Establishment and characterization of a novel human immature megakaryoblastic leukemia cell line, M-MOK, dependent on fibroblasts for its viability

Exp Hematol. 1995 Nov;23(12):1301-9.


A novel fibroblast-dependent human immature megakaryoblastic leukemia cell line (M-MOK) was established from the bone marrow of a girl with acute megakaryoblastic leukemia, and its growth was determined to be completely dependent on the presence of human embryonic lung-derived fibroblasts, HEL-O. Adhesive interaction between M-MOK and HEL-O was crucial for viability; once HEL-O was removed from the culture, mortality was total within a few days. On HEL-O cells, M-MOK could be passaged for more than 2 years. With regard to surface marker profile, the established cells were positive for CD11a, CD13, CD18, CD33, CD34, CD41b, CD42b, CD54, and c-kit antigens, but negative for HLA class II antigen and glycophorin. Histochemically, the cells were negative for myeloperoxidase, nonspecific esterase, and naphthol ASD chloroacetate esterase staining. Electron-microscope examination revealed the cells to be negative for platelet peroxidase (PPO). After induction of differentiation by a phorbol ester, however, the cells were demonstrated to be positive for PPO with a morphological change to megakaryocytes. From these results, M-MOK was considered to represent an immature cell line of megakaryocyte lineage. Studies of the mechanisms sustaining the HEL-O-dependent continuous in vitro growth of M-MOK cells revealed the following results: (1) M-MOK could grow even when separated from HEL-O by a nucleopore membrane; (2) conditioned medium (CM) from HEL-O supported the growth of M-MOK for more than 1 month without feeder cells; (3) the growth of M-MOK on HEL-O or CM supplement was nearly entirely inhibited by anti-GM-CSF (1 microgram/mL); (4) GM-CSF mRNA was detected in HEL-O cells; and (5) HEL-O was found to secrete GM-CSF into the culture medium. Taken together, the growth of M-MOK might therefore be driven by a soluble factor, that is, GM-CSF secreted from HEL-O cells. The presence of HEL-O, however, inhibited anti-GM-CSF-induced M-MOK death. Co-culture of M-MOK and HEL-O cells thus offers a useful experimental model for analysis of interactions between hematopoietic stem cells and stromal cells.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Blood Platelets / enzymology
  • Bone Marrow / pathology
  • Cell Adhesion
  • Cell Survival*
  • Culture Media, Conditioned
  • Embryo, Mammalian
  • Female
  • Fibroblasts / physiology*
  • Granulocyte-Macrophage Colony-Stimulating Factor / antagonists & inhibitors
  • Granulocyte-Macrophage Colony-Stimulating Factor / genetics
  • Granulocyte-Macrophage Colony-Stimulating Factor / physiology
  • Histocytochemistry
  • Humans
  • Immunophenotyping
  • Infant
  • Leukemia, Megakaryoblastic, Acute / pathology*
  • Lung
  • Molecular Sequence Data
  • Peroxidase / analysis
  • RNA, Messenger / analysis
  • Tumor Cells, Cultured


  • Culture Media, Conditioned
  • RNA, Messenger
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Peroxidase