Rapid decline of clonogenic hemopoietic progenitors in semisolid cultures of bone marrow samples derived from patients with chronic myeloid leukemia

Bone marrow samples, from newly diagnosed patients with chronic myeloid leukemia (CML) and normal individuals, were grown in methylcellulose and serially recultured under identical conditions. Specimens derived from normal individuals gave rise to multilineage and megakaryocyte colonies for one to two sequential cultures. Erythroid bursts and granulocyte-macrophage colonies were observed for three to five sequential cultures. Cultures initiated from samples of patients with CML showed a rapid decline of all types of colonies. Colonies were rarely seen for more than two sequential cultures. When pooled colonies and background cells were recloned separately, secondary colonies were mainly seen in cultures of background cells. This observation is consistent with the view that secondary colonies are more likely to arise from dormant clonogenic progenitors, rather than through cells that have formed primary colonies through a self-renewal process.