Résumé
<p><b>AIM</b>To characterize the matrix metalloproteinases (MMP)-2 promoter and to identify androgen response elements (AREs) involved in androgen-induced MMP-2 expression.</p><p><b>METHODS</b>MMP-2 mRNA levels was determined by reverse transcription-polymerase chain reaction (RT-PCR). MMP-2 promoter-driven luciferase assays were used to determine the fragments responsible for androgen-induced activity. Chromatin-immunoprecipitation assay and electrophoretic mobility shift assays (EMSA) were used to verify the identified AREs in the MMP-2 promoter.</p><p><b>RESULTS</b>Androgen significantly induced MMP-2 expression at the mRNA level, which was blocked by the androgen antagonist bicalutamide. Deletion of a region encompassing base pairs -1591 to -1259 (relative to the start codon) of the MMP-2 promoter led to a significant loss of androgen-induced reporter activity. Additional deletion of the 5'-region up to -562 bp further reduced the androgen-induced MMP-2 promoter activity. Sequence analysis of these two regions revealed two putative ARE motifs. Introducing mutations in the putative ARE motifs by site-directed mutagenesis approach resulted in a dramatic loss of androgen-induced MMP-2 promoter activity, indicating that the putative ARE motifs are required for androgen-stimulated MMP-2 expression. Most importantly, the androgen receptor (AR) interacted with both motif-containing promoter regions in vivo in a chromatin immunoprecipitation assay after androgen treatment. Furthermore, the AR specifically bound to the wild-type but not mutated ARE motifs-containing probes in an in vitro EMSA assay.</p><p><b>CONCLUSION</b>Two ARE motifs were identified to be responsible for androgen-induced MMP-2 expression in prostate cancer cells.</p>
Sujets)
Humains , Mâle , Androgènes , Pharmacologie , Lignée cellulaire tumorale , Chromatine , Génétique , Amorces ADN , Régulation de l'expression des gènes codant pour des enzymes , Régulation de l'expression des gènes tumoraux , Gènes rapporteurs , Luciferases , Génétique , Matrix metalloproteinase 2 , Génétique , Métabolisme , Mutagenèse dirigée , Régions promotrices (génétique) , Tumeurs de la prostate , ARN messager , Génétique , RT-PCR , Délétion de séquenceRésumé
<p><b>OBJECTIVE</b>To investigate the diagnosis and differential diagnosis of granulocytic sarcoma (GS).</p><p><b>METHODS</b>The morphological and immunological characteristics of 12 cases of GS were studied. FAB classification was made by peripheral blood, bone marrow picture and bone marrow biopsy assay.</p><p><b>RESULTS</b>All of the 12 cases presented with lymphadenopathy and soft tissue mass. Histologically, the tissue infiltration of GS was composed of blastic cells with round to oval nuclei showing an even, pale chromatin pattern. Some with cleaved or notched nuclei. There were prominent nucleoli and scant cytoplasm in the cells and mitosis was easily found. Immunohistochemically, CD(45) and lysozyme were positive in all of the cases, MPO in 11 (92%), CD(68) in 10 (83%), CD(34) in 5 (42%), and TdT in 2 cases (17%). CD(15) and Mac387 were mainly expressed in mature granulocytes. Examination of bone marrow sections and marrow aspirate smears showed that out of the 11 cases tested 8 were AML-M(2), 2 AML-M(1) and 1 AML-M(0). Only 1 case was nonleukemic, ie. solitary granulocytic sarcoma.</p><p><b>CONCLUSION</b>Granulocytic sarcomas are difficult to identify in routine paraffin-embedded tissue sections and usually misdiagnosed as non-Hodgkin's lymphomas. Immunohistochemistry study with a panel of antibodies in combination with bone marrow and peripheral blood examination are helpful in identification of granulocytic sarcoma.</p>