A. Kehlen - Academia.edu (original) (raw)
Papers by A. Kehlen
International Journal of Molecular Medicine, 2004
International journal of molecular medicine, 2004
Human monocytic cells express considerable amounts of aminopeptidase N (APN)/CD13, a transmembran... more Human monocytic cells express considerable amounts of aminopeptidase N (APN)/CD13, a transmembrane protein proposed to play a role in the modulation of kinins, neuropeptides and chemotactic mediators as well as in adhesion and cell-cell interactions. Previous studies have shown that APN/CD13 participates in antigen processing and presentation, trimming peptides protruding out of MHC class II molecules. In several inflammatory processes, macrophages have been shown to express especially high amounts of MHC class II molecules and of this peptidase. To learn more about the regulation of APN/CD13 on monocytes we investigated its expression under the influence of cytokines. Here, we report a dose- and time-dependent up-regulation of APN/CD13 mRNA and protein expression by transforming growth factor (TGF)-beta on human monocytes. To the contrary, we found IL-10 down-regulating the expression of APN/CD13 mRNA and protein. Both the regulation of the APN/CD13 protein assessed by immunofluore...
European cytokine network
In rheumatic joints, high concentrations of interleukin-8 (IL-8) have been measured in synovial f... more In rheumatic joints, high concentrations of interleukin-8 (IL-8) have been measured in synovial fluid and in pannus tissue. In both locations aminopeptidase N (APN)/CD13, an exopeptidase with reported activity towards IL-8 is also present. The surprising stability of IL-8 in the presence of an alleged IL-8-degrading peptidase prompted us to undertake the present study. Cocultivation of fibroblast-like synoviocytes (SFC) with T cells or with T lymphocytic cell membranes, or of T cells with SFC cell membranes, all resulted in increased IL-8 mRNA expression and IL-8 secretion into the medium, and an increase of APN expression on lymphocytes. IL-8 degradation was monitored by Western blots and HPLC. IL-8(72), as a partially processed form, was used throughout this study since it is abundant in tissues and has increased biological activity in comparison to IL-8(77). Thus its degradation/inactivation is considered of high biological significance. Whereas trypsin as a positive control rapi...
European cytokine network, 2000
Using random arbitrarily primed-reverse transcribed-PCR and sequence analysis, we investigated ch... more Using random arbitrarily primed-reverse transcribed-PCR and sequence analysis, we investigated changes in lymphocytic molecules after cell-cell contact with fibroblasts. An mRNA species which was upregulated in Jurkat T cells by cell-cell contact with MRHF cells (a human foreskin fibroblast line) was identified as coding for the human interleukin-17 receptor. This finding was confirmed by quantitative RT-PCR for the HUT78 and Jurkat T cell lines, for peripheral blood lymphocytes, and for tonsillar T cells. Furthermore, the interleukin-17 mRNA, coding for a proinflammatory cytokine, was also upregulated in peripheral blood lymphocytes and tonsillar T cells after cell-cell contact with fibroblasts. Supernatants obtained from cell-cell contact-stimulated peripheral blood lymphocytes enhance the production of interleukin-6 and interleukin-8 by fibroblast-like synoviocytes and this effect could be blocked by interleukin-17 antibodies. Changes in the mRNA levels of Jurkat T cells induced ...
Journal of neuroimmunology, 1999
Interleukin-17 (IL-17) has been characterized as a proinflammatory cytokine produced by CD4+ acti... more Interleukin-17 (IL-17) has been characterized as a proinflammatory cytokine produced by CD4+ activated memory T cells. In an effort to elucidate the biological effects of IL-17 in glial cells, we investigated the ability of this cytokine in order to activate nuclear factor (NF)-kappaB, which is being discussed as one of the most important transcription factors in the regulation of neuronal and glial cell function. Activation of NF-kappaB involves the degradation of its cytoplasmatic inhibitor IkappaB-alpha, which allows the nuclear translocation of NF-kappaB, and ensures transcriptional activation of genes including IkappaB-alpha itself. Using a competitive RT-PCR, we examined the IL-17-induced IkappaB-alpha mRNA expression in glioblastoma cells, and we examined IL-17 up-regulated IkappaB-alpha mRNA expression in a dose- and time-dependent fashion with a maximum time between 1 and 3 h. This induction could be inhibited by Calphostin C (protein kinase C inhibitor) and genistein (tyro...
Journal of immunology (Baltimore, Md. : 1950), 1997
Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. I... more Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. In contrast to monocytes and granulocytes, lymphocytes of peripheral blood do not express CD13 Ag. However, tumor-infiltrating T cells in renal cell cancer as well as synovial fluid T cells from patients suffering from various forms of arthritis can be CD13 positive. To learn more about expression of CD13 in these tissues, we cocultured lymphocytes with different adherent cell lines. CD13 expression was induced in T and B lymphocytes upon adhesion to fibroblast-like synoviocytes, HUVEC, renal tubular epithelial cells, and monocytes/macrophages but not always upon interaction with different tumor cell lines. Induction of APN was rapid, occurring as early as 1 h after coincubation. Expression persisted for >3 days and partially resisted inhibition by cycloheximide. Fixation of adherent cells with paraformaldehyde could not prevent induction of CD13 in lymphocytes. Soluble APN from human ...
ABSTRACT The S/T kinase CDK9 is part of the P-TEFb complex which promotes the productive transcri... more ABSTRACT The S/T kinase CDK9 is part of the P-TEFb complex which promotes the productive transcriptional elongation via phosphorylation of serine-2 residues within the RNA polymerase II C-terminal repeat domain. P-TEFb, recruited to responsive promoters via binding to transcription factors or chromatin assocd. proteins (e.g. NF-kB), is specifically required for the expression of highly inducible genes controlled by extracellular stimuli such as inflammatory processes. Consequently, the selective inhibition of CDK9 leads to a reduced expression of pro-inflammatory mediators, thereby avoiding the interference with processes of the normal cell homeostasis. Selective CDK9 inhibitors, resulting from our lead development program, have shown to be effective in various acute as well as chronic inflammation models, thereby confirming the proposed mode of action. The lead optimization process resulted in a CDK9 inhibitor, effective and well tolerated in two mouse models of arthritis under prophylactic as well as therapeutic treatment, now entering drug the development phase.
Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2005
The oral squamous cell carcinoma (OSCC) is the sixth most common malignant tumor worldwide. No si... more The oral squamous cell carcinoma (OSCC) is the sixth most common malignant tumor worldwide. No significant better progress has been made in the treatment of OSCCs during the last decades. The heterodimeric CD97 protein is a epidermal growth factor seven-transmembrane family member and was identified as a dedifferentiation marker in thyroid carcinomas. Nothing is known about CD97 in OSCCs. Employing UV-laser microdissection, CD97 and its ligand CD55 were investigated in normal oral mucosa and OSCCs (n = 78) by multiplex reverse transcription-PCR. Frozen sections were investigated by immunohistochemistry. The effects of retinoic acid and sodium butyrate on the CD97/CD55 expression in OSCC cell lines were determined by quantitative PCR, immunocytochemistry, and flow cytometry. Weak CD97 transcripts were expressed in normal mucosa and normal basal epithelial cells revealed specific CD97 immunostaining. Strong CD97 transcripts were detected in pT(3)/T(4) and G3/G4 OSCC tissues, whereas p...
Planta, 1993
A monoclonal antibody (MAB JAH1-8-B4) for the analysis of 3R, 7R-jasmonic acid and its methyl est... more A monoclonal antibody (MAB JAH1-8-B4) for the analysis of 3R, 7R-jasmonic acid and its methyl ester is described. An IgGl(kappa) immunoglobulin, MAB JAH1-8-B4, was used to set up a competitive enzymelinked immunoassay employing 3R, 7R-jasmonate coupled to alkaline phosphatase as tracer. The assay has a linearity range (logit/log) between 50 fmol and 50 pmol (approx. 10 pg-10 ng) of 3R, 7R-methyljasmonate, the assay standard. A procedure combining prepurification of plant extracts by solid-phase extraction, followed by high-performance liquid chromatography and quantitation has been worked out, which uses 4 g of fresh plant material and has a detection limit between 0.2 and 0.4 gg of 3R, 7R-jasmonic acid (determined as its methyl ester) per kg of tissue, depending on the tissue. Internal standards of 3R, 7R-methyljasmonate, added to split samples during extraction as well as a second internal standard, 3R, 7R-methyljasmonate-[O-C3H3], added to all samples prior to methylation, served to correct for workup losses and for the monitoring of chromatographic separations. Using this assay, it was found that levels of jasmonic acid rise immediately and transiently in the tissues analyzed as a consequence of wounding. These data provide further and direct evidence for the hypothesis that wound-induction of the plant defense reactions is mediated by endogenous jasmonates.
Oncogene, 2007
Cancer stem cells can play an important role in tumorigenesis and tumor progression. However, it ... more Cancer stem cells can play an important role in tumorigenesis and tumor progression. However, it is still difficult to detect and isolate cancer stem cells. An alternative approach is to analyse stem cell-associated gene expression. We investigated the coexpression of three stem cell-associated genes, Hiwi, hTERT and survivin, by quantitative real-time-PCR in 104 primary soft-tissue sarcomas (STS). Multivariate Cox's proportional hazards regression analyses allowed correlating gene expression with overall survival for STS patients. Coexpression of all three stem cell-associated genes resulted in a significantly increased risk of tumor-related death. Importantly, tumors of patients with the poorest prognosis were of all four tumor stages, suggesting that their risk is based upon coexpression of stem cell-associated genes rather than on tumor stage.
Oncogene, 2007
Self-renewal is considered as a common property of stem cells. Dysregulation of stem cell self-re... more Self-renewal is considered as a common property of stem cells. Dysregulation of stem cell self-renewal is likely a requirement for the development of cancer. Hiwi, the human Piwi gene, encodes a protein responsible for stem cell self-renewal. In this study, we investigated the expression of Hiwi at the RNA level by real-time quantitative PCR in 65 primary soft-tissue sarcomas (STS) and ascertained its impact on prognosis for STS patients. In a multivariate Cox's proportional hazards regression model, we found that an increased expression of Hiwi mRNA is a significant negative prognostic factor for patients with STS (P ¼ 0.017; relative risk 4.6, 95% confidence interval (CI) 1.3-16.1) compared to medium expression of Hiwi transcript. However, a low expression of Hiwi transcript is correlated with a 2.4-fold (CI 0.7-8.0) increased risk, but this effect was not significant (P ¼ 0.17). Altogether, high-level expression of Hiwi mRNA identifies STS patients at high risk of tumourrelated death. This is the first report showing a correlation between expression of a gene involved in stem cell selfrenewal and prognosis of cancer patients.
Molecular Human Reproduction, 2011
Kidney International, 1993
Journal of Neuroimmunology, 1999
q Interleukin-17 IL-17 has been characterized as a proinflammatory cytokine produced by CD4 activ... more q Interleukin-17 IL-17 has been characterized as a proinflammatory cytokine produced by CD4 activated memory T cells. In an effort to elucidate the biological effects of IL-17 in glial cells, we investigated the ability of this cytokine in order to activate nuclear Ž . factor NF -k B, which is being discussed as one of the most important transcription factors in the regulation of neuronal and glial cell function. Activation of NF-kB involves the degradation of its cytoplasmatic inhibitor Ik B-a, which allows the nuclear translocation of NF-kB, and ensures transcriptional activation of genes including Ik B-a itself. Using a competitive RT-PCR, we examined the IL-17-induced Ik B-a mRNA expression in glioblastoma cells, and we examined IL-17 up-regulated Ik B-a mRNA expression in a dose-Ž and time-dependent fashion with a maximum time between 1 and 3 h. This induction could be inhibited by Calphostin C proteinkinase C . Ž . inhibitor and genistein tyrosine kinase inhibitor . After 60 min of IL-17 stimulation, a degradation of the Ik B-a protein was detectable. Furthermore, IL-17 stimulated the secretion of IL-6 and IL-8 in glial cells, and IL-17 and IL-1b in combination showed a superadditive effect. We suggest IL-17 to play a role as an immune factor, possibly involved in complex pathophysiological interactions of neurodegenerative diseases. q
The Journal of Immunology, 2008
The Journal of …, 1997
Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. I... more Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. In contrast to monocytes and granulocytes, lymphocytes of peripheral blood do not express CD13 Ag. However, tumor-infiltrating T cells in renal cell cancer as well as synovial fluid T cells from patients suffering from various forms of arthritis can be CD13 positive. To learn more about expression of CD13 in these tissues, we cocultured lymphocytes with different adherent cell lines. CD13 expression was induced in T and B lymphocytes upon adhesion to fibroblast-like synoviocytes, HUVEC, renal tubular epithelial cells, and monocytes/macrophages but not always upon interaction with different tumor cell lines. Induction of APN was rapid, occurring as early as 1 h after coincubation. Expression persisted for >3 days and partially resisted inhibition by cycloheximide. Fixation of adherent cells with paraformaldehyde could not prevent induction of CD13 in lymphocytes. Soluble APN from human kidneys or placenta could not induce CD13 expression on lymphocytes. Induction of CD13 Ag on lymphocytes required direct cell-to-cell contact as shown in experiments using dual chambers. Lymphocytes exhibited an induction not only in CD13 protein but also in Ala-pNA-cleaving enzyme activity and in CD13 mRNA. Lymphocytic expression of CD13 represents a potentially increased cellular ability to inactivate inflammatory mediators. Furthermore, CD13 could be involved in adhesion, in lymphocytic migration, or in the Ag processing of peptides bound in the groove of MHC class II molecules.
Journal of Cellular Biochemistry, 2001
Aminopeptidase N (APN)/CD13 is a transmembrane ectoenzyme expressed on a wide variety of cells. W... more Aminopeptidase N (APN)/CD13 is a transmembrane ectoenzyme expressed on a wide variety of cells. With respect to haematopoietic cells, APN/CD13 has been considered specific for the myeloid lineage, because granulocytes and monocytes/macrophages, but not lymphocytes of peripheral blood, show a surface expression of CD13 antigen. However, we could recently show that cell-cell contact of lymphocytes with endothelial cells, monocytes, and fibroblast-like synoviocytes (SFCs) results in an increase of steady-state APN/CD13 mRNA and a rapid expression of cell-surface protein on the lymphocytes. In this study using the Dual-Luciferase reporter assay, we demonstrate that interaction of the T-cell line Jurkat with SFCs results in a higher activity of the APN/CD13 myeloid promoter in T cells. An enhancer located between the myeloid and epithelial APN/CD13 promoter increases the response of the promoter to the cell-cell contact-induced expression of APN/CD13 in lymphocytes. Adhesion of lymphocytes to extracellular matrix did not result in increased promoter activity. The lymphocytic promoter response induced by direct cell-cell contact with SFCs is not affected by mutations of a proximal promoter element (nucleotides -48 to -35), which has a possible functional role in the basal APN/CD13 gene expression in lymphocytes. Upregulated peptidase-promoter activity via cell-cell contact shown in this study for the first time is discussed as a general mechanism in peptidase induction.
International Journal of Molecular Medicine, 2004
International journal of molecular medicine, 2004
Human monocytic cells express considerable amounts of aminopeptidase N (APN)/CD13, a transmembran... more Human monocytic cells express considerable amounts of aminopeptidase N (APN)/CD13, a transmembrane protein proposed to play a role in the modulation of kinins, neuropeptides and chemotactic mediators as well as in adhesion and cell-cell interactions. Previous studies have shown that APN/CD13 participates in antigen processing and presentation, trimming peptides protruding out of MHC class II molecules. In several inflammatory processes, macrophages have been shown to express especially high amounts of MHC class II molecules and of this peptidase. To learn more about the regulation of APN/CD13 on monocytes we investigated its expression under the influence of cytokines. Here, we report a dose- and time-dependent up-regulation of APN/CD13 mRNA and protein expression by transforming growth factor (TGF)-beta on human monocytes. To the contrary, we found IL-10 down-regulating the expression of APN/CD13 mRNA and protein. Both the regulation of the APN/CD13 protein assessed by immunofluore...
European cytokine network
In rheumatic joints, high concentrations of interleukin-8 (IL-8) have been measured in synovial f... more In rheumatic joints, high concentrations of interleukin-8 (IL-8) have been measured in synovial fluid and in pannus tissue. In both locations aminopeptidase N (APN)/CD13, an exopeptidase with reported activity towards IL-8 is also present. The surprising stability of IL-8 in the presence of an alleged IL-8-degrading peptidase prompted us to undertake the present study. Cocultivation of fibroblast-like synoviocytes (SFC) with T cells or with T lymphocytic cell membranes, or of T cells with SFC cell membranes, all resulted in increased IL-8 mRNA expression and IL-8 secretion into the medium, and an increase of APN expression on lymphocytes. IL-8 degradation was monitored by Western blots and HPLC. IL-8(72), as a partially processed form, was used throughout this study since it is abundant in tissues and has increased biological activity in comparison to IL-8(77). Thus its degradation/inactivation is considered of high biological significance. Whereas trypsin as a positive control rapi...
European cytokine network, 2000
Using random arbitrarily primed-reverse transcribed-PCR and sequence analysis, we investigated ch... more Using random arbitrarily primed-reverse transcribed-PCR and sequence analysis, we investigated changes in lymphocytic molecules after cell-cell contact with fibroblasts. An mRNA species which was upregulated in Jurkat T cells by cell-cell contact with MRHF cells (a human foreskin fibroblast line) was identified as coding for the human interleukin-17 receptor. This finding was confirmed by quantitative RT-PCR for the HUT78 and Jurkat T cell lines, for peripheral blood lymphocytes, and for tonsillar T cells. Furthermore, the interleukin-17 mRNA, coding for a proinflammatory cytokine, was also upregulated in peripheral blood lymphocytes and tonsillar T cells after cell-cell contact with fibroblasts. Supernatants obtained from cell-cell contact-stimulated peripheral blood lymphocytes enhance the production of interleukin-6 and interleukin-8 by fibroblast-like synoviocytes and this effect could be blocked by interleukin-17 antibodies. Changes in the mRNA levels of Jurkat T cells induced ...
Journal of neuroimmunology, 1999
Interleukin-17 (IL-17) has been characterized as a proinflammatory cytokine produced by CD4+ acti... more Interleukin-17 (IL-17) has been characterized as a proinflammatory cytokine produced by CD4+ activated memory T cells. In an effort to elucidate the biological effects of IL-17 in glial cells, we investigated the ability of this cytokine in order to activate nuclear factor (NF)-kappaB, which is being discussed as one of the most important transcription factors in the regulation of neuronal and glial cell function. Activation of NF-kappaB involves the degradation of its cytoplasmatic inhibitor IkappaB-alpha, which allows the nuclear translocation of NF-kappaB, and ensures transcriptional activation of genes including IkappaB-alpha itself. Using a competitive RT-PCR, we examined the IL-17-induced IkappaB-alpha mRNA expression in glioblastoma cells, and we examined IL-17 up-regulated IkappaB-alpha mRNA expression in a dose- and time-dependent fashion with a maximum time between 1 and 3 h. This induction could be inhibited by Calphostin C (protein kinase C inhibitor) and genistein (tyro...
Journal of immunology (Baltimore, Md. : 1950), 1997
Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. I... more Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. In contrast to monocytes and granulocytes, lymphocytes of peripheral blood do not express CD13 Ag. However, tumor-infiltrating T cells in renal cell cancer as well as synovial fluid T cells from patients suffering from various forms of arthritis can be CD13 positive. To learn more about expression of CD13 in these tissues, we cocultured lymphocytes with different adherent cell lines. CD13 expression was induced in T and B lymphocytes upon adhesion to fibroblast-like synoviocytes, HUVEC, renal tubular epithelial cells, and monocytes/macrophages but not always upon interaction with different tumor cell lines. Induction of APN was rapid, occurring as early as 1 h after coincubation. Expression persisted for >3 days and partially resisted inhibition by cycloheximide. Fixation of adherent cells with paraformaldehyde could not prevent induction of CD13 in lymphocytes. Soluble APN from human ...
ABSTRACT The S/T kinase CDK9 is part of the P-TEFb complex which promotes the productive transcri... more ABSTRACT The S/T kinase CDK9 is part of the P-TEFb complex which promotes the productive transcriptional elongation via phosphorylation of serine-2 residues within the RNA polymerase II C-terminal repeat domain. P-TEFb, recruited to responsive promoters via binding to transcription factors or chromatin assocd. proteins (e.g. NF-kB), is specifically required for the expression of highly inducible genes controlled by extracellular stimuli such as inflammatory processes. Consequently, the selective inhibition of CDK9 leads to a reduced expression of pro-inflammatory mediators, thereby avoiding the interference with processes of the normal cell homeostasis. Selective CDK9 inhibitors, resulting from our lead development program, have shown to be effective in various acute as well as chronic inflammation models, thereby confirming the proposed mode of action. The lead optimization process resulted in a CDK9 inhibitor, effective and well tolerated in two mouse models of arthritis under prophylactic as well as therapeutic treatment, now entering drug the development phase.
Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2005
The oral squamous cell carcinoma (OSCC) is the sixth most common malignant tumor worldwide. No si... more The oral squamous cell carcinoma (OSCC) is the sixth most common malignant tumor worldwide. No significant better progress has been made in the treatment of OSCCs during the last decades. The heterodimeric CD97 protein is a epidermal growth factor seven-transmembrane family member and was identified as a dedifferentiation marker in thyroid carcinomas. Nothing is known about CD97 in OSCCs. Employing UV-laser microdissection, CD97 and its ligand CD55 were investigated in normal oral mucosa and OSCCs (n = 78) by multiplex reverse transcription-PCR. Frozen sections were investigated by immunohistochemistry. The effects of retinoic acid and sodium butyrate on the CD97/CD55 expression in OSCC cell lines were determined by quantitative PCR, immunocytochemistry, and flow cytometry. Weak CD97 transcripts were expressed in normal mucosa and normal basal epithelial cells revealed specific CD97 immunostaining. Strong CD97 transcripts were detected in pT(3)/T(4) and G3/G4 OSCC tissues, whereas p...
Planta, 1993
A monoclonal antibody (MAB JAH1-8-B4) for the analysis of 3R, 7R-jasmonic acid and its methyl est... more A monoclonal antibody (MAB JAH1-8-B4) for the analysis of 3R, 7R-jasmonic acid and its methyl ester is described. An IgGl(kappa) immunoglobulin, MAB JAH1-8-B4, was used to set up a competitive enzymelinked immunoassay employing 3R, 7R-jasmonate coupled to alkaline phosphatase as tracer. The assay has a linearity range (logit/log) between 50 fmol and 50 pmol (approx. 10 pg-10 ng) of 3R, 7R-methyljasmonate, the assay standard. A procedure combining prepurification of plant extracts by solid-phase extraction, followed by high-performance liquid chromatography and quantitation has been worked out, which uses 4 g of fresh plant material and has a detection limit between 0.2 and 0.4 gg of 3R, 7R-jasmonic acid (determined as its methyl ester) per kg of tissue, depending on the tissue. Internal standards of 3R, 7R-methyljasmonate, added to split samples during extraction as well as a second internal standard, 3R, 7R-methyljasmonate-[O-C3H3], added to all samples prior to methylation, served to correct for workup losses and for the monitoring of chromatographic separations. Using this assay, it was found that levels of jasmonic acid rise immediately and transiently in the tissues analyzed as a consequence of wounding. These data provide further and direct evidence for the hypothesis that wound-induction of the plant defense reactions is mediated by endogenous jasmonates.
Oncogene, 2007
Cancer stem cells can play an important role in tumorigenesis and tumor progression. However, it ... more Cancer stem cells can play an important role in tumorigenesis and tumor progression. However, it is still difficult to detect and isolate cancer stem cells. An alternative approach is to analyse stem cell-associated gene expression. We investigated the coexpression of three stem cell-associated genes, Hiwi, hTERT and survivin, by quantitative real-time-PCR in 104 primary soft-tissue sarcomas (STS). Multivariate Cox's proportional hazards regression analyses allowed correlating gene expression with overall survival for STS patients. Coexpression of all three stem cell-associated genes resulted in a significantly increased risk of tumor-related death. Importantly, tumors of patients with the poorest prognosis were of all four tumor stages, suggesting that their risk is based upon coexpression of stem cell-associated genes rather than on tumor stage.
Oncogene, 2007
Self-renewal is considered as a common property of stem cells. Dysregulation of stem cell self-re... more Self-renewal is considered as a common property of stem cells. Dysregulation of stem cell self-renewal is likely a requirement for the development of cancer. Hiwi, the human Piwi gene, encodes a protein responsible for stem cell self-renewal. In this study, we investigated the expression of Hiwi at the RNA level by real-time quantitative PCR in 65 primary soft-tissue sarcomas (STS) and ascertained its impact on prognosis for STS patients. In a multivariate Cox's proportional hazards regression model, we found that an increased expression of Hiwi mRNA is a significant negative prognostic factor for patients with STS (P ¼ 0.017; relative risk 4.6, 95% confidence interval (CI) 1.3-16.1) compared to medium expression of Hiwi transcript. However, a low expression of Hiwi transcript is correlated with a 2.4-fold (CI 0.7-8.0) increased risk, but this effect was not significant (P ¼ 0.17). Altogether, high-level expression of Hiwi mRNA identifies STS patients at high risk of tumourrelated death. This is the first report showing a correlation between expression of a gene involved in stem cell selfrenewal and prognosis of cancer patients.
Molecular Human Reproduction, 2011
Kidney International, 1993
Journal of Neuroimmunology, 1999
q Interleukin-17 IL-17 has been characterized as a proinflammatory cytokine produced by CD4 activ... more q Interleukin-17 IL-17 has been characterized as a proinflammatory cytokine produced by CD4 activated memory T cells. In an effort to elucidate the biological effects of IL-17 in glial cells, we investigated the ability of this cytokine in order to activate nuclear Ž . factor NF -k B, which is being discussed as one of the most important transcription factors in the regulation of neuronal and glial cell function. Activation of NF-kB involves the degradation of its cytoplasmatic inhibitor Ik B-a, which allows the nuclear translocation of NF-kB, and ensures transcriptional activation of genes including Ik B-a itself. Using a competitive RT-PCR, we examined the IL-17-induced Ik B-a mRNA expression in glioblastoma cells, and we examined IL-17 up-regulated Ik B-a mRNA expression in a dose-Ž and time-dependent fashion with a maximum time between 1 and 3 h. This induction could be inhibited by Calphostin C proteinkinase C . Ž . inhibitor and genistein tyrosine kinase inhibitor . After 60 min of IL-17 stimulation, a degradation of the Ik B-a protein was detectable. Furthermore, IL-17 stimulated the secretion of IL-6 and IL-8 in glial cells, and IL-17 and IL-1b in combination showed a superadditive effect. We suggest IL-17 to play a role as an immune factor, possibly involved in complex pathophysiological interactions of neurodegenerative diseases. q
The Journal of Immunology, 2008
The Journal of …, 1997
Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. I... more Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. In contrast to monocytes and granulocytes, lymphocytes of peripheral blood do not express CD13 Ag. However, tumor-infiltrating T cells in renal cell cancer as well as synovial fluid T cells from patients suffering from various forms of arthritis can be CD13 positive. To learn more about expression of CD13 in these tissues, we cocultured lymphocytes with different adherent cell lines. CD13 expression was induced in T and B lymphocytes upon adhesion to fibroblast-like synoviocytes, HUVEC, renal tubular epithelial cells, and monocytes/macrophages but not always upon interaction with different tumor cell lines. Induction of APN was rapid, occurring as early as 1 h after coincubation. Expression persisted for >3 days and partially resisted inhibition by cycloheximide. Fixation of adherent cells with paraformaldehyde could not prevent induction of CD13 in lymphocytes. Soluble APN from human kidneys or placenta could not induce CD13 expression on lymphocytes. Induction of CD13 Ag on lymphocytes required direct cell-to-cell contact as shown in experiments using dual chambers. Lymphocytes exhibited an induction not only in CD13 protein but also in Ala-pNA-cleaving enzyme activity and in CD13 mRNA. Lymphocytic expression of CD13 represents a potentially increased cellular ability to inactivate inflammatory mediators. Furthermore, CD13 could be involved in adhesion, in lymphocytic migration, or in the Ag processing of peptides bound in the groove of MHC class II molecules.
Journal of Cellular Biochemistry, 2001
Aminopeptidase N (APN)/CD13 is a transmembrane ectoenzyme expressed on a wide variety of cells. W... more Aminopeptidase N (APN)/CD13 is a transmembrane ectoenzyme expressed on a wide variety of cells. With respect to haematopoietic cells, APN/CD13 has been considered specific for the myeloid lineage, because granulocytes and monocytes/macrophages, but not lymphocytes of peripheral blood, show a surface expression of CD13 antigen. However, we could recently show that cell-cell contact of lymphocytes with endothelial cells, monocytes, and fibroblast-like synoviocytes (SFCs) results in an increase of steady-state APN/CD13 mRNA and a rapid expression of cell-surface protein on the lymphocytes. In this study using the Dual-Luciferase reporter assay, we demonstrate that interaction of the T-cell line Jurkat with SFCs results in a higher activity of the APN/CD13 myeloid promoter in T cells. An enhancer located between the myeloid and epithelial APN/CD13 promoter increases the response of the promoter to the cell-cell contact-induced expression of APN/CD13 in lymphocytes. Adhesion of lymphocytes to extracellular matrix did not result in increased promoter activity. The lymphocytic promoter response induced by direct cell-cell contact with SFCs is not affected by mutations of a proximal promoter element (nucleotides -48 to -35), which has a possible functional role in the basal APN/CD13 gene expression in lymphocytes. Upregulated peptidase-promoter activity via cell-cell contact shown in this study for the first time is discussed as a general mechanism in peptidase induction.