Assessment of human pluripotent hemopoietic progenitors and leukemic blast-forming cells in culture.

Myeloproliferative diseases such as acute myeloid leukemia (AML), chronic myeloid leukemia (CML) , and polycythemia vera (PV) are now generally considered to be clonal disorders originating in abnormal stern cells (Wiggans et al. 1978; Fialkow et al. 1967, 1977; Adamson et al. 1976; McCuIloch and Till 1977; McCuIloch 1979). A growth advantage typically displayed by the abnormal clone appears to be responsible for the increased production of phenotypically normal or abnormal cells. The underlying mechanisms for the altered growth rate are presently not understood. Further investigations of this phenomenon are dependent upon the development of assays that facilitate assessment of normal human pluripotent stern cells and permit identification of members of the abnormal clone present in these disorders. We have recently described such an assay for human pluripotent progenitors (Messner and Fauser 1978; Fauser and Messner 1978, 1979a). They can be readily identified in culture by their ability to form mixed hemopoietic colonies that contain components of all myeloid lineages. Blast-forming cells in patients with acute myeloid leukemia are also accessible for studies in culture (Dicke et al. 1976; Park et al. 1977; Buick et al. 1977). They give rise to colonies of cells with leukemic phenotype. In addition, blast colonies from patients with cytogenetic markers displayed the same chromosomal abnormality as that