ABSTRACT
This study concerns the role of endogenous polyamines in the proliferation of normal hematopoietic progenitor cells: high-proliferative potential colony-forming cells (HPP-CFC), and low-proliferative potential colony-forming cells (LPP-CFC) in CFW/ep mouse bone marrow cells in the agar culture system. DL-a-difluoromethylornithine (DFMO) was used as a selective and irreversible inhibitor of ornithine decarboxylase which is the first limiting step in polyamine biosynthesis. The polyamines have been implicated in cell proliferation and differentiation. The results showed that DFMO significantly inhibited the formation of LPP-CFC colonies and completely inhibited the growth of the HPP-CFC colonies. Addition of exogenous putrescine at the concentration of 10(-7) M reverses the suppressive action of DFMO in both progenitor cells. At this concentration putrescine alone had no affect on the number or the size of the colonies. It was then concluded that endogenous polyamines appear to be essential for HPP-CFC proliferation and an important requirement for LPP-CFC proliferation.
Subject(s)
Hematopoietic Stem Cells/cytology , Polyamines/pharmacology , Animals , Antineoplastic Agents/pharmacology , Bone Marrow Cells , Cell Division/drug effects , Cells, Cultured/cytology , Cells, Cultured/drug effects , Eflornithine/pharmacology , Female , Hematopoietic Stem Cells/drug effects , Mice , Mice, Inbred Strains , Putrescine/pharmacologyABSTRACT
In this paper we describe a crude pregnant mouse uterus and embryo extract (PMUE) prepared from CFW/ep mice which was able to stimulate the proliferation of high-proliferative-potential colony-forming cells (HPP-CFC) of bone marrow of normal mice, in vitro, in semisolid agar culture system. The development of that primitive murine progenitor cells requires the presence of a macrophage-stimulating factor (CSF-1) plus a synergistic factor (SF). The biological activity of both factors was present in our extracts. The higher SF activity was found in uterine plus placental tissues extracts. The SF was precipitated over 45 per cent ammonium sulfate saturation, and behaved as a nondialyzable substance, remained unaffected by trypsin digestion, and was heat-stable (70 degrees C for 15 min).
Subject(s)
Bone Marrow Cells , Colony-Stimulating Factors/analysis , Embryo, Mammalian/analysis , Uterus/analysis , Animals , Colony-Stimulating Factors/isolation & purification , Colony-Stimulating Factors/pharmacology , Female , Growth Substances/isolation & purification , Growth Substances/pharmacology , Hematopoietic Cell Growth Factors , In Vitro Techniques , Macrophage Colony-Stimulating Factor , Mice , Mice, Inbred Strains , Pregnancy , Trypsin/metabolismABSTRACT
In this paper we describe a crude pregnant mouse uterus and embryo extract (PMUE) prepared from CFW/ep mice which was able to stimulate the proliferation of high-proliferative-potential colony-forming cells (HPP-CFC) of bone marrow of normal mice, in vitro, in semisolid agar culture system. The development of that primitive murine progenitor cells requires the presence of a macrophage-stimulating factor (CSF-1) plus a synergistic factor (SF). The biological activity of both factors was present in our extracts. The higher SF activity was found in uterine plus placental tissues extracts. The SF was precipitated over 45 per cent ammonium sulfate saturation, and behaved as a nondialyzable substance, remained unaffected by trypsin digestion, and was heat-stable (70 degrees C for 15 min).