This study evaluates the effect of recombinant human stem cell factor (SCF) on the in vitro response of human bone marrow progenitor cells to irradiation. Light density nonadherent mononuclear cells were isolated from human bone marrow and resuspended in either semisolid culture or liquid culture with or without 100 ng/ml SCF. After 24 h in culture, cells were irradiated and assessed for surviv...

Polypeptide growth factors are involved in the regulation ofcell proliferation (1). These factors bind to specific receptors on the cell surface, stimulating the formation of intracellular second messengers that elicit a variety of responses . Transient increases in intracellular pH (2) and calcium concentration (3) can occur soon after growth factor addition . Other early responses induced by ...

In murine leukemia virus-induced myeloid leukemias, insertional mutagenesis of the c-myb locus has been shown to occur frequently. Proto-oncogene activation is achieved in most leukemias by integration of murine leukemia virus upstream of exons 3 or 4 or by integration into exon 9 with consequent truncation of the protein. The present study investigates the effect of ectopic expression of full-...