Lutz Konrad

Justus-Liebig-Universität Gießen, Gießen, Hesse, Germany

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Publications (23)77.14 Total impact

  • Article: Cardiac glycoside ouabain induces activation of ATF-1 and StAR expression by interacting with the α4 isoform of the sodium pump in Sertoli cells.
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    ABSTRACT: Sertoli cells express α1 and α4 isoforms of the catalytic subunit of Na(+),K(+)-ATPase (sodium pump). Our recent findings demonstrated that interactions of the α4 isoform with cardiotonic steroids (CTS) like ouabain induce signaling cascades that resemble the so-called non-classical testosterone pathway characterized by activation of the c-Src/c-Raf/Erk1/2/CREB signaling cascade. Here we investigate a possible physiological significance of the activated cascade. The results obtained in the current investigation show that the ouabain-induced signaling cascade also leads to the activation of the CREB-related activating transcription factor 1 (ATF-1) in the Sertoli cell line 93RS2 in a concentration- and time-dependent manner, as demonstrated by detection of ATF-1 phosphorylated on Ser63 in western blots. The ouabain-activated ATF-1 protein was found to localize to the cell nuclei. The sodium pump α4 isoform mediates this activation, as it is ablated when cells are incubated with siRNA to the α4 isoform. Ouabain also leads to increased expression of steroidogenic acute regulator (StAR) protein, which has been shown to be a downstream consequence of CREB/ATF-1 activation. Taking into consideration that CTS are most likely produced endogenously, the demonstrated induction of StAR expression by ouabain establishes a link between CTS, the α4 isoform of the sodium pump, and steroidogenesis crucial for male fertility and reproduction.
    Biochimica et Biophysica Acta 12/2012; · 4.66 Impact Factor
  • Article: Cardiotonic steroids trigger non-classical testosterone signaling in Sertoli cells via the α4 isoform of the sodium pump.
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    ABSTRACT: The α4 isoform of the Na(+),K(+)-ATPase (sodium pump) is known to be expressed in spermatozoa and to be critical for their motility. In the investigation presented here, we find that the rat-derived Sertoli cell line 93RS2 also expresses considerable amounts of the α4 isoform in addition to the α1 isoform. Since Sertoli cells are not motile, one can assume that the function of the α4 isoform in these cells must differ from that in spermatozoa. Thus, we assessed a potential involvement of this isoform in signaling pathways that are activated by the cardiotonic steroid (CTS) ouabain, a highly specific sodium pump ligand. Treatment of 93RS2 cells with ouabain leads to activation of the c-Src/c-Raf/Erk1/2 signaling cascade. Furthermore, we show for the first time that the activation of this cascade by ouabain results in phosphorylation and activation of the transcription factor CREB. This signaling cascade is induced at low nanomolar concentrations of ouabain, consistent with the involvement of the α4 isoform. This is further supported by experiments involving siRNA: silencing of α4 expression entirely blocks ouabain-induced activation of Erk1/2 whereas silencing of α1 has no effect. The findings of this study unveil new aspects in CTS/sodium pump interactions by demonstrating for the first time ouabain-induced signaling through the α4 isoform. The c-Src/c-Raf/Erk1/2/CREB cascade activated by ouabain is identical to the so-called non-classical signaling cascade that is normally triggered in Sertoli cells by testosterone. Taking into consideration that CTS are produced endogenously, our results may help to gain new insights into the physiological mechanisms associated with male fertility and reproduction.
    Biochimica et Biophysica Acta 07/2011; 1813(12):2118-24. · 4.66 Impact Factor
  • Article: Reduced numbers of Sertoli, germ, and spermatogonial stem cells in impaired spermatogenesis.
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    ABSTRACT: A key step in the investigation of male infertility is the appropriate classification of impaired spermatogenesis. In this study, we precisely identified Sertoli and distinct germ-cell types in the rat, the mouse, and in the human testis. As a proof of principle, we studied testis biopsy samples from azoospermic patients with defined spermatogenic defects. Remarkably, we found that already the numbers of Sertoli cells, spermatogonia and a subset of spermatogonia including stem cells are significantly reduced in patients with maturation arrest at the level of primary spermatocytes (n=33) compared with patients with histologically normal spermatogenesis (n=33). In patients with hypospermatogenesis (n=44) a significant reduction of spermatogonial cell numbers was observed. The numbers of primary and diplotene spermatocytes were reduced by 84%. However, the strongest reduction (96%) was revealed in the numbers of spermatids in patients with maturation arrest. In contrast, patients with hypospermatogenesis showed only modestly reduced numbers of spermatocytes and spermatids compared with normal spermatogenesis. No correlation was found with age or obstruction. For a detailed analysis of the patients, we distinguished between 'pool of founder cells'-related deficiencies (reduced numbers of Sertoli cells, spermatogonia, and spermatogonial stem cells) and 'meiotic' deficiencies (reduced numbers of spermatocytes, meiotic divisions, and spermatids). Interestingly, patients with maturation arrest showed meiotic deficiencies (36%), while the majority additionally demonstrated deficiencies in the founder pool (58%). In contrast, patients with normal spermatogenesis most often had no deficiencies at all (45%) or founder pool-related deficiencies (33%) but an apparently normal meiosis. This is the first report showing that many infertile patients face besides meiotic defects the problem of reduced numbers of Sertoli cells, spermatogonia, and spermatogonial stem cells.
    Modern Pathology 06/2011; 24(10):1380-9. · 4.79 Impact Factor
  • Article: A structured questionnaire improves preoperative assessment of endometriosis patients: a retrospective analysis and prospective trial.
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    ABSTRACT: To determine whether a structured questionnaire can improve preoperative assessment of patients with endometriosis. Hospital records for patients with endometriosis were evaluated retrospectively to determine the completeness of information. A structured electronic questionnaire was developed and used to assess preoperatively patients with suspected or proved endometriosis. Data from both assessments were compared. Data analysed retrospectively showed that there were valid answers for 89.2% of questions on a standard patient history template, but information was available for only 46.3% of parameters considered specific to endometriosis. Data from 69 patients investigated by structured electronic questionnaire gave improved rates of 90.3% for standard patient history items and 88.5% for endometriosis-specific parameters. Significant improvement in valid answers was achieved in 66.7%. A structured questionnaire improved the documentation of endometriosis-specific parameters. Further studies are needed to ensure that it enhances the effectiveness of preoperative counselling and decisions about surgery.
    Archives of Gynecology 01/2011; 284(5):1179-88. · 0.91 Impact Factor
  • Article: Role of TGF-betas in normal human endometrium and endometriosis.
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    ABSTRACT: Endometriosis is characterized by presence of endometrial tissue outside the uterus. Prevalence is estimated at 6-10% in the general female population and many patients experience pain and/or infertility. Diagnosis is achieved by laparoscopic intervention followed by histological confirmation of viable endometriotic tissue. Mild cases are managed medically with contraceptive steroids and non-steroidal anti-inflammatory agents. Surgery provides relief to women in pain but symptoms recur in 75% of cases within 2 years. Starting with menstruation, we have categorized endometriosis into six stages, namely (1) shedding of cells, (2) cell survival, (3) escape from immune surveillance, (4) adhesion to peritoneum, (5) angiogenesis and (6) bleeding. In most of these biological processes, which resemble metastasis, transforming growth factor-beta (TGF-betas) and their high-affinity receptors are involved directly or indirectly. TGF-betas are abundantly and differentially expressed in the endometrium under hormonal control. Although they are preferentially synthesized in the stroma, glands and macrophages also secrete TGF-betas into the uterine fluid, where interaction with preimplantation embryos is suspected. Because mRNA and protein expression of all three TGF-betas is increased around menstruation, we suggest that TGF-betas might be involved in initiation of menstruation. Furthermore, because of high postmenstrual TGF-beta3 levels, we suppose that it might participate in scarless postmenstrual regeneration of endometrium. Our suggestions pave the way to novel routes of investigation into the roles of TGF-betas during menstruation and endometriosis.
    Human Reproduction 11/2009; 25(1):101-9. · 4.47 Impact Factor
  • Article: Impact of endometriosis on quality of life: a pilot study.
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    ABSTRACT: Endometriosis affects 6-10% of women in reproductive age, 35-50% of whom experience pain, infertility or both. Mild cases are managed medically but surgery provides relief to women in pain. However, symptoms recur in 75% of cases within 2 years. We investigated the impact of endometriosis on quality of life among 65 women aged 18-60 years working at a city supermarket in Giessen, Germany. Of the 65 women, 12 had undergone surgeries, 22 had dysmenorrhoea, 24 dyspareunia and 3 were infertile. Of the 22 women with dysmenorrhoea, 10 had difficulties performing gardening, housework, sports and leisure activities. Five of these 10 women experienced social isolation, 6 professional setbacks; 6 declined efficiency at work and 3 had taken time off work. Of the 24 women with dyspareunia, 7 experienced minimal, 12 light and 5 moderate to strong pain. Only 16 of these 24 women discussed the problem with their partners. This study demonstrates that pain is a major cause of physical, psycho-social, emotional and professional or work related impairment among women with endometriosis. Because endometriosis is likely to impose emotional and financial burdens, we suggest that future studies should be extended to include interviews with family members.
    Gynecological Endocrinology 11/2009; 25(11):722-5. · 1.58 Impact Factor
  • Article: Aberrant epigenetic modifications in the CTCF binding domain of the IGF2/H19 gene in prostate cancer compared with benign prostate hyperplasia.
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    ABSTRACT: Expression of the imprinted genes insulin-like growth factor 2 (IGF2) and H19 depends on the methylation pattern of their common imprinting control region (ICR) located on chromosome 11p15. As the somatic imprinting pattern may be lost during tumorigenesis due to epigenetic alterations, in the present study, we analyzed the DNA methylation and histone modifications in the differentially methylated region (DMR) of IGF2/H19 in benign prostate hyperplasia (BPH) and prostate carcinoma (PCa). Sodium bisulfite sequencing was performed on frozen tissue collected after radical prostatectomy. Thirty tumors and 17 non-cancerous tissue samples were analyzed. Histological diagnosis was, in addition, confirmed by amplification of the epithelial tumor marker alpha-methylacyl coenzyme-A racemase. Chromatin immunoprecipitation assay (ChIP) was carried out on sonificated chromatin from fresh tissue samples from 10 PCa, 10 BPH using antibodies against trimethyl histone H3K9, dimethyl histone H3K9, trimethyl H3K27 and acetyl H3K9. The methylation pattern of 17 CpGs within 227 bp of the H19 fragment was characterized from each DNA sample. All (BPH) samples demonstrated >80% methylation of CpGs. In contrast, we found 41% of CpGs methylated in 9 out of 30 PCa specimens. We observed statistically significant differences in the methylation state between PCa and BPH groups, especially in the DMR of H19 (p<0.0001) and in the ICR (p=0.0034), which corresponds to CTCF binding domain. ChIP assay revealed that dimethyl H3K9 is associated with the ICR of IGF2/H19 in BPH, but not in PCa (p<0.0001). Our data demonstrate that DNA methylation and histone methylation analysis of the ICR within the DMR of IGF2/H19 provides important insights into early steps of carcinogenesis and, therefore, may contribute to improving diagnosis of PCa.
    International Journal of Oncology 07/2009; 35(1):87-96. · 2.40 Impact Factor
  • Article: Upregulation of mRNA expression of MCP-1 by TGF-beta1 in fibroblast cells from Peyronie's disease.
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    ABSTRACT: Peyronie's disease (PD) is a localized connective tissue disorder of the penile tunica albuginea (TA) with a still obscure etiopathology. Recent studies from our laboratory have demonstrated differences in Smad3 and Smad4 gene expression of PD-fibroblasts and non-PD-fibroblasts after stimulation with recombinant TGF-beta1 for 1 h. In the present study, we investigated gene expression of Smad2-Smad4 and Smad7 up to 6 h after stimulation with TGF-beta1. As a positive control, MCP-1 gene expression was monitored. Cells with fibroblast characteristics were isolated from seven PD plaques and three TA controls. The cells were incubated with recombinant TGF-beta1 for 2-6 h and expression of Smad2-Smad4, Smad7, and monocyte chemotactic protein-1 (MCP-1) was determined by quantitative real-time PCR. TGF-beta1 treatment resulted in a statistically significant up-regulation of Smad7 and MCP-1 gene expression. Smad7 expression was increased after 2 h (P < 0.001) and was still high after 4 h (P < 0.05). No significant differences between fibroblasts from PD-patients compared to non-PD-patients were observed. MCP-1 peaked after 4 h (P < 0.001) and remained high up to 6 h (P < 0.01). PD-fibroblasts revealed a significantly increased MCP-1 gene expression compared to non-PD-fibroblasts (P = 0.013) after 2 h and remained significantly different also after 6 h (P = 0.038). Gene expression of Smad2-Smad4 did not change during stimulation with TGF-beta1. In conclusion, analysis of MCP-1 expression might be a useful marker for Peyronie's disease.
    World Journal of Urology 08/2008; 27(1):123-30. · 2.41 Impact Factor
  • Article: Expression of connexin 43 in normal canine testes and canine testicular tumors.
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    ABSTRACT: In human testis, gap junctions containing connexin(Cx)43 are located within the seminiferous epithelium between Sertoli cells and between Sertoli and germ cells. Cx43 is known to play a role in the differentiation and proliferation of these cell types. It can further be associated with human seminoma development. The dog has been proposed as a model for studies of the male reproductive system, because of the frequent occurrence of testicular neoplasms. Thus, we investigated Cx43-mRNA and -protein expression in testes of normal prepubertal dogs, adult dogs, and in canine testicular tumors. Sertoli cells in prepubertal cords express Cx43 mRNA, but do synthesize only less Cx43 protein. Within the seminiferous tubules, Cx43 mRNA was detected in Sertoli cells, spermatogonia, and spermatocytes. Cx43 protein was mainly present in the basal compartment. In canine testicular tumors Cx43 mRNA was detectable in both seminoma and neoplastic Sertoli cells, whereas Cx43 protein was only found in neoplastic Sertoli cells. Our data indicate that Cx43 is regulated differentially in testicular tumors and that alterations of Cx43 expression may be involved in the pathogenesis of canine testicular malignancies. This study represents the first morphological work on the spatiotemporal expression pattern of Cx43 in normal and neoplastic canine testis.
    Histochemie 05/2008; 130(3):537-48. · 2.59 Impact Factor
  • Article: Both protamine-1 to protamine-2 mRNA ratio and Bcl2 mRNA content in testicular spermatids and ejaculated spermatozoa discriminate between fertile and infertile men.
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    ABSTRACT: Human sperm contain similar amounts of protamine-1 (P1) and protamine-2 (P2). Although aberrant protamine ratios have been observed in infertile men, functional evidence is provided by protamine knockout mice exhibiting male infertility. As sperm DNA integrity is known to be linked with DNA fragmentation and apoptosis, we investigated whether the protamine ratio or Bcl2 content represent a reliable biomarker to discriminate fertile and infertile men. Real-time quantitative RT-PCR was used for P1, P2 and the apoptotic marker Bcl2 in testicular biopsies (TB; 74 infertile men versus 17 controls) and ejaculates (E; 95 infertile men versus 10 controls). The P1-P2 mRNA ratio differed significantly between groups, namely 1:4 versus 1:3.2 in TB (P = 0.0038) and 1:1.7 versus 1:1 in E (P = 0.0002), for infertile men and controls, respectively. Bcl2 mRNA content was correlated with protamine mRNA ratio (P = 0.0250 for TB; P = 0.0003 for E). Infertile men exhibit a more than 10-fold (P = 0.0155 for TB; P = 7.0 x 10(-6) for E) higher Bcl2 mRNA content versus controls. No correlation was found between absolute sperm density and the protamine mRNA ratio or Bcl2 mRNA content. No significant correlation was demonstrated with fertilization rate after ICSI and either protamine ratio or Bcl2 content. We found significantly aberrant protamine ratios and a higher Bcl2 content in TB and E of infertile men compared to controls, suggesting that these molecules may be useful biomarkers for predicting male infertility.
    Human Reproduction 02/2008; 23(1):11-6. · 4.47 Impact Factor
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    Article: A sertoli cell-specific knockout of connexin43 prevents initiation of spermatogenesis.
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    ABSTRACT: The predominant testicular gap junctional protein connexin43 (cx43) is located between neighboring Sertoli cells (SCs) and between SCs and germ cells. It is assumed to be involved in testicular development, cell differentiation, initiation, and maintenance of spermatogenesis with alterations of its expression being correlated with various testicular disorders. Because total disruption of the cx43 gene leads to perinatal death, we generated a conditional cx43 knockout (KO) mouse using the Cre/loxP recombination system, which lacks the cx43 gene solely in SCs (SCCx43KO), to evaluate the SC-specific functions of cx43 on spermatogenesis in vivo. Adult SCCx43KO(-/-) mice showed normal testis descent and development of the urogenital tract, but testis size and weight were drastically lower compared with heterozygous and wild-type littermates. Histological analysis and quantitation of mRNA expression of germ cell-specific marker genes revealed a significant reduction in the number of spermatogonia but increased SC numbers/tubule with only a few tubules left showing normal spermatogenesis. Thus, SC-specific deletion of cx43 mostly resulted in an arrest of spermatogenesis at the level of spermatogonia or SC-only syndrome and in intratubular SC clusters. Our data demonstrate for the first time that cx43 expression in SCs is an absolute requirement for normal testicular development and spermatogenesis.
    American Journal Of Pathology 08/2007; 171(1):19-31. · 4.89 Impact Factor
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    Article: Alternative splicing of TGF-betas and their high-affinity receptors T beta RI, T beta RII and T beta RIII (betaglycan) reveal new variants in human prostatic cells.
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    ABSTRACT: The transforming growth factors (TGF)-beta, TGF-beta1, TGF-beta2 and TGF-beta 3, and their receptors [T beta RI, T beta RII, T beta R III (betaglycan)] elicit pleiotropic functions in the prostate. Although expression of the ligands and receptors have been investigated, the splice variants have never been analyzed. We therefore have analyzed all ligands, the receptors and the splice variants T beta RIB, T beta RIIB and TGF-beta 2B in human prostatic cells. Interestingly, a novel human receptor transcript T beta RIIC was identified, encoding additional 36 amino acids in the extracellular domain, that is expressed in the prostatic cancer cells PC-3, stromal hPCPs, and other human tissues. Furthermore, the receptor variant T beta RIB with four additional amino acids was identified also in human. Expression of the variant T beta RIIB was found in all prostate cell lines studied with a preferential localization in epithelial cells in some human prostatic glands. Similarly, we observed localization of T beta RIIC and TGF-beta 2B mainly in the epithelial cells with a preferential localization of TGF-beta 2B in the apical cell compartment. Whereas in the androgen-independent hPCPs and PC-3 cells all TGF-beta ligands and receptors are expressed, the androgen-dependent LNCaP cells failed to express all ligands. Additionally, stimulation of PC-3 cells with TGF-beta2 resulted in a significant and strong increase in secretion of plasminogen activator inhibitor-1 (PAI-1) with a major participation of T beta RII. In general, expression of the splice variants was more heterogeneous in contrast to the well-known isoforms. The identification of the splice variants T beta RIB and the novel isoform T beta RIIC in man clearly contributes to the growing complexity of the TGF-beta family.
    BMC Genomics 02/2007; 8:318. · 4.07 Impact Factor
  • Article: Alternative splicing of TGF-betas and their high-affinity receptors TβRI, TβRII and TβRIII (betaglycan) reveal new variants in human prostatic cells
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    ABSTRACT: Abstract Background The transforming growth factors (TGF)-β, TGF-β1, TGF-β2 and TGF-β3, and their receptors [TβRI, TβRII, TβRIII (betaglycan)] elicit pleiotropic functions in the prostate. Although expression of the ligands and receptors have been investigated, the splice variants have never been analyzed. We therefore have analyzed all ligands, the receptors and the splice variants TβRIB, TβRIIB and TGF-β2B in human prostatic cells. Results Interestingly, a novel human receptor transcript TβRIIC was identified, encoding additional 36 amino acids in the extracellular domain, that is expressed in the prostatic cancer cells PC-3, stromal hPCPs, and other human tissues. Furthermore, the receptor variant TβRIB with four additional amino acids was identified also in human. Expression of the variant TβRIIB was found in all prostate cell lines studied with a preferential localization in epithelial cells in some human prostatic glands. Similarly, we observed localization of TβRIIC and TGF-β2B mainly in the epithelial cells with a preferential localization of TGF-β2B in the apical cell compartment. Whereas in the androgen-independent hPCPs and PC-3 cells all TGF-β ligands and receptors are expressed, the androgen-dependent LNCaP cells failed to express all ligands. Additionally, stimulation of PC-3 cells with TGF-β2 resulted in a significant and strong increase in secretion of plasminogen activator inhibitor-1 (PAI-1) with a major participation of TβRII. Conclusion In general, expression of the splice variants was more heterogeneous in contrast to the well-known isoforms. The identification of the splice variants TβRIB and the novel isoform TβRIIC in man clearly contributes to the growing complexity of the TGF-β family.
    BMC Genomics. 01/2007;
  • Article: Analysis of the mRNA expression of the TGF-Beta family in testicular cells and localization of the splice variant TGF-beta2B in testis.
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    ABSTRACT: The transforming growth factors (TGF)-beta, TGF-beta1, TGF-beta2, and TGF-beta3, and their receptors [TbetaRI, TbetaRII, TbetaRIII (betaglycan)] elicit many functions in the testis, for example, they perturb the blood testis barrier (BTB). Although expression of the ligands and receptors have been investigated, the alternative splice variants are incompletely examined. We therefore have analyzed all ligands, the receptors, and the splice variants TbetaRIB, TbetaRIIB, and TGF-beta2B in testicular cells from rat and mouse. In mouse, the novel transcript variant TGF-beta2B was identified and was found in Leydig cells, spermatogonia, pachytene spermatocytes, and in the apical regions of the Sertoli cells in adult testis. Even though expression of the splice variant TbetaRIB could be shown in mouse and rat, we never found the isoform TbetaRIIB in the rat cell lines studied. Whereas in all testicular cells expression of all TGF-beta ligands could be shown, receptor mRNA expression was slightly more diverse. Furthermore, expression pattern of the splice variants was more heterogeneous, for example, TbetaRIB was not detectable in adult Sertoli cells, primary peritubular cells, and immortalized peritubular cells. The heterogeneous expression of the receptors and especially of the splice variants might provide possible clues for the different functions of the TGF-beta ligands in testicular cells.
    Molecular Reproduction and Development 11/2006; 73(10):1211-20. · 2.53 Impact Factor
  • Article: Rat Sertoli cells express epithelial but also mesenchymal genes after immortalization with SV40.
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    ABSTRACT: A new immortal Sertoli cell line from pubertal rat testis was established and characterized. We have generated the clonal line SCIT-C8 expressing established markers for Sertoli cells (SC) like transferrin, clusterin and steel factor/stem cell factor (SCF). Additionally, the immortalized cells express afadin, a protein which is a member of tight and adherens junctions, therefore the cells may be useful for studies of the blood-testis barrier (BTB) in vitro. In contrast to primary SC, the immortalized cells lost expression of androgen receptor and responsiveness to androgens and follicle-stimulating hormone. Surprisingly, we found mRNA expression and protein secretion of the mesenchymal markers, fibronectin and entactin-1, which we also observed for the immortalized SC lines, ASC-17D and 93RS2. In comparison to primary SC, the immortalized cells demonstrated enhanced adhesion in vitro. This correlated with the expression of entactin-1 because adhesion was strongly reduced by antibody perturbation experiments. Additionally, we found the alternatively spliced and primarily muscle cell-specific long variant of TGF-beta2 not only in peritubular cells (PC), but also in the primary and immortalized SC. Furthermore, all immortalized cell lines secreted higher amounts of TGF-beta2 than primary SC. In conclusion, the immortalized SC lines from different developmental stages showed a similar pattern of epithelial and mesenchymal markers.
    Biochimica et Biophysica Acta 03/2005; 1722(1):6-14. · 4.66 Impact Factor
  • Article: Genetic pathways and new progression markers for prostate cancer defined by microsatellite allelotyping.
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    ABSTRACT: A prospective study was carried out on a large cohort of males undergoing radical retropubic prostatectomy in order to identify genetic marker regions significantly associated with tumor formation. By comprehensive allotyping of chromosomes known to be associated with prostate carcinogenesis, an algorithm could be formulated for the genetic pathway and a method of discrimination between aggressive and less aggressive forms could be identified.
    Der Urologe 10/2004; 43 Suppl 3:S149-52. · 0.50 Impact Factor
  • Article: Prognostic value of combined "triple"-reverse transcription-PCR analysis for prostate-specific antigen, human kallikrein 2, and prostate-specific membrane antigen mRNA in peripheral blood and lymph nodes of prostate cancer patients.
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    ABSTRACT: We present the largest study of both peripheral blood and lymph node samples examining the utility of reverse transcription-polymerase chain reaction (RT-PCR) for established molecular markers as a diagnostic tool in the molecular staging of prostate cancer patients undergoing radical prostatectomy. Peripheral blood from 358 patients was obtained before radical prostatectomy. Corresponding obturatory lymph node samples were collected from 153 of these patients. Nested RT-PCR for prostate-specific antigen (PSA), human kallikrein 2 (hK2), and prostate-specific membrane antigen (PSMA) were performed on cDNA from peripheral blood. The lymph node cDNA was analyzed for PSA und hK2 expression. RT-PCR in peripheral blood was positive in 124 (34.6%) of 358 samples for PSA, 215 (60.1%) of 358 for PSMA, and 97 (27.1%) of 358 for hK2. Comparison of positive RT-PCR rates of pT(2) and pT(3) tumors in corresponding peripheral blood for PSA, PSMA, and hK2 were 31.9 and 40.0%, 58.8 and 62.5%, and 26.9 and 27.5%, respectively. Histopathologically, cancer-free lymph node samples were positive in RT-PCR for PSA and hK2 in 70 (49.6%) of 141 and 89 (63.2%) of 141 of cases. All histologically positive lymph node samples (n = 12, pN+) were positive for PSA RT-PCR. PSA RT-PCR alone, as well as combined PSA/PSMA RT-PCR evaluation, in peripheral blood showed a significant association with grading. PSA RT-PCR lymph node-negative samples were significantly less likely positive in their corresponding peripheral blood RT-PCR sample. Although the preoperative PSA RT-PCR in peripheral blood correlated with the grading of prostate cancer, no combination of RT-PCR results using "triple" markers (PSA, hK2, PSMA) in peripheral blood and/or lymph nodes yielded additional preoperative staging information.
    Clinical Cancer Research 10/2004; 10(17):5808-14. · 7.74 Impact Factor
  • Article: Genetic pathways and new progression markers for prostate cancer suggested by microsatellite allelotyping.
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    ABSTRACT: At diagnosis, the biological behavior of prostate cancer is uncertain, making the choice of an adequate therapy option difficult. Performing microsatellite allelotyping on a large series of consecutive prostate cancers procured during radical prostatectomy at our institution, we sought to identify molecular markers associated with disease progression. A total of 156 consecutive fresh tumor samples was prospectively collected and macroscopically dissected from the whole prostatectomy specimen immediately after operation. Histologically 100 samples contained >75% tumor cells and were therefore enrolled in the microsatellite allelotyping, using a total of 24 polymorphic markers for the chromosomal regions 5p, 5q, 7q, 8p, 9p, 9q, 13q, 17p, 17q, and 18q. Fresh paired normal and tumor DNA was investigated in fluorescent microsatellite analysis with automated laser product detection. The incidence of tumor-DNA alterations [loss of heterozygosity or allelic imbalance (AI)] was highest for chromosomal regions 13q and 8p with 72 and 71%, respectively, followed by chromosomes 7q, 18q, 5q, and 17p with 57, 53, 41, and 39%, respectively. Alterations at chromosomes 8p, 9p, 13q, and 17p were significantly (P < 0.05) associated with advanced tumor stage, whereas AI at 8p and 17p was also associated with high Gleason score (P < 0.05). AI at 5q and 9p was associated with regional lymph node metastasis (P < 0.05). The combination of AI at 8p and 13q was strongly associated with advanced tumor stage (P < 0.0001). With the obtained results, we are able to postulate three distinct pathways in prostate carcinogenesis, and we identified microsatellite markers of prognostic value.
    Clinical Cancer Research 03/2004; 10(3):1064-73. · 7.74 Impact Factor
  • Article: Quantitative PSA RT-PCR for preoperative staging of prostate cancer.
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    ABSTRACT: The clinical value of detecting prostate specific antigen (PSA) mRNA in the peripheral blood mononuclear cell fraction of patients (pts) by standard RT-PCR assays with localized prostate cancer remains controversial. We used a quantitative RT-PCR assay to measure the PSA mRNA copy number in addition to the qualitative PSA RT-PCR and correlated the results with clinical parameters. Total RNA was extracted from the peripheral blood mononuclear cell fraction of 115 prostate cancer pts prior to radical retropubic prostatectomy (RP) who received 3 months of neoadjuvant androgen deprivation. For quantitative RT-PCR, a PSA-like internal standard (IS) was added to each sample prior to reverse transcription and the PCR products for PSA and IS were selectively detected with fluorescent europium chelates after hybridization. Corresponding qualitative PSA-RT-PCR was performed for all samples. The median PSA copy number was 126 (range: 0-37988). There were no significant correlations established between qualitative or quantitative RT-PCR results and given clinical parameters. Corresponding quantitative and qualitative RT-PCR results were significantly associated (P = 0.01). We were unable to show any additional value of quantitative as well as qualitative PSA RT-PCR for preoperative staging of prostate cancer so far. Nevertheless, the long-term follow up of the patients has to be awaited.
    The Prostate 10/2003; 56(4):263-9. · 3.48 Impact Factor
  • Article: Immunohistochemistry of a prostate membrane specific protein during development and maturation of the human prostate
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    ABSTRACT: An antiserum against secretory vesicles from human seminal fluid (prostasomes) was used to study the localisation and distribution of the respective antigen(s) during prenatal development and pubertal maturation of the human prostate. The crude antiserum stained both secretory and membrane proteins in the adult prostate and other glands, such as pancreas and parotid gland. An immunoaffinity purified fraction from the antiserum selectively reacted with the apical plasma membrane of prostatic epithelium adluminal cells, recognizing a 100 kDa antigen (PMS). Even in the earliest stages of embryonic prostate specimens studied, the adluminal plasma membrane of the epithelial cells from developing glandular anlagen reacted strongly. The occurrence of PMS immunoreactivity in prostatic anlagen was directly correlated with lumen formation. As the antigen is an androgen-independently synthesised membrane protein of the prostate, it may possibly be used as a marker of cell polarity in the normal and pathologically altered prostate.
    Journal of Anatomy 03/1997; 190(3):343 - 349. · 2.37 Impact Factor