The thrombopoietic factor, Mpl-ligand.
Mpl-ligand (thrombopoietin [TPO] or Megakaryocyte growth and development factor [MGDF]), was identified following the discovery of the oncogene, mpl. This oncogene encodes a truncated receptor belonging to the hemopoietin-receptor superfamily. Mpl-ligand consists of two domains; a carbohydrate-rich domain and an amino-terminal domain which displays homology to erythropoietin and is fully active. Mpl-ligand mRNA is predominantly expressed in liver and kidney and plasma levels are regulated by receptors expressed on megakaryocytes and platelets. Mpl-ligand is the most active single agent capable of promoting proliferation and maturation of cells within the megakaryocyte lineage. In addition to this 'lineage-specific' action, Mpl-ligand also acts on progenitor/stem cells of multiple hemopoietic lineages. Pre-clinical and early clinical studies have demonstrated the ability of Mpl-ligand to increase platelet counts and hasten platelet recovery after chemotherapy. This offers considerable promise for its use in clinical oncology.
Rasko
J E
JE
Walter and Eliza Hall Institute of Medical Research, Post Office Royal Melbourne Hospital, Parkville, Victoria, Australia. jrasko@fred.fhcrc.org
Begley
C G
CG
D000818:Animals; D004194:Disease / Q000209:etiology; D006801:Humans; D013926:Thrombopoietin / Q000235:genetics / Q000378:metabolism / Q000502:physiology / Q000627:therapeutic use
D013926:Thrombopoietin