Insulin-like growth factors and the multiplication of Tera-2, a human teratoma-derived cell line

1988 ◽  
Vol 90 (3) ◽  
pp. 475-484
Author(s):  
C. Biddle ◽  
C.H. Li ◽  
P.N. Schofield ◽  
V.E. Tate ◽  
B. Hopkins ◽  
...  
Keyword(s):  
Growth Factors ◽  
Cell Line ◽  
Serum Free Medium ◽  
Free Medium ◽  
Maximal Stimulation ◽  
Igf Receptors ◽  
Igf I ◽  
Insulin Like Growth Factors

A human teratoma cell line (Tera-2) was grown in serum-free medium, and the population multiplication was stimulated by the addition of somatomedins/insulin-like growth factors (IGFs). Both IGF-I and IGF-II gave maximal stimulation when added daily at 10 ng ml-1. The IGFs did not substantially change the labelling index of the cells, and the IGFs appeared to exert their effect on population multiplication by increasing cell survival. Membranes isolated from Tera-2 cells displayed both type 1 and type 2 IGF receptors.

scholarly journals The effects of various hormones and growth factors on the growth of human insulin-producing cell line in serum-free medium

1997 ◽  
Vol 29 (4) ◽  
pp. 209-216 ◽  
Author(s):  
Jae-Jeong Lee ◽  
Jai-Hyun Kwon ◽  
Yong Keun Park ◽  
Ohoak Kwon ◽  
Tai-Wook Yoon
Keyword(s):  
Growth Factors ◽  
Cell Line ◽  
Human Insulin ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free

scholarly journals Comparative binding of bovine, human and rat insulin-like growth factors to membrane receptors and to antibodies against human insulin-like growth factor-1

1986 ◽  
Vol 233 (1) ◽  
pp. 215-221 ◽  
Author(s):  
L C Read ◽  
F J Ballard ◽  
G L Francis ◽  
R C Baxter ◽  
C J Bagley ◽  
...  
Keyword(s):  
Growth Factors ◽  
Polyclonal Antiserum ◽  
Competitive Binding ◽  
Membrane Receptors ◽  
Binding Studies ◽  
Comparative Binding ◽  
Placental Membranes ◽  
Insulin Like Growth Factors

The immunological properties of human, bovine and rat insulin-like growth factors (IGF) and insulin were compared in competitive binding studies with Tr10 and NPA polyclonal antisera raised in rabbits against human IGF-1. Bovine IGF-1 was 11-19% as effective as human IGF-1 in competing for binding with 125I-labelled human IGF-1, whereas IGF-2 reacted poorly and insulin did not compete. Similar competitive binding curves were obtained with the mouse monoclonal anti-(human IGF-1) antibody 3D1, except that bovine IGF-1 showed a severalfold greater affinity for the monoclonal antibody than for either polyclonal antiserum. Membranes isolated from human placenta, sheep placenta and foetal-human liver were used as sources of cellular receptors. In human placental membranes, most of the binding of IGF-1 tracers could be attributed to a type-1 receptor, because insulin inhibited up to 65% of tracer binding. The other two tissues apparently contain only type-2 receptors, as evidenced by the very low potency of bovine or human IGF-1 in competing for binding with IGF-2 tracers and the absence of any competition by insulin. In competition for binding with labelled bovine or human IGF-1 to human placental membranes, bovine IGF-1 had a similar potency to human IGF-1, whereas bovine IGF-1 was more potent in binding studies with tissues rich in type-2 receptors. Rat IGF-2 was considerably less effective than human IGF-2 in competition for receptors on any of the membrane preparations.

scholarly journals Specific binding of insulin-like growth factors 1 and 2 to the type 1 and type 2 receptors respectively

1988 ◽  
Vol 249 (3) ◽  
pp. 721-726 ◽  
Author(s):  
F J Ballard ◽  
M Ross ◽  
F M Upton ◽  
G L Francis
Keyword(s):  
Growth Factors ◽  
Specific Binding ◽  
Protein A ◽  
Cell Types ◽  
Bovine Insulin ◽  
Lung Fibroblasts ◽  
Ligand Interactions ◽  
Insulin Like Growth Factors

1. Competitive binding and receptor cross-linking experiments have been used to examine the receptor-ligand interactions between three bovine insulin-like growth factors (IGF) and monolayer cultures of myoblasts and fibroblasts. 2. Labelled IGF-2 bound predominantly to the type 2 receptor with negligible label cross-linked to the type 1 receptor, notwithstanding the ability of IGF-2 to compete effectively for the binding of IGF-1 to the type 1 receptor. Approx. 100-fold higher concentrations of IGF-1 or the N-terminal truncated (des-Gly-Pro-Glu) IGF-1 (-3N:IGF-1) were required to produce competition equivalent to IGF-2. 3. All IGF peptides, but especially IGF-1, enhanced the binding of labelled IGF-2 to the type 2 receptor of lung fibroblasts. This unusual effect was probably a consequence of the displacement of labelled IGF-2 otherwise bound to a medium protein, a conclusion supported by the demonstration of a 38 kDa membrane protein cross-linked to labelled IGF-2. 4. Both IGF-1 and -3N:IGF-1 bound only to the type 1 IGF receptor in L6 myoblasts, rat vascular smooth-muscle cells and human lung fibroblasts. The peptides competed for labelled IGF-1 binding with potencies in the order -3N:IGF-1 greater than IGF-1 greater than IGF-2 much greater than insulin. Since the IGF peptides were equipotent in skin fibroblasts, it was proposed that the apparently higher affinity of -3N:IGF-1 for receptors in the other cell types was instead a consequence of a low affinity of this peptide for the competing 38 kDa binding protein.

scholarly journals Somatomedins/insulin-like growth factors, their receptors and binding proteins are present during mouse embryogenesis

Development ◽  
1987 ◽  
Vol 101 (1) ◽  
pp. 73-82
Author(s):  
E.P. Smith ◽  
T.W. Sadler ◽  
A.J. D'Ercole
Keyword(s):  
Growth Factors ◽  
Cell Line ◽  
Binding Proteins ◽  
Insulin Receptors ◽  
Embryonal Carcinoma Cell ◽  
Igf Binding Proteins ◽  
Embryonic Tissues ◽  
Embryonic Growth ◽  
Igf I ◽  
Insulin Like Growth Factors

Somatomedins/insulin-like growth factors (Sm/IGFs) are considered to have important roles in regulating fetal growth; however, because of limited quantities of tissue, few studies have been performed on their effects on embryonic growth. To assess a potential role for these factors, we evaluated mouse embryonic tissues for the presence of Sm/IGF and insulin receptors and Sm/IGF-binding proteins by chemical affinity labelling. In addition, we measured extractable Sm-C/IGF-I radioimmunoactivity in mouse embryonic tissues. Finally, we compared these data with those from the embryonal carcinoma cell line, PC13. All embryos from day 9 (3–4 somites) to day 12 (45 somites) possessed both Sm-C/IGF-I and IGF-II receptors in apparent greater abundance than insulin receptors. The visceral yolk sac appeared to have proportionally more insulin receptors than the corresponding embryonic tissue. Extracts from the embryos contained immunoreactive Sm-C/IGF-I and binding proteins of 30–45 X 10(3) Mr. PC13 cells possessed all three receptors and the apparent abundance of the insulin and IGF-II receptors was reduced after differentiation was induced with retinoic acid. PC13 cells released both immunoreactive Sm-C/IGF-I- and Sm-C/IGF-I-binding proteins into their medium. When differentiated, the binding proteins resembled the native ones extracted from the intact embryos. The presence of Sm/IGF activity, receptors and binding proteins in early embryogenesis suggests a role for these factors in embryonic growth. The PC13 cell line appears to only partially reflect normal development.

scholarly journals Autocrine role of IGF-II in proliferation of human adrenocortical carcinoma NCI H295R cell line

1999 ◽  
Vol 23 (1) ◽  
pp. 23-32 ◽  
Author(s):  
A Logie ◽  
N Boulle ◽  
V Gaston ◽  
L Perin ◽  
P Boudou ◽  
...  
Keyword(s):  
Cell Line ◽  
In Vitro Model ◽  
Igf System ◽  
Igf Receptors ◽  
Igf I ◽  
H295r Cells ◽  
Igf Receptor ◽  
Vitro Model

In adrenocortical tumors, the malignant phenotype is associated with rearrangements (paternal isodisomy) at the 11p15 locus and IGF-II gene overexpression, strongly suggesting that the IGF system is a major determinant of adrenocortical tumor progression. The aim of this study was to validate an in vitro model for investigating the involvement of the IGF system in adrenocortical tumorigenesis. We analyzed the production of IGF mRNA and proteins, IGF-binding proteins (IGFBPs) and IGF receptors by the NCI H295R cell line, which is derived from a human adult adrenocortical carcinoma. H295R cells were shown to proliferate for a long period (26 days) in the absence of serum or any added growth factor. Northern blot analyses showed high IGF-II mRNA contents in H295R cells. The cells secreted large amounts of IGF-II protein (14 ng/10(6) cells per 48 h) although no IGF-I protein was detected. Western ligand blot analyses of conditioned media detected the presence of large amounts of a 34 kDa protein, which was identified as IGFBP-2 by immunoblotting. The presence of high-affinity binding sites for IGF-I and IGF-II on H295R cells was shown by binding experiments using radiolabeled IGFs and confirmed by reverse transcription PCR analyses showing type 1 and type 2 IGF receptors. Proliferation of H295R cells was inhibited by anti-IGF-II antibody (45%) and by anti-type 1 IGF receptor antibody (53%) indicating that IGF-II is an autocrine growth factor for these cells and that its effects are, at least in part, mediated by the type 1 IGF receptor. These findings confirm the involvement of the IGF system in adrenocortical tumors and suggest that the H295R cell line is a suitable in vitro model for studying the molecular mechanisms of adrenocortical tumor proliferation.

scholarly journals Binding properties and biological potencies of insulin-like growth factors in L6 myoblasts

1986 ◽  
Vol 233 (1) ◽  
pp. 223-230 ◽  
Author(s):  
F J Ballard ◽  
L C Read ◽  
G L Francis ◽  
C J Bagley ◽  
J C Wallace
Keyword(s):  
Protein Synthesis ◽  
Growth Factors ◽  
Radioligand Binding ◽  
Cross Linking ◽  
Protein Accumulation ◽  
Igf Receptor ◽  
H Protein ◽  
Insulin Like Growth Factors

Protein synthesis in rat L6 myoblasts is stimulated and protein breakdown inhibited in a co-ordinate manner by insulin-like growth factors (IGF) or insulin. For both processes, bovine IGF-1 was somewhat more potent than human IGF-1, which was effective at a tenth the concentration of insulin, rat IGF-2 or human IGF-2. A similar order of potency is noted when DNA synthesis or protein accumulation is monitored over a 24 h period, but between 20- and 50-fold higher concentrations of each growth factor are required than those needed to produce effects in the 4 h protein-synthesis or -breakdown measurements. Binding experiments with labelled human or bovine IGF-1 as ligand demonstrated competition at concentrations of IGF-2, especially human IGF-2, lower than that of either IGF-1 preparation. This pattern was much more pronounced when the radioligand was either human IGF-2 or rat IGF-2. Insulin competed 10-15% for the binding of labelled IGF-1, but not at all with labelled IGF-2. Ligand-receptor cross-linking experiments showed that labelled bovine IGF-1 bound approximately equally to the type 1 IGF receptor (Mr 130000 after reduction) and to the type 2 IGF receptor (Mr 270000 after reduction), and that unlabelled IGF-1 competed equally with radioligand binding to both receptors. On the other hand, rat IGF-2 competed more effectively for binding to the type-2 receptor, and insulin competed only for binding to the type-1 receptor. Further cross-linking experiments with rat IGF-2 as radioligand demonstrated binding only to the type-2 receptor and to proteins with Mr values after reduction of 230000 and 200000. This binding was prevented by high rat IGF-2 concentrations, less effectively by bovine IGF-1 and not at all by insulin. The apparently conflicting biological potencies and receptor binding of the different growth factors can be explained if all the biological actions are mediated via the type-1 IGF receptor, rather than through the abundant type-2 receptor.

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