Autocrine role of insulin-like growth factor (IGF)-I in a human thyroid cancer cell line.
An established cell line (TC-cell, clone 78) derived from human thyroid papillary cancer cells was investigated for production of peptide growth factors. The cells had specific binding sites for insulin-like growth factor-I (IGF-I) and responded to this growth factor with increased proliferation. Culture medium conditioned by TC cells was found to contain insulin-like growth factor (IGF)-I and IGF-binding protein(s). Furthermore, reverse transcription-polymerase chain reaction revealed expression of IGF-I mRNA. When monoclonal antibody to IGF-I receptors (alpha IR3) was added, the growth of TC cells cultured in serum-free medium was significantly reduced. The growth rate of the cells was restored when the antibody was removed from the medium. These results strongly suggest that TC cells produce IGF-I, which is involved in the regulation of their own growth.
Onoda
N
N
Department of Medicine, Tokyo Women's Medical College, Japan.
Ohmura
E
E
Tsushima
T
T
Ohba
Y
Y
Emoto
N
N
Isozaki
O
O
Sato
Y
Y
Shizume
K
K
Demura
H
H
D002291:Carcinoma, Papillary / Q000378:metabolism; D002352:Carrier Proteins / Q000096:biosynthesis; D002452:Cell Count / Q000187:drug effects; D004273:DNA, Neoplasm / Q000096:biosynthesis; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000494:pharmacology / Q000502:physiology; D016133:Polymerase Chain Reaction; D013964:Thyroid Neoplasms / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000378:metabolism
D002352:Carrier Proteins; D004273:DNA, Neoplasm; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I