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C Wagener

Publications and source records attributed to C Wagener.

At least 19 recordsLinked to original sources
PubMed2001

The microbial receptor CEACAM3 is linked to the calprotectin complex in granulocytes.

Engulfment of foreign pathogens is an evolutionary ancient host cell endocytic response. Signaling pathways effecting phagocytosis are divergent and largely depend on the structural features of the cell surface receptor utilized. CEACAM3, a member of the CD66 complex on human neutrophils, has been implicated as a cellular receptor promoting phagocytosis of microorganisms. The cytoplasmic domain of CEACAM3 (CEACAM3(cyt)) contains an immunoreceptor tyrosine-based activation motif. In this study we demonstrate that CEACAM3(cyt) is phosphorylated by protein kinase C, casein kinase I, and Src-kinase in vitro. To identify molecules binding to CEACAM3(cyt) in vivo, we used differentially phosphorylated recombinant expressed CEACAM cytoplasmic domains to isolate CEACAM3(cyt)-associated proteins from granulocyte extracts. Calprotectin, which modulates neutrophil integrin-mediated adhesion and leukocyte trafficking and displays antimicrobial activity, interacts specifically with CEACAM3(cyt). This interaction is calcium-modulated but independent of phosphorylation of CEACAM3(cyt). Although tyrosine-phosphorylated CEACAM3(cyt) binds and stimulates Src-kinases in vitro, no CEACAM3(cyt)-associated phosphokinase activity was copurified.

Calcium Signaling↗
PubMed2001

Binding inhibition of type 1 fimbriae to human granulocytes: a flow cytometric inhibition assay using trivalent cluster mannosides.

The binding of type 1 fimbriae from Escherichia coli to vital human neutrophilic granulocytes was inhibited by synthetic trivalent cluster mannosides. Binding of type 1 fimbriae was measured in a flow cytometric assay. Based on the molarity of mannosyl residues, the clusters exceed the inhibitory potency of methyl alpha-D-mannoside by a factor of more than 1,000 and the inhibitory potency of p-nitrophenyl alpha-D-mannoside by a factor of more than 10. The inhibition studies indicate that the trivalent cluster mannosides are very potent inhibitors of the binding of type 1 fimbriae to human neutrophilic granulocytes. Based on their defined structure, cluster mannosides are well suited for characterizing the molecular interactions of mannose-sensitive fimbriae with their cell membrane receptors.

Bacterial Adhesion↗
PubMed2001

cis Interaction of the cell adhesion molecule CEACAM1 with integrin beta(3).

CEACAM1 is a cell adhesion molecule that has been implicated in a number of physiological processes (eg, tumor suppressor in epithelial tissues, potent angiogenic factor in microvessel formation, microbial receptor in human granulocytes and epithelial cells). The mechanism of CEACAM1 action is still largely unresolved but recent findings demonstrated that the cytoplasmic CEACAM1 domain is linked indirectly to the actin-based cytoskeleton. We have isolated integrin beta(3) as an associated protein using CEACAM1 tail affinity purification. This association depends on phosphorylation of Tyr-488 in the CEACAM1 cytoplasmic domain. Confocal laser scanning microscopy confirmed in vivo colocalization of both molecules in human granulocytes and epithelial cells. Furthermore, the concentrated colocalization at the tumor-stroma interface of invading melanoma masses suggests a functional role of CEACAM1-integrin beta(3) interaction in melanoma invasion. Moreover, colocalization of the two adhesion molecules is also found at the apical surface of glandular cells of pregnancy endometrium. Colocalization of CEACAM1 and integrin beta(3) at the transitional zone from proliferative to invasive extravillous trophoblast of the maternal-fetal interface supports a role for CEACAM1/integrin beta(3) complexes in cell invasion.

Antigens, CD↗
PubMed2001

Enrichment of mutant KRAS alleles in pancreatic juice by subtractive iterative polymerase chain reaction.

SUMMARY: The detection of mutant tumor genes holds great promise for an early diagnosis of primary tumors and residual malignant disease. When few tumor cells are present with an excess of nonmalignant cells of the same lineage, the excess of wild-type alleles over mutant tumor alleles presents an analytical problem. The subtractive iterative PCR (siPCR) assay presents a new approach to solving this problem. To achieve an enrichment of mutant alleles, wild-type alleles are removed by differential hybridization to complementary oligonucleotides spanning the region of the gene in which point mutations are expected. The nonbound fraction is reamplified by PCR. By iterating this process, mutant alleles can be detected in the presence of an excess of wild-type alleles with high sensitivity. To prove the feasibility of siPCR, pancreatic juice samples were analyzed for KRAS mutations. Pancreatic juice obtained from patients with pancreatic carcinoma or chronic pancreatitis during endoscopic retrograde cholangiopancreatography was analyzed for point mutations in codons 12 and 13 of the KRAS gene. In each of six samples from tumor patients, mutations in codon 12 were detected. One of nine samples from patients with chronic pancreatitis scored positive.

Alleles↗
PubMed2001

Consequences of a National Mammography Screening Program on diagnostic procedures and tumor sizes in breast cancer. A retrospective study of 1540 cases diagnosed and histologically confirmed between 1995 and 1997.

In 1992, a national screening mammography program, including female patients between 50 and 64 years of age, was launched in Luxembourg. The effects of this campaign on the different diagnostic procedures, especially fine needle aspirations (FNA), large core needle biopsies (LCNB), and surgical specimens, were analyzed. From 1983 to 1997, the National Cancer Registry recorded 3167 new cases of invasive female breast cancer, all histologically diagnosed in one central pathology department. In 1996, the population consisted of 418,300 inhabitants (212,900 females). The number of breast cancer, tumor size, the nature of the diagnostic procedures, their diagnostic value as well as the number of physicians, "aspirators", and "biopsists" were evaluated. Between 1992 and 1994, the incidence of invasive breast cancers increased, concomitant with the launching of a National Screening Mammography Program. The diagnosis of in situ cancers tripled, and the mean size of invasive breast cancer decreased from 2.1-2.4 cm to 1.1-1.4 cm. Since 1994, the number of FNA had remained stable, LCNB had increased by 417.5%, and surgical biopsies had decreased by 18.95%. Between 1995 and 1997, 28.37% of 1075 FNA, and only 9.6% of 465 LCNB yielded inadequate samples. FNA were done by 77 different doctors (53.25% being gynecologists) and LCNB by 34 (52.94% being radiologists). The first diagnoses of all invasive cancers (n = 790) were made by using frozen sections from surgical specimens in 58.35% (n = 461), LCNB in 18.23% (n = 144), mastectomy in 10.13% (n = 80), formalin-fixed biopsies in 9.49% (n = 75), and FNA in 3.17% (n = 25). There are beneficial effects (increase in the number of diagnoses of in situ cancer; decrease in tumor sizes) not only for the "target" age group (50-64 years), but also for all female age groups (> 15 years). For quality assurance purposes, it is absolutely recommended to carry out pathological, radiological, and diagnostic work in specialized centers.

Aged↗
PubMed2001

Expression pattern of the adhesion molecule CEACAM1 (C-CAM, CD66a, BGP) in gestational trophoblastic lesions.

CEACAM1 (CD66a, BGP, C-CAM) is an adhesion molecule of the carcinoembryonic antigen (CEA) family which has been shown to be normally expressed at the apical pole of epithelial cells and to show a dysregulated expression pattern in tumors derived from the latter. The purpose of the present study was to investigate the expression pattern of CEACAM1 in gestational trophoblastic lesions and to compare this expression with the one observed in the normal trophoblast. For this purpose, we performed immunohistochemistry using the 4D1/C2 monoclonal antibody which specifically recognizes CEACAM1 and does not interact with other members of the CEA family. Immunohistochemistry was performed on a total of 20 cases of gestational trophoblastic lesions including complete hydatidiform moles, one placental site trophoblastic nodule (PSN), one placental site trophoblastic tumor (PSTT), and three choriocarcinomas. Immunostaining for cytokeratin, hPL, hCG, and Ki-67 was also performed. Normal placental samples served as a control. CEACAM1 was absent from villous cyto- and syncytiotrophoblast in both normal placenta and hydatidiform molar samples. It was present in the benign extravillous trophoblast, with stronger expression in the proximal extravillous trophoblast of anchoring villi, but was also observed in interstitial and endovascular intermediate trophoblast and chorionic intermediate-like trophoblast. Partial expression was observed in the trophoblast proliferating from the surface of molar villi. In choriocarcinomas, areas of weak expression could be observed along with large areas without CEACAM1 expression. In the PSN and especially in the PSTT, CEACAM1 expression was stronger and more diffuse. The specific localization to extravillous trophoblast and its expression pattern in gestational trophoblastic lesions indicate that CEACAM1 can potentially be a helpful additional diagnostic marker in the differential diagnosis of such lesions.

Antigens, CD↗
PubMed2000

Angiogenic properties of the carcinoembryonic antigen-related cell adhesion molecule 1.

The carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), a member of the immunoglobulin superfamily, is expressed in microvessels of proliferating tissues such as endometrium, in tissues after wounding, and in solid human tumors. In microvascular human endothelial cells, purified native and recombinant CEACAM1 stimulates proliferation, chemotaxis, and tube formation. In the chorioallantoic membrane of the chicken, CEACAM1 induces angiogenesis. The angiogenic effects of CEACAM1 are additive to those of the vascular endothelial growth factor (VEGF). The expression of CEACAM1 is up-regulated by VEGF, and VEGF-induced in vitro tube formation is blocked completely by a monoclonal CEACAM1 antibody. These findings indicate that CEACAM1 is an angiogenic factor and an effector of VEGF.

Adenosine Triphosphatases↗
PubMed2000

Cell adhesion molecule CEACAM1 associates with paxillin in granulocytes and epithelial and endothelial cells.

CEACAM1 functions as an epithelial tumor suppressor and as an angiogenic growth factor. In the present study, utilizing differentially (serine/threonine or tyrosine) phosphorylated cytoplasmic domains of CEACAM1 and CEACAM3 as bait to isolate associated proteins from granulocyte extracts, we have identified human paxillin as a binding partner of the tyrosine-phosphorylated cytoplasmic CEACAM1 domain. CEACAM1-paxillin complexes were coimmunoprecipitated from extracts of granulocytes, the colonic cell line HT29, and HUVECs. We identified phosphorylated Tyr-488-a residue in the cytoplasmic CEACAM1 domain known to be essential for the tumor suppressive effect-to be necessary for this association. The CEACAM1-paxillin interaction was confirmed using laser scanning confocal microscopy analyses in granulocytes and HT29 cells, where CEACAM1 colocalizes with paxillin at the plasma membrane. In HUVECs a highly polarized expression pattern and colocalization of paxillin and CEACAM1 was observed. These findings support the findings that CEACAM1 is linked to the actin-based cytoskeleton.

Adenosine Triphosphatases↗
PubMed2000

Cell cycle- and cell growth-regulated proteolysis of mammalian CDC6 is dependent on APC-CDH1.

CDC6 is conserved during evolution and is essential and limiting for the initiation of eukaryotic DNA replication. Human CDC6 activity is regulated by periodic transcription and CDK-regulated subcellular localization. Here, we show that, in addition to being absent from nonproliferating cells, CDC6 is targeted for ubiquitin-mediated proteolysis by the anaphase promoting complex (APC)/cyclosome in G(1). A combination of point mutations in the destruction box and KEN-box motifs in CDC6 stabilizes the protein in G(1) and in quiescent cells. Furthermore, APC, in association with CDH1, ubiquitinates CDC6 in vitro, and both APC and CDH1 are required and limiting for CDC6 proteolysis in vivo. Although a stable mutant of CDC6 is biologically active, overexpression of this mutant or wild-type CDC6 is not sufficient to induce multiple rounds of DNA replication in the same cell cycle. The APC-CDH1-dependent proteolysis of CDC6 in early G(1) and in quiescent cells suggests that this process is part of a mechanism that ensures the timely licensing of replication origins during G(1).

Amino Acid Sequence↗
PubMed2000

In vitro differentiation of endothelial cells from AC133-positive progenitor cells.

Recent findings support the hypothesis that the CD34(+)-cell population in bone marrow and peripheral blood contains hematopoietic and endothelial progenitor and stem cells. In this study, we report that human AC133(+) cells from granulocyte colony-stimulating factor-mobilized peripheral blood have the capacity to differentiate into endothelial cells (ECs). When cultured in the presence of vascular endothelial growth factor (VEGF) and the novel cytokine stem cell growth factor (SCGF), AC133(+) progenitors generate both adherent and proliferating nonadherent cells. Phenotypic analysis of the cells within the adherent population reveals that the majority display endothelial features, including the expression of KDR, Tie-2, Ulex europaeus agglutinin-1, and von Willebrand factor. Electron microscopic studies of these cells show structures compatible with Weibel-Palade bodies that are found exclusively in vascular endothelium. AC133-derived nonadherent cells give rise to both hematopoietic and endothelial colonies in semisolid medium. On transfer to fresh liquid culture with VEGF and SCGF, nonadherent cells again produce an adherent and a nonadherent population. In mice with severe combined immunodeficiency, AC133-derived cells form new blood vessels in vivo when injected subcutaneously together with A549 lung cancer cells. These data indicate that the AC133(+)-cell population consists of progenitor and stem cells not only with hematopoietic potential but also with the capacity to differentiate into ECs. Whether these hematopoietic and endothelial progenitors develop from a common precursor, the hemangioblast will be studied at the single-cell level.

Animals↗
PubMed2000

E2F family members are differentially regulated by reversible acetylation.

The six members of the E2F family of transcription factors play a key role in the control of cell cycle progression by regulating the expression of genes involved in DNA replication and cell proliferation. E2F-1, -2, and -3 belong to a structural and functional subfamily distinct from those of the other E2F family members. Here we report that E2F-1, -2, and -3, but not E2F-4, -5, and -6, associate with and are acetylated by p300 and cAMP-response element-binding protein acetyltransferases. Acetylation occurs at three conserved lysine residues located at the N-terminal boundary of their DNA binding domains. Acetylation of E2F-1 in vitro and in vivo markedly increases its binding affinity for a consensus E2F DNA-binding site, which is paralleled by enhanced transactivation of an E2F-responsive promoter. Acetylation of E2F-1 can be reversed by histone deacetylase-1, indicating that reversible acetylation is a mechanism for regulation also of non-histone proteins.

Acetylation↗
PubMed2000

High background levels compromise the use of cardiac troponin I RNA detection in peripheral blood as a diagnostic tool in cardiology.

The detection of cardiac troponins in peripheral blood as protein markers of myocardial infarction is a new diagnostic tool in the diagnosis of cardiac disease. In order to increase the sensitivity and specificity of this diagnostic approach, a reverse transcription polymerase chain reaction assay has been developed to detect the mRNA encoding cardiac troponin I from myocardial cells hypothetically released from damaged cardiac tissue. The detection is specific for cardiac troponin I mRNA, with no amplification of homologous sequences of other troponin I isoforms, i.e., troponin I from skeletal muscle cells. However, a strong amplification signal for cardiac troponin I mRNA was detected in samples of peripheral blood from healthy human volunteers. In patients with acute myocardial infarction or angina pectoris, the cardiac troponin I mRNA levels were not increased over background levels. In conclusion, a reverse transcription polymerase chain reaction approach based on the amplification of cardiac troponin I mRNA is not feasible in the diagnosis of cardiac diseases.

Angina Pectoris↗
PubMed2000

The adhesion molecule CEACAM1 (CD66a, C-CAM, BGP) is specifically expressed by the extravillous intermediate trophoblast.

CEACAM1 (CD66a, C-CAM, BGP) is an adhesion molecule of the carcinoembryonic antigen family which has been shown to be normally expressed at the apical pole of epithelial cells, including the apical pole of endometrial surface and glandular epithelia. The purpose of the present study was to investigate its expression pattern at the maternal-fetal interface, and thus to determine whether CEACAM1 could be implicated in the human implantation process. For this purpose, we performed immunohistochemistry using the 4D1/C2 monoclonal antibody (mAb) as well as flow cytometry and Western blot on isolated trophoblast populations. On the maternal side of the maternal-fetal interface, CEACAM1 was present in epithelial cells of pregnancy endometrium as well as in small endometrial vessels, whereas it was absent from decidual cells. On the fetal side, CEACAM1 was strongly expressed by the extravillous (intermediate) trophoblast at the implantation site, as well as by extravillous trophoblast cells with invasive phenotype in primary culture, as shown by flow cytometry and Western blot. Expression was also observed in placental villous core vessels but was absent from both villous cyto- and syncytiotrophoblasts throughout the pregnancy. We conclude that, given its specific expression pattern, CEACAM1 can be a useful marker for extravillous intermediate trophoblast and might be functionally implicated in mediating trophoblast/endometrial and/or trophoblast/endothelial interactions during the trophoblastic invasion of the endometrium.

Antigens, CD↗
PubMed2000

Cervical cancer screening in Luxembourg.

In 1962, a programme for early detection of cervical cancer was established at the national level. The programme is based on the collaboration of different groups of doctors and not on a system of sending out invitations to every woman. This programme was re-adapted twice according to the needs for assuring quality in a system of mainly liberal medicine. At present the programme is 'institutionalised' and is carried out according to the criteria defined in 1990. This includes a centralisation of the smear readings and handing out the material needed to take the smears. The contribution of the doctors is regulated by a system of bonuses given by the government and a reimbursement by the Health Fund. The annual cervical smear is free of charge for every woman. The participation of the women targeted by the programme (>15 years old) has increased by approximately 50% every decade from the early 1970s increasing from 10950 in 1972 to 70441 in 1999. Between 1980 and 1999, the number of women at risk taking part in the programme increased from 10.80 to 38.92%. The number of all the doctors taking smear samples increased from 68 to 105 and the number of gynaecologists increased from 19 (ratio Gyn/GP (gynaecologists/General Practitioners) of 28%) to 52 (ratio Gyn/GP of 50%). The mortality rate has decreased continuously from 6. 1/100000 in 1990 to 0.9/100000 in 1997. In conclusion, to be successful, a cervical cancer screening programme should be flexible enough to allow short-term adaptations to unexpected local situations and needs a highly motivated team of the different participants involved in the regional and national health policy.

Data Collection↗
PubMed2000

CEA-related cell adhesion molecule 1: a potent angiogenic factor and a major effector of vascular endothelial growth factor.

CEA-related cell adhesion molecule 1 (CEACAM1) exhibits angiogenic properties in in vitro and in vivo angiogenesis assays. CEACAM1 purified from granulocytes and endothelial cell media as well as recombinant CEACAM1 expressed in HEK293 cells stimulate proliferation, chemotaxis, and capillary-like tube formation of human microvascular endothelial cells. They increase vascularization of chick chorioallantoic membrane and potentiate the effects of vascular endothelial growth factor (VEGF)165. VEGF165 increases CEACAM1 expression both on the mRNA and the protein level. VEGF165-induced endothelial tube formation is blocked by a monoclonal CEACAM1 antibody. These data suggest that CEACAM1 is a major effector of VEGF in the early microvessel formation. Since CEACAM1 is expressed in tumor microvessels but not in large blood vessels, CEACAM1 may be a target for the inhibition of tumor angiogenesis.

Adenosine Triphosphatases↗
PubMed1999

Detection of micrometastasis by cytokeratin 20 RT-PCR is limited due to stable background transcription in granulocytes.

The reverse transcription polymerase chain reaction (RT-PCR) amplification of cytokeratin 20 (CK20) mRNA is considered a promising candidate method for the detection of circulating tumour cells in bone marrow and peripheral blood of cancer patients. In this study we have investigated the diagnostic specificity of the CK20 mRNA detection in samples from healthy donors (HD; n = 33), intensive care units patients (ICU; n = 20) and bone marrow obtained from patients suffering from chronic inflammatory diseases (CID; n = 14). RNAs purified from stabilized lysates showed positive results in 24% of the HD group (8/33), 35% of the ICU group (8/20) and in 40% of the CID group (5/14). The use of Ficoll gradients to separate nucleated cells completely restored the specificity of this CK20 RT-PCR assay. The CK20-expressing cells are positively identified to belong to the granulocyte fraction of leucocytes, which appear to express the gene on a background level. Our results demonstrate for the first time that CK20 mRNA expression is not limited to epithelium. Its occurrence in normal granulocytes has to be considered in tests designed to detect circulating cancer cells or micrometastases.

Biomarkers, Tumor↗