Growth factor-dependent inhibition of normal hematopoiesis by N-ras antisense oligodeoxynucleotides.
To determine whether N-ras expression is required at specific stages of the process of in vitro normal human hematopoiesis, adherent- and T lymphocyte-depleted mononuclear marrow cells (A-T-MNC) or highly purified progenitors (CD34+ cells) were cultured in semisolid medium, under conditions that favor the growth of specific progenitor cell types, after exposure to N-ras sense and antisense oligodeoxynucleotides. N-ras antisense, but not sense, oligodeoxynucleotide treatment of A-T-MNC and CD34+ cells resulted in a significantly decreased number of granulocyte/macrophage colony-forming units (CFU-GM) induced by interleukin 3 (IL-3) or granulocyte/macrophage colony-stimulating factor (GM-CSF) and of macrophage colonies (CFU-M) induced by M-CSF, but not of granulocytic colonies induced with G-CSF or IL-5. However, the same treatment significantly inhibited colony formation induced by each of the above factors in combination with IL-3. Megakaryocytic colony (CFU-Meg) formation from A-T-MNC or CD34+ cells in the presence of IL-6 + IL-3 + erythropoietin (Epo) was also markedly decreased after antisense oligodeoxynucleotide treatment. Erythroid colonies derived from A-T-MNC in the presence of Epo (CFU-E) were not inhibited upon antisense treatment, whereas those arising from A-T-MNC or CD34+ cells in the presence of IL-3 + Epo (BFU-E) were markedly affected. These results are consistent with the hypothesis that distinct signal transduction pathways, involving N-ras or not, are activated by different growth factors in different hematopoietic progenitor cells.
Jefferson Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
T
T
Skorski
C
C
Szczylik
M Z
MZ
Ratajczak
L
L
Malaguarnera
A M
AM
Gewirtz
B
B
Calabretta
D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34; D001483:Base Sequence; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D003864:Depression, Chemical; D015672:Erythroid Precursor Cells / Q000187:drug effects; D011905:Genes, ras / Q000235:genetics; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000187:drug effects; D006133:Growth Substances / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000235:genetics* / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D013234:Stem Cells / Q000187:drug effects; D014158:Transcription, Genetic
D015703:Antigens, CD; D018952:Antigens, CD34; D006133:Growth Substances; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D016178:Granulocyte-Macrophage Colony-Stimulating Factor