title: Constitutive expression of the thrombopoietin gene in a human hepatoma cell line.
abstract: The gene of thrombopoietin (TPO) has been cloned and identified to be identical to gene of the c-mpl ligand. It is known that the mRNA of TPO is expressed in liver and kidney. However, it is not clarified which cells in the liver produce TPO. Using a human hepatoma cell line, HepG2, we demonstrated that the TPO mRNA was expressed by liver parenchymal cells without any stimulation. To clarify the regulation of the expression of the TPO mRNA in HepG2 cells by cytokines, we assessed the effects of 5 cytokines, transforming growth factor-beta 1, activin A, platelet-derived growth factor, hepatocyte growth factor, and interleukin-6. These cytokines have no significant regulative effect on the expression of the TPO mRNA in HepG2 cells. Our results suggest that liver parenchymal cells may be the TPO producing cells and also suggest that some hepatoma cells may produce TPO constitutively.
authors.affiliation: Department of Clinical Hematology, Osaka City University Medical School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hino
authors.forename: Y
authors.initials: Y
authors.lastname: Nishizawa
authors.forename: S
authors.initials: S
authors.lastname: Tagawa
authors.forename: T
authors.initials: T
authors.lastname: Yamane
authors.forename: H
authors.initials: H
authors.lastname: Morii
authors.forename: N
authors.initials: N
authors.lastname: Tatsumi
mesh_terms: D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D016207:Cytokines / Q000494:pharmacology; D017931:DNA Primers / Q000737:chemistry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D013926:Thrombopoietin / Q000235:genetics*; D014407:Tumor Cells, Cultured
chemical_list: D016207:Cytokines; D017931:DNA Primers; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D013926:Thrombopoietin