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.     

Immunohistochemical demonstration of cytokeratins in the human prostate

The behaviour of keratins in the human prostate is investigated immunohistochemically by polyclonal rabbit antibodies against keratins from human stratum corneum (kit from ORTHO/Heidelberg) and compared to the behaviour of prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA). In normal glands and cribriform as well as adenomatous hyperplasia only basal cells contain keratin. The secretory epithelium is keratin-negative and in contrast to the basal cells PAP- as well as PSA-positive. In prostatic ducts and utriculus prostaticus keratin is demonstrable in basal cells and urothelium. As in normal glands, the light cylindric epithelium is keratin-negative and PAP- as well as PSA-positive. The cells in atrophic glands and postatrophic hyperplasia may contain keratin as well as PAP and PSA. Urothelial and squamous metaplasia are strongly keratin-positive. PAP and PSA are not found. The cylindric epithelium of the ejaculatory ducts contains keratin at many places. PAP and PSA are not demonstrable. The utriculus does not differ from normal prostatic glands immunohistochemically. This supports the view that the epithelium of the sinus urogenitalis is involved in the embryogenesis of normal prostatic glands and the utriculus as well. Urothelial and squamous metaplasia obviously arise from basal cells which share the same immunohistochemical features. Whether the cells in atrophic glands and postatrophic hyperplasia derive from basal cells or secretory epithelium cannot be decided. The keratin composition of the prostate should be further analyzed by keratin-specific monoclonal antibodies.     

Ultrastructure of the normal adult human female prostate gland (Skene's gland)

The predominant cells of female prostatic glands lining their lumen were found to be tall cylindrical secretory cells with short stubby microvilli, protuberances of the apical cytoplasm, and with bleb formation. Abundant secretory vacuoles and granules, rough endoplasmic reticulum, developed Golgi complexes and numerous mitochondria are characteristic of their active secretory configuration with apocrine (apical blebs) and merocrine (secretory vacuoles and granules) type of secretion. Basal (reserve) cells were seen to be located between the secretory (luminal) cells and the basement membrane. Their ground cytoplasm is dense with rough endoplasmic reticulum and mitochondria. Their nuclei, unlike those of secretory cells, possess more peripheral condensed chromatin, denser dispersed chromatin and sporadic nucleoli. Besides the two basic types of mature prostatic cells intermediary cells were also seen, located between the basal and secretory cells or in their close vicinity. Their cytoplasm exhibits numerous profiles of rough endoplasmic reticulum and free ribosomes. Secretory vacuoles and granules were mostly practically absent (type 1 intermediary cells) so that they resembled basal (reserve) cells. In some of them, however, as in secretory cells, such secretory elements do gradually appear (type 2 intermediary cells). The finding of intermediary cells in the lining of prostatic glands supports the role of basal (reserve) cells in the renewal of cells in glands of the female prostate. The first ultrastructural analysis of the normal female prostate performed by transmission electron microscopy showed that, as in the postpubertal male, the prostatic glands in the adult female display mature secretory and basal cells. The results of the presented study further corroborate the contemporary concept of the female prostate as a functional genitourinary organ.     

Ultrastructure of the normal adult human female prostate gland (Skene’s gland)

The predominant cells of female prostatic glands lining their lumen were found to be tall cylindrical secretory cells with short stubby microvilli, protuberances of the apical cytoplasm, and with bleb formation. Abundant secretory vacuoles and granules, rough endoplasmic reticulum, developed Golgi complexes and numerous mitochondria are characteristic of their active secretory configuration with apocrine (apical blebs) and merocrine (secretory vacuoles and granules) type of secretion. Basal (reserve) cells were seen to be located between the secretory (luminal) cells and the basement membrane. Their ground cytoplasm is dense with rough endoplasmic reticulum and mitochondria. Their nuclei, unlike those of secretory cells, possess more peripheral condensed chromatin, denser dispersed chromatin and sporadic nucleoli. Besides the two basic types of mature prostatic cells intermediary cells were also seen, located between the basal and secretory cells or in their close vicinity. Their cytoplasm exhibits numerous profiles of rough endoplasmic reticulum and free ribosomes. Secretory vacuoles and granules were mostly practically absent (type 1 intermediary cells) so that they resembled basal (reserve) cells. In some of them, however, as in secretory cells, such secretory elements do gradually appear (type 2 intermediary cells). The finding of intermediary cells in the lining of prostatic glands supports the role of basal (reserve) cells in the renewal of cells in glands of the female prostate. The first ultrastructural analysis of the normal female prostate performed by transmission electron microscopy showed that, as in the postpubertal male, the prostatic glands in the adult female display mature secretory and basal cells. The results of the presented study further corroborate the contemporary concept of the female prostate as a functional genitourinary organ.     

Antibody-mediated lysis of the bovine subcommissural organ maintained in culture

The subcommissural organ (SCO) is a brain gland that secretes glycoproteins into the cerebrospinal fluid (CSF). It is an ancient and conserved secretory structure of the brain, developing very early in ontogeny. However, the function of the SCO is unknown. The secretory cells of the SCO are arranged into a single or double, irregularly shaped layer located at the interface of the CSF and nervous tissue. This has prevented its selective surgical destruction. The present investigation was designed to destroy the secretory cells of 30-day-old expiants of bovine SCO by use of an immunological approach. A membrane preparation enriched with plasma membrane of the secretory cells of the bovine SCO was obtained. This preparation was further processed to separate the structural proteins. A similar procedure was applied to obtain a fraction of integral proteins of the plasma membrane of a nonsecretory ciliated ependyma. Antisera were prepared against both preparations of integral proteins. The antiserum against the fraction obtained from the SCO cells immunostained the plasma membrane of the bovine SCO cells and in immunoblot it reacted with several proteins of the membrane preparation from SCO cells. When added to the culture medium this antibody bound to the apical plasma membrane of the secretory ependyma of the bovine SCO kept in culture; it caused the lysis of these cells when used together with complement. None of these properties were displayed by the antiserum raised against the integral proteins of the plasma membrane of the ciliated ependyma. This antiserum, however, immunostained the bovine ciliated ependyma neighboring the SCO. These results indicate that immunological surgery of the SCO in living animals may be possible to achieve.     

Immunohistochemical investigation of different cytokeratins and vimentin in the prostate from the fetal period up to adulthood and in prostate carcinoma

From the fetal period up to puberty the immature epithelium of the prostate glands, the prostatic ducts, the ejaculatory ducts and the seminal vesicles as well as the urothelium of the prostatic urethra are extensively positive for different keratin antibodies (antibody against keratins from human stratum corneum, broadly reacting antibody "AE1 and AE" and antibodies against the keratins 7, 8, 18 and 19) immunohistochemically. The epithelium of the ejaculatory ducts and seminal vesicles in addition regularly exprimates vimentin which is found in the epithelium of the prostate glands focally. During puberty, the immature epithelium of the prostate glands differentiates into the two cell types basal cell and secretory epithelium which differ immunohistochemically: Keratins from human stratum corneum are exclusively demonstrable in the basal cells, the keratins 8 and 18 only in the secretory epithelium. For keratin 7, 19 and the antibody "AE1 and AE3" both cell types are positive. Keratin 7 is demonstrable only focally. The secretory epithelium partly co-exprimates keratins and vimentin. Prostatic carcinomas of different grades virtually contain no keratins from stratum corneum. All other keratins are found in variable extension in the vast majority of the tumors independent of the differentiation. Vimentin is positive mostly focally in about 50% of the tumors. Prostatic carcinoma and the secretory epithelium of the prostate glands share identical immunohistochemical features and differ from the basal cell by several markers. This indicates that prostatic carcinoma rather derives directly from the secretory epithelium than from the basal cell.     

Expression of KAI1 in paraffin-embedded normal, hyperplastic and neoplastic prostate and prostate carcinoma cell lines

Expression of KAI1, a tumor metastasis suppressor gene, was studied with different fixatives in frozen and paraffin-embedded sections of human and rat prostate carcinoma cell lines and human prostate lesions by Immunohisto-chemistry. Immunoreactivity of the membrane antigen in cell lines was associated with known expression levels in these lines and the fixative used. Formalin and paraformaldehyde helped maintain the immunoreactivity of cells. In human prostate, frozen sections revealed diffuse reactivity of the antigen in normal and neoplastic tissues while paraffin-embedded tissues usually showed focal reactivity, although more than 50% of cases with normal epithelium and adenocarcinomas were reactive. In some cases, pretreatment with trypsln enhanced immunoreactivity. Benign prostatic hyperplasia (BPH) showed the most intense diffuse immunoreactivity, which suggested enhanced expression. Prostatic intraepithelial neoplasia (PIN) also often expressed high levels of KAI1. Three of five metastases were reactive but two primaries and their metastases were not. Lymphocytes in primary carcinomas and lymphocytes and germinal center cells in lymph nodes were immunoreactive, while adjacent primary or metastatic prostate adenocarcinoma epithelium was not immunoreactive. Although paraffin-embedded human tissues were not optimal for determining levels of expression of KAI1, they did show immunoreactivity that could have prognostic value and showed the specific cytoplasmlc localization of the protein in cells.     

Pleomorphic giant cell carcinoma of the prostate

We report the clinical and pathologic features of 2 cases of pleomorphic giant cell carcinoma of the prostate. One case was found at autopsy in a 77-year-old man and was composed of high-grade prostatic adenocarcinoma with prominent anaplastic giant cells. The patient presented with metastases to multiple retroperitoneal lymph nodes, liver, and lumbar vertebrae. The second case occurred in a 45-year-old man who underwent transurethral resection of the prostate and was found to have high-grade prostatic adenocarcinoma with an extensive anaplastic giant cell component. The patient presented with distant metastases and died within 9 months. Both regular adenocarcinoma and anaplastic giant tumor cells displayed cytoplasmic immunoreactivity for prostate-specific antigen, prostatic acid phosphatase, and keratin AE1/AE3; in one case, scattered cells were also positive for chromogranin and epithelial membrane antigen. Pleomorphic giant cell carcinoma is a rare variant of prostatic adenocarcinoma with a poor prognosis that should be considered in the differential diagnosis of prostatic pleomorphic tumors.     

The role of the detection of hematogenous micrometastasis in prostate adenocarcinoma and malignant melanoma by RT-PCR

Recent studies reported the possibility of detecting prostate adenocarcinoma and malignant melanoma cells in peripheral blood using RT-PCR of prostatic specific antigen (PSA), prostatic specific membrane antigen (PSMA) and Tyrosinase mRNAs. The PCR results showed high variability, ranging between 0% and 100% of positivity in patients with advanced disease. Our purpose was to evaluate the presence of tumor marker mRNAs in peripheral blood of prostate cancer and melanoma patients by means of RT-nested-PCR. We tested 70 and 36 peripheral blood samples from prostate carcinoma and malignant melanoma patients, respectively. The RT-PCR analysis showed the presence of PSA cDNA in 9 out of 70 (12.9%); PSMA cDNA in 14 out of 70 (20%); and Tyrosinase cDNA in 2 out of 36 (5.5%) peripheral blood samples from melanoma patients. Our study confirms the applicability of this sensitive method to monitor disease status. Although, the RT-nested-PCR of Tyrosinase is able to detect neoplastic cells in peripheral blood specimens, we suggest the necessity of a great caution in interpreting PCR results when the nested method has been used.     

Gastricsin in the benign and malignant prostate.

An immunoperoxidase (peroxidase-antiperoxidase) method was used to localise the gastric acid proteinase gastricsin in prostate. The enzyme was present, probably as zymogen, in acinar lining cells in 66 (69%) of 96 cases of benign prostatic enlargement; other normal tissues from male genital tract were negative. It was also present in the tumour cells in 21 (39%) of 54 cases of prostatic adenocarcinoma. The findings support the suggestion that the prostate is the source of the gastricsin of normal seminal fluid. It is not yet clear whether its presence in prostatic carcinomas will be of diagnostic use.     

The intercellular adhesion molecule, cadherin-10, is a marker for human prostate luminal epithelial cells that is not expressed in prostate cancer.

During the normal turnover of prostate epithelium, stem cells in the basal cell layer produce an intermediate cell population that gives rise to fully differentiated secretory luminal cells. This process is extensively studied in relation to the development of prostate disease, in particular, to elucidate the origin and nature of prostate cancer. We previously showed that the mRNA of a poorly characterised intercellular adhesion molecule, cadherin-10, is strongly expressed in human prostate. Using anticadherin-10 antibodies, immunohistochemistry, and confocal microscopy, we have examined the pattern of cadherin-10 expression in relation to human prostate epithelial differentiation markers (E-cadherin, CD44, and cytokeratins (CK) 14, 18 and 19) in archival paraffin-embedded and fixed-frozen histopathological specimens in individual and serial sections. In non-neoplastic prostate, E-cadherin is expressed by all basal and luminal epithelial cells, while cadherin-10 is variably expressed in luminal cells where it is colocalised with E-cadherin at basolateral plasma membranes. Cadherin-10 is absent in CK14- and/or CD44-positive basal cells, but is expressed in CK18-positive luminal cells (differentiated secretory cells), a subset of CK19-positive intermediate/luminal cells, but not CK19-positive basal cells. Small foci of prostate cancer express E-cadherin, CK19 and CK18, but cadherin-10 expression is low or undetectable. These findings suggest that the expression of cadherin-10 is associated with the later stages of differentiation of luminal secretory cells, indicating a specific role in secretory cell terminal differentiation. While prostate cancer cells express secretory cell markers (eg, CK18, prostate-specific antigen) and the more generally expressed E-cadherin, their failure to express cadherin-10 further emphasises a role for this cadherin in normal prostate organisation and function.     

Effects of combination endocrine treatment on normal prostate, prostatic intraepithelial neoplasia, and prostatic adenocarcinoma.

AIMS--To investigate the effect of combination endocrine treatment (CET) or luteinising hormone releasing hormone agonist and flutamide on non-neoplastic prostate, prostatic intraepithelial neoplasia, and prostatic adenocarcinoma. METHODS--The morphology, including the mitotic activity, of 12 radical prostatectomies from patients with prostatic adenocarcinoma pretreated for three months with CET was evaluated in haematoxylin and eosin stained sections and compared with an untreated age and stage matched control group. RESULTS--A differential effect on the non-neoplastic prostate was observed. In fact, the transition zone of the treated prostate showed simplification of the glandular lobules: the ducts and acini were small without undulations of the epithelial border and with a prominent basal cell layer. Within the peripheral zone there was inconspicuous branching of the ducts and acini which looked dilatated and lined by flattened atrophic epithelium. Prostatic intraepithelial neoplasia occurred in scattered ducts and acini in the peripheral zone of 10 of the 12 patients. The epithelial cell lining showed a prominent basal cell layer. A certain degree of secretory cell type stratification was always present. However, crowding was less evident than in the untreated prostate because of cytoplasmic clearing and enlargement as a result of coalescence of vacuoles. The treated adenocarcinomas had neoplastic acini which looked small and shrunken, and areas of individual infiltrating tumour cells separated by abundant interglandular connective tissue. The secretory cells of the nonneoplastic, prostatic intraepithelial neoplasia, and prostatic adenocarcinoma lesions had inconspicuous nucleoli, nuclear shrinkage, chromatin condensation, and cytoplasmic clearing. Apoptotic bodies were easily identifiable in all the cell layers. The lumina were rich in macrophages, sloughed secretory cells with degenerative features, and apoptotic bodies. Mitoses were not observed in any of the treated non-neoplastic prostate, prostatic intraepithelial neoplasia, or prostatic adenocarcinomas, whereas the mitotic frequency increased from non-neoplastic prostate through prostatic intraepithelial neoplasia up to prostatic adenocarcinomas in the untreated specimens. CONCLUSIONS--CET before radical prostatectomy causes regressive epithelial changes together with enhanced apoptosis and blocked mitotic activity.     

新型前列腺特异膜抗原剪接变异体的发现及临床意义初步探讨

目的:探讨前列腺特异膜抗原（PSMA）及其与前列腺癌发生、发展的关系，寻求更为特异的前列腺癌诊断和治疗的靶点。 方法:采用RT-PCR和DNA测序技术，克隆PSMA基因新的剪接变异体，并根据其序列信息，设计特异性引物，检测其在不同病变前列腺组织及不同组织来源肿瘤细胞中的表达。 结果:发现了一种新的PSMA剪接变异体，其在前列腺癌、前列腺增生及正常前列腺组织中的表达率分别为92.6％、78.8％及10.0％，且特异表达于前列腺癌LNCaP细胞株，而在前列腺癌PC3细胞株、膀胱癌、肾癌、肝癌细胞株中均不表达。 结论:发现了一种新型PSMA剪接变异体（定名为PSMA5），并证实该变异体与前列腺癌及前列腺增生有明显相关性，为研究前列腺癌的发生机制和寻求前列腺癌特异性诊治靶点提供了新的线索。     

Expression of ras oncogene p21 in prostate cancer

The major neoplastic transformation-inducing genes of human solid tumors are members of the ras oncogene family. We used an immunohistochemical assay to assess expression of both the unaltered and the mutated ras oncogene protein (p21) in normal and neoplastic prostatic cells. With the concentration of monoclonal antibody used in this study, epithelial and stromal cells from subjects with normal prostates and from 19 patients with benign prostatic hyperplasia were negative for p21 antigen. This antigen was detected in 2 of 6 prostates with Grade I carcinoma, 4 of 6 with Grade II, and all of 17 with higher grades. A semiquantitative immunohistochemical method demonstrated that expression of the p21 antigen in a carcinoma strongly correlated with nuclear anaplasia and was inversely related to the degree of glandular differentiation. However, markedly anaplastic tumors were often more heterogeneous in expression of p21 and contained areas of low staining for the antigen. Comparison of p21 antigen with tumor carcinoembryonic antigen and prostate-specific antigen demonstrated that ras p21 was the only phenotypic marker that correlated with histologic tumor grade. Thus, ras oncogene p21 may represent a new class of biologically relevant tumor markers and may be a useful adjunct to histopathologic examination in determining the prognosis of patients with prostate cancer.     

p63 is a prostate basal cell marker and is required for prostate development

The p53 homologue p63 encodes for different isotypes able to either transactivate p53 reporter genes (TAp63) or act as p53-dominant-negatives (DeltaNp63). p63 is expressed in the basal cells of many epithelial organs and its germline inactivation in the mouse results in agenesis of organs such as skin appendages and the breast. Here, we show that prostate basal cells, but not secretory or neuroendocrine cells, express p63. In addition, prostate basal cells in culture predominantly express the DeltaNp63alpha isotype. In contrast, p63 protein is not detected in human prostate adenocarcinomas. Finally, and most importantly, p63(-/-) mice do not develop the prostate. These results indicate that p63 is required for prostate development and support the hypothesis that basal cells represent and/or include prostate stem cells. Furthermore, our results show that p63 immunohistochemistry may be a valuable tool in the differential diagnosis of benign versus malignant prostatic lesions.     

Recombinant Semliki forest virus infects and kills human prostate cancer cell lines and prostatic duct epithelial cells ex vivo

Semliki Forest Virus (SFV) is a broad host range RNA virus capable of high-level recombinant protein expression and apoptosis induction in many cell types. We have successfully used a recombinant, replication deficient SFV vector to express the LacZ marker gene product in seven human prostate cell lines, as well as in human prostate tissue explants. Flow cytometry revealed that 40-60% of PPC-1 prostate cancer cells died 24-72 h after infection with SFV-LacZ virus. Most human prostate cancer cell lines expressed high levels of recombinant protein. Infection of human prostate tissue ex vivo led to similarly high expression levels but the recombinant beta-galactosidase was confined to duct epithelial cells. Infection of cell and tissue cultures resulted in detachment of adherent cells from the culture surface and detachment of epithelial cells from the basement membrane of tissue. Our results indicate that SFV may be useful in targeting recombinant protein expression and apoptosis to prostatic duct epithelial cells.     

Cytokeratin and vimentin expression in normal and neoplastic canine prostate

Intermediate filament expression in the canine prostate, unlike that in human prostate, is represented in the literature by only a few reports. In this study, the expression of cytokeratin (CK) and vimentin was examined in three normal canine prostates and 11 canine prostatic carcinomas. Monoclonal antibodies directed against vimentin, CK AE1/AE3, CK 18-8 (for luminal epithelial cells), CK 5, CK clone 8.12 and CK 14 (for basal cells) were employed. As in man, normal canine prostatic luminal cells were positive for CK 8-18. Basal cells were positive for CK 5 and CK clone 8.12 but, in contrast to findings in man, were negative for CK 14. Luminal cells were vimentin-negative, whereas in man they have been reported as vimentin-positive. The majority of carcinomas showed an undifferentiated histological pattern and all were positive for CK AE1/AE3 and for vimentin. Ten tumours were positive for CK 8-12, but six of them showed many cells co-expressing CK 14. Moreover, in two of these six cases a large number of neoplastic cells also reacted with CK clone 8.12 antibody, and in one of them co-expression of CK 5 was detectable. This co-expression, of luminal and basal cytokeratins, suggests a possible origin of the tumours from prostatic epithelial stem cells. Vimentin expression is an inconstant finding in human prostatic carcinomas; its almost uniform occurrence in canine carcinomas suggests a lesser degree of differentiation than in the human neoplasm.