Cyclic-AMP inhibits cell growth and negatively interacts with platelet membrane glycoprotein expression on the Dami human megakaryoblastic cell line

Authors

  • Daniel Vittet,

    Corresponding author
    1. Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 300, Faculté de Pharmacie, 34060 Montpellier cédex 01, France
    2. Unité 291, Service Commun de Cytométrie en Flux, 34090 Montpellier, France
    Current affiliation:
    1. INSERM U.217, CENG, DBMS/Hématologie, 17 rue des martyrs, 38054 Grenoble cedex 9, France
    • INSERM U.217, CENG, DBMS/Hématologie, 17 rue des martyrs, 38054 Grenoble cedex 9, France
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  • Christophe Duperray,

    1. Unité 291, Service Commun de Cytométrie en Flux, 34090 Montpellier, France
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  • Claude Chevillard

    1. Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 300, Faculté de Pharmacie, 34060 Montpellier cédex 01, France
    2. Unité 291, Service Commun de Cytométrie en Flux, 34090 Montpellier, France
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Abstract

Intracellular signaling processes by which hematopoietic growth factors regulate megakaryocytopoiesis remain uncompletely understood. Cyclic AMP (cAMP) has been shown to be implicated in the regulation of growth and differentiation in various normal and malignant cell types. Since a few studies have suggested the possible involvement of the cAMP pathway as one of the intracellular mechanisms whereby megakaryocytopoiesis may be regulated, we investigated the functional effects of cAMP on the human megakaryoblastic Dami cell line. We observed that exposure of Dami cells to cAMP analogs or to agents elevating intracellular cAMP levels yielded dose-dependent cell growth inhibition. Cell cycle progression analysis of cells predominantly synchronized at the G1/S boundary by prior treatment with hydroxyurea revealed that cAMP transiently accumulated cells in the G2/M phase, then slowing down cell cycle. On the other hand, immunofluorescence and Northern blot analysis of megakaryocytic differentiation marker expression showed that probes we have used significantly inhibited GPlb expression. Moreover, although these agents used alone did not affect GPllb/llla expression, they markedly reversed phorbol ester-induced GPllb/llla expression increase. These inhibitory cAMP actions on glycoprotein expression were not the result of cell cycle perturbation since we observed that GPlb and GPllb/llla expression were not cell cycle dependent. All these data may then be consistent with a potential negative regulatory role of the cAMP intracellular signaling pathway during megakaryocytopoiesis. © 1995 Wiley-Liss, Inc.

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