Insulin-like growth factor II effects mediated through insulin-like growth factor II receptors.
Insulin-like growth factor II (IGF-II) resembles the homologous peptide insulin-like growth factor I (IGF-I) in that it stimulates cellular growth in vitro. This effect is generally believed to be mediated through IGF type 1 receptors; the role of the IGF type 2 receptor remains, as yet, unknown. IGF-II has been shown to stimulate clonal expansion in cells from the human erythroleukaemia cell line K562, which displays binding of IGF-II and insulin but not IGF-I. This IGF-II effect was dose-dependent and correlated to the amount of specific binding; IGF-I did not stimulate growth. A similar effect on clonal growth was observed in the human T-cell line Jurkat. Furthermore, IGF-II was found to stimulate the cytotoxic activity of natural killer cells (as does interleukin 2). This effect was not inhibited by addition of IGF binding protein 1. Thus, it can be concluded that IGF-II, besides demonstrating standard IGF properties, exhibits unique biological effects in certain cells.
Tally
M
M
Department of Endocrinology, Karolinska Institute, Stockholm, Sweden.
Hall
K
K
D002460:Cell Line; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000378:metabolism / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects; D008970:Molecular Weight; D011972:Receptor, Insulin / Q000187:drug effects*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism
D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D011972:Receptor, Insulin