Cloning and expression of unique murine macrophage colony-stimulating factor transcripts.
Cocultivation of cells from the gamma-irradiated D2XRII murine bone marrow stromal cell line with an interleukin-3/granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent hematopoietic progenitor cell line FDC-P1JL26 stimulates the emergence of factor-independent hematopoietic cell sublines. Several lines of evidence suggested that M-CSF or a protein antigenically related to M-CSF, termed leukemogenic stromal factor (LSF), that was expressed by D2XRII cells may have played a role in the emergence of the factor-independent sublines. In an effort to isolate a factor antigenically related to M-CSF, molecular clones were isolated from a D2XRII cDNA library that hybridized to a mouse M-CSF genetic probe. Two of these molecular clones, designated 60.8.2 and 6452, contained an 885-bp deletion in the M-CSF coding region. Such a cDNA clone has not been previously described in the mouse, but a cDNA clone homologous to it has been isolated from a human pancreatic tumor cell line, MIA-PaCa-2. Three transcripts (4.8, 3.4, and 1.8 kb) were detected that hybridized to an oligonucleotide probe that was specific to RNA transcripts containing the 60.8.2 deletion. The level of the 1.8-kb transcript was not detectably induced by ionizing irradiation; however, the levels of the 4.8-kb and 3.4-kb transcripts and two other M-CSF transcripts of sizes to 4.4 kb and 2.3 kb showed a 1.4- to 2.2-fold increase after gamma irradiation. Reverse transcription-polymerase chain reaction showed that the deletion-specific transcript(s) was detected in multiple mouse bone marrow stromal cell lines and in normal mouse tissues. The present studies establish the existence of an increased spectrum of murine M-CSF transcripts in bone marrow stromal cells and other tissues. This complexity of transcripts along with their increased accumulation after irradiation provides additional evidence for a role of proteins encoded by M-CSF transcripts in the response of bone marrow stromal cells to ionizing irradiation.
Pogue-Geile
K
K
Department of Radiation Oncology, University of Pittsburgh Medical Center, PA, USA.
Sakakeeny
M A
MA
Panza
J L
JL
Sell
S L
SL
Greenberger
J S
JS
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001853:Bone Marrow / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D015723:Gene Library; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D051379:Mice; D008969:Molecular Sequence Data; D016415:Sequence Alignment
D018076:DNA, Complementary; D016173:Macrophage Colony-Stimulating Factor