Historically, the field of hematopoietic growth factor research began
with the work of Carnot and Deflandre-in 1906 they suggested that the
rate of erythropoiesis is regulated by a humoral factor found in the
blood, namely, erythropoietin. From this comparatively early start,
accelerating progress has been made in erythropoietin research, which
demon- strates the general trends in this field of study. Erythropoietin
was purified to homogeneity by 1977 (from enormous quantities of urine
from aplastic anemia patients). Subsequently, the gene for
erythropoietin has been cloned (1985), and massive quantities of this
growth factor have been produced for clinical trials (late 1980s
onward). Erythropoietin has become established as a pharmaceutical
product of great value in the treatment of a number of diseases, most
notably chronic renal failure. Once the ligand had been cloned, interest
turned to the erythropoietin receptor, which was cloned in 1989. Since
then, structure/ function studies have been performed on receptor
mutants, cellular signaling events down- stream from the occupied
receptor have been identified, and the specific producer cell types and
molecular stimuli for erythropoietin production have been thoroughly
investigated, as has the regulation of erythropoietin gene
transcription. This schedule of events since the 1970s typifies that
seen for a number of hematopoietic growth factors. Along the way, the
hematopoietic growth factors have been recognized as members of the
cytokine family of signaling molecules that are important in a number of
different physiological and patholog- ical situations (see below).
