Insulin-like growth factor-I (IGF-I) and IGF-binding proteins blood serum levels in women with early- and late-stage breast cancer: mutual relationship and possible correlations with patients' hormonal status.
The pathogenesis and progression of breast cancer involve complex interactions between hormones and polypeptide growth factors such as insulin-like growth factor-I (IGF-I). IGF-I has been found in stromal fibroblasts derived from malignant and benign breast tissue and it is a mitogen for several breast cancer cell lines. It circulates bound to specific high-affinity binding proteins, which could act as either positive or negative modulators of tumorigenesis. This study has been addressed to characterize IGF-I and its binding proteins in the serum of 85 unselected patients with early breast cancer. The IGF-I concentration was assessed by radioimmunoassay of 69 out of 85 samples before and after dissociation of the IGF-I and IGF-binding protein (IGF-BP) complex whereas IGF-BP of all 85 sera were analyzed by Western ligand blotting; estradiol and progesterone were measured by radioimmunoassay in native serum samples. In our study no differences in IGF-I serum levels between pre- and post-menopausal patients were observed. Patients with higher estradiol and progesterone serum levels did not present different IGF-I concentrations compared to patients with lower serum levels. Furthermore, IGF-I median values were not found to depend on estrogen receptor (ER) status. A heterogeneous quali-quantitative molecular pattern of binding proteins was detected: IGF-BP3 and IGF-BP1 were the most and the least expressed respectively. No correlations between ER status, or parameters related to the hormonal status, and IGF-I or binding proteins expression were observed. No significant differences in IGF-I concentration and IGF-BP expression were observed between cancer patients and a control group matched for age and menopausal status. Finally, preliminary collection of 20 sera derived from patients with late breast cancer was analyzed for IGF-I and its binding proteins content.
Favoni
R E
RE
Istituto Nazionale per la Ricerca sul Cancro, Department of Experimental Pharmacology, Genova, Italy.
de Cupis
A
A
Perrotta
A
A
Sforzini
S
S
Amoroso
D
D
Pensa
F
F
Miglietta
L
L
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000097:blood; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008875:Middle Aged; D011374:Progesterone / Q000097:blood; D011863:Radioimmunoassay; D011869:Radioligand Assay; D011960:Receptors, Estrogen / Q000032:analysis; D018709:Statistics, Nonparametric
D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D018974:Insulin-Like Growth Factor Binding Protein 4; D018969:Insulin-Like Growth Factor Binding Proteins; D011960:Receptors, Estrogen; D011374:Progesterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I