Search

Down Syndrome (DS) is caused by the presence of three copies of the whole human chromosome 21 (HC21) or of a HC21 restricted region; the phenotype is likely to have originated from the altered expression of genes in the HC21. We apply the cDNA microarray method to the study of gene expression in human T lymphocytes with trisomy 21 in comparison to normal cells.Two patients with DS were investigated, along with two normal subjects as a control, all being tested in independent, duplicated cell culture experiments. The most consistent finding was the overexpression of the superoxide dismutase gene (SOD1), located on 21q, and of MHC DR beta 3 (HLA-DRB3), GABA receptor A gamma 2 (GABRG2), acetyltransferase Coenzyme, A 2 (ACAT2) and ras suppressor protein 1 (RSU1) genes. When the data were clustered according to chromosome localization, the HC21 gene set showed, on average, the highest expression in DS cells in all the experiments. Moreover, separate clustering of patients and controls was obtained when analysis was restricted to HC21 gene expression values.These findings reinforce the specific gene dosage theory for the pathogenesis of the DS phenotype, and show a consistent overexpression of theSOD1gene on 21q. [ABSTRACT FROM AUTHOR]

In vitro hemopoiesis and hemopoietic cytokines production were evaluated in 9 centenarians (median age 100.5 years, age range: 100-104 years), 10 old people (median age: 71 years, age range: 66-73 years), and 10 young people (median age: 35 years, age range: 30-45 years), all carefully selected for their healthy status. The main findings were the following: (i) a trend towards a decreased absolute number of CD34+ progenitor cells in the peripheral blood of old people and centenarians, in comparison to young subjects; (ii) a well-preserved capability of CD34+ cells from old people and centenarians to respond to hemopoietic cytokines, and to form erythroid (BFU-E), granulocyte-macrophagic (CFU-GM), and mixed colonies (CFU-GEMM) in a way (number, size, and morphology) indistinguishable from that of young subjects; (iii) an age-related decreased in vitro production of granulocyte-macrophagic colony-stimulating factor (GM-CSF) and a decreased production of interleukin-3 (IL-3) in centenarians by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC); (iv) a linear increase of the serum level of stem cell factor (SCF), measured in the above-mentioned subjects and in 65 additional subjects, including 4 centenarians. These data suggest that basal hematopoietic potential is well preserved in healthy centenarians, and that the hemopoietic cytokine network undergoes a complex remodeling with age. [ABSTRACT FROM AUTHOR]

Granulocyte macrophage colony-stimulating factor (GM-CSF) has emerged as an important growth factor for trophoblast and other placental cells, leading to improved placental functioning and fetal survival. Recent observations have indicated that GM-CSF is synthesized by epithelial cells in the murine pregnant and non-pregnant uterus. In this study, the production of GM-CSF by cells derived from human endometrium is assessed using a sensitive bioassay and specific neutralization of the cytokine bioactivity with a monoclonal antibody to GM-CSF. Originally, GM-CSF was assayed in the culture supernatants of explant cultures of human endometria. Concentrations of GM-CSF up to 4440 pg/ml were detected. Subsequently, enriched epithelial cell cultures were prepared from glands isolated from human endometrium. The purity of epithelial cultures was demonstrated by the expression of cytokeratin, a weak immunoreactivity for vimentin and a lack of immunoreactivity for leukocyte common antigen, CD68, a macrophage-specific protein and endothelial marker (factor VIII-related antigens). Detected concentrations of GM-CSF were as high as 18,800 pg/ml. Furthermore, pure epithelial cells of a neoplastic endometrial cell line ECC1 secreted GM-CSF, confirming the ability of endometrial epithelial cells to secrete this cytokine. The immunostaining of dated endometria from proliferative and secretory phases showed primarily that epithelial cells, and to a lesser extent stromal cells, exhibited immunoreactivity for GM-CSF. A Western blot analysis, performed to validate the immunohistochemical data, confirmed the presence of an immunoreactive gene product for GM-CSF in human endometrium throughout the menstrual cycle. These findings indicate that human endometrium synthesizes GM-CSF and that epithelial cells are a major contributor to its production. [ABSTRACT FROM AUTHOR]

Background: EGFR is frequently overexpressed in colon cancer. We characterized HT-29 and Caco-2, human colon cancer cell lines, untreated and treated with cetuximab or gefitinib alone and in combination with EGF.Methods: Cell growth was determined using a variation on the MTT assay. Cell-cycle analysis was conducted by flow cytometry. Immunohistochemistry was performed to evaluate EGFR expression and scanning electron microscopy (SEM) evidenced the ultrastructural morphology. Gene expression profiling was performed using hybridization of the microarray Ocimum Pan Human 40 K array A.Results: Caco-2 and HT-29 were respectively 66.25 and 59.24 % in G0/G1. They maintained this level of cell cycle distribution after treatment, suggesting a predominantly differentiated state. Treatment of Caco-2 with EGF or the two EGFR inhibitors produced a significant reduction in their viability. SEM clearly showed morphological cellular transformations in the direction of cellular death in both cell lines treated with EGFR inhibitors. HT-29 and Caco-2 displayed an important reduction of the microvilli (which also lose their erect position in Caco-2), possibly invalidating microvilli absorption function. HT-29 treated with cetuximab lost their boundary contacts and showed filipodi; when treated with gefitinib, they showed some vesicles: generally membrane reshaping is evident. Both cell lines showed a similar behavior in terms of on/off switched genes upon treatment with cetuximab. The gefitinib global gene expression pattern was different for the 2 cell lines; gefitinib treatment induced more changes, but directly correlated with EGF treatment. In cetuximab or gefitinib plus EGF treatments there was possible summation of the morphological effects: cells seemed more weakly affected by the transformation towards apoptosis. The genes appeared to be less stimulated than for single drug cases.Conclusion: This is the first study to have systematically investigated the effect of cetuximab or gefitinib, alone and in combination with EGF, on human colon cancer cell lines. The EGFR inhibitors have a weaker effect in the presence of EGF that binds EGFR. Cetuximab treatment showed an expression pattern that inversely correlates with EGF treatment. We found interesting cyto-morphological features closely relating to gene expression profile. Both drugs have an effect on differentiation towards cellular death. [ABSTRACT FROM AUTHOR]