Insulin-like growth factors (IGFs) reduce IGF-binding protein-4 (IGFBP- 4) concentration and stimulate IGFBP-3 independently of IGF receptors in human fibroblasts and epidermal cells

120 Background: Epidemiological data suggest that Insulin-like growth factor 1 (IGF-1) and IGF binding protein 3 (IGFBP-3) are associated with breast cancer risk, apoptosis and other carcinogenic mechanisms. This metaanalysis evaluates the effects of exercise interventions in controlling serum concentrations of Insulin-like growth factors (IGF1-IGF2) and IGFBP-3 in women with breast cancer. Methods: We incorporated the PRISMA statement. Databases of MEDLINE, Ovid, EMBASE and Cochrane Central Registers were searched to identify randomized controlled trials until March 2014, reporting effect estimates for IGF-1, IGF-2, IGFBP-3 and other secondary outcomes such as insulin, glucose and waist circumference as a body composition measure. An Inverse of variance (IV) with Mantel–Haenszel method was selected for analysis, and a random-effects models were used to assess the pooled estimates in addition to sensitivity analyses, whilst heterogeneity was evaluated using the Chi2 test (P<0.10) and I2 statistics (I2>50%).STATA 12.0 was used for metaanalysis procedures. Results: Six studies were included in the pooled analysis involving 321 patients. Effect estimates showed that exercise training improved IGF-1 (MD= -12.9, 95CI% -16.73 to -9.14, P<0.001), IGF-2 (MD= -43.4, 95CI% -58.5 to -28.3, P<0.001), IGFBP-3 (MD= -0.61, 95CI% -0.69 to -0.53, P<0.001) and waist circumference (MD= -1.133, 95CI% -2.20 to -0.05, P=0.03) in women with breast cancer. Conversely, non-significant differences were observed for Insulin (MD= 0.046, 95CI% -0.24 to 0.34, P=0.7), Glucose (MD=0.22, 95CI% -0.32 to 0.78, P=0.419) and Insulin Resistance (MD= 0.64, 95CI% -0.006 to 1.29, P= 0.06). There was no evidence of publication bias. Conclusions: Exercise is an effective and safe intervention in improving the serum concentrations of insulin like growth factors (IGF1-IGF2) and IGFBP-3 in women with breast cancer, strengthening the physiological effects of exercise in regulating cellular proliferation and apoptosis in breast cancer. Further evidences are encouraged.

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POSTNATAL SERUM INSULIN LIKE GROWTH FACTORS (IGFS) AND IGF BINDING PROTEIN 3(IGFBP-3) IN VLBW INFANTS. † 1461

Pediatric Research ◽

10.1203/00006450-199604001-01484 ◽

1996 ◽

Vol 39 ◽

pp. 246-246

Author(s):

A Sobowale ◽

S. Y Wu ◽

R. S Pildes ◽

S Ehmann ◽

S. P Singh

Keyword(s):

Growth Factors ◽

Binding Protein ◽

Serum Insulin ◽

Vlbw Infants ◽

Igf Binding ◽

Igf Binding Protein ◽

Igfbp 3 ◽

Insulin Like Growth Factors

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Developmentally regulated expression of insulin-like growth factors by differentiated murine teratocarcinomas and extraembryonic mesoderm

Development ◽

10.1242/dev.95.1.193 ◽

1986 ◽

Vol 95 (1) ◽

pp. 193-212

Author(s):

John K. Heath ◽

Wai-Kang Shi

Keyword(s):

Plasma Membrane ◽

Binding Protein ◽

Membrane Receptors ◽

Developmentally Regulated ◽

Igf Receptors ◽

Igf Binding ◽

Plasma Membrane Receptors ◽

Igf Binding Protein ◽

Culture Supernatants ◽

Insulin Like Growth Factors

The expression of plasma membrane receptors for insulin-like growth factors (IGFs) by PC13 embryonal carcinoma (EC) cells, and their immediate differentiated progeny PC13END was examined by binding radiolabelled IGF-I to cell monolayers. Both cell types express high-affinity IGF receptors, but the apparent number of unoccupied receptor sites falls by about 60% upon differentiation. Crosslinking studies reveal that both type 1 and type 2 IGF receptors are expressed by PC13EC cells. PC13END-cell-conditioned medium contains developmentally regulated, separable activities, one of which reacts directly with IGF-II, and the other with IGF for plasma membrane receptors. The former activity represents a soluble secreted IGF-binding protein. The latter activity is structurally and functionally similar to rat IGF-II. Polyclonal antibodies raised against purified rat IGF-II specifically recognize multiple forms of IGF in radiolabelled culture supernatants and material which closely resembles the soluble IGF-binding protein. Immunoprecipitation of radiolabelled culture supernatants with anti-rat IGF-II reveals that the differentiation of PC13EC cells is accompanied by the coexpression of IGF-like molecules and the soluble binding protein, and that IGF-like molecules are expressed by extraembryonic tissues of mesodermal origin in the early postimplantation mouse embryo. These findings show that IGF-like molecules are expressed in early mammalian development and may act in an autocrine fashion in vivo.

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