Insulin-like growth factor-I (IGF-I) dependent phosphorylation of the IGF-I receptor in MG-63 cells

Somatostatin analog RC-160 inhibits the growth of human osteosarcomas in nude mice

“…The growth of some osteosarcoma cell lines could be inhibited in vitro by monoclonal antibodies and anti-sense oligonucleotides to the IGF-I receptor (Kappel et al, 1994;Pollak et al, 1990;Raile et al, 1994). Our finding of high-affinity binding sites for IGF-I in membranes of MNNG/HOS and SK-ES-1 tumors is in agreement with previous reports by other groups on the existence of high-affinity receptors for IGF-I in various human and murine osteogenic sarcoma cell lines (Fournier et a/., 1993;Kappel et al, 1994;Lopaczynski et a/., 1993;Pollak et a/., 1990Pollak et a/., , 1992Raile et al, 1994). IGF-I and IGF-I1 bind with different affinities to the type-I IGF receptor, which is thought to mediate the biological effects of both ligands through tyrosine kinase-type activity (Fournier et al, 1993).…”

“…A significant fall in G H levels induced by RC-160 could, through mechanisms involving suppression of endogenous growth factors, particularly IGF-I, be of major importance for the inhibition of tumor growth. IGF-I has been shown to play an important role in growth of osteosarcomas (Fournier et al, 1993;Kappel et al, 1994;Lopaczynski et al, 1993;Pirskanen et al, 1993;Pollak et al, 1990Pollak et al, , 1992Raile et al, 1994;Scheven et al, 1991). Stimulatory effects of IGF-I on the proliferation of various human and murine osteosarcoma cell lines have been clearly demonstrated (Fournier et al, 1993;Kappel et al, 1994;Lopaczynski et al, 1993;Pollak et al, 1990Pollak et al, , 1992Raile et al, 1994).…”

“…IGF-I has been shown to play an important role in growth of osteosarcomas (Fournier et al, 1993;Kappel et al, 1994;Lopaczynski et al, 1993;Pirskanen et al, 1993;Pollak et al, 1990Pollak et al, , 1992Raile et al, 1994;Scheven et al, 1991). Stimulatory effects of IGF-I on the proliferation of various human and murine osteosarcoma cell lines have been clearly demonstrated (Fournier et al, 1993;Kappel et al, 1994;Lopaczynski et al, 1993;Pollak et al, 1990Pollak et al, , 1992Raile et al, 1994). The growth of some osteosarcoma cell lines could be inhibited in vitro by monoclonal antibodies and anti-sense oligonucleotides to the IGF-I receptor (Kappel et al, 1994;Pollak et al, 1990;Raile et al, 1994).…”

“…It has been demonstrated that the receptors for IGF-I are present on osteogenic sarcomas (Fournier et at., 1993;Kappel et al, 1994;Lopaczynskietal., 1993;Pollaketal., 1990Pollaketal., ,1992Raileetaf, 1994). It has also been shown that proliferation of human and murine osteosarcomas in cell cultures i s enhanced by the addition of IGF-I (Fournier et al, 1993;Kappel et al, 1994;Lopaczynski et al, 1993;Pirskanen et al, 1993;Pollak et al, 1990Pollak et al, , 1992Raile et al, 1994;Scheven et al, 1994). GH can likewise exert a direct stimulatory effect on the growth of human osteosarcoma cells in vitro (Scheven et al, 1991).…”

“…Surgery, radiation and chemotherapy are of limited effectiveness in the treatment of osteosarcomas, and other therapeutic approaches must be explored. Insulin-like growth factor-I (IGF-I) is a potent stimulant of human and murine osteosarcoma cell growth (Fournier et al, 1993;Kappel et al, 1994;Lopaczynski et al, 1993;Pirskanen et al, 1993;Pollak et al, 1990Pollak et al, , 1992Raile et al, 1994;Scheven et al, 1991). Most of the circulating IGF-I is produced in the liver, where transcription of the IGF-I gene is positively regulated by growth hormone (GH) (Pollak et al, 1990(Pollak et al, ,1992.…”