CHARACTERIZATION OF A NEW MEGAKARYOCYTIC CELL-LINE - THE DAMI CELL

  • 1 December 1988
    • journal article
    • research article
    • Vol. 72  (6) , 1968-1977
Abstract
A new human megakaryocytic cell line (Dami) has been established from the blood of a patient with megakaryoblastic leukemia. The Dami cells grow primarily in suspension with a doubling time of 24 to 30 hours. By light and electron microscopy, the Dami cells range in size from 12 to 120 .mu.m in diameter and have lobulated nuclei characteristic of megakaryocytes. At least 89% of the cells react with monoclonal antibodies against platelet glycoproteins (GP) lb and llb/llla, and glycophorin. The cells do not react with antibodies against lymphoid, monocyte, granulocyte, or macrophage antigens. Thirteen percent of the cells become polyploid, spontaneously achieving >4N DNA ploidy levels. In response to phorbol myristate acetate (PMA), the proportion of proportion of cells with ploidy levels greater than 4N increased threefold and could be separated into discrete ploidy groups. PMA also increased the expression of GPlb, the CPiib/GPiia complex, and von Willebrand factor. Cytogenetic analysis revealed a human male hyperdiploid karyotype with a model chromosome number of 54 to 64 and several consistent clonal chromosomal abnormalities. These included a paritial deletion of chromosome 5 and a translocation involving chromosome 3. In contrast to other megakaryocytic cell lines in which only a small portion of the cells express the megakaryocytic phenotype, nearly all of the Dami cells express platelet glycorproteins. Thus, the Dami cells provides a superior model in which to study human megakaryocyte biochemistry and differentiation.