Differential expression of 5 alpha-reductase isoenzymes in the human prostate and prostatic carcinomas

BACKGROUND

Steroid 5 alpha-reductase is essential for the intracellular accumulation of dihydrotestosterone (DHT), which mediates androgen effects on target tissue.

METHODS

In the present study, we describe the differential expression and cellular localization of 5 alpha-reductase 1 and 2 isoenzymes in the human prostate, and untreated and hormone-resistant prostatic carcinomas. The secretory epithelium of normal and hyperplastic glands showed strong nuclear 5 alpha-reductase 1 reactivity. Accordingly, the DHT forming 5 alpha-reductase process in secretory luminal cell types may be mediated predominantly by the type 1 isoenzyme. The androgen-independent basal cell layer variably expressed type 1 and 2 isoenzymes in nuclear and cytoplasmatic compartments. This suggests that circulating androgens are involved to control the basal cell layer, which represents the proliferative compartment of the human prostate.

RESULTS

When compared with benign prostate tissue, increased 5 alpha-reductase reactivity was detected in prostate cancer, particularly in high-grade tumors and androgen-insensitive states of the disease. In cancerous lesions, the type 1 isoenzyme tended to shift to the cytoplasm, while the nuclear staining remained unchanged or slightly increased. Referring to the type 2 isoenzyme, increased cytoplasmatic and nuclear enzyme activity was detected in malignant cells when compared with adjacent benign prostate tissue. Even endocrine differentiated tumor cells that consistently lacked the nuclear androgen receptor variably expressed 5 alpha-reductase immunoreactivity.

CONCLUSIONS

Although the functional significance of the differential subcellular localization of type 1 and 2 isoenzymes is currently unknown, the present data suggest that prostate cancer retains the DHT forming 5 alpha-reductase process in high-grade lesions and recurrent disease. Accordingly, circulating androgens may be still significant in these hormone-refractory malignancies.

Prevalence of adrenal and extra-adrenal Conn syndrome in hypertensive patients

BACKGROUND

Primary aldosteronism (PA) is caused by an adrenal aldosterone-producing tumor (A-APT) or adrenal hyperplasia. An extra-adrenal APT (E-APT) as a cause of PA has been reported in 5 cases. Autopsy studies show a high incidence of ectopic adrenocortical tissue. We did a prospective study of the prevalence of A-APTs and E-APTs and the biochemical features of E-APTs in patients with PA.

METHODS

Hypertensive patients (N = 3900) referred to our unit were screened for PA by measuring renin activity, urinary aldosterone-18-glucuronide, tetrahydroaldosterone, and 18-hydroxycorticosterone (18-OH-B). Primary aldosteronism was found in 257 cases. The differentiation between A-APTs and adrenal hyperplasia was based on the results of postural response of renin, plasma aldosterone, 18-OH-B, computed tomography, isotope scanning, or adrenal venous aldosterone. Ultrasound examination of the abdomen was used to screen for E-APT.

RESULTS

The cause of PA was bilateral adrenal hyperplasia in 101 cases, unilateral adrenal hyperplasia in 2, an A-APT in 146, and an E-APT in 1. The site of aldosterone production was uncertain in 7 patients who had normal adrenal glands on computed tomography but refused to undergo isotopic scanning and adrenal venous catheterization. Ultrasound examination disclosed normal retroperitoneum in 4 of the 7 cases but could not rule out E-APT in 3 cases. The biochemical features of the patient with the E-APT were similar to classic A-APT, with low renin, high aldosterone, and high 18-OH-B values without appropriate response to posture or to short-term volume expansion. The excision of the E-APT in the right kidney resulted in normalization of blood pressure and renin, aldosterone, and 18-OH-B levels.

CONCLUSION

Although E-APT is rare, it should be considered in the interests of specific therapy for PA because aldosterone-secreting malignant ovarian tumors also have been reported.

DNA amplification on chromosome 3q26.1-q26.3 in squamous cell carcinoma of the lung detected by reverse chromosome painting

Multiple genetic lesions have been reported in small cell lung carcinoma (SCLC), while considerably less information is available on squamous cell carcinoma (SCC). We used reverse chromosome painting to screen a total of nine SCCs for DNA amplifications. In three of the nine SCCs, hybridisation signals were found at chromosome region 3q26.1-q26.3, which does not contain any known oncogene. In one of the three SCCs, there were additional hybridisation signals at 1q, 5p and 6p21.1. The high frequency of a consistent amplification (3q26.1-q26.3) in SCC strongly indicates a novel gene at 3q26.1-q26.3 that is important in the pathology of SCC.

Constitutive expression of c-fos and c-jun, overexpression of ets-2, and reduced expression of metastasis suppressor gene nm23-H1 in rheumatoid arthritis

OBJECTIVES

To identify genes that are involved in the development and progression of rheumatoid arthritis (RA).

METHODS

We used a multiple gene analysis system and a set of available genes participating in processes such as proliferation, differentiation, tumour progression, and metastasis, to identify their RA related expression. Synovial tissues from 22 patients with RA were evaluated in comparison with those from six patients with osteoarthritis and two patients with non-inflamed joints as controls, using northern blot and reverse transcriptase polymerase chain reaction experiments.

RESULTS

Our data confirm the role of c-fos and c-jun as constitutive signal transmitters in solid RA tissues, thus demonstrating the potential of the approach. Activation of both genes persisted through multiple passages of the cells in tissue cultures derived from the synovial lining of RA tissues. There was an increased expression of ets-2 in 30% of RA samples and an up to 30-fold decreased expression of the potential metastasis suppressor gene nm23-H1 in 90% of RA tissues, compared with control tissues.

CONCLUSIONS

The data presented show for the first time a significant decrease of nm23-H1 expression in RA, which is possibly involved in local invasiveness, and a strong activation of the ets-2 nuclear oncogene in about one third of RA tissues, which may also be part of a pathway leading to advanced disease stages. The constitutive expression of c-fos and c-jun in RA tissue most probably results from a continuing inflammatory stimulus. These findings with cell cultures suggest an intrinsic activation mechanism of these early response genes in RA.

Pulmonary capillary hemangiomatosis as a rare cause of pulmonary hypertension

Pulmonary capillary hemangiomatosis (PCH), first described by Wagenvoort et al. in 1978, is a rare cause of pulmonary hypertension which occurs predominantly in young adults. In the literature only 18 cases have been reported. In 1988 Langleben et al. proposed a hereditary form of PCH with probable autosomal-recessive transmission. Histologic findings include irregular small nodular foci of thin-walled capillary-sized vessels which diffusely invade the lung parenchyma, the bronchial/bronchiolar walls and the adventitia of large vessels. We report on a case of PCH in a 24 year old man who presented the clinical signs of interstitial lung disease.

Differentiation pathways and histogenetic aspects of normal and abnormal prostatic growth: a stem cell model

A stem cell model is presented for the organization of the prostatic epithelium that may explain normal and abnormal growth in the human prostate. This model is based on recent data indicating that: 1) The three basic cell types encountered in the prostatic epithelium--i.e., secretory luminal, basal, and endocrine paracrine (EP) cells--are linked in the precursor progeny relationship. 2) The proliferative compartment of the normal and hyperplastic epithelium is located in the basal cell layer. 3) The proliferative compartment of the prostatic epithelium is androgen-independent but contains andro-responsive target cells. 4) During the malignant transformation of the prostatic epithelium, the proliferative zone is inverted and shifts to luminal cell types. 5) Formation of neoplastic basement membrane (BM) material is crucial for the development of the invasive phenotype in prostate cancer. 6) The proliferative activities in prostate cancer are exclusively restricted to exocrine cell types, whereas endocrine differentiated tumor cells are postmitotic cells. 7) The majority of exocrine tumor cells are androgen-responsive in contrast to endocrine differentiated cell types that consistently lack the nuclear androgen receptor (AR). In this model, a small stem cell population located in the basal cell layer gives rise to all epithelial cell lineages encountered in the normal, hyperplastic, and neoplastic prostate. The differentiating process from basal cells to secretory luminal cells via intermediate phenotypes is induced by circulating androgens, and largely depends on the presence of androgen-responsive target cells in the basal cell layer. Accordingly, the abnormal growth of the secretory epithelium in benign prostate hyperplasia (BPH) may be related to an increase in the total number of androgen-responsive basal cells in the proliferative compartment. Prostate cancer derives from transformed stem cells located in the basal cell layer that acquire secretory luminal characteristics under androgenic stimulation. During tumor invasion, the malignant phenotypes adhere via specific receptors to newly formed BM-material, which, in turn, may facilitate their passage through the extracellular matrix. The occurrence of endocrine differentiation in prostate cancer reflects the pluripotency of its stem cells. The widespread absence of nuclear AR in endocrine differentiated tumor cells clearly indicates that this phenotype belongs to those cell clones in prostate cancer, that are initially androgen-independent and refractory to hormonal therapy. Accordingly, the progressive emergence of endocrine cell clones during tumor progression may represent one mechanism by which prostate cancer cells escape hormonal control.

A novel site of DNA amplification on chromosome 1p32-33 in a rhabdomyosarcoma revealed by comparative genomic hybridization

Cytogenetic analysis of a human embryonal rhabdomyosarcoma revealed a near-diploid karyotype with structural chromosome aberrations not involving the typical rearrangements of rhabdomyosarcomas, plus a large number of double minutes. Comparative genomic hybridization revealed a previously undescribed site of DNA amplification on the short arm of chromosome 1 (band 1p32-33).

Proliferation enhancement by spontaneous multiplication of chromosome 7 in rheumatic synovial cells in vitro

Mosaic trisomy of chromosome 7 is known to occur in a variety of non-neoplastic hyperproliferative disorders. In long-term cell cultures established from rheumatic synovium with mosaic trisomy 7, we observed a continuous increase in the proportion of cells with trisomy 7 to over 50% by the 10th in vitro passage. Simultaneous in situ hybridization with a repetitive chromosome-7-specific DNA probe and fluorescent Ki-67 labelling showed a strong correlation between trisomy 7 and an elevated proliferation index in cultured rheumatic synovial cells. Moreover, we observed a fraction of rapidly proliferating cells with up to eight copies of chromosome 7 as the sole cytogenetic change. Frequent somatic pairing of centromeres of two chromosomes 7 in interphase nuclei suggests either atypical non-disjunction with a persisting centromere or selective endoreduplication of chromosome 7.

Morphogenetic aspects of normal and abnormal prostatic growth

Studies of cancerogenesis in the human prostate have been hampered by a number of factors, including the complex composition of the prostatic epithelium by three different cell types, the lack of good animal models and the relative inaccessibility of the gland. More information about the basic biology of epithelial cell types in the development of the various neoplastic disorders of the prostate gland is required. This article reviews recent data about differentiation and proliferation processes in the human prostate and proposes a stem cell model that may explain the morphogenisis of normal and abnormal prostatic growth.

Differential expression of the pS2 protein in the human prostate and prostate cancer: association with premalignant changes and neuroendocrine differentiation

The distribution of the estrogen inducible pS2 protein was investigated in benign and malignant prostate tissue by the avidin-biotin complex method. Prostate tissue obtained from 20 patients without clinical and histological evidence of malignant disease consistently lacked pS2 immunoreactivity. Conversely, nonneoplastic tissue from 36 total prostatectomies with locally advanced prostate cancer showed a variable degree of pS2 reactivity in normal or hyperplastic glands and in prostatic intraepithelial neoplasia (PIN) adjacent to the cancerous lesions. This suggests that the pS2 gene expression detected in nonmalignant tissue may be related to early premalignant changes of prostate glands harboring significant carcinomas. In prostate cancer the pS2 protein was detected in close association with neuroendocrine (NE) differentiation as assessed by Chromogranin A (Chr A) immunoreactivity. Double labeling techniques showed that pS2 immunoreactivity recognizes both endocrine (Chr A-positive) and adjacent exocrine (Chr A-negative) cell types within NE foci. Whereas pS2 expression was consistently confined to NE differentiation in untreated tumors, carcinomas that relapsed after hormonal therapy showed increased pS2 immunoreactivity, even in the absence of NE features. The differential expression of the pS2 peptide in nonneoplastic tissue from patients with and without malignant disease indicates that pS2 immunohistochemistry may be useful in the diagnostic evaluation of negative biopsy specimens. Furthermore, the results suggest that the immunohistochemical spectrum of pS2 in prostate cancer may include endocrine differentiated and presumably related cell populations.

Influence of indomethacin and difluoromethylornithine on human tumour growth in nude mice

Biopsy material from six human colorectal carcinomas was transplanted to 114 nude mice. A treatment protocol was established which included no treatment (control, C), indomethacin (I), difluoromethylornithine (D) or a combination of both (ID). The influence of the various drugs on tumour weight and protein kinase CK2 activity was monitored. CK2 activity was measured because in all tumours examined so far the enzyme activity was found to be enhanced several-fold when compared to the non-neoplastic tissue of the same patient. More than half of the investigated tumours showed a conspicuous reduction in weight after drug treatment, and I and the combination of D/I were significantly effective using the mixed model analysis. Furthermore, we have tried to discover whether there is a change in the subcellular localisation of protein kinase CK2 subunits associated with drug treatment. We analysed the tumours and the non-neoplastic control tissues by immunohistochemistry using antibodies directed against the CK2 subunits and against the proliferation marker Mib. In addition, we have also investigated the behaviour of the nucleolar protein B23 which has also been shown to be enhanced several-fold in rapidly proliferating tissue and which is also a substrate for CK2. The immunohistochemical data suggest that, irrespective of the drug treatment and the observed reduction in CK2 activity, the CK2 subunits remain localised in the nucleus.

Adamantinoma of long bones. A histopathological and immunohistochemical study of 23 cases

The clinical and histological data of twenty-three cases of adamantinomas of the long bone collected by the Working Group on Bone Tumors at the DKFZ/FRG are reported including immunohistochemical observations in twenty-one of the cases. Females and males between 5 and 67 years (mean, 25.4 years) were affected equally (11/12). All adamantinomas were positive for cytokeratins often in coexpression with vimentin, at least focally. Although exhibiting varying histological patterns, no correlation between histology and clinical course was seen. However, sex and mode of initial therapy seem to influence an unfavorable clinical outcome. All three decreased patients were males receiving marginal or delayed surgery. This underlines the low-grade malignant character of adamantinoma. To assure the histological diagnosis pathologists should employ immunohistochemistry for demonstrating the sometimes sparse epithelial cell nests when radiology is suggestive for adamantinoma. Correct diagnosis should lead to resection with wide surgical margins.

A new subset of mineralocorticoid hypertension with excess of 21-deoxyaldosterone and Kelly's-M1 steroid: clinical and morphological findings

Ten cases of adrenal adenomas, one case with unilateral adrenal hyperplasia, and another case with apparent bilateral are reported, in whom an alternative pathway of aldosterone via 21-deoxyaldosterone is operative. They all manifested hypertension, low renin activity, low normal potassium values, as well as high urinary excretion rates of 21-deoxyaldosterone and its related metabolite Kelly's-M1 steroid. In all cases, urinary aldosterone metabolites (aldosterone-18-glucuronide and tetrahydroaldosterone) and aldosterone precursor 18-hydroxycorticosterone levels were normal. Hence, the adrenal lesions give rise to hyper-21-deoxyaldosteronism. 21-Deoxyaldosterone is a weak mineralocorticoid, and its elevated production in the presence of normal aldosterone can induce a pathological state of hypermineralocorticoidism. Adrenalectomy resulted in normalization of hypertension in six of eight and amelioration in two of eight cases. Six of seven adenoma cases examined as well as the case of unilateral adrenal hyperplasia were sensitive to ACTH. One of the seven adenomas and, as expected, the case with apparent bilateral hyperplasia were angiotensin responsive. Histologically and electron microscopically, the operated adenomas consisted predominantly of clear cells, characterized by mitochondria with tubulo-vesicular internal structure similar to those of the zona fasciculata (in contrast, our classical Conn's adenoma with normal 21-deoxyaldosterone excretion exhibited a more heterogenous histological appearance and were, in terms of ultrastructure, more similar to cells of the zona glomerulosa). Ultrastructurally and immunocytochemically, the clear cells of 21-deoxyaldosterone adenomas showed features of both the zona glomerulosa and the zona fasciculata and are, hence, considered to be hybrid cells. We conclude that the determination of 21-deoxyaldosterone and Kelly's-M1 should be considered in the diagnosis of mineralocorticoid-induced forms of hypertension, especially when an adrenal adenoma has been detected with an imaging procedure.

Endocrine-paracrine cell types in the prostate and prostatic adenocarcinoma are postmitotic cells

Neuroendocrine (NE) differentiation frequently occurs in common prostatic malignancies and has potential prognostic and therapeutic implications. In a recent study we were able to provide immunohistochemical evidence that endocrine-paracrine cell types represent an androgen-insensitive cell population in prostate cancer, documented by the consistent lack of the pertinent receptor. In this study we investigated the proliferative activity of endocrine-paracrine cell types in normal, hyperplastic, and neoplastic prostate tissue. Using double-label techniques for the endocrine marker chromogranin A (chr A) and the proliferation-associated MIB-1 antigen, we evaluated the proliferative status of endocrine-paracrine cell types in the prostate and prostatic adenocarcinoma showing marked NE differentiation. In this series of carcinomas and in nonneoplastic tissue the proliferative activities were exclusively restricted to nonendocrine cell populations, whereas endocrine-paracrine cell types characterized by Chr A consistently lack MIB-1 immunoreactivity. This may indicate that prostatic endocrine-paracrine cell types do not participate in the cell cycle during normal, hyperplastic, and neoplastic prostatic growth. Based on the present information, the endocrine phenotype can be considered to be an androgen-insensitive, postmitotic subpopulation in the prostate and prostate cancer.

Human endogenous retrovirus K10: expression of Gag protein and detection of antibodies in patients with seminomas

The human endogenous retrovirus K10 (HERV-K10) has been identified in the human genome by its homology to retroviruses of other vertebrates (M. Ono, T. Yasunaga, T. Miyata, and H. Ushikubo, J. Virol. 60:589-598, 1986). Using PCR amplification, DNA cloning, sequencing, and procaryotic expression, we were able to demonstrate that HERV-K10 encodes a 73-kDa protein which was processed by a HERV-K10-encoded protease to yield proteins p22/p26, p30, and p15/16. Analysis of the teratocarcinoma cell line Tera 1 or tumor tissues by immunoblotting demonstrated that the 80-kDa polyprotein of HERV-K10 gag and a processed protein of 39 kDa were expressed. In addition, a major protein of 39 kDa and additional species of 30, 22, 19, and 17 kDa could be detected in the supernatant of Tera 1 cells, suggesting that HERV-K10 Gag proteins are either secreted or processed to probably incomplete viral particles. In addition, the gag gene of HERV-K10 was expressed in the baculovirus system. Using this recombinant system to test antisera from patients with different diseases and healthy individuals, we were able to detect antibodies against the N-terminal part of HERV-K10 Gag in 2 to 4% of groups of tumor patients with titers ranging between 1:80 and 1:640, while approximately 0.1 to 0.5% of healthy individuals exhibited antibodies with lower titers. In contrast, patients with seminoma had antibody titers in the range of 1:2,560 at the time when the tumor was detected. Immunohistochemistry using specific rabbit sera or monoclonal antibodies against HERV-K10 Gag revealed that the Gag protein is expressed in the cytoplasm of the tumor cells. Furthermore, an 80-kDa protein corresponding to the HERV-K10 Gag polyprotein could be detected in tumor biopsies. For the first time, these data indicate that HERV-K10 Gag proteins are synthesized in seminoma cells and tumors exhibit relatively high antibody titers against Gag. So far, no information on which role HERV-K10 plays in the development of this tumor exists.

Monoclonal antibodies directed against the Epstein-Barr virus-encoded nuclear antigen 1 (EBNA1): immunohistologic detection of EBNA1 in the malignant cells of Hodgkin's disease

Monoclonal antibodies directed against the Epstein-Barr virus nuclear protein 1 (EBNA1) were used to examine conventional paraffin sections from a series of EBV-associated lymphoproliferative disorders by immunohistochemistry. The presence of latent EBV infection in tumor cells was determined by in situ hybridization for the Epstein-Barr virus early RNAs (EBERs). Of those EBER-positive cases a total of 28 of 40 cases of Hodgkin's disease, 3 of 3 cases of Burkitt's lymphoma, and 8 of 8 cases of human immunodeficiency virus-associated cerebral B-cell lymphoma expressed detectable amounts of EBNA1. In the positive cases, expression was confined to the tumor cells. No reactivity was detected in EBV-negative cases of the above tumors or in 8 cases of EBV-negative cases of large cell anaplastic non-Hodgkin lymphoma. This report provides the first unequivocal evidence for the expression of the EBNA1 protein in the tumor cells of Hodgkin's disease and validates an important reagent with which to analyze the role of EBV in various virus-associated malignancies.

Asymmetric expression of protein kinase CK2 subunits in human kidney tumors

Renal clear cell carcinomas and the corresponding ipsilateral control tissues were investigated for protein kinase CK2 activity and subunit ratio. The average protein kinase CK2 activity from 21 different kidney samples was 318 U/mg and that from the corresponding tumors 610 U/mg. The subunit ratio of protein kinase CK2 alpha in tumors/normal tissue (T/N) was 1.58 and that of the protein kinase CK2 beta (T/N) was 2.65. The data suggest that the generally described increase in protein kinase CK2 activity in tumor cells may to some extent result from a deregulation in subunit biosynthesis or degradation. This at least partly owing to the presence of excess enzymatically active protein kinase alpha-subunit but also to a significantly higher presence of the non-catalytic beta-subunit.

[Spontaneous osteonecrosis of the iliac crest. Description of a formerly unverified location]

In a 27-years old male a radiographically well defined and compact area with some lucent sections was found incidentally at the top of the left iliac crest. The resection and the following histomorphologic examination of this tissue brought the diagnosis: spontaneous osteonecrosis of the iliac crest. To our knowledge this is the first time that the iliac crest has been proved as a localisation of the spontaneous osteonecrosis by histomorphologic examination.

Multidirectional differentiation in the normal, hyperplastic, and neoplastic human prostate: simultaneous demonstration of cell-specific epithelial markers

The prostatic epithelium is composed of three distinct cell populations: secretory luminal, basal, and endocrine-paracrine cells. It is currently unknown whether these basic epithelial cell types are related in a hierarchical pathway of differentiation or are independent and separate entities. In the present study we used double-label techniques for cell-specific markers to search for multidirectional differentiation in normal, hyperplastic, and neoplastic prostate tissue. In normal and hyperplastic conditions subsets of basal cells revealed synchronous expression of basal cell-specific cytokeratins and the prostate-specific antigen, indicating intermediate differentiation between basal and secretory luminal cell types. Furthermore, endocrine-paracrine cells of the closed type focally showed simultaneous expression of chromogranin A and basal cell-specific cytokeratins. These findings highlight the phenotypic plasticity of the basal cell layer in the human prostate. In prostatic adenocarcinoma co-expression of exocrine (prostate-specific antigen) and endocrine (chromogranin A) markers was detected frequently in subsets of malignant cells. Conversely, this amphicrine phenotype was rarely found in hyperplastic glands. The occurrence of multidirectional differentiation within the prostatic endocrine cell system may indicate that endocrine-paracine cells derive from pluripotent stem cells of endodermal origin. Furthermore, the phenotypic plasticity of basal cells suggests that this epithelial compartment houses stem cell populations that give rise to all epithelial cell lineages encountered in the normal, hyperplastic, and neoplastic human prostate.

The proliferative function of basal cells in the normal and hyperplastic human prostate

To obtain more insight into the proliferative function of basal and secretory cell types in human prostate, we studied the immunoprofile of three well-characterized proliferation-associated antigens (Ki-67, PCNA, MIB 1) in normal and hyperplastic prostate tissue. Distinction between labeled basal and secretory cell types was made by simultaneous demonstration of the proliferation-associated antigens and basal cell-specific cytokeratins in identical sections. In normal and hyperplastic acini, approximately 70% of labeled cells were of the basal cell phenotype. These data clearly suggest that the proliferative compartment of the normal and hyperplastic epithelium is located in the basal cell layer. Compared to normal and hyperplastic conditions, severe proliferative abnormalities were detected in high-grade prostate intraepithelial neoplasias (PIN), as documented by the extension of the proliferative compartment up to the luminal border. Conversely, approximately 70% of proliferating cells detected in atypical hyperplasias that progressed in invasive carcinomas were localized in the remaining basal cell layer. These findings may indicate the proliferative role of basal cells in the epithelial renewal, and the development of hyperplastic and neoplastic disorders in the human prostate.

Androgen receptor status in endocrine-paracrine cell types of the normal, hyperplastic, and neoplastic human prostate

Neuroendocrine differentiation is a frequent occurrence in common prostatic adenocarcinomas and may have prognostic implications in prostatic malignancies. In the present study, we used immunohistochemical double label methods to evaluate the nuclear androgen receptor (AR) status in endocrine-paracrine (EP) cells of normal, hyperplastic, and neoplastic prostate including tumours that recurred after hormonal and radiation therapy. In normal and hyperplastic glands, EP cells characterized by the panendocrine marker chromogranin A (Chr A) did not reveal AR-positivity. This may indicate that prostatic EP cells represent an androgen-independent cell population whose regulatory functions are not influenced by circulating androgens. Unequivocal co-expression of Chr A and AR was very rarely detected in subsets of endocrine differentiated tumour cells in treated and untreated specimens. The widespread absence of nuclear AR in neuroendocrine tumour cells suggests that this phenotype belongs to those cell clones in prostate cancer which are initially androgen-independent and refractory to hormonal therapy.

Ossifying renal tumor of infancy

Ossifying renal tumor of infancy is a rare but distinctive tumor that presents as a mass in the pelvicaliceal system. It is usually suspected to be a calculus until surgical exploration reveals dense tumor attachment to the renal parenchyma. The histogenesis of this lesion has not been established. We present a case of this unusual neoplasm. A renal sparing procedure was performed on this biologically benign tumor. Followup after 20 months showed no evidence of recurrence.

Clonal chromosome aberrations in cell cultures of synovial tissue from patients with rheumatoid arthritis

Cytogenetic analysis of primary cell cultures and/or passages 1-3 of synovial tissue from seven patients with rheumatoid arthritis was performed. As the only recurrent chromosome aberration, trisomy 7 was found in six of seven cultures. In four cultures, trisomy 7 occurred as a clonal change in up to 20% of the analyzed cells, with an increase of the proportion of cells with +7 with the duration of the in vitro culture. Apart from this recurrent change, a variety of partly clonal, partly nonclonal numerical and structural chromosome aberrations were observed in all cases. These findings support the view that clonal chromosome aberrations may play a role in the pathogenesis of invasive growth of the synovial tissue in rheumatoid arthritis although the localized synovial hyperproliferation is not a true neoplastic process.

Differential expression of alpha 6 and alpha 2 very late antigen integrins in the normal, hyperplastic, and neoplastic prostate: simultaneous demonstration of cell surface receptors and their extracellular ligands

The very late antigens (VLAs) are alpha beta-heterodimeric transmembrane proteins that include surface cell receptors for laminin (VLA-6) and collagen (VLA-2), which mediate cell-matrix and cell-cell adhesion. We investigated the distribution of VLA-6 (alpha 6, beta 1) and VLA-2 (alpha 2, beta 1) proteins in normal, hyperplastic, and neoplastic human prostate tissue and lymph node metastases by the avidin-biotin complex method. In normal and hyperplastic glands we observed two staining patterns that differed according to the density of alpha 6- and alpha 2-receptors at the site of co-expression with their corresponding ligands (laminin, type IV collagen) in acinar basement membranes (BMs). Band-like deposits with high receptor density suggested strong anchorage of the prostate epithelium to acinar BMs, whereas the absence of this pattern most probably reflected reduced cellular attachment. Very late antigen-6 immunoreactivity showed the band-like pattern in approximately 70% of normal and hyperplastic glands compared with VLA-2, which showed the same pattern in only 5% of cases. In prostatic adenocarcinoma the band-like pattern significantly decreased with dedifferentiation and was consistently absent in grade III lesions. Compared with staining intensities in normal and hyperplastic conditions, grade I and II tumors maintained or overexpressed the VLA-6 receptor in 85% of cases, whereas the VLA-2 receptor was downregulated in approximately 70% of cases. Grade III tumors were characterized by a heterogeneous expression of VLA-6 and VLA-2 proteins, but frequently upregulated their receptors in corresponding lymph node metastases. Regardless of the staining intensity, all primary and metastatic carcinomas investigated expressed VLA-6 and VLA-2 receptors whose extracellular domains were extensively co-expressed with their ligands in neoplastic BM formations. These findings suggest that VLA-6 and VLA-2 receptors mediate attachment of tumor cells to neoplastic BM material, which, in turn, may endow these cells with an increased ability to invade the extracellular matrix.

Oncogenic osteomalacia: imaging studies

X-ray und NMR imaging studies of a 34-year-old patient with tumor-induced hypophosphatemic osteomalacia (OM) are presented. Besides typical features of OM, periosteal new bone formation was noticed initially. After 17 months of conservative treatment with supplements of inorganic phosphorus and 1,25-dihydroxyvitamin D, bone density had increased but Looser's zones were still present, while periosteal new bone formation was strikingly less evident. At this time a tumor in the first left metatarsal space became palpable, was surgically excised and proved to be a low-grade synovial sarcoma with hypervascular and partially calcified structures. Six months later an X-ray survey showed no more signs of metabolic osteopathy. Preoperatively, the pronounced vascularity of the tumor could be demonstrated by angiography and NMR scanning.