Matrix metalloproteinase-7 degrades all insulin-like growth factor binding proteins and facilitates insulin-like growth factor bioavailability

Biochem Biophys Res Commun. 2005 Aug 5;333(3):1011-6. doi: 10.1016/j.bbrc.2005.06.010.

Abstract

Proteolytic modification of insulin-like growth factor binding proteins (IGFBPs) plays an important physiological role in regulating insulin-like growth factor (IGF) bioavailability. Recently, we demonstrated that matrix metalloproteinase-7 (MMP-7)/Matrilysin produced by various cancer cells catalyzes the proteolysis of IGFBP-3 in vitro and regulates IGF bioavailability, resulting in an anti-apoptotic effect against anchorage-independent culture. In the present study, we investigated whether MMP-7 contributes to proteolysis of the other five IGFBPs, IGFBP-1, IGFBP-2, IGFBP-4, IGFBP-5, and IGFBP-6, and whether this results in phosphorylation of the IGF type 1 receptor (IGF-1R). MMP-7 cleaved all six IGFBPs, resulting in IGF-mediated IGF-1R phosphorylation, which was inhibited by EDTA treatment. These results suggest that MMP-7 derived from cancer cells can regulate IGF bioavailability in the microenvironment surrounding the tumor, where various kinds of IGF/IGFBP complexes are found, thereby favoring cancer cell growth and survival during the processes of invasion and metastasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Biological Availability
  • Electrophoresis, Polyacrylamide Gel
  • Hydrolysis
  • Insulin-Like Growth Factor Binding Proteins / metabolism*
  • Kinetics
  • Matrix Metalloproteinase 7 / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Phosphorylation
  • Signal Transduction
  • Somatomedins / metabolism*

Substances

  • Insulin-Like Growth Factor Binding Proteins
  • Somatomedins
  • Matrix Metalloproteinase 7