H. Daino et al., EXTRACELLULAR UBIQUITIN REGULATES THE GROWTH OF HUMAN HEMATOPOIETIC-CELLS, Biochemical and biophysical research communications, 223(2), 1996, pp. 226-228
We investigated the effects of extracellular ubiquitin on the colony f
ormation of human hematopoietic progenitor cells (CFU-GM, CFU-E and BF
U-E) and a granulocyte-colony stimulating factor (G-CSF)-dependent hum
an myeloblastic leukemic cell line, OCI/AML/1a. Ubiquitin exhibited in
hibitory effects on CFU-GM, CFU-E, BFU-E and OCI/AML/1a colony formati
on. Extracellular ubiquitin also inhibited the growth of KT3 (T lympho
blast), K562 (erythroleukemia) and Daudi (Burkitt's lymphoma) cells, s
timulated the growth of HL60 (promyelocytic leukemia) and Jurkat (T-AL
L) cells and showed no effect on the growth of U937 cells (monocytic l
eukemia). These results indicate that another, previously unrecognized
function of extracellular ubiquitin is to regulate hematopoiesis. (C)
1996 Academic Press, Inc.