A new peptide analog (RM06) modulates the growth of hematopoietic cells

The bombesin carboxy terminal dipeptide Leu-Met, was bound to hypoxanthine with a pentoxy-carbonyl chain. The new purine derivative, N-omega-[5(1,6-dihydro-6-oxo-9-purinyl)] pentoxy-carbonyl-L-leucil-L- methionine-COOH (RM06), significantly augmented human bone-marrow derived granulocyte-monocyte colony forming units (CFU-GM) when added to the cell-culture medium. Moreover, in vivo hemopoietic reconstitution was more rapid in lethally irradiated bone-marrow reconstituted BDF-1 mice, treated with RM06. Both in vitro and in vivo effects were similar to those exerted by recombinant granulocyte-monocyte colony stimulating factor (GM-CSF). It is concluded that the new modified dipeptide modulates the growth of both human and murine hematopoietic cells in vitro and in vivo.