Inhibition of murine monocyte proliferation by a colony-stimulating factor-1 antisense oligodeoxynucleotide. Evidence for autocrine regulation.
Using a combination of v-myc and v-ras oncogenes, we have established a growth factor-independent monocyte cell line from murine fetal liver (FL-ras/myc). Biologic and molecular characterization demonstrated that the gene for the macrophage growth factor CSF-1 and the c-fms proto-oncogene (CSF-1 receptor) are expressed in this cell line, thus suggesting autocrine regulation as a possible mechanism for the unregulated growth of these cells. To study this possibility, we used 1) mAb, to neutralize the CSF-1 protein produced by the cell line, and 2) antisense oligomers, to inhibit CSF-1 gene products by specific base-pairing of complementary nucleic acids. We report here that both approaches inhibited in vitro cell growth by 60 to 70%, whereas the combination of oligomer and mAb inhibited proliferation by 95%. However, control antisense oligomers (50% bp mismatch with CSF-1 mRNA) did not inhibit FL-ras/myc cell growth. Furthermore, the inhibitory effects of mAb and oligomers were reversible when they were removed from the media. Detection of cell-associated CSF-1 protein by immunofluorescence showed that cells treated with the antisense oligomer expressed significantly less CSF-1 protein. These results indicate that the FL-ras/myc cell line requires CSF-1 for autonomous growth and that oligomers can efficiently block production of autocrine growth factors.
Birchenall-Roberts
M C
MC
Division of Cancer Treatment, National Cancer Institute, Frederick Cancer Research Facility, MD 21701.
Ferrer
C
C
Ferris
D
D
Falk
L A
LA
Kasper
J
J
White
G
G
Ruscetti
F W
FW
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002455:Cell Division; D002460:Cell Line; D006706:Homeostasis; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D051379:Mice; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000235:genetics
D000911:Antibodies, Monoclonal; D016376:Oligonucleotides, Antisense; D016173:Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor