different concentrations of added purified PSA demonstrated that binding was PSA specific. Finally, Western-blot analysis confirmed that full-length and shorter degradation products of the fusion between PSA and protein III were visible as probed with anti-PSA antibody.
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