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.
Walter and Eliza Hall Institute of Medical Research, Post Office Royal Melbourne Hospital, Parkville, Victoria, Australia. jrasko@fred.fhcrc.org
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Rasko
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Begley
D000818:Animals; D004194:Disease / Q000209:etiology; D006801:Humans; D013926:Thrombopoietin / Q000235:genetics / Q000378:metabolism / Q000502:physiology / Q000627:therapeutic use
D013926:Thrombopoietin