Biomedical subjects

P Champelovier

Publications and source records attributed to P Champelovier.

15 recordsLinked to original sources

PubMed2001

Dag-1 carcinoma cell in studying the mechanisms of progression and therapeutic resistance in bladder cancer.

OBJECTIVE: We describe a new human bladder carcinoma cell line (DAG-1) established from a resected bladder cancer fragment and maintained in culture for more than 5 years and over 300 passages. METHODS AND RESULTS: Immunological, biochemical and molecular analysis showed that the DAG-1 cells (62 chromosomes) express the cytokeratines 8, 13, 18 and 20 that confirm their epithelial origin as well as numerous cytokine and cytokine receptor mRNAs. They secrete tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitors (PAI-1 and PAI-2), and express u-PA receptors (u-PAR/CD87) at their surface. DAG-1 cells are resistant to TNFalpha- and IFNgamma-induced apoptosis, two cytokines secreted in the urine of Calmette-Guérin bacillus-treated patients and involved in the tumor regression. CONCLUSION: The DAG-1 cell line is a useful tool, both in vitro and in vivo, to study the progression of bladder tumors and their mechanisms of resistance to immunotherapy in relation with PAI-2 and antioxidant enzymes.

Aged↗

PubMed2000

Expression of E-, P-, n-cadherins and catenins in human bladder carcinoma cell lines.

PURPOSE: Cadherins are cell surface glycoproteins that mediate Ca2+-dependent, homophilic cell-cell adhesion. The classical cadherins, E-, P- and N-cadherins, are known to self-associate from their extracellular domain, while their cytoplasmic domain interacts with either beta-catenin or plakoglobin (gamma-catenin), which in turn is bound to alpha-catenin that links the complex to the actin cytoskeleton. The aim of the present study was to analyze the expression of E-, P- and N-cadherins and catenins in human bladder carcinoma cells. MATERIALS AND METHODS: Five human bladder carcinoma cell lines, representing a variety of differentiation states, were grown in cell culture. We performed a cell aggregation assay, specific for biological cadherin activity. The expression of cadherins and catenins was analyzed by immunocytochemistry, Western blotting and RT-PCR. The interactions between cadherins and catenins were assessed by immunoprecipitation. RESULTS: We observed a reduced E-cadherin expression in the poorly differentiated and invasive-tumor derived cells. Interestingly, immunofluorescence study reveals the persistent localization of catenins at intercellular contacts in two E-cadherin deficient cell lines (T24 and TCCSUP) which yet exhibit an epithelial-like morphology and a calcium-dependent adhesive capacity. This suggests that other cadherin(s) are expressed in these both cell lines. P-cadherin, another epithelial cadherin, is expressed only in E-cadherin positive cells. On the other hand, N-cadherin is present at cell-cell borders in the very anaplastic cell lines, T24 and TCCSUP, and is able to link beta-catenin or plakoglobin. CONCLUSION: These results indicate that N-cadherin may participate in intercellular adhesion, while facilitating bladder tumorigenesis.

Actins↗

PubMed1997

Proliferation of LAMA-84 and LAMA-87 cell lines is modulated by autocrine loops involving M-CSF and TGF-beta.

The erythromegakaryocytic cell line (LAMA-84) and the erythroeosinophilic cell line (LAMA-87) were used to study receptor expression and receptor-mediated response to monocyte/macrophage colony-stimulating factor (M-CSF) and transforming growth factor beta (TGF-beta), two modulators of cell proliferation. As demonstrated by Northern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR), c-fms and M-CSF mRNA were expressed in both cell lines. M-CSF was detected in the supernatant of both cell lines and addition of a neutralizing anti-M-CSF antibody inhibited cell growth. The two LAMA cell lines were found to express TGF-beta1, -beta2, and -beta3 mRNAs and to secrete TGF-beta mostly in latent form. Addition of anti-TGF-beta antibodies to the culture medium increased their proliferation, whereas TGF-beta1 inhibited cell proliferation by downregulating the c-myc mRNA. These results show that the proliferation of both LAMA cell lines is positively and negatively regulated by autocrine mechanisms, implying the presence of M-CSF and TGF-beta, respectively. They suggest that similar autocrine loops could be involved in the growth regulation of leukemic cells in vivo.

Animals↗

PubMed1996

Quantitative analysis of three-dimensional distribution of AgNOR proteins during interphase in leukemic cells.

Acidic proteins of the nucleolar organizer regions, selectively stained by silver (AgNOR-proteins), were investigated during interphase in leukemia cells with a confocal scanning laser microscope (CSLM). Simultaneous confocal fluorescence (for specific labeling of DNA, using propidium iodide) and transmitted light microscopy combined with digital deconvolution (for the location of the AgNOR proteins in nonconfocal mode) were used. The distribution of the AgNOR proteins measured by 3D microscopy was described by their number, the volume occupation of the nucleus by the AgNOR aggregates, the distance between each AgNOR, the distance of each AgNOR to the nucleolar border, and their anisotropy. The results of the 3D analysis were compared to those obtained by conventional 2D analysis, cytogenetical analysis of metaphase nucleolar organiser regions (NORs), and cell duplication rate. The descriptive power of these 3D parameters were assessed for nine leukemic cell lines. The measurements of the 3D spatial distribution of AgNORs was a better discriminant parameter than the morphological parameters (i.e., number and volume). The 3D expression of AgNORs is also a reliable parameter for assessing proliferative activity of leukemic cells and seems to be in relation with the differentiation stage of these leukemic cells.

Cell Division↗

PubMed1994

Selection and characterization of an erythroeosinophilic subclone (LAMA-87) and an eosinophilic subclone (LAMA-88) from the multipotential cell line LAMA-84.

The human leukemic cell line LAMA-84 was established and characterized as an erythromegakaryocytic cell line. In the present study we show that these cells can differentiate in estrone-treated athymic mice and give rise to an erythroeosinophilic cell line (LAMA-87). This new cell line expressed glycoporin A, alpha beta and gamma globin chain mRNA but also eosinophilic peroxidase. Hemin slightly increased the total hemoglobin production of the cells and phorbol diester (TPA), dimethyl sulfoxide (DMSO) and sodium butyrate (SB) increased the expression of megakaryocytic markers (gpIIb/IIIa complex). When inoculated into non-treated athymic mice, LAMA-87 cells can differentiate to give rise to eosinomonocytic cells (LAMA-88). This new cell line expresses eosinophilic peroxidase, Luxol fast blue stain and synthesizes lysozyme. Depending on the inducer used, LAMA-88 can differentiate along a monocytic lineage (TPA, DMSO, SB and vitamin D3). These three LAMA cell lines should be useful in further studies of the molecular regulation of the pluripotent cell commitment and may provide a model for the understanding of human hematopoiesis.

Animals↗

PubMed1994

Image analysis as a tool for quantitative enzyme determination at the cellular level: application for monocytic differentiation of the UM-384 cell line.

Image analysis has been used to determined enzyme activity at the cellular level in individual smeared cells. The counterstains used to visualize smeared cells were chosen to avoid overlap with the chromogene. The amount of the reaction product was quantified by computerised scanning cytophotometry when the conditions of incubation, time and temperature of the reaction, and substrate concentration varied. Under optimal conditions for time, temperature and substrate concentration, a linear relationship was found between enzyme activity determined on smeared cells and in cell lysate. Using these defined conditions, differentiation of UM-384 cells was studied by measuring enzyme activity. After a monocytic differentiation process, induced by sodium butyrate, non-specific esterase cell activity was compared either with differentiation markers (HLA-DR, plasminogen activator inhibitor type 2 and lysozyme) or with markers of proliferation (DNA content) or functional properties (nitroblue tetrazolium reduction and phagocytosis). The results show that, using image analysis, non-specific esterase seems to be a useful means for the assessment of monocytic differentiation whereas myeloperoxidase is not. More generally, quantification of enzyme activity at the cellular level using image analysis can be applied to the study of the differentiation process and may help in the classification of leukemic cells.

Acid Phosphatase↗

PubMed1993

The O2- generating oxidase of B lymphocytes: Epstein-Barr virus-immortalized B lymphocytes as a tool for the identification of defective components of the oxidase in chronic granulomatous disease.

The O2- generating NADPH oxidase of human Epstein-Barr virus immortalized B lymphocytes (EBV-B lymphocytes) and the NADPH oxidase of human neutrophils were compared. The capacity of the oxidase of EBV-B lymphocytes to generate O2- is 100-fold less than that of neutrophils. Like the oxidase of neutrophils, the oxidase of EBV-B lymphocytes is decreased or abolished in chronic granulomatous disease (CGD). Activation of neutrophil oxidase in an heterologous cell-free system, using human neutrophil membranes and EBV-B lymphocyte cytosol from healthy and CGD patients, combined with immunoblotting investigations of the cytosolic activating factors p47 and p67 involved in O2- production, suggests that neutrophils and EBV-B lymphocytes possess similar complements of cytosolic factors p47 and p67. Cytochrome b -245, the major membrane redox component of the O2- generating oxidase, is only slightly expressed in the membrane of EBV-B lymphocytes. A sensitive and specific immunocytochemical method for detection of the two subunits of cytochrome b -245 is described; it shows that both subunits are virtually absent in EBV-B lymphocytes from CGD patients deficient in the large subunit.

Animals↗

PubMed1993

Absence of both subunits of cytochrome b558 in the UM384 cell line relative to the inability to generate superoxide anions.

Phagocytic cells are characterized by their ability to generate superoxide anions upon activation by appropriate stimuli. UM384, a myelomonocytic cell line, was shown to be defective in this oxidase activity as measured by nitroblue tetrazolium or cytochrome c reduction. Cytochrome b558, a unique pigment present in phagocytes and implicated in electron transfer from NADPH to O2, was absent in the differentiated UM384 cells. Both subunits of the cytochrome b558 appeared to be absent or present in strongly reduced amounts compared to the mother cell line U937, as indicated by immunocytochemistry or Western blot analysis using monoclonal antibodies (MABs). On the other hand, cytosolic factors also involved in NADPH oxidase activity were shown to be present, either immunologically or by using the capacity of the cytosol to activate the oxidase in a membrane fraction from bovine neutrophils. At the molecular level, the mRNA that encodes the gp91-phox was shown to be absent in the differentiated UM384 cells, whereas the mRNA that encodes the p22-phox was normally expressed. These results suggest that the defect in superoxide production by the UM384 cells is related to the absence of cytochrome b558, a situation mimicking that observed in phagocytes from patients with X-linked chronic granulomatous disease (X-CGD).

Antibodies, Monoclonal↗

PubMed1991

Quantification by image analysis of immunocytochemical reactions: application for determination of lysozyme content in individual smeared cells.

The objective of the present study was to develop a cytophotometric technique to quantitate immunocytochemical reactions. Cell antigens were detected after immunophosphatase alkaline staining procedure. The amount of reaction product was quantitated by computerized scanning cytophotometry. The technical conditions (dilution of primary antibody; incubation time of the three antibodies; volume and pH of the enzyme substrate reaction; storage of the slides) required for optimal cytophotometric determination of the reaction product were determined. Under these optimally defined conditions, a linear relationship between cell protein content (lysozyme) and microdensitometric measure of the colored reaction product was found. This method could be used for other cells, antigens, and enzymatic indicators.

Alkaline Phosphatase↗

PubMed1989

Establishment and characterization of a granulocytic subclone (UM 384) from the monoblastic cell line U 937.

The human cell line U 937 spontaneously expresses monocytic maturation and can be induced into macrophage-like cells when treated with retinoic acid, sodium butyrate, or 2,3-O-tetra decanoylphorbol-13-acetate. We have selected a subclone, designated UM 384, that expresses granulocytic characteristics and can be induced to mature to granulocytes after exposure to retinoic acid, actinomycin D, and dimethylsulfoxide, and to monocyte-like cells when treated with sodium butyrate and phytohemagglutinin-stimulated leukocyte-conditioned medium. These cells retain the same constitutive markers as the parent line including histocompatibility leukocyte antigens and karyotype but share numerous chromosomal abnormalities, mainly t(X;8) (p21;q12).

Antigens, Differentiation↗

PubMed1987

Human chronic myeloid leukemic cell line with positive Philadelphia chromosome exhibits megakaryocytic and erythroid characteristics.

A cell line (LAMA-84) has been established from the blood of a patient with chronic myeloid leukemia in acute phase. LAMA-84 cells retained the patient's chromosome abnormalities, i.e., triplication of all chromosomes except chromosome 18, the presence of Philadelphia (Ph) chromosome in 4-5 copies, and the presence of chromosome markers. LAMA-84 cells have morphological features of undifferentiated blast cells, but analyses have indicated that they belong to the megakaryocytic lineage; platelet peroxidase (PPO) was found in 8.5% of cells; LAMA-84 cells reacted spontaneously with poly- and monoclonal antibodies against the platelet glycoproteins (GP) IIb, IIIa, and the GPIIb/IIIa complex, whose presence was confirmed by crossed immunoelectrophoresis. LAMA-84 cells lack the membrane characteristics of lymphoid and mature granulocytic cells but do, however, react with certain antibodies to immature myeloid cells. Furthermore, they are positive with an antiglycophorin antibody, and contain alpha- and gamma-globin mRNA, thus demonstrating erythroid marker expression. Thus LAMA-84 is a tripotent, megakaryocytic, erythroid, and granulocytic cell line. The megakaryocytic and erythroid markers were enhanced by the addition of DMSO, butyrate, TPA, and hemin. The LAMA-84 cell line represents an interesting tool for the study of megakaryocytic and erythroid differentiation and the mechanisms of neoplastic growth.

Adult↗

PubMed1985

Proliferation and maturation of human leukemic cells in liquid culture: activity of human placenta conditioned medium and retinoic acid.

Marrow or peripheral blood cells from 28 patients with acute myeloid leukemia (AML) or chronic myeloid leukemia in blastic crisis (CML-BC) were studied in both liquid and agar cultures. The proliferation and maturation of these cells were followed for 15-20 days in liquid culture with or without the addition of human placenta conditioned medium (HPCM) and/or retinoic acid (RA). In nine patients (group 1), cells underwent both proliferation and maturation, i.e., the percentage of peroxidase-positive cells (PO), phagocytic cells, and mature forms increased. For the remaining 19 patients (group 2), no proliferation was observed. However, 11 of these leukemic cell samples showed maturation (group 2A), while the eight others remained immature (group 2B). In agar culture, cell samples from group 1 showed cluster growth, group 2 no growth. Maturation without proliferation was observed for group-1 liquid cultures not containing HPCM and those containing HPCM and RA. The viability rapidly decreased in liquid cultures with only addition of RA. HPCM and RA showed no effect on group-2 cell cultures.

Adult↗

PubMed1982

A comparison on 3 cell separation media: application to the enrichment for immature cells of the granular myeloid line.

Three common cell separation media (Bovine Serum Albumin Percoll and Lymphoprep), used for enrichment for immature cells of the granular myeloid line, were compared for simplicity of use, maximum recovery of Granulo-Macrophagic colony forming cells and myeloblasts, and minimum contamination with other cell types; Percoll, at a density of 1.078 g/cm3, was found to be best suited to our uses.

Bone Marrow Cells↗

PubMedDate not supplied

CK20 gene expression: technical limits for the detection of circulating tumor cells.

The suitability of CK20 mRNA expression as a marker for the detection of minimum residual disease in patients with cancer of epithelial origin was evaluated. A sensitive nested RT-PCR assay with multiple replicates was optimised to detect a minimum number of circulating tumor cells expressing cytokeratin 20 (CK20) mRNA. Using this optimal procedure, we examined CK20 mRNA expression in ten epithelial and seven leukemic cell lines, in eight bladder tumors, in peripheral blood samples from 18 tumor patients and from 29 healthy controls and in 8 bone marrow samples from healthy donors. CK20 mRNA was found in 13 of 18 (72%) blood samples from patients with cancer of epithelial origin and in all the epithelial tumor cells tested. However, CK20 mRNA was also detected in 21 of 29 (72%) bloods, in 8 of 8 bone marrow samples from healthy donors and in 4 of 7 leukemic cell lines. These results highlight a requirement for either determination of threshold levels of CK20 normal expression or the development of quantitative techniques to distinguish between a tumor-specific CK20 gene expression and a low level background transcription of this marker. These results would also advise caution in using CK20 as a tumor specific marker in clinical investigations.

Biomarkers, Tumor↗

PubMedDate not supplied

Autocrine regulation of TPA-induced apoptosis in monoblastic cell-line U-937: role for TNF-alpha, MnSOD and IL-6.

The present studies were undertaken to analyse the factors regulating TPA-induced apoptosis. Treatment of the monoblastic U-937 cells with the phorbol ester, TPA, was found to induce apoptosis in two distinct phases. In phase I (from 0 to 72 hours following TPA induction), apoptotic cells appeared, despite the expression of high levels of the anti-apoptotic Bcl-2 protein. After 96 h. of TPA treatment (phase II), the percentage of apoptotic cells increased as did the cell differentiation stage. The first phase apoptotic response could be significantly reduced (70%) by treatment with anti-tumor necrosis factor-alpha (TNF-alpha) antibody. TNF-alpha protein required de novo RNA and protein synthesis and was found to be mediated by protein kinase and protein tyrosine kinases. Manganese superoxide dismutase (MnSOD) inhibited, whereas IL-6 increased TPA-induced apoptosis. These findings suggest that both TPA, via TNF-alpha synthesis, exerts its protective function intracellularly by inducing MnSOD production and IL-6 may be an effective adjunct to TNF-alpha in the clinic, increasing the antitumor potency of this cytokine.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗