Expression and Down‐Regulation by Retinoic Acid of IGF Binding Protein‐2 and ‐4 in Medium from Human Neuroblastoma Cells

1 August 1994

journal article
Published by Wiley in Journal of Neuroendocrinology

Vol. 6 (4) , 409-413
https://doi.org/10.1111/j.1365-2826.1994.tb00601.x

Abstract

Insulin-like growth factors (IGFs) regulate the autocrine/paracrine growth of neuroblastomas. The IGFs bind to specific binding proteins (IGFBPs) which modulate their biological activity. We investigated, by Western ligand blotting (WLB), the presence of IGFBPs and their possible modulation by retinoic acid (RA), IGF-I, IGF-II and truncated Des(1-3)IGF-l in conditioned medium (CM) of the human neuroblastoma SK-N-BE(2) cell line. We demonstrated the presence of two IGFBPs, with MW 37 kDa and 25 kDa. Following immunoprecipitation, they turned out to be IGFBP-2 and -4, respectively. The RA-induced differentiation in SK-N-BE(2) cells was accompanied by a marked reduction of the intensity of both IGFBP bands after 48 h (32% and 24% of control, respectively) and 72 h (2% and 0% of control, respectively) incubation. The addition of exogenous IGFs, which did not induce cell differentiation, did not change the IGFBP pattern significantly, except for the truncated form of IGF-I, which induced a marked decrease in both the 37 kDa and 25kDa bands after 72 h incubation (45% and 18% of control, respectively). These findings suggest that IGFBPs have a role in RA-induced differentiation in human neuroblastoma cells.

Keywords

This publication has 23 references indexed in Scilit:

Glucose does not influence the insulin-like growth factor (IGF) binding to carrier proteins (IGFBPs): Analysis of rat and human serum by western ligand blotting
Cellular and Molecular Life Sciences, 1993
Modulation of a Novel Thermolysin-like Metallo-Endopeptidase Activity during Retinoic Acid-Induced Differentiation of Human Neuroectodermal Tumor Cell Lines
Biochemical and Biophysical Research Communications, 1993
Measurement and characterization of insulin-like growth factor binding protein-3 in human biological fluids: discrepancies between radioimmunoassay and ligand blotting
Endocrinology, 1992
Prostate-specific antigen (PSA) is an insulin-like growth factor binding protein-3 protease found in seminal plasma
Journal of Clinical Endocrinology & Metabolism, 1992
Insulin-like growth-factor-binding protein gene expression and protein production by human tumour cell lines
International Journal of Cancer, 1992
Differential regulation of insulin‐like growth factor binding protein (IGFBP)‐2 mRNA in liver and bone cells by insulin and retinoic acid in vitro
FEBS Letters, 1992
Retinoic acid regulates insulin-like growth factor II expression in a neuroblastoma cell line
Endocrinology, 1992
Identification and molecular characterization of insulin-like growth factor binding proteins (IGFBP-1, -2, -3, -4, -5 and -6)
Progress in Growth Factor Research, 1991
Insulin-like growth factor I expression by tumors of neuroectodermal origin with the t(11;22) chromosomal translocation. A potential autocrine growth factor.
Journal of Clinical Investigation, 1990
Regulation of binding proteins for insulin-like growth factors (IGF) in humans. Increased expression of IGF binding protein 2 during IGF I treatment of healthy adults and in patients with extrapancreatic tumor hypoglycemia.
Journal of Clinical Investigation, 1990