A novel cytokine exhibiting megakaryocyte potentiating activity from a human pancreatic tumor cell line HPC-Y5.
Sixty-four kinds of cell lines were examined for their ability to produce megakaryocyte potentiating activity by means of conditioned media obtained from a protein-free culture system. Six human tumor cell lines were shown to produce this activity, and the cell line HPC-Y5, established from human pancreatic cancer, was shown to have the highest level of activity. The megakaryocyte potentiating factor (MPF) was purified from an HPC-Y5 conditioned medium by a combination of ion-exchange chromatography, gel filtration and reverse-phase HPLC. The purified MPF showed a megakaryocyte potentiating activity almost equal to human interleukin-6 in the presence of murine interleukin-3 in a colony formation assay with mouse bone marrow cells. The apparent molecular weight of MPF is 32,000 when determined by SDS-polyacrylamide gel electrophoresis. Glycopeptidase F digestion, and amino sugar analysis of the factor demonstrated that MPF is a glycoprotein carrying at least one N-linked sugar chain. The N-terminal amino acid sequence of MPF was determined to be Leu-Ala-Gly-Glu-Thr-Gly-Gln-Glu-Ala-Ala-Pro-Leu- Asp-Gly-Val-Leu-Ala-Asn. The same or homologous amino acid sequence has not been found in known proteins, demonstrating that MPF is a novel cytokine that has megakaryocyte potentiating activity in the murine assay system.
Yamaguchi
N
N
Department of Cell Biology, Research Institute for Neurological Disease and Geriatrics, Kyoto, Japan.
Hattori
K
K
Oh-eda
M
M
Kojima
T
T
Imai
N
N
Ochi
N
N
D000595:Amino Acid Sequence; D000818:Animals; D001854:Bone Marrow Cells; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008533:Megakaryocytes / Q000166:cytology*; D000090204:Mesothelin; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010190:Pancreatic Neoplasms / Q000737:chemistry*; D014407:Tumor Cells, Cultured
D016207:Cytokines; C000715527:MSLN protein, human; C000715528:Msln protein, mouse; D000090204:Mesothelin