Over-expression of c-src or v-src in bone marrow stromal cells stimulates hematopoiesis in long-term bone marrow culture.
The S17 murine stromal cell line was infected with retroviral vectors encoding the v-src and c-src oncogenes and cells expressing high levels of either pp60v-src or pp60c-src were isolated. Long-term bone marrow cultures (LTBMCs) established with these different stromal cell lines showed that progenitor cells proliferated to a greater extent in cultures with stromal cells that over-expressed either c-src or v-src. An increase in the number of granulocytes, monocytes, and colony-forming units granulocyte-macrophage (CFU-GM) in the nonadherent cell population of LTBMCs prepared with S17/v-src or S17/c-src stromal cells was observed. Conditioned media from the S17/v-src and S17/src stromal cell lines stimulated the formation of CFU-GM in the absence of additional hematopoietic cell growth factors. Conditioned media from S17/v-src and S17/c-src stimulated proliferation of the granulocyte-macrophage colony-stimulating factor (GM-CSF)-responsive cell line FDCP-1 and this stimulation was inhibited by neutralizing antisera to murine GM-CSF. An increase in the concentration of GM-CSF was confirmed by enzyme-linked immunosorbent assay. No secretion of interleukin-1 alpha (IL-1 alpha) or tumor necrosis factor-alpha was detected by any of the stromal cell lines. There was no increase in the secretion of either CSF-1 or IL-6 by either S17/v-src or S17/c-src. The addition of 1 micrograms/mL monoclonal anti-GM-CSF antibody to LTBMCs caused a decrease in the number of nonadherent cells in cultures established with each of the different stromal cell lines. Northern blot analysis showed no difference in the level of GM-CSF RNA among the different stromal cell lines. These studies suggest that the increased proliferation of hematopoietic progenitor cells in LTBMCs with S17/v-src or S17/c-src cells may result from a posttranscriptional event that elevates production of GM-CSF by the S17/c-src and S17/v-src stromal cells.
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001853:Bone Marrow / Q000502:physiology*; D002460:Cell Line; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000032:analysis / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D016391:Genes, src; D005822:Genetic Vectors; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction; D011494:Protein Kinases / Q000032:analysis; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012190:Retroviridae / Q000235:genetics; D014162:Transfection
D016207:Cytokines; D009838:Oligodeoxyribonucleotides; D012313:RNA; D011494:Protein Kinases