title: Effects of gamma-irradiation on the M-CSF-promoter linked to a chloramphenicol aminoacyl transferase reporter gene expressed in a clonal murine bone marrow stromal cell line.
abstract: The effects of cytokines produced by bone marrow stromal cells on closely associated hematopoietic cells constitute a major component of the physiology of the hematopoietic microenvironment. A major cytokine produced by marrow stromal cells is macrophage colony-stimulating factor (M-CSF). To determine the effect of gamma-irradiation on the M-CSF promoter in bone marrow stromal cells, we selected a clonal cell line from the C3H/HeJ mouse marrow stromal cell line D2XRII and stably transfected a reporter construct containing the murine M-CSF-promoter linked to a chloramphenicol aminoacyl transferase (CAT) gene. CAT activity was measured at serial time points after gamma-irradiation in vitro to doses between 500 and 10,000 cGy at a dose rate of 116 cGy/min. D2XRII marrow stromal cells treated with phorbol myristate acetate (40 micrograms/ml, four h), demonstrated a significant two-fold increase in CAT activity. In contrast, CAT activity measured immediately, 24 h, 72 h or 1 week after gamma-irradiation, showed no significant increase or decrease in CAT activity. An increase in CAT activity was detected 48 h after irradiation with cells that received 5,000 cGy. Thus, single fraction gamma-irradiation of plateau phase bone marrow stromal cells did not decrease M-CSF-promoter activity. These results are consistent with prior experimental data demonstrating stable levels of release of M-CSF protein following gamma-irradiation of bone marrow stromal cells and imply that the stability of transcription of the gene for this important cytokine is protected from irradiation.
authors.affiliation: Department of Radiation Oncology, University of Massachusetts Medical Center, Worcester.
authors.forename: M A
authors.initials: MA
authors.lastname: Sakakeeny
authors.forename: M
authors.initials: M
authors.lastname: Harrington
authors.forename: J
authors.initials: J
authors.lastname: Leif
authors.forename: W
authors.initials: W
authors.lastname: Merrill
authors.forename: D
authors.initials: D
authors.lastname: Pratt
authors.forename: E
authors.initials: E
authors.lastname: Romanik
authors.forename: M
authors.initials: M
authors.lastname: McKenna
authors.forename: T J
authors.initials: TJ
authors.lastname: FitzGerald
authors.forename: J S
authors.initials: JS
authors.lastname: Greenberger
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000528:radiation effects; D001854:Bone Marrow Cells; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D005720:Gamma Rays; D015870:Gene Expression; D017930:Genes, Reporter / Q000502:physiology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism / Q000528:radiation effects*; D066298:In Vitro Techniques; D051379:Mice
chemical_list: D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D015500:Chloramphenicol O-Acetyltransferase