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). Studies "in vitro"

RESUMO

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.