Synthetic emmprin peptides with chitobiose substitution stimulate MMP-2 production by fibroblasts

Takehito Kawakami,Kazuki Nabeshima,Junji Suzumiya,Kaori Koga,Yoshiaki Nakahara,Tetsuro Sameshima,Hironobu Hojo,Akinori Iwasaki,Bryan P Toole,Yasunori Okada

doi:10.1186/1471-2407-11-300

Abstract

BackgroundEmmprin, a glycoprotein containing two Ig domains, is enriched on tumor cell surfaces and stimulates matrix metalloproteinase (MMP) production by adjacent stromal cells. Its first Ig domain (ECI) contains the biologically active site. The dependence of emmprin activity on N-glycosylation is controversial. We investigated whether synthetic ECI with the shortest sugar is functionally active.MethodsThe whole ECI peptides carrying sugar chains, a chitobiose unit or N-linked core pentasaccharide, were synthesized by the thioester method and added to fibroblasts to examine whether they stimulate MMP-2 production.ResultsECI carrying a chitobiose unit, ECI-(GlcNAc) 2, but not ECI without a chitobiose unit or the chitobiose unit alone, dose-dependently stimulated MMP-2 production by fibroblasts. ECI with longer chitobiose units, ECI-[(Man)3(GlcNAc)2], also stimulated MMP-2 production, but the extent of its stimulation was lower than that of ECI-(GlcNAc)2.ConclusionsOur results indicate that ECI can mimic emmprin activity when substituted with chitobiose, the disaccharide with which N-glycosylation starts.

Highlights

Emmprin, a glycoprotein containing two Ig domains, is enriched on tumor cell surfaces and stimulates matrix metalloproteinase (MMP) production by adjacent stromal cells
The results showed that synthetic ECI substituted with a chitobiose unit, but not ECI alone, stimulates fibroblasts to produce MMP-2
Effects of ECI with or without a chitobiose unit on MMP production by fibroblasts Previous studies showed two important findings with regard to emmprin activity, namely that the activity resides in ECI [6], and that it depends on N-glycosylation of extracellular domains of emmprin [17,18]

Summary

Introduction

A glycoprotein containing two Ig domains, is enriched on tumor cell surfaces and stimulates matrix metalloproteinase (MMP) production by adjacent stromal cells. Malignant cells stimulate nearby fibroblasts to produce MMPs via soluble cytokines and growth factors or through cell surface interactions mediated by plasma membrane proteins, such as emmprin [5]. Known as basigin/ CD147, is an integral plasma membrane glycoprotein of nonglycosylated recombinant emmprin could stimulate fibroblasts to express the mRNAs of MMP-1, 2 and 3 [19]. The objective of the present study was to determine whether the activity of synthetic emmprin ECI peptides, with or without a chitobiose unit (GlcNAc-GlcNAc), the disaccharide with which N-glycosylation starts, mimics that of emmprin. The results showed that synthetic ECI substituted with a chitobiose unit, but not ECI alone, stimulates fibroblasts to produce MMP-2

Objectives

Methods

Results

Conclusion