Identification of Hepatocyte Growth Factor Autocrine Loops in Breast Carcinomas: Possible Target for Therapeutic Intervention
Abstract
Hepatocyte growth factor (HGF) binding to its transmembrane receptor, Met, results in an increase in breast epithelial cell motility, morphogenesis and metastasis. ELISA methods have been used to assess the role of divalent metal cations on HGF/Met-IgG binding. Copper (11) and Zinc (11) significantly inhibited HGF/Met-IgG binding with IC50 values of 230 to 270 M each, while manganese (11) and magnesium (11) were less inhibitory with IC50 values between 5 to 15 mM and 30 to 70 mM, respectively. A concentration of 1 mM copper (11) incubated with HGF resulted in an HGF mobility shift in non-denatruing PAGE, indicating direct interaction of copper (11) with HGF, while 1 mM manganese (11) exhibited no effect. The activation of Met and cell scatter, functions both induced by exogenous HGF, were inhibited upon addition of HGF in the presence of 1 mM and 500 M copper (IT), respectively. Chemical protonation, with DEPC, of HGF histidine residues impeded the ability of 500 M copper (11) to inhibit HGF/Met-IgG binding. A proposed ribbon diagram indicates that the HGF copper (11)- binding domain contains two histidine and these histidine are in close proximity to some key residues implicated in the Met binding domain. HGF-immunoreactive secretion products, 55 kDa and 32 kDa, of the human breast epithelial carcinoma cell line, MCFl0AlT3B, were purified and inhibited HGF/Met-IgG binding. Sequencing of these products may also identify key residues implicated in the inhibition of HGF/Met binding.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2003
- Accession Number
- ADA423724
Entities
People
- Theodore G. Wright
Organizations
- Queen's University