Effects of ubenimex on erythroid progenitors (CFU-E and BFU-E) in human bone marrow.
Ubenimex (UBX, bestatin) is known to be an immunomodulator and host-mediated antineoplastic agent. Effects of UBX on human bone marrow erythroid progenitors (erythroid colony-forming units, CFU-E; and erythroid burst-forming units, BFU-E) were investigated in vitro. UBX enhanced CFU-E and BFU-E growth in the nonseparated bone marrow mononuclear cell fraction at concentrations from 0.005 to 5 micrograms/ml. The enhancements of CFU-E and BFU-E were independent of the concentration of erythropoietin added to culture system. In the T-cell-depleted bone marrow fraction, UBX also increased CFU-E and BFU-E growth, but it failed to stimulate these cells in the nonphagocytic and nonadherent bone marrow fraction. These findings indicate that UBX may stimulate erythroid progenitors mediated through monocytes and macrophages.
Aoki
I
I
Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan.
Higashi
K
K
Nishijima
K
K
Homori
M
M
Chikazawa
H
H
Ishikawa
K
K
D001854:Bone Marrow Cells; D003470:Culture Media / Q000494:pharmacology; D015672:Erythroid Precursor Cells / Q000187:drug effects*; D006801:Humans; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology
D003470:Culture Media; D007930:Leucine; C012211:ubenimex