Reddy, G. Prem VeerQuesenberry, Peter J.2022-08-232022-08-231996-04-152008-04-14Blood. 1996 Apr 15;87(8):3195-202.0006-4971 (Print)8605334https://hdl.handle.net/20.500.14038/40109Stem cell factor (SCF) is known to act synergistically with other hematopoietic factors in increasing the colony formation of hematopoietic progenitor cells. We have shown that interleukin-3 (IL-3)-dependent proliferation of NFS-60 cells is associated with the induction of a specific calmodulin-binding protein of about 68 kD (CaM-BP68). To evaluate the relationship between proliferative stimulation and the induction of CaM-BP68 by cytokines, we examined whether the increased proliferative potential of NFS-60 cells in response to SCF is reflected in an increased induction of the CaM-BP68. We observed that SCF alone has a limited effect on proliferative stimulation and on the induction of CaM-BP68 in factor-deprived NFS-60 cells. However, when combined with IL-3, granulocyte colony-stimulating factor (G-CSF), or IL-6, it caused a significant increase in cytokine-dependent proliferative stimulation, as well as in the induction of CaM-BP68. Furthermore, an increase in IL-3-dependent induction of CaM-BP68 in the presence of SCF coincided with a corresponding increase in thymidine kinase activity, whose expression is linked to G1/S transition of the cells. At low concentrations SCF caused a synergistic increase in IL-3-dependent induction of both CaM-BP68 and thymidine kinase activity. In contrast to the changes in CaM-BP68 and thymidine kinase activity, no significant changes in DNA polymerase alpha were observed in factor-deprived NFS-60 cells in response to IL-3 and/or SCF. These observations suggest an increased expression of CaM-BP68 and thymidine kinase are associated with the synergistic effect of SCF on factor-dependent proliferation of hematopoietic progenitor cells.en-USAnimalsCalmodulin-Binding ProteinsCell DivisionCulture Media, Serum-FreeDNA Polymerase IIDrug SynergismGene Expression Regulation, LeukemicGranulocyte-Macrophage Colony-Stimulating FactorHematopoietic Stem CellsHumansInterleukin-3Interleukin-6Leukemia, MyeloidMiceNeoplasm ProteinsNeoplastic Stem CellsStem Cell FactorThymidine KinaseTumor Cells, CulturedTumor Stem Cell AssayCancer BiologyCell and Developmental BiologyJournal Articlehttps://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=1290&context=oapubs&unstamped=1https://escholarship.umassmed.edu/oapubs/291489629oapubs/291