Indirect immunofluorescence for identification of prostatic epithelial cells

Immunocytochemistry of male reproductive organs

Immunological techniques have enabled us to see that mammalian sperm undergo complex surface changes during maturation in the male reproductive tract. Binding affinity and sperm surface binding domains have been demonstrated using immunocytochemical technique. Recent studies using monoclonal antibodies suggest that these highly specific probes are useful for detecting changes in the sperm surface during epididymal transit and in defining the role of these complex changes in sperm maturation and the process of fertilization. Studies involving immunological mapping of the sperm surface, in parallel with immunohistological and functional inhibition test, have provided important information concerning the role of individual sperm antigens in fertility. A better understanding of local antibody production and cell-mediated immune responses in the male reproductive tract has also led to the understanding of immunological infertility. Sperm membrane is comprised of multiple domains each of which is sharply demarcated, with a unique composition and physiological role.

Prostatic-specific antigen: clinical experience utilizing immunoperoxidase staining techniques in patients with metastatic prostate cancer

A human prostatic-specific antigen was first purified in 1979 by M.C. Wang et al. In the years to follow, investigators have been able to develop antisera to prostatic-specific antigen. Using an immunoperoxidase technique to stain both fresh and archival specimens, tissue of prostatic origin can be identified. The stain in our experience has been both specific and sensitive as an indicator of extraprostatic spread of carcinoma. We describe five cases where this technique has been useful in clinical practice.

Detection of tumor cells in bone marrow of patients with prostatic carcinoma by immunocytochemical techniques

We used a mixture of antisera to prostatic specific acid phosphatase, prostatic specific antigen, epithelial membrane antigen and cytokeratin to examine multiple marrow aspirates from patients with local (15) and metastatic prostatic carcinoma (15), and benign prostatic hypertrophy (10). We found moderate to large numbers of tumor cells in the bone marrow of 11 of 15 (73 per cent) patients with known metastatic disease and small numbers of abnormal cells in 2 of 15 (13 per cent) patients with apparently local disease. No tumor cells were found in patients with benign prostatic hypertrophy, and only 2 patients with metastatic disease had tumor cells in the bone marrow when conventional hematomorphological preparations were examined. These findings suggest that immunocytochemistry can increase the detection rate of metastatic prostatic carcinoma cells. Further followup of larger numbers of patients with local carcinoma will reveal whether the presence of micrometastases denotes a poor prognosis.

Ectopic prostatic glands in bulbar urethra. Immunoperoxidase study

Ectopic prostatic glands in the bulbar urethra of a sixty-year-old man were identified by an indirect immunoperoxidase stain for prostatic acid phosphatase. Cystoscopically the appearances were those of "urethritis" without the polypoid appearance previously reported in cases of ectopic prostatic tissue.

Immunofluorescent localization of an androgen-dependent isoenzyme of prostatic acid phosphatase in rat ventral prostate

Isoenzymes of rat ventral prostate (RVP) acid phosphatase were isolated and partially purified by ultracentrifugation, Sephadex G-100 column chromatography, and isoelectric focusing. Antisera were raised to the isoenzymes of prostatic acid phosphatase by immunization of New Zealand white rabbits. Rabbit antisera reacting specifically to homologous but not heterologous isoenzymes of acid phosphatase were then reacted with a variety of tissues using indirect immunofluorescence. The tissues included prostate, spleen, bone marrow, liver, kidney, salivary gland complex, small intestine, and adrenal glands. An antiserum against a RVP acid phosphatase isoenzyme with a pI of 4.5 (A-PAP) localized acid phosphatase only in the supranuclear region of rat ventral prostate epithelial cells, and did not react with acid phosphatase in any of the other organs tested. A-PAP did not localize acid phosphatase in the ventral prostate from rats 14 days after castration. A-PAP did localize acid phosphatase in the ventral prostate from castrated animals that were treated with testosterone. These results indicate the A-PAP localized an androgen-dependent isoenzyme of acid phosphatase in RVP epithelial cells that may be secretory in nature. This antiserum should prove to be an ideal marker for studies involving hormonal regulation of prostatic epithelial function in vivo and in vitro.

Epithelial markers in prostatic, bladder, and colorectal cancer: an immunoperoxidase study of epithelial membrane antigen, carcinoembryonic antigen, and prostatic acid phosphatase

Twenty prostatic adenocarcinomas, 20 transitional cell carcinomas of the bladder, and 20 colorectal adenocarcinomas were stained for epithelial membrane antigen, carcinoembryonic antigen, and prostatic acid phosphatase. Polyclonal affinity purified first and second antibodies and an indirect immunoperoxidase technique were used. All of the colorectal and bladder tumours and 16/20 prostatic tumours were positive for epithelial membrane antigen. All 20 colorectal, 7/20 bladder, and 5/20 prostatic tumours stained for carcinoembryonic antigen. All of the prostatic adenocarcinomas and none of the colorectal or bladder tumours were positive for prostatic acid phosphatase. These markers may be used to discriminate between tumours arising from these sites.

Immunohistochemical markers for prostatic cancer

In a patient with an unclassifiable primary or metastatic neoplasm, with or without a history of prostatic cancer, immunostaining for PA or PSAP may prove invaluable. The procedure is simple, rapid, inexpensive, and extremely accurate in demonstrating the prostatic origin of tumors. It should be noted however, that the specificity of results is entirely dependent upon the specificity of the primary antibody, which should be meticulously defined before the procedure is used for diagnostic purposes.

Pre-treatment and post-treatment evaluation of prostatic adenocarcinoma for prostatic specific acid phosphatase and prostatic specific antigen by immunohistochemistry

Prostatic specific acid phosphatase and prostatic specific antigen have been used as specific markers of prostatic adenocarcinoma in immunohistochemical studies, particularly when seeking the primary site of a poorly differentiated metastasis. We herein evaluate the effect of therapy on the persistence of these markers in surgically obtained tissues. Prostatic biopsies from 30 patients with adenocarcinoma of the prostate gland before and after treatment with orchiectomy alone, diethylstilbestrol, external beam radiation or combined radiation and diethylstilbestrol were studied for prostatic specific acid phosphatase and prostatic specific antigen using the indirect immunoperoxidase technique. The interval between biopsies ranged from 3 to 72 months, with an average of 28 months. All pre-treatment biopsies stained positively for prostatic specific acid phosphatase and prostatic specific antigen. Staining for prostatic specific antigen and prostatic specific acid phosphatase was seen easily in 29 of 30 post-treatment biopsies, while in 1 case infiltrating anaplastic cells surrounded by stroma showed staining for these antigens in an extremely small percentage of cells, which were overlooked easily unless examined carefully. In view of this small number of positively staining cells this case was designated as equivocal. While some cases demonstrated less intense staining in post-treatment biopsies compared to pre-treatment, this finding was by no means constant. With these primary antisera a higher percentage of cytologically malignant cells stained positively for prostatic specific acid phosphatase than for prostatic specific antigen in adjacent tissue sections in some cases. Prostatic specific acid phosphatase and prostatic specific antigen appear to be sensitive and persistent markers of prostatic adenocarcinoma despite morphologic changes accompanying various therapies.

Evaluation of prostate specific acid phosphatase and prostate specific antigen in identification of prostatic cancer

The peroxidase-anti-peroxidase technique was used to stain for prostate specific acid phosphatase and prostate specific antigen in 12 patients with primary tumors and in 12 patients with metastases in whom the nature of the tumor was in doubt after routine histopathological studies. Nine of the primary tumors were positive for both markers and an additional 2 tumors stained for prostate specific antigen only. Six metastatic lesions stained for both markers and a seventh for prostate specific antigen alone. Thus, 11 of 12 primary tumors and 7 of 12 metastases studied were proved to be of prostatic orgin. While the peroxidase staining was sometimes weak and uneven this method, using prostate specific antigen and prostate specific acid phosphatase, allowed for ready identification of metastases. The heterogeneity of the tumors in regard to these 2 prostate markers is demonstrated, and the value of staining for prostate specific acid phosphatase and prostate specific antigen is emphasized.

Human prostate specific and shared differentiation antigens defined by monoclonal antibodies

Splenic lymphocytes of BALB/c mice immunized with membrane-enriched fractions of human benign prostatic hyperplasia tissues were fused with the NS-1 light chain-secreting murine myeloma cell line. This generated hybridoma cultures that secreted immunoglobulins reactive in solid-phase radioimmunoassays with membrane preparations of prostatic tissues but not with membrane preparations of apparently normal human liver, spleen, thymus, or erythrocytes. After further screening of immunoglobulin reactivities and cloning of cultures, eight monoclonal antibodies were chosen that demonstrated reactivity with human prostate tissues. These monoclonal antibodies could be placed into at least three major groups--epithelium-specific, polyepithelial, and stroma-specific--on the basis of differential binding to the surfaces of various component cells in the prostate and other epithelia. Two antibodies defined unique protein antigens specific for prostate epithelia that were not crossreactive with prostatic acid phosphatase or the recently described "prostatic antigens." These antibodies also detected antigens on malignant prostate tissues as well as other malignant tissues. Four antibodies defined three unique polyepithelial protein antigens (two of the antibodies were different isotypes defining the same protein). Each of the polyepithelial antigens was expressed on a different spectrum of normal epithelial tissues. Two displayed brain tissue crossreactivity, one was present on pancreas, and one was present on platelets. The two antibodies that detected prostatic stromal protein antigens showed different spectra of reactivities. One antibody reacted with apparently all prostatic stromal cells as well as endothelial cells in the prostate and other organs. The other antibody apparently reacted with all prostatic stromal cells as well as myoepithelial and muscle cells in other organs.

Immunofluorescent identification of antibodies specific for prostatic acid phosphatase

Antisera demonstrated by precipitation and passive haemagglutination to possess antibodies specific for prostatic tissue-specific acid phosphatase have been employed to localize this isoenzyme in the prostate by indirect immunofluorescence. Antisera specific for prostatic acid phosphatase may permit the immunohistological localization of this enzyme, thereby serving as a biological marker for metastatic prostatic cancer, where histological and/or clinical staging of the primary tumour remain uncertain.

Immunofluorescence for prostatic acid phosphatase: clinical applications

An indirect immunofluorescence technique to detect cells producing prostatic acid phosphatase was used to evaluate 12 biopsies of soft tissue masses of possible metastatic prostatic carcinoma. In 10 patients varying degrees of immunofluorescence were observed, confirming the origin of the primary tumor. Specimens from 34 patients with prostatic carcinoma were obtained either by radical prostatectomy or transurethral resection of the prostate. A comparison of histological grade (Gleason), semiquantitative immunofluorescence for prostatic acid phosphatase and hormonal responsiveness was done. There was a suggestion of higher hormonal responsiveness in the group with a low Gleason score and a high percentage of positive immunofluorescence that presently cannot be evaluated completely since some patients still are under therapy. This method may be used in the future in conjunction with other techniques, such as androgen receptors, to define a population of patients most likely to respond to hormonal manipulation.

The significance of prostatic acid phosphatase in adenocarcinoma of the prostate

Our radioimmunoassay for prostatic acid phosphatase was compared to commercial radioimmunoassay kits. A close correlation among all 3 assays was found in control groups, and in patients with benign prostatic hyperplasia and adenocarcinoma of the prostate. These results also were compared to recent reports from other centers using similar methodologies. In 7 to 15 per cent of the patients with bone metastasis normal levels of serum prostatic acid phosphatase were found. Variability in prostatic acid phosphatase production by the tumor may account for this finding. Elevated levels of prostatic acid phosphatase were associated more commonly with less differentiated primary tumors. A low percentage of prostatic acid phosphatase elevations in patients with early localized and incidental adenocarcinoma was found for the 3 assays evaluated. These factors, along with the falsely positive rates in patients with benign disease, limit severely the application of these assays to the screening of male patients at risk for adenocarcinoma of the prostate.

Androgens and prostate-specific acid phosphatase in whole tissue and in separated epithelium from human benign prostatic hypertrophic glands

The concentrations of prostate-specific acid phosphatase (PAP), testosterone, 5 alpha-dihydrotestosterone (5 alpha-DHT), 5 alpha-androstane-3 alpha, 17 beta-diol, androstenedione, 5 alpha-androstanedione, and androsterone were measured by specific radioimmunoassays in whole pieces and in separated epithelium from human benign prostatic hypertrophic (BPH) tissues. Significant correlations were noted between the concentrations of PAP and 5 alpha-DHT, and PAP and 5 alpha-androstane-3 alpha, 17 beta-diol in the epithelium, and between PAP and androstenedione, and PAP and testosterone PAP is androgen dependent, particularly as regards 5 alpha-DHT, whereas 5 alpha-androstane-3 alpha, 17 beta-diol may operate after conversion to 5 alpha-DHT. There is no obvious explanation for the correlations noted in whole tissue, but is suggested that circulating androgens, representing the androgen source for the prostate, primarily determine the production of PAP. The majority of the PAP in BPH tissues is located extracellularly.

Evaluation of chemotherapy of prostatic cancer in nude mice

The effect of chemotherapy for treatment of prostatic cancer was studied in two different types of human prostatic tumors grown in nude mice based on growth curves and histological examination. As single agents, cis-platinum and vincristine showed significant growth inhibition in both strains; cyclophosphamide, methotrexate, Adriamycin, and peplomycin were effective in only one strain, whereas 5-fluorouracil (5-FU), ACNU, and Estracyt were not effective in either strain, even at relatively high doses. A study was also carried out on multimodal combination chemotherapy with fewer side effects, and such therapy is in clinical use. The treatment is composed of VPM (vincristine, peplomycin, and methotrexate) followed by CCF (cis-platinum, cytosine arabinoside, and 5-FU) and ACF (Adriamycin, cytosine arabinoside, and 5-FU). Antitumor effects related to synchronization of tumor cells were investigated by sequential autoradiography and DNA histography.

Immunohistochemical evaluation of prostatic carcinoma before and after radiotherapy

Immunohistochemical procedures were applied to the examination of human tissues for prostatic acid phosphatase. With antisera against purified human prostatic acid phosphatase 173 normal and neoplastic tissues were tested. Samples of 45 non-prostatic carcinomas and their respective normal tissues were negative. Of 4 seminal vesicles studied 2 showed weak reactivity. The epithelial cells of normal prostatic acini were uniformly positive in 25 patients studied. In contrast to normal prostatic tissue the malignant acini in 53 of 55 patients with prostatic carcinoma had variable but positive reactivity. Of 27 patients receiving radiotherapy for adenocarcinoma of the prostate variable staining was observed in the neoplastic cells of 24, 8 to 52 months after treatment. The continued production of prostatic acid phosphatase in the malignant cells after radiotherapy suggests that they also may maintain metabolic activities necessary for growth and metastasis.

Immunohistological approaches to human prostatic epithelial cells

Specific anti-acid phosphatase antisera were prepared by the use of purified prostatic acid phosphatase (PAP) from prostatic tissue and lysosomal acid phosphatase (L-AcP) from diploid fibroblast (WI-38) as antigen. Since the antigenic difference between the PAP and L-AcP was established, distribution of these enzymes among various tissues and tissue culture cells was investigated by the indirect immunofluorescence method and the unlabeled antibody method [14]. The L-AcP has been detected as granules localized in a perinuclear portion of all of the epithelial cells, fibroblasts, and peripheral blood cells except erythrocytes. Presence of the PAP was limited to the prostatic epithelial cells. It is also noted that the biosynthesis of the PAP is strikingly diminished in the long-term culture of prostatic epithelial cells. However, because of the antigenic difference between the PAP and L-AcP, and because of the high concentration of PAP in the cytoplasm of prostatic epithelial cells, it is feasible to apply the anti-PAP immunofluorescence method to the identification of metastatic prostatic carcinoma cells in the biopsy materials.

MA 160 and EB33 cell lines: HeLa cell contaminants, hybrids or prostatic epithelial cells?

Studies of acid phosphates produced by cell lines MA 160 and EB 33 demonstrated immunochemically their prostatic origin. MA 160 and EB 33, rather than being HeLa contaminants, may be hybrids of prostatic epithelial and HeLa cells or true prostatic cell lines with chromosomal changes common to all long-term cultivated cell lines.

Bone marrow acid phosphatase in staging of prostatic cancer: how reliable is it?

To evaluate the reliability of bone marrow acid phosphatase in the staging of prostatic carcinoma we analyzed 50 bone marrow samples collected at random from the hematology service at this hospital. The samples were assayed for acid phosphatase content by a colorimetric method using sodium thymolphthalein monophosphate as a substrate and by 2 immunochemical assays developed at our laboratory (counter immunoelectrophoresis and radioimmunoassay). We found a high percentage (61 per cent) of falsely positive results in patients with various hematological diseases without evidence of prostatic carcinoma by the colorimetric evaluation. All of these patients except 1 had negative immunochemical assay. Until a specific assay for prostatic acid phosphatase is developed for clinical use we caution the use of a single elevation of bone marrow acid phosphatase as a parameter of metastatic disease.

Purification and characterization of human prostatic acid phosphatase

Human prostatic acid phosphatase (orthophosphoric monoester phosphohydrase, EC 3.1.3.2) is purified to homogeneity by standard procedures which include CM-Sephadex, Con A affinity chromatography and gel filtration. The purified enzyme is antigenically specific and has a M.W. of 100,000 with subunit M.W. of 48,000. However, the enzyme exhibited charge heterogeneity. Two major electrophoretic or chromatographic isozymic forms of PAP were separated by DEAE-Sephadex chromatography and their immunochemical identity was studied by immunodiffusion before and after the neuraminidase digestion. Quantitative precipitin and inhibition experiments showed immunological identity of the two chromatographic isozymes. Immunologic specificity of this enzyme resides on the protein moiety rather than the carbohydrate residue, although the latter group is mostly responsible for the charge group heterogeneity of the enzyme.