Cloning and expression of unique murine macrophage colony-stimulating
factor transcripts
K Pogue-Geile, MA Sakakeeny, JL Panza, SL Sell and JS Greenberger
Department of Radiation Oncology, University of Pittsburgh Medical Center,
PA, USA.
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.
Volume 85,
Issue 12,
pp. 3478-3486,
06/15/1995
Copyright © 1995 by The American Society of Hematology